fix: nil HTTP recorder ref in WebSocket goroutines, add tunnel loop detection

- handler/http/websocket, forwarder/sniffer_ws, sniffing/sniffer_ws: nil
  ro2.HTTP in WebSocket copy goroutines to avoid data races on the shared
  HTTP recorder object
- handler/tunnel/bind: remove ingress rule check that incorrectly
  overrode the endpoint host for non-matching ingress rules
- handler/tunnel/entrypoint: add forwarding loop detection by checking
  Gost-Forwarded-Node header for the entrypoint's own node ID

handler/http/websocket.go

@@ -51,6 +51,7 @@ func (h *httpHandler) copyWebsocketDirection(ctx context.Context, r io.Reader, w
 	}
 	ro2 := &xrecorder.HandlerRecorderObject{}
 	*ro2 = *ro
+	ro2.HTTP = nil
 	r2 := ro2
 
 	limiter := rate.NewLimiter(rate.Limit(sampleRate), int(sampleRate))

handler/tunnel/bind.go

@@ -41,9 +41,7 @@ func (h *tunnelHandler) handleBind(ctx context.Context, conn net.Conn, network,
 	if host == "" || h.md.ingress == nil {
 		host = endpoint
 	} else if host != endpoint {
-		if rule := h.md.ingress.GetRule(ctx, host, ingress.WithService(h.options.Service)); rule != nil && rule.Endpoint != tunnelID.String() {
-			host = endpoint
-		}
+		host = endpoint
 	}
 	addr := net.JoinHostPort(host, port)
 

handler/tunnel/entrypoint.go

@@ -278,6 +278,24 @@ func (ep *entrypoint) httpRoundTrip(ctx context.Context, rw io.ReadWriteCloser,
 	} else {
 		req.Header.Set(httpHeaderSID, ro.SID)
 	}
+
+	// Loop detection: if Gost-Forwarded-Node contains our own node ID,
+	// the request has already passed through this entrypoint and is looping.
+	for _, node := range strings.Split(req.Header.Get(httpHeaderForwardedNode), ",") {
+		if strings.TrimSpace(node) == ep.node {
+			log.Warn("forwarding loop detected, rejecting request")
+			res := &http.Response{
+				ProtoMajor: req.ProtoMajor,
+				ProtoMinor: req.ProtoMinor,
+				Header:     http.Header{},
+				StatusCode: http.StatusServiceUnavailable,
+			}
+			ro.HTTP.StatusCode = res.StatusCode
+			res.Write(rw)
+			return nil
+		}
+	}
+
 	req.Header.Set(httpHeaderForwardedNode, ro.Node)
 
 	host := req.Host