863 lines
31 KiB
Python
863 lines
31 KiB
Python
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"""Implementation of the WebSocket protocol.
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`WebSockets <http://dev.w3.org/html5/websockets/>`_ allow for bidirectional
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communication between the browser and server.
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.. warning::
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The WebSocket protocol was recently finalized as `RFC 6455
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<http://tools.ietf.org/html/rfc6455>`_ and is not yet supported in
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all browsers. Refer to http://caniuse.com/websockets for details
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on compatibility. In addition, during development the protocol
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went through several incompatible versions, and some browsers only
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support older versions. By default this module only supports the
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latest version of the protocol, but optional support for an older
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version (known as "draft 76" or "hixie-76") can be enabled by
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overriding `WebSocketHandler.allow_draft76` (see that method's
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documentation for caveats).
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"""
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from __future__ import absolute_import, division, print_function, with_statement
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# Author: Jacob Kristhammar, 2010
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import array
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import base64
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import collections
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import functools
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import hashlib
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import os
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import struct
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import time
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import tornado.escape
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import tornado.web
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from tornado.concurrent import Future
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from tornado.escape import utf8, native_str
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from tornado import httpclient
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from tornado.ioloop import IOLoop
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from tornado.iostream import StreamClosedError
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from tornado.log import gen_log, app_log
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from tornado.netutil import Resolver
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from tornado import simple_httpclient
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from tornado.util import bytes_type, unicode_type
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try:
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xrange # py2
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except NameError:
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xrange = range # py3
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class WebSocketError(Exception):
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pass
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class WebSocketHandler(tornado.web.RequestHandler):
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"""Subclass this class to create a basic WebSocket handler.
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Override `on_message` to handle incoming messages, and use
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`write_message` to send messages to the client. You can also
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override `open` and `on_close` to handle opened and closed
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connections.
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See http://dev.w3.org/html5/websockets/ for details on the
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JavaScript interface. The protocol is specified at
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http://tools.ietf.org/html/rfc6455.
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Here is an example WebSocket handler that echos back all received messages
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back to the client::
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class EchoWebSocket(websocket.WebSocketHandler):
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def open(self):
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print "WebSocket opened"
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def on_message(self, message):
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self.write_message(u"You said: " + message)
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def on_close(self):
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print "WebSocket closed"
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WebSockets are not standard HTTP connections. The "handshake" is
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HTTP, but after the handshake, the protocol is
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message-based. Consequently, most of the Tornado HTTP facilities
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are not available in handlers of this type. The only communication
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methods available to you are `write_message()`, `ping()`, and
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`close()`. Likewise, your request handler class should implement
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`open()` method rather than ``get()`` or ``post()``.
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If you map the handler above to ``/websocket`` in your application, you can
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invoke it in JavaScript with::
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var ws = new WebSocket("ws://localhost:8888/websocket");
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ws.onopen = function() {
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ws.send("Hello, world");
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};
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ws.onmessage = function (evt) {
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alert(evt.data);
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};
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This script pops up an alert box that says "You said: Hello, world".
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"""
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def __init__(self, application, request, **kwargs):
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tornado.web.RequestHandler.__init__(self, application, request,
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**kwargs)
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self.stream = request.connection.stream
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self.ws_connection = None
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def _execute(self, transforms, *args, **kwargs):
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self.open_args = args
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self.open_kwargs = kwargs
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# Websocket only supports GET method
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if self.request.method != 'GET':
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self.stream.write(tornado.escape.utf8(
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"HTTP/1.1 405 Method Not Allowed\r\n\r\n"
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))
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self.stream.close()
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return
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# Upgrade header should be present and should be equal to WebSocket
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if self.request.headers.get("Upgrade", "").lower() != 'websocket':
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self.stream.write(tornado.escape.utf8(
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"HTTP/1.1 400 Bad Request\r\n\r\n"
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"Can \"Upgrade\" only to \"WebSocket\"."
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))
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self.stream.close()
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return
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# Connection header should be upgrade. Some proxy servers/load balancers
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# might mess with it.
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headers = self.request.headers
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connection = map(lambda s: s.strip().lower(), headers.get("Connection", "").split(","))
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if 'upgrade' not in connection:
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self.stream.write(tornado.escape.utf8(
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"HTTP/1.1 400 Bad Request\r\n\r\n"
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"\"Connection\" must be \"Upgrade\"."
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))
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self.stream.close()
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return
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# The difference between version 8 and 13 is that in 8 the
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# client sends a "Sec-Websocket-Origin" header and in 13 it's
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# simply "Origin".
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if self.request.headers.get("Sec-WebSocket-Version") in ("7", "8", "13"):
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self.ws_connection = WebSocketProtocol13(self)
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self.ws_connection.accept_connection()
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elif (self.allow_draft76() and
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"Sec-WebSocket-Version" not in self.request.headers):
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self.ws_connection = WebSocketProtocol76(self)
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self.ws_connection.accept_connection()
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else:
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self.stream.write(tornado.escape.utf8(
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"HTTP/1.1 426 Upgrade Required\r\n"
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"Sec-WebSocket-Version: 8\r\n\r\n"))
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self.stream.close()
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def write_message(self, message, binary=False):
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"""Sends the given message to the client of this Web Socket.
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The message may be either a string or a dict (which will be
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encoded as json). If the ``binary`` argument is false, the
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message will be sent as utf8; in binary mode any byte string
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is allowed.
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"""
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if isinstance(message, dict):
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message = tornado.escape.json_encode(message)
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self.ws_connection.write_message(message, binary=binary)
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def select_subprotocol(self, subprotocols):
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"""Invoked when a new WebSocket requests specific subprotocols.
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``subprotocols`` is a list of strings identifying the
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subprotocols proposed by the client. This method may be
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overridden to return one of those strings to select it, or
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``None`` to not select a subprotocol. Failure to select a
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subprotocol does not automatically abort the connection,
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although clients may close the connection if none of their
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proposed subprotocols was selected.
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"""
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return None
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def open(self):
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"""Invoked when a new WebSocket is opened.
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The arguments to `open` are extracted from the `tornado.web.URLSpec`
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regular expression, just like the arguments to
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`tornado.web.RequestHandler.get`.
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"""
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pass
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def on_message(self, message):
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"""Handle incoming messages on the WebSocket
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This method must be overridden.
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"""
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raise NotImplementedError
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def ping(self, data):
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"""Send ping frame to the remote end."""
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self.ws_connection.write_ping(data)
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def on_pong(self, data):
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"""Invoked when the response to a ping frame is received."""
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pass
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def on_close(self):
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"""Invoked when the WebSocket is closed."""
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pass
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def close(self):
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"""Closes this Web Socket.
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Once the close handshake is successful the socket will be closed.
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"""
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self.ws_connection.close()
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self.ws_connection = None
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def allow_draft76(self):
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"""Override to enable support for the older "draft76" protocol.
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The draft76 version of the websocket protocol is disabled by
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default due to security concerns, but it can be enabled by
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overriding this method to return True.
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Connections using the draft76 protocol do not support the
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``binary=True`` flag to `write_message`.
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Support for the draft76 protocol is deprecated and will be
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removed in a future version of Tornado.
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"""
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return False
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def set_nodelay(self, value):
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"""Set the no-delay flag for this stream.
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By default, small messages may be delayed and/or combined to minimize
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the number of packets sent. This can sometimes cause 200-500ms delays
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due to the interaction between Nagle's algorithm and TCP delayed
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ACKs. To reduce this delay (at the expense of possibly increasing
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bandwidth usage), call ``self.set_nodelay(True)`` once the websocket
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connection is established.
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See `.BaseIOStream.set_nodelay` for additional details.
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.. versionadded:: 3.1
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"""
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self.stream.set_nodelay(value)
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def get_websocket_scheme(self):
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"""Return the url scheme used for this request, either "ws" or "wss".
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This is normally decided by HTTPServer, but applications
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may wish to override this if they are using an SSL proxy
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that does not provide the X-Scheme header as understood
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by HTTPServer.
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Note that this is only used by the draft76 protocol.
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"""
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return "wss" if self.request.protocol == "https" else "ws"
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def async_callback(self, callback, *args, **kwargs):
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"""Obsolete - catches exceptions from the wrapped function.
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This function is normally unncecessary thanks to
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`tornado.stack_context`.
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"""
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return self.ws_connection.async_callback(callback, *args, **kwargs)
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def _not_supported(self, *args, **kwargs):
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raise Exception("Method not supported for Web Sockets")
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def on_connection_close(self):
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if self.ws_connection:
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self.ws_connection.on_connection_close()
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self.ws_connection = None
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self.on_close()
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for method in ["write", "redirect", "set_header", "send_error", "set_cookie",
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"set_status", "flush", "finish"]:
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setattr(WebSocketHandler, method, WebSocketHandler._not_supported)
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class WebSocketProtocol(object):
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"""Base class for WebSocket protocol versions.
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"""
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def __init__(self, handler):
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self.handler = handler
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self.request = handler.request
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self.stream = handler.stream
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self.client_terminated = False
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self.server_terminated = False
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def async_callback(self, callback, *args, **kwargs):
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"""Wrap callbacks with this if they are used on asynchronous requests.
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Catches exceptions properly and closes this WebSocket if an exception
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is uncaught.
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"""
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if args or kwargs:
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callback = functools.partial(callback, *args, **kwargs)
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def wrapper(*args, **kwargs):
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try:
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return callback(*args, **kwargs)
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except Exception:
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app_log.error("Uncaught exception in %s",
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self.request.path, exc_info=True)
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self._abort()
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return wrapper
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def on_connection_close(self):
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self._abort()
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def _abort(self):
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"""Instantly aborts the WebSocket connection by closing the socket"""
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self.client_terminated = True
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self.server_terminated = True
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self.stream.close() # forcibly tear down the connection
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self.close() # let the subclass cleanup
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class WebSocketProtocol76(WebSocketProtocol):
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"""Implementation of the WebSockets protocol, version hixie-76.
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This class provides basic functionality to process WebSockets requests as
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specified in
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http://tools.ietf.org/html/draft-hixie-thewebsocketprotocol-76
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"""
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def __init__(self, handler):
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WebSocketProtocol.__init__(self, handler)
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self.challenge = None
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self._waiting = None
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def accept_connection(self):
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try:
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self._handle_websocket_headers()
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except ValueError:
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gen_log.debug("Malformed WebSocket request received")
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self._abort()
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return
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scheme = self.handler.get_websocket_scheme()
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# draft76 only allows a single subprotocol
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subprotocol_header = ''
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subprotocol = self.request.headers.get("Sec-WebSocket-Protocol", None)
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if subprotocol:
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selected = self.handler.select_subprotocol([subprotocol])
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if selected:
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assert selected == subprotocol
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subprotocol_header = "Sec-WebSocket-Protocol: %s\r\n" % selected
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# Write the initial headers before attempting to read the challenge.
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# This is necessary when using proxies (such as HAProxy), which
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# need to see the Upgrade headers before passing through the
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# non-HTTP traffic that follows.
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self.stream.write(tornado.escape.utf8(
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"HTTP/1.1 101 WebSocket Protocol Handshake\r\n"
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"Upgrade: WebSocket\r\n"
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"Connection: Upgrade\r\n"
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"Server: TornadoServer/%(version)s\r\n"
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"Sec-WebSocket-Origin: %(origin)s\r\n"
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"Sec-WebSocket-Location: %(scheme)s://%(host)s%(uri)s\r\n"
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"%(subprotocol)s"
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"\r\n" % (dict(
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version=tornado.version,
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origin=self.request.headers["Origin"],
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scheme=scheme,
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host=self.request.host,
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uri=self.request.uri,
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subprotocol=subprotocol_header))))
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self.stream.read_bytes(8, self._handle_challenge)
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def challenge_response(self, challenge):
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"""Generates the challenge response that's needed in the handshake
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The challenge parameter should be the raw bytes as sent from the
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client.
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"""
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key_1 = self.request.headers.get("Sec-Websocket-Key1")
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|
|
key_2 = self.request.headers.get("Sec-Websocket-Key2")
|
||
|
|
try:
|
||
|
|
part_1 = self._calculate_part(key_1)
|
||
|
|
part_2 = self._calculate_part(key_2)
|
||
|
|
except ValueError:
|
||
|
|
raise ValueError("Invalid Keys/Challenge")
|
||
|
|
return self._generate_challenge_response(part_1, part_2, challenge)
|
||
|
|
|
||
|
|
def _handle_challenge(self, challenge):
|
||
|
|
try:
|
||
|
|
challenge_response = self.challenge_response(challenge)
|
||
|
|
except ValueError:
|
||
|
|
gen_log.debug("Malformed key data in WebSocket request")
|
||
|
|
self._abort()
|
||
|
|
return
|
||
|
|
self._write_response(challenge_response)
|
||
|
|
|
||
|
|
def _write_response(self, challenge):
|
||
|
|
self.stream.write(challenge)
|
||
|
|
self.async_callback(self.handler.open)(*self.handler.open_args, **self.handler.open_kwargs)
|
||
|
|
self._receive_message()
|
||
|
|
|
||
|
|
def _handle_websocket_headers(self):
|
||
|
|
"""Verifies all invariant- and required headers
|
||
|
|
|
||
|
|
If a header is missing or have an incorrect value ValueError will be
|
||
|
|
raised
|
||
|
|
"""
|
||
|
|
fields = ("Origin", "Host", "Sec-Websocket-Key1",
|
||
|
|
"Sec-Websocket-Key2")
|
||
|
|
if not all(map(lambda f: self.request.headers.get(f), fields)):
|
||
|
|
raise ValueError("Missing/Invalid WebSocket headers")
|
||
|
|
|
||
|
|
def _calculate_part(self, key):
|
||
|
|
"""Processes the key headers and calculates their key value.
|
||
|
|
|
||
|
|
Raises ValueError when feed invalid key."""
|
||
|
|
# pyflakes complains about variable reuse if both of these lines use 'c'
|
||
|
|
number = int(''.join(c for c in key if c.isdigit()))
|
||
|
|
spaces = len([c2 for c2 in key if c2.isspace()])
|
||
|
|
try:
|
||
|
|
key_number = number // spaces
|
||
|
|
except (ValueError, ZeroDivisionError):
|
||
|
|
raise ValueError
|
||
|
|
return struct.pack(">I", key_number)
|
||
|
|
|
||
|
|
def _generate_challenge_response(self, part_1, part_2, part_3):
|
||
|
|
m = hashlib.md5()
|
||
|
|
m.update(part_1)
|
||
|
|
m.update(part_2)
|
||
|
|
m.update(part_3)
|
||
|
|
return m.digest()
|
||
|
|
|
||
|
|
def _receive_message(self):
|
||
|
|
self.stream.read_bytes(1, self._on_frame_type)
|
||
|
|
|
||
|
|
def _on_frame_type(self, byte):
|
||
|
|
frame_type = ord(byte)
|
||
|
|
if frame_type == 0x00:
|
||
|
|
self.stream.read_until(b"\xff", self._on_end_delimiter)
|
||
|
|
elif frame_type == 0xff:
|
||
|
|
self.stream.read_bytes(1, self._on_length_indicator)
|
||
|
|
else:
|
||
|
|
self._abort()
|
||
|
|
|
||
|
|
def _on_end_delimiter(self, frame):
|
||
|
|
if not self.client_terminated:
|
||
|
|
self.async_callback(self.handler.on_message)(
|
||
|
|
frame[:-1].decode("utf-8", "replace"))
|
||
|
|
if not self.client_terminated:
|
||
|
|
self._receive_message()
|
||
|
|
|
||
|
|
def _on_length_indicator(self, byte):
|
||
|
|
if ord(byte) != 0x00:
|
||
|
|
self._abort()
|
||
|
|
return
|
||
|
|
self.client_terminated = True
|
||
|
|
self.close()
|
||
|
|
|
||
|
|
def write_message(self, message, binary=False):
|
||
|
|
"""Sends the given message to the client of this Web Socket."""
|
||
|
|
if binary:
|
||
|
|
raise ValueError(
|
||
|
|
"Binary messages not supported by this version of websockets")
|
||
|
|
if isinstance(message, unicode_type):
|
||
|
|
message = message.encode("utf-8")
|
||
|
|
assert isinstance(message, bytes_type)
|
||
|
|
self.stream.write(b"\x00" + message + b"\xff")
|
||
|
|
|
||
|
|
def write_ping(self, data):
|
||
|
|
"""Send ping frame."""
|
||
|
|
raise ValueError("Ping messages not supported by this version of websockets")
|
||
|
|
|
||
|
|
def close(self):
|
||
|
|
"""Closes the WebSocket connection."""
|
||
|
|
if not self.server_terminated:
|
||
|
|
if not self.stream.closed():
|
||
|
|
self.stream.write("\xff\x00")
|
||
|
|
self.server_terminated = True
|
||
|
|
if self.client_terminated:
|
||
|
|
if self._waiting is not None:
|
||
|
|
self.stream.io_loop.remove_timeout(self._waiting)
|
||
|
|
self._waiting = None
|
||
|
|
self.stream.close()
|
||
|
|
elif self._waiting is None:
|
||
|
|
self._waiting = self.stream.io_loop.add_timeout(
|
||
|
|
time.time() + 5, self._abort)
|
||
|
|
|
||
|
|
|
||
|
|
class WebSocketProtocol13(WebSocketProtocol):
|
||
|
|
"""Implementation of the WebSocket protocol from RFC 6455.
|
||
|
|
|
||
|
|
This class supports versions 7 and 8 of the protocol in addition to the
|
||
|
|
final version 13.
|
||
|
|
"""
|
||
|
|
def __init__(self, handler, mask_outgoing=False):
|
||
|
|
WebSocketProtocol.__init__(self, handler)
|
||
|
|
self.mask_outgoing = mask_outgoing
|
||
|
|
self._final_frame = False
|
||
|
|
self._frame_opcode = None
|
||
|
|
self._masked_frame = None
|
||
|
|
self._frame_mask = None
|
||
|
|
self._frame_length = None
|
||
|
|
self._fragmented_message_buffer = None
|
||
|
|
self._fragmented_message_opcode = None
|
||
|
|
self._waiting = None
|
||
|
|
|
||
|
|
def accept_connection(self):
|
||
|
|
try:
|
||
|
|
self._handle_websocket_headers()
|
||
|
|
self._accept_connection()
|
||
|
|
except ValueError:
|
||
|
|
gen_log.debug("Malformed WebSocket request received", exc_info=True)
|
||
|
|
self._abort()
|
||
|
|
return
|
||
|
|
|
||
|
|
def _handle_websocket_headers(self):
|
||
|
|
"""Verifies all invariant- and required headers
|
||
|
|
|
||
|
|
If a header is missing or have an incorrect value ValueError will be
|
||
|
|
raised
|
||
|
|
"""
|
||
|
|
fields = ("Host", "Sec-Websocket-Key", "Sec-Websocket-Version")
|
||
|
|
if not all(map(lambda f: self.request.headers.get(f), fields)):
|
||
|
|
raise ValueError("Missing/Invalid WebSocket headers")
|
||
|
|
|
||
|
|
@staticmethod
|
||
|
|
def compute_accept_value(key):
|
||
|
|
"""Computes the value for the Sec-WebSocket-Accept header,
|
||
|
|
given the value for Sec-WebSocket-Key.
|
||
|
|
"""
|
||
|
|
sha1 = hashlib.sha1()
|
||
|
|
sha1.update(utf8(key))
|
||
|
|
sha1.update(b"258EAFA5-E914-47DA-95CA-C5AB0DC85B11") # Magic value
|
||
|
|
return native_str(base64.b64encode(sha1.digest()))
|
||
|
|
|
||
|
|
def _challenge_response(self):
|
||
|
|
return WebSocketProtocol13.compute_accept_value(
|
||
|
|
self.request.headers.get("Sec-Websocket-Key"))
|
||
|
|
|
||
|
|
def _accept_connection(self):
|
||
|
|
subprotocol_header = ''
|
||
|
|
subprotocols = self.request.headers.get("Sec-WebSocket-Protocol", '')
|
||
|
|
subprotocols = [s.strip() for s in subprotocols.split(',')]
|
||
|
|
if subprotocols:
|
||
|
|
selected = self.handler.select_subprotocol(subprotocols)
|
||
|
|
if selected:
|
||
|
|
assert selected in subprotocols
|
||
|
|
subprotocol_header = "Sec-WebSocket-Protocol: %s\r\n" % selected
|
||
|
|
|
||
|
|
self.stream.write(tornado.escape.utf8(
|
||
|
|
"HTTP/1.1 101 Switching Protocols\r\n"
|
||
|
|
"Upgrade: websocket\r\n"
|
||
|
|
"Connection: Upgrade\r\n"
|
||
|
|
"Sec-WebSocket-Accept: %s\r\n"
|
||
|
|
"%s"
|
||
|
|
"\r\n" % (self._challenge_response(), subprotocol_header)))
|
||
|
|
|
||
|
|
self.async_callback(self.handler.open)(*self.handler.open_args, **self.handler.open_kwargs)
|
||
|
|
self._receive_frame()
|
||
|
|
|
||
|
|
def _write_frame(self, fin, opcode, data):
|
||
|
|
if fin:
|
||
|
|
finbit = 0x80
|
||
|
|
else:
|
||
|
|
finbit = 0
|
||
|
|
frame = struct.pack("B", finbit | opcode)
|
||
|
|
l = len(data)
|
||
|
|
if self.mask_outgoing:
|
||
|
|
mask_bit = 0x80
|
||
|
|
else:
|
||
|
|
mask_bit = 0
|
||
|
|
if l < 126:
|
||
|
|
frame += struct.pack("B", l | mask_bit)
|
||
|
|
elif l <= 0xFFFF:
|
||
|
|
frame += struct.pack("!BH", 126 | mask_bit, l)
|
||
|
|
else:
|
||
|
|
frame += struct.pack("!BQ", 127 | mask_bit, l)
|
||
|
|
if self.mask_outgoing:
|
||
|
|
mask = os.urandom(4)
|
||
|
|
data = mask + self._apply_mask(mask, data)
|
||
|
|
frame += data
|
||
|
|
self.stream.write(frame)
|
||
|
|
|
||
|
|
def write_message(self, message, binary=False):
|
||
|
|
"""Sends the given message to the client of this Web Socket."""
|
||
|
|
if binary:
|
||
|
|
opcode = 0x2
|
||
|
|
else:
|
||
|
|
opcode = 0x1
|
||
|
|
message = tornado.escape.utf8(message)
|
||
|
|
assert isinstance(message, bytes_type)
|
||
|
|
try:
|
||
|
|
self._write_frame(True, opcode, message)
|
||
|
|
except StreamClosedError:
|
||
|
|
self._abort()
|
||
|
|
|
||
|
|
def write_ping(self, data):
|
||
|
|
"""Send ping frame."""
|
||
|
|
assert isinstance(data, bytes_type)
|
||
|
|
self._write_frame(True, 0x9, data)
|
||
|
|
|
||
|
|
def _receive_frame(self):
|
||
|
|
try:
|
||
|
|
self.stream.read_bytes(2, self._on_frame_start)
|
||
|
|
except StreamClosedError:
|
||
|
|
self._abort()
|
||
|
|
|
||
|
|
def _on_frame_start(self, data):
|
||
|
|
header, payloadlen = struct.unpack("BB", data)
|
||
|
|
self._final_frame = header & 0x80
|
||
|
|
reserved_bits = header & 0x70
|
||
|
|
self._frame_opcode = header & 0xf
|
||
|
|
self._frame_opcode_is_control = self._frame_opcode & 0x8
|
||
|
|
if reserved_bits:
|
||
|
|
# client is using as-yet-undefined extensions; abort
|
||
|
|
self._abort()
|
||
|
|
return
|
||
|
|
self._masked_frame = bool(payloadlen & 0x80)
|
||
|
|
payloadlen = payloadlen & 0x7f
|
||
|
|
if self._frame_opcode_is_control and payloadlen >= 126:
|
||
|
|
# control frames must have payload < 126
|
||
|
|
self._abort()
|
||
|
|
return
|
||
|
|
try:
|
||
|
|
if payloadlen < 126:
|
||
|
|
self._frame_length = payloadlen
|
||
|
|
if self._masked_frame:
|
||
|
|
self.stream.read_bytes(4, self._on_masking_key)
|
||
|
|
else:
|
||
|
|
self.stream.read_bytes(self._frame_length, self._on_frame_data)
|
||
|
|
elif payloadlen == 126:
|
||
|
|
self.stream.read_bytes(2, self._on_frame_length_16)
|
||
|
|
elif payloadlen == 127:
|
||
|
|
self.stream.read_bytes(8, self._on_frame_length_64)
|
||
|
|
except StreamClosedError:
|
||
|
|
self._abort()
|
||
|
|
|
||
|
|
def _on_frame_length_16(self, data):
|
||
|
|
self._frame_length = struct.unpack("!H", data)[0]
|
||
|
|
try:
|
||
|
|
if self._masked_frame:
|
||
|
|
self.stream.read_bytes(4, self._on_masking_key)
|
||
|
|
else:
|
||
|
|
self.stream.read_bytes(self._frame_length, self._on_frame_data)
|
||
|
|
except StreamClosedError:
|
||
|
|
self._abort()
|
||
|
|
|
||
|
|
def _on_frame_length_64(self, data):
|
||
|
|
self._frame_length = struct.unpack("!Q", data)[0]
|
||
|
|
try:
|
||
|
|
if self._masked_frame:
|
||
|
|
self.stream.read_bytes(4, self._on_masking_key)
|
||
|
|
else:
|
||
|
|
self.stream.read_bytes(self._frame_length, self._on_frame_data)
|
||
|
|
except StreamClosedError:
|
||
|
|
self._abort()
|
||
|
|
|
||
|
|
def _on_masking_key(self, data):
|
||
|
|
self._frame_mask = data
|
||
|
|
try:
|
||
|
|
self.stream.read_bytes(self._frame_length, self._on_masked_frame_data)
|
||
|
|
except StreamClosedError:
|
||
|
|
self._abort()
|
||
|
|
|
||
|
|
def _apply_mask(self, mask, data):
|
||
|
|
mask = array.array("B", mask)
|
||
|
|
unmasked = array.array("B", data)
|
||
|
|
for i in xrange(len(data)):
|
||
|
|
unmasked[i] = unmasked[i] ^ mask[i % 4]
|
||
|
|
if hasattr(unmasked, 'tobytes'):
|
||
|
|
# tostring was deprecated in py32. It hasn't been removed,
|
||
|
|
# but since we turn on deprecation warnings in our tests
|
||
|
|
# we need to use the right one.
|
||
|
|
return unmasked.tobytes()
|
||
|
|
else:
|
||
|
|
return unmasked.tostring()
|
||
|
|
|
||
|
|
def _on_masked_frame_data(self, data):
|
||
|
|
self._on_frame_data(self._apply_mask(self._frame_mask, data))
|
||
|
|
|
||
|
|
def _on_frame_data(self, data):
|
||
|
|
if self._frame_opcode_is_control:
|
||
|
|
# control frames may be interleaved with a series of fragmented
|
||
|
|
# data frames, so control frames must not interact with
|
||
|
|
# self._fragmented_*
|
||
|
|
if not self._final_frame:
|
||
|
|
# control frames must not be fragmented
|
||
|
|
self._abort()
|
||
|
|
return
|
||
|
|
opcode = self._frame_opcode
|
||
|
|
elif self._frame_opcode == 0: # continuation frame
|
||
|
|
if self._fragmented_message_buffer is None:
|
||
|
|
# nothing to continue
|
||
|
|
self._abort()
|
||
|
|
return
|
||
|
|
self._fragmented_message_buffer += data
|
||
|
|
if self._final_frame:
|
||
|
|
opcode = self._fragmented_message_opcode
|
||
|
|
data = self._fragmented_message_buffer
|
||
|
|
self._fragmented_message_buffer = None
|
||
|
|
else: # start of new data message
|
||
|
|
if self._fragmented_message_buffer is not None:
|
||
|
|
# can't start new message until the old one is finished
|
||
|
|
self._abort()
|
||
|
|
return
|
||
|
|
if self._final_frame:
|
||
|
|
opcode = self._frame_opcode
|
||
|
|
else:
|
||
|
|
self._fragmented_message_opcode = self._frame_opcode
|
||
|
|
self._fragmented_message_buffer = data
|
||
|
|
|
||
|
|
if self._final_frame:
|
||
|
|
self._handle_message(opcode, data)
|
||
|
|
|
||
|
|
if not self.client_terminated:
|
||
|
|
self._receive_frame()
|
||
|
|
|
||
|
|
def _handle_message(self, opcode, data):
|
||
|
|
if self.client_terminated:
|
||
|
|
return
|
||
|
|
|
||
|
|
if opcode == 0x1:
|
||
|
|
# UTF-8 data
|
||
|
|
try:
|
||
|
|
decoded = data.decode("utf-8")
|
||
|
|
except UnicodeDecodeError:
|
||
|
|
self._abort()
|
||
|
|
return
|
||
|
|
self.async_callback(self.handler.on_message)(decoded)
|
||
|
|
elif opcode == 0x2:
|
||
|
|
# Binary data
|
||
|
|
self.async_callback(self.handler.on_message)(data)
|
||
|
|
elif opcode == 0x8:
|
||
|
|
# Close
|
||
|
|
self.client_terminated = True
|
||
|
|
self.close()
|
||
|
|
elif opcode == 0x9:
|
||
|
|
# Ping
|
||
|
|
self._write_frame(True, 0xA, data)
|
||
|
|
elif opcode == 0xA:
|
||
|
|
# Pong
|
||
|
|
self.async_callback(self.handler.on_pong)(data)
|
||
|
|
else:
|
||
|
|
self._abort()
|
||
|
|
|
||
|
|
def close(self):
|
||
|
|
"""Closes the WebSocket connection."""
|
||
|
|
if not self.server_terminated:
|
||
|
|
if not self.stream.closed():
|
||
|
|
self._write_frame(True, 0x8, b"")
|
||
|
|
self.server_terminated = True
|
||
|
|
if self.client_terminated:
|
||
|
|
if self._waiting is not None:
|
||
|
|
self.stream.io_loop.remove_timeout(self._waiting)
|
||
|
|
self._waiting = None
|
||
|
|
self.stream.close()
|
||
|
|
elif self._waiting is None:
|
||
|
|
# Give the client a few seconds to complete a clean shutdown,
|
||
|
|
# otherwise just close the connection.
|
||
|
|
self._waiting = self.stream.io_loop.add_timeout(
|
||
|
|
self.stream.io_loop.time() + 5, self._abort)
|
||
|
|
|
||
|
|
|
||
|
|
class WebSocketClientConnection(simple_httpclient._HTTPConnection):
|
||
|
|
"""WebSocket client connection."""
|
||
|
|
def __init__(self, io_loop, request):
|
||
|
|
self.connect_future = Future()
|
||
|
|
self.read_future = None
|
||
|
|
self.read_queue = collections.deque()
|
||
|
|
self.key = base64.b64encode(os.urandom(16))
|
||
|
|
|
||
|
|
scheme, sep, rest = request.url.partition(':')
|
||
|
|
scheme = {'ws': 'http', 'wss': 'https'}[scheme]
|
||
|
|
request.url = scheme + sep + rest
|
||
|
|
request.headers.update({
|
||
|
|
'Upgrade': 'websocket',
|
||
|
|
'Connection': 'Upgrade',
|
||
|
|
'Sec-WebSocket-Key': self.key,
|
||
|
|
'Sec-WebSocket-Version': '13',
|
||
|
|
})
|
||
|
|
|
||
|
|
self.resolver = Resolver(io_loop=io_loop)
|
||
|
|
super(WebSocketClientConnection, self).__init__(
|
||
|
|
io_loop, None, request, lambda: None, self._on_http_response,
|
||
|
|
104857600, self.resolver)
|
||
|
|
|
||
|
|
def _on_close(self):
|
||
|
|
self.on_message(None)
|
||
|
|
self.resolver.close()
|
||
|
|
|
||
|
|
def _on_http_response(self, response):
|
||
|
|
if not self.connect_future.done():
|
||
|
|
if response.error:
|
||
|
|
self.connect_future.set_exception(response.error)
|
||
|
|
else:
|
||
|
|
self.connect_future.set_exception(WebSocketError(
|
||
|
|
"Non-websocket response"))
|
||
|
|
|
||
|
|
def _handle_1xx(self, code):
|
||
|
|
assert code == 101
|
||
|
|
assert self.headers['Upgrade'].lower() == 'websocket'
|
||
|
|
assert self.headers['Connection'].lower() == 'upgrade'
|
||
|
|
accept = WebSocketProtocol13.compute_accept_value(self.key)
|
||
|
|
assert self.headers['Sec-Websocket-Accept'] == accept
|
||
|
|
|
||
|
|
self.protocol = WebSocketProtocol13(self, mask_outgoing=True)
|
||
|
|
self.protocol._receive_frame()
|
||
|
|
|
||
|
|
if self._timeout is not None:
|
||
|
|
self.io_loop.remove_timeout(self._timeout)
|
||
|
|
self._timeout = None
|
||
|
|
|
||
|
|
self.connect_future.set_result(self)
|
||
|
|
|
||
|
|
def write_message(self, message, binary=False):
|
||
|
|
"""Sends a message to the WebSocket server."""
|
||
|
|
self.protocol.write_message(message, binary)
|
||
|
|
|
||
|
|
def read_message(self, callback=None):
|
||
|
|
"""Reads a message from the WebSocket server.
|
||
|
|
|
||
|
|
Returns a future whose result is the message, or None
|
||
|
|
if the connection is closed. If a callback argument
|
||
|
|
is given it will be called with the future when it is
|
||
|
|
ready.
|
||
|
|
"""
|
||
|
|
assert self.read_future is None
|
||
|
|
future = Future()
|
||
|
|
if self.read_queue:
|
||
|
|
future.set_result(self.read_queue.popleft())
|
||
|
|
else:
|
||
|
|
self.read_future = future
|
||
|
|
if callback is not None:
|
||
|
|
self.io_loop.add_future(future, callback)
|
||
|
|
return future
|
||
|
|
|
||
|
|
def on_message(self, message):
|
||
|
|
if self.read_future is not None:
|
||
|
|
self.read_future.set_result(message)
|
||
|
|
self.read_future = None
|
||
|
|
else:
|
||
|
|
self.read_queue.append(message)
|
||
|
|
|
||
|
|
def on_pong(self, data):
|
||
|
|
pass
|
||
|
|
|
||
|
|
|
||
|
|
def websocket_connect(url, io_loop=None, callback=None, connect_timeout=None):
|
||
|
|
"""Client-side websocket support.
|
||
|
|
|
||
|
|
Takes a url and returns a Future whose result is a
|
||
|
|
`WebSocketClientConnection`.
|
||
|
|
"""
|
||
|
|
if io_loop is None:
|
||
|
|
io_loop = IOLoop.current()
|
||
|
|
request = httpclient.HTTPRequest(url, connect_timeout=connect_timeout)
|
||
|
|
request = httpclient._RequestProxy(
|
||
|
|
request, httpclient.HTTPRequest._DEFAULTS)
|
||
|
|
conn = WebSocketClientConnection(io_loop, request)
|
||
|
|
if callback is not None:
|
||
|
|
io_loop.add_future(conn.connect_future, callback)
|
||
|
|
return conn.connect_future
|