Max connections error (#123)

* Output a better error code for max connections Signed-off-by: Nate Koenig <nate@openrobotics.org> * Documentation Signed-off-by: Nate Koenig <nate@openrobotics.org> Co-authored-by: Nate Koenig <nate@openrobotics.org>
gazebosim · Jul 16, 2021 · 605614a · 605614a
1 parent be46811
commit 605614a
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Showing 2 changed files with 25 additions and 14 deletions.
diff --git a/plugins/websocket_server/WebsocketServer.cc b/plugins/websocket_server/WebsocketServer.cc
@@ -230,19 +230,6 @@ int rootCallback(struct lws *_wsi,
   // std::lock_guard<std::mutex> mainLock(self->mutex);
   switch (_reason)
   {
-    // Filter network connections.
-    case LWS_CALLBACK_FILTER_NETWORK_CONNECTION:
-      // Prevent too many connections.
-      if (self->maxConnections >= 0 &&
-          self->connections.size()+1 > self->maxConnections)
-      {
-        ignerr << "Skipping new connection, limit of "
-          << self->maxConnections << " has been reached\n";
-        // Return non-zero to close the connection.
-        return -1;
-      }
-      break;
-
     // Open connections.
     case LWS_CALLBACK_ESTABLISHED:
       igndbg << "LWS_CALLBACK_ESTABLISHED\n";
@@ -300,6 +287,23 @@ int rootCallback(struct lws *_wsi,
     // Handle incoming messages
     case LWS_CALLBACK_RECEIVE:
       igndbg << "LWS_CALLBACK_RECEIVE\n";
+
+      // Prevent too many connections.
+      if (self->maxConnections >= 0 &&
+          self->connections.size()+1 > self->maxConnections)
+      {
+        ignerr << "Skipping new connection, limit of "
+          << self->maxConnections << " has been reached\n";
+
+        // This will return an error code of 1008 with a reason of
+        // "max_connections".
+        std::string reason = "max_connections";
+        lws_close_reason(_wsi, LWS_CLOSE_STATUS_POLICY_VIOLATION,
+          reinterpret_cast<unsigned char *>(reason.data()), reason.size());
+
+        // Return non-zero to close the connection.
+        return -1;
+      }
       self->OnMessage(fd, std::string((const char *)_in));
       break;
 

diff --git a/plugins/websocket_server/WebsocketServer.hh b/plugins/websocket_server/WebsocketServer.hh
@@ -4,7 +4,7 @@
  * 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
@@ -52,6 +52,13 @@ namespace ignition
     /// "auth" call on the websocket. If the <authorization_key> is set, then
     /// the connection can provide that key.
     ///
+    /// * <max_connections> : An integer that specifies the maximum number
+    /// of active websocket connections. A value less than zero indicates an
+    /// unlimited number, this is the default. A websocket client error
+    /// code of 1008 along with a reason set to "max_connections" will be
+    /// returned if a new connection is rejected due to the max connection
+    /// threshold.
+    ///
     /// * <ssl> : Element that contains SSL configuration. For testing
     ///           purposes you can create self-signed SSL certificates. Run
     ///