From a52926d01749b7e121fb94f6c5b9522beaf81a2d Mon Sep 17 00:00:00 2001
From: hyung-hwan <hyunghwan.chung@gmail.com>
Date: Tue, 14 Jan 2025 16:47:14 +0900
Subject: [PATCH] fixed a bug of not unlocking a mutex when checking port
 uniqueness in adding a route listener

---
 server-proxy.go |  8 +++++---
 server.go       | 39 +++++++++++++++++++--------------------
 2 files changed, 24 insertions(+), 23 deletions(-)

diff --git a/server-proxy.go b/server-proxy.go
index ec31954..85e4b1c 100644
--- a/server-proxy.go
+++ b/server-proxy.go
@@ -51,12 +51,14 @@ type server_proxy_http_wpx struct {
 
 // this is minimal information for wpx to work
 type ServerRouteProxyInfo struct {
+	// command fields with ServerRoute
 	SvcOption   RouteOption
 	PtcAddr     string
 	PtcName     string
 	SvcAddr     *net.TCPAddr
 	SvcPermNet  netip.Prefix
 
+	// extra fields added after proessing
 	PathPrefix  string
 	ConnId      string
 	RouteId     string
@@ -192,7 +194,7 @@ func prevent_follow_redirect (req *http.Request, via []*http.Request) error {
 	return http.ErrUseLastResponse
 }
 
-func (pxy *server_proxy_http_main) get_route(req *http.Request, in_wpx_mode bool) (*ServerRouteProxyInfo, error) {
+func (pxy *server_proxy_http_main) get_route_proxy_info(req *http.Request, in_wpx_mode bool) (*ServerRouteProxyInfo, error) {
 	var conn_id string
 	var route_id string
 	var r *ServerRoute
@@ -202,7 +204,7 @@ func (pxy *server_proxy_http_main) get_route(req *http.Request, in_wpx_mode bool
 
 	if in_wpx_mode { // for wpx
 		conn_id = req.PathValue("port_id")
-		route_id = pxy.prefix
+		route_id = pxy.prefix // this is PORT_ID_MARKER
 	} else {
 		conn_id = req.PathValue("conn_id")
 		route_id = req.PathValue("route_id")
@@ -348,7 +350,7 @@ func (pxy *server_proxy_http_main) ServeHTTP(w http.ResponseWriter, req *http.Re
 	s = pxy.s
 	in_wpx_mode = (pxy.prefix == PORT_ID_MARKER)
 
-	pi, err = pxy.get_route(req, in_wpx_mode)
+	pi, err = pxy.get_route_proxy_info(req, in_wpx_mode)
 	if err != nil {
 		status_code = write_empty_resp_header(w, http.StatusNotFound)
 		goto oops
diff --git a/server.go b/server.go
index bc762d5..e4b8366 100644
--- a/server.go
+++ b/server.go
@@ -188,9 +188,7 @@ func NewServerRoute(cts *ServerConn, id RouteId, option RouteOption, ptc_addr st
 	}
 
 	l, svcaddr, err = cts.make_route_listener(id, option, svc_requested_addr)
-	if err != nil {
-		return nil, err
-	}
+	if err != nil { return nil, err }
 
 	if svc_permitted_net == "" {
 		if svcaddr.IP.To4() != nil {
@@ -363,34 +361,36 @@ func (cts *ServerConn) make_route_listener(id RouteId, option RouteOption, svc_r
 	}
 
 	if option & RouteOption(ROUTE_OPTION_TCP) != 0 {
-			nw = "tcp"
-			if svcaddr == nil {
-				svcaddr = &net.TCPAddr{Port: 0} // port 0 for automatic assignment.
-			}
+		nw = "tcp"
+		if svcaddr == nil {
+			// port 0 for automatic assignment.
+			svcaddr = &net.TCPAddr{Port: 0}
+		}
 	} else if option & RouteOption(ROUTE_OPTION_TCP4) != 0 {
-			nw = "tcp4"
-			if svcaddr == nil {
-				svcaddr = &net.TCPAddr{IP: net.IPv4zero, Port: 0} // port 0 for automatic assignment.
-			}
+		nw = "tcp4"
+		if svcaddr == nil {
+			svcaddr = &net.TCPAddr{IP: net.IPv4zero, Port: 0}
+		}
 	} else if option & RouteOption(ROUTE_OPTION_TCP6) != 0 {
-			nw = "tcp6"
-			if svcaddr == nil {
-				svcaddr = &net.TCPAddr{IP: net.IPv6zero, Port: 0} // port 0 for automatic assignment.
-			}
+		nw = "tcp6"
+		if svcaddr == nil {
+			svcaddr = &net.TCPAddr{IP: net.IPv6zero, Port: 0}
+		}
 	} else {
-			return nil, nil, fmt.Errorf("invalid route option value %d(%s)", option, option.string())
+		return nil, nil, fmt.Errorf("invalid route option value %d(%s)", option, option.string())
 	}
 
 	l, err = net.ListenTCP(nw, svcaddr) // make the binding address configurable. support multiple binding addresses???
-	if err != nil {
-		return nil, nil, err
-	}
+	if err != nil { return nil, nil, err }
 
 	svcaddr = l.Addr().(*net.TCPAddr)
 
+	// uniqueness by port id can be checked after listener creation,
+	// especially when automatic assignment is requested.
 	cts.svr.svc_port_mtx.Lock()
 	prev_cri, ok = cts.svr.svc_port_map[PortId(svcaddr.Port)]
 	if ok {
+		cts.svr.svc_port_mtx.Unlock()
 		cts.svr.log.Write(cts.sid, LOG_ERROR,
 			"Route(%d,%d) on %s not unique by port number - existing route(%d,%d)",
 			cts.Id, id, prev_cri.conn_id, prev_cri.route_id, svcaddr.String())
@@ -1134,7 +1134,6 @@ func NewServer(ctx context.Context, logger Logger, ctl_addrs []string, rpc_addrs
 			Handler: s.wpx_mux,
 			TLSConfig: s.wpxtlscfg,
 			ErrorLog: hs_log,
-			// TODO: more settings
 		}
 	}
 	// ---------------------------------------------------------