support xtcp for making nat hole

server/control.go

@@ -97,9 +97,10 @@ func NewControl(svr *Service, ctlConn net.Conn, loginMsg *msg.Login) *Control {
 // Start send a login success message to client and start working.
 func (ctl *Control) Start() {
 	loginRespMsg := &msg.LoginResp{
-		Version: version.Full(),
-		RunId:   ctl.runId,
-		Error:   "",
+		Version:       version.Full(),
+		RunId:         ctl.runId,
+		ServerUdpPort: config.ServerCommonCfg.BindUdpPort,
+		Error:         "",
 	}
 	msg.WriteMsg(ctl.conn, loginRespMsg)
 

server/nathole.go

@@ -0,0 +1,182 @@
+package server
+
+import (
+	"bytes"
+	"fmt"
+	"net"
+	"sync"
+	"time"
+
+	"github.com/fatedier/frp/models/msg"
+	"github.com/fatedier/frp/utils/errors"
+	"github.com/fatedier/frp/utils/log"
+	"github.com/fatedier/frp/utils/pool"
+	"github.com/fatedier/frp/utils/util"
+)
+
+// Timeout seconds.
+var NatHoleTimeout int64 = 10
+
+type NatHoleController struct {
+	listener *net.UDPConn
+
+	clientCfgs map[string]*NatHoleClientCfg
+	sessions   map[string]*NatHoleSession
+
+	mu sync.RWMutex
+}
+
+func NewNatHoleController(udpBindAddr string) (nc *NatHoleController, err error) {
+	addr, err := net.ResolveUDPAddr("udp", udpBindAddr)
+	if err != nil {
+		return nil, err
+	}
+	lconn, err := net.ListenUDP("udp", addr)
+	if err != nil {
+		return nil, err
+	}
+	nc = &NatHoleController{
+		listener:   lconn,
+		clientCfgs: make(map[string]*NatHoleClientCfg),
+		sessions:   make(map[string]*NatHoleSession),
+	}
+	return nc, nil
+}
+
+func (nc *NatHoleController) ListenClient(name string, sk string) (sidCh chan string) {
+	clientCfg := &NatHoleClientCfg{
+		Name:  name,
+		Sk:    sk,
+		SidCh: make(chan string),
+	}
+	nc.mu.Lock()
+	nc.clientCfgs[name] = clientCfg
+	nc.mu.Unlock()
+	return clientCfg.SidCh
+}
+
+func (nc *NatHoleController) CloseClient(name string) {
+	nc.mu.Lock()
+	defer nc.mu.Unlock()
+	delete(nc.clientCfgs, name)
+}
+
+func (nc *NatHoleController) Run() {
+	for {
+		buf := pool.GetBuf(1024)
+		n, raddr, err := nc.listener.ReadFromUDP(buf)
+		if err != nil {
+			log.Trace("nat hole listener read from udp error: %v", err)
+			return
+		}
+
+		rd := bytes.NewReader(buf[:n])
+		rawMsg, err := msg.ReadMsg(rd)
+		if err != nil {
+			log.Trace("read nat hole message error: %v", err)
+			continue
+		}
+
+		switch m := rawMsg.(type) {
+		case *msg.NatHoleVistor:
+			go nc.HandleVistor(m, raddr)
+		case *msg.NatHoleClient:
+			go nc.HandleClient(m, raddr)
+		default:
+			log.Trace("error nat hole message type")
+			continue
+		}
+		pool.PutBuf(buf)
+	}
+}
+
+func (nc *NatHoleController) GenSid() string {
+	t := time.Now().Unix()
+	id, _ := util.RandId()
+	return fmt.Sprintf("%d%s", t, id)
+}
+
+func (nc *NatHoleController) HandleVistor(m *msg.NatHoleVistor, raddr *net.UDPAddr) {
+	sid := nc.GenSid()
+	session := &NatHoleSession{
+		Sid:        sid,
+		VistorAddr: raddr,
+		NotifyCh:   make(chan struct{}, 0),
+	}
+	nc.mu.Lock()
+	clientCfg, ok := nc.clientCfgs[m.ProxyName]
+	if !ok || m.SignKey != util.GetAuthKey(clientCfg.Sk, m.Timestamp) {
+		nc.mu.Unlock()
+		return
+	}
+	nc.sessions[sid] = session
+	nc.mu.Unlock()
+	log.Trace("handle vistor message, sid [%s]", sid)
+
+	defer func() {
+		nc.mu.Lock()
+		delete(nc.sessions, sid)
+		nc.mu.Unlock()
+	}()
+
+	err := errors.PanicToError(func() {
+		clientCfg.SidCh <- sid
+	})
+	if err != nil {
+		return
+	}
+
+	// Wait client connections.
+	select {
+	case <-session.NotifyCh:
+		resp := nc.GenNatHoleResponse(raddr, session)
+		log.Trace("send nat hole response to vistor")
+		nc.listener.WriteToUDP(resp, raddr)
+	case <-time.After(time.Duration(NatHoleTimeout) * time.Second):
+		return
+	}
+}
+
+func (nc *NatHoleController) HandleClient(m *msg.NatHoleClient, raddr *net.UDPAddr) {
+	nc.mu.RLock()
+	session, ok := nc.sessions[m.Sid]
+	nc.mu.RUnlock()
+	if !ok {
+		return
+	}
+	log.Trace("handle client message, sid [%s]", session.Sid)
+	session.ClientAddr = raddr
+	session.NotifyCh <- struct{}{}
+
+	resp := nc.GenNatHoleResponse(raddr, session)
+	log.Trace("send nat hole response to client")
+	nc.listener.WriteToUDP(resp, raddr)
+}
+
+func (nc *NatHoleController) GenNatHoleResponse(raddr *net.UDPAddr, session *NatHoleSession) []byte {
+	m := &msg.NatHoleResp{
+		Sid:        session.Sid,
+		VistorAddr: session.VistorAddr.String(),
+		ClientAddr: session.ClientAddr.String(),
+	}
+	b := bytes.NewBuffer(nil)
+	err := msg.WriteMsg(b, m)
+	if err != nil {
+		return []byte("")
+	}
+	return b.Bytes()
+}
+
+type NatHoleSession struct {
+	Sid        string
+	VistorAddr *net.UDPAddr
+	ClientAddr *net.UDPAddr
+
+	NotifyCh chan struct{}
+}
+
+type NatHoleClientCfg struct {
+	Name  string
+	Sk    string
+	SidCh chan string
+}

server/proxy.go

@@ -148,6 +148,11 @@ func NewProxy(ctl *Control, pxyConf config.ProxyConf) (pxy Proxy, err error) {
 			BaseProxy: basePxy,
 			cfg:       cfg,
 		}
+	case *config.XtcpProxyConf:
+		pxy = &XtcpProxy{
+			BaseProxy: basePxy,
+			cfg:       cfg,
+		}
 	default:
 		return pxy, fmt.Errorf("proxy type not support")
 	}
@@ -306,6 +311,54 @@ func (pxy *StcpProxy) Close() {
 	pxy.ctl.svr.vistorManager.CloseListener(pxy.GetName())
 }
 
+type XtcpProxy struct {
+	BaseProxy
+	cfg *config.XtcpProxyConf
+
+	closeCh chan struct{}
+}
+
+func (pxy *XtcpProxy) Run() error {
+	if pxy.ctl.svr.natHoleController == nil {
+		pxy.Error("udp port for xtcp is not specified.")
+		return fmt.Errorf("xtcp is not supported in frps")
+	}
+	sidCh := pxy.ctl.svr.natHoleController.ListenClient(pxy.GetName(), pxy.cfg.Sk)
+	go func() {
+		for {
+			select {
+			case <-pxy.closeCh:
+				break
+			case sid := <-sidCh:
+				workConn, err := pxy.GetWorkConnFromPool()
+				if err != nil {
+					continue
+				}
+				m := &msg.NatHoleSid{
+					Sid: sid,
+				}
+				err = msg.WriteMsg(workConn, m)
+				if err != nil {
+					pxy.Warn("write nat hole sid package error, %v", err)
+				}
+			}
+		}
+	}()
+	return nil
+}
+
+func (pxy *XtcpProxy) GetConf() config.ProxyConf {
+	return pxy.cfg
+}
+
+func (pxy *XtcpProxy) Close() {
+	pxy.BaseProxy.Close()
+	pxy.ctl.svr.natHoleController.CloseClient(pxy.GetName())
+	errors.PanicToError(func() {
+		close(pxy.closeCh)
+	})
+}
+
 type UdpProxy struct {
 	BaseProxy
 	cfg *config.UdpProxyConf

server/service.go

@@ -58,6 +58,9 @@ type Service struct {
 
 	// Manage all vistor listeners.
 	vistorManager *VistorManager
+
+	// Controller for nat hole connections.
+	natHoleController *NatHoleController
 }
 
 func NewService() (svr *Service, err error) {
@@ -66,36 +69,37 @@ func NewService() (svr *Service, err error) {
 		pxyManager:    NewProxyManager(),
 		vistorManager: NewVistorManager(),
 	}
+	cfg := config.ServerCommonCfg
 
 	// Init assets.
-	err = assets.Load(config.ServerCommonCfg.AssetsDir)
+	err = assets.Load(cfg.AssetsDir)
 	if err != nil {
 		err = fmt.Errorf("Load assets error: %v", err)
 		return
 	}
 
 	// Listen for accepting connections from client.
-	svr.listener, err = frpNet.ListenTcp(config.ServerCommonCfg.BindAddr, config.ServerCommonCfg.BindPort)
+	svr.listener, err = frpNet.ListenTcp(cfg.BindAddr, cfg.BindPort)
 	if err != nil {
 		err = fmt.Errorf("Create server listener error, %v", err)
 		return
 	}
-	log.Info("frps tcp listen on %s:%d", config.ServerCommonCfg.BindAddr, config.ServerCommonCfg.BindPort)
+	log.Info("frps tcp listen on %s:%d", cfg.BindAddr, cfg.BindPort)
 
 	// Listen for accepting connections from client using kcp protocol.
-	if config.ServerCommonCfg.KcpBindPort > 0 {
-		svr.kcpListener, err = frpNet.ListenKcp(config.ServerCommonCfg.BindAddr, config.ServerCommonCfg.KcpBindPort)
+	if cfg.KcpBindPort > 0 {
+		svr.kcpListener, err = frpNet.ListenKcp(cfg.BindAddr, cfg.KcpBindPort)
 		if err != nil {
-			err = fmt.Errorf("Listen on kcp address udp [%s:%d] error: %v", config.ServerCommonCfg.BindAddr, config.ServerCommonCfg.KcpBindPort, err)
+			err = fmt.Errorf("Listen on kcp address udp [%s:%d] error: %v", cfg.BindAddr, cfg.KcpBindPort, err)
 			return
 		}
-		log.Info("frps kcp listen on udp %s:%d", config.ServerCommonCfg.BindAddr, config.ServerCommonCfg.BindPort)
+		log.Info("frps kcp listen on udp %s:%d", cfg.BindAddr, cfg.BindPort)
 	}
 
 	// Create http vhost muxer.
-	if config.ServerCommonCfg.VhostHttpPort > 0 {
+	if cfg.VhostHttpPort > 0 {
 		var l frpNet.Listener
-		l, err = frpNet.ListenTcp(config.ServerCommonCfg.ProxyBindAddr, config.ServerCommonCfg.VhostHttpPort)
+		l, err = frpNet.ListenTcp(cfg.ProxyBindAddr, cfg.VhostHttpPort)
 		if err != nil {
 			err = fmt.Errorf("Create vhost http listener error, %v", err)
 			return
@@ -105,13 +109,13 @@ func NewService() (svr *Service, err error) {
 			err = fmt.Errorf("Create vhost httpMuxer error, %v", err)
 			return
 		}
-		log.Info("http service listen on %s:%d", config.ServerCommonCfg.ProxyBindAddr, config.ServerCommonCfg.VhostHttpPort)
+		log.Info("http service listen on %s:%d", cfg.ProxyBindAddr, cfg.VhostHttpPort)
 	}
 
 	// Create https vhost muxer.
-	if config.ServerCommonCfg.VhostHttpsPort > 0 {
+	if cfg.VhostHttpsPort > 0 {
 		var l frpNet.Listener
-		l, err = frpNet.ListenTcp(config.ServerCommonCfg.ProxyBindAddr, config.ServerCommonCfg.VhostHttpsPort)
+		l, err = frpNet.ListenTcp(cfg.ProxyBindAddr, cfg.VhostHttpsPort)
 		if err != nil {
 			err = fmt.Errorf("Create vhost https listener error, %v", err)
 			return
@@ -121,22 +125,38 @@ func NewService() (svr *Service, err error) {
 			err = fmt.Errorf("Create vhost httpsMuxer error, %v", err)
 			return
 		}
-		log.Info("https service listen on %s:%d", config.ServerCommonCfg.ProxyBindAddr, config.ServerCommonCfg.VhostHttpsPort)
+		log.Info("https service listen on %s:%d", cfg.ProxyBindAddr, cfg.VhostHttpsPort)
+	}
+
+	// Create nat hole controller.
+	if cfg.BindUdpPort > 0 {
+		var nc *NatHoleController
+		addr := fmt.Sprintf("%s:%d", cfg.BindAddr, cfg.BindUdpPort)
+		nc, err = NewNatHoleController(addr)
+		if err != nil {
+			err = fmt.Errorf("Create nat hole controller error, %v", err)
+			return
+		}
+		svr.natHoleController = nc
+		log.Info("nat hole udp service listen on %s:%d", cfg.BindAddr, cfg.BindUdpPort)
 	}
 
 	// Create dashboard web server.
-	if config.ServerCommonCfg.DashboardPort > 0 {
-		err = RunDashboardServer(config.ServerCommonCfg.BindAddr, config.ServerCommonCfg.DashboardPort)
+	if cfg.DashboardPort > 0 {
+		err = RunDashboardServer(cfg.BindAddr, cfg.DashboardPort)
 		if err != nil {
 			err = fmt.Errorf("Create dashboard web server error, %v", err)
 			return
 		}
-		log.Info("Dashboard listen on %s:%d", config.ServerCommonCfg.BindAddr, config.ServerCommonCfg.DashboardPort)
+		log.Info("Dashboard listen on %s:%d", cfg.BindAddr, cfg.DashboardPort)
 	}
 	return
 }
 
 func (svr *Service) Run() {
+	if svr.natHoleController != nil {
+		go svr.natHoleController.Run()
+	}
 	if config.ServerCommonCfg.KcpBindPort > 0 {
 		go svr.HandleListener(svr.kcpListener)
 	}