tor-browser

The Tor Browser
git clone https://git.dasho.dev/tor-browser.git
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__init__.py (4186B)

      1 # Copyright 2011, Google Inc.
      2 # All rights reserved.
      3 #
      4 # Redistribution and use in source and binary forms, with or without
      5 # modification, are permitted provided that the following conditions are
      6 # met:
      7 #
      8 #     * Redistributions of source code must retain the above copyright
      9 # notice, this list of conditions and the following disclaimer.
     10 #     * Redistributions in binary form must reproduce the above
     11 # copyright notice, this list of conditions and the following disclaimer
     12 # in the documentation and/or other materials provided with the
     13 # distribution.
     14 #     * Neither the name of Google Inc. nor the names of its
     15 # contributors may be used to endorse or promote products derived from
     16 # this software without specific prior written permission.
     17 #
     18 # THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
     19 # "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
     20 # LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
     21 # A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
     22 # OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
     23 # SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
     24 # LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     25 # DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     26 # THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     27 # (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
     28 # OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     29 """WebSocket opening handshake processor. This class try to apply available
     30 opening handshake processors for each protocol version until a connection is
     31 successfully established.
     32 """
     33 
     34 from __future__ import absolute_import
     35 import logging
     36 
     37 from mod_pywebsocket import common
     38 from mod_pywebsocket.handshake import hybi
     39 # Export AbortedByUserException, HandshakeException, and VersionException
     40 # symbol from this module.
     41 from mod_pywebsocket.handshake.base import AbortedByUserException
     42 from mod_pywebsocket.handshake.base import HandshakeException
     43 from mod_pywebsocket.handshake.base import VersionException
     44 
     45 _LOGGER = logging.getLogger(__name__)
     46 
     47 
     48 def do_handshake(request, dispatcher):
     49    """Performs WebSocket handshake.
     50 
     51    Args:
     52        request: mod_python request.
     53        dispatcher: Dispatcher (dispatch.Dispatcher).
     54 
     55    Handshaker will add attributes such as ws_resource in performing
     56    handshake.
     57    """
     58 
     59    _LOGGER.debug('Client\'s opening handshake resource: %r', request.uri)
     60    # To print mimetools.Message as escaped one-line string, we converts
     61    # headers_in to dict object. Without conversion, if we use %r, it just
     62    # prints the type and address, and if we use %s, it prints the original
     63    # header string as multiple lines.
     64    #
     65    # Both mimetools.Message and MpTable_Type of mod_python can be
     66    # converted to dict.
     67    #
     68    # mimetools.Message.__str__ returns the original header string.
     69    # dict(mimetools.Message object) returns the map from header names to
     70    # header values. While MpTable_Type doesn't have such __str__ but just
     71    # __repr__ which formats itself as well as dictionary object.
     72    _LOGGER.debug('Client\'s opening handshake headers: %r',
     73                  dict(request.headers_in))
     74 
     75    handshakers = []
     76    handshakers.append(('RFC 6455', hybi.Handshaker(request, dispatcher)))
     77 
     78    for name, handshaker in handshakers:
     79        _LOGGER.debug('Trying protocol version %s', name)
     80        try:
     81            handshaker.do_handshake()
     82            _LOGGER.info('Established (%s protocol)', name)
     83            return
     84        except HandshakeException as e:
     85            _LOGGER.debug(
     86                'Failed to complete opening handshake as %s protocol: %r',
     87                name, e)
     88            if e.status:
     89                raise e
     90        except AbortedByUserException as e:
     91            raise
     92        except VersionException as e:
     93            raise
     94 
     95    # TODO(toyoshim): Add a test to cover the case all handshakers fail.
     96    raise HandshakeException(
     97        'Failed to complete opening handshake for all available protocols',
     98        status=common.HTTP_STATUS_BAD_REQUEST)
     99 
    100 
    101 # vi:sts=4 sw=4 et