Maximum connections for websockets listener (#271)

Check current number of connections before accepting new websockets clients.

Signed-off-by: tucic <[email protected]>

src/websockets.c

@@ -193,7 +193,10 @@ static int callback_mqtt(struct libwebsocket_context *context,
  }
  }
  }
-
+ if(!mosq->listener){
+ _mosquitto_free(mosq);
+ return -1;
+ }
 #if !defined(LWS_LIBRARY_VERSION_NUMBER)
  mosq->ws_context = context;
 #endif
@@ -209,6 +212,12 @@ static int callback_mqtt(struct libwebsocket_context *context,
  u->mosq = NULL;
  return -1;
  }
+ if(mosq->listener->max_connections > 0 && mosq->listener->client_count > mosq->listener->max_connections){
+ _mosquitto_log_printf(NULL, MOSQ_LOG_NOTICE, "Client connection from %s denied: max_connections exceeded.", mosq->address);
+ _mosquitto_free(mosq);
+ u->mosq = NULL;
+ return -1;
+ }
  break;
 
  case LWS_CALLBACK_CLOSED: