add remote tcp port forwarding

README.md

@@ -55,7 +55,7 @@ scheme://[bind_address]:port/[host]:hostport
 
 > bind_address:port - 本地监听地址
 
-> host:hostport - 远程监听地址
+> host:hostport - 远程地址
 
 当在bind_address:port上收到连接信息，则会(通过转发链)与host:hostport建立连接，创建一条数据通道。
 

conn.go

@@ -52,10 +52,12 @@ func listenAndServe(arg Args) error {
 	case "tls": // tls connection
 		ln, err = tls.Listen("tcp", arg.Addr,
 			&tls.Config{Certificates: []tls.Certificate{arg.Cert}})
-	case "tcp": // TCP port forwarding
+	case "tcp": // Local TCP port forwarding
 		return listenAndServeTcpForward(arg)
-	case "udp": // UDP port forwarding
+	case "udp": // Local UDP port forwarding
 		return listenAndServeUdpForward(arg)
+	case "rtcp": // Remote TCP port forwarding
+		return serveRTcpForward(arg)
 	default:
 		ln, err = net.Listen("tcp", arg.Addr)
 	}
@@ -76,6 +78,49 @@ func listenAndServe(arg Args) error {
 	}
 }
 
+func serveRTcpForward(arg Args) error {
+	if arg.Forward == "" {
+		ln, err := net.Listen("tcp", arg.Addr)
+		if err != nil {
+			return err
+		}
+		defer ln.Close()
+
+		for {
+			conn, err := ln.Accept()
+			if err != nil {
+				glog.V(LWARNING).Infoln(err)
+				continue
+			}
+
+			tc := conn.(*net.TCPConn)
+			tc.SetKeepAlive(true)
+			tc.SetKeepAlivePeriod(time.Second * 60)
+
+			go handleRTcpForwardConn(conn, arg)
+		}
+	} else {
+		retry := 0
+		for {
+			conn, err := Connect(arg.Forward)
+			if err != nil {
+				glog.V(LWARNING).Infof("[rtcp] %s -> %s : %s", arg.Addr, arg.Forward, err)
+				time.Sleep((1 << uint(retry)) * time.Second)
+				if retry < 5 {
+					retry++
+				}
+				continue
+			}
+			retry = 0
+
+			if err := connectRTcpForward(conn, arg); err != nil {
+				conn.Close()
+				time.Sleep(10 * time.Second)
+			}
+		}
+	}
+}
+
 func listenAndServeTcpForward(arg Args) error {
 	ln, err := net.Listen("tcp", arg.Addr)
 	if err != nil {
@@ -122,10 +167,10 @@ func listenAndServeUdpForward(arg Args) error {
 
 func handleConn(conn net.Conn, arg Args) {
 	atomic.AddInt32(&connCounter, 1)
-	glog.V(LINFO).Infof("%s connected, connections: %d",
+	glog.V(LDEBUG).Infof("%s connected, connections: %d",
 		conn.RemoteAddr(), atomic.LoadInt32(&connCounter))
 
-	if glog.V(LINFO) {
+	if glog.V(LDEBUG) {
 		defer func() {
 			glog.Infof("%s disconnected, connections: %d",
 				conn.RemoteAddr(), atomic.LoadInt32(&connCounter))
@@ -153,7 +198,7 @@ func handleConn(conn net.Conn, arg Args) {
 	case "http":
 		req, err := http.ReadRequest(bufio.NewReader(conn))
 		if err != nil {
-			glog.V(LWARNING).Infoln("http:", err)
+			glog.V(LWARNING).Infoln("[http]", err)
 			return
 		}
 		handleHttpRequest(req, conn, arg)
@@ -162,7 +207,7 @@ func handleConn(conn net.Conn, arg Args) {
 		conn = gosocks5.ServerConn(conn, selector)
 		req, err := gosocks5.ReadRequest(conn)
 		if err != nil {
-			glog.V(LWARNING).Infoln("socks5:", err)
+			glog.V(LWARNING).Infoln("[socks5] request:", err)
 			return
 		}
 		handleSocks5Request(req, conn)
@@ -177,7 +222,7 @@ func handleConn(conn net.Conn, arg Args) {
 
 	n, err := io.ReadAtLeast(conn, b, 2)
 	if err != nil {
-		glog.V(LWARNING).Infoln("client:", err)
+		glog.V(LWARNING).Infoln("[client]", err)
 		return
 	}
 
@@ -186,26 +231,26 @@ func handleConn(conn net.Conn, arg Args) {
 		length := 2 + mn
 		if n < length {
 			if _, err := io.ReadFull(conn, b[n:length]); err != nil {
-				glog.V(LWARNING).Infoln("socks5:", err)
+				glog.V(LWARNING).Infoln("[socks5]", err)
 				return
 			}
 		}
 		methods := b[2 : 2+mn]
 		method := selector.Select(methods...)
 		if _, err := conn.Write([]byte{gosocks5.Ver5, method}); err != nil {
-			glog.V(LWARNING).Infoln("socks5 select:", err)
+			glog.V(LWARNING).Infoln("[socks5] select:", err)
 			return
 		}
 		c, err := selector.OnSelected(method, conn)
 		if err != nil {
-			glog.V(LWARNING).Infoln("socks5 onselected:", err)
+			glog.V(LWARNING).Infoln("[socks5] onselected:", err)
 			return
 		}
 		conn = c
 
 		req, err := gosocks5.ReadRequest(conn)
 		if err != nil {
-			glog.V(LWARNING).Infoln("socks5 request:", err)
+			glog.V(LWARNING).Infoln("[socks5] request:", err)
 			return
 		}
 		handleSocks5Request(req, conn)
@@ -214,7 +259,7 @@ func handleConn(conn net.Conn, arg Args) {
 
 	req, err := http.ReadRequest(bufio.NewReader(newReqReader(b[:n], conn)))
 	if err != nil {
-		glog.V(LWARNING).Infoln("http:", err)
+		glog.V(LWARNING).Infoln("[http]", err)
 		return
 	}
 	handleHttpRequest(req, conn, arg)
@@ -247,7 +292,7 @@ func Connect(addr string) (conn net.Conn, err error) {
 		addr += ":80"
 	}
 	if len(forwardArgs) == 0 {
-		return net.DialTimeout("tcp", addr, time.Second*60)
+		return net.DialTimeout("tcp", addr, time.Second*90)
 	}
 
 	var end Args
@@ -306,7 +351,7 @@ func forward(conn net.Conn, arg Args) (net.Conn, error) {
 		if trans == "" { // default is tcp
 			trans = "tcp"
 		}
-		glog.Infof("forward: %s/%s %s", proto, trans, arg.Addr)
+		glog.V(LDEBUG).Infof("forward: %s/%s %s", proto, trans, arg.Addr)
 	}
 
 	var tlsUsed bool

forward.go

@@ -1,6 +1,7 @@
 package main
 
 import (
+	"errors"
 	"github.com/ginuerzh/gosocks5"
 	"github.com/golang/glog"
 	"net"
@@ -10,6 +11,7 @@ import (
 
 func handleTcpForward(conn net.Conn, arg Args) {
 	defer conn.Close()
+
 	if !strings.Contains(arg.Forward, ":") {
 		arg.Forward += ":22" // default is ssh service
 	}
@@ -21,9 +23,9 @@ func handleTcpForward(conn net.Conn, arg Args) {
 	}
 	defer c.Close()
 
-	glog.V(LINFO).Infof("[tcp-forward] %s <-> %s OK", conn.RemoteAddr(), arg.Forward)
+	glog.V(LINFO).Infof("[tcp-forward] %s <-> %s", conn.RemoteAddr(), arg.Forward)
 	Transport(conn, c)
-	glog.V(LINFO).Infof("[tcp-forward] %s >-< %s DISCONNECTED", conn.RemoteAddr(), arg.Forward)
+	glog.V(LINFO).Infof("[tcp-forward] %s >-< %s", conn.RemoteAddr(), arg.Forward)
 }
 
 func handleUdpForward(conn *net.UDPConn, raddr *net.UDPAddr, data []byte, arg Args) {
@@ -51,7 +53,7 @@ func handleUdpForward(conn *net.UDPConn, raddr *net.UDPAddr, data []byte, arg Ar
 			glog.V(LWARNING).Infof("[udp-forward] %s -> %s : %s", raddr, arg.Forward, err)
 			return
 		}
-		glog.V(LINFO).Infof("[udp-forward] %s >>> %s length %d", raddr, arg.Forward, len(data))
+		glog.V(LDEBUG).Infof("[udp-forward] %s >>> %s length %d", raddr, arg.Forward, len(data))
 
 		b := udpPool.Get().([]byte)
 		defer udpPool.Put(b)
@@ -61,12 +63,12 @@ func handleUdpForward(conn *net.UDPConn, raddr *net.UDPAddr, data []byte, arg Ar
 			glog.V(LWARNING).Infof("[udp-forward] %s <- %s : %s", raddr, arg.Forward, err)
 			return
 		}
-		glog.V(LINFO).Infof("[udp-forward] %s <<< %s length %d", raddr, addr, n)
+		glog.V(LDEBUG).Infof("[udp-forward] %s <<< %s length %d", raddr, addr, n)
 
 		if _, err := conn.WriteToUDP(b[:n], raddr); err != nil {
 			glog.V(LWARNING).Infof("[udp-forward] %s <- %s : %s", raddr, arg.Forward, err)
 		}
-		glog.V(LINFO).Infof("[udp-forward] %s >-< %s DONE", raddr, arg.Forward)
+		glog.V(LINFO).Infof("[udp-forward] %s >-< %s", raddr, arg.Forward)
 		return
 	}
 
@@ -99,29 +101,179 @@ func handleUdpForward(conn *net.UDPConn, raddr *net.UDPAddr, data []byte, arg Ar
 		glog.V(LWARNING).Infof("[udp-forward] %s <- %s ASSOCIATE failured", raddr, arg.Forward)
 		return
 	}
-	glog.V(LINFO).Infof("[udp-forward] %s <-> %s ASSOCIATE ON %s OK", raddr, arg.Forward, rep.Addr)
+	glog.V(LINFO).Infof("[udp-forward] %s <-> %s ASSOCIATE ON %s", raddr, arg.Forward, rep.Addr)
 
 	dgram := gosocks5.NewUDPDatagram(
 		gosocks5.NewUDPHeader(uint16(len(data)), 0, ToSocksAddr(faddr)), data)
 
-	fconn.SetWriteDeadline(time.Now().Add(time.Second * 60))
+	fconn.SetWriteDeadline(time.Now().Add(time.Second * 90))
 	if err = dgram.Write(fconn); err != nil {
 		glog.V(LWARNING).Infof("[udp-forward] %s -> %s : %s", raddr, arg.Forward, err)
 		return
 	}
-	glog.V(LINFO).Infof("[udp-forward] %s >>> %s length %d", raddr, arg.Forward, len(data))
+	glog.V(LDEBUG).Infof("[udp-forward] %s >>> %s length %d", raddr, arg.Forward, len(data))
 
-	fconn.SetReadDeadline(time.Now().Add(time.Second * 60))
+	fconn.SetReadDeadline(time.Now().Add(time.Second * 90))
 	dgram, err = gosocks5.ReadUDPDatagram(fconn)
 	if err != nil {
 		glog.V(LWARNING).Infof("[udp-forward] %s <- %s : %s", raddr, arg.Forward, err)
 		return
 	}
-	glog.V(LINFO).Infof("[udp-forward] %s <<< %s length %d", raddr, dgram.Header.Addr, len(dgram.Data))
+	glog.V(LDEBUG).Infof("[udp-forward] %s <<< %s length %d", raddr, dgram.Header.Addr, len(dgram.Data))
 
 	if _, err = conn.WriteToUDP(dgram.Data, raddr); err != nil {
 		glog.V(LWARNING).Infof("[udp-forward] %s <- %s : %s", raddr, arg.Forward, err)
 	}
 
-	glog.V(LINFO).Infof("[udp-forward] %s >-< %s DONE", raddr, arg.Forward)
+	glog.V(LINFO).Infof("[udp-forward] %s >-< %s", raddr, arg.Forward)
+}
+
+func handleRTcpForwardConn(conn net.Conn, arg Args) {
+	defer conn.Close()
+
+	req, err := gosocks5.ReadRequest(conn)
+	if err != nil {
+		glog.V(LWARNING).Infof("[rtcp] %s -> %s : %s", conn.RemoteAddr(), arg.Addr, err)
+		return
+	}
+	bindAddr, _ := net.ResolveTCPAddr("tcp", req.Addr.String())
+	ln, err := net.ListenTCP("tcp", bindAddr)
+	if err != nil {
+		glog.V(LWARNING).Infof("[rtcp] %s -> %s : %s", conn.RemoteAddr(), req.Addr, err)
+		rep := gosocks5.NewReply(gosocks5.Failure, nil)
+		if err := rep.Write(conn); err != nil {
+			glog.V(LWARNING).Infof("[rtcp] %s <- %s : %s", conn.RemoteAddr(), req.Addr, err)
+		}
+		return
+	}
+
+	addr := ToSocksAddr(ln.Addr())
+	addr.Host, _, _ = net.SplitHostPort(conn.LocalAddr().String())
+
+	rep := gosocks5.NewReply(gosocks5.Succeeded, addr)
+	if err := rep.Write(conn); err != nil {
+		glog.V(LWARNING).Infof("[rtcp] %s <- %s : %s", conn.RemoteAddr(), req.Addr, err)
+		ln.Close()
+		return
+	}
+	glog.V(LINFO).Infof("[rtcp] %s - %s BIND ON %s OK", conn.RemoteAddr(), req.Addr, addr)
+
+	lnChan := make(chan net.Conn, 1)
+	go func() {
+		defer close(lnChan)
+		c, err := ln.AcceptTCP()
+		if err != nil {
+			// glog.V(LWARNING).Infof("[rtcp] %s <- %s ACCEPT : %s", conn.RemoteAddr(), addr, err)
+			return
+		}
+		lnChan <- c
+	}()
+
+	peerChan := make(chan *gosocks5.Reply, 1)
+	go func() {
+		defer close(peerChan)
+		reply, err := gosocks5.ReadReply(conn)
+		if err != nil {
+			return
+		}
+		peerChan <- reply
+	}()
+
+	var pconn net.Conn
+
+	for {
+		select {
+		case c := <-lnChan:
+			ln.Close() // only accept one peer
+			if c == nil {
+				if err := gosocks5.NewReply(gosocks5.Failure, nil).Write(conn); err != nil {
+					glog.V(LWARNING).Infoln("[rtcp] %s <- %s : %s", conn.RemoteAddr(), addr, err)
+				}
+				glog.V(LWARNING).Infof("[rtcp] %s >-< %s : %s", conn.RemoteAddr(), addr)
+				return
+			}
+			glog.V(LINFO).Infof("[rtcp] %s <- %s PEER %s ACCEPTED", conn.RemoteAddr(), addr, c.RemoteAddr())
+			gosocks5.NewReply(gosocks5.Succeeded, ToSocksAddr(c.RemoteAddr())).Write(conn)
+			pconn = c
+			lnChan = nil
+			ln = nil
+		case reply := <-peerChan:
+			if reply == nil {
+				if ln != nil {
+					ln.Close()
+				}
+				if pconn != nil {
+					pconn.Close()
+				}
+				glog.V(LWARNING).Infof("[rtcp] %s >-< %s", conn.RemoteAddr(), addr)
+				return
+			}
+			goto out
+		}
+	}
+
+out:
+	defer pconn.Close()
+
+	glog.V(LINFO).Infof("[rtcp] %s <-> %s", conn.RemoteAddr(), pconn.RemoteAddr())
+	Transport(conn, pconn)
+	glog.V(LINFO).Infof("[rtcp] %s >-< %s", conn.RemoteAddr(), pconn.RemoteAddr())
+}
+
+func connectRTcpForward(conn net.Conn, arg Args) error {
+	glog.V(LINFO).Infof("[rtcp] %s - %s", arg.Addr, arg.Forward)
+
+	addr, _ := net.ResolveTCPAddr("tcp", arg.Bind)
+	req := gosocks5.NewRequest(gosocks5.CmdBind, ToSocksAddr(addr))
+	if err := req.Write(conn); err != nil {
+		glog.V(LWARNING).Infof("[rtcp] %s -> %s : %s", arg.Addr, arg.Forward, err)
+		return err
+	}
+
+	// first reply, bind status
+	rep, err := gosocks5.ReadReply(conn)
+	if err != nil {
+		glog.V(LWARNING).Infof("[rtcp] %s <- %s : %s", arg.Addr, arg.Forward, err)
+		return err
+	}
+	if rep.Rep != gosocks5.Succeeded {
+		glog.V(LWARNING).Infof("[rtcp] %s <- %s : bind on %s failure", arg.Addr, arg.Forward, arg.Bind)
+		return errors.New("Bind on " + arg.Bind + " failure")
+	}
+	glog.V(LINFO).Infof("[rtcp] %s - %s BIND ON %s OK", arg.Addr, arg.Forward, arg.Bind)
+
+	// second reply, peer connection
+	rep, err = gosocks5.ReadReply(conn)
+	if err != nil {
+		glog.V(LWARNING).Infof("[rtcp] %s <- %s : %s", arg.Addr, arg.Forward, err)
+		return err
+	}
+	if rep.Rep != gosocks5.Succeeded {
+		glog.V(LWARNING).Infof("[rtcp] %s <- %s : peer connect failure", arg.Addr, arg.Forward)
+		return errors.New("peer connect failure")
+	}
+
+	glog.V(LINFO).Infof("[rtcp] %s <- %s PEER %s CONNECTED", conn.RemoteAddr(), req.Addr, rep.Addr)
+
+	go func() {
+		defer conn.Close()
+
+		lconn, err := net.Dial("tcp", arg.Addr)
+		if err != nil {
+			glog.V(LWARNING).Infof("[rtcp] %s <- %s : %s", arg.Addr, arg.Forward, err)
+			return
+		}
+		defer lconn.Close()
+
+		if err := gosocks5.NewReply(gosocks5.Succeeded, nil).Write(conn); err != nil {
+			glog.V(LWARNING).Infof("[rtcp] %s -> %s : %s", arg.Addr, arg.Forward, err)
+			return
+		}
+
+		glog.V(LINFO).Infof("[rtcp] %s <-> %s", arg.Addr, arg.Forward)
+		Transport(lconn, conn)
+		glog.V(LINFO).Infof("[rtcp] %s >-< %s", arg.Addr, arg.Forward)
+	}()
+
+	return nil
 }

http.go

@@ -73,9 +73,9 @@ func handleHttpRequest(req *http.Request, conn net.Conn, arg Args) {
 		}
 	}
 
-	glog.V(LINFO).Infof("[http] %s <-> %s OK", conn.RemoteAddr(), req.Host)
+	glog.V(LINFO).Infof("[http] %s <-> %s", conn.RemoteAddr(), req.Host)
 	Transport(conn, c)
-	glog.V(LINFO).Infof("[http] %s >-< %s DISCONNECTED", conn.RemoteAddr(), req.Host)
+	glog.V(LINFO).Infof("[http] %s >-< %s", conn.RemoteAddr(), req.Host)
 }
 
 func basicAuth(authInfo string) (username, password string, ok bool) {

socks.go

@@ -6,7 +6,8 @@ import (
 	"errors"
 	"github.com/ginuerzh/gosocks5"
 	"github.com/golang/glog"
-	"io"
+	//"os/exec"
+	//"io"
 	"io/ioutil"
 	"net"
 	"net/url"
@@ -124,10 +125,10 @@ func (selector *serverSelector) OnSelected(method uint8, conn net.Conn) (net.Con
 
 		req, err := gosocks5.ReadUserPassRequest(conn)
 		if err != nil {
-			glog.V(LWARNING).Infoln("socks5 auth:", err)
+			glog.V(LWARNING).Infoln("[socks5-auth]", err)
 			return nil, err
 		}
-		glog.V(LDEBUG).Infoln(req.String())
+		glog.V(LDEBUG).Infoln("[socks5]", req.String())
 
 		var username, password string
 		if selector.user != nil {
@@ -138,18 +139,18 @@ func (selector *serverSelector) OnSelected(method uint8, conn net.Conn) (net.Con
 		if (username != "" && req.Username != username) || (password != "" && req.Password != password) {
 			resp := gosocks5.NewUserPassResponse(gosocks5.UserPassVer, gosocks5.Failure)
 			if err := resp.Write(conn); err != nil {
-				glog.V(LWARNING).Infoln("socks5 auth:", err)
+				glog.V(LWARNING).Infoln("[socks5-auth]", err)
 				return nil, err
 			}
-			glog.V(LDEBUG).Infoln(resp)
+			glog.V(LDEBUG).Infoln("[socks5]", resp)
-			glog.V(LWARNING).Infoln("socks5: proxy authentication required")
+			glog.V(LWARNING).Infoln("[socks5-auth] proxy authentication required")
 
 			return nil, gosocks5.ErrAuthFailure
 		}
 
 		resp := gosocks5.NewUserPassResponse(gosocks5.UserPassVer, gosocks5.Succeeded)
 		if err := resp.Write(conn); err != nil {
-			glog.V(LWARNING).Infoln("socks5 auth:", err)
+			glog.V(LWARNING).Infoln("[socks5-auth]", err)
 			return nil, err
 		}
 		glog.V(LDEBUG).Infoln(resp)
@@ -162,7 +163,7 @@ func (selector *serverSelector) OnSelected(method uint8, conn net.Conn) (net.Con
 }
 
 func handleSocks5Request(req *gosocks5.Request, conn net.Conn) {
-	glog.V(LDEBUG).Infof("[socks5-connect] %s -> %s\n%s", conn.RemoteAddr(), req.Addr, req)
+	glog.V(LDEBUG).Infof("[socks5] %s -> %s\n%s", conn.RemoteAddr(), req.Addr, req)
 
 	switch req.Cmd {
 	case gosocks5.CmdConnect:
@@ -188,18 +189,21 @@ func handleSocks5Request(req *gosocks5.Request, conn net.Conn) {
 		}
 		glog.V(LDEBUG).Infof("[socks5-connect] %s <- %s\n%s", conn.RemoteAddr(), req.Addr, rep)
 
-		glog.V(LINFO).Infof("[socks5-connect] %s <-> %s OK", conn.RemoteAddr(), req.Addr)
+		glog.V(LINFO).Infof("[socks5-connect] %s <-> %s", conn.RemoteAddr(), req.Addr)
 		Transport(conn, tconn)
-		glog.V(LINFO).Infof("[socks5-connect] %s >-< %s DISCONNECTED", conn.RemoteAddr(), req.Addr)
+		glog.V(LINFO).Infof("[socks5-connect] %s >-< %s", conn.RemoteAddr(), req.Addr)
 	case gosocks5.CmdBind:
 		glog.V(LINFO).Infof("[socks5-bind] %s - %s", conn.RemoteAddr(), req.Addr)
 
 		if len(forwardArgs) > 0 {
 			forwardBind(req, conn)
 		} else {
-			serveBind(conn)
+			tc := conn.(*net.TCPConn)
+			tc.SetKeepAlive(true)
+			tc.SetKeepAlivePeriod(time.Second * 60)
+
+			serveBind(req, conn)
 		}
-		glog.V(LINFO).Infof("[socks5-bind] %s >-< %s DISCONNECTED", conn.RemoteAddr(), req.Addr)
 	case gosocks5.CmdUdp, CmdUdpTun:
 		// TODO: udp tunnel <-> forward chain
 		glog.V(LINFO).Infof("[socks5-udp] %s - %s ASSOCIATE", conn.RemoteAddr(), req.Addr)
@@ -288,90 +292,143 @@ func handleSocks5Request(req *gosocks5.Request, conn net.Conn) {
 			TransportUDP(cc, sc)
 		}
 	default:
-		glog.V(LWARNING).Infoln("Unrecognized request: ", req)
+		glog.V(LWARNING).Infoln("[socks5] Unrecognized request:", req.Cmd)
 	}
 }
 
-func serveBind(conn net.Conn) error {
+func serveBind(req *gosocks5.Request, conn net.Conn) error {
-	l, err := net.ListenTCP("tcp", nil)
+	bindAddr, _ := net.ResolveTCPAddr("tcp", req.Addr.String())
+	ln, err := net.ListenTCP("tcp", bindAddr)
 	if err != nil {
-		glog.V(LWARNING).Infoln("socks5 bind listen:", err)
+		glog.V(LWARNING).Infof("[socks5-bind] %s -> %s : %s", conn.RemoteAddr(), req.Addr, err)
-
+		if bindAddr != nil {
+			ln, err = net.ListenTCP("tcp", nil)
+		}
+		if err != nil {
+			glog.V(LWARNING).Infof("[socks5-bind] %s -> %s : %s", conn.RemoteAddr(), req.Addr, err)
 			rep := gosocks5.NewReply(gosocks5.Failure, nil)
 			if err := rep.Write(conn); err != nil {
-			glog.V(LWARNING).Infoln("socks5 bind listen:", err)
+				glog.V(LWARNING).Infof("[socks5-bind] %s <- %s : %s", conn.RemoteAddr(), req.Addr, err)
 			} else {
-			glog.V(LDEBUG).Infoln(rep)
+				glog.V(LDEBUG).Infof("[socks5-bind] %s <- %s\n%s", conn.RemoteAddr(), req.Addr, rep)
 			}
 			return err
 		}
+	}
 
-	addr := ToSocksAddr(l.Addr())
+	addr := ToSocksAddr(ln.Addr())
 	// Issue: may not reachable when host has two interfaces
 	addr.Host, _, _ = net.SplitHostPort(conn.LocalAddr().String())
 
 	rep := gosocks5.NewReply(gosocks5.Succeeded, addr)
 	if err := rep.Write(conn); err != nil {
-		glog.V(LWARNING).Infoln("socks5 bind:", err)
+		glog.V(LWARNING).Infof("[socks5-bind] %s <- %s : %s", conn.RemoteAddr(), req.Addr, err)
-		l.Close()
+		ln.Close()
 		return err
 	}
-	glog.V(LDEBUG).Infoln(rep)
+	glog.V(LDEBUG).Infof("[socks5-bind] %s <- %s\n%s", conn.RemoteAddr(), req.Addr, rep)
-	glog.V(LINFO).Infoln("[socks5] BIND on", addr, "OK")
+	glog.V(LINFO).Infof("[socks5-bind] %s - %s BIND ON %s OK", conn.RemoteAddr(), req.Addr, addr)
 
-	l.SetDeadline(time.Now().Add(time.Minute * 30)) // wait 30 minutes at most
+	lnChan := make(chan net.Conn, 1)
-	tconn, err := l.AcceptTCP()
+	go func() {
-	l.Close() // only accept one peer
+		defer close(lnChan)
+		c, err := ln.AcceptTCP()
 		if err != nil {
-		glog.V(LWARNING).Infoln("socks5 bind accept:", err)
+			return
-
-		rep = gosocks5.NewReply(gosocks5.Failure, nil)
-		if err := rep.Write(conn); err != nil {
-			glog.V(LWARNING).Infoln("socks5 bind accept:", err)
-		} else {
-			glog.V(LDEBUG).Infoln(rep)
 		}
+		lnChan <- c
+	}()
+
+	peerChan := make(chan error, 1)
+	go func() {
+		defer close(peerChan)
+		_, err := ioutil.ReadAll(conn)
+		if err != nil {
+			if opErr, ok := err.(*net.OpError); ok && opErr.Timeout() {
+				return
+			}
+			peerChan <- err
+		}
+	}()
+
+	var pconn net.Conn
+
+	for {
+		select {
+		case c := <-lnChan:
+			ln.Close() // only accept one peer
+			if c == nil {
+				if err := gosocks5.NewReply(gosocks5.Failure, nil).Write(conn); err != nil {
+					glog.V(LWARNING).Infoln("[socks5-bind] %s <- %s : %s", conn.RemoteAddr(), addr, err)
+				}
+				glog.V(LWARNING).Infof("[socks5-bind] %s >-< %s", conn.RemoteAddr(), addr)
+				return errors.New("accept error")
+			}
+			// glog.V(LINFO).Infof("[socks5-bind] %s <- %s PEER %s ACCEPTED", conn.RemoteAddr(), req.Addr, c.RemoteAddr())
+			// gosocks5.NewReply(gosocks5.Succeeded, ToSocksAddr(c.RemoteAddr())).Write(conn)
+			pconn = c
+			lnChan = nil
+			ln = nil
+			conn.SetReadDeadline(time.Now()) // timeout right now ,so we can break out of blocking
+		case err := <-peerChan:
+			if err != nil || pconn == nil {
+				if ln != nil {
+					ln.Close()
+				}
+				if pconn != nil {
+					pconn.Close()
+				}
+				glog.V(LWARNING).Infof("[socks5-bind] %s >-< %s", conn.RemoteAddr(), addr)
 				return err
 			}
-	defer tconn.Close()
+			goto out
+		}
+	}
 
-	addr = ToSocksAddr(tconn.RemoteAddr())
+out:
-	glog.V(LINFO).Infoln("[socks5] BIND accept", addr)
+	defer pconn.Close()
+	conn.SetReadDeadline(time.Time{})
 
-	rep = gosocks5.NewReply(gosocks5.Succeeded, addr)
+	paddr := ToSocksAddr(pconn.RemoteAddr())
+	glog.V(LINFO).Infof("[socks5-bind] %s <- %s PEER %s ACCEPTED", conn.RemoteAddr(), addr, paddr)
+
+	rep = gosocks5.NewReply(gosocks5.Succeeded, paddr)
 	if err := rep.Write(conn); err != nil {
-		glog.V(LWARNING).Infoln("socks5 bind accept:", err)
+		glog.V(LWARNING).Infof("[socks5 bind] %s <- %s : %s", conn.RemoteAddr(), addr, err)
 		return err
 	}
-	glog.V(LDEBUG).Infoln(rep)
+	glog.V(LDEBUG).Infof("[socks5 bind] %s <- %s\n%s", conn.RemoteAddr(), addr, rep)
 
-	return Transport(conn, tconn)
+	glog.V(LINFO).Infof("[socks5-bind] %s <-> %s", conn.RemoteAddr(), paddr)
+	defer glog.V(LINFO).Infof("[socks5-bind] %s >-< %s", conn.RemoteAddr(), paddr)
+	return Transport(conn, pconn)
 }
 
 func forwardBind(req *gosocks5.Request, conn net.Conn) error {
 	fconn, _, err := forwardChain(forwardArgs...)
 	if err != nil {
-		glog.V(LWARNING).Infoln("[socks5] BIND forward", req.Addr, err)
+		glog.V(LWARNING).Infof("[socks5-bind] %s -> %s : %s", conn.RemoteAddr(), req.Addr, err)
 		if fconn != nil {
 			fconn.Close()
 		}
 		rep := gosocks5.NewReply(gosocks5.Failure, nil)
 		if err := rep.Write(conn); err != nil {
-			glog.V(LWARNING).Infoln("socks5 bind forward:", err)
+			glog.V(LWARNING).Infof("[socks5-bind] %s <- %s : %s", conn.RemoteAddr(), req.Addr, err)
 		} else {
-			glog.V(LDEBUG).Infoln(rep)
+			glog.V(LDEBUG).Infof("[socks5-bind] %s <- %s\n%s", conn.RemoteAddr(), req.Addr, rep)
 		}
 		return err
 	}
 	defer fconn.Close()
 
 	if err := req.Write(fconn); err != nil {
-		glog.V(LWARNING).Infoln("[socks5] BIND forward", err)
+		glog.V(LWARNING).Infoln("[socks5-bind] %s -> %s : %s", conn.RemoteAddr(), req.Addr, err)
 		gosocks5.NewReply(gosocks5.Failure, nil).Write(conn)
 		return err
 	}
-	glog.V(LDEBUG).Infoln(req)
+	glog.V(LDEBUG).Infof("[socks5-bind] %s -> %s\n%s", conn.RemoteAddr(), req.Addr, req)
 
+	/*
 		// first reply
 		rep, err := peekReply(conn, fconn)
 		if err != nil {
@@ -387,20 +444,23 @@ func forwardBind(req *gosocks5.Request, conn net.Conn) error {
 			return err
 		}
 		glog.V(LINFO).Infoln("[socks5] BIND forward accept", rep.Addr)
-
+	*/
+	glog.V(LINFO).Infof("[socks5-bind] %s <-> %s", conn.RemoteAddr(), req.Addr)
+	defer glog.V(LINFO).Infof("[socks5-bind] %s >-< %s", conn.RemoteAddr(), req.Addr)
 	return Transport(conn, fconn)
 }
 
-func peekReply(dst io.Writer, src io.Reader) (rep *gosocks5.Reply, err error) {
+/*
+func peekReply(dst, src net.Conn) (rep *gosocks5.Reply, err error) {
 	rep, err = gosocks5.ReadReply(src)
 	if err != nil {
-		glog.V(LWARNING).Infoln(err)
+		glog.V(LWARNING).Infof("[socks5-bind] FORWARD %s <- : %s", dst.RemoteAddr(), err)
 		rep = gosocks5.NewReply(gosocks5.Failure, nil)
 	}
 	if err = rep.Write(dst); err != nil {
 		return
 	}
-	glog.V(LDEBUG).Infoln(rep)
+	glog.V(LDEBUG).Infof("[socks5-bind] FORWARD %s <-\n%s", dst.RemoteAddr(), rep)
 
 	if rep.Rep != gosocks5.Succeeded {
 		err = errors.New("Failure")
@@ -408,6 +468,7 @@ func peekReply(dst io.Writer, src io.Reader) (rep *gosocks5.Reply, err error) {
 
 	return
 }
+*/
 
 func createServerConn(uconn *net.UDPConn) (c *UDPConn, err error) {
 	if len(forwardArgs) == 0 {
@@ -448,13 +509,17 @@ func createServerConn(uconn *net.UDPConn) (c *UDPConn, err error) {
 }
 
 func ToSocksAddr(addr net.Addr) *gosocks5.Addr {
-	host, port, _ := net.SplitHostPort(addr.String())
+	host := ""
-	p, _ := strconv.Atoi(port)
+	port := 0
-
+	if addr != nil {
+		h, p, _ := net.SplitHostPort(addr.String())
+		host = h
+		port, _ = strconv.Atoi(p)
+	}
 	return &gosocks5.Addr{
 		Type: gosocks5.AddrIPv4,
 		Host: host,
-		Port: uint16(p),
+		Port: uint16(port),
 	}
 }
 

util.go

@@ -24,9 +24,10 @@ func (ss *strSlice) Set(value string) error {
 type Args struct {
 	Addr      string          // host:port
 	Protocol  string          // protocol: http/socks(5)/ss
-	Transport string // transport: ws(s)/tls/tcp/udp
+	Transport string          // transport: ws(s)/tls/tcp/udp/rtcp/rudp
-	Forward   string // forward address, used by tcp/udp port forwarding
+	Forward   string          // forward address, used by local tcp/udp port forwarding
-	User      *url.Userinfo
+	Bind      string          // remote binding port, used by remote tcp/udp port forwarding
+	User      *url.Userinfo   // authentication for proxy
 	Cert      tls.Certificate // tls certificate
 }
 
@@ -55,7 +56,6 @@ func parseArgs(ss []string) (args []Args) {
 			Addr: u.Host,
 			User: u.User,
 			Cert: tlsCert,
-			Forward: strings.Trim(u.EscapedPath(), "/"),
 		}
 
 		schemes := strings.Split(u.Scheme, "+")
@@ -76,8 +76,14 @@ func parseArgs(ss []string) (args []Args) {
 
 		switch arg.Transport {
 		case "ws", "wss", "tls":
-		case "tcp", "udp": // started from v2.1, tcp and udp are for port forwarding
+		case "tcp", "udp": // started from v2.1, tcp and udp are for local port forwarding
-			arg.Protocol = ""
+			arg.Forward = strings.Trim(u.EscapedPath(), "/")
+		case "rtcp", "rudp": // started from v2.1, rtcp and rudp are for remote port forwarding\
+			if a := strings.Split(strings.Trim(u.EscapedPath(), "/"), ":"); len(a) == 3 {
+				arg.Forward = a[0] + ":" + a[1]
+				arg.Bind = ":" + a[2]
+				glog.V(LINFO).Infoln(arg.Forward, arg.Bind)
+			}
 		default:
 			arg.Transport = ""
 		}