feat: support sudp proxy (#1730)

client/admin_api.go

@@ -88,6 +88,7 @@ type StatusResp struct {
 	Https []ProxyStatusResp `json:"https"`
 	Stcp  []ProxyStatusResp `json:"stcp"`
 	Xtcp  []ProxyStatusResp `json:"xtcp"`
+	Sudp  []ProxyStatusResp `json:"sudp"`
 }
 
 type ProxyStatusResp struct {
@@ -155,6 +156,11 @@ func NewProxyStatusResp(status *proxy.ProxyStatus, serverAddr string) ProxyStatu
 			psr.LocalAddr = fmt.Sprintf("%s:%d", cfg.LocalIp, cfg.LocalPort)
 		}
 		psr.Plugin = cfg.Plugin
+	case *config.SudpProxyConf:
+		if cfg.LocalPort != 0 {
+			psr.LocalAddr = fmt.Sprintf("%s:%d", cfg.LocalIp, cfg.LocalPort)
+		}
+		psr.Plugin = cfg.Plugin
 	}
 	return psr
 }
@@ -171,6 +177,7 @@ func (svr *Service) apiStatus(w http.ResponseWriter, r *http.Request) {
 	res.Https = make([]ProxyStatusResp, 0)
 	res.Stcp = make([]ProxyStatusResp, 0)
 	res.Xtcp = make([]ProxyStatusResp, 0)
+	res.Sudp = make([]ProxyStatusResp, 0)
 
 	log.Info("Http request [/api/status]")
 	defer func() {
@@ -194,6 +201,8 @@ func (svr *Service) apiStatus(w http.ResponseWriter, r *http.Request) {
 			res.Stcp = append(res.Stcp, NewProxyStatusResp(status, svr.cfg.ServerAddr))
 		case "xtcp":
 			res.Xtcp = append(res.Xtcp, NewProxyStatusResp(status, svr.cfg.ServerAddr))
+		case "sudp":
+			res.Sudp = append(res.Sudp, NewProxyStatusResp(status, svr.cfg.ServerAddr))
 		}
 	}
 	sort.Sort(ByProxyStatusResp(res.Tcp))
@@ -202,6 +211,7 @@ func (svr *Service) apiStatus(w http.ResponseWriter, r *http.Request) {
 	sort.Sort(ByProxyStatusResp(res.Https))
 	sort.Sort(ByProxyStatusResp(res.Stcp))
 	sort.Sort(ByProxyStatusResp(res.Xtcp))
+	sort.Sort(ByProxyStatusResp(res.Sudp))
 	return
 }
 

client/proxy/proxy.go

@@ -102,6 +102,12 @@ func NewProxy(ctx context.Context, pxyConf config.ProxyConf, clientCfg config.Cl
 			BaseProxy: &baseProxy,
 			cfg:       cfg,
 		}
+	case *config.SudpProxyConf:
+		pxy = &SudpProxy{
+			BaseProxy: &baseProxy,
+			cfg:       cfg,
+			closeCh:   make(chan struct{}),
+		}
 	}
 	return
 }
@@ -540,6 +546,151 @@ func (pxy *UdpProxy) InWorkConn(conn net.Conn, m *msg.StartWorkConn) {
 	udp.Forwarder(pxy.localAddr, pxy.readCh, pxy.sendCh)
 }
 
+type SudpProxy struct {
+	*BaseProxy
+
+	cfg *config.SudpProxyConf
+
+	localAddr *net.UDPAddr
+
+	closeCh chan struct{}
+}
+
+func (pxy *SudpProxy) Run() (err error) {
+	pxy.localAddr, err = net.ResolveUDPAddr("udp", fmt.Sprintf("%s:%d", pxy.cfg.LocalIp, pxy.cfg.LocalPort))
+	if err != nil {
+		return
+	}
+	return
+}
+
+func (pxy *SudpProxy) Close() {
+	pxy.mu.Lock()
+	defer pxy.mu.Unlock()
+	select {
+	case <-pxy.closeCh:
+		return
+	default:
+		close(pxy.closeCh)
+	}
+}
+
+func (pxy *SudpProxy) InWorkConn(conn net.Conn, m *msg.StartWorkConn) {
+	xl := pxy.xl
+	xl.Info("incoming a new work connection for sudp proxy, %s", conn.RemoteAddr().String())
+
+	if pxy.limiter != nil {
+		rwc := frpIo.WrapReadWriteCloser(limit.NewReader(conn, pxy.limiter), limit.NewWriter(conn, pxy.limiter), func() error {
+			return conn.Close()
+		})
+		conn = frpNet.WrapReadWriteCloserToConn(rwc, conn)
+	}
+
+	workConn := conn
+	readCh := make(chan *msg.UdpPacket, 1024)
+	sendCh := make(chan msg.Message, 1024)
+	isClose := false
+
+	mu := &sync.Mutex{}
+
+	closeFn := func() {
+		mu.Lock()
+		defer mu.Unlock()
+		if isClose {
+			return
+		}
+
+		isClose = true
+		if workConn != nil {
+			workConn.Close()
+		}
+		close(readCh)
+		close(sendCh)
+	}
+
+	// udp service <- frpc <- frps <- frpc visitor <- user
+	workConnReaderFn := func(conn net.Conn, readCh chan *msg.UdpPacket) {
+		defer closeFn()
+
+		for {
+			// first to check sudp proxy is closed or not
+			select {
+			case <-pxy.closeCh:
+				xl.Trace("frpc sudp proxy is closed")
+				return
+			default:
+			}
+
+			var udpMsg msg.UdpPacket
+			if errRet := msg.ReadMsgInto(conn, &udpMsg); errRet != nil {
+				xl.Warn("read from workConn for sudp error: %v", errRet)
+				return
+			}
+
+			if errRet := errors.PanicToError(func() {
+				readCh <- &udpMsg
+			}); errRet != nil {
+				xl.Warn("reader goroutine for sudp work connection closed: %v", errRet)
+				return
+			}
+		}
+	}
+
+	// udp service -> frpc -> frps -> frpc visitor -> user
+	workConnSenderFn := func(conn net.Conn, sendCh chan msg.Message) {
+		defer func() {
+			closeFn()
+			xl.Info("writer goroutine for sudp work connection closed")
+		}()
+
+		var errRet error
+		for rawMsg := range sendCh {
+			switch m := rawMsg.(type) {
+			case *msg.UdpPacket:
+				xl.Trace("frpc send udp package to frpc visitor, [udp local: %v, remote: %v], [tcp work conn local: %v, remote: %v]",
+					m.LocalAddr.String(), m.RemoteAddr.String(), conn.LocalAddr().String(), conn.RemoteAddr().String())
+			case *msg.Ping:
+				xl.Trace("frpc send ping message to frpc visitor")
+			}
+
+			if errRet = msg.WriteMsg(conn, rawMsg); errRet != nil {
+				xl.Error("sudp work write error: %v", errRet)
+				return
+			}
+		}
+	}
+
+	heartbeatFn := func(conn net.Conn, sendCh chan msg.Message) {
+		ticker := time.NewTicker(30 * time.Second)
+		defer func() {
+			ticker.Stop()
+			closeFn()
+		}()
+
+		var errRet error
+		for {
+			select {
+			case <-ticker.C:
+				if errRet = errors.PanicToError(func() {
+					sendCh <- &msg.Ping{}
+				}); errRet != nil {
+					xl.Warn("heartbeat goroutine for sudp work connection closed")
+					return
+				}
+			case <-pxy.closeCh:
+				xl.Trace("frpc sudp proxy is closed")
+				return
+			}
+		}
+	}
+
+	go workConnSenderFn(workConn, sendCh)
+	go workConnReaderFn(workConn, readCh)
+	go heartbeatFn(workConn, sendCh)
+
+	udp.Forwarder(pxy.localAddr, readCh, sendCh)
+}
+
 // Common handler for tcp work connections.
 func HandleTcpWorkConnection(ctx context.Context, localInfo *config.LocalSvrConf, proxyPlugin plugin.Plugin,
 	baseInfo *config.BaseProxyConf, limiter *rate.Limiter, workConn net.Conn, encKey []byte, m *msg.StartWorkConn) {

client/visitor.go

@@ -26,10 +26,12 @@ import (
 
 	"github.com/fatedier/frp/models/config"
 	"github.com/fatedier/frp/models/msg"
+	"github.com/fatedier/frp/models/proto/udp"
 	frpNet "github.com/fatedier/frp/utils/net"
 	"github.com/fatedier/frp/utils/util"
 	"github.com/fatedier/frp/utils/xlog"
 
+	"github.com/fatedier/golib/errors"
 	frpIo "github.com/fatedier/golib/io"
 	"github.com/fatedier/golib/pool"
 	fmux "github.com/hashicorp/yamux"
@@ -58,6 +60,12 @@ func NewVisitor(ctx context.Context, ctl *Control, cfg config.VisitorConf) (visi
 			BaseVisitor: &baseVisitor,
 			cfg:         cfg,
 		}
+	case *config.SudpVisitorConf:
+		visitor = &SudpVisitor{
+			BaseVisitor:  &baseVisitor,
+			cfg:          cfg,
+			checkCloseCh: make(chan struct{}),
+		}
 	}
 	return
 }
@@ -328,3 +336,204 @@ func (sv *XtcpVisitor) handleConn(userConn net.Conn) {
 	frpIo.Join(userConn, muxConnRWCloser)
 	xl.Debug("join connections closed")
 }
+
+type SudpVisitor struct {
+	*BaseVisitor
+
+	checkCloseCh chan struct{}
+	// udpConn is the listener of udp packet
+	udpConn *net.UDPConn
+	readCh  chan *msg.UdpPacket
+	sendCh  chan *msg.UdpPacket
+
+	cfg *config.SudpVisitorConf
+}
+
+// SUDP Run start listen a udp port
+func (sv *SudpVisitor) Run() (err error) {
+	xl := xlog.FromContextSafe(sv.ctx)
+
+	addr, err := net.ResolveUDPAddr("udp", fmt.Sprintf("%s:%d", sv.cfg.BindAddr, sv.cfg.BindPort))
+	if err != nil {
+		return fmt.Errorf("sudp ResolveUDPAddr error: %v", err)
+	}
+
+	sv.udpConn, err = net.ListenUDP("udp", addr)
+	if err != nil {
+		return fmt.Errorf("listen udp port %s error: %v", addr.String(), err)
+	}
+
+	sv.sendCh = make(chan *msg.UdpPacket, 1024)
+	sv.readCh = make(chan *msg.UdpPacket, 1024)
+
+	xl.Info("sudp start to work")
+
+	go sv.dispatcher()
+	go udp.ForwardUserConn(sv.udpConn, sv.readCh, sv.sendCh)
+
+	return
+}
+
+func (sv *SudpVisitor) dispatcher() {
+	xl := xlog.FromContextSafe(sv.ctx)
+
+	for {
+		// loop for get frpc to frps tcp conn
+		// setup worker
+		// wait worker to finished
+		// retry or exit
+		visitorConn, err := sv.getNewVisitorConn()
+		if err != nil {
+			// check if proxy is closed
+			// if checkCloseCh is close, we will return, other case we will continue to reconnect
+			select {
+			case <-sv.checkCloseCh:
+				xl.Info("frpc sudp visitor proxy is closed")
+				return
+			default:
+			}
+
+			time.Sleep(3 * time.Second)
+
+			xl.Warn("newVisitorConn to frps error: %v, try to reconnect", err)
+			continue
+		}
+
+		sv.worker(visitorConn)
+
+		select {
+		case <-sv.checkCloseCh:
+			return
+		default:
+		}
+	}
+}
+
+func (sv *SudpVisitor) worker(workConn net.Conn) {
+	xl := xlog.FromContextSafe(sv.ctx)
+	xl.Debug("starting sudp proxy worker")
+
+	wg := &sync.WaitGroup{}
+	wg.Add(2)
+	closeCh := make(chan struct{})
+
+	// udp service -> frpc -> frps -> frpc visitor -> user
+	workConnReaderFn := func(conn net.Conn) {
+		defer func() {
+			conn.Close()
+			close(closeCh)
+			wg.Done()
+		}()
+
+		for {
+			var (
+				rawMsg msg.Message
+				errRet error
+			)
+
+			// frpc will send heartbeat in workConn to frpc visitor for keeping alive
+			conn.SetReadDeadline(time.Now().Add(60 * time.Second))
+			if rawMsg, errRet = msg.ReadMsg(conn); errRet != nil {
+				xl.Warn("read from workconn for user udp conn error: %v", errRet)
+				return
+			}
+
+			conn.SetReadDeadline(time.Time{})
+			switch m := rawMsg.(type) {
+			case *msg.Ping:
+				xl.Debug("frpc visitor get ping message from frpc")
+				continue
+			case *msg.UdpPacket:
+				if errRet := errors.PanicToError(func() {
+					sv.readCh <- m
+					xl.Trace("frpc visitor get udp packet from frpc")
+				}); errRet != nil {
+					xl.Info("reader goroutine for udp work connection closed")
+					return
+				}
+			}
+		}
+	}
+
+	// udp service <- frpc <- frps <- frpc visitor <- user
+	workConnSenderFn := func(conn net.Conn) {
+		defer func() {
+			conn.Close()
+			wg.Done()
+		}()
+
+		var errRet error
+		for {
+			select {
+			case udpMsg, ok := <-sv.sendCh:
+				if !ok {
+					xl.Info("sender goroutine for udp work connection closed")
+					return
+				}
+
+				if errRet = msg.WriteMsg(conn, udpMsg); errRet != nil {
+					xl.Warn("sender goroutine for udp work connection closed: %v", errRet)
+					return
+				}
+			case <-closeCh:
+				return
+			}
+		}
+	}
+
+	go workConnReaderFn(workConn)
+	go workConnSenderFn(workConn)
+
+	wg.Wait()
+	xl.Info("sudp worker is closed")
+}
+
+func (sv *SudpVisitor) getNewVisitorConn() (visitorConn net.Conn, err error) {
+	visitorConn, err = sv.ctl.connectServer()
+	if err != nil {
+		return nil, fmt.Errorf("frpc connect frps error: %v", err)
+	}
+
+	now := time.Now().Unix()
+	newVisitorConnMsg := &msg.NewVisitorConn{
+		ProxyName:      sv.cfg.ServerName,
+		SignKey:        util.GetAuthKey(sv.cfg.Sk, now),
+		Timestamp:      now,
+		UseEncryption:  sv.cfg.UseEncryption,
+		UseCompression: sv.cfg.UseCompression,
+	}
+	err = msg.WriteMsg(visitorConn, newVisitorConnMsg)
+	if err != nil {
+		return nil, fmt.Errorf("frpc send newVisitorConnMsg to frps error: %v", err)
+	}
+
+	var newVisitorConnRespMsg msg.NewVisitorConnResp
+	visitorConn.SetReadDeadline(time.Now().Add(10 * time.Second))
+	err = msg.ReadMsgInto(visitorConn, &newVisitorConnRespMsg)
+	if err != nil {
+		return nil, fmt.Errorf("frpc read newVisitorConnRespMsg error: %v", err)
+	}
+	visitorConn.SetReadDeadline(time.Time{})
+
+	if newVisitorConnRespMsg.Error != "" {
+		return nil, fmt.Errorf("start new visitor connection error: %s", newVisitorConnRespMsg.Error)
+	}
+	return
+}
+
+func (sv *SudpVisitor) Close() {
+	sv.mu.Lock()
+	defer sv.mu.Unlock()
+
+	select {
+	case <-sv.checkCloseCh:
+		return
+	default:
+		close(sv.checkCloseCh)
+	}
+	if sv.udpConn != nil {
+		sv.udpConn.Close()
+	}
+	close(sv.readCh)
+	close(sv.sendCh)
+}

cmd/frpc/sub/sudp.go

+// Copyright 2018 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 sub
+
+import (
+	"fmt"
+	"os"
+
+	"github.com/spf13/cobra"
+
+	"github.com/fatedier/frp/models/config"
+	"github.com/fatedier/frp/models/consts"
+)
+
+func init() {
+	sudpCmd.PersistentFlags().StringVarP(&serverAddr, "server_addr", "s", "127.0.0.1:7000", "frp server's address")
+	sudpCmd.PersistentFlags().StringVarP(&user, "user", "u", "", "user")
+	sudpCmd.PersistentFlags().StringVarP(&protocol, "protocol", "p", "tcp", "tcp or kcp or websocket")
+	sudpCmd.PersistentFlags().StringVarP(&token, "token", "t", "", "auth token")
+	sudpCmd.PersistentFlags().StringVarP(&logLevel, "log_level", "", "info", "log level")
+	sudpCmd.PersistentFlags().StringVarP(&logFile, "log_file", "", "console", "console or file path")
+	sudpCmd.PersistentFlags().IntVarP(&logMaxDays, "log_max_days", "", 3, "log file reversed days")
+	sudpCmd.PersistentFlags().BoolVarP(&disableLogColor, "disable_log_color", "", false, "disable log color in console")
+
+	sudpCmd.PersistentFlags().StringVarP(&proxyName, "proxy_name", "n", "", "proxy name")
+	sudpCmd.PersistentFlags().StringVarP(&role, "role", "", "server", "role")
+	sudpCmd.PersistentFlags().StringVarP(&sk, "sk", "", "", "secret key")
+	sudpCmd.PersistentFlags().StringVarP(&serverName, "server_name", "", "", "server name")
+	sudpCmd.PersistentFlags().StringVarP(&localIp, "local_ip", "i", "127.0.0.1", "local ip")
+	sudpCmd.PersistentFlags().IntVarP(&localPort, "local_port", "l", 0, "local port")
+	sudpCmd.PersistentFlags().StringVarP(&bindAddr, "bind_addr", "", "", "bind addr")
+	sudpCmd.PersistentFlags().IntVarP(&bindPort, "bind_port", "", 0, "bind port")
+	sudpCmd.PersistentFlags().BoolVarP(&useEncryption, "ue", "", false, "use encryption")
+	sudpCmd.PersistentFlags().BoolVarP(&useCompression, "uc", "", false, "use compression")
+
+	rootCmd.AddCommand(sudpCmd)
+}
+
+var sudpCmd = &cobra.Command{
+	Use:   "sudp",
+	Short: "Run frpc with a single sudp proxy",
+	RunE: func(cmd *cobra.Command, args []string) error {
+		clientCfg, err := parseClientCommonCfg(CfgFileTypeCmd, "")
+		if err != nil {
+			fmt.Println(err)
+			os.Exit(1)
+		}
+
+		proxyConfs := make(map[string]config.ProxyConf)
+		visitorConfs := make(map[string]config.VisitorConf)
+
+		var prefix string
+		if user != "" {
+			prefix = user + "."
+		}
+
+		if role == "server" {
+			cfg := &config.SudpProxyConf{}
+			cfg.ProxyName = prefix + proxyName
+			cfg.ProxyType = consts.SudpProxy
+			cfg.UseEncryption = useEncryption
+			cfg.UseCompression = useCompression
+			cfg.Role = role
+			cfg.Sk = sk
+			cfg.LocalIp = localIp
+			cfg.LocalPort = localPort
+			err = cfg.CheckForCli()
+			if err != nil {
+				fmt.Println(err)
+				os.Exit(1)
+			}
+			proxyConfs[cfg.ProxyName] = cfg
+		} else if role == "visitor" {
+			cfg := &config.SudpVisitorConf{}
+			cfg.ProxyName = prefix + proxyName
+			cfg.ProxyType = consts.SudpProxy
+			cfg.UseEncryption = useEncryption
+			cfg.UseCompression = useCompression
+			cfg.Role = role
+			cfg.Sk = sk
+			cfg.ServerName = serverName
+			cfg.BindAddr = bindAddr
+			cfg.BindPort = bindPort
+			err = cfg.Check()
+			if err != nil {
+				fmt.Println(err)
+				os.Exit(1)
+			}
+			visitorConfs[cfg.ProxyName] = cfg
+		} else {
+			fmt.Println("invalid role")
+			os.Exit(1)
+		}
+
+		err = startService(clientCfg, proxyConfs, visitorConfs, "")
+		if err != nil {
+			os.Exit(1)
+		}
+		return nil
+	},
+}

models/config/proxy.go

@@ -40,6 +40,7 @@ func init() {
 	proxyConfTypeMap[consts.HttpsProxy] = reflect.TypeOf(HttpsProxyConf{})
 	proxyConfTypeMap[consts.StcpProxy] = reflect.TypeOf(StcpProxyConf{})
 	proxyConfTypeMap[consts.XtcpProxy] = reflect.TypeOf(XtcpProxyConf{})
+	proxyConfTypeMap[consts.SudpProxy] = reflect.TypeOf(SudpProxyConf{})
 }
 
 // NewConfByType creates a empty ProxyConf object by proxyType.
@@ -875,6 +876,72 @@ func (cfg *HttpsProxyConf) CheckForSvr(serverCfg ServerCommonConf) (err error) {
 	return
 }
 
+// SUDP
+type SudpProxyConf struct {
+	BaseProxyConf
+
+	Role string `json:"role"`
+	Sk   string `json:"sk"`
+}
+
+func (cfg *SudpProxyConf) Compare(cmp ProxyConf) bool {
+	cmpConf, ok := cmp.(*SudpProxyConf)
+	if !ok {
+		return false
+	}
+
+	if !cfg.BaseProxyConf.compare(&cmpConf.BaseProxyConf) ||
+		cfg.Role != cmpConf.Role ||
+		cfg.Sk != cmpConf.Sk {
+		return false
+	}
+	return true
+}
+
+func (cfg *SudpProxyConf) UnmarshalFromIni(prefix string, name string, section ini.Section) (err error) {
+	if err = cfg.BaseProxyConf.UnmarshalFromIni(prefix, name, section); err != nil {
+		return
+	}
+
+	cfg.Role = section["role"]
+	if cfg.Role != "server" {
+		return fmt.Errorf("Parse conf error: proxy [%s] incorrect role [%s]", name, cfg.Role)
+	}
+
+	cfg.Sk = section["sk"]
+
+	if err = cfg.LocalSvrConf.UnmarshalFromIni(prefix, name, section); err != nil {
+		return
+	}
+	return
+}
+
+func (cfg *SudpProxyConf) MarshalToMsg(pMsg *msg.NewProxy) {
+	cfg.BaseProxyConf.MarshalToMsg(pMsg)
+	pMsg.Sk = cfg.Sk
+}
+
+func (cfg *SudpProxyConf) CheckForCli() (err error) {
+	if err = cfg.BaseProxyConf.checkForCli(); err != nil {
+		return
+	}
+	if cfg.Role != "server" {
+		err = fmt.Errorf("role should be 'server'")
+		return
+	}
+	return
+}
+
+func (cfg *SudpProxyConf) CheckForSvr(serverCfg ServerCommonConf) (err error) {
+	return
+}
+
+// Only for role server.
+func (cfg *SudpProxyConf) UnmarshalFromMsg(pMsg *msg.NewProxy) {
+	cfg.BaseProxyConf.UnmarshalFromMsg(pMsg)
+	cfg.Sk = pMsg.Sk
+}
+
 // STCP
 type StcpProxyConf struct {
 	BaseProxyConf

models/config/visitor.go

@@ -32,6 +32,7 @@ func init() {
 	visitorConfTypeMap = make(map[string]reflect.Type)
 	visitorConfTypeMap[consts.StcpProxy] = reflect.TypeOf(StcpVisitorConf{})
 	visitorConfTypeMap[consts.XtcpProxy] = reflect.TypeOf(XtcpVisitorConf{})
+	visitorConfTypeMap[consts.SudpProxy] = reflect.TypeOf(SudpVisitorConf{})
 }
 
 type VisitorConf interface {
@@ -152,6 +153,36 @@ func (cfg *BaseVisitorConf) UnmarshalFromIni(prefix string, name string, section
 	return nil
 }
 
+type SudpVisitorConf struct {
+	BaseVisitorConf
+}
+
+func (cfg *SudpVisitorConf) Compare(cmp VisitorConf) bool {
+	cmpConf, ok := cmp.(*SudpVisitorConf)
+	if !ok {
+		return false
+	}
+
+	if !cfg.BaseVisitorConf.compare(&cmpConf.BaseVisitorConf) {
+		return false
+	}
+	return true
+}
+
+func (cfg *SudpVisitorConf) UnmarshalFromIni(prefix string, name string, section ini.Section) (err error) {
+	if err = cfg.BaseVisitorConf.UnmarshalFromIni(prefix, name, section); err != nil {
+		return
+	}
+	return
+}
+
+func (cfg *SudpVisitorConf) Check() (err error) {
+	if err = cfg.BaseVisitorConf.check(); err != nil {
+		return
+	}
+	return
+}
+
 type StcpVisitorConf struct {
 	BaseVisitorConf
 }

models/consts/consts.go

@@ -30,6 +30,7 @@ var (
 	HttpsProxy  string = "https"
 	StcpProxy   string = "stcp"
 	XtcpProxy   string = "xtcp"
+	SudpProxy   string = "sudp"
 
 	// authentication method
 	TokenAuthMethod string = "token"

models/proto/udp/udp.go

@@ -57,11 +57,11 @@ func ForwardUserConn(udpConn *net.UDPConn, readCh <-chan *msg.UdpPacket, sendCh
 	for {
 		n, remoteAddr, err := udpConn.ReadFromUDP(buf)
 		if err != nil {
-			udpConn.Close()
 			return
 		}
 		// buf[:n] will be encoded to string, so the bytes can be reused
 		udpMsg := NewUdpPacket(buf[:n], nil, remoteAddr)
+
 		select {
 		case sendCh <- udpMsg:
 		default:

server/proxy/proxy.go

@@ -219,6 +219,11 @@ func NewProxy(ctx context.Context, userInfo plugin.UserInfo, rc *controller.Reso
 			BaseProxy: &basePxy,
 			cfg:       cfg,
 		}
+	case *config.SudpProxyConf:
+		pxy = &SudpProxy{
+			BaseProxy: &basePxy,
+			cfg:       cfg,
+		}
 	default:
 		return pxy, fmt.Errorf("proxy type not support")
 	}

server/proxy/sudp.go

+// 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 SudpProxy struct {
+	*BaseProxy
+	cfg *config.SudpProxyConf
+}
+
+func (pxy *SudpProxy) Run() (remoteAddr string, err error) {
+	xl := pxy.xl
+
+	listener, errRet := pxy.rc.VisitorManager.Listen(pxy.GetName(), pxy.cfg.Sk)
+	if errRet != nil {
+		err = errRet
+		return
+	}
+	pxy.listeners = append(pxy.listeners, listener)
+	xl.Info("sudp proxy custom listen success")
+
+	pxy.startListenHandler(pxy, HandleUserTcpConnection)
+	return
+}
+
+func (pxy *SudpProxy) GetConf() config.ProxyConf {
+	return pxy.cfg
+}
+
+func (pxy *SudpProxy) Close() {
+	pxy.BaseProxy.Close()
+	pxy.rc.VisitorManager.CloseListener(pxy.GetName())
+}

tests/ci/auto_test_frpc.ini

@@ -72,6 +72,12 @@ local_port = 10701
 use_encryption = true
 use_compression = true
 
+[sudp]
+type = sudp
+sk = abcdefg
+local_ip = 127.0.0.1
+local_port = 10702
+
 [web01]
 type = http
 local_ip = 127.0.0.1

tests/ci/auto_test_frpc_visitor.ini

@@ -23,3 +23,12 @@ bind_addr = 127.0.0.1
 bind_port = 10905
 use_encryption = true
 use_compression = true
+
+
+[sudp_visitor]
+type = sudp
+role = visitor
+server_name = sudp
+sk = abcdefg
+bind_addr = 127.0.0.1
+bind_port = 10816

tests/ci/normal_test.go

@@ -118,6 +118,16 @@ func TestStcp(t *testing.T) {
 	}
 }
 
+func TestSudp(t *testing.T) {
+	assert := assert.New(t)
+	// Normal
+	addr := fmt.Sprintf("127.0.0.1:%d", consts.TEST_SUDP_FRP_PORT)
+	res, err := util.SendUdpMsg(addr, consts.TEST_SUDP_ECHO_STR)
+
+	assert.NoError(err)
+	assert.Equal(consts.TEST_SUDP_ECHO_STR, res)
+}
+
 func TestHttp(t *testing.T) {
 	assert := assert.New(t)
 	// web01

tests/consts/consts.go

@@ -46,6 +46,9 @@ var (
 	TEST_STCP_EC_FRP_PORT int    = 10905
 	TEST_STCP_ECHO_STR    string = "stcp type:" + TEST_STR
 
+	TEST_SUDP_FRP_PORT int    = 10816
+	TEST_SUDP_ECHO_STR string = "sudp type:" + TEST_STR
+
 	ProxyTcpPortNotAllowed  string = "tcp_port_not_allowed"
 	ProxyTcpPortUnavailable string = "tcp_port_unavailable"
 	ProxyTcpPortNormal      string = "tcp_port_normal"

tests/util/util.go

@@ -71,6 +71,11 @@ func GetProxyStatus(statusAddr string, user string, passwd string, name string)
 			return &s, nil
 		}
 	}
+	for _, s := range allStatus.Sudp {
+		if s.Name == name {
+			return &s, nil
+		}
+	}
 
 	return status, errors.New("no proxy status found")
 }