add default.pgo in client &

added an option to enable pprof on client

.github/ISSUE_TEMPLATE

@@ -1,27 +1,29 @@
 问问题前先搜索ISSUE，并搞清楚下面的问题:
 
 1. 检查 ```-key xxx``` 至少三遍, ***保证***两边一致。
-2. 保证```-nocomp, -datashard, -parityshard,  -key, -crypt```两边一致。
+2. 保证```-nocomp, -datashard, -parityshard,  -key, -crypt, -smuxver```两边一致。
 3. 是否在服务器端，正确设定了转发的目标服务器地址 ***--target***。
-4. 如果第3条不确定，尝试在服务器上telnet target port试试。
-5. 防火墙是否关闭了UDP通信。
-6. 两端的版本是否一致？
-7. 是不是最新版本？
-8. 两端分别是什么操作系统？
-9. 两端的输出日志是什么？
+4. 是否在客户端，正确的连接到了 client的监听端口。
+5. 如果第3条不确定，尝试在服务器上telnet target port试试。
+6. 防火墙是否关闭了UDP通信，或者设置了UDP的最大发包速率？
+7. 两端的版本是否一致？
+8. 是不是最新版本？
+9. 两端分别是什么操作系统？
+10. 两端的输出日志是什么？
 
 Before firing issue, make sure you figured out the following common questions.
 
 PLEASE DO SEARCH FIRST.
 
 1. Check your ```-key xxx``` for at least 3 times, ***MAKE SURE*** both sides share the same secret.
-2. ```-nocomp, -datashard, -parityshard,  -key, -crypt``` ***must be the same*** on both side.
+2. ```-nocomp, -datashard, -parityshard,  -key, -crypt, -smuxver``` ***must be the same*** on both side.
 3. Did you correctly set the ***-target*** on the server side?
-4. ***MAKE SURE*** ```telnet target port``` on your server successful(don't ask me why couldn't).
-5. Does your ***firewall allows UDP*** communications? (including your ISP Cable-Modem)
-6. Are you using the **same version** for both client & server
-7. Are you using the **latest release**?
-8. Which **OS** do you use?
-9. Which end for this issue related to, **client or server**?
+4. Did you correctly connected to the listening port on client side?
+5. ***MAKE SURE*** ```telnet target port``` on your server successful(don't ask me why couldn't).
+6. Does your ***firewall allows UDP*** communications? (including your ISP Cable-Modem)
+7. Are you using the **same version** for both client & server
+8. Are you using the **latest release**?
+9. Which **OS** do you use?
+10. Which end for this issue related to, **client or server**?
 
 

.travis.yml

@@ -1,18 +1,16 @@
 language: go
 go:
-    - 1.10.x
-    - 1.11.x
-    - 1.12.x
+    - 1.13.x
 before_install:
     - go get github.com/mattn/goveralls
     - go get golang.org/x/tools/cmd/cover
 install:
-    - go get github.com/xtaci/kcptun/client
-    - go get github.com/xtaci/kcptun/server
+    - env GO111MODULE=on go get github.com/xtaci/kcptun/client
+    - env GO111MODULE=on go get github.com/xtaci/kcptun/server
 before_script:
 script:
     - cd $HOME/gopath/src/github.com/xtaci/kcptun/client
-    - $HOME/gopath/bin/goveralls -service=travis-ci
+    - env GO111MODULE=on $HOME/gopath/bin/goveralls -service=travis-ci
     - cd $HOME/gopath/src/github.com/xtaci/kcptun/server
-    - $HOME/gopath/bin/goveralls -service=travis-ci
+    - env GO111MODULE=on $HOME/gopath/bin/goveralls -service=travis-ci
     - exit 0

Dockerfile

@@ -1,11 +1,15 @@
-FROM golang:alpine as builder
+FROM golang:1.21.0-alpine3.18 as builder
 MAINTAINER xtaci <daniel820313@gmail.com>
-RUN apk update && \
-    apk upgrade && \
-    apk add git gcc libc-dev linux-headers
-RUN go get -ldflags "-X main.VERSION=$(date -u +%Y%m%d) -s -w" github.com/xtaci/kcptun/client && go get -ldflags "-X main.VERSION=$(date -u +%Y%m%d) -s -w" github.com/xtaci/kcptun/server
+ENV GO111MODULE=on
+RUN apk add git
+RUN git clone https://github.com/xtaci/kcptun.git
+RUN cd kcptun && \
+	go build -mod=vendor -ldflags "-X main.VERSION=$(date -u +%Y%m%d) -s -w" -o /client github.com/xtaci/kcptun/client && \
+	go build -mod=vendor -ldflags "-X main.VERSION=$(date -u +%Y%m%d) -s -w" -o /server github.com/xtaci/kcptun/server
 
-FROM alpine:3.9
-COPY --from=builder /go/bin /bin
+FROM alpine:3.18
+RUN apk add --no-cache iptables
+COPY --from=builder /client /bin
+COPY --from=builder /server /bin
 EXPOSE 29900/udp
 EXPOSE 12948

README.md

@@ -1,20 +1,18 @@
 # <img src="logo.png" alt="kcptun" height="54px" /> 
 
-[![Release][13]][14] [![Powered][17]][18] [![MIT licensed][11]][12] [![Build Status][3]][4] [![Go Report Card][5]][6] [![Downloads][15]][16] [![Docker][1]][2]
+[![Release][13]][14] [![Powered][17]][18] [![MIT licensed][11]][12] [![Build Status][3]][4] [![Go Report Card][5]][6] [![Downloads][15]][16] [![Docker][1]][2] 
 
-[1]: https://images.microbadger.com/badges/image/xtaci/kcptun.svg
-[2]: https://microbadger.com/images/xtaci/kcptun
+[1]: https://img.shields.io/docker/pulls/xtaci/kcptun
+[2]: https://hub.docker.com/r/xtaci/kcptun
 [3]: https://travis-ci.org/xtaci/kcptun.svg?branch=master
 [4]: https://travis-ci.org/xtaci/kcptun
 [5]: https://goreportcard.com/badge/github.com/xtaci/kcptun
 [6]: https://goreportcard.com/report/github.com/xtaci/kcptun
-[7]: https://img.shields.io/badge/license-MIT-blue.svg
-[8]: https://raw.githubusercontent.com/xtaci/kcptun/master/LICENSE.md
-[11]: https://img.shields.io/badge/license-MIT-blue.svg
+[11]: https://img.shields.io/github/license/xtaci/kcptun
 [12]: LICENSE.md
-[13]: https://img.shields.io/github/release/xtaci/kcptun.svg
+[13]: https://img.shields.io/github/v/release/xtaci/kcptun?color=orange
 [14]: https://github.com/xtaci/kcptun/releases/latest
-[15]: https://img.shields.io/github/downloads/xtaci/kcptun/total.svg?maxAge=1800
+[15]: https://img.shields.io/github/downloads/xtaci/kcptun/total.svg?maxAge=1800&color=orange
 [16]: https://github.com/xtaci/kcptun/releases
 [17]: https://img.shields.io/badge/KCP-Powered-blue.svg
 [18]: https://github.com/skywind3000/kcp
@@ -23,6 +21,15 @@
 
 > *Disclaimer: kcptun maintains a single website — [github.com/xtaci/kcptun](https://github.com/xtaci/kcptun). Any websites other than [github.com/xtaci/kcptun](https://github.com/xtaci/kcptun) are not endorsed by xtaci.*
 
+### Requirements
+
+| Target | Minimum | Recommended |
+| --- | --- | --- |
+| System | aix darwin dragonfly freebsd linux netbsd openbsd solaris windows | linux |
+| Memory | >20MB | >32MB |
+| CPU | ANY | amd64 with AES-NI & AVX2 |
+
+
 ### QuickStart
 
 Increase the number of open files on your server, as:
@@ -59,10 +66,13 @@ which tunnels the original connection:
 
 > Application -> Target Server(8388/tcp) 
 
-### Install from source
+### Build from source
 
 ```
-$go get -u github.com/xtaci/kcptun/...
+$ git clone https://github.com/xtaci/kcptun.git
+$ cd kcptun
+$ ./build-release.sh
+$ cd build
 ```
 
 All precompiled releases are genereated from `build-release.sh` script.
@@ -96,7 +106,7 @@ All precompiled releases are genereated from `build-release.sh` script.
 
 > eg: `-mode fast3`    
 
-> Aggresiveness/Responsiveness on retransmission for embeded modes are:
+> Aggresiveness/Responsiveness on retransmission for embedded modes are:
 
 > *fast3 > fast2 > fast > normal > default*
 
@@ -105,6 +115,8 @@ All precompiled releases are genereated from `build-release.sh` script.
 Since streams are multiplexed into a single physical channel, head of line blocking may appear under certain circumstances, by
 increasing `-smuxbuf` to a larger value (default 4MB) may mitigate this problem, obviously this will costs more memory.
 
+For versions >= v20190924, you can switch to smux version 2, smux v2 has options to limit per-stream memory usage, now set `-smuxver 2` to enable smux v2, and adjust `-streambuf` to limit per-stream memory usage, eg: `-streambuf 2097152` can limit per-stream memory usage to 2MB. By limiting stream buffer on the receiver side, a back-pressure will be conducted to the sender and limits reading, and finally prevent source from sending too much data to occupy every bits of buffer along the link. (Setting -smuxver **MUST** be **IDENTICAL** on both side, default is 1. )
+
 #### Slow Devices
 
 kcptun made use of **ReedSolomon-Codes** to recover lost packets, which requires massive amount of computation, a low-end ARM device cannot satisfy kcptun well. To unleash the full potential of kcptun, a multi-core x86 homeserver CPU like AMD Opteron is recommended.
@@ -119,7 +131,7 @@ If you insist on running under some ARM routers, you'd better turn off `FEC` and
 #### Usage
 
 ```
-xtaci@gw:~$ ./client_linux_amd64 -h
+➜  ~ ./client_linux_amd64 -h
 NAME:
    kcptun - client(with SMUX)
 
@@ -127,20 +139,20 @@ USAGE:
    client_linux_amd64 [global options] command [command options] [arguments...]
 
 VERSION:
-   20190409
+   20190924
 
 COMMANDS:
-     help, h  Shows a list of commands or help for one command
+   help, h  Shows a list of commands or help for one command
 
 GLOBAL OPTIONS:
    --localaddr value, -l value      local listen address (default: ":12948")
-   --remoteaddr value, -r value     kcp server address (default: "vps:29900")
+   --remoteaddr value, -r value     kcp server address, eg: "IP:29900" a for single port, "IP:minport-maxport" for port range (default: "vps:29900")
    --key value                      pre-shared secret between client and server (default: "it's a secrect") [$KCPTUN_KEY]
    --crypt value                    aes, aes-128, aes-192, salsa20, blowfish, twofish, cast5, 3des, tea, xtea, xor, sm4, none (default: "aes")
    --mode value                     profiles: fast3, fast2, fast, normal, manual (default: "fast")
    --conn value                     set num of UDP connections to server (default: 1)
    --autoexpire value               set auto expiration time(in seconds) for a single UDP connection, 0 to disable (default: 0)
-   --scavengettl value              set how long an expired connection can live(in sec), -1 to disable (default: 600)
+   --scavengettl value              set how long an expired connection can live (in seconds) (default: 600)
    --mtu value                      set maximum transmission unit for UDP packets (default: 1350)
    --sndwnd value                   set send window size(num of packets) (default: 128)
    --rcvwnd value                   set receive window size(num of packets) (default: 512)
@@ -149,17 +161,20 @@ GLOBAL OPTIONS:
    --dscp value                     set DSCP(6bit) (default: 0)
    --nocomp                         disable compression
    --sockbuf value                  per-socket buffer in bytes (default: 4194304)
+   --smuxver value                  specify smux version, available 1,2 (default: 1)
    --smuxbuf value                  the overall de-mux buffer in bytes (default: 4194304)
+   --streambuf value                per stream receive buffer in bytes, smux v2+ (default: 2097152)
    --keepalive value                seconds between heartbeats (default: 10)
    --snmplog value                  collect snmp to file, aware of timeformat in golang, like: ./snmp-20060102.log
    --snmpperiod value               snmp collect period, in seconds (default: 60)
    --log value                      specify a log file to output, default goes to stderr
    --quiet                          to suppress the 'stream open/close' messages
+   --tcp                            to emulate a TCP connection(linux)
    -c value                         config from json file, which will override the command from shell
    --help, -h                       show help
    --version, -v                    print the version
    
-xtaci@gw:~$ ./server_linux_amd64 -h
+➜  ~ ./server_linux_amd64 -h
 NAME:
    kcptun - server(with SMUX)
 
@@ -167,14 +182,14 @@ USAGE:
    server_linux_amd64 [global options] command [command options] [arguments...]
 
 VERSION:
-   20190409
+   20190924
 
 COMMANDS:
-     help, h  Shows a list of commands or help for one command
+   help, h  Shows a list of commands or help for one command
 
 GLOBAL OPTIONS:
-   --listen value, -l value         kcp server listen address (default: ":29900")
-   --target value, -t value         target server address (default: "127.0.0.1:12948")
+   --listen value, -l value         kcp server listen address, eg: "IP:29900" for a single port, "IP:minport-maxport" for port range (default: ":29900")
+   --target value, -t value         target server address, or path/to/unix_socket (default: "127.0.0.1:12948")
    --key value                      pre-shared secret between client and server (default: "it's a secrect") [$KCPTUN_KEY]
    --crypt value                    aes, aes-128, aes-192, salsa20, blowfish, twofish, cast5, 3des, tea, xtea, xor, sm4, none (default: "aes")
    --mode value                     profiles: fast3, fast2, fast, normal, manual (default: "fast")
@@ -186,18 +201,36 @@ GLOBAL OPTIONS:
    --dscp value                     set DSCP(6bit) (default: 0)
    --nocomp                         disable compression
    --sockbuf value                  per-socket buffer in bytes (default: 4194304)
+   --smuxver value                  specify smux version, available 1,2 (default: 1)
    --smuxbuf value                  the overall de-mux buffer in bytes (default: 4194304)
+   --streambuf value                per stream receive buffer in bytes, smux v2+ (default: 2097152)
    --keepalive value                seconds between heartbeats (default: 10)
    --snmplog value                  collect snmp to file, aware of timeformat in golang, like: ./snmp-20060102.log
    --snmpperiod value               snmp collect period, in seconds (default: 60)
    --pprof                          start profiling server on :6060
    --log value                      specify a log file to output, default goes to stderr
    --quiet                          to suppress the 'stream open/close' messages
+   --tcp                            to emulate a TCP connection(linux)
    -c value                         config from json file, which will override the command from shell
    --help, -h                       show help
    --version, -v                    print the version
 ```
 
+#### Multiport Dialer
+
+kcptun supports multi-port dialer like below:
+
+```
+client: --remoteaddr IP:minport-maxport
+server: --listen IP:minport-maxport
+
+eg:
+client: --remoteaddr IP:3000-4000
+server: --listen 0.0.0.0:3000-4000
+```
+by specifying port-range, kcptun will automatically switch to next random port within port-range when establishing each new connection.
+
+
 #### Forward Error Correction
 
 In coding theory, the [Reed–Solomon code](https://en.wikipedia.org/wiki/Reed%E2%80%93Solomon_error_correction) belongs to the class of non-binary cyclic error-correcting codes. The Reed–Solomon code is based on univariate polynomials over finite fields.
@@ -206,8 +239,6 @@ It is able to detect and correct multiple symbol errors. By adding t check symbo
 
 ![FED](FEC.png)
 
-Setting parameters of RS-Code with ```-datashard m -parityshard n``` on **BOTH** KCP Client & KCP Server **MUST** be **IDENTICAL**.
-
 #### DSCP
 
 Differentiated services or DiffServ is a computer networking architecture that specifies a simple, scalable and coarse-grained mechanism for classifying and managing network traffic and providing quality of service (QoS) on modern IP networks. DiffServ can, for example, be used to provide low-latency to critical network traffic such as voice or streaming media while providing simple best-effort service to non-critical services such as web traffic or file transfers.
@@ -275,7 +306,7 @@ Reference: https://blog.golang.org/go15gc
 Primary memory allocation are done from a global buffer pool *xmit.Buf*, in kcp-go, when we need to allocate some bytes, we can get from that pool, and a *fixed-capacity* 1500 bytes(mtuLimit) will be returned, the *rx queue*, *tx queue* and *fec queue* all receive bytes from there, and they will return the bytes to the pool after using to prevent *unnecessary zer0ing* of bytes. 
 The pool mechanism maintained a *high watermark* for slice objects, these *in-flight* objects from the pool will survive from the perodical garbage collection, meanwhile the pool kept the ability to return the memory to runtime if in idle, `-sndwnd`,`-rcvwnd`,`-ds`, `-ps`, these parameters affect this *high watermark*, the larger the value, the bigger the memory consumption will be.
 
-`-smuxbuf` also affects the maximum memory consumption, this parameter maintains a subtle balance between *concurrency* and *resource*, you can increase this value(default 4MB) to boost concurrency if you have many clients to serve and you get a powerful server at the same time, and also you can decrease this value to serve only 1 or 2 clients and hope this program can run under some embeded SoC system with limited memory and only you can access. (Notice that the `-smuxbuf` value is not proprotional to concurrency, you need to test.)
+`-smuxbuf` also affects the maximum memory consumption, this parameter maintains a subtle balance between *concurrency* and *resource*, you can increase this value(default 4MB) to boost concurrency if you have many clients to serve and you get a powerful server at the same time, and also you can decrease this value to serve only 1 or 2 clients and hope this program can run under some embedded SoC system with limited memory and only you can access. (Notice that the `-smuxbuf` value is not proprotional to concurrency, you need to test.)
 
 
 #### Compression
@@ -339,13 +370,12 @@ Low-level KCP configuration can be altered by using manual mode like above, make
 
 ### Identical Parmeters
 
-The parameters below **MUST** be **IDENTICAL** on **BOTH** side:
+These parameters **MUST** be **IDENTICAL** on **BOTH** side:
 
 1. -key
 1. -crypt
 1. -nocomp
-1. -datashard
-1. -parityshard
+1. -smuxver
 
 ### References
 
@@ -364,15 +394,7 @@ The parameters below **MUST** be **IDENTICAL** on **BOTH** side:
 1. http://http2.github.io/ -- What is HTTP/2?
 1. http://www.lartc.org/ -- Linux Advanced Routing & Traffic Control
 1. https://en.wikipedia.org/wiki/Noisy-channel_coding_theorem -- Noisy channel coding theorem
+1. https://zhuanlan.zhihu.com/p/53849089 -- kcptun开发小记
 
-### Donate 
-
-via Ethereum(ETH): Address: 0x2e4b43ab3d0983da282592571eef61ae5e60f726 , Or scan here:
-
-<img src="0x2e4b43ab3d0983da282592571eef61ae5e60f726.png" alt="kcptun" height="120px" /> 
-
-via WeChat
-
-<img src="wechat_donate.jpg" alt="kcptun" height="120px" /> 
 
 （注意：我没有任何社交网站的账号，请小心骗子。）

build-release.sh

@@ -6,11 +6,8 @@ cd $BUILD_DIR
 
 sum="sha1sum"
 
-if [ "$GO111MODULE" != "on" ]; then
-	echo "GO111MODULE is off"
-else
-	echo "GO111MODULE is on"
-fi 
+export GO111MODULE=on
+echo "Setting GO111MODULE to" $GO111MODULE
 
 if ! hash sha1sum 2>/dev/null; then
 	if ! hash shasum 2>/dev/null; then
@@ -38,8 +35,8 @@ for os in ${OSES[@]}; do
 	then
 		suffix=".exe"
 	fi
-	env CGO_ENABLED=0 GOOS=$os GOARCH=amd64 go build -ldflags "$LDFLAGS" -gcflags "$GCFLAGS" -o client_${os}_amd64${suffix} github.com/xtaci/kcptun/client
-	env CGO_ENABLED=0 GOOS=$os GOARCH=amd64 go build -ldflags "$LDFLAGS" -gcflags "$GCFLAGS" -o server_${os}_amd64${suffix} github.com/xtaci/kcptun/server
+	env CGO_ENABLED=0 GOOS=$os GOARCH=amd64 go build -mod=vendor -ldflags "$LDFLAGS" -gcflags "$GCFLAGS" -o client_${os}_amd64${suffix} github.com/xtaci/kcptun/client
+	env CGO_ENABLED=0 GOOS=$os GOARCH=amd64 go build -mod=vendor -ldflags "$LDFLAGS" -gcflags "$GCFLAGS" -o server_${os}_amd64${suffix} github.com/xtaci/kcptun/server
 	if $UPX; then upx -9 client_${os}_amd64${suffix} server_${os}_amd64${suffix};fi
 	tar -zcf kcptun-${os}-amd64-$VERSION.tar.gz client_${os}_amd64${suffix} server_${os}_amd64${suffix}
 	$sum kcptun-${os}-amd64-$VERSION.tar.gz
@@ -53,8 +50,8 @@ for os in ${OSES[@]}; do
 	then
 		suffix=".exe"
 	fi
-	env CGO_ENABLED=0 GOOS=$os GOARCH=386 go build -ldflags "$LDFLAGS" -gcflags "$GCFLAGS" -o client_${os}_386${suffix} github.com/xtaci/kcptun/client
-	env CGO_ENABLED=0 GOOS=$os GOARCH=386 go build -ldflags "$LDFLAGS" -gcflags "$GCFLAGS" -o server_${os}_386${suffix} github.com/xtaci/kcptun/server
+	env CGO_ENABLED=0 GOOS=$os GOARCH=386 go build -mod=vendor -ldflags "$LDFLAGS" -gcflags "$GCFLAGS" -o client_${os}_386${suffix} github.com/xtaci/kcptun/client
+	env CGO_ENABLED=0 GOOS=$os GOARCH=386 go build -mod=vendor -ldflags "$LDFLAGS" -gcflags "$GCFLAGS" -o server_${os}_386${suffix} github.com/xtaci/kcptun/server
 	if $UPX; then upx -9 client_${os}_386${suffix} server_${os}_386${suffix};fi
 	tar -zcf kcptun-${os}-386-$VERSION.tar.gz client_${os}_386${suffix} server_${os}_386${suffix}
 	$sum kcptun-${os}-386-$VERSION.tar.gz
@@ -63,25 +60,33 @@ done
 # ARM
 ARMS=(5 6 7)
 for v in ${ARMS[@]}; do
-	env CGO_ENABLED=0 GOOS=linux GOARCH=arm GOARM=$v go build -ldflags "$LDFLAGS" -gcflags "$GCFLAGS" -o client_linux_arm$v  github.com/xtaci/kcptun/client
-	env CGO_ENABLED=0 GOOS=linux GOARCH=arm GOARM=$v go build -ldflags "$LDFLAGS" -gcflags "$GCFLAGS" -o server_linux_arm$v  github.com/xtaci/kcptun/server
+	env CGO_ENABLED=0 GOOS=linux GOARCH=arm GOARM=$v go build -mod=vendor -ldflags "$LDFLAGS" -gcflags "$GCFLAGS" -o client_linux_arm$v  github.com/xtaci/kcptun/client
+	env CGO_ENABLED=0 GOOS=linux GOARCH=arm GOARM=$v go build -mod=vendor -ldflags "$LDFLAGS" -gcflags "$GCFLAGS" -o server_linux_arm$v  github.com/xtaci/kcptun/server
 if $UPX; then upx -9 client_linux_arm$v server_linux_arm$v;fi
 tar -zcf kcptun-linux-arm$v-$VERSION.tar.gz client_linux_arm$v server_linux_arm$v
 $sum kcptun-linux-arm$v-$VERSION.tar.gz
 done
 
 # ARM64
-env CGO_ENABLED=0 GOOS=linux GOARCH=arm64 go build -ldflags "$LDFLAGS" -gcflags "$GCFLAGS" -o client_linux_arm64  github.com/xtaci/kcptun/client
-env CGO_ENABLED=0 GOOS=linux GOARCH=arm64 go build -ldflags "$LDFLAGS" -gcflags "$GCFLAGS" -o server_linux_arm64  github.com/xtaci/kcptun/server
-if $UPX; then upx -9 client_linux_arm64 server_linux_arm64*;fi
-tar -zcf kcptun-linux-arm64-$VERSION.tar.gz client_linux_arm64 server_linux_arm64
-$sum kcptun-linux-arm64-$VERSION.tar.gz
+OSES=(linux darwin windows)
+for os in ${OSES[@]}; do
+	suffix=""
+	if [ "$os" == "windows" ]
+	then
+		suffix=".exe"
+	fi
+	env CGO_ENABLED=0 GOOS=$os GOARCH=arm64 go build -mod=vendor -ldflags "$LDFLAGS" -gcflags "$GCFLAGS" -o client_${os}_arm64${suffix} github.com/xtaci/kcptun/client
+	env CGO_ENABLED=0 GOOS=$os GOARCH=arm64 go build -mod=vendor -ldflags "$LDFLAGS" -gcflags "$GCFLAGS" -o server_${os}_arm64${suffix} github.com/xtaci/kcptun/server
+	if $UPX; then upx -9 client_${os}_arm64${suffix} server_${os}_arm64${suffix};fi
+	tar -zcf kcptun-${os}-arm64-$VERSION.tar.gz client_${os}_arm64${suffix} server_${os}_arm64${suffix}
+	$sum kcptun-${os}-arm64-$VERSION.tar.gz
+done
 
 #MIPS32LE
-env CGO_ENABLED=0 GOOS=linux GOARCH=mipsle GOMIPS=softfloat go build -ldflags "$LDFLAGS" -gcflags "$GCFLAGS" -o client_linux_mipsle github.com/xtaci/kcptun/client
-env CGO_ENABLED=0 GOOS=linux GOARCH=mipsle GOMIPS=softfloat go build -ldflags "$LDFLAGS" -gcflags "$GCFLAGS" -o server_linux_mipsle github.com/xtaci/kcptun/server
-env CGO_ENABLED=0 GOOS=linux GOARCH=mips GOMIPS=softfloat go build -ldflags "$LDFLAGS" -gcflags "$GCFLAGS" -o client_linux_mips github.com/xtaci/kcptun/client
-env CGO_ENABLED=0 GOOS=linux GOARCH=mips GOMIPS=softfloat go build -ldflags "$LDFLAGS" -gcflags "$GCFLAGS" -o server_linux_mips github.com/xtaci/kcptun/server
+env CGO_ENABLED=0 GOOS=linux GOARCH=mipsle GOMIPS=softfloat go build -mod=vendor -ldflags "$LDFLAGS" -gcflags "$GCFLAGS" -o client_linux_mipsle github.com/xtaci/kcptun/client
+env CGO_ENABLED=0 GOOS=linux GOARCH=mipsle GOMIPS=softfloat go build -mod=vendor -ldflags "$LDFLAGS" -gcflags "$GCFLAGS" -o server_linux_mipsle github.com/xtaci/kcptun/server
+env CGO_ENABLED=0 GOOS=linux GOARCH=mips GOMIPS=softfloat go build -mod=vendor -ldflags "$LDFLAGS" -gcflags "$GCFLAGS" -o client_linux_mips github.com/xtaci/kcptun/client
+env CGO_ENABLED=0 GOOS=linux GOARCH=mips GOMIPS=softfloat go build -mod=vendor -ldflags "$LDFLAGS" -gcflags "$GCFLAGS" -o server_linux_mips github.com/xtaci/kcptun/server
 
 if $UPX; then upx -9 client_linux_mips* server_linux_mips*;fi
 tar -zcf kcptun-linux-mipsle-$VERSION.tar.gz client_linux_mipsle server_linux_mipsle

client/config.go

@@ -28,13 +28,16 @@ type Config struct {
 	Resend       int    `json:"resend"`
 	NoCongestion int    `json:"nc"`
 	SockBuf      int    `json:"sockbuf"`
+	SmuxVer      int    `json:"smuxver"`
 	SmuxBuf      int    `json:"smuxbuf"`
+	StreamBuf    int    `json:"streambuf"`
 	KeepAlive    int    `json:"keepalive"`
 	Log          string `json:"log"`
 	SnmpLog      string `json:"snmplog"`
 	SnmpPeriod   int    `json:"snmpperiod"`
 	Quiet        bool   `json:"quiet"`
 	TCP          bool   `json:"tcp"`
+	Pprof        bool   `json:"pprof"`
 }
 
 func parseJSONConfig(config *Config, path string) error {

client/dial.go

@@ -1,18 +1,37 @@
 package main
 
 import (
+	"crypto/rand"
+	"encoding/binary"
+	"fmt"
+
 	"github.com/pkg/errors"
-	kcp "github.com/xtaci/kcp-go"
+	kcp "github.com/xtaci/kcp-go/v5"
+	"github.com/xtaci/kcptun/generic"
 	"github.com/xtaci/tcpraw"
 )
 
 func dial(config *Config, block kcp.BlockCrypt) (*kcp.UDPSession, error) {
+	mp, err := generic.ParseMultiPort(config.RemoteAddr)
+	if err != nil {
+		return nil, err
+	}
+
+	var randport uint64
+	err = binary.Read(rand.Reader, binary.LittleEndian, &randport)
+	if err != nil {
+		return nil, err
+	}
+
+	remoteAddr := fmt.Sprintf("%v:%v", mp.Host, uint64(mp.MinPort)+randport%uint64(mp.MaxPort-mp.MinPort+1))
+
 	if config.TCP {
-		conn, err := tcpraw.Dial("tcp", config.RemoteAddr)
+		conn, err := tcpraw.Dial("tcp", remoteAddr)
 		if err != nil {
 			return nil, errors.Wrap(err, "tcpraw.Dial()")
 		}
-		return kcp.NewConn(config.RemoteAddr, block, config.DataShard, config.ParityShard, conn)
+		return kcp.NewConn(remoteAddr, block, config.DataShard, config.ParityShard, conn)
 	}
-	return kcp.DialWithOptions(config.RemoteAddr, block, config.DataShard, config.ParityShard)
+	return kcp.DialWithOptions(remoteAddr, block, config.DataShard, config.ParityShard)
+
 }

client/main.go

@@ -7,36 +7,41 @@ import (
 	"log"
 	"math/rand"
 	"net"
+	"net/http"
+	_ "net/http/pprof"
 	"os"
-	"sync"
 	"time"
 
 	"golang.org/x/crypto/pbkdf2"
 
 	"github.com/pkg/errors"
 	"github.com/urfave/cli"
-	kcp "github.com/xtaci/kcp-go"
+	kcp "github.com/xtaci/kcp-go/v5"
 	"github.com/xtaci/kcptun/generic"
 	"github.com/xtaci/smux"
 )
 
-// SALT is use for pbkdf2 key expansion
-const SALT = "kcp-go"
+const (
+	// SALT is use for pbkdf2 key expansion
+	SALT = "kcp-go"
+	// maximum supported smux version
+	maxSmuxVer = 2
+	// stream copy buffer size
+	bufSize = 4096
+)
 
 // VERSION is injected by buildflags
 var VERSION = "SELFBUILD"
 
-// A pool for stream copying
-var xmitBuf sync.Pool
-
-func handleClient(sess *smux.Session, p1 net.Conn, quiet bool) {
+// handleClient aggregates connection p1 on mux with 'writeLock'
+func handleClient(session *smux.Session, p1 net.Conn, quiet bool) {
 	logln := func(v ...interface{}) {
 		if !quiet {
 			log.Println(v...)
 		}
 	}
 	defer p1.Close()
-	p2, err := sess.OpenStream()
+	p2, err := session.OpenStream()
 	if err != nil {
 		logln(err)
 		return
@@ -48,21 +53,19 @@ func handleClient(sess *smux.Session, p1 net.Conn, quiet bool) {
 	defer logln("stream closed", "in:", p1.RemoteAddr(), "out:", fmt.Sprint(p2.RemoteAddr(), "(", p2.ID(), ")"))
 
 	// start tunnel & wait for tunnel termination
-	streamCopy := func(dst io.Writer, src io.ReadCloser) chan struct{} {
-		die := make(chan struct{})
-		go func() {
-			buf := xmitBuf.Get().([]byte)
-			generic.CopyBuffer(dst, src, buf)
-			xmitBuf.Put(buf)
-			close(die)
-		}()
-		return die
+	streamCopy := func(dst io.Writer, src io.ReadCloser) {
+		if _, err := generic.Copy(dst, src); err != nil {
+			// report protocol error
+			if err == smux.ErrInvalidProtocol {
+				log.Println("smux", err, "in:", p1.RemoteAddr(), "out:", fmt.Sprint(p2.RemoteAddr(), "(", p2.ID(), ")"))
+			}
+		}
+		p1.Close()
+		p2.Close()
 	}
 
-	select {
-	case <-streamCopy(p1, p2):
-	case <-streamCopy(p2, p1):
-	}
+	go streamCopy(p1, p2)
+	streamCopy(p2, p1)
 }
 
 func checkError(err error) {
@@ -72,15 +75,17 @@ func checkError(err error) {
 	}
 }
 
+type timedSession struct {
+	session    *smux.Session
+	expiryDate time.Time
+}
+
 func main() {
 	rand.Seed(int64(time.Now().Nanosecond()))
 	if VERSION == "SELFBUILD" {
 		// add more log flags for debugging
 		log.SetFlags(log.LstdFlags | log.Lshortfile)
 	}
-	xmitBuf.New = func() interface{} {
-		return make([]byte, 32768)
-	}
 
 	myApp := cli.NewApp()
 	myApp.Name = "kcptun"
@@ -95,7 +100,7 @@ func main() {
 		cli.StringFlag{
 			Name:  "remoteaddr, r",
 			Value: "vps:29900",
-			Usage: "kcp server address",
+			Usage: `kcp server address, eg: "IP:29900" a for single port, "IP:minport-maxport" for port range`,
 		},
 		cli.StringFlag{
 			Name:   "key",
@@ -106,7 +111,7 @@ func main() {
 		cli.StringFlag{
 			Name:  "crypt",
 			Value: "aes",
-			Usage: "aes, aes-128, aes-192, salsa20, blowfish, twofish, cast5, 3des, tea, xtea, xor, sm4, none",
+			Usage: "aes, aes-128, aes-192, salsa20, blowfish, twofish, cast5, 3des, tea, xtea, xor, sm4, none, null",
 		},
 		cli.StringFlag{
 			Name:  "mode",
@@ -126,7 +131,7 @@ func main() {
 		cli.IntFlag{
 			Name:  "scavengettl",
 			Value: 600,
-			Usage: "set how long an expired connection can live(in sec), -1 to disable",
+			Usage: "set how long an expired connection can live (in seconds)",
 		},
 		cli.IntFlag{
 			Name:  "mtu",
@@ -192,11 +197,21 @@ func main() {
 			Value: 4194304, // socket buffer size in bytes
 			Usage: "per-socket buffer in bytes",
 		},
+		cli.IntFlag{
+			Name:  "smuxver",
+			Value: 1,
+			Usage: "specify smux version, available 1,2",
+		},
 		cli.IntFlag{
 			Name:  "smuxbuf",
 			Value: 4194304,
 			Usage: "the overall de-mux buffer in bytes",
 		},
+		cli.IntFlag{
+			Name:  "streambuf",
+			Value: 2097152,
+			Usage: "per stream receive buffer in bytes, smux v2+",
+		},
 		cli.IntFlag{
 			Name:  "keepalive",
 			Value: 10, // nat keepalive interval in seconds
@@ -230,6 +245,10 @@ func main() {
 			Value: "", // when the value is not empty, the config path must exists
 			Usage: "config from json file, which will override the command from shell",
 		},
+		cli.BoolFlag{
+			Name:  "pprof",
+			Usage: "start profiling server on :6060",
+		},
 	}
 	myApp.Action = func(c *cli.Context) error {
 		config := Config{}
@@ -255,12 +274,15 @@ func main() {
 		config.NoCongestion = c.Int("nc")
 		config.SockBuf = c.Int("sockbuf")
 		config.SmuxBuf = c.Int("smuxbuf")
+		config.StreamBuf = c.Int("streambuf")
+		config.SmuxVer = c.Int("smuxver")
 		config.KeepAlive = c.Int("keepalive")
 		config.Log = c.String("log")
 		config.SnmpLog = c.String("snmplog")
 		config.SnmpPeriod = c.Int("snmpperiod")
 		config.Quiet = c.Bool("quiet")
 		config.TCP = c.Bool("tcp")
+		config.Pprof = c.Bool("pprof")
 
 		if c.String("c") != "" {
 			err := parseJSONConfig(&config, c.String("c"))
@@ -287,15 +309,59 @@ func main() {
 		}
 
 		log.Println("version:", VERSION)
-		addr, err := net.ResolveTCPAddr("tcp", config.LocalAddr)
-		checkError(err)
-		listener, err := net.ListenTCP("tcp", addr)
-		checkError(err)
+		var listener net.Listener
+		var isUnix bool
+		if _, _, err := net.SplitHostPort(config.LocalAddr); err != nil {
+			isUnix = true
+		}
+		if isUnix {
+			addr, err := net.ResolveUnixAddr("unix", config.LocalAddr)
+			checkError(err)
+			listener, err = net.ListenUnix("unix", addr)
+			checkError(err)
+		} else {
+			addr, err := net.ResolveTCPAddr("tcp", config.LocalAddr)
+			checkError(err)
+			listener, err = net.ListenTCP("tcp", addr)
+			checkError(err)
+		}
+
+		log.Println("smux version:", config.SmuxVer)
+		log.Println("listening on:", listener.Addr())
+		log.Println("encryption:", config.Crypt)
+		log.Println("nodelay parameters:", config.NoDelay, config.Interval, config.Resend, config.NoCongestion)
+		log.Println("remote address:", config.RemoteAddr)
+		log.Println("sndwnd:", config.SndWnd, "rcvwnd:", config.RcvWnd)
+		log.Println("compression:", !config.NoComp)
+		log.Println("mtu:", config.MTU)
+		log.Println("datashard:", config.DataShard, "parityshard:", config.ParityShard)
+		log.Println("acknodelay:", config.AckNodelay)
+		log.Println("dscp:", config.DSCP)
+		log.Println("sockbuf:", config.SockBuf)
+		log.Println("smuxbuf:", config.SmuxBuf)
+		log.Println("streambuf:", config.StreamBuf)
+		log.Println("keepalive:", config.KeepAlive)
+		log.Println("conn:", config.Conn)
+		log.Println("autoexpire:", config.AutoExpire)
+		log.Println("scavengettl:", config.ScavengeTTL)
+		log.Println("snmplog:", config.SnmpLog)
+		log.Println("snmpperiod:", config.SnmpPeriod)
+		log.Println("quiet:", config.Quiet)
+		log.Println("tcp:", config.TCP)
+		log.Println("pprof:", config.Pprof)
+
+		// parameters check
+		if config.SmuxVer > maxSmuxVer {
+			log.Fatal("unsupported smux version:", config.SmuxVer)
+		}
 
 		log.Println("initiating key derivation")
 		pass := pbkdf2.Key([]byte(config.Key), []byte(SALT), 4096, 32, sha1.New)
+		log.Println("key derivation done")
 		var block kcp.BlockCrypt
 		switch config.Crypt {
+		case "null":
+			block = nil
 		case "sm4":
 			block, _ = kcp.NewSM4BlockCrypt(pass[:16])
 		case "tea":
@@ -325,31 +391,6 @@ func main() {
 			block, _ = kcp.NewAESBlockCrypt(pass)
 		}
 
-		log.Println("listening on:", listener.Addr())
-		log.Println("encryption:", config.Crypt)
-		log.Println("nodelay parameters:", config.NoDelay, config.Interval, config.Resend, config.NoCongestion)
-		log.Println("remote address:", config.RemoteAddr)
-		log.Println("sndwnd:", config.SndWnd, "rcvwnd:", config.RcvWnd)
-		log.Println("compression:", !config.NoComp)
-		log.Println("mtu:", config.MTU)
-		log.Println("datashard:", config.DataShard, "parityshard:", config.ParityShard)
-		log.Println("acknodelay:", config.AckNodelay)
-		log.Println("dscp:", config.DSCP)
-		log.Println("sockbuf:", config.SockBuf)
-		log.Println("smuxbuf:", config.SmuxBuf)
-		log.Println("keepalive:", config.KeepAlive)
-		log.Println("conn:", config.Conn)
-		log.Println("autoexpire:", config.AutoExpire)
-		log.Println("scavengettl:", config.ScavengeTTL)
-		log.Println("snmplog:", config.SnmpLog)
-		log.Println("snmpperiod:", config.SnmpPeriod)
-		log.Println("quiet:", config.Quiet)
-		log.Println("tcp:", config.TCP)
-
-		smuxConfig := smux.DefaultConfig()
-		smuxConfig.MaxReceiveBuffer = config.SmuxBuf
-		smuxConfig.KeepAliveInterval = time.Duration(config.KeepAlive) * time.Second
-
 		createConn := func() (*smux.Session, error) {
 			kcpconn, err := dial(&config, block)
 			if err != nil {
@@ -371,6 +412,16 @@ func main() {
 			if err := kcpconn.SetWriteBuffer(config.SockBuf); err != nil {
 				log.Println("SetWriteBuffer:", err)
 			}
+			log.Println("smux version:", config.SmuxVer, "on connection:", kcpconn.LocalAddr(), "->", kcpconn.RemoteAddr())
+			smuxConfig := smux.DefaultConfig()
+			smuxConfig.Version = config.SmuxVer
+			smuxConfig.MaxReceiveBuffer = config.SmuxBuf
+			smuxConfig.MaxStreamBuffer = config.StreamBuf
+			smuxConfig.KeepAliveInterval = time.Duration(config.KeepAlive) * time.Second
+
+			if err := smux.VerifyConfig(smuxConfig); err != nil {
+				log.Fatalf("%+v", err)
+			}
 
 			// stream multiplex
 			var session *smux.Session
@@ -382,7 +433,6 @@ func main() {
 			if err != nil {
 				return nil, errors.Wrap(err, "createConn()")
 			}
-			log.Println("connection:", kcpconn.LocalAddr(), "->", kcpconn.RemoteAddr())
 			return session, nil
 		}
 
@@ -398,33 +448,37 @@ func main() {
 			}
 		}
 
-		numconn := uint16(config.Conn)
-		muxes := make([]struct {
-			session *smux.Session
-			ttl     time.Time
-		}, numconn)
+		// start snmp logger
+		go generic.SnmpLogger(config.SnmpLog, config.SnmpPeriod)
 
-		for k := range muxes {
-			muxes[k].session = waitConn()
-			muxes[k].ttl = time.Now().Add(time.Duration(config.AutoExpire) * time.Second)
+		// start pprof
+		if config.Pprof {
+			go http.ListenAndServe(":6060", nil)
 		}
 
-		chScavenger := make(chan *smux.Session, 128)
-		go scavenger(chScavenger, config.ScavengeTTL)
-		go generic.SnmpLogger(config.SnmpLog, config.SnmpPeriod)
+		// start scavenger
+		chScavenger := make(chan timedSession, 128)
+		go scavenger(chScavenger, &config)
+
+		// start listener
+		numconn := uint16(config.Conn)
+		muxes := make([]timedSession, numconn)
 		rr := uint16(0)
 		for {
-			p1, err := listener.AcceptTCP()
+			p1, err := listener.Accept()
 			if err != nil {
 				log.Fatalf("%+v", err)
 			}
 			idx := rr % numconn
 
 			// do auto expiration && reconnection
-			if muxes[idx].session.IsClosed() || (config.AutoExpire > 0 && time.Now().After(muxes[idx].ttl)) {
-				chScavenger <- muxes[idx].session
+			if muxes[idx].session == nil || muxes[idx].session.IsClosed() ||
+				(config.AutoExpire > 0 && time.Now().After(muxes[idx].expiryDate)) {
 				muxes[idx].session = waitConn()
-				muxes[idx].ttl = time.Now().Add(time.Duration(config.AutoExpire) * time.Second)
+				muxes[idx].expiryDate = time.Now().Add(time.Duration(config.AutoExpire) * time.Second)
+				if config.AutoExpire > 0 { // only when autoexpire set
+					chScavenger <- muxes[idx]
+				}
 			}
 
 			go handleClient(muxes[idx].session, p1, config.Quiet)
@@ -434,30 +488,35 @@ func main() {
 	myApp.Run(os.Args)
 }
 
-type scavengeSession struct {
-	session *smux.Session
-	ts      time.Time
-}
+func scavenger(ch chan timedSession, config *Config) {
+	// When AutoExpire is set to 0 (default), sessionList will keep empty.
+	// Then this routine won't need to do anything; thus just terminate it.
+	if config.AutoExpire <= 0 {
+		return
+	}
 
-func scavenger(ch chan *smux.Session, ttl int) {
 	ticker := time.NewTicker(time.Second)
 	defer ticker.Stop()
-	var sessionList []scavengeSession
+	var sessionList []timedSession
 	for {
 		select {
-		case sess := <-ch:
-			sessionList = append(sessionList, scavengeSession{sess, time.Now()})
-			log.Println("session marked as expired", sess.RemoteAddr())
+		case item := <-ch:
+			sessionList = append(sessionList, timedSession{
+				item.session,
+				item.expiryDate.Add(time.Duration(config.ScavengeTTL) * time.Second)})
 		case <-ticker.C:
-			var newList []scavengeSession
+			if len(sessionList) == 0 {
+				continue
+			}
+
+			var newList []timedSession
 			for k := range sessionList {
 				s := sessionList[k]
-				if s.session.NumStreams() == 0 || s.session.IsClosed() {
-					log.Println("session normally closed", s.session.RemoteAddr())
-					s.session.Close()
-				} else if ttl >= 0 && time.Since(s.ts) >= time.Duration(ttl)*time.Second {
-					log.Println("session reached scavenge ttl", s.session.RemoteAddr())
+				if s.session.IsClosed() {
+					log.Println("scavenger: session normally closed:", s.session.LocalAddr())
+				} else if time.Now().After(s.expiryDate) {
 					s.session.Close()
+					log.Println("scavenger: session closed due to ttl:", s.session.LocalAddr())
 				} else {
 					newList = append(newList, sessionList[k])
 				}

client/signal.go

@@ -8,7 +8,7 @@ import (
 	"os/signal"
 	"syscall"
 
-	kcp "github.com/xtaci/kcp-go"
+	kcp "github.com/xtaci/kcp-go/v5"
 )
 
 func init() {

examples/kcptun.service

@@ -0,0 +1,17 @@
+[unit]
+Description=kcptun
+
+Wants=network.target
+After=syslog.target network-online.target
+
+[Service]
+Type=simple
+Environment=GOGC=20
+ExecStart=/home/user/client_linux_amd64 -c /home/user/local.json
+Restart=on-failure
+RestartSec=10
+KillMode=process
+LimitNOFILE=65536
+
+[Install]
+WantedBy=multi-user.target

examples/local.json

@@ -0,0 +1,27 @@
+{
+	"localaddr": ":2000",
+	"remoteaddr": "11.22.33.44:2000",
+	"key": "PASSWORD",
+	"crypt": "aes-128",
+	"mode": "fast3",
+	"mtu": 1400,
+	"sndwnd": 128,
+	"rcvwnd": 1024,
+	"datashard": 10,
+	"parityshard": 3,
+	"dscp": 46,
+	"nocomp": true,
+	"acknodelay": false,
+	"nodelay": 1,
+	"interval": 40,
+	"resend": 2,
+	"nc": 1,
+	"sockbuf": 16777217,
+	"smuxver": 1,
+	"smuxbuf": 16777217,
+	"streambuf": 2097152,
+	"keepalive": 10,
+	"autoexpire": 1800,
+	"quiet": false,
+	"tcp": false
+}

examples/server.json

@@ -0,0 +1,27 @@
+{
+        "listen": ":2000",
+        "target": "127.0.0.1:9999",
+        "key": "PASSWORD",
+        "crypt": "aes-128",
+        "mode": "fast3",
+        "mtu": 1400,
+        "sndwnd": 2048,
+        "rcvwnd": 2048,
+        "datashard": 10,
+        "parityshard": 3,
+        "dscp": 46,
+        "nocomp": true,
+        "acknodelay": false,
+        "nodelay": 1,
+        "interval": 40,
+        "resend": 2,
+        "nc": 1,
+        "sockbuf": 16777217,
+        "smuxver": 1,
+        "smuxbuf": 16777217,
+        "streambuf": 2097152,
+        "keepalive": 10,
+        "pprof":false,
+        "quiet":false,
+        "tcp":false
+}

generic/comp.go

@@ -2,6 +2,7 @@ package generic
 
 import (
 	"net"
+	"time"
 
 	"github.com/golang/snappy"
 	"github.com/pkg/errors"
@@ -32,6 +33,26 @@ func (c *CompStream) Close() error {
 	return c.conn.Close()
 }
 
+func (c *CompStream) LocalAddr() net.Addr {
+	return c.conn.LocalAddr()
+}
+
+func (c *CompStream) RemoteAddr() net.Addr {
+	return c.conn.RemoteAddr()
+}
+
+func (c *CompStream) SetDeadline(t time.Time) error {
+	return c.conn.SetDeadline(t)
+}
+
+func (c *CompStream) SetReadDeadline(t time.Time) error {
+	return c.conn.SetReadDeadline(t)
+}
+
+func (c *CompStream) SetWriteDeadline(t time.Time) error {
+	return c.conn.SetWriteDeadline(t)
+}
+
 func NewCompStream(conn net.Conn) *CompStream {
 	c := new(CompStream)
 	c.conn = conn

generic/copy.go

@@ -1,36 +1,24 @@
 package generic
 
-import "io"
+import (
+	"io"
+)
 
-// io.CopyBuffer has extra tests for interface like io.ReaderFrom and io.WriterTo
-// which is not efficient in memory management from tests
-func CopyBuffer(dst io.Writer, src io.Reader, buf []byte) (written int64, err error) {
-	if buf != nil && len(buf) == 0 {
-		panic("empty buffer in copyBuffer")
+const bufSize = 4096
+
+// Memory optimized io.Copy function specified for this library
+func Copy(dst io.Writer, src io.Reader) (written int64, err error) {
+	// If the reader has a WriteTo method, use it to do the copy.
+	// Avoids an allocation and a copy.
+	if wt, ok := src.(io.WriterTo); ok {
+		return wt.WriteTo(dst)
+	}
+	// Similarly, if the writer has a ReadFrom method, use it to do the copy.
+	if rt, ok := dst.(io.ReaderFrom); ok {
+		return rt.ReadFrom(src)
 	}
 
-	for {
-		nr, er := src.Read(buf)
-		if nr > 0 {
-			nw, ew := dst.Write(buf[0:nr])
-			if nw > 0 {
-				written += int64(nw)
-			}
-			if ew != nil {
-				err = ew
-				break
-			}
-			if nr != nw {
-				err = io.ErrShortWrite
-				break
-			}
-		}
-		if er != nil {
-			if er != io.EOF {
-				err = er
-			}
-			break
-		}
-	}
-	return written, err
+	// fallback to standard io.CopyBuffer
+	buf := make([]byte, bufSize)
+	return io.CopyBuffer(dst, src, buf)
 }

generic/multiport.go

@@ -0,0 +1,50 @@
+package generic
+
+import (
+	"regexp"
+	"strconv"
+
+	"github.com/pkg/errors"
+)
+
+type MultiPort struct {
+	Host    string
+	MinPort uint64
+	MaxPort uint64
+}
+
+// Parse mulitport listener or dialer
+func ParseMultiPort(addr string) (*MultiPort, error) {
+	remoteAddrMatcher := regexp.MustCompile(`(.*)\:([0-9]{1,5})-?([0-9]{1,5})?`)
+	matches := remoteAddrMatcher.FindStringSubmatch(addr)
+
+	if len(matches) >= 4 {
+		var minPort, maxPort int
+		minPort, err := strconv.Atoi(matches[2])
+		if err != nil {
+			return nil, err
+		}
+		maxPort = minPort
+
+		// multiport assignment
+		if matches[3] != "" {
+			maxPort, err = strconv.Atoi(matches[3])
+			if err != nil {
+				return nil, err
+			}
+		}
+
+		if (minPort > maxPort) || minPort > 65535 || maxPort > 65535 || minPort == 0 || maxPort == 0 {
+			return nil, errors.Errorf("invalid port range specified: minport:%v -> maxport %v", minPort, maxPort)
+		}
+
+		mp := new(MultiPort)
+		mp.Host = matches[1]
+		mp.MinPort = uint64(minPort)
+		mp.MaxPort = uint64(maxPort)
+		return mp, nil
+	}
+
+	return nil, errors.Errorf("malformed address:%v", addr)
+
+}

generic/multiport_test.go

@@ -0,0 +1,51 @@
+package generic
+
+import (
+	"fmt"
+	"regexp"
+	"strconv"
+	"testing"
+)
+
+func TestDial(t *testing.T) {
+	reg := regexp.MustCompile(`(.*)\:([0-9]{1,5})-?([0-9]{1,5})?`)
+	matches := reg.FindStringSubmatch("www.unknown.unknown:20000-21000")
+	for i := 0; i < len(matches); i++ {
+		fmt.Println(matches[i])
+	}
+
+	minPort, err := strconv.Atoi(matches[2])
+	if err != nil {
+		t.Fatal(err)
+	}
+	maxPort, err := strconv.Atoi(matches[3])
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	t.Log("minport:", minPort)
+	t.Log("maxport:", maxPort)
+
+	remoteAddr := fmt.Sprintf("%v:%v", matches[1], uint64(minPort)+1000%uint64(maxPort-minPort+1))
+
+	t.Log("RemoteAddr:", remoteAddr)
+
+	testcase2 := "1.2.3.4:20000"
+	matches = reg.FindStringSubmatch(testcase2)
+	for i := 0; i < len(matches); i++ {
+		t.Log(testcase2, "submatch", i, matches[i])
+	}
+
+	testcase3 := ":20000-20001"
+	matches = reg.FindStringSubmatch(testcase3)
+	for i := 0; i < len(matches); i++ {
+		t.Log(testcase3, "submatch", i, matches[i])
+	}
+
+	testcase4 := ":20000"
+	matches = reg.FindStringSubmatch(testcase4)
+	for i := 0; i < len(matches); i++ {
+		t.Log(testcase4, "submatch", i, matches[i])
+	}
+
+}

generic/snmp.go

@@ -8,7 +8,7 @@ import (
 	"path/filepath"
 	"time"
 
-	"github.com/xtaci/kcp-go"
+	kcp "github.com/xtaci/kcp-go/v5"
 )
 
 func SnmpLogger(path string, interval int) {

go.mod

@@ -1,22 +1,29 @@
 module github.com/xtaci/kcptun
 
 require (
-	github.com/coreos/go-iptables v0.4.1 // indirect
-	github.com/golang/snappy v0.0.1
-	github.com/google/gopacket v1.1.17 // indirect
-	github.com/klauspost/cpuid v1.2.1 // indirect
-	github.com/klauspost/reedsolomon v1.9.2 // indirect
-	github.com/pkg/errors v0.8.1
-	github.com/templexxx/cpufeat v0.0.0-20180724012125-cef66df7f161 // indirect
-	github.com/templexxx/xor v0.0.0-20181023030647-4e92f724b73b // indirect
-	github.com/tjfoc/gmsm v1.0.1 // indirect
-	github.com/urfave/cli v1.20.0
-	github.com/xtaci/kcp-go v5.4.2+incompatible
-	github.com/xtaci/smux v1.3.4
-	github.com/xtaci/tcpraw v1.2.0
-	golang.org/x/crypto v0.0.0-20190605123033-f99c8df09eb5
-	golang.org/x/net v0.0.0-20190607181551-461777fb6f67 // indirect
-	golang.org/x/sys v0.0.0-20190610200419-93c9922d18ae // indirect
-	golang.org/x/text v0.3.2 // indirect
-	golang.org/x/tools v0.0.0-20190610231749-f8d1dee965f7 // indirect
+	github.com/golang/snappy v0.0.4
+	github.com/pkg/errors v0.9.1
+	github.com/urfave/cli v1.22.14
+	github.com/xtaci/kcp-go/v5 v5.6.3
+	github.com/xtaci/smux v1.5.24
+	github.com/xtaci/tcpraw v1.2.25
+	golang.org/x/crypto v0.12.0
 )
+
+require (
+	github.com/coreos/go-iptables v0.7.0 // indirect
+	github.com/cpuguy83/go-md2man/v2 v2.0.2 // indirect
+	github.com/google/gopacket v1.1.19 // indirect
+	github.com/klauspost/cpuid/v2 v2.2.5 // indirect
+	github.com/klauspost/reedsolomon v1.11.8 // indirect
+	github.com/russross/blackfriday/v2 v2.1.0 // indirect
+	github.com/templexxx/cpu v0.1.0 // indirect
+	github.com/templexxx/xorsimd v0.4.2 // indirect
+	github.com/tjfoc/gmsm v1.4.1 // indirect
+	golang.org/x/net v0.14.0 // indirect
+	golang.org/x/sys v0.11.0 // indirect
+)
+
+go 1.21
+
+toolchain go1.21.0

go.sum

@@ -1,201 +1,132 @@
-github.com/coreos/go-iptables v0.4.1 h1:TyEMaK2xD/EcB0385QcvX/OvI2XI7s4SJEI2EhZFfEU=
-github.com/coreos/go-iptables v0.4.1/go.mod h1:/mVI274lEDI2ns62jHCDnCyBF9Iwsmekav8Dbxlm1MU=
-github.com/golang/snappy v0.0.1 h1:Qgr9rKW7uDUkrbSmQeiDsGa8SjGyCOGtuasMWwvp2P4=
-github.com/golang/snappy v0.0.1/go.mod h1:/XxbfmMg8lxefKM7IXC3fBNl/7bRcc72aCRzEWrmP2Q=
-github.com/google/gopacket v1.1.17 h1:rMrlX2ZY2UbvT+sdz3+6J+pp2z+msCq9MxTU6ymxbBY=
-github.com/google/gopacket v1.1.17/go.mod h1:UdDNZ1OO62aGYVnPhxT1U6aI7ukYtA/kB8vaU0diBUM=
-github.com/klauspost/cpuid v1.2.0 h1:NMpwD2G9JSFOE1/TJjGSo5zG7Yb2bTe7eq1jH+irmeE=
-github.com/klauspost/cpuid v1.2.0/go.mod h1:Pj4uuM528wm8OyEC2QMXAi2YiTZ96dNQPGgoMS4s3ek=
-github.com/klauspost/cpuid v1.2.1 h1:vJi+O/nMdFt0vqm8NZBI6wzALWdA2X+egi0ogNyrC/w=
-github.com/klauspost/cpuid v1.2.1/go.mod h1:Pj4uuM528wm8OyEC2QMXAi2YiTZ96dNQPGgoMS4s3ek=
-github.com/klauspost/reedsolomon v1.9.1 h1:kYrT1MlR4JH6PqOpC+okdb9CDTcwEC/BqpzK4WFyXL8=
-github.com/klauspost/reedsolomon v1.9.1/go.mod h1:CwCi+NUr9pqSVktrkN+Ondf06rkhYZ/pcNv7fu+8Un4=
-github.com/klauspost/reedsolomon v1.9.2 h1:E9CMS2Pqbv+C7tsrYad4YC9MfhnMVWhMRsTi7U0UB18=
-github.com/klauspost/reedsolomon v1.9.2/go.mod h1:CwCi+NUr9pqSVktrkN+Ondf06rkhYZ/pcNv7fu+8Un4=
-github.com/pkg/errors v0.8.1 h1:iURUrRGxPUNPdy5/HRSm+Yj6okJ6UtLINN0Q9M4+h3I=
-github.com/pkg/errors v0.8.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
-github.com/templexxx/cpufeat v0.0.0-20180724012125-cef66df7f161 h1:89CEmDvlq/F7SJEOqkIdNDGJXrQIhuIx9D2DBXjavSU=
-github.com/templexxx/cpufeat v0.0.0-20180724012125-cef66df7f161/go.mod h1:wM7WEvslTq+iOEAMDLSzhVuOt5BRZ05WirO+b09GHQU=
-github.com/templexxx/xor v0.0.0-20181023030647-4e92f724b73b h1:mnG1fcsIB1d/3vbkBak2MM0u+vhGhlQwpeimUi7QncM=
-github.com/templexxx/xor v0.0.0-20181023030647-4e92f724b73b/go.mod h1:5XA7W9S6mni3h5uvOC75dA3m9CCCaS83lltmc0ukdi4=
-github.com/tjfoc/gmsm v1.0.1 h1:R11HlqhXkDospckjZEihx9SW/2VW0RgdwrykyWMFOQU=
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-github.com/urfave/cli v1.20.0/go.mod h1:70zkFmudgCuE/ngEzBv17Jvp/497gISqfk5gWijbERA=
-github.com/xtaci/kcp-go v5.0.7+incompatible/go.mod h1:bN6vIwHQbfHaHtFpEssmWsN45a+AZwO7eyRCmEIbtvE=
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-github.com/xtaci/smux v1.2.10 h1:DQiH08XfO+33X7l5XOGV5urQHrgK8PRFWYxT/z9Hrnw=
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kcptun.spec

@@ -0,0 +1,131 @@
+%global         debug_package   %{nil}
+%global         _dwz_low_mem_die_limit 0
+%global         __os_install_post /usr/lib/rpm/brp-compress %{nil}
+
+Name:           kcptun
+Version:        20210922
+Release:        1
+Summary:        A Stable & Secure Tunnel based on KCP with N:M multiplexing and FEC
+
+License:        MIT
+URL:            https://github.com/xtaci/kcptun
+Source0:        %{name}-%{version}.tar.gz
+
+BuildRequires:  golang
+BuildRequires:  glibc-static
+
+%description
+A Stable & Secure Tunnel based on KCP with N:M multiplexing and FEC
+
+%package	server
+Summary:	kcptun-server
+Requires:       systemd
+
+%description	server
+A Stable & Secure Tunnel based on KCP with N:M multiplexing and FEC
+
+%package	client
+Summary:	kcptun-client
+Requires:       systemd
+
+%description	client
+A Stable & Secure Tunnel based on KCP with N:M multiplexing and FEC
+
+%prep
+%autosetup
+
+%build
+LDFLAGS='-s -w -linkmode=external -extldflags -static -X main.VERSION=%{version}'
+go build -ldflags "$LDFLAGS" -o %{name}-server github.com/xtaci/kcptun/server
+go build -ldflags "$LDFLAGS" -o %{name}-client github.com/xtaci/kcptun/client
+
+%install
+rm -rf $RPM_BUILD_ROOT
+
+%{__mkdir} -p $RPM_BUILD_ROOT%{_bindir}
+%{__install} -p -m 755 kcptun-server $RPM_BUILD_ROOT%{_bindir}/kcptun-server
+%{__install} -p -m 755 kcptun-client $RPM_BUILD_ROOT%{_bindir}/kcptun-client
+
+%{__mkdir} -p $RPM_BUILD_ROOT%{_sysconfdir}/%{name}
+%{__install} -p -m 644 examples/server.json $RPM_BUILD_ROOT%{_sysconfdir}/%{name}/server.json
+%{__install} -p -m 644 examples/local.json $RPM_BUILD_ROOT%{_sysconfdir}/%{name}/client.json
+
+%{__mkdir} -p $RPM_BUILD_ROOT%{_unitdir}
+cat > $RPM_BUILD_ROOT%{_unitdir}/kcptun-server.service <<EOF
+[Unit]
+Description=kcptun-server
+Wants=network.target
+After=syslog.target network-online.target
+ConditionFileIsExecutable=/usr/bin/kcptun-server
+ConditionPathExists=/etc/kcptun/server.json
+
+[Service]
+Type=simple
+Environment=GOGC=20
+ExecStart=/usr/bin/kcptun-server -c /etc/kcptun/server.json
+Restart=on-failure
+RestartSec=10
+KillMode=process
+LimitNOFILE=65536
+
+[Install]
+WantedBy=multi-user.target
+EOF
+
+cat > $RPM_BUILD_ROOT%{_unitdir}/kcptun-client.service <<EOF
+[Unit]
+Description=kcptun-client
+After=syslog.target network-online.target
+ConditionFileIsExecutable=/usr/bin/kcptun-client
+ConditionPathExists=/etc/kcptun/client.json
+
+[Service]
+Type=simple
+Environment=GOGC=20
+ExecStart=/usr/bin/kcptun-client -c /etc/kcptun/client.json
+Restart=on-failure
+RestartSec=10
+KillMode=process
+LimitNOFILE=65536
+
+[Install]
+WantedBy=multi-user.target
+EOF
+
+%post server
+%systemd_post %{name}-server.service
+
+%preun server
+%systemd_preun %{name}-server.service
+
+%postun server
+%systemd_postun_with_restart %{name}-server.service
+
+%post client
+%systemd_post %{name}-client.service
+
+%preun client
+%systemd_preun %{name}-client.service
+
+%postun client
+%systemd_postun_with_restart %{name}-client.service
+
+%files server
+%defattr(-,root,root,-)
+%{_bindir}/kcptun-server
+%config(noreplace) %{_sysconfdir}/%{name}/server.json
+%{_unitdir}/kcptun-server.service
+%license LICENSE.md
+%doc README.md Dockerfile
+
+%files client
+%defattr(-,root,root,-)
+%{_bindir}/kcptun-client
+%config(noreplace) %{_sysconfdir}/%{name}/client.json
+%{_unitdir}/kcptun-client.service
+%license LICENSE.md
+%doc README.md Dockerfile
+
+%changelog
+* Thu Dec 30 2021 Purple Grape <purplegrape4@gmail.com>
+- First package for kcptun

server/config.go

@@ -26,6 +26,8 @@ type Config struct {
 	NoCongestion int    `json:"nc"`
 	SockBuf      int    `json:"sockbuf"`
 	SmuxBuf      int    `json:"smuxbuf"`
+	StreamBuf    int    `json:"streambuf"`
+	SmuxVer      int    `json:"smuxver"`
 	KeepAlive    int    `json:"keepalive"`
 	Log          string `json:"log"`
 	SnmpLog      string `json:"snmplog"`

server/listen.go

@@ -1,18 +0,0 @@
-package main
-
-import (
-	"github.com/pkg/errors"
-	kcp "github.com/xtaci/kcp-go"
-	"github.com/xtaci/tcpraw"
-)
-
-func listen(config *Config, block kcp.BlockCrypt) (*kcp.Listener, error) {
-	if config.TCP {
-		conn, err := tcpraw.Listen("tcp", config.Listen)
-		if err != nil {
-			return nil, errors.Wrap(err, "tcpraw.Listen()")
-		}
-		return kcp.ServeConn(block, config.DataShard, config.ParityShard, conn)
-	}
-	return kcp.ListenWithOptions(config.Listen, block, config.DataShard, config.ParityShard)
-}

server/main.go

@@ -16,25 +16,38 @@ import (
 	"golang.org/x/crypto/pbkdf2"
 
 	"github.com/urfave/cli"
-	kcp "github.com/xtaci/kcp-go"
+	kcp "github.com/xtaci/kcp-go/v5"
 	"github.com/xtaci/kcptun/generic"
 	"github.com/xtaci/smux"
+	"github.com/xtaci/tcpraw"
 )
 
-// SALT is use for pbkdf2 key expansion
-const SALT = "kcp-go"
+const (
+	// SALT is use for pbkdf2 key expansion
+	SALT = "kcp-go"
+	// maximum supported smux version
+	maxSmuxVer = 2
+	// stream copy buffer size
+	bufSize = 4096
+)
 
 // VERSION is injected by buildflags
 var VERSION = "SELFBUILD"
 
-// A pool for stream copying
-var xmitBuf sync.Pool
-
 // handle multiplex-ed connection
-func handleMux(conn io.ReadWriteCloser, config *Config) {
+func handleMux(conn net.Conn, config *Config) {
+	// check if target is unix domain socket
+	var isUnix bool
+	if _, _, err := net.SplitHostPort(config.Target); err != nil {
+		isUnix = true
+	}
+	log.Println("smux version:", config.SmuxVer, "on connection:", conn.LocalAddr(), "->", conn.RemoteAddr())
+
 	// stream multiplex
 	smuxConfig := smux.DefaultConfig()
+	smuxConfig.Version = config.SmuxVer
 	smuxConfig.MaxReceiveBuffer = config.SmuxBuf
+	smuxConfig.MaxStreamBuffer = config.StreamBuf
 	smuxConfig.KeepAliveInterval = time.Duration(config.KeepAlive) * time.Second
 
 	mux, err := smux.Server(conn, smuxConfig)
@@ -43,6 +56,7 @@ func handleMux(conn io.ReadWriteCloser, config *Config) {
 		return
 	}
 	defer mux.Close()
+
 	for {
 		stream, err := mux.AcceptStream()
 		if err != nil {
@@ -51,7 +65,14 @@ func handleMux(conn io.ReadWriteCloser, config *Config) {
 		}
 
 		go func(p1 *smux.Stream) {
-			p2, err := net.Dial("tcp", config.Target)
+			var p2 net.Conn
+			var err error
+			if !isUnix {
+				p2, err = net.Dial("tcp", config.Target)
+			} else {
+				p2, err = net.Dial("unix", config.Target)
+			}
+
 			if err != nil {
 				log.Println(err)
 				p1.Close()
@@ -76,21 +97,18 @@ func handleClient(p1 *smux.Stream, p2 net.Conn, quiet bool) {
 	defer logln("stream closed", "in:", fmt.Sprint(p1.RemoteAddr(), "(", p1.ID(), ")"), "out:", p2.RemoteAddr())
 
 	// start tunnel & wait for tunnel termination
-	streamCopy := func(dst io.Writer, src io.ReadCloser) chan struct{} {
-		die := make(chan struct{})
-		go func() {
-			buf := xmitBuf.Get().([]byte)
-			generic.CopyBuffer(dst, src, buf)
-			xmitBuf.Put(buf)
-			close(die)
-		}()
-		return die
+	streamCopy := func(dst io.Writer, src io.ReadCloser) {
+		if _, err := generic.Copy(dst, src); err != nil {
+			if err == smux.ErrInvalidProtocol {
+				log.Println("smux", err, "in:", fmt.Sprint(p1.RemoteAddr(), "(", p1.ID(), ")"), "out:", p2.RemoteAddr())
+			}
+		}
+		p1.Close()
+		p2.Close()
 	}
 
-	select {
-	case <-streamCopy(p1, p2):
-	case <-streamCopy(p2, p1):
-	}
+	go streamCopy(p2, p1)
+	streamCopy(p1, p2)
 }
 
 func checkError(err error) {
@@ -106,9 +124,6 @@ func main() {
 		// add more log flags for debugging
 		log.SetFlags(log.LstdFlags | log.Lshortfile)
 	}
-	xmitBuf.New = func() interface{} {
-		return make([]byte, 32768)
-	}
 
 	myApp := cli.NewApp()
 	myApp.Name = "kcptun"
@@ -118,12 +133,12 @@ func main() {
 		cli.StringFlag{
 			Name:  "listen,l",
 			Value: ":29900",
-			Usage: "kcp server listen address",
+			Usage: `kcp server listen address, eg: "IP:29900" for a single port, "IP:minport-maxport" for port range`,
 		},
 		cli.StringFlag{
 			Name:  "target, t",
 			Value: "127.0.0.1:12948",
-			Usage: "target server address",
+			Usage: "target server address, or path/to/unix_socket",
 		},
 		cli.StringFlag{
 			Name:   "key",
@@ -134,7 +149,7 @@ func main() {
 		cli.StringFlag{
 			Name:  "crypt",
 			Value: "aes",
-			Usage: "aes, aes-128, aes-192, salsa20, blowfish, twofish, cast5, 3des, tea, xtea, xor, sm4, none",
+			Usage: "aes, aes-128, aes-192, salsa20, blowfish, twofish, cast5, 3des, tea, xtea, xor, sm4, none, null",
 		},
 		cli.StringFlag{
 			Name:  "mode",
@@ -205,11 +220,21 @@ func main() {
 			Value: 4194304, // socket buffer size in bytes
 			Usage: "per-socket buffer in bytes",
 		},
+		cli.IntFlag{
+			Name:  "smuxver",
+			Value: 1,
+			Usage: "specify smux version, available 1,2",
+		},
 		cli.IntFlag{
 			Name:  "smuxbuf",
 			Value: 4194304,
 			Usage: "the overall de-mux buffer in bytes",
 		},
+		cli.IntFlag{
+			Name:  "streambuf",
+			Value: 2097152,
+			Usage: "per stream receive buffer in bytes, smux v2+",
+		},
 		cli.IntFlag{
 			Name:  "keepalive",
 			Value: 10, // nat keepalive interval in seconds
@@ -269,6 +294,8 @@ func main() {
 		config.NoCongestion = c.Int("nc")
 		config.SockBuf = c.Int("sockbuf")
 		config.SmuxBuf = c.Int("smuxbuf")
+		config.StreamBuf = c.Int("streambuf")
+		config.SmuxVer = c.Int("smuxver")
 		config.KeepAlive = c.Int("keepalive")
 		config.Log = c.String("log")
 		config.SnmpLog = c.String("snmplog")
@@ -303,10 +330,39 @@ func main() {
 		}
 
 		log.Println("version:", VERSION)
+		log.Println("smux version:", config.SmuxVer)
+		log.Println("listening on:", config.Listen)
+		log.Println("target:", config.Target)
+		log.Println("encryption:", config.Crypt)
+		log.Println("nodelay parameters:", config.NoDelay, config.Interval, config.Resend, config.NoCongestion)
+		log.Println("sndwnd:", config.SndWnd, "rcvwnd:", config.RcvWnd)
+		log.Println("compression:", !config.NoComp)
+		log.Println("mtu:", config.MTU)
+		log.Println("datashard:", config.DataShard, "parityshard:", config.ParityShard)
+		log.Println("acknodelay:", config.AckNodelay)
+		log.Println("dscp:", config.DSCP)
+		log.Println("sockbuf:", config.SockBuf)
+		log.Println("smuxbuf:", config.SmuxBuf)
+		log.Println("streambuf:", config.StreamBuf)
+		log.Println("keepalive:", config.KeepAlive)
+		log.Println("snmplog:", config.SnmpLog)
+		log.Println("snmpperiod:", config.SnmpPeriod)
+		log.Println("pprof:", config.Pprof)
+		log.Println("quiet:", config.Quiet)
+		log.Println("tcp:", config.TCP)
+
+		// parameters check
+		if config.SmuxVer > maxSmuxVer {
+			log.Fatal("unsupported smux version:", config.SmuxVer)
+		}
+
 		log.Println("initiating key derivation")
 		pass := pbkdf2.Key([]byte(config.Key), []byte(SALT), 4096, 32, sha1.New)
+		log.Println("key derivation done")
 		var block kcp.BlockCrypt
 		switch config.Crypt {
+		case "null":
+			block = nil
 		case "sm4":
 			block, _ = kcp.NewSM4BlockCrypt(pass[:16])
 		case "tea":
@@ -336,61 +392,77 @@ func main() {
 			block, _ = kcp.NewAESBlockCrypt(pass)
 		}
 
-		lis, err := listen(&config, block)
-		checkError(err)
-		log.Println("listening on:", lis.Addr())
-		log.Println("target:", config.Target)
-		log.Println("encryption:", config.Crypt)
-		log.Println("nodelay parameters:", config.NoDelay, config.Interval, config.Resend, config.NoCongestion)
-		log.Println("sndwnd:", config.SndWnd, "rcvwnd:", config.RcvWnd)
-		log.Println("compression:", !config.NoComp)
-		log.Println("mtu:", config.MTU)
-		log.Println("datashard:", config.DataShard, "parityshard:", config.ParityShard)
-		log.Println("acknodelay:", config.AckNodelay)
-		log.Println("dscp:", config.DSCP)
-		log.Println("sockbuf:", config.SockBuf)
-		log.Println("smuxbuf:", config.SmuxBuf)
-		log.Println("keepalive:", config.KeepAlive)
-		log.Println("snmplog:", config.SnmpLog)
-		log.Println("snmpperiod:", config.SnmpPeriod)
-		log.Println("pprof:", config.Pprof)
-		log.Println("quiet:", config.Quiet)
-		log.Println("tcp:", config.TCP)
-
-		if err := lis.SetDSCP(config.DSCP); err != nil {
-			log.Println("SetDSCP:", err)
-		}
-		if err := lis.SetReadBuffer(config.SockBuf); err != nil {
-			log.Println("SetReadBuffer:", err)
-		}
-		if err := lis.SetWriteBuffer(config.SockBuf); err != nil {
-			log.Println("SetWriteBuffer:", err)
-		}
-
 		go generic.SnmpLogger(config.SnmpLog, config.SnmpPeriod)
 		if config.Pprof {
 			go http.ListenAndServe(":6060", nil)
 		}
 
-		for {
-			if conn, err := lis.AcceptKCP(); err == nil {
-				log.Println("remote address:", conn.RemoteAddr())
-				conn.SetStreamMode(true)
-				conn.SetWriteDelay(false)
-				conn.SetNoDelay(config.NoDelay, config.Interval, config.Resend, config.NoCongestion)
-				conn.SetMtu(config.MTU)
-				conn.SetWindowSize(config.SndWnd, config.RcvWnd)
-				conn.SetACKNoDelay(config.AckNodelay)
+		// main loop
+		var wg sync.WaitGroup
+		loop := func(lis *kcp.Listener) {
+			defer wg.Done()
+			if err := lis.SetDSCP(config.DSCP); err != nil {
+				log.Println("SetDSCP:", err)
+			}
+			if err := lis.SetReadBuffer(config.SockBuf); err != nil {
+				log.Println("SetReadBuffer:", err)
+			}
+			if err := lis.SetWriteBuffer(config.SockBuf); err != nil {
+				log.Println("SetWriteBuffer:", err)
+			}
 
-				if config.NoComp {
-					go handleMux(conn, &config)
+			for {
+				if conn, err := lis.AcceptKCP(); err == nil {
+					log.Println("remote address:", conn.RemoteAddr())
+					conn.SetStreamMode(true)
+					conn.SetWriteDelay(false)
+					conn.SetNoDelay(config.NoDelay, config.Interval, config.Resend, config.NoCongestion)
+					conn.SetMtu(config.MTU)
+					conn.SetWindowSize(config.SndWnd, config.RcvWnd)
+					conn.SetACKNoDelay(config.AckNodelay)
+
+					if config.NoComp {
+						go handleMux(conn, &config)
+					} else {
+						go handleMux(generic.NewCompStream(conn), &config)
+					}
 				} else {
-					go handleMux(generic.NewCompStream(conn), &config)
+					log.Printf("%+v", err)
 				}
-			} else {
-				log.Printf("%+v", err)
 			}
 		}
+
+		mp, err := generic.ParseMultiPort(config.Listen)
+		if err != nil {
+			log.Println(err)
+			return err
+		}
+
+		// create multiple listener
+		for port := mp.MinPort; port <= mp.MaxPort; port++ {
+			listenAddr := fmt.Sprintf("%v:%v", mp.Host, port)
+			if config.TCP { // tcp dual stack
+				if conn, err := tcpraw.Listen("tcp", listenAddr); err == nil {
+					log.Printf("Listening on: %v/tcp", listenAddr)
+					lis, err := kcp.ServeConn(block, config.DataShard, config.ParityShard, conn)
+					checkError(err)
+					wg.Add(1)
+					go loop(lis)
+				} else {
+					log.Println(err)
+				}
+			}
+
+			// udp stack
+			log.Printf("Listening on: %v/udp", listenAddr)
+			lis, err := kcp.ListenWithOptions(listenAddr, block, config.DataShard, config.ParityShard)
+			checkError(err)
+			wg.Add(1)
+			go loop(lis)
+		}
+
+		wg.Wait()
+		return nil
 	}
 	myApp.Run(os.Args)
 }

server/signal.go

@@ -8,7 +8,7 @@ import (
 	"os/signal"
 	"syscall"
 
-	kcp "github.com/xtaci/kcp-go"
+	kcp "github.com/xtaci/kcp-go/v5"
 )
 
 func init() {

vendor/github.com/coreos/go-iptables/LICENSE

@@ -0,0 +1,191 @@
+Apache License
+Version 2.0, January 2004
+http://www.apache.org/licenses/
+
+TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
+
+1. Definitions.
+
+"License" shall mean the terms and conditions for use, reproduction, and
+distribution as defined by Sections 1 through 9 of this document.
+
+"Licensor" shall mean the copyright owner or entity authorized by the copyright
+owner that is granting the License.
+
+"Legal Entity" shall mean the union of the acting entity and all other entities
+that control, are controlled by, or are under common control with that entity.
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+
+"You" (or "Your") shall mean an individual or Legal Entity exercising
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+
+"Source" form shall mean the preferred form for making modifications, including
+but not limited to software source code, documentation source, and configuration
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+"Object" form shall mean any form resulting from mechanical transformation or
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+     http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.

vendor/github.com/coreos/go-iptables/NOTICE

@@ -0,0 +1,5 @@
+CoreOS Project
+Copyright 2018 CoreOS, Inc
+
+This product includes software developed at CoreOS, Inc.
+(http://www.coreos.com/).

vendor/github.com/coreos/go-iptables/iptables/iptables.go

@@ -0,0 +1,719 @@
+// Copyright 2015 CoreOS, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package iptables
+
+import (
+	"bytes"
+	"fmt"
+	"io"
+	"net"
+	"os/exec"
+	"regexp"
+	"strconv"
+	"strings"
+	"syscall"
+)
+
+// Adds the output of stderr to exec.ExitError
+type Error struct {
+	exec.ExitError
+	cmd        exec.Cmd
+	msg        string
+	exitStatus *int //for overriding
+}
+
+func (e *Error) ExitStatus() int {
+	if e.exitStatus != nil {
+		return *e.exitStatus
+	}
+	return e.Sys().(syscall.WaitStatus).ExitStatus()
+}
+
+func (e *Error) Error() string {
+	return fmt.Sprintf("running %v: exit status %v: %v", e.cmd.Args, e.ExitStatus(), e.msg)
+}
+
+// IsNotExist returns true if the error is due to the chain or rule not existing
+func (e *Error) IsNotExist() bool {
+	if e.ExitStatus() != 1 {
+		return false
+	}
+	msgNoRuleExist := "Bad rule (does a matching rule exist in that chain?).\n"
+	msgNoChainExist := "No chain/target/match by that name.\n"
+	msgENOENT := "No such file or directory"
+	return strings.Contains(e.msg, msgNoRuleExist) || strings.Contains(e.msg, msgNoChainExist) || strings.Contains(e.msg, msgENOENT)
+}
+
+// Protocol to differentiate between IPv4 and IPv6
+type Protocol byte
+
+const (
+	ProtocolIPv4 Protocol = iota
+	ProtocolIPv6
+)
+
+type IPTables struct {
+	path              string
+	proto             Protocol
+	hasCheck          bool
+	hasWait           bool
+	waitSupportSecond bool
+	hasRandomFully    bool
+	v1                int
+	v2                int
+	v3                int
+	mode              string // the underlying iptables operating mode, e.g. nf_tables
+	timeout           int    // time to wait for the iptables lock, default waits forever
+}
+
+// Stat represents a structured statistic entry.
+type Stat struct {
+	Packets     uint64     `json:"pkts"`
+	Bytes       uint64     `json:"bytes"`
+	Target      string     `json:"target"`
+	Protocol    string     `json:"prot"`
+	Opt         string     `json:"opt"`
+	Input       string     `json:"in"`
+	Output      string     `json:"out"`
+	Source      *net.IPNet `json:"source"`
+	Destination *net.IPNet `json:"destination"`
+	Options     string     `json:"options"`
+}
+
+type option func(*IPTables)
+
+func IPFamily(proto Protocol) option {
+	return func(ipt *IPTables) {
+		ipt.proto = proto
+	}
+}
+
+func Timeout(timeout int) option {
+	return func(ipt *IPTables) {
+		ipt.timeout = timeout
+	}
+}
+
+// New creates a new IPTables configured with the options passed as parameter.
+// For backwards compatibility, by default always uses IPv4 and timeout 0.
+// i.e. you can create an IPv6 IPTables using a timeout of 5 seconds passing
+// the IPFamily and Timeout options as follow:
+//
+//	ip6t := New(IPFamily(ProtocolIPv6), Timeout(5))
+func New(opts ...option) (*IPTables, error) {
+
+	ipt := &IPTables{
+		proto:   ProtocolIPv4,
+		timeout: 0,
+	}
+
+	for _, opt := range opts {
+		opt(ipt)
+	}
+
+	path, err := exec.LookPath(getIptablesCommand(ipt.proto))
+	if err != nil {
+		return nil, err
+	}
+	ipt.path = path
+
+	vstring, err := getIptablesVersionString(path)
+	if err != nil {
+		return nil, fmt.Errorf("could not get iptables version: %v", err)
+	}
+	v1, v2, v3, mode, err := extractIptablesVersion(vstring)
+	if err != nil {
+		return nil, fmt.Errorf("failed to extract iptables version from [%s]: %v", vstring, err)
+	}
+	ipt.v1 = v1
+	ipt.v2 = v2
+	ipt.v3 = v3
+	ipt.mode = mode
+
+	checkPresent, waitPresent, waitSupportSecond, randomFullyPresent := getIptablesCommandSupport(v1, v2, v3)
+	ipt.hasCheck = checkPresent
+	ipt.hasWait = waitPresent
+	ipt.waitSupportSecond = waitSupportSecond
+	ipt.hasRandomFully = randomFullyPresent
+
+	return ipt, nil
+}
+
+// New creates a new IPTables for the given proto.
+// The proto will determine which command is used, either "iptables" or "ip6tables".
+func NewWithProtocol(proto Protocol) (*IPTables, error) {
+	return New(IPFamily(proto), Timeout(0))
+}
+
+// Proto returns the protocol used by this IPTables.
+func (ipt *IPTables) Proto() Protocol {
+	return ipt.proto
+}
+
+// Exists checks if given rulespec in specified table/chain exists
+func (ipt *IPTables) Exists(table, chain string, rulespec ...string) (bool, error) {
+	if !ipt.hasCheck {
+		return ipt.existsForOldIptables(table, chain, rulespec)
+
+	}
+	cmd := append([]string{"-t", table, "-C", chain}, rulespec...)
+	err := ipt.run(cmd...)
+	eerr, eok := err.(*Error)
+	switch {
+	case err == nil:
+		return true, nil
+	case eok && eerr.ExitStatus() == 1:
+		return false, nil
+	default:
+		return false, err
+	}
+}
+
+// Insert inserts rulespec to specified table/chain (in specified pos)
+func (ipt *IPTables) Insert(table, chain string, pos int, rulespec ...string) error {
+	cmd := append([]string{"-t", table, "-I", chain, strconv.Itoa(pos)}, rulespec...)
+	return ipt.run(cmd...)
+}
+
+// Replace replaces rulespec to specified table/chain (in specified pos)
+func (ipt *IPTables) Replace(table, chain string, pos int, rulespec ...string) error {
+	cmd := append([]string{"-t", table, "-R", chain, strconv.Itoa(pos)}, rulespec...)
+	return ipt.run(cmd...)
+}
+
+// InsertUnique acts like Insert except that it won't insert a duplicate (no matter the position in the chain)
+func (ipt *IPTables) InsertUnique(table, chain string, pos int, rulespec ...string) error {
+	exists, err := ipt.Exists(table, chain, rulespec...)
+	if err != nil {
+		return err
+	}
+
+	if !exists {
+		return ipt.Insert(table, chain, pos, rulespec...)
+	}
+
+	return nil
+}
+
+// Append appends rulespec to specified table/chain
+func (ipt *IPTables) Append(table, chain string, rulespec ...string) error {
+	cmd := append([]string{"-t", table, "-A", chain}, rulespec...)
+	return ipt.run(cmd...)
+}
+
+// AppendUnique acts like Append except that it won't add a duplicate
+func (ipt *IPTables) AppendUnique(table, chain string, rulespec ...string) error {
+	exists, err := ipt.Exists(table, chain, rulespec...)
+	if err != nil {
+		return err
+	}
+
+	if !exists {
+		return ipt.Append(table, chain, rulespec...)
+	}
+
+	return nil
+}
+
+// Delete removes rulespec in specified table/chain
+func (ipt *IPTables) Delete(table, chain string, rulespec ...string) error {
+	cmd := append([]string{"-t", table, "-D", chain}, rulespec...)
+	return ipt.run(cmd...)
+}
+
+func (ipt *IPTables) DeleteIfExists(table, chain string, rulespec ...string) error {
+	exists, err := ipt.Exists(table, chain, rulespec...)
+	if err == nil && exists {
+		err = ipt.Delete(table, chain, rulespec...)
+	}
+	return err
+}
+
+// List rules in specified table/chain
+func (ipt *IPTables) ListById(table, chain string, id int) (string, error) {
+	args := []string{"-t", table, "-S", chain, strconv.Itoa(id)}
+	rule, err := ipt.executeList(args)
+	if err != nil {
+		return "", err
+	}
+	return rule[0], nil
+}
+
+// List rules in specified table/chain
+func (ipt *IPTables) List(table, chain string) ([]string, error) {
+	args := []string{"-t", table, "-S", chain}
+	return ipt.executeList(args)
+}
+
+// List rules (with counters) in specified table/chain
+func (ipt *IPTables) ListWithCounters(table, chain string) ([]string, error) {
+	args := []string{"-t", table, "-v", "-S", chain}
+	return ipt.executeList(args)
+}
+
+// ListChains returns a slice containing the name of each chain in the specified table.
+func (ipt *IPTables) ListChains(table string) ([]string, error) {
+	args := []string{"-t", table, "-S"}
+
+	result, err := ipt.executeList(args)
+	if err != nil {
+		return nil, err
+	}
+
+	// Iterate over rules to find all default (-P) and user-specified (-N) chains.
+	// Chains definition always come before rules.
+	// Format is the following:
+	// -P OUTPUT ACCEPT
+	// -N Custom
+	var chains []string
+	for _, val := range result {
+		if strings.HasPrefix(val, "-P") || strings.HasPrefix(val, "-N") {
+			chains = append(chains, strings.Fields(val)[1])
+		} else {
+			break
+		}
+	}
+	return chains, nil
+}
+
+// '-S' is fine with non existing rule index as long as the chain exists
+// therefore pass index 1 to reduce overhead for large chains
+func (ipt *IPTables) ChainExists(table, chain string) (bool, error) {
+	err := ipt.run("-t", table, "-S", chain, "1")
+	eerr, eok := err.(*Error)
+	switch {
+	case err == nil:
+		return true, nil
+	case eok && eerr.ExitStatus() == 1:
+		return false, nil
+	default:
+		return false, err
+	}
+}
+
+// Stats lists rules including the byte and packet counts
+func (ipt *IPTables) Stats(table, chain string) ([][]string, error) {
+	args := []string{"-t", table, "-L", chain, "-n", "-v", "-x"}
+	lines, err := ipt.executeList(args)
+	if err != nil {
+		return nil, err
+	}
+
+	appendSubnet := func(addr string) string {
+		if strings.IndexByte(addr, byte('/')) < 0 {
+			if strings.IndexByte(addr, '.') < 0 {
+				return addr + "/128"
+			}
+			return addr + "/32"
+		}
+		return addr
+	}
+
+	ipv6 := ipt.proto == ProtocolIPv6
+
+	// Skip the warning if exist
+	if strings.HasPrefix(lines[0], "#") {
+		lines = lines[1:]
+	}
+
+	rows := [][]string{}
+	for i, line := range lines {
+		// Skip over chain name and field header
+		if i < 2 {
+			continue
+		}
+
+		// Fields:
+		// 0=pkts 1=bytes 2=target 3=prot 4=opt 5=in 6=out 7=source 8=destination 9=options
+		line = strings.TrimSpace(line)
+		fields := strings.Fields(line)
+
+		// The ip6tables verbose output cannot be naively split due to the default "opt"
+		// field containing 2 single spaces.
+		if ipv6 {
+			// Check if field 6 is "opt" or "source" address
+			dest := fields[6]
+			ip, _, _ := net.ParseCIDR(dest)
+			if ip == nil {
+				ip = net.ParseIP(dest)
+			}
+
+			// If we detected a CIDR or IP, the "opt" field is empty.. insert it.
+			if ip != nil {
+				f := []string{}
+				f = append(f, fields[:4]...)
+				f = append(f, "  ") // Empty "opt" field for ip6tables
+				f = append(f, fields[4:]...)
+				fields = f
+			}
+		}
+
+		// Adjust "source" and "destination" to include netmask, to match regular
+		// List output
+		fields[7] = appendSubnet(fields[7])
+		fields[8] = appendSubnet(fields[8])
+
+		// Combine "options" fields 9... into a single space-delimited field.
+		options := fields[9:]
+		fields = fields[:9]
+		fields = append(fields, strings.Join(options, " "))
+		rows = append(rows, fields)
+	}
+	return rows, nil
+}
+
+// ParseStat parses a single statistic row into a Stat struct. The input should
+// be a string slice that is returned from calling the Stat method.
+func (ipt *IPTables) ParseStat(stat []string) (parsed Stat, err error) {
+	// For forward-compatibility, expect at least 10 fields in the stat
+	if len(stat) < 10 {
+		return parsed, fmt.Errorf("stat contained fewer fields than expected")
+	}
+
+	// Convert the fields that are not plain strings
+	parsed.Packets, err = strconv.ParseUint(stat[0], 0, 64)
+	if err != nil {
+		return parsed, fmt.Errorf(err.Error(), "could not parse packets")
+	}
+	parsed.Bytes, err = strconv.ParseUint(stat[1], 0, 64)
+	if err != nil {
+		return parsed, fmt.Errorf(err.Error(), "could not parse bytes")
+	}
+	_, parsed.Source, err = net.ParseCIDR(stat[7])
+	if err != nil {
+		return parsed, fmt.Errorf(err.Error(), "could not parse source")
+	}
+	_, parsed.Destination, err = net.ParseCIDR(stat[8])
+	if err != nil {
+		return parsed, fmt.Errorf(err.Error(), "could not parse destination")
+	}
+
+	// Put the fields that are strings
+	parsed.Target = stat[2]
+	parsed.Protocol = stat[3]
+	parsed.Opt = stat[4]
+	parsed.Input = stat[5]
+	parsed.Output = stat[6]
+	parsed.Options = stat[9]
+
+	return parsed, nil
+}
+
+// StructuredStats returns statistics as structured data which may be further
+// parsed and marshaled.
+func (ipt *IPTables) StructuredStats(table, chain string) ([]Stat, error) {
+	rawStats, err := ipt.Stats(table, chain)
+	if err != nil {
+		return nil, err
+	}
+
+	structStats := []Stat{}
+	for _, rawStat := range rawStats {
+		stat, err := ipt.ParseStat(rawStat)
+		if err != nil {
+			return nil, err
+		}
+		structStats = append(structStats, stat)
+	}
+
+	return structStats, nil
+}
+
+func (ipt *IPTables) executeList(args []string) ([]string, error) {
+	var stdout bytes.Buffer
+	if err := ipt.runWithOutput(args, &stdout); err != nil {
+		return nil, err
+	}
+
+	rules := strings.Split(stdout.String(), "\n")
+
+	// strip trailing newline
+	if len(rules) > 0 && rules[len(rules)-1] == "" {
+		rules = rules[:len(rules)-1]
+	}
+
+	for i, rule := range rules {
+		rules[i] = filterRuleOutput(rule)
+	}
+
+	return rules, nil
+}
+
+// NewChain creates a new chain in the specified table.
+// If the chain already exists, it will result in an error.
+func (ipt *IPTables) NewChain(table, chain string) error {
+	return ipt.run("-t", table, "-N", chain)
+}
+
+const existsErr = 1
+
+// ClearChain flushed (deletes all rules) in the specified table/chain.
+// If the chain does not exist, a new one will be created
+func (ipt *IPTables) ClearChain(table, chain string) error {
+	err := ipt.NewChain(table, chain)
+
+	eerr, eok := err.(*Error)
+	switch {
+	case err == nil:
+		return nil
+	case eok && eerr.ExitStatus() == existsErr:
+		// chain already exists. Flush (clear) it.
+		return ipt.run("-t", table, "-F", chain)
+	default:
+		return err
+	}
+}
+
+// RenameChain renames the old chain to the new one.
+func (ipt *IPTables) RenameChain(table, oldChain, newChain string) error {
+	return ipt.run("-t", table, "-E", oldChain, newChain)
+}
+
+// DeleteChain deletes the chain in the specified table.
+// The chain must be empty
+func (ipt *IPTables) DeleteChain(table, chain string) error {
+	return ipt.run("-t", table, "-X", chain)
+}
+
+func (ipt *IPTables) ClearAndDeleteChain(table, chain string) error {
+	exists, err := ipt.ChainExists(table, chain)
+	if err != nil || !exists {
+		return err
+	}
+	err = ipt.run("-t", table, "-F", chain)
+	if err == nil {
+		err = ipt.run("-t", table, "-X", chain)
+	}
+	return err
+}
+
+func (ipt *IPTables) ClearAll() error {
+	return ipt.run("-F")
+}
+
+func (ipt *IPTables) DeleteAll() error {
+	return ipt.run("-X")
+}
+
+// ChangePolicy changes policy on chain to target
+func (ipt *IPTables) ChangePolicy(table, chain, target string) error {
+	return ipt.run("-t", table, "-P", chain, target)
+}
+
+// Check if the underlying iptables command supports the --random-fully flag
+func (ipt *IPTables) HasRandomFully() bool {
+	return ipt.hasRandomFully
+}
+
+// Return version components of the underlying iptables command
+func (ipt *IPTables) GetIptablesVersion() (int, int, int) {
+	return ipt.v1, ipt.v2, ipt.v3
+}
+
+// run runs an iptables command with the given arguments, ignoring
+// any stdout output
+func (ipt *IPTables) run(args ...string) error {
+	return ipt.runWithOutput(args, nil)
+}
+
+// runWithOutput runs an iptables command with the given arguments,
+// writing any stdout output to the given writer
+func (ipt *IPTables) runWithOutput(args []string, stdout io.Writer) error {
+	args = append([]string{ipt.path}, args...)
+	if ipt.hasWait {
+		args = append(args, "--wait")
+		if ipt.timeout != 0 && ipt.waitSupportSecond {
+			args = append(args, strconv.Itoa(ipt.timeout))
+		}
+	} else {
+		fmu, err := newXtablesFileLock()
+		if err != nil {
+			return err
+		}
+		ul, err := fmu.tryLock()
+		if err != nil {
+			syscall.Close(fmu.fd)
+			return err
+		}
+		defer func() {
+			_ = ul.Unlock()
+		}()
+	}
+
+	var stderr bytes.Buffer
+	cmd := exec.Cmd{
+		Path:   ipt.path,
+		Args:   args,
+		Stdout: stdout,
+		Stderr: &stderr,
+	}
+
+	if err := cmd.Run(); err != nil {
+		switch e := err.(type) {
+		case *exec.ExitError:
+			return &Error{*e, cmd, stderr.String(), nil}
+		default:
+			return err
+		}
+	}
+
+	return nil
+}
+
+// getIptablesCommand returns the correct command for the given protocol, either "iptables" or "ip6tables".
+func getIptablesCommand(proto Protocol) string {
+	if proto == ProtocolIPv6 {
+		return "ip6tables"
+	} else {
+		return "iptables"
+	}
+}
+
+// Checks if iptables has the "-C" and "--wait" flag
+func getIptablesCommandSupport(v1 int, v2 int, v3 int) (bool, bool, bool, bool) {
+	return iptablesHasCheckCommand(v1, v2, v3), iptablesHasWaitCommand(v1, v2, v3), iptablesWaitSupportSecond(v1, v2, v3), iptablesHasRandomFully(v1, v2, v3)
+}
+
+// getIptablesVersion returns the first three components of the iptables version
+// and the operating mode (e.g. nf_tables or legacy)
+// e.g. "iptables v1.3.66" would return (1, 3, 66, legacy, nil)
+func extractIptablesVersion(str string) (int, int, int, string, error) {
+	versionMatcher := regexp.MustCompile(`v([0-9]+)\.([0-9]+)\.([0-9]+)(?:\s+\((\w+))?`)
+	result := versionMatcher.FindStringSubmatch(str)
+	if result == nil {
+		return 0, 0, 0, "", fmt.Errorf("no iptables version found in string: %s", str)
+	}
+
+	v1, err := strconv.Atoi(result[1])
+	if err != nil {
+		return 0, 0, 0, "", err
+	}
+
+	v2, err := strconv.Atoi(result[2])
+	if err != nil {
+		return 0, 0, 0, "", err
+	}
+
+	v3, err := strconv.Atoi(result[3])
+	if err != nil {
+		return 0, 0, 0, "", err
+	}
+
+	mode := "legacy"
+	if result[4] != "" {
+		mode = result[4]
+	}
+	return v1, v2, v3, mode, nil
+}
+
+// Runs "iptables --version" to get the version string
+func getIptablesVersionString(path string) (string, error) {
+	cmd := exec.Command(path, "--version")
+	var out bytes.Buffer
+	cmd.Stdout = &out
+	err := cmd.Run()
+	if err != nil {
+		return "", err
+	}
+	return out.String(), nil
+}
+
+// Checks if an iptables version is after 1.4.11, when --check was added
+func iptablesHasCheckCommand(v1 int, v2 int, v3 int) bool {
+	if v1 > 1 {
+		return true
+	}
+	if v1 == 1 && v2 > 4 {
+		return true
+	}
+	if v1 == 1 && v2 == 4 && v3 >= 11 {
+		return true
+	}
+	return false
+}
+
+// Checks if an iptables version is after 1.4.20, when --wait was added
+func iptablesHasWaitCommand(v1 int, v2 int, v3 int) bool {
+	if v1 > 1 {
+		return true
+	}
+	if v1 == 1 && v2 > 4 {
+		return true
+	}
+	if v1 == 1 && v2 == 4 && v3 >= 20 {
+		return true
+	}
+	return false
+}
+
+// Checks if an iptablse version is after 1.6.0, when --wait support second
+func iptablesWaitSupportSecond(v1 int, v2 int, v3 int) bool {
+	if v1 > 1 {
+		return true
+	}
+	if v1 == 1 && v2 >= 6 {
+		return true
+	}
+	return false
+}
+
+// Checks if an iptables version is after 1.6.2, when --random-fully was added
+func iptablesHasRandomFully(v1 int, v2 int, v3 int) bool {
+	if v1 > 1 {
+		return true
+	}
+	if v1 == 1 && v2 > 6 {
+		return true
+	}
+	if v1 == 1 && v2 == 6 && v3 >= 2 {
+		return true
+	}
+	return false
+}
+
+// Checks if a rule specification exists for a table
+func (ipt *IPTables) existsForOldIptables(table, chain string, rulespec []string) (bool, error) {
+	rs := strings.Join(append([]string{"-A", chain}, rulespec...), " ")
+	args := []string{"-t", table, "-S"}
+	var stdout bytes.Buffer
+	err := ipt.runWithOutput(args, &stdout)
+	if err != nil {
+		return false, err
+	}
+	return strings.Contains(stdout.String(), rs), nil
+}
+
+// counterRegex is the regex used to detect nftables counter format
+var counterRegex = regexp.MustCompile(`^\[([0-9]+):([0-9]+)\] `)
+
+// filterRuleOutput works around some inconsistencies in output.
+// For example, when iptables is in legacy vs. nftables mode, it produces
+// different results.
+func filterRuleOutput(rule string) string {
+	out := rule
+
+	// work around an output difference in nftables mode where counters
+	// are output in iptables-save format, rather than iptables -S format
+	// The string begins with "[0:0]"
+	//
+	// Fixes #49
+	if groups := counterRegex.FindStringSubmatch(out); groups != nil {
+		// drop the brackets
+		out = out[len(groups[0]):]
+		out = fmt.Sprintf("%s -c %s %s", out, groups[1], groups[2])
+	}
+
+	return out
+}

vendor/github.com/coreos/go-iptables/iptables/lock.go

@@ -0,0 +1,84 @@
+// Copyright 2015 CoreOS, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package iptables
+
+import (
+	"os"
+	"sync"
+	"syscall"
+)
+
+const (
+	// In earlier versions of iptables, the xtables lock was implemented
+	// via a Unix socket, but now flock is used via this lockfile:
+	// http://git.netfilter.org/iptables/commit/?id=aa562a660d1555b13cffbac1e744033e91f82707
+	// Note the LSB-conforming "/run" directory does not exist on old
+	// distributions, so assume "/var" is symlinked
+	xtablesLockFilePath = "/var/run/xtables.lock"
+
+	defaultFilePerm = 0600
+)
+
+type Unlocker interface {
+	Unlock() error
+}
+
+type nopUnlocker struct{}
+
+func (_ nopUnlocker) Unlock() error { return nil }
+
+type fileLock struct {
+	// mu is used to protect against concurrent invocations from within this process
+	mu sync.Mutex
+	fd int
+}
+
+// tryLock takes an exclusive lock on the xtables lock file without blocking.
+// This is best-effort only: if the exclusive lock would block (i.e. because
+// another process already holds it), no error is returned. Otherwise, any
+// error encountered during the locking operation is returned.
+// The returned Unlocker should be used to release the lock when the caller is
+// done invoking iptables commands.
+func (l *fileLock) tryLock() (Unlocker, error) {
+	l.mu.Lock()
+	err := syscall.Flock(l.fd, syscall.LOCK_EX|syscall.LOCK_NB)
+	switch err {
+	case syscall.EWOULDBLOCK:
+		l.mu.Unlock()
+		return nopUnlocker{}, nil
+	case nil:
+		return l, nil
+	default:
+		l.mu.Unlock()
+		return nil, err
+	}
+}
+
+// Unlock closes the underlying file, which implicitly unlocks it as well. It
+// also unlocks the associated mutex.
+func (l *fileLock) Unlock() error {
+	defer l.mu.Unlock()
+	return syscall.Close(l.fd)
+}
+
+// newXtablesFileLock opens a new lock on the xtables lockfile without
+// acquiring the lock
+func newXtablesFileLock() (*fileLock, error) {
+	fd, err := syscall.Open(xtablesLockFilePath, os.O_CREATE, defaultFilePerm)
+	if err != nil {
+		return nil, err
+	}
+	return &fileLock{fd: fd}, nil
+}

vendor/github.com/cpuguy83/go-md2man/v2/LICENSE.md

@@ -0,0 +1,21 @@
+The MIT License (MIT)
+
+Copyright (c) 2014 Brian Goff
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

vendor/github.com/cpuguy83/go-md2man/v2/md2man/md2man.go

@@ -0,0 +1,14 @@
+package md2man
+
+import (
+	"github.com/russross/blackfriday/v2"
+)
+
+// Render converts a markdown document into a roff formatted document.
+func Render(doc []byte) []byte {
+	renderer := NewRoffRenderer()
+
+	return blackfriday.Run(doc,
+		[]blackfriday.Option{blackfriday.WithRenderer(renderer),
+			blackfriday.WithExtensions(renderer.GetExtensions())}...)
+}

vendor/github.com/cpuguy83/go-md2man/v2/md2man/roff.go

@@ -0,0 +1,336 @@
+package md2man
+
+import (
+	"fmt"
+	"io"
+	"os"
+	"strings"
+
+	"github.com/russross/blackfriday/v2"
+)
+
+// roffRenderer implements the blackfriday.Renderer interface for creating
+// roff format (manpages) from markdown text
+type roffRenderer struct {
+	extensions   blackfriday.Extensions
+	listCounters []int
+	firstHeader  bool
+	firstDD      bool
+	listDepth    int
+}
+
+const (
+	titleHeader      = ".TH "
+	topLevelHeader   = "\n\n.SH "
+	secondLevelHdr   = "\n.SH "
+	otherHeader      = "\n.SS "
+	crTag            = "\n"
+	emphTag          = "\\fI"
+	emphCloseTag     = "\\fP"
+	strongTag        = "\\fB"
+	strongCloseTag   = "\\fP"
+	breakTag         = "\n.br\n"
+	paraTag          = "\n.PP\n"
+	hruleTag         = "\n.ti 0\n\\l'\\n(.lu'\n"
+	linkTag          = "\n\\[la]"
+	linkCloseTag     = "\\[ra]"
+	codespanTag      = "\\fB\\fC"
+	codespanCloseTag = "\\fR"
+	codeTag          = "\n.PP\n.RS\n\n.nf\n"
+	codeCloseTag     = "\n.fi\n.RE\n"
+	quoteTag         = "\n.PP\n.RS\n"
+	quoteCloseTag    = "\n.RE\n"
+	listTag          = "\n.RS\n"
+	listCloseTag     = "\n.RE\n"
+	dtTag            = "\n.TP\n"
+	dd2Tag           = "\n"
+	tableStart       = "\n.TS\nallbox;\n"
+	tableEnd         = ".TE\n"
+	tableCellStart   = "T{\n"
+	tableCellEnd     = "\nT}\n"
+)
+
+// NewRoffRenderer creates a new blackfriday Renderer for generating roff documents
+// from markdown
+func NewRoffRenderer() *roffRenderer { // nolint: golint
+	var extensions blackfriday.Extensions
+
+	extensions |= blackfriday.NoIntraEmphasis
+	extensions |= blackfriday.Tables
+	extensions |= blackfriday.FencedCode
+	extensions |= blackfriday.SpaceHeadings
+	extensions |= blackfriday.Footnotes
+	extensions |= blackfriday.Titleblock
+	extensions |= blackfriday.DefinitionLists
+	return &roffRenderer{
+		extensions: extensions,
+	}
+}
+
+// GetExtensions returns the list of extensions used by this renderer implementation
+func (r *roffRenderer) GetExtensions() blackfriday.Extensions {
+	return r.extensions
+}
+
+// RenderHeader handles outputting the header at document start
+func (r *roffRenderer) RenderHeader(w io.Writer, ast *blackfriday.Node) {
+	// disable hyphenation
+	out(w, ".nh\n")
+}
+
+// RenderFooter handles outputting the footer at the document end; the roff
+// renderer has no footer information
+func (r *roffRenderer) RenderFooter(w io.Writer, ast *blackfriday.Node) {
+}
+
+// RenderNode is called for each node in a markdown document; based on the node
+// type the equivalent roff output is sent to the writer
+func (r *roffRenderer) RenderNode(w io.Writer, node *blackfriday.Node, entering bool) blackfriday.WalkStatus {
+
+	var walkAction = blackfriday.GoToNext
+
+	switch node.Type {
+	case blackfriday.Text:
+		escapeSpecialChars(w, node.Literal)
+	case blackfriday.Softbreak:
+		out(w, crTag)
+	case blackfriday.Hardbreak:
+		out(w, breakTag)
+	case blackfriday.Emph:
+		if entering {
+			out(w, emphTag)
+		} else {
+			out(w, emphCloseTag)
+		}
+	case blackfriday.Strong:
+		if entering {
+			out(w, strongTag)
+		} else {
+			out(w, strongCloseTag)
+		}
+	case blackfriday.Link:
+		if !entering {
+			out(w, linkTag+string(node.LinkData.Destination)+linkCloseTag)
+		}
+	case blackfriday.Image:
+		// ignore images
+		walkAction = blackfriday.SkipChildren
+	case blackfriday.Code:
+		out(w, codespanTag)
+		escapeSpecialChars(w, node.Literal)
+		out(w, codespanCloseTag)
+	case blackfriday.Document:
+		break
+	case blackfriday.Paragraph:
+		// roff .PP markers break lists
+		if r.listDepth > 0 {
+			return blackfriday.GoToNext
+		}
+		if entering {
+			out(w, paraTag)
+		} else {
+			out(w, crTag)
+		}
+	case blackfriday.BlockQuote:
+		if entering {
+			out(w, quoteTag)
+		} else {
+			out(w, quoteCloseTag)
+		}
+	case blackfriday.Heading:
+		r.handleHeading(w, node, entering)
+	case blackfriday.HorizontalRule:
+		out(w, hruleTag)
+	case blackfriday.List:
+		r.handleList(w, node, entering)
+	case blackfriday.Item:
+		r.handleItem(w, node, entering)
+	case blackfriday.CodeBlock:
+		out(w, codeTag)
+		escapeSpecialChars(w, node.Literal)
+		out(w, codeCloseTag)
+	case blackfriday.Table:
+		r.handleTable(w, node, entering)
+	case blackfriday.TableHead:
+	case blackfriday.TableBody:
+	case blackfriday.TableRow:
+		// no action as cell entries do all the nroff formatting
+		return blackfriday.GoToNext
+	case blackfriday.TableCell:
+		r.handleTableCell(w, node, entering)
+	case blackfriday.HTMLSpan:
+		// ignore other HTML tags
+	default:
+		fmt.Fprintln(os.Stderr, "WARNING: go-md2man does not handle node type "+node.Type.String())
+	}
+	return walkAction
+}
+
+func (r *roffRenderer) handleHeading(w io.Writer, node *blackfriday.Node, entering bool) {
+	if entering {
+		switch node.Level {
+		case 1:
+			if !r.firstHeader {
+				out(w, titleHeader)
+				r.firstHeader = true
+				break
+			}
+			out(w, topLevelHeader)
+		case 2:
+			out(w, secondLevelHdr)
+		default:
+			out(w, otherHeader)
+		}
+	}
+}
+
+func (r *roffRenderer) handleList(w io.Writer, node *blackfriday.Node, entering bool) {
+	openTag := listTag
+	closeTag := listCloseTag
+	if node.ListFlags&blackfriday.ListTypeDefinition != 0 {
+		// tags for definition lists handled within Item node
+		openTag = ""
+		closeTag = ""
+	}
+	if entering {
+		r.listDepth++
+		if node.ListFlags&blackfriday.ListTypeOrdered != 0 {
+			r.listCounters = append(r.listCounters, 1)
+		}
+		out(w, openTag)
+	} else {
+		if node.ListFlags&blackfriday.ListTypeOrdered != 0 {
+			r.listCounters = r.listCounters[:len(r.listCounters)-1]
+		}
+		out(w, closeTag)
+		r.listDepth--
+	}
+}
+
+func (r *roffRenderer) handleItem(w io.Writer, node *blackfriday.Node, entering bool) {
+	if entering {
+		if node.ListFlags&blackfriday.ListTypeOrdered != 0 {
+			out(w, fmt.Sprintf(".IP \"%3d.\" 5\n", r.listCounters[len(r.listCounters)-1]))
+			r.listCounters[len(r.listCounters)-1]++
+		} else if node.ListFlags&blackfriday.ListTypeTerm != 0 {
+			// DT (definition term): line just before DD (see below).
+			out(w, dtTag)
+			r.firstDD = true
+		} else if node.ListFlags&blackfriday.ListTypeDefinition != 0 {
+			// DD (definition description): line that starts with ": ".
+			//
+			// We have to distinguish between the first DD and the
+			// subsequent ones, as there should be no vertical
+			// whitespace between the DT and the first DD.
+			if r.firstDD {
+				r.firstDD = false
+			} else {
+				out(w, dd2Tag)
+			}
+		} else {
+			out(w, ".IP \\(bu 2\n")
+		}
+	} else {
+		out(w, "\n")
+	}
+}
+
+func (r *roffRenderer) handleTable(w io.Writer, node *blackfriday.Node, entering bool) {
+	if entering {
+		out(w, tableStart)
+		// call walker to count cells (and rows?) so format section can be produced
+		columns := countColumns(node)
+		out(w, strings.Repeat("l ", columns)+"\n")
+		out(w, strings.Repeat("l ", columns)+".\n")
+	} else {
+		out(w, tableEnd)
+	}
+}
+
+func (r *roffRenderer) handleTableCell(w io.Writer, node *blackfriday.Node, entering bool) {
+	if entering {
+		var start string
+		if node.Prev != nil && node.Prev.Type == blackfriday.TableCell {
+			start = "\t"
+		}
+		if node.IsHeader {
+			start += codespanTag
+		} else if nodeLiteralSize(node) > 30 {
+			start += tableCellStart
+		}
+		out(w, start)
+	} else {
+		var end string
+		if node.IsHeader {
+			end = codespanCloseTag
+		} else if nodeLiteralSize(node) > 30 {
+			end = tableCellEnd
+		}
+		if node.Next == nil && end != tableCellEnd {
+			// Last cell: need to carriage return if we are at the end of the
+			// header row and content isn't wrapped in a "tablecell"
+			end += crTag
+		}
+		out(w, end)
+	}
+}
+
+func nodeLiteralSize(node *blackfriday.Node) int {
+	total := 0
+	for n := node.FirstChild; n != nil; n = n.FirstChild {
+		total += len(n.Literal)
+	}
+	return total
+}
+
+// because roff format requires knowing the column count before outputting any table
+// data we need to walk a table tree and count the columns
+func countColumns(node *blackfriday.Node) int {
+	var columns int
+
+	node.Walk(func(node *blackfriday.Node, entering bool) blackfriday.WalkStatus {
+		switch node.Type {
+		case blackfriday.TableRow:
+			if !entering {
+				return blackfriday.Terminate
+			}
+		case blackfriday.TableCell:
+			if entering {
+				columns++
+			}
+		default:
+		}
+		return blackfriday.GoToNext
+	})
+	return columns
+}
+
+func out(w io.Writer, output string) {
+	io.WriteString(w, output) // nolint: errcheck
+}
+
+func escapeSpecialChars(w io.Writer, text []byte) {
+	for i := 0; i < len(text); i++ {
+		// escape initial apostrophe or period
+		if len(text) >= 1 && (text[0] == '\'' || text[0] == '.') {
+			out(w, "\\&")
+		}
+
+		// directly copy normal characters
+		org := i
+
+		for i < len(text) && text[i] != '\\' {
+			i++
+		}
+		if i > org {
+			w.Write(text[org:i]) // nolint: errcheck
+		}
+
+		// escape a character
+		if i >= len(text) {
+			break
+		}
+
+		w.Write([]byte{'\\', text[i]}) // nolint: errcheck
+	}
+}

vendor/github.com/golang/snappy/.gitignore

@@ -0,0 +1,16 @@
+cmd/snappytool/snappytool
+testdata/bench
+
+# These explicitly listed benchmark data files are for an obsolete version of
+# snappy_test.go.
+testdata/alice29.txt
+testdata/asyoulik.txt
+testdata/fireworks.jpeg
+testdata/geo.protodata
+testdata/html
+testdata/html_x_4
+testdata/kppkn.gtb
+testdata/lcet10.txt
+testdata/paper-100k.pdf
+testdata/plrabn12.txt
+testdata/urls.10K

vendor/github.com/golang/snappy/AUTHORS

@@ -0,0 +1,18 @@
+# This is the official list of Snappy-Go authors for copyright purposes.
+# This file is distinct from the CONTRIBUTORS files.
+# See the latter for an explanation.
+
+# Names should be added to this file as
+#	Name or Organization <email address>
+# The email address is not required for organizations.
+
+# Please keep the list sorted.
+
+Amazon.com, Inc
+Damian Gryski <dgryski@gmail.com>
+Eric Buth <eric@topos.com>
+Google Inc.
+Jan Mercl <0xjnml@gmail.com>
+Klaus Post <klauspost@gmail.com>
+Rodolfo Carvalho <rhcarvalho@gmail.com>
+Sebastien Binet <seb.binet@gmail.com>

vendor/github.com/golang/snappy/CONTRIBUTORS

@@ -0,0 +1,41 @@
+# This is the official list of people who can contribute
+# (and typically have contributed) code to the Snappy-Go repository.
+# The AUTHORS file lists the copyright holders; this file
+# lists people.  For example, Google employees are listed here
+# but not in AUTHORS, because Google holds the copyright.
+#
+# The submission process automatically checks to make sure
+# that people submitting code are listed in this file (by email address).
+#
+# Names should be added to this file only after verifying that
+# the individual or the individual's organization has agreed to
+# the appropriate Contributor License Agreement, found here:
+#
+#     http://code.google.com/legal/individual-cla-v1.0.html
+#     http://code.google.com/legal/corporate-cla-v1.0.html
+#
+# The agreement for individuals can be filled out on the web.
+#
+# When adding J Random Contributor's name to this file,
+# either J's name or J's organization's name should be
+# added to the AUTHORS file, depending on whether the
+# individual or corporate CLA was used.
+
+# Names should be added to this file like so:
+#     Name <email address>
+
+# Please keep the list sorted.
+
+Alex Legg <alexlegg@google.com>
+Damian Gryski <dgryski@gmail.com>
+Eric Buth <eric@topos.com>
+Jan Mercl <0xjnml@gmail.com>
+Jonathan Swinney <jswinney@amazon.com>
+Kai Backman <kaib@golang.org>
+Klaus Post <klauspost@gmail.com>
+Marc-Antoine Ruel <maruel@chromium.org>
+Nigel Tao <nigeltao@golang.org>
+Rob Pike <r@golang.org>
+Rodolfo Carvalho <rhcarvalho@gmail.com>
+Russ Cox <rsc@golang.org>
+Sebastien Binet <seb.binet@gmail.com>

vendor/github.com/golang/snappy/LICENSE

@@ -0,0 +1,27 @@
+Copyright (c) 2011 The Snappy-Go Authors. All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are
+met:
+
+   * Redistributions of source code must retain the above copyright
+notice, this list of conditions and the following disclaimer.
+   * Redistributions in binary form must reproduce the above
+copyright notice, this list of conditions and the following disclaimer
+in the documentation and/or other materials provided with the
+distribution.
+   * Neither the name of Google Inc. nor the names of its
+contributors may be used to endorse or promote products derived from
+this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

vendor/github.com/golang/snappy/README

@@ -0,0 +1,107 @@
+The Snappy compression format in the Go programming language.
+
+To download and install from source:
+$ go get github.com/golang/snappy
+
+Unless otherwise noted, the Snappy-Go source files are distributed
+under the BSD-style license found in the LICENSE file.
+
+
+
+Benchmarks.
+
+The golang/snappy benchmarks include compressing (Z) and decompressing (U) ten
+or so files, the same set used by the C++ Snappy code (github.com/google/snappy
+and note the "google", not "golang"). On an "Intel(R) Core(TM) i7-3770 CPU @
+3.40GHz", Go's GOARCH=amd64 numbers as of 2016-05-29:
+
+"go test -test.bench=."
+
+_UFlat0-8         2.19GB/s ± 0%  html
+_UFlat1-8         1.41GB/s ± 0%  urls
+_UFlat2-8         23.5GB/s ± 2%  jpg
+_UFlat3-8         1.91GB/s ± 0%  jpg_200
+_UFlat4-8         14.0GB/s ± 1%  pdf
+_UFlat5-8         1.97GB/s ± 0%  html4
+_UFlat6-8          814MB/s ± 0%  txt1
+_UFlat7-8          785MB/s ± 0%  txt2
+_UFlat8-8          857MB/s ± 0%  txt3
+_UFlat9-8          719MB/s ± 1%  txt4
+_UFlat10-8        2.84GB/s ± 0%  pb
+_UFlat11-8        1.05GB/s ± 0%  gaviota
+
+_ZFlat0-8         1.04GB/s ± 0%  html
+_ZFlat1-8          534MB/s ± 0%  urls
+_ZFlat2-8         15.7GB/s ± 1%  jpg
+_ZFlat3-8          740MB/s ± 3%  jpg_200
+_ZFlat4-8         9.20GB/s ± 1%  pdf
+_ZFlat5-8          991MB/s ± 0%  html4
+_ZFlat6-8          379MB/s ± 0%  txt1
+_ZFlat7-8          352MB/s ± 0%  txt2
+_ZFlat8-8          396MB/s ± 1%  txt3
+_ZFlat9-8          327MB/s ± 1%  txt4
+_ZFlat10-8        1.33GB/s ± 1%  pb
+_ZFlat11-8         605MB/s ± 1%  gaviota
+
+
+
+"go test -test.bench=. -tags=noasm"
+
+_UFlat0-8          621MB/s ± 2%  html
+_UFlat1-8          494MB/s ± 1%  urls
+_UFlat2-8         23.2GB/s ± 1%  jpg
+_UFlat3-8         1.12GB/s ± 1%  jpg_200
+_UFlat4-8         4.35GB/s ± 1%  pdf
+_UFlat5-8          609MB/s ± 0%  html4
+_UFlat6-8          296MB/s ± 0%  txt1
+_UFlat7-8          288MB/s ± 0%  txt2
+_UFlat8-8          309MB/s ± 1%  txt3
+_UFlat9-8          280MB/s ± 1%  txt4
+_UFlat10-8         753MB/s ± 0%  pb
+_UFlat11-8         400MB/s ± 0%  gaviota
+
+_ZFlat0-8          409MB/s ± 1%  html
+_ZFlat1-8          250MB/s ± 1%  urls
+_ZFlat2-8         12.3GB/s ± 1%  jpg
+_ZFlat3-8          132MB/s ± 0%  jpg_200
+_ZFlat4-8         2.92GB/s ± 0%  pdf
+_ZFlat5-8          405MB/s ± 1%  html4
+_ZFlat6-8          179MB/s ± 1%  txt1
+_ZFlat7-8          170MB/s ± 1%  txt2
+_ZFlat8-8          189MB/s ± 1%  txt3
+_ZFlat9-8          164MB/s ± 1%  txt4
+_ZFlat10-8         479MB/s ± 1%  pb
+_ZFlat11-8         270MB/s ± 1%  gaviota
+
+
+
+For comparison (Go's encoded output is byte-for-byte identical to C++'s), here
+are the numbers from C++ Snappy's
+
+make CXXFLAGS="-O2 -DNDEBUG -g" clean snappy_unittest.log && cat snappy_unittest.log
+
+BM_UFlat/0     2.4GB/s  html
+BM_UFlat/1     1.4GB/s  urls
+BM_UFlat/2    21.8GB/s  jpg
+BM_UFlat/3     1.5GB/s  jpg_200
+BM_UFlat/4    13.3GB/s  pdf
+BM_UFlat/5     2.1GB/s  html4
+BM_UFlat/6     1.0GB/s  txt1
+BM_UFlat/7   959.4MB/s  txt2
+BM_UFlat/8     1.0GB/s  txt3
+BM_UFlat/9   864.5MB/s  txt4
+BM_UFlat/10    2.9GB/s  pb
+BM_UFlat/11    1.2GB/s  gaviota
+
+BM_ZFlat/0   944.3MB/s  html (22.31 %)
+BM_ZFlat/1   501.6MB/s  urls (47.78 %)
+BM_ZFlat/2    14.3GB/s  jpg (99.95 %)
+BM_ZFlat/3   538.3MB/s  jpg_200 (73.00 %)
+BM_ZFlat/4     8.3GB/s  pdf (83.30 %)
+BM_ZFlat/5   903.5MB/s  html4 (22.52 %)
+BM_ZFlat/6   336.0MB/s  txt1 (57.88 %)
+BM_ZFlat/7   312.3MB/s  txt2 (61.91 %)
+BM_ZFlat/8   353.1MB/s  txt3 (54.99 %)
+BM_ZFlat/9   289.9MB/s  txt4 (66.26 %)
+BM_ZFlat/10    1.2GB/s  pb (19.68 %)
+BM_ZFlat/11  527.4MB/s  gaviota (37.72 %)

vendor/github.com/golang/snappy/decode.go

@@ -0,0 +1,264 @@
+// Copyright 2011 The Snappy-Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package snappy
+
+import (
+	"encoding/binary"
+	"errors"
+	"io"
+)
+
+var (
+	// ErrCorrupt reports that the input is invalid.
+	ErrCorrupt = errors.New("snappy: corrupt input")
+	// ErrTooLarge reports that the uncompressed length is too large.
+	ErrTooLarge = errors.New("snappy: decoded block is too large")
+	// ErrUnsupported reports that the input isn't supported.
+	ErrUnsupported = errors.New("snappy: unsupported input")
+
+	errUnsupportedLiteralLength = errors.New("snappy: unsupported literal length")
+)
+
+// DecodedLen returns the length of the decoded block.
+func DecodedLen(src []byte) (int, error) {
+	v, _, err := decodedLen(src)
+	return v, err
+}
+
+// decodedLen returns the length of the decoded block and the number of bytes
+// that the length header occupied.
+func decodedLen(src []byte) (blockLen, headerLen int, err error) {
+	v, n := binary.Uvarint(src)
+	if n <= 0 || v > 0xffffffff {
+		return 0, 0, ErrCorrupt
+	}
+
+	const wordSize = 32 << (^uint(0) >> 32 & 1)
+	if wordSize == 32 && v > 0x7fffffff {
+		return 0, 0, ErrTooLarge
+	}
+	return int(v), n, nil
+}
+
+const (
+	decodeErrCodeCorrupt                  = 1
+	decodeErrCodeUnsupportedLiteralLength = 2
+)
+
+// Decode returns the decoded form of src. The returned slice may be a sub-
+// slice of dst if dst was large enough to hold the entire decoded block.
+// Otherwise, a newly allocated slice will be returned.
+//
+// The dst and src must not overlap. It is valid to pass a nil dst.
+//
+// Decode handles the Snappy block format, not the Snappy stream format.
+func Decode(dst, src []byte) ([]byte, error) {
+	dLen, s, err := decodedLen(src)
+	if err != nil {
+		return nil, err
+	}
+	if dLen <= len(dst) {
+		dst = dst[:dLen]
+	} else {
+		dst = make([]byte, dLen)
+	}
+	switch decode(dst, src[s:]) {
+	case 0:
+		return dst, nil
+	case decodeErrCodeUnsupportedLiteralLength:
+		return nil, errUnsupportedLiteralLength
+	}
+	return nil, ErrCorrupt
+}
+
+// NewReader returns a new Reader that decompresses from r, using the framing
+// format described at
+// https://github.com/google/snappy/blob/master/framing_format.txt
+func NewReader(r io.Reader) *Reader {
+	return &Reader{
+		r:       r,
+		decoded: make([]byte, maxBlockSize),
+		buf:     make([]byte, maxEncodedLenOfMaxBlockSize+checksumSize),
+	}
+}
+
+// Reader is an io.Reader that can read Snappy-compressed bytes.
+//
+// Reader handles the Snappy stream format, not the Snappy block format.
+type Reader struct {
+	r       io.Reader
+	err     error
+	decoded []byte
+	buf     []byte
+	// decoded[i:j] contains decoded bytes that have not yet been passed on.
+	i, j       int
+	readHeader bool
+}
+
+// Reset discards any buffered data, resets all state, and switches the Snappy
+// reader to read from r. This permits reusing a Reader rather than allocating
+// a new one.
+func (r *Reader) Reset(reader io.Reader) {
+	r.r = reader
+	r.err = nil
+	r.i = 0
+	r.j = 0
+	r.readHeader = false
+}
+
+func (r *Reader) readFull(p []byte, allowEOF bool) (ok bool) {
+	if _, r.err = io.ReadFull(r.r, p); r.err != nil {
+		if r.err == io.ErrUnexpectedEOF || (r.err == io.EOF && !allowEOF) {
+			r.err = ErrCorrupt
+		}
+		return false
+	}
+	return true
+}
+
+func (r *Reader) fill() error {
+	for r.i >= r.j {
+		if !r.readFull(r.buf[:4], true) {
+			return r.err
+		}
+		chunkType := r.buf[0]
+		if !r.readHeader {
+			if chunkType != chunkTypeStreamIdentifier {
+				r.err = ErrCorrupt
+				return r.err
+			}
+			r.readHeader = true
+		}
+		chunkLen := int(r.buf[1]) | int(r.buf[2])<<8 | int(r.buf[3])<<16
+		if chunkLen > len(r.buf) {
+			r.err = ErrUnsupported
+			return r.err
+		}
+
+		// The chunk types are specified at
+		// https://github.com/google/snappy/blob/master/framing_format.txt
+		switch chunkType {
+		case chunkTypeCompressedData:
+			// Section 4.2. Compressed data (chunk type 0x00).
+			if chunkLen < checksumSize {
+				r.err = ErrCorrupt
+				return r.err
+			}
+			buf := r.buf[:chunkLen]
+			if !r.readFull(buf, false) {
+				return r.err
+			}
+			checksum := uint32(buf[0]) | uint32(buf[1])<<8 | uint32(buf[2])<<16 | uint32(buf[3])<<24
+			buf = buf[checksumSize:]
+
+			n, err := DecodedLen(buf)
+			if err != nil {
+				r.err = err
+				return r.err
+			}
+			if n > len(r.decoded) {
+				r.err = ErrCorrupt
+				return r.err
+			}
+			if _, err := Decode(r.decoded, buf); err != nil {
+				r.err = err
+				return r.err
+			}
+			if crc(r.decoded[:n]) != checksum {
+				r.err = ErrCorrupt
+				return r.err
+			}
+			r.i, r.j = 0, n
+			continue
+
+		case chunkTypeUncompressedData:
+			// Section 4.3. Uncompressed data (chunk type 0x01).
+			if chunkLen < checksumSize {
+				r.err = ErrCorrupt
+				return r.err
+			}
+			buf := r.buf[:checksumSize]
+			if !r.readFull(buf, false) {
+				return r.err
+			}
+			checksum := uint32(buf[0]) | uint32(buf[1])<<8 | uint32(buf[2])<<16 | uint32(buf[3])<<24
+			// Read directly into r.decoded instead of via r.buf.
+			n := chunkLen - checksumSize
+			if n > len(r.decoded) {
+				r.err = ErrCorrupt
+				return r.err
+			}
+			if !r.readFull(r.decoded[:n], false) {
+				return r.err
+			}
+			if crc(r.decoded[:n]) != checksum {
+				r.err = ErrCorrupt
+				return r.err
+			}
+			r.i, r.j = 0, n
+			continue
+
+		case chunkTypeStreamIdentifier:
+			// Section 4.1. Stream identifier (chunk type 0xff).
+			if chunkLen != len(magicBody) {
+				r.err = ErrCorrupt
+				return r.err
+			}
+			if !r.readFull(r.buf[:len(magicBody)], false) {
+				return r.err
+			}
+			for i := 0; i < len(magicBody); i++ {
+				if r.buf[i] != magicBody[i] {
+					r.err = ErrCorrupt
+					return r.err
+				}
+			}
+			continue
+		}
+
+		if chunkType <= 0x7f {
+			// Section 4.5. Reserved unskippable chunks (chunk types 0x02-0x7f).
+			r.err = ErrUnsupported
+			return r.err
+		}
+		// Section 4.4 Padding (chunk type 0xfe).
+		// Section 4.6. Reserved skippable chunks (chunk types 0x80-0xfd).
+		if !r.readFull(r.buf[:chunkLen], false) {
+			return r.err
+		}
+	}
+
+	return nil
+}
+
+// Read satisfies the io.Reader interface.
+func (r *Reader) Read(p []byte) (int, error) {
+	if r.err != nil {
+		return 0, r.err
+	}
+
+	if err := r.fill(); err != nil {
+		return 0, err
+	}
+
+	n := copy(p, r.decoded[r.i:r.j])
+	r.i += n
+	return n, nil
+}
+
+// ReadByte satisfies the io.ByteReader interface.
+func (r *Reader) ReadByte() (byte, error) {
+	if r.err != nil {
+		return 0, r.err
+	}
+
+	if err := r.fill(); err != nil {
+		return 0, err
+	}
+
+	c := r.decoded[r.i]
+	r.i++
+	return c, nil
+}

vendor/github.com/golang/snappy/decode_amd64.s

@@ -0,0 +1,490 @@
+// Copyright 2016 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build !appengine
+// +build gc
+// +build !noasm
+
+#include "textflag.h"
+
+// The asm code generally follows the pure Go code in decode_other.go, except
+// where marked with a "!!!".
+
+// func decode(dst, src []byte) int
+//
+// All local variables fit into registers. The non-zero stack size is only to
+// spill registers and push args when issuing a CALL. The register allocation:
+//	- AX	scratch
+//	- BX	scratch
+//	- CX	length or x
+//	- DX	offset
+//	- SI	&src[s]
+//	- DI	&dst[d]
+//	+ R8	dst_base
+//	+ R9	dst_len
+//	+ R10	dst_base + dst_len
+//	+ R11	src_base
+//	+ R12	src_len
+//	+ R13	src_base + src_len
+//	- R14	used by doCopy
+//	- R15	used by doCopy
+//
+// The registers R8-R13 (marked with a "+") are set at the start of the
+// function, and after a CALL returns, and are not otherwise modified.
+//
+// The d variable is implicitly DI - R8,  and len(dst)-d is R10 - DI.
+// The s variable is implicitly SI - R11, and len(src)-s is R13 - SI.
+TEXT ·decode(SB), NOSPLIT, $48-56
+	// Initialize SI, DI and R8-R13.
+	MOVQ dst_base+0(FP), R8
+	MOVQ dst_len+8(FP), R9
+	MOVQ R8, DI
+	MOVQ R8, R10
+	ADDQ R9, R10
+	MOVQ src_base+24(FP), R11
+	MOVQ src_len+32(FP), R12
+	MOVQ R11, SI
+	MOVQ R11, R13
+	ADDQ R12, R13
+
+loop:
+	// for s < len(src)
+	CMPQ SI, R13
+	JEQ  end
+
+	// CX = uint32(src[s])
+	//
+	// switch src[s] & 0x03
+	MOVBLZX (SI), CX
+	MOVL    CX, BX
+	ANDL    $3, BX
+	CMPL    BX, $1
+	JAE     tagCopy
+
+	// ----------------------------------------
+	// The code below handles literal tags.
+
+	// case tagLiteral:
+	// x := uint32(src[s] >> 2)
+	// switch
+	SHRL $2, CX
+	CMPL CX, $60
+	JAE  tagLit60Plus
+
+	// case x < 60:
+	// s++
+	INCQ SI
+
+doLit:
+	// This is the end of the inner "switch", when we have a literal tag.
+	//
+	// We assume that CX == x and x fits in a uint32, where x is the variable
+	// used in the pure Go decode_other.go code.
+
+	// length = int(x) + 1
+	//
+	// Unlike the pure Go code, we don't need to check if length <= 0 because
+	// CX can hold 64 bits, so the increment cannot overflow.
+	INCQ CX
+
+	// Prepare to check if copying length bytes will run past the end of dst or
+	// src.
+	//
+	// AX = len(dst) - d
+	// BX = len(src) - s
+	MOVQ R10, AX
+	SUBQ DI, AX
+	MOVQ R13, BX
+	SUBQ SI, BX
+
+	// !!! Try a faster technique for short (16 or fewer bytes) copies.
+	//
+	// if length > 16 || len(dst)-d < 16 || len(src)-s < 16 {
+	//   goto callMemmove // Fall back on calling runtime·memmove.
+	// }
+	//
+	// The C++ snappy code calls this TryFastAppend. It also checks len(src)-s
+	// against 21 instead of 16, because it cannot assume that all of its input
+	// is contiguous in memory and so it needs to leave enough source bytes to
+	// read the next tag without refilling buffers, but Go's Decode assumes
+	// contiguousness (the src argument is a []byte).
+	CMPQ CX, $16
+	JGT  callMemmove
+	CMPQ AX, $16
+	JLT  callMemmove
+	CMPQ BX, $16
+	JLT  callMemmove
+
+	// !!! Implement the copy from src to dst as a 16-byte load and store.
+	// (Decode's documentation says that dst and src must not overlap.)
+	//
+	// This always copies 16 bytes, instead of only length bytes, but that's
+	// OK. If the input is a valid Snappy encoding then subsequent iterations
+	// will fix up the overrun. Otherwise, Decode returns a nil []byte (and a
+	// non-nil error), so the overrun will be ignored.
+	//
+	// Note that on amd64, it is legal and cheap to issue unaligned 8-byte or
+	// 16-byte loads and stores. This technique probably wouldn't be as
+	// effective on architectures that are fussier about alignment.
+	MOVOU 0(SI), X0
+	MOVOU X0, 0(DI)
+
+	// d += length
+	// s += length
+	ADDQ CX, DI
+	ADDQ CX, SI
+	JMP  loop
+
+callMemmove:
+	// if length > len(dst)-d || length > len(src)-s { etc }
+	CMPQ CX, AX
+	JGT  errCorrupt
+	CMPQ CX, BX
+	JGT  errCorrupt
+
+	// copy(dst[d:], src[s:s+length])
+	//
+	// This means calling runtime·memmove(&dst[d], &src[s], length), so we push
+	// DI, SI and CX as arguments. Coincidentally, we also need to spill those
+	// three registers to the stack, to save local variables across the CALL.
+	MOVQ DI, 0(SP)
+	MOVQ SI, 8(SP)
+	MOVQ CX, 16(SP)
+	MOVQ DI, 24(SP)
+	MOVQ SI, 32(SP)
+	MOVQ CX, 40(SP)
+	CALL runtime·memmove(SB)
+
+	// Restore local variables: unspill registers from the stack and
+	// re-calculate R8-R13.
+	MOVQ 24(SP), DI
+	MOVQ 32(SP), SI
+	MOVQ 40(SP), CX
+	MOVQ dst_base+0(FP), R8
+	MOVQ dst_len+8(FP), R9
+	MOVQ R8, R10
+	ADDQ R9, R10
+	MOVQ src_base+24(FP), R11
+	MOVQ src_len+32(FP), R12
+	MOVQ R11, R13
+	ADDQ R12, R13
+
+	// d += length
+	// s += length
+	ADDQ CX, DI
+	ADDQ CX, SI
+	JMP  loop
+
+tagLit60Plus:
+	// !!! This fragment does the
+	//
+	// s += x - 58; if uint(s) > uint(len(src)) { etc }
+	//
+	// checks. In the asm version, we code it once instead of once per switch case.
+	ADDQ CX, SI
+	SUBQ $58, SI
+	MOVQ SI, BX
+	SUBQ R11, BX
+	CMPQ BX, R12
+	JA   errCorrupt
+
+	// case x == 60:
+	CMPL CX, $61
+	JEQ  tagLit61
+	JA   tagLit62Plus
+
+	// x = uint32(src[s-1])
+	MOVBLZX -1(SI), CX
+	JMP     doLit
+
+tagLit61:
+	// case x == 61:
+	// x = uint32(src[s-2]) | uint32(src[s-1])<<8
+	MOVWLZX -2(SI), CX
+	JMP     doLit
+
+tagLit62Plus:
+	CMPL CX, $62
+	JA   tagLit63
+
+	// case x == 62:
+	// x = uint32(src[s-3]) | uint32(src[s-2])<<8 | uint32(src[s-1])<<16
+	MOVWLZX -3(SI), CX
+	MOVBLZX -1(SI), BX
+	SHLL    $16, BX
+	ORL     BX, CX
+	JMP     doLit
+
+tagLit63:
+	// case x == 63:
+	// x = uint32(src[s-4]) | uint32(src[s-3])<<8 | uint32(src[s-2])<<16 | uint32(src[s-1])<<24
+	MOVL -4(SI), CX
+	JMP  doLit
+
+// The code above handles literal tags.
+// ----------------------------------------
+// The code below handles copy tags.
+
+tagCopy4:
+	// case tagCopy4:
+	// s += 5
+	ADDQ $5, SI
+
+	// if uint(s) > uint(len(src)) { etc }
+	MOVQ SI, BX
+	SUBQ R11, BX
+	CMPQ BX, R12
+	JA   errCorrupt
+
+	// length = 1 + int(src[s-5])>>2
+	SHRQ $2, CX
+	INCQ CX
+
+	// offset = int(uint32(src[s-4]) | uint32(src[s-3])<<8 | uint32(src[s-2])<<16 | uint32(src[s-1])<<24)
+	MOVLQZX -4(SI), DX
+	JMP     doCopy
+
+tagCopy2:
+	// case tagCopy2:
+	// s += 3
+	ADDQ $3, SI
+
+	// if uint(s) > uint(len(src)) { etc }
+	MOVQ SI, BX
+	SUBQ R11, BX
+	CMPQ BX, R12
+	JA   errCorrupt
+
+	// length = 1 + int(src[s-3])>>2
+	SHRQ $2, CX
+	INCQ CX
+
+	// offset = int(uint32(src[s-2]) | uint32(src[s-1])<<8)
+	MOVWQZX -2(SI), DX
+	JMP     doCopy
+
+tagCopy:
+	// We have a copy tag. We assume that:
+	//	- BX == src[s] & 0x03
+	//	- CX == src[s]
+	CMPQ BX, $2
+	JEQ  tagCopy2
+	JA   tagCopy4
+
+	// case tagCopy1:
+	// s += 2
+	ADDQ $2, SI
+
+	// if uint(s) > uint(len(src)) { etc }
+	MOVQ SI, BX
+	SUBQ R11, BX
+	CMPQ BX, R12
+	JA   errCorrupt
+
+	// offset = int(uint32(src[s-2])&0xe0<<3 | uint32(src[s-1]))
+	MOVQ    CX, DX
+	ANDQ    $0xe0, DX
+	SHLQ    $3, DX
+	MOVBQZX -1(SI), BX
+	ORQ     BX, DX
+
+	// length = 4 + int(src[s-2])>>2&0x7
+	SHRQ $2, CX
+	ANDQ $7, CX
+	ADDQ $4, CX
+
+doCopy:
+	// This is the end of the outer "switch", when we have a copy tag.
+	//
+	// We assume that:
+	//	- CX == length && CX > 0
+	//	- DX == offset
+
+	// if offset <= 0 { etc }
+	CMPQ DX, $0
+	JLE  errCorrupt
+
+	// if d < offset { etc }
+	MOVQ DI, BX
+	SUBQ R8, BX
+	CMPQ BX, DX
+	JLT  errCorrupt
+
+	// if length > len(dst)-d { etc }
+	MOVQ R10, BX
+	SUBQ DI, BX
+	CMPQ CX, BX
+	JGT  errCorrupt
+
+	// forwardCopy(dst[d:d+length], dst[d-offset:]); d += length
+	//
+	// Set:
+	//	- R14 = len(dst)-d
+	//	- R15 = &dst[d-offset]
+	MOVQ R10, R14
+	SUBQ DI, R14
+	MOVQ DI, R15
+	SUBQ DX, R15
+
+	// !!! Try a faster technique for short (16 or fewer bytes) forward copies.
+	//
+	// First, try using two 8-byte load/stores, similar to the doLit technique
+	// above. Even if dst[d:d+length] and dst[d-offset:] can overlap, this is
+	// still OK if offset >= 8. Note that this has to be two 8-byte load/stores
+	// and not one 16-byte load/store, and the first store has to be before the
+	// second load, due to the overlap if offset is in the range [8, 16).
+	//
+	// if length > 16 || offset < 8 || len(dst)-d < 16 {
+	//   goto slowForwardCopy
+	// }
+	// copy 16 bytes
+	// d += length
+	CMPQ CX, $16
+	JGT  slowForwardCopy
+	CMPQ DX, $8
+	JLT  slowForwardCopy
+	CMPQ R14, $16
+	JLT  slowForwardCopy
+	MOVQ 0(R15), AX
+	MOVQ AX, 0(DI)
+	MOVQ 8(R15), BX
+	MOVQ BX, 8(DI)
+	ADDQ CX, DI
+	JMP  loop
+
+slowForwardCopy:
+	// !!! If the forward copy is longer than 16 bytes, or if offset < 8, we
+	// can still try 8-byte load stores, provided we can overrun up to 10 extra
+	// bytes. As above, the overrun will be fixed up by subsequent iterations
+	// of the outermost loop.
+	//
+	// The C++ snappy code calls this technique IncrementalCopyFastPath. Its
+	// commentary says:
+	//
+	// ----
+	//
+	// The main part of this loop is a simple copy of eight bytes at a time
+	// until we've copied (at least) the requested amount of bytes.  However,
+	// if d and d-offset are less than eight bytes apart (indicating a
+	// repeating pattern of length < 8), we first need to expand the pattern in
+	// order to get the correct results. For instance, if the buffer looks like
+	// this, with the eight-byte <d-offset> and <d> patterns marked as
+	// intervals:
+	//
+	//    abxxxxxxxxxxxx
+	//    [------]           d-offset
+	//      [------]         d
+	//
+	// a single eight-byte copy from <d-offset> to <d> will repeat the pattern
+	// once, after which we can move <d> two bytes without moving <d-offset>:
+	//
+	//    ababxxxxxxxxxx
+	//    [------]           d-offset
+	//        [------]       d
+	//
+	// and repeat the exercise until the two no longer overlap.
+	//
+	// This allows us to do very well in the special case of one single byte
+	// repeated many times, without taking a big hit for more general cases.
+	//
+	// The worst case of extra writing past the end of the match occurs when
+	// offset == 1 and length == 1; the last copy will read from byte positions
+	// [0..7] and write to [4..11], whereas it was only supposed to write to
+	// position 1. Thus, ten excess bytes.
+	//
+	// ----
+	//
+	// That "10 byte overrun" worst case is confirmed by Go's
+	// TestSlowForwardCopyOverrun, which also tests the fixUpSlowForwardCopy
+	// and finishSlowForwardCopy algorithm.
+	//
+	// if length > len(dst)-d-10 {
+	//   goto verySlowForwardCopy
+	// }
+	SUBQ $10, R14
+	CMPQ CX, R14
+	JGT  verySlowForwardCopy
+
+makeOffsetAtLeast8:
+	// !!! As above, expand the pattern so that offset >= 8 and we can use
+	// 8-byte load/stores.
+	//
+	// for offset < 8 {
+	//   copy 8 bytes from dst[d-offset:] to dst[d:]
+	//   length -= offset
+	//   d      += offset
+	//   offset += offset
+	//   // The two previous lines together means that d-offset, and therefore
+	//   // R15, is unchanged.
+	// }
+	CMPQ DX, $8
+	JGE  fixUpSlowForwardCopy
+	MOVQ (R15), BX
+	MOVQ BX, (DI)
+	SUBQ DX, CX
+	ADDQ DX, DI
+	ADDQ DX, DX
+	JMP  makeOffsetAtLeast8
+
+fixUpSlowForwardCopy:
+	// !!! Add length (which might be negative now) to d (implied by DI being
+	// &dst[d]) so that d ends up at the right place when we jump back to the
+	// top of the loop. Before we do that, though, we save DI to AX so that, if
+	// length is positive, copying the remaining length bytes will write to the
+	// right place.
+	MOVQ DI, AX
+	ADDQ CX, DI
+
+finishSlowForwardCopy:
+	// !!! Repeat 8-byte load/stores until length <= 0. Ending with a negative
+	// length means that we overrun, but as above, that will be fixed up by
+	// subsequent iterations of the outermost loop.
+	CMPQ CX, $0
+	JLE  loop
+	MOVQ (R15), BX
+	MOVQ BX, (AX)
+	ADDQ $8, R15
+	ADDQ $8, AX
+	SUBQ $8, CX
+	JMP  finishSlowForwardCopy
+
+verySlowForwardCopy:
+	// verySlowForwardCopy is a simple implementation of forward copy. In C
+	// parlance, this is a do/while loop instead of a while loop, since we know
+	// that length > 0. In Go syntax:
+	//
+	// for {
+	//   dst[d] = dst[d - offset]
+	//   d++
+	//   length--
+	//   if length == 0 {
+	//     break
+	//   }
+	// }
+	MOVB (R15), BX
+	MOVB BX, (DI)
+	INCQ R15
+	INCQ DI
+	DECQ CX
+	JNZ  verySlowForwardCopy
+	JMP  loop
+
+// The code above handles copy tags.
+// ----------------------------------------
+
+end:
+	// This is the end of the "for s < len(src)".
+	//
+	// if d != len(dst) { etc }
+	CMPQ DI, R10
+	JNE  errCorrupt
+
+	// return 0
+	MOVQ $0, ret+48(FP)
+	RET
+
+errCorrupt:
+	// return decodeErrCodeCorrupt
+	MOVQ $1, ret+48(FP)
+	RET

vendor/github.com/golang/snappy/decode_arm64.s

@@ -0,0 +1,494 @@
+// Copyright 2020 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build !appengine
+// +build gc
+// +build !noasm
+
+#include "textflag.h"
+
+// The asm code generally follows the pure Go code in decode_other.go, except
+// where marked with a "!!!".
+
+// func decode(dst, src []byte) int
+//
+// All local variables fit into registers. The non-zero stack size is only to
+// spill registers and push args when issuing a CALL. The register allocation:
+//	- R2	scratch
+//	- R3	scratch
+//	- R4	length or x
+//	- R5	offset
+//	- R6	&src[s]
+//	- R7	&dst[d]
+//	+ R8	dst_base
+//	+ R9	dst_len
+//	+ R10	dst_base + dst_len
+//	+ R11	src_base
+//	+ R12	src_len
+//	+ R13	src_base + src_len
+//	- R14	used by doCopy
+//	- R15	used by doCopy
+//
+// The registers R8-R13 (marked with a "+") are set at the start of the
+// function, and after a CALL returns, and are not otherwise modified.
+//
+// The d variable is implicitly R7 - R8,  and len(dst)-d is R10 - R7.
+// The s variable is implicitly R6 - R11, and len(src)-s is R13 - R6.
+TEXT ·decode(SB), NOSPLIT, $56-56
+	// Initialize R6, R7 and R8-R13.
+	MOVD dst_base+0(FP), R8
+	MOVD dst_len+8(FP), R9
+	MOVD R8, R7
+	MOVD R8, R10
+	ADD  R9, R10, R10
+	MOVD src_base+24(FP), R11
+	MOVD src_len+32(FP), R12
+	MOVD R11, R6
+	MOVD R11, R13
+	ADD  R12, R13, R13
+
+loop:
+	// for s < len(src)
+	CMP R13, R6
+	BEQ end
+
+	// R4 = uint32(src[s])
+	//
+	// switch src[s] & 0x03
+	MOVBU (R6), R4
+	MOVW  R4, R3
+	ANDW  $3, R3
+	MOVW  $1, R1
+	CMPW  R1, R3
+	BGE   tagCopy
+
+	// ----------------------------------------
+	// The code below handles literal tags.
+
+	// case tagLiteral:
+	// x := uint32(src[s] >> 2)
+	// switch
+	MOVW $60, R1
+	LSRW $2, R4, R4
+	CMPW R4, R1
+	BLS  tagLit60Plus
+
+	// case x < 60:
+	// s++
+	ADD $1, R6, R6
+
+doLit:
+	// This is the end of the inner "switch", when we have a literal tag.
+	//
+	// We assume that R4 == x and x fits in a uint32, where x is the variable
+	// used in the pure Go decode_other.go code.
+
+	// length = int(x) + 1
+	//
+	// Unlike the pure Go code, we don't need to check if length <= 0 because
+	// R4 can hold 64 bits, so the increment cannot overflow.
+	ADD $1, R4, R4
+
+	// Prepare to check if copying length bytes will run past the end of dst or
+	// src.
+	//
+	// R2 = len(dst) - d
+	// R3 = len(src) - s
+	MOVD R10, R2
+	SUB  R7, R2, R2
+	MOVD R13, R3
+	SUB  R6, R3, R3
+
+	// !!! Try a faster technique for short (16 or fewer bytes) copies.
+	//
+	// if length > 16 || len(dst)-d < 16 || len(src)-s < 16 {
+	//   goto callMemmove // Fall back on calling runtime·memmove.
+	// }
+	//
+	// The C++ snappy code calls this TryFastAppend. It also checks len(src)-s
+	// against 21 instead of 16, because it cannot assume that all of its input
+	// is contiguous in memory and so it needs to leave enough source bytes to
+	// read the next tag without refilling buffers, but Go's Decode assumes
+	// contiguousness (the src argument is a []byte).
+	CMP $16, R4
+	BGT callMemmove
+	CMP $16, R2
+	BLT callMemmove
+	CMP $16, R3
+	BLT callMemmove
+
+	// !!! Implement the copy from src to dst as a 16-byte load and store.
+	// (Decode's documentation says that dst and src must not overlap.)
+	//
+	// This always copies 16 bytes, instead of only length bytes, but that's
+	// OK. If the input is a valid Snappy encoding then subsequent iterations
+	// will fix up the overrun. Otherwise, Decode returns a nil []byte (and a
+	// non-nil error), so the overrun will be ignored.
+	//
+	// Note that on arm64, it is legal and cheap to issue unaligned 8-byte or
+	// 16-byte loads and stores. This technique probably wouldn't be as
+	// effective on architectures that are fussier about alignment.
+	LDP 0(R6), (R14, R15)
+	STP (R14, R15), 0(R7)
+
+	// d += length
+	// s += length
+	ADD R4, R7, R7
+	ADD R4, R6, R6
+	B   loop
+
+callMemmove:
+	// if length > len(dst)-d || length > len(src)-s { etc }
+	CMP R2, R4
+	BGT errCorrupt
+	CMP R3, R4
+	BGT errCorrupt
+
+	// copy(dst[d:], src[s:s+length])
+	//
+	// This means calling runtime·memmove(&dst[d], &src[s], length), so we push
+	// R7, R6 and R4 as arguments. Coincidentally, we also need to spill those
+	// three registers to the stack, to save local variables across the CALL.
+	MOVD R7, 8(RSP)
+	MOVD R6, 16(RSP)
+	MOVD R4, 24(RSP)
+	MOVD R7, 32(RSP)
+	MOVD R6, 40(RSP)
+	MOVD R4, 48(RSP)
+	CALL runtime·memmove(SB)
+
+	// Restore local variables: unspill registers from the stack and
+	// re-calculate R8-R13.
+	MOVD 32(RSP), R7
+	MOVD 40(RSP), R6
+	MOVD 48(RSP), R4
+	MOVD dst_base+0(FP), R8
+	MOVD dst_len+8(FP), R9
+	MOVD R8, R10
+	ADD  R9, R10, R10
+	MOVD src_base+24(FP), R11
+	MOVD src_len+32(FP), R12
+	MOVD R11, R13
+	ADD  R12, R13, R13
+
+	// d += length
+	// s += length
+	ADD R4, R7, R7
+	ADD R4, R6, R6
+	B   loop
+
+tagLit60Plus:
+	// !!! This fragment does the
+	//
+	// s += x - 58; if uint(s) > uint(len(src)) { etc }
+	//
+	// checks. In the asm version, we code it once instead of once per switch case.
+	ADD  R4, R6, R6
+	SUB  $58, R6, R6
+	MOVD R6, R3
+	SUB  R11, R3, R3
+	CMP  R12, R3
+	BGT  errCorrupt
+
+	// case x == 60:
+	MOVW $61, R1
+	CMPW R1, R4
+	BEQ  tagLit61
+	BGT  tagLit62Plus
+
+	// x = uint32(src[s-1])
+	MOVBU -1(R6), R4
+	B     doLit
+
+tagLit61:
+	// case x == 61:
+	// x = uint32(src[s-2]) | uint32(src[s-1])<<8
+	MOVHU -2(R6), R4
+	B     doLit
+
+tagLit62Plus:
+	CMPW $62, R4
+	BHI  tagLit63
+
+	// case x == 62:
+	// x = uint32(src[s-3]) | uint32(src[s-2])<<8 | uint32(src[s-1])<<16
+	MOVHU -3(R6), R4
+	MOVBU -1(R6), R3
+	ORR   R3<<16, R4
+	B     doLit
+
+tagLit63:
+	// case x == 63:
+	// x = uint32(src[s-4]) | uint32(src[s-3])<<8 | uint32(src[s-2])<<16 | uint32(src[s-1])<<24
+	MOVWU -4(R6), R4
+	B     doLit
+
+	// The code above handles literal tags.
+	// ----------------------------------------
+	// The code below handles copy tags.
+
+tagCopy4:
+	// case tagCopy4:
+	// s += 5
+	ADD $5, R6, R6
+
+	// if uint(s) > uint(len(src)) { etc }
+	MOVD R6, R3
+	SUB  R11, R3, R3
+	CMP  R12, R3
+	BGT  errCorrupt
+
+	// length = 1 + int(src[s-5])>>2
+	MOVD $1, R1
+	ADD  R4>>2, R1, R4
+
+	// offset = int(uint32(src[s-4]) | uint32(src[s-3])<<8 | uint32(src[s-2])<<16 | uint32(src[s-1])<<24)
+	MOVWU -4(R6), R5
+	B     doCopy
+
+tagCopy2:
+	// case tagCopy2:
+	// s += 3
+	ADD $3, R6, R6
+
+	// if uint(s) > uint(len(src)) { etc }
+	MOVD R6, R3
+	SUB  R11, R3, R3
+	CMP  R12, R3
+	BGT  errCorrupt
+
+	// length = 1 + int(src[s-3])>>2
+	MOVD $1, R1
+	ADD  R4>>2, R1, R4
+
+	// offset = int(uint32(src[s-2]) | uint32(src[s-1])<<8)
+	MOVHU -2(R6), R5
+	B     doCopy
+
+tagCopy:
+	// We have a copy tag. We assume that:
+	//	- R3 == src[s] & 0x03
+	//	- R4 == src[s]
+	CMP $2, R3
+	BEQ tagCopy2
+	BGT tagCopy4
+
+	// case tagCopy1:
+	// s += 2
+	ADD $2, R6, R6
+
+	// if uint(s) > uint(len(src)) { etc }
+	MOVD R6, R3
+	SUB  R11, R3, R3
+	CMP  R12, R3
+	BGT  errCorrupt
+
+	// offset = int(uint32(src[s-2])&0xe0<<3 | uint32(src[s-1]))
+	MOVD  R4, R5
+	AND   $0xe0, R5
+	MOVBU -1(R6), R3
+	ORR   R5<<3, R3, R5
+
+	// length = 4 + int(src[s-2])>>2&0x7
+	MOVD $7, R1
+	AND  R4>>2, R1, R4
+	ADD  $4, R4, R4
+
+doCopy:
+	// This is the end of the outer "switch", when we have a copy tag.
+	//
+	// We assume that:
+	//	- R4 == length && R4 > 0
+	//	- R5 == offset
+
+	// if offset <= 0 { etc }
+	MOVD $0, R1
+	CMP  R1, R5
+	BLE  errCorrupt
+
+	// if d < offset { etc }
+	MOVD R7, R3
+	SUB  R8, R3, R3
+	CMP  R5, R3
+	BLT  errCorrupt
+
+	// if length > len(dst)-d { etc }
+	MOVD R10, R3
+	SUB  R7, R3, R3
+	CMP  R3, R4
+	BGT  errCorrupt
+
+	// forwardCopy(dst[d:d+length], dst[d-offset:]); d += length
+	//
+	// Set:
+	//	- R14 = len(dst)-d
+	//	- R15 = &dst[d-offset]
+	MOVD R10, R14
+	SUB  R7, R14, R14
+	MOVD R7, R15
+	SUB  R5, R15, R15
+
+	// !!! Try a faster technique for short (16 or fewer bytes) forward copies.
+	//
+	// First, try using two 8-byte load/stores, similar to the doLit technique
+	// above. Even if dst[d:d+length] and dst[d-offset:] can overlap, this is
+	// still OK if offset >= 8. Note that this has to be two 8-byte load/stores
+	// and not one 16-byte load/store, and the first store has to be before the
+	// second load, due to the overlap if offset is in the range [8, 16).
+	//
+	// if length > 16 || offset < 8 || len(dst)-d < 16 {
+	//   goto slowForwardCopy
+	// }
+	// copy 16 bytes
+	// d += length
+	CMP  $16, R4
+	BGT  slowForwardCopy
+	CMP  $8, R5
+	BLT  slowForwardCopy
+	CMP  $16, R14
+	BLT  slowForwardCopy
+	MOVD 0(R15), R2
+	MOVD R2, 0(R7)
+	MOVD 8(R15), R3
+	MOVD R3, 8(R7)
+	ADD  R4, R7, R7
+	B    loop
+
+slowForwardCopy:
+	// !!! If the forward copy is longer than 16 bytes, or if offset < 8, we
+	// can still try 8-byte load stores, provided we can overrun up to 10 extra
+	// bytes. As above, the overrun will be fixed up by subsequent iterations
+	// of the outermost loop.
+	//
+	// The C++ snappy code calls this technique IncrementalCopyFastPath. Its
+	// commentary says:
+	//
+	// ----
+	//
+	// The main part of this loop is a simple copy of eight bytes at a time
+	// until we've copied (at least) the requested amount of bytes.  However,
+	// if d and d-offset are less than eight bytes apart (indicating a
+	// repeating pattern of length < 8), we first need to expand the pattern in
+	// order to get the correct results. For instance, if the buffer looks like
+	// this, with the eight-byte <d-offset> and <d> patterns marked as
+	// intervals:
+	//
+	//    abxxxxxxxxxxxx
+	//    [------]           d-offset
+	//      [------]         d
+	//
+	// a single eight-byte copy from <d-offset> to <d> will repeat the pattern
+	// once, after which we can move <d> two bytes without moving <d-offset>:
+	//
+	//    ababxxxxxxxxxx
+	//    [------]           d-offset
+	//        [------]       d
+	//
+	// and repeat the exercise until the two no longer overlap.
+	//
+	// This allows us to do very well in the special case of one single byte
+	// repeated many times, without taking a big hit for more general cases.
+	//
+	// The worst case of extra writing past the end of the match occurs when
+	// offset == 1 and length == 1; the last copy will read from byte positions
+	// [0..7] and write to [4..11], whereas it was only supposed to write to
+	// position 1. Thus, ten excess bytes.
+	//
+	// ----
+	//
+	// That "10 byte overrun" worst case is confirmed by Go's
+	// TestSlowForwardCopyOverrun, which also tests the fixUpSlowForwardCopy
+	// and finishSlowForwardCopy algorithm.
+	//
+	// if length > len(dst)-d-10 {
+	//   goto verySlowForwardCopy
+	// }
+	SUB $10, R14, R14
+	CMP R14, R4
+	BGT verySlowForwardCopy
+
+makeOffsetAtLeast8:
+	// !!! As above, expand the pattern so that offset >= 8 and we can use
+	// 8-byte load/stores.
+	//
+	// for offset < 8 {
+	//   copy 8 bytes from dst[d-offset:] to dst[d:]
+	//   length -= offset
+	//   d      += offset
+	//   offset += offset
+	//   // The two previous lines together means that d-offset, and therefore
+	//   // R15, is unchanged.
+	// }
+	CMP  $8, R5
+	BGE  fixUpSlowForwardCopy
+	MOVD (R15), R3
+	MOVD R3, (R7)
+	SUB  R5, R4, R4
+	ADD  R5, R7, R7
+	ADD  R5, R5, R5
+	B    makeOffsetAtLeast8
+
+fixUpSlowForwardCopy:
+	// !!! Add length (which might be negative now) to d (implied by R7 being
+	// &dst[d]) so that d ends up at the right place when we jump back to the
+	// top of the loop. Before we do that, though, we save R7 to R2 so that, if
+	// length is positive, copying the remaining length bytes will write to the
+	// right place.
+	MOVD R7, R2
+	ADD  R4, R7, R7
+
+finishSlowForwardCopy:
+	// !!! Repeat 8-byte load/stores until length <= 0. Ending with a negative
+	// length means that we overrun, but as above, that will be fixed up by
+	// subsequent iterations of the outermost loop.
+	MOVD $0, R1
+	CMP  R1, R4
+	BLE  loop
+	MOVD (R15), R3
+	MOVD R3, (R2)
+	ADD  $8, R15, R15
+	ADD  $8, R2, R2
+	SUB  $8, R4, R4
+	B    finishSlowForwardCopy
+
+verySlowForwardCopy:
+	// verySlowForwardCopy is a simple implementation of forward copy. In C
+	// parlance, this is a do/while loop instead of a while loop, since we know
+	// that length > 0. In Go syntax:
+	//
+	// for {
+	//   dst[d] = dst[d - offset]
+	//   d++
+	//   length--
+	//   if length == 0 {
+	//     break
+	//   }
+	// }
+	MOVB (R15), R3
+	MOVB R3, (R7)
+	ADD  $1, R15, R15
+	ADD  $1, R7, R7
+	SUB  $1, R4, R4
+	CBNZ R4, verySlowForwardCopy
+	B    loop
+
+	// The code above handles copy tags.
+	// ----------------------------------------
+
+end:
+	// This is the end of the "for s < len(src)".
+	//
+	// if d != len(dst) { etc }
+	CMP R10, R7
+	BNE errCorrupt
+
+	// return 0
+	MOVD $0, ret+48(FP)
+	RET
+
+errCorrupt:
+	// return decodeErrCodeCorrupt
+	MOVD $1, R2
+	MOVD R2, ret+48(FP)
+	RET

vendor/github.com/golang/snappy/decode_asm.go

@@ -0,0 +1,15 @@
+// Copyright 2016 The Snappy-Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build !appengine
+// +build gc
+// +build !noasm
+// +build amd64 arm64
+
+package snappy
+
+// decode has the same semantics as in decode_other.go.
+//
+//go:noescape
+func decode(dst, src []byte) int

vendor/github.com/golang/snappy/decode_other.go

@@ -0,0 +1,115 @@
+// Copyright 2016 The Snappy-Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build !amd64,!arm64 appengine !gc noasm
+
+package snappy
+
+// decode writes the decoding of src to dst. It assumes that the varint-encoded
+// length of the decompressed bytes has already been read, and that len(dst)
+// equals that length.
+//
+// It returns 0 on success or a decodeErrCodeXxx error code on failure.
+func decode(dst, src []byte) int {
+	var d, s, offset, length int
+	for s < len(src) {
+		switch src[s] & 0x03 {
+		case tagLiteral:
+			x := uint32(src[s] >> 2)
+			switch {
+			case x < 60:
+				s++
+			case x == 60:
+				s += 2
+				if uint(s) > uint(len(src)) { // The uint conversions catch overflow from the previous line.
+					return decodeErrCodeCorrupt
+				}
+				x = uint32(src[s-1])
+			case x == 61:
+				s += 3
+				if uint(s) > uint(len(src)) { // The uint conversions catch overflow from the previous line.
+					return decodeErrCodeCorrupt
+				}
+				x = uint32(src[s-2]) | uint32(src[s-1])<<8
+			case x == 62:
+				s += 4
+				if uint(s) > uint(len(src)) { // The uint conversions catch overflow from the previous line.
+					return decodeErrCodeCorrupt
+				}
+				x = uint32(src[s-3]) | uint32(src[s-2])<<8 | uint32(src[s-1])<<16
+			case x == 63:
+				s += 5
+				if uint(s) > uint(len(src)) { // The uint conversions catch overflow from the previous line.
+					return decodeErrCodeCorrupt
+				}
+				x = uint32(src[s-4]) | uint32(src[s-3])<<8 | uint32(src[s-2])<<16 | uint32(src[s-1])<<24
+			}
+			length = int(x) + 1
+			if length <= 0 {
+				return decodeErrCodeUnsupportedLiteralLength
+			}
+			if length > len(dst)-d || length > len(src)-s {
+				return decodeErrCodeCorrupt
+			}
+			copy(dst[d:], src[s:s+length])
+			d += length
+			s += length
+			continue
+
+		case tagCopy1:
+			s += 2
+			if uint(s) > uint(len(src)) { // The uint conversions catch overflow from the previous line.
+				return decodeErrCodeCorrupt
+			}
+			length = 4 + int(src[s-2])>>2&0x7
+			offset = int(uint32(src[s-2])&0xe0<<3 | uint32(src[s-1]))
+
+		case tagCopy2:
+			s += 3
+			if uint(s) > uint(len(src)) { // The uint conversions catch overflow from the previous line.
+				return decodeErrCodeCorrupt
+			}
+			length = 1 + int(src[s-3])>>2
+			offset = int(uint32(src[s-2]) | uint32(src[s-1])<<8)
+
+		case tagCopy4:
+			s += 5
+			if uint(s) > uint(len(src)) { // The uint conversions catch overflow from the previous line.
+				return decodeErrCodeCorrupt
+			}
+			length = 1 + int(src[s-5])>>2
+			offset = int(uint32(src[s-4]) | uint32(src[s-3])<<8 | uint32(src[s-2])<<16 | uint32(src[s-1])<<24)
+		}
+
+		if offset <= 0 || d < offset || length > len(dst)-d {
+			return decodeErrCodeCorrupt
+		}
+		// Copy from an earlier sub-slice of dst to a later sub-slice.
+		// If no overlap, use the built-in copy:
+		if offset >= length {
+			copy(dst[d:d+length], dst[d-offset:])
+			d += length
+			continue
+		}
+
+		// Unlike the built-in copy function, this byte-by-byte copy always runs
+		// forwards, even if the slices overlap. Conceptually, this is:
+		//
+		// d += forwardCopy(dst[d:d+length], dst[d-offset:])
+		//
+		// We align the slices into a and b and show the compiler they are the same size.
+		// This allows the loop to run without bounds checks.
+		a := dst[d : d+length]
+		b := dst[d-offset:]
+		b = b[:len(a)]
+		for i := range a {
+			a[i] = b[i]
+		}
+		d += length
+	}
+	if d != len(dst) {
+		return decodeErrCodeCorrupt
+	}
+	return 0
+}

vendor/github.com/golang/snappy/encode.go

@@ -0,0 +1,289 @@
+// Copyright 2011 The Snappy-Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package snappy
+
+import (
+	"encoding/binary"
+	"errors"
+	"io"
+)
+
+// Encode returns the encoded form of src. The returned slice may be a sub-
+// slice of dst if dst was large enough to hold the entire encoded block.
+// Otherwise, a newly allocated slice will be returned.
+//
+// The dst and src must not overlap. It is valid to pass a nil dst.
+//
+// Encode handles the Snappy block format, not the Snappy stream format.
+func Encode(dst, src []byte) []byte {
+	if n := MaxEncodedLen(len(src)); n < 0 {
+		panic(ErrTooLarge)
+	} else if len(dst) < n {
+		dst = make([]byte, n)
+	}
+
+	// The block starts with the varint-encoded length of the decompressed bytes.
+	d := binary.PutUvarint(dst, uint64(len(src)))
+
+	for len(src) > 0 {
+		p := src
+		src = nil
+		if len(p) > maxBlockSize {
+			p, src = p[:maxBlockSize], p[maxBlockSize:]
+		}
+		if len(p) < minNonLiteralBlockSize {
+			d += emitLiteral(dst[d:], p)
+		} else {
+			d += encodeBlock(dst[d:], p)
+		}
+	}
+	return dst[:d]
+}
+
+// inputMargin is the minimum number of extra input bytes to keep, inside
+// encodeBlock's inner loop. On some architectures, this margin lets us
+// implement a fast path for emitLiteral, where the copy of short (<= 16 byte)
+// literals can be implemented as a single load to and store from a 16-byte
+// register. That literal's actual length can be as short as 1 byte, so this
+// can copy up to 15 bytes too much, but that's OK as subsequent iterations of
+// the encoding loop will fix up the copy overrun, and this inputMargin ensures
+// that we don't overrun the dst and src buffers.
+const inputMargin = 16 - 1
+
+// minNonLiteralBlockSize is the minimum size of the input to encodeBlock that
+// could be encoded with a copy tag. This is the minimum with respect to the
+// algorithm used by encodeBlock, not a minimum enforced by the file format.
+//
+// The encoded output must start with at least a 1 byte literal, as there are
+// no previous bytes to copy. A minimal (1 byte) copy after that, generated
+// from an emitCopy call in encodeBlock's main loop, would require at least
+// another inputMargin bytes, for the reason above: we want any emitLiteral
+// calls inside encodeBlock's main loop to use the fast path if possible, which
+// requires being able to overrun by inputMargin bytes. Thus,
+// minNonLiteralBlockSize equals 1 + 1 + inputMargin.
+//
+// The C++ code doesn't use this exact threshold, but it could, as discussed at
+// https://groups.google.com/d/topic/snappy-compression/oGbhsdIJSJ8/discussion
+// The difference between Go (2+inputMargin) and C++ (inputMargin) is purely an
+// optimization. It should not affect the encoded form. This is tested by
+// TestSameEncodingAsCppShortCopies.
+const minNonLiteralBlockSize = 1 + 1 + inputMargin
+
+// MaxEncodedLen returns the maximum length of a snappy block, given its
+// uncompressed length.
+//
+// It will return a negative value if srcLen is too large to encode.
+func MaxEncodedLen(srcLen int) int {
+	n := uint64(srcLen)
+	if n > 0xffffffff {
+		return -1
+	}
+	// Compressed data can be defined as:
+	//    compressed := item* literal*
+	//    item       := literal* copy
+	//
+	// The trailing literal sequence has a space blowup of at most 62/60
+	// since a literal of length 60 needs one tag byte + one extra byte
+	// for length information.
+	//
+	// Item blowup is trickier to measure. Suppose the "copy" op copies
+	// 4 bytes of data. Because of a special check in the encoding code,
+	// we produce a 4-byte copy only if the offset is < 65536. Therefore
+	// the copy op takes 3 bytes to encode, and this type of item leads
+	// to at most the 62/60 blowup for representing literals.
+	//
+	// Suppose the "copy" op copies 5 bytes of data. If the offset is big
+	// enough, it will take 5 bytes to encode the copy op. Therefore the
+	// worst case here is a one-byte literal followed by a five-byte copy.
+	// That is, 6 bytes of input turn into 7 bytes of "compressed" data.
+	//
+	// This last factor dominates the blowup, so the final estimate is:
+	n = 32 + n + n/6
+	if n > 0xffffffff {
+		return -1
+	}
+	return int(n)
+}
+
+var errClosed = errors.New("snappy: Writer is closed")
+
+// NewWriter returns a new Writer that compresses to w.
+//
+// The Writer returned does not buffer writes. There is no need to Flush or
+// Close such a Writer.
+//
+// Deprecated: the Writer returned is not suitable for many small writes, only
+// for few large writes. Use NewBufferedWriter instead, which is efficient
+// regardless of the frequency and shape of the writes, and remember to Close
+// that Writer when done.
+func NewWriter(w io.Writer) *Writer {
+	return &Writer{
+		w:    w,
+		obuf: make([]byte, obufLen),
+	}
+}
+
+// NewBufferedWriter returns a new Writer that compresses to w, using the
+// framing format described at
+// https://github.com/google/snappy/blob/master/framing_format.txt
+//
+// The Writer returned buffers writes. Users must call Close to guarantee all
+// data has been forwarded to the underlying io.Writer. They may also call
+// Flush zero or more times before calling Close.
+func NewBufferedWriter(w io.Writer) *Writer {
+	return &Writer{
+		w:    w,
+		ibuf: make([]byte, 0, maxBlockSize),
+		obuf: make([]byte, obufLen),
+	}
+}
+
+// Writer is an io.Writer that can write Snappy-compressed bytes.
+//
+// Writer handles the Snappy stream format, not the Snappy block format.
+type Writer struct {
+	w   io.Writer
+	err error
+
+	// ibuf is a buffer for the incoming (uncompressed) bytes.
+	//
+	// Its use is optional. For backwards compatibility, Writers created by the
+	// NewWriter function have ibuf == nil, do not buffer incoming bytes, and
+	// therefore do not need to be Flush'ed or Close'd.
+	ibuf []byte
+
+	// obuf is a buffer for the outgoing (compressed) bytes.
+	obuf []byte
+
+	// wroteStreamHeader is whether we have written the stream header.
+	wroteStreamHeader bool
+}
+
+// Reset discards the writer's state and switches the Snappy writer to write to
+// w. This permits reusing a Writer rather than allocating a new one.
+func (w *Writer) Reset(writer io.Writer) {
+	w.w = writer
+	w.err = nil
+	if w.ibuf != nil {
+		w.ibuf = w.ibuf[:0]
+	}
+	w.wroteStreamHeader = false
+}
+
+// Write satisfies the io.Writer interface.
+func (w *Writer) Write(p []byte) (nRet int, errRet error) {
+	if w.ibuf == nil {
+		// Do not buffer incoming bytes. This does not perform or compress well
+		// if the caller of Writer.Write writes many small slices. This
+		// behavior is therefore deprecated, but still supported for backwards
+		// compatibility with code that doesn't explicitly Flush or Close.
+		return w.write(p)
+	}
+
+	// The remainder of this method is based on bufio.Writer.Write from the
+	// standard library.
+
+	for len(p) > (cap(w.ibuf)-len(w.ibuf)) && w.err == nil {
+		var n int
+		if len(w.ibuf) == 0 {
+			// Large write, empty buffer.
+			// Write directly from p to avoid copy.
+			n, _ = w.write(p)
+		} else {
+			n = copy(w.ibuf[len(w.ibuf):cap(w.ibuf)], p)
+			w.ibuf = w.ibuf[:len(w.ibuf)+n]
+			w.Flush()
+		}
+		nRet += n
+		p = p[n:]
+	}
+	if w.err != nil {
+		return nRet, w.err
+	}
+	n := copy(w.ibuf[len(w.ibuf):cap(w.ibuf)], p)
+	w.ibuf = w.ibuf[:len(w.ibuf)+n]
+	nRet += n
+	return nRet, nil
+}
+
+func (w *Writer) write(p []byte) (nRet int, errRet error) {
+	if w.err != nil {
+		return 0, w.err
+	}
+	for len(p) > 0 {
+		obufStart := len(magicChunk)
+		if !w.wroteStreamHeader {
+			w.wroteStreamHeader = true
+			copy(w.obuf, magicChunk)
+			obufStart = 0
+		}
+
+		var uncompressed []byte
+		if len(p) > maxBlockSize {
+			uncompressed, p = p[:maxBlockSize], p[maxBlockSize:]
+		} else {
+			uncompressed, p = p, nil
+		}
+		checksum := crc(uncompressed)
+
+		// Compress the buffer, discarding the result if the improvement
+		// isn't at least 12.5%.
+		compressed := Encode(w.obuf[obufHeaderLen:], uncompressed)
+		chunkType := uint8(chunkTypeCompressedData)
+		chunkLen := 4 + len(compressed)
+		obufEnd := obufHeaderLen + len(compressed)
+		if len(compressed) >= len(uncompressed)-len(uncompressed)/8 {
+			chunkType = chunkTypeUncompressedData
+			chunkLen = 4 + len(uncompressed)
+			obufEnd = obufHeaderLen
+		}
+
+		// Fill in the per-chunk header that comes before the body.
+		w.obuf[len(magicChunk)+0] = chunkType
+		w.obuf[len(magicChunk)+1] = uint8(chunkLen >> 0)
+		w.obuf[len(magicChunk)+2] = uint8(chunkLen >> 8)
+		w.obuf[len(magicChunk)+3] = uint8(chunkLen >> 16)
+		w.obuf[len(magicChunk)+4] = uint8(checksum >> 0)
+		w.obuf[len(magicChunk)+5] = uint8(checksum >> 8)
+		w.obuf[len(magicChunk)+6] = uint8(checksum >> 16)
+		w.obuf[len(magicChunk)+7] = uint8(checksum >> 24)
+
+		if _, err := w.w.Write(w.obuf[obufStart:obufEnd]); err != nil {
+			w.err = err
+			return nRet, err
+		}
+		if chunkType == chunkTypeUncompressedData {
+			if _, err := w.w.Write(uncompressed); err != nil {
+				w.err = err
+				return nRet, err
+			}
+		}
+		nRet += len(uncompressed)
+	}
+	return nRet, nil
+}
+
+// Flush flushes the Writer to its underlying io.Writer.
+func (w *Writer) Flush() error {
+	if w.err != nil {
+		return w.err
+	}
+	if len(w.ibuf) == 0 {
+		return nil
+	}
+	w.write(w.ibuf)
+	w.ibuf = w.ibuf[:0]
+	return w.err
+}
+
+// Close calls Flush and then closes the Writer.
+func (w *Writer) Close() error {
+	w.Flush()
+	ret := w.err
+	if w.err == nil {
+		w.err = errClosed
+	}
+	return ret
+}

vendor/github.com/golang/snappy/encode_amd64.s

@@ -0,0 +1,730 @@
+// Copyright 2016 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build !appengine
+// +build gc
+// +build !noasm
+
+#include "textflag.h"
+
+// The XXX lines assemble on Go 1.4, 1.5 and 1.7, but not 1.6, due to a
+// Go toolchain regression. See https://github.com/golang/go/issues/15426 and
+// https://github.com/golang/snappy/issues/29
+//
+// As a workaround, the package was built with a known good assembler, and
+// those instructions were disassembled by "objdump -d" to yield the
+//	4e 0f b7 7c 5c 78       movzwq 0x78(%rsp,%r11,2),%r15
+// style comments, in AT&T asm syntax. Note that rsp here is a physical
+// register, not Go/asm's SP pseudo-register (see https://golang.org/doc/asm).
+// The instructions were then encoded as "BYTE $0x.." sequences, which assemble
+// fine on Go 1.6.
+
+// The asm code generally follows the pure Go code in encode_other.go, except
+// where marked with a "!!!".
+
+// ----------------------------------------------------------------------------
+
+// func emitLiteral(dst, lit []byte) int
+//
+// All local variables fit into registers. The register allocation:
+//	- AX	len(lit)
+//	- BX	n
+//	- DX	return value
+//	- DI	&dst[i]
+//	- R10	&lit[0]
+//
+// The 24 bytes of stack space is to call runtime·memmove.
+//
+// The unusual register allocation of local variables, such as R10 for the
+// source pointer, matches the allocation used at the call site in encodeBlock,
+// which makes it easier to manually inline this function.
+TEXT ·emitLiteral(SB), NOSPLIT, $24-56
+	MOVQ dst_base+0(FP), DI
+	MOVQ lit_base+24(FP), R10
+	MOVQ lit_len+32(FP), AX
+	MOVQ AX, DX
+	MOVL AX, BX
+	SUBL $1, BX
+
+	CMPL BX, $60
+	JLT  oneByte
+	CMPL BX, $256
+	JLT  twoBytes
+
+threeBytes:
+	MOVB $0xf4, 0(DI)
+	MOVW BX, 1(DI)
+	ADDQ $3, DI
+	ADDQ $3, DX
+	JMP  memmove
+
+twoBytes:
+	MOVB $0xf0, 0(DI)
+	MOVB BX, 1(DI)
+	ADDQ $2, DI
+	ADDQ $2, DX
+	JMP  memmove
+
+oneByte:
+	SHLB $2, BX
+	MOVB BX, 0(DI)
+	ADDQ $1, DI
+	ADDQ $1, DX
+
+memmove:
+	MOVQ DX, ret+48(FP)
+
+	// copy(dst[i:], lit)
+	//
+	// This means calling runtime·memmove(&dst[i], &lit[0], len(lit)), so we push
+	// DI, R10 and AX as arguments.
+	MOVQ DI, 0(SP)
+	MOVQ R10, 8(SP)
+	MOVQ AX, 16(SP)
+	CALL runtime·memmove(SB)
+	RET
+
+// ----------------------------------------------------------------------------
+
+// func emitCopy(dst []byte, offset, length int) int
+//
+// All local variables fit into registers. The register allocation:
+//	- AX	length
+//	- SI	&dst[0]
+//	- DI	&dst[i]
+//	- R11	offset
+//
+// The unusual register allocation of local variables, such as R11 for the
+// offset, matches the allocation used at the call site in encodeBlock, which
+// makes it easier to manually inline this function.
+TEXT ·emitCopy(SB), NOSPLIT, $0-48
+	MOVQ dst_base+0(FP), DI
+	MOVQ DI, SI
+	MOVQ offset+24(FP), R11
+	MOVQ length+32(FP), AX
+
+loop0:
+	// for length >= 68 { etc }
+	CMPL AX, $68
+	JLT  step1
+
+	// Emit a length 64 copy, encoded as 3 bytes.
+	MOVB $0xfe, 0(DI)
+	MOVW R11, 1(DI)
+	ADDQ $3, DI
+	SUBL $64, AX
+	JMP  loop0
+
+step1:
+	// if length > 64 { etc }
+	CMPL AX, $64
+	JLE  step2
+
+	// Emit a length 60 copy, encoded as 3 bytes.
+	MOVB $0xee, 0(DI)
+	MOVW R11, 1(DI)
+	ADDQ $3, DI
+	SUBL $60, AX
+
+step2:
+	// if length >= 12 || offset >= 2048 { goto step3 }
+	CMPL AX, $12
+	JGE  step3
+	CMPL R11, $2048
+	JGE  step3
+
+	// Emit the remaining copy, encoded as 2 bytes.
+	MOVB R11, 1(DI)
+	SHRL $8, R11
+	SHLB $5, R11
+	SUBB $4, AX
+	SHLB $2, AX
+	ORB  AX, R11
+	ORB  $1, R11
+	MOVB R11, 0(DI)
+	ADDQ $2, DI
+
+	// Return the number of bytes written.
+	SUBQ SI, DI
+	MOVQ DI, ret+40(FP)
+	RET
+
+step3:
+	// Emit the remaining copy, encoded as 3 bytes.
+	SUBL $1, AX
+	SHLB $2, AX
+	ORB  $2, AX
+	MOVB AX, 0(DI)
+	MOVW R11, 1(DI)
+	ADDQ $3, DI
+
+	// Return the number of bytes written.
+	SUBQ SI, DI
+	MOVQ DI, ret+40(FP)
+	RET
+
+// ----------------------------------------------------------------------------
+
+// func extendMatch(src []byte, i, j int) int
+//
+// All local variables fit into registers. The register allocation:
+//	- DX	&src[0]
+//	- SI	&src[j]
+//	- R13	&src[len(src) - 8]
+//	- R14	&src[len(src)]
+//	- R15	&src[i]
+//
+// The unusual register allocation of local variables, such as R15 for a source
+// pointer, matches the allocation used at the call site in encodeBlock, which
+// makes it easier to manually inline this function.
+TEXT ·extendMatch(SB), NOSPLIT, $0-48
+	MOVQ src_base+0(FP), DX
+	MOVQ src_len+8(FP), R14
+	MOVQ i+24(FP), R15
+	MOVQ j+32(FP), SI
+	ADDQ DX, R14
+	ADDQ DX, R15
+	ADDQ DX, SI
+	MOVQ R14, R13
+	SUBQ $8, R13
+
+cmp8:
+	// As long as we are 8 or more bytes before the end of src, we can load and
+	// compare 8 bytes at a time. If those 8 bytes are equal, repeat.
+	CMPQ SI, R13
+	JA   cmp1
+	MOVQ (R15), AX
+	MOVQ (SI), BX
+	CMPQ AX, BX
+	JNE  bsf
+	ADDQ $8, R15
+	ADDQ $8, SI
+	JMP  cmp8
+
+bsf:
+	// If those 8 bytes were not equal, XOR the two 8 byte values, and return
+	// the index of the first byte that differs. The BSF instruction finds the
+	// least significant 1 bit, the amd64 architecture is little-endian, and
+	// the shift by 3 converts a bit index to a byte index.
+	XORQ AX, BX
+	BSFQ BX, BX
+	SHRQ $3, BX
+	ADDQ BX, SI
+
+	// Convert from &src[ret] to ret.
+	SUBQ DX, SI
+	MOVQ SI, ret+40(FP)
+	RET
+
+cmp1:
+	// In src's tail, compare 1 byte at a time.
+	CMPQ SI, R14
+	JAE  extendMatchEnd
+	MOVB (R15), AX
+	MOVB (SI), BX
+	CMPB AX, BX
+	JNE  extendMatchEnd
+	ADDQ $1, R15
+	ADDQ $1, SI
+	JMP  cmp1
+
+extendMatchEnd:
+	// Convert from &src[ret] to ret.
+	SUBQ DX, SI
+	MOVQ SI, ret+40(FP)
+	RET
+
+// ----------------------------------------------------------------------------
+
+// func encodeBlock(dst, src []byte) (d int)
+//
+// All local variables fit into registers, other than "var table". The register
+// allocation:
+//	- AX	.	.
+//	- BX	.	.
+//	- CX	56	shift (note that amd64 shifts by non-immediates must use CX).
+//	- DX	64	&src[0], tableSize
+//	- SI	72	&src[s]
+//	- DI	80	&dst[d]
+//	- R9	88	sLimit
+//	- R10	.	&src[nextEmit]
+//	- R11	96	prevHash, currHash, nextHash, offset
+//	- R12	104	&src[base], skip
+//	- R13	.	&src[nextS], &src[len(src) - 8]
+//	- R14	.	len(src), bytesBetweenHashLookups, &src[len(src)], x
+//	- R15	112	candidate
+//
+// The second column (56, 64, etc) is the stack offset to spill the registers
+// when calling other functions. We could pack this slightly tighter, but it's
+// simpler to have a dedicated spill map independent of the function called.
+//
+// "var table [maxTableSize]uint16" takes up 32768 bytes of stack space. An
+// extra 56 bytes, to call other functions, and an extra 64 bytes, to spill
+// local variables (registers) during calls gives 32768 + 56 + 64 = 32888.
+TEXT ·encodeBlock(SB), 0, $32888-56
+	MOVQ dst_base+0(FP), DI
+	MOVQ src_base+24(FP), SI
+	MOVQ src_len+32(FP), R14
+
+	// shift, tableSize := uint32(32-8), 1<<8
+	MOVQ $24, CX
+	MOVQ $256, DX
+
+calcShift:
+	// for ; tableSize < maxTableSize && tableSize < len(src); tableSize *= 2 {
+	//	shift--
+	// }
+	CMPQ DX, $16384
+	JGE  varTable
+	CMPQ DX, R14
+	JGE  varTable
+	SUBQ $1, CX
+	SHLQ $1, DX
+	JMP  calcShift
+
+varTable:
+	// var table [maxTableSize]uint16
+	//
+	// In the asm code, unlike the Go code, we can zero-initialize only the
+	// first tableSize elements. Each uint16 element is 2 bytes and each MOVOU
+	// writes 16 bytes, so we can do only tableSize/8 writes instead of the
+	// 2048 writes that would zero-initialize all of table's 32768 bytes.
+	SHRQ $3, DX
+	LEAQ table-32768(SP), BX
+	PXOR X0, X0
+
+memclr:
+	MOVOU X0, 0(BX)
+	ADDQ  $16, BX
+	SUBQ  $1, DX
+	JNZ   memclr
+
+	// !!! DX = &src[0]
+	MOVQ SI, DX
+
+	// sLimit := len(src) - inputMargin
+	MOVQ R14, R9
+	SUBQ $15, R9
+
+	// !!! Pre-emptively spill CX, DX and R9 to the stack. Their values don't
+	// change for the rest of the function.
+	MOVQ CX, 56(SP)
+	MOVQ DX, 64(SP)
+	MOVQ R9, 88(SP)
+
+	// nextEmit := 0
+	MOVQ DX, R10
+
+	// s := 1
+	ADDQ $1, SI
+
+	// nextHash := hash(load32(src, s), shift)
+	MOVL  0(SI), R11
+	IMULL $0x1e35a7bd, R11
+	SHRL  CX, R11
+
+outer:
+	// for { etc }
+
+	// skip := 32
+	MOVQ $32, R12
+
+	// nextS := s
+	MOVQ SI, R13
+
+	// candidate := 0
+	MOVQ $0, R15
+
+inner0:
+	// for { etc }
+
+	// s := nextS
+	MOVQ R13, SI
+
+	// bytesBetweenHashLookups := skip >> 5
+	MOVQ R12, R14
+	SHRQ $5, R14
+
+	// nextS = s + bytesBetweenHashLookups
+	ADDQ R14, R13
+
+	// skip += bytesBetweenHashLookups
+	ADDQ R14, R12
+
+	// if nextS > sLimit { goto emitRemainder }
+	MOVQ R13, AX
+	SUBQ DX, AX
+	CMPQ AX, R9
+	JA   emitRemainder
+
+	// candidate = int(table[nextHash])
+	// XXX: MOVWQZX table-32768(SP)(R11*2), R15
+	// XXX: 4e 0f b7 7c 5c 78       movzwq 0x78(%rsp,%r11,2),%r15
+	BYTE $0x4e
+	BYTE $0x0f
+	BYTE $0xb7
+	BYTE $0x7c
+	BYTE $0x5c
+	BYTE $0x78
+
+	// table[nextHash] = uint16(s)
+	MOVQ SI, AX
+	SUBQ DX, AX
+
+	// XXX: MOVW AX, table-32768(SP)(R11*2)
+	// XXX: 66 42 89 44 5c 78       mov    %ax,0x78(%rsp,%r11,2)
+	BYTE $0x66
+	BYTE $0x42
+	BYTE $0x89
+	BYTE $0x44
+	BYTE $0x5c
+	BYTE $0x78
+
+	// nextHash = hash(load32(src, nextS), shift)
+	MOVL  0(R13), R11
+	IMULL $0x1e35a7bd, R11
+	SHRL  CX, R11
+
+	// if load32(src, s) != load32(src, candidate) { continue } break
+	MOVL 0(SI), AX
+	MOVL (DX)(R15*1), BX
+	CMPL AX, BX
+	JNE  inner0
+
+fourByteMatch:
+	// As per the encode_other.go code:
+	//
+	// A 4-byte match has been found. We'll later see etc.
+
+	// !!! Jump to a fast path for short (<= 16 byte) literals. See the comment
+	// on inputMargin in encode.go.
+	MOVQ SI, AX
+	SUBQ R10, AX
+	CMPQ AX, $16
+	JLE  emitLiteralFastPath
+
+	// ----------------------------------------
+	// Begin inline of the emitLiteral call.
+	//
+	// d += emitLiteral(dst[d:], src[nextEmit:s])
+
+	MOVL AX, BX
+	SUBL $1, BX
+
+	CMPL BX, $60
+	JLT  inlineEmitLiteralOneByte
+	CMPL BX, $256
+	JLT  inlineEmitLiteralTwoBytes
+
+inlineEmitLiteralThreeBytes:
+	MOVB $0xf4, 0(DI)
+	MOVW BX, 1(DI)
+	ADDQ $3, DI
+	JMP  inlineEmitLiteralMemmove
+
+inlineEmitLiteralTwoBytes:
+	MOVB $0xf0, 0(DI)
+	MOVB BX, 1(DI)
+	ADDQ $2, DI
+	JMP  inlineEmitLiteralMemmove
+
+inlineEmitLiteralOneByte:
+	SHLB $2, BX
+	MOVB BX, 0(DI)
+	ADDQ $1, DI
+
+inlineEmitLiteralMemmove:
+	// Spill local variables (registers) onto the stack; call; unspill.
+	//
+	// copy(dst[i:], lit)
+	//
+	// This means calling runtime·memmove(&dst[i], &lit[0], len(lit)), so we push
+	// DI, R10 and AX as arguments.
+	MOVQ DI, 0(SP)
+	MOVQ R10, 8(SP)
+	MOVQ AX, 16(SP)
+	ADDQ AX, DI              // Finish the "d +=" part of "d += emitLiteral(etc)".
+	MOVQ SI, 72(SP)
+	MOVQ DI, 80(SP)
+	MOVQ R15, 112(SP)
+	CALL runtime·memmove(SB)
+	MOVQ 56(SP), CX
+	MOVQ 64(SP), DX
+	MOVQ 72(SP), SI
+	MOVQ 80(SP), DI
+	MOVQ 88(SP), R9
+	MOVQ 112(SP), R15
+	JMP  inner1
+
+inlineEmitLiteralEnd:
+	// End inline of the emitLiteral call.
+	// ----------------------------------------
+
+emitLiteralFastPath:
+	// !!! Emit the 1-byte encoding "uint8(len(lit)-1)<<2".
+	MOVB AX, BX
+	SUBB $1, BX
+	SHLB $2, BX
+	MOVB BX, (DI)
+	ADDQ $1, DI
+
+	// !!! Implement the copy from lit to dst as a 16-byte load and store.
+	// (Encode's documentation says that dst and src must not overlap.)
+	//
+	// This always copies 16 bytes, instead of only len(lit) bytes, but that's
+	// OK. Subsequent iterations will fix up the overrun.
+	//
+	// Note that on amd64, it is legal and cheap to issue unaligned 8-byte or
+	// 16-byte loads and stores. This technique probably wouldn't be as
+	// effective on architectures that are fussier about alignment.
+	MOVOU 0(R10), X0
+	MOVOU X0, 0(DI)
+	ADDQ  AX, DI
+
+inner1:
+	// for { etc }
+
+	// base := s
+	MOVQ SI, R12
+
+	// !!! offset := base - candidate
+	MOVQ R12, R11
+	SUBQ R15, R11
+	SUBQ DX, R11
+
+	// ----------------------------------------
+	// Begin inline of the extendMatch call.
+	//
+	// s = extendMatch(src, candidate+4, s+4)
+
+	// !!! R14 = &src[len(src)]
+	MOVQ src_len+32(FP), R14
+	ADDQ DX, R14
+
+	// !!! R13 = &src[len(src) - 8]
+	MOVQ R14, R13
+	SUBQ $8, R13
+
+	// !!! R15 = &src[candidate + 4]
+	ADDQ $4, R15
+	ADDQ DX, R15
+
+	// !!! s += 4
+	ADDQ $4, SI
+
+inlineExtendMatchCmp8:
+	// As long as we are 8 or more bytes before the end of src, we can load and
+	// compare 8 bytes at a time. If those 8 bytes are equal, repeat.
+	CMPQ SI, R13
+	JA   inlineExtendMatchCmp1
+	MOVQ (R15), AX
+	MOVQ (SI), BX
+	CMPQ AX, BX
+	JNE  inlineExtendMatchBSF
+	ADDQ $8, R15
+	ADDQ $8, SI
+	JMP  inlineExtendMatchCmp8
+
+inlineExtendMatchBSF:
+	// If those 8 bytes were not equal, XOR the two 8 byte values, and return
+	// the index of the first byte that differs. The BSF instruction finds the
+	// least significant 1 bit, the amd64 architecture is little-endian, and
+	// the shift by 3 converts a bit index to a byte index.
+	XORQ AX, BX
+	BSFQ BX, BX
+	SHRQ $3, BX
+	ADDQ BX, SI
+	JMP  inlineExtendMatchEnd
+
+inlineExtendMatchCmp1:
+	// In src's tail, compare 1 byte at a time.
+	CMPQ SI, R14
+	JAE  inlineExtendMatchEnd
+	MOVB (R15), AX
+	MOVB (SI), BX
+	CMPB AX, BX
+	JNE  inlineExtendMatchEnd
+	ADDQ $1, R15
+	ADDQ $1, SI
+	JMP  inlineExtendMatchCmp1
+
+inlineExtendMatchEnd:
+	// End inline of the extendMatch call.
+	// ----------------------------------------
+
+	// ----------------------------------------
+	// Begin inline of the emitCopy call.
+	//
+	// d += emitCopy(dst[d:], base-candidate, s-base)
+
+	// !!! length := s - base
+	MOVQ SI, AX
+	SUBQ R12, AX
+
+inlineEmitCopyLoop0:
+	// for length >= 68 { etc }
+	CMPL AX, $68
+	JLT  inlineEmitCopyStep1
+
+	// Emit a length 64 copy, encoded as 3 bytes.
+	MOVB $0xfe, 0(DI)
+	MOVW R11, 1(DI)
+	ADDQ $3, DI
+	SUBL $64, AX
+	JMP  inlineEmitCopyLoop0
+
+inlineEmitCopyStep1:
+	// if length > 64 { etc }
+	CMPL AX, $64
+	JLE  inlineEmitCopyStep2
+
+	// Emit a length 60 copy, encoded as 3 bytes.
+	MOVB $0xee, 0(DI)
+	MOVW R11, 1(DI)
+	ADDQ $3, DI
+	SUBL $60, AX
+
+inlineEmitCopyStep2:
+	// if length >= 12 || offset >= 2048 { goto inlineEmitCopyStep3 }
+	CMPL AX, $12
+	JGE  inlineEmitCopyStep3
+	CMPL R11, $2048
+	JGE  inlineEmitCopyStep3
+
+	// Emit the remaining copy, encoded as 2 bytes.
+	MOVB R11, 1(DI)
+	SHRL $8, R11
+	SHLB $5, R11
+	SUBB $4, AX
+	SHLB $2, AX
+	ORB  AX, R11
+	ORB  $1, R11
+	MOVB R11, 0(DI)
+	ADDQ $2, DI
+	JMP  inlineEmitCopyEnd
+
+inlineEmitCopyStep3:
+	// Emit the remaining copy, encoded as 3 bytes.
+	SUBL $1, AX
+	SHLB $2, AX
+	ORB  $2, AX
+	MOVB AX, 0(DI)
+	MOVW R11, 1(DI)
+	ADDQ $3, DI
+
+inlineEmitCopyEnd:
+	// End inline of the emitCopy call.
+	// ----------------------------------------
+
+	// nextEmit = s
+	MOVQ SI, R10
+
+	// if s >= sLimit { goto emitRemainder }
+	MOVQ SI, AX
+	SUBQ DX, AX
+	CMPQ AX, R9
+	JAE  emitRemainder
+
+	// As per the encode_other.go code:
+	//
+	// We could immediately etc.
+
+	// x := load64(src, s-1)
+	MOVQ -1(SI), R14
+
+	// prevHash := hash(uint32(x>>0), shift)
+	MOVL  R14, R11
+	IMULL $0x1e35a7bd, R11
+	SHRL  CX, R11
+
+	// table[prevHash] = uint16(s-1)
+	MOVQ SI, AX
+	SUBQ DX, AX
+	SUBQ $1, AX
+
+	// XXX: MOVW AX, table-32768(SP)(R11*2)
+	// XXX: 66 42 89 44 5c 78       mov    %ax,0x78(%rsp,%r11,2)
+	BYTE $0x66
+	BYTE $0x42
+	BYTE $0x89
+	BYTE $0x44
+	BYTE $0x5c
+	BYTE $0x78
+
+	// currHash := hash(uint32(x>>8), shift)
+	SHRQ  $8, R14
+	MOVL  R14, R11
+	IMULL $0x1e35a7bd, R11
+	SHRL  CX, R11
+
+	// candidate = int(table[currHash])
+	// XXX: MOVWQZX table-32768(SP)(R11*2), R15
+	// XXX: 4e 0f b7 7c 5c 78       movzwq 0x78(%rsp,%r11,2),%r15
+	BYTE $0x4e
+	BYTE $0x0f
+	BYTE $0xb7
+	BYTE $0x7c
+	BYTE $0x5c
+	BYTE $0x78
+
+	// table[currHash] = uint16(s)
+	ADDQ $1, AX
+
+	// XXX: MOVW AX, table-32768(SP)(R11*2)
+	// XXX: 66 42 89 44 5c 78       mov    %ax,0x78(%rsp,%r11,2)
+	BYTE $0x66
+	BYTE $0x42
+	BYTE $0x89
+	BYTE $0x44
+	BYTE $0x5c
+	BYTE $0x78
+
+	// if uint32(x>>8) == load32(src, candidate) { continue }
+	MOVL (DX)(R15*1), BX
+	CMPL R14, BX
+	JEQ  inner1
+
+	// nextHash = hash(uint32(x>>16), shift)
+	SHRQ  $8, R14
+	MOVL  R14, R11
+	IMULL $0x1e35a7bd, R11
+	SHRL  CX, R11
+
+	// s++
+	ADDQ $1, SI
+
+	// break out of the inner1 for loop, i.e. continue the outer loop.
+	JMP outer
+
+emitRemainder:
+	// if nextEmit < len(src) { etc }
+	MOVQ src_len+32(FP), AX
+	ADDQ DX, AX
+	CMPQ R10, AX
+	JEQ  encodeBlockEnd
+
+	// d += emitLiteral(dst[d:], src[nextEmit:])
+	//
+	// Push args.
+	MOVQ DI, 0(SP)
+	MOVQ $0, 8(SP)   // Unnecessary, as the callee ignores it, but conservative.
+	MOVQ $0, 16(SP)  // Unnecessary, as the callee ignores it, but conservative.
+	MOVQ R10, 24(SP)
+	SUBQ R10, AX
+	MOVQ AX, 32(SP)
+	MOVQ AX, 40(SP)  // Unnecessary, as the callee ignores it, but conservative.
+
+	// Spill local variables (registers) onto the stack; call; unspill.
+	MOVQ DI, 80(SP)
+	CALL ·emitLiteral(SB)
+	MOVQ 80(SP), DI
+
+	// Finish the "d +=" part of "d += emitLiteral(etc)".
+	ADDQ 48(SP), DI
+
+encodeBlockEnd:
+	MOVQ dst_base+0(FP), AX
+	SUBQ AX, DI
+	MOVQ DI, d+48(FP)
+	RET

vendor/github.com/golang/snappy/encode_arm64.s

@@ -0,0 +1,722 @@
+// Copyright 2020 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build !appengine
+// +build gc
+// +build !noasm
+
+#include "textflag.h"
+
+// The asm code generally follows the pure Go code in encode_other.go, except
+// where marked with a "!!!".
+
+// ----------------------------------------------------------------------------
+
+// func emitLiteral(dst, lit []byte) int
+//
+// All local variables fit into registers. The register allocation:
+//	- R3	len(lit)
+//	- R4	n
+//	- R6	return value
+//	- R8	&dst[i]
+//	- R10	&lit[0]
+//
+// The 32 bytes of stack space is to call runtime·memmove.
+//
+// The unusual register allocation of local variables, such as R10 for the
+// source pointer, matches the allocation used at the call site in encodeBlock,
+// which makes it easier to manually inline this function.
+TEXT ·emitLiteral(SB), NOSPLIT, $32-56
+	MOVD dst_base+0(FP), R8
+	MOVD lit_base+24(FP), R10
+	MOVD lit_len+32(FP), R3
+	MOVD R3, R6
+	MOVW R3, R4
+	SUBW $1, R4, R4
+
+	CMPW $60, R4
+	BLT  oneByte
+	CMPW $256, R4
+	BLT  twoBytes
+
+threeBytes:
+	MOVD $0xf4, R2
+	MOVB R2, 0(R8)
+	MOVW R4, 1(R8)
+	ADD  $3, R8, R8
+	ADD  $3, R6, R6
+	B    memmove
+
+twoBytes:
+	MOVD $0xf0, R2
+	MOVB R2, 0(R8)
+	MOVB R4, 1(R8)
+	ADD  $2, R8, R8
+	ADD  $2, R6, R6
+	B    memmove
+
+oneByte:
+	LSLW $2, R4, R4
+	MOVB R4, 0(R8)
+	ADD  $1, R8, R8
+	ADD  $1, R6, R6
+
+memmove:
+	MOVD R6, ret+48(FP)
+
+	// copy(dst[i:], lit)
+	//
+	// This means calling runtime·memmove(&dst[i], &lit[0], len(lit)), so we push
+	// R8, R10 and R3 as arguments.
+	MOVD R8, 8(RSP)
+	MOVD R10, 16(RSP)
+	MOVD R3, 24(RSP)
+	CALL runtime·memmove(SB)
+	RET
+
+// ----------------------------------------------------------------------------
+
+// func emitCopy(dst []byte, offset, length int) int
+//
+// All local variables fit into registers. The register allocation:
+//	- R3	length
+//	- R7	&dst[0]
+//	- R8	&dst[i]
+//	- R11	offset
+//
+// The unusual register allocation of local variables, such as R11 for the
+// offset, matches the allocation used at the call site in encodeBlock, which
+// makes it easier to manually inline this function.
+TEXT ·emitCopy(SB), NOSPLIT, $0-48
+	MOVD dst_base+0(FP), R8
+	MOVD R8, R7
+	MOVD offset+24(FP), R11
+	MOVD length+32(FP), R3
+
+loop0:
+	// for length >= 68 { etc }
+	CMPW $68, R3
+	BLT  step1
+
+	// Emit a length 64 copy, encoded as 3 bytes.
+	MOVD $0xfe, R2
+	MOVB R2, 0(R8)
+	MOVW R11, 1(R8)
+	ADD  $3, R8, R8
+	SUB  $64, R3, R3
+	B    loop0
+
+step1:
+	// if length > 64 { etc }
+	CMP $64, R3
+	BLE step2
+
+	// Emit a length 60 copy, encoded as 3 bytes.
+	MOVD $0xee, R2
+	MOVB R2, 0(R8)
+	MOVW R11, 1(R8)
+	ADD  $3, R8, R8
+	SUB  $60, R3, R3
+
+step2:
+	// if length >= 12 || offset >= 2048 { goto step3 }
+	CMP  $12, R3
+	BGE  step3
+	CMPW $2048, R11
+	BGE  step3
+
+	// Emit the remaining copy, encoded as 2 bytes.
+	MOVB R11, 1(R8)
+	LSRW $3, R11, R11
+	AND  $0xe0, R11, R11
+	SUB  $4, R3, R3
+	LSLW $2, R3
+	AND  $0xff, R3, R3
+	ORRW R3, R11, R11
+	ORRW $1, R11, R11
+	MOVB R11, 0(R8)
+	ADD  $2, R8, R8
+
+	// Return the number of bytes written.
+	SUB  R7, R8, R8
+	MOVD R8, ret+40(FP)
+	RET
+
+step3:
+	// Emit the remaining copy, encoded as 3 bytes.
+	SUB  $1, R3, R3
+	AND  $0xff, R3, R3
+	LSLW $2, R3, R3
+	ORRW $2, R3, R3
+	MOVB R3, 0(R8)
+	MOVW R11, 1(R8)
+	ADD  $3, R8, R8
+
+	// Return the number of bytes written.
+	SUB  R7, R8, R8
+	MOVD R8, ret+40(FP)
+	RET
+
+// ----------------------------------------------------------------------------
+
+// func extendMatch(src []byte, i, j int) int
+//
+// All local variables fit into registers. The register allocation:
+//	- R6	&src[0]
+//	- R7	&src[j]
+//	- R13	&src[len(src) - 8]
+//	- R14	&src[len(src)]
+//	- R15	&src[i]
+//
+// The unusual register allocation of local variables, such as R15 for a source
+// pointer, matches the allocation used at the call site in encodeBlock, which
+// makes it easier to manually inline this function.
+TEXT ·extendMatch(SB), NOSPLIT, $0-48
+	MOVD src_base+0(FP), R6
+	MOVD src_len+8(FP), R14
+	MOVD i+24(FP), R15
+	MOVD j+32(FP), R7
+	ADD  R6, R14, R14
+	ADD  R6, R15, R15
+	ADD  R6, R7, R7
+	MOVD R14, R13
+	SUB  $8, R13, R13
+
+cmp8:
+	// As long as we are 8 or more bytes before the end of src, we can load and
+	// compare 8 bytes at a time. If those 8 bytes are equal, repeat.
+	CMP  R13, R7
+	BHI  cmp1
+	MOVD (R15), R3
+	MOVD (R7), R4
+	CMP  R4, R3
+	BNE  bsf
+	ADD  $8, R15, R15
+	ADD  $8, R7, R7
+	B    cmp8
+
+bsf:
+	// If those 8 bytes were not equal, XOR the two 8 byte values, and return
+	// the index of the first byte that differs.
+	// RBIT reverses the bit order, then CLZ counts the leading zeros, the
+	// combination of which finds the least significant bit which is set.
+	// The arm64 architecture is little-endian, and the shift by 3 converts
+	// a bit index to a byte index.
+	EOR  R3, R4, R4
+	RBIT R4, R4
+	CLZ  R4, R4
+	ADD  R4>>3, R7, R7
+
+	// Convert from &src[ret] to ret.
+	SUB  R6, R7, R7
+	MOVD R7, ret+40(FP)
+	RET
+
+cmp1:
+	// In src's tail, compare 1 byte at a time.
+	CMP  R7, R14
+	BLS  extendMatchEnd
+	MOVB (R15), R3
+	MOVB (R7), R4
+	CMP  R4, R3
+	BNE  extendMatchEnd
+	ADD  $1, R15, R15
+	ADD  $1, R7, R7
+	B    cmp1
+
+extendMatchEnd:
+	// Convert from &src[ret] to ret.
+	SUB  R6, R7, R7
+	MOVD R7, ret+40(FP)
+	RET
+
+// ----------------------------------------------------------------------------
+
+// func encodeBlock(dst, src []byte) (d int)
+//
+// All local variables fit into registers, other than "var table". The register
+// allocation:
+//	- R3	.	.
+//	- R4	.	.
+//	- R5	64	shift
+//	- R6	72	&src[0], tableSize
+//	- R7	80	&src[s]
+//	- R8	88	&dst[d]
+//	- R9	96	sLimit
+//	- R10	.	&src[nextEmit]
+//	- R11	104	prevHash, currHash, nextHash, offset
+//	- R12	112	&src[base], skip
+//	- R13	.	&src[nextS], &src[len(src) - 8]
+//	- R14	.	len(src), bytesBetweenHashLookups, &src[len(src)], x
+//	- R15	120	candidate
+//	- R16	.	hash constant, 0x1e35a7bd
+//	- R17	.	&table
+//	- .  	128	table
+//
+// The second column (64, 72, etc) is the stack offset to spill the registers
+// when calling other functions. We could pack this slightly tighter, but it's
+// simpler to have a dedicated spill map independent of the function called.
+//
+// "var table [maxTableSize]uint16" takes up 32768 bytes of stack space. An
+// extra 64 bytes, to call other functions, and an extra 64 bytes, to spill
+// local variables (registers) during calls gives 32768 + 64 + 64 = 32896.
+TEXT ·encodeBlock(SB), 0, $32896-56
+	MOVD dst_base+0(FP), R8
+	MOVD src_base+24(FP), R7
+	MOVD src_len+32(FP), R14
+
+	// shift, tableSize := uint32(32-8), 1<<8
+	MOVD  $24, R5
+	MOVD  $256, R6
+	MOVW  $0xa7bd, R16
+	MOVKW $(0x1e35<<16), R16
+
+calcShift:
+	// for ; tableSize < maxTableSize && tableSize < len(src); tableSize *= 2 {
+	//	shift--
+	// }
+	MOVD $16384, R2
+	CMP  R2, R6
+	BGE  varTable
+	CMP  R14, R6
+	BGE  varTable
+	SUB  $1, R5, R5
+	LSL  $1, R6, R6
+	B    calcShift
+
+varTable:
+	// var table [maxTableSize]uint16
+	//
+	// In the asm code, unlike the Go code, we can zero-initialize only the
+	// first tableSize elements. Each uint16 element is 2 bytes and each
+	// iterations writes 64 bytes, so we can do only tableSize/32 writes
+	// instead of the 2048 writes that would zero-initialize all of table's
+	// 32768 bytes. This clear could overrun the first tableSize elements, but
+	// it won't overrun the allocated stack size.
+	ADD  $128, RSP, R17
+	MOVD R17, R4
+
+	// !!! R6 = &src[tableSize]
+	ADD R6<<1, R17, R6
+
+memclr:
+	STP.P (ZR, ZR), 64(R4)
+	STP   (ZR, ZR), -48(R4)
+	STP   (ZR, ZR), -32(R4)
+	STP   (ZR, ZR), -16(R4)
+	CMP   R4, R6
+	BHI   memclr
+
+	// !!! R6 = &src[0]
+	MOVD R7, R6
+
+	// sLimit := len(src) - inputMargin
+	MOVD R14, R9
+	SUB  $15, R9, R9
+
+	// !!! Pre-emptively spill R5, R6 and R9 to the stack. Their values don't
+	// change for the rest of the function.
+	MOVD R5, 64(RSP)
+	MOVD R6, 72(RSP)
+	MOVD R9, 96(RSP)
+
+	// nextEmit := 0
+	MOVD R6, R10
+
+	// s := 1
+	ADD $1, R7, R7
+
+	// nextHash := hash(load32(src, s), shift)
+	MOVW 0(R7), R11
+	MULW R16, R11, R11
+	LSRW R5, R11, R11
+
+outer:
+	// for { etc }
+
+	// skip := 32
+	MOVD $32, R12
+
+	// nextS := s
+	MOVD R7, R13
+
+	// candidate := 0
+	MOVD $0, R15
+
+inner0:
+	// for { etc }
+
+	// s := nextS
+	MOVD R13, R7
+
+	// bytesBetweenHashLookups := skip >> 5
+	MOVD R12, R14
+	LSR  $5, R14, R14
+
+	// nextS = s + bytesBetweenHashLookups
+	ADD R14, R13, R13
+
+	// skip += bytesBetweenHashLookups
+	ADD R14, R12, R12
+
+	// if nextS > sLimit { goto emitRemainder }
+	MOVD R13, R3
+	SUB  R6, R3, R3
+	CMP  R9, R3
+	BHI  emitRemainder
+
+	// candidate = int(table[nextHash])
+	MOVHU 0(R17)(R11<<1), R15
+
+	// table[nextHash] = uint16(s)
+	MOVD R7, R3
+	SUB  R6, R3, R3
+
+	MOVH R3, 0(R17)(R11<<1)
+
+	// nextHash = hash(load32(src, nextS), shift)
+	MOVW 0(R13), R11
+	MULW R16, R11
+	LSRW R5, R11, R11
+
+	// if load32(src, s) != load32(src, candidate) { continue } break
+	MOVW 0(R7), R3
+	MOVW (R6)(R15), R4
+	CMPW R4, R3
+	BNE  inner0
+
+fourByteMatch:
+	// As per the encode_other.go code:
+	//
+	// A 4-byte match has been found. We'll later see etc.
+
+	// !!! Jump to a fast path for short (<= 16 byte) literals. See the comment
+	// on inputMargin in encode.go.
+	MOVD R7, R3
+	SUB  R10, R3, R3
+	CMP  $16, R3
+	BLE  emitLiteralFastPath
+
+	// ----------------------------------------
+	// Begin inline of the emitLiteral call.
+	//
+	// d += emitLiteral(dst[d:], src[nextEmit:s])
+
+	MOVW R3, R4
+	SUBW $1, R4, R4
+
+	MOVW $60, R2
+	CMPW R2, R4
+	BLT  inlineEmitLiteralOneByte
+	MOVW $256, R2
+	CMPW R2, R4
+	BLT  inlineEmitLiteralTwoBytes
+
+inlineEmitLiteralThreeBytes:
+	MOVD $0xf4, R1
+	MOVB R1, 0(R8)
+	MOVW R4, 1(R8)
+	ADD  $3, R8, R8
+	B    inlineEmitLiteralMemmove
+
+inlineEmitLiteralTwoBytes:
+	MOVD $0xf0, R1
+	MOVB R1, 0(R8)
+	MOVB R4, 1(R8)
+	ADD  $2, R8, R8
+	B    inlineEmitLiteralMemmove
+
+inlineEmitLiteralOneByte:
+	LSLW $2, R4, R4
+	MOVB R4, 0(R8)
+	ADD  $1, R8, R8
+
+inlineEmitLiteralMemmove:
+	// Spill local variables (registers) onto the stack; call; unspill.
+	//
+	// copy(dst[i:], lit)
+	//
+	// This means calling runtime·memmove(&dst[i], &lit[0], len(lit)), so we push
+	// R8, R10 and R3 as arguments.
+	MOVD R8, 8(RSP)
+	MOVD R10, 16(RSP)
+	MOVD R3, 24(RSP)
+
+	// Finish the "d +=" part of "d += emitLiteral(etc)".
+	ADD   R3, R8, R8
+	MOVD  R7, 80(RSP)
+	MOVD  R8, 88(RSP)
+	MOVD  R15, 120(RSP)
+	CALL  runtime·memmove(SB)
+	MOVD  64(RSP), R5
+	MOVD  72(RSP), R6
+	MOVD  80(RSP), R7
+	MOVD  88(RSP), R8
+	MOVD  96(RSP), R9
+	MOVD  120(RSP), R15
+	ADD   $128, RSP, R17
+	MOVW  $0xa7bd, R16
+	MOVKW $(0x1e35<<16), R16
+	B     inner1
+
+inlineEmitLiteralEnd:
+	// End inline of the emitLiteral call.
+	// ----------------------------------------
+
+emitLiteralFastPath:
+	// !!! Emit the 1-byte encoding "uint8(len(lit)-1)<<2".
+	MOVB R3, R4
+	SUBW $1, R4, R4
+	AND  $0xff, R4, R4
+	LSLW $2, R4, R4
+	MOVB R4, (R8)
+	ADD  $1, R8, R8
+
+	// !!! Implement the copy from lit to dst as a 16-byte load and store.
+	// (Encode's documentation says that dst and src must not overlap.)
+	//
+	// This always copies 16 bytes, instead of only len(lit) bytes, but that's
+	// OK. Subsequent iterations will fix up the overrun.
+	//
+	// Note that on arm64, it is legal and cheap to issue unaligned 8-byte or
+	// 16-byte loads and stores. This technique probably wouldn't be as
+	// effective on architectures that are fussier about alignment.
+	LDP 0(R10), (R0, R1)
+	STP (R0, R1), 0(R8)
+	ADD R3, R8, R8
+
+inner1:
+	// for { etc }
+
+	// base := s
+	MOVD R7, R12
+
+	// !!! offset := base - candidate
+	MOVD R12, R11
+	SUB  R15, R11, R11
+	SUB  R6, R11, R11
+
+	// ----------------------------------------
+	// Begin inline of the extendMatch call.
+	//
+	// s = extendMatch(src, candidate+4, s+4)
+
+	// !!! R14 = &src[len(src)]
+	MOVD src_len+32(FP), R14
+	ADD  R6, R14, R14
+
+	// !!! R13 = &src[len(src) - 8]
+	MOVD R14, R13
+	SUB  $8, R13, R13
+
+	// !!! R15 = &src[candidate + 4]
+	ADD $4, R15, R15
+	ADD R6, R15, R15
+
+	// !!! s += 4
+	ADD $4, R7, R7
+
+inlineExtendMatchCmp8:
+	// As long as we are 8 or more bytes before the end of src, we can load and
+	// compare 8 bytes at a time. If those 8 bytes are equal, repeat.
+	CMP  R13, R7
+	BHI  inlineExtendMatchCmp1
+	MOVD (R15), R3
+	MOVD (R7), R4
+	CMP  R4, R3
+	BNE  inlineExtendMatchBSF
+	ADD  $8, R15, R15
+	ADD  $8, R7, R7
+	B    inlineExtendMatchCmp8
+
+inlineExtendMatchBSF:
+	// If those 8 bytes were not equal, XOR the two 8 byte values, and return
+	// the index of the first byte that differs.
+	// RBIT reverses the bit order, then CLZ counts the leading zeros, the
+	// combination of which finds the least significant bit which is set.
+	// The arm64 architecture is little-endian, and the shift by 3 converts
+	// a bit index to a byte index.
+	EOR  R3, R4, R4
+	RBIT R4, R4
+	CLZ  R4, R4
+	ADD  R4>>3, R7, R7
+	B    inlineExtendMatchEnd
+
+inlineExtendMatchCmp1:
+	// In src's tail, compare 1 byte at a time.
+	CMP  R7, R14
+	BLS  inlineExtendMatchEnd
+	MOVB (R15), R3
+	MOVB (R7), R4
+	CMP  R4, R3
+	BNE  inlineExtendMatchEnd
+	ADD  $1, R15, R15
+	ADD  $1, R7, R7
+	B    inlineExtendMatchCmp1
+
+inlineExtendMatchEnd:
+	// End inline of the extendMatch call.
+	// ----------------------------------------
+
+	// ----------------------------------------
+	// Begin inline of the emitCopy call.
+	//
+	// d += emitCopy(dst[d:], base-candidate, s-base)
+
+	// !!! length := s - base
+	MOVD R7, R3
+	SUB  R12, R3, R3
+
+inlineEmitCopyLoop0:
+	// for length >= 68 { etc }
+	MOVW $68, R2
+	CMPW R2, R3
+	BLT  inlineEmitCopyStep1
+
+	// Emit a length 64 copy, encoded as 3 bytes.
+	MOVD $0xfe, R1
+	MOVB R1, 0(R8)
+	MOVW R11, 1(R8)
+	ADD  $3, R8, R8
+	SUBW $64, R3, R3
+	B    inlineEmitCopyLoop0
+
+inlineEmitCopyStep1:
+	// if length > 64 { etc }
+	MOVW $64, R2
+	CMPW R2, R3
+	BLE  inlineEmitCopyStep2
+
+	// Emit a length 60 copy, encoded as 3 bytes.
+	MOVD $0xee, R1
+	MOVB R1, 0(R8)
+	MOVW R11, 1(R8)
+	ADD  $3, R8, R8
+	SUBW $60, R3, R3
+
+inlineEmitCopyStep2:
+	// if length >= 12 || offset >= 2048 { goto inlineEmitCopyStep3 }
+	MOVW $12, R2
+	CMPW R2, R3
+	BGE  inlineEmitCopyStep3
+	MOVW $2048, R2
+	CMPW R2, R11
+	BGE  inlineEmitCopyStep3
+
+	// Emit the remaining copy, encoded as 2 bytes.
+	MOVB R11, 1(R8)
+	LSRW $8, R11, R11
+	LSLW $5, R11, R11
+	SUBW $4, R3, R3
+	AND  $0xff, R3, R3
+	LSLW $2, R3, R3
+	ORRW R3, R11, R11
+	ORRW $1, R11, R11
+	MOVB R11, 0(R8)
+	ADD  $2, R8, R8
+	B    inlineEmitCopyEnd
+
+inlineEmitCopyStep3:
+	// Emit the remaining copy, encoded as 3 bytes.
+	SUBW $1, R3, R3
+	LSLW $2, R3, R3
+	ORRW $2, R3, R3
+	MOVB R3, 0(R8)
+	MOVW R11, 1(R8)
+	ADD  $3, R8, R8
+
+inlineEmitCopyEnd:
+	// End inline of the emitCopy call.
+	// ----------------------------------------
+
+	// nextEmit = s
+	MOVD R7, R10
+
+	// if s >= sLimit { goto emitRemainder }
+	MOVD R7, R3
+	SUB  R6, R3, R3
+	CMP  R3, R9
+	BLS  emitRemainder
+
+	// As per the encode_other.go code:
+	//
+	// We could immediately etc.
+
+	// x := load64(src, s-1)
+	MOVD -1(R7), R14
+
+	// prevHash := hash(uint32(x>>0), shift)
+	MOVW R14, R11
+	MULW R16, R11, R11
+	LSRW R5, R11, R11
+
+	// table[prevHash] = uint16(s-1)
+	MOVD R7, R3
+	SUB  R6, R3, R3
+	SUB  $1, R3, R3
+
+	MOVHU R3, 0(R17)(R11<<1)
+
+	// currHash := hash(uint32(x>>8), shift)
+	LSR  $8, R14, R14
+	MOVW R14, R11
+	MULW R16, R11, R11
+	LSRW R5, R11, R11
+
+	// candidate = int(table[currHash])
+	MOVHU 0(R17)(R11<<1), R15
+
+	// table[currHash] = uint16(s)
+	ADD   $1, R3, R3
+	MOVHU R3, 0(R17)(R11<<1)
+
+	// if uint32(x>>8) == load32(src, candidate) { continue }
+	MOVW (R6)(R15), R4
+	CMPW R4, R14
+	BEQ  inner1
+
+	// nextHash = hash(uint32(x>>16), shift)
+	LSR  $8, R14, R14
+	MOVW R14, R11
+	MULW R16, R11, R11
+	LSRW R5, R11, R11
+
+	// s++
+	ADD $1, R7, R7
+
+	// break out of the inner1 for loop, i.e. continue the outer loop.
+	B outer
+
+emitRemainder:
+	// if nextEmit < len(src) { etc }
+	MOVD src_len+32(FP), R3
+	ADD  R6, R3, R3
+	CMP  R3, R10
+	BEQ  encodeBlockEnd
+
+	// d += emitLiteral(dst[d:], src[nextEmit:])
+	//
+	// Push args.
+	MOVD R8, 8(RSP)
+	MOVD $0, 16(RSP)  // Unnecessary, as the callee ignores it, but conservative.
+	MOVD $0, 24(RSP)  // Unnecessary, as the callee ignores it, but conservative.
+	MOVD R10, 32(RSP)
+	SUB  R10, R3, R3
+	MOVD R3, 40(RSP)
+	MOVD R3, 48(RSP)  // Unnecessary, as the callee ignores it, but conservative.
+
+	// Spill local variables (registers) onto the stack; call; unspill.
+	MOVD R8, 88(RSP)
+	CALL ·emitLiteral(SB)
+	MOVD 88(RSP), R8
+
+	// Finish the "d +=" part of "d += emitLiteral(etc)".
+	MOVD 56(RSP), R1
+	ADD  R1, R8, R8
+
+encodeBlockEnd:
+	MOVD dst_base+0(FP), R3
+	SUB  R3, R8, R8
+	MOVD R8, d+48(FP)
+	RET

vendor/github.com/golang/snappy/encode_asm.go

@@ -0,0 +1,30 @@
+// Copyright 2016 The Snappy-Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build !appengine
+// +build gc
+// +build !noasm
+// +build amd64 arm64
+
+package snappy
+
+// emitLiteral has the same semantics as in encode_other.go.
+//
+//go:noescape
+func emitLiteral(dst, lit []byte) int
+
+// emitCopy has the same semantics as in encode_other.go.
+//
+//go:noescape
+func emitCopy(dst []byte, offset, length int) int
+
+// extendMatch has the same semantics as in encode_other.go.
+//
+//go:noescape
+func extendMatch(src []byte, i, j int) int
+
+// encodeBlock has the same semantics as in encode_other.go.
+//
+//go:noescape
+func encodeBlock(dst, src []byte) (d int)

vendor/github.com/golang/snappy/encode_other.go

@@ -0,0 +1,238 @@
+// Copyright 2016 The Snappy-Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build !amd64,!arm64 appengine !gc noasm
+
+package snappy
+
+func load32(b []byte, i int) uint32 {
+	b = b[i : i+4 : len(b)] // Help the compiler eliminate bounds checks on the next line.
+	return uint32(b[0]) | uint32(b[1])<<8 | uint32(b[2])<<16 | uint32(b[3])<<24
+}
+
+func load64(b []byte, i int) uint64 {
+	b = b[i : i+8 : len(b)] // Help the compiler eliminate bounds checks on the next line.
+	return uint64(b[0]) | uint64(b[1])<<8 | uint64(b[2])<<16 | uint64(b[3])<<24 |
+		uint64(b[4])<<32 | uint64(b[5])<<40 | uint64(b[6])<<48 | uint64(b[7])<<56
+}
+
+// emitLiteral writes a literal chunk and returns the number of bytes written.
+//
+// It assumes that:
+//	dst is long enough to hold the encoded bytes
+//	1 <= len(lit) && len(lit) <= 65536
+func emitLiteral(dst, lit []byte) int {
+	i, n := 0, uint(len(lit)-1)
+	switch {
+	case n < 60:
+		dst[0] = uint8(n)<<2 | tagLiteral
+		i = 1
+	case n < 1<<8:
+		dst[0] = 60<<2 | tagLiteral
+		dst[1] = uint8(n)
+		i = 2
+	default:
+		dst[0] = 61<<2 | tagLiteral
+		dst[1] = uint8(n)
+		dst[2] = uint8(n >> 8)
+		i = 3
+	}
+	return i + copy(dst[i:], lit)
+}
+
+// emitCopy writes a copy chunk and returns the number of bytes written.
+//
+// It assumes that:
+//	dst is long enough to hold the encoded bytes
+//	1 <= offset && offset <= 65535
+//	4 <= length && length <= 65535
+func emitCopy(dst []byte, offset, length int) int {
+	i := 0
+	// The maximum length for a single tagCopy1 or tagCopy2 op is 64 bytes. The
+	// threshold for this loop is a little higher (at 68 = 64 + 4), and the
+	// length emitted down below is is a little lower (at 60 = 64 - 4), because
+	// it's shorter to encode a length 67 copy as a length 60 tagCopy2 followed
+	// by a length 7 tagCopy1 (which encodes as 3+2 bytes) than to encode it as
+	// a length 64 tagCopy2 followed by a length 3 tagCopy2 (which encodes as
+	// 3+3 bytes). The magic 4 in the 64±4 is because the minimum length for a
+	// tagCopy1 op is 4 bytes, which is why a length 3 copy has to be an
+	// encodes-as-3-bytes tagCopy2 instead of an encodes-as-2-bytes tagCopy1.
+	for length >= 68 {
+		// Emit a length 64 copy, encoded as 3 bytes.
+		dst[i+0] = 63<<2 | tagCopy2
+		dst[i+1] = uint8(offset)
+		dst[i+2] = uint8(offset >> 8)
+		i += 3
+		length -= 64
+	}
+	if length > 64 {
+		// Emit a length 60 copy, encoded as 3 bytes.
+		dst[i+0] = 59<<2 | tagCopy2
+		dst[i+1] = uint8(offset)
+		dst[i+2] = uint8(offset >> 8)
+		i += 3
+		length -= 60
+	}
+	if length >= 12 || offset >= 2048 {
+		// Emit the remaining copy, encoded as 3 bytes.
+		dst[i+0] = uint8(length-1)<<2 | tagCopy2
+		dst[i+1] = uint8(offset)
+		dst[i+2] = uint8(offset >> 8)
+		return i + 3
+	}
+	// Emit the remaining copy, encoded as 2 bytes.
+	dst[i+0] = uint8(offset>>8)<<5 | uint8(length-4)<<2 | tagCopy1
+	dst[i+1] = uint8(offset)
+	return i + 2
+}
+
+// extendMatch returns the largest k such that k <= len(src) and that
+// src[i:i+k-j] and src[j:k] have the same contents.
+//
+// It assumes that:
+//	0 <= i && i < j && j <= len(src)
+func extendMatch(src []byte, i, j int) int {
+	for ; j < len(src) && src[i] == src[j]; i, j = i+1, j+1 {
+	}
+	return j
+}
+
+func hash(u, shift uint32) uint32 {
+	return (u * 0x1e35a7bd) >> shift
+}
+
+// encodeBlock encodes a non-empty src to a guaranteed-large-enough dst. It
+// assumes that the varint-encoded length of the decompressed bytes has already
+// been written.
+//
+// It also assumes that:
+//	len(dst) >= MaxEncodedLen(len(src)) &&
+// 	minNonLiteralBlockSize <= len(src) && len(src) <= maxBlockSize
+func encodeBlock(dst, src []byte) (d int) {
+	// Initialize the hash table. Its size ranges from 1<<8 to 1<<14 inclusive.
+	// The table element type is uint16, as s < sLimit and sLimit < len(src)
+	// and len(src) <= maxBlockSize and maxBlockSize == 65536.
+	const (
+		maxTableSize = 1 << 14
+		// tableMask is redundant, but helps the compiler eliminate bounds
+		// checks.
+		tableMask = maxTableSize - 1
+	)
+	shift := uint32(32 - 8)
+	for tableSize := 1 << 8; tableSize < maxTableSize && tableSize < len(src); tableSize *= 2 {
+		shift--
+	}
+	// In Go, all array elements are zero-initialized, so there is no advantage
+	// to a smaller tableSize per se. However, it matches the C++ algorithm,
+	// and in the asm versions of this code, we can get away with zeroing only
+	// the first tableSize elements.
+	var table [maxTableSize]uint16
+
+	// sLimit is when to stop looking for offset/length copies. The inputMargin
+	// lets us use a fast path for emitLiteral in the main loop, while we are
+	// looking for copies.
+	sLimit := len(src) - inputMargin
+
+	// nextEmit is where in src the next emitLiteral should start from.
+	nextEmit := 0
+
+	// The encoded form must start with a literal, as there are no previous
+	// bytes to copy, so we start looking for hash matches at s == 1.
+	s := 1
+	nextHash := hash(load32(src, s), shift)
+
+	for {
+		// Copied from the C++ snappy implementation:
+		//
+		// Heuristic match skipping: If 32 bytes are scanned with no matches
+		// found, start looking only at every other byte. If 32 more bytes are
+		// scanned (or skipped), look at every third byte, etc.. When a match
+		// is found, immediately go back to looking at every byte. This is a
+		// small loss (~5% performance, ~0.1% density) for compressible data
+		// due to more bookkeeping, but for non-compressible data (such as
+		// JPEG) it's a huge win since the compressor quickly "realizes" the
+		// data is incompressible and doesn't bother looking for matches
+		// everywhere.
+		//
+		// The "skip" variable keeps track of how many bytes there are since
+		// the last match; dividing it by 32 (ie. right-shifting by five) gives
+		// the number of bytes to move ahead for each iteration.
+		skip := 32
+
+		nextS := s
+		candidate := 0
+		for {
+			s = nextS
+			bytesBetweenHashLookups := skip >> 5
+			nextS = s + bytesBetweenHashLookups
+			skip += bytesBetweenHashLookups
+			if nextS > sLimit {
+				goto emitRemainder
+			}
+			candidate = int(table[nextHash&tableMask])
+			table[nextHash&tableMask] = uint16(s)
+			nextHash = hash(load32(src, nextS), shift)
+			if load32(src, s) == load32(src, candidate) {
+				break
+			}
+		}
+
+		// A 4-byte match has been found. We'll later see if more than 4 bytes
+		// match. But, prior to the match, src[nextEmit:s] are unmatched. Emit
+		// them as literal bytes.
+		d += emitLiteral(dst[d:], src[nextEmit:s])
+
+		// Call emitCopy, and then see if another emitCopy could be our next
+		// move. Repeat until we find no match for the input immediately after
+		// what was consumed by the last emitCopy call.
+		//
+		// If we exit this loop normally then we need to call emitLiteral next,
+		// though we don't yet know how big the literal will be. We handle that
+		// by proceeding to the next iteration of the main loop. We also can
+		// exit this loop via goto if we get close to exhausting the input.
+		for {
+			// Invariant: we have a 4-byte match at s, and no need to emit any
+			// literal bytes prior to s.
+			base := s
+
+			// Extend the 4-byte match as long as possible.
+			//
+			// This is an inlined version of:
+			//	s = extendMatch(src, candidate+4, s+4)
+			s += 4
+			for i := candidate + 4; s < len(src) && src[i] == src[s]; i, s = i+1, s+1 {
+			}
+
+			d += emitCopy(dst[d:], base-candidate, s-base)
+			nextEmit = s
+			if s >= sLimit {
+				goto emitRemainder
+			}
+
+			// We could immediately start working at s now, but to improve
+			// compression we first update the hash table at s-1 and at s. If
+			// another emitCopy is not our next move, also calculate nextHash
+			// at s+1. At least on GOARCH=amd64, these three hash calculations
+			// are faster as one load64 call (with some shifts) instead of
+			// three load32 calls.
+			x := load64(src, s-1)
+			prevHash := hash(uint32(x>>0), shift)
+			table[prevHash&tableMask] = uint16(s - 1)
+			currHash := hash(uint32(x>>8), shift)
+			candidate = int(table[currHash&tableMask])
+			table[currHash&tableMask] = uint16(s)
+			if uint32(x>>8) != load32(src, candidate) {
+				nextHash = hash(uint32(x>>16), shift)
+				s++
+				break
+			}
+		}
+	}
+
+emitRemainder:
+	if nextEmit < len(src) {
+		d += emitLiteral(dst[d:], src[nextEmit:])
+	}
+	return d
+}

vendor/github.com/golang/snappy/snappy.go

@@ -0,0 +1,98 @@
+// Copyright 2011 The Snappy-Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package snappy implements the Snappy compression format. It aims for very
+// high speeds and reasonable compression.
+//
+// There are actually two Snappy formats: block and stream. They are related,
+// but different: trying to decompress block-compressed data as a Snappy stream
+// will fail, and vice versa. The block format is the Decode and Encode
+// functions and the stream format is the Reader and Writer types.
+//
+// The block format, the more common case, is used when the complete size (the
+// number of bytes) of the original data is known upfront, at the time
+// compression starts. The stream format, also known as the framing format, is
+// for when that isn't always true.
+//
+// The canonical, C++ implementation is at https://github.com/google/snappy and
+// it only implements the block format.
+package snappy // import "github.com/golang/snappy"
+
+import (
+	"hash/crc32"
+)
+
+/*
+Each encoded block begins with the varint-encoded length of the decoded data,
+followed by a sequence of chunks. Chunks begin and end on byte boundaries. The
+first byte of each chunk is broken into its 2 least and 6 most significant bits
+called l and m: l ranges in [0, 4) and m ranges in [0, 64). l is the chunk tag.
+Zero means a literal tag. All other values mean a copy tag.
+
+For literal tags:
+  - If m < 60, the next 1 + m bytes are literal bytes.
+  - Otherwise, let n be the little-endian unsigned integer denoted by the next
+    m - 59 bytes. The next 1 + n bytes after that are literal bytes.
+
+For copy tags, length bytes are copied from offset bytes ago, in the style of
+Lempel-Ziv compression algorithms. In particular:
+  - For l == 1, the offset ranges in [0, 1<<11) and the length in [4, 12).
+    The length is 4 + the low 3 bits of m. The high 3 bits of m form bits 8-10
+    of the offset. The next byte is bits 0-7 of the offset.
+  - For l == 2, the offset ranges in [0, 1<<16) and the length in [1, 65).
+    The length is 1 + m. The offset is the little-endian unsigned integer
+    denoted by the next 2 bytes.
+  - For l == 3, this tag is a legacy format that is no longer issued by most
+    encoders. Nonetheless, the offset ranges in [0, 1<<32) and the length in
+    [1, 65). The length is 1 + m. The offset is the little-endian unsigned
+    integer denoted by the next 4 bytes.
+*/
+const (
+	tagLiteral = 0x00
+	tagCopy1   = 0x01
+	tagCopy2   = 0x02
+	tagCopy4   = 0x03
+)
+
+const (
+	checksumSize    = 4
+	chunkHeaderSize = 4
+	magicChunk      = "\xff\x06\x00\x00" + magicBody
+	magicBody       = "sNaPpY"
+
+	// maxBlockSize is the maximum size of the input to encodeBlock. It is not
+	// part of the wire format per se, but some parts of the encoder assume
+	// that an offset fits into a uint16.
+	//
+	// Also, for the framing format (Writer type instead of Encode function),
+	// https://github.com/google/snappy/blob/master/framing_format.txt says
+	// that "the uncompressed data in a chunk must be no longer than 65536
+	// bytes".
+	maxBlockSize = 65536
+
+	// maxEncodedLenOfMaxBlockSize equals MaxEncodedLen(maxBlockSize), but is
+	// hard coded to be a const instead of a variable, so that obufLen can also
+	// be a const. Their equivalence is confirmed by
+	// TestMaxEncodedLenOfMaxBlockSize.
+	maxEncodedLenOfMaxBlockSize = 76490
+
+	obufHeaderLen = len(magicChunk) + checksumSize + chunkHeaderSize
+	obufLen       = obufHeaderLen + maxEncodedLenOfMaxBlockSize
+)
+
+const (
+	chunkTypeCompressedData   = 0x00
+	chunkTypeUncompressedData = 0x01
+	chunkTypePadding          = 0xfe
+	chunkTypeStreamIdentifier = 0xff
+)
+
+var crcTable = crc32.MakeTable(crc32.Castagnoli)
+
+// crc implements the checksum specified in section 3 of
+// https://github.com/google/snappy/blob/master/framing_format.txt
+func crc(b []byte) uint32 {
+	c := crc32.Update(0, crcTable, b)
+	return uint32(c>>15|c<<17) + 0xa282ead8
+}

vendor/github.com/google/gopacket/.gitignore

@@ -0,0 +1,38 @@
+# Compiled Object files, Static and Dynamic libs (Shared Objects)
+*.o
+*.a
+*.so
+
+# Folders
+_obj
+_test
+
+# Architecture specific extensions/prefixes
+*.[568vq]
+[568vq].out
+
+*.cgo1.go
+*.cgo2.c
+_cgo_defun.c
+_cgo_gotypes.go
+_cgo_export.*
+
+_testmain.go
+
+*.exe
+#*
+*~
+
+# examples binaries
+examples/synscan/synscan
+examples/pfdump/pfdump
+examples/pcapdump/pcapdump
+examples/httpassembly/httpassembly
+examples/statsassembly/statsassembly
+examples/arpscan/arpscan
+examples/bidirectional/bidirectional
+examples/bytediff/bytediff
+examples/reassemblydump/reassemblydump
+layers/gen
+macs/gen
+pcap/pcap_tester

vendor/github.com/google/gopacket/.travis.gofmt.sh

@@ -0,0 +1,7 @@
+#!/bin/bash
+
+cd "$(dirname $0)"
+if [ -n "$(go fmt ./...)" ]; then
+  echo "Go code is not formatted, run 'go fmt github.com/google/stenographer/...'" >&2
+  exit 1
+fi

vendor/github.com/google/gopacket/.travis.golint.sh

@@ -0,0 +1,28 @@
+#!/bin/bash
+
+cd "$(dirname $0)"
+
+go get golang.org/x/lint/golint
+DIRS=". tcpassembly tcpassembly/tcpreader ip4defrag reassembly macs pcapgo pcap afpacket pfring routing defrag/lcmdefrag"
+# Add subdirectories here as we clean up golint on each.
+for subdir in $DIRS; do
+  pushd $subdir
+  if golint |
+      grep -v CannotSetRFMon |  # pcap exported error name
+      grep -v DataLost |        # tcpassembly/tcpreader exported error name
+      grep .; then
+    exit 1
+  fi
+  popd
+done
+
+pushd layers
+for file in *.go; do
+  if cat .lint_blacklist | grep -q $file; then
+    echo "Skipping lint of $file due to .lint_blacklist"
+  elif golint $file | grep .; then
+    echo "Lint error in file $file"
+    exit 1
+  fi
+done
+popd

vendor/github.com/google/gopacket/.travis.govet.sh

@@ -0,0 +1,10 @@
+#!/bin/bash
+
+cd "$(dirname $0)"
+DIRS=". layers pcap pcapgo tcpassembly tcpassembly/tcpreader routing ip4defrag bytediff macs defrag/lcmdefrag"
+set -e
+for subdir in $DIRS; do
+  pushd $subdir
+  go vet
+  popd
+done

vendor/github.com/google/gopacket/.travis.install.sh

@@ -0,0 +1,9 @@
+#!/bin/bash
+
+set -ev
+
+go get github.com/google/gopacket
+go get github.com/google/gopacket/layers
+go get github.com/google/gopacket/tcpassembly
+go get github.com/google/gopacket/reassembly
+go get github.com/google/gopacket/pcapgo

vendor/github.com/google/gopacket/.travis.script.sh

@@ -0,0 +1,10 @@
+#!/bin/bash
+
+set -ev
+
+go test github.com/google/gopacket
+go test github.com/google/gopacket/layers
+go test github.com/google/gopacket/tcpassembly
+go test github.com/google/gopacket/reassembly
+go test github.com/google/gopacket/pcapgo 
+go test github.com/google/gopacket/pcap

vendor/github.com/google/gopacket/.travis.yml

@@ -0,0 +1,57 @@
+language: go
+go:
+ - 1.11.x
+ - 1.12.x
+ - 1.13.x
+ - master
+
+addons:
+  apt:
+    packages:
+      libpcap-dev
+
+# use modules except for older versions (see below)
+install: true
+
+env:
+  - GO111MODULE=on
+
+script: ./.travis.script.sh
+
+matrix:
+  fast_finish: true
+  allow_failures:
+    - go: master
+
+jobs:
+  include:
+    - go: 1.5.x
+      install: ./.travis.install.sh
+    - go: 1.6.x
+      install: ./.travis.install.sh
+    - go: 1.7.x
+      install: ./.travis.install.sh
+    - go: 1.8.x
+      install: ./.travis.install.sh
+    - go: 1.9.x
+      install: ./.travis.install.sh
+    - go: 1.10.x
+      install: ./.travis.install.sh
+    - os: osx
+      go: 1.x
+# windows doesn't work on travis (package installation just hangs and then errors out)
+#    - os: windows
+#      go: 1.x
+#      # We don't need nmap - but that's the only way to get npcap:
+#      before_install: choco install npcap --version 0.86 -y
+    - stage: style
+      name: "fmt/vet/lint"
+      go: 1.x
+      script:
+        - ./.travis.gofmt.sh
+        - ./.travis.govet.sh
+        - ./.travis.golint.sh
+
+stages:
+  - style
+  - test

vendor/github.com/google/gopacket/AUTHORS

@@ -0,0 +1,54 @@
+AUTHORS AND MAINTAINERS:
+
+MAIN DEVELOPERS:
+Graeme Connell   <gconnell@google.com, gsconnell@gmail.com>
+
+AUTHORS:
+Nigel Tao <nigeltao@google.com>
+Cole Mickens <cole.mickens@gmail.com>
+Ben Daglish <bdaglish@restorepoint.com>
+Luis Martinez <martinezlc99@gmail.com>
+Remco Verhoef <remco@dutchcoders.io>
+Hiroaki Kawai <Hiroaki.Kawai@gmail.com>
+Lukas Lueg <lukas.lueg@gmail.com>
+Laurent Hausermann <laurent.hausermann@gmail.com>
+Bill Green <bgreen@newrelic.com>
+Christian Mäder <christian.maeder@nine.ch>
+Gernot Vormayr <gvormayr@gmail.com>
+Vitor Garcia Graveto <victor.graveto@gmail.com>
+Elias Chavarria Reyes <elchavar@cisco.com>
+Daniel Rittweiler <ripx80@protonmail.com>
+
+CONTRIBUTORS:
+Attila Oláh <attila@attilaolah.eu>
+Vittus Mikiassen <matt.miki.vimik@gmail.com>
+Matthias Radestock <matthias.radestock@gmail.com>
+Matthew Sackman <matthew@wellquite.org>
+Loic Prylli <loicp@google.com>
+Alexandre Fiori <fiorix@gmail.com>
+Adrian Tam <adrian.c.m.tam@gmail.com>
+Satoshi Matsumoto <kaorimatz@gmail.com>
+David Stainton <dstainton415@gmail.com>
+Jesse Ward <jesse@jesseward.com>
+Kane Mathers <kane@kanemathers.name>
+Jose Selvi <jselvi@pentester.es>
+Yerden Zhumabekov <yerden.zhumabekov@gmail.com>
+Jensen Hwa <jensenhwa@gmail.com>
+
+-----------------------------------------------
+FORKED FROM github.com/akrennmair/gopcap
+ALL THE FOLLOWING ARE FOR THAT PROJECT
+
+MAIN DEVELOPERS:
+Andreas Krennmair <ak@synflood.at>
+
+CONTRIBUTORS:
+Andrea Nall <anall@andreanall.com>
+Daniel Arndt <danielarndt@gmail.com>
+Dustin Sallings <dustin@spy.net>
+Graeme Connell <gconnell@google.com, gsconnell@gmail.com>
+Guillaume Savary <guillaume@savary.name>
+Mark Smith <mark@qq.is>
+Miek Gieben <miek@miek.nl>
+Mike Bell <mike@mikebell.org>
+Trevor Strohman <strohman@google.com>

vendor/github.com/google/gopacket/CONTRIBUTING.md

@@ -0,0 +1,215 @@
+Contributing To gopacket
+========================
+
+So you've got some code and you'd like it to be part of gopacket... wonderful!
+We're happy to accept contributions, whether they're fixes to old protocols, new
+protocols entirely, or anything else you think would improve the gopacket
+library.  This document is designed to help you to do just that.
+
+The first section deals with the plumbing:  how to actually get a change
+submitted.
+
+The second section deals with coding style... Go is great in that it
+has a uniform style implemented by 'go fmt', but there's still some decisions
+we've made that go above and beyond, and if you follow them, they won't come up
+in your code review.
+
+The third section deals with some of the implementation decisions we've made,
+which may help you to understand the current code and which we may ask you to
+conform to (or provide compelling reasons for ignoring).
+
+Overall, we hope this document will help you to understand our system and write
+great code which fits in, and help us to turn around on your code review quickly
+so the code can make it into the master branch as quickly as possible.
+
+
+How To Submit Code
+------------------
+
+We use github.com's Pull Request feature to receive code contributions from
+external contributors.  See
+https://help.github.com/articles/creating-a-pull-request/ for details on
+how to create a request.
+
+Also, there's a local script `gc` in the base directory of GoPacket that
+runs a local set of checks, which should give you relatively high confidence
+that your pull won't fail github pull checks.
+
+```sh
+go get github.com/google/gopacket
+cd $GOROOT/src/pkg/github.com/google/gopacket
+git checkout -b <mynewfeature>  # create a new branch to work from
+... code code code ...
+./gc  # Run this to do local commits, it performs a number of checks
+```
+
+To sum up:
+
+* DO
+    + Pull down the latest version.
+    + Make a feature-specific branch.
+    + Code using the style and methods discussed in the rest of this document.
+    + Use the ./gc command to do local commits or check correctness.
+    + Push your new feature branch up to github.com, as a pull request.
+    + Handle comments and requests from reviewers, pushing new commits up to
+      your feature branch as problems are addressed.
+    + Put interesting comments and discussions into commit comments.
+* DON'T
+    + Push to someone else's branch without their permission.
+
+
+Coding Style
+------------
+
+* Go code must be run through `go fmt`, `go vet`, and `golint`
+* Follow http://golang.org/doc/effective_go.html as much as possible.
+    + In particular, http://golang.org/doc/effective_go.html#mixed-caps.  Enums
+      should be be CamelCase, with acronyms capitalized (TCPSourcePort, vs.
+      TcpSourcePort or TCP_SOURCE_PORT).
+* Bonus points for giving enum types a String() field.
+* Any exported types or functions should have commentary
+  (http://golang.org/doc/effective_go.html#commentary)
+
+
+Coding Methods And Implementation Notes
+---------------------------------------
+
+### Error Handling
+
+Many times, you'll be decoding a protocol and run across something bad, a packet
+corruption or the like.  How do you handle this?  First off, ALWAYS report the
+error.  You can do this either by returning the error from the decode() function
+(most common), or if you're up for it you can implement and add an ErrorLayer
+through the packet builder (the first method is a simple shortcut that does
+exactly this, then stops any future decoding).
+
+Often, you'll already have decode some part of your protocol by the time you hit
+your error.  Use your own discretion to determine whether the stuff you've
+already decoded should be returned to the caller or not:
+
+```go
+func decodeMyProtocol(data []byte, p gopacket.PacketBuilder) error {
+  prot := &MyProtocol{}
+  if len(data) < 10 {
+    // This error occurred before we did ANYTHING, so there's nothing in my
+    // protocol that the caller could possibly want.  Just return the error.
+    return fmt.Errorf("Length %d less than 10", len(data))
+  }
+  prot.ImportantField1 = data[:5]
+  prot.ImportantField2 = data[5:10]
+  // At this point, we've already got enough information in 'prot' to
+  // warrant returning it to the caller, so we'll add it now.
+  p.AddLayer(prot)
+  if len(data) < 15 {
+    // We encountered an error later in the packet, but the caller already
+    // has the important info we've gleaned so far.
+    return fmt.Errorf("Length %d less than 15", len(data))
+  }
+  prot.ImportantField3 = data[10:15]
+  return nil  // We've already added the layer, we can just return success.
+}
+```
+
+In general, our code follows the approach of returning the first error it
+encounters.  In general, we don't trust any bytes after the first error we see.
+
+### What Is A Layer?
+
+The definition of a layer is up to the discretion of the coder.  It should be
+something important enough that it's actually useful to the caller (IE: every
+TLV value should probably NOT be a layer).  However, it can be more granular
+than a single protocol... IPv6 and SCTP both implement many layers to handle the
+various parts of the protocol.  Use your best judgement, and prepare to defend
+your decisions during code review. ;)
+
+### Performance
+
+We strive to make gopacket as fast as possible while still providing lots of
+features.  In general, this means:
+
+* Focus performance tuning on common protocols (IP4/6, TCP, etc), and optimize
+  others on an as-needed basis (tons of MPLS on your network?  Time to optimize
+  MPLS!)
+* Use fast operations.  See the toplevel benchmark_test for benchmarks of some
+  of Go's underlying features and types.
+* Test your performance changes!  You should use the ./gc script's --benchmark
+  flag to submit any performance-related changes.  Use pcap/gopacket_benchmark
+  to test your change against a PCAP file based on your traffic patterns.
+* Don't be TOO hacky.  Sometimes, removing an unused struct from a field causes
+  a huge performance hit, due to the way that Go currently handles its segmented
+  stack... don't be afraid to clean it up anyway.  We'll trust the Go compiler
+  to get good enough over time to handle this.  Also, this type of
+  compiler-specific optimization is very fragile; someone adding a field to an
+  entirely different struct elsewhere in the codebase could reverse any gains
+  you might achieve by aligning your allocations.
+* Try to minimize memory allocations.  If possible, use []byte to reference
+  pieces of the input, instead of using string, which requires copying the bytes
+  into a new memory allocation.
+* Think hard about what should be evaluated lazily vs. not.  In general, a
+  layer's struct should almost exactly mirror the layer's frame.  Anything
+  that's more interesting should be a function.  This may not always be
+  possible, but it's a good rule of thumb.
+* Don't fear micro-optimizations.  With the above in mind, we welcome
+  micro-optimizations that we think will have positive/neutral impacts on the
+  majority of workloads.  A prime example of this is pre-allocating certain
+  structs within a larger one:
+
+```go
+type MyProtocol struct {
+  // Most packets have 1-4 of VeryCommon, so we preallocate it here.
+  initialAllocation [4]uint32
+  VeryCommon []uint32
+}
+
+func decodeMyProtocol(data []byte, p gopacket.PacketBuilder) error {
+  prot := &MyProtocol{}
+  prot.VeryCommon = proto.initialAllocation[:0]
+  for len(data) > 4 {
+    field := binary.BigEndian.Uint32(data[:4])
+    data = data[4:]
+    // Since we're using the underlying initialAllocation, we won't need to
+    // allocate new memory for the following append unless we more than 16
+    // bytes of data, which should be the uncommon case.
+    prot.VeryCommon = append(prot.VeryCommon, field)
+  }
+  p.AddLayer(prot)
+  if len(data) > 0 {
+    return fmt.Errorf("MyProtocol packet has %d bytes left after decoding", len(data))
+  }
+  return nil
+}
+```
+
+### Slices And Data
+
+If you're pulling a slice from the data you're decoding, don't copy it.  Just
+use the slice itself.
+
+```go
+type MyProtocol struct {
+  A, B net.IP
+}
+func decodeMyProtocol(data []byte, p gopacket.PacketBuilder) error {
+  p.AddLayer(&MyProtocol{
+    A: data[:4],
+    B: data[4:8],
+  })
+  return nil
+}
+```
+
+The caller has already agreed, by using this library, that they won't modify the
+set of bytes they pass in to the decoder, or the library has already copied the
+set of bytes to a read-only location.  See DecodeOptions.NoCopy for more
+information.
+
+### Enums/Types
+
+If a protocol has an integer field (uint8, uint16, etc) with a couple of known
+values that mean something special, make it a type.  This allows us to do really
+nice things like adding a String() function to them, so we can more easily
+display those to users.  Check out layers/enums.go for one example, as well as
+layers/icmp.go for layer-specific enums.
+
+When naming things, try for descriptiveness over suscinctness.  For example,
+choose DNSResponseRecord over DNSRR.

vendor/github.com/google/gopacket/LICENSE

@@ -0,0 +1,28 @@
+Copyright (c) 2012 Google, Inc. All rights reserved.
+Copyright (c) 2009-2011 Andreas Krennmair. All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are
+met:
+
+   * Redistributions of source code must retain the above copyright
+notice, this list of conditions and the following disclaimer.
+   * Redistributions in binary form must reproduce the above
+copyright notice, this list of conditions and the following disclaimer
+in the documentation and/or other materials provided with the
+distribution.
+   * Neither the name of Andreas Krennmair, Google, nor the names of its
+contributors may be used to endorse or promote products derived from
+this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

vendor/github.com/google/gopacket/README.md

@@ -0,0 +1,12 @@
+# GoPacket
+
+This library provides packet decoding capabilities for Go.
+See [godoc](https://godoc.org/github.com/google/gopacket) for more details.
+
+[![Build Status](https://travis-ci.org/google/gopacket.svg?branch=master)](https://travis-ci.org/google/gopacket)
+[![GoDoc](https://godoc.org/github.com/google/gopacket?status.svg)](https://godoc.org/github.com/google/gopacket)
+
+Minimum Go version required is 1.5 except for pcapgo/EthernetHandle, afpacket, and bsdbpf which need at least 1.9 due to x/sys/unix dependencies.
+
+Originally forked from the gopcap project written by Andreas
+Krennmair <ak@synflood.at> (http://github.com/akrennmair/gopcap).

vendor/github.com/google/gopacket/base.go

@@ -0,0 +1,178 @@
+// Copyright 2012 Google, Inc. All rights reserved.
+//
+// Use of this source code is governed by a BSD-style license
+// that can be found in the LICENSE file in the root of the source
+// tree.
+
+package gopacket
+
+import (
+	"fmt"
+)
+
+// Layer represents a single decoded packet layer (using either the
+// OSI or TCP/IP definition of a layer).  When decoding, a packet's data is
+// broken up into a number of layers.  The caller may call LayerType() to
+// figure out which type of layer they've received from the packet.  Optionally,
+// they may then use a type assertion to get the actual layer type for deep
+// inspection of the data.
+type Layer interface {
+	// LayerType is the gopacket type for this layer.
+	LayerType() LayerType
+	// LayerContents returns the set of bytes that make up this layer.
+	LayerContents() []byte
+	// LayerPayload returns the set of bytes contained within this layer, not
+	// including the layer itself.
+	LayerPayload() []byte
+}
+
+// Payload is a Layer containing the payload of a packet.  The definition of
+// what constitutes the payload of a packet depends on previous layers; for
+// TCP and UDP, we stop decoding above layer 4 and return the remaining
+// bytes as a Payload.  Payload is an ApplicationLayer.
+type Payload []byte
+
+// LayerType returns LayerTypePayload
+func (p Payload) LayerType() LayerType { return LayerTypePayload }
+
+// LayerContents returns the bytes making up this layer.
+func (p Payload) LayerContents() []byte { return []byte(p) }
+
+// LayerPayload returns the payload within this layer.
+func (p Payload) LayerPayload() []byte { return nil }
+
+// Payload returns this layer as bytes.
+func (p Payload) Payload() []byte { return []byte(p) }
+
+// String implements fmt.Stringer.
+func (p Payload) String() string { return fmt.Sprintf("%d byte(s)", len(p)) }
+
+// GoString implements fmt.GoStringer.
+func (p Payload) GoString() string { return LongBytesGoString([]byte(p)) }
+
+// CanDecode implements DecodingLayer.
+func (p Payload) CanDecode() LayerClass { return LayerTypePayload }
+
+// NextLayerType implements DecodingLayer.
+func (p Payload) NextLayerType() LayerType { return LayerTypeZero }
+
+// DecodeFromBytes implements DecodingLayer.
+func (p *Payload) DecodeFromBytes(data []byte, df DecodeFeedback) error {
+	*p = Payload(data)
+	return nil
+}
+
+// SerializeTo writes the serialized form of this layer into the
+// SerializationBuffer, implementing gopacket.SerializableLayer.
+// See the docs for gopacket.SerializableLayer for more info.
+func (p Payload) SerializeTo(b SerializeBuffer, opts SerializeOptions) error {
+	bytes, err := b.PrependBytes(len(p))
+	if err != nil {
+		return err
+	}
+	copy(bytes, p)
+	return nil
+}
+
+// decodePayload decodes data by returning it all in a Payload layer.
+func decodePayload(data []byte, p PacketBuilder) error {
+	payload := &Payload{}
+	if err := payload.DecodeFromBytes(data, p); err != nil {
+		return err
+	}
+	p.AddLayer(payload)
+	p.SetApplicationLayer(payload)
+	return nil
+}
+
+// Fragment is a Layer containing a fragment of a larger frame, used by layers
+// like IPv4 and IPv6 that allow for fragmentation of their payloads.
+type Fragment []byte
+
+// LayerType returns LayerTypeFragment
+func (p *Fragment) LayerType() LayerType { return LayerTypeFragment }
+
+// LayerContents implements Layer.
+func (p *Fragment) LayerContents() []byte { return []byte(*p) }
+
+// LayerPayload implements Layer.
+func (p *Fragment) LayerPayload() []byte { return nil }
+
+// Payload returns this layer as a byte slice.
+func (p *Fragment) Payload() []byte { return []byte(*p) }
+
+// String implements fmt.Stringer.
+func (p *Fragment) String() string { return fmt.Sprintf("%d byte(s)", len(*p)) }
+
+// CanDecode implements DecodingLayer.
+func (p *Fragment) CanDecode() LayerClass { return LayerTypeFragment }
+
+// NextLayerType implements DecodingLayer.
+func (p *Fragment) NextLayerType() LayerType { return LayerTypeZero }
+
+// DecodeFromBytes implements DecodingLayer.
+func (p *Fragment) DecodeFromBytes(data []byte, df DecodeFeedback) error {
+	*p = Fragment(data)
+	return nil
+}
+
+// SerializeTo writes the serialized form of this layer into the
+// SerializationBuffer, implementing gopacket.SerializableLayer.
+// See the docs for gopacket.SerializableLayer for more info.
+func (p *Fragment) SerializeTo(b SerializeBuffer, opts SerializeOptions) error {
+	bytes, err := b.PrependBytes(len(*p))
+	if err != nil {
+		return err
+	}
+	copy(bytes, *p)
+	return nil
+}
+
+// decodeFragment decodes data by returning it all in a Fragment layer.
+func decodeFragment(data []byte, p PacketBuilder) error {
+	payload := &Fragment{}
+	if err := payload.DecodeFromBytes(data, p); err != nil {
+		return err
+	}
+	p.AddLayer(payload)
+	p.SetApplicationLayer(payload)
+	return nil
+}
+
+// These layers correspond to Internet Protocol Suite (TCP/IP) layers, and their
+// corresponding OSI layers, as best as possible.
+
+// LinkLayer is the packet layer corresponding to TCP/IP layer 1 (OSI layer 2)
+type LinkLayer interface {
+	Layer
+	LinkFlow() Flow
+}
+
+// NetworkLayer is the packet layer corresponding to TCP/IP layer 2 (OSI
+// layer 3)
+type NetworkLayer interface {
+	Layer
+	NetworkFlow() Flow
+}
+
+// TransportLayer is the packet layer corresponding to the TCP/IP layer 3 (OSI
+// layer 4)
+type TransportLayer interface {
+	Layer
+	TransportFlow() Flow
+}
+
+// ApplicationLayer is the packet layer corresponding to the TCP/IP layer 4 (OSI
+// layer 7), also known as the packet payload.
+type ApplicationLayer interface {
+	Layer
+	Payload() []byte
+}
+
+// ErrorLayer is a packet layer created when decoding of the packet has failed.
+// Its payload is all the bytes that we were unable to decode, and the returned
+// error details why the decoding failed.
+type ErrorLayer interface {
+	Layer
+	Error() error
+}

vendor/github.com/google/gopacket/decode.go

@@ -0,0 +1,157 @@
+// Copyright 2012 Google, Inc. All rights reserved.
+//
+// Use of this source code is governed by a BSD-style license
+// that can be found in the LICENSE file in the root of the source
+// tree.
+
+package gopacket
+
+import (
+	"errors"
+)
+
+// DecodeFeedback is used by DecodingLayer layers to provide decoding metadata.
+type DecodeFeedback interface {
+	// SetTruncated should be called if during decoding you notice that a packet
+	// is shorter than internal layer variables (HeaderLength, or the like) say it
+	// should be.  It sets packet.Metadata().Truncated.
+	SetTruncated()
+}
+
+type nilDecodeFeedback struct{}
+
+func (nilDecodeFeedback) SetTruncated() {}
+
+// NilDecodeFeedback implements DecodeFeedback by doing nothing.
+var NilDecodeFeedback DecodeFeedback = nilDecodeFeedback{}
+
+// PacketBuilder is used by layer decoders to store the layers they've decoded,
+// and to defer future decoding via NextDecoder.
+// Typically, the pattern for use is:
+//  func (m *myDecoder) Decode(data []byte, p PacketBuilder) error {
+//    if myLayer, err := myDecodingLogic(data); err != nil {
+//      return err
+//    } else {
+//      p.AddLayer(myLayer)
+//    }
+//    // maybe do this, if myLayer is a LinkLayer
+//    p.SetLinkLayer(myLayer)
+//    return p.NextDecoder(nextDecoder)
+//  }
+type PacketBuilder interface {
+	DecodeFeedback
+	// AddLayer should be called by a decoder immediately upon successful
+	// decoding of a layer.
+	AddLayer(l Layer)
+	// The following functions set the various specific layers in the final
+	// packet.  Note that if many layers call SetX, the first call is kept and all
+	// other calls are ignored.
+	SetLinkLayer(LinkLayer)
+	SetNetworkLayer(NetworkLayer)
+	SetTransportLayer(TransportLayer)
+	SetApplicationLayer(ApplicationLayer)
+	SetErrorLayer(ErrorLayer)
+	// NextDecoder should be called by a decoder when they're done decoding a
+	// packet layer but not done with decoding the entire packet.  The next
+	// decoder will be called to decode the last AddLayer's LayerPayload.
+	// Because of this, NextDecoder must only be called once all other
+	// PacketBuilder calls have been made.  Set*Layer and AddLayer calls after
+	// NextDecoder calls will behave incorrectly.
+	NextDecoder(next Decoder) error
+	// DumpPacketData is used solely for decoding.  If you come across an error
+	// you need to diagnose while processing a packet, call this and your packet's
+	// data will be dumped to stderr so you can create a test.  This should never
+	// be called from a production decoder.
+	DumpPacketData()
+	// DecodeOptions returns the decode options
+	DecodeOptions() *DecodeOptions
+}
+
+// Decoder is an interface for logic to decode a packet layer.  Users may
+// implement a Decoder to handle their own strange packet types, or may use one
+// of the many decoders available in the 'layers' subpackage to decode things
+// for them.
+type Decoder interface {
+	// Decode decodes the bytes of a packet, sending decoded values and other
+	// information to PacketBuilder, and returning an error if unsuccessful.  See
+	// the PacketBuilder documentation for more details.
+	Decode([]byte, PacketBuilder) error
+}
+
+// DecodeFunc wraps a function to make it a Decoder.
+type DecodeFunc func([]byte, PacketBuilder) error
+
+// Decode implements Decoder by calling itself.
+func (d DecodeFunc) Decode(data []byte, p PacketBuilder) error {
+	// function, call thyself.
+	return d(data, p)
+}
+
+// DecodePayload is a Decoder that returns a Payload layer containing all
+// remaining bytes.
+var DecodePayload Decoder = DecodeFunc(decodePayload)
+
+// DecodeUnknown is a Decoder that returns an Unknown layer containing all
+// remaining bytes, useful if you run up against a layer that you're unable to
+// decode yet.  This layer is considered an ErrorLayer.
+var DecodeUnknown Decoder = DecodeFunc(decodeUnknown)
+
+// DecodeFragment is a Decoder that returns a Fragment layer containing all
+// remaining bytes.
+var DecodeFragment Decoder = DecodeFunc(decodeFragment)
+
+// LayerTypeZero is an invalid layer type, but can be used to determine whether
+// layer type has actually been set correctly.
+var LayerTypeZero = RegisterLayerType(0, LayerTypeMetadata{Name: "Unknown", Decoder: DecodeUnknown})
+
+// LayerTypeDecodeFailure is the layer type for the default error layer.
+var LayerTypeDecodeFailure = RegisterLayerType(1, LayerTypeMetadata{Name: "DecodeFailure", Decoder: DecodeUnknown})
+
+// LayerTypePayload is the layer type for a payload that we don't try to decode
+// but treat as a success, IE: an application-level payload.
+var LayerTypePayload = RegisterLayerType(2, LayerTypeMetadata{Name: "Payload", Decoder: DecodePayload})
+
+// LayerTypeFragment is the layer type for a fragment of a layer transported
+// by an underlying layer that supports fragmentation.
+var LayerTypeFragment = RegisterLayerType(3, LayerTypeMetadata{Name: "Fragment", Decoder: DecodeFragment})
+
+// DecodeFailure is a packet layer created if decoding of the packet data failed
+// for some reason.  It implements ErrorLayer.  LayerContents will be the entire
+// set of bytes that failed to parse, and Error will return the reason parsing
+// failed.
+type DecodeFailure struct {
+	data  []byte
+	err   error
+	stack []byte
+}
+
+// Error returns the error encountered during decoding.
+func (d *DecodeFailure) Error() error { return d.err }
+
+// LayerContents implements Layer.
+func (d *DecodeFailure) LayerContents() []byte { return d.data }
+
+// LayerPayload implements Layer.
+func (d *DecodeFailure) LayerPayload() []byte { return nil }
+
+// String implements fmt.Stringer.
+func (d *DecodeFailure) String() string {
+	return "Packet decoding error: " + d.Error().Error()
+}
+
+// Dump implements Dumper.
+func (d *DecodeFailure) Dump() (s string) {
+	if d.stack != nil {
+		s = string(d.stack)
+	}
+	return
+}
+
+// LayerType returns LayerTypeDecodeFailure
+func (d *DecodeFailure) LayerType() LayerType { return LayerTypeDecodeFailure }
+
+// decodeUnknown "decodes" unsupported data types by returning an error.
+// This decoder will thus always return a DecodeFailure layer.
+func decodeUnknown(data []byte, p PacketBuilder) error {
+	return errors.New("Layer type not currently supported")
+}

vendor/github.com/google/gopacket/doc.go

@@ -0,0 +1,432 @@
+// Copyright 2012 Google, Inc. All rights reserved.
+//
+// Use of this source code is governed by a BSD-style license
+// that can be found in the LICENSE file in the root of the source
+// tree.
+
+/*
+Package gopacket provides packet decoding for the Go language.
+
+gopacket contains many sub-packages with additional functionality you may find
+useful, including:
+
+ * layers: You'll probably use this every time.  This contains of the logic
+     built into gopacket for decoding packet protocols.  Note that all example
+     code below assumes that you have imported both gopacket and
+     gopacket/layers.
+ * pcap: C bindings to use libpcap to read packets off the wire.
+ * pfring: C bindings to use PF_RING to read packets off the wire.
+ * afpacket: C bindings for Linux's AF_PACKET to read packets off the wire.
+ * tcpassembly: TCP stream reassembly
+
+Also, if you're looking to dive right into code, see the examples subdirectory
+for numerous simple binaries built using gopacket libraries.
+
+Minimum go version required is 1.5 except for pcapgo/EthernetHandle, afpacket,
+and bsdbpf which need at least 1.7 due to x/sys/unix dependencies.
+
+Basic Usage
+
+gopacket takes in packet data as a []byte and decodes it into a packet with
+a non-zero number of "layers".  Each layer corresponds to a protocol
+within the bytes.  Once a packet has been decoded, the layers of the packet
+can be requested from the packet.
+
+ // Decode a packet
+ packet := gopacket.NewPacket(myPacketData, layers.LayerTypeEthernet, gopacket.Default)
+ // Get the TCP layer from this packet
+ if tcpLayer := packet.Layer(layers.LayerTypeTCP); tcpLayer != nil {
+   fmt.Println("This is a TCP packet!")
+   // Get actual TCP data from this layer
+   tcp, _ := tcpLayer.(*layers.TCP)
+   fmt.Printf("From src port %d to dst port %d\n", tcp.SrcPort, tcp.DstPort)
+ }
+ // Iterate over all layers, printing out each layer type
+ for _, layer := range packet.Layers() {
+   fmt.Println("PACKET LAYER:", layer.LayerType())
+ }
+
+Packets can be decoded from a number of starting points.  Many of our base
+types implement Decoder, which allow us to decode packets for which
+we don't have full data.
+
+ // Decode an ethernet packet
+ ethP := gopacket.NewPacket(p1, layers.LayerTypeEthernet, gopacket.Default)
+ // Decode an IPv6 header and everything it contains
+ ipP := gopacket.NewPacket(p2, layers.LayerTypeIPv6, gopacket.Default)
+ // Decode a TCP header and its payload
+ tcpP := gopacket.NewPacket(p3, layers.LayerTypeTCP, gopacket.Default)
+
+
+Reading Packets From A Source
+
+Most of the time, you won't just have a []byte of packet data lying around.
+Instead, you'll want to read packets in from somewhere (file, interface, etc)
+and process them.  To do that, you'll want to build a PacketSource.
+
+First, you'll need to construct an object that implements the PacketDataSource
+interface.  There are implementations of this interface bundled with gopacket
+in the gopacket/pcap and gopacket/pfring subpackages... see their documentation
+for more information on their usage.  Once you have a PacketDataSource, you can
+pass it into NewPacketSource, along with a Decoder of your choice, to create
+a PacketSource.
+
+Once you have a PacketSource, you can read packets from it in multiple ways.
+See the docs for PacketSource for more details.  The easiest method is the
+Packets function, which returns a channel, then asynchronously writes new
+packets into that channel, closing the channel if the packetSource hits an
+end-of-file.
+
+  packetSource := ...  // construct using pcap or pfring
+  for packet := range packetSource.Packets() {
+    handlePacket(packet)  // do something with each packet
+  }
+
+You can change the decoding options of the packetSource by setting fields in
+packetSource.DecodeOptions... see the following sections for more details.
+
+
+Lazy Decoding
+
+gopacket optionally decodes packet data lazily, meaning it
+only decodes a packet layer when it needs to handle a function call.
+
+ // Create a packet, but don't actually decode anything yet
+ packet := gopacket.NewPacket(myPacketData, layers.LayerTypeEthernet, gopacket.Lazy)
+ // Now, decode the packet up to the first IPv4 layer found but no further.
+ // If no IPv4 layer was found, the whole packet will be decoded looking for
+ // it.
+ ip4 := packet.Layer(layers.LayerTypeIPv4)
+ // Decode all layers and return them.  The layers up to the first IPv4 layer
+ // are already decoded, and will not require decoding a second time.
+ layers := packet.Layers()
+
+Lazily-decoded packets are not concurrency-safe.  Since layers have not all been
+decoded, each call to Layer() or Layers() has the potential to mutate the packet
+in order to decode the next layer.  If a packet is used
+in multiple goroutines concurrently, don't use gopacket.Lazy.  Then gopacket
+will decode the packet fully, and all future function calls won't mutate the
+object.
+
+
+NoCopy Decoding
+
+By default, gopacket will copy the slice passed to NewPacket and store the
+copy within the packet, so future mutations to the bytes underlying the slice
+don't affect the packet and its layers.  If you can guarantee that the
+underlying slice bytes won't be changed, you can use NoCopy to tell
+gopacket.NewPacket, and it'll use the passed-in slice itself.
+
+ // This channel returns new byte slices, each of which points to a new
+ // memory location that's guaranteed immutable for the duration of the
+ // packet.
+ for data := range myByteSliceChannel {
+   p := gopacket.NewPacket(data, layers.LayerTypeEthernet, gopacket.NoCopy)
+   doSomethingWithPacket(p)
+ }
+
+The fastest method of decoding is to use both Lazy and NoCopy, but note from
+the many caveats above that for some implementations either or both may be
+dangerous.
+
+
+Pointers To Known Layers
+
+During decoding, certain layers are stored in the packet as well-known
+layer types.  For example, IPv4 and IPv6 are both considered NetworkLayer
+layers, while TCP and UDP are both TransportLayer layers.  We support 4
+layers, corresponding to the 4 layers of the TCP/IP layering scheme (roughly
+anagalous to layers 2, 3, 4, and 7 of the OSI model).  To access these,
+you can use the packet.LinkLayer, packet.NetworkLayer,
+packet.TransportLayer, and packet.ApplicationLayer functions.  Each of
+these functions returns a corresponding interface
+(gopacket.{Link,Network,Transport,Application}Layer).  The first three
+provide methods for getting src/dst addresses for that particular layer,
+while the final layer provides a Payload function to get payload data.
+This is helpful, for example, to get payloads for all packets regardless
+of their underlying data type:
+
+ // Get packets from some source
+ for packet := range someSource {
+   if app := packet.ApplicationLayer(); app != nil {
+     if strings.Contains(string(app.Payload()), "magic string") {
+       fmt.Println("Found magic string in a packet!")
+     }
+   }
+ }
+
+A particularly useful layer is ErrorLayer, which is set whenever there's
+an error parsing part of the packet.
+
+ packet := gopacket.NewPacket(myPacketData, layers.LayerTypeEthernet, gopacket.Default)
+ if err := packet.ErrorLayer(); err != nil {
+   fmt.Println("Error decoding some part of the packet:", err)
+ }
+
+Note that we don't return an error from NewPacket because we may have decoded
+a number of layers successfully before running into our erroneous layer.  You
+may still be able to get your Ethernet and IPv4 layers correctly, even if
+your TCP layer is malformed.
+
+
+Flow And Endpoint
+
+gopacket has two useful objects, Flow and Endpoint, for communicating in a protocol
+independent manner the fact that a packet is coming from A and going to B.
+The general layer types LinkLayer, NetworkLayer, and TransportLayer all provide
+methods for extracting their flow information, without worrying about the type
+of the underlying Layer.
+
+A Flow is a simple object made up of a set of two Endpoints, one source and one
+destination.  It details the sender and receiver of the Layer of the Packet.
+
+An Endpoint is a hashable representation of a source or destination.  For
+example, for LayerTypeIPv4, an Endpoint contains the IP address bytes for a v4
+IP packet.  A Flow can be broken into Endpoints, and Endpoints can be combined
+into Flows:
+
+ packet := gopacket.NewPacket(myPacketData, layers.LayerTypeEthernet, gopacket.Lazy)
+ netFlow := packet.NetworkLayer().NetworkFlow()
+ src, dst := netFlow.Endpoints()
+ reverseFlow := gopacket.NewFlow(dst, src)
+
+Both Endpoint and Flow objects can be used as map keys, and the equality
+operator can compare them, so you can easily group together all packets
+based on endpoint criteria:
+
+ flows := map[gopacket.Endpoint]chan gopacket.Packet
+ packet := gopacket.NewPacket(myPacketData, layers.LayerTypeEthernet, gopacket.Lazy)
+ // Send all TCP packets to channels based on their destination port.
+ if tcp := packet.Layer(layers.LayerTypeTCP); tcp != nil {
+   flows[tcp.TransportFlow().Dst()] <- packet
+ }
+ // Look for all packets with the same source and destination network address
+ if net := packet.NetworkLayer(); net != nil {
+   src, dst := net.NetworkFlow().Endpoints()
+   if src == dst {
+     fmt.Println("Fishy packet has same network source and dst: %s", src)
+   }
+ }
+ // Find all packets coming from UDP port 1000 to UDP port 500
+ interestingFlow := gopacket.FlowFromEndpoints(layers.NewUDPPortEndpoint(1000), layers.NewUDPPortEndpoint(500))
+ if t := packet.NetworkLayer(); t != nil && t.TransportFlow() == interestingFlow {
+   fmt.Println("Found that UDP flow I was looking for!")
+ }
+
+For load-balancing purposes, both Flow and Endpoint have FastHash() functions,
+which provide quick, non-cryptographic hashes of their contents.  Of particular
+importance is the fact that Flow FastHash() is symmetric: A->B will have the same
+hash as B->A.  An example usage could be:
+
+ channels := [8]chan gopacket.Packet
+ for i := 0; i < 8; i++ {
+   channels[i] = make(chan gopacket.Packet)
+   go packetHandler(channels[i])
+ }
+ for packet := range getPackets() {
+   if net := packet.NetworkLayer(); net != nil {
+     channels[int(net.NetworkFlow().FastHash()) & 0x7] <- packet
+   }
+ }
+
+This allows us to split up a packet stream while still making sure that each
+stream sees all packets for a flow (and its bidirectional opposite).
+
+
+Implementing Your Own Decoder
+
+If your network has some strange encapsulation, you can implement your own
+decoder.  In this example, we handle Ethernet packets which are encapsulated
+in a 4-byte header.
+
+ // Create a layer type, should be unique and high, so it doesn't conflict,
+ // giving it a name and a decoder to use.
+ var MyLayerType = gopacket.RegisterLayerType(12345, gopacket.LayerTypeMetadata{Name: "MyLayerType", Decoder: gopacket.DecodeFunc(decodeMyLayer)})
+
+ // Implement my layer
+ type MyLayer struct {
+   StrangeHeader []byte
+   payload []byte
+ }
+ func (m MyLayer) LayerType() gopacket.LayerType { return MyLayerType }
+ func (m MyLayer) LayerContents() []byte { return m.StrangeHeader }
+ func (m MyLayer) LayerPayload() []byte { return m.payload }
+
+ // Now implement a decoder... this one strips off the first 4 bytes of the
+ // packet.
+ func decodeMyLayer(data []byte, p gopacket.PacketBuilder) error {
+   // Create my layer
+   p.AddLayer(&MyLayer{data[:4], data[4:]})
+   // Determine how to handle the rest of the packet
+   return p.NextDecoder(layers.LayerTypeEthernet)
+ }
+
+ // Finally, decode your packets:
+ p := gopacket.NewPacket(data, MyLayerType, gopacket.Lazy)
+
+See the docs for Decoder and PacketBuilder for more details on how coding
+decoders works, or look at RegisterLayerType and RegisterEndpointType to see how
+to add layer/endpoint types to gopacket.
+
+
+Fast Decoding With DecodingLayerParser
+
+TLDR:  DecodingLayerParser takes about 10% of the time as NewPacket to decode
+packet data, but only for known packet stacks.
+
+Basic decoding using gopacket.NewPacket or PacketSource.Packets is somewhat slow
+due to its need to allocate a new packet and every respective layer.  It's very
+versatile and can handle all known layer types, but sometimes you really only
+care about a specific set of layers regardless, so that versatility is wasted.
+
+DecodingLayerParser avoids memory allocation altogether by decoding packet
+layers directly into preallocated objects, which you can then reference to get
+the packet's information.  A quick example:
+
+ func main() {
+   var eth layers.Ethernet
+   var ip4 layers.IPv4
+   var ip6 layers.IPv6
+   var tcp layers.TCP
+   parser := gopacket.NewDecodingLayerParser(layers.LayerTypeEthernet, &eth, &ip4, &ip6, &tcp)
+   decoded := []gopacket.LayerType{}
+   for packetData := range somehowGetPacketData() {
+     if err := parser.DecodeLayers(packetData, &decoded); err != nil {
+       fmt.Fprintf(os.Stderr, "Could not decode layers: %v\n", err)
+       continue
+     }
+     for _, layerType := range decoded {
+       switch layerType {
+         case layers.LayerTypeIPv6:
+           fmt.Println("    IP6 ", ip6.SrcIP, ip6.DstIP)
+         case layers.LayerTypeIPv4:
+           fmt.Println("    IP4 ", ip4.SrcIP, ip4.DstIP)
+       }
+     }
+   }
+ }
+
+The important thing to note here is that the parser is modifying the passed in
+layers (eth, ip4, ip6, tcp) instead of allocating new ones, thus greatly
+speeding up the decoding process.  It's even branching based on layer type...
+it'll handle an (eth, ip4, tcp) or (eth, ip6, tcp) stack.  However, it won't
+handle any other type... since no other decoders were passed in, an (eth, ip4,
+udp) stack will stop decoding after ip4, and only pass back [LayerTypeEthernet,
+LayerTypeIPv4] through the 'decoded' slice (along with an error saying it can't
+decode a UDP packet).
+
+Unfortunately, not all layers can be used by DecodingLayerParser... only those
+implementing the DecodingLayer interface are usable.  Also, it's possible to
+create DecodingLayers that are not themselves Layers... see
+layers.IPv6ExtensionSkipper for an example of this.
+
+Faster And Customized Decoding with DecodingLayerContainer
+
+By default, DecodingLayerParser uses native map to store and search for a layer
+to decode. Though being versatile, in some cases this solution may be not so
+optimal. For example, if you have only few layers faster operations may be
+provided by sparse array indexing or linear array scan.
+
+To accomodate these scenarios, DecodingLayerContainer interface is introduced
+along with its implementations: DecodingLayerSparse, DecodingLayerArray and
+DecodingLayerMap. You can specify a container implementation to
+DecodingLayerParser with SetDecodingLayerContainer method. Example:
+
+ dlp := gopacket.NewDecodingLayerParser(LayerTypeEthernet)
+ dlp.SetDecodingLayerContainer(gopacket.DecodingLayerSparse(nil))
+ var eth layers.Ethernet
+ dlp.AddDecodingLayer(&eth)
+ // ... add layers and use DecodingLayerParser as usual...
+
+To skip one level of indirection (though sacrificing some capabilities) you may
+also use DecodingLayerContainer as a decoding tool as it is. In this case you have to
+handle unknown layer types and layer panics by yourself. Example:
+
+ func main() {
+   var eth layers.Ethernet
+   var ip4 layers.IPv4
+   var ip6 layers.IPv6
+   var tcp layers.TCP
+   dlc := gopacket.DecodingLayerContainer(gopacket.DecodingLayerArray(nil))
+   dlc = dlc.Put(&eth)
+   dlc = dlc.Put(&ip4)
+   dlc = dlc.Put(&ip6)
+   dlc = dlc.Put(&tcp)
+   // you may specify some meaningful DecodeFeedback
+   decoder := dlc.LayersDecoder(LayerTypeEthernet, gopacket.NilDecodeFeedback)
+   decoded := make([]gopacket.LayerType, 0, 20)
+   for packetData := range somehowGetPacketData() {
+     lt, err := decoder(packetData, &decoded)
+     if err != nil {
+       fmt.Fprintf(os.Stderr, "Could not decode layers: %v\n", err)
+       continue
+     }
+     if lt != gopacket.LayerTypeZero {
+       fmt.Fprintf(os.Stderr, "unknown layer type: %v\n", lt)
+       continue
+     }
+     for _, layerType := range decoded {
+       // examine decoded layertypes just as already shown above
+     }
+   }
+ }
+
+DecodingLayerSparse is the fastest but most effective when LayerType values
+that layers in use can decode are not large because otherwise that would lead
+to bigger memory footprint. DecodingLayerArray is very compact and primarily
+usable if the number of decoding layers is not big (up to ~10-15, but please do
+your own benchmarks). DecodingLayerMap is the most versatile one and used by
+DecodingLayerParser by default. Please refer to tests and benchmarks in layers
+subpackage to further examine usage examples and performance measurements.
+
+You may also choose to implement your own DecodingLayerContainer if you want to
+make use of your own internal packet decoding logic.
+
+Creating Packet Data
+
+As well as offering the ability to decode packet data, gopacket will allow you
+to create packets from scratch, as well.  A number of gopacket layers implement
+the SerializableLayer interface; these layers can be serialized to a []byte in
+the following manner:
+
+  ip := &layers.IPv4{
+    SrcIP: net.IP{1, 2, 3, 4},
+    DstIP: net.IP{5, 6, 7, 8},
+    // etc...
+  }
+  buf := gopacket.NewSerializeBuffer()
+  opts := gopacket.SerializeOptions{}  // See SerializeOptions for more details.
+  err := ip.SerializeTo(buf, opts)
+  if err != nil { panic(err) }
+  fmt.Println(buf.Bytes())  // prints out a byte slice containing the serialized IPv4 layer.
+
+SerializeTo PREPENDS the given layer onto the SerializeBuffer, and they treat
+the current buffer's Bytes() slice as the payload of the serializing layer.
+Therefore, you can serialize an entire packet by serializing a set of layers in
+reverse order (Payload, then TCP, then IP, then Ethernet, for example).  The
+SerializeBuffer's SerializeLayers function is a helper that does exactly that.
+
+To generate a (empty and useless, because no fields are set)
+Ethernet(IPv4(TCP(Payload))) packet, for example, you can run:
+
+  buf := gopacket.NewSerializeBuffer()
+  opts := gopacket.SerializeOptions{}
+  gopacket.SerializeLayers(buf, opts,
+    &layers.Ethernet{},
+    &layers.IPv4{},
+    &layers.TCP{},
+    gopacket.Payload([]byte{1, 2, 3, 4}))
+  packetData := buf.Bytes()
+
+A Final Note
+
+If you use gopacket, you'll almost definitely want to make sure gopacket/layers
+is imported, since when imported it sets all the LayerType variables and fills
+in a lot of interesting variables/maps (DecodersByLayerName, etc).  Therefore,
+it's recommended that even if you don't use any layers functions directly, you still import with:
+
+  import (
+    _ "github.com/google/gopacket/layers"
+  )
+*/
+package gopacket

vendor/github.com/google/gopacket/flows.go

@@ -0,0 +1,236 @@
+// Copyright 2012 Google, Inc. All rights reserved.
+//
+// Use of this source code is governed by a BSD-style license
+// that can be found in the LICENSE file in the root of the source
+// tree.
+
+package gopacket
+
+import (
+	"bytes"
+	"fmt"
+	"strconv"
+)
+
+// MaxEndpointSize determines the maximum size in bytes of an endpoint address.
+//
+// Endpoints/Flows have a problem:  They need to be hashable.  Therefore, they
+// can't use a byte slice.  The two obvious choices are to use a string or a
+// byte array.  Strings work great, but string creation requires memory
+// allocation, which can be slow.  Arrays work great, but have a fixed size.  We
+// originally used the former, now we've switched to the latter.  Use of a fixed
+// byte-array doubles the speed of constructing a flow (due to not needing to
+// allocate).  This is a huge increase... too much for us to pass up.
+//
+// The end result of this, though, is that an endpoint/flow can't be created
+// using more than MaxEndpointSize bytes per address.
+const MaxEndpointSize = 16
+
+// Endpoint is the set of bytes used to address packets at various layers.
+// See LinkLayer, NetworkLayer, and TransportLayer specifications.
+// Endpoints are usable as map keys.
+type Endpoint struct {
+	typ EndpointType
+	len int
+	raw [MaxEndpointSize]byte
+}
+
+// EndpointType returns the endpoint type associated with this endpoint.
+func (a Endpoint) EndpointType() EndpointType { return a.typ }
+
+// Raw returns the raw bytes of this endpoint.  These aren't human-readable
+// most of the time, but they are faster than calling String.
+func (a Endpoint) Raw() []byte { return a.raw[:a.len] }
+
+// LessThan provides a stable ordering for all endpoints.  It sorts first based
+// on the EndpointType of an endpoint, then based on the raw bytes of that
+// endpoint.
+//
+// For some endpoints, the actual comparison may not make sense, however this
+// ordering does provide useful information for most Endpoint types.
+// Ordering is based first on endpoint type, then on raw endpoint bytes.
+// Endpoint bytes are sorted lexicographically.
+func (a Endpoint) LessThan(b Endpoint) bool {
+	return a.typ < b.typ || (a.typ == b.typ && bytes.Compare(a.raw[:a.len], b.raw[:b.len]) < 0)
+}
+
+// fnvHash is used by our FastHash functions, and implements the FNV hash
+// created by Glenn Fowler, Landon Curt Noll, and Phong Vo.
+// See http://isthe.com/chongo/tech/comp/fnv/.
+func fnvHash(s []byte) (h uint64) {
+	h = fnvBasis
+	for i := 0; i < len(s); i++ {
+		h ^= uint64(s[i])
+		h *= fnvPrime
+	}
+	return
+}
+
+const fnvBasis = 14695981039346656037
+const fnvPrime = 1099511628211
+
+// FastHash provides a quick hashing function for an endpoint, useful if you'd
+// like to split up endpoints by modulos or other load-balancing techniques.
+// It uses a variant of Fowler-Noll-Vo hashing.
+//
+// The output of FastHash is not guaranteed to remain the same through future
+// code revisions, so should not be used to key values in persistent storage.
+func (a Endpoint) FastHash() (h uint64) {
+	h = fnvHash(a.raw[:a.len])
+	h ^= uint64(a.typ)
+	h *= fnvPrime
+	return
+}
+
+// NewEndpoint creates a new Endpoint object.
+//
+// The size of raw must be less than MaxEndpointSize, otherwise this function
+// will panic.
+func NewEndpoint(typ EndpointType, raw []byte) (e Endpoint) {
+	e.len = len(raw)
+	if e.len > MaxEndpointSize {
+		panic("raw byte length greater than MaxEndpointSize")
+	}
+	e.typ = typ
+	copy(e.raw[:], raw)
+	return
+}
+
+// EndpointTypeMetadata is used to register a new endpoint type.
+type EndpointTypeMetadata struct {
+	// Name is the string returned by an EndpointType's String function.
+	Name string
+	// Formatter is called from an Endpoint's String function to format the raw
+	// bytes in an Endpoint into a human-readable string.
+	Formatter func([]byte) string
+}
+
+// EndpointType is the type of a gopacket Endpoint.  This type determines how
+// the bytes stored in the endpoint should be interpreted.
+type EndpointType int64
+
+var endpointTypes = map[EndpointType]EndpointTypeMetadata{}
+
+// RegisterEndpointType creates a new EndpointType and registers it globally.
+// It MUST be passed a unique number, or it will panic.  Numbers 0-999 are
+// reserved for gopacket's use.
+func RegisterEndpointType(num int, meta EndpointTypeMetadata) EndpointType {
+	t := EndpointType(num)
+	if _, ok := endpointTypes[t]; ok {
+		panic("Endpoint type number already in use")
+	}
+	endpointTypes[t] = meta
+	return t
+}
+
+func (e EndpointType) String() string {
+	if t, ok := endpointTypes[e]; ok {
+		return t.Name
+	}
+	return strconv.Itoa(int(e))
+}
+
+func (a Endpoint) String() string {
+	if t, ok := endpointTypes[a.typ]; ok && t.Formatter != nil {
+		return t.Formatter(a.raw[:a.len])
+	}
+	return fmt.Sprintf("%v:%v", a.typ, a.raw)
+}
+
+// Flow represents the direction of traffic for a packet layer, as a source and destination Endpoint.
+// Flows are usable as map keys.
+type Flow struct {
+	typ        EndpointType
+	slen, dlen int
+	src, dst   [MaxEndpointSize]byte
+}
+
+// FlowFromEndpoints creates a new flow by pasting together two endpoints.
+// The endpoints must have the same EndpointType, or this function will return
+// an error.
+func FlowFromEndpoints(src, dst Endpoint) (_ Flow, err error) {
+	if src.typ != dst.typ {
+		err = fmt.Errorf("Mismatched endpoint types: %v->%v", src.typ, dst.typ)
+		return
+	}
+	return Flow{src.typ, src.len, dst.len, src.raw, dst.raw}, nil
+}
+
+// FastHash provides a quick hashing function for a flow, useful if you'd
+// like to split up flows by modulos or other load-balancing techniques.
+// It uses a variant of Fowler-Noll-Vo hashing, and is guaranteed to collide
+// with its reverse flow.  IE: the flow A->B will have the same hash as the flow
+// B->A.
+//
+// The output of FastHash is not guaranteed to remain the same through future
+// code revisions, so should not be used to key values in persistent storage.
+func (f Flow) FastHash() (h uint64) {
+	// This combination must be commutative.  We don't use ^, since that would
+	// give the same hash for all A->A flows.
+	h = fnvHash(f.src[:f.slen]) + fnvHash(f.dst[:f.dlen])
+	h ^= uint64(f.typ)
+	h *= fnvPrime
+	return
+}
+
+// String returns a human-readable representation of this flow, in the form
+// "Src->Dst"
+func (f Flow) String() string {
+	s, d := f.Endpoints()
+	return fmt.Sprintf("%v->%v", s, d)
+}
+
+// EndpointType returns the EndpointType for this Flow.
+func (f Flow) EndpointType() EndpointType {
+	return f.typ
+}
+
+// Endpoints returns the two Endpoints for this flow.
+func (f Flow) Endpoints() (src, dst Endpoint) {
+	return Endpoint{f.typ, f.slen, f.src}, Endpoint{f.typ, f.dlen, f.dst}
+}
+
+// Src returns the source Endpoint for this flow.
+func (f Flow) Src() (src Endpoint) {
+	src, _ = f.Endpoints()
+	return
+}
+
+// Dst returns the destination Endpoint for this flow.
+func (f Flow) Dst() (dst Endpoint) {
+	_, dst = f.Endpoints()
+	return
+}
+
+// Reverse returns a new flow with endpoints reversed.
+func (f Flow) Reverse() Flow {
+	return Flow{f.typ, f.dlen, f.slen, f.dst, f.src}
+}
+
+// NewFlow creates a new flow.
+//
+// src and dst must have length <= MaxEndpointSize, otherwise NewFlow will
+// panic.
+func NewFlow(t EndpointType, src, dst []byte) (f Flow) {
+	f.slen = len(src)
+	f.dlen = len(dst)
+	if f.slen > MaxEndpointSize || f.dlen > MaxEndpointSize {
+		panic("flow raw byte length greater than MaxEndpointSize")
+	}
+	f.typ = t
+	copy(f.src[:], src)
+	copy(f.dst[:], dst)
+	return
+}
+
+// EndpointInvalid is an endpoint type used for invalid endpoints, IE endpoints
+// that are specified incorrectly during creation.
+var EndpointInvalid = RegisterEndpointType(0, EndpointTypeMetadata{Name: "invalid", Formatter: func(b []byte) string {
+	return fmt.Sprintf("%v", b)
+}})
+
+// InvalidEndpoint is a singleton Endpoint of type EndpointInvalid.
+var InvalidEndpoint = NewEndpoint(EndpointInvalid, nil)
+
+// InvalidFlow is a singleton Flow of type EndpointInvalid.
+var InvalidFlow = NewFlow(EndpointInvalid, nil, nil)

vendor/github.com/google/gopacket/gc

@@ -0,0 +1,288 @@
+#!/bin/bash
+# Copyright 2012 Google, Inc. All rights reserved.
+
+# This script provides a simple way to run benchmarks against previous code and
+# keep a log of how benchmarks change over time.  When used with the --benchmark
+# flag, it runs benchmarks from the current code and from the last commit run
+# with --benchmark, then stores the results in the git commit description.  We
+# rerun the old benchmarks along with the new ones, since there's no guarantee
+# that git commits will happen on the same machine, so machine differences could
+# cause wildly inaccurate results.
+#
+# If you're making changes to 'gopacket' which could cause performance changes,
+# you may be requested to use this commit script to make sure your changes don't
+# have large detrimental effects (or to show off how awesome your performance
+# improvements are).
+#
+# If not run with the --benchmark flag, this script is still very useful... it
+# makes sure all the correct go formatting, building, and testing work as
+# expected.
+
+function Usage {
+  cat <<EOF
+USAGE:  $0 [--benchmark regexp] [--root] [--gen] <git commit flags...>
+
+--benchmark:  Run benchmark comparisons against last benchmark'd commit
+--root:  Run tests that require root priviledges
+--gen:  Generate code for MACs/ports by pulling down external data
+
+Note, some 'git commit' flags are necessary, if all else fails, pass in -a
+EOF
+  exit 1
+}
+
+BENCH=""
+GEN=""
+ROOT=""
+while [ ! -z "$1" ]; do
+  case "$1" in
+    "--benchmark")
+      BENCH="$2"
+      shift
+      shift
+      ;;
+    "--gen")
+      GEN="yes"
+      shift
+      ;;
+    "--root")
+      ROOT="yes"
+      shift
+      ;;
+    "--help")
+      Usage
+      ;;
+    "-h")
+      Usage
+      ;;
+    "help")
+      Usage
+      ;;
+    *)
+      break
+      ;;
+  esac
+done
+
+function Root {
+  if [ ! -z "$ROOT" ]; then
+    local exec="$1"
+    # Some folks (like me) keep source code in places inaccessible by root (like
+    # NFS), so to make sure things run smoothly we copy them to a /tmp location.
+    local tmpfile="$(mktemp -t gopacket_XXXXXXXX)"
+    echo "Running root test executable $exec as $tmpfile"
+    cp "$exec" "$tmpfile"
+    chmod a+x "$tmpfile"
+    shift
+    sudo "$tmpfile" "$@"
+  fi
+}
+
+if [ "$#" -eq "0" ]; then
+  Usage
+fi
+
+cd $(dirname $0)
+
+# Check for copyright notices.
+for filename in $(find ./ -type f -name '*.go'); do
+  if ! head -n 1 "$filename" | grep -q Copyright; then
+    echo "File '$filename' may not have copyright notice"
+    exit 1
+  fi
+done
+
+set -e
+set -x
+
+if [ ! -z "$ROOT" ]; then
+  echo "Running SUDO to get root priviledges for root tests"
+  sudo echo "have root"
+fi
+
+if [ ! -z "$GEN" ]; then
+  pushd macs
+  go run gen.go | gofmt > valid_mac_prefixes.go
+  popd
+  pushd layers
+  go run gen.go | gofmt > iana_ports.go
+  go run gen2.go | gofmt > enums_generated.go
+  popd
+fi
+
+# Make sure everything is formatted, compiles, and tests pass.
+go fmt ./...
+go test -i ./... 2>/dev/null >/dev/null || true
+go test
+go build
+pushd examples/bytediff
+go build
+popd
+if [ -f /usr/include/pcap.h ]; then
+  pushd pcap
+  go test ./...
+  go build ./...
+  go build pcap_tester.go
+  Root pcap_tester --mode=basic
+  Root pcap_tester --mode=filtered
+  Root pcap_tester --mode=timestamp || echo "You might not support timestamp sources"
+  popd
+  pushd examples/afpacket
+  go build
+  popd
+  pushd examples/pcapdump
+  go build
+  popd
+  pushd examples/arpscan
+  go build
+  popd
+  pushd examples/bidirectional
+  go build
+  popd
+  pushd examples/synscan
+  go build
+  popd
+  pushd examples/httpassembly
+  go build
+  popd
+  pushd examples/statsassembly
+  go build
+  popd
+fi
+pushd macs
+go test ./...
+gofmt -w gen.go
+go build gen.go
+popd
+pushd tcpassembly
+go test ./...
+popd
+pushd reassembly
+go test ./...
+popd
+pushd layers
+gofmt -w gen.go
+go build gen.go
+go test ./...
+popd
+pushd pcapgo
+go test ./...
+go build ./...
+popd
+if [ -f /usr/include/linux/if_packet.h ]; then
+  if grep -q TPACKET_V3 /usr/include/linux/if_packet.h; then
+    pushd afpacket
+    go build ./...
+    go test ./...
+    popd
+  fi
+fi
+if [ -f /usr/include/pfring.h ]; then
+  pushd pfring
+  go test ./...
+  go build ./...
+  popd
+  pushd examples/pfdump
+  go build
+  popd
+fi
+pushd ip4defrag
+go test ./...
+popd
+pushd defrag
+go test ./...
+popd
+
+for travis_script in `ls .travis.*.sh`; do
+  ./$travis_script
+done
+
+# Run our initial commit
+git commit "$@"
+
+if [ -z "$BENCH" ]; then
+  set +x
+  echo "We're not benchmarking and we've committed... we're done!"
+  exit
+fi
+
+### If we get here, we want to run benchmarks from current commit, and compare
+### then to benchmarks from the last --benchmark commit.
+
+# Get our current branch.
+BRANCH="$(git branch | grep '^*' | awk '{print $2}')"
+
+# File we're going to build our commit description in.
+COMMIT_FILE="$(mktemp /tmp/tmp.XXXXXXXX)"
+
+# Add the word "BENCH" to the start of the git commit.
+echo -n "BENCH " > $COMMIT_FILE
+
+# Get the current description... there must be an easier way.
+git log -n 1 | grep '^ ' | sed 's/^    //' >> $COMMIT_FILE
+
+# Get the commit sha for the last benchmark commit
+PREV=$(git log -n 1 --grep='BENCHMARK_MARKER_DO_NOT_CHANGE' | head -n 1 | awk '{print $2}')
+
+## Run current benchmarks
+
+cat >> $COMMIT_FILE <<EOF
+
+
+----------------------------------------------------------
+BENCHMARK_MARKER_DO_NOT_CHANGE
+----------------------------------------------------------
+
+Go version $(go version)
+
+
+TEST BENCHMARKS "$BENCH"
+EOF
+# go seems to have trouble with 'go test --bench=. ./...'
+go test --test.bench="$BENCH" 2>&1 | tee -a $COMMIT_FILE
+pushd layers
+go test --test.bench="$BENCH" 2>&1 | tee -a $COMMIT_FILE
+popd
+cat >> $COMMIT_FILE <<EOF
+
+
+PCAP BENCHMARK
+EOF
+if [ "$BENCH" -eq ".*" ]; then
+  go run pcap/gopacket_benchmark/*.go 2>&1 | tee -a $COMMIT_FILE
+fi
+
+
+
+## Reset to last benchmark commit, run benchmarks
+
+git checkout $PREV
+
+cat >> $COMMIT_FILE <<EOF
+----------------------------------------------------------
+BENCHMARKING AGAINST COMMIT $PREV
+----------------------------------------------------------
+
+
+OLD TEST BENCHMARKS
+EOF
+# go seems to have trouble with 'go test --bench=. ./...'
+go test --test.bench="$BENCH" 2>&1 | tee -a $COMMIT_FILE
+pushd layers
+go test --test.bench="$BENCH" 2>&1 | tee -a $COMMIT_FILE
+popd
+cat >> $COMMIT_FILE <<EOF
+
+
+OLD PCAP BENCHMARK
+EOF
+if [ "$BENCH" -eq ".*" ]; then
+  go run pcap/gopacket_benchmark/*.go 2>&1 | tee -a $COMMIT_FILE
+fi
+
+
+
+## Reset back to the most recent commit, edit the commit message by appending
+## benchmark results.
+git checkout $BRANCH
+git commit --amend -F $COMMIT_FILE

vendor/github.com/google/gopacket/layerclass.go

@@ -0,0 +1,107 @@
+// Copyright 2012 Google, Inc. All rights reserved.
+//
+// Use of this source code is governed by a BSD-style license
+// that can be found in the LICENSE file in the root of the source
+// tree.
+
+package gopacket
+
+// LayerClass is a set of LayerTypes, used for grabbing one of a number of
+// different types from a packet.
+type LayerClass interface {
+	// Contains returns true if the given layer type should be considered part
+	// of this layer class.
+	Contains(LayerType) bool
+	// LayerTypes returns the set of all layer types in this layer class.
+	// Note that this may not be a fast operation on all LayerClass
+	// implementations.
+	LayerTypes() []LayerType
+}
+
+// Contains implements LayerClass.
+func (l LayerType) Contains(a LayerType) bool {
+	return l == a
+}
+
+// LayerTypes implements LayerClass.
+func (l LayerType) LayerTypes() []LayerType {
+	return []LayerType{l}
+}
+
+// LayerClassSlice implements a LayerClass with a slice.
+type LayerClassSlice []bool
+
+// Contains returns true if the given layer type should be considered part
+// of this layer class.
+func (s LayerClassSlice) Contains(t LayerType) bool {
+	return int(t) < len(s) && s[t]
+}
+
+// LayerTypes returns all layer types in this LayerClassSlice.
+// Because of LayerClassSlice's implementation, this could be quite slow.
+func (s LayerClassSlice) LayerTypes() (all []LayerType) {
+	for i := 0; i < len(s); i++ {
+		if s[i] {
+			all = append(all, LayerType(i))
+		}
+	}
+	return
+}
+
+// NewLayerClassSlice creates a new LayerClassSlice by creating a slice of
+// size max(types) and setting slice[t] to true for each type t.  Note, if
+// you implement your own LayerType and give it a high value, this WILL create
+// a very large slice.
+func NewLayerClassSlice(types []LayerType) LayerClassSlice {
+	var max LayerType
+	for _, typ := range types {
+		if typ > max {
+			max = typ
+		}
+	}
+	t := make([]bool, int(max+1))
+	for _, typ := range types {
+		t[typ] = true
+	}
+	return t
+}
+
+// LayerClassMap implements a LayerClass with a map.
+type LayerClassMap map[LayerType]bool
+
+// Contains returns true if the given layer type should be considered part
+// of this layer class.
+func (m LayerClassMap) Contains(t LayerType) bool {
+	return m[t]
+}
+
+// LayerTypes returns all layer types in this LayerClassMap.
+func (m LayerClassMap) LayerTypes() (all []LayerType) {
+	for t := range m {
+		all = append(all, t)
+	}
+	return
+}
+
+// NewLayerClassMap creates a LayerClassMap and sets map[t] to true for each
+// type in types.
+func NewLayerClassMap(types []LayerType) LayerClassMap {
+	m := LayerClassMap{}
+	for _, typ := range types {
+		m[typ] = true
+	}
+	return m
+}
+
+// NewLayerClass creates a LayerClass, attempting to be smart about which type
+// it creates based on which types are passed in.
+func NewLayerClass(types []LayerType) LayerClass {
+	for _, typ := range types {
+		if typ > maxLayerType {
+			// NewLayerClassSlice could create a very large object, so instead create
+			// a map.
+			return NewLayerClassMap(types)
+		}
+	}
+	return NewLayerClassSlice(types)
+}

vendor/github.com/google/gopacket/layers/.lint_blacklist

@@ -0,0 +1,39 @@
+dot11.go
+eap.go
+endpoints.go
+enums_generated.go
+enums.go
+ethernet.go
+geneve.go
+icmp4.go
+icmp6.go
+igmp.go
+ip4.go
+ip6.go
+layertypes.go
+linux_sll.go
+llc.go
+lldp.go
+mpls.go
+ndp.go
+ntp.go
+ospf.go
+pflog.go
+pppoe.go
+prism.go
+radiotap.go
+rudp.go
+sctp.go
+sflow.go
+tcp.go
+tcpip.go
+tls.go
+tls_alert.go
+tls_appdata.go
+tls_cipherspec.go
+tls_hanshake.go
+tls_test.go
+udp.go
+udplite.go
+usb.go
+vrrp.go

vendor/github.com/google/gopacket/layers/arp.go

@@ -0,0 +1,118 @@
+// Copyright 2012 Google, Inc. All rights reserved.
+// Copyright 2009-2011 Andreas Krennmair. All rights reserved.
+//
+// Use of this source code is governed by a BSD-style license
+// that can be found in the LICENSE file in the root of the source
+// tree.
+
+package layers
+
+import (
+	"encoding/binary"
+	"errors"
+	"fmt"
+
+	"github.com/google/gopacket"
+)
+
+// Potential values for ARP.Operation.
+const (
+	ARPRequest = 1
+	ARPReply   = 2
+)
+
+// ARP is a ARP packet header.
+type ARP struct {
+	BaseLayer
+	AddrType          LinkType
+	Protocol          EthernetType
+	HwAddressSize     uint8
+	ProtAddressSize   uint8
+	Operation         uint16
+	SourceHwAddress   []byte
+	SourceProtAddress []byte
+	DstHwAddress      []byte
+	DstProtAddress    []byte
+}
+
+// LayerType returns LayerTypeARP
+func (arp *ARP) LayerType() gopacket.LayerType { return LayerTypeARP }
+
+// DecodeFromBytes decodes the given bytes into this layer.
+func (arp *ARP) DecodeFromBytes(data []byte, df gopacket.DecodeFeedback) error {
+	if len(data) < 8 {
+		df.SetTruncated()
+		return fmt.Errorf("ARP length %d too short", len(data))
+	}
+	arp.AddrType = LinkType(binary.BigEndian.Uint16(data[0:2]))
+	arp.Protocol = EthernetType(binary.BigEndian.Uint16(data[2:4]))
+	arp.HwAddressSize = data[4]
+	arp.ProtAddressSize = data[5]
+	arp.Operation = binary.BigEndian.Uint16(data[6:8])
+	arpLength := 8 + 2*arp.HwAddressSize + 2*arp.ProtAddressSize
+	if len(data) < int(arpLength) {
+		df.SetTruncated()
+		return fmt.Errorf("ARP length %d too short, %d expected", len(data), arpLength)
+	}
+	arp.SourceHwAddress = data[8 : 8+arp.HwAddressSize]
+	arp.SourceProtAddress = data[8+arp.HwAddressSize : 8+arp.HwAddressSize+arp.ProtAddressSize]
+	arp.DstHwAddress = data[8+arp.HwAddressSize+arp.ProtAddressSize : 8+2*arp.HwAddressSize+arp.ProtAddressSize]
+	arp.DstProtAddress = data[8+2*arp.HwAddressSize+arp.ProtAddressSize : 8+2*arp.HwAddressSize+2*arp.ProtAddressSize]
+
+	arp.Contents = data[:arpLength]
+	arp.Payload = data[arpLength:]
+	return nil
+}
+
+// SerializeTo writes the serialized form of this layer into the
+// SerializationBuffer, implementing gopacket.SerializableLayer.
+// See the docs for gopacket.SerializableLayer for more info.
+func (arp *ARP) SerializeTo(b gopacket.SerializeBuffer, opts gopacket.SerializeOptions) error {
+	size := 8 + len(arp.SourceHwAddress) + len(arp.SourceProtAddress) + len(arp.DstHwAddress) + len(arp.DstProtAddress)
+	bytes, err := b.PrependBytes(size)
+	if err != nil {
+		return err
+	}
+	if opts.FixLengths {
+		if len(arp.SourceHwAddress) != len(arp.DstHwAddress) {
+			return errors.New("mismatched hardware address sizes")
+		}
+		arp.HwAddressSize = uint8(len(arp.SourceHwAddress))
+		if len(arp.SourceProtAddress) != len(arp.DstProtAddress) {
+			return errors.New("mismatched prot address sizes")
+		}
+		arp.ProtAddressSize = uint8(len(arp.SourceProtAddress))
+	}
+	binary.BigEndian.PutUint16(bytes, uint16(arp.AddrType))
+	binary.BigEndian.PutUint16(bytes[2:], uint16(arp.Protocol))
+	bytes[4] = arp.HwAddressSize
+	bytes[5] = arp.ProtAddressSize
+	binary.BigEndian.PutUint16(bytes[6:], arp.Operation)
+	start := 8
+	for _, addr := range [][]byte{
+		arp.SourceHwAddress,
+		arp.SourceProtAddress,
+		arp.DstHwAddress,
+		arp.DstProtAddress,
+	} {
+		copy(bytes[start:], addr)
+		start += len(addr)
+	}
+	return nil
+}
+
+// CanDecode returns the set of layer types that this DecodingLayer can decode.
+func (arp *ARP) CanDecode() gopacket.LayerClass {
+	return LayerTypeARP
+}
+
+// NextLayerType returns the layer type contained by this DecodingLayer.
+func (arp *ARP) NextLayerType() gopacket.LayerType {
+	return gopacket.LayerTypePayload
+}
+
+func decodeARP(data []byte, p gopacket.PacketBuilder) error {
+
+	arp := &ARP{}
+	return decodingLayerDecoder(arp, data, p)
+}

vendor/github.com/google/gopacket/layers/asf.go

@@ -0,0 +1,166 @@
+// Copyright 2019 The GoPacket Authors. All rights reserved.
+//
+// Use of this source code is governed by a BSD-style license that can be found
+// in the LICENSE file in the root of the source tree.
+
+package layers
+
+// This file implements the ASF RMCP payload specified in section 3.2.2.3 of
+// https://www.dmtf.org/sites/default/files/standards/documents/DSP0136.pdf
+
+import (
+	"encoding/binary"
+	"fmt"
+
+	"github.com/google/gopacket"
+)
+
+const (
+	// ASFRMCPEnterprise is the IANA-assigned Enterprise Number of the ASF-RMCP.
+	ASFRMCPEnterprise uint32 = 4542
+)
+
+// ASFDataIdentifier encapsulates fields used to uniquely identify the format of
+// the data block.
+//
+// While the enterprise number is almost always 4542 (ASF-RMCP), we support
+// registering layers using structs of this type as a key in case any users are
+// using OEM-extensions.
+type ASFDataIdentifier struct {
+
+	// Enterprise is the IANA Enterprise Number associated with the entity that
+	// defines the message type. A list can be found at
+	// https://www.iana.org/assignments/enterprise-numbers/enterprise-numbers.
+	// This can be thought of as the namespace for the message type.
+	Enterprise uint32
+
+	// Type is the message type, defined by the entity associated with the
+	// enterprise above. No pressure, but in the context of EN 4542, 1 byte is
+	// the difference between sending a ping and telling a machine to do an
+	// unconditional power down (0x80 and 0x12 respectively).
+	Type uint8
+}
+
+// LayerType returns the payload layer type corresponding to an ASF message
+// type.
+func (a ASFDataIdentifier) LayerType() gopacket.LayerType {
+	if lt := asfDataLayerTypes[a]; lt != 0 {
+		return lt
+	}
+
+	// some layer types don't have a payload, e.g. ASF-RMCP Presence Ping.
+	return gopacket.LayerTypePayload
+}
+
+// RegisterASFLayerType allows specifying that the data block of ASF packets
+// with a given enterprise number and type should be processed by a given layer
+// type. This overrides any existing registrations, including defaults.
+func RegisterASFLayerType(a ASFDataIdentifier, l gopacket.LayerType) {
+	asfDataLayerTypes[a] = l
+}
+
+var (
+	// ASFDataIdentifierPresencePong is the message type of the response to a
+	// Presence Ping message. It indicates the sender is ASF-RMCP-aware.
+	ASFDataIdentifierPresencePong = ASFDataIdentifier{
+		Enterprise: ASFRMCPEnterprise,
+		Type:       0x40,
+	}
+
+	// ASFDataIdentifierPresencePing is a message type sent to a managed client
+	// to solicit a Presence Pong response. Clients may ignore this if the RMCP
+	// version is unsupported. Sending this message with a sequence number <255
+	// is the recommended way of finding out whether an implementation sends
+	// RMCP ACKs (e.g. iDRAC does, Super Micro does not).
+	//
+	// Systems implementing IPMI must respond to this ping to conform to the
+	// spec, so it is a good substitute for an ICMP ping.
+	ASFDataIdentifierPresencePing = ASFDataIdentifier{
+		Enterprise: ASFRMCPEnterprise,
+		Type:       0x80,
+	}
+
+	// asfDataLayerTypes is used to find the next layer for a given ASF header.
+	asfDataLayerTypes = map[ASFDataIdentifier]gopacket.LayerType{
+		ASFDataIdentifierPresencePong: LayerTypeASFPresencePong,
+	}
+)
+
+// ASF defines ASF's generic RMCP message Data block format. See section
+// 3.2.2.3.
+type ASF struct {
+	BaseLayer
+	ASFDataIdentifier
+
+	// Tag is used to match request/response pairs. The tag of a response is set
+	// to that of the message it is responding to. If a message is
+	// unidirectional, i.e. not part of a request/response pair, this is set to
+	// 255.
+	Tag uint8
+
+	// 1 byte reserved, set to 0x00.
+
+	// Length is the length of this layer's payload in bytes.
+	Length uint8
+}
+
+// LayerType returns LayerTypeASF. It partially satisfies Layer and
+// SerializableLayer.
+func (*ASF) LayerType() gopacket.LayerType {
+	return LayerTypeASF
+}
+
+// CanDecode returns LayerTypeASF. It partially satisfies DecodingLayer.
+func (a *ASF) CanDecode() gopacket.LayerClass {
+	return a.LayerType()
+}
+
+// DecodeFromBytes makes the layer represent the provided bytes. It partially
+// satisfies DecodingLayer.
+func (a *ASF) DecodeFromBytes(data []byte, df gopacket.DecodeFeedback) error {
+	if len(data) < 8 {
+		df.SetTruncated()
+		return fmt.Errorf("invalid ASF data header, length %v less than 8",
+			len(data))
+	}
+
+	a.BaseLayer.Contents = data[:8]
+	a.BaseLayer.Payload = data[8:]
+
+	a.Enterprise = binary.BigEndian.Uint32(data[:4])
+	a.Type = uint8(data[4])
+	a.Tag = uint8(data[5])
+	// 1 byte reserved
+	a.Length = uint8(data[7])
+	return nil
+}
+
+// NextLayerType returns the layer type corresponding to the message type of
+// this ASF data layer. This partially satisfies DecodingLayer.
+func (a *ASF) NextLayerType() gopacket.LayerType {
+	return a.ASFDataIdentifier.LayerType()
+}
+
+// SerializeTo writes the serialized fom of this layer into the SerializeBuffer,
+// partially satisfying SerializableLayer.
+func (a *ASF) SerializeTo(b gopacket.SerializeBuffer, opts gopacket.SerializeOptions) error {
+	payload := b.Bytes()
+	bytes, err := b.PrependBytes(8)
+	if err != nil {
+		return err
+	}
+	binary.BigEndian.PutUint32(bytes[:4], a.Enterprise)
+	bytes[4] = uint8(a.Type)
+	bytes[5] = a.Tag
+	bytes[6] = 0x00
+	if opts.FixLengths {
+		a.Length = uint8(len(payload))
+	}
+	bytes[7] = a.Length
+	return nil
+}
+
+// decodeASF decodes the byte slice into an RMCP-ASF data struct.
+func decodeASF(data []byte, p gopacket.PacketBuilder) error {
+	return decodingLayerDecoder(&ASF{}, data, p)
+}

vendor/github.com/google/gopacket/layers/asf_presencepong.go

@@ -0,0 +1,194 @@
+// Copyright 2019 The GoPacket Authors. All rights reserved.
+//
+// Use of this source code is governed by a BSD-style license that can be found
+// in the LICENSE file in the root of the source tree.
+
+package layers
+
+// This file implements the RMCP ASF Presence Pong message, specified in section
+// 3.2.4.3 of
+// https://www.dmtf.org/sites/default/files/standards/documents/DSP0136.pdf. It
+// also contains non-competing elements from IPMI v2.0, specified in section
+// 13.2.4 of
+// https://www.intel.com/content/dam/www/public/us/en/documents/specification-updates/ipmi-intelligent-platform-mgt-interface-spec-2nd-gen-v2-0-spec-update.pdf.
+
+import (
+	"encoding/binary"
+	"fmt"
+
+	"github.com/google/gopacket"
+)
+
+type (
+	// ASFEntity is the type of individual entities that a Presence Pong
+	// response can indicate support of. The entities currently implemented by
+	// the spec are IPMI and ASFv1.
+	ASFEntity uint8
+
+	// ASFInteraction is the type of individual interactions that a Presence
+	// Pong response can indicate support for. The interactions currently
+	// implemented by the spec are RMCP security extensions. Although not
+	// specified, IPMI uses this field to indicate support for DASH, which is
+	// supported as well.
+	ASFInteraction uint8
+)
+
+const (
+	// ASFDCMIEnterprise is the IANA-assigned Enterprise Number of the Data
+	// Center Manageability Interface Forum. The Presence Pong response's
+	// Enterprise field being set to this value indicates support for DCMI. The
+	// DCMI spec regards the OEM field as reserved, so these should be null.
+	ASFDCMIEnterprise uint32 = 36465
+
+	// ASFPresencePongEntityIPMI ANDs with Presence Pong's supported entities
+	// field if the managed system supports IPMI.
+	ASFPresencePongEntityIPMI ASFEntity = 1 << 7
+
+	// ASFPresencePongEntityASFv1 ANDs with Presence Pong's supported entities
+	// field if the managed system supports ASF v1.0.
+	ASFPresencePongEntityASFv1 ASFEntity = 1
+
+	// ASFPresencePongInteractionSecurityExtensions ANDs with Presence Pong's
+	// supported interactions field if the managed system supports RMCP v2.0
+	// security extensions. See section 3.2.3.
+	ASFPresencePongInteractionSecurityExtensions ASFInteraction = 1 << 7
+
+	// ASFPresencePongInteractionDASH ANDs with Presence Pong's supported
+	// interactions field if the managed system supports DMTF DASH. See
+	// https://www.dmtf.org/standards/dash.
+	ASFPresencePongInteractionDASH ASFInteraction = 1 << 5
+)
+
+// ASFPresencePong defines the structure of a Presence Pong message's payload.
+// See section 3.2.4.3.
+type ASFPresencePong struct {
+	BaseLayer
+
+	// Enterprise is the IANA Enterprise Number of an entity that has defined
+	// OEM-specific capabilities for the managed client. If no such capabilities
+	// exist, this is set to ASF's IANA Enterprise Number.
+	Enterprise uint32
+
+	// OEM identifies OEM-specific capabilities. Its structure is defined by the
+	// OEM. This is set to 0s if no OEM-specific capabilities exist. This
+	// implementation does not change byte order from the wire for this field.
+	OEM [4]byte
+
+	// We break out entities and interactions into separate booleans as
+	// discovery is the entire point of this type of message, so we assume they
+	// are accessed. It also makes gopacket's default layer printing more
+	// useful.
+
+	// IPMI is true if IPMI is supported by the managed system. There is no
+	// explicit version in the specification, however given the dates, this is
+	// assumed to be IPMI v1.0.  Support for IPMI is contained in the "supported
+	// entities" field of the presence pong payload.
+	IPMI bool
+
+	// ASFv1 indicates support for ASF v1.0. This seems somewhat redundant as
+	// ASF must be supported in order to receive a response. This is contained
+	// in the "supported entities" field of the presence pong payload.
+	ASFv1 bool
+
+	// SecurityExtensions indicates support for RMCP Security Extensions,
+	// specified in ASF v2.0. This will always be false for v1.x
+	// implementations. This is contained in the "supported interactions" field
+	// of the presence pong payload. This field is defined in ASF v1.0, but has
+	// no useful value.
+	SecurityExtensions bool
+
+	// DASH is true if DMTF DASH is supported. This is not specified in ASF
+	// v2.0, but in IPMI v2.0, however the former does not preclude it, so we
+	// support it.
+	DASH bool
+
+	// 6 bytes reserved after the entities and interactions fields, set to 0s.
+}
+
+// SupportsDCMI returns whether the Presence Pong message indicates support for
+// the Data Center Management Interface, which is an extension of IPMI v2.0.
+func (a *ASFPresencePong) SupportsDCMI() bool {
+	return a.Enterprise == ASFDCMIEnterprise && a.IPMI && a.ASFv1
+}
+
+// LayerType returns LayerTypeASFPresencePong. It partially satisfies Layer and
+// SerializableLayer.
+func (*ASFPresencePong) LayerType() gopacket.LayerType {
+	return LayerTypeASFPresencePong
+}
+
+// CanDecode returns LayerTypeASFPresencePong. It partially satisfies
+// DecodingLayer.
+func (a *ASFPresencePong) CanDecode() gopacket.LayerClass {
+	return a.LayerType()
+}
+
+// DecodeFromBytes makes the layer represent the provided bytes. It partially
+// satisfies DecodingLayer.
+func (a *ASFPresencePong) DecodeFromBytes(data []byte, df gopacket.DecodeFeedback) error {
+	if len(data) < 16 {
+		df.SetTruncated()
+		return fmt.Errorf("invalid ASF presence pong payload, length %v less than 16",
+			len(data))
+	}
+
+	a.BaseLayer.Contents = data[:16]
+	a.BaseLayer.Payload = data[16:]
+
+	a.Enterprise = binary.BigEndian.Uint32(data[:4])
+	copy(a.OEM[:], data[4:8]) // N.B. no byte order change
+	a.IPMI = data[8]&uint8(ASFPresencePongEntityIPMI) != 0
+	a.ASFv1 = data[8]&uint8(ASFPresencePongEntityASFv1) != 0
+	a.SecurityExtensions = data[9]&uint8(ASFPresencePongInteractionSecurityExtensions) != 0
+	a.DASH = data[9]&uint8(ASFPresencePongInteractionDASH) != 0
+	// ignore remaining 6 bytes; should be set to 0s
+	return nil
+}
+
+// NextLayerType returns LayerTypePayload, as there are no further layers to
+// decode. This partially satisfies DecodingLayer.
+func (a *ASFPresencePong) NextLayerType() gopacket.LayerType {
+	return gopacket.LayerTypePayload
+}
+
+// SerializeTo writes the serialized fom of this layer into the SerializeBuffer,
+// partially satisfying SerializableLayer.
+func (a *ASFPresencePong) SerializeTo(b gopacket.SerializeBuffer, _ gopacket.SerializeOptions) error {
+	bytes, err := b.PrependBytes(16)
+	if err != nil {
+		return err
+	}
+
+	binary.BigEndian.PutUint32(bytes[:4], a.Enterprise)
+
+	copy(bytes[4:8], a.OEM[:])
+
+	bytes[8] = 0
+	if a.IPMI {
+		bytes[8] |= uint8(ASFPresencePongEntityIPMI)
+	}
+	if a.ASFv1 {
+		bytes[8] |= uint8(ASFPresencePongEntityASFv1)
+	}
+
+	bytes[9] = 0
+	if a.SecurityExtensions {
+		bytes[9] |= uint8(ASFPresencePongInteractionSecurityExtensions)
+	}
+	if a.DASH {
+		bytes[9] |= uint8(ASFPresencePongInteractionDASH)
+	}
+
+	// zero-out remaining 6 bytes
+	for i := 10; i < len(bytes); i++ {
+		bytes[i] = 0x00
+	}
+
+	return nil
+}
+
+// decodeASFPresencePong decodes the byte slice into an RMCP-ASF Presence Pong
+// struct.
+func decodeASFPresencePong(data []byte, p gopacket.PacketBuilder) error {
+	return decodingLayerDecoder(&ASFPresencePong{}, data, p)
+}

vendor/github.com/google/gopacket/layers/base.go

@@ -0,0 +1,52 @@
+// Copyright 2012 Google, Inc. All rights reserved.
+//
+// Use of this source code is governed by a BSD-style license
+// that can be found in the LICENSE file in the root of the source
+// tree.
+
+package layers
+
+import (
+	"github.com/google/gopacket"
+)
+
+// BaseLayer is a convenience struct which implements the LayerData and
+// LayerPayload functions of the Layer interface.
+type BaseLayer struct {
+	// Contents is the set of bytes that make up this layer.  IE: for an
+	// Ethernet packet, this would be the set of bytes making up the
+	// Ethernet frame.
+	Contents []byte
+	// Payload is the set of bytes contained by (but not part of) this
+	// Layer.  Again, to take Ethernet as an example, this would be the
+	// set of bytes encapsulated by the Ethernet protocol.
+	Payload []byte
+}
+
+// LayerContents returns the bytes of the packet layer.
+func (b *BaseLayer) LayerContents() []byte { return b.Contents }
+
+// LayerPayload returns the bytes contained within the packet layer.
+func (b *BaseLayer) LayerPayload() []byte { return b.Payload }
+
+type layerDecodingLayer interface {
+	gopacket.Layer
+	DecodeFromBytes([]byte, gopacket.DecodeFeedback) error
+	NextLayerType() gopacket.LayerType
+}
+
+func decodingLayerDecoder(d layerDecodingLayer, data []byte, p gopacket.PacketBuilder) error {
+	err := d.DecodeFromBytes(data, p)
+	if err != nil {
+		return err
+	}
+	p.AddLayer(d)
+	next := d.NextLayerType()
+	if next == gopacket.LayerTypeZero {
+		return nil
+	}
+	return p.NextDecoder(next)
+}
+
+// hacky way to zero out memory... there must be a better way?
+var lotsOfZeros [1024]byte

vendor/github.com/google/gopacket/layers/bfd.go

@@ -0,0 +1,481 @@
+// Copyright 2017 Google, Inc. All rights reserved.
+//
+// Use of this source code is governed by a BSD-style license
+// that can be found in the LICENSE file in the root of the source
+// tree.
+//
+
+package layers
+
+import (
+	"encoding/binary"
+	"errors"
+
+	"github.com/google/gopacket"
+)
+
+// BFD Control Packet Format
+// -------------------------
+// The current version of BFD's RFC (RFC 5880) contains the following
+// diagram for the BFD Control packet format:
+//
+//      0                   1                   2                   3
+//      0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+//     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+//     |Vers |  Diag   |Sta|P|F|C|A|D|M|  Detect Mult  |    Length     |
+//     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+//     |                       My Discriminator                        |
+//     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+//     |                      Your Discriminator                       |
+//     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+//     |                    Desired Min TX Interval                    |
+//     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+//     |                   Required Min RX Interval                    |
+//     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+//     |                 Required Min Echo RX Interval                 |
+//     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+//
+//     An optional Authentication Section MAY be present:
+//
+//      0                   1                   2                   3
+//      0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+//     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+//     |   Auth Type   |   Auth Len    |    Authentication Data...     |
+//     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+//
+//
+//     Simple Password Authentication Section Format
+//     ---------------------------------------------
+//      0                   1                   2                   3
+//      0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+//     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+//     |   Auth Type   |   Auth Len    |  Auth Key ID  |  Password...  |
+//     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+//     |                              ...                              |
+//     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+//
+//
+//     Keyed MD5 and Meticulous Keyed MD5 Authentication Section Format
+//     ----------------------------------------------------------------
+//      0                   1                   2                   3
+//      0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+//     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+//     |   Auth Type   |   Auth Len    |  Auth Key ID  |   Reserved    |
+//     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+//     |                        Sequence Number                        |
+//     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+//     |                      Auth Key/Digest...                       |
+//     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+//     |                              ...                              |
+//     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+//
+//
+//     Keyed SHA1 and Meticulous Keyed SHA1 Authentication Section Format
+//     ------------------------------------------------------------------
+//      0                   1                   2                   3
+//      0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+//     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+//     |   Auth Type   |   Auth Len    |  Auth Key ID  |   Reserved    |
+//     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+//     |                        Sequence Number                        |
+//     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+//     |                       Auth Key/Hash...                        |
+//     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+//     |                              ...                              |
+//     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+//
+//     From https://tools.ietf.org/rfc/rfc5880.txt
+const bfdMinimumRecordSizeInBytes int = 24
+
+// BFDVersion represents the version as decoded from the BFD control message
+type BFDVersion uint8
+
+// BFDDiagnostic represents diagnostic infomation about a BFD session
+type BFDDiagnostic uint8
+
+// constants that define BFDDiagnostic flags
+const (
+	BFDDiagnosticNone               BFDDiagnostic = 0 // No Diagnostic
+	BFDDiagnosticTimeExpired        BFDDiagnostic = 1 // Control Detection Time Expired
+	BFDDiagnosticEchoFailed         BFDDiagnostic = 2 // Echo Function Failed
+	BFDDiagnosticNeighborSignalDown BFDDiagnostic = 3 // Neighbor Signaled Session Down
+	BFDDiagnosticForwardPlaneReset  BFDDiagnostic = 4 // Forwarding Plane Reset
+	BFDDiagnosticPathDown           BFDDiagnostic = 5 // Path Down
+	BFDDiagnosticConcatPathDown     BFDDiagnostic = 6 // Concatenated Path Down
+	BFDDiagnosticAdminDown          BFDDiagnostic = 7 // Administratively Down
+	BFDDiagnosticRevConcatPathDown  BFDDiagnostic = 8 // Reverse Concatenated Path Dow
+)
+
+// String returns a string version of BFDDiagnostic
+func (bd BFDDiagnostic) String() string {
+	switch bd {
+	default:
+		return "Unknown"
+	case BFDDiagnosticNone:
+		return "None"
+	case BFDDiagnosticTimeExpired:
+		return "Control Detection Time Expired"
+	case BFDDiagnosticEchoFailed:
+		return "Echo Function Failed"
+	case BFDDiagnosticNeighborSignalDown:
+		return "Neighbor Signaled Session Down"
+	case BFDDiagnosticForwardPlaneReset:
+		return "Forwarding Plane Reset"
+	case BFDDiagnosticPathDown:
+		return "Path Down"
+	case BFDDiagnosticConcatPathDown:
+		return "Concatenated Path Down"
+	case BFDDiagnosticAdminDown:
+		return "Administratively Down"
+	case BFDDiagnosticRevConcatPathDown:
+		return "Reverse Concatenated Path Down"
+	}
+}
+
+// BFDState represents the state of a BFD session
+type BFDState uint8
+
+// constants that define BFDState
+const (
+	BFDStateAdminDown BFDState = 0
+	BFDStateDown      BFDState = 1
+	BFDStateInit      BFDState = 2
+	BFDStateUp        BFDState = 3
+)
+
+// String returns a string version of BFDState
+func (s BFDState) String() string {
+	switch s {
+	default:
+		return "Unknown"
+	case BFDStateAdminDown:
+		return "Admin Down"
+	case BFDStateDown:
+		return "Down"
+	case BFDStateInit:
+		return "Init"
+	case BFDStateUp:
+		return "Up"
+	}
+}
+
+// BFDDetectMultiplier represents the negotiated transmit interval,
+// multiplied by this value, provides the Detection Time for the
+// receiving system in Asynchronous mode.
+type BFDDetectMultiplier uint8
+
+// BFDDiscriminator is a unique, nonzero discriminator value used
+// to demultiplex multiple BFD sessions between the same pair of systems.
+type BFDDiscriminator uint32
+
+// BFDTimeInterval represents a time interval in microseconds
+type BFDTimeInterval uint32
+
+// BFDAuthType represents the authentication used in the BFD session
+type BFDAuthType uint8
+
+// constants that define the BFDAuthType
+const (
+	BFDAuthTypeNone                BFDAuthType = 0 // No Auth
+	BFDAuthTypePassword            BFDAuthType = 1 // Simple Password
+	BFDAuthTypeKeyedMD5            BFDAuthType = 2 // Keyed MD5
+	BFDAuthTypeMeticulousKeyedMD5  BFDAuthType = 3 // Meticulous Keyed MD5
+	BFDAuthTypeKeyedSHA1           BFDAuthType = 4 // Keyed SHA1
+	BFDAuthTypeMeticulousKeyedSHA1 BFDAuthType = 5 // Meticulous Keyed SHA1
+)
+
+// String returns a string version of BFDAuthType
+func (at BFDAuthType) String() string {
+	switch at {
+	default:
+		return "Unknown"
+	case BFDAuthTypeNone:
+		return "No Authentication"
+	case BFDAuthTypePassword:
+		return "Simple Password"
+	case BFDAuthTypeKeyedMD5:
+		return "Keyed MD5"
+	case BFDAuthTypeMeticulousKeyedMD5:
+		return "Meticulous Keyed MD5"
+	case BFDAuthTypeKeyedSHA1:
+		return "Keyed SHA1"
+	case BFDAuthTypeMeticulousKeyedSHA1:
+		return "Meticulous Keyed SHA1"
+	}
+}
+
+// BFDAuthKeyID represents the authentication key ID in use for
+// this packet.  This allows multiple keys to be active simultaneously.
+type BFDAuthKeyID uint8
+
+// BFDAuthSequenceNumber represents the sequence number for this packet.
+// For Keyed Authentication, this value is incremented occasionally.  For
+// Meticulous Keyed Authentication, this value is incremented for each
+// successive packet transmitted for a session.  This provides protection
+// against replay attacks.
+type BFDAuthSequenceNumber uint32
+
+// BFDAuthData represents the authentication key or digest
+type BFDAuthData []byte
+
+// BFDAuthHeader represents authentication data used in the BFD session
+type BFDAuthHeader struct {
+	AuthType       BFDAuthType
+	KeyID          BFDAuthKeyID
+	SequenceNumber BFDAuthSequenceNumber
+	Data           BFDAuthData
+}
+
+// Length returns the data length of the BFDAuthHeader based on the
+// authentication type
+func (h *BFDAuthHeader) Length() int {
+	switch h.AuthType {
+	case BFDAuthTypePassword:
+		return 3 + len(h.Data)
+	case BFDAuthTypeKeyedMD5, BFDAuthTypeMeticulousKeyedMD5:
+		return 8 + len(h.Data)
+	case BFDAuthTypeKeyedSHA1, BFDAuthTypeMeticulousKeyedSHA1:
+		return 8 + len(h.Data)
+	default:
+		return 0
+	}
+}
+
+// BFD represents a BFD control message packet whose payload contains
+// the control information required to for a BFD session.
+//
+// References
+// ----------
+//
+// Wikipedia's BFD entry:
+//     https://en.wikipedia.org/wiki/Bidirectional_Forwarding_Detection
+//     This is the best place to get an overview of BFD.
+//
+// RFC 5880 "Bidirectional Forwarding Detection (BFD)" (2010)
+//     https://tools.ietf.org/html/rfc5880
+//     This is the original BFD specification.
+//
+// RFC 5881 "Bidirectional Forwarding Detection (BFD) for IPv4 and IPv6 (Single Hop)" (2010)
+//     https://tools.ietf.org/html/rfc5881
+//     Describes the use of the Bidirectional Forwarding Detection (BFD)
+//     protocol over IPv4 and IPv6 for single IP hops.
+type BFD struct {
+	BaseLayer // Stores the packet bytes and payload bytes.
+
+	Version                   BFDVersion          // Version of the BFD protocol.
+	Diagnostic                BFDDiagnostic       // Diagnostic code for last state change
+	State                     BFDState            // Current state
+	Poll                      bool                // Requesting verification
+	Final                     bool                // Responding to a received BFD Control packet that had the Poll (P) bit set.
+	ControlPlaneIndependent   bool                // BFD implementation does not share fate with its control plane
+	AuthPresent               bool                // Authentication Section is present and the session is to be authenticated
+	Demand                    bool                // Demand mode is active
+	Multipoint                bool                // For future point-to-multipoint extensions. Must always be zero
+	DetectMultiplier          BFDDetectMultiplier // Detection time multiplier
+	MyDiscriminator           BFDDiscriminator    // A unique, nonzero discriminator value
+	YourDiscriminator         BFDDiscriminator    // discriminator received from the remote system.
+	DesiredMinTxInterval      BFDTimeInterval     // Minimum interval, in microseconds,  the local system would like to use when transmitting BFD Control packets
+	RequiredMinRxInterval     BFDTimeInterval     // Minimum interval, in microseconds, between received BFD Control packets that this system is capable of supporting
+	RequiredMinEchoRxInterval BFDTimeInterval     // Minimum interval, in microseconds, between received BFD Echo packets that this system is capable of supporting
+	AuthHeader                *BFDAuthHeader      // Authentication data, variable length.
+}
+
+// Length returns the data length of a BFD Control message which
+// changes based on the presence and type of authentication
+// contained in the message
+func (d *BFD) Length() int {
+	if d.AuthPresent && (d.AuthHeader != nil) {
+		return bfdMinimumRecordSizeInBytes + d.AuthHeader.Length()
+	}
+
+	return bfdMinimumRecordSizeInBytes
+}
+
+// LayerType returns the layer type of the BFD object, which is LayerTypeBFD.
+func (d *BFD) LayerType() gopacket.LayerType {
+	return LayerTypeBFD
+}
+
+// decodeBFD analyses a byte slice and attempts to decode it as a BFD
+// control packet
+//
+// If it succeeds, it loads p with information about the packet and returns nil.
+// If it fails, it returns an error (non nil).
+//
+// This function is employed in layertypes.go to register the BFD layer.
+func decodeBFD(data []byte, p gopacket.PacketBuilder) error {
+
+	// Attempt to decode the byte slice.
+	d := &BFD{}
+	err := d.DecodeFromBytes(data, p)
+	if err != nil {
+		return err
+	}
+
+	// If the decoding worked, add the layer to the packet and set it
+	// as the application layer too, if there isn't already one.
+	p.AddLayer(d)
+	p.SetApplicationLayer(d)
+
+	return nil
+}
+
+// DecodeFromBytes analyses a byte slice and attempts to decode it as a BFD
+// control packet.
+//
+// Upon succeeds, it loads the BFD object with information about the packet
+// and returns nil.
+// Upon failure, it returns an error (non nil).
+func (d *BFD) DecodeFromBytes(data []byte, df gopacket.DecodeFeedback) error {
+
+	// If the data block is too short to be a BFD record, then return an error.
+	if len(data) < bfdMinimumRecordSizeInBytes {
+		df.SetTruncated()
+		return errors.New("BFD packet too short")
+	}
+
+	pLen := uint8(data[3])
+	if len(data) != int(pLen) {
+		return errors.New("BFD packet length does not match")
+	}
+
+	// BFD type embeds type BaseLayer which contains two fields:
+	//    Contents is supposed to contain the bytes of the data at this level.
+	//    Payload is supposed to contain the payload of this level.
+	// Here we set the baselayer to be the bytes of the BFD record.
+	d.BaseLayer = BaseLayer{Contents: data[:len(data)]}
+
+	// Extract the fields from the block of bytes.
+	// To make sense of this, refer to the packet diagram
+	// above and the section on endian conventions.
+
+	// The first few fields are all packed into the first 32 bits. Unpack them.
+	d.Version = BFDVersion(((data[0] & 0xE0) >> 5))
+	d.Diagnostic = BFDDiagnostic(data[0] & 0x1F)
+	data = data[1:]
+
+	d.State = BFDState((data[0] & 0xC0) >> 6)
+	d.Poll = data[0]&0x20 != 0
+	d.Final = data[0]&0x10 != 0
+	d.ControlPlaneIndependent = data[0]&0x08 != 0
+	d.AuthPresent = data[0]&0x04 != 0
+	d.Demand = data[0]&0x02 != 0
+	d.Multipoint = data[0]&0x01 != 0
+	data = data[1:]
+
+	data, d.DetectMultiplier = data[1:], BFDDetectMultiplier(data[0])
+	data, _ = data[1:], uint8(data[0]) // Consume length
+
+	// The remaining fields can just be copied in big endian order.
+	data, d.MyDiscriminator = data[4:], BFDDiscriminator(binary.BigEndian.Uint32(data[:4]))
+	data, d.YourDiscriminator = data[4:], BFDDiscriminator(binary.BigEndian.Uint32(data[:4]))
+	data, d.DesiredMinTxInterval = data[4:], BFDTimeInterval(binary.BigEndian.Uint32(data[:4]))
+	data, d.RequiredMinRxInterval = data[4:], BFDTimeInterval(binary.BigEndian.Uint32(data[:4]))
+	data, d.RequiredMinEchoRxInterval = data[4:], BFDTimeInterval(binary.BigEndian.Uint32(data[:4]))
+
+	if d.AuthPresent && (len(data) > 2) {
+		d.AuthHeader = &BFDAuthHeader{}
+		data, d.AuthHeader.AuthType = data[1:], BFDAuthType(data[0])
+		data, _ = data[1:], uint8(data[0]) // Consume length
+		data, d.AuthHeader.KeyID = data[1:], BFDAuthKeyID(data[0])
+
+		switch d.AuthHeader.AuthType {
+		case BFDAuthTypePassword:
+			d.AuthHeader.Data = BFDAuthData(data)
+		case BFDAuthTypeKeyedMD5, BFDAuthTypeMeticulousKeyedMD5:
+			// Skipped reserved byte
+			data, d.AuthHeader.SequenceNumber = data[5:], BFDAuthSequenceNumber(binary.BigEndian.Uint32(data[1:5]))
+			d.AuthHeader.Data = BFDAuthData(data)
+		case BFDAuthTypeKeyedSHA1, BFDAuthTypeMeticulousKeyedSHA1:
+			// Skipped reserved byte
+			data, d.AuthHeader.SequenceNumber = data[5:], BFDAuthSequenceNumber(binary.BigEndian.Uint32(data[1:5]))
+			d.AuthHeader.Data = BFDAuthData(data)
+		}
+	}
+
+	return nil
+}
+
+// SerializeTo writes the serialized form of this layer into the
+// SerializationBuffer, implementing gopacket.SerializableLayer.
+// See the docs for gopacket.SerializableLayer for more info.
+func (d *BFD) SerializeTo(b gopacket.SerializeBuffer, opts gopacket.SerializeOptions) error {
+	data, err := b.PrependBytes(bfdMinimumRecordSizeInBytes)
+	if err != nil {
+		return err
+	}
+
+	// Pack the first few fields into the first 32 bits.
+	data[0] = byte(byte(d.Version<<5) | byte(d.Diagnostic))
+	h := uint8(0)
+	h |= (uint8(d.State) << 6)
+	h |= (uint8(bool2uint8(d.Poll)) << 5)
+	h |= (uint8(bool2uint8(d.Final)) << 4)
+	h |= (uint8(bool2uint8(d.ControlPlaneIndependent)) << 3)
+	h |= (uint8(bool2uint8(d.AuthPresent)) << 2)
+	h |= (uint8(bool2uint8(d.Demand)) << 1)
+	h |= uint8(bool2uint8(d.Multipoint))
+	data[1] = byte(h)
+	data[2] = byte(d.DetectMultiplier)
+	data[3] = byte(d.Length())
+
+	// The remaining fields can just be copied in big endian order.
+	binary.BigEndian.PutUint32(data[4:], uint32(d.MyDiscriminator))
+	binary.BigEndian.PutUint32(data[8:], uint32(d.YourDiscriminator))
+	binary.BigEndian.PutUint32(data[12:], uint32(d.DesiredMinTxInterval))
+	binary.BigEndian.PutUint32(data[16:], uint32(d.RequiredMinRxInterval))
+	binary.BigEndian.PutUint32(data[20:], uint32(d.RequiredMinEchoRxInterval))
+
+	if d.AuthPresent && (d.AuthHeader != nil) {
+		auth, err := b.AppendBytes(int(d.AuthHeader.Length()))
+		if err != nil {
+			return err
+		}
+
+		auth[0] = byte(d.AuthHeader.AuthType)
+		auth[1] = byte(d.AuthHeader.Length())
+		auth[2] = byte(d.AuthHeader.KeyID)
+
+		switch d.AuthHeader.AuthType {
+		case BFDAuthTypePassword:
+			copy(auth[3:], d.AuthHeader.Data)
+		case BFDAuthTypeKeyedMD5, BFDAuthTypeMeticulousKeyedMD5:
+			auth[3] = byte(0)
+			binary.BigEndian.PutUint32(auth[4:], uint32(d.AuthHeader.SequenceNumber))
+			copy(auth[8:], d.AuthHeader.Data)
+		case BFDAuthTypeKeyedSHA1, BFDAuthTypeMeticulousKeyedSHA1:
+			auth[3] = byte(0)
+			binary.BigEndian.PutUint32(auth[4:], uint32(d.AuthHeader.SequenceNumber))
+			copy(auth[8:], d.AuthHeader.Data)
+		}
+	}
+
+	return nil
+}
+
+// CanDecode returns a set of layers that BFD objects can decode.
+// As BFD objects can only decide the BFD layer, we can return just that layer.
+// Apparently a single layer type implements LayerClass.
+func (d *BFD) CanDecode() gopacket.LayerClass {
+	return LayerTypeBFD
+}
+
+// NextLayerType specifies the next layer that GoPacket should attempt to
+// analyse after this (BFD) layer. As BFD packets do not contain any payload
+// bytes, there are no further layers to analyse.
+func (d *BFD) NextLayerType() gopacket.LayerType {
+	return gopacket.LayerTypeZero
+}
+
+// Payload returns an empty byte slice as BFD packets do not carry a payload
+func (d *BFD) Payload() []byte {
+	return nil
+}
+
+// bool2uint8 converts a bool to uint8
+func bool2uint8(b bool) uint8 {
+	if b {
+		return 1
+	}
+	return 0
+}

vendor/github.com/google/gopacket/layers/cdp.go

@@ -0,0 +1,659 @@
+// Copyright 2012 Google, Inc. All rights reserved.
+//
+// Use of this source code is governed by a BSD-style license
+// that can be found in the LICENSE file in the root of the source
+// tree.
+
+// Enum types courtesy of...
+//   http://search.cpan.org/~mchapman/Net-CDP-0.09/lib/Net/CDP.pm
+//   https://code.google.com/p/ladvd/
+//   http://anonsvn.wireshark.org/viewvc/releases/wireshark-1.8.6/epan/dissectors/packet-cdp.c
+
+package layers
+
+import (
+	"encoding/binary"
+	"errors"
+	"fmt"
+	"net"
+
+	"github.com/google/gopacket"
+)
+
+// CDPTLVType is the type of each TLV value in a CiscoDiscovery packet.
+type CDPTLVType uint16
+
+// CDPTLVType values.
+const (
+	CDPTLVDevID              CDPTLVType = 0x0001
+	CDPTLVAddress            CDPTLVType = 0x0002
+	CDPTLVPortID             CDPTLVType = 0x0003
+	CDPTLVCapabilities       CDPTLVType = 0x0004
+	CDPTLVVersion            CDPTLVType = 0x0005
+	CDPTLVPlatform           CDPTLVType = 0x0006
+	CDPTLVIPPrefix           CDPTLVType = 0x0007
+	CDPTLVHello              CDPTLVType = 0x0008
+	CDPTLVVTPDomain          CDPTLVType = 0x0009
+	CDPTLVNativeVLAN         CDPTLVType = 0x000a
+	CDPTLVFullDuplex         CDPTLVType = 0x000b
+	CDPTLVVLANReply          CDPTLVType = 0x000e
+	CDPTLVVLANQuery          CDPTLVType = 0x000f
+	CDPTLVPower              CDPTLVType = 0x0010
+	CDPTLVMTU                CDPTLVType = 0x0011
+	CDPTLVExtendedTrust      CDPTLVType = 0x0012
+	CDPTLVUntrustedCOS       CDPTLVType = 0x0013
+	CDPTLVSysName            CDPTLVType = 0x0014
+	CDPTLVSysOID             CDPTLVType = 0x0015
+	CDPTLVMgmtAddresses      CDPTLVType = 0x0016
+	CDPTLVLocation           CDPTLVType = 0x0017
+	CDPTLVExternalPortID     CDPTLVType = 0x0018
+	CDPTLVPowerRequested     CDPTLVType = 0x0019
+	CDPTLVPowerAvailable     CDPTLVType = 0x001a
+	CDPTLVPortUnidirectional CDPTLVType = 0x001b
+	CDPTLVEnergyWise         CDPTLVType = 0x001d
+	CDPTLVSparePairPOE       CDPTLVType = 0x001f
+)
+
+// CiscoDiscoveryValue is a TLV value inside a CiscoDiscovery packet layer.
+type CiscoDiscoveryValue struct {
+	Type   CDPTLVType
+	Length uint16
+	Value  []byte
+}
+
+// CiscoDiscovery is a packet layer containing the Cisco Discovery Protocol.
+// See http://www.cisco.com/univercd/cc/td/doc/product/lan/trsrb/frames.htm#31885
+type CiscoDiscovery struct {
+	BaseLayer
+	Version  byte
+	TTL      byte
+	Checksum uint16
+	Values   []CiscoDiscoveryValue
+}
+
+// CDPCapability is the set of capabilities advertised by a CDP device.
+type CDPCapability uint32
+
+// CDPCapability values.
+const (
+	CDPCapMaskRouter     CDPCapability = 0x0001
+	CDPCapMaskTBBridge   CDPCapability = 0x0002
+	CDPCapMaskSPBridge   CDPCapability = 0x0004
+	CDPCapMaskSwitch     CDPCapability = 0x0008
+	CDPCapMaskHost       CDPCapability = 0x0010
+	CDPCapMaskIGMPFilter CDPCapability = 0x0020
+	CDPCapMaskRepeater   CDPCapability = 0x0040
+	CDPCapMaskPhone      CDPCapability = 0x0080
+	CDPCapMaskRemote     CDPCapability = 0x0100
+)
+
+// CDPCapabilities represents the capabilities of a device
+type CDPCapabilities struct {
+	L3Router        bool
+	TBBridge        bool
+	SPBridge        bool
+	L2Switch        bool
+	IsHost          bool
+	IGMPFilter      bool
+	L1Repeater      bool
+	IsPhone         bool
+	RemotelyManaged bool
+}
+
+// CDP Power-over-Ethernet values.
+const (
+	CDPPoEFourWire  byte = 0x01
+	CDPPoEPDArch    byte = 0x02
+	CDPPoEPDRequest byte = 0x04
+	CDPPoEPSE       byte = 0x08
+)
+
+// CDPSparePairPoE provides information on PoE.
+type CDPSparePairPoE struct {
+	PSEFourWire  bool // Supported / Not supported
+	PDArchShared bool // Shared / Independent
+	PDRequestOn  bool // On / Off
+	PSEOn        bool // On / Off
+}
+
+// CDPVLANDialogue encapsulates a VLAN Query/Reply
+type CDPVLANDialogue struct {
+	ID   uint8
+	VLAN uint16
+}
+
+// CDPPowerDialogue encapsulates a Power Query/Reply
+type CDPPowerDialogue struct {
+	ID     uint16
+	MgmtID uint16
+	Values []uint32
+}
+
+// CDPLocation provides location information for a CDP device.
+type CDPLocation struct {
+	Type     uint8 // Undocumented
+	Location string
+}
+
+// CDPHello is a Cisco Hello message (undocumented, hence the "Unknown" fields)
+type CDPHello struct {
+	OUI              []byte
+	ProtocolID       uint16
+	ClusterMaster    net.IP
+	Unknown1         net.IP
+	Version          byte
+	SubVersion       byte
+	Status           byte
+	Unknown2         byte
+	ClusterCommander net.HardwareAddr
+	SwitchMAC        net.HardwareAddr
+	Unknown3         byte
+	ManagementVLAN   uint16
+}
+
+// CDPEnergyWiseSubtype is used within CDP to define TLV values.
+type CDPEnergyWiseSubtype uint32
+
+// CDPEnergyWiseSubtype values.
+const (
+	CDPEnergyWiseRole    CDPEnergyWiseSubtype = 0x00000007
+	CDPEnergyWiseDomain  CDPEnergyWiseSubtype = 0x00000008
+	CDPEnergyWiseName    CDPEnergyWiseSubtype = 0x00000009
+	CDPEnergyWiseReplyTo CDPEnergyWiseSubtype = 0x00000017
+)
+
+// CDPEnergyWise is used by CDP to monitor and control power usage.
+type CDPEnergyWise struct {
+	EncryptedData  []byte
+	Unknown1       uint32
+	SequenceNumber uint32
+	ModelNumber    string
+	Unknown2       uint16
+	HardwareID     string
+	SerialNum      string
+	Unknown3       []byte
+	Role           string
+	Domain         string
+	Name           string
+	ReplyUnknown1  []byte
+	ReplyPort      []byte
+	ReplyAddress   []byte
+	ReplyUnknown2  []byte
+	ReplyUnknown3  []byte
+}
+
+// CiscoDiscoveryInfo represents the decoded details for a set of CiscoDiscoveryValues
+type CiscoDiscoveryInfo struct {
+	BaseLayer
+	CDPHello
+	DeviceID         string
+	Addresses        []net.IP
+	PortID           string
+	Capabilities     CDPCapabilities
+	Version          string
+	Platform         string
+	IPPrefixes       []net.IPNet
+	VTPDomain        string
+	NativeVLAN       uint16
+	FullDuplex       bool
+	VLANReply        CDPVLANDialogue
+	VLANQuery        CDPVLANDialogue
+	PowerConsumption uint16
+	MTU              uint32
+	ExtendedTrust    uint8
+	UntrustedCOS     uint8
+	SysName          string
+	SysOID           string
+	MgmtAddresses    []net.IP
+	Location         CDPLocation
+	PowerRequest     CDPPowerDialogue
+	PowerAvailable   CDPPowerDialogue
+	SparePairPoe     CDPSparePairPoE
+	EnergyWise       CDPEnergyWise
+	Unknown          []CiscoDiscoveryValue
+}
+
+// LayerType returns gopacket.LayerTypeCiscoDiscovery.
+func (c *CiscoDiscovery) LayerType() gopacket.LayerType {
+	return LayerTypeCiscoDiscovery
+}
+
+func decodeCiscoDiscovery(data []byte, p gopacket.PacketBuilder) error {
+	c := &CiscoDiscovery{
+		Version:  data[0],
+		TTL:      data[1],
+		Checksum: binary.BigEndian.Uint16(data[2:4]),
+	}
+	if c.Version != 1 && c.Version != 2 {
+		return fmt.Errorf("Invalid CiscoDiscovery version number %d", c.Version)
+	}
+	var err error
+	c.Values, err = decodeCiscoDiscoveryTLVs(data[4:], p)
+	if err != nil {
+		return err
+	}
+	c.Contents = data[0:4]
+	c.Payload = data[4:]
+	p.AddLayer(c)
+	return p.NextDecoder(gopacket.DecodeFunc(decodeCiscoDiscoveryInfo))
+}
+
+// LayerType returns gopacket.LayerTypeCiscoDiscoveryInfo.
+func (c *CiscoDiscoveryInfo) LayerType() gopacket.LayerType {
+	return LayerTypeCiscoDiscoveryInfo
+}
+
+func decodeCiscoDiscoveryTLVs(data []byte, p gopacket.PacketBuilder) (values []CiscoDiscoveryValue, err error) {
+	for len(data) > 0 {
+		if len(data) < 4 {
+			p.SetTruncated()
+			return nil, errors.New("CDP TLV < 4 bytes")
+		}
+		val := CiscoDiscoveryValue{
+			Type:   CDPTLVType(binary.BigEndian.Uint16(data[:2])),
+			Length: binary.BigEndian.Uint16(data[2:4]),
+		}
+		if val.Length < 4 {
+			err = fmt.Errorf("Invalid CiscoDiscovery value length %d", val.Length)
+			break
+		} else if len(data) < int(val.Length) {
+			p.SetTruncated()
+			return nil, fmt.Errorf("CDP TLV < length %d", val.Length)
+		}
+		val.Value = data[4:val.Length]
+		values = append(values, val)
+		data = data[val.Length:]
+	}
+	return
+}
+
+func decodeCiscoDiscoveryInfo(data []byte, p gopacket.PacketBuilder) error {
+	var err error
+	info := &CiscoDiscoveryInfo{BaseLayer: BaseLayer{Contents: data}}
+	p.AddLayer(info)
+	values, err := decodeCiscoDiscoveryTLVs(data, p)
+	if err != nil { // Unlikely, as parent decode will fail, but better safe...
+		return err
+	}
+	for _, val := range values {
+		switch val.Type {
+		case CDPTLVDevID:
+			info.DeviceID = string(val.Value)
+		case CDPTLVAddress:
+			if err = checkCDPTLVLen(val, 4); err != nil {
+				return err
+			}
+			info.Addresses, err = decodeAddresses(val.Value)
+			if err != nil {
+				return err
+			}
+		case CDPTLVPortID:
+			info.PortID = string(val.Value)
+		case CDPTLVCapabilities:
+			if err = checkCDPTLVLen(val, 4); err != nil {
+				return err
+			}
+			val := CDPCapability(binary.BigEndian.Uint32(val.Value[0:4]))
+			info.Capabilities.L3Router = (val&CDPCapMaskRouter > 0)
+			info.Capabilities.TBBridge = (val&CDPCapMaskTBBridge > 0)
+			info.Capabilities.SPBridge = (val&CDPCapMaskSPBridge > 0)
+			info.Capabilities.L2Switch = (val&CDPCapMaskSwitch > 0)
+			info.Capabilities.IsHost = (val&CDPCapMaskHost > 0)
+			info.Capabilities.IGMPFilter = (val&CDPCapMaskIGMPFilter > 0)
+			info.Capabilities.L1Repeater = (val&CDPCapMaskRepeater > 0)
+			info.Capabilities.IsPhone = (val&CDPCapMaskPhone > 0)
+			info.Capabilities.RemotelyManaged = (val&CDPCapMaskRemote > 0)
+		case CDPTLVVersion:
+			info.Version = string(val.Value)
+		case CDPTLVPlatform:
+			info.Platform = string(val.Value)
+		case CDPTLVIPPrefix:
+			v := val.Value
+			l := len(v)
+			if l%5 == 0 && l >= 5 {
+				for len(v) > 0 {
+					_, ipnet, _ := net.ParseCIDR(fmt.Sprintf("%d.%d.%d.%d/%d", v[0], v[1], v[2], v[3], v[4]))
+					info.IPPrefixes = append(info.IPPrefixes, *ipnet)
+					v = v[5:]
+				}
+			} else {
+				return fmt.Errorf("Invalid TLV %v length %d", val.Type, len(val.Value))
+			}
+		case CDPTLVHello:
+			if err = checkCDPTLVLen(val, 32); err != nil {
+				return err
+			}
+			v := val.Value
+			info.CDPHello.OUI = v[0:3]
+			info.CDPHello.ProtocolID = binary.BigEndian.Uint16(v[3:5])
+			info.CDPHello.ClusterMaster = v[5:9]
+			info.CDPHello.Unknown1 = v[9:13]
+			info.CDPHello.Version = v[13]
+			info.CDPHello.SubVersion = v[14]
+			info.CDPHello.Status = v[15]
+			info.CDPHello.Unknown2 = v[16]
+			info.CDPHello.ClusterCommander = v[17:23]
+			info.CDPHello.SwitchMAC = v[23:29]
+			info.CDPHello.Unknown3 = v[29]
+			info.CDPHello.ManagementVLAN = binary.BigEndian.Uint16(v[30:32])
+		case CDPTLVVTPDomain:
+			info.VTPDomain = string(val.Value)
+		case CDPTLVNativeVLAN:
+			if err = checkCDPTLVLen(val, 2); err != nil {
+				return err
+			}
+			info.NativeVLAN = binary.BigEndian.Uint16(val.Value[0:2])
+		case CDPTLVFullDuplex:
+			if err = checkCDPTLVLen(val, 1); err != nil {
+				return err
+			}
+			info.FullDuplex = (val.Value[0] == 1)
+		case CDPTLVVLANReply:
+			if err = checkCDPTLVLen(val, 3); err != nil {
+				return err
+			}
+			info.VLANReply.ID = uint8(val.Value[0])
+			info.VLANReply.VLAN = binary.BigEndian.Uint16(val.Value[1:3])
+		case CDPTLVVLANQuery:
+			if err = checkCDPTLVLen(val, 3); err != nil {
+				return err
+			}
+			info.VLANQuery.ID = uint8(val.Value[0])
+			info.VLANQuery.VLAN = binary.BigEndian.Uint16(val.Value[1:3])
+		case CDPTLVPower:
+			if err = checkCDPTLVLen(val, 2); err != nil {
+				return err
+			}
+			info.PowerConsumption = binary.BigEndian.Uint16(val.Value[0:2])
+		case CDPTLVMTU:
+			if err = checkCDPTLVLen(val, 4); err != nil {
+				return err
+			}
+			info.MTU = binary.BigEndian.Uint32(val.Value[0:4])
+		case CDPTLVExtendedTrust:
+			if err = checkCDPTLVLen(val, 1); err != nil {
+				return err
+			}
+			info.ExtendedTrust = uint8(val.Value[0])
+		case CDPTLVUntrustedCOS:
+			if err = checkCDPTLVLen(val, 1); err != nil {
+				return err
+			}
+			info.UntrustedCOS = uint8(val.Value[0])
+		case CDPTLVSysName:
+			info.SysName = string(val.Value)
+		case CDPTLVSysOID:
+			info.SysOID = string(val.Value)
+		case CDPTLVMgmtAddresses:
+			if err = checkCDPTLVLen(val, 4); err != nil {
+				return err
+			}
+			info.MgmtAddresses, err = decodeAddresses(val.Value)
+			if err != nil {
+				return err
+			}
+		case CDPTLVLocation:
+			if err = checkCDPTLVLen(val, 2); err != nil {
+				return err
+			}
+			info.Location.Type = uint8(val.Value[0])
+			info.Location.Location = string(val.Value[1:])
+
+			//		case CDPTLVLExternalPortID:
+			//			Undocumented
+		case CDPTLVPowerRequested:
+			if err = checkCDPTLVLen(val, 4); err != nil {
+				return err
+			}
+			info.PowerRequest.ID = binary.BigEndian.Uint16(val.Value[0:2])
+			info.PowerRequest.MgmtID = binary.BigEndian.Uint16(val.Value[2:4])
+			for n := 4; n < len(val.Value); n += 4 {
+				info.PowerRequest.Values = append(info.PowerRequest.Values, binary.BigEndian.Uint32(val.Value[n:n+4]))
+			}
+		case CDPTLVPowerAvailable:
+			if err = checkCDPTLVLen(val, 4); err != nil {
+				return err
+			}
+			info.PowerAvailable.ID = binary.BigEndian.Uint16(val.Value[0:2])
+			info.PowerAvailable.MgmtID = binary.BigEndian.Uint16(val.Value[2:4])
+			for n := 4; n < len(val.Value); n += 4 {
+				info.PowerAvailable.Values = append(info.PowerAvailable.Values, binary.BigEndian.Uint32(val.Value[n:n+4]))
+			}
+			//		case CDPTLVPortUnidirectional
+			//			Undocumented
+		case CDPTLVEnergyWise:
+			if err = checkCDPTLVLen(val, 72); err != nil {
+				return err
+			}
+			info.EnergyWise.EncryptedData = val.Value[0:20]
+			info.EnergyWise.Unknown1 = binary.BigEndian.Uint32(val.Value[20:24])
+			info.EnergyWise.SequenceNumber = binary.BigEndian.Uint32(val.Value[24:28])
+			info.EnergyWise.ModelNumber = string(val.Value[28:44])
+			info.EnergyWise.Unknown2 = binary.BigEndian.Uint16(val.Value[44:46])
+			info.EnergyWise.HardwareID = string(val.Value[46:49])
+			info.EnergyWise.SerialNum = string(val.Value[49:60])
+			info.EnergyWise.Unknown3 = val.Value[60:68]
+			tlvLen := binary.BigEndian.Uint16(val.Value[68:70])
+			tlvNum := binary.BigEndian.Uint16(val.Value[70:72])
+			data := val.Value[72:]
+			if len(data) < int(tlvLen) {
+				return fmt.Errorf("Invalid TLV length %d vs %d", tlvLen, len(data))
+			}
+			numSeen := 0
+			for len(data) > 8 {
+				numSeen++
+				if numSeen > int(tlvNum) { // Too many TLV's ?
+					return fmt.Errorf("Too many TLV's - wanted %d, saw %d", tlvNum, numSeen)
+				}
+				tType := CDPEnergyWiseSubtype(binary.BigEndian.Uint32(data[0:4]))
+				tLen := int(binary.BigEndian.Uint32(data[4:8]))
+				if tLen > len(data)-8 {
+					return fmt.Errorf("Invalid TLV length %d vs %d", tLen, len(data)-8)
+				}
+				data = data[8:]
+				switch tType {
+				case CDPEnergyWiseRole:
+					info.EnergyWise.Role = string(data[:])
+				case CDPEnergyWiseDomain:
+					info.EnergyWise.Domain = string(data[:])
+				case CDPEnergyWiseName:
+					info.EnergyWise.Name = string(data[:])
+				case CDPEnergyWiseReplyTo:
+					if len(data) >= 18 {
+						info.EnergyWise.ReplyUnknown1 = data[0:2]
+						info.EnergyWise.ReplyPort = data[2:4]
+						info.EnergyWise.ReplyAddress = data[4:8]
+						info.EnergyWise.ReplyUnknown2 = data[8:10]
+						info.EnergyWise.ReplyUnknown3 = data[10:14]
+					}
+				}
+				data = data[tLen:]
+			}
+		case CDPTLVSparePairPOE:
+			if err = checkCDPTLVLen(val, 1); err != nil {
+				return err
+			}
+			v := val.Value[0]
+			info.SparePairPoe.PSEFourWire = (v&CDPPoEFourWire > 0)
+			info.SparePairPoe.PDArchShared = (v&CDPPoEPDArch > 0)
+			info.SparePairPoe.PDRequestOn = (v&CDPPoEPDRequest > 0)
+			info.SparePairPoe.PSEOn = (v&CDPPoEPSE > 0)
+		default:
+			info.Unknown = append(info.Unknown, val)
+		}
+	}
+	return nil
+}
+
+// CDP Protocol Types
+const (
+	CDPProtocolTypeNLPID byte = 1
+	CDPProtocolType802_2 byte = 2
+)
+
+// CDPAddressType is used to define TLV values within CDP addresses.
+type CDPAddressType uint64
+
+// CDP Address types.
+const (
+	CDPAddressTypeCLNP      CDPAddressType = 0x81
+	CDPAddressTypeIPV4      CDPAddressType = 0xcc
+	CDPAddressTypeIPV6      CDPAddressType = 0xaaaa030000000800
+	CDPAddressTypeDECNET    CDPAddressType = 0xaaaa030000006003
+	CDPAddressTypeAPPLETALK CDPAddressType = 0xaaaa03000000809b
+	CDPAddressTypeIPX       CDPAddressType = 0xaaaa030000008137
+	CDPAddressTypeVINES     CDPAddressType = 0xaaaa0300000080c4
+	CDPAddressTypeXNS       CDPAddressType = 0xaaaa030000000600
+	CDPAddressTypeAPOLLO    CDPAddressType = 0xaaaa030000008019
+)
+
+func decodeAddresses(v []byte) (addresses []net.IP, err error) {
+	numaddr := int(binary.BigEndian.Uint32(v[0:4]))
+	if numaddr < 1 {
+		return nil, fmt.Errorf("Invalid Address TLV number %d", numaddr)
+	}
+	v = v[4:]
+	if len(v) < numaddr*8 {
+		return nil, fmt.Errorf("Invalid Address TLV length %d", len(v))
+	}
+	for i := 0; i < numaddr; i++ {
+		prottype := v[0]
+		if prottype != CDPProtocolTypeNLPID && prottype != CDPProtocolType802_2 { // invalid protocol type
+			return nil, fmt.Errorf("Invalid Address Protocol %d", prottype)
+		}
+		protlen := int(v[1])
+		if (prottype == CDPProtocolTypeNLPID && protlen != 1) ||
+			(prottype == CDPProtocolType802_2 && protlen != 3 && protlen != 8) { // invalid length
+			return nil, fmt.Errorf("Invalid Address Protocol length %d", protlen)
+		}
+		plen := make([]byte, 8)
+		copy(plen[8-protlen:], v[2:2+protlen])
+		protocol := CDPAddressType(binary.BigEndian.Uint64(plen))
+		v = v[2+protlen:]
+		addrlen := binary.BigEndian.Uint16(v[0:2])
+		ab := v[2 : 2+addrlen]
+		if protocol == CDPAddressTypeIPV4 && addrlen == 4 {
+			addresses = append(addresses, net.IPv4(ab[0], ab[1], ab[2], ab[3]))
+		} else if protocol == CDPAddressTypeIPV6 && addrlen == 16 {
+			addresses = append(addresses, net.IP(ab))
+		} else {
+			// only handle IPV4 & IPV6 for now
+		}
+		v = v[2+addrlen:]
+		if len(v) < 8 {
+			break
+		}
+	}
+	return
+}
+
+func (t CDPTLVType) String() (s string) {
+	switch t {
+	case CDPTLVDevID:
+		s = "Device ID"
+	case CDPTLVAddress:
+		s = "Addresses"
+	case CDPTLVPortID:
+		s = "Port ID"
+	case CDPTLVCapabilities:
+		s = "Capabilities"
+	case CDPTLVVersion:
+		s = "Software Version"
+	case CDPTLVPlatform:
+		s = "Platform"
+	case CDPTLVIPPrefix:
+		s = "IP Prefix"
+	case CDPTLVHello:
+		s = "Protocol Hello"
+	case CDPTLVVTPDomain:
+		s = "VTP Management Domain"
+	case CDPTLVNativeVLAN:
+		s = "Native VLAN"
+	case CDPTLVFullDuplex:
+		s = "Full Duplex"
+	case CDPTLVVLANReply:
+		s = "VoIP VLAN Reply"
+	case CDPTLVVLANQuery:
+		s = "VLANQuery"
+	case CDPTLVPower:
+		s = "Power consumption"
+	case CDPTLVMTU:
+		s = "MTU"
+	case CDPTLVExtendedTrust:
+		s = "Extended Trust Bitmap"
+	case CDPTLVUntrustedCOS:
+		s = "Untrusted Port CoS"
+	case CDPTLVSysName:
+		s = "System Name"
+	case CDPTLVSysOID:
+		s = "System OID"
+	case CDPTLVMgmtAddresses:
+		s = "Management Addresses"
+	case CDPTLVLocation:
+		s = "Location"
+	case CDPTLVExternalPortID:
+		s = "External Port ID"
+	case CDPTLVPowerRequested:
+		s = "Power Requested"
+	case CDPTLVPowerAvailable:
+		s = "Power Available"
+	case CDPTLVPortUnidirectional:
+		s = "Port Unidirectional"
+	case CDPTLVEnergyWise:
+		s = "Energy Wise"
+	case CDPTLVSparePairPOE:
+		s = "Spare Pair POE"
+	default:
+		s = "Unknown"
+	}
+	return
+}
+
+func (a CDPAddressType) String() (s string) {
+	switch a {
+	case CDPAddressTypeCLNP:
+		s = "Connectionless Network Protocol"
+	case CDPAddressTypeIPV4:
+		s = "IPv4"
+	case CDPAddressTypeIPV6:
+		s = "IPv6"
+	case CDPAddressTypeDECNET:
+		s = "DECnet Phase IV"
+	case CDPAddressTypeAPPLETALK:
+		s = "Apple Talk"
+	case CDPAddressTypeIPX:
+		s = "Novell IPX"
+	case CDPAddressTypeVINES:
+		s = "Banyan VINES"
+	case CDPAddressTypeXNS:
+		s = "Xerox Network Systems"
+	case CDPAddressTypeAPOLLO:
+		s = "Apollo"
+	default:
+		s = "Unknown"
+	}
+	return
+}
+
+func (t CDPEnergyWiseSubtype) String() (s string) {
+	switch t {
+	case CDPEnergyWiseRole:
+		s = "Role"
+	case CDPEnergyWiseDomain:
+		s = "Domain"
+	case CDPEnergyWiseName:
+		s = "Name"
+	case CDPEnergyWiseReplyTo:
+		s = "ReplyTo"
+	default:
+		s = "Unknown"
+	}
+	return
+}
+
+func checkCDPTLVLen(v CiscoDiscoveryValue, l int) (err error) {
+	if len(v.Value) < l {
+		err = fmt.Errorf("Invalid TLV %v length %d", v.Type, len(v.Value))
+	}
+	return
+}

vendor/github.com/google/gopacket/layers/ctp.go

@@ -0,0 +1,109 @@
+// Copyright 2012 Google, Inc. All rights reserved.
+//
+// Use of this source code is governed by a BSD-style license
+// that can be found in the LICENSE file in the root of the source
+// tree.
+
+package layers
+
+import (
+	"encoding/binary"
+	"fmt"
+	"github.com/google/gopacket"
+)
+
+// EthernetCTPFunction is the function code used by the EthernetCTP protocol to identify each
+// EthernetCTP layer.
+type EthernetCTPFunction uint16
+
+// EthernetCTPFunction values.
+const (
+	EthernetCTPFunctionReply       EthernetCTPFunction = 1
+	EthernetCTPFunctionForwardData EthernetCTPFunction = 2
+)
+
+// EthernetCTP implements the EthernetCTP protocol, see http://www.mit.edu/people/jhawk/ctp.html.
+// We split EthernetCTP up into the top-level EthernetCTP layer, followed by zero or more
+// EthernetCTPForwardData layers, followed by a final EthernetCTPReply layer.
+type EthernetCTP struct {
+	BaseLayer
+	SkipCount uint16
+}
+
+// LayerType returns gopacket.LayerTypeEthernetCTP.
+func (c *EthernetCTP) LayerType() gopacket.LayerType {
+	return LayerTypeEthernetCTP
+}
+
+// EthernetCTPForwardData is the ForwardData layer inside EthernetCTP.  See EthernetCTP's docs for more
+// details.
+type EthernetCTPForwardData struct {
+	BaseLayer
+	Function       EthernetCTPFunction
+	ForwardAddress []byte
+}
+
+// LayerType returns gopacket.LayerTypeEthernetCTPForwardData.
+func (c *EthernetCTPForwardData) LayerType() gopacket.LayerType {
+	return LayerTypeEthernetCTPForwardData
+}
+
+// ForwardEndpoint returns the EthernetCTPForwardData ForwardAddress as an endpoint.
+func (c *EthernetCTPForwardData) ForwardEndpoint() gopacket.Endpoint {
+	return gopacket.NewEndpoint(EndpointMAC, c.ForwardAddress)
+}
+
+// EthernetCTPReply is the Reply layer inside EthernetCTP.  See EthernetCTP's docs for more details.
+type EthernetCTPReply struct {
+	BaseLayer
+	Function      EthernetCTPFunction
+	ReceiptNumber uint16
+	Data          []byte
+}
+
+// LayerType returns gopacket.LayerTypeEthernetCTPReply.
+func (c *EthernetCTPReply) LayerType() gopacket.LayerType {
+	return LayerTypeEthernetCTPReply
+}
+
+// Payload returns the EthernetCTP reply's Data bytes.
+func (c *EthernetCTPReply) Payload() []byte { return c.Data }
+
+func decodeEthernetCTP(data []byte, p gopacket.PacketBuilder) error {
+	c := &EthernetCTP{
+		SkipCount: binary.LittleEndian.Uint16(data[:2]),
+		BaseLayer: BaseLayer{data[:2], data[2:]},
+	}
+	if c.SkipCount%2 != 0 {
+		return fmt.Errorf("EthernetCTP skip count is odd: %d", c.SkipCount)
+	}
+	p.AddLayer(c)
+	return p.NextDecoder(gopacket.DecodeFunc(decodeEthernetCTPFromFunctionType))
+}
+
+// decodeEthernetCTPFromFunctionType reads in the first 2 bytes to determine the EthernetCTP
+// layer type to decode next, then decodes based on that.
+func decodeEthernetCTPFromFunctionType(data []byte, p gopacket.PacketBuilder) error {
+	function := EthernetCTPFunction(binary.LittleEndian.Uint16(data[:2]))
+	switch function {
+	case EthernetCTPFunctionReply:
+		reply := &EthernetCTPReply{
+			Function:      function,
+			ReceiptNumber: binary.LittleEndian.Uint16(data[2:4]),
+			Data:          data[4:],
+			BaseLayer:     BaseLayer{data, nil},
+		}
+		p.AddLayer(reply)
+		p.SetApplicationLayer(reply)
+		return nil
+	case EthernetCTPFunctionForwardData:
+		forward := &EthernetCTPForwardData{
+			Function:       function,
+			ForwardAddress: data[2:8],
+			BaseLayer:      BaseLayer{data[:8], data[8:]},
+		}
+		p.AddLayer(forward)
+		return p.NextDecoder(gopacket.DecodeFunc(decodeEthernetCTPFromFunctionType))
+	}
+	return fmt.Errorf("Unknown EthernetCTP function type %v", function)
+}

vendor/github.com/google/gopacket/layers/dhcpv4.go

@@ -0,0 +1,592 @@
+// Copyright 2016 Google, Inc. All rights reserved.
+//
+// Use of this source code is governed by a BSD-style license
+// that can be found in the LICENSE file in the root of the source
+// tree.
+
+package layers
+
+import (
+	"bytes"
+	"encoding/binary"
+	"fmt"
+	"net"
+
+	"github.com/google/gopacket"
+)
+
+// DHCPOp rerprents a bootp operation
+type DHCPOp byte
+
+// bootp operations
+const (
+	DHCPOpRequest DHCPOp = 1
+	DHCPOpReply   DHCPOp = 2
+)
+
+// String returns a string version of a DHCPOp.
+func (o DHCPOp) String() string {
+	switch o {
+	case DHCPOpRequest:
+		return "Request"
+	case DHCPOpReply:
+		return "Reply"
+	default:
+		return "Unknown"
+	}
+}
+
+// DHCPMsgType represents a DHCP operation
+type DHCPMsgType byte
+
+// Constants that represent DHCP operations
+const (
+	DHCPMsgTypeUnspecified DHCPMsgType = iota
+	DHCPMsgTypeDiscover
+	DHCPMsgTypeOffer
+	DHCPMsgTypeRequest
+	DHCPMsgTypeDecline
+	DHCPMsgTypeAck
+	DHCPMsgTypeNak
+	DHCPMsgTypeRelease
+	DHCPMsgTypeInform
+)
+
+// String returns a string version of a DHCPMsgType.
+func (o DHCPMsgType) String() string {
+	switch o {
+	case DHCPMsgTypeUnspecified:
+		return "Unspecified"
+	case DHCPMsgTypeDiscover:
+		return "Discover"
+	case DHCPMsgTypeOffer:
+		return "Offer"
+	case DHCPMsgTypeRequest:
+		return "Request"
+	case DHCPMsgTypeDecline:
+		return "Decline"
+	case DHCPMsgTypeAck:
+		return "Ack"
+	case DHCPMsgTypeNak:
+		return "Nak"
+	case DHCPMsgTypeRelease:
+		return "Release"
+	case DHCPMsgTypeInform:
+		return "Inform"
+	default:
+		return "Unknown"
+	}
+}
+
+//DHCPMagic is the RFC 2131 "magic cooke" for DHCP.
+var DHCPMagic uint32 = 0x63825363
+
+// DHCPv4 contains data for a single DHCP packet.
+type DHCPv4 struct {
+	BaseLayer
+	Operation    DHCPOp
+	HardwareType LinkType
+	HardwareLen  uint8
+	HardwareOpts uint8
+	Xid          uint32
+	Secs         uint16
+	Flags        uint16
+	ClientIP     net.IP
+	YourClientIP net.IP
+	NextServerIP net.IP
+	RelayAgentIP net.IP
+	ClientHWAddr net.HardwareAddr
+	ServerName   []byte
+	File         []byte
+	Options      DHCPOptions
+}
+
+// DHCPOptions is used to get nicely printed option lists which would normally
+// be cut off after 5 options.
+type DHCPOptions []DHCPOption
+
+// String returns a string version of the options list.
+func (o DHCPOptions) String() string {
+	buf := &bytes.Buffer{}
+	buf.WriteByte('[')
+	for i, opt := range o {
+		buf.WriteString(opt.String())
+		if i+1 != len(o) {
+			buf.WriteString(", ")
+		}
+	}
+	buf.WriteByte(']')
+	return buf.String()
+}
+
+// LayerType returns gopacket.LayerTypeDHCPv4
+func (d *DHCPv4) LayerType() gopacket.LayerType { return LayerTypeDHCPv4 }
+
+// DecodeFromBytes decodes the given bytes into this layer.
+func (d *DHCPv4) DecodeFromBytes(data []byte, df gopacket.DecodeFeedback) error {
+	if len(data) < 240 {
+		df.SetTruncated()
+		return fmt.Errorf("DHCPv4 length %d too short", len(data))
+	}
+	d.Options = d.Options[:0]
+	d.Operation = DHCPOp(data[0])
+	d.HardwareType = LinkType(data[1])
+	d.HardwareLen = data[2]
+	d.HardwareOpts = data[3]
+	d.Xid = binary.BigEndian.Uint32(data[4:8])
+	d.Secs = binary.BigEndian.Uint16(data[8:10])
+	d.Flags = binary.BigEndian.Uint16(data[10:12])
+	d.ClientIP = net.IP(data[12:16])
+	d.YourClientIP = net.IP(data[16:20])
+	d.NextServerIP = net.IP(data[20:24])
+	d.RelayAgentIP = net.IP(data[24:28])
+	d.ClientHWAddr = net.HardwareAddr(data[28 : 28+d.HardwareLen])
+	d.ServerName = data[44:108]
+	d.File = data[108:236]
+	if binary.BigEndian.Uint32(data[236:240]) != DHCPMagic {
+		return InvalidMagicCookie
+	}
+
+	if len(data) <= 240 {
+		// DHCP Packet could have no option (??)
+		return nil
+	}
+
+	options := data[240:]
+
+	stop := len(options)
+	start := 0
+	for start < stop {
+		o := DHCPOption{}
+		if err := o.decode(options[start:]); err != nil {
+			return err
+		}
+		if o.Type == DHCPOptEnd {
+			break
+		}
+		d.Options = append(d.Options, o)
+		// Check if the option is a single byte pad
+		if o.Type == DHCPOptPad {
+			start++
+		} else {
+			start += int(o.Length) + 2
+		}
+	}
+
+	d.Contents = data
+
+	return nil
+}
+
+// Len returns the length of a DHCPv4 packet.
+func (d *DHCPv4) Len() uint16 {
+	n := uint16(240)
+	for _, o := range d.Options {
+		if o.Type == DHCPOptPad {
+			n++
+		} else {
+			n += uint16(o.Length) + 2
+		}
+	}
+	n++ // for opt end
+	return n
+}
+
+// SerializeTo writes the serialized form of this layer into the
+// SerializationBuffer, implementing gopacket.SerializableLayer.
+// See the docs for gopacket.SerializableLayer for more info.
+func (d *DHCPv4) SerializeTo(b gopacket.SerializeBuffer, opts gopacket.SerializeOptions) error {
+	plen := int(d.Len())
+
+	data, err := b.PrependBytes(plen)
+	if err != nil {
+		return err
+	}
+
+	data[0] = byte(d.Operation)
+	data[1] = byte(d.HardwareType)
+	if opts.FixLengths {
+		d.HardwareLen = uint8(len(d.ClientHWAddr))
+	}
+	data[2] = d.HardwareLen
+	data[3] = d.HardwareOpts
+	binary.BigEndian.PutUint32(data[4:8], d.Xid)
+	binary.BigEndian.PutUint16(data[8:10], d.Secs)
+	binary.BigEndian.PutUint16(data[10:12], d.Flags)
+	copy(data[12:16], d.ClientIP.To4())
+	copy(data[16:20], d.YourClientIP.To4())
+	copy(data[20:24], d.NextServerIP.To4())
+	copy(data[24:28], d.RelayAgentIP.To4())
+	copy(data[28:44], d.ClientHWAddr)
+	copy(data[44:108], d.ServerName)
+	copy(data[108:236], d.File)
+	binary.BigEndian.PutUint32(data[236:240], DHCPMagic)
+
+	if len(d.Options) > 0 {
+		offset := 240
+		for _, o := range d.Options {
+			if err := o.encode(data[offset:]); err != nil {
+				return err
+			}
+			// A pad option is only a single byte
+			if o.Type == DHCPOptPad {
+				offset++
+			} else {
+				offset += 2 + len(o.Data)
+			}
+		}
+		optend := NewDHCPOption(DHCPOptEnd, nil)
+		if err := optend.encode(data[offset:]); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+// CanDecode returns the set of layer types that this DecodingLayer can decode.
+func (d *DHCPv4) CanDecode() gopacket.LayerClass {
+	return LayerTypeDHCPv4
+}
+
+// NextLayerType returns the layer type contained by this DecodingLayer.
+func (d *DHCPv4) NextLayerType() gopacket.LayerType {
+	return gopacket.LayerTypePayload
+}
+
+func decodeDHCPv4(data []byte, p gopacket.PacketBuilder) error {
+	dhcp := &DHCPv4{}
+	err := dhcp.DecodeFromBytes(data, p)
+	if err != nil {
+		return err
+	}
+	p.AddLayer(dhcp)
+	return p.NextDecoder(gopacket.LayerTypePayload)
+}
+
+// DHCPOpt represents a DHCP option or parameter from RFC-2132
+type DHCPOpt byte
+
+// Constants for the DHCPOpt options.
+const (
+	DHCPOptPad                   DHCPOpt = 0
+	DHCPOptSubnetMask            DHCPOpt = 1   // 4, net.IP
+	DHCPOptTimeOffset            DHCPOpt = 2   // 4, int32 (signed seconds from UTC)
+	DHCPOptRouter                DHCPOpt = 3   // n*4, [n]net.IP
+	DHCPOptTimeServer            DHCPOpt = 4   // n*4, [n]net.IP
+	DHCPOptNameServer            DHCPOpt = 5   // n*4, [n]net.IP
+	DHCPOptDNS                   DHCPOpt = 6   // n*4, [n]net.IP
+	DHCPOptLogServer             DHCPOpt = 7   // n*4, [n]net.IP
+	DHCPOptCookieServer          DHCPOpt = 8   // n*4, [n]net.IP
+	DHCPOptLPRServer             DHCPOpt = 9   // n*4, [n]net.IP
+	DHCPOptImpressServer         DHCPOpt = 10  // n*4, [n]net.IP
+	DHCPOptResLocServer          DHCPOpt = 11  // n*4, [n]net.IP
+	DHCPOptHostname              DHCPOpt = 12  // n, string
+	DHCPOptBootfileSize          DHCPOpt = 13  // 2, uint16
+	DHCPOptMeritDumpFile         DHCPOpt = 14  // >1, string
+	DHCPOptDomainName            DHCPOpt = 15  // n, string
+	DHCPOptSwapServer            DHCPOpt = 16  // n*4, [n]net.IP
+	DHCPOptRootPath              DHCPOpt = 17  // n, string
+	DHCPOptExtensionsPath        DHCPOpt = 18  // n, string
+	DHCPOptIPForwarding          DHCPOpt = 19  // 1, bool
+	DHCPOptSourceRouting         DHCPOpt = 20  // 1, bool
+	DHCPOptPolicyFilter          DHCPOpt = 21  // 8*n, [n]{net.IP/net.IP}
+	DHCPOptDatagramMTU           DHCPOpt = 22  // 2, uint16
+	DHCPOptDefaultTTL            DHCPOpt = 23  // 1, byte
+	DHCPOptPathMTUAgingTimeout   DHCPOpt = 24  // 4, uint32
+	DHCPOptPathPlateuTableOption DHCPOpt = 25  // 2*n, []uint16
+	DHCPOptInterfaceMTU          DHCPOpt = 26  // 2, uint16
+	DHCPOptAllSubsLocal          DHCPOpt = 27  // 1, bool
+	DHCPOptBroadcastAddr         DHCPOpt = 28  // 4, net.IP
+	DHCPOptMaskDiscovery         DHCPOpt = 29  // 1, bool
+	DHCPOptMaskSupplier          DHCPOpt = 30  // 1, bool
+	DHCPOptRouterDiscovery       DHCPOpt = 31  // 1, bool
+	DHCPOptSolicitAddr           DHCPOpt = 32  // 4, net.IP
+	DHCPOptStaticRoute           DHCPOpt = 33  // n*8, [n]{net.IP/net.IP} -- note the 2nd is router not mask
+	DHCPOptARPTrailers           DHCPOpt = 34  // 1, bool
+	DHCPOptARPTimeout            DHCPOpt = 35  // 4, uint32
+	DHCPOptEthernetEncap         DHCPOpt = 36  // 1, bool
+	DHCPOptTCPTTL                DHCPOpt = 37  // 1, byte
+	DHCPOptTCPKeepAliveInt       DHCPOpt = 38  // 4, uint32
+	DHCPOptTCPKeepAliveGarbage   DHCPOpt = 39  // 1, bool
+	DHCPOptNISDomain             DHCPOpt = 40  // n, string
+	DHCPOptNISServers            DHCPOpt = 41  // 4*n,  [n]net.IP
+	DHCPOptNTPServers            DHCPOpt = 42  // 4*n, [n]net.IP
+	DHCPOptVendorOption          DHCPOpt = 43  // n, [n]byte // may be encapsulated.
+	DHCPOptNetBIOSTCPNS          DHCPOpt = 44  // 4*n, [n]net.IP
+	DHCPOptNetBIOSTCPDDS         DHCPOpt = 45  // 4*n, [n]net.IP
+	DHCPOptNETBIOSTCPNodeType    DHCPOpt = 46  // 1, magic byte
+	DHCPOptNetBIOSTCPScope       DHCPOpt = 47  // n, string
+	DHCPOptXFontServer           DHCPOpt = 48  // n, string
+	DHCPOptXDisplayManager       DHCPOpt = 49  // n, string
+	DHCPOptRequestIP             DHCPOpt = 50  // 4, net.IP
+	DHCPOptLeaseTime             DHCPOpt = 51  // 4, uint32
+	DHCPOptExtOptions            DHCPOpt = 52  // 1, 1/2/3
+	DHCPOptMessageType           DHCPOpt = 53  // 1, 1-7
+	DHCPOptServerID              DHCPOpt = 54  // 4, net.IP
+	DHCPOptParamsRequest         DHCPOpt = 55  // n, []byte
+	DHCPOptMessage               DHCPOpt = 56  // n, 3
+	DHCPOptMaxMessageSize        DHCPOpt = 57  // 2, uint16
+	DHCPOptT1                    DHCPOpt = 58  // 4, uint32
+	DHCPOptT2                    DHCPOpt = 59  // 4, uint32
+	DHCPOptClassID               DHCPOpt = 60  // n, []byte
+	DHCPOptClientID              DHCPOpt = 61  // n >=  2, []byte
+	DHCPOptDomainSearch          DHCPOpt = 119 // n, string
+	DHCPOptSIPServers            DHCPOpt = 120 // n, url
+	DHCPOptClasslessStaticRoute  DHCPOpt = 121 //
+	DHCPOptEnd                   DHCPOpt = 255
+)
+
+// String returns a string version of a DHCPOpt.
+func (o DHCPOpt) String() string {
+	switch o {
+	case DHCPOptPad:
+		return "(padding)"
+	case DHCPOptSubnetMask:
+		return "SubnetMask"
+	case DHCPOptTimeOffset:
+		return "TimeOffset"
+	case DHCPOptRouter:
+		return "Router"
+	case DHCPOptTimeServer:
+		return "rfc868" // old time server protocol stringified to dissuade confusion w. NTP
+	case DHCPOptNameServer:
+		return "ien116" // obscure nameserver protocol stringified to dissuade confusion w. DNS
+	case DHCPOptDNS:
+		return "DNS"
+	case DHCPOptLogServer:
+		return "mitLCS" // MIT LCS server protocol yada yada w. Syslog
+	case DHCPOptCookieServer:
+		return "CookieServer"
+	case DHCPOptLPRServer:
+		return "LPRServer"
+	case DHCPOptImpressServer:
+		return "ImpressServer"
+	case DHCPOptResLocServer:
+		return "ResourceLocationServer"
+	case DHCPOptHostname:
+		return "Hostname"
+	case DHCPOptBootfileSize:
+		return "BootfileSize"
+	case DHCPOptMeritDumpFile:
+		return "MeritDumpFile"
+	case DHCPOptDomainName:
+		return "DomainName"
+	case DHCPOptSwapServer:
+		return "SwapServer"
+	case DHCPOptRootPath:
+		return "RootPath"
+	case DHCPOptExtensionsPath:
+		return "ExtensionsPath"
+	case DHCPOptIPForwarding:
+		return "IPForwarding"
+	case DHCPOptSourceRouting:
+		return "SourceRouting"
+	case DHCPOptPolicyFilter:
+		return "PolicyFilter"
+	case DHCPOptDatagramMTU:
+		return "DatagramMTU"
+	case DHCPOptDefaultTTL:
+		return "DefaultTTL"
+	case DHCPOptPathMTUAgingTimeout:
+		return "PathMTUAgingTimeout"
+	case DHCPOptPathPlateuTableOption:
+		return "PathPlateuTableOption"
+	case DHCPOptInterfaceMTU:
+		return "InterfaceMTU"
+	case DHCPOptAllSubsLocal:
+		return "AllSubsLocal"
+	case DHCPOptBroadcastAddr:
+		return "BroadcastAddress"
+	case DHCPOptMaskDiscovery:
+		return "MaskDiscovery"
+	case DHCPOptMaskSupplier:
+		return "MaskSupplier"
+	case DHCPOptRouterDiscovery:
+		return "RouterDiscovery"
+	case DHCPOptSolicitAddr:
+		return "SolicitAddr"
+	case DHCPOptStaticRoute:
+		return "StaticRoute"
+	case DHCPOptARPTrailers:
+		return "ARPTrailers"
+	case DHCPOptARPTimeout:
+		return "ARPTimeout"
+	case DHCPOptEthernetEncap:
+		return "EthernetEncap"
+	case DHCPOptTCPTTL:
+		return "TCPTTL"
+	case DHCPOptTCPKeepAliveInt:
+		return "TCPKeepAliveInt"
+	case DHCPOptTCPKeepAliveGarbage:
+		return "TCPKeepAliveGarbage"
+	case DHCPOptNISDomain:
+		return "NISDomain"
+	case DHCPOptNISServers:
+		return "NISServers"
+	case DHCPOptNTPServers:
+		return "NTPServers"
+	case DHCPOptVendorOption:
+		return "VendorOption"
+	case DHCPOptNetBIOSTCPNS:
+		return "NetBIOSOverTCPNS"
+	case DHCPOptNetBIOSTCPDDS:
+		return "NetBiosOverTCPDDS"
+	case DHCPOptNETBIOSTCPNodeType:
+		return "NetBIOSOverTCPNodeType"
+	case DHCPOptNetBIOSTCPScope:
+		return "NetBIOSOverTCPScope"
+	case DHCPOptXFontServer:
+		return "XFontServer"
+	case DHCPOptXDisplayManager:
+		return "XDisplayManager"
+	case DHCPOptEnd:
+		return "(end)"
+	case DHCPOptSIPServers:
+		return "SipServers"
+	case DHCPOptRequestIP:
+		return "RequestIP"
+	case DHCPOptLeaseTime:
+		return "LeaseTime"
+	case DHCPOptExtOptions:
+		return "ExtOpts"
+	case DHCPOptMessageType:
+		return "MessageType"
+	case DHCPOptServerID:
+		return "ServerID"
+	case DHCPOptParamsRequest:
+		return "ParamsRequest"
+	case DHCPOptMessage:
+		return "Message"
+	case DHCPOptMaxMessageSize:
+		return "MaxDHCPSize"
+	case DHCPOptT1:
+		return "Timer1"
+	case DHCPOptT2:
+		return "Timer2"
+	case DHCPOptClassID:
+		return "ClassID"
+	case DHCPOptClientID:
+		return "ClientID"
+	case DHCPOptDomainSearch:
+		return "DomainSearch"
+	case DHCPOptClasslessStaticRoute:
+		return "ClasslessStaticRoute"
+	default:
+		return "Unknown"
+	}
+}
+
+// DHCPOption rerpresents a DHCP option.
+type DHCPOption struct {
+	Type   DHCPOpt
+	Length uint8
+	Data   []byte
+}
+
+// String returns a string version of a DHCP Option.
+func (o DHCPOption) String() string {
+	switch o.Type {
+
+	case DHCPOptHostname, DHCPOptMeritDumpFile, DHCPOptDomainName, DHCPOptRootPath,
+		DHCPOptExtensionsPath, DHCPOptNISDomain, DHCPOptNetBIOSTCPScope, DHCPOptXFontServer,
+		DHCPOptXDisplayManager, DHCPOptMessage, DHCPOptDomainSearch: // string
+		return fmt.Sprintf("Option(%s:%s)", o.Type, string(o.Data))
+
+	case DHCPOptMessageType:
+		if len(o.Data) != 1 {
+			return fmt.Sprintf("Option(%s:INVALID)", o.Type)
+		}
+		return fmt.Sprintf("Option(%s:%s)", o.Type, DHCPMsgType(o.Data[0]))
+
+	case DHCPOptSubnetMask, DHCPOptServerID, DHCPOptBroadcastAddr,
+		DHCPOptSolicitAddr, DHCPOptRequestIP: // net.IP
+		if len(o.Data) < 4 {
+			return fmt.Sprintf("Option(%s:INVALID)", o.Type)
+		}
+		return fmt.Sprintf("Option(%s:%s)", o.Type, net.IP(o.Data))
+
+	case DHCPOptT1, DHCPOptT2, DHCPOptLeaseTime, DHCPOptPathMTUAgingTimeout,
+		DHCPOptARPTimeout, DHCPOptTCPKeepAliveInt: // uint32
+		if len(o.Data) != 4 {
+			return fmt.Sprintf("Option(%s:INVALID)", o.Type)
+		}
+		return fmt.Sprintf("Option(%s:%d)", o.Type,
+			uint32(o.Data[0])<<24|uint32(o.Data[1])<<16|uint32(o.Data[2])<<8|uint32(o.Data[3]))
+
+	case DHCPOptParamsRequest:
+		buf := &bytes.Buffer{}
+		buf.WriteString(fmt.Sprintf("Option(%s:", o.Type))
+		for i, v := range o.Data {
+			buf.WriteString(DHCPOpt(v).String())
+			if i+1 != len(o.Data) {
+				buf.WriteByte(',')
+			}
+		}
+		buf.WriteString(")")
+		return buf.String()
+
+	default:
+		return fmt.Sprintf("Option(%s:%v)", o.Type, o.Data)
+	}
+}
+
+// NewDHCPOption constructs a new DHCPOption with a given type and data.
+func NewDHCPOption(t DHCPOpt, data []byte) DHCPOption {
+	o := DHCPOption{Type: t}
+	if data != nil {
+		o.Data = data
+		o.Length = uint8(len(data))
+	}
+	return o
+}
+
+func (o *DHCPOption) encode(b []byte) error {
+	switch o.Type {
+	case DHCPOptPad, DHCPOptEnd:
+		b[0] = byte(o.Type)
+	default:
+		b[0] = byte(o.Type)
+		b[1] = o.Length
+		copy(b[2:], o.Data)
+	}
+	return nil
+}
+
+func (o *DHCPOption) decode(data []byte) error {
+	if len(data) < 1 {
+		// Pad/End have a length of 1
+		return DecOptionNotEnoughData
+	}
+	o.Type = DHCPOpt(data[0])
+	switch o.Type {
+	case DHCPOptPad, DHCPOptEnd:
+		o.Data = nil
+	default:
+		if len(data) < 2 {
+			return DecOptionNotEnoughData
+		}
+		o.Length = data[1]
+		if int(o.Length) > len(data[2:]) {
+			return DecOptionMalformed
+		}
+		o.Data = data[2 : 2+int(o.Length)]
+	}
+	return nil
+}
+
+// DHCPv4Error is used for constant errors for DHCPv4. It is needed for test asserts.
+type DHCPv4Error string
+
+// DHCPv4Error implements error interface.
+func (d DHCPv4Error) Error() string {
+	return string(d)
+}
+
+const (
+	// DecOptionNotEnoughData is returned when there is not enough data during option's decode process
+	DecOptionNotEnoughData = DHCPv4Error("Not enough data to decode")
+	// DecOptionMalformed is returned when the option is malformed
+	DecOptionMalformed = DHCPv4Error("Option is malformed")
+	// InvalidMagicCookie is returned when Magic cookie is missing into BOOTP header
+	InvalidMagicCookie = DHCPv4Error("Bad DHCP header")
+)

vendor/github.com/google/gopacket/layers/dhcpv6.go

@@ -0,0 +1,360 @@
+// Copyright 2018 Google, Inc. All rights reserved.
+//
+// Use of this source code is governed by a BSD-style license
+// that can be found in the LICENSE file in the root of the source
+// tree.
+
+package layers
+
+import (
+	"encoding/binary"
+	"fmt"
+	"net"
+
+	"github.com/google/gopacket"
+)
+
+// DHCPv6MsgType represents a DHCPv6 operation
+type DHCPv6MsgType byte
+
+// Constants that represent DHCP operations
+const (
+	DHCPv6MsgTypeUnspecified DHCPv6MsgType = iota
+	DHCPv6MsgTypeSolicit
+	DHCPv6MsgTypeAdverstise
+	DHCPv6MsgTypeRequest
+	DHCPv6MsgTypeConfirm
+	DHCPv6MsgTypeRenew
+	DHCPv6MsgTypeRebind
+	DHCPv6MsgTypeReply
+	DHCPv6MsgTypeRelease
+	DHCPv6MsgTypeDecline
+	DHCPv6MsgTypeReconfigure
+	DHCPv6MsgTypeInformationRequest
+	DHCPv6MsgTypeRelayForward
+	DHCPv6MsgTypeRelayReply
+)
+
+// String returns a string version of a DHCPv6MsgType.
+func (o DHCPv6MsgType) String() string {
+	switch o {
+	case DHCPv6MsgTypeUnspecified:
+		return "Unspecified"
+	case DHCPv6MsgTypeSolicit:
+		return "Solicit"
+	case DHCPv6MsgTypeAdverstise:
+		return "Adverstise"
+	case DHCPv6MsgTypeRequest:
+		return "Request"
+	case DHCPv6MsgTypeConfirm:
+		return "Confirm"
+	case DHCPv6MsgTypeRenew:
+		return "Renew"
+	case DHCPv6MsgTypeRebind:
+		return "Rebind"
+	case DHCPv6MsgTypeReply:
+		return "Reply"
+	case DHCPv6MsgTypeRelease:
+		return "Release"
+	case DHCPv6MsgTypeDecline:
+		return "Decline"
+	case DHCPv6MsgTypeReconfigure:
+		return "Reconfigure"
+	case DHCPv6MsgTypeInformationRequest:
+		return "InformationRequest"
+	case DHCPv6MsgTypeRelayForward:
+		return "RelayForward"
+	case DHCPv6MsgTypeRelayReply:
+		return "RelayReply"
+	default:
+		return "Unknown"
+	}
+}
+
+// DHCPv6 contains data for a single DHCP packet.
+type DHCPv6 struct {
+	BaseLayer
+	MsgType       DHCPv6MsgType
+	HopCount      uint8
+	LinkAddr      net.IP
+	PeerAddr      net.IP
+	TransactionID []byte
+	Options       DHCPv6Options
+}
+
+// LayerType returns gopacket.LayerTypeDHCPv6
+func (d *DHCPv6) LayerType() gopacket.LayerType { return LayerTypeDHCPv6 }
+
+// DecodeFromBytes decodes the given bytes into this layer.
+func (d *DHCPv6) DecodeFromBytes(data []byte, df gopacket.DecodeFeedback) error {
+	if len(data) < 4 {
+		df.SetTruncated()
+		return fmt.Errorf("DHCPv6 length %d too short", len(data))
+	}
+	d.BaseLayer = BaseLayer{Contents: data}
+	d.Options = d.Options[:0]
+	d.MsgType = DHCPv6MsgType(data[0])
+
+	offset := 0
+	if d.MsgType == DHCPv6MsgTypeRelayForward || d.MsgType == DHCPv6MsgTypeRelayReply {
+		if len(data) < 34 {
+			df.SetTruncated()
+			return fmt.Errorf("DHCPv6 length %d too short for message type %d", len(data), d.MsgType)
+		}
+		d.HopCount = data[1]
+		d.LinkAddr = net.IP(data[2:18])
+		d.PeerAddr = net.IP(data[18:34])
+		offset = 34
+	} else {
+		d.TransactionID = data[1:4]
+		offset = 4
+	}
+
+	stop := len(data)
+	for offset < stop {
+		o := DHCPv6Option{}
+		if err := o.decode(data[offset:]); err != nil {
+			return err
+		}
+		d.Options = append(d.Options, o)
+		offset += int(o.Length) + 4 // 2 from option code, 2 from option length
+	}
+
+	return nil
+}
+
+// Len returns the length of a DHCPv6 packet.
+func (d *DHCPv6) Len() int {
+	n := 1
+	if d.MsgType == DHCPv6MsgTypeRelayForward || d.MsgType == DHCPv6MsgTypeRelayReply {
+		n += 33
+	} else {
+		n += 3
+	}
+
+	for _, o := range d.Options {
+		n += int(o.Length) + 4 // 2 from option code, 2 from option length
+	}
+
+	return n
+}
+
+// SerializeTo writes the serialized form of this layer into the
+// SerializationBuffer, implementing gopacket.SerializableLayer.
+// See the docs for gopacket.SerializableLayer for more info.
+func (d *DHCPv6) SerializeTo(b gopacket.SerializeBuffer, opts gopacket.SerializeOptions) error {
+	plen := int(d.Len())
+
+	data, err := b.PrependBytes(plen)
+	if err != nil {
+		return err
+	}
+
+	offset := 0
+	data[0] = byte(d.MsgType)
+	if d.MsgType == DHCPv6MsgTypeRelayForward || d.MsgType == DHCPv6MsgTypeRelayReply {
+		data[1] = byte(d.HopCount)
+		copy(data[2:18], d.LinkAddr.To16())
+		copy(data[18:34], d.PeerAddr.To16())
+		offset = 34
+	} else {
+		copy(data[1:4], d.TransactionID)
+		offset = 4
+	}
+
+	if len(d.Options) > 0 {
+		for _, o := range d.Options {
+			if err := o.encode(data[offset:], opts); err != nil {
+				return err
+			}
+			offset += int(o.Length) + 4 // 2 from option code, 2 from option length
+		}
+	}
+	return nil
+}
+
+// CanDecode returns the set of layer types that this DecodingLayer can decode.
+func (d *DHCPv6) CanDecode() gopacket.LayerClass {
+	return LayerTypeDHCPv6
+}
+
+// NextLayerType returns the layer type contained by this DecodingLayer.
+func (d *DHCPv6) NextLayerType() gopacket.LayerType {
+	return gopacket.LayerTypePayload
+}
+
+func decodeDHCPv6(data []byte, p gopacket.PacketBuilder) error {
+	dhcp := &DHCPv6{}
+	err := dhcp.DecodeFromBytes(data, p)
+	if err != nil {
+		return err
+	}
+	p.AddLayer(dhcp)
+	return p.NextDecoder(gopacket.LayerTypePayload)
+}
+
+// DHCPv6StatusCode represents a DHCP status code - RFC-3315
+type DHCPv6StatusCode uint16
+
+// Constants for the DHCPv6StatusCode.
+const (
+	DHCPv6StatusCodeSuccess DHCPv6StatusCode = iota
+	DHCPv6StatusCodeUnspecFail
+	DHCPv6StatusCodeNoAddrsAvail
+	DHCPv6StatusCodeNoBinding
+	DHCPv6StatusCodeNotOnLink
+	DHCPv6StatusCodeUseMulticast
+)
+
+// String returns a string version of a DHCPv6StatusCode.
+func (o DHCPv6StatusCode) String() string {
+	switch o {
+	case DHCPv6StatusCodeSuccess:
+		return "Success"
+	case DHCPv6StatusCodeUnspecFail:
+		return "UnspecifiedFailure"
+	case DHCPv6StatusCodeNoAddrsAvail:
+		return "NoAddressAvailable"
+	case DHCPv6StatusCodeNoBinding:
+		return "NoBinding"
+	case DHCPv6StatusCodeNotOnLink:
+		return "NotOnLink"
+	case DHCPv6StatusCodeUseMulticast:
+		return "UseMulticast"
+	default:
+		return "Unknown"
+	}
+}
+
+// DHCPv6DUIDType represents a DHCP DUID - RFC-3315
+type DHCPv6DUIDType uint16
+
+// Constants for the DHCPv6DUIDType.
+const (
+	DHCPv6DUIDTypeLLT DHCPv6DUIDType = iota + 1
+	DHCPv6DUIDTypeEN
+	DHCPv6DUIDTypeLL
+)
+
+// String returns a string version of a DHCPv6DUIDType.
+func (o DHCPv6DUIDType) String() string {
+	switch o {
+	case DHCPv6DUIDTypeLLT:
+		return "LLT"
+	case DHCPv6DUIDTypeEN:
+		return "EN"
+	case DHCPv6DUIDTypeLL:
+		return "LL"
+	default:
+		return "Unknown"
+	}
+}
+
+// DHCPv6DUID means DHCP Unique Identifier as stated in RFC 3315, section 9 (https://tools.ietf.org/html/rfc3315#page-19)
+type DHCPv6DUID struct {
+	Type DHCPv6DUIDType
+	// LLT, LL
+	HardwareType []byte
+	// EN
+	EnterpriseNumber []byte
+	// LLT
+	Time []byte
+	// LLT, LL
+	LinkLayerAddress net.HardwareAddr
+	// EN
+	Identifier []byte
+}
+
+// DecodeFromBytes decodes the given bytes into a DHCPv6DUID
+func (d *DHCPv6DUID) DecodeFromBytes(data []byte) error {
+	if len(data) < 2 {
+		return fmt.Errorf("Not enough bytes to decode: %d", len(data))
+	}
+
+	d.Type = DHCPv6DUIDType(binary.BigEndian.Uint16(data[:2]))
+	if d.Type == DHCPv6DUIDTypeLLT || d.Type == DHCPv6DUIDTypeLL {
+		if len(data) < 4 {
+			return fmt.Errorf("Not enough bytes to decode: %d", len(data))
+		}
+		d.HardwareType = data[2:4]
+	}
+
+	if d.Type == DHCPv6DUIDTypeLLT {
+		if len(data) < 8 {
+			return fmt.Errorf("Not enough bytes to decode: %d", len(data))
+		}
+		d.Time = data[4:8]
+		d.LinkLayerAddress = net.HardwareAddr(data[8:])
+	} else if d.Type == DHCPv6DUIDTypeEN {
+		if len(data) < 6 {
+			return fmt.Errorf("Not enough bytes to decode: %d", len(data))
+		}
+		d.EnterpriseNumber = data[2:6]
+		d.Identifier = data[6:]
+	} else { // DHCPv6DUIDTypeLL
+		if len(data) < 4 {
+			return fmt.Errorf("Not enough bytes to decode: %d", len(data))
+		}
+		d.LinkLayerAddress = net.HardwareAddr(data[4:])
+	}
+
+	return nil
+}
+
+// Encode encodes the DHCPv6DUID in a slice of bytes
+func (d *DHCPv6DUID) Encode() []byte {
+	length := d.Len()
+	data := make([]byte, length)
+	binary.BigEndian.PutUint16(data[0:2], uint16(d.Type))
+
+	if d.Type == DHCPv6DUIDTypeLLT || d.Type == DHCPv6DUIDTypeLL {
+		copy(data[2:4], d.HardwareType)
+	}
+
+	if d.Type == DHCPv6DUIDTypeLLT {
+		copy(data[4:8], d.Time)
+		copy(data[8:], d.LinkLayerAddress)
+	} else if d.Type == DHCPv6DUIDTypeEN {
+		copy(data[2:6], d.EnterpriseNumber)
+		copy(data[6:], d.Identifier)
+	} else {
+		copy(data[4:], d.LinkLayerAddress)
+	}
+
+	return data
+}
+
+// Len returns the length of the DHCPv6DUID, respecting the type
+func (d *DHCPv6DUID) Len() int {
+	length := 2 // d.Type
+	if d.Type == DHCPv6DUIDTypeLLT {
+		length += 2 /*HardwareType*/ + 4 /*d.Time*/ + len(d.LinkLayerAddress)
+	} else if d.Type == DHCPv6DUIDTypeEN {
+		length += 4 /*d.EnterpriseNumber*/ + len(d.Identifier)
+	} else { // LL
+		length += 2 /*d.HardwareType*/ + len(d.LinkLayerAddress)
+	}
+
+	return length
+}
+
+func (d *DHCPv6DUID) String() string {
+	duid := "Type: " + d.Type.String() + ", "
+	if d.Type == DHCPv6DUIDTypeLLT {
+		duid += fmt.Sprintf("HardwareType: %v, Time: %v, LinkLayerAddress: %v", d.HardwareType, d.Time, d.LinkLayerAddress)
+	} else if d.Type == DHCPv6DUIDTypeEN {
+		duid += fmt.Sprintf("EnterpriseNumber: %v, Identifier: %v", d.EnterpriseNumber, d.Identifier)
+	} else { // DHCPv6DUIDTypeLL
+		duid += fmt.Sprintf("HardwareType: %v, LinkLayerAddress: %v", d.HardwareType, d.LinkLayerAddress)
+	}
+	return duid
+}
+
+func decodeDHCPv6DUID(data []byte) (*DHCPv6DUID, error) {
+	duid := &DHCPv6DUID{}
+	err := duid.DecodeFromBytes(data)
+	if err != nil {
+		return nil, err
+	}
+	return duid, nil
+}

vendor/github.com/google/gopacket/layers/dhcpv6_options.go

@@ -0,0 +1,621 @@
+// Copyright 2018 The GoPacket Authors. All rights reserved.
+//
+// Use of this source code is governed by a BSD-style license
+// that can be found in the LICENSE file in the root of the source
+// tree.
+
+package layers
+
+import (
+	"bytes"
+	"encoding/binary"
+	"errors"
+	"fmt"
+	"github.com/google/gopacket"
+)
+
+// DHCPv6Opt represents a DHCP option or parameter from RFC-3315
+type DHCPv6Opt uint16
+
+// Constants for the DHCPv6Opt options.
+const (
+	DHCPv6OptClientID           DHCPv6Opt = 1
+	DHCPv6OptServerID           DHCPv6Opt = 2
+	DHCPv6OptIANA               DHCPv6Opt = 3
+	DHCPv6OptIATA               DHCPv6Opt = 4
+	DHCPv6OptIAAddr             DHCPv6Opt = 5
+	DHCPv6OptOro                DHCPv6Opt = 6
+	DHCPv6OptPreference         DHCPv6Opt = 7
+	DHCPv6OptElapsedTime        DHCPv6Opt = 8
+	DHCPv6OptRelayMessage       DHCPv6Opt = 9
+	DHCPv6OptAuth               DHCPv6Opt = 11
+	DHCPv6OptUnicast            DHCPv6Opt = 12
+	DHCPv6OptStatusCode         DHCPv6Opt = 13
+	DHCPv6OptRapidCommit        DHCPv6Opt = 14
+	DHCPv6OptUserClass          DHCPv6Opt = 15
+	DHCPv6OptVendorClass        DHCPv6Opt = 16
+	DHCPv6OptVendorOpts         DHCPv6Opt = 17
+	DHCPv6OptInterfaceID        DHCPv6Opt = 18
+	DHCPv6OptReconfigureMessage DHCPv6Opt = 19
+	DHCPv6OptReconfigureAccept  DHCPv6Opt = 20
+
+	// RFC 3319 Session Initiation Protocol (SIP)
+	DHCPv6OptSIPServersDomainList  DHCPv6Opt = 21
+	DHCPv6OptSIPServersAddressList DHCPv6Opt = 22
+
+	// RFC 3646 DNS Configuration
+	DHCPv6OptDNSServers DHCPv6Opt = 23
+	DHCPv6OptDomainList DHCPv6Opt = 24
+
+	// RFC 3633 Prefix Delegation
+	DHCPv6OptIAPD     DHCPv6Opt = 25
+	DHCPv6OptIAPrefix DHCPv6Opt = 26
+
+	// RFC 3898 Network Information Service (NIS)
+	DHCPv6OptNISServers     DHCPv6Opt = 27
+	DHCPv6OptNISPServers    DHCPv6Opt = 28
+	DHCPv6OptNISDomainName  DHCPv6Opt = 29
+	DHCPv6OptNISPDomainName DHCPv6Opt = 30
+
+	// RFC 4075 Simple Network Time Protocol (SNTP)
+	DHCPv6OptSNTPServers DHCPv6Opt = 31
+
+	// RFC 4242 Information Refresh Time Option
+	DHCPv6OptInformationRefreshTime DHCPv6Opt = 32
+
+	// RFC 4280 Broadcast and Multicast Control Servers
+	DHCPv6OptBCMCSServerDomainNameList DHCPv6Opt = 33
+	DHCPv6OptBCMCSServerAddressList    DHCPv6Opt = 34
+
+	// RFC 4776 Civic Address ConfigurationOption
+	DHCPv6OptGeoconfCivic DHCPv6Opt = 36
+
+	// RFC 4649 Relay Agent Remote-ID
+	DHCPv6OptRemoteID DHCPv6Opt = 37
+
+	// RFC 4580 Relay Agent Subscriber-ID
+	DHCPv6OptSubscriberID DHCPv6Opt = 38
+
+	// RFC 4704 Client Full Qualified Domain Name (FQDN)
+	DHCPv6OptClientFQDN DHCPv6Opt = 39
+
+	// RFC 5192 Protocol for Carrying Authentication for Network Access (PANA)
+	DHCPv6OptPanaAgent DHCPv6Opt = 40
+
+	// RFC 4833 Timezone Options
+	DHCPv6OptNewPOSIXTimezone DHCPv6Opt = 41
+	DHCPv6OptNewTZDBTimezone  DHCPv6Opt = 42
+
+	// RFC 4994 Relay Agent Echo Request
+	DHCPv6OptEchoRequestOption DHCPv6Opt = 43
+
+	// RFC 5007 Leasequery
+	DHCPv6OptLQQuery      DHCPv6Opt = 44
+	DHCPv6OptCLTTime      DHCPv6Opt = 45
+	DHCPv6OptClientData   DHCPv6Opt = 46
+	DHCPv6OptLQRelayData  DHCPv6Opt = 47
+	DHCPv6OptLQClientLink DHCPv6Opt = 48
+
+	// RFC 6610 Home Information Discovery in Mobile IPv6 (MIPv6)
+	DHCPv6OptMIP6HNIDF DHCPv6Opt = 49
+	DHCPv6OptMIP6VDINF DHCPv6Opt = 50
+	DHCPv6OptMIP6IDINF DHCPv6Opt = 69
+	DHCPv6OptMIP6UDINF DHCPv6Opt = 70
+	DHCPv6OptMIP6HNP   DHCPv6Opt = 71
+	DHCPv6OptMIP6HAA   DHCPv6Opt = 72
+	DHCPv6OptMIP6HAF   DHCPv6Opt = 73
+
+	// RFC 5223 Discovering Location-to-Service Translation (LoST) Servers
+	DHCPv6OptV6LOST DHCPv6Opt = 51
+
+	// RFC 5417 Control And Provisioning of Wireless Access Points (CAPWAP)
+	DHCPv6OptCAPWAPACV6 DHCPv6Opt = 52
+
+	// RFC 5460 Bulk Leasequery
+	DHCPv6OptRelayID DHCPv6Opt = 53
+
+	// RFC 5678 IEEE 802.21 Mobility Services (MoS) Discovery
+	DHCPv6OptIPv6AddressMoS DHCPv6Opt = 54
+	DHCPv6OptIPv6FQDNMoS    DHCPv6Opt = 55
+
+	// RFC 5908 NTP Server Option
+	DHCPv6OptNTPServer DHCPv6Opt = 56
+
+	// RFC 5986 Discovering the Local Location Information Server (LIS)
+	DHCPv6OptV6AccessDomain DHCPv6Opt = 57
+
+	// RFC 5986 SIP User Agent
+	DHCPv6OptSIPUACSList DHCPv6Opt = 58
+
+	// RFC 5970 Options for Network Boot
+	DHCPv6OptBootFileURL    DHCPv6Opt = 59
+	DHCPv6OptBootFileParam  DHCPv6Opt = 60
+	DHCPv6OptClientArchType DHCPv6Opt = 61
+	DHCPv6OptNII            DHCPv6Opt = 62
+
+	// RFC 6225 Coordinate-Based Location Configuration Information
+	DHCPv6OptGeolocation DHCPv6Opt = 63
+
+	// RFC 6334 Dual-Stack Lite
+	DHCPv6OptAFTRName DHCPv6Opt = 64
+
+	// RFC 6440 EAP Re-authentication Protocol (ERP)
+	DHCPv6OptERPLocalDomainName DHCPv6Opt = 65
+
+	// RFC 6422 Relay-Supplied DHCP Options
+	DHCPv6OptRSOO DHCPv6Opt = 66
+
+	// RFC 6603 Prefix Exclude Option for DHCPv6-based Prefix Delegation
+	DHCPv6OptPDExclude DHCPv6Opt = 67
+
+	// RFC 6607 Virtual Subnet Selection
+	DHCPv6OptVSS DHCPv6Opt = 68
+
+	// RFC 6731 Improved Recursive DNS Server Selection for Multi-Interfaced Nodes
+	DHCPv6OptRDNSSSelection DHCPv6Opt = 74
+
+	// RFC 6784 Kerberos Options for DHCPv6
+	DHCPv6OptKRBPrincipalName DHCPv6Opt = 75
+	DHCPv6OptKRBRealmName     DHCPv6Opt = 76
+	DHCPv6OptKRBKDC           DHCPv6Opt = 77
+
+	// RFC 6939 Client Link-Layer Address Option
+	DHCPv6OptClientLinkLayerAddress DHCPv6Opt = 79
+
+	// RFC 6977 Triggering DHCPv6 Reconfiguration from Relay Agents
+	DHCPv6OptLinkAddress DHCPv6Opt = 80
+
+	// RFC 7037 RADIUS Option for the DHCPv6 Relay Agent
+	DHCPv6OptRADIUS DHCPv6Opt = 81
+
+	// RFC 7083 Modification to Default Values of SOL_MAX_RT and INF_MAX_RT
+	DHCPv6OptSolMaxRt DHCPv6Opt = 82
+	DHCPv6OptInfMaxRt DHCPv6Opt = 83
+
+	// RFC 7078 Distributing Address Selection Policy
+	DHCPv6OptAddrSel      DHCPv6Opt = 84
+	DHCPv6OptAddrSelTable DHCPv6Opt = 85
+
+	// RFC 7291 DHCP Options for the Port Control Protocol (PCP)
+	DHCPv6OptV6PCPServer DHCPv6Opt = 86
+
+	// RFC 7341 DHCPv4-over-DHCPv6 (DHCP 4o6) Transport
+	DHCPv6OptDHCPv4Message          DHCPv6Opt = 87
+	DHCPv6OptDHCPv4OverDHCPv6Server DHCPv6Opt = 88
+
+	// RFC 7598 Configuration of Softwire Address and Port-Mapped Clients
+	DHCPv6OptS46Rule           DHCPv6Opt = 89
+	DHCPv6OptS46BR             DHCPv6Opt = 90
+	DHCPv6OptS46DMR            DHCPv6Opt = 91
+	DHCPv6OptS46V4V4Bind       DHCPv6Opt = 92
+	DHCPv6OptS46PortParameters DHCPv6Opt = 93
+	DHCPv6OptS46ContMAPE       DHCPv6Opt = 94
+	DHCPv6OptS46ContMAPT       DHCPv6Opt = 95
+	DHCPv6OptS46ContLW         DHCPv6Opt = 96
+
+	// RFC 7600 IPv4 Residual Deployment via IPv6
+	DHCPv6Opt4RD           DHCPv6Opt = 97
+	DHCPv6Opt4RDMapRule    DHCPv6Opt = 98
+	DHCPv6Opt4RDNonMapRule DHCPv6Opt = 99
+
+	// RFC 7653 Active Leasequery
+	DHCPv6OptLQBaseTime  DHCPv6Opt = 100
+	DHCPv6OptLQStartTime DHCPv6Opt = 101
+	DHCPv6OptLQEndTime   DHCPv6Opt = 102
+
+	// RFC 7710 Captive-Portal Identification
+	DHCPv6OptCaptivePortal DHCPv6Opt = 103
+
+	// RFC 7774 Multicast Protocol for Low-Power and Lossy Networks (MPL) Parameter Configuration
+	DHCPv6OptMPLParameters DHCPv6Opt = 104
+
+	// RFC 7839 Access-Network-Identifier (ANI)
+	DHCPv6OptANIATT           DHCPv6Opt = 105
+	DHCPv6OptANINetworkName   DHCPv6Opt = 106
+	DHCPv6OptANIAPName        DHCPv6Opt = 107
+	DHCPv6OptANIAPBSSID       DHCPv6Opt = 108
+	DHCPv6OptANIOperatorID    DHCPv6Opt = 109
+	DHCPv6OptANIOperatorRealm DHCPv6Opt = 110
+
+	// RFC 8026 Unified IPv4-in-IPv6 Softwire Customer Premises Equipment (CPE)
+	DHCPv6OptS46Priority DHCPv6Opt = 111
+
+	// draft-ietf-opsawg-mud-25 Manufacturer Usage Description (MUD)
+	DHCPv6OptMUDURLV6 DHCPv6Opt = 112
+
+	// RFC 8115 IPv4-Embedded Multicast and Unicast IPv6 Prefixes
+	DHCPv6OptV6Prefix64 DHCPv6Opt = 113
+
+	// RFC 8156 DHCPv6 Failover Protocol
+	DHCPv6OptFBindingStatus           DHCPv6Opt = 114
+	DHCPv6OptFConnectFlags            DHCPv6Opt = 115
+	DHCPv6OptFDNSRemovalInfo          DHCPv6Opt = 116
+	DHCPv6OptFDNSHostName             DHCPv6Opt = 117
+	DHCPv6OptFDNSZoneName             DHCPv6Opt = 118
+	DHCPv6OptFDNSFlags                DHCPv6Opt = 119
+	DHCPv6OptFExpirationTime          DHCPv6Opt = 120
+	DHCPv6OptFMaxUnacknowledgedBNDUPD DHCPv6Opt = 121
+	DHCPv6OptFMCLT                    DHCPv6Opt = 122
+	DHCPv6OptFPartnerLifetime         DHCPv6Opt = 123
+	DHCPv6OptFPartnerLifetimeSent     DHCPv6Opt = 124
+	DHCPv6OptFPartnerDownTime         DHCPv6Opt = 125
+	DHCPv6OptFPartnerRawCltTime       DHCPv6Opt = 126
+	DHCPv6OptFProtocolVersion         DHCPv6Opt = 127
+	DHCPv6OptFKeepaliveTime           DHCPv6Opt = 128
+	DHCPv6OptFReconfigureData         DHCPv6Opt = 129
+	DHCPv6OptFRelationshipName        DHCPv6Opt = 130
+	DHCPv6OptFServerFlags             DHCPv6Opt = 131
+	DHCPv6OptFServerState             DHCPv6Opt = 132
+	DHCPv6OptFStartTimeOfState        DHCPv6Opt = 133
+	DHCPv6OptFStateExpirationTime     DHCPv6Opt = 134
+
+	// RFC 8357 Generalized UDP Source Port for DHCP Relay
+	DHCPv6OptRelayPort DHCPv6Opt = 135
+
+	// draft-ietf-netconf-zerotouch-25 Zero Touch Provisioning for Networking Devices
+	DHCPv6OptV6ZeroTouchRedirect DHCPv6Opt = 136
+
+	// RFC 6153 Access Network Discovery and Selection Function (ANDSF) Discovery
+	DHCPv6OptIPV6AddressANDSF DHCPv6Opt = 143
+)
+
+// String returns a string version of a DHCPv6Opt.
+func (o DHCPv6Opt) String() string {
+	switch o {
+	case DHCPv6OptClientID:
+		return "ClientID"
+	case DHCPv6OptServerID:
+		return "ServerID"
+	case DHCPv6OptIANA:
+		return "IA_NA"
+	case DHCPv6OptIATA:
+		return "IA_TA"
+	case DHCPv6OptIAAddr:
+		return "IAAddr"
+	case DHCPv6OptOro:
+		return "Oro"
+	case DHCPv6OptPreference:
+		return "Preference"
+	case DHCPv6OptElapsedTime:
+		return "ElapsedTime"
+	case DHCPv6OptRelayMessage:
+		return "RelayMessage"
+	case DHCPv6OptAuth:
+		return "Auth"
+	case DHCPv6OptUnicast:
+		return "Unicast"
+	case DHCPv6OptStatusCode:
+		return "StatusCode"
+	case DHCPv6OptRapidCommit:
+		return "RapidCommit"
+	case DHCPv6OptUserClass:
+		return "UserClass"
+	case DHCPv6OptVendorClass:
+		return "VendorClass"
+	case DHCPv6OptVendorOpts:
+		return "VendorOpts"
+	case DHCPv6OptInterfaceID:
+		return "InterfaceID"
+	case DHCPv6OptReconfigureMessage:
+		return "ReconfigureMessage"
+	case DHCPv6OptReconfigureAccept:
+		return "ReconfigureAccept"
+	case DHCPv6OptSIPServersDomainList:
+		return "SIPServersDomainList"
+	case DHCPv6OptSIPServersAddressList:
+		return "SIPServersAddressList"
+	case DHCPv6OptDNSServers:
+		return "DNSRecursiveNameServer"
+	case DHCPv6OptDomainList:
+		return "DomainSearchList"
+	case DHCPv6OptIAPD:
+		return "IdentityAssociationPrefixDelegation"
+	case DHCPv6OptIAPrefix:
+		return "IAPDPrefix"
+	case DHCPv6OptNISServers:
+		return "NISServers"
+	case DHCPv6OptNISPServers:
+		return "NISv2Servers"
+	case DHCPv6OptNISDomainName:
+		return "NISDomainName"
+	case DHCPv6OptNISPDomainName:
+		return "NISv2DomainName"
+	case DHCPv6OptSNTPServers:
+		return "SNTPServers"
+	case DHCPv6OptInformationRefreshTime:
+		return "InformationRefreshTime"
+	case DHCPv6OptBCMCSServerDomainNameList:
+		return "BCMCSControlServersDomainNameList"
+	case DHCPv6OptBCMCSServerAddressList:
+		return "BCMCSControlServersAddressList"
+	case DHCPv6OptGeoconfCivic:
+		return "CivicAddress"
+	case DHCPv6OptRemoteID:
+		return "RelayAgentRemoteID"
+	case DHCPv6OptSubscriberID:
+		return "RelayAgentSubscriberID"
+	case DHCPv6OptClientFQDN:
+		return "ClientFQDN"
+	case DHCPv6OptPanaAgent:
+		return "PANAAuthenticationAgent"
+	case DHCPv6OptNewPOSIXTimezone:
+		return "NewPOSIXTimezone"
+	case DHCPv6OptNewTZDBTimezone:
+		return "NewTZDBTimezone"
+	case DHCPv6OptEchoRequestOption:
+		return "EchoRequest"
+	case DHCPv6OptLQQuery:
+		return "LeasequeryQuery"
+	case DHCPv6OptClientData:
+		return "LeasequeryClientData"
+	case DHCPv6OptCLTTime:
+		return "LeasequeryClientLastTransactionTime"
+	case DHCPv6OptLQRelayData:
+		return "LeasequeryRelayData"
+	case DHCPv6OptLQClientLink:
+		return "LeasequeryClientLink"
+	case DHCPv6OptMIP6HNIDF:
+		return "MIPv6HomeNetworkIDFQDN"
+	case DHCPv6OptMIP6VDINF:
+		return "MIPv6VisitedHomeNetworkInformation"
+	case DHCPv6OptMIP6IDINF:
+		return "MIPv6IdentifiedHomeNetworkInformation"
+	case DHCPv6OptMIP6UDINF:
+		return "MIPv6UnrestrictedHomeNetworkInformation"
+	case DHCPv6OptMIP6HNP:
+		return "MIPv6HomeNetworkPrefix"
+	case DHCPv6OptMIP6HAA:
+		return "MIPv6HomeAgentAddress"
+	case DHCPv6OptMIP6HAF:
+		return "MIPv6HomeAgentFQDN"
+	case DHCPv6OptV6LOST:
+		return "LoST Server"
+	case DHCPv6OptCAPWAPACV6:
+		return "CAPWAPAccessControllerV6"
+	case DHCPv6OptRelayID:
+		return "LeasequeryRelayID"
+	case DHCPv6OptIPv6AddressMoS:
+		return "MoSIPv6Address"
+	case DHCPv6OptIPv6FQDNMoS:
+		return "MoSDomainNameList"
+	case DHCPv6OptNTPServer:
+		return "NTPServer"
+	case DHCPv6OptV6AccessDomain:
+		return "AccessNetworkDomainName"
+	case DHCPv6OptSIPUACSList:
+		return "SIPUserAgentConfigurationServiceDomains"
+	case DHCPv6OptBootFileURL:
+		return "BootFileURL"
+	case DHCPv6OptBootFileParam:
+		return "BootFileParameters"
+	case DHCPv6OptClientArchType:
+		return "ClientSystemArchitectureType"
+	case DHCPv6OptNII:
+		return "ClientNetworkInterfaceIdentifier"
+	case DHCPv6OptGeolocation:
+		return "Geolocation"
+	case DHCPv6OptAFTRName:
+		return "AFTRName"
+	case DHCPv6OptERPLocalDomainName:
+		return "AFTRName"
+	case DHCPv6OptRSOO:
+		return "RSOOption"
+	case DHCPv6OptPDExclude:
+		return "PrefixExclude"
+	case DHCPv6OptVSS:
+		return "VirtualSubnetSelection"
+	case DHCPv6OptRDNSSSelection:
+		return "RDNSSSelection"
+	case DHCPv6OptKRBPrincipalName:
+		return "KerberosPrincipalName"
+	case DHCPv6OptKRBRealmName:
+		return "KerberosRealmName"
+	case DHCPv6OptKRBKDC:
+		return "KerberosKDC"
+	case DHCPv6OptClientLinkLayerAddress:
+		return "ClientLinkLayerAddress"
+	case DHCPv6OptLinkAddress:
+		return "LinkAddress"
+	case DHCPv6OptRADIUS:
+		return "RADIUS"
+	case DHCPv6OptSolMaxRt:
+		return "SolMaxRt"
+	case DHCPv6OptInfMaxRt:
+		return "InfMaxRt"
+	case DHCPv6OptAddrSel:
+		return "AddressSelection"
+	case DHCPv6OptAddrSelTable:
+		return "AddressSelectionTable"
+	case DHCPv6OptV6PCPServer:
+		return "PCPServer"
+	case DHCPv6OptDHCPv4Message:
+		return "DHCPv4Message"
+	case DHCPv6OptDHCPv4OverDHCPv6Server:
+		return "DHCP4o6ServerAddress"
+	case DHCPv6OptS46Rule:
+		return "S46Rule"
+	case DHCPv6OptS46BR:
+		return "S46BR"
+	case DHCPv6OptS46DMR:
+		return "S46DMR"
+	case DHCPv6OptS46V4V4Bind:
+		return "S46IPv4IPv6AddressBinding"
+	case DHCPv6OptS46PortParameters:
+		return "S46PortParameters"
+	case DHCPv6OptS46ContMAPE:
+		return "S46MAPEContainer"
+	case DHCPv6OptS46ContMAPT:
+		return "S46MAPTContainer"
+	case DHCPv6OptS46ContLW:
+		return "S46Lightweight4Over6Container"
+	case DHCPv6Opt4RD:
+		return "4RD"
+	case DHCPv6Opt4RDMapRule:
+		return "4RDMapRule"
+	case DHCPv6Opt4RDNonMapRule:
+		return "4RDNonMapRule"
+	case DHCPv6OptLQBaseTime:
+		return "LQBaseTime"
+	case DHCPv6OptLQStartTime:
+		return "LQStartTime"
+	case DHCPv6OptLQEndTime:
+		return "LQEndTime"
+	case DHCPv6OptCaptivePortal:
+		return "CaptivePortal"
+	case DHCPv6OptMPLParameters:
+		return "MPLParameterConfiguration"
+	case DHCPv6OptANIATT:
+		return "ANIAccessTechnologyType"
+	case DHCPv6OptANINetworkName:
+		return "ANINetworkName"
+	case DHCPv6OptANIAPName:
+		return "ANIAccessPointName"
+	case DHCPv6OptANIAPBSSID:
+		return "ANIAccessPointBSSID"
+	case DHCPv6OptANIOperatorID:
+		return "ANIOperatorIdentifier"
+	case DHCPv6OptANIOperatorRealm:
+		return "ANIOperatorRealm"
+	case DHCPv6OptS46Priority:
+		return "S64Priority"
+	case DHCPv6OptMUDURLV6:
+		return "ManufacturerUsageDescriptionURL"
+	case DHCPv6OptV6Prefix64:
+		return "V6Prefix64"
+	case DHCPv6OptFBindingStatus:
+		return "FailoverBindingStatus"
+	case DHCPv6OptFConnectFlags:
+		return "FailoverConnectFlags"
+	case DHCPv6OptFDNSRemovalInfo:
+		return "FailoverDNSRemovalInfo"
+	case DHCPv6OptFDNSHostName:
+		return "FailoverDNSHostName"
+	case DHCPv6OptFDNSZoneName:
+		return "FailoverDNSZoneName"
+	case DHCPv6OptFDNSFlags:
+		return "FailoverDNSFlags"
+	case DHCPv6OptFExpirationTime:
+		return "FailoverExpirationTime"
+	case DHCPv6OptFMaxUnacknowledgedBNDUPD:
+		return "FailoverMaxUnacknowledgedBNDUPDMessages"
+	case DHCPv6OptFMCLT:
+		return "FailoverMaximumClientLeadTime"
+	case DHCPv6OptFPartnerLifetime:
+		return "FailoverPartnerLifetime"
+	case DHCPv6OptFPartnerLifetimeSent:
+		return "FailoverPartnerLifetimeSent"
+	case DHCPv6OptFPartnerDownTime:
+		return "FailoverPartnerDownTime"
+	case DHCPv6OptFPartnerRawCltTime:
+		return "FailoverPartnerRawClientLeadTime"
+	case DHCPv6OptFProtocolVersion:
+		return "FailoverProtocolVersion"
+	case DHCPv6OptFKeepaliveTime:
+		return "FailoverKeepaliveTime"
+	case DHCPv6OptFReconfigureData:
+		return "FailoverReconfigureData"
+	case DHCPv6OptFRelationshipName:
+		return "FailoverRelationshipName"
+	case DHCPv6OptFServerFlags:
+		return "FailoverServerFlags"
+	case DHCPv6OptFServerState:
+		return "FailoverServerState"
+	case DHCPv6OptFStartTimeOfState:
+		return "FailoverStartTimeOfState"
+	case DHCPv6OptFStateExpirationTime:
+		return "FailoverStateExpirationTime"
+	case DHCPv6OptRelayPort:
+		return "RelayPort"
+	case DHCPv6OptV6ZeroTouchRedirect:
+		return "ZeroTouch"
+	case DHCPv6OptIPV6AddressANDSF:
+		return "ANDSFIPv6Address"
+	default:
+		return fmt.Sprintf("Unknown(%d)", uint16(o))
+	}
+}
+
+// DHCPv6Options is used to get nicely printed option lists which would normally
+// be cut off after 5 options.
+type DHCPv6Options []DHCPv6Option
+
+// String returns a string version of the options list.
+func (o DHCPv6Options) String() string {
+	buf := &bytes.Buffer{}
+	buf.WriteByte('[')
+	for i, opt := range o {
+		buf.WriteString(opt.String())
+		if i+1 != len(o) {
+			buf.WriteString(", ")
+		}
+	}
+	buf.WriteByte(']')
+	return buf.String()
+}
+
+// DHCPv6Option rerpresents a DHCP option.
+type DHCPv6Option struct {
+	Code   DHCPv6Opt
+	Length uint16
+	Data   []byte
+}
+
+// String returns a string version of a DHCP Option.
+func (o DHCPv6Option) String() string {
+	switch o.Code {
+	case DHCPv6OptClientID, DHCPv6OptServerID:
+		duid, err := decodeDHCPv6DUID(o.Data)
+		if err != nil {
+			return fmt.Sprintf("Option(%s:INVALID)", o.Code)
+		}
+		return fmt.Sprintf("Option(%s:[%s])", o.Code, duid.String())
+	case DHCPv6OptOro:
+		options := ""
+		for i := 0; i < int(o.Length); i += 2 {
+			if options != "" {
+				options += ","
+			}
+			option := DHCPv6Opt(binary.BigEndian.Uint16(o.Data[i : i+2]))
+			options += option.String()
+		}
+		return fmt.Sprintf("Option(%s:[%s])", o.Code, options)
+	default:
+		return fmt.Sprintf("Option(%s:%v)", o.Code, o.Data)
+	}
+}
+
+// NewDHCPv6Option constructs a new DHCPv6Option with a given type and data.
+func NewDHCPv6Option(code DHCPv6Opt, data []byte) DHCPv6Option {
+	o := DHCPv6Option{Code: code}
+	if data != nil {
+		o.Data = data
+		o.Length = uint16(len(data))
+	}
+
+	return o
+}
+
+func (o *DHCPv6Option) encode(b []byte, opts gopacket.SerializeOptions) error {
+	binary.BigEndian.PutUint16(b[0:2], uint16(o.Code))
+	if opts.FixLengths {
+		binary.BigEndian.PutUint16(b[2:4], uint16(len(o.Data)))
+	} else {
+		binary.BigEndian.PutUint16(b[2:4], o.Length)
+	}
+	copy(b[4:], o.Data)
+
+	return nil
+}
+
+func (o *DHCPv6Option) decode(data []byte) error {
+	if len(data) < 4 {
+		return errors.New("not enough data to decode")
+	}
+	o.Code = DHCPv6Opt(binary.BigEndian.Uint16(data[0:2]))
+	o.Length = binary.BigEndian.Uint16(data[2:4])
+	if len(data) < 4+int(o.Length) {
+		return fmt.Errorf("dhcpv6 option size < length %d", 4+o.Length)
+	}
+	o.Data = data[4 : 4+o.Length]
+	return nil
+}

vendor/github.com/google/gopacket/layers/doc.go

@@ -0,0 +1,61 @@
+// Copyright 2012 Google, Inc. All rights reserved.
+//
+// Use of this source code is governed by a BSD-style license
+// that can be found in the LICENSE file in the root of the source
+// tree.
+
+/*
+Package layers provides decoding layers for many common protocols.
+
+The layers package contains decode implementations for a number of different
+types of packet layers.  Users of gopacket will almost always want to also use
+layers to actually decode packet data into useful pieces. To see the set of
+protocols that gopacket/layers is currently able to decode,
+look at the set of LayerTypes defined in the Variables sections. The
+layers package also defines endpoints for many of the common packet layers
+that have source/destination addresses associated with them, for example IPv4/6
+(IPs) and TCP/UDP (ports).
+Finally, layers contains a number of useful enumerations (IPProtocol,
+EthernetType, LinkType, PPPType, etc...).  Many of these implement the
+gopacket.Decoder interface, so they can be passed into gopacket as decoders.
+
+Most common protocol layers are named using acronyms or other industry-common
+names (IPv4, TCP, PPP).  Some of the less common ones have their names expanded
+(CiscoDiscoveryProtocol).
+For certain protocols, sub-parts of the protocol are split out into their own
+layers (SCTP, for example).  This is done mostly in cases where portions of the
+protocol may fulfill the capabilities of interesting layers (SCTPData implements
+ApplicationLayer, while base SCTP implements TransportLayer), or possibly
+because splitting a protocol into a few layers makes decoding easier.
+
+This package is meant to be used with its parent,
+http://github.com/google/gopacket.
+
+Port Types
+
+Instead of using raw uint16 or uint8 values for ports, we use a different port
+type for every protocol, for example TCPPort and UDPPort.  This allows us to
+override string behavior for each port, which we do by setting up port name
+maps (TCPPortNames, UDPPortNames, etc...).  Well-known ports are annotated with
+their protocol names, and their String function displays these names:
+
+  p := TCPPort(80)
+  fmt.Printf("Number: %d  String: %v", p, p)
+  // Prints: "Number: 80  String: 80(http)"
+
+Modifying Decode Behavior
+
+layers links together decoding through its enumerations.  For example, after
+decoding layer type Ethernet, it uses Ethernet.EthernetType as its next decoder.
+All enumerations that act as decoders, like EthernetType, can be modified by
+users depending on their preferences.  For example, if you have a spiffy new
+IPv4 decoder that works way better than the one built into layers, you can do
+this:
+
+ var mySpiffyIPv4Decoder gopacket.Decoder = ...
+ layers.EthernetTypeMetadata[EthernetTypeIPv4].DecodeWith = mySpiffyIPv4Decoder
+
+This will make all future ethernet packets use your new decoder to decode IPv4
+packets, instead of the built-in decoder used by gopacket.
+*/
+package layers

vendor/github.com/google/gopacket/layers/dot1q.go

@@ -0,0 +1,75 @@
+// Copyright 2012 Google, Inc. All rights reserved.
+// Copyright 2009-2011 Andreas Krennmair. All rights reserved.
+//
+// Use of this source code is governed by a BSD-style license
+// that can be found in the LICENSE file in the root of the source
+// tree.
+
+package layers
+
+import (
+	"encoding/binary"
+	"fmt"
+	"github.com/google/gopacket"
+)
+
+// Dot1Q is the packet layer for 802.1Q VLAN headers.
+type Dot1Q struct {
+	BaseLayer
+	Priority       uint8
+	DropEligible   bool
+	VLANIdentifier uint16
+	Type           EthernetType
+}
+
+// LayerType returns gopacket.LayerTypeDot1Q
+func (d *Dot1Q) LayerType() gopacket.LayerType { return LayerTypeDot1Q }
+
+// DecodeFromBytes decodes the given bytes into this layer.
+func (d *Dot1Q) DecodeFromBytes(data []byte, df gopacket.DecodeFeedback) error {
+	if len(data) < 4 {
+		df.SetTruncated()
+		return fmt.Errorf("802.1Q tag length %d too short", len(data))
+	}
+	d.Priority = (data[0] & 0xE0) >> 5
+	d.DropEligible = data[0]&0x10 != 0
+	d.VLANIdentifier = binary.BigEndian.Uint16(data[:2]) & 0x0FFF
+	d.Type = EthernetType(binary.BigEndian.Uint16(data[2:4]))
+	d.BaseLayer = BaseLayer{Contents: data[:4], Payload: data[4:]}
+	return nil
+}
+
+// CanDecode returns the set of layer types that this DecodingLayer can decode.
+func (d *Dot1Q) CanDecode() gopacket.LayerClass {
+	return LayerTypeDot1Q
+}
+
+// NextLayerType returns the layer type contained by this DecodingLayer.
+func (d *Dot1Q) NextLayerType() gopacket.LayerType {
+	return d.Type.LayerType()
+}
+
+func decodeDot1Q(data []byte, p gopacket.PacketBuilder) error {
+	d := &Dot1Q{}
+	return decodingLayerDecoder(d, data, p)
+}
+
+// SerializeTo writes the serialized form of this layer into the
+// SerializationBuffer, implementing gopacket.SerializableLayer.
+// See the docs for gopacket.SerializableLayer for more info.
+func (d *Dot1Q) SerializeTo(b gopacket.SerializeBuffer, opts gopacket.SerializeOptions) error {
+	bytes, err := b.PrependBytes(4)
+	if err != nil {
+		return err
+	}
+	if d.VLANIdentifier > 0xFFF {
+		return fmt.Errorf("vlan identifier %v is too high", d.VLANIdentifier)
+	}
+	firstBytes := uint16(d.Priority)<<13 | d.VLANIdentifier
+	if d.DropEligible {
+		firstBytes |= 0x1000
+	}
+	binary.BigEndian.PutUint16(bytes, firstBytes)
+	binary.BigEndian.PutUint16(bytes[2:], uint16(d.Type))
+	return nil
+}

vendor/github.com/google/gopacket/layers/eap.go

@@ -0,0 +1,114 @@
+// Copyright 2012 Google, Inc. All rights reserved.
+//
+// Use of this source code is governed by a BSD-style license
+// that can be found in the LICENSE file in the root of the source
+// tree.
+
+package layers
+
+import (
+	"encoding/binary"
+	"fmt"
+	"github.com/google/gopacket"
+)
+
+type EAPCode uint8
+type EAPType uint8
+
+const (
+	EAPCodeRequest  EAPCode = 1
+	EAPCodeResponse EAPCode = 2
+	EAPCodeSuccess  EAPCode = 3
+	EAPCodeFailure  EAPCode = 4
+
+	// EAPTypeNone means that this EAP layer has no Type or TypeData.
+	// Success and Failure EAPs will have this set.
+	EAPTypeNone EAPType = 0
+
+	EAPTypeIdentity     EAPType = 1
+	EAPTypeNotification EAPType = 2
+	EAPTypeNACK         EAPType = 3
+	EAPTypeOTP          EAPType = 4
+	EAPTypeTokenCard    EAPType = 5
+)
+
+// EAP defines an Extensible Authentication Protocol (rfc 3748) layer.
+type EAP struct {
+	BaseLayer
+	Code     EAPCode
+	Id       uint8
+	Length   uint16
+	Type     EAPType
+	TypeData []byte
+}
+
+// LayerType returns LayerTypeEAP.
+func (e *EAP) LayerType() gopacket.LayerType { return LayerTypeEAP }
+
+// DecodeFromBytes decodes the given bytes into this layer.
+func (e *EAP) DecodeFromBytes(data []byte, df gopacket.DecodeFeedback) error {
+	if len(data) < 4 {
+		df.SetTruncated()
+		return fmt.Errorf("EAP length %d too short", len(data))
+	}
+	e.Code = EAPCode(data[0])
+	e.Id = data[1]
+	e.Length = binary.BigEndian.Uint16(data[2:4])
+	if len(data) < int(e.Length) {
+		df.SetTruncated()
+		return fmt.Errorf("EAP length %d too short, %d expected", len(data), e.Length)
+	}
+	switch {
+	case e.Length > 4:
+		e.Type = EAPType(data[4])
+		e.TypeData = data[5:]
+	case e.Length == 4:
+		e.Type = 0
+		e.TypeData = nil
+	default:
+		return fmt.Errorf("invalid EAP length %d", e.Length)
+	}
+	e.BaseLayer.Contents = data[:e.Length]
+	e.BaseLayer.Payload = data[e.Length:] // Should be 0 bytes
+	return nil
+}
+
+// SerializeTo writes the serialized form of this layer into the
+// SerializationBuffer, implementing gopacket.SerializableLayer.
+// See the docs for gopacket.SerializableLayer for more info.
+func (e *EAP) SerializeTo(b gopacket.SerializeBuffer, opts gopacket.SerializeOptions) error {
+	if opts.FixLengths {
+		e.Length = uint16(len(e.TypeData) + 1)
+	}
+	size := len(e.TypeData) + 4
+	if size > 4 {
+		size++
+	}
+	bytes, err := b.PrependBytes(size)
+	if err != nil {
+		return err
+	}
+	bytes[0] = byte(e.Code)
+	bytes[1] = e.Id
+	binary.BigEndian.PutUint16(bytes[2:], e.Length)
+	if size > 4 {
+		bytes[4] = byte(e.Type)
+		copy(bytes[5:], e.TypeData)
+	}
+	return nil
+}
+
+// CanDecode returns the set of layer types that this DecodingLayer can decode.
+func (e *EAP) CanDecode() gopacket.LayerClass {
+	return LayerTypeEAP
+}
+
+// NextLayerType returns the layer type contained by this DecodingLayer.
+func (e *EAP) NextLayerType() gopacket.LayerType {
+	return gopacket.LayerTypeZero
+}
+
+func decodeEAP(data []byte, p gopacket.PacketBuilder) error {
+	e := &EAP{}
+	return decodingLayerDecoder(e, data, p)
+}

vendor/github.com/google/gopacket/layers/eapol.go

@@ -0,0 +1,302 @@
+// Copyright 2012 Google, Inc. All rights reserved.
+//
+// Use of this source code is governed by a BSD-style license
+// that can be found in the LICENSE file in the root of the source
+// tree.
+
+package layers
+
+import (
+	"encoding/binary"
+	"fmt"
+	"github.com/google/gopacket"
+)
+
+// EAPOL defines an EAP over LAN (802.1x) layer.
+type EAPOL struct {
+	BaseLayer
+	Version uint8
+	Type    EAPOLType
+	Length  uint16
+}
+
+// LayerType returns LayerTypeEAPOL.
+func (e *EAPOL) LayerType() gopacket.LayerType { return LayerTypeEAPOL }
+
+// DecodeFromBytes decodes the given bytes into this layer.
+func (e *EAPOL) DecodeFromBytes(data []byte, df gopacket.DecodeFeedback) error {
+	if len(data) < 4 {
+		df.SetTruncated()
+		return fmt.Errorf("EAPOL length %d too short", len(data))
+	}
+	e.Version = data[0]
+	e.Type = EAPOLType(data[1])
+	e.Length = binary.BigEndian.Uint16(data[2:4])
+	e.BaseLayer = BaseLayer{data[:4], data[4:]}
+	return nil
+}
+
+// SerializeTo writes the serialized form of this layer into the
+// SerializationBuffer, implementing gopacket.SerializableLayer
+func (e *EAPOL) SerializeTo(b gopacket.SerializeBuffer, opts gopacket.SerializeOptions) error {
+	bytes, _ := b.PrependBytes(4)
+	bytes[0] = e.Version
+	bytes[1] = byte(e.Type)
+	binary.BigEndian.PutUint16(bytes[2:], e.Length)
+	return nil
+}
+
+// CanDecode returns the set of layer types that this DecodingLayer can decode.
+func (e *EAPOL) CanDecode() gopacket.LayerClass {
+	return LayerTypeEAPOL
+}
+
+// NextLayerType returns the layer type contained by this DecodingLayer.
+func (e *EAPOL) NextLayerType() gopacket.LayerType {
+	return e.Type.LayerType()
+}
+
+func decodeEAPOL(data []byte, p gopacket.PacketBuilder) error {
+	e := &EAPOL{}
+	return decodingLayerDecoder(e, data, p)
+}
+
+// EAPOLKeyDescriptorType is an enumeration of key descriptor types
+// as specified by 802.1x in the EAPOL-Key frame
+type EAPOLKeyDescriptorType uint8
+
+// Enumeration of EAPOLKeyDescriptorType
+const (
+	EAPOLKeyDescriptorTypeRC4   EAPOLKeyDescriptorType = 1
+	EAPOLKeyDescriptorTypeDot11 EAPOLKeyDescriptorType = 2
+	EAPOLKeyDescriptorTypeWPA   EAPOLKeyDescriptorType = 254
+)
+
+func (kdt EAPOLKeyDescriptorType) String() string {
+	switch kdt {
+	case EAPOLKeyDescriptorTypeRC4:
+		return "RC4"
+	case EAPOLKeyDescriptorTypeDot11:
+		return "802.11"
+	case EAPOLKeyDescriptorTypeWPA:
+		return "WPA"
+	default:
+		return fmt.Sprintf("unknown descriptor type %d", kdt)
+	}
+}
+
+// EAPOLKeyDescriptorVersion is an enumeration of versions specifying the
+// encryption algorithm for the key data and the authentication for the
+// message integrity code (MIC)
+type EAPOLKeyDescriptorVersion uint8
+
+// Enumeration of EAPOLKeyDescriptorVersion
+const (
+	EAPOLKeyDescriptorVersionOther       EAPOLKeyDescriptorVersion = 0
+	EAPOLKeyDescriptorVersionRC4HMACMD5  EAPOLKeyDescriptorVersion = 1
+	EAPOLKeyDescriptorVersionAESHMACSHA1 EAPOLKeyDescriptorVersion = 2
+	EAPOLKeyDescriptorVersionAES128CMAC  EAPOLKeyDescriptorVersion = 3
+)
+
+func (v EAPOLKeyDescriptorVersion) String() string {
+	switch v {
+	case EAPOLKeyDescriptorVersionOther:
+		return "Other"
+	case EAPOLKeyDescriptorVersionRC4HMACMD5:
+		return "RC4-HMAC-MD5"
+	case EAPOLKeyDescriptorVersionAESHMACSHA1:
+		return "AES-HMAC-SHA1-128"
+	case EAPOLKeyDescriptorVersionAES128CMAC:
+		return "AES-128-CMAC"
+	default:
+		return fmt.Sprintf("unknown version %d", v)
+	}
+}
+
+// EAPOLKeyType is an enumeration of key derivation types describing
+// the purpose of the keys being derived.
+type EAPOLKeyType uint8
+
+// Enumeration of EAPOLKeyType
+const (
+	EAPOLKeyTypeGroupSMK EAPOLKeyType = 0
+	EAPOLKeyTypePairwise EAPOLKeyType = 1
+)
+
+func (kt EAPOLKeyType) String() string {
+	switch kt {
+	case EAPOLKeyTypeGroupSMK:
+		return "Group/SMK"
+	case EAPOLKeyTypePairwise:
+		return "Pairwise"
+	default:
+		return fmt.Sprintf("unknown key type %d", kt)
+	}
+}
+
+// EAPOLKey defines an EAPOL-Key frame for 802.1x authentication
+type EAPOLKey struct {
+	BaseLayer
+	KeyDescriptorType    EAPOLKeyDescriptorType
+	KeyDescriptorVersion EAPOLKeyDescriptorVersion
+	KeyType              EAPOLKeyType
+	KeyIndex             uint8
+	Install              bool
+	KeyACK               bool
+	KeyMIC               bool
+	Secure               bool
+	MICError             bool
+	Request              bool
+	HasEncryptedKeyData  bool
+	SMKMessage           bool
+	KeyLength            uint16
+	ReplayCounter        uint64
+	Nonce                []byte
+	IV                   []byte
+	RSC                  uint64
+	ID                   uint64
+	MIC                  []byte
+	KeyDataLength        uint16
+	EncryptedKeyData     []byte
+}
+
+// LayerType returns LayerTypeEAPOLKey.
+func (ek *EAPOLKey) LayerType() gopacket.LayerType {
+	return LayerTypeEAPOLKey
+}
+
+// CanDecode returns the set of layer types that this DecodingLayer can decode.
+func (ek *EAPOLKey) CanDecode() gopacket.LayerType {
+	return LayerTypeEAPOLKey
+}
+
+// NextLayerType returns layers.LayerTypeDot11InformationElement if the key
+// data exists and is unencrypted, otherwise it does not expect a next layer.
+func (ek *EAPOLKey) NextLayerType() gopacket.LayerType {
+	if !ek.HasEncryptedKeyData && ek.KeyDataLength > 0 {
+		return LayerTypeDot11InformationElement
+	}
+	return gopacket.LayerTypePayload
+}
+
+const eapolKeyFrameLen = 95
+
+// DecodeFromBytes decodes the given bytes into this layer.
+func (ek *EAPOLKey) DecodeFromBytes(data []byte, df gopacket.DecodeFeedback) error {
+	if len(data) < eapolKeyFrameLen {
+		df.SetTruncated()
+		return fmt.Errorf("EAPOLKey length %v too short, %v required",
+			len(data), eapolKeyFrameLen)
+	}
+
+	ek.KeyDescriptorType = EAPOLKeyDescriptorType(data[0])
+
+	info := binary.BigEndian.Uint16(data[1:3])
+	ek.KeyDescriptorVersion = EAPOLKeyDescriptorVersion(info & 0x0007)
+	ek.KeyType = EAPOLKeyType((info & 0x0008) >> 3)
+	ek.KeyIndex = uint8((info & 0x0030) >> 4)
+	ek.Install = (info & 0x0040) != 0
+	ek.KeyACK = (info & 0x0080) != 0
+	ek.KeyMIC = (info & 0x0100) != 0
+	ek.Secure = (info & 0x0200) != 0
+	ek.MICError = (info & 0x0400) != 0
+	ek.Request = (info & 0x0800) != 0
+	ek.HasEncryptedKeyData = (info & 0x1000) != 0
+	ek.SMKMessage = (info & 0x2000) != 0
+
+	ek.KeyLength = binary.BigEndian.Uint16(data[3:5])
+	ek.ReplayCounter = binary.BigEndian.Uint64(data[5:13])
+
+	ek.Nonce = data[13:45]
+	ek.IV = data[45:61]
+	ek.RSC = binary.BigEndian.Uint64(data[61:69])
+	ek.ID = binary.BigEndian.Uint64(data[69:77])
+	ek.MIC = data[77:93]
+
+	ek.KeyDataLength = binary.BigEndian.Uint16(data[93:95])
+
+	totalLength := eapolKeyFrameLen + int(ek.KeyDataLength)
+	if len(data) < totalLength {
+		df.SetTruncated()
+		return fmt.Errorf("EAPOLKey data length %d too short, %d required",
+			len(data)-eapolKeyFrameLen, ek.KeyDataLength)
+	}
+
+	if ek.HasEncryptedKeyData {
+		ek.EncryptedKeyData = data[eapolKeyFrameLen:totalLength]
+		ek.BaseLayer = BaseLayer{
+			Contents: data[:totalLength],
+			Payload:  data[totalLength:],
+		}
+	} else {
+		ek.BaseLayer = BaseLayer{
+			Contents: data[:eapolKeyFrameLen],
+			Payload:  data[eapolKeyFrameLen:],
+		}
+	}
+
+	return nil
+}
+
+// SerializeTo writes the serialized form of this layer into the
+// SerializationBuffer, implementing gopacket.SerializableLayer.
+// See the docs for gopacket.SerializableLayer for more info.
+func (ek *EAPOLKey) SerializeTo(b gopacket.SerializeBuffer, opts gopacket.SerializeOptions) error {
+	buf, err := b.PrependBytes(eapolKeyFrameLen + len(ek.EncryptedKeyData))
+	if err != nil {
+		return err
+	}
+
+	buf[0] = byte(ek.KeyDescriptorType)
+
+	var info uint16
+	info |= uint16(ek.KeyDescriptorVersion)
+	info |= uint16(ek.KeyType) << 3
+	info |= uint16(ek.KeyIndex) << 4
+	if ek.Install {
+		info |= 0x0040
+	}
+	if ek.KeyACK {
+		info |= 0x0080
+	}
+	if ek.KeyMIC {
+		info |= 0x0100
+	}
+	if ek.Secure {
+		info |= 0x0200
+	}
+	if ek.MICError {
+		info |= 0x0400
+	}
+	if ek.Request {
+		info |= 0x0800
+	}
+	if ek.HasEncryptedKeyData {
+		info |= 0x1000
+	}
+	if ek.SMKMessage {
+		info |= 0x2000
+	}
+	binary.BigEndian.PutUint16(buf[1:3], info)
+
+	binary.BigEndian.PutUint16(buf[3:5], ek.KeyLength)
+	binary.BigEndian.PutUint64(buf[5:13], ek.ReplayCounter)
+
+	copy(buf[13:45], ek.Nonce)
+	copy(buf[45:61], ek.IV)
+	binary.BigEndian.PutUint64(buf[61:69], ek.RSC)
+	binary.BigEndian.PutUint64(buf[69:77], ek.ID)
+	copy(buf[77:93], ek.MIC)
+
+	binary.BigEndian.PutUint16(buf[93:95], ek.KeyDataLength)
+	if len(ek.EncryptedKeyData) > 0 {
+		copy(buf[95:95+len(ek.EncryptedKeyData)], ek.EncryptedKeyData)
+	}
+
+	return nil
+}
+
+func decodeEAPOLKey(data []byte, p gopacket.PacketBuilder) error {
+	ek := &EAPOLKey{}
+	return decodingLayerDecoder(ek, data, p)
+}

vendor/github.com/google/gopacket/layers/endpoints.go

@@ -0,0 +1,97 @@
+// Copyright 2012 Google, Inc. All rights reserved.
+//
+// Use of this source code is governed by a BSD-style license
+// that can be found in the LICENSE file in the root of the source
+// tree.
+
+package layers
+
+import (
+	"encoding/binary"
+	"github.com/google/gopacket"
+	"net"
+	"strconv"
+)
+
+var (
+	// We use two different endpoint types for IPv4 vs IPv6 addresses, so that
+	// ordering with endpointA.LessThan(endpointB) sanely groups all IPv4
+	// addresses and all IPv6 addresses, such that IPv6 > IPv4 for all addresses.
+	EndpointIPv4 = gopacket.RegisterEndpointType(1, gopacket.EndpointTypeMetadata{Name: "IPv4", Formatter: func(b []byte) string {
+		return net.IP(b).String()
+	}})
+	EndpointIPv6 = gopacket.RegisterEndpointType(2, gopacket.EndpointTypeMetadata{Name: "IPv6", Formatter: func(b []byte) string {
+		return net.IP(b).String()
+	}})
+
+	EndpointMAC = gopacket.RegisterEndpointType(3, gopacket.EndpointTypeMetadata{Name: "MAC", Formatter: func(b []byte) string {
+		return net.HardwareAddr(b).String()
+	}})
+	EndpointTCPPort = gopacket.RegisterEndpointType(4, gopacket.EndpointTypeMetadata{Name: "TCP", Formatter: func(b []byte) string {
+		return strconv.Itoa(int(binary.BigEndian.Uint16(b)))
+	}})
+	EndpointUDPPort = gopacket.RegisterEndpointType(5, gopacket.EndpointTypeMetadata{Name: "UDP", Formatter: func(b []byte) string {
+		return strconv.Itoa(int(binary.BigEndian.Uint16(b)))
+	}})
+	EndpointSCTPPort = gopacket.RegisterEndpointType(6, gopacket.EndpointTypeMetadata{Name: "SCTP", Formatter: func(b []byte) string {
+		return strconv.Itoa(int(binary.BigEndian.Uint16(b)))
+	}})
+	EndpointRUDPPort = gopacket.RegisterEndpointType(7, gopacket.EndpointTypeMetadata{Name: "RUDP", Formatter: func(b []byte) string {
+		return strconv.Itoa(int(b[0]))
+	}})
+	EndpointUDPLitePort = gopacket.RegisterEndpointType(8, gopacket.EndpointTypeMetadata{Name: "UDPLite", Formatter: func(b []byte) string {
+		return strconv.Itoa(int(binary.BigEndian.Uint16(b)))
+	}})
+	EndpointPPP = gopacket.RegisterEndpointType(9, gopacket.EndpointTypeMetadata{Name: "PPP", Formatter: func([]byte) string {
+		return "point"
+	}})
+)
+
+// NewIPEndpoint creates a new IP (v4 or v6) endpoint from a net.IP address.
+// It returns gopacket.InvalidEndpoint if the IP address is invalid.
+func NewIPEndpoint(a net.IP) gopacket.Endpoint {
+	ipv4 := a.To4()
+	if ipv4 != nil {
+		return gopacket.NewEndpoint(EndpointIPv4, []byte(ipv4))
+	}
+
+	ipv6 := a.To16()
+	if ipv6 != nil {
+		return gopacket.NewEndpoint(EndpointIPv6, []byte(ipv6))
+	}
+
+	return gopacket.InvalidEndpoint
+}
+
+// NewMACEndpoint returns a new MAC address endpoint.
+func NewMACEndpoint(a net.HardwareAddr) gopacket.Endpoint {
+	return gopacket.NewEndpoint(EndpointMAC, []byte(a))
+}
+func newPortEndpoint(t gopacket.EndpointType, p uint16) gopacket.Endpoint {
+	return gopacket.NewEndpoint(t, []byte{byte(p >> 8), byte(p)})
+}
+
+// NewTCPPortEndpoint returns an endpoint based on a TCP port.
+func NewTCPPortEndpoint(p TCPPort) gopacket.Endpoint {
+	return newPortEndpoint(EndpointTCPPort, uint16(p))
+}
+
+// NewUDPPortEndpoint returns an endpoint based on a UDP port.
+func NewUDPPortEndpoint(p UDPPort) gopacket.Endpoint {
+	return newPortEndpoint(EndpointUDPPort, uint16(p))
+}
+
+// NewSCTPPortEndpoint returns an endpoint based on a SCTP port.
+func NewSCTPPortEndpoint(p SCTPPort) gopacket.Endpoint {
+	return newPortEndpoint(EndpointSCTPPort, uint16(p))
+}
+
+// NewRUDPPortEndpoint returns an endpoint based on a RUDP port.
+func NewRUDPPortEndpoint(p RUDPPort) gopacket.Endpoint {
+	return gopacket.NewEndpoint(EndpointRUDPPort, []byte{byte(p)})
+}
+
+// NewUDPLitePortEndpoint returns an endpoint based on a UDPLite port.
+func NewUDPLitePortEndpoint(p UDPLitePort) gopacket.Endpoint {
+	return newPortEndpoint(EndpointUDPLitePort, uint16(p))
+}

vendor/github.com/google/gopacket/layers/enums.go

@@ -0,0 +1,443 @@
+// Copyright 2012 Google, Inc. All rights reserved.
+// Copyright 2009-2011 Andreas Krennmair. All rights reserved.
+//
+// Use of this source code is governed by a BSD-style license
+// that can be found in the LICENSE file in the root of the source
+// tree.
+
+package layers
+
+import (
+	"fmt"
+	"runtime"
+
+	"github.com/google/gopacket"
+)
+
+// EnumMetadata keeps track of a set of metadata for each enumeration value
+// for protocol enumerations.
+type EnumMetadata struct {
+	// DecodeWith is the decoder to use to decode this protocol's data.
+	DecodeWith gopacket.Decoder
+	// Name is the name of the enumeration value.
+	Name string
+	// LayerType is the layer type implied by the given enum.
+	LayerType gopacket.LayerType
+}
+
+// EthernetType is an enumeration of ethernet type values, and acts as a decoder
+// for any type it supports.
+type EthernetType uint16
+
+const (
+	// EthernetTypeLLC is not an actual ethernet type.  It is instead a
+	// placeholder we use in Ethernet frames that use the 802.3 standard of
+	// srcmac|dstmac|length|LLC instead of srcmac|dstmac|ethertype.
+	EthernetTypeLLC                         EthernetType = 0
+	EthernetTypeIPv4                        EthernetType = 0x0800
+	EthernetTypeARP                         EthernetType = 0x0806
+	EthernetTypeIPv6                        EthernetType = 0x86DD
+	EthernetTypeCiscoDiscovery              EthernetType = 0x2000
+	EthernetTypeNortelDiscovery             EthernetType = 0x01a2
+	EthernetTypeTransparentEthernetBridging EthernetType = 0x6558
+	EthernetTypeDot1Q                       EthernetType = 0x8100
+	EthernetTypePPP                         EthernetType = 0x880b
+	EthernetTypePPPoEDiscovery              EthernetType = 0x8863
+	EthernetTypePPPoESession                EthernetType = 0x8864
+	EthernetTypeMPLSUnicast                 EthernetType = 0x8847
+	EthernetTypeMPLSMulticast               EthernetType = 0x8848
+	EthernetTypeEAPOL                       EthernetType = 0x888e
+	EthernetTypeERSPAN                      EthernetType = 0x88be
+	EthernetTypeQinQ                        EthernetType = 0x88a8
+	EthernetTypeLinkLayerDiscovery          EthernetType = 0x88cc
+	EthernetTypeEthernetCTP                 EthernetType = 0x9000
+)
+
+// IPProtocol is an enumeration of IP protocol values, and acts as a decoder
+// for any type it supports.
+type IPProtocol uint8
+
+const (
+	IPProtocolIPv6HopByHop    IPProtocol = 0
+	IPProtocolICMPv4          IPProtocol = 1
+	IPProtocolIGMP            IPProtocol = 2
+	IPProtocolIPv4            IPProtocol = 4
+	IPProtocolTCP             IPProtocol = 6
+	IPProtocolUDP             IPProtocol = 17
+	IPProtocolRUDP            IPProtocol = 27
+	IPProtocolIPv6            IPProtocol = 41
+	IPProtocolIPv6Routing     IPProtocol = 43
+	IPProtocolIPv6Fragment    IPProtocol = 44
+	IPProtocolGRE             IPProtocol = 47
+	IPProtocolESP             IPProtocol = 50
+	IPProtocolAH              IPProtocol = 51
+	IPProtocolICMPv6          IPProtocol = 58
+	IPProtocolNoNextHeader    IPProtocol = 59
+	IPProtocolIPv6Destination IPProtocol = 60
+	IPProtocolOSPF            IPProtocol = 89
+	IPProtocolIPIP            IPProtocol = 94
+	IPProtocolEtherIP         IPProtocol = 97
+	IPProtocolVRRP            IPProtocol = 112
+	IPProtocolSCTP            IPProtocol = 132
+	IPProtocolUDPLite         IPProtocol = 136
+	IPProtocolMPLSInIP        IPProtocol = 137
+)
+
+// LinkType is an enumeration of link types, and acts as a decoder for any
+// link type it supports.
+type LinkType uint8
+
+const (
+	// According to pcap-linktype(7) and http://www.tcpdump.org/linktypes.html
+	LinkTypeNull           LinkType = 0
+	LinkTypeEthernet       LinkType = 1
+	LinkTypeAX25           LinkType = 3
+	LinkTypeTokenRing      LinkType = 6
+	LinkTypeArcNet         LinkType = 7
+	LinkTypeSLIP           LinkType = 8
+	LinkTypePPP            LinkType = 9
+	LinkTypeFDDI           LinkType = 10
+	LinkTypePPP_HDLC       LinkType = 50
+	LinkTypePPPEthernet    LinkType = 51
+	LinkTypeATM_RFC1483    LinkType = 100
+	LinkTypeRaw            LinkType = 101
+	LinkTypeC_HDLC         LinkType = 104
+	LinkTypeIEEE802_11     LinkType = 105
+	LinkTypeFRelay         LinkType = 107
+	LinkTypeLoop           LinkType = 108
+	LinkTypeLinuxSLL       LinkType = 113
+	LinkTypeLTalk          LinkType = 114
+	LinkTypePFLog          LinkType = 117
+	LinkTypePrismHeader    LinkType = 119
+	LinkTypeIPOverFC       LinkType = 122
+	LinkTypeSunATM         LinkType = 123
+	LinkTypeIEEE80211Radio LinkType = 127
+	LinkTypeARCNetLinux    LinkType = 129
+	LinkTypeIPOver1394     LinkType = 138
+	LinkTypeMTP2Phdr       LinkType = 139
+	LinkTypeMTP2           LinkType = 140
+	LinkTypeMTP3           LinkType = 141
+	LinkTypeSCCP           LinkType = 142
+	LinkTypeDOCSIS         LinkType = 143
+	LinkTypeLinuxIRDA      LinkType = 144
+	LinkTypeLinuxLAPD      LinkType = 177
+	LinkTypeLinuxUSB       LinkType = 220
+	LinkTypeFC2            LinkType = 224
+	LinkTypeFC2Framed      LinkType = 225
+	LinkTypeIPv4           LinkType = 228
+	LinkTypeIPv6           LinkType = 229
+)
+
+// PPPoECode is the PPPoE code enum, taken from http://tools.ietf.org/html/rfc2516
+type PPPoECode uint8
+
+const (
+	PPPoECodePADI    PPPoECode = 0x09
+	PPPoECodePADO    PPPoECode = 0x07
+	PPPoECodePADR    PPPoECode = 0x19
+	PPPoECodePADS    PPPoECode = 0x65
+	PPPoECodePADT    PPPoECode = 0xA7
+	PPPoECodeSession PPPoECode = 0x00
+)
+
+// PPPType is an enumeration of PPP type values, and acts as a decoder for any
+// type it supports.
+type PPPType uint16
+
+const (
+	PPPTypeIPv4          PPPType = 0x0021
+	PPPTypeIPv6          PPPType = 0x0057
+	PPPTypeMPLSUnicast   PPPType = 0x0281
+	PPPTypeMPLSMulticast PPPType = 0x0283
+)
+
+// SCTPChunkType is an enumeration of chunk types inside SCTP packets.
+type SCTPChunkType uint8
+
+const (
+	SCTPChunkTypeData             SCTPChunkType = 0
+	SCTPChunkTypeInit             SCTPChunkType = 1
+	SCTPChunkTypeInitAck          SCTPChunkType = 2
+	SCTPChunkTypeSack             SCTPChunkType = 3
+	SCTPChunkTypeHeartbeat        SCTPChunkType = 4
+	SCTPChunkTypeHeartbeatAck     SCTPChunkType = 5
+	SCTPChunkTypeAbort            SCTPChunkType = 6
+	SCTPChunkTypeShutdown         SCTPChunkType = 7
+	SCTPChunkTypeShutdownAck      SCTPChunkType = 8
+	SCTPChunkTypeError            SCTPChunkType = 9
+	SCTPChunkTypeCookieEcho       SCTPChunkType = 10
+	SCTPChunkTypeCookieAck        SCTPChunkType = 11
+	SCTPChunkTypeShutdownComplete SCTPChunkType = 14
+)
+
+// FDDIFrameControl is an enumeration of FDDI frame control bytes.
+type FDDIFrameControl uint8
+
+const (
+	FDDIFrameControlLLC FDDIFrameControl = 0x50
+)
+
+// EAPOLType is an enumeration of EAPOL packet types.
+type EAPOLType uint8
+
+const (
+	EAPOLTypeEAP      EAPOLType = 0
+	EAPOLTypeStart    EAPOLType = 1
+	EAPOLTypeLogOff   EAPOLType = 2
+	EAPOLTypeKey      EAPOLType = 3
+	EAPOLTypeASFAlert EAPOLType = 4
+)
+
+// ProtocolFamily is the set of values defined as PF_* in sys/socket.h
+type ProtocolFamily uint8
+
+const (
+	ProtocolFamilyIPv4 ProtocolFamily = 2
+	// BSDs use different values for INET6... glory be.  These values taken from
+	// tcpdump 4.3.0.
+	ProtocolFamilyIPv6BSD     ProtocolFamily = 24
+	ProtocolFamilyIPv6FreeBSD ProtocolFamily = 28
+	ProtocolFamilyIPv6Darwin  ProtocolFamily = 30
+	ProtocolFamilyIPv6Linux   ProtocolFamily = 10
+)
+
+// Dot11Type is a combination of IEEE 802.11 frame's Type and Subtype fields.
+// By combining these two fields together into a single type, we're able to
+// provide a String function that correctly displays the subtype given the
+// top-level type.
+//
+// If you just care about the top-level type, use the MainType function.
+type Dot11Type uint8
+
+// MainType strips the subtype information from the given type,
+// returning just the overarching type (Mgmt, Ctrl, Data, Reserved).
+func (d Dot11Type) MainType() Dot11Type {
+	return d & dot11TypeMask
+}
+
+func (d Dot11Type) QOS() bool {
+	return d&dot11QOSMask == Dot11TypeDataQOSData
+}
+
+const (
+	Dot11TypeMgmt     Dot11Type = 0x00
+	Dot11TypeCtrl     Dot11Type = 0x01
+	Dot11TypeData     Dot11Type = 0x02
+	Dot11TypeReserved Dot11Type = 0x03
+	dot11TypeMask               = 0x03
+	dot11QOSMask                = 0x23
+
+	// The following are type/subtype conglomerations.
+
+	// Management
+	Dot11TypeMgmtAssociationReq    Dot11Type = 0x00
+	Dot11TypeMgmtAssociationResp   Dot11Type = 0x04
+	Dot11TypeMgmtReassociationReq  Dot11Type = 0x08
+	Dot11TypeMgmtReassociationResp Dot11Type = 0x0c
+	Dot11TypeMgmtProbeReq          Dot11Type = 0x10
+	Dot11TypeMgmtProbeResp         Dot11Type = 0x14
+	Dot11TypeMgmtMeasurementPilot  Dot11Type = 0x18
+	Dot11TypeMgmtBeacon            Dot11Type = 0x20
+	Dot11TypeMgmtATIM              Dot11Type = 0x24
+	Dot11TypeMgmtDisassociation    Dot11Type = 0x28
+	Dot11TypeMgmtAuthentication    Dot11Type = 0x2c
+	Dot11TypeMgmtDeauthentication  Dot11Type = 0x30
+	Dot11TypeMgmtAction            Dot11Type = 0x34
+	Dot11TypeMgmtActionNoAck       Dot11Type = 0x38
+
+	// Control
+	Dot11TypeCtrlWrapper       Dot11Type = 0x1d
+	Dot11TypeCtrlBlockAckReq   Dot11Type = 0x21
+	Dot11TypeCtrlBlockAck      Dot11Type = 0x25
+	Dot11TypeCtrlPowersavePoll Dot11Type = 0x29
+	Dot11TypeCtrlRTS           Dot11Type = 0x2d
+	Dot11TypeCtrlCTS           Dot11Type = 0x31
+	Dot11TypeCtrlAck           Dot11Type = 0x35
+	Dot11TypeCtrlCFEnd         Dot11Type = 0x39
+	Dot11TypeCtrlCFEndAck      Dot11Type = 0x3d
+
+	// Data
+	Dot11TypeDataCFAck              Dot11Type = 0x06
+	Dot11TypeDataCFPoll             Dot11Type = 0x0a
+	Dot11TypeDataCFAckPoll          Dot11Type = 0x0e
+	Dot11TypeDataNull               Dot11Type = 0x12
+	Dot11TypeDataCFAckNoData        Dot11Type = 0x16
+	Dot11TypeDataCFPollNoData       Dot11Type = 0x1a
+	Dot11TypeDataCFAckPollNoData    Dot11Type = 0x1e
+	Dot11TypeDataQOSData            Dot11Type = 0x22
+	Dot11TypeDataQOSDataCFAck       Dot11Type = 0x26
+	Dot11TypeDataQOSDataCFPoll      Dot11Type = 0x2a
+	Dot11TypeDataQOSDataCFAckPoll   Dot11Type = 0x2e
+	Dot11TypeDataQOSNull            Dot11Type = 0x32
+	Dot11TypeDataQOSCFPollNoData    Dot11Type = 0x3a
+	Dot11TypeDataQOSCFAckPollNoData Dot11Type = 0x3e
+)
+
+// Decode a raw v4 or v6 IP packet.
+func decodeIPv4or6(data []byte, p gopacket.PacketBuilder) error {
+	version := data[0] >> 4
+	switch version {
+	case 4:
+		return decodeIPv4(data, p)
+	case 6:
+		return decodeIPv6(data, p)
+	}
+	return fmt.Errorf("Invalid IP packet version %v", version)
+}
+
+func initActualTypeData() {
+	// Each of the XXXTypeMetadata arrays contains mappings of how to handle enum
+	// values for various enum types in gopacket/layers.
+	// These arrays are actually created by gen2.go and stored in
+	// enums_generated.go.
+	//
+	// So, EthernetTypeMetadata[2] contains information on how to handle EthernetType
+	// 2, including which name to give it and which decoder to use to decode
+	// packet data of that type.  These arrays are filled by default with all of the
+	// protocols gopacket/layers knows how to handle, but users of the library can
+	// add new decoders or override existing ones.  For example, if you write a better
+	// TCP decoder, you can override IPProtocolMetadata[IPProtocolTCP].DecodeWith
+	// with your new decoder, and all gopacket/layers decoding will use your new
+	// decoder whenever they encounter that IPProtocol.
+
+	// Here we link up all enumerations with their respective names and decoders.
+	EthernetTypeMetadata[EthernetTypeLLC] = EnumMetadata{DecodeWith: gopacket.DecodeFunc(decodeLLC), Name: "LLC", LayerType: LayerTypeLLC}
+	EthernetTypeMetadata[EthernetTypeIPv4] = EnumMetadata{DecodeWith: gopacket.DecodeFunc(decodeIPv4), Name: "IPv4", LayerType: LayerTypeIPv4}
+	EthernetTypeMetadata[EthernetTypeIPv6] = EnumMetadata{DecodeWith: gopacket.DecodeFunc(decodeIPv6), Name: "IPv6", LayerType: LayerTypeIPv6}
+	EthernetTypeMetadata[EthernetTypeARP] = EnumMetadata{DecodeWith: gopacket.DecodeFunc(decodeARP), Name: "ARP", LayerType: LayerTypeARP}
+	EthernetTypeMetadata[EthernetTypeDot1Q] = EnumMetadata{DecodeWith: gopacket.DecodeFunc(decodeDot1Q), Name: "Dot1Q", LayerType: LayerTypeDot1Q}
+	EthernetTypeMetadata[EthernetTypePPP] = EnumMetadata{DecodeWith: gopacket.DecodeFunc(decodePPP), Name: "PPP", LayerType: LayerTypePPP}
+	EthernetTypeMetadata[EthernetTypePPPoEDiscovery] = EnumMetadata{DecodeWith: gopacket.DecodeFunc(decodePPPoE), Name: "PPPoEDiscovery", LayerType: LayerTypePPPoE}
+	EthernetTypeMetadata[EthernetTypePPPoESession] = EnumMetadata{DecodeWith: gopacket.DecodeFunc(decodePPPoE), Name: "PPPoESession", LayerType: LayerTypePPPoE}
+	EthernetTypeMetadata[EthernetTypeEthernetCTP] = EnumMetadata{DecodeWith: gopacket.DecodeFunc(decodeEthernetCTP), Name: "EthernetCTP", LayerType: LayerTypeEthernetCTP}
+	EthernetTypeMetadata[EthernetTypeCiscoDiscovery] = EnumMetadata{DecodeWith: gopacket.DecodeFunc(decodeCiscoDiscovery), Name: "CiscoDiscovery", LayerType: LayerTypeCiscoDiscovery}
+	EthernetTypeMetadata[EthernetTypeNortelDiscovery] = EnumMetadata{DecodeWith: gopacket.DecodeFunc(decodeNortelDiscovery), Name: "NortelDiscovery", LayerType: LayerTypeNortelDiscovery}
+	EthernetTypeMetadata[EthernetTypeLinkLayerDiscovery] = EnumMetadata{DecodeWith: gopacket.DecodeFunc(decodeLinkLayerDiscovery), Name: "LinkLayerDiscovery", LayerType: LayerTypeLinkLayerDiscovery}
+	EthernetTypeMetadata[EthernetTypeMPLSUnicast] = EnumMetadata{DecodeWith: gopacket.DecodeFunc(decodeMPLS), Name: "MPLSUnicast", LayerType: LayerTypeMPLS}
+	EthernetTypeMetadata[EthernetTypeMPLSMulticast] = EnumMetadata{DecodeWith: gopacket.DecodeFunc(decodeMPLS), Name: "MPLSMulticast", LayerType: LayerTypeMPLS}
+	EthernetTypeMetadata[EthernetTypeEAPOL] = EnumMetadata{DecodeWith: gopacket.DecodeFunc(decodeEAPOL), Name: "EAPOL", LayerType: LayerTypeEAPOL}
+	EthernetTypeMetadata[EthernetTypeQinQ] = EnumMetadata{DecodeWith: gopacket.DecodeFunc(decodeDot1Q), Name: "Dot1Q", LayerType: LayerTypeDot1Q}
+	EthernetTypeMetadata[EthernetTypeTransparentEthernetBridging] = EnumMetadata{DecodeWith: gopacket.DecodeFunc(decodeEthernet), Name: "TransparentEthernetBridging", LayerType: LayerTypeEthernet}
+	EthernetTypeMetadata[EthernetTypeERSPAN] = EnumMetadata{DecodeWith: gopacket.DecodeFunc(decodeERSPANII), Name: "ERSPAN Type II", LayerType: LayerTypeERSPANII}
+
+	IPProtocolMetadata[IPProtocolIPv4] = EnumMetadata{DecodeWith: gopacket.DecodeFunc(decodeIPv4), Name: "IPv4", LayerType: LayerTypeIPv4}
+	IPProtocolMetadata[IPProtocolTCP] = EnumMetadata{DecodeWith: gopacket.DecodeFunc(decodeTCP), Name: "TCP", LayerType: LayerTypeTCP}
+	IPProtocolMetadata[IPProtocolUDP] = EnumMetadata{DecodeWith: gopacket.DecodeFunc(decodeUDP), Name: "UDP", LayerType: LayerTypeUDP}
+	IPProtocolMetadata[IPProtocolICMPv4] = EnumMetadata{DecodeWith: gopacket.DecodeFunc(decodeICMPv4), Name: "ICMPv4", LayerType: LayerTypeICMPv4}
+	IPProtocolMetadata[IPProtocolICMPv6] = EnumMetadata{DecodeWith: gopacket.DecodeFunc(decodeICMPv6), Name: "ICMPv6", LayerType: LayerTypeICMPv6}
+	IPProtocolMetadata[IPProtocolSCTP] = EnumMetadata{DecodeWith: gopacket.DecodeFunc(decodeSCTP), Name: "SCTP", LayerType: LayerTypeSCTP}
+	IPProtocolMetadata[IPProtocolIPv6] = EnumMetadata{DecodeWith: gopacket.DecodeFunc(decodeIPv6), Name: "IPv6", LayerType: LayerTypeIPv6}
+	IPProtocolMetadata[IPProtocolIPIP] = EnumMetadata{DecodeWith: gopacket.DecodeFunc(decodeIPv4), Name: "IPv4", LayerType: LayerTypeIPv4}
+	IPProtocolMetadata[IPProtocolEtherIP] = EnumMetadata{DecodeWith: gopacket.DecodeFunc(decodeEtherIP), Name: "EtherIP", LayerType: LayerTypeEtherIP}
+	IPProtocolMetadata[IPProtocolRUDP] = EnumMetadata{DecodeWith: gopacket.DecodeFunc(decodeRUDP), Name: "RUDP", LayerType: LayerTypeRUDP}
+	IPProtocolMetadata[IPProtocolGRE] = EnumMetadata{DecodeWith: gopacket.DecodeFunc(decodeGRE), Name: "GRE", LayerType: LayerTypeGRE}
+	IPProtocolMetadata[IPProtocolIPv6HopByHop] = EnumMetadata{DecodeWith: gopacket.DecodeFunc(decodeIPv6HopByHop), Name: "IPv6HopByHop", LayerType: LayerTypeIPv6HopByHop}
+	IPProtocolMetadata[IPProtocolIPv6Routing] = EnumMetadata{DecodeWith: gopacket.DecodeFunc(decodeIPv6Routing), Name: "IPv6Routing", LayerType: LayerTypeIPv6Routing}
+	IPProtocolMetadata[IPProtocolIPv6Fragment] = EnumMetadata{DecodeWith: gopacket.DecodeFunc(decodeIPv6Fragment), Name: "IPv6Fragment", LayerType: LayerTypeIPv6Fragment}
+	IPProtocolMetadata[IPProtocolIPv6Destination] = EnumMetadata{DecodeWith: gopacket.DecodeFunc(decodeIPv6Destination), Name: "IPv6Destination", LayerType: LayerTypeIPv6Destination}
+	IPProtocolMetadata[IPProtocolOSPF] = EnumMetadata{DecodeWith: gopacket.DecodeFunc(decodeOSPF), Name: "OSPF", LayerType: LayerTypeOSPF}
+	IPProtocolMetadata[IPProtocolAH] = EnumMetadata{DecodeWith: gopacket.DecodeFunc(decodeIPSecAH), Name: "IPSecAH", LayerType: LayerTypeIPSecAH}
+	IPProtocolMetadata[IPProtocolESP] = EnumMetadata{DecodeWith: gopacket.DecodeFunc(decodeIPSecESP), Name: "IPSecESP", LayerType: LayerTypeIPSecESP}
+	IPProtocolMetadata[IPProtocolUDPLite] = EnumMetadata{DecodeWith: gopacket.DecodeFunc(decodeUDPLite), Name: "UDPLite", LayerType: LayerTypeUDPLite}
+	IPProtocolMetadata[IPProtocolMPLSInIP] = EnumMetadata{DecodeWith: gopacket.DecodeFunc(decodeMPLS), Name: "MPLS", LayerType: LayerTypeMPLS}
+	IPProtocolMetadata[IPProtocolNoNextHeader] = EnumMetadata{DecodeWith: gopacket.DecodePayload, Name: "NoNextHeader", LayerType: gopacket.LayerTypePayload}
+	IPProtocolMetadata[IPProtocolIGMP] = EnumMetadata{DecodeWith: gopacket.DecodeFunc(decodeIGMP), Name: "IGMP", LayerType: LayerTypeIGMP}
+	IPProtocolMetadata[IPProtocolVRRP] = EnumMetadata{DecodeWith: gopacket.DecodeFunc(decodeVRRP), Name: "VRRP", LayerType: LayerTypeVRRP}
+
+	SCTPChunkTypeMetadata[SCTPChunkTypeData] = EnumMetadata{DecodeWith: gopacket.DecodeFunc(decodeSCTPData), Name: "Data"}
+	SCTPChunkTypeMetadata[SCTPChunkTypeInit] = EnumMetadata{DecodeWith: gopacket.DecodeFunc(decodeSCTPInit), Name: "Init"}
+	SCTPChunkTypeMetadata[SCTPChunkTypeInitAck] = EnumMetadata{DecodeWith: gopacket.DecodeFunc(decodeSCTPInit), Name: "InitAck"}
+	SCTPChunkTypeMetadata[SCTPChunkTypeSack] = EnumMetadata{DecodeWith: gopacket.DecodeFunc(decodeSCTPSack), Name: "Sack"}
+	SCTPChunkTypeMetadata[SCTPChunkTypeHeartbeat] = EnumMetadata{DecodeWith: gopacket.DecodeFunc(decodeSCTPHeartbeat), Name: "Heartbeat"}
+	SCTPChunkTypeMetadata[SCTPChunkTypeHeartbeatAck] = EnumMetadata{DecodeWith: gopacket.DecodeFunc(decodeSCTPHeartbeat), Name: "HeartbeatAck"}
+	SCTPChunkTypeMetadata[SCTPChunkTypeAbort] = EnumMetadata{DecodeWith: gopacket.DecodeFunc(decodeSCTPError), Name: "Abort"}
+	SCTPChunkTypeMetadata[SCTPChunkTypeError] = EnumMetadata{DecodeWith: gopacket.DecodeFunc(decodeSCTPError), Name: "Error"}
+	SCTPChunkTypeMetadata[SCTPChunkTypeShutdown] = EnumMetadata{DecodeWith: gopacket.DecodeFunc(decodeSCTPShutdown), Name: "Shutdown"}
+	SCTPChunkTypeMetadata[SCTPChunkTypeShutdownAck] = EnumMetadata{DecodeWith: gopacket.DecodeFunc(decodeSCTPShutdownAck), Name: "ShutdownAck"}
+	SCTPChunkTypeMetadata[SCTPChunkTypeCookieEcho] = EnumMetadata{DecodeWith: gopacket.DecodeFunc(decodeSCTPCookieEcho), Name: "CookieEcho"}
+	SCTPChunkTypeMetadata[SCTPChunkTypeCookieAck] = EnumMetadata{DecodeWith: gopacket.DecodeFunc(decodeSCTPEmptyLayer), Name: "CookieAck"}
+	SCTPChunkTypeMetadata[SCTPChunkTypeShutdownComplete] = EnumMetadata{DecodeWith: gopacket.DecodeFunc(decodeSCTPEmptyLayer), Name: "ShutdownComplete"}
+
+	PPPTypeMetadata[PPPTypeIPv4] = EnumMetadata{DecodeWith: gopacket.DecodeFunc(decodeIPv4), Name: "IPv4"}
+	PPPTypeMetadata[PPPTypeIPv6] = EnumMetadata{DecodeWith: gopacket.DecodeFunc(decodeIPv6), Name: "IPv6"}
+	PPPTypeMetadata[PPPTypeMPLSUnicast] = EnumMetadata{DecodeWith: gopacket.DecodeFunc(decodeMPLS), Name: "MPLSUnicast"}
+	PPPTypeMetadata[PPPTypeMPLSMulticast] = EnumMetadata{DecodeWith: gopacket.DecodeFunc(decodeMPLS), Name: "MPLSMulticast"}
+
+	PPPoECodeMetadata[PPPoECodeSession] = EnumMetadata{DecodeWith: gopacket.DecodeFunc(decodePPP), Name: "PPP"}
+
+	LinkTypeMetadata[LinkTypeEthernet] = EnumMetadata{DecodeWith: gopacket.DecodeFunc(decodeEthernet), Name: "Ethernet"}
+	LinkTypeMetadata[LinkTypePPP] = EnumMetadata{DecodeWith: gopacket.DecodeFunc(decodePPP), Name: "PPP"}
+	LinkTypeMetadata[LinkTypeFDDI] = EnumMetadata{DecodeWith: gopacket.DecodeFunc(decodeFDDI), Name: "FDDI"}
+	LinkTypeMetadata[LinkTypeNull] = EnumMetadata{DecodeWith: gopacket.DecodeFunc(decodeLoopback), Name: "Null"}
+	LinkTypeMetadata[LinkTypeIEEE802_11] = EnumMetadata{DecodeWith: gopacket.DecodeFunc(decodeDot11), Name: "Dot11"}
+	LinkTypeMetadata[LinkTypeLoop] = EnumMetadata{DecodeWith: gopacket.DecodeFunc(decodeLoopback), Name: "Loop"}
+	LinkTypeMetadata[LinkTypeIEEE802_11] = EnumMetadata{DecodeWith: gopacket.DecodeFunc(decodeDot11), Name: "802.11"}
+	LinkTypeMetadata[LinkTypeRaw] = EnumMetadata{DecodeWith: gopacket.DecodeFunc(decodeIPv4or6), Name: "Raw"}
+	// See https://github.com/the-tcpdump-group/libpcap/blob/170f717e6e818cdc4bcbbfd906b63088eaa88fa0/pcap/dlt.h#L85
+	// Or https://github.com/wireshark/wireshark/blob/854cfe53efe44080609c78053ecfb2342ad84a08/wiretap/pcap-common.c#L508
+	if runtime.GOOS == "openbsd" {
+		LinkTypeMetadata[14] = EnumMetadata{DecodeWith: gopacket.DecodeFunc(decodeIPv4or6), Name: "Raw"}
+	} else {
+		LinkTypeMetadata[12] = EnumMetadata{DecodeWith: gopacket.DecodeFunc(decodeIPv4or6), Name: "Raw"}
+	}
+	LinkTypeMetadata[LinkTypePFLog] = EnumMetadata{DecodeWith: gopacket.DecodeFunc(decodePFLog), Name: "PFLog"}
+	LinkTypeMetadata[LinkTypeIEEE80211Radio] = EnumMetadata{DecodeWith: gopacket.DecodeFunc(decodeRadioTap), Name: "RadioTap"}
+	LinkTypeMetadata[LinkTypeLinuxUSB] = EnumMetadata{DecodeWith: gopacket.DecodeFunc(decodeUSB), Name: "USB"}
+	LinkTypeMetadata[LinkTypeLinuxSLL] = EnumMetadata{DecodeWith: gopacket.DecodeFunc(decodeLinuxSLL), Name: "Linux SLL"}
+	LinkTypeMetadata[LinkTypePrismHeader] = EnumMetadata{DecodeWith: gopacket.DecodeFunc(decodePrismHeader), Name: "Prism"}
+
+	FDDIFrameControlMetadata[FDDIFrameControlLLC] = EnumMetadata{DecodeWith: gopacket.DecodeFunc(decodeLLC), Name: "LLC"}
+
+	EAPOLTypeMetadata[EAPOLTypeEAP] = EnumMetadata{DecodeWith: gopacket.DecodeFunc(decodeEAP), Name: "EAP", LayerType: LayerTypeEAP}
+	EAPOLTypeMetadata[EAPOLTypeKey] = EnumMetadata{DecodeWith: gopacket.DecodeFunc(decodeEAPOLKey), Name: "EAPOLKey", LayerType: LayerTypeEAPOLKey}
+
+	ProtocolFamilyMetadata[ProtocolFamilyIPv4] = EnumMetadata{DecodeWith: gopacket.DecodeFunc(decodeIPv4), Name: "IPv4", LayerType: LayerTypeIPv4}
+	ProtocolFamilyMetadata[ProtocolFamilyIPv6BSD] = EnumMetadata{DecodeWith: gopacket.DecodeFunc(decodeIPv6), Name: "IPv6", LayerType: LayerTypeIPv6}
+	ProtocolFamilyMetadata[ProtocolFamilyIPv6FreeBSD] = EnumMetadata{DecodeWith: gopacket.DecodeFunc(decodeIPv6), Name: "IPv6", LayerType: LayerTypeIPv6}
+	ProtocolFamilyMetadata[ProtocolFamilyIPv6Darwin] = EnumMetadata{DecodeWith: gopacket.DecodeFunc(decodeIPv6), Name: "IPv6", LayerType: LayerTypeIPv6}
+	ProtocolFamilyMetadata[ProtocolFamilyIPv6Linux] = EnumMetadata{DecodeWith: gopacket.DecodeFunc(decodeIPv6), Name: "IPv6", LayerType: LayerTypeIPv6}
+
+	Dot11TypeMetadata[Dot11TypeMgmtAssociationReq] = EnumMetadata{DecodeWith: gopacket.DecodeFunc(decodeDot11MgmtAssociationReq), Name: "MgmtAssociationReq", LayerType: LayerTypeDot11MgmtAssociationReq}
+	Dot11TypeMetadata[Dot11TypeMgmtAssociationResp] = EnumMetadata{DecodeWith: gopacket.DecodeFunc(decodeDot11MgmtAssociationResp), Name: "MgmtAssociationResp", LayerType: LayerTypeDot11MgmtAssociationResp}
+	Dot11TypeMetadata[Dot11TypeMgmtReassociationReq] = EnumMetadata{DecodeWith: gopacket.DecodeFunc(decodeDot11MgmtReassociationReq), Name: "MgmtReassociationReq", LayerType: LayerTypeDot11MgmtReassociationReq}
+	Dot11TypeMetadata[Dot11TypeMgmtReassociationResp] = EnumMetadata{DecodeWith: gopacket.DecodeFunc(decodeDot11MgmtReassociationResp), Name: "MgmtReassociationResp", LayerType: LayerTypeDot11MgmtReassociationResp}
+	Dot11TypeMetadata[Dot11TypeMgmtProbeReq] = EnumMetadata{DecodeWith: gopacket.DecodeFunc(decodeDot11MgmtProbeReq), Name: "MgmtProbeReq", LayerType: LayerTypeDot11MgmtProbeReq}
+	Dot11TypeMetadata[Dot11TypeMgmtProbeResp] = EnumMetadata{DecodeWith: gopacket.DecodeFunc(decodeDot11MgmtProbeResp), Name: "MgmtProbeResp", LayerType: LayerTypeDot11MgmtProbeResp}
+	Dot11TypeMetadata[Dot11TypeMgmtMeasurementPilot] = EnumMetadata{DecodeWith: gopacket.DecodeFunc(decodeDot11MgmtMeasurementPilot), Name: "MgmtMeasurementPilot", LayerType: LayerTypeDot11MgmtMeasurementPilot}
+	Dot11TypeMetadata[Dot11TypeMgmtBeacon] = EnumMetadata{DecodeWith: gopacket.DecodeFunc(decodeDot11MgmtBeacon), Name: "MgmtBeacon", LayerType: LayerTypeDot11MgmtBeacon}
+	Dot11TypeMetadata[Dot11TypeMgmtATIM] = EnumMetadata{DecodeWith: gopacket.DecodeFunc(decodeDot11MgmtATIM), Name: "MgmtATIM", LayerType: LayerTypeDot11MgmtATIM}
+	Dot11TypeMetadata[Dot11TypeMgmtDisassociation] = EnumMetadata{DecodeWith: gopacket.DecodeFunc(decodeDot11MgmtDisassociation), Name: "MgmtDisassociation", LayerType: LayerTypeDot11MgmtDisassociation}
+	Dot11TypeMetadata[Dot11TypeMgmtAuthentication] = EnumMetadata{DecodeWith: gopacket.DecodeFunc(decodeDot11MgmtAuthentication), Name: "MgmtAuthentication", LayerType: LayerTypeDot11MgmtAuthentication}
+	Dot11TypeMetadata[Dot11TypeMgmtDeauthentication] = EnumMetadata{DecodeWith: gopacket.DecodeFunc(decodeDot11MgmtDeauthentication), Name: "MgmtDeauthentication", LayerType: LayerTypeDot11MgmtDeauthentication}
+	Dot11TypeMetadata[Dot11TypeMgmtAction] = EnumMetadata{DecodeWith: gopacket.DecodeFunc(decodeDot11MgmtAction), Name: "MgmtAction", LayerType: LayerTypeDot11MgmtAction}
+	Dot11TypeMetadata[Dot11TypeMgmtActionNoAck] = EnumMetadata{DecodeWith: gopacket.DecodeFunc(decodeDot11MgmtActionNoAck), Name: "MgmtActionNoAck", LayerType: LayerTypeDot11MgmtActionNoAck}
+	Dot11TypeMetadata[Dot11TypeCtrl] = EnumMetadata{DecodeWith: gopacket.DecodeFunc(decodeDot11Ctrl), Name: "Ctrl", LayerType: LayerTypeDot11Ctrl}
+	Dot11TypeMetadata[Dot11TypeCtrlWrapper] = EnumMetadata{DecodeWith: gopacket.DecodeFunc(decodeDot11Ctrl), Name: "CtrlWrapper", LayerType: LayerTypeDot11Ctrl}
+	Dot11TypeMetadata[Dot11TypeCtrlBlockAckReq] = EnumMetadata{DecodeWith: gopacket.DecodeFunc(decodeDot11CtrlBlockAckReq), Name: "CtrlBlockAckReq", LayerType: LayerTypeDot11CtrlBlockAckReq}
+	Dot11TypeMetadata[Dot11TypeCtrlBlockAck] = EnumMetadata{DecodeWith: gopacket.DecodeFunc(decodeDot11CtrlBlockAck), Name: "CtrlBlockAck", LayerType: LayerTypeDot11CtrlBlockAck}
+	Dot11TypeMetadata[Dot11TypeCtrlPowersavePoll] = EnumMetadata{DecodeWith: gopacket.DecodeFunc(decodeDot11CtrlPowersavePoll), Name: "CtrlPowersavePoll", LayerType: LayerTypeDot11CtrlPowersavePoll}
+	Dot11TypeMetadata[Dot11TypeCtrlRTS] = EnumMetadata{DecodeWith: gopacket.DecodeFunc(decodeDot11CtrlRTS), Name: "CtrlRTS", LayerType: LayerTypeDot11CtrlRTS}
+	Dot11TypeMetadata[Dot11TypeCtrlCTS] = EnumMetadata{DecodeWith: gopacket.DecodeFunc(decodeDot11CtrlCTS), Name: "CtrlCTS", LayerType: LayerTypeDot11CtrlCTS}
+	Dot11TypeMetadata[Dot11TypeCtrlAck] = EnumMetadata{DecodeWith: gopacket.DecodeFunc(decodeDot11CtrlAck), Name: "CtrlAck", LayerType: LayerTypeDot11CtrlAck}
+	Dot11TypeMetadata[Dot11TypeCtrlCFEnd] = EnumMetadata{DecodeWith: gopacket.DecodeFunc(decodeDot11CtrlCFEnd), Name: "CtrlCFEnd", LayerType: LayerTypeDot11CtrlCFEnd}
+	Dot11TypeMetadata[Dot11TypeCtrlCFEndAck] = EnumMetadata{DecodeWith: gopacket.DecodeFunc(decodeDot11CtrlCFEndAck), Name: "CtrlCFEndAck", LayerType: LayerTypeDot11CtrlCFEndAck}
+	Dot11TypeMetadata[Dot11TypeData] = EnumMetadata{DecodeWith: gopacket.DecodeFunc(decodeDot11Data), Name: "Data", LayerType: LayerTypeDot11Data}
+	Dot11TypeMetadata[Dot11TypeDataCFAck] = EnumMetadata{DecodeWith: gopacket.DecodeFunc(decodeDot11DataCFAck), Name: "DataCFAck", LayerType: LayerTypeDot11DataCFAck}
+	Dot11TypeMetadata[Dot11TypeDataCFPoll] = EnumMetadata{DecodeWith: gopacket.DecodeFunc(decodeDot11DataCFPoll), Name: "DataCFPoll", LayerType: LayerTypeDot11DataCFPoll}
+	Dot11TypeMetadata[Dot11TypeDataCFAckPoll] = EnumMetadata{DecodeWith: gopacket.DecodeFunc(decodeDot11DataCFAckPoll), Name: "DataCFAckPoll", LayerType: LayerTypeDot11DataCFAckPoll}
+	Dot11TypeMetadata[Dot11TypeDataNull] = EnumMetadata{DecodeWith: gopacket.DecodeFunc(decodeDot11DataNull), Name: "DataNull", LayerType: LayerTypeDot11DataNull}
+	Dot11TypeMetadata[Dot11TypeDataCFAckNoData] = EnumMetadata{DecodeWith: gopacket.DecodeFunc(decodeDot11DataCFAckNoData), Name: "DataCFAckNoData", LayerType: LayerTypeDot11DataCFAckNoData}
+	Dot11TypeMetadata[Dot11TypeDataCFPollNoData] = EnumMetadata{DecodeWith: gopacket.DecodeFunc(decodeDot11DataCFPollNoData), Name: "DataCFPollNoData", LayerType: LayerTypeDot11DataCFPollNoData}
+	Dot11TypeMetadata[Dot11TypeDataCFAckPollNoData] = EnumMetadata{DecodeWith: gopacket.DecodeFunc(decodeDot11DataCFAckPollNoData), Name: "DataCFAckPollNoData", LayerType: LayerTypeDot11DataCFAckPollNoData}
+	Dot11TypeMetadata[Dot11TypeDataQOSData] = EnumMetadata{DecodeWith: gopacket.DecodeFunc(decodeDot11DataQOSData), Name: "DataQOSData", LayerType: LayerTypeDot11DataQOSData}
+	Dot11TypeMetadata[Dot11TypeDataQOSDataCFAck] = EnumMetadata{DecodeWith: gopacket.DecodeFunc(decodeDot11DataQOSDataCFAck), Name: "DataQOSDataCFAck", LayerType: LayerTypeDot11DataQOSDataCFAck}
+	Dot11TypeMetadata[Dot11TypeDataQOSDataCFPoll] = EnumMetadata{DecodeWith: gopacket.DecodeFunc(decodeDot11DataQOSDataCFPoll), Name: "DataQOSDataCFPoll", LayerType: LayerTypeDot11DataQOSDataCFPoll}
+	Dot11TypeMetadata[Dot11TypeDataQOSDataCFAckPoll] = EnumMetadata{DecodeWith: gopacket.DecodeFunc(decodeDot11DataQOSDataCFAckPoll), Name: "DataQOSDataCFAckPoll", LayerType: LayerTypeDot11DataQOSDataCFAckPoll}
+	Dot11TypeMetadata[Dot11TypeDataQOSNull] = EnumMetadata{DecodeWith: gopacket.DecodeFunc(decodeDot11DataQOSNull), Name: "DataQOSNull", LayerType: LayerTypeDot11DataQOSNull}
+	Dot11TypeMetadata[Dot11TypeDataQOSCFPollNoData] = EnumMetadata{DecodeWith: gopacket.DecodeFunc(decodeDot11DataQOSCFPollNoData), Name: "DataQOSCFPollNoData", LayerType: LayerTypeDot11DataQOSCFPollNoData}
+	Dot11TypeMetadata[Dot11TypeDataQOSCFAckPollNoData] = EnumMetadata{DecodeWith: gopacket.DecodeFunc(decodeDot11DataQOSCFAckPollNoData), Name: "DataQOSCFAckPollNoData", LayerType: LayerTypeDot11DataQOSCFAckPollNoData}
+
+	USBTransportTypeMetadata[USBTransportTypeInterrupt] = EnumMetadata{DecodeWith: gopacket.DecodeFunc(decodeUSBInterrupt), Name: "Interrupt", LayerType: LayerTypeUSBInterrupt}
+	USBTransportTypeMetadata[USBTransportTypeControl] = EnumMetadata{DecodeWith: gopacket.DecodeFunc(decodeUSBControl), Name: "Control", LayerType: LayerTypeUSBControl}
+	USBTransportTypeMetadata[USBTransportTypeBulk] = EnumMetadata{DecodeWith: gopacket.DecodeFunc(decodeUSBBulk), Name: "Bulk", LayerType: LayerTypeUSBBulk}
+}

vendor/github.com/google/gopacket/layers/enums_generated.go

@@ -0,0 +1,434 @@
+// Copyright 2012 Google, Inc. All rights reserved.
+
+package layers
+
+// Created by gen2.go, don't edit manually
+// Generated at 2017-10-23 10:20:24.458771856 -0600 MDT m=+0.001159033
+
+import (
+	"fmt"
+
+	"github.com/google/gopacket"
+)
+
+func init() {
+	initUnknownTypesForLinkType()
+	initUnknownTypesForEthernetType()
+	initUnknownTypesForPPPType()
+	initUnknownTypesForIPProtocol()
+	initUnknownTypesForSCTPChunkType()
+	initUnknownTypesForPPPoECode()
+	initUnknownTypesForFDDIFrameControl()
+	initUnknownTypesForEAPOLType()
+	initUnknownTypesForProtocolFamily()
+	initUnknownTypesForDot11Type()
+	initUnknownTypesForUSBTransportType()
+	initActualTypeData()
+}
+
+// Decoder calls LinkTypeMetadata.DecodeWith's decoder.
+func (a LinkType) Decode(data []byte, p gopacket.PacketBuilder) error {
+	return LinkTypeMetadata[a].DecodeWith.Decode(data, p)
+}
+
+// String returns LinkTypeMetadata.Name.
+func (a LinkType) String() string {
+	return LinkTypeMetadata[a].Name
+}
+
+// LayerType returns LinkTypeMetadata.LayerType.
+func (a LinkType) LayerType() gopacket.LayerType {
+	return LinkTypeMetadata[a].LayerType
+}
+
+type errorDecoderForLinkType int
+
+func (a *errorDecoderForLinkType) Decode(data []byte, p gopacket.PacketBuilder) error {
+	return a
+}
+func (a *errorDecoderForLinkType) Error() string {
+	return fmt.Sprintf("Unable to decode LinkType %d", int(*a))
+}
+
+var errorDecodersForLinkType [256]errorDecoderForLinkType
+var LinkTypeMetadata [256]EnumMetadata
+
+func initUnknownTypesForLinkType() {
+	for i := 0; i < 256; i++ {
+		errorDecodersForLinkType[i] = errorDecoderForLinkType(i)
+		LinkTypeMetadata[i] = EnumMetadata{
+			DecodeWith: &errorDecodersForLinkType[i],
+			Name:       "UnknownLinkType",
+		}
+	}
+}
+
+// Decoder calls EthernetTypeMetadata.DecodeWith's decoder.
+func (a EthernetType) Decode(data []byte, p gopacket.PacketBuilder) error {
+	return EthernetTypeMetadata[a].DecodeWith.Decode(data, p)
+}
+
+// String returns EthernetTypeMetadata.Name.
+func (a EthernetType) String() string {
+	return EthernetTypeMetadata[a].Name
+}
+
+// LayerType returns EthernetTypeMetadata.LayerType.
+func (a EthernetType) LayerType() gopacket.LayerType {
+	return EthernetTypeMetadata[a].LayerType
+}
+
+type errorDecoderForEthernetType int
+
+func (a *errorDecoderForEthernetType) Decode(data []byte, p gopacket.PacketBuilder) error {
+	return a
+}
+func (a *errorDecoderForEthernetType) Error() string {
+	return fmt.Sprintf("Unable to decode EthernetType %d", int(*a))
+}
+
+var errorDecodersForEthernetType [65536]errorDecoderForEthernetType
+var EthernetTypeMetadata [65536]EnumMetadata
+
+func initUnknownTypesForEthernetType() {
+	for i := 0; i < 65536; i++ {
+		errorDecodersForEthernetType[i] = errorDecoderForEthernetType(i)
+		EthernetTypeMetadata[i] = EnumMetadata{
+			DecodeWith: &errorDecodersForEthernetType[i],
+			Name:       "UnknownEthernetType",
+		}
+	}
+}
+
+// Decoder calls PPPTypeMetadata.DecodeWith's decoder.
+func (a PPPType) Decode(data []byte, p gopacket.PacketBuilder) error {
+	return PPPTypeMetadata[a].DecodeWith.Decode(data, p)
+}
+
+// String returns PPPTypeMetadata.Name.
+func (a PPPType) String() string {
+	return PPPTypeMetadata[a].Name
+}
+
+// LayerType returns PPPTypeMetadata.LayerType.
+func (a PPPType) LayerType() gopacket.LayerType {
+	return PPPTypeMetadata[a].LayerType
+}
+
+type errorDecoderForPPPType int
+
+func (a *errorDecoderForPPPType) Decode(data []byte, p gopacket.PacketBuilder) error {
+	return a
+}
+func (a *errorDecoderForPPPType) Error() string {
+	return fmt.Sprintf("Unable to decode PPPType %d", int(*a))
+}
+
+var errorDecodersForPPPType [65536]errorDecoderForPPPType
+var PPPTypeMetadata [65536]EnumMetadata
+
+func initUnknownTypesForPPPType() {
+	for i := 0; i < 65536; i++ {
+		errorDecodersForPPPType[i] = errorDecoderForPPPType(i)
+		PPPTypeMetadata[i] = EnumMetadata{
+			DecodeWith: &errorDecodersForPPPType[i],
+			Name:       "UnknownPPPType",
+		}
+	}
+}
+
+// Decoder calls IPProtocolMetadata.DecodeWith's decoder.
+func (a IPProtocol) Decode(data []byte, p gopacket.PacketBuilder) error {
+	return IPProtocolMetadata[a].DecodeWith.Decode(data, p)
+}
+
+// String returns IPProtocolMetadata.Name.
+func (a IPProtocol) String() string {
+	return IPProtocolMetadata[a].Name
+}
+
+// LayerType returns IPProtocolMetadata.LayerType.
+func (a IPProtocol) LayerType() gopacket.LayerType {
+	return IPProtocolMetadata[a].LayerType
+}
+
+type errorDecoderForIPProtocol int
+
+func (a *errorDecoderForIPProtocol) Decode(data []byte, p gopacket.PacketBuilder) error {
+	return a
+}
+func (a *errorDecoderForIPProtocol) Error() string {
+	return fmt.Sprintf("Unable to decode IPProtocol %d", int(*a))
+}
+
+var errorDecodersForIPProtocol [256]errorDecoderForIPProtocol
+var IPProtocolMetadata [256]EnumMetadata
+
+func initUnknownTypesForIPProtocol() {
+	for i := 0; i < 256; i++ {
+		errorDecodersForIPProtocol[i] = errorDecoderForIPProtocol(i)
+		IPProtocolMetadata[i] = EnumMetadata{
+			DecodeWith: &errorDecodersForIPProtocol[i],
+			Name:       "UnknownIPProtocol",
+		}
+	}
+}
+
+// Decoder calls SCTPChunkTypeMetadata.DecodeWith's decoder.
+func (a SCTPChunkType) Decode(data []byte, p gopacket.PacketBuilder) error {
+	return SCTPChunkTypeMetadata[a].DecodeWith.Decode(data, p)
+}
+
+// String returns SCTPChunkTypeMetadata.Name.
+func (a SCTPChunkType) String() string {
+	return SCTPChunkTypeMetadata[a].Name
+}
+
+// LayerType returns SCTPChunkTypeMetadata.LayerType.
+func (a SCTPChunkType) LayerType() gopacket.LayerType {
+	return SCTPChunkTypeMetadata[a].LayerType
+}
+
+type errorDecoderForSCTPChunkType int
+
+func (a *errorDecoderForSCTPChunkType) Decode(data []byte, p gopacket.PacketBuilder) error {
+	return a
+}
+func (a *errorDecoderForSCTPChunkType) Error() string {
+	return fmt.Sprintf("Unable to decode SCTPChunkType %d", int(*a))
+}
+
+var errorDecodersForSCTPChunkType [256]errorDecoderForSCTPChunkType
+var SCTPChunkTypeMetadata [256]EnumMetadata
+
+func initUnknownTypesForSCTPChunkType() {
+	for i := 0; i < 256; i++ {
+		errorDecodersForSCTPChunkType[i] = errorDecoderForSCTPChunkType(i)
+		SCTPChunkTypeMetadata[i] = EnumMetadata{
+			DecodeWith: &errorDecodersForSCTPChunkType[i],
+			Name:       "UnknownSCTPChunkType",
+		}
+	}
+}
+
+// Decoder calls PPPoECodeMetadata.DecodeWith's decoder.
+func (a PPPoECode) Decode(data []byte, p gopacket.PacketBuilder) error {
+	return PPPoECodeMetadata[a].DecodeWith.Decode(data, p)
+}
+
+// String returns PPPoECodeMetadata.Name.
+func (a PPPoECode) String() string {
+	return PPPoECodeMetadata[a].Name
+}
+
+// LayerType returns PPPoECodeMetadata.LayerType.
+func (a PPPoECode) LayerType() gopacket.LayerType {
+	return PPPoECodeMetadata[a].LayerType
+}
+
+type errorDecoderForPPPoECode int
+
+func (a *errorDecoderForPPPoECode) Decode(data []byte, p gopacket.PacketBuilder) error {
+	return a
+}
+func (a *errorDecoderForPPPoECode) Error() string {
+	return fmt.Sprintf("Unable to decode PPPoECode %d", int(*a))
+}
+
+var errorDecodersForPPPoECode [256]errorDecoderForPPPoECode
+var PPPoECodeMetadata [256]EnumMetadata
+
+func initUnknownTypesForPPPoECode() {
+	for i := 0; i < 256; i++ {
+		errorDecodersForPPPoECode[i] = errorDecoderForPPPoECode(i)
+		PPPoECodeMetadata[i] = EnumMetadata{
+			DecodeWith: &errorDecodersForPPPoECode[i],
+			Name:       "UnknownPPPoECode",
+		}
+	}
+}
+
+// Decoder calls FDDIFrameControlMetadata.DecodeWith's decoder.
+func (a FDDIFrameControl) Decode(data []byte, p gopacket.PacketBuilder) error {
+	return FDDIFrameControlMetadata[a].DecodeWith.Decode(data, p)
+}
+
+// String returns FDDIFrameControlMetadata.Name.
+func (a FDDIFrameControl) String() string {
+	return FDDIFrameControlMetadata[a].Name
+}
+
+// LayerType returns FDDIFrameControlMetadata.LayerType.
+func (a FDDIFrameControl) LayerType() gopacket.LayerType {
+	return FDDIFrameControlMetadata[a].LayerType
+}
+
+type errorDecoderForFDDIFrameControl int
+
+func (a *errorDecoderForFDDIFrameControl) Decode(data []byte, p gopacket.PacketBuilder) error {
+	return a
+}
+func (a *errorDecoderForFDDIFrameControl) Error() string {
+	return fmt.Sprintf("Unable to decode FDDIFrameControl %d", int(*a))
+}
+
+var errorDecodersForFDDIFrameControl [256]errorDecoderForFDDIFrameControl
+var FDDIFrameControlMetadata [256]EnumMetadata
+
+func initUnknownTypesForFDDIFrameControl() {
+	for i := 0; i < 256; i++ {
+		errorDecodersForFDDIFrameControl[i] = errorDecoderForFDDIFrameControl(i)
+		FDDIFrameControlMetadata[i] = EnumMetadata{
+			DecodeWith: &errorDecodersForFDDIFrameControl[i],
+			Name:       "UnknownFDDIFrameControl",
+		}
+	}
+}
+
+// Decoder calls EAPOLTypeMetadata.DecodeWith's decoder.
+func (a EAPOLType) Decode(data []byte, p gopacket.PacketBuilder) error {
+	return EAPOLTypeMetadata[a].DecodeWith.Decode(data, p)
+}
+
+// String returns EAPOLTypeMetadata.Name.
+func (a EAPOLType) String() string {
+	return EAPOLTypeMetadata[a].Name
+}
+
+// LayerType returns EAPOLTypeMetadata.LayerType.
+func (a EAPOLType) LayerType() gopacket.LayerType {
+	return EAPOLTypeMetadata[a].LayerType
+}
+
+type errorDecoderForEAPOLType int
+
+func (a *errorDecoderForEAPOLType) Decode(data []byte, p gopacket.PacketBuilder) error {
+	return a
+}
+func (a *errorDecoderForEAPOLType) Error() string {
+	return fmt.Sprintf("Unable to decode EAPOLType %d", int(*a))
+}
+
+var errorDecodersForEAPOLType [256]errorDecoderForEAPOLType
+var EAPOLTypeMetadata [256]EnumMetadata
+
+func initUnknownTypesForEAPOLType() {
+	for i := 0; i < 256; i++ {
+		errorDecodersForEAPOLType[i] = errorDecoderForEAPOLType(i)
+		EAPOLTypeMetadata[i] = EnumMetadata{
+			DecodeWith: &errorDecodersForEAPOLType[i],
+			Name:       "UnknownEAPOLType",
+		}
+	}
+}
+
+// Decoder calls ProtocolFamilyMetadata.DecodeWith's decoder.
+func (a ProtocolFamily) Decode(data []byte, p gopacket.PacketBuilder) error {
+	return ProtocolFamilyMetadata[a].DecodeWith.Decode(data, p)
+}
+
+// String returns ProtocolFamilyMetadata.Name.
+func (a ProtocolFamily) String() string {
+	return ProtocolFamilyMetadata[a].Name
+}
+
+// LayerType returns ProtocolFamilyMetadata.LayerType.
+func (a ProtocolFamily) LayerType() gopacket.LayerType {
+	return ProtocolFamilyMetadata[a].LayerType
+}
+
+type errorDecoderForProtocolFamily int
+
+func (a *errorDecoderForProtocolFamily) Decode(data []byte, p gopacket.PacketBuilder) error {
+	return a
+}
+func (a *errorDecoderForProtocolFamily) Error() string {
+	return fmt.Sprintf("Unable to decode ProtocolFamily %d", int(*a))
+}
+
+var errorDecodersForProtocolFamily [256]errorDecoderForProtocolFamily
+var ProtocolFamilyMetadata [256]EnumMetadata
+
+func initUnknownTypesForProtocolFamily() {
+	for i := 0; i < 256; i++ {
+		errorDecodersForProtocolFamily[i] = errorDecoderForProtocolFamily(i)
+		ProtocolFamilyMetadata[i] = EnumMetadata{
+			DecodeWith: &errorDecodersForProtocolFamily[i],
+			Name:       "UnknownProtocolFamily",
+		}
+	}
+}
+
+// Decoder calls Dot11TypeMetadata.DecodeWith's decoder.
+func (a Dot11Type) Decode(data []byte, p gopacket.PacketBuilder) error {
+	return Dot11TypeMetadata[a].DecodeWith.Decode(data, p)
+}
+
+// String returns Dot11TypeMetadata.Name.
+func (a Dot11Type) String() string {
+	return Dot11TypeMetadata[a].Name
+}
+
+// LayerType returns Dot11TypeMetadata.LayerType.
+func (a Dot11Type) LayerType() gopacket.LayerType {
+	return Dot11TypeMetadata[a].LayerType
+}
+
+type errorDecoderForDot11Type int
+
+func (a *errorDecoderForDot11Type) Decode(data []byte, p gopacket.PacketBuilder) error {
+	return a
+}
+func (a *errorDecoderForDot11Type) Error() string {
+	return fmt.Sprintf("Unable to decode Dot11Type %d", int(*a))
+}
+
+var errorDecodersForDot11Type [256]errorDecoderForDot11Type
+var Dot11TypeMetadata [256]EnumMetadata
+
+func initUnknownTypesForDot11Type() {
+	for i := 0; i < 256; i++ {
+		errorDecodersForDot11Type[i] = errorDecoderForDot11Type(i)
+		Dot11TypeMetadata[i] = EnumMetadata{
+			DecodeWith: &errorDecodersForDot11Type[i],
+			Name:       "UnknownDot11Type",
+		}
+	}
+}
+
+// Decoder calls USBTransportTypeMetadata.DecodeWith's decoder.
+func (a USBTransportType) Decode(data []byte, p gopacket.PacketBuilder) error {
+	return USBTransportTypeMetadata[a].DecodeWith.Decode(data, p)
+}
+
+// String returns USBTransportTypeMetadata.Name.
+func (a USBTransportType) String() string {
+	return USBTransportTypeMetadata[a].Name
+}
+
+// LayerType returns USBTransportTypeMetadata.LayerType.
+func (a USBTransportType) LayerType() gopacket.LayerType {
+	return USBTransportTypeMetadata[a].LayerType
+}
+
+type errorDecoderForUSBTransportType int
+
+func (a *errorDecoderForUSBTransportType) Decode(data []byte, p gopacket.PacketBuilder) error {
+	return a
+}
+func (a *errorDecoderForUSBTransportType) Error() string {
+	return fmt.Sprintf("Unable to decode USBTransportType %d", int(*a))
+}
+
+var errorDecodersForUSBTransportType [256]errorDecoderForUSBTransportType
+var USBTransportTypeMetadata [256]EnumMetadata
+
+func initUnknownTypesForUSBTransportType() {
+	for i := 0; i < 256; i++ {
+		errorDecodersForUSBTransportType[i] = errorDecoderForUSBTransportType(i)
+		USBTransportTypeMetadata[i] = EnumMetadata{
+			DecodeWith: &errorDecodersForUSBTransportType[i],
+			Name:       "UnknownUSBTransportType",
+		}
+	}
+}

vendor/github.com/google/gopacket/layers/erspan2.go

@@ -0,0 +1,86 @@
+// Copyright 2018 Google, Inc. All rights reserved.
+//
+// Use of this source code is governed by a BSD-style license
+// that can be found in the LICENSE file in the root of the source
+// tree.
+
+package layers
+
+import (
+	"encoding/binary"
+
+	"github.com/google/gopacket"
+)
+
+const (
+	//ERSPANIIVersionObsolete - The obsolete value for the version field
+	ERSPANIIVersionObsolete = 0x0
+	// ERSPANIIVersion - The current value for the version field
+	ERSPANIIVersion = 0x1
+)
+
+// ERSPANII contains all of the fields found in an ERSPAN Type II header
+// https://tools.ietf.org/html/draft-foschiano-erspan-03
+type ERSPANII struct {
+	BaseLayer
+	IsTruncated                         bool
+	Version, CoS, TrunkEncap            uint8
+	VLANIdentifier, SessionID, Reserved uint16
+	Index                               uint32
+}
+
+func (erspan2 *ERSPANII) LayerType() gopacket.LayerType { return LayerTypeERSPANII }
+
+// DecodeFromBytes decodes the given bytes into this layer.
+func (erspan2 *ERSPANII) DecodeFromBytes(data []byte, df gopacket.DecodeFeedback) error {
+	erspan2Length := 8
+	erspan2.Version = data[0] & 0xF0 >> 4
+	erspan2.VLANIdentifier = binary.BigEndian.Uint16(data[:2]) & 0x0FFF
+	erspan2.CoS = data[2] & 0xE0 >> 5
+	erspan2.TrunkEncap = data[2] & 0x18 >> 3
+	erspan2.IsTruncated = data[2]&0x4>>2 != 0
+	erspan2.SessionID = binary.BigEndian.Uint16(data[2:4]) & 0x03FF
+	erspan2.Reserved = binary.BigEndian.Uint16(data[4:6]) & 0xFFF0 >> 4
+	erspan2.Index = binary.BigEndian.Uint32(data[4:8]) & 0x000FFFFF
+	erspan2.Contents = data[:erspan2Length]
+	erspan2.Payload = data[erspan2Length:]
+	return nil
+}
+
+// SerializeTo writes the serialized form of this layer into the
+// SerializationBuffer, implementing gopacket.SerializableLayer.
+// See the docs for gopacket.SerializableLayer for more info.
+func (erspan2 *ERSPANII) SerializeTo(b gopacket.SerializeBuffer, opts gopacket.SerializeOptions) error {
+	bytes, err := b.PrependBytes(8)
+	if err != nil {
+		return err
+	}
+
+	twoByteInt := uint16(erspan2.Version&0xF)<<12 | erspan2.VLANIdentifier&0x0FFF
+	binary.BigEndian.PutUint16(bytes, twoByteInt)
+
+	twoByteInt = uint16(erspan2.CoS&0x7)<<13 | uint16(erspan2.TrunkEncap&0x3)<<11 | erspan2.SessionID&0x03FF
+	if erspan2.IsTruncated {
+		twoByteInt |= 0x400
+	}
+	binary.BigEndian.PutUint16(bytes[2:], twoByteInt)
+
+	fourByteInt := uint32(erspan2.Reserved&0x0FFF)<<20 | erspan2.Index&0x000FFFFF
+	binary.BigEndian.PutUint32(bytes[4:], fourByteInt)
+	return nil
+}
+
+// CanDecode returns the set of layer types that this DecodingLayer can decode.
+func (erspan2 *ERSPANII) CanDecode() gopacket.LayerClass {
+	return LayerTypeERSPANII
+}
+
+// NextLayerType returns the layer type contained by this DecodingLayer.
+func (erspan2 *ERSPANII) NextLayerType() gopacket.LayerType {
+	return LayerTypeEthernet
+}
+
+func decodeERSPANII(data []byte, p gopacket.PacketBuilder) error {
+	erspan2 := &ERSPANII{}
+	return decodingLayerDecoder(erspan2, data, p)
+}

vendor/github.com/google/gopacket/layers/etherip.go

@@ -0,0 +1,45 @@
+// Copyright 2012 Google, Inc. All rights reserved.
+//
+// Use of this source code is governed by a BSD-style license
+// that can be found in the LICENSE file in the root of the source
+// tree.
+
+package layers
+
+import (
+	"encoding/binary"
+	"github.com/google/gopacket"
+)
+
+// EtherIP is the struct for storing RFC 3378 EtherIP packet headers.
+type EtherIP struct {
+	BaseLayer
+	Version  uint8
+	Reserved uint16
+}
+
+// LayerType returns gopacket.LayerTypeEtherIP.
+func (e *EtherIP) LayerType() gopacket.LayerType { return LayerTypeEtherIP }
+
+// DecodeFromBytes decodes the given bytes into this layer.
+func (e *EtherIP) DecodeFromBytes(data []byte, df gopacket.DecodeFeedback) error {
+	e.Version = data[0] >> 4
+	e.Reserved = binary.BigEndian.Uint16(data[:2]) & 0x0fff
+	e.BaseLayer = BaseLayer{data[:2], data[2:]}
+	return nil
+}
+
+// CanDecode returns the set of layer types that this DecodingLayer can decode.
+func (e *EtherIP) CanDecode() gopacket.LayerClass {
+	return LayerTypeEtherIP
+}
+
+// NextLayerType returns the layer type contained by this DecodingLayer.
+func (e *EtherIP) NextLayerType() gopacket.LayerType {
+	return LayerTypeEthernet
+}
+
+func decodeEtherIP(data []byte, p gopacket.PacketBuilder) error {
+	e := &EtherIP{}
+	return decodingLayerDecoder(e, data, p)
+}

vendor/github.com/google/gopacket/layers/ethernet.go

@@ -0,0 +1,123 @@
+// Copyright 2012 Google, Inc. All rights reserved.
+// Copyright 2009-2011 Andreas Krennmair. All rights reserved.
+//
+// Use of this source code is governed by a BSD-style license
+// that can be found in the LICENSE file in the root of the source
+// tree.
+
+package layers
+
+import (
+	"encoding/binary"
+	"errors"
+	"fmt"
+	"github.com/google/gopacket"
+	"net"
+)
+
+// EthernetBroadcast is the broadcast MAC address used by Ethernet.
+var EthernetBroadcast = net.HardwareAddr{0xff, 0xff, 0xff, 0xff, 0xff, 0xff}
+
+// Ethernet is the layer for Ethernet frame headers.
+type Ethernet struct {
+	BaseLayer
+	SrcMAC, DstMAC net.HardwareAddr
+	EthernetType   EthernetType
+	// Length is only set if a length field exists within this header.  Ethernet
+	// headers follow two different standards, one that uses an EthernetType, the
+	// other which defines a length the follows with a LLC header (802.3).  If the
+	// former is the case, we set EthernetType and Length stays 0.  In the latter
+	// case, we set Length and EthernetType = EthernetTypeLLC.
+	Length uint16
+}
+
+// LayerType returns LayerTypeEthernet
+func (e *Ethernet) LayerType() gopacket.LayerType { return LayerTypeEthernet }
+
+func (e *Ethernet) LinkFlow() gopacket.Flow {
+	return gopacket.NewFlow(EndpointMAC, e.SrcMAC, e.DstMAC)
+}
+
+func (eth *Ethernet) DecodeFromBytes(data []byte, df gopacket.DecodeFeedback) error {
+	if len(data) < 14 {
+		return errors.New("Ethernet packet too small")
+	}
+	eth.DstMAC = net.HardwareAddr(data[0:6])
+	eth.SrcMAC = net.HardwareAddr(data[6:12])
+	eth.EthernetType = EthernetType(binary.BigEndian.Uint16(data[12:14]))
+	eth.BaseLayer = BaseLayer{data[:14], data[14:]}
+	eth.Length = 0
+	if eth.EthernetType < 0x0600 {
+		eth.Length = uint16(eth.EthernetType)
+		eth.EthernetType = EthernetTypeLLC
+		if cmp := len(eth.Payload) - int(eth.Length); cmp < 0 {
+			df.SetTruncated()
+		} else if cmp > 0 {
+			// Strip off bytes at the end, since we have too many bytes
+			eth.Payload = eth.Payload[:len(eth.Payload)-cmp]
+		}
+		//	fmt.Println(eth)
+	}
+	return nil
+}
+
+// SerializeTo writes the serialized form of this layer into the
+// SerializationBuffer, implementing gopacket.SerializableLayer.
+// See the docs for gopacket.SerializableLayer for more info.
+func (eth *Ethernet) SerializeTo(b gopacket.SerializeBuffer, opts gopacket.SerializeOptions) error {
+	if len(eth.DstMAC) != 6 {
+		return fmt.Errorf("invalid dst MAC: %v", eth.DstMAC)
+	}
+	if len(eth.SrcMAC) != 6 {
+		return fmt.Errorf("invalid src MAC: %v", eth.SrcMAC)
+	}
+	payload := b.Bytes()
+	bytes, err := b.PrependBytes(14)
+	if err != nil {
+		return err
+	}
+	copy(bytes, eth.DstMAC)
+	copy(bytes[6:], eth.SrcMAC)
+	if eth.Length != 0 || eth.EthernetType == EthernetTypeLLC {
+		if opts.FixLengths {
+			eth.Length = uint16(len(payload))
+		}
+		if eth.EthernetType != EthernetTypeLLC {
+			return fmt.Errorf("ethernet type %v not compatible with length value %v", eth.EthernetType, eth.Length)
+		} else if eth.Length > 0x0600 {
+			return fmt.Errorf("invalid ethernet length %v", eth.Length)
+		}
+		binary.BigEndian.PutUint16(bytes[12:], eth.Length)
+	} else {
+		binary.BigEndian.PutUint16(bytes[12:], uint16(eth.EthernetType))
+	}
+	length := len(b.Bytes())
+	if length < 60 {
+		// Pad out to 60 bytes.
+		padding, err := b.AppendBytes(60 - length)
+		if err != nil {
+			return err
+		}
+		copy(padding, lotsOfZeros[:])
+	}
+	return nil
+}
+
+func (eth *Ethernet) CanDecode() gopacket.LayerClass {
+	return LayerTypeEthernet
+}
+
+func (eth *Ethernet) NextLayerType() gopacket.LayerType {
+	return eth.EthernetType.LayerType()
+}
+
+func decodeEthernet(data []byte, p gopacket.PacketBuilder) error {
+	eth := &Ethernet{}
+	err := eth.DecodeFromBytes(data, p)
+	if err != nil {
+		return err
+	}
+	p.AddLayer(eth)
+	p.SetLinkLayer(eth)
+	return p.NextDecoder(eth.EthernetType)
+}

vendor/github.com/google/gopacket/layers/fddi.go

@@ -0,0 +1,41 @@
+// Copyright 2012 Google, Inc. All rights reserved.
+//
+// Use of this source code is governed by a BSD-style license
+// that can be found in the LICENSE file in the root of the source
+// tree.
+
+package layers
+
+import (
+	"github.com/google/gopacket"
+	"net"
+)
+
+// FDDI contains the header for FDDI frames.
+type FDDI struct {
+	BaseLayer
+	FrameControl   FDDIFrameControl
+	Priority       uint8
+	SrcMAC, DstMAC net.HardwareAddr
+}
+
+// LayerType returns LayerTypeFDDI.
+func (f *FDDI) LayerType() gopacket.LayerType { return LayerTypeFDDI }
+
+// LinkFlow returns a new flow of type EndpointMAC.
+func (f *FDDI) LinkFlow() gopacket.Flow {
+	return gopacket.NewFlow(EndpointMAC, f.SrcMAC, f.DstMAC)
+}
+
+func decodeFDDI(data []byte, p gopacket.PacketBuilder) error {
+	f := &FDDI{
+		FrameControl: FDDIFrameControl(data[0] & 0xF8),
+		Priority:     data[0] & 0x07,
+		SrcMAC:       net.HardwareAddr(data[1:7]),
+		DstMAC:       net.HardwareAddr(data[7:13]),
+		BaseLayer:    BaseLayer{data[:13], data[13:]},
+	}
+	p.SetLinkLayer(f)
+	p.AddLayer(f)
+	return p.NextDecoder(f.FrameControl)
+}

vendor/github.com/google/gopacket/layers/fuzz_layer.go

@@ -0,0 +1,39 @@
+// Copyright 2019 The GoPacket Authors. All rights reserved.
+//
+// Use of this source code is governed by a BSD-style license that can be found
+// in the LICENSE file in the root of the source tree.
+
+package layers
+
+import (
+	"encoding/binary"
+
+	"github.com/google/gopacket"
+)
+
+// FuzzLayer is a fuzz target for the layers package of gopacket
+// A fuzz target is a function processing a binary blob (byte slice)
+// The process here is to interpret this data as a packet, and print the layers contents.
+// The decoding options and the starting layer are encoded in the first bytes.
+// The function returns 1 if this is a valid packet (no error layer)
+func FuzzLayer(data []byte) int {
+	if len(data) < 3 {
+		return 0
+	}
+	// use the first two bytes to choose the top level layer
+	startLayer := binary.BigEndian.Uint16(data[:2])
+	var fuzzOpts = gopacket.DecodeOptions{
+		Lazy:                     data[2]&0x1 != 0,
+		NoCopy:                   data[2]&0x2 != 0,
+		SkipDecodeRecovery:       data[2]&0x4 != 0,
+		DecodeStreamsAsDatagrams: data[2]&0x8 != 0,
+	}
+	p := gopacket.NewPacket(data[3:], gopacket.LayerType(startLayer), fuzzOpts)
+	for _, l := range p.Layers() {
+		gopacket.LayerString(l)
+	}
+	if p.ErrorLayer() != nil {
+		return 0
+	}
+	return 1
+}

vendor/github.com/google/gopacket/layers/gen_linted.sh

@@ -0,0 +1,3 @@
+#!/bin/bash
+
+for i in *.go; do golint $i | grep -q . || echo $i; done > .linted

vendor/github.com/google/gopacket/layers/geneve.go

@@ -0,0 +1,121 @@
+// Copyright 2016 Google, Inc. All rights reserved.
+//
+// Use of this source code is governed by a BSD-style license
+// that can be found in the LICENSE file in the root of the source
+// tree.
+
+package layers
+
+import (
+	"encoding/binary"
+	"errors"
+
+	"github.com/google/gopacket"
+)
+
+// Geneve is specifed here https://tools.ietf.org/html/draft-ietf-nvo3-geneve-03
+// Geneve Header:
+// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+// |Ver|  Opt Len  |O|C|    Rsvd.  |          Protocol Type        |
+// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+// |        Virtual Network Identifier (VNI)       |    Reserved   |
+// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+// |                    Variable Length Options                    |
+// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+type Geneve struct {
+	BaseLayer
+	Version        uint8        // 2 bits
+	OptionsLength  uint8        // 6 bits
+	OAMPacket      bool         // 1 bits
+	CriticalOption bool         // 1 bits
+	Protocol       EthernetType // 16 bits
+	VNI            uint32       // 24bits
+	Options        []*GeneveOption
+}
+
+// Geneve Tunnel Options
+// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+// |          Option Class         |      Type     |R|R|R| Length  |
+// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+// |                      Variable Option Data                     |
+// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+type GeneveOption struct {
+	Class  uint16 // 16 bits
+	Type   uint8  // 8 bits
+	Flags  uint8  // 3 bits
+	Length uint8  // 5 bits
+	Data   []byte
+}
+
+// LayerType returns LayerTypeGeneve
+func (gn *Geneve) LayerType() gopacket.LayerType { return LayerTypeGeneve }
+
+func decodeGeneveOption(data []byte, gn *Geneve, df gopacket.DecodeFeedback) (*GeneveOption, uint8, error) {
+	if len(data) < 3 {
+		df.SetTruncated()
+		return nil, 0, errors.New("geneve option too small")
+	}
+	opt := &GeneveOption{}
+
+	opt.Class = binary.BigEndian.Uint16(data[0:2])
+	opt.Type = data[2]
+	opt.Flags = data[3] >> 4
+	opt.Length = (data[3]&0xf)*4 + 4
+
+	if len(data) < int(opt.Length) {
+		df.SetTruncated()
+		return nil, 0, errors.New("geneve option too small")
+	}
+	opt.Data = make([]byte, opt.Length-4)
+	copy(opt.Data, data[4:opt.Length])
+
+	return opt, opt.Length, nil
+}
+
+func (gn *Geneve) DecodeFromBytes(data []byte, df gopacket.DecodeFeedback) error {
+	if len(data) < 7 {
+		df.SetTruncated()
+		return errors.New("geneve packet too short")
+	}
+
+	gn.Version = data[0] >> 7
+	gn.OptionsLength = (data[0] & 0x3f) * 4
+
+	gn.OAMPacket = data[1]&0x80 > 0
+	gn.CriticalOption = data[1]&0x40 > 0
+	gn.Protocol = EthernetType(binary.BigEndian.Uint16(data[2:4]))
+
+	var buf [4]byte
+	copy(buf[1:], data[4:7])
+	gn.VNI = binary.BigEndian.Uint32(buf[:])
+
+	offset, length := uint8(8), int32(gn.OptionsLength)
+	if len(data) < int(length+7) {
+		df.SetTruncated()
+		return errors.New("geneve packet too short")
+	}
+
+	for length > 0 {
+		opt, len, err := decodeGeneveOption(data[offset:], gn, df)
+		if err != nil {
+			return err
+		}
+		gn.Options = append(gn.Options, opt)
+
+		length -= int32(len)
+		offset += len
+	}
+
+	gn.BaseLayer = BaseLayer{data[:offset], data[offset:]}
+
+	return nil
+}
+
+func (gn *Geneve) NextLayerType() gopacket.LayerType {
+	return gn.Protocol.LayerType()
+}
+
+func decodeGeneve(data []byte, p gopacket.PacketBuilder) error {
+	gn := &Geneve{}
+	return decodingLayerDecoder(gn, data, p)
+}

vendor/github.com/google/gopacket/layers/gre.go

@@ -0,0 +1,200 @@
+// Copyright 2012 Google, Inc. All rights reserved.
+//
+// Use of this source code is governed by a BSD-style license
+// that can be found in the LICENSE file in the root of the source
+// tree.
+
+package layers
+
+import (
+	"encoding/binary"
+
+	"github.com/google/gopacket"
+)
+
+// GRE is a Generic Routing Encapsulation header.
+type GRE struct {
+	BaseLayer
+	ChecksumPresent, RoutingPresent, KeyPresent, SeqPresent, StrictSourceRoute, AckPresent bool
+	RecursionControl, Flags, Version                                                       uint8
+	Protocol                                                                               EthernetType
+	Checksum, Offset                                                                       uint16
+	Key, Seq, Ack                                                                          uint32
+	*GRERouting
+}
+
+// GRERouting is GRE routing information, present if the RoutingPresent flag is
+// set.
+type GRERouting struct {
+	AddressFamily        uint16
+	SREOffset, SRELength uint8
+	RoutingInformation   []byte
+	Next                 *GRERouting
+}
+
+// LayerType returns gopacket.LayerTypeGRE.
+func (g *GRE) LayerType() gopacket.LayerType { return LayerTypeGRE }
+
+// DecodeFromBytes decodes the given bytes into this layer.
+func (g *GRE) DecodeFromBytes(data []byte, df gopacket.DecodeFeedback) error {
+	g.ChecksumPresent = data[0]&0x80 != 0
+	g.RoutingPresent = data[0]&0x40 != 0
+	g.KeyPresent = data[0]&0x20 != 0
+	g.SeqPresent = data[0]&0x10 != 0
+	g.StrictSourceRoute = data[0]&0x08 != 0
+	g.AckPresent = data[1]&0x80 != 0
+	g.RecursionControl = data[0] & 0x7
+	g.Flags = data[1] >> 3
+	g.Version = data[1] & 0x7
+	g.Protocol = EthernetType(binary.BigEndian.Uint16(data[2:4]))
+	offset := 4
+	if g.ChecksumPresent || g.RoutingPresent {
+		g.Checksum = binary.BigEndian.Uint16(data[offset : offset+2])
+		g.Offset = binary.BigEndian.Uint16(data[offset+2 : offset+4])
+		offset += 4
+	}
+	if g.KeyPresent {
+		g.Key = binary.BigEndian.Uint32(data[offset : offset+4])
+		offset += 4
+	}
+	if g.SeqPresent {
+		g.Seq = binary.BigEndian.Uint32(data[offset : offset+4])
+		offset += 4
+	}
+	if g.RoutingPresent {
+		tail := &g.GRERouting
+		for {
+			sre := &GRERouting{
+				AddressFamily: binary.BigEndian.Uint16(data[offset : offset+2]),
+				SREOffset:     data[offset+2],
+				SRELength:     data[offset+3],
+			}
+			sre.RoutingInformation = data[offset+4 : offset+4+int(sre.SRELength)]
+			offset += 4 + int(sre.SRELength)
+			if sre.AddressFamily == 0 && sre.SRELength == 0 {
+				break
+			}
+			(*tail) = sre
+			tail = &sre.Next
+		}
+	}
+	if g.AckPresent {
+		g.Ack = binary.BigEndian.Uint32(data[offset : offset+4])
+		offset += 4
+	}
+	g.BaseLayer = BaseLayer{data[:offset], data[offset:]}
+	return nil
+}
+
+// SerializeTo writes the serialized form of this layer into the SerializationBuffer,
+// implementing gopacket.SerializableLayer. See the docs for gopacket.SerializableLayer for more info.
+func (g *GRE) SerializeTo(b gopacket.SerializeBuffer, opts gopacket.SerializeOptions) error {
+	size := 4
+	if g.ChecksumPresent || g.RoutingPresent {
+		size += 4
+	}
+	if g.KeyPresent {
+		size += 4
+	}
+	if g.SeqPresent {
+		size += 4
+	}
+	if g.RoutingPresent {
+		r := g.GRERouting
+		for r != nil {
+			size += 4 + int(r.SRELength)
+			r = r.Next
+		}
+		size += 4
+	}
+	if g.AckPresent {
+		size += 4
+	}
+	buf, err := b.PrependBytes(size)
+	if err != nil {
+		return err
+	}
+	// Reset any potentially dirty memory in the first 2 bytes, as these use OR to set flags.
+	buf[0] = 0
+	buf[1] = 0
+	if g.ChecksumPresent {
+		buf[0] |= 0x80
+	}
+	if g.RoutingPresent {
+		buf[0] |= 0x40
+	}
+	if g.KeyPresent {
+		buf[0] |= 0x20
+	}
+	if g.SeqPresent {
+		buf[0] |= 0x10
+	}
+	if g.StrictSourceRoute {
+		buf[0] |= 0x08
+	}
+	if g.AckPresent {
+		buf[1] |= 0x80
+	}
+	buf[0] |= g.RecursionControl
+	buf[1] |= g.Flags << 3
+	buf[1] |= g.Version
+	binary.BigEndian.PutUint16(buf[2:4], uint16(g.Protocol))
+	offset := 4
+	if g.ChecksumPresent || g.RoutingPresent {
+		// Don't write the checksum value yet, as we may need to compute it,
+		// which requires the entire header be complete.
+		// Instead we zeroize the memory in case it is dirty.
+		buf[offset] = 0
+		buf[offset+1] = 0
+		binary.BigEndian.PutUint16(buf[offset+2:offset+4], g.Offset)
+		offset += 4
+	}
+	if g.KeyPresent {
+		binary.BigEndian.PutUint32(buf[offset:offset+4], g.Key)
+		offset += 4
+	}
+	if g.SeqPresent {
+		binary.BigEndian.PutUint32(buf[offset:offset+4], g.Seq)
+		offset += 4
+	}
+	if g.RoutingPresent {
+		sre := g.GRERouting
+		for sre != nil {
+			binary.BigEndian.PutUint16(buf[offset:offset+2], sre.AddressFamily)
+			buf[offset+2] = sre.SREOffset
+			buf[offset+3] = sre.SRELength
+			copy(buf[offset+4:offset+4+int(sre.SRELength)], sre.RoutingInformation)
+			offset += 4 + int(sre.SRELength)
+			sre = sre.Next
+		}
+		// Terminate routing field with a "NULL" SRE.
+		binary.BigEndian.PutUint32(buf[offset:offset+4], 0)
+	}
+	if g.AckPresent {
+		binary.BigEndian.PutUint32(buf[offset:offset+4], g.Ack)
+		offset += 4
+	}
+	if g.ChecksumPresent {
+		if opts.ComputeChecksums {
+			g.Checksum = tcpipChecksum(b.Bytes(), 0)
+		}
+
+		binary.BigEndian.PutUint16(buf[4:6], g.Checksum)
+	}
+	return nil
+}
+
+// CanDecode returns the set of layer types that this DecodingLayer can decode.
+func (g *GRE) CanDecode() gopacket.LayerClass {
+	return LayerTypeGRE
+}
+
+// NextLayerType returns the layer type contained by this DecodingLayer.
+func (g *GRE) NextLayerType() gopacket.LayerType {
+	return g.Protocol.LayerType()
+}
+
+func decodeGRE(data []byte, p gopacket.PacketBuilder) error {
+	g := &GRE{}
+	return decodingLayerDecoder(g, data, p)
+}

vendor/github.com/google/gopacket/layers/gtp.go

@@ -0,0 +1,184 @@
+// Copyright 2017 Google, Inc. All rights reserved.
+//
+// Use of this source code is governed by a BSD-style license
+// that can be found in the LICENSE file in the root of the source
+// tree.
+//
+
+package layers
+
+import (
+	"encoding/binary"
+	"fmt"
+	"github.com/google/gopacket"
+)
+
+const gtpMinimumSizeInBytes int = 8
+
+// GTPExtensionHeader is used to carry extra data and enable future extensions of the GTP  without the need to use another version number.
+type GTPExtensionHeader struct {
+	Type    uint8
+	Content []byte
+}
+
+// GTPv1U protocol is used to exchange user data over GTP tunnels across the Sx interfaces.
+// Defined in https://portal.3gpp.org/desktopmodules/Specifications/SpecificationDetails.aspx?specificationId=1595
+type GTPv1U struct {
+	BaseLayer
+	Version             uint8
+	ProtocolType        uint8
+	Reserved            uint8
+	ExtensionHeaderFlag bool
+	SequenceNumberFlag  bool
+	NPDUFlag            bool
+	MessageType         uint8
+	MessageLength       uint16
+	TEID                uint32
+	SequenceNumber      uint16
+	NPDU                uint8
+	GTPExtensionHeaders []GTPExtensionHeader
+}
+
+// LayerType returns LayerTypeGTPV1U
+func (g *GTPv1U) LayerType() gopacket.LayerType { return LayerTypeGTPv1U }
+
+// DecodeFromBytes analyses a byte slice and attempts to decode it as a GTPv1U packet
+func (g *GTPv1U) DecodeFromBytes(data []byte, df gopacket.DecodeFeedback) error {
+	hLen := gtpMinimumSizeInBytes
+	dLen := len(data)
+	if dLen < hLen {
+		return fmt.Errorf("GTP packet too small: %d bytes", dLen)
+	}
+	g.Version = (data[0] >> 5) & 0x07
+	g.ProtocolType = (data[0] >> 4) & 0x01
+	g.Reserved = (data[0] >> 3) & 0x01
+	g.SequenceNumberFlag = ((data[0] >> 1) & 0x01) == 1
+	g.NPDUFlag = (data[0] & 0x01) == 1
+	g.ExtensionHeaderFlag = ((data[0] >> 2) & 0x01) == 1
+	g.MessageType = data[1]
+	g.MessageLength = binary.BigEndian.Uint16(data[2:4])
+	pLen := 8 + g.MessageLength
+	if uint16(dLen) < pLen {
+		return fmt.Errorf("GTP packet too small: %d bytes", dLen)
+	}
+	//  Field used to multiplex different connections in the same GTP tunnel.
+	g.TEID = binary.BigEndian.Uint32(data[4:8])
+	cIndex := uint16(hLen)
+	if g.SequenceNumberFlag || g.NPDUFlag || g.ExtensionHeaderFlag {
+		hLen += 4
+		cIndex += 4
+		if dLen < hLen {
+			return fmt.Errorf("GTP packet too small: %d bytes", dLen)
+		}
+		if g.SequenceNumberFlag {
+			g.SequenceNumber = binary.BigEndian.Uint16(data[8:10])
+		}
+		if g.NPDUFlag {
+			g.NPDU = data[10]
+		}
+		if g.ExtensionHeaderFlag {
+			extensionFlag := true
+			for extensionFlag {
+				extensionType := uint8(data[cIndex-1])
+				extensionLength := uint(data[cIndex])
+				if extensionLength == 0 {
+					return fmt.Errorf("GTP packet with invalid extension header")
+				}
+				// extensionLength is in 4-octet units
+				lIndex := cIndex + (uint16(extensionLength) * 4)
+				if uint16(dLen) < lIndex {
+					fmt.Println(dLen, lIndex)
+					return fmt.Errorf("GTP packet with small extension header: %d bytes", dLen)
+				}
+				content := data[cIndex+1 : lIndex-1]
+				eh := GTPExtensionHeader{Type: extensionType, Content: content}
+				g.GTPExtensionHeaders = append(g.GTPExtensionHeaders, eh)
+				cIndex = lIndex
+				// Check if coming bytes are from an extension header
+				extensionFlag = data[cIndex-1] != 0
+
+			}
+		}
+	}
+	g.BaseLayer = BaseLayer{Contents: data[:cIndex], Payload: data[cIndex:]}
+	return nil
+
+}
+
+// SerializeTo writes the serialized form of this layer into the
+// SerializationBuffer, implementing gopacket.SerializableLayer.
+// See the docs for gopacket.SerializableLayer for more info.
+func (g *GTPv1U) SerializeTo(b gopacket.SerializeBuffer, opts gopacket.SerializeOptions) error {
+	data, err := b.PrependBytes(gtpMinimumSizeInBytes)
+	if err != nil {
+		return err
+	}
+	data[0] |= (g.Version << 5)
+	data[0] |= (1 << 4)
+	if len(g.GTPExtensionHeaders) > 0 {
+		data[0] |= 0x04
+		g.ExtensionHeaderFlag = true
+	}
+	if g.SequenceNumberFlag {
+		data[0] |= 0x02
+	}
+	if g.NPDUFlag {
+		data[0] |= 0x01
+	}
+	data[1] = g.MessageType
+	binary.BigEndian.PutUint16(data[2:4], g.MessageLength)
+	binary.BigEndian.PutUint32(data[4:8], g.TEID)
+	if g.ExtensionHeaderFlag || g.SequenceNumberFlag || g.NPDUFlag {
+		data, err := b.AppendBytes(4)
+		if err != nil {
+			return err
+		}
+		binary.BigEndian.PutUint16(data[:2], g.SequenceNumber)
+		data[2] = g.NPDU
+		for _, eh := range g.GTPExtensionHeaders {
+			data[len(data)-1] = eh.Type
+			lContent := len(eh.Content)
+			// extensionLength is in 4-octet units
+			extensionLength := (lContent + 2) / 4
+			// Get two extra byte for the next extension header type and length
+			data, err = b.AppendBytes(lContent + 2)
+			if err != nil {
+				return err
+			}
+			data[0] = byte(extensionLength)
+			copy(data[1:lContent+1], eh.Content)
+		}
+	}
+	return nil
+
+}
+
+// CanDecode returns a set of layers that GTP objects can decode.
+func (g *GTPv1U) CanDecode() gopacket.LayerClass {
+	return LayerTypeGTPv1U
+}
+
+// NextLayerType specifies the next layer that GoPacket should attempt to
+func (g *GTPv1U) NextLayerType() gopacket.LayerType {
+	if len(g.LayerPayload()) == 0 {
+		return gopacket.LayerTypeZero
+	}
+	version := uint8(g.LayerPayload()[0]) >> 4
+	if version == 4 {
+		return LayerTypeIPv4
+	} else if version == 6 {
+		return LayerTypeIPv6
+	} else {
+		return LayerTypePPP
+	}
+}
+
+func decodeGTPv1u(data []byte, p gopacket.PacketBuilder) error {
+	gtp := &GTPv1U{}
+	err := gtp.DecodeFromBytes(data, p)
+	if err != nil {
+		return err
+	}
+	p.AddLayer(gtp)
+	return p.NextDecoder(gtp.NextLayerType())
+}

vendor/github.com/google/gopacket/layers/icmp4.go

@@ -0,0 +1,267 @@
+// Copyright 2012 Google, Inc. All rights reserved.
+// Copyright 2009-2011 Andreas Krennmair. All rights reserved.
+//
+// Use of this source code is governed by a BSD-style license
+// that can be found in the LICENSE file in the root of the source
+// tree.
+
+package layers
+
+import (
+	"encoding/binary"
+	"errors"
+	"fmt"
+	"reflect"
+
+	"github.com/google/gopacket"
+)
+
+const (
+	ICMPv4TypeEchoReply              = 0
+	ICMPv4TypeDestinationUnreachable = 3
+	ICMPv4TypeSourceQuench           = 4
+	ICMPv4TypeRedirect               = 5
+	ICMPv4TypeEchoRequest            = 8
+	ICMPv4TypeRouterAdvertisement    = 9
+	ICMPv4TypeRouterSolicitation     = 10
+	ICMPv4TypeTimeExceeded           = 11
+	ICMPv4TypeParameterProblem       = 12
+	ICMPv4TypeTimestampRequest       = 13
+	ICMPv4TypeTimestampReply         = 14
+	ICMPv4TypeInfoRequest            = 15
+	ICMPv4TypeInfoReply              = 16
+	ICMPv4TypeAddressMaskRequest     = 17
+	ICMPv4TypeAddressMaskReply       = 18
+)
+
+const (
+	// DestinationUnreachable
+	ICMPv4CodeNet                 = 0
+	ICMPv4CodeHost                = 1
+	ICMPv4CodeProtocol            = 2
+	ICMPv4CodePort                = 3
+	ICMPv4CodeFragmentationNeeded = 4
+	ICMPv4CodeSourceRoutingFailed = 5
+	ICMPv4CodeNetUnknown          = 6
+	ICMPv4CodeHostUnknown         = 7
+	ICMPv4CodeSourceIsolated      = 8
+	ICMPv4CodeNetAdminProhibited  = 9
+	ICMPv4CodeHostAdminProhibited = 10
+	ICMPv4CodeNetTOS              = 11
+	ICMPv4CodeHostTOS             = 12
+	ICMPv4CodeCommAdminProhibited = 13
+	ICMPv4CodeHostPrecedence      = 14
+	ICMPv4CodePrecedenceCutoff    = 15
+
+	// TimeExceeded
+	ICMPv4CodeTTLExceeded                    = 0
+	ICMPv4CodeFragmentReassemblyTimeExceeded = 1
+
+	// ParameterProblem
+	ICMPv4CodePointerIndicatesError = 0
+	ICMPv4CodeMissingOption         = 1
+	ICMPv4CodeBadLength             = 2
+
+	// Redirect
+	// ICMPv4CodeNet  = same as for DestinationUnreachable
+	// ICMPv4CodeHost = same as for DestinationUnreachable
+	ICMPv4CodeTOSNet  = 2
+	ICMPv4CodeTOSHost = 3
+)
+
+type icmpv4TypeCodeInfoStruct struct {
+	typeStr string
+	codeStr *map[uint8]string
+}
+
+var (
+	icmpv4TypeCodeInfo = map[uint8]icmpv4TypeCodeInfoStruct{
+		ICMPv4TypeDestinationUnreachable: icmpv4TypeCodeInfoStruct{
+			"DestinationUnreachable", &map[uint8]string{
+				ICMPv4CodeNet:                 "Net",
+				ICMPv4CodeHost:                "Host",
+				ICMPv4CodeProtocol:            "Protocol",
+				ICMPv4CodePort:                "Port",
+				ICMPv4CodeFragmentationNeeded: "FragmentationNeeded",
+				ICMPv4CodeSourceRoutingFailed: "SourceRoutingFailed",
+				ICMPv4CodeNetUnknown:          "NetUnknown",
+				ICMPv4CodeHostUnknown:         "HostUnknown",
+				ICMPv4CodeSourceIsolated:      "SourceIsolated",
+				ICMPv4CodeNetAdminProhibited:  "NetAdminProhibited",
+				ICMPv4CodeHostAdminProhibited: "HostAdminProhibited",
+				ICMPv4CodeNetTOS:              "NetTOS",
+				ICMPv4CodeHostTOS:             "HostTOS",
+				ICMPv4CodeCommAdminProhibited: "CommAdminProhibited",
+				ICMPv4CodeHostPrecedence:      "HostPrecedence",
+				ICMPv4CodePrecedenceCutoff:    "PrecedenceCutoff",
+			},
+		},
+		ICMPv4TypeTimeExceeded: icmpv4TypeCodeInfoStruct{
+			"TimeExceeded", &map[uint8]string{
+				ICMPv4CodeTTLExceeded:                    "TTLExceeded",
+				ICMPv4CodeFragmentReassemblyTimeExceeded: "FragmentReassemblyTimeExceeded",
+			},
+		},
+		ICMPv4TypeParameterProblem: icmpv4TypeCodeInfoStruct{
+			"ParameterProblem", &map[uint8]string{
+				ICMPv4CodePointerIndicatesError: "PointerIndicatesError",
+				ICMPv4CodeMissingOption:         "MissingOption",
+				ICMPv4CodeBadLength:             "BadLength",
+			},
+		},
+		ICMPv4TypeSourceQuench: icmpv4TypeCodeInfoStruct{
+			"SourceQuench", nil,
+		},
+		ICMPv4TypeRedirect: icmpv4TypeCodeInfoStruct{
+			"Redirect", &map[uint8]string{
+				ICMPv4CodeNet:     "Net",
+				ICMPv4CodeHost:    "Host",
+				ICMPv4CodeTOSNet:  "TOS+Net",
+				ICMPv4CodeTOSHost: "TOS+Host",
+			},
+		},
+		ICMPv4TypeEchoRequest: icmpv4TypeCodeInfoStruct{
+			"EchoRequest", nil,
+		},
+		ICMPv4TypeEchoReply: icmpv4TypeCodeInfoStruct{
+			"EchoReply", nil,
+		},
+		ICMPv4TypeTimestampRequest: icmpv4TypeCodeInfoStruct{
+			"TimestampRequest", nil,
+		},
+		ICMPv4TypeTimestampReply: icmpv4TypeCodeInfoStruct{
+			"TimestampReply", nil,
+		},
+		ICMPv4TypeInfoRequest: icmpv4TypeCodeInfoStruct{
+			"InfoRequest", nil,
+		},
+		ICMPv4TypeInfoReply: icmpv4TypeCodeInfoStruct{
+			"InfoReply", nil,
+		},
+		ICMPv4TypeRouterSolicitation: icmpv4TypeCodeInfoStruct{
+			"RouterSolicitation", nil,
+		},
+		ICMPv4TypeRouterAdvertisement: icmpv4TypeCodeInfoStruct{
+			"RouterAdvertisement", nil,
+		},
+		ICMPv4TypeAddressMaskRequest: icmpv4TypeCodeInfoStruct{
+			"AddressMaskRequest", nil,
+		},
+		ICMPv4TypeAddressMaskReply: icmpv4TypeCodeInfoStruct{
+			"AddressMaskReply", nil,
+		},
+	}
+)
+
+type ICMPv4TypeCode uint16
+
+// Type returns the ICMPv4 type field.
+func (a ICMPv4TypeCode) Type() uint8 {
+	return uint8(a >> 8)
+}
+
+// Code returns the ICMPv4 code field.
+func (a ICMPv4TypeCode) Code() uint8 {
+	return uint8(a)
+}
+
+func (a ICMPv4TypeCode) String() string {
+	t, c := a.Type(), a.Code()
+	strInfo, ok := icmpv4TypeCodeInfo[t]
+	if !ok {
+		// Unknown ICMPv4 type field
+		return fmt.Sprintf("%d(%d)", t, c)
+	}
+	typeStr := strInfo.typeStr
+	if strInfo.codeStr == nil && c == 0 {
+		// The ICMPv4 type does not make use of the code field
+		return fmt.Sprintf("%s", strInfo.typeStr)
+	}
+	if strInfo.codeStr == nil && c != 0 {
+		// The ICMPv4 type does not make use of the code field, but it is present anyway
+		return fmt.Sprintf("%s(Code: %d)", typeStr, c)
+	}
+	codeStr, ok := (*strInfo.codeStr)[c]
+	if !ok {
+		// We don't know this ICMPv4 code; print the numerical value
+		return fmt.Sprintf("%s(Code: %d)", typeStr, c)
+	}
+	return fmt.Sprintf("%s(%s)", typeStr, codeStr)
+}
+
+func (a ICMPv4TypeCode) GoString() string {
+	t := reflect.TypeOf(a)
+	return fmt.Sprintf("%s(%d, %d)", t.String(), a.Type(), a.Code())
+}
+
+// SerializeTo writes the ICMPv4TypeCode value to the 'bytes' buffer.
+func (a ICMPv4TypeCode) SerializeTo(bytes []byte) {
+	binary.BigEndian.PutUint16(bytes, uint16(a))
+}
+
+// CreateICMPv4TypeCode is a convenience function to create an ICMPv4TypeCode
+// gopacket type from the ICMPv4 type and code values.
+func CreateICMPv4TypeCode(typ uint8, code uint8) ICMPv4TypeCode {
+	return ICMPv4TypeCode(binary.BigEndian.Uint16([]byte{typ, code}))
+}
+
+// ICMPv4 is the layer for IPv4 ICMP packet data.
+type ICMPv4 struct {
+	BaseLayer
+	TypeCode ICMPv4TypeCode
+	Checksum uint16
+	Id       uint16
+	Seq      uint16
+}
+
+// LayerType returns LayerTypeICMPv4.
+func (i *ICMPv4) LayerType() gopacket.LayerType { return LayerTypeICMPv4 }
+
+// DecodeFromBytes decodes the given bytes into this layer.
+func (i *ICMPv4) DecodeFromBytes(data []byte, df gopacket.DecodeFeedback) error {
+	if len(data) < 8 {
+		df.SetTruncated()
+		return errors.New("ICMP layer less then 8 bytes for ICMPv4 packet")
+	}
+	i.TypeCode = CreateICMPv4TypeCode(data[0], data[1])
+	i.Checksum = binary.BigEndian.Uint16(data[2:4])
+	i.Id = binary.BigEndian.Uint16(data[4:6])
+	i.Seq = binary.BigEndian.Uint16(data[6:8])
+	i.BaseLayer = BaseLayer{data[:8], data[8:]}
+	return nil
+}
+
+// SerializeTo writes the serialized form of this layer into the
+// SerializationBuffer, implementing gopacket.SerializableLayer.
+// See the docs for gopacket.SerializableLayer for more info.
+func (i *ICMPv4) SerializeTo(b gopacket.SerializeBuffer, opts gopacket.SerializeOptions) error {
+	bytes, err := b.PrependBytes(8)
+	if err != nil {
+		return err
+	}
+	i.TypeCode.SerializeTo(bytes)
+	binary.BigEndian.PutUint16(bytes[4:], i.Id)
+	binary.BigEndian.PutUint16(bytes[6:], i.Seq)
+	if opts.ComputeChecksums {
+		bytes[2] = 0
+		bytes[3] = 0
+		i.Checksum = tcpipChecksum(b.Bytes(), 0)
+	}
+	binary.BigEndian.PutUint16(bytes[2:], i.Checksum)
+	return nil
+}
+
+// CanDecode returns the set of layer types that this DecodingLayer can decode.
+func (i *ICMPv4) CanDecode() gopacket.LayerClass {
+	return LayerTypeICMPv4
+}
+
+// NextLayerType returns the layer type contained by this DecodingLayer.
+func (i *ICMPv4) NextLayerType() gopacket.LayerType {
+	return gopacket.LayerTypePayload
+}
+
+func decodeICMPv4(data []byte, p gopacket.PacketBuilder) error {
+	i := &ICMPv4{}
+	return decodingLayerDecoder(i, data, p)
+}

vendor/github.com/google/gopacket/layers/icmp6.go

@@ -0,0 +1,266 @@
+// Copyright 2012 Google, Inc. All rights reserved.
+// Copyright 2009-2011 Andreas Krennmair. All rights reserved.
+//
+// Use of this source code is governed by a BSD-style license
+// that can be found in the LICENSE file in the root of the source
+// tree.
+
+package layers
+
+import (
+	"encoding/binary"
+	"errors"
+	"fmt"
+	"reflect"
+
+	"github.com/google/gopacket"
+)
+
+const (
+	// The following are from RFC 4443
+	ICMPv6TypeDestinationUnreachable = 1
+	ICMPv6TypePacketTooBig           = 2
+	ICMPv6TypeTimeExceeded           = 3
+	ICMPv6TypeParameterProblem       = 4
+	ICMPv6TypeEchoRequest            = 128
+	ICMPv6TypeEchoReply              = 129
+
+	// The following are from RFC 4861
+	ICMPv6TypeRouterSolicitation    = 133
+	ICMPv6TypeRouterAdvertisement   = 134
+	ICMPv6TypeNeighborSolicitation  = 135
+	ICMPv6TypeNeighborAdvertisement = 136
+	ICMPv6TypeRedirect              = 137
+
+	// The following are from RFC 2710
+	ICMPv6TypeMLDv1MulticastListenerQueryMessage  = 130
+	ICMPv6TypeMLDv1MulticastListenerReportMessage = 131
+	ICMPv6TypeMLDv1MulticastListenerDoneMessage   = 132
+
+	// The following are from RFC 3810
+	ICMPv6TypeMLDv2MulticastListenerReportMessageV2 = 143
+)
+
+const (
+	// DestinationUnreachable
+	ICMPv6CodeNoRouteToDst           = 0
+	ICMPv6CodeAdminProhibited        = 1
+	ICMPv6CodeBeyondScopeOfSrc       = 2
+	ICMPv6CodeAddressUnreachable     = 3
+	ICMPv6CodePortUnreachable        = 4
+	ICMPv6CodeSrcAddressFailedPolicy = 5
+	ICMPv6CodeRejectRouteToDst       = 6
+
+	// TimeExceeded
+	ICMPv6CodeHopLimitExceeded               = 0
+	ICMPv6CodeFragmentReassemblyTimeExceeded = 1
+
+	// ParameterProblem
+	ICMPv6CodeErroneousHeaderField   = 0
+	ICMPv6CodeUnrecognizedNextHeader = 1
+	ICMPv6CodeUnrecognizedIPv6Option = 2
+)
+
+type icmpv6TypeCodeInfoStruct struct {
+	typeStr string
+	codeStr *map[uint8]string
+}
+
+var (
+	icmpv6TypeCodeInfo = map[uint8]icmpv6TypeCodeInfoStruct{
+		ICMPv6TypeDestinationUnreachable: icmpv6TypeCodeInfoStruct{
+			"DestinationUnreachable", &map[uint8]string{
+				ICMPv6CodeNoRouteToDst:           "NoRouteToDst",
+				ICMPv6CodeAdminProhibited:        "AdminProhibited",
+				ICMPv6CodeBeyondScopeOfSrc:       "BeyondScopeOfSrc",
+				ICMPv6CodeAddressUnreachable:     "AddressUnreachable",
+				ICMPv6CodePortUnreachable:        "PortUnreachable",
+				ICMPv6CodeSrcAddressFailedPolicy: "SrcAddressFailedPolicy",
+				ICMPv6CodeRejectRouteToDst:       "RejectRouteToDst",
+			},
+		},
+		ICMPv6TypePacketTooBig: icmpv6TypeCodeInfoStruct{
+			"PacketTooBig", nil,
+		},
+		ICMPv6TypeTimeExceeded: icmpv6TypeCodeInfoStruct{
+			"TimeExceeded", &map[uint8]string{
+				ICMPv6CodeHopLimitExceeded:               "HopLimitExceeded",
+				ICMPv6CodeFragmentReassemblyTimeExceeded: "FragmentReassemblyTimeExceeded",
+			},
+		},
+		ICMPv6TypeParameterProblem: icmpv6TypeCodeInfoStruct{
+			"ParameterProblem", &map[uint8]string{
+				ICMPv6CodeErroneousHeaderField:   "ErroneousHeaderField",
+				ICMPv6CodeUnrecognizedNextHeader: "UnrecognizedNextHeader",
+				ICMPv6CodeUnrecognizedIPv6Option: "UnrecognizedIPv6Option",
+			},
+		},
+		ICMPv6TypeEchoRequest: icmpv6TypeCodeInfoStruct{
+			"EchoRequest", nil,
+		},
+		ICMPv6TypeEchoReply: icmpv6TypeCodeInfoStruct{
+			"EchoReply", nil,
+		},
+		ICMPv6TypeRouterSolicitation: icmpv6TypeCodeInfoStruct{
+			"RouterSolicitation", nil,
+		},
+		ICMPv6TypeRouterAdvertisement: icmpv6TypeCodeInfoStruct{
+			"RouterAdvertisement", nil,
+		},
+		ICMPv6TypeNeighborSolicitation: icmpv6TypeCodeInfoStruct{
+			"NeighborSolicitation", nil,
+		},
+		ICMPv6TypeNeighborAdvertisement: icmpv6TypeCodeInfoStruct{
+			"NeighborAdvertisement", nil,
+		},
+		ICMPv6TypeRedirect: icmpv6TypeCodeInfoStruct{
+			"Redirect", nil,
+		},
+	}
+)
+
+type ICMPv6TypeCode uint16
+
+// Type returns the ICMPv6 type field.
+func (a ICMPv6TypeCode) Type() uint8 {
+	return uint8(a >> 8)
+}
+
+// Code returns the ICMPv6 code field.
+func (a ICMPv6TypeCode) Code() uint8 {
+	return uint8(a)
+}
+
+func (a ICMPv6TypeCode) String() string {
+	t, c := a.Type(), a.Code()
+	strInfo, ok := icmpv6TypeCodeInfo[t]
+	if !ok {
+		// Unknown ICMPv6 type field
+		return fmt.Sprintf("%d(%d)", t, c)
+	}
+	typeStr := strInfo.typeStr
+	if strInfo.codeStr == nil && c == 0 {
+		// The ICMPv6 type does not make use of the code field
+		return fmt.Sprintf("%s", strInfo.typeStr)
+	}
+	if strInfo.codeStr == nil && c != 0 {
+		// The ICMPv6 type does not make use of the code field, but it is present anyway
+		return fmt.Sprintf("%s(Code: %d)", typeStr, c)
+	}
+	codeStr, ok := (*strInfo.codeStr)[c]
+	if !ok {
+		// We don't know this ICMPv6 code; print the numerical value
+		return fmt.Sprintf("%s(Code: %d)", typeStr, c)
+	}
+	return fmt.Sprintf("%s(%s)", typeStr, codeStr)
+}
+
+func (a ICMPv6TypeCode) GoString() string {
+	t := reflect.TypeOf(a)
+	return fmt.Sprintf("%s(%d, %d)", t.String(), a.Type(), a.Code())
+}
+
+// SerializeTo writes the ICMPv6TypeCode value to the 'bytes' buffer.
+func (a ICMPv6TypeCode) SerializeTo(bytes []byte) {
+	binary.BigEndian.PutUint16(bytes, uint16(a))
+}
+
+// CreateICMPv6TypeCode is a convenience function to create an ICMPv6TypeCode
+// gopacket type from the ICMPv6 type and code values.
+func CreateICMPv6TypeCode(typ uint8, code uint8) ICMPv6TypeCode {
+	return ICMPv6TypeCode(binary.BigEndian.Uint16([]byte{typ, code}))
+}
+
+// ICMPv6 is the layer for IPv6 ICMP packet data
+type ICMPv6 struct {
+	BaseLayer
+	TypeCode ICMPv6TypeCode
+	Checksum uint16
+	// TypeBytes is deprecated and always nil. See the different ICMPv6 message types
+	// instead (e.g. ICMPv6TypeRouterSolicitation).
+	TypeBytes []byte
+	tcpipchecksum
+}
+
+// LayerType returns LayerTypeICMPv6.
+func (i *ICMPv6) LayerType() gopacket.LayerType { return LayerTypeICMPv6 }
+
+// DecodeFromBytes decodes the given bytes into this layer.
+func (i *ICMPv6) DecodeFromBytes(data []byte, df gopacket.DecodeFeedback) error {
+	if len(data) < 4 {
+		df.SetTruncated()
+		return errors.New("ICMP layer less then 4 bytes for ICMPv6 packet")
+	}
+	i.TypeCode = CreateICMPv6TypeCode(data[0], data[1])
+	i.Checksum = binary.BigEndian.Uint16(data[2:4])
+	i.BaseLayer = BaseLayer{data[:4], data[4:]}
+	return nil
+}
+
+// SerializeTo writes the serialized form of this layer into the
+// SerializationBuffer, implementing gopacket.SerializableLayer.
+// See the docs for gopacket.SerializableLayer for more info.
+func (i *ICMPv6) SerializeTo(b gopacket.SerializeBuffer, opts gopacket.SerializeOptions) error {
+	bytes, err := b.PrependBytes(4)
+	if err != nil {
+		return err
+	}
+	i.TypeCode.SerializeTo(bytes)
+
+	if opts.ComputeChecksums {
+		bytes[2] = 0
+		bytes[3] = 0
+		csum, err := i.computeChecksum(b.Bytes(), IPProtocolICMPv6)
+		if err != nil {
+			return err
+		}
+		i.Checksum = csum
+	}
+	binary.BigEndian.PutUint16(bytes[2:], i.Checksum)
+
+	return nil
+}
+
+// CanDecode returns the set of layer types that this DecodingLayer can decode.
+func (i *ICMPv6) CanDecode() gopacket.LayerClass {
+	return LayerTypeICMPv6
+}
+
+// NextLayerType returns the layer type contained by this DecodingLayer.
+func (i *ICMPv6) NextLayerType() gopacket.LayerType {
+	switch i.TypeCode.Type() {
+	case ICMPv6TypeEchoRequest:
+		return LayerTypeICMPv6Echo
+	case ICMPv6TypeEchoReply:
+		return LayerTypeICMPv6Echo
+	case ICMPv6TypeRouterSolicitation:
+		return LayerTypeICMPv6RouterSolicitation
+	case ICMPv6TypeRouterAdvertisement:
+		return LayerTypeICMPv6RouterAdvertisement
+	case ICMPv6TypeNeighborSolicitation:
+		return LayerTypeICMPv6NeighborSolicitation
+	case ICMPv6TypeNeighborAdvertisement:
+		return LayerTypeICMPv6NeighborAdvertisement
+	case ICMPv6TypeRedirect:
+		return LayerTypeICMPv6Redirect
+	case ICMPv6TypeMLDv1MulticastListenerQueryMessage: // Same Code for MLDv1 Query and MLDv2 Query
+		if len(i.Payload) > 20 { // Only payload size differs
+			return LayerTypeMLDv2MulticastListenerQuery
+		} else {
+			return LayerTypeMLDv1MulticastListenerQuery
+		}
+	case ICMPv6TypeMLDv1MulticastListenerDoneMessage:
+		return LayerTypeMLDv1MulticastListenerDone
+	case ICMPv6TypeMLDv1MulticastListenerReportMessage:
+		return LayerTypeMLDv1MulticastListenerReport
+	case ICMPv6TypeMLDv2MulticastListenerReportMessageV2:
+		return LayerTypeMLDv2MulticastListenerReport
+	}
+
+	return gopacket.LayerTypePayload
+}
+
+func decodeICMPv6(data []byte, p gopacket.PacketBuilder) error {
+	i := &ICMPv6{}
+	return decodingLayerDecoder(i, data, p)
+}

vendor/github.com/google/gopacket/layers/icmp6msg.go

@@ -0,0 +1,578 @@
+// Copyright 2012 Google, Inc. All rights reserved.
+// Copyright 2009-2011 Andreas Krennmair. All rights reserved.
+//
+// Use of this source code is governed by a BSD-style license
+// that can be found in the LICENSE file in the root of the source
+// tree.
+
+package layers
+
+import (
+	"encoding/binary"
+	"encoding/hex"
+	"errors"
+	"fmt"
+	"net"
+	"time"
+
+	"github.com/google/gopacket"
+)
+
+// Based on RFC 4861
+
+// ICMPv6Opt indicate how to decode the data associated with each ICMPv6Option.
+type ICMPv6Opt uint8
+
+const (
+	_ ICMPv6Opt = iota
+
+	// ICMPv6OptSourceAddress contains the link-layer address of the sender of
+	// the packet. It is used in the Neighbor Solicitation, Router
+	// Solicitation, and Router Advertisement packets. Must be ignored for other
+	// Neighbor discovery messages.
+	ICMPv6OptSourceAddress
+
+	// ICMPv6OptTargetAddress contains the link-layer address of the target. It
+	// is used in Neighbor Advertisement and Redirect packets. Must be ignored
+	// for other Neighbor discovery messages.
+	ICMPv6OptTargetAddress
+
+	// ICMPv6OptPrefixInfo provides hosts with on-link prefixes and prefixes
+	// for Address Autoconfiguration. The Prefix Information option appears in
+	// Router Advertisement packets and MUST be silently ignored for other
+	// messages.
+	ICMPv6OptPrefixInfo
+
+	// ICMPv6OptRedirectedHeader is used in Redirect messages and contains all
+	// or part of the packet that is being redirected.
+	ICMPv6OptRedirectedHeader
+
+	// ICMPv6OptMTU is used in Router Advertisement messages to ensure that all
+	// nodes on a link use the same MTU value in those cases where the link MTU
+	// is not well known. This option MUST be silently ignored for other
+	// Neighbor Discovery messages.
+	ICMPv6OptMTU
+)
+
+// ICMPv6Echo represents the structure of a ping.
+type ICMPv6Echo struct {
+	BaseLayer
+	Identifier uint16
+	SeqNumber  uint16
+}
+
+// ICMPv6RouterSolicitation is sent by hosts to find routers.
+type ICMPv6RouterSolicitation struct {
+	BaseLayer
+	Options ICMPv6Options
+}
+
+// ICMPv6RouterAdvertisement is sent by routers in response to Solicitation.
+type ICMPv6RouterAdvertisement struct {
+	BaseLayer
+	HopLimit       uint8
+	Flags          uint8
+	RouterLifetime uint16
+	ReachableTime  uint32
+	RetransTimer   uint32
+	Options        ICMPv6Options
+}
+
+// ICMPv6NeighborSolicitation is sent to request the link-layer address of a
+// target node.
+type ICMPv6NeighborSolicitation struct {
+	BaseLayer
+	TargetAddress net.IP
+	Options       ICMPv6Options
+}
+
+// ICMPv6NeighborAdvertisement is sent by nodes in response to Solicitation.
+type ICMPv6NeighborAdvertisement struct {
+	BaseLayer
+	Flags         uint8
+	TargetAddress net.IP
+	Options       ICMPv6Options
+}
+
+// ICMPv6Redirect is sent by routers to inform hosts of a better first-hop node
+// on the path to a destination.
+type ICMPv6Redirect struct {
+	BaseLayer
+	TargetAddress      net.IP
+	DestinationAddress net.IP
+	Options            ICMPv6Options
+}
+
+// ICMPv6Option contains the type and data for a single option.
+type ICMPv6Option struct {
+	Type ICMPv6Opt
+	Data []byte
+}
+
+// ICMPv6Options is a slice of ICMPv6Option.
+type ICMPv6Options []ICMPv6Option
+
+func (i ICMPv6Opt) String() string {
+	switch i {
+	case ICMPv6OptSourceAddress:
+		return "SourceAddress"
+	case ICMPv6OptTargetAddress:
+		return "TargetAddress"
+	case ICMPv6OptPrefixInfo:
+		return "PrefixInfo"
+	case ICMPv6OptRedirectedHeader:
+		return "RedirectedHeader"
+	case ICMPv6OptMTU:
+		return "MTU"
+	default:
+		return fmt.Sprintf("Unknown(%d)", i)
+	}
+}
+
+// CanDecode returns the set of layer types that this DecodingLayer can decode.
+func (i *ICMPv6Echo) CanDecode() gopacket.LayerClass {
+	return LayerTypeICMPv6Echo
+}
+
+// LayerType returns LayerTypeICMPv6Echo.
+func (i *ICMPv6Echo) LayerType() gopacket.LayerType {
+	return LayerTypeICMPv6Echo
+}
+
+// NextLayerType returns the layer type contained by this DecodingLayer.
+func (i *ICMPv6Echo) NextLayerType() gopacket.LayerType {
+	return gopacket.LayerTypePayload
+}
+
+// DecodeFromBytes decodes the given bytes into this layer.
+func (i *ICMPv6Echo) DecodeFromBytes(data []byte, df gopacket.DecodeFeedback) error {
+	if len(data) < 4 {
+		df.SetTruncated()
+		return errors.New("ICMP layer less then 4 bytes for ICMPv6 Echo")
+	}
+	i.Identifier = binary.BigEndian.Uint16(data[0:2])
+	i.SeqNumber = binary.BigEndian.Uint16(data[2:4])
+
+	return nil
+}
+
+// SerializeTo writes the serialized form of this layer into the
+// SerializationBuffer, implementing gopacket.SerializableLayer.
+// See the docs for gopacket.SerializableLayer for more info.
+func (i *ICMPv6Echo) SerializeTo(b gopacket.SerializeBuffer, opts gopacket.SerializeOptions) error {
+	buf, err := b.PrependBytes(4)
+	if err != nil {
+		return err
+	}
+
+	binary.BigEndian.PutUint16(buf, i.Identifier)
+	binary.BigEndian.PutUint16(buf[2:], i.SeqNumber)
+	return nil
+}
+
+// LayerType returns LayerTypeICMPv6.
+func (i *ICMPv6RouterSolicitation) LayerType() gopacket.LayerType {
+	return LayerTypeICMPv6RouterSolicitation
+}
+
+// NextLayerType returns the layer type contained by this DecodingLayer.
+func (i *ICMPv6RouterSolicitation) NextLayerType() gopacket.LayerType {
+	return gopacket.LayerTypePayload
+}
+
+// DecodeFromBytes decodes the given bytes into this layer.
+func (i *ICMPv6RouterSolicitation) DecodeFromBytes(data []byte, df gopacket.DecodeFeedback) error {
+	// first 4 bytes are reserved followed by options
+	if len(data) < 4 {
+		df.SetTruncated()
+		return errors.New("ICMP layer less then 4 bytes for ICMPv6 router solicitation")
+	}
+
+	// truncate old options
+	i.Options = i.Options[:0]
+
+	return i.Options.DecodeFromBytes(data[4:], df)
+}
+
+// SerializeTo writes the serialized form of this layer into the
+// SerializationBuffer, implementing gopacket.SerializableLayer.
+// See the docs for gopacket.SerializableLayer for more info.
+func (i *ICMPv6RouterSolicitation) SerializeTo(b gopacket.SerializeBuffer, opts gopacket.SerializeOptions) error {
+	if err := i.Options.SerializeTo(b, opts); err != nil {
+		return err
+	}
+
+	buf, err := b.PrependBytes(4)
+	if err != nil {
+		return err
+	}
+
+	copy(buf, lotsOfZeros[:4])
+	return nil
+}
+
+// CanDecode returns the set of layer types that this DecodingLayer can decode.
+func (i *ICMPv6RouterSolicitation) CanDecode() gopacket.LayerClass {
+	return LayerTypeICMPv6RouterSolicitation
+}
+
+// LayerType returns LayerTypeICMPv6RouterAdvertisement.
+func (i *ICMPv6RouterAdvertisement) LayerType() gopacket.LayerType {
+	return LayerTypeICMPv6RouterAdvertisement
+}
+
+// NextLayerType returns the layer type contained by this DecodingLayer.
+func (i *ICMPv6RouterAdvertisement) NextLayerType() gopacket.LayerType {
+	return gopacket.LayerTypePayload
+}
+
+// DecodeFromBytes decodes the given bytes into this layer.
+func (i *ICMPv6RouterAdvertisement) DecodeFromBytes(data []byte, df gopacket.DecodeFeedback) error {
+	if len(data) < 12 {
+		df.SetTruncated()
+		return errors.New("ICMP layer less then 12 bytes for ICMPv6 router advertisement")
+	}
+
+	i.HopLimit = uint8(data[0])
+	// M, O bit followed by 6 reserved bits
+	i.Flags = uint8(data[1])
+	i.RouterLifetime = binary.BigEndian.Uint16(data[2:4])
+	i.ReachableTime = binary.BigEndian.Uint32(data[4:8])
+	i.RetransTimer = binary.BigEndian.Uint32(data[8:12])
+	i.BaseLayer = BaseLayer{data, nil} // assume no payload
+
+	// truncate old options
+	i.Options = i.Options[:0]
+
+	return i.Options.DecodeFromBytes(data[12:], df)
+}
+
+// SerializeTo writes the serialized form of this layer into the
+// SerializationBuffer, implementing gopacket.SerializableLayer.
+// See the docs for gopacket.SerializableLayer for more info.
+func (i *ICMPv6RouterAdvertisement) SerializeTo(b gopacket.SerializeBuffer, opts gopacket.SerializeOptions) error {
+	if err := i.Options.SerializeTo(b, opts); err != nil {
+		return err
+	}
+
+	buf, err := b.PrependBytes(12)
+	if err != nil {
+		return err
+	}
+
+	buf[0] = byte(i.HopLimit)
+	buf[1] = byte(i.Flags)
+	binary.BigEndian.PutUint16(buf[2:], i.RouterLifetime)
+	binary.BigEndian.PutUint32(buf[4:], i.ReachableTime)
+	binary.BigEndian.PutUint32(buf[8:], i.RetransTimer)
+	return nil
+}
+
+// CanDecode returns the set of layer types that this DecodingLayer can decode.
+func (i *ICMPv6RouterAdvertisement) CanDecode() gopacket.LayerClass {
+	return LayerTypeICMPv6RouterAdvertisement
+}
+
+// ManagedAddressConfig is true when addresses are available via DHCPv6. If
+// set, the OtherConfig flag is redundant.
+func (i *ICMPv6RouterAdvertisement) ManagedAddressConfig() bool {
+	return i.Flags&0x80 != 0
+}
+
+// OtherConfig is true when there is other configuration information available
+// via DHCPv6. For example, DNS-related information.
+func (i *ICMPv6RouterAdvertisement) OtherConfig() bool {
+	return i.Flags&0x40 != 0
+}
+
+// LayerType returns LayerTypeICMPv6NeighborSolicitation.
+func (i *ICMPv6NeighborSolicitation) LayerType() gopacket.LayerType {
+	return LayerTypeICMPv6NeighborSolicitation
+}
+
+// NextLayerType returns the layer type contained by this DecodingLayer.
+func (i *ICMPv6NeighborSolicitation) NextLayerType() gopacket.LayerType {
+	return gopacket.LayerTypePayload
+}
+
+// DecodeFromBytes decodes the given bytes into this layer.
+func (i *ICMPv6NeighborSolicitation) DecodeFromBytes(data []byte, df gopacket.DecodeFeedback) error {
+	if len(data) < 20 {
+		df.SetTruncated()
+		return errors.New("ICMP layer less then 20 bytes for ICMPv6 neighbor solicitation")
+	}
+
+	i.TargetAddress = net.IP(data[4:20])
+	i.BaseLayer = BaseLayer{data, nil} // assume no payload
+
+	// truncate old options
+	i.Options = i.Options[:0]
+
+	return i.Options.DecodeFromBytes(data[20:], df)
+}
+
+// SerializeTo writes the serialized form of this layer into the
+// SerializationBuffer, implementing gopacket.SerializableLayer.
+// See the docs for gopacket.SerializableLayer for more info.
+func (i *ICMPv6NeighborSolicitation) SerializeTo(b gopacket.SerializeBuffer, opts gopacket.SerializeOptions) error {
+	if err := i.Options.SerializeTo(b, opts); err != nil {
+		return err
+	}
+
+	buf, err := b.PrependBytes(20)
+	if err != nil {
+		return err
+	}
+
+	copy(buf, lotsOfZeros[:4])
+	copy(buf[4:], i.TargetAddress)
+	return nil
+}
+
+// CanDecode returns the set of layer types that this DecodingLayer can decode.
+func (i *ICMPv6NeighborSolicitation) CanDecode() gopacket.LayerClass {
+	return LayerTypeICMPv6NeighborSolicitation
+}
+
+// LayerType returns LayerTypeICMPv6NeighborAdvertisement.
+func (i *ICMPv6NeighborAdvertisement) LayerType() gopacket.LayerType {
+	return LayerTypeICMPv6NeighborAdvertisement
+}
+
+// NextLayerType returns the layer type contained by this DecodingLayer.
+func (i *ICMPv6NeighborAdvertisement) NextLayerType() gopacket.LayerType {
+	return gopacket.LayerTypePayload
+}
+
+// DecodeFromBytes decodes the given bytes into this layer.
+func (i *ICMPv6NeighborAdvertisement) DecodeFromBytes(data []byte, df gopacket.DecodeFeedback) error {
+	if len(data) < 20 {
+		df.SetTruncated()
+		return errors.New("ICMP layer less then 20 bytes for ICMPv6 neighbor advertisement")
+	}
+
+	i.Flags = uint8(data[0])
+	i.TargetAddress = net.IP(data[4:20])
+	i.BaseLayer = BaseLayer{data, nil} // assume no payload
+
+	// truncate old options
+	i.Options = i.Options[:0]
+
+	return i.Options.DecodeFromBytes(data[20:], df)
+}
+
+// SerializeTo writes the serialized form of this layer into the
+// SerializationBuffer, implementing gopacket.SerializableLayer.
+// See the docs for gopacket.SerializableLayer for more info.
+func (i *ICMPv6NeighborAdvertisement) SerializeTo(b gopacket.SerializeBuffer, opts gopacket.SerializeOptions) error {
+	if err := i.Options.SerializeTo(b, opts); err != nil {
+		return err
+	}
+
+	buf, err := b.PrependBytes(20)
+	if err != nil {
+		return err
+	}
+
+	buf[0] = byte(i.Flags)
+	copy(buf[1:], lotsOfZeros[:3])
+	copy(buf[4:], i.TargetAddress)
+	return nil
+}
+
+// CanDecode returns the set of layer types that this DecodingLayer can decode.
+func (i *ICMPv6NeighborAdvertisement) CanDecode() gopacket.LayerClass {
+	return LayerTypeICMPv6NeighborAdvertisement
+}
+
+// Router indicates whether the sender is a router or not.
+func (i *ICMPv6NeighborAdvertisement) Router() bool {
+	return i.Flags&0x80 != 0
+}
+
+// Solicited indicates whether the advertisement was solicited or not.
+func (i *ICMPv6NeighborAdvertisement) Solicited() bool {
+	return i.Flags&0x40 != 0
+}
+
+// Override indicates whether the advertisement should Override an existing
+// cache entry.
+func (i *ICMPv6NeighborAdvertisement) Override() bool {
+	return i.Flags&0x20 != 0
+}
+
+// LayerType returns LayerTypeICMPv6Redirect.
+func (i *ICMPv6Redirect) LayerType() gopacket.LayerType {
+	return LayerTypeICMPv6Redirect
+}
+
+// NextLayerType returns the layer type contained by this DecodingLayer.
+func (i *ICMPv6Redirect) NextLayerType() gopacket.LayerType {
+	return gopacket.LayerTypePayload
+}
+
+// DecodeFromBytes decodes the given bytes into this layer.
+func (i *ICMPv6Redirect) DecodeFromBytes(data []byte, df gopacket.DecodeFeedback) error {
+	if len(data) < 36 {
+		df.SetTruncated()
+		return errors.New("ICMP layer less then 36 bytes for ICMPv6 redirect")
+	}
+
+	i.TargetAddress = net.IP(data[4:20])
+	i.DestinationAddress = net.IP(data[20:36])
+	i.BaseLayer = BaseLayer{data, nil} // assume no payload
+
+	// truncate old options
+	i.Options = i.Options[:0]
+
+	return i.Options.DecodeFromBytes(data[36:], df)
+}
+
+// SerializeTo writes the serialized form of this layer into the
+// SerializationBuffer, implementing gopacket.SerializableLayer.
+// See the docs for gopacket.SerializableLayer for more info.
+func (i *ICMPv6Redirect) SerializeTo(b gopacket.SerializeBuffer, opts gopacket.SerializeOptions) error {
+	if err := i.Options.SerializeTo(b, opts); err != nil {
+		return err
+	}
+
+	buf, err := b.PrependBytes(36)
+	if err != nil {
+		return err
+	}
+
+	copy(buf, lotsOfZeros[:4])
+	copy(buf[4:], i.TargetAddress)
+	copy(buf[20:], i.DestinationAddress)
+	return nil
+}
+
+// CanDecode returns the set of layer types that this DecodingLayer can decode.
+func (i *ICMPv6Redirect) CanDecode() gopacket.LayerClass {
+	return LayerTypeICMPv6Redirect
+}
+
+func (i ICMPv6Option) String() string {
+	hd := hex.EncodeToString(i.Data)
+	if len(hd) > 0 {
+		hd = " 0x" + hd
+	}
+
+	switch i.Type {
+	case ICMPv6OptSourceAddress, ICMPv6OptTargetAddress:
+		return fmt.Sprintf("ICMPv6Option(%s:%v)",
+			i.Type,
+			net.HardwareAddr(i.Data))
+	case ICMPv6OptPrefixInfo:
+		if len(i.Data) == 30 {
+			prefixLen := uint8(i.Data[0])
+			onLink := (i.Data[1]&0x80 != 0)
+			autonomous := (i.Data[1]&0x40 != 0)
+			validLifetime := time.Duration(binary.BigEndian.Uint32(i.Data[2:6])) * time.Second
+			preferredLifetime := time.Duration(binary.BigEndian.Uint32(i.Data[6:10])) * time.Second
+
+			prefix := net.IP(i.Data[14:])
+
+			return fmt.Sprintf("ICMPv6Option(%s:%v/%v:%t:%t:%v:%v)",
+				i.Type,
+				prefix, prefixLen,
+				onLink, autonomous,
+				validLifetime, preferredLifetime)
+		}
+	case ICMPv6OptRedirectedHeader:
+		// could invoke IP decoder on data... probably best not to
+		break
+	case ICMPv6OptMTU:
+		if len(i.Data) == 6 {
+			return fmt.Sprintf("ICMPv6Option(%s:%v)",
+				i.Type,
+				binary.BigEndian.Uint32(i.Data[2:]))
+		}
+
+	}
+	return fmt.Sprintf("ICMPv6Option(%s:%s)", i.Type, hd)
+}
+
+// DecodeFromBytes decodes the given bytes into this layer.
+func (i *ICMPv6Options) DecodeFromBytes(data []byte, df gopacket.DecodeFeedback) error {
+	for len(data) > 0 {
+		if len(data) < 2 {
+			df.SetTruncated()
+			return errors.New("ICMP layer less then 2 bytes for ICMPv6 message option")
+		}
+
+		// unit is 8 octets, convert to bytes
+		length := int(data[1]) * 8
+
+		if length == 0 {
+			df.SetTruncated()
+			return errors.New("ICMPv6 message option with length 0")
+		}
+
+		if len(data) < length {
+			df.SetTruncated()
+			return fmt.Errorf("ICMP layer only %v bytes for ICMPv6 message option with length %v", len(data), length)
+		}
+
+		o := ICMPv6Option{
+			Type: ICMPv6Opt(data[0]),
+			Data: data[2:length],
+		}
+
+		// chop off option we just consumed
+		data = data[length:]
+
+		*i = append(*i, o)
+	}
+
+	return nil
+}
+
+// SerializeTo writes the serialized form of this layer into the
+// SerializationBuffer, implementing gopacket.SerializableLayer.
+// See the docs for gopacket.SerializableLayer for more info.
+func (i *ICMPv6Options) SerializeTo(b gopacket.SerializeBuffer, opts gopacket.SerializeOptions) error {
+	for _, opt := range []ICMPv6Option(*i) {
+		length := len(opt.Data) + 2
+		buf, err := b.PrependBytes(length)
+		if err != nil {
+			return err
+		}
+
+		buf[0] = byte(opt.Type)
+		buf[1] = byte(length / 8)
+		copy(buf[2:], opt.Data)
+	}
+
+	return nil
+}
+
+func decodeICMPv6Echo(data []byte, p gopacket.PacketBuilder) error {
+	i := &ICMPv6Echo{}
+	return decodingLayerDecoder(i, data, p)
+}
+
+func decodeICMPv6RouterSolicitation(data []byte, p gopacket.PacketBuilder) error {
+	i := &ICMPv6RouterSolicitation{}
+	return decodingLayerDecoder(i, data, p)
+}
+
+func decodeICMPv6RouterAdvertisement(data []byte, p gopacket.PacketBuilder) error {
+	i := &ICMPv6RouterAdvertisement{}
+	return decodingLayerDecoder(i, data, p)
+}
+
+func decodeICMPv6NeighborSolicitation(data []byte, p gopacket.PacketBuilder) error {
+	i := &ICMPv6NeighborSolicitation{}
+	return decodingLayerDecoder(i, data, p)
+}
+
+func decodeICMPv6NeighborAdvertisement(data []byte, p gopacket.PacketBuilder) error {
+	i := &ICMPv6NeighborAdvertisement{}
+	return decodingLayerDecoder(i, data, p)
+}
+
+func decodeICMPv6Redirect(data []byte, p gopacket.PacketBuilder) error {
+	i := &ICMPv6Redirect{}
+	return decodingLayerDecoder(i, data, p)
+}

vendor/github.com/google/gopacket/layers/igmp.go

@@ -0,0 +1,355 @@
+// Copyright 2012 Google, Inc. All rights reserved.
+// Copyright 2009-2011 Andreas Krennmair. All rights reserved.
+//
+// Use of this source code is governed by a BSD-style license
+// that can be found in the LICENSE file in the root of the source
+// tree.
+
+package layers
+
+import (
+	"encoding/binary"
+	"errors"
+	"net"
+	"time"
+
+	"github.com/google/gopacket"
+)
+
+type IGMPType uint8
+
+const (
+	IGMPMembershipQuery    IGMPType = 0x11 // General or group specific query
+	IGMPMembershipReportV1 IGMPType = 0x12 // Version 1 Membership Report
+	IGMPMembershipReportV2 IGMPType = 0x16 // Version 2 Membership Report
+	IGMPLeaveGroup         IGMPType = 0x17 // Leave Group
+	IGMPMembershipReportV3 IGMPType = 0x22 // Version 3 Membership Report
+)
+
+// String conversions for IGMP message types
+func (i IGMPType) String() string {
+	switch i {
+	case IGMPMembershipQuery:
+		return "IGMP Membership Query"
+	case IGMPMembershipReportV1:
+		return "IGMPv1 Membership Report"
+	case IGMPMembershipReportV2:
+		return "IGMPv2 Membership Report"
+	case IGMPMembershipReportV3:
+		return "IGMPv3 Membership Report"
+	case IGMPLeaveGroup:
+		return "Leave Group"
+	default:
+		return ""
+	}
+}
+
+type IGMPv3GroupRecordType uint8
+
+const (
+	IGMPIsIn  IGMPv3GroupRecordType = 0x01 // Type MODE_IS_INCLUDE, source addresses x
+	IGMPIsEx  IGMPv3GroupRecordType = 0x02 // Type MODE_IS_EXCLUDE, source addresses x
+	IGMPToIn  IGMPv3GroupRecordType = 0x03 // Type CHANGE_TO_INCLUDE_MODE, source addresses x
+	IGMPToEx  IGMPv3GroupRecordType = 0x04 // Type CHANGE_TO_EXCLUDE_MODE, source addresses x
+	IGMPAllow IGMPv3GroupRecordType = 0x05 // Type ALLOW_NEW_SOURCES, source addresses x
+	IGMPBlock IGMPv3GroupRecordType = 0x06 // Type BLOCK_OLD_SOURCES, source addresses x
+)
+
+func (i IGMPv3GroupRecordType) String() string {
+	switch i {
+	case IGMPIsIn:
+		return "MODE_IS_INCLUDE"
+	case IGMPIsEx:
+		return "MODE_IS_EXCLUDE"
+	case IGMPToIn:
+		return "CHANGE_TO_INCLUDE_MODE"
+	case IGMPToEx:
+		return "CHANGE_TO_EXCLUDE_MODE"
+	case IGMPAllow:
+		return "ALLOW_NEW_SOURCES"
+	case IGMPBlock:
+		return "BLOCK_OLD_SOURCES"
+	default:
+		return ""
+	}
+}
+
+// IGMP represents an IGMPv3 message.
+type IGMP struct {
+	BaseLayer
+	Type                    IGMPType
+	MaxResponseTime         time.Duration
+	Checksum                uint16
+	GroupAddress            net.IP
+	SupressRouterProcessing bool
+	RobustnessValue         uint8
+	IntervalTime            time.Duration
+	SourceAddresses         []net.IP
+	NumberOfGroupRecords    uint16
+	NumberOfSources         uint16
+	GroupRecords            []IGMPv3GroupRecord
+	Version                 uint8 // IGMP protocol version
+}
+
+// IGMPv1or2 stores header details for an IGMPv1 or IGMPv2 packet.
+//
+//  0                   1                   2                   3
+//  0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+// |      Type     | Max Resp Time |           Checksum            |
+// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+// |                         Group Address                         |
+// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+type IGMPv1or2 struct {
+	BaseLayer
+	Type            IGMPType      // IGMP message type
+	MaxResponseTime time.Duration // meaningful only in Membership Query messages
+	Checksum        uint16        // 16-bit checksum of entire ip payload
+	GroupAddress    net.IP        // either 0 or an IP multicast address
+	Version         uint8
+}
+
+// decodeResponse dissects IGMPv1 or IGMPv2 packet.
+func (i *IGMPv1or2) decodeResponse(data []byte) error {
+	if len(data) < 8 {
+		return errors.New("IGMP packet too small")
+	}
+
+	i.MaxResponseTime = igmpTimeDecode(data[1])
+	i.Checksum = binary.BigEndian.Uint16(data[2:4])
+	i.GroupAddress = net.IP(data[4:8])
+
+	return nil
+}
+
+//  0                   1                   2                   3
+//  0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+// |  Type = 0x22  |    Reserved   |           Checksum            |
+// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+// |           Reserved            |  Number of Group Records (M)  |
+// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+// |                                                               |
+// .                        Group Record [1]                       .
+// |                                                               |
+// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+// |                                                               |
+// .                        Group Record [2]                       .
+// |                                                               |
+// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+// |                                                               |
+// .                        Group Record [M]                       .
+// |                                                               |
+// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+
+// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+// |  Record Type  |  Aux Data Len |     Number of Sources (N)     |
+// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+// |                       Multicast Address                       |
+// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+// |                       Source Address [1]                      |
+// +-                                                             -+
+// |                       Source Address [2]                      |
+// +-                                                             -+
+// |                       Source Address [N]                      |
+// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+// |                                                               |
+// .                         Auxiliary Data                        .
+// |                                                               |
+// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+
+// IGMPv3GroupRecord stores individual group records for a V3 Membership Report message.
+type IGMPv3GroupRecord struct {
+	Type             IGMPv3GroupRecordType
+	AuxDataLen       uint8 // this should always be 0 as per IGMPv3 spec.
+	NumberOfSources  uint16
+	MulticastAddress net.IP
+	SourceAddresses  []net.IP
+	AuxData          uint32 // NOT USED
+}
+
+func (i *IGMP) decodeIGMPv3MembershipReport(data []byte) error {
+	if len(data) < 8 {
+		return errors.New("IGMPv3 Membership Report too small #1")
+	}
+
+	i.Checksum = binary.BigEndian.Uint16(data[2:4])
+	i.NumberOfGroupRecords = binary.BigEndian.Uint16(data[6:8])
+
+	recordOffset := 8
+	for j := 0; j < int(i.NumberOfGroupRecords); j++ {
+		if len(data) < recordOffset+8 {
+			return errors.New("IGMPv3 Membership Report too small #2")
+		}
+
+		var gr IGMPv3GroupRecord
+		gr.Type = IGMPv3GroupRecordType(data[recordOffset])
+		gr.AuxDataLen = data[recordOffset+1]
+		gr.NumberOfSources = binary.BigEndian.Uint16(data[recordOffset+2 : recordOffset+4])
+		gr.MulticastAddress = net.IP(data[recordOffset+4 : recordOffset+8])
+
+		if len(data) < recordOffset+8+int(gr.NumberOfSources)*4 {
+			return errors.New("IGMPv3 Membership Report too small #3")
+		}
+
+		// append source address records.
+		for i := 0; i < int(gr.NumberOfSources); i++ {
+			sourceAddr := net.IP(data[recordOffset+8+i*4 : recordOffset+12+i*4])
+			gr.SourceAddresses = append(gr.SourceAddresses, sourceAddr)
+		}
+
+		i.GroupRecords = append(i.GroupRecords, gr)
+		recordOffset += 8 + 4*int(gr.NumberOfSources)
+	}
+	return nil
+}
+
+//  0                   1                   2                   3
+//  0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+// |  Type = 0x11  | Max Resp Code |           Checksum            |
+// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+// |                         Group Address                         |
+// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+// | Resv  |S| QRV |     QQIC      |     Number of Sources (N)     |
+// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+// |                       Source Address [1]                      |
+// +-                                                             -+
+// |                       Source Address [2]                      |
+// +-                              .                              -+
+// |                       Source Address [N]                      |
+// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+//
+// decodeIGMPv3MembershipQuery parses the IGMPv3 message of type 0x11
+func (i *IGMP) decodeIGMPv3MembershipQuery(data []byte) error {
+	if len(data) < 12 {
+		return errors.New("IGMPv3 Membership Query too small #1")
+	}
+
+	i.MaxResponseTime = igmpTimeDecode(data[1])
+	i.Checksum = binary.BigEndian.Uint16(data[2:4])
+	i.SupressRouterProcessing = data[8]&0x8 != 0
+	i.GroupAddress = net.IP(data[4:8])
+	i.RobustnessValue = data[8] & 0x7
+	i.IntervalTime = igmpTimeDecode(data[9])
+	i.NumberOfSources = binary.BigEndian.Uint16(data[10:12])
+
+	if len(data) < 12+int(i.NumberOfSources)*4 {
+		return errors.New("IGMPv3 Membership Query too small #2")
+	}
+
+	for j := 0; j < int(i.NumberOfSources); j++ {
+		i.SourceAddresses = append(i.SourceAddresses, net.IP(data[12+j*4:16+j*4]))
+	}
+
+	return nil
+}
+
+// igmpTimeDecode decodes the duration created by the given byte, using the
+// algorithm in http://www.rfc-base.org/txt/rfc-3376.txt section 4.1.1.
+func igmpTimeDecode(t uint8) time.Duration {
+	if t&0x80 == 0 {
+		return time.Millisecond * 100 * time.Duration(t)
+	}
+	mant := (t & 0x70) >> 4
+	exp := t & 0x0F
+	return time.Millisecond * 100 * time.Duration((mant|0x10)<<(exp+3))
+}
+
+// LayerType returns LayerTypeIGMP for the V1,2,3 message protocol formats.
+func (i *IGMP) LayerType() gopacket.LayerType      { return LayerTypeIGMP }
+func (i *IGMPv1or2) LayerType() gopacket.LayerType { return LayerTypeIGMP }
+
+func (i *IGMPv1or2) DecodeFromBytes(data []byte, df gopacket.DecodeFeedback) error {
+	if len(data) < 8 {
+		return errors.New("IGMP Packet too small")
+	}
+
+	i.Type = IGMPType(data[0])
+	i.MaxResponseTime = igmpTimeDecode(data[1])
+	i.Checksum = binary.BigEndian.Uint16(data[2:4])
+	i.GroupAddress = net.IP(data[4:8])
+
+	return nil
+}
+
+func (i *IGMPv1or2) NextLayerType() gopacket.LayerType {
+	return gopacket.LayerTypeZero
+}
+
+func (i *IGMPv1or2) CanDecode() gopacket.LayerClass {
+	return LayerTypeIGMP
+}
+
+// DecodeFromBytes decodes the given bytes into this layer.
+func (i *IGMP) DecodeFromBytes(data []byte, df gopacket.DecodeFeedback) error {
+	if len(data) < 1 {
+		return errors.New("IGMP packet is too small")
+	}
+
+	// common IGMP header values between versions 1..3 of IGMP specification..
+	i.Type = IGMPType(data[0])
+
+	switch i.Type {
+	case IGMPMembershipQuery:
+		i.decodeIGMPv3MembershipQuery(data)
+	case IGMPMembershipReportV3:
+		i.decodeIGMPv3MembershipReport(data)
+	default:
+		return errors.New("unsupported IGMP type")
+	}
+
+	return nil
+}
+
+// CanDecode returns the set of layer types that this DecodingLayer can decode.
+func (i *IGMP) CanDecode() gopacket.LayerClass {
+	return LayerTypeIGMP
+}
+
+// NextLayerType returns the layer type contained by this DecodingLayer.
+func (i *IGMP) NextLayerType() gopacket.LayerType {
+	return gopacket.LayerTypeZero
+}
+
+// decodeIGMP will parse IGMP v1,2 or 3 protocols. Checks against the
+// IGMP type are performed against byte[0], logic then iniitalizes and
+// passes the appropriate struct (IGMP or IGMPv1or2) to
+// decodingLayerDecoder.
+func decodeIGMP(data []byte, p gopacket.PacketBuilder) error {
+	if len(data) < 1 {
+		return errors.New("IGMP packet is too small")
+	}
+
+	// byte 0 contains IGMP message type.
+	switch IGMPType(data[0]) {
+	case IGMPMembershipQuery:
+		// IGMPv3 Membership Query payload is >= 12
+		if len(data) >= 12 {
+			i := &IGMP{Version: 3}
+			return decodingLayerDecoder(i, data, p)
+		} else if len(data) == 8 {
+			i := &IGMPv1or2{}
+			if data[1] == 0x00 {
+				i.Version = 1 // IGMPv1 has a query length of 8 and MaxResp = 0
+			} else {
+				i.Version = 2 // IGMPv2 has a query length of 8 and MaxResp != 0
+			}
+
+			return decodingLayerDecoder(i, data, p)
+		}
+	case IGMPMembershipReportV3:
+		i := &IGMP{Version: 3}
+		return decodingLayerDecoder(i, data, p)
+	case IGMPMembershipReportV1:
+		i := &IGMPv1or2{Version: 1}
+		return decodingLayerDecoder(i, data, p)
+	case IGMPLeaveGroup, IGMPMembershipReportV2:
+		// leave group and Query Report v2 used in IGMPv2 only.
+		i := &IGMPv1or2{Version: 2}
+		return decodingLayerDecoder(i, data, p)
+	default:
+	}
+
+	return errors.New("Unable to determine IGMP type.")
+}