add bind forward

conn.go

@@ -111,7 +111,7 @@ func handleConn(conn net.Conn, arg Args) {
 			}
 			return
 		}
-		handleSocks5Request(req, conn, arg)
+		handleSocks5Request(req, conn)
 		return
 	}
 
@@ -162,7 +162,7 @@ func handleConn(conn net.Conn, arg Args) {
 			}
 			return
 		}
-		handleSocks5Request(req, conn, arg)
+		handleSocks5Request(req, conn)
 		return
 	}
 
@@ -198,41 +198,43 @@ func (r *reqReader) Read(p []byte) (n int, err error) {
 	return
 }
 
-func connect(addr string) (conn net.Conn, err error) {
+func Connect(addr string) (conn net.Conn, err error) {
 	if !strings.Contains(addr, ":") {
 		addr += ":80"
 	}
 	if len(forwardArgs) == 0 {
 		return net.Dial("tcp", addr)
 	}
-	return forwardChain(addr, forwardArgs[0], forwardArgs[1:]...)
-}
 
-func forwardChain(addr string, level1 Args, chain ...Args) (conn net.Conn, err error) {
-	if glog.V(LINFO) {
-		glog.Infof("forward: %s/%s %s", level1.Protocol, level1.Transport, level1.Addr)
-	}
-	if conn, err = net.Dial("tcp", level1.Addr); err != nil {
-		return
-	}
-	c, err := forward(conn, level1)
+	var end Args
+	conn, end, err = forwardChain(forwardArgs...)
 	if err != nil {
+		if conn != nil {
 			conn.Close()
+		}
 		return nil, err
 	}
-	conn = c
-
-	if len(chain) == 0 {
-		if err := establish(conn, addr, level1); err != nil {
+	if err := establish(conn, addr, end); err != nil {
 		conn.Close()
 		return nil, err
 	}
+	return conn, nil
+}
+
+func forwardChain(chain ...Args) (conn net.Conn, end Args, err error) {
+	end = chain[0]
+	if conn, err = net.Dial("tcp", end.Addr); err != nil {
+		return
+	}
+	c, err := forward(conn, end)
+	if err != nil {
 		return
 	}
+	conn = c
 
-	cur := level1
+	chain = chain[1:]
 	for _, arg := range chain {
-		if err = establish(conn, arg.Addr, cur); err != nil {
+		if err = establish(conn, arg.Addr, end); err != nil {
 			goto exit
 		}
 
@@ -241,26 +243,18 @@ func forwardChain(addr string, level1 Args, chain ...Args) (conn net.Conn, err e
 			goto exit
 		}
 		conn = c
-		cur = arg
+		end = arg
 	}
 
 exit:
-	if err != nil {
-		conn.Close()
-		return nil, err
-	}
-
-	if err := establish(conn, addr, cur); err != nil {
-		conn.Close()
-		return nil, err
-	}
-
 	return
 }
 
 func forward(conn net.Conn, arg Args) (net.Conn, error) {
 	var err error
-
+	if glog.V(LINFO) {
+		glog.Infof("forward: %s/%s %s", arg.Protocol, arg.Transport, arg.Addr)
+	}
 	switch arg.Transport {
 	case "ws": // websocket connection
 		conn, err = wsClient(conn, arg.Addr)
@@ -312,10 +306,19 @@ func establish(conn net.Conn, addr string, arg Args) error {
 			Host: host,
 			Port: uint16(p),
 		})
-		rep, err := requestSocks5(conn, req)
+		if err := req.Write(conn); err != nil {
+			return err
+		}
+		if glog.V(LDEBUG) {
+			glog.Infoln(req)
+		}
+		rep, err := gosocks5.ReadReply(conn)
 		if err != nil {
 			return err
 		}
+		if glog.V(LDEBUG) {
+			glog.Infoln(rep)
+		}
 		if rep.Rep != gosocks5.Succeeded {
 			return errors.New("Service unavailable")
 		}

http.go

@@ -47,7 +47,7 @@ func handleHttpRequest(req *http.Request, conn net.Conn, arg Args) {
 		return
 	}
 
-	c, err := connect(req.Host)
+	c, err := Connect(req.Host)
 	if err != nil {
 		if glog.V(LWARNING) {
 			glog.Warningln(err)

socks.go

@@ -2,6 +2,7 @@ package main
 
 import (
 	"crypto/tls"
+	"errors"
 	"github.com/ginuerzh/gosocks5"
 	"github.com/golang/glog"
 	"net"
@@ -175,24 +176,7 @@ func (selector *serverSelector) OnSelected(method uint8, conn net.Conn) (net.Con
 	return conn, nil
 }
 
-func requestSocks5(conn net.Conn, req *gosocks5.Request) (*gosocks5.Reply, error) {
-	if err := req.Write(conn); err != nil {
-		return nil, err
-	}
-	if glog.V(LDEBUG) {
-		glog.Infoln(req.String())
-	}
-	rep, err := gosocks5.ReadReply(conn)
-	if err != nil {
-		return nil, err
-	}
-	if glog.V(LDEBUG) {
-		glog.Infoln(rep.String())
-	}
-	return rep, nil
-}
-
-func handleSocks5Request(req *gosocks5.Request, conn net.Conn, arg Args) {
+func handleSocks5Request(req *gosocks5.Request, conn net.Conn) {
 	if glog.V(LDEBUG) {
 		glog.Infoln(req)
 	}
@@ -202,7 +186,7 @@ func handleSocks5Request(req *gosocks5.Request, conn net.Conn, arg Args) {
 		if glog.V(LINFO) {
 			glog.Infoln("socks5 connect:", req.Addr.String())
 		}
-		tconn, err := connect(req.Addr.String())
+		tconn, err := Connect(req.Addr.String())
 		if err != nil {
 			if glog.V(LWARNING) {
 				glog.Warningln("socks5 connect:", err)
@@ -234,6 +218,52 @@ func handleSocks5Request(req *gosocks5.Request, conn net.Conn, arg Args) {
 
 		Transport(conn, tconn)
 	case gosocks5.CmdBind:
+		if len(forwardArgs) > 0 {
+			forwardBind(req, conn)
+		} else {
+			serveBind(conn)
+		}
+	case gosocks5.CmdUdp:
+		uconn, err := net.ListenUDP("udp", nil)
+		if err != nil {
+			if glog.V(LWARNING) {
+				glog.Warningln("socks5 udp listen:", err)
+			}
+			rep := gosocks5.NewReply(gosocks5.Failure, nil)
+			if err := rep.Write(conn); err != nil {
+				if glog.V(LWARNING) {
+					glog.Warningln("socks5 udp listen:", err)
+				}
+			} else {
+				if glog.V(LDEBUG) {
+					glog.Infoln(rep)
+				}
+			}
+			return
+		}
+		defer uconn.Close()
+
+		addr := ToSocksAddr(uconn.LocalAddr())
+		addr.Host, _, _ = net.SplitHostPort(conn.LocalAddr().String())
+		if glog.V(LINFO) {
+			glog.Infoln("socks5 udp:", addr)
+		}
+		rep := gosocks5.NewReply(gosocks5.Succeeded, addr)
+		if err := rep.Write(conn); err != nil {
+			if glog.V(LWARNING) {
+				glog.Warningln("socks5 udp:", err)
+			}
+			return
+		} else {
+			if glog.V(LDEBUG) {
+				glog.Infoln(rep)
+			}
+		}
+		srvTunnelUDP(conn, uconn)
+	}
+}
+
+func serveBind(conn net.Conn) error {
 	l, err := net.ListenTCP("tcp", nil)
 	if err != nil {
 		if glog.V(LWARNING) {
@@ -249,10 +279,11 @@ func handleSocks5Request(req *gosocks5.Request, conn net.Conn, arg Args) {
 				glog.Infoln(rep)
 			}
 		}
-			return
+		return err
 	}
 
 	addr := ToSocksAddr(l.Addr())
+	// Issue: may not reachable when host has two interfaces
 	addr.Host, _, _ = net.SplitHostPort(conn.LocalAddr().String())
 	if glog.V(LINFO) {
 		glog.Infoln("socks5 bind:", addr)
@@ -263,7 +294,7 @@ func handleSocks5Request(req *gosocks5.Request, conn net.Conn, arg Args) {
 			glog.Warningln("socks5 bind:", err)
 		}
 		l.Close()
-			return
+		return err
 	}
 	if glog.V(LDEBUG) {
 		glog.Infoln(rep)
@@ -285,7 +316,7 @@ func handleSocks5Request(req *gosocks5.Request, conn net.Conn, arg Args) {
 				glog.Infoln(rep)
 			}
 		}
-			return
+		return err
 	}
 	defer tconn.Close()
 
@@ -298,55 +329,105 @@ func handleSocks5Request(req *gosocks5.Request, conn net.Conn, arg Args) {
 		if glog.V(LWARNING) {
 			glog.Warningln("socks5 bind accept:", err)
 		}
-			return
+		return err
 	}
 	if glog.V(LDEBUG) {
 		glog.Infoln(rep)
 	}
 
-		if err := Transport(conn, tconn); err != nil {
-			//log.Println(err)
-		}
-	case gosocks5.CmdUdp:
-		uconn, err := net.ListenUDP("udp", nil)
+	return Transport(conn, tconn)
+}
+
+func forwardBind(req *gosocks5.Request, conn net.Conn) error {
+	fc, _, err := forwardChain(forwardArgs...)
 	if err != nil {
-			if glog.V(LWARNING) {
-				glog.Warningln("socks5 udp listen:", err)
+		if fc != nil {
+			fc.Close()
 		}
 		rep := gosocks5.NewReply(gosocks5.Failure, nil)
 		if err := rep.Write(conn); err != nil {
 			if glog.V(LWARNING) {
-					glog.Warningln("socks5 udp listen:", err)
+				glog.Warningln("socks5 bind:", err)
 			}
 		} else {
 			if glog.V(LDEBUG) {
 				glog.Infoln(rep)
 			}
 		}
-			return
+		return err
 	}
-		defer uconn.Close()
+	defer fc.Close()
 
-		addr := ToSocksAddr(uconn.LocalAddr())
-		addr.Host, _, _ = net.SplitHostPort(conn.LocalAddr().String())
-		if glog.V(LINFO) {
-			glog.Infoln("socks5 udp:", addr)
+	if err := req.Write(fc); err != nil {
+		if glog.V(LWARNING) {
+			glog.Warningln("socks5 bind:", err)
+		}
+		gosocks5.NewReply(gosocks5.Failure, nil).Write(conn)
+		return err
+	}
+	if glog.V(LDEBUG) {
+		glog.Infoln(req)
+	}
+
+	// first reply
+	if err := peekBindReply(conn, fc); err != nil {
+		return err
+	}
+	// second reply
+	if err := peekBindReply(conn, fc); err != nil {
+		return err
+	}
+
+	return Transport(conn, fc)
+}
+
+func peekBindReply(conn, fc net.Conn) error {
+	rep, err := gosocks5.ReadReply(fc)
+	if err != nil {
+		if glog.V(LWARNING) {
+			glog.Warningln("socks5 bind:", err)
+		}
+		rep = gosocks5.NewReply(gosocks5.Failure, nil)
 	}
-		rep := gosocks5.NewReply(gosocks5.Succeeded, addr)
 	if err := rep.Write(conn); err != nil {
 		if glog.V(LWARNING) {
-				glog.Warningln("socks5 udp:", err)
+			glog.Warningln("socks5 bind:", err)
+		}
+		return err
+	}
+	if glog.V(LDEBUG) {
+		glog.Infoln(rep)
+	}
+	if rep.Rep != gosocks5.Succeeded {
+		return errors.New("Bind failure")
+	}
+
+	return nil
+}
+
+/*
+func forwardUDP() error {
+	fc, _, err := forwardChain(forwardArgs...)
+	if err != nil {
+		if fc != nil {
+			fc.Close()
+		}
+		rep := gosocks5.NewReply(gosocks5.Failure, nil)
+		if err := rep.Write(conn); err != nil {
+			if glog.V(LWARNING) {
+				glog.Warningln("socks5 bind:", err)
 			}
-			return
 		} else {
 			if glog.V(LDEBUG) {
 				glog.Infoln(rep)
 			}
 		}
-		srvTunnelUDP(conn, uconn)
+		return err
 	}
-}
+	defer fc.Close()
 
+}
+*/
 func srvTunnelUDP(conn net.Conn, uconn *net.UDPConn) {
 	go func() {
 		b := make([]byte, 16*1024)