SOCKS5: add mux-bind request CMD

cmd/gost/main.go

@@ -14,7 +14,6 @@ import (
 	"net/url"
 	"os"
 	"runtime"
-	"strconv"
 	"strings"
 	"time"
 
@@ -117,7 +116,7 @@ func (r *route) initChain() (*gost.Chain, error) {
 		ngroup.AddNode(nodes...)
 
 		// parse peer nodes if exists
-		peerCfg, err := loadPeerConfig(nodes[0].Values.Get("peer"))
+		peerCfg, err := loadPeerConfig(nodes[0].Get("peer"))
 		if err != nil {
 			log.Log(err)
 		}
@@ -156,7 +155,7 @@ func parseChainNode(ns string) (nodes []gost.Node, err error) {
 		return
 	}
 
-	users, err := parseUsers(node.Values.Get("secrets"))
+	users, err := parseUsers(node.Get("secrets"))
 	if err != nil {
 		return
 	}
@@ -168,20 +167,20 @@ func parseChainNode(ns string) (nodes []gost.Node, err error) {
 		serverName = "localhost" // default server name
 	}
 
-	rootCAs, err := loadCA(node.Values.Get("ca"))
+	rootCAs, err := loadCA(node.Get("ca"))
 	if err != nil {
 		return
 	}
 	tlsCfg := &tls.Config{
 		ServerName:         serverName,
-		InsecureSkipVerify: !toBool(node.Values.Get("secure")),
+		InsecureSkipVerify: !node.GetBool("secure"),
 		RootCAs:            rootCAs,
 	}
 	wsOpts := &gost.WSOptions{}
-	wsOpts.EnableCompression = toBool(node.Values.Get("compression"))
+	wsOpts.EnableCompression = node.GetBool("compression")
-	wsOpts.ReadBufferSize, _ = strconv.Atoi(node.Values.Get("rbuf"))
+	wsOpts.ReadBufferSize = node.GetInt("rbuf")
-	wsOpts.WriteBufferSize, _ = strconv.Atoi(node.Values.Get("wbuf"))
+	wsOpts.WriteBufferSize = node.GetInt("wbuf")
-	wsOpts.UserAgent = node.Values.Get("agent")
+	wsOpts.UserAgent = node.Get("agent")
 
 	var tr gost.Transporter
 	switch node.Transport {
@@ -203,7 +202,7 @@ func parseChainNode(ns string) (nodes []gost.Node, err error) {
 				return nil, errors.New("KCP must be the first node in the proxy chain")
 			}
 		*/
-		config, err := parseKCPConfig(node.Values.Get("c"))
+		config, err := parseKCPConfig(node.Get("c"))
 		if err != nil {
 			return nil, err
 		}
@@ -222,16 +221,13 @@ func parseChainNode(ns string) (nodes []gost.Node, err error) {
 		*/
 		config := &gost.QUICConfig{
 			TLSConfig: tlsCfg,
-			KeepAlive: toBool(node.Values.Get("keepalive")),
+			KeepAlive: node.GetBool("keepalive"),
 		}
 
-		timeout, _ := strconv.Atoi(node.Values.Get("timeout"))
+		config.Timeout = time.Duration(node.GetInt("timeout")) * time.Second
-		config.Timeout = time.Duration(timeout) * time.Second
+		config.IdleTimeout = time.Duration(node.GetInt("idle")) * time.Second
 
-		idle, _ := strconv.Atoi(node.Values.Get("idle"))
+		if key := node.Get("key"); key != "" {
-		config.IdleTimeout = time.Duration(idle) * time.Second
-
-		if key := node.Values.Get("key"); key != "" {
 			sum := sha256.Sum256([]byte(key))
 			config.Key = sum[:]
 		}
@@ -274,7 +270,7 @@ func parseChainNode(ns string) (nodes []gost.Node, err error) {
 	case "forward":
 		connector = gost.ForwardConnector()
 	case "sni":
-		connector = gost.SNIConnector(node.Values.Get("host"))
+		connector = gost.SNIConnector(node.Get("host"))
 	case "http":
 		fallthrough
 	default:
@@ -282,28 +278,26 @@ func parseChainNode(ns string) (nodes []gost.Node, err error) {
 		connector = gost.HTTPConnector(node.User)
 	}
 
-	timeout, _ := strconv.Atoi(node.Values.Get("timeout"))
+	timeout := node.GetInt("timeout")
 	node.DialOptions = append(node.DialOptions,
 		gost.TimeoutDialOption(time.Duration(timeout)*time.Second),
 	)
 
-	interval, _ := strconv.Atoi(node.Values.Get("ping"))
-	retry, _ := strconv.Atoi(node.Values.Get("retry"))
 	handshakeOptions := []gost.HandshakeOption{
 		gost.AddrHandshakeOption(node.Addr),
 		gost.HostHandshakeOption(node.Host),
 		gost.UserHandshakeOption(node.User),
 		gost.TLSConfigHandshakeOption(tlsCfg),
-		gost.IntervalHandshakeOption(time.Duration(interval) * time.Second),
+		gost.IntervalHandshakeOption(time.Duration(node.GetInt("ping")) * time.Second),
 		gost.TimeoutHandshakeOption(time.Duration(timeout) * time.Second),
-		gost.RetryHandshakeOption(retry),
+		gost.RetryHandshakeOption(node.GetInt("retry")),
 	}
 	node.Client = &gost.Client{
 		Connector:   connector,
 		Transporter: tr,
 	}
 
-	ips := parseIP(node.Values.Get("ip"), sport)
+	ips := parseIP(node.Get("ip"), sport)
 	for _, ip := range ips {
 		node.Addr = ip
 		node.HandshakeOptions = append(handshakeOptions, gost.AddrHandshakeOption(ip))
@@ -328,23 +322,23 @@ func (r *route) serve() error {
 		if err != nil {
 			return err
 		}
-		users, err := parseUsers(node.Values.Get("secrets"))
+		users, err := parseUsers(node.Get("secrets"))
 		if err != nil {
 			return err
 		}
 		if node.User != nil {
 			users = append(users, node.User)
 		}
-		certFile, keyFile := node.Values.Get("cert"), node.Values.Get("key")
+		certFile, keyFile := node.Get("cert"), node.Get("key")
 		tlsCfg, err := tlsConfig(certFile, keyFile)
 		if err != nil && certFile != "" && keyFile != "" {
 			return err
 		}
 
 		wsOpts := &gost.WSOptions{}
-		wsOpts.EnableCompression = toBool(node.Values.Get("compression"))
+		wsOpts.EnableCompression = node.GetBool("compression")
-		wsOpts.ReadBufferSize, _ = strconv.Atoi(node.Values.Get("rbuf"))
+		wsOpts.ReadBufferSize = node.GetInt("rbuf")
-		wsOpts.WriteBufferSize, _ = strconv.Atoi(node.Values.Get("wbuf"))
+		wsOpts.WriteBufferSize = node.GetInt("wbuf")
 
 		var ln gost.Listener
 		switch node.Transport {
@@ -353,7 +347,7 @@ func (r *route) serve() error {
 		case "mtls":
 			ln, err = gost.MTLSListener(node.Addr, tlsCfg)
 		case "ws":
-			wsOpts.WriteBufferSize, _ = strconv.Atoi(node.Values.Get("wbuf"))
+			wsOpts.WriteBufferSize = node.GetInt("wbuf")
 			ln, err = gost.WSListener(node.Addr, wsOpts)
 		case "mws":
 			ln, err = gost.MWSListener(node.Addr, wsOpts)
@@ -362,7 +356,7 @@ func (r *route) serve() error {
 		case "mwss":
 			ln, err = gost.MWSSListener(node.Addr, tlsCfg, wsOpts)
 		case "kcp":
-			config, er := parseKCPConfig(node.Values.Get("c"))
+			config, er := parseKCPConfig(node.Get("c"))
 			if er != nil {
 				return er
 			}
@@ -380,15 +374,12 @@ func (r *route) serve() error {
 		case "quic":
 			config := &gost.QUICConfig{
 				TLSConfig: tlsCfg,
-				KeepAlive: toBool(node.Values.Get("keepalive")),
+				KeepAlive: node.GetBool("keepalive"),
 			}
-			timeout, _ := strconv.Atoi(node.Values.Get("timeout"))
+			config.Timeout = time.Duration(node.GetInt("timeout")) * time.Second
-			config.Timeout = time.Duration(timeout) * time.Second
+			config.IdleTimeout = time.Duration(node.GetInt("idle")) * time.Second
 
-			idle, _ := strconv.Atoi(node.Values.Get("idle"))
+			if key := node.Get("key"); key != "" {
-			config.IdleTimeout = time.Duration(idle) * time.Second
-
-			if key := node.Values.Get("key"); key != "" {
 				sum := sha256.Sum256([]byte(key))
 				config.Key = sum[:]
 			}
@@ -415,14 +406,11 @@ func (r *route) serve() error {
 			}
 			ln, err = gost.TCPRemoteForwardListener(node.Addr, chain)
 		case "udp":
-			ttl, _ := strconv.Atoi(node.Values.Get("ttl"))
+			ln, err = gost.UDPDirectForwardListener(node.Addr, time.Duration(node.GetInt("ttl"))*time.Second)
-			ln, err = gost.UDPDirectForwardListener(node.Addr, time.Duration(ttl)*time.Second)
 		case "rudp":
-			ttl, _ := strconv.Atoi(node.Values.Get("ttl"))
+			ln, err = gost.UDPRemoteForwardListener(node.Addr, chain, time.Duration(node.GetInt("ttl"))*time.Second)
-			ln, err = gost.UDPRemoteForwardListener(node.Addr, chain, time.Duration(ttl)*time.Second)
 		case "ssu":
-			ttl, _ := strconv.Atoi(node.Values.Get("ttl"))
+			ln, err = gost.ShadowUDPListener(node.Addr, node.User, time.Duration(node.GetInt("ttl"))*time.Second)
-			ln, err = gost.ShadowUDPListener(node.Addr, node.User, time.Duration(ttl)*time.Second)
 		case "obfs4":
 			if err = gost.Obfs4Init(node, true); err != nil {
 				return err
@@ -572,14 +560,6 @@ func (l *stringList) Set(value string) error {
 	return nil
 }
 
-func toBool(s string) bool {
-	if b, _ := strconv.ParseBool(s); b {
-		return b
-	}
-	n, _ := strconv.Atoi(s)
-	return n > 0
-}
-
 func parseKCPConfig(configFile string) (*gost.KCPConfig, error) {
 	if configFile == "" {
 		return nil, nil

forward.go

@@ -425,6 +425,9 @@ type tcpRemoteForwardListener struct {
 	addr    net.Addr
 	chain   *Chain
 	ln      net.Listener
+	session *muxSession
+	once    sync.Once
+	mutex   sync.Mutex
 	closed  chan struct{}
 }
 
@@ -474,6 +477,10 @@ func (l *tcpRemoteForwardListener) accept() (conn net.Conn, err error) {
 	if lastNode.Protocol == "forward" && lastNode.Transport == "ssh" {
 		conn, err = l.chain.Dial(l.addr.String())
 	} else if lastNode.Protocol == "socks5" {
+		if lastNode.GetBool("mbind") {
+			return l.muxAccept() // multiplexing support for binding.
+		}
+
 		cc, er := l.chain.Conn()
 		if er != nil {
 			return nil, er
@@ -494,6 +501,14 @@ func (l *tcpRemoteForwardListener) accept() (conn net.Conn, err error) {
 	return
 }
 
+func (l *tcpRemoteForwardListener) muxAccept() (conn net.Conn, err error) {
+	l.mutex.Lock()
+	defer l.mutex.Unlock()
+
+	
+	return nil, nil
+}
+
 func (l *tcpRemoteForwardListener) waitConnectSOCKS5(conn net.Conn) (net.Conn, error) {
 	conn, err := socks5Handshake(conn, l.chain.LastNode().User)
 	if err != nil {

node.go

@@ -3,6 +3,7 @@ package gost
 import (
 	"fmt"
 	"net/url"
+	"strconv"
 	"strings"
 	"sync/atomic"
 	"time"
@@ -141,6 +142,23 @@ func (node *Node) Clone() Node {
 	}
 }
 
+// Get returns node parameter specified by key.
+func (node *Node) Get(key string) string {
+	return node.Values.Get(key)
+}
+
+// GetBool likes Get, but convert parameter value to bool.
+func (node *Node) GetBool(key string) bool {
+	b, _ := strconv.ParseBool(node.Values.Get(key))
+	return b
+}
+
+// GetInt likes Get, but convert parameter value to int.
+func (node *Node) GetInt(key string) int {
+	n, _ := strconv.Atoi(node.Values.Get(key))
+	return n
+}
+
 func (node *Node) String() string {
 	return fmt.Sprintf("%d@%s", node.ID, node.Addr)
 }

socks.go

@@ -5,16 +5,16 @@ import (
 	"crypto/tls"
 	"errors"
 	"fmt"
+	"io"
 	"net"
 	"net/url"
 	"strconv"
 	"time"
 
-	"io"
-
 	"github.com/ginuerzh/gosocks4"
 	"github.com/ginuerzh/gosocks5"
 	"github.com/go-log/log"
+	smux "gopkg.in/xtaci/smux.v1"
 )
 
 const (
@@ -22,10 +22,15 @@ const (
 	MethodTLS uint8 = 0x80
 	// MethodTLSAuth is an extended SOCKS5 method for TLS+AUTH.
 	MethodTLSAuth uint8 = 0x82
+	// MethodMux is an extended SOCKS5 method for stream multiplexing.
+	MethodMux = 0x88
 )
 
 const (
-	// CmdUDPTun is an extended SOCKS5 method for UDP over TCP.
+	// CMDMuxBind is an extended SOCKS5 request CMD for
+	// multiplexing transport with the binding server.
+	CMDMuxBind uint8 = 0xF2
+	// CmdUDPTun is an extended SOCKS5 request CMD for UDP over TCP.
 	CmdUDPTun uint8 = 0xF3
 )
 
@@ -392,6 +397,9 @@ func (h *socks5Handler) Handle(conn net.Conn) {
 	case gosocks5.CmdUdp:
 		h.handleUDPRelay(conn, req)
 
+	case CMDMuxBind:
+		h.handleMuxBind(conn, req)
+
 	case CmdUDPTun:
 		h.handleUDPTunnel(conn, req)
 
@@ -942,6 +950,98 @@ func (h *socks5Handler) tunnelServerUDP(cc net.Conn, uc *net.UDPConn) (err error
 	return
 }
 
+func (h *socks5Handler) handleMuxBind(conn net.Conn, req *gosocks5.Request) {
+	if h.options.Chain.IsEmpty() {
+		addr := req.Addr.String()
+		if !Can("rtcp", addr, h.options.Whitelist, h.options.Blacklist) {
+			log.Logf("Unauthorized to tcp mbind to %s", addr)
+			return
+		}
+		h.muxBindOn(conn, addr)
+		return
+	}
+
+	cc, err := h.options.Chain.Conn()
+	if err != nil {
+		log.Logf("[socks5-mbind] %s <- %s : %s", conn.RemoteAddr(), req.Addr, err)
+		reply := gosocks5.NewReply(gosocks5.Failure, nil)
+		reply.Write(conn)
+		if Debug {
+			log.Logf("[socks5-mbind] %s <- %s\n%s", conn.RemoteAddr(), req.Addr, reply)
+		}
+		return
+	}
+
+	// forward request
+	// note: this type of request forwarding is defined when starting server,
+	// so we don't need to authenticate it, as it's as explicit as whitelisting.
+	defer cc.Close()
+	req.Write(cc)
+	log.Logf("[socks5-mbind] %s <-> %s", conn.RemoteAddr(), cc.RemoteAddr())
+	transport(conn, cc)
+	log.Logf("[socks5-mbind] %s >-< %s", conn.RemoteAddr(), cc.RemoteAddr())
+}
+
+func (h *socks5Handler) muxBindOn(conn net.Conn, addr string) {
+	bindAddr, _ := net.ResolveTCPAddr("tcp", addr)
+	ln, err := net.ListenTCP("tcp", bindAddr) // strict mode: if the port already in use, it will return error
+	if err != nil {
+		log.Logf("[socks5-mbind] %s -> %s : %s", conn.RemoteAddr(), addr, err)
+		gosocks5.NewReply(gosocks5.Failure, nil).Write(conn)
+		return
+	}
+	defer ln.Close()
+
+	socksAddr := toSocksAddr(ln.Addr())
+	// Issue: may not reachable when host has multi-interface.
+	socksAddr.Host, _, _ = net.SplitHostPort(conn.LocalAddr().String())
+	reply := gosocks5.NewReply(gosocks5.Succeeded, socksAddr)
+	if err := reply.Write(conn); err != nil {
+		log.Logf("[socks5-mbind] %s <- %s : %s", conn.RemoteAddr(), addr, err)
+		return
+	}
+	if Debug {
+		log.Logf("[socks5-mbind] %s <- %s\n%s", conn.RemoteAddr(), addr, reply)
+	}
+	log.Logf("[socks5-mbind] %s - %s BIND ON %s OK", conn.RemoteAddr(), addr, socksAddr)
+
+	// Upgrade connection to multiplex stream.
+	s, err := smux.Client(conn, smux.DefaultConfig())
+	if err != nil {
+		log.Logf("[socks5-mbind] %s - %s : %s", conn.RemoteAddr(), socksAddr, err)
+		return
+	}
+
+	log.Logf("[socks5-mbind] %s <-> %s", conn.RemoteAddr(), socksAddr)
+	defer log.Logf("[socks5-mbind] %s >-< %s", conn.RemoteAddr(), socksAddr)
+
+	session := &muxSession{
+		conn:    conn,
+		session: s,
+	}
+
+	for {
+		cc, err := ln.Accept()
+		if err != nil {
+			log.Logf("[socks5-mbind] %s <- %s : %v", conn.RemoteAddr(), socksAddr, err)
+			return
+		}
+		log.Logf("[socks5-mbind %s <- %s : ACCEPT peer %s",
+			conn.RemoteAddr(), socksAddr, cc.RemoteAddr())
+
+		go func(c net.Conn) {
+			defer c.Close()
+
+			sc, err := session.GetConn()
+			if err != nil {
+				log.Logf("[socks5-mbind %s <- %s : %s", conn.RemoteAddr(), socksAddr, err)
+				return
+			}
+			transport(sc, c)
+		}(cc)
+	}
+}
+
 func toSocksAddr(addr net.Addr) *gosocks5.Addr {
 	host := "0.0.0.0"
 	port := 0