tun: add chain support

forward.go

@@ -187,14 +187,15 @@ func (h *udpDirectForwardHandler) Handle(conn net.Conn) {
 		return
 	}
 
+	raddr, err := net.ResolveUDPAddr("udp", node.Addr)
+	if err != nil {
+		node.MarkDead()
+		log.Logf("[udp] %s - %s : %s", conn.LocalAddr(), node.Addr, err)
+		return
+	}
+
 	var cc net.Conn
 	if h.options.Chain.IsEmpty() {
-		raddr, err := net.ResolveUDPAddr("udp", node.Addr)
-		if err != nil {
-			node.MarkDead()
-			log.Logf("[udp] %s - %s : %s", conn.LocalAddr(), node.Addr, err)
-			return
-		}
 		cc, err = net.DialUDP("udp", nil, raddr)
 		if err != nil {
 			node.MarkDead()
@@ -208,7 +209,8 @@ func (h *udpDirectForwardHandler) Handle(conn net.Conn) {
 			log.Logf("[udp] %s - %s : %s", conn.LocalAddr(), node.Addr, err)
 			return
 		}
-		cc = &udpTunnelConn{Conn: cc, raddr: node.Addr}
+
+		cc = &udpTunnelConn{Conn: cc, raddr: raddr}
 	}
 
 	defer cc.Close()
@@ -763,7 +765,7 @@ func (l *tcpRemoteForwardListener) getSession() (s *muxSession, err error) {
 	conn.SetDeadline(time.Now().Add(HandshakeTimeout))
 	defer conn.SetDeadline(time.Time{})
 
-	conn, err = socks5Handshake(conn, nil, l.chain.LastNode().User)
+	conn, err = socks5Handshake(conn, userSocks5HandshakeOption(l.chain.LastNode().User))
 	if err != nil {
 		return nil, err
 	}
@@ -798,7 +800,7 @@ func (l *tcpRemoteForwardListener) getSession() (s *muxSession, err error) {
 }
 
 func (l *tcpRemoteForwardListener) waitConnectSOCKS5(conn net.Conn) (net.Conn, error) {
-	conn, err := socks5Handshake(conn, nil, l.chain.LastNode().User)
+	conn, err := socks5Handshake(conn, userSocks5HandshakeOption(l.chain.LastNode().User))
 	if err != nil {
 		return nil, err
 	}

gost.go

@@ -20,7 +20,7 @@ import (
 )
 
 // Version is the gost version.
-const Version = "2.9.0"
+const Version = "2.9.1-dev"
 
 // Debug is a flag that enables the debug log.
 var Debug bool

snapcraft.yaml

 name: gost
 type: app
-version: '2.9.0'
+version: '2.9.1'
 title: GO Simple Tunnel
 summary: A simple security tunnel written in golang
 description: |

socks.go

@@ -213,7 +213,9 @@ func (c *socks5Connector) Connect(conn net.Conn, addr string, options ...Connect
 	if user == nil {
 		user = c.User
 	}
-	cc, err := socks5Handshake(conn, opts.Selector, user)
+	cc, err := socks5Handshake(conn,
+		selectorSocks5HandshakeOption(opts.Selector),
+		userSocks5HandshakeOption(user))
 	if err != nil {
 		return nil, err
 	}
@@ -281,7 +283,9 @@ func (c *socks5BindConnector) Connect(conn net.Conn, addr string, options ...Con
 	if user == nil {
 		user = c.User
 	}
-	cc, err := socks5Handshake(conn, opts.Selector, user)
+	cc, err := socks5Handshake(conn,
+		selectorSocks5HandshakeOption(opts.Selector),
+		userSocks5HandshakeOption(user))
 	if err != nil {
 		return nil, err
 	}
@@ -431,7 +435,7 @@ func (tr *socks5MuxBindTransporter) initSession(conn net.Conn, addr string, opts
 		opts = &HandshakeOptions{}
 	}
 
-	cc, err := socks5Handshake(conn, nil, opts.User)
+	cc, err := socks5Handshake(conn, userSocks5HandshakeOption(opts.User))
 	if err != nil {
 		return nil, err
 	}
@@ -515,7 +519,9 @@ func (c *socks5UDPConnector) Connect(conn net.Conn, addr string, options ...Conn
 	if user == nil {
 		user = c.User
 	}
-	cc, err := socks5Handshake(conn, opts.Selector, user)
+	cc, err := socks5Handshake(conn,
+		selectorSocks5HandshakeOption(opts.Selector),
+		userSocks5HandshakeOption(user))
 	if err != nil {
 		return nil, err
 	}
@@ -594,7 +600,9 @@ func (c *socks5UDPTunConnector) Connect(conn net.Conn, addr string, options ...C
 	if user == nil {
 		user = c.User
 	}
-	cc, err := socks5Handshake(conn, opts.Selector, user)
+	cc, err := socks5Handshake(conn,
+		selectorSocks5HandshakeOption(opts.Selector),
+		userSocks5HandshakeOption(user))
 	if err != nil {
 		return nil, err
 	}
@@ -636,7 +644,7 @@ func (c *socks5UDPTunConnector) Connect(conn net.Conn, addr string, options ...C
 	}
 	log.Logf("[socks5] udp-tun associate on %s OK", baddr)
 
-	return &udpTunnelConn{Conn: conn, raddr: taddr.String()}, nil
+	return &udpTunnelConn{Conn: conn, raddr: taddr}, nil
 }
 
 type socks4Connector struct{}
@@ -1122,7 +1130,7 @@ func (h *socks5Handler) handleUDPRelay(conn net.Conn, req *gosocks5.Request) {
 	}
 	defer cc.Close()
 
-	cc, err = socks5Handshake(cc, nil, h.options.Chain.LastNode().User)
+	cc, err = socks5Handshake(cc, userSocks5HandshakeOption(h.options.Chain.LastNode().User))
 	if err != nil {
 		log.Logf("[socks5-udp] %s -> %s : %s", conn.RemoteAddr(), socksAddr, err)
 		return
@@ -1386,7 +1394,7 @@ func (h *socks5Handler) handleUDPTunnel(conn net.Conn, req *gosocks5.Request) {
 	}
 	defer cc.Close()
 
-	cc, err = socks5Handshake(cc, nil, h.options.Chain.LastNode().User)
+	cc, err = socks5Handshake(cc, userSocks5HandshakeOption(h.options.Chain.LastNode().User))
 	if err != nil {
 		log.Logf("[socks5-udp] %s -> %s : %s", conn.RemoteAddr(), req.Addr, err)
 		return
@@ -1780,7 +1788,11 @@ func getSOCKS5UDPTunnel(chain *Chain, addr net.Addr) (net.Conn, error) {
 	conn.SetDeadline(time.Now().Add(HandshakeTimeout))
 	defer conn.SetDeadline(time.Time{})
 
-	cc, err := socks5Handshake(conn, nil, chain.LastNode().User)
+	node := chain.LastNode()
+	cc, err := socks5Handshake(conn,
+		userSocks5HandshakeOption(node.User),
+		noTLSSocks5HandshakeOption(node.GetBool("notls")),
+	)
 	if err != nil {
 		conn.Close()
 		return nil, err
@@ -1813,17 +1825,51 @@ func getSOCKS5UDPTunnel(chain *Chain, addr net.Addr) (net.Conn, error) {
 	return conn, nil
 }
 
-func socks5Handshake(conn net.Conn, selector gosocks5.Selector, user *url.Userinfo) (net.Conn, error) {
+type socks5HandshakeOptions struct {
+	selector  gosocks5.Selector
+	user      *url.Userinfo
+	tlsConfig *tls.Config
+	noTLS     bool
+}
+
+type socks5HandshakeOption func(opts *socks5HandshakeOptions)
+
+func selectorSocks5HandshakeOption(selector gosocks5.Selector) socks5HandshakeOption {
+	return func(opts *socks5HandshakeOptions) {
+		opts.selector = selector
+	}
+}
+
+func userSocks5HandshakeOption(user *url.Userinfo) socks5HandshakeOption {
+	return func(opts *socks5HandshakeOptions) {
+		opts.user = user
+	}
+}
+
+func noTLSSocks5HandshakeOption(noTLS bool) socks5HandshakeOption {
+	return func(opts *socks5HandshakeOptions) {
+		opts.noTLS = noTLS
+	}
+}
+
+func socks5Handshake(conn net.Conn, opts ...socks5HandshakeOption) (net.Conn, error) {
+	options := socks5HandshakeOptions{}
+	for _, opt := range opts {
+		opt(&options)
+	}
+	selector := options.selector
 	if selector == nil {
 		cs := &clientSelector{
 			TLSConfig: &tls.Config{InsecureSkipVerify: true},
-			User:      user,
+			User:      options.user,
 		}
 		cs.AddMethod(
 			gosocks5.MethodNoAuth,
 			gosocks5.MethodUserPass,
-			MethodTLS,
 		)
+		if !options.noTLS {
+			cs.AddMethod(MethodTLS)
+		}
 		selector = cs
 	}
 
@@ -1835,7 +1881,7 @@ func socks5Handshake(conn net.Conn, selector gosocks5.Selector, user *url.Userin
 }
 
 type udpTunnelConn struct {
-	raddr string
+	raddr net.Addr
 	net.Conn
 }
 
@@ -1859,11 +1905,7 @@ func (c *udpTunnelConn) ReadFrom(b []byte) (n int, addr net.Addr, err error) {
 }
 
 func (c *udpTunnelConn) Write(b []byte) (n int, err error) {
-	addr, err := net.ResolveUDPAddr("udp", c.raddr)
-	if err != nil {
-		return
-	}
-	dgram := gosocks5.NewUDPDatagram(gosocks5.NewUDPHeader(uint16(len(b)), 0, toSocksAddr(addr)), b)
+	dgram := gosocks5.NewUDPDatagram(gosocks5.NewUDPHeader(uint16(len(b)), 0, toSocksAddr(c.raddr)), b)
 	if err = dgram.Write(c.Conn); err != nil {
 		return
 	}

tuntap.go

@@ -114,12 +114,14 @@ func (l *tunListener) Close() error {
 type tunHandler struct {
 	options *HandlerOptions
 	routes  sync.Map
+	chExit  chan struct{}
 }
 
 // TunHandler creates a handler for tun tunnel.
 func TunHandler(opts ...HandlerOption) Handler {
 	h := &tunHandler{
 		options: &HandlerOptions{},
+		chExit:  make(chan struct{}, 1),
 	}
 	for _, opt := range opts {
 		opt(h.options)
@@ -141,44 +143,76 @@ func (h *tunHandler) Handle(conn net.Conn) {
 	defer os.Exit(0)
 	defer conn.Close()
 
-	laddr, raddr := h.options.Node.Addr, h.options.Node.Remote
-	var pc net.PacketConn
 	var err error
-	if h.options.TCPMode {
-		if raddr != "" {
-			pc, err = tcpraw.Dial("tcp", raddr)
-		} else {
-			pc, err = tcpraw.Listen("tcp", laddr)
+	var raddr net.Addr
+	if addr := h.options.Node.Remote; addr != "" {
+		raddr, err = net.ResolveUDPAddr("udp", addr)
+		if err != nil {
+			log.Logf("[tun] %s: remote addr: %v", conn.LocalAddr(), err)
+			return
 		}
-	} else {
-		addr, _ := net.ResolveUDPAddr("udp", laddr)
-		pc, err = net.ListenUDP("udp", addr)
-	}
-	if err != nil {
-		log.Logf("[tun] %s: %v", conn.LocalAddr(), err)
-		return
 	}
 
-	if len(h.options.Users) > 0 && h.options.Users[0] != nil {
-		passwd, _ := h.options.Users[0].Password()
-		cipher, err := core.PickCipher(h.options.Users[0].Username(), nil, passwd)
+	var tempDelay time.Duration
+	for {
+		err := func() error {
+			var err error
+			var pc net.PacketConn
+			if raddr != nil && !h.options.Chain.IsEmpty() {
+				var cc net.Conn
+				cc, err = getSOCKS5UDPTunnel(h.options.Chain, nil)
+				pc = &udpTunnelConn{Conn: cc, raddr: raddr}
+			} else {
+				laddr, _ := net.ResolveUDPAddr("udp", h.options.Node.Addr)
+				pc, err = net.ListenUDP("udp", laddr)
+			}
+			if err != nil {
+				return err
+			}
+
+			pc, err = h.initTunnelConn(pc)
+			if err != nil {
+				return err
+			}
+
+			return h.transportTun(conn, pc, raddr)
+		}()
 		if err != nil {
-			log.Logf("[tun] %s - %s cipher: %v", conn.LocalAddr(), pc.LocalAddr(), err)
+			log.Logf("[tun] %s: %v", conn.LocalAddr(), err)
+		}
+
+		select {
+		case <-h.chExit:
 			return
+		default:
 		}
-		pc = cipher.PacketConn(pc)
-	}
 
-	var ra net.Addr
-	if raddr != "" {
-		ra, err = net.ResolveUDPAddr("udp", raddr)
 		if err != nil {
-			log.Logf("[tun] %s - %s: remote addr: %v", conn.LocalAddr(), pc.LocalAddr(), err)
-			return
+			if tempDelay == 0 {
+				tempDelay = 1000 * time.Millisecond
+			} else {
+				tempDelay *= 2
+			}
+			if max := 6 * time.Second; tempDelay > max {
+				tempDelay = max
+			}
+			time.Sleep(tempDelay)
+			continue
 		}
+		tempDelay = 0
 	}
+}
 
-	h.transportTun(conn, pc, ra)
+func (h *tunHandler) initTunnelConn(pc net.PacketConn) (net.PacketConn, error) {
+	if len(h.options.Users) > 0 && h.options.Users[0] != nil {
+		passwd, _ := h.options.Users[0].Password()
+		cipher, err := core.PickCipher(h.options.Users[0].Username(), nil, passwd)
+		if err != nil {
+			return nil, err
+		}
+		pc = cipher.PacketConn(pc)
+	}
+	return pc, nil
 }
 
 func (h *tunHandler) transportTun(tun net.Conn, conn net.PacketConn, raddr net.Addr) error {
@@ -192,6 +226,10 @@ func (h *tunHandler) transportTun(tun net.Conn, conn net.PacketConn, raddr net.A
 
 				n, err := tun.Read(b)
 				if err != nil {
+					select {
+					case h.chExit <- struct{}{}:
+					default:
+					}
 					return err
 				}
 
@@ -323,6 +361,10 @@ func (h *tunHandler) transportTun(tun net.Conn, conn net.PacketConn, raddr net.A
 				}
 
 				if _, err := tun.Write(b[:n]); err != nil {
+					select {
+					case h.chExit <- struct{}{}:
+					default:
+					}
 					return err
 				}
 				return nil
@@ -339,7 +381,6 @@ func (h *tunHandler) transportTun(tun net.Conn, conn net.PacketConn, raddr net.A
 	if err != nil && err == io.EOF {
 		err = nil
 	}
-	log.Logf("[tun] %s - %s: %v", tun.LocalAddr(), conn.LocalAddr(), err)
 	return err
 }