upd

This reverts commit 3803993529.

.github/ISSUE_TEMPLATE

@@ -2,11 +2,12 @@ Before firing issue, make sure you figured out the following common questions.
 
 PLEASE DO SEARCH FIRST.
 
-1. Are you using the **latest release**?
-2. Which **OS** do you use?
-3. Which end for this issue related to, **client or server**?
-4. Are you using the **same version** for both client & server
-5. Did you correctly set the ***-target value, -t value	target server address (default: "127.0.0.1:12948")*** on the server side?
-6. Can ```telnet target port``` successful?
-7. ```-nocomp, -datashard, -parityshard,  -key, -crypt``` ***must be the same*** on both side.
-8. Does your ***firewall allows UDP*** communications? (including your ISP Cable-Modem)
+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.
+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**?

Dockerfile

@@ -3,7 +3,6 @@ MAINTAINER xtaci <daniel820313@gmail.com>
 RUN apk update && \
     apk upgrade && \
     apk add git
-RUN go get github.com/xtaci/kcptun/client
-RUN go get github.com/xtaci/kcptun/server
+RUN go get github.com/xtaci/kcptun/client && go get github.com/xtaci/kcptun/server
 EXPOSE 29900/udp
 EXPOSE 12948

README.en.md

@@ -1,7 +1,7 @@
 # <img src="logo.png" alt="kcptun" height="60px" /> 
-[![GoDoc][1]][2] [![Release][13]][14] [![Powered][17]][18] [![MIT licensed][11]][12] [![Build Status][3]][4] [![Go Report Card][5]][6] [![Downloads][15]][16] [![Gitter][19]][20]
-[1]: https://godoc.org/github.com/xtaci/kcptun?status.svg
-[2]: https://godoc.org/github.com/xtaci/kcptun
+[![Release][13]][14] [![Powered][17]][18] [![MIT licensed][11]][12] [![Build Status][3]][4] [![Go Report Card][5]][6] [![Downloads][15]][16] [![Gitter][19]][20] [![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
@@ -40,6 +40,7 @@ Client Side: ./client_darwin_amd64 -r "SERVERIP:4000" -l ":1080" -mode fast2  //
 * WIFI: 5GHz TL-WDR3320
 
 ### *Usage* :lollipop:
+Help output under MacOS X:
 ```
 $ ./client_darwin_amd64 -h
 NAME:
@@ -49,7 +50,7 @@ USAGE:
    client_darwin_amd64 [global options] command [command options] [arguments...]
 
 VERSION:
-   20160811
+   20160820
 
 COMMANDS:
      help, h  Shows a list of commands or help for one command
@@ -57,22 +58,21 @@ COMMANDS:
 GLOBAL OPTIONS:
    --localaddr value, -l value   local listen address (default: ":12948")
    --remoteaddr value, -r value  kcp server address (default: "vps:29900")
-   --key value                   key for communcation, must be the same as kcptun server (default: "it's a secrect") [$KCPTUN_KEY]
-   --crypt value                 methods for encryption: aes, tea, xor, none (default: "aes")
-   --mode value                  mode for communication: fast3, fast2, fast, normal (default: "fast")
-   --conn value                  establish N physical connections as specified by 'conn' to server (default: 1)
-   --mtu value                   set MTU of UDP packets, suggest 'tracepath' to discover path mtu (default: 1350)
+   --key value                   pre-shared secret for client and server (default: "it's a secrect") [$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)
+   --mtu value                   set maximum transmission unit of 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: 1024)
-   --nocomp                      disable compression
    --datashard value             set reed-solomon erasure coding - datashard (default: 10)
    --parityshard value           set reed-solomon erasure coding - parityshard (default: 3)
    --dscp value                  set DSCP(6bit) (default: 0)
+   --nocomp                      disable compression
    --help, -h                    show help
    --version, -v                 print the version
-```
 
-```
+
 $ ./server_darwin_amd64 -h
 NAME:
    kcptun - kcptun server
@@ -81,7 +81,7 @@ USAGE:
    server_darwin_amd64 [global options] command [command options] [arguments...]
 
 VERSION:
-   20160811
+   20160820
 
 COMMANDS:
      help, h  Shows a list of commands or help for one command
@@ -89,16 +89,16 @@ COMMANDS:
 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               key for communcation, must be the same as kcptun client (default: "it's a secrect") [$KCPTUN_KEY]
-   --crypt value             methods for encryption: aes, tea, xor, none (default: "aes")
-   --mode value              mode for communication: fast3, fast2, fast, normal (default: "fast")
-   --mtu value               set MTU of UDP packets, suggest 'tracepath' to discover path mtu (default: 1350)
+   --key value               pre-shared secret for client and server (default: "it's a secrect") [$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 of 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)
-   --nocomp                  disable compression
    --datashard value         set reed-solomon erasure coding - datashard (default: 10)
    --parityshard value       set reed-solomon erasure coding - parityshard (default: 3)
    --dscp value              set DSCP(6bit) (default: 0)
+   --nocomp                  disable compression
    --help, -h                show help
    --version, -v             print the version
 ```
@@ -124,6 +124,12 @@ other parameters can be set independently.
 
 ***NOTICE: if too much retranmission happens, it's quite possible the windows are too large***
 
+### *Security* :lollipop: 
+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 .
+
+NOTICE: ```-crypt xor``` is also insecure, do not use this unless you know what you are doing.
+
 ### *Memory Control* :lollipop: 
 Routers, mobile devices are sensitive to memory consumption; by setting GOGC environment(eg: GOGC=20) will lower memory consumption.
 Reference: https://blog.golang.org/go15gc
@@ -159,6 +165,7 @@ Manual control is supported with hidden parameters, you must understand KCP prot
 ```
  -mode manual -nodelay 1 -resend 2 -nc 1 -interval 20
 ```
+I suggest fast2 for high-loss network, normal for low-loss network.
 
 ### *Forward Error Correction* :lollipop: 
 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.

README.md

@@ -1,7 +1,7 @@
 # <img src="logo.png" alt="kcptun" height="60px" /> 
-[![GoDoc][1]][2] [![Release][13]][14] [![Powered][17]][18] [![MIT licensed][11]][12] [![Build Status][3]][4] [![Go Report Card][5]][6] [![Downloads][15]][16] [![Gitter][19]][20]
-[1]: https://godoc.org/github.com/xtaci/kcptun?status.svg
-[2]: https://godoc.org/github.com/xtaci/kcptun
+[![Release][13]][14] [![Powered][17]][18] [![MIT licensed][11]][12] [![Build Status][3]][4] [![Go Report Card][5]][6] [![Downloads][15]][16] [![Gitter][19]][20] [![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
@@ -47,7 +47,7 @@ USAGE:
    client_darwin_amd64 [global options] command [command options] [arguments...]
 
 VERSION:
-   20160811
+   20160820
 
 COMMANDS:
      help, h  Shows a list of commands or help for one command
@@ -55,22 +55,21 @@ COMMANDS:
 GLOBAL OPTIONS:
    --localaddr value, -l value   local listen address (default: ":12948")
    --remoteaddr value, -r value  kcp server address (default: "vps:29900")
-   --key value                   key for communcation, must be the same as kcptun server (default: "it's a secrect") [$KCPTUN_KEY]
-   --crypt value                 methods for encryption: aes, tea, xor, none (default: "aes")
-   --mode value                  mode for communication: fast3, fast2, fast, normal (default: "fast")
-   --conn value                  establish N physical connections as specified by 'conn' to server (default: 1)
-   --mtu value                   set MTU of UDP packets, suggest 'tracepath' to discover path mtu (default: 1350)
+   --key value                   pre-shared secret for client and server (default: "it's a secrect") [$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)
+   --mtu value                   set maximum transmission unit of 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: 1024)
-   --nocomp                      disable compression
    --datashard value             set reed-solomon erasure coding - datashard (default: 10)
    --parityshard value           set reed-solomon erasure coding - parityshard (default: 3)
    --dscp value                  set DSCP(6bit) (default: 0)
+   --nocomp                      disable compression
    --help, -h                    show help
    --version, -v                 print the version
-```
 
-```
+
 $ ./server_darwin_amd64 -h
 NAME:
    kcptun - kcptun server
@@ -79,7 +78,7 @@ USAGE:
    server_darwin_amd64 [global options] command [command options] [arguments...]
 
 VERSION:
-   20160811
+   20160820
 
 COMMANDS:
      help, h  Shows a list of commands or help for one command
@@ -87,16 +86,16 @@ COMMANDS:
 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               key for communcation, must be the same as kcptun client (default: "it's a secrect") [$KCPTUN_KEY]
-   --crypt value             methods for encryption: aes, tea, xor, none (default: "aes")
-   --mode value              mode for communication: fast3, fast2, fast, normal (default: "fast")
-   --mtu value               set MTU of UDP packets, suggest 'tracepath' to discover path mtu (default: 1350)
+   --key value               pre-shared secret for client and server (default: "it's a secrect") [$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 of 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)
-   --nocomp                  disable compression
    --datashard value         set reed-solomon erasure coding - datashard (default: 10)
    --parityshard value       set reed-solomon erasure coding - parityshard (default: 3)
    --dscp value              set DSCP(6bit) (default: 0)
+   --nocomp                  disable compression
    --help, -h                show help
    --version, -v             print the version
 ```
@@ -142,6 +141,11 @@ GLOBAL OPTIONS:
 		max_bandwidth_fec = max_bandwidth * (10 + 3) /10 = 1.3*max_bandwidth ＝ 1.3 * 25Mbps = 32.5Mbps
 ```
 
+### *安全* :lollipop: 
+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。
+
+注意: ```-crypt xor``` 也是不安全的，除非你知道你在做什么。
+
 ### *内存控制* :lollipop: 
 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
@@ -201,6 +205,7 @@ DSCP差分服务代码点（Differentiated Services Code Point），IETF于1998
 ```
  -mode manual -nodelay 1 -resend 2 -nc 1 -interval 20
 ```
+高丢包率的网络建议采用fast2, 低丢包率的网络，建议采用normal。
 
 ### *SNMP* :lollipop:
 ```go

build-release.sh

@@ -12,6 +12,7 @@ fi
 
 VERSION=`date -u +%Y%m%d`
 LDFLAGS="-X main.VERSION=$VERSION -s -w"
+GCFLAGS="-B"
 
 OSES=(linux darwin windows freebsd)
 ARCHS=(amd64 386)
@@ -22,8 +23,8 @@ for os in ${OSES[@]}; do
 		then
 			suffix=".exe"
 		fi
-		env CGO_ENABLED=0 GOOS=$os GOARCH=$arch go build -ldflags "$LDFLAGS" -o client_${os}_${arch}${suffix} github.com/xtaci/kcptun/client
-		env CGO_ENABLED=0 GOOS=$os GOARCH=$arch go build -ldflags "$LDFLAGS" -o server_${os}_${arch}${suffix} github.com/xtaci/kcptun/server
+		env CGO_ENABLED=0 GOOS=$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}
 		$MD5 kcptun-${os}-${arch}-$VERSION.tar.gz
@@ -33,8 +34,8 @@ done
 # ARM
 ARMS=(5 6 7)
 for v in ${ARMS[@]}; do
-	env CGO_ENABLED=0 GOOS=linux GOARCH=arm GOARM=$v go build -ldflags "$LDFLAGS" -o client_linux_arm$v  github.com/xtaci/kcptun/client
-	env CGO_ENABLED=0 GOOS=linux GOARCH=arm GOARM=$v go build -ldflags "$LDFLAGS" -o server_linux_arm$v  github.com/xtaci/kcptun/server
+	env CGO_ENABLED=0 GOOS=linux GOARCH=arm GOARM=$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
 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*

client/main.go

@@ -7,14 +7,15 @@ import (
 	"math/rand"
 	"net"
 	"os"
+	"runtime"
 	"time"
 
 	"golang.org/x/crypto/pbkdf2"
 
 	"github.com/golang/snappy"
-	"github.com/hashicorp/yamux"
 	"github.com/urfave/cli"
 	kcp "github.com/xtaci/kcp-go"
+	"github.com/xtaci/yamux"
 )
 
 var (
@@ -109,28 +110,33 @@ func main() {
 		cli.StringFlag{
 			Name:   "key",
 			Value:  "it's a secrect",
-			Usage:  "key for communcation, must be the same as kcptun server",
+			Usage:  "pre-shared secret between client and server",
 			EnvVar: "KCPTUN_KEY",
 		},
 		cli.StringFlag{
 			Name:  "crypt",
 			Value: "aes",
-			Usage: "methods for encryption: aes, aes-128, aes-192, tea, xor, none",
+			Usage: "aes, aes-128, aes-192, salsa20, blowfish, twofish, cast5, 3des, tea, xtea, xor, none",
 		},
 		cli.StringFlag{
 			Name:  "mode",
 			Value: "fast",
-			Usage: "mode for communication: fast3, fast2, fast, normal",
+			Usage: "profiles: fast3, fast2, fast, normal",
 		},
 		cli.IntFlag{
 			Name:  "conn",
 			Value: 1,
-			Usage: "establish N physical connections as specified by 'conn' to server",
+			Usage: "set num of UDP connections to server",
+		},
+		cli.IntFlag{
+			Name:  "autoexpire",
+			Value: 0,
+			Usage: "set auto expiration time(in seconds) for a single UDP connection, 0 to disable",
 		},
 		cli.IntFlag{
 			Name:  "mtu",
 			Value: 1350,
-			Usage: "set MTU of UDP packets, suggest 'tracepath' to discover path mtu",
+			Usage: "set maximum transmission unit for UDP packets",
 		},
 		cli.IntFlag{
 			Name:  "sndwnd",
@@ -142,10 +148,6 @@ func main() {
 			Value: 1024,
 			Usage: "set receive window size(num of packets)",
 		},
-		cli.BoolFlag{
-			Name:  "nocomp",
-			Usage: "disable compression",
-		},
 		cli.IntFlag{
 			Name:  "datashard",
 			Value: 10,
@@ -166,6 +168,10 @@ func main() {
 			Value: 0,
 			Usage: "set DSCP(6bit)",
 		},
+		cli.BoolFlag{
+			Name:  "nocomp",
+			Usage: "disable compression",
+		},
 		cli.IntFlag{
 			Name:   "nodelay",
 			Value:  0,
@@ -232,7 +238,20 @@ func main() {
 			block, _ = kcp.NewAESBlockCrypt(pass[:16])
 		case "aes-192":
 			block, _ = kcp.NewAESBlockCrypt(pass[:24])
+		case "blowfish":
+			block, _ = kcp.NewBlowfishBlockCrypt(pass)
+		case "twofish":
+			block, _ = kcp.NewTwofishBlockCrypt(pass)
+		case "cast5":
+			block, _ = kcp.NewCast5BlockCrypt(pass[:16])
+		case "3des":
+			block, _ = kcp.NewTripleDESBlockCrypt(pass[:24])
+		case "xtea":
+			block, _ = kcp.NewXTEABlockCrypt(pass[:16])
+		case "salsa20":
+			block, _ = kcp.NewSalsa20BlockCrypt(pass)
 		default:
+			crypt = "aes"
 			block, _ = kcp.NewAESBlockCrypt(pass)
 		}
 
@@ -241,6 +260,7 @@ func main() {
 		mtu, sndwnd, rcvwnd := c.Int("mtu"), c.Int("sndwnd"), c.Int("rcvwnd")
 		nocomp, acknodelay := c.Bool("nocomp"), c.Bool("acknodelay")
 		dscp, sockbuf, keepalive, conn := c.Int("dscp"), c.Int("sockbuf"), c.Int("keepalive"), c.Int("conn")
+		autoexpire := c.Int("autoexpire")
 
 		log.Println("listening on:", listener.Addr())
 		log.Println("encryption:", crypt)
@@ -255,12 +275,13 @@ func main() {
 		log.Println("sockbuf:", sockbuf)
 		log.Println("keepalive:", keepalive)
 		log.Println("conn:", conn)
+		log.Println("autoexpire:", autoexpire)
 
 		config := &yamux.Config{
 			AcceptBacklog:          256,
 			EnableKeepAlive:        true,
 			KeepAliveInterval:      30 * time.Second,
-			ConnectionWriteTimeout: 30 * time.Second,
+			ConnectionWriteTimeout: 10 * time.Second,
 			MaxStreamWindowSize:    uint32(sockbuf),
 			LogOutput:              os.Stderr,
 		}
@@ -292,27 +313,49 @@ func main() {
 				session, err = yamux.Client(newCompStream(kcpconn), config)
 			}
 			checkError(err)
+			runtime.SetFinalizer(session, func(s *yamux.Session) {
+				s.Close()
+			})
 			return session
 		}
 
 		numconn := uint16(conn)
-		var muxes []*yamux.Session
-		for i := uint16(0); i < numconn; i++ {
-			muxes = append(muxes, createConn())
+		muxes := make([]struct {
+			session *yamux.Session
+			ttl     time.Time
+		}, numconn)
+
+		for k := range muxes {
+			muxes[k].session = createConn()
+			muxes[k].ttl = time.Now().Add(time.Duration(autoexpire) * time.Second)
 		}
 
 		rr := uint16(0)
 		for {
 			p1, err := listener.AcceptTCP()
+			if err := p1.SetReadBuffer(sockbuf); err != nil {
+				log.Println("TCP SetReadBuffer:", err)
+			}
+			if err := p1.SetWriteBuffer(sockbuf); err != nil {
+				log.Println("TCP SetWriteBuffer:", err)
+			}
 			checkError(err)
-			mux := muxes[rr%numconn]
-			p2, err := mux.Open()
+			idx := rr % numconn
+
+		OPEN_P2:
+			// do auto expiration
+			if autoexpire > 0 && time.Now().After(muxes[idx].ttl) {
+				log.Println("autoexpired")
+				muxes[idx].session = createConn()
+				muxes[idx].ttl = time.Now().Add(time.Duration(autoexpire) * time.Second)
+			}
+
+			// do session open
+			p2, err := muxes[idx].session.Open()
 			if err != nil { // yamux failure
-				log.Println(err)
-				p1.Close()
-				muxes[rr%numconn] = createConn()
-				mux.Close()
-				continue
+				muxes[idx].session = createConn()
+				muxes[idx].ttl = time.Now().Add(time.Duration(autoexpire) * time.Second)
+				goto OPEN_P2
 			}
 			go handleClient(p1, p2)
 			rr++

server/main.go

@@ -12,9 +12,9 @@ import (
 	"golang.org/x/crypto/pbkdf2"
 
 	"github.com/golang/snappy"
-	"github.com/hashicorp/yamux"
 	"github.com/urfave/cli"
 	kcp "github.com/xtaci/kcp-go"
+	"github.com/xtaci/yamux"
 )
 
 var (
@@ -61,18 +61,26 @@ func handleMux(conn io.ReadWriteCloser, target string, config *yamux.Config) {
 		return
 	}
 	defer mux.Close()
-
 	for {
 		p1, err := mux.Accept()
 		if err != nil {
 			log.Println(err)
 			return
 		}
+		sockbuf := int(config.MaxStreamWindowSize)
 		p2, err := net.DialTimeout("tcp", target, 5*time.Second)
 		if err != nil {
 			log.Println(err)
 			return
 		}
+
+		if err := p2.(*net.TCPConn).SetReadBuffer(sockbuf); err != nil {
+			log.Println("TCP SetReadBuffer:", err)
+		}
+		if err := p2.(*net.TCPConn).SetWriteBuffer(sockbuf); err != nil {
+			log.Println("TCP SetWriteBuffer:", err)
+		}
+
 		go handleClient(p1, p2)
 	}
 }
@@ -127,23 +135,23 @@ func main() {
 		cli.StringFlag{
 			Name:   "key",
 			Value:  "it's a secrect",
-			Usage:  "key for communcation, must be the same as kcptun client",
+			Usage:  "pre-shared secret between client and server",
 			EnvVar: "KCPTUN_KEY",
 		},
 		cli.StringFlag{
 			Name:  "crypt",
 			Value: "aes",
-			Usage: "methods for encryption: aes, aes-128, aes-192, tea, xor, none",
+			Usage: "aes, aes-128, aes-192, salsa20, blowfish, twofish, cast5, 3des, tea, xtea, xor, none",
 		},
 		cli.StringFlag{
 			Name:  "mode",
 			Value: "fast",
-			Usage: "mode for communication: fast3, fast2, fast, normal",
+			Usage: "profiles: fast3, fast2, fast, normal",
 		},
 		cli.IntFlag{
 			Name:  "mtu",
 			Value: 1350,
-			Usage: "set MTU of UDP packets, suggest 'tracepath' to discover path mtu",
+			Usage: "set maximum transmission unit for UDP packets",
 		},
 		cli.IntFlag{
 			Name:  "sndwnd",
@@ -155,10 +163,6 @@ func main() {
 			Value: 1024,
 			Usage: "set receive window size(num of packets)",
 		},
-		cli.BoolFlag{
-			Name:  "nocomp",
-			Usage: "disable compression",
-		},
 		cli.IntFlag{
 			Name:  "datashard",
 			Value: 10,
@@ -179,6 +183,10 @@ func main() {
 			Value: 0,
 			Usage: "set DSCP(6bit)",
 		},
+		cli.BoolFlag{
+			Name:  "nocomp",
+			Usage: "disable compression",
+		},
 		cli.IntFlag{
 			Name:   "nodelay",
 			Value:  0,
@@ -238,7 +246,20 @@ func main() {
 			block, _ = kcp.NewAESBlockCrypt(pass[:16])
 		case "aes-192":
 			block, _ = kcp.NewAESBlockCrypt(pass[:24])
+		case "blowfish":
+			block, _ = kcp.NewBlowfishBlockCrypt(pass)
+		case "twofish":
+			block, _ = kcp.NewTwofishBlockCrypt(pass)
+		case "cast5":
+			block, _ = kcp.NewCast5BlockCrypt(pass[:16])
+		case "3des":
+			block, _ = kcp.NewTripleDESBlockCrypt(pass[:24])
+		case "xtea":
+			block, _ = kcp.NewXTEABlockCrypt(pass[:16])
+		case "salsa20":
+			block, _ = kcp.NewSalsa20BlockCrypt(pass)
 		default:
+			crypt = "aes"
 			block, _ = kcp.NewAESBlockCrypt(pass)
 		}
 
@@ -278,12 +299,12 @@ func main() {
 			AcceptBacklog:          256,
 			EnableKeepAlive:        true,
 			KeepAliveInterval:      30 * time.Second,
-			ConnectionWriteTimeout: 30 * time.Second,
+			ConnectionWriteTimeout: 10 * time.Second,
 			MaxStreamWindowSize:    uint32(sockbuf),
 			LogOutput:              os.Stderr,
 		}
 		for {
-			if conn, err := lis.Accept(); err == nil {
+			if conn, err := lis.AcceptKCP(); err == nil {
 				log.Println("remote address:", conn.RemoteAddr())
 				conn.SetStreamMode(true)
 				conn.SetNoDelay(nodelay, interval, resend, nc)