Usefulness in websocket version 0?

vladic4t · June 18, 2020, 1:59pm

Hello! I’m going through the websocket protocol in autobahn and stumbled across some logic that uses the websocket version 0

github.com

crossbario/autobahn-python/blob/master/autobahn/websocket/protocol.py#L587


            self.wasMaxMessagePayloadSizeExceeded = True
            self._max_message_size_exceeded(self.message_data_total_length,
                                            self.maxMessagePayloadSize,
                                            'received WebSocket message size {} exceeds payload limit of {} octets'.format(self.message_data_total_length, self.maxMessagePayloadSize))
        elif 0 < self.maxFramePayloadSize < length:
            self.wasMaxFramePayloadSizeExceeded = True
            self._max_message_size_exceeded(length,
                                            self.maxFramePayloadSize,
                                            'received WebSocket frame size {} exceeds payload limit of {} octets'.format(length, self.maxFramePayloadSize))


def onMessageFrameData(self, payload):
    """
    Implements :func:`autobahn.websocket.interfaces.IWebSocketChannel.onMessageFrameData`
    """
    if not self.failedByMe:
        if self.websocket_version == 0:
            self.message_data_total_length += len(payload)
            if 0 < self.maxMessagePayloadSize < self.message_data_total_length:
                self.wasMaxMessagePayloadSizeExceeded = True
                self._max_message_size_exceeded(self.message_data_total_length,
                                                self.maxMessagePayloadSize,

See the above attached function. Instead of appending the data directly to the framer buffer it has a prior check to determining if the websocket version is 0. If it is then it appends the data directly to the “message_data” buffer instead of the frame_data buffer.

Is this something internal for testing or does a websocket version 0 exist that needs separate logic?