fix the issue of duplicate xtcp proxies will cause the previous proxy to become ineffective (#3489)

server/control.go

@@ -577,6 +577,11 @@ func (ctl *Control) RegisterProxy(pxyMsg *msg.NewProxy) (remoteAddr string, err
 		}()
 	}
 
+	if ctl.pxyManager.Exist(pxyMsg.ProxyName) {
+		err = fmt.Errorf("proxy [%s] already exists", pxyMsg.ProxyName)
+		return
+	}
+
 	remoteAddr, err = pxy.Run()
 	if err != nil {
 		return

server/proxy/proxy.go

@@ -324,6 +324,13 @@ func (pm *Manager) Add(name string, pxy Proxy) error {
 	return nil
 }
 
+func (pm *Manager) Exist(name string) bool {
+	pm.mu.RLock()
+	defer pm.mu.RUnlock()
+	_, ok := pm.pxys[name]
+	return ok
+}
+
 func (pm *Manager) Del(name string) {
 	pm.mu.Lock()
 	defer pm.mu.Unlock()

server/proxy/xtcp.go

@@ -58,7 +58,10 @@ func (pxy *XTCPProxy) Run() (remoteAddr string, err error) {
 	if len(allowUsers) == 0 {
 		allowUsers = []string{pxy.GetUserInfo().User}
 	}
-	sidCh := pxy.rc.NatHoleController.ListenClient(pxy.GetName(), pxy.cfg.Sk, allowUsers)
+	sidCh, err := pxy.rc.NatHoleController.ListenClient(pxy.GetName(), pxy.cfg.Sk, allowUsers)
+	if err != nil {
+		return "", err
+	}
 	go func() {
 		for {
 			select {