server: adjust code structure

server/proxy/http.go

@@ -0,0 +1,138 @@
+// Copyright 2019 fatedier, fatedier@gmail.com
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package proxy
+
+import (
+	"io"
+	"strings"
+
+	"github.com/fatedier/frp/g"
+	"github.com/fatedier/frp/models/config"
+	"github.com/fatedier/frp/server/stats"
+	frpNet "github.com/fatedier/frp/utils/net"
+	"github.com/fatedier/frp/utils/util"
+	"github.com/fatedier/frp/utils/vhost"
+
+	frpIo "github.com/fatedier/golib/io"
+)
+
+type HttpProxy struct {
+	BaseProxy
+	cfg *config.HttpProxyConf
+
+	closeFuncs []func()
+}
+
+func (pxy *HttpProxy) Run() (remoteAddr string, err error) {
+	routeConfig := vhost.VhostRouteConfig{
+		RewriteHost:  pxy.cfg.HostHeaderRewrite,
+		Headers:      pxy.cfg.Headers,
+		Username:     pxy.cfg.HttpUser,
+		Password:     pxy.cfg.HttpPwd,
+		CreateConnFn: pxy.GetRealConn,
+	}
+
+	locations := pxy.cfg.Locations
+	if len(locations) == 0 {
+		locations = []string{""}
+	}
+
+	addrs := make([]string, 0)
+	for _, domain := range pxy.cfg.CustomDomains {
+		routeConfig.Domain = domain
+		for _, location := range locations {
+			routeConfig.Location = location
+			err = pxy.rc.HttpReverseProxy.Register(routeConfig)
+			if err != nil {
+				return
+			}
+			tmpDomain := routeConfig.Domain
+			tmpLocation := routeConfig.Location
+			addrs = append(addrs, util.CanonicalAddr(tmpDomain, int(g.GlbServerCfg.VhostHttpPort)))
+			pxy.closeFuncs = append(pxy.closeFuncs, func() {
+				pxy.rc.HttpReverseProxy.UnRegister(tmpDomain, tmpLocation)
+			})
+			pxy.Info("http proxy listen for host [%s] location [%s]", routeConfig.Domain, routeConfig.Location)
+		}
+	}
+
+	if pxy.cfg.SubDomain != "" {
+		routeConfig.Domain = pxy.cfg.SubDomain + "." + g.GlbServerCfg.SubDomainHost
+		for _, location := range locations {
+			routeConfig.Location = location
+			err = pxy.rc.HttpReverseProxy.Register(routeConfig)
+			if err != nil {
+				return
+			}
+			tmpDomain := routeConfig.Domain
+			tmpLocation := routeConfig.Location
+			addrs = append(addrs, util.CanonicalAddr(tmpDomain, g.GlbServerCfg.VhostHttpPort))
+			pxy.closeFuncs = append(pxy.closeFuncs, func() {
+				pxy.rc.HttpReverseProxy.UnRegister(tmpDomain, tmpLocation)
+			})
+			pxy.Info("http proxy listen for host [%s] location [%s]", routeConfig.Domain, routeConfig.Location)
+		}
+	}
+	remoteAddr = strings.Join(addrs, ",")
+	return
+}
+
+func (pxy *HttpProxy) GetConf() config.ProxyConf {
+	return pxy.cfg
+}
+
+func (pxy *HttpProxy) GetRealConn() (workConn frpNet.Conn, err error) {
+	tmpConn, errRet := pxy.GetWorkConnFromPool()
+	if errRet != nil {
+		err = errRet
+		return
+	}
+
+	var rwc io.ReadWriteCloser = tmpConn
+	if pxy.cfg.UseEncryption {
+		rwc, err = frpIo.WithEncryption(rwc, []byte(g.GlbServerCfg.Token))
+		if err != nil {
+			pxy.Error("create encryption stream error: %v", err)
+			return
+		}
+	}
+	if pxy.cfg.UseCompression {
+		rwc = frpIo.WithCompression(rwc)
+	}
+	workConn = frpNet.WrapReadWriteCloserToConn(rwc, tmpConn)
+	workConn = frpNet.WrapStatsConn(workConn, pxy.updateStatsAfterClosedConn)
+	pxy.statsCollector.Mark(stats.TypeOpenConnection, &stats.OpenConnectionPayload{ProxyName: pxy.GetName()})
+	return
+}
+
+func (pxy *HttpProxy) updateStatsAfterClosedConn(totalRead, totalWrite int64) {
+	name := pxy.GetName()
+	pxy.statsCollector.Mark(stats.TypeCloseProxy, &stats.CloseConnectionPayload{ProxyName: name})
+	pxy.statsCollector.Mark(stats.TypeAddTrafficIn, &stats.AddTrafficInPayload{
+		ProxyName:    name,
+		TrafficBytes: totalWrite,
+	})
+	pxy.statsCollector.Mark(stats.TypeAddTrafficOut, &stats.AddTrafficOutPayload{
+		ProxyName:    name,
+		TrafficBytes: totalRead,
+	})
+}
+
+func (pxy *HttpProxy) Close() {
+	pxy.BaseProxy.Close()
+	for _, closeFn := range pxy.closeFuncs {
+		closeFn()
+	}
+}

server/proxy/https.go

@@ -0,0 +1,72 @@
+// Copyright 2019 fatedier, fatedier@gmail.com
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package proxy
+
+import (
+	"strings"
+
+	"github.com/fatedier/frp/g"
+	"github.com/fatedier/frp/models/config"
+	"github.com/fatedier/frp/utils/util"
+	"github.com/fatedier/frp/utils/vhost"
+)
+
+type HttpsProxy struct {
+	BaseProxy
+	cfg *config.HttpsProxyConf
+}
+
+func (pxy *HttpsProxy) Run() (remoteAddr string, err error) {
+	routeConfig := &vhost.VhostRouteConfig{}
+
+	addrs := make([]string, 0)
+	for _, domain := range pxy.cfg.CustomDomains {
+		routeConfig.Domain = domain
+		l, errRet := pxy.rc.VhostHttpsMuxer.Listen(routeConfig)
+		if errRet != nil {
+			err = errRet
+			return
+		}
+		l.AddLogPrefix(pxy.name)
+		pxy.Info("https proxy listen for host [%s]", routeConfig.Domain)
+		pxy.listeners = append(pxy.listeners, l)
+		addrs = append(addrs, util.CanonicalAddr(routeConfig.Domain, g.GlbServerCfg.VhostHttpsPort))
+	}
+
+	if pxy.cfg.SubDomain != "" {
+		routeConfig.Domain = pxy.cfg.SubDomain + "." + g.GlbServerCfg.SubDomainHost
+		l, errRet := pxy.rc.VhostHttpsMuxer.Listen(routeConfig)
+		if errRet != nil {
+			err = errRet
+			return
+		}
+		l.AddLogPrefix(pxy.name)
+		pxy.Info("https proxy listen for host [%s]", routeConfig.Domain)
+		pxy.listeners = append(pxy.listeners, l)
+		addrs = append(addrs, util.CanonicalAddr(routeConfig.Domain, int(g.GlbServerCfg.VhostHttpsPort)))
+	}
+
+	pxy.startListenHandler(pxy, HandleUserTcpConnection)
+	remoteAddr = strings.Join(addrs, ",")
+	return
+}
+
+func (pxy *HttpsProxy) GetConf() config.ProxyConf {
+	return pxy.cfg
+}
+
+func (pxy *HttpsProxy) Close() {
+	pxy.BaseProxy.Close()
+}

server/proxy/proxy.go

@@ -0,0 +1,250 @@
+// Copyright 2017 fatedier, fatedier@gmail.com
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package proxy
+
+import (
+	"fmt"
+	"io"
+	"sync"
+
+	"github.com/fatedier/frp/g"
+	"github.com/fatedier/frp/models/config"
+	"github.com/fatedier/frp/models/msg"
+	"github.com/fatedier/frp/server/controller"
+	"github.com/fatedier/frp/server/stats"
+	"github.com/fatedier/frp/utils/log"
+	frpNet "github.com/fatedier/frp/utils/net"
+
+	frpIo "github.com/fatedier/golib/io"
+)
+
+type GetWorkConnFn func() (frpNet.Conn, error)
+
+type Proxy interface {
+	Run() (remoteAddr string, err error)
+	GetName() string
+	GetConf() config.ProxyConf
+	GetWorkConnFromPool() (workConn frpNet.Conn, err error)
+	GetUsedPortsNum() int
+	Close()
+	log.Logger
+}
+
+type BaseProxy struct {
+	name           string
+	rc             *controller.ResourceController
+	statsCollector stats.Collector
+	listeners      []frpNet.Listener
+	usedPortsNum   int
+	poolCount      int
+	getWorkConnFn  GetWorkConnFn
+
+	mu sync.RWMutex
+	log.Logger
+}
+
+func (pxy *BaseProxy) GetName() string {
+	return pxy.name
+}
+
+func (pxy *BaseProxy) GetUsedPortsNum() int {
+	return pxy.usedPortsNum
+}
+
+func (pxy *BaseProxy) Close() {
+	pxy.Info("proxy closing")
+	for _, l := range pxy.listeners {
+		l.Close()
+	}
+}
+
+func (pxy *BaseProxy) GetWorkConnFromPool() (workConn frpNet.Conn, err error) {
+	// try all connections from the pool
+	for i := 0; i < pxy.poolCount+1; i++ {
+		if workConn, err = pxy.getWorkConnFn(); err != nil {
+			pxy.Warn("failed to get work connection: %v", err)
+			return
+		}
+		pxy.Info("get a new work connection: [%s]", workConn.RemoteAddr().String())
+		workConn.AddLogPrefix(pxy.GetName())
+
+		err := msg.WriteMsg(workConn, &msg.StartWorkConn{
+			ProxyName: pxy.GetName(),
+		})
+		if err != nil {
+			workConn.Warn("failed to send message to work connection from pool: %v, times: %d", err, i)
+			workConn.Close()
+		} else {
+			break
+		}
+	}
+
+	if err != nil {
+		pxy.Error("try to get work connection failed in the end")
+		return
+	}
+	return
+}
+
+// startListenHandler start a goroutine handler for each listener.
+// p: p will just be passed to handler(Proxy, frpNet.Conn).
+// handler: each proxy type can set different handler function to deal with connections accepted from listeners.
+func (pxy *BaseProxy) startListenHandler(p Proxy, handler func(Proxy, frpNet.Conn, stats.Collector)) {
+	for _, listener := range pxy.listeners {
+		go func(l frpNet.Listener) {
+			for {
+				// block
+				// if listener is closed, err returned
+				c, err := l.Accept()
+				if err != nil {
+					pxy.Info("listener is closed")
+					return
+				}
+				pxy.Debug("get a user connection [%s]", c.RemoteAddr().String())
+				go handler(p, c, pxy.statsCollector)
+			}
+		}(listener)
+	}
+}
+
+func NewProxy(runId string, rc *controller.ResourceController, statsCollector stats.Collector, poolCount int,
+	getWorkConnFn GetWorkConnFn, pxyConf config.ProxyConf) (pxy Proxy, err error) {
+
+	basePxy := BaseProxy{
+		name:           pxyConf.GetBaseInfo().ProxyName,
+		rc:             rc,
+		statsCollector: statsCollector,
+		listeners:      make([]frpNet.Listener, 0),
+		poolCount:      poolCount,
+		getWorkConnFn:  getWorkConnFn,
+		Logger:         log.NewPrefixLogger(runId),
+	}
+	switch cfg := pxyConf.(type) {
+	case *config.TcpProxyConf:
+		basePxy.usedPortsNum = 1
+		pxy = &TcpProxy{
+			BaseProxy: basePxy,
+			cfg:       cfg,
+		}
+	case *config.HttpProxyConf:
+		pxy = &HttpProxy{
+			BaseProxy: basePxy,
+			cfg:       cfg,
+		}
+	case *config.HttpsProxyConf:
+		pxy = &HttpsProxy{
+			BaseProxy: basePxy,
+			cfg:       cfg,
+		}
+	case *config.UdpProxyConf:
+		basePxy.usedPortsNum = 1
+		pxy = &UdpProxy{
+			BaseProxy: basePxy,
+			cfg:       cfg,
+		}
+	case *config.StcpProxyConf:
+		pxy = &StcpProxy{
+			BaseProxy: basePxy,
+			cfg:       cfg,
+		}
+	case *config.XtcpProxyConf:
+		pxy = &XtcpProxy{
+			BaseProxy: basePxy,
+			cfg:       cfg,
+		}
+	default:
+		return pxy, fmt.Errorf("proxy type not support")
+	}
+	pxy.AddLogPrefix(pxy.GetName())
+	return
+}
+
+// HandleUserTcpConnection is used for incoming tcp user connections.
+// It can be used for tcp, http, https type.
+func HandleUserTcpConnection(pxy Proxy, userConn frpNet.Conn, statsCollector stats.Collector) {
+	defer userConn.Close()
+
+	// try all connections from the pool
+	workConn, err := pxy.GetWorkConnFromPool()
+	if err != nil {
+		return
+	}
+	defer workConn.Close()
+
+	var local io.ReadWriteCloser = workConn
+	cfg := pxy.GetConf().GetBaseInfo()
+	if cfg.UseEncryption {
+		local, err = frpIo.WithEncryption(local, []byte(g.GlbServerCfg.Token))
+		if err != nil {
+			pxy.Error("create encryption stream error: %v", err)
+			return
+		}
+	}
+	if cfg.UseCompression {
+		local = frpIo.WithCompression(local)
+	}
+	pxy.Debug("join connections, workConn(l[%s] r[%s]) userConn(l[%s] r[%s])", workConn.LocalAddr().String(),
+		workConn.RemoteAddr().String(), userConn.LocalAddr().String(), userConn.RemoteAddr().String())
+
+	statsCollector.Mark(stats.TypeOpenConnection, &stats.OpenConnectionPayload{ProxyName: pxy.GetName()})
+	inCount, outCount := frpIo.Join(local, userConn)
+	statsCollector.Mark(stats.TypeCloseConnection, &stats.CloseConnectionPayload{ProxyName: pxy.GetName()})
+	statsCollector.Mark(stats.TypeAddTrafficIn, &stats.AddTrafficInPayload{
+		ProxyName:    pxy.GetName(),
+		TrafficBytes: inCount,
+	})
+	statsCollector.Mark(stats.TypeAddTrafficOut, &stats.AddTrafficOutPayload{
+		ProxyName:    pxy.GetName(),
+		TrafficBytes: outCount,
+	})
+	pxy.Debug("join connections closed")
+}
+
+type ProxyManager struct {
+	// proxies indexed by proxy name
+	pxys map[string]Proxy
+
+	mu sync.RWMutex
+}
+
+func NewProxyManager() *ProxyManager {
+	return &ProxyManager{
+		pxys: make(map[string]Proxy),
+	}
+}
+
+func (pm *ProxyManager) Add(name string, pxy Proxy) error {
+	pm.mu.Lock()
+	defer pm.mu.Unlock()
+	if _, ok := pm.pxys[name]; ok {
+		return fmt.Errorf("proxy name [%s] is already in use", name)
+	}
+
+	pm.pxys[name] = pxy
+	return nil
+}
+
+func (pm *ProxyManager) Del(name string) {
+	pm.mu.Lock()
+	defer pm.mu.Unlock()
+	delete(pm.pxys, name)
+}
+
+func (pm *ProxyManager) GetByName(name string) (pxy Proxy, ok bool) {
+	pm.mu.RLock()
+	defer pm.mu.RUnlock()
+	pxy, ok = pm.pxys[name]
+	return
+}

server/proxy/stcp.go

@@ -0,0 +1,47 @@
+// Copyright 2019 fatedier, fatedier@gmail.com
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package proxy
+
+import (
+	"github.com/fatedier/frp/models/config"
+)
+
+type StcpProxy struct {
+	BaseProxy
+	cfg *config.StcpProxyConf
+}
+
+func (pxy *StcpProxy) Run() (remoteAddr string, err error) {
+	listener, errRet := pxy.rc.VisitorManager.Listen(pxy.GetName(), pxy.cfg.Sk)
+	if errRet != nil {
+		err = errRet
+		return
+	}
+	listener.AddLogPrefix(pxy.name)
+	pxy.listeners = append(pxy.listeners, listener)
+	pxy.Info("stcp proxy custom listen success")
+
+	pxy.startListenHandler(pxy, HandleUserTcpConnection)
+	return
+}
+
+func (pxy *StcpProxy) GetConf() config.ProxyConf {
+	return pxy.cfg
+}
+
+func (pxy *StcpProxy) Close() {
+	pxy.BaseProxy.Close()
+	pxy.rc.VisitorManager.CloseListener(pxy.GetName())
+}

server/proxy/tcp.go

@@ -0,0 +1,84 @@
+// Copyright 2019 fatedier, fatedier@gmail.com
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package proxy
+
+import (
+	"fmt"
+
+	"github.com/fatedier/frp/g"
+	"github.com/fatedier/frp/models/config"
+	frpNet "github.com/fatedier/frp/utils/net"
+)
+
+type TcpProxy struct {
+	BaseProxy
+	cfg *config.TcpProxyConf
+
+	realPort int
+}
+
+func (pxy *TcpProxy) Run() (remoteAddr string, err error) {
+	if pxy.cfg.Group != "" {
+		l, realPort, errRet := pxy.rc.TcpGroupCtl.Listen(pxy.name, pxy.cfg.Group, pxy.cfg.GroupKey, g.GlbServerCfg.ProxyBindAddr, pxy.cfg.RemotePort)
+		if errRet != nil {
+			err = errRet
+			return
+		}
+		defer func() {
+			if err != nil {
+				l.Close()
+			}
+		}()
+		pxy.realPort = realPort
+		listener := frpNet.WrapLogListener(l)
+		listener.AddLogPrefix(pxy.name)
+		pxy.listeners = append(pxy.listeners, listener)
+		pxy.Info("tcp proxy listen port [%d] in group [%s]", pxy.cfg.RemotePort, pxy.cfg.Group)
+	} else {
+		pxy.realPort, err = pxy.rc.TcpPortManager.Acquire(pxy.name, pxy.cfg.RemotePort)
+		if err != nil {
+			return
+		}
+		defer func() {
+			if err != nil {
+				pxy.rc.TcpPortManager.Release(pxy.realPort)
+			}
+		}()
+		listener, errRet := frpNet.ListenTcp(g.GlbServerCfg.ProxyBindAddr, pxy.realPort)
+		if errRet != nil {
+			err = errRet
+			return
+		}
+		listener.AddLogPrefix(pxy.name)
+		pxy.listeners = append(pxy.listeners, listener)
+		pxy.Info("tcp proxy listen port [%d]", pxy.cfg.RemotePort)
+	}
+
+	pxy.cfg.RemotePort = pxy.realPort
+	remoteAddr = fmt.Sprintf(":%d", pxy.realPort)
+	pxy.startListenHandler(pxy, HandleUserTcpConnection)
+	return
+}
+
+func (pxy *TcpProxy) GetConf() config.ProxyConf {
+	return pxy.cfg
+}
+
+func (pxy *TcpProxy) Close() {
+	pxy.BaseProxy.Close()
+	if pxy.cfg.Group == "" {
+		pxy.rc.TcpPortManager.Release(pxy.realPort)
+	}
+}

server/proxy/udp.go

@@ -0,0 +1,225 @@
+// Copyright 2019 fatedier, fatedier@gmail.com
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package proxy
+
+import (
+	"context"
+	"fmt"
+	"net"
+	"time"
+
+	"github.com/fatedier/frp/g"
+	"github.com/fatedier/frp/models/config"
+	"github.com/fatedier/frp/models/msg"
+	"github.com/fatedier/frp/models/proto/udp"
+	"github.com/fatedier/frp/server/stats"
+
+	"github.com/fatedier/golib/errors"
+)
+
+type UdpProxy struct {
+	BaseProxy
+	cfg *config.UdpProxyConf
+
+	realPort int
+
+	// udpConn is the listener of udp packages
+	udpConn *net.UDPConn
+
+	// there are always only one workConn at the same time
+	// get another one if it closed
+	workConn net.Conn
+
+	// sendCh is used for sending packages to workConn
+	sendCh chan *msg.UdpPacket
+
+	// readCh is used for reading packages from workConn
+	readCh chan *msg.UdpPacket
+
+	// checkCloseCh is used for watching if workConn is closed
+	checkCloseCh chan int
+
+	isClosed bool
+}
+
+func (pxy *UdpProxy) Run() (remoteAddr string, err error) {
+	pxy.realPort, err = pxy.rc.UdpPortManager.Acquire(pxy.name, pxy.cfg.RemotePort)
+	if err != nil {
+		return
+	}
+	defer func() {
+		if err != nil {
+			pxy.rc.UdpPortManager.Release(pxy.realPort)
+		}
+	}()
+
+	remoteAddr = fmt.Sprintf(":%d", pxy.realPort)
+	pxy.cfg.RemotePort = pxy.realPort
+	addr, errRet := net.ResolveUDPAddr("udp", fmt.Sprintf("%s:%d", g.GlbServerCfg.ProxyBindAddr, pxy.realPort))
+	if errRet != nil {
+		err = errRet
+		return
+	}
+	udpConn, errRet := net.ListenUDP("udp", addr)
+	if errRet != nil {
+		err = errRet
+		pxy.Warn("listen udp port error: %v", err)
+		return
+	}
+	pxy.Info("udp proxy listen port [%d]", pxy.cfg.RemotePort)
+
+	pxy.udpConn = udpConn
+	pxy.sendCh = make(chan *msg.UdpPacket, 1024)
+	pxy.readCh = make(chan *msg.UdpPacket, 1024)
+	pxy.checkCloseCh = make(chan int)
+
+	// read message from workConn, if it returns any error, notify proxy to start a new workConn
+	workConnReaderFn := func(conn net.Conn) {
+		for {
+			var (
+				rawMsg msg.Message
+				errRet error
+			)
+			pxy.Trace("loop waiting message from udp workConn")
+			// client will send heartbeat in workConn for keeping alive
+			conn.SetReadDeadline(time.Now().Add(time.Duration(60) * time.Second))
+			if rawMsg, errRet = msg.ReadMsg(conn); errRet != nil {
+				pxy.Warn("read from workConn for udp error: %v", errRet)
+				conn.Close()
+				// notify proxy to start a new work connection
+				// ignore error here, it means the proxy is closed
+				errors.PanicToError(func() {
+					pxy.checkCloseCh <- 1
+				})
+				return
+			}
+			conn.SetReadDeadline(time.Time{})
+			switch m := rawMsg.(type) {
+			case *msg.Ping:
+				pxy.Trace("udp work conn get ping message")
+				continue
+			case *msg.UdpPacket:
+				if errRet := errors.PanicToError(func() {
+					pxy.Trace("get udp message from workConn: %s", m.Content)
+					pxy.readCh <- m
+					pxy.statsCollector.Mark(stats.TypeAddTrafficOut, &stats.AddTrafficOutPayload{
+						ProxyName:    pxy.GetName(),
+						TrafficBytes: int64(len(m.Content)),
+					})
+				}); errRet != nil {
+					conn.Close()
+					pxy.Info("reader goroutine for udp work connection closed")
+					return
+				}
+			}
+		}
+	}
+
+	// send message to workConn
+	workConnSenderFn := func(conn net.Conn, ctx context.Context) {
+		var errRet error
+		for {
+			select {
+			case udpMsg, ok := <-pxy.sendCh:
+				if !ok {
+					pxy.Info("sender goroutine for udp work connection closed")
+					return
+				}
+				if errRet = msg.WriteMsg(conn, udpMsg); errRet != nil {
+					pxy.Info("sender goroutine for udp work connection closed: %v", errRet)
+					conn.Close()
+					return
+				} else {
+					pxy.Trace("send message to udp workConn: %s", udpMsg.Content)
+					pxy.statsCollector.Mark(stats.TypeAddTrafficIn, &stats.AddTrafficInPayload{
+						ProxyName:    pxy.GetName(),
+						TrafficBytes: int64(len(udpMsg.Content)),
+					})
+					continue
+				}
+			case <-ctx.Done():
+				pxy.Info("sender goroutine for udp work connection closed")
+				return
+			}
+		}
+	}
+
+	go func() {
+		// Sleep a while for waiting control send the NewProxyResp to client.
+		time.Sleep(500 * time.Millisecond)
+		for {
+			workConn, err := pxy.GetWorkConnFromPool()
+			if err != nil {
+				time.Sleep(1 * time.Second)
+				// check if proxy is closed
+				select {
+				case _, ok := <-pxy.checkCloseCh:
+					if !ok {
+						return
+					}
+				default:
+				}
+				continue
+			}
+			// close the old workConn and replac it with a new one
+			if pxy.workConn != nil {
+				pxy.workConn.Close()
+			}
+			pxy.workConn = workConn
+			ctx, cancel := context.WithCancel(context.Background())
+			go workConnReaderFn(workConn)
+			go workConnSenderFn(workConn, ctx)
+			_, ok := <-pxy.checkCloseCh
+			cancel()
+			if !ok {
+				return
+			}
+		}
+	}()
+
+	// Read from user connections and send wrapped udp message to sendCh (forwarded by workConn).
+	// Client will transfor udp message to local udp service and waiting for response for a while.
+	// Response will be wrapped to be forwarded by work connection to server.
+	// Close readCh and sendCh at the end.
+	go func() {
+		udp.ForwardUserConn(udpConn, pxy.readCh, pxy.sendCh)
+		pxy.Close()
+	}()
+	return remoteAddr, nil
+}
+
+func (pxy *UdpProxy) GetConf() config.ProxyConf {
+	return pxy.cfg
+}
+
+func (pxy *UdpProxy) Close() {
+	pxy.mu.Lock()
+	defer pxy.mu.Unlock()
+	if !pxy.isClosed {
+		pxy.isClosed = true
+
+		pxy.BaseProxy.Close()
+		if pxy.workConn != nil {
+			pxy.workConn.Close()
+		}
+		pxy.udpConn.Close()
+
+		// all channels only closed here
+		close(pxy.checkCloseCh)
+		close(pxy.readCh)
+		close(pxy.sendCh)
+	}
+	pxy.rc.UdpPortManager.Release(pxy.realPort)
+}

server/proxy/xtcp.go

@@ -0,0 +1,73 @@
+// Copyright 2019 fatedier, fatedier@gmail.com
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package proxy
+
+import (
+	"fmt"
+
+	"github.com/fatedier/frp/models/config"
+	"github.com/fatedier/frp/models/msg"
+
+	"github.com/fatedier/golib/errors"
+)
+
+type XtcpProxy struct {
+	BaseProxy
+	cfg *config.XtcpProxyConf
+
+	closeCh chan struct{}
+}
+
+func (pxy *XtcpProxy) Run() (remoteAddr string, err error) {
+	if pxy.rc.NatHoleController == nil {
+		pxy.Error("udp port for xtcp is not specified.")
+		err = fmt.Errorf("xtcp is not supported in frps")
+		return
+	}
+	sidCh := pxy.rc.NatHoleController.ListenClient(pxy.GetName(), pxy.cfg.Sk)
+	go func() {
+		for {
+			select {
+			case <-pxy.closeCh:
+				break
+			case sid := <-sidCh:
+				workConn, errRet := pxy.GetWorkConnFromPool()
+				if errRet != nil {
+					continue
+				}
+				m := &msg.NatHoleSid{
+					Sid: sid,
+				}
+				errRet = msg.WriteMsg(workConn, m)
+				if errRet != nil {
+					pxy.Warn("write nat hole sid package error, %v", errRet)
+				}
+			}
+		}
+	}()
+	return
+}
+
+func (pxy *XtcpProxy) GetConf() config.ProxyConf {
+	return pxy.cfg
+}
+
+func (pxy *XtcpProxy) Close() {
+	pxy.BaseProxy.Close()
+	pxy.rc.NatHoleController.CloseClient(pxy.GetName())
+	errors.PanicToError(func() {
+		close(pxy.closeCh)
+	})
+}