add UDP port forwarding support

gost/examples/bench/srv.go

@@ -156,7 +156,10 @@ func rtcpForwardServer() {
 	if err != nil {
 		log.Fatal()
 	}
-	h := gost.RTCPForwardHandler(":1222", "localhost:22")
+	h := gost.RTCPForwardHandler(
+		":1222",
+		gost.AddrHandlerOption("127.0.0.1:22"),
+	)
 	log.Fatal(s.Serve(ln, h))
 }
 

gost/examples/forward/udp/cli.go

@@ -0,0 +1,53 @@
+package main
+
+import (
+	"flag"
+	"log"
+	"net"
+	"time"
+)
+
+var (
+	concurrency int
+	saddr       string
+)
+
+func init() {
+	log.SetFlags(log.LstdFlags | log.Lshortfile)
+
+	flag.StringVar(&saddr, "S", ":18080", "server address")
+	flag.IntVar(&concurrency, "c", 1, "Number of multiple echo to make at a time")
+	flag.Parse()
+}
+
+func main() {
+	for i := 0; i < concurrency; i++ {
+		go udpEchoLoop()
+	}
+	select{}
+}
+
+func udpEchoLoop() {
+	addr, err := net.ResolveUDPAddr("udp", saddr)
+	if err != nil {
+		log.Fatal(err)
+	}
+	conn, err := net.DialUDP("udp", nil, addr)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	msg := []byte(`abcdefghijklmnopqrstuvwxyz`)
+	for {
+		if _, err := conn.Write(msg); err != nil {
+			log.Fatal(err)
+		}
+		b := make([]byte, 1024)
+		_, err := conn.Read(b)
+		if err != nil {
+			log.Fatal(err)
+		}
+		// log.Println(string(b[:n]))
+		time.Sleep(100 * time.Millisecond)
+	}
+}

gost/examples/forward/udp/forward.go

@@ -0,0 +1,56 @@
+package main
+
+import (
+	"flag"
+	"log"
+	"net/url"
+	"time"
+
+	"github.com/ginuerzh/gost/gost"
+)
+
+var (
+	laddr, faddr string
+	quiet        bool
+)
+
+func init() {
+	log.SetFlags(log.LstdFlags | log.Lshortfile)
+
+	flag.StringVar(&laddr, "L", ":18080", "listen address")
+	flag.StringVar(&faddr, "F", ":8080", "forward address")
+	flag.BoolVar(&quiet, "q", false, "quiet mode")
+	flag.BoolVar(&gost.Debug, "d", false, "debug mode")
+	flag.Parse()
+
+	if quiet {
+		gost.SetLogger(&gost.NopLogger{})
+	}
+}
+func main() {
+	udpForwardServer()
+}
+
+func udpForwardServer() {
+	s := &gost.Server{}
+	ln, err := gost.UDPForwardListener(laddr, time.Second*3)
+	if err != nil {
+		log.Fatal(err)
+	}
+	h := gost.UDPForwardHandler(
+		faddr,
+		gost.ChainHandlerOption(gost.NewChain(gost.Node{
+			Protocol:  "socks5",
+			Transport: "tcp",
+			Addr:      ":11080",
+			User:      url.UserPassword("admin", "123456"),
+			Client: &gost.Client{
+				Connector: gost.SOCKS5Connector(
+					url.UserPassword("admin", "123456"),
+				),
+				Transporter: gost.TCPTransporter(),
+			},
+		})),
+	)
+	log.Fatal(s.Serve(ln, h))
+}

gost/examples/forward/udp/srv.go

@@ -0,0 +1,44 @@
+package main
+
+import (
+	"flag"
+	"log"
+	"net"
+)
+
+var (
+	laddr string
+)
+
+func init() {
+	log.SetFlags(log.LstdFlags | log.Lshortfile)
+
+	flag.StringVar(&laddr, "L", ":8080", "listen address")
+	flag.Parse()
+}
+func main() {
+	udpEchoServer()
+}
+
+func udpEchoServer() {
+	addr, err := net.ResolveUDPAddr("udp", laddr)
+	if err != nil {
+		log.Fatal(err)
+	}
+	conn, err := net.ListenUDP("udp", addr)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	for {
+		b := make([]byte, 1024)
+		n, raddr, err := conn.ReadFromUDP(b)
+		if err != nil {
+			log.Fatal(err)
+		}
+		if _, err = conn.WriteToUDP(b[:n], raddr); err != nil {
+			log.Fatal(err)
+		}
+
+	}
+}

gost/forward.go

@@ -3,6 +3,7 @@ package gost
 import (
 	"errors"
 	"net"
+	"sync"
 	"time"
 
 	"fmt"
@@ -20,10 +21,8 @@ type tcpForwardHandler struct {
 // The raddr is the remote address that the server will forward to.
 func TCPForwardHandler(raddr string, opts ...HandlerOption) Handler {
 	h := &tcpForwardHandler{
-		raddr: raddr,
-		options: &HandlerOptions{
-			Chain: new(Chain),
-		},
+		raddr:   raddr,
+		options: &HandlerOptions{},
 	}
 	for _, opt := range opts {
 		opt(h.options)
@@ -55,13 +54,10 @@ type udpForwardHandler struct {
 
 // UDPForwardHandler creates a server Handler for UDP port forwarding server.
 // The raddr is the remote address that the server will forward to.
-func UDPForwardHandler(raddr string, ttl time.Duration, opts ...HandlerOption) Handler {
+func UDPForwardHandler(raddr string, opts ...HandlerOption) Handler {
 	h := &udpForwardHandler{
-		raddr: raddr,
-		ttl:   ttl,
-		options: &HandlerOptions{
-			Chain: new(Chain),
-		},
+		raddr:   raddr,
+		options: &HandlerOptions{},
 	}
 	for _, opt := range opts {
 		opt(h.options)
@@ -71,6 +67,68 @@ func UDPForwardHandler(raddr string, ttl time.Duration, opts ...HandlerOption) H
 
 func (h *udpForwardHandler) Handle(conn net.Conn) {
 	defer conn.Close()
+
+	var cc net.Conn
+	if h.options.Chain.IsEmpty() {
+		raddr, err := net.ResolveUDPAddr("udp", h.raddr)
+		if err != nil {
+			log.Logf("[udp] %s - %s : %s", conn.LocalAddr(), h.raddr, err)
+			return
+		}
+		cc, err = net.DialUDP("udp", nil, raddr)
+		if err != nil {
+			log.Logf("[udp] %s - %s : %s", conn.LocalAddr(), h.raddr, err)
+			return
+		}
+	} else {
+		var err error
+		cc, err = h.getUDPTunnel()
+		if err != nil {
+			log.Logf("[udp] %s - %s : %s", conn.LocalAddr(), h.raddr, err)
+			return
+		}
+		cc = &udpTunnelConn{Conn: cc, raddr: h.raddr}
+	}
+
+	defer cc.Close()
+
+	log.Logf("[udp] %s <-> %s", conn.RemoteAddr(), h.raddr)
+	transport(conn, cc)
+	log.Logf("[udp] %s >-< %s", conn.RemoteAddr(), h.raddr)
+}
+
+func (h *udpForwardHandler) getUDPTunnel() (net.Conn, error) {
+	conn, err := h.options.Chain.Conn()
+	if err != nil {
+		return nil, err
+	}
+	cc, err := socks5Handshake(conn, h.options.Chain.LastNode().User)
+	if err != nil {
+		conn.Close()
+		return nil, err
+	}
+	conn = cc
+
+	conn.SetWriteDeadline(time.Now().Add(WriteTimeout))
+	if err = gosocks5.NewRequest(CmdUDPTun, nil).Write(conn); err != nil {
+		conn.Close()
+		return nil, err
+	}
+	conn.SetWriteDeadline(time.Time{})
+
+	conn.SetReadDeadline(time.Now().Add(ReadTimeout))
+	reply, err := gosocks5.ReadReply(conn)
+	if err != nil {
+		conn.Close()
+		return nil, err
+	}
+	conn.SetReadDeadline(time.Time{})
+
+	if reply.Rep != gosocks5.Succeeded {
+		conn.Close()
+		return nil, errors.New("UDP tunnel failure")
+	}
+	return conn, nil
 }
 
 type rtcpForwardHandler struct {
@@ -184,34 +242,265 @@ func (h *rudpForwardHandler) Handle(conn net.Conn) {
 }
 
 type udpForwardListener struct {
-	addr *net.UDPAddr
-	conn *net.UDPConn
+	ln        *net.UDPConn
+	conns     map[string]*udpServerConn
+	connMutex sync.Mutex
+	connChan  chan net.Conn
+	errChan   chan error
+	ttl       time.Duration
 }
 
 // UDPForwardListener creates a Listener for UDP port forwarding server.
-func UDPForwardListener(addr string) (Listener, error) {
+func UDPForwardListener(addr string, ttl time.Duration) (Listener, error) {
 	laddr, err := net.ResolveUDPAddr("udp", addr)
 	if err != nil {
 		return nil, err
 	}
-	conn, err := net.ListenUDP("udp", laddr)
+	ln, err := net.ListenUDP("udp", laddr)
 	if err != nil {
 		return nil, err
 	}
-	return &udpForwardListener{conn: conn}, nil
+	l := &udpForwardListener{
+		ln:       ln,
+		conns:    make(map[string]*udpServerConn),
+		connChan: make(chan net.Conn, 1024),
+		errChan:  make(chan error, 1),
+		ttl:      ttl,
+	}
+	go l.listenLoop()
+	return l, nil
 }
 
-func (l *udpForwardListener) Accept() (net.Conn, error) {
-	// TODO: create udp forward connection
-	return nil, nil
+func (l *udpForwardListener) listenLoop() {
+	for {
+		b := make([]byte, mediumBufferSize)
+		n, raddr, err := l.ln.ReadFromUDP(b)
+		if err != nil {
+			log.Logf("[udp] peer -> %s : %s", l.Addr(), err)
+			l.ln.Close()
+			l.errChan <- err
+			close(l.errChan)
+		}
+		if Debug {
+			log.Logf("[udp] %s >>> %s : length %d", raddr, l.Addr(), n)
+		}
+		conn, ok := l.conns[raddr.String()]
+		if !ok || conn.Closed() {
+			conn = newUDPServerConn(l.ln, raddr, l.ttl)
+			l.conns[raddr.String()] = conn
+
+			select {
+			case l.connChan <- conn:
+			default:
+				conn.Close()
+				log.Logf("[udp] %s - %s: connection queue is full", raddr, l.Addr())
+			}
+		}
+
+		select {
+		case conn.rChan <- b[:n]:
+		default:
+			log.Logf("[udp] %s -> %s : write queue is full", raddr, l.Addr())
+		}
+	}
+}
+
+func (l *udpForwardListener) Accept() (conn net.Conn, err error) {
+	var ok bool
+	select {
+	case conn = <-l.connChan:
+	case err, ok = <-l.errChan:
+		if !ok {
+			err = errors.New("accpet on closed listener")
+		}
+	}
+	return
 }
 
 func (l *udpForwardListener) Addr() net.Addr {
-	return l.addr
+	return l.ln.LocalAddr()
 }
 
 func (l *udpForwardListener) Close() error {
-	return l.conn.Close()
+	return l.ln.Close()
+}
+
+type udpServerConn struct {
+	conn         *net.UDPConn
+	raddr        *net.UDPAddr
+	rChan, wChan chan []byte
+	closed       chan struct{}
+	brokenChan   chan struct{}
+	closeMutex   sync.Mutex
+	ttl          time.Duration
+	nopChan      chan int
+}
+
+func newUDPServerConn(conn *net.UDPConn, raddr *net.UDPAddr, ttl time.Duration) *udpServerConn {
+	c := &udpServerConn{
+		conn:       conn,
+		raddr:      raddr,
+		rChan:      make(chan []byte, 128),
+		wChan:      make(chan []byte, 128),
+		closed:     make(chan struct{}),
+		brokenChan: make(chan struct{}),
+		nopChan:    make(chan int),
+		ttl:        ttl,
+	}
+	go c.writeLoop()
+	go c.ttlWait()
+	return c
+}
+
+func (c *udpServerConn) Read(b []byte) (n int, err error) {
+	select {
+	case bb := <-c.rChan:
+		n = copy(b, bb)
+		if n != len(bb) {
+			err = errors.New("read partial data")
+			return
+		}
+	case <-c.brokenChan:
+		err = errors.New("Broken pipe")
+	case <-c.closed:
+		err = errors.New("read from closed connection")
+		return
+	}
+
+	select {
+	case c.nopChan <- n:
+	default:
+	}
+	return
+}
+
+func (c *udpServerConn) Write(b []byte) (n int, err error) {
+	if len(b) == 0 {
+		return 0, nil
+	}
+	select {
+	case c.wChan <- b:
+		n = len(b)
+	case <-c.brokenChan:
+		err = errors.New("Broken pipe")
+	case <-c.closed:
+		err = errors.New("write to closed connection")
+		return
+	}
+
+	select {
+	case c.nopChan <- n:
+	default:
+	}
+
+	return
+}
+
+func (c *udpServerConn) Close() error {
+	c.closeMutex.Lock()
+	defer c.closeMutex.Unlock()
+
+	select {
+	case <-c.closed:
+		return errors.New("connection is closed")
+	default:
+		close(c.closed)
+	}
+	return nil
+}
+
+func (c *udpServerConn) Closed() bool {
+	select {
+	case <-c.closed:
+		return true
+	default:
+		return false
+	}
+}
+
+func (c *udpServerConn) writeLoop() {
+	for {
+		select {
+		case b, ok := <-c.wChan:
+			if !ok {
+				return
+			}
+			n, err := c.conn.WriteToUDP(b, c.raddr)
+			if err != nil {
+				log.Logf("[udp] %s <<< %s : %s", c.RemoteAddr(), c.LocalAddr(), err)
+				return
+			}
+			if Debug {
+				log.Logf("[udp] %s <<< %s : length %d", c.RemoteAddr(), c.LocalAddr(), n)
+			}
+		case <-c.brokenChan:
+			return
+		case <-c.closed:
+			return
+		}
+	}
+}
+
+func (c *udpServerConn) ttlWait() {
+	timer := time.NewTimer(c.ttl)
+
+	for {
+		select {
+		case <-c.nopChan:
+			timer.Reset(c.ttl)
+		case <-timer.C:
+			close(c.brokenChan)
+			return
+		case <-c.closed:
+			return
+		}
+	}
+}
+
+func (c *udpServerConn) LocalAddr() net.Addr {
+	return c.conn.LocalAddr()
+}
+
+func (c *udpServerConn) RemoteAddr() net.Addr {
+	return c.raddr
+}
+
+func (c *udpServerConn) SetDeadline(t time.Time) error {
+	return nil
+}
+
+func (c *udpServerConn) SetReadDeadline(t time.Time) error {
+	return nil
+}
+
+func (c *udpServerConn) SetWriteDeadline(t time.Time) error {
+	return nil
+}
+
+type udpTunnelConn struct {
+	raddr string
+	net.Conn
+}
+
+func (c *udpTunnelConn) Read(b []byte) (n int, err error) {
+	dgram, err := gosocks5.ReadUDPDatagram(c.Conn)
+	if err != nil {
+		return
+	}
+	n = copy(b, dgram.Data)
+	return
+}
+
+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)
+	if err = dgram.Write(c.Conn); err != nil {
+		return
+	}
+	return len(b), nil
 }
 
 type rtcpForwardListener struct {

gost/kcp.go

@@ -95,10 +95,6 @@ type kcpConn struct {
 	stream *smux.Stream
 }
 
-func newKCPConn(conn net.Conn, stream *smux.Stream) *kcpConn {
-	return &kcpConn{conn: conn, stream: stream}
-}
-
 func (c *kcpConn) Read(b []byte) (n int, err error) {
 	return c.stream.Read(b)
 }
@@ -141,7 +137,7 @@ func (session *kcpSession) GetConn() (*kcpConn, error) {
 	if err != nil {
 		return nil, err
 	}
-	return newKCPConn(session.conn, stream), nil
+	return &kcpConn{conn: session.conn, stream: stream}, nil
 }
 
 func (session *kcpSession) Close() error {
@@ -378,9 +374,11 @@ func (l *kcpListener) mux(conn net.Conn) {
 			return
 		}
 
+		cc := &kcpConn{conn: conn, stream: stream}
 		select {
-		case l.connChan <- newKCPConn(conn, stream):
+		case l.connChan <- cc:
 		default:
+			cc.Close()
 			log.Logf("[kcp] %s - %s: connection queue is full", conn.RemoteAddr(), conn.LocalAddr())
 		}
 	}

gost/quic.go

@@ -191,9 +191,12 @@ func (l *quicListener) sessionLoop(session quic.Session) {
 			log.Log("[quic] accept stream:", err)
 			return
 		}
+
+		cc := &quicConn{Stream: stream, laddr: session.LocalAddr(), raddr: session.RemoteAddr()}
 		select {
-		case l.connChan <- &quicConn{Stream: stream, laddr: session.LocalAddr(), raddr: session.RemoteAddr()}:
+		case l.connChan <- cc:
 		default:
+			cc.Close()
 			log.Logf("[quic] %s - %s: connection queue is full", session.RemoteAddr(), session.LocalAddr())
 		}
 	}

gost/socks.go

@@ -340,9 +340,7 @@ type socks5Handler struct {
 
 // SOCKS5Handler creates a server Handler for SOCKS5 proxy server.
 func SOCKS5Handler(opts ...HandlerOption) Handler {
-	options := &HandlerOptions{
-		Chain: new(Chain),
-	}
+	options := &HandlerOptions{}
 	for _, opt := range opts {
 		opt(options)
 	}
@@ -972,9 +970,7 @@ type socks4Handler struct {
 
 // SOCKS4Handler creates a server Handler for SOCKS4(A) proxy server.
 func SOCKS4Handler(opts ...HandlerOption) Handler {
-	options := &HandlerOptions{
-		Chain: new(Chain),
-	}
+	options := &HandlerOptions{}
 	for _, opt := range opts {
 		opt(options)
 	}

gost/ss.go

@@ -95,9 +95,7 @@ type shadowHandler struct {
 // ShadowHandler creates a server Handler for shadowsocks proxy server.
 func ShadowHandler(opts ...HandlerOption) Handler {
 	h := &shadowHandler{
-		options: &HandlerOptions{
-			Chain: new(Chain),
-		},
+		options: &HandlerOptions{},
 	}
 	for _, opt := range opts {
 		opt(h.options)

gost/ssh.go

@@ -85,6 +85,7 @@ func (c *sshRemoteForwardConnector) Connect(conn net.Conn, addr string) (net.Con
 				select {
 				case cc.session.connChan <- rc:
 				default:
+					rc.Close()
 					log.Logf("[ssh-rtcp] %s - %s: connection queue is full", ln.Addr(), addr)
 				}
 			}
@@ -670,9 +671,11 @@ func (l *sshTunnelListener) serveConn(conn net.Conn) {
 					continue
 				}
 				go ssh.DiscardRequests(requests)
+				cc := &sshConn{conn: conn, channel: channel}
 				select {
-				case l.connChan <- &sshConn{conn: conn, channel: channel}:
+				case l.connChan <- cc:
 				default:
+					cc.Close()
 					log.Logf("[ssh] %s - %s: connection queue is full", conn.RemoteAddr(), l.Addr())
 				}
 

gost/ws.go

@@ -217,6 +217,7 @@ func (l *wsListener) upgrade(w http.ResponseWriter, r *http.Request) {
 	select {
 	case l.connChan <- websocketServerConn(conn):
 	default:
+		conn.Close()
 		log.Logf("[ws] %s - %s: connection queue is full", r.RemoteAddr, l.addr)
 	}
 }