upd deps to kcp-go@v5.6.8

Bumps [golang.org/x/net](https://github.com/golang/net) from 0.14.0 to 0.17.0.
- [Commits](https://github.com/golang/net/compare/v0.14.0...v0.17.0)

---
updated-dependencies:
- dependency-name: golang.org/x/net
  dependency-type: indirect
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

.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**?
 
 

.gitignore

@@ -24,3 +24,5 @@ _testmain.go
 *.prof
 client/client
 server/server
+build/*
+.DS_Store

.travis.yml

@@ -1,16 +1,16 @@
 language: go
 go:
-    - 1.6
+    - 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

@@ -1,8 +1,15 @@
-FROM golang:alpine
+FROM golang:1.21.0-alpine3.18 as builder
 MAINTAINER xtaci <daniel820313@gmail.com>
-RUN apk update && \
-    apk upgrade && \
-    apk add git
-RUN go get github.com/xtaci/kcptun/client && go get 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:3.18
+RUN apk add --no-cache iptables
+COPY --from=builder /client /bin
+COPY --from=builder /server /bin
 EXPOSE 29900/udp
 EXPOSE 12948

README-CN.md

@@ -1,362 +0,0 @@
-# <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]
-[1]: https://images.microbadger.com/badges/image/xtaci/kcptun.svg
-[2]: https://microbadger.com/images/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
-[12]: LICENSE.md
-[13]: https://img.shields.io/github/release/xtaci/kcptun.svg
-[14]: https://github.com/xtaci/kcptun/releases/latest
-[15]: https://img.shields.io/github/downloads/xtaci/kcptun/total.svg?maxAge=1800
-[16]: https://github.com/xtaci/kcptun/releases
-[17]: https://img.shields.io/badge/KCP-Powered-blue.svg
-[18]: https://github.com/skywind3000/kcp
-
-
-<img src="kcptun.png" alt="kcptun" height="300px"/>
-
--
-
-### 快速设定
-
-客户端、服务器分别**下载**对应平台的[预编译版本](https://github.com/xtaci/kcptun/releases)，并**解压**，通过下面的命令**启动**端口转发。
-```
-KCP客户端: ./client_darwin_amd64 -r "KCP服务器IP地址:4000" -l ":8388" -mode fast2
-KCP服务器: ./server_linux_amd64 -t "目标服务器IP地址:8388" -l ":4000" -mode fast2
-```
-以上命令可以实现8388/tcp端口的转发（通过4000/udp端口），即：
-
-Application -> KCP客户端(8388/tcp) -> KCP服务器(4000/udp) -> Server(8388/tcp)
-
-### 从源码安装
-```
-$go get -u github.com/xtaci/kcptun/client
-$go get -u github.com/xtaci/kcptun/server
-```
-注意: 如果出现错误提示，请确保依赖库能正确访问到。
-
-Release中的所有二进制版本，是通过 `build-release.sh` 脚本生成并优化。
-
-### 速度对比
-
-<img src="fast.png" alt="fast.com" height="256px" />       
-* 测速网站: https://fast.com
-* 接入速度: 100Mbps
-* WIFI: 5GHz TL-WDR3320
-
-### 使用方法
-
-在Mac OS X El Capitan下的帮助输出，注意默认值: 
-
-```
-$ ./client_darwin_amd64 -h
-NAME:
-   kcptun - client(with SMUX)
-
-USAGE:
-   client_darwin_amd64 [global options] command [command options] [arguments...]
-
-VERSION:
-   20170120
-
-COMMANDS:
-     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")
-   --key value                      pre-shared secret between client and server (default: "it's a secrect") [$KCPTUN_KEY]
-   --crypt value                    aes, aes-128, aes-192, salsa20, blowfish, twofish, cast5, 3des, tea, xtea, xor, none (default: "aes")
-   --mode value                     profiles: fast3, fast2, fast, normal (default: "fast")
-   --conn value                     set num of UDP connections to server (default: 1)
-   --autoexpire value               set auto expiration time(in seconds) for a single UDP connection, 0 to disable (default: 0)
-   --mtu value                      set maximum transmission unit for UDP packets (default: 1350)
-   --sndwnd value                   set send window size(num of packets) (default: 128)
-   --rcvwnd value                   set receive window size(num of packets) (default: 512)
-   --datashard value, --ds value    set reed-solomon erasure coding - datashard (default: 10)
-   --parityshard value, --ps value  set reed-solomon erasure coding - parityshard (default: 3)
-   --dscp value                     set DSCP(6bit) (default: 0)
-   --nocomp                         disable compression
-   --snmplog value                  collect snmp to file, aware of timeformat in golang, like: ./snmp-20060102.log
-   --snmpperiod value               snmp collect period, in seconds (default: 60)
-   --log value                      specify a log file to output, default goes to stderr
-   -c value                         config from json file, which will override the command from shell
-   --help, -h                       show help
-   --version, -v                    print the version
-
-$ ./server_darwin_amd64 -h
-NAME:
-   kcptun - server(with SMUX)
-
-USAGE:
-   server_darwin_amd64 [global options] command [command options] [arguments...]
-
-VERSION:
-   20170120
-
-COMMANDS:
-     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")
-   --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, none (default: "aes")
-   --mode value                     profiles: fast3, fast2, fast, normal (default: "fast")
-   --mtu value                      set maximum transmission unit for UDP packets (default: 1350)
-   --sndwnd value                   set send window size(num of packets) (default: 1024)
-   --rcvwnd value                   set receive window size(num of packets) (default: 1024)
-   --datashard value, --ds value    set reed-solomon erasure coding - datashard (default: 10)
-   --parityshard value, --ps value  set reed-solomon erasure coding - parityshard (default: 3)
-   --dscp value                     set DSCP(6bit) (default: 0)
-   --nocomp                         disable compression
-   --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
-   -c value                         config from json file, which will override the command from shell
-   --help, -h                       show help
-   --version, -v                    print the version
-```
-
-#### 分层参数图
-
-<p align="left"><img src="layeredparams.png" alt="params" height="450px"/></p>
-
-**两端参数必须一致的有**:
-
-* datashard --前向纠错
-* parityshard --前向纠错
-* nocomp --压缩
-* key --密钥
-* crypt --加密算法
-
-其余为两边可独立设定的参数
-
-### 内置模式
-
-响应速度:     
-*fast3 > fast2 >* **[fast]** *> normal > default*        
-有效载荷比:     
-*default > normal >* **[fast]** *> fast2 > fast3*       
-中间-mode参数比较均衡，总之就是越快，包重传越激进。       
-更高级的 **手动档** 需要理解KCP协议，并通过 **隐藏参数** 调整，例如:
-```
- -mode manual -nodelay 1 -resend 2 -nc 1 -interval 20
-```
-
-* 搭配1. fast + FEC(5,5)
-* 搭配2. fast2 + FEC(10,3)
-* 搭配3. fast2 + FEC(0,0)
-
-默认profile参考: https://github.com/xtaci/kcptun/blob/master/client/main.go#L248
-
-### 前向纠错
-
-前向纠错采用Reed Solomon纠删码, 它的基本原理如下： 给定n个数据块d1, d2,…, dn，n和一个正整数m， RS根据n个数据块生成m个校验块， c1, c2,…, cm。 对于任意的n和m， 从n个原始数据块和m 个校验块中任取n块就能解码出原始数据， 即RS最多**容忍m个数据块或者校验块同时丢失**。
-
-![reed-solomon](rs.png)
-
-通过参数```-datashard n -parityshard m``` 在两端同时设定。
-
-数据包发送顺序严格遵循: n个datashard紧接m个parityshard，重复。
-
-注意：为了发挥FEC最佳效果，设置 parityshard/(parity+datashard) > packet loss，比如5/(5+5) > 30%
-
-### 窗口调整
-**简易窗口自我调优方法**：
-
-> 第一步：同时在两端逐步增大client rcvwnd和server sndwnd;        
-> 第二步：尝试下载，观察如果带宽利用率（服务器＋客户端两端都要观察）到达预期则停止，否则跳转到第一步。
-
-**注意：产生大量重传时，一定是窗口偏大了**
-
-### 安全
-
-无论你上层如何加密，如果```-crypt none```，那么**协议头部**都是**明文**的，建议至少采用```-crypt aes-128```加密，并修改密码。
-
-密码可以通过`-key`指定，也可以通过环境变量`KCPTUN_KEY`指定。
-
-注意: ```-crypt xor``` 也是不安全的，除非你知道你在做什么。 
-
-附加密速度Benchmark：
-
-```
-BenchmarkAES128-4      	  200000	     11182 ns/op
-BenchmarkAES192-4      	  200000	     12699 ns/op
-BenchmarkAES256-4      	  100000	     13757 ns/op
-BenchmarkTEA-4         	   50000	     26441 ns/op
-BenchmarkSimpleXOR-4   	 3000000	       441 ns/op
-BenchmarkBlowfish-4    	   30000	     48036 ns/op
-BenchmarkNone-4        	20000000	       106 ns/op
-BenchmarkCast5-4       	   20000	     60222 ns/op
-BenchmarkTripleDES-4   	    2000	    878759 ns/op
-BenchmarkTwofish-4     	   20000	     68501 ns/op
-BenchmarkXTEA-4        	   20000	     77417 ns/op
-BenchmarkSalsa20-4     	  300000	      4998 ns/op
-```
-
-### 内存控制
-
-路由器，手机等嵌入式设备通常对**内存用量敏感**，通过调节环境变量GOGC（例如GOGC=20)后启动client，可以降低内存使用。      
-参考：https://blog.golang.org/go15gc
-
-
-### DSCP
-
-DSCP差分服务代码点（Differentiated Services Code Point），IETF于1998年12月发布了Diff-Serv（Differentiated Service）的QoS分类标准。它在每个数据包IP头部的服务类别TOS标识字节中，利用已使用的**6比特**和未使用的2比特，通过编码值来区分优先级。     
-常用DSCP值可以参考[Wikipedia DSCP](https://en.wikipedia.org/wiki/Differentiated_services#Commonly_used_DSCP_values)，至于有没有用，完全取决于数据包经过的设备。 
-
-通过 ```-dscp ``` 参数指定dscp值，两端可分别设定。
-
-注意：设置dscp不一定会更好，需要尝试。
-
-### Snappy数据流压缩
-
-> Snappy is a compression/decompression library. It does not aim for maximum
-> compression, or compatibility with any other compression library; instead,
-> it aims for very high speeds and reasonable compression. For instance,
-> compared to the fastest mode of zlib, Snappy is an order of magnitude faster
-> for most inputs, but the resulting compressed files are anywhere from 20% to
-> 100% bigger.
-
-> Reference: http://google.github.io/snappy/
-
-压缩对于非加密，非压缩的数据能降低传输数据量，比如点对点的HTTP数据转发。
-
-通过参数 ```-nocomp``` 在两端同时设定以关闭压缩。
-> 提示: 关闭压缩可能会降低延迟。
-
-### 流量控制
-
-**必要性: 针对流量敏感的服务器，做双保险。**      
-
-> 基本原则: SERVER的发送速率不能超过ADSL下行带宽，否则只会浪费您的服务器带宽。  
-
-在server通过linux tc，可以限制服务器发送带宽。   
-举例:  用linux tc限制server发送带宽为32mbit/s: 
-```
-root@kcptun:~# cat tc.sh
-tc qdisc del dev eth0 root
-tc qdisc add dev eth0 root handle 1: htb
-tc class add dev eth0 parent 1: classid 1:1 htb rate 32mbit
-tc filter add dev eth0 protocol ip parent 1:0 prio 1 handle 10 fw flowid 1:1
-iptables -t mangle -A POSTROUTING -o eth0  -j MARK --set-mark 10
-root@kcptun:~#
-```
-其中eth0为网卡，有些服务器为ens3，有些为p2p1，通过ifconfig查询修改。
-
-### SNMP
-
-```go
-// Snmp defines network statistics indicator
-type Snmp struct {
-    BytesSent        uint64 // raw bytes sent
-    BytesReceived    uint64
-    MaxConn          uint64
-    ActiveOpens      uint64
-    PassiveOpens     uint64
-    CurrEstab        uint64 // count of connections for now
-    InErrs           uint64 // udp read errors
-    InCsumErrors     uint64 // checksum errors from CRC32
-    KCPInErrors      uint64 // packet iput errors from kcp
-    InSegs           uint64
-    OutSegs          uint64
-    InBytes          uint64 // udp bytes received
-    OutBytes         uint64 // udp bytes sent
-    RetransSegs      uint64
-    FastRetransSegs  uint64
-    EarlyRetransSegs uint64
-    LostSegs         uint64 // number of segs infered as lost
-    RepeatSegs       uint64 // number of segs duplicated
-    FECRecovered     uint64 // correct packets recovered from FEC
-    FECErrs          uint64 // incorrect packets recovered from FEC
-    FECSegs          uint64 // FEC segments received
-    FECShortShards   uint64 // number of data shards that's not enough for recovery
-}
-```
-
-使用```kill -SIGUSR1 pid``` 可以在控制台打印出SNMP信息，通常用于精细调整**当前链路的有效载荷比**。        
-观察```RetransSegs,FastRetransSegs,LostSegs,OutSegs```这几者的数值比例，用于参考调整```-mode manual,fec```的参数。    
-
-#### 带宽计算公式
-
-```
-在不丢包的情况下，有最大-rcvwnd 个数据包在网络上正在向你传输，以平均数据包大小avgsize计算，在任意时刻，有：     
-
-		network_cap = rcvwnd*avgsize
-
-数据流向你，这个值再除以ping值(rtt)，等于最大带宽使用量。
-
-		max_bandwidth = network_cap/rtt = rcvwnd*avgsize/rtt
-		
-举例，设rcvwnd = 1024, avgsize = 1KB, rtt = 400ms，则：
-
-		max_bandwidth = 1024 * 1KB / 400ms = 2.5MB/s ~= 25Mbps
-		
-（注：以上计算不包括前向纠错的数据量）
-
-前向纠错是最大带宽量的一个固定比例增加：
-
-		max_bandwidth_fec = max_bandwidth*(datashard+parityshard)/datashard
-
-举例，设datashard = 10 , partiyshard = 3，则：
-
-		max_bandwidth_fec = max_bandwidth * (10 + 3) /10 = 1.3*max_bandwidth ＝ 1.3 * 25Mbps = 32.5Mbps
-```
-
-### 故障排除
-
-> Q: 客户端和服务器端**皆无** ```stream opened```信息。       
-> A: 连接客户端程序的端口设置错误。     
-
-> Q: 客户端有 ```stream opened```信息，服务器端没有。     
-> A: 连接服务器的端口设置错误，或者被防火墙拦截。     
-
-> Q: 客户端服务器**皆有** ```stream opened```信息，但无法通信。      
-> A: 上层软件的设定错误。     
-
-### 免责申明
-
-**用户以各种方式使用本软件（包括但不限于修改使用、直接使用、通过第三方使用）的过程中，不得以任何方式利用本软件直接或间接从事违反中国法律、以及社会公德的行为。软件的使用者需对自身行为负责，因使用软件引发的一切纠纷，由使用者承担全部法律及连带责任。作者不承担任何法律及连带责任。**       
-
-**对免责声明的解释、修改及更新权均属于作者本人所有。**
-
-### 特别鸣谢
-
-> 郑H立, 南东风, Li, 七七, 凌君, 昶，LesMiserables, KyOn, 噼里啪啦, 继斌, 小苍辛苦, **Ken**, 
-> 乔槁, 佳晨, 猪肉佬, lcx, 昊文, 冰峰, 凡, alex, **海豹叔叔**, 奥姐, 张冰, 司成, 
-> 武子, **慎**，Alex43211，**Coxxs**，荣，NeroNg，吴骁，定一，我不是林J，Patrick, 超, 陈，windfarer, 宇,
-> 今晶，斌，晓东，最后一缕阳光，亮，Ethan，一心不乱，allenm，冬卯，GELATO，用户1，Butterfly，光子曲面，
-> 丞佳，捉鱼，Talon，Biny，李勇，***阿彪***，***rinex20***，Fabre，路过发光体，池子，kk，杰，维维
-
-好人一生平安!
-
-### 相关软件
-
-1. https://github.com/bettermanbao/openwrt-kcptun
-2. https://github.com/EasyPi/openwrt-kcptun
-3. https://github.com/kuoruan/luci-app-kcptun
-4. https://github.com/dfdragon/kcptun_gclient
-5. https://github.com/dfdragon/kcptun_xclient
-
-### 参考资料
-
-1. https://github.com/skywind3000/kcp -- KCP - A Fast and Reliable ARQ Protocol.
-2. https://github.com/klauspost/reedsolomon -- Reed-Solomon Erasure Coding in Go.
-3. https://en.wikipedia.org/wiki/Differentiated_services -- DSCP.
-4. http://google.github.io/snappy/ -- A fast compressor/decompressor.
-5. https://www.backblaze.com/blog/reed-solomon/ -- Reed-Solomon Explained.
-6. http://www.qualcomm.cn/products/raptorq -- RaptorQ Forward Error Correction Scheme for Object Delivery.
-7. https://en.wikipedia.org/wiki/PBKDF2 -- Key stretching.
-8. http://blog.appcanary.com/2016/encrypt-or-compress.html -- Should you encrypt or compress first?
-9. https://github.com/hashicorp/yamux -- Connection multiplexing library.
-10. https://tools.ietf.org/html/rfc6937 -- Proportional Rate Reduction for TCP.
-11. https://tools.ietf.org/html/rfc5827 -- Early Retransmit for TCP and Stream Control Transmission Protocol (SCTP).
-12. http://http2.github.io/ -- What is HTTP/2?
-13. http://www.lartc.org/LARTC-zh_CN.GB2312.pdf -- Linux Advanced Routing & Traffic Control
-14. https://en.wikipedia.org/wiki/Noisy-channel_coding_theorem -- Noisy channel coding theorem

README.md

@@ -1,53 +1,95 @@
 # <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]
-[1]: https://images.microbadger.com/badges/image/xtaci/kcptun.svg
-[2]: https://microbadger.com/images/xtaci/kcptun
+
+[![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://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
 
-
 <img src="kcptun.png" alt="kcptun" height="300px"/>
 
-[简体中文](README-CN.md)
+> *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 |
+
+*NOTE: if you are using kvm, make sure the guest os can do AES instructions*
+<img src="https://github.com/xtaci/kcptun/assets/2346725/9358e8e5-2a4a-4be9-9859-62f1aaa553b0" alt="cpuinfo" height="400px"/>
 
 ### QuickStart
 
-Download precompiled [Releases](https://github.com/xtaci/kcptun/releases).
+Increase the number of open files on your server, as:
+
+`ulimit -n 65535`, or write it in `~/.bashrc`.
+
+Suggested `sysctl.conf` parameters for better handling of UDP packets:
 
 ```
-KCP Client: ./client_darwin_amd64 -r "KCP_SERVER_IP:4000" -l ":8388" -mode fast2
-KCP Server: ./server_linux_amd64 -t "TARGET_IP:8388" -l ":4000" -mode fast2
+net.core.rmem_max=26214400 // BDP - bandwidth delay product
+net.core.rmem_default=26214400
+net.core.wmem_max=26214400
+net.core.wmem_default=26214400
+net.core.netdev_max_backlog=2048 // proportional to -rcvwnd
 ```
-The above commands will establish port forwarding for 8388/tcp as:
 
-Application -> KCP Client(8388/tcp) -> KCP Server(4000/udp) -> Server(8388/tcp) 
+You can also increase the per-socket buffer by adding parameter(default 4MB):
+```
+-sockbuf 16777217
+```
+for **slow processors**, increasing this buffer is **CRITICAL** to receive packets properly.
 
-### Install from source
+Download a corresponding one from precompiled [Releases](https://github.com/xtaci/kcptun/releases).
 
 ```
-$go get -u github.com/xtaci/kcptun/client
-$go get -u github.com/xtaci/kcptun/server
+KCP Client: ./client_darwin_amd64 -r "KCP_SERVER_IP:4000" -l ":8388" -mode fast3 -nocomp -autoexpire 900 -sockbuf 16777217 -dscp 46
+KCP Server: ./server_linux_amd64 -t "TARGET_IP:8388" -l ":4000" -mode fast3 -nocomp -sockbuf 16777217 -dscp 46
+```
+The above commands will establish port forwarding channel for 8388/tcp as:
+
+> Application -> **KCP Client(8388/tcp) -> KCP Server(4000/udp)** -> Target Server(8388/tcp) 
+
+which tunnels the original connection:
+
+> Application -> Target Server(8388/tcp) 
+
+### Build from source
+
+```
+$ 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.
 
 ### Performance
 
-<img src="fast.png" alt="fast.com" height="256px" />       
+<img src="fast.png" alt="fast.com" height="256px" />  
+
+![bandwidth](bw.png)
+
+![flame](flame.png)
+
+> Practical bandwidth graph with parameters:  -mode fast3 -ds 10 -ps 3
+
+
 
 ### Basic Tuning Guide
 
@@ -55,7 +97,8 @@ All precompiled releases are genereated from `build-release.sh` script.
 
 > **Q: I have a high speed network link, how to reach the maximum bandwidth?**        
 
-> **A:** Increase `-rcvwnd` on KCP Client and `-sndwnd` on KCP Server **simultaneously & gradually**, the mininum one decides the maximum transfer rate of the link, as `wnd * mtu / rtt`; Then try downloading something and to see if it meets your requirements.
+> **A:** Increase `-rcvwnd` on KCP Client and `-sndwnd` on KCP Server **simultaneously & gradually**, the mininum one decides the maximum transfer rate of the link, as `wnd * mtu / rtt`; Then try downloading something and to see if it meets your requirements. 
+(mtu is adjustable by `-mtu`)
 
 #### Improving Latency
 
@@ -65,11 +108,21 @@ 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*
 
--
+#### HOLB
+
+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.
+If you insist on running under some ARM routers, you'd better turn off `FEC` and use `salsa20` as the encryption method.
 
 ### Expert Tuning Guide
 
@@ -80,27 +133,28 @@ All precompiled releases are genereated from `build-release.sh` script.
 #### Usage
 
 ```
-$ ./client_darwin_amd64 -h
+➜  ~ ./client_linux_amd64 -h
 NAME:
    kcptun - client(with SMUX)
 
 USAGE:
-   client_darwin_amd64 [global options] command [command options] [arguments...]
+   client_linux_amd64 [global options] command [command options] [arguments...]
 
 VERSION:
-   20170120
+   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, none (default: "aes")
-   --mode value                     profiles: fast3, fast2, fast, normal (default: "fast")
+   --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 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)
@@ -108,32 +162,39 @@ GLOBAL OPTIONS:
    --parityshard value, --ps value  set reed-solomon erasure coding - parityshard (default: 3)
    --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
-
-$ ./server_darwin_amd64 -h
+   
+➜  ~ ./server_linux_amd64 -h
 NAME:
    kcptun - server(with SMUX)
 
 USAGE:
-   server_darwin_amd64 [global options] command [command options] [arguments...]
+   server_linux_amd64 [global options] command [command options] [arguments...]
 
 VERSION:
-   20170120
+   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, none (default: "aes")
-   --mode value                     profiles: fast3, fast2, fast, normal (default: "fast")
+   --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")
    --mtu value                      set maximum transmission unit for UDP packets (default: 1350)
    --sndwnd value                   set send window size(num of packets) (default: 1024)
    --rcvwnd value                   set receive window size(num of packets) (default: 1024)
@@ -141,23 +202,44 @@ GLOBAL OPTIONS:
    --parityshard value, --ps value  set reed-solomon erasure coding - parityshard (default: 3)
    --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 belongs to the class of non-binary cyclic error-correcting codes. The Reed–Solomon code is based on univariate polynomials over finite fields.
+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.
 
 It is able to detect and correct multiple symbol errors. By adding t check symbols to the data, a Reed–Solomon code can detect any combination of up to t erroneous symbols, or correct up to ⌊t/2⌋ symbols. As an erasure code, it can correct up to t known erasures, or it can detect and correct combinations of errors and erasures. Furthermore, Reed–Solomon codes are suitable as multiple-burst bit-error correcting codes, since a sequence of b + 1 consecutive bit errors can affect at most two symbols of size b. The choice of t is up to the designer of the code, and may be selected within wide limits.
 
-![reed-solomon](rs.png)
-
-Setting parameters of RS-Code with ```-datashard m -parityshard n``` on both KCP Client & KCP Server.
+![FED](FEC.png)
 
 #### DSCP
 
@@ -167,39 +249,68 @@ DiffServ uses a 6-bit differentiated services code point (DSCP) in the 8-bit dif
 
 setting each side with ```-dscp value```, Here are some [Commonly used DSCP values](https://en.wikipedia.org/wiki/Differentiated_services#Commonly_used_DSCP_values).
 
-#### Security
+#### Cryptanalysis
 
-No matter what encryption you are using for application layer, if you specify ```-crypt none``` to kcptun, 
-the header will be ***PLAINTEXT*** to everyone; I suggest ```-crypt aes-128``` for encryption at least .
+kcptun is shipped with builtin packet encryption powered by various block encryption algorithms and works in [Cipher Feedback Mode](https://en.wikipedia.org/wiki/Block_cipher_mode_of_operation#Cipher_Feedback_(CFB)), for each packet to be sent, the encryption process will start from encrypting a [nonce](https://en.wikipedia.org/wiki/Cryptographic_nonce) from the [system entropy](https://en.wikipedia.org/wiki//dev/random), so encryption to same plaintexts never leads to a same ciphertexts thereafter.
 
-`-crypt` and `-key` must be the same on both KCP Client & KCP Server.
+The contents of the packets are completely anonymous with encryption, including the headers(FEC,KCP), checksums and contents. Note that, no matter which encryption method you choose on you upper layer, if you disable encryption by specifying `-crypt none` to kcptun, the transmit will be insecure somehow, since the header is ***PLAINTEXT*** to everyone it would be susceptible to header tampering, such as jamming the *sliding window size*, *round-trip time*, *FEC property* and *checksums*. ```aes-128``` is suggested for minimal encryption since modern CPUs are shipped with [AES-NI](https://en.wikipedia.org/wiki/AES_instruction_set) instructions and performs even better than `salsa20`(check the table below).
 
-NOTICE: ```-crypt xor``` is also insecure, do not use this unless you know what you are doing.
+Other possible attacks to kcptun includes: a) [traffic analysis](https://en.wikipedia.org/wiki/Traffic_analysis), dataflow on specific websites may have pattern while interchanging data, but this type of eavesdropping has been mitigated by adapting [smux](https://github.com/xtaci/smux) to mix data streams so as to introduce noises, perfect solution to this has not appeared yet, theroretically by shuffling/mixing messages on larger scale network may mitigate this problem.  b) [replay attack](https://en.wikipedia.org/wiki/Replay_attack), since the asymmetrical encryption has not been introduced into kcptun for some reason, capturing the packets and replay them on a different machine is possible, (notice: hijacking the session and decrypting the contents is still *impossible*), so upper layers should contain a asymmetrical encryption system to guarantee the authenticity of each message(to process message exactly once), such as HTTPS/OpenSSL/LibreSSL, only by signing the requests with private keys can eliminate this type of attack. 
+
+Important: 
+1. `-crypt` and `-key` must be the same on both KCP Client & KCP Server.
+2. `-crypt xor` is also insecure and vulnerable to [known-plaintext attack](https://en.wikipedia.org/wiki/Known-plaintext_attack), do not use this unless you know what you are doing. (*cryptanalysis note: any type of [counter mode](https://en.wikipedia.org/wiki/Block_cipher_mode_of_operation#Counter_(CTR)) is insecure in packet encryption due to the shorten of counter period and leads to iv/nonce collision*)
 
 Benchmarks for crypto algorithms supported by kcptun:
 
 ```
-BenchmarkAES128-4      	  200000	     11182 ns/op
-BenchmarkAES192-4      	  200000	     12699 ns/op
-BenchmarkAES256-4      	  100000	     13757 ns/op
-BenchmarkTEA-4         	   50000	     26441 ns/op
-BenchmarkSimpleXOR-4   	 3000000	       441 ns/op
-BenchmarkBlowfish-4    	   30000	     48036 ns/op
-BenchmarkNone-4        	20000000	       106 ns/op
-BenchmarkCast5-4       	   20000	     60222 ns/op
-BenchmarkTripleDES-4   	    2000	    878759 ns/op
-BenchmarkTwofish-4     	   20000	     68501 ns/op
-BenchmarkXTEA-4        	   20000	     77417 ns/op
-BenchmarkSalsa20-4     	  300000	      4998 ns/op
+BenchmarkSM4-4                 	   50000	     32087 ns/op	  93.49 MB/s	       0 B/op	       0 allocs/op
+BenchmarkAES128-4              	  500000	      3274 ns/op	 916.15 MB/s	       0 B/op	       0 allocs/op
+BenchmarkAES192-4              	  500000	      3587 ns/op	 836.34 MB/s	       0 B/op	       0 allocs/op
+BenchmarkAES256-4              	  300000	      3828 ns/op	 783.60 MB/s	       0 B/op	       0 allocs/op
+BenchmarkTEA-4                 	  100000	     15359 ns/op	 195.32 MB/s	       0 B/op	       0 allocs/op
+BenchmarkXOR-4                 	20000000	        90.2 ns/op	33249.02 MB/s	       0 B/op	       0 allocs/op
+BenchmarkBlowfish-4            	   50000	     26885 ns/op	 111.58 MB/s	       0 B/op	       0 allocs/op
+BenchmarkNone-4                	30000000	        45.8 ns/op	65557.11 MB/s	       0 B/op	       0 allocs/op
+BenchmarkCast5-4               	   50000	     34370 ns/op	  87.29 MB/s	       0 B/op	       0 allocs/op
+Benchmark3DES-4                	   10000	    117893 ns/op	  25.45 MB/s	       0 B/op	       0 allocs/op
+BenchmarkTwofish-4             	   50000	     33477 ns/op	  89.61 MB/s	       0 B/op	       0 allocs/op
+BenchmarkXTEA-4                	   30000	     45825 ns/op	  65.47 MB/s	       0 B/op	       0 allocs/op
+BenchmarkSalsa20-4             	  500000	      3282 ns/op	 913.90 MB/s	       0 B/op	       0 allocs/op
 ```
 
+Benchmark result from openssl
+
+```
+$ openssl speed -evp aes-128-cfb
+Doing aes-128-cfb for 3s on 16 size blocks: 157794127 aes-128-cfb's in 2.98s
+Doing aes-128-cfb for 3s on 64 size blocks: 39614018 aes-128-cfb's in 2.98s
+Doing aes-128-cfb for 3s on 256 size blocks: 9971090 aes-128-cfb's in 2.99s
+Doing aes-128-cfb for 3s on 1024 size blocks: 2510877 aes-128-cfb's in 2.99s
+Doing aes-128-cfb for 3s on 8192 size blocks: 310865 aes-128-cfb's in 2.98s
+OpenSSL 1.0.2p  14 Aug 2018
+built on: reproducible build, date unspecified
+options:bn(64,64) rc4(ptr,int) des(idx,cisc,16,int) aes(partial) idea(int) blowfish(idx)
+compiler: clang -I. -I.. -I../include  -fPIC -fno-common -DOPENSSL_PIC -DOPENSSL_THREADS -D_REENTRANT -DDSO_DLFCN -DHAVE_DLFCN_H -arch x86_64 -O3 -DL_ENDIAN -Wall -DOPENSSL_IA32_SSE2 -DOPENSSL_BN_ASM_MONT -DOPENSSL_BN_ASM_MONT5 -DOPENSSL_BN_ASM_GF2m -DSHA1_ASM -DSHA256_ASM -DSHA512_ASM -DMD5_ASM -DAES_ASM -DVPAES_ASM -DBSAES_ASM -DWHIRLPOOL_ASM -DGHASH_ASM -DECP_NISTZ256_ASM
+The 'numbers' are in 1000s of bytes per second processed.
+type             16 bytes     64 bytes    256 bytes   1024 bytes   8192 bytes
+aes-128-cfb     847216.79k   850770.86k   853712.05k   859912.39k   854565.80k
+```
+
+The encrytion performance in kcptun is as fast as in openssl library(if not faster).
 
 
 #### Memory Control
 
-Routers, mobile devices are sensitive to memory consumption; by setting GOGC environment(eg: GOGC=20) will lower memory consumption.
+Routers, mobile devices are susceptible to memory consumption; by setting GOGC environment(eg: GOGC=20) will make the garbage collector to recycle faster.
 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 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
 
 kcptun has builtin snappy algorithms for compressing streams:
@@ -213,36 +324,37 @@ kcptun has builtin snappy algorithms for compressing streams:
 
 > Reference: http://google.github.io/snappy/
 
-Compression may save bandwidth for **PLAINTEXT** data, such as HTTP data.
+Compression may save bandwidth for **PLAINTEXT** data, it's quite useful for specific scenarios as cross-datacenter replications, by compressing the redologs in dbms or kafka-like message queues and then transfer the data streams across the continent can be much faster.
 
-Compression is enabled by default, you can disable it by setting ```-nocomp``` on both KCP Client & KCP Server.
+Compression is enabled by default, you can disable it by setting ```-nocomp``` on **BOTH** KCP Client & KCP Server **MUST** be **IDENTICAL**.
 
 #### SNMP
 
 ```go
-// Snmp defines network statistics indicator
 type Snmp struct {
-    BytesSent        uint64 // raw bytes sent
-    BytesReceived    uint64
-    MaxConn          uint64
-    ActiveOpens      uint64
-    PassiveOpens     uint64
-    CurrEstab        uint64 // count of connections for now
-    InErrs           uint64 // udp read errors
+    BytesSent        uint64 // bytes sent from upper level
+    BytesReceived    uint64 // bytes received to upper level
+    MaxConn          uint64 // max number of connections ever reached
+    ActiveOpens      uint64 // accumulated active open connections
+    PassiveOpens     uint64 // accumulated passive open connections
+    CurrEstab        uint64 // current number of established connections
+    InErrs           uint64 // UDP read errors reported from net.PacketConn
     InCsumErrors     uint64 // checksum errors from CRC32
-    KCPInErrors      uint64 // packet iput errors from kcp
-    InSegs           uint64
-    OutSegs          uint64
-    InBytes          uint64 // udp bytes received
-    OutBytes         uint64 // udp bytes sent
-    RetransSegs      uint64
-    FastRetransSegs  uint64
-    EarlyRetransSegs uint64
+    KCPInErrors      uint64 // packet iput errors reported from KCP
+    InPkts           uint64 // incoming packets count
+    OutPkts          uint64 // outgoing packets count
+    InSegs           uint64 // incoming KCP segments
+    OutSegs          uint64 // outgoing KCP segments
+    InBytes          uint64 // UDP bytes received
+    OutBytes         uint64 // UDP bytes sent
+    RetransSegs      uint64 // accmulated retransmited segments
+    FastRetransSegs  uint64 // accmulated fast retransmitted segments
+    EarlyRetransSegs uint64 // accmulated early retransmitted segments
     LostSegs         uint64 // number of segs infered as lost
     RepeatSegs       uint64 // number of segs duplicated
     FECRecovered     uint64 // correct packets recovered from FEC
     FECErrs          uint64 // incorrect packets recovered from FEC
-    FECSegs          uint64 // FEC segments received
+    FECParityShards  uint64 // FEC segments received
     FECShortShards   uint64 // number of data shards that's not enough for recovery
 }
 ```
@@ -257,31 +369,34 @@ https://github.com/skywind3000/kcp/blob/master/README.en.md#protocol-configurati
 
 Low-level KCP configuration can be altered by using manual mode like above, make sure you really **UNDERSTAND** what these means before doing **ANY** manual settings.
 
-### Support
 
-You can support this project by the following methods:
+### Identical Parmeters
 
-1. Vultr promotion code:     
-http://www.vultr.com/?ref=6897065
+These parameters **MUST** be **IDENTICAL** on **BOTH** side:
 
-2. Paypal    
-https://www.paypal.me/xtaci
-
-Your name or github name will be listed on this page by default.
+1. -key
+1. -crypt
+1. -nocomp
+1. -smuxver
 
 ### References
 
 1. https://github.com/skywind3000/kcp -- KCP - A Fast and Reliable ARQ Protocol.
-2. https://github.com/klauspost/reedsolomon -- Reed-Solomon Erasure Coding in Go.
-3. https://en.wikipedia.org/wiki/Differentiated_services -- DSCP.
-4. http://google.github.io/snappy/ -- A fast compressor/decompressor.
-5. https://www.backblaze.com/blog/reed-solomon/ -- Reed-Solomon Explained.
-6. http://www.qualcomm.cn/products/raptorq -- RaptorQ Forward Error Correction Scheme for Object Delivery.
-7. https://en.wikipedia.org/wiki/PBKDF2 -- Key stretching.
-8. http://blog.appcanary.com/2016/encrypt-or-compress.html -- Should you encrypt or compress first?
-9. https://github.com/hashicorp/yamux -- Connection multiplexing library.
-10. https://tools.ietf.org/html/rfc6937 -- Proportional Rate Reduction for TCP.
-11. https://tools.ietf.org/html/rfc5827 -- Early Retransmit for TCP and Stream Control Transmission Protocol (SCTP).
-12. http://http2.github.io/ -- What is HTTP/2?
-13. http://www.lartc.org/ -- Linux Advanced Routing & Traffic Control
-14. https://en.wikipedia.org/wiki/Noisy-channel_coding_theorem -- Noisy channel coding theorem
+1. https://github.com/xtaci/kcp-go/ -- A Production-Grade Reliable-UDP Library for golang
+1. https://github.com/klauspost/reedsolomon -- Reed-Solomon Erasure Coding in Go.
+1. https://en.wikipedia.org/wiki/Differentiated_services -- DSCP.
+1. http://google.github.io/snappy/ -- A fast compressor/decompressor.
+1. https://www.backblaze.com/blog/reed-solomon/ -- Reed-Solomon Explained.
+1. http://www.qualcomm.cn/products/raptorq -- RaptorQ Forward Error Correction Scheme for Object Delivery.
+1. https://en.wikipedia.org/wiki/PBKDF2 -- Key stretching.
+1. http://blog.appcanary.com/2016/encrypt-or-compress.html -- Should you encrypt or compress first?
+1. https://github.com/hashicorp/yamux -- Connection multiplexing library.
+1. https://tools.ietf.org/html/rfc6937 -- Proportional Rate Reduction for TCP.
+1. https://tools.ietf.org/html/rfc5827 -- Early Retransmit for TCP and Stream Control Transmission Protocol (SCTP).
+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
+
+
+（注意：我没有任何社交网站的账号，请小心骗子。）

build-release-cgo.sh

@@ -0,0 +1,139 @@
+#!/bin/bash
+
+BUILD_DIR=$(dirname "$0")/build
+mkdir -p $BUILD_DIR
+cd $BUILD_DIR
+
+sum="sha1sum"
+
+if [ "$GO111MODULE" != "on" ]; then
+	echo "GO111MODULE is off"
+else
+	echo "GO111MODULE is on"
+fi 
+
+echo "Prerequisites for cross-compiling were written in build-release.sh"
+
+# required library for cross-compiling
+# sudo apt-get install -y automake autogen build-essential ca-certificates   gcc-5-arm-linux-gnueabi g++-5-arm-linux-gnueabi libc6-dev-armel-cross   gcc-5-arm-linux-gnueabihf g++-5-arm-linux-gnueabihf libc6-dev-armhf-cross gcc-5-aarch64-linux-gnu g++-5-aarch64-linux-gnu libc6-dev-arm64-cross  gcc-5-mips-linux-gnu g++-5-mips-linux-gnu libc6-dev-mips-cross gcc-5-mipsel-linux-gnu g++-5-mipsel-linux-gnu libc6-dev-mipsel-cross  gcc-5-mips64-linux-gnuabi64 g++-5-mips64-linux-gnuabi64 libc6-dev-mips64-cross  gcc-5-mips64el-linux-gnuabi64 g++-5-mips64el-linux-gnuabi64 libc6-dev-mips64el-cross  gcc-5-multilib g++-5-multilib gcc-mingw-w64 g++-mingw-w64 clang llvm-dev   libtool libxml2-dev uuid-dev libssl-dev swig openjdk-8-jdk pkg-config patch  make xz-utils cpio wget zip unzip p7zip git mercurial bzr texinfo help2man --no-install-recommends
+
+# if error message:
+#     /usr/include/linux/errno.h:1:23: fatal error: asm/errno.h: No such file or directory
+# try:
+#    ln -s /usr/include/asm-generic /usr/include/asm
+
+if ! hash sha1sum 2>/dev/null; then
+	if ! hash shasum 2>/dev/null; then
+		echo "I can't see 'sha1sum' or 'shasum'"
+		echo "Please install one of them!"
+		exit
+	fi
+	sum="shasum"
+fi
+
+UPX=false
+if hash upx 2>/dev/null; then
+	UPX=true
+fi
+
+VERSION=`date -u +%Y%m%d`
+LDFLAGS="-X main.VERSION=$VERSION -s -w"
+LDFLAGS_LINUX='-X main.VERSION='$VERSION' -s -w -linkmode "external" -extldflags "-static"'
+LDFLAGS_LINUX32='-X main.VERSION='$VERSION' -s -w -linkmode "external" -extldflags "-static -m32 -L/usr/lib32"'
+echo "-ldflag for linux/amd64:" $LDFLAGS_LINUX
+echo "-ldflag for linux/386:" $LDFLAGS_LINUX32
+echo "-ldflag for other:" $LDFLAGS
+
+echo "=== Building ==="
+
+# 386
+OSES=(linux windows)
+for os in ${OSES[@]}; do
+	suffix=""
+	if [ "$os" == "windows" ]
+	then
+		suffix=".exe"
+	fi
+
+	if [ "$os" == "linux" ];then
+		CC=gcc-5 CGO_ENABLED=1 GOOS=$os GOARCH=386 CGO_CFLAGS="-m32 -L/usr/lib32" CGO_CXXFLAGS="-m32 -L/usr/lib32" go build -ldflags "$LDFLAGS_LINUX32" -o client_${os}_386${suffix} github.com/xtaci/kcptun/client
+		CC=gcc-5 CGO_ENABLED=1 GOOS=$os GOARCH=386 CGO_CFLAGS="-m32 -L/usr/lib32" CGO_CXXFLAGS="-m32 -L/usr/lib32" go build -ldflags "$LDFLAGS_LINUX32" -o server_${os}_386${suffix} github.com/xtaci/kcptun/server
+	else 
+		CGO_ENABLED=0 GOOS=$os GOARCH=386 go build -ldflags "$LDFLAGS" -o client_${os}_386${suffix} github.com/xtaci/kcptun/client
+		CGO_ENABLED=0 GOOS=$os GOARCH=386 go build -ldflags "$LDFLAGS" -o server_${os}_386${suffix} github.com/xtaci/kcptun/server
+	fi
+
+	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
+done
+
+# AMD64 
+OSES=(linux darwin windows freebsd)
+for os in ${OSES[@]}; do
+	suffix=""
+	if [ "$os" == "windows" ]
+	then
+		suffix=".exe"
+	fi
+
+	if [ "$os" == "linux" ];then
+		CC=gcc-5 CGO_ENABLED=1 GOOS=$os GOARCH=amd64 go build -ldflags "$LDFLAGS_LINUX" -o client_${os}_amd64${suffix} github.com/xtaci/kcptun/client
+		CC=gcc-5 CGO_ENABLED=1 GOOS=$os GOARCH=amd64 go build -ldflags "$LDFLAGS_LINUX" -o server_${os}_amd64${suffix} github.com/xtaci/kcptun/server
+	else 
+		CGO_ENABLED=0 GOOS=$os GOARCH=amd64 go build -ldflags "$LDFLAGS" -o client_${os}_amd64${suffix} github.com/xtaci/kcptun/client
+		CGO_ENABLED=0 GOOS=$os GOARCH=amd64 go build -ldflags "$LDFLAGS" -o server_${os}_amd64${suffix} github.com/xtaci/kcptun/server
+	fi
+
+	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-$VERSION.tar.gz
+done
+
+# ARM-5
+#CC=arm-linux-gnueabi-gcc-5 GOOS=linux GOARCH=arm GOARM=5 CGO_ENABLED=1 CGO_CFLAGS="-march=armv5" CGO_CXXFLAGS="-march=armv5" go install std
+CC=arm-linux-gnueabi-gcc-5 CXX=arm-linux-gnueabi-g++-5 GOOS=linux GOARCH=arm GOARM=5 CGO_ENABLED=1 CGO_CFLAGS="-march=armv5" CGO_CXXFLAGS="-march=armv5" go build -ldflags "$LDFLAGS_LINUX"  -o client_linux_arm5  github.com/xtaci/kcptun/client
+CC=arm-linux-gnueabi-gcc-5 CXX=arm-linux-gnueabi-g++-5 GOOS=linux GOARCH=arm GOARM=5 CGO_ENABLED=1 CGO_CFLAGS="-march=armv5" CGO_CXXFLAGS="-march=armv5" go build -ldflags "$LDFLAGS_LINUX"  -o server_linux_arm5  github.com/xtaci/kcptun/server
+if $UPX; then upx -9 client_linux_arm5 server_linux_arm5;fi
+tar -zcf kcptun-linux-arm5-$VERSION.tar.gz client_linux_arm5 server_linux_arm5
+$sum kcptun-linux-arm5-$VERSION.tar.gz
+
+# ARM-6
+#CC=arm-linux-gnueabi-gcc-5 GOOS=linux GOARCH=arm GOARM=6 CGO_ENABLED=1 CGO_CFLAGS="-march=armv6" CGO_CXXFLAGS="-march=armv6" go install std
+CC=arm-linux-gnueabi-gcc-5 CXX=arm-linux-gnueabi-g++-5 GOOS=linux GOARCH=arm GOARM=6 CGO_ENABLED=1 CGO_CFLAGS="-march=armv6" CGO_CXXFLAGS="-march=armv6" go build -ldflags "$LDFLAGS_LINUX"  -o client_linux_arm6 github.com/xtaci/kcptun/client
+CC=arm-linux-gnueabi-gcc-5 CXX=arm-linux-gnueabi-g++-5 GOOS=linux GOARCH=arm GOARM=6 CGO_ENABLED=1 CGO_CFLAGS="-march=armv6" CGO_CXXFLAGS="-march=armv6" go build -ldflags "$LDFLAGS_LINUX"  -o server_linux_arm6 github.com/xtaci/kcptun/server
+if $UPX; then upx -9 client_linux_arm6 server_linux_arm6;fi
+tar -zcf kcptun-linux-arm6-$VERSION.tar.gz client_linux_arm6 server_linux_arm6
+$sum kcptun-linux-arm6-$VERSION.tar.gz
+
+# ARM-7
+ARMS=(7)
+#CC=arm-linux-gnueabihf-gcc-5 GOOS=linux GOARCH=arm GOARM=7 CGO_ENABLED=1 CGO_CFLAGS="-march=armv7-a" CGO_CXXFLAGS="-march=armv7-a" go install std
+CC=arm-linux-gnueabihf-gcc-5 CXX=arm-linux-gnueabihf-g++-5 GOOS=linux GOARCH=arm GOARM=7 CGO_ENABLED=1 CGO_CFLAGS="-march=armv7-a -fPIC" CGO_CXXFLAGS="-march=armv7-a -fPIC" go build -ldflags "$LDFLAGS_LINUX"  -o client_linux_arm7  github.com/xtaci/kcptun/client
+CC=arm-linux-gnueabihf-gcc-5 CXX=arm-linux-gnueabihf-g++-5 GOOS=linux GOARCH=arm GOARM=7 CGO_ENABLED=1 CGO_CFLAGS="-march=armv7-a -fPIC" CGO_CXXFLAGS="-march=armv7-a -fPIC" go build -ldflags "$LDFLAGS_LINUX"  -o server_linux_arm7  github.com/xtaci/kcptun/server
+if $UPX; then upx -9 client_linux_arm7 server_linux_arm7;fi
+tar -zcf kcptun-linux-arm7-$VERSION.tar.gz client_linux_arm7 server_linux_arm7
+$sum kcptun-linux-arm7-$VERSION.tar.gz
+
+# ARM64
+CC=aarch64-linux-gnu-gcc-5 CXX=aarch64-linux-gnu-g++-5 GOOS=linux GOARCH=arm64 CGO_ENABLED=1 go build -ldflags "$LDFLAGS_LINUX"  -o client_linux_arm64  github.com/xtaci/kcptun/client
+CC=aarch64-linux-gnu-gcc-5 CXX=aarch64-linux-gnu-g++-5 GOOS=linux GOARCH=arm64 CGO_ENABLED=1 go build -ldflags "$LDFLAGS_LINUX"  -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
+
+#MIPS32LE
+CC=mipsel-linux-gnu-gcc-5 CXX=mipsel-linux-gnu-g++-5 GOOS=linux GOARCH=mipsle CGO_ENABLED=1 GOMIPS=softfloat go build -ldflags "$LDFLAGS_LINUX"  -o client_linux_mipsle github.com/xtaci/kcptun/client
+CC=mipsel-linux-gnu-gcc-5 CXX=mipsel-linux-gnu-g++-5 GOOS=linux GOARCH=mipsle CGO_ENABLED=1 GOMIPS=softfloat go build -ldflags "$LDFLAGS_LINUX"  -o server_linux_mipsle github.com/xtaci/kcptun/server
+
+#MIPS32
+CC=mips-linux-gnu-gcc-5 CXX=mips-linux-gnu-g++-5 GOOS=linux GOARCH=mips CGO_ENABLED=1 GOMIPS=softfloat go build -ldflags "$LDFLAGS_LINUX"  -o client_linux_mips github.com/xtaci/kcptun/client
+CC=mips-linux-gnu-gcc-5 CXX=mips-linux-gnu-g++-5 GOOS=linux GOARCH=mips CGO_ENABLED=1 GOMIPS=softfloat go build -ldflags "$LDFLAGS_LINUX"  -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
+tar -zcf kcptun-linux-mips-$VERSION.tar.gz client_linux_mips server_linux_mips
+$sum kcptun-linux-mipsle-$VERSION.tar.gz
+$sum kcptun-linux-mips-$VERSION.tar.gz
+
+echo "=== Building Completed ==="

build-release.sh

@@ -1,6 +1,14 @@
 #!/bin/bash
+
+BUILD_DIR=$(dirname "$0")/build
+mkdir -p $BUILD_DIR
+cd $BUILD_DIR
+
 sum="sha1sum"
 
+export GO111MODULE=on
+echo "Setting GO111MODULE to" $GO111MODULE
+
 if ! hash sha1sum 2>/dev/null; then
 	if ! hash shasum 2>/dev/null; then
 		echo "I can't see 'sha1sum' or 'shasum'"
@@ -19,38 +27,66 @@ VERSION=`date -u +%Y%m%d`
 LDFLAGS="-X main.VERSION=$VERSION -s -w"
 GCFLAGS=""
 
+# AMD64 
 OSES=(linux darwin windows freebsd)
-ARCHS=(amd64 386)
 for os in ${OSES[@]}; do
-	for arch in ${ARCHS[@]}; do
-		suffix=""
-		if [ "$os" == "windows" ]
-		then
-			suffix=".exe"
-		fi
-		env CGO_ENABLED=0 GOOS=$os GOARCH=$arch go build -ldflags "$LDFLAGS" -gcflags "$GCFLAGS" -o client_${os}_${arch}${suffix} github.com/xtaci/kcptun/client
-		env CGO_ENABLED=0 GOOS=$os GOARCH=$arch go build -ldflags "$LDFLAGS" -gcflags "$GCFLAGS" -o server_${os}_${arch}${suffix} github.com/xtaci/kcptun/server
-		if $UPX; then upx -9 client_${os}_${arch}${suffix} server_${os}_${arch}${suffix};fi
-		tar -zcf kcptun-${os}-${arch}-$VERSION.tar.gz client_${os}_${arch}${suffix} server_${os}_${arch}${suffix}
-		$sum kcptun-${os}-${arch}-$VERSION.tar.gz
-	done
+	suffix=""
+	if [ "$os" == "windows" ]
+	then
+		suffix=".exe"
+	fi
+	env CGO_ENABLED=0 GOOS=$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
+done
+
+# 386
+OSES=(linux windows)
+for os in ${OSES[@]}; do
+	suffix=""
+	if [ "$os" == "windows" ]
+	then
+		suffix=".exe"
+	fi
+	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
 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
+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
-if $UPX; then upx -9 client_linux_arm* server_linux_arm*;fi
-tar -zcf kcptun-linux-arm-$VERSION.tar.gz client_linux_arm* server_linux_arm*
-$sum kcptun-linux-arm-$VERSION.tar.gz
 
 #MIPS32LE
-env CGO_ENABLED=0 GOOS=linux GOARCH=mipsle go build -ldflags "$LDFLAGS" -gcflags "$GCFLAGS" -o client_linux_mipsle github.com/xtaci/kcptun/client
-env CGO_ENABLED=0 GOOS=linux GOARCH=mipsle go build -ldflags "$LDFLAGS" -gcflags "$GCFLAGS" -o server_linux_mipsle github.com/xtaci/kcptun/server
-env CGO_ENABLED=0 GOOS=linux GOARCH=mips go build -ldflags "$LDFLAGS" -gcflags "$GCFLAGS" -o client_linux_mips github.com/xtaci/kcptun/client
-env CGO_ENABLED=0 GOOS=linux GOARCH=mips 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

@@ -28,10 +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

@@ -0,0 +1,37 @@
+package main
+
+import (
+	"crypto/rand"
+	"encoding/binary"
+	"fmt"
+
+	"github.com/pkg/errors"
+	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", remoteAddr)
+		if err != nil {
+			return nil, errors.Wrap(err, "tcpraw.Dial()")
+		}
+		return kcp.NewConn(remoteAddr, block, config.DataShard, config.ParityShard, conn)
+	}
+	return kcp.DialWithOptions(remoteAddr, block, config.DataShard, config.ParityShard)
+
+}

client/main.go

@@ -2,82 +2,70 @@ package main
 
 import (
 	"crypto/sha1"
-	"encoding/csv"
 	"fmt"
 	"io"
 	"log"
 	"math/rand"
 	"net"
+	"net/http"
+	_ "net/http/pprof"
 	"os"
 	"time"
 
 	"golang.org/x/crypto/pbkdf2"
 
-	"github.com/golang/snappy"
 	"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"
 )
 
-var (
-	// VERSION is injected by buildflags
-	VERSION = "SELFBUILD"
+const (
 	// SALT is use for pbkdf2 key expansion
 	SALT = "kcp-go"
+	// maximum supported smux version
+	maxSmuxVer = 2
+	// stream copy buffer size
+	bufSize = 4096
 )
 
-type compStream struct {
-	conn net.Conn
-	w    *snappy.Writer
-	r    *snappy.Reader
-}
+// VERSION is injected by buildflags
+var VERSION = "SELFBUILD"
 
-func (c *compStream) Read(p []byte) (n int, err error) {
-	return c.r.Read(p)
-}
-
-func (c *compStream) Write(p []byte) (n int, err error) {
-	n, err = c.w.Write(p)
-	err = c.w.Flush()
-	return n, err
-}
-
-func (c *compStream) Close() error {
-	return c.conn.Close()
-}
-
-func newCompStream(conn net.Conn) *compStream {
-	c := new(compStream)
-	c.conn = conn
-	c.w = snappy.NewBufferedWriter(conn)
-	c.r = snappy.NewReader(conn)
-	return c
-}
-
-func handleClient(sess *smux.Session, p1 io.ReadWriteCloser) {
-	p2, err := sess.OpenStream()
+// 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 := session.OpenStream()
 	if err != nil {
+		logln(err)
 		return
 	}
 
-	log.Println("stream opened")
-	defer log.Println("stream closed")
-	defer p1.Close()
 	defer p2.Close()
 
-	// start tunnel
-	p1die := make(chan struct{})
-	go func() { io.Copy(p1, p2); close(p1die) }()
+	logln("stream opened", "in:", p1.RemoteAddr(), "out:", fmt.Sprint(p2.RemoteAddr(), "(", p2.ID(), ")"))
+	defer logln("stream closed", "in:", p1.RemoteAddr(), "out:", fmt.Sprint(p2.RemoteAddr(), "(", p2.ID(), ")"))
 
-	p2die := make(chan struct{})
-	go func() { io.Copy(p2, p1); close(p2die) }()
-
-	// wait for tunnel termination
-	select {
-	case <-p1die:
-	case <-p2die:
+	// start tunnel & wait for tunnel termination
+	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()
 	}
+
+	go streamCopy(p1, p2)
+	streamCopy(p2, p1)
 }
 
 func checkError(err error) {
@@ -87,12 +75,18 @@ 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)
 	}
+
 	myApp := cli.NewApp()
 	myApp.Name = "kcptun"
 	myApp.Usage = "client(with SMUX)"
@@ -106,7 +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",
@@ -117,7 +111,7 @@ func main() {
 		cli.StringFlag{
 			Name:  "crypt",
 			Value: "aes",
-			Usage: "aes, aes-128, aes-192, salsa20, blowfish, twofish, cast5, 3des, tea, xtea, xor, none",
+			Usage: "aes, aes-128, aes-192, salsa20, blowfish, twofish, cast5, 3des, tea, xtea, xor, sm4, none, null",
 		},
 		cli.StringFlag{
 			Name:  "mode",
@@ -137,7 +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",
@@ -185,7 +179,7 @@ func main() {
 		},
 		cli.IntFlag{
 			Name:   "interval",
-			Value:  40,
+			Value:  50,
 			Hidden: true,
 		},
 		cli.IntFlag{
@@ -199,14 +193,29 @@ func main() {
 			Hidden: true,
 		},
 		cli.IntFlag{
-			Name:   "sockbuf",
-			Value:  4194304, // socket buffer size in bytes
-			Hidden: true,
+			Name:  "sockbuf",
+			Value: 4194304, // socket buffer size in bytes
+			Usage: "per-socket buffer in bytes",
 		},
 		cli.IntFlag{
-			Name:   "keepalive",
-			Value:  10, // nat keepalive interval in seconds
-			Hidden: true,
+			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
+			Usage: "seconds between heartbeats",
 		},
 		cli.StringFlag{
 			Name:  "snmplog",
@@ -223,11 +232,23 @@ func main() {
 			Value: "",
 			Usage: "specify a log file to output, default goes to stderr",
 		},
+		cli.BoolFlag{
+			Name:  "quiet",
+			Usage: "to suppress the 'stream open/close' messages",
+		},
+		cli.BoolFlag{
+			Name:  "tcp",
+			Usage: "to emulate a TCP connection(linux)",
+		},
 		cli.StringFlag{
 			Name:  "c",
 			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{}
@@ -252,10 +273,16 @@ func main() {
 		config.Resend = c.Int("resend")
 		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"))
@@ -272,9 +299,9 @@ func main() {
 
 		switch config.Mode {
 		case "normal":
-			config.NoDelay, config.Interval, config.Resend, config.NoCongestion = 0, 30, 2, 1
+			config.NoDelay, config.Interval, config.Resend, config.NoCongestion = 0, 40, 2, 1
 		case "fast":
-			config.NoDelay, config.Interval, config.Resend, config.NoCongestion = 0, 20, 2, 1
+			config.NoDelay, config.Interval, config.Resend, config.NoCongestion = 0, 30, 2, 1
 		case "fast2":
 			config.NoDelay, config.Interval, config.Resend, config.NoCongestion = 1, 20, 2, 1
 		case "fast3":
@@ -282,14 +309,61 @@ 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":
 			block, _ = kcp.NewTEABlockCrypt(pass[:16])
 		case "xor":
@@ -317,38 +391,17 @@ 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("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)
-
-		smuxConfig := smux.DefaultConfig()
-		smuxConfig.MaxReceiveBuffer = config.SockBuf
-
 		createConn := func() (*smux.Session, error) {
-			kcpconn, err := kcp.DialWithOptions(config.RemoteAddr, block, config.DataShard, config.ParityShard)
+			kcpconn, err := dial(&config, block)
 			if err != nil {
-				return nil, errors.Wrap(err, "createConn()")
+				return nil, errors.Wrap(err, "dial()")
 			}
 			kcpconn.SetStreamMode(true)
+			kcpconn.SetWriteDelay(false)
 			kcpconn.SetNoDelay(config.NoDelay, config.Interval, config.Resend, config.NoCongestion)
 			kcpconn.SetWindowSize(config.SndWnd, config.RcvWnd)
 			kcpconn.SetMtu(config.MTU)
 			kcpconn.SetACKNoDelay(config.AckNodelay)
-			kcpconn.SetKeepAlive(config.KeepAlive)
 
 			if err := kcpconn.SetDSCP(config.DSCP); err != nil {
 				log.Println("SetDSCP:", err)
@@ -359,18 +412,27 @@ 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
 			if config.NoComp {
 				session, err = smux.Client(kcpconn, smuxConfig)
 			} else {
-				session, err = smux.Client(newCompStream(kcpconn), smuxConfig)
+				session, err = smux.Client(generic.NewCompStream(kcpconn), smuxConfig)
 			}
 			if err != nil {
 				return nil, errors.Wrap(err, "createConn()")
 			}
-			log.Println("connection:", kcpconn.LocalAddr(), "->", kcpconn.RemoteAddr())
 			return session, nil
 		}
 
@@ -380,78 +442,81 @@ func main() {
 				if session, err := createConn(); err == nil {
 					return session
 				} else {
+					log.Println("re-connecting:", err)
 					time.Sleep(time.Second)
 				}
 			}
 		}
 
-		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 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.Fatalln(err)
+				log.Fatalf("%+v", err)
 			}
-			if err := p1.SetReadBuffer(config.SockBuf); err != nil {
-				log.Println("TCP SetReadBuffer:", err)
-			}
-			if err := p1.SetWriteBuffer(config.SockBuf); err != nil {
-				log.Println("TCP SetWriteBuffer:", err)
-			}
-			checkError(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)
+			go handleClient(muxes[idx].session, p1, config.Quiet)
 			rr++
 		}
 	}
 	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")
+		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.Close()
-				} else if ttl >= 0 && time.Since(s.ts) >= time.Duration(ttl)*time.Second {
-					log.Println("session reached scavenge ttl")
+				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])
 				}
@@ -460,34 +525,3 @@ func scavenger(ch chan *smux.Session, ttl int) {
 		}
 	}
 }
-
-func snmpLogger(path string, interval int) {
-	if path == "" || interval == 0 {
-		return
-	}
-	ticker := time.NewTicker(time.Duration(interval) * time.Second)
-	defer ticker.Stop()
-	for {
-		select {
-		case <-ticker.C:
-			f, err := os.OpenFile(time.Now().Format(path), os.O_RDWR|os.O_CREATE|os.O_APPEND, 0666)
-			if err != nil {
-				log.Println(err)
-				return
-			}
-			w := csv.NewWriter(f)
-			// write header in empty file
-			if stat, err := f.Stat(); err == nil && stat.Size() == 0 {
-				if err := w.Write(append([]string{"Unix"}, kcp.DefaultSnmp.Header()...)); err != nil {
-					log.Println(err)
-				}
-			}
-			if err := w.Write(append([]string{fmt.Sprint(time.Now().Unix())}, kcp.DefaultSnmp.ToSlice()...)); err != nil {
-				log.Println(err)
-			}
-			kcp.DefaultSnmp.Reset()
-			w.Flush()
-			f.Close()
-		}
-	}
-}

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() {
@@ -18,6 +18,7 @@ func init() {
 func sigHandler() {
 	ch := make(chan os.Signal, 1)
 	signal.Notify(ch, syscall.SIGUSR1)
+	signal.Ignore(syscall.SIGPIPE)
 
 	for {
 		switch <-ch {

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

@@ -0,0 +1,62 @@
+package generic
+
+import (
+	"net"
+	"time"
+
+	"github.com/golang/snappy"
+	"github.com/pkg/errors"
+)
+
+type CompStream struct {
+	conn net.Conn
+	w    *snappy.Writer
+	r    *snappy.Reader
+}
+
+func (c *CompStream) Read(p []byte) (n int, err error) {
+	return c.r.Read(p)
+}
+
+func (c *CompStream) Write(p []byte) (n int, err error) {
+	if _, err := c.w.Write(p); err != nil {
+		return 0, errors.WithStack(err)
+	}
+
+	if err := c.w.Flush(); err != nil {
+		return 0, errors.WithStack(err)
+	}
+	return len(p), err
+}
+
+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
+	c.w = snappy.NewBufferedWriter(conn)
+	c.r = snappy.NewReader(conn)
+	return c
+}

generic/copy.go

@@ -0,0 +1,24 @@
+package generic
+
+import (
+	"io"
+)
+
+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)
+	}
+
+	// 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

@@ -0,0 +1,46 @@
+package generic
+
+import (
+	"encoding/csv"
+	"fmt"
+	"log"
+	"os"
+	"path/filepath"
+	"time"
+
+	kcp "github.com/xtaci/kcp-go/v5"
+)
+
+func SnmpLogger(path string, interval int) {
+	if path == "" || interval == 0 {
+		return
+	}
+	ticker := time.NewTicker(time.Duration(interval) * time.Second)
+	defer ticker.Stop()
+	for {
+		select {
+		case <-ticker.C:
+			// split path into dirname and filename
+			logdir, logfile := filepath.Split(path)
+			// only format logfile
+			f, err := os.OpenFile(logdir+time.Now().Format(logfile), os.O_RDWR|os.O_CREATE|os.O_APPEND, 0666)
+			if err != nil {
+				log.Println(err)
+				return
+			}
+			w := csv.NewWriter(f)
+			// write header in empty file
+			if stat, err := f.Stat(); err == nil && stat.Size() == 0 {
+				if err := w.Write(append([]string{"Unix"}, kcp.DefaultSnmp.Header()...)); err != nil {
+					log.Println(err)
+				}
+			}
+			if err := w.Write(append([]string{fmt.Sprint(time.Now().Unix())}, kcp.DefaultSnmp.ToSlice()...)); err != nil {
+				log.Println(err)
+			}
+			// kcp.DefaultSnmp.Reset()
+			w.Flush()
+			f.Close()
+		}
+	}
+}

go.mod

@@ -0,0 +1,29 @@
+module github.com/xtaci/kcptun
+
+require (
+	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 v5.6.8
+	github.com/xtaci/smux v1.5.24
+	github.com/xtaci/tcpraw v1.2.25
+	golang.org/x/crypto v0.17.0
+)
+
+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 v2.2.6 // indirect
+	github.com/klauspost/reedsolomon v1.12.0 // 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 v0.19.0 // indirect
+	golang.org/x/sys v0.16.0 // indirect
+)
+
+go 1.21
+
+toolchain go1.21.0

go.sum

@@ -0,0 +1,136 @@
+cloud.google.com/go v0.26.0/go.mod h1:aQUYkXzVsufM+DwF1aE+0xfcU+56JwCaLick0ClmMTw=
+github.com/BurntSushi/toml v0.3.1/go.mod h1:xHWCNGjB5oqiDr8zfno3MHue2Ht5sIBksp03qcyfWMU=
+github.com/BurntSushi/toml v1.3.2/go.mod h1:CxXYINrC8qIiEnFrOxCa7Jy5BFHlXnUU2pbicEuybxQ=
+github.com/census-instrumentation/opencensus-proto v0.2.1/go.mod h1:f6KPmirojxKA12rnyqOA5BBL4O983OfeGPqjHWSTneU=
+github.com/client9/misspell v0.3.4/go.mod h1:qj6jICC3Q7zFZvVWo7KLAzC3yx5G7kyvSDkc90ppPyw=
+github.com/cncf/udpa/go v0.0.0-20191209042840-269d4d468f6f/go.mod h1:M8M6+tZqaGXZJjfX53e64911xZQV5JYwmTeXPW+k8Sc=
+github.com/coreos/go-iptables v0.7.0 h1:XWM3V+MPRr5/q51NuWSgU0fqMad64Zyxs8ZUoMsamr8=
+github.com/coreos/go-iptables v0.7.0/go.mod h1:Qe8Bv2Xik5FyTXwgIbLAnv2sWSBmvWdFETJConOQ//Q=
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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

@@ -25,10 +25,16 @@ type Config struct {
 	Resend       int    `json:"resend"`
 	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"`
 	SnmpPeriod   int    `json:"snmpperiod"`
+	Pprof        bool   `json:"pprof"`
+	Quiet        bool   `json:"quiet"`
+	TCP          bool   `json:"tcp"`
 }
 
 func parseJSONConfig(config *Config, path string) error {

server/main.go

@@ -2,109 +2,113 @@ package main
 
 import (
 	"crypto/sha1"
-	"encoding/csv"
 	"fmt"
 	"io"
 	"log"
 	"math/rand"
 	"net"
+	"net/http"
+	_ "net/http/pprof"
 	"os"
+	"sync"
 	"time"
 
 	"golang.org/x/crypto/pbkdf2"
 
-	"github.com/golang/snappy"
 	"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"
 )
 
-var (
-	// VERSION is injected by buildflags
-	VERSION = "SELFBUILD"
+const (
 	// SALT is use for pbkdf2 key expansion
 	SALT = "kcp-go"
+	// maximum supported smux version
+	maxSmuxVer = 2
+	// stream copy buffer size
+	bufSize = 4096
 )
 
-type compStream struct {
-	conn net.Conn
-	w    *snappy.Writer
-	r    *snappy.Reader
-}
-
-func (c *compStream) Read(p []byte) (n int, err error) {
-	return c.r.Read(p)
-}
-
-func (c *compStream) Write(p []byte) (n int, err error) {
-	n, err = c.w.Write(p)
-	err = c.w.Flush()
-	return n, err
-}
-
-func (c *compStream) Close() error {
-	return c.conn.Close()
-}
-
-func newCompStream(conn net.Conn) *compStream {
-	c := new(compStream)
-	c.conn = conn
-	c.w = snappy.NewBufferedWriter(conn)
-	c.r = snappy.NewReader(conn)
-	return c
-}
+// VERSION is injected by buildflags
+var VERSION = "SELFBUILD"
 
 // 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.MaxReceiveBuffer = config.SockBuf
+	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)
 	if err != nil {
 		log.Println(err)
 		return
 	}
 	defer mux.Close()
+
 	for {
-		p1, err := mux.AcceptStream()
+		stream, err := mux.AcceptStream()
 		if err != nil {
 			log.Println(err)
 			return
 		}
-		p2, err := net.DialTimeout("tcp", config.Target, 5*time.Second)
-		if err != nil {
-			p1.Close()
-			log.Println(err)
-			continue
-		}
-		if err := p2.(*net.TCPConn).SetReadBuffer(config.SockBuf); err != nil {
-			log.Println("TCP SetReadBuffer:", err)
-		}
-		if err := p2.(*net.TCPConn).SetWriteBuffer(config.SockBuf); err != nil {
-			log.Println("TCP SetWriteBuffer:", err)
-		}
-		go handleClient(p1, p2)
+
+		go func(p1 *smux.Stream) {
+			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()
+				return
+			}
+			handleClient(p1, p2, config.Quiet)
+		}(stream)
 	}
 }
 
-func handleClient(p1, p2 io.ReadWriteCloser) {
-	log.Println("stream opened")
-	defer log.Println("stream closed")
+func handleClient(p1 *smux.Stream, p2 net.Conn, quiet bool) {
+	logln := func(v ...interface{}) {
+		if !quiet {
+			log.Println(v...)
+		}
+	}
+
 	defer p1.Close()
 	defer p2.Close()
 
-	// start tunnel
-	p1die := make(chan struct{})
-	go func() { io.Copy(p1, p2); close(p1die) }()
+	logln("stream opened", "in:", fmt.Sprint(p1.RemoteAddr(), "(", p1.ID(), ")"), "out:", p2.RemoteAddr())
+	defer logln("stream closed", "in:", fmt.Sprint(p1.RemoteAddr(), "(", p1.ID(), ")"), "out:", p2.RemoteAddr())
 
-	p2die := make(chan struct{})
-	go func() { io.Copy(p2, p1); close(p2die) }()
-
-	// wait for tunnel termination
-	select {
-	case <-p1die:
-	case <-p2die:
+	// start tunnel & wait for tunnel termination
+	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()
 	}
+
+	go streamCopy(p2, p1)
+	streamCopy(p1, p2)
 }
 
 func checkError(err error) {
@@ -120,6 +124,7 @@ func main() {
 		// add more log flags for debugging
 		log.SetFlags(log.LstdFlags | log.Lshortfile)
 	}
+
 	myApp := cli.NewApp()
 	myApp.Name = "kcptun"
 	myApp.Usage = "server(with SMUX)"
@@ -128,12 +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",
@@ -144,7 +149,7 @@ func main() {
 		cli.StringFlag{
 			Name:  "crypt",
 			Value: "aes",
-			Usage: "aes, aes-128, aes-192, salsa20, blowfish, twofish, cast5, 3des, tea, xtea, xor, none",
+			Usage: "aes, aes-128, aes-192, salsa20, blowfish, twofish, cast5, 3des, tea, xtea, xor, sm4, none, null",
 		},
 		cli.StringFlag{
 			Name:  "mode",
@@ -197,7 +202,7 @@ func main() {
 		},
 		cli.IntFlag{
 			Name:   "interval",
-			Value:  40,
+			Value:  50,
 			Hidden: true,
 		},
 		cli.IntFlag{
@@ -211,14 +216,29 @@ func main() {
 			Hidden: true,
 		},
 		cli.IntFlag{
-			Name:   "sockbuf",
-			Value:  4194304, // socket buffer size in bytes
-			Hidden: true,
+			Name:  "sockbuf",
+			Value: 4194304, // socket buffer size in bytes
+			Usage: "per-socket buffer in bytes",
 		},
 		cli.IntFlag{
-			Name:   "keepalive",
-			Value:  10, // nat keepalive interval in seconds
-			Hidden: true,
+			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
+			Usage: "seconds between heartbeats",
 		},
 		cli.StringFlag{
 			Name:  "snmplog",
@@ -230,11 +250,23 @@ func main() {
 			Value: 60,
 			Usage: "snmp collect period, in seconds",
 		},
+		cli.BoolFlag{
+			Name:  "pprof",
+			Usage: "start profiling server on :6060",
+		},
 		cli.StringFlag{
 			Name:  "log",
 			Value: "",
 			Usage: "specify a log file to output, default goes to stderr",
 		},
+		cli.BoolFlag{
+			Name:  "quiet",
+			Usage: "to suppress the 'stream open/close' messages",
+		},
+		cli.BoolFlag{
+			Name:  "tcp",
+			Usage: "to emulate a TCP connection(linux)",
+		},
 		cli.StringFlag{
 			Name:  "c",
 			Value: "", // when the value is not empty, the config path must exists
@@ -261,10 +293,16 @@ func main() {
 		config.Resend = c.Int("resend")
 		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.Pprof = c.Bool("pprof")
+		config.Quiet = c.Bool("quiet")
+		config.TCP = c.Bool("tcp")
 
 		if c.String("c") != "" {
 			//Now only support json config file
@@ -282,9 +320,9 @@ func main() {
 
 		switch config.Mode {
 		case "normal":
-			config.NoDelay, config.Interval, config.Resend, config.NoCongestion = 0, 30, 2, 1
+			config.NoDelay, config.Interval, config.Resend, config.NoCongestion = 0, 40, 2, 1
 		case "fast":
-			config.NoDelay, config.Interval, config.Resend, config.NoCongestion = 0, 20, 2, 1
+			config.NoDelay, config.Interval, config.Resend, config.NoCongestion = 0, 30, 2, 1
 		case "fast2":
 			config.NoDelay, config.Interval, config.Resend, config.NoCongestion = 1, 20, 2, 1
 		case "fast3":
@@ -292,9 +330,41 @@ 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":
 			block, _ = kcp.NewTEABlockCrypt(pass[:16])
 		case "xor":
@@ -322,84 +392,77 @@ func main() {
 			block, _ = kcp.NewAESBlockCrypt(pass)
 		}
 
-		lis, err := kcp.ListenWithOptions(config.Listen, block, config.DataShard, config.ParityShard)
-		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("keepalive:", config.KeepAlive)
-		log.Println("snmplog:", config.SnmpLog)
-		log.Println("snmpperiod:", config.SnmpPeriod)
-
-		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)
 		}
 
-		go snmpLogger(config.SnmpLog, config.SnmpPeriod)
-		for {
-			if conn, err := lis.AcceptKCP(); err == nil {
-				log.Println("remote address:", conn.RemoteAddr())
-				conn.SetStreamMode(true)
-				conn.SetNoDelay(config.NoDelay, config.Interval, config.Resend, config.NoCongestion)
-				conn.SetMtu(config.MTU)
-				conn.SetWindowSize(config.SndWnd, config.RcvWnd)
-				conn.SetACKNoDelay(config.AckNodelay)
-				conn.SetKeepAlive(config.KeepAlive)
+		// 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(newCompStream(conn), &config)
+					log.Printf("%+v", err)
 				}
-			} else {
-				log.Printf("%+v", err)
 			}
 		}
-	}
-	myApp.Run(os.Args)
-}
 
-func snmpLogger(path string, interval int) {
-	if path == "" || interval == 0 {
-		return
-	}
-	ticker := time.NewTicker(time.Duration(interval) * time.Second)
-	defer ticker.Stop()
-	for {
-		select {
-		case <-ticker.C:
-			f, err := os.OpenFile(time.Now().Format(path), os.O_RDWR|os.O_CREATE|os.O_APPEND, 0666)
-			if err != nil {
-				log.Println(err)
-				return
-			}
-			w := csv.NewWriter(f)
-			// write header in empty file
-			if stat, err := f.Stat(); err == nil && stat.Size() == 0 {
-				if err := w.Write(append([]string{"Unix"}, kcp.DefaultSnmp.Header()...)); err != nil {
+		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)
 				}
 			}
-			if err := w.Write(append([]string{fmt.Sprint(time.Now().Unix())}, kcp.DefaultSnmp.ToSlice()...)); err != nil {
-				log.Println(err)
-			}
-			kcp.DefaultSnmp.Reset()
-			w.Flush()
-			f.Close()
+
+			// 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() {
@@ -18,6 +18,7 @@ func init() {
 func sigHandler() {
 	ch := make(chan os.Signal, 1)
 	signal.Notify(ch, syscall.SIGUSR1)
+	signal.Ignore(syscall.SIGPIPE)
 
 	for {
 		switch <-ch {

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.
+For the purposes of this definition, "control" means (i) the power, direct or
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+contract or otherwise, or (ii) ownership of fifty percent (50%) or more of the
+outstanding shares, or (iii) beneficial ownership of such entity.
+
+"You" (or "Your") shall mean an individual or Legal Entity exercising
+permissions granted by this License.
+
+"Source" form shall mean the preferred form for making modifications, including
+but not limited to software source code, documentation source, and configuration
+files.
+
+"Object" form shall mean any form resulting from mechanical transformation or
+translation of a Source form, including but not limited to compiled object code,
+generated documentation, and conversions to other media types.
+
+"Work" shall mean the work of authorship, whether in Source or Object form, made
+available under the License, as indicated by a copyright notice that is included
+in or attached to the work (an example is provided in the Appendix below).
+
+"Derivative Works" shall mean any work, whether in Source or Object form, that
+is based on (or derived from) the Work and for which the editorial revisions,
+annotations, elaborations, or other modifications represent, as a whole, an
+original work of authorship. For the purposes of this License, Derivative Works
+shall not include works that remain separable from, or merely link (or bind by
+name) to the interfaces of, the Work and Derivative Works thereof.
+
+"Contribution" shall mean any work of authorship, including the original version
+of the Work and any modifications or additions to that Work or Derivative Works
+thereof, that is intentionally submitted to Licensor for inclusion in the Work
+by the copyright owner or by an individual or Legal Entity authorized to submit
+on behalf of the copyright owner. For the purposes of this definition,
+"submitted" means any form of electronic, verbal, or written communication sent
+to the Licensor or its representatives, including but not limited to
+communication on electronic mailing lists, source code control systems, and
+issue tracking systems that are managed by, or on behalf of, the Licensor for
+the purpose of discussing and improving the Work, but excluding communication
+that is conspicuously marked or otherwise designated in writing by the copyright
+owner as "Not a Contribution."
+
+"Contributor" shall mean Licensor and any individual or Legal Entity on behalf
+of whom a Contribution has been received by Licensor and subsequently
+incorporated within the Work.
+
+2. Grant of Copyright License.
+
+Subject to the terms and conditions of this License, each Contributor hereby
+grants to You a perpetual, worldwide, non-exclusive, no-charge, royalty-free,
+irrevocable copyright license to reproduce, prepare Derivative Works of,
+publicly display, publicly perform, sublicense, and distribute the Work and such
+Derivative Works in Source or Object form.
+
+3. Grant of Patent License.
+
+Subject to the terms and conditions of this License, each Contributor hereby
+grants to You a perpetual, worldwide, non-exclusive, no-charge, royalty-free,
+irrevocable (except as stated in this section) patent license to make, have
+made, use, offer to sell, sell, import, and otherwise transfer the Work, where
+such license applies only to those patent claims licensable by such Contributor
+that are necessarily infringed by their Contribution(s) alone or by combination
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+submitted. If You institute patent litigation against any entity (including a
+cross-claim or counterclaim in a lawsuit) alleging that the Work or a
+Contribution incorporated within the Work constitutes direct or contributory
+patent infringement, then any patent licenses granted to You under this License
+for that Work shall terminate as of the date such litigation is filed.
+
+4. Redistribution.
+
+You may reproduce and distribute copies of the Work or Derivative Works thereof
+in any medium, with or without modifications, and in Source or Object form,
+provided that You meet the following conditions:
+
+You must give any other recipients of the Work or Derivative Works a copy of
+this License; and
+You must cause any modified files to carry prominent notices stating that You
+changed the files; and
+You must retain, in the Source form of any Derivative Works that You distribute,
+all copyright, patent, trademark, and attribution notices from the Source form
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+Derivative Works; and
+If the Work includes a "NOTICE" text file as part of its distribution, then any
+Derivative Works that You distribute must include a readable copy of the
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+following places: within a NOTICE text file distributed as part of the
+Derivative Works; within the Source form or documentation, if provided along
+with the Derivative Works; or, within a display generated by the Derivative
+Works, if and wherever such third-party notices normally appear. The contents of
+the NOTICE file are for informational purposes only and do not modify the
+License. You may add Your own attribution notices within Derivative Works that
+You distribute, alongside or as an addendum to the NOTICE text from the Work,
+provided that such additional attribution notices cannot be construed as
+modifying the License.
+You may add Your own copyright statement to Your modifications and may provide
+additional or different license terms and conditions for use, reproduction, or
+distribution of Your modifications, or for any such Derivative Works as a whole,
+provided Your use, reproduction, and distribution of the Work otherwise complies
+with the conditions stated in this License.
+
+5. Submission of Contributions.
+
+Unless You explicitly state otherwise, any Contribution intentionally submitted
+for inclusion in the Work by You to the Licensor shall be under the terms and
+conditions of this License, without any additional terms or conditions.
+Notwithstanding the above, nothing herein shall supersede or modify the terms of
+any separate license agreement you may have executed with Licensor regarding
+such Contributions.
+
+6. Trademarks.
+
+This License does not grant permission to use the trade names, trademarks,
+service marks, or product names of the Licensor, except as required for
+reasonable and customary use in describing the origin of the Work and
+reproducing the content of the NOTICE file.
+
+7. Disclaimer of Warranty.
+
+Unless required by applicable law or agreed to in writing, Licensor provides the
+Work (and each Contributor provides its Contributions) on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied,
+including, without limitation, any warranties or conditions of TITLE,
+NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A PARTICULAR PURPOSE. You are
+solely responsible for determining the appropriateness of using or
+redistributing the Work and assume any risks associated with Your exercise of
+permissions under this License.
+
+8. Limitation of Liability.
+
+In no event and under no legal theory, whether in tort (including negligence),
+contract, or otherwise, unless required by applicable law (such as deliberate
+and grossly negligent acts) or agreed to in writing, shall any Contributor be
+liable to You for damages, including any direct, indirect, special, incidental,
+or consequential damages of any character arising as a result of this License or
+out of the use or inability to use the Work (including but not limited to
+damages for loss of goodwill, work stoppage, computer failure or malfunction, or
+any and all other commercial damages or losses), even if such Contributor has
+been advised of the possibility of such damages.
+
+9. Accepting Warranty or Additional Liability.
+
+While redistributing the Work or Derivative Works thereof, You may choose to
+offer, and charge a fee for, acceptance of support, warranty, indemnity, or
+other liability obligations and/or rights consistent with this License. However,
+in accepting such obligations, You may act only on Your own behalf and on Your
+sole responsibility, not on behalf of any other Contributor, and only if You
+agree to indemnify, defend, and hold each Contributor harmless for any liability
+incurred by, or claims asserted against, such Contributor by reason of your
+accepting any such warranty or additional liability.
+
+END OF TERMS AND CONDITIONS
+
+APPENDIX: How to apply the Apache License to your work
+
+To apply the Apache License to your work, attach the following boilerplate
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+
+   Licensed under the Apache License, Version 2.0 (the "License");
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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)
+}