improve the stability of xtcp

client/proxy/proxy.go

@@ -20,6 +20,8 @@ import (
 	"io"
 	"io/ioutil"
 	"net"
+	"strconv"
+	"strings"
 	"sync"
 	"time"
 
@@ -280,25 +282,56 @@ func (pxy *XtcpProxy) InWorkConn(conn frpNet.Conn) {
 		return
 	}
 
-	pxy.Trace("get natHoleRespMsg, sid [%s], client address [%s]", natHoleRespMsg.Sid, natHoleRespMsg.ClientAddr)
+	pxy.Trace("get natHoleRespMsg, sid [%s], client address [%s] visitor address [%s]", natHoleRespMsg.Sid, natHoleRespMsg.ClientAddr, natHoleRespMsg.VisitorAddr)
 
-	// Send sid to visitor udp address.
+	// Send detect message
-	time.Sleep(time.Second)
+	array := strings.Split(natHoleRespMsg.VisitorAddr, ":")
+	if len(array) <= 1 {
+		pxy.Error("get NatHoleResp visitor address error: %v", natHoleRespMsg.VisitorAddr)
+	}
 	laddr, _ := net.ResolveUDPAddr("udp", clientConn.LocalAddr().String())
-	daddr, err := net.ResolveUDPAddr("udp", natHoleRespMsg.VisitorAddr)
+	/*
+		for i := 1000; i < 65000; i++ {
+			pxy.sendDetectMsg(array[0], int64(i), laddr, "a")
+		}
+	*/
+	port, err := strconv.ParseInt(array[1], 10, 64)
 	if err != nil {
-		pxy.Error("resolve visitor udp address error: %v", err)
+		pxy.Error("get natHoleResp visitor address error: %v", natHoleRespMsg.VisitorAddr)
 		return
 	}
+	pxy.sendDetectMsg(array[0], int(port), laddr, []byte(natHoleRespMsg.Sid))
+	pxy.Trace("send all detect msg done")
 
-	lConn, err := net.DialUDP("udp", laddr, daddr)
+	msg.WriteMsg(conn, &msg.NatHoleClientDetectOK{})
+
+	// Listen for clientConn's address and wait for visitor connection
+	lConn, err := net.ListenUDP("udp", laddr)
 	if err != nil {
-		pxy.Error("dial visitor udp address error: %v", err)
+		pxy.Error("listen on visitorConn's local adress error: %v", err)
 		return
 	}
-	lConn.Write([]byte(natHoleRespMsg.Sid))
+	defer lConn.Close()
 
-	kcpConn, err := frpNet.NewKcpConnFromUdp(lConn, true, natHoleRespMsg.VisitorAddr)
+	lConn.SetReadDeadline(time.Now().Add(8 * time.Second))
+	sidBuf := pool.GetBuf(1024)
+	var uAddr *net.UDPAddr
+	n, uAddr, err = lConn.ReadFromUDP(sidBuf)
+	if err != nil {
+		pxy.Warn("get sid from visitor error: %v", err)
+		return
+	}
+	lConn.SetReadDeadline(time.Time{})
+	if string(sidBuf[:n]) != natHoleRespMsg.Sid {
+		pxy.Warn("incorrect sid from visitor")
+		return
+	}
+	pool.PutBuf(sidBuf)
+	pxy.Info("nat hole connection make success, sid [%s]", natHoleRespMsg.Sid)
+
+	lConn.WriteToUDP(sidBuf[:n], uAddr)
+
+	kcpConn, err := frpNet.NewKcpConnFromUdp(lConn, false, natHoleRespMsg.VisitorAddr)
 	if err != nil {
 		pxy.Error("create kcp connection from udp connection error: %v", err)
 		return
@@ -323,6 +356,25 @@ func (pxy *XtcpProxy) InWorkConn(conn frpNet.Conn) {
 		frpNet.WrapConn(muxConn), []byte(pxy.cfg.Sk))
 }
 
+func (pxy *XtcpProxy) sendDetectMsg(addr string, port int, laddr *net.UDPAddr, content []byte) (err error) {
+	daddr, err := net.ResolveUDPAddr("udp", fmt.Sprintf("%s:%d", addr, port))
+	if err != nil {
+		return err
+	}
+
+	tConn, err := net.DialUDP("udp", laddr, daddr)
+	if err != nil {
+		return err
+	}
+
+	//uConn := ipv4.NewConn(tConn)
+	//uConn.SetTTL(3)
+
+	tConn.Write(content)
+	tConn.Close()
+	return nil
+}
+
 // UDP
 type UdpProxy struct {
 	*BaseProxy

client/visitor.go

@@ -20,13 +20,9 @@ import (
 	"io"
 	"io/ioutil"
 	"net"
-	"strconv"
-	"strings"
 	"sync"
 	"time"
 
-	"golang.org/x/net/ipv4"
-
 	"github.com/fatedier/frp/g"
 	"github.com/fatedier/frp/models/config"
 	"github.com/fatedier/frp/models/msg"
@@ -251,42 +247,31 @@ func (sv *XtcpVisitor) handleConn(userConn frpNet.Conn) {
 		return
 	}
 
-	sv.Trace("get natHoleRespMsg, sid [%s], client address [%s]", natHoleRespMsg.Sid, natHoleRespMsg.ClientAddr)
+	sv.Trace("get natHoleRespMsg, sid [%s], client address [%s], visitor address [%s]", natHoleRespMsg.Sid, natHoleRespMsg.ClientAddr, natHoleRespMsg.VisitorAddr)
 
 	// Close visitorConn, so we can use it's local address.
 	visitorConn.Close()
 
-	// Send detect message.
+	// send sid message to client
-	array := strings.Split(natHoleRespMsg.ClientAddr, ":")
-	if len(array) <= 1 {
-		sv.Error("get natHoleResp client address error: %s", natHoleRespMsg.ClientAddr)
-		return
-	}
 	laddr, _ := net.ResolveUDPAddr("udp", visitorConn.LocalAddr().String())
-	/*
+	daddr, err := net.ResolveUDPAddr("udp", natHoleRespMsg.ClientAddr)
-		for i := 1000; i < 65000; i++ {
-			sv.sendDetectMsg(array[0], int64(i), laddr, "a")
-		}
-	*/
-	port, err := strconv.ParseInt(array[1], 10, 64)
 	if err != nil {
-		sv.Error("get natHoleResp client address error: %s", natHoleRespMsg.ClientAddr)
+		sv.Error("resolve client udp address error: %v", err)
 		return
 	}
-	sv.sendDetectMsg(array[0], int(port), laddr, []byte(natHoleRespMsg.Sid))
+	lConn, err := net.DialUDP("udp", laddr, daddr)
-	sv.Trace("send all detect msg done")
-
-	// Listen for visitorConn's address and wait for client connection.
-	lConn, err := net.ListenUDP("udp", laddr)
 	if err != nil {
-		sv.Error("listen on visitorConn's local adress error: %v", err)
+		sv.Error("dial client udp address error: %v", err)
 		return
 	}
 	defer lConn.Close()
 
-	lConn.SetReadDeadline(time.Now().Add(5 * time.Second))
+	lConn.Write([]byte(natHoleRespMsg.Sid))
+
+	// read ack sid from client
 	sidBuf := pool.GetBuf(1024)
-	n, _, err = lConn.ReadFromUDP(sidBuf)
+	lConn.SetReadDeadline(time.Now().Add(8 * time.Second))
+	n, err = lConn.Read(sidBuf)
 	if err != nil {
 		sv.Warn("get sid from client error: %v", err)
 		return
@@ -296,11 +281,13 @@ func (sv *XtcpVisitor) handleConn(userConn frpNet.Conn) {
 		sv.Warn("incorrect sid from client")
 		return
 	}
-	sv.Info("nat hole connection make success, sid [%s]", string(sidBuf[:n]))
 	pool.PutBuf(sidBuf)
 
+	sv.Info("nat hole connection make success, sid [%s]", natHoleRespMsg.Sid)
+
+	// wrap kcp connection
 	var remote io.ReadWriteCloser
-	remote, err = frpNet.NewKcpConnFromUdp(lConn, false, natHoleRespMsg.ClientAddr)
+	remote, err = frpNet.NewKcpConnFromUdp(lConn, true, natHoleRespMsg.ClientAddr)
 	if err != nil {
 		sv.Error("create kcp connection from udp connection error: %v", err)
 		return
@@ -336,22 +323,3 @@ func (sv *XtcpVisitor) handleConn(userConn frpNet.Conn) {
 	frpIo.Join(userConn, muxConn)
 	sv.Debug("join connections closed")
 }
-
-func (sv *XtcpVisitor) sendDetectMsg(addr string, port int, laddr *net.UDPAddr, content []byte) (err error) {
-	daddr, err := net.ResolveUDPAddr("udp", fmt.Sprintf("%s:%d", addr, port))
-	if err != nil {
-		return err
-	}
-
-	tConn, err := net.DialUDP("udp", laddr, daddr)
-	if err != nil {
-		return err
-	}
-
-	uConn := ipv4.NewConn(tConn)
-	uConn.SetTTL(3)
-
-	tConn.Write(content)
-	tConn.Close()
-	return nil
-}

models/msg/msg.go

@@ -33,6 +33,7 @@ const (
 	TypeNatHoleVisitor        = 'i'
 	TypeNatHoleClient         = 'n'
 	TypeNatHoleResp           = 'm'
+	TypeNatHoleClientDetectOK = 'd'
 	TypeNatHoleSid            = '5'
 )
 
@@ -54,6 +55,7 @@ var (
 		TypeNatHoleVisitor:        NatHoleVisitor{},
 		TypeNatHoleClient:         NatHoleClient{},
 		TypeNatHoleResp:           NatHoleResp{},
+		TypeNatHoleClientDetectOK: NatHoleClientDetectOK{},
 		TypeNatHoleSid:            NatHoleSid{},
 	}
 )
@@ -169,6 +171,9 @@ type NatHoleResp struct {
 	Error       string `json:"error"`
 }
 
+type NatHoleClientDetectOK struct {
+}
+
 type NatHoleSid struct {
 	Sid string `json:"sid"`
 }

models/nathole/nathole.go

@@ -18,6 +18,11 @@ import (
 // Timeout seconds.
 var NatHoleTimeout int64 = 10
 
+type SidRequest struct {
+	Sid      string
+	NotifyCh chan struct{}
+}
+
 type NatHoleController struct {
 	listener *net.UDPConn
 
@@ -44,11 +49,11 @@ func NewNatHoleController(udpBindAddr string) (nc *NatHoleController, err error)
 	return nc, nil
 }
 
-func (nc *NatHoleController) ListenClient(name string, sk string) (sidCh chan string) {
+func (nc *NatHoleController) ListenClient(name string, sk string) (sidCh chan *SidRequest) {
 	clientCfg := &NatHoleClientCfg{
 		Name:  name,
 		Sk:    sk,
-		SidCh: make(chan string),
+		SidCh: make(chan *SidRequest),
 	}
 	nc.mu.Lock()
 	nc.clientCfgs[name] = clientCfg
@@ -132,7 +137,10 @@ func (nc *NatHoleController) HandleVisitor(m *msg.NatHoleVisitor, raddr *net.UDP
 	}()
 
 	err := errors.PanicToError(func() {
-		clientCfg.SidCh <- sid
+		clientCfg.SidCh <- &SidRequest{
+			Sid:      sid,
+			NotifyCh: session.NotifyCh,
+		}
 	})
 	if err != nil {
 		return
@@ -158,7 +166,6 @@ func (nc *NatHoleController) HandleClient(m *msg.NatHoleClient, raddr *net.UDPAd
 	}
 	log.Trace("handle client message, sid [%s]", session.Sid)
 	session.ClientAddr = raddr
-	session.NotifyCh <- struct{}{}
 
 	resp := nc.GenNatHoleResponse(session, "")
 	log.Trace("send nat hole response to client")
@@ -201,5 +208,5 @@ type NatHoleSession struct {
 type NatHoleClientCfg struct {
 	Name  string
 	Sk    string
-	SidCh chan string
+	SidCh chan *SidRequest
 }

server/proxy/xtcp.go

@@ -42,18 +42,40 @@ func (pxy *XtcpProxy) Run() (remoteAddr string, err error) {
 			select {
 			case <-pxy.closeCh:
 				break
-			case sid := <-sidCh:
+			case sidRequest := <-sidCh:
+				sr := sidRequest
 				workConn, errRet := pxy.GetWorkConnFromPool()
 				if errRet != nil {
 					continue
 				}
 				m := &msg.NatHoleSid{
-					Sid: sid,
+					Sid: sr.Sid,
 				}
 				errRet = msg.WriteMsg(workConn, m)
 				if errRet != nil {
 					pxy.Warn("write nat hole sid package error, %v", errRet)
+					workConn.Close()
+					break
 				}
+
+				go func() {
+					raw, errRet := msg.ReadMsg(workConn)
+					if errRet != nil {
+						pxy.Warn("read nat hole client ok package error: %v", errRet)
+						workConn.Close()
+						return
+					}
+					if _, ok := raw.(*msg.NatHoleClientDetectOK); !ok {
+						pxy.Warn("read nat hole client ok package format error")
+						workConn.Close()
+						return
+					}
+
+					select {
+					case sr.NotifyCh <- struct{}{}:
+					default:
+					}
+				}()
 			}
 		}
 	}()