ws: add support responding CRLF pong to ping

libsofia-sip-ua/tport/tport_type_ws.c

@@ -233,6 +233,16 @@ int tport_recv_stream_ws(tport_t *self)
 	  return 0;
   }
 
+  // DH: Check for "ping" message (CRLF)
+  if (N == 2 || N == 4) {
+    if ((data[0] == '\r' && data[1] == '\n') &&
+        (N == 2 || (data[2] == '\r' && data[3] == '\n'))) {
+      // "ping" message detected, send "pong"
+      tport_ws_pong(self);
+      return 1;
+    }
+  }
+
   veclen = tport_recv_iovec(self, &self->tp_msg, iovec, N, 0);
   if (veclen < 0)
     return -1;
@@ -696,4 +706,4 @@ void tport_ws_timer(tport_t *self, su_time_t now)
     tport_keepalive_timer(self, now);
   }
   tport_base_timer(self, now);
-}
+}