Revert "passive tunnel termination"

This reverts commit bf1d0d6419.

.travis.yml

@@ -1,6 +1,6 @@
 language: go
 go:
-    - 1.6
+    - 1.9
 before_install:
     - go get github.com/mattn/goveralls
     - go get golang.org/x/tools/cmd/cover

Dockerfile

@@ -1,8 +1,11 @@
-FROM golang:alpine
+FROM golang:alpine 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
+RUN go get -ldflags "-X main.VERSION=$(date -u +%Y%m%d) -s -w" github.com/xtaci/kcptun/client && go get -ldflags "-X main.VERSION=$(date -u +%Y%m%d) -s -w" github.com/xtaci/kcptun/server
+
+FROM alpine:3.6
+COPY --from=builder /go/bin /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

@@ -1,5 +1,7 @@
 # <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
@@ -17,15 +19,18 @@
 [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)
+> *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. kcptun won't publish anything on any social media.*
 
--
+> *KCP communication group: 364933586 (QQ group number), KCP integration, tuning, network transmission and related technical discussions.*
 
 ### QuickStart
 
+Increase number of open files on your server, as:
+
+`ulimit -n 65535`, or write it in `~/.bashrc`.
+
 Download precompiled [Releases](https://github.com/xtaci/kcptun/releases).
 
 ```
@@ -34,7 +39,11 @@ KCP Server: ./server_linux_amd64 -t "TARGET_IP:8388" -l ":4000" -mode fast2
 ```
 The above commands will establish port forwarding for 8388/tcp as:
 
-Application -> KCP Client(8388/tcp) -> KCP Server(4000/udp) -> Server(8388/tcp) 
+> Application -> **KCP Client(8388/tcp) -> KCP Server(4000/udp)** -> Target Server(8388/tcp) 
+
+Tunnels the original connection:
+
+> Application -> Target Server(8388/tcp) 
 
 ### Install from source
 
@@ -55,7 +64,8 @@ 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
 
@@ -157,7 +167,7 @@ It is able to detect and correct multiple symbol errors. By adding t check symbo
 
 ![reed-solomon](rs.png)
 
-Setting parameters of RS-Code with ```-datashard m -parityshard n``` on both KCP Client & KCP Server.
+Setting parameters of RS-Code with ```-datashard m -parityshard n``` on **BOTH** KCP Client & KCP Server **MUST** be **IDENTICAL**.
 
 #### DSCP
 
@@ -215,7 +225,7 @@ kcptun has builtin snappy algorithms for compressing streams:
 
 Compression may save bandwidth for **PLAINTEXT** data, such as HTTP data.
 
-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
 
@@ -257,31 +267,38 @@ 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
+The parameters below **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. -datashard
+1. -parityshard
 
 ### 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://play.google.com/store/apps/details?id=com.k17game.k3 -- Battle Zone - Earth 2048, an online strategy game using kcp.
+
+### Donate via Ethereum(ETH)
+
+Address: 0x2e4b43ab3d0983da282592571eef61ae5e60f726 , Or scan here:
+
+<img src="0x2e4b43ab3d0983da282592571eef61ae5e60f726.png" alt="kcptun" height="100px" /> 

client/config.go

@@ -32,6 +32,7 @@ type Config struct {
 	Log          string `json:"log"`
 	SnmpLog      string `json:"snmplog"`
 	SnmpPeriod   int    `json:"snmpperiod"`
+	Quiet        bool   `json:"quiet"`
 }
 
 func parseJSONConfig(config *Config, path string) error {

client/main.go

@@ -55,15 +55,17 @@ func newCompStream(conn net.Conn) *compStream {
 	return c
 }
 
-func handleClient(sess *smux.Session, p1 io.ReadWriteCloser) {
+func handleClient(sess *smux.Session, p1 io.ReadWriteCloser, quiet bool) {
+	if !quiet {
+		log.Println("stream opened")
+		defer log.Println("stream closed")
+	}
+
+	defer p1.Close()
 	p2, err := sess.OpenStream()
 	if err != nil {
 		return
 	}
-
-	log.Println("stream opened")
-	defer log.Println("stream closed")
-	defer p1.Close()
 	defer p2.Close()
 
 	// start tunnel
@@ -117,7 +119,7 @@ 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",
 		},
 		cli.StringFlag{
 			Name:  "mode",
@@ -185,7 +187,7 @@ func main() {
 		},
 		cli.IntFlag{
 			Name:   "interval",
-			Value:  40,
+			Value:  50,
 			Hidden: true,
 		},
 		cli.IntFlag{
@@ -223,6 +225,10 @@ 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.StringFlag{
 			Name:  "c",
 			Value: "", // when the value is not empty, the config path must exists
@@ -256,6 +262,7 @@ func main() {
 		config.Log = c.String("log")
 		config.SnmpLog = c.String("snmplog")
 		config.SnmpPeriod = c.Int("snmpperiod")
+		config.Quiet = c.Bool("quiet")
 
 		if c.String("c") != "" {
 			err := parseJSONConfig(&config, c.String("c"))
@@ -272,9 +279,9 @@ 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":
@@ -290,6 +297,8 @@ func main() {
 		pass := pbkdf2.Key([]byte(config.Key), []byte(SALT), 4096, 32, sha1.New)
 		var block kcp.BlockCrypt
 		switch config.Crypt {
+		case "sm4":
+			block, _ = kcp.NewSM4BlockCrypt(pass[:16])
 		case "tea":
 			block, _ = kcp.NewTEABlockCrypt(pass[:16])
 		case "xor":
@@ -334,9 +343,11 @@ func main() {
 		log.Println("scavengettl:", config.ScavengeTTL)
 		log.Println("snmplog:", config.SnmpLog)
 		log.Println("snmpperiod:", config.SnmpPeriod)
+		log.Println("quiet:", config.Quiet)
 
 		smuxConfig := smux.DefaultConfig()
 		smuxConfig.MaxReceiveBuffer = config.SockBuf
+		smuxConfig.KeepAliveInterval = time.Duration(config.KeepAlive) * time.Second
 
 		createConn := func() (*smux.Session, error) {
 			kcpconn, err := kcp.DialWithOptions(config.RemoteAddr, block, config.DataShard, config.ParityShard)
@@ -344,11 +355,11 @@ func main() {
 				return nil, errors.Wrap(err, "createConn()")
 			}
 			kcpconn.SetStreamMode(true)
+			kcpconn.SetWriteDelay(true)
 			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)
@@ -380,6 +391,7 @@ func main() {
 				if session, err := createConn(); err == nil {
 					return session
 				} else {
+					log.Println("re-connecting:", err)
 					time.Sleep(time.Second)
 				}
 			}
@@ -405,12 +417,6 @@ func main() {
 			if err != nil {
 				log.Fatalln(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
 
@@ -421,7 +427,7 @@ func main() {
 				muxes[idx].ttl = time.Now().Add(time.Duration(config.AutoExpire) * time.Second)
 			}
 
-			go handleClient(muxes[idx].session, p1)
+			go handleClient(muxes[idx].session, p1, config.Quiet)
 			rr++
 		}
 	}

client/signal.go

@@ -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 {

server/config.go

@@ -29,6 +29,8 @@ type Config struct {
 	Log          string `json:"log"`
 	SnmpLog      string `json:"snmplog"`
 	SnmpPeriod   int    `json:"snmpperiod"`
+	Pprof        bool   `json:"pprof"`
+	Quiet        bool   `json:"quiet"`
 }
 
 func parseJSONConfig(config *Config, path string) error {

server/main.go

@@ -8,6 +8,8 @@ import (
 	"log"
 	"math/rand"
 	"net"
+	"net/http"
+	_ "net/http/pprof"
 	"os"
 	"time"
 
@@ -59,6 +61,8 @@ func handleMux(conn io.ReadWriteCloser, config *Config) {
 	// stream multiplex
 	smuxConfig := smux.DefaultConfig()
 	smuxConfig.MaxReceiveBuffer = config.SockBuf
+	smuxConfig.KeepAliveInterval = time.Duration(config.KeepAlive) * time.Second
+
 	mux, err := smux.Server(conn, smuxConfig)
 	if err != nil {
 		log.Println(err)
@@ -77,19 +81,15 @@ func handleMux(conn io.ReadWriteCloser, config *Config) {
 			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 handleClient(p1, p2, config.Quiet)
 	}
 }
 
-func handleClient(p1, p2 io.ReadWriteCloser) {
-	log.Println("stream opened")
-	defer log.Println("stream closed")
+func handleClient(p1, p2 io.ReadWriteCloser, quiet bool) {
+	if !quiet {
+		log.Println("stream opened")
+		defer log.Println("stream closed")
+	}
 	defer p1.Close()
 	defer p2.Close()
 
@@ -144,7 +144,7 @@ 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",
 		},
 		cli.StringFlag{
 			Name:  "mode",
@@ -197,7 +197,7 @@ func main() {
 		},
 		cli.IntFlag{
 			Name:   "interval",
-			Value:  40,
+			Value:  50,
 			Hidden: true,
 		},
 		cli.IntFlag{
@@ -230,11 +230,19 @@ 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.StringFlag{
 			Name:  "c",
 			Value: "", // when the value is not empty, the config path must exists
@@ -265,6 +273,8 @@ func main() {
 		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")
 
 		if c.String("c") != "" {
 			//Now only support json config file
@@ -282,9 +292,9 @@ 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":
@@ -295,6 +305,8 @@ func main() {
 		pass := pbkdf2.Key([]byte(config.Key), []byte(SALT), 4096, 32, sha1.New)
 		var block kcp.BlockCrypt
 		switch config.Crypt {
+		case "sm4":
+			block, _ = kcp.NewSM4BlockCrypt(pass[:16])
 		case "tea":
 			block, _ = kcp.NewTEABlockCrypt(pass[:16])
 		case "xor":
@@ -338,6 +350,8 @@ func main() {
 		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)
 
 		if err := lis.SetDSCP(config.DSCP); err != nil {
 			log.Println("SetDSCP:", err)
@@ -350,15 +364,19 @@ func main() {
 		}
 
 		go snmpLogger(config.SnmpLog, config.SnmpPeriod)
+		if config.Pprof {
+			go http.ListenAndServe(":6060", nil)
+		}
+
 		for {
 			if conn, err := lis.AcceptKCP(); err == nil {
 				log.Println("remote address:", conn.RemoteAddr())
 				conn.SetStreamMode(true)
+				conn.SetWriteDelay(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)
 
 				if config.NoComp {
 					go handleMux(conn, &config)

server/signal.go

@@ -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 {