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Update lib: Tornado

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This commit is contained in:
Ruud
2014-08-30 14:01:12 +02:00
parent 73d37584ad
commit e0dffe20a4
21 changed files with 504 additions and 605 deletions
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libs/tornado/websocket.py
+87 -272
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@@ -3,18 +3,17 @@
`WebSockets <http://dev.w3.org/html5/websockets/>`_ allow for bidirectional
communication between the browser and server.
.. warning::
WebSockets are supported in the current versions of all major browsers,
although older versions that do not support WebSockets are still in use
(refer to http://caniuse.com/websockets for details).
The WebSocket protocol was recently finalized as `RFC 6455
<http://tools.ietf.org/html/rfc6455>`_ and is not yet supported in
all browsers. Refer to http://caniuse.com/websockets for details
on compatibility. In addition, during development the protocol
went through several incompatible versions, and some browsers only
support older versions. By default this module only supports the
latest version of the protocol, but optional support for an older
version (known as "draft 76" or "hixie-76") can be enabled by
overriding `WebSocketHandler.allow_draft76` (see that method's
documentation for caveats).
This module implements the final version of the WebSocket protocol as
defined in `RFC 6455 <http://tools.ietf.org/html/rfc6455>`_. Certain
browser versions (notably Safari 5.x) implemented an earlier draft of
the protocol (known as "draft 76") and are not compatible with this module.
.. versionchanged:: 4.0
Removed support for the draft 76 protocol version.
"""
from __future__ import absolute_import, division, print_function, with_statement
@@ -22,11 +21,9 @@ from __future__ import absolute_import, division, print_function, with_statement
import base64
import collections
import functools
import hashlib
import os
import struct
import time
import tornado.escape
import tornado.web
@@ -38,7 +35,7 @@ from tornado.iostream import StreamClosedError
from tornado.log import gen_log, app_log
from tornado import simple_httpclient
from tornado.tcpclient import TCPClient
from tornado.util import bytes_type, unicode_type, _websocket_mask
from tornado.util import bytes_type, _websocket_mask
try:
from urllib.parse import urlparse # py2
@@ -108,6 +105,21 @@ class WebSocketHandler(tornado.web.RequestHandler):
};
This script pops up an alert box that says "You said: Hello, world".
Web browsers allow any site to open a websocket connection to any other,
instead of using the same-origin policy that governs other network
access from javascript. This can be surprising and is a potential
security hole, so since Tornado 4.0 `WebSocketHandler` requires
applications that wish to receive cross-origin websockets to opt in
by overriding the `~WebSocketHandler.check_origin` method (see that
method's docs for details). Failure to do so is the most likely
cause of 403 errors when making a websocket connection.
When using a secure websocket connection (``wss://``) with a self-signed
certificate, the connection from a browser may fail because it wants
to show the "accept this certificate" dialog but has nowhere to show it.
You must first visit a regular HTML page using the same certificate
to accept it before the websocket connection will succeed.
"""
def __init__(self, application, request, **kwargs):
tornado.web.RequestHandler.__init__(self, application, request,
@@ -115,22 +127,17 @@ class WebSocketHandler(tornado.web.RequestHandler):
self.ws_connection = None
self.close_code = None
self.close_reason = None
self.stream = None
@tornado.web.asynchronous
def get(self, *args, **kwargs):
self.open_args = args
self.open_kwargs = kwargs
self.stream = self.request.connection.detach()
self.stream.set_close_callback(self.on_connection_close)
# Upgrade header should be present and should be equal to WebSocket
if self.request.headers.get("Upgrade", "").lower() != 'websocket':
self.stream.write(tornado.escape.utf8(
"HTTP/1.1 400 Bad Request\r\n\r\n"
"Can \"Upgrade\" only to \"WebSocket\"."
))
self.stream.close()
self.set_status(400)
self.finish("Can \"Upgrade\" only to \"WebSocket\".")
return
# Connection header should be upgrade. Some proxy servers/load balancers
@@ -138,11 +145,8 @@ class WebSocketHandler(tornado.web.RequestHandler):
headers = self.request.headers
connection = map(lambda s: s.strip().lower(), headers.get("Connection", "").split(","))
if 'upgrade' not in connection:
self.stream.write(tornado.escape.utf8(
"HTTP/1.1 400 Bad Request\r\n\r\n"
"\"Connection\" must be \"Upgrade\"."
))
self.stream.close()
self.set_status(400)
self.finish("\"Connection\" must be \"Upgrade\".")
return
# Handle WebSocket Origin naming convention differences
@@ -159,19 +163,16 @@ class WebSocketHandler(tornado.web.RequestHandler):
# according to check_origin. When the origin is None, we assume it
# did not come from a browser and that it can be passed on.
if origin is not None and not self.check_origin(origin):
self.stream.write(tornado.escape.utf8(
"HTTP/1.1 403 Cross Origin Websockets Disabled\r\n\r\n"
))
self.stream.close()
self.set_status(403)
self.finish("Cross origin websockets not allowed")
return
self.stream = self.request.connection.detach()
self.stream.set_close_callback(self.on_connection_close)
if self.request.headers.get("Sec-WebSocket-Version") in ("7", "8", "13"):
self.ws_connection = WebSocketProtocol13(self)
self.ws_connection.accept_connection()
elif (self.allow_draft76() and
"Sec-WebSocket-Version" not in self.request.headers):
self.ws_connection = WebSocketProtocol76(self)
self.ws_connection.accept_connection()
else:
self.stream.write(tornado.escape.utf8(
"HTTP/1.1 426 Upgrade Required\r\n"
@@ -245,7 +246,7 @@ class WebSocketHandler(tornado.web.RequestHandler):
phrase was supplied, these values will be available as the attributes
``self.close_code`` and ``self.close_reason``.
.. versionchanged:: 3.3
.. versionchanged:: 4.0
Added ``close_code`` and ``close_reason`` attributes.
"""
@@ -263,10 +264,7 @@ class WebSocketHandler(tornado.web.RequestHandler):
closing. These values are made available to the client, but are
not otherwise interpreted by the websocket protocol.
The ``code`` and ``reason`` arguments are ignored in the "draft76"
protocol version.
.. versionchanged:: 3.3
.. versionchanged:: 4.0
Added the ``code`` and ``reason`` arguments.
"""
@@ -292,7 +290,20 @@ class WebSocketHandler(tornado.web.RequestHandler):
browsers, since WebSockets are allowed to bypass the usual same-origin
policies and don't use CORS headers.
.. versionadded:: 3.3
To accept all cross-origin traffic (which was the default prior to
Tornado 4.0), simply override this method to always return true::
def check_origin(self, origin):
return True
To allow connections from any subdomain of your site, you might
do something like::
def check_origin(self, origin):
parsed_origin = urllib.parse.urlparse(origin)
return parsed_origin.netloc.endswith(".mydomain.com")
.. versionadded:: 4.0
"""
parsed_origin = urlparse(origin)
origin = parsed_origin.netloc
@@ -303,21 +314,6 @@ class WebSocketHandler(tornado.web.RequestHandler):
# Check to see that origin matches host directly, including ports
return origin == host
def allow_draft76(self):
"""Override to enable support for the older "draft76" protocol.
The draft76 version of the websocket protocol is disabled by
default due to security concerns, but it can be enabled by
overriding this method to return True.
Connections using the draft76 protocol do not support the
``binary=True`` flag to `write_message`.
Support for the draft76 protocol is deprecated and will be
removed in a future version of Tornado.
"""
return False
def set_nodelay(self, value):
"""Set the no-delay flag for this stream.
@@ -334,29 +330,6 @@ class WebSocketHandler(tornado.web.RequestHandler):
"""
self.stream.set_nodelay(value)
def get_websocket_scheme(self):
"""Return the url scheme used for this request, either "ws" or "wss".
This is normally decided by HTTPServer, but applications
may wish to override this if they are using an SSL proxy
that does not provide the X-Scheme header as understood
by HTTPServer.
Note that this is only used by the draft76 protocol.
"""
return "wss" if self.request.protocol == "https" else "ws"
def async_callback(self, callback, *args, **kwargs):
"""Obsolete - catches exceptions from the wrapped function.
This function is normally unncecessary thanks to
`tornado.stack_context`.
"""
return self.ws_connection.async_callback(callback, *args, **kwargs)
def _not_supported(self, *args, **kwargs):
raise Exception("Method not supported for Web Sockets")
def on_connection_close(self):
if self.ws_connection:
self.ws_connection.on_connection_close()
@@ -364,9 +337,17 @@ class WebSocketHandler(tornado.web.RequestHandler):
self.on_close()
def _wrap_method(method):
def _disallow_for_websocket(self, *args, **kwargs):
if self.stream is None:
method(self, *args, **kwargs)
else:
raise RuntimeError("Method not supported for Web Sockets")
return _disallow_for_websocket
for method in ["write", "redirect", "set_header", "send_error", "set_cookie",
"set_status", "flush", "finish"]:
setattr(WebSocketHandler, method, WebSocketHandler._not_supported)
setattr(WebSocketHandler, method,
_wrap_method(getattr(WebSocketHandler, method)))
class WebSocketProtocol(object):
@@ -379,23 +360,17 @@ class WebSocketProtocol(object):
self.client_terminated = False
self.server_terminated = False
def async_callback(self, callback, *args, **kwargs):
"""Wrap callbacks with this if they are used on asynchronous requests.
def _run_callback(self, callback, *args, **kwargs):
"""Runs the given callback with exception handling.
Catches exceptions properly and closes this WebSocket if an exception
is uncaught.
On error, aborts the websocket connection and returns False.
"""
if args or kwargs:
callback = functools.partial(callback, *args, **kwargs)
def wrapper(*args, **kwargs):
try:
return callback(*args, **kwargs)
except Exception:
app_log.error("Uncaught exception in %s",
self.request.path, exc_info=True)
self._abort()
return wrapper
try:
callback(*args, **kwargs)
except Exception:
app_log.error("Uncaught exception in %s",
self.request.path, exc_info=True)
self._abort()
def on_connection_close(self):
self._abort()
@@ -408,174 +383,6 @@ class WebSocketProtocol(object):
self.close() # let the subclass cleanup
class WebSocketProtocol76(WebSocketProtocol):
"""Implementation of the WebSockets protocol, version hixie-76.
This class provides basic functionality to process WebSockets requests as
specified in
http://tools.ietf.org/html/draft-hixie-thewebsocketprotocol-76
"""
def __init__(self, handler):
WebSocketProtocol.__init__(self, handler)
self.challenge = None
self._waiting = None
def accept_connection(self):
try:
self._handle_websocket_headers()
except ValueError:
gen_log.debug("Malformed WebSocket request received")
self._abort()
return
scheme = self.handler.get_websocket_scheme()
# draft76 only allows a single subprotocol
subprotocol_header = ''
subprotocol = self.request.headers.get("Sec-WebSocket-Protocol", None)
if subprotocol:
selected = self.handler.select_subprotocol([subprotocol])
if selected:
assert selected == subprotocol
subprotocol_header = "Sec-WebSocket-Protocol: %s\r\n" % selected
# Write the initial headers before attempting to read the challenge.
# This is necessary when using proxies (such as HAProxy), which
# need to see the Upgrade headers before passing through the
# non-HTTP traffic that follows.
self.stream.write(tornado.escape.utf8(
"HTTP/1.1 101 WebSocket Protocol Handshake\r\n"
"Upgrade: WebSocket\r\n"
"Connection: Upgrade\r\n"
"Server: TornadoServer/%(version)s\r\n"
"Sec-WebSocket-Origin: %(origin)s\r\n"
"Sec-WebSocket-Location: %(scheme)s://%(host)s%(uri)s\r\n"
"%(subprotocol)s"
"\r\n" % (dict(
version=tornado.version,
origin=self.request.headers["Origin"],
scheme=scheme,
host=self.request.host,
uri=self.request.uri,
subprotocol=subprotocol_header))))
self.stream.read_bytes(8, self._handle_challenge)
def challenge_response(self, challenge):
"""Generates the challenge response that's needed in the handshake
The challenge parameter should be the raw bytes as sent from the
client.
"""
key_1 = self.request.headers.get("Sec-Websocket-Key1")
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, code=None, reason=None):
"""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.
@@ -645,7 +452,8 @@ class WebSocketProtocol13(WebSocketProtocol):
"%s"
"\r\n" % (self._challenge_response(), subprotocol_header)))
self.async_callback(self.handler.open)(*self.handler.open_args, **self.handler.open_kwargs)
self._run_callback(self.handler.open, *self.handler.open_args,
**self.handler.open_kwargs)
self._receive_frame()
def _write_frame(self, fin, opcode, data):
@@ -803,10 +611,10 @@ class WebSocketProtocol13(WebSocketProtocol):
except UnicodeDecodeError:
self._abort()
return
self.async_callback(self.handler.on_message)(decoded)
self._run_callback(self.handler.on_message, decoded)
elif opcode == 0x2:
# Binary data
self.async_callback(self.handler.on_message)(data)
self._run_callback(self.handler.on_message, data)
elif opcode == 0x8:
# Close
self.client_terminated = True
@@ -820,7 +628,7 @@ class WebSocketProtocol13(WebSocketProtocol):
self._write_frame(True, 0xA, data)
elif opcode == 0xA:
# Pong
self.async_callback(self.handler.on_pong)(data)
self._run_callback(self.handler.on_pong, data)
else:
self._abort()
@@ -885,7 +693,7 @@ class WebSocketClientConnection(simple_httpclient._HTTPConnection):
.. versionadded:: 3.2
.. versionchanged:: 3.3
.. versionchanged:: 4.0
Added the ``code`` and ``reason`` arguments.
"""
@@ -893,10 +701,12 @@ class WebSocketClientConnection(simple_httpclient._HTTPConnection):
self.protocol.close(code, reason)
self.protocol = None
def _on_close(self):
def on_connection_close(self):
if not self.connect_future.done():
self.connect_future.set_exception(StreamClosedError())
self.on_message(None)
self.resolver.close()
super(WebSocketClientConnection, self)._on_close()
self.tcp_client.close()
super(WebSocketClientConnection, self).on_connection_close()
def _on_http_response(self, response):
if not self.connect_future.done():
@@ -925,7 +735,12 @@ class WebSocketClientConnection(simple_httpclient._HTTPConnection):
self._timeout = None
self.stream = self.connection.detach()
self.stream.set_close_callback(self._on_close)
self.stream.set_close_callback(self.on_connection_close)
# Once we've taken over the connection, clear the final callback
# we set on the http request. This deactivates the error handling
# in simple_httpclient that would otherwise interfere with our
# ability to see exceptions.
self.final_callback = None
self.connect_future.set_result(self)