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| -rw-r--r-- | testing/mochitest/pywebsocket3/mod_pywebsocket/util.py | 405 |
1 files changed, 405 insertions, 0 deletions
diff --git a/testing/mochitest/pywebsocket3/mod_pywebsocket/util.py b/testing/mochitest/pywebsocket3/mod_pywebsocket/util.py new file mode 100644 index 0000000000..e164e6b8e4 --- /dev/null +++ b/testing/mochitest/pywebsocket3/mod_pywebsocket/util.py @@ -0,0 +1,405 @@ +# Copyright 2011, Google Inc. +# All rights reserved. +# +# Redistribution and use in source and binary forms, with or without +# modification, are permitted provided that the following conditions are +# met: +# +# * Redistributions of source code must retain the above copyright +# notice, this list of conditions and the following disclaimer. +# * Redistributions in binary form must reproduce the above +# copyright notice, this list of conditions and the following disclaimer +# in the documentation and/or other materials provided with the +# distribution. +# * Neither the name of Google Inc. nor the names of its +# contributors may be used to endorse or promote products derived from +# this software without specific prior written permission. +# +# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS +# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT +# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR +# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT +# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, +# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT +# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, +# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY +# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT +# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE +# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. +"""WebSocket utilities.""" + +from __future__ import absolute_import +import array +import errno +import logging +import os +import re +import six +from six.moves import map +from six.moves import range +import socket +import struct +import zlib + +try: + from mod_pywebsocket import fast_masking +except ImportError: + pass + + +def prepend_message_to_exception(message, exc): + """Prepend message to the exception.""" + exc.args = (message + str(exc), ) + return + + +def __translate_interp(interp, cygwin_path): + """Translate interp program path for Win32 python to run cygwin program + (e.g. perl). Note that it doesn't support path that contains space, + which is typically true for Unix, where #!-script is written. + For Win32 python, cygwin_path is a directory of cygwin binaries. + + Args: + interp: interp command line + cygwin_path: directory name of cygwin binary, or None + Returns: + translated interp command line. + """ + if not cygwin_path: + return interp + m = re.match('^[^ ]*/([^ ]+)( .*)?', interp) + if m: + cmd = os.path.join(cygwin_path, m.group(1)) + return cmd + m.group(2) + return interp + + +def get_script_interp(script_path, cygwin_path=None): + r"""Get #!-interpreter command line from the script. + + It also fixes command path. When Cygwin Python is used, e.g. in WebKit, + it could run "/usr/bin/perl -wT hello.pl". + When Win32 Python is used, e.g. in Chromium, it couldn't. So, fix + "/usr/bin/perl" to "<cygwin_path>\perl.exe". + + Args: + script_path: pathname of the script + cygwin_path: directory name of cygwin binary, or None + Returns: + #!-interpreter command line, or None if it is not #!-script. + """ + fp = open(script_path) + line = fp.readline() + fp.close() + m = re.match('^#!(.*)', line) + if m: + return __translate_interp(m.group(1), cygwin_path) + return None + + +def wrap_popen3_for_win(cygwin_path): + """Wrap popen3 to support #!-script on Windows. + + Args: + cygwin_path: path for cygwin binary if command path is needed to be + translated. None if no translation required. + """ + __orig_popen3 = os.popen3 + + def __wrap_popen3(cmd, mode='t', bufsize=-1): + cmdline = cmd.split(' ') + interp = get_script_interp(cmdline[0], cygwin_path) + if interp: + cmd = interp + ' ' + cmd + return __orig_popen3(cmd, mode, bufsize) + + os.popen3 = __wrap_popen3 + + +def hexify(s): + return ' '.join(['%02x' % x for x in six.iterbytes(s)]) + + +def get_class_logger(o): + """Return the logging class information.""" + return logging.getLogger('%s.%s' % + (o.__class__.__module__, o.__class__.__name__)) + + +def pack_byte(b): + """Pack an integer to network-ordered byte""" + return struct.pack('!B', b) + + +class NoopMasker(object): + """A NoOp masking object. + + This has the same interface as RepeatedXorMasker but just returns + the string passed in without making any change. + """ + def __init__(self): + """NoOp.""" + pass + + def mask(self, s): + """NoOp.""" + return s + + +class RepeatedXorMasker(object): + """A masking object that applies XOR on the string. + + Applies XOR on the byte string given to mask method with the masking bytes + given to the constructor repeatedly. This object remembers the position + in the masking bytes the last mask method call ended and resumes from + that point on the next mask method call. + """ + def __init__(self, masking_key): + self._masking_key = masking_key + self._masking_key_index = 0 + + def _mask_using_swig(self, s): + """Perform the mask via SWIG.""" + masked_data = fast_masking.mask(s, self._masking_key, + self._masking_key_index) + self._masking_key_index = ((self._masking_key_index + len(s)) % + len(self._masking_key)) + return masked_data + + def _mask_using_array(self, s): + """Perform the mask via python.""" + if isinstance(s, six.text_type): + raise Exception( + 'Masking Operation should not process unicode strings') + + result = bytearray(s) + + # Use temporary local variables to eliminate the cost to access + # attributes + masking_key = [c for c in six.iterbytes(self._masking_key)] + masking_key_size = len(masking_key) + masking_key_index = self._masking_key_index + + for i in range(len(result)): + result[i] ^= masking_key[masking_key_index] + masking_key_index = (masking_key_index + 1) % masking_key_size + + self._masking_key_index = masking_key_index + + return bytes(result) + + if 'fast_masking' in globals(): + mask = _mask_using_swig + else: + mask = _mask_using_array + + +# By making wbits option negative, we can suppress CMF/FLG (2 octet) and +# ADLER32 (4 octet) fields of zlib so that we can use zlib module just as +# deflate library. DICTID won't be added as far as we don't set dictionary. +# LZ77 window of 32K will be used for both compression and decompression. +# For decompression, we can just use 32K to cover any windows size. For +# compression, we use 32K so receivers must use 32K. +# +# Compression level is Z_DEFAULT_COMPRESSION. We don't have to match level +# to decode. +# +# See zconf.h, deflate.cc, inflate.cc of zlib library, and zlibmodule.c of +# Python. See also RFC1950 (ZLIB 3.3). + + +class _Deflater(object): + def __init__(self, window_bits): + self._logger = get_class_logger(self) + + # Using the smallest window bits of 9 for generating input frames. + # On WebSocket spec, the smallest window bit is 8. However, zlib does + # not accept window_bit = 8. + # + # Because of a zlib deflate quirk, back-references will not use the + # entire range of 1 << window_bits, but will instead use a restricted + # range of (1 << window_bits) - 262. With an increased window_bits = 9, + # back-references will be within a range of 250. These can still be + # decompressed with window_bits = 8 and the 256-byte window used there. + # + # Similar disscussions can be found in https://crbug.com/691074 + window_bits = max(window_bits, 9) + + self._compress = zlib.compressobj(zlib.Z_DEFAULT_COMPRESSION, + zlib.DEFLATED, -window_bits) + + def compress(self, bytes): + compressed_bytes = self._compress.compress(bytes) + self._logger.debug('Compress input %r', bytes) + self._logger.debug('Compress result %r', compressed_bytes) + return compressed_bytes + + def compress_and_flush(self, bytes): + compressed_bytes = self._compress.compress(bytes) + compressed_bytes += self._compress.flush(zlib.Z_SYNC_FLUSH) + self._logger.debug('Compress input %r', bytes) + self._logger.debug('Compress result %r', compressed_bytes) + return compressed_bytes + + def compress_and_finish(self, bytes): + compressed_bytes = self._compress.compress(bytes) + compressed_bytes += self._compress.flush(zlib.Z_FINISH) + self._logger.debug('Compress input %r', bytes) + self._logger.debug('Compress result %r', compressed_bytes) + return compressed_bytes + + +class _Inflater(object): + def __init__(self, window_bits): + self._logger = get_class_logger(self) + self._window_bits = window_bits + + self._unconsumed = b'' + + self.reset() + + def decompress(self, size): + if not (size == -1 or size > 0): + raise Exception('size must be -1 or positive') + + data = b'' + + while True: + data += self._decompress.decompress(self._unconsumed, + max(0, size - len(data))) + self._unconsumed = self._decompress.unconsumed_tail + if self._decompress.unused_data: + # Encountered a last block (i.e. a block with BFINAL = 1) and + # found a new stream (unused_data). We cannot use the same + # zlib.Decompress object for the new stream. Create a new + # Decompress object to decompress the new one. + # + # It's fine to ignore unconsumed_tail if unused_data is not + # empty. + self._unconsumed = self._decompress.unused_data + self.reset() + if size >= 0 and len(data) == size: + # data is filled. Don't call decompress again. + break + else: + # Re-invoke Decompress.decompress to try to decompress all + # available bytes before invoking read which blocks until + # any new byte is available. + continue + else: + # Here, since unused_data is empty, even if unconsumed_tail is + # not empty, bytes of requested length are already in data. We + # don't have to "continue" here. + break + + if data: + self._logger.debug('Decompressed %r', data) + return data + + def append(self, data): + self._logger.debug('Appended %r', data) + self._unconsumed += data + + def reset(self): + self._logger.debug('Reset') + self._decompress = zlib.decompressobj(-self._window_bits) + + +# Compresses/decompresses given octets using the method introduced in RFC1979. + + +class _RFC1979Deflater(object): + """A compressor class that applies DEFLATE to given byte sequence and + flushes using the algorithm described in the RFC1979 section 2.1. + """ + def __init__(self, window_bits, no_context_takeover): + self._deflater = None + if window_bits is None: + window_bits = zlib.MAX_WBITS + self._window_bits = window_bits + self._no_context_takeover = no_context_takeover + + def filter(self, bytes, end=True, bfinal=False): + if self._deflater is None: + self._deflater = _Deflater(self._window_bits) + + if bfinal: + result = self._deflater.compress_and_finish(bytes) + # Add a padding block with BFINAL = 0 and BTYPE = 0. + result = result + pack_byte(0) + self._deflater = None + return result + + result = self._deflater.compress_and_flush(bytes) + if end: + # Strip last 4 octets which is LEN and NLEN field of a + # non-compressed block added for Z_SYNC_FLUSH. + result = result[:-4] + + if self._no_context_takeover and end: + self._deflater = None + + return result + + +class _RFC1979Inflater(object): + """A decompressor class a la RFC1979. + + A decompressor class for byte sequence compressed and flushed following + the algorithm described in the RFC1979 section 2.1. + """ + def __init__(self, window_bits=zlib.MAX_WBITS): + self._inflater = _Inflater(window_bits) + + def filter(self, bytes): + # Restore stripped LEN and NLEN field of a non-compressed block added + # for Z_SYNC_FLUSH. + self._inflater.append(bytes + b'\x00\x00\xff\xff') + return self._inflater.decompress(-1) + + +class DeflateSocket(object): + """A wrapper class for socket object to intercept send and recv to perform + deflate compression and decompression transparently. + """ + + # Size of the buffer passed to recv to receive compressed data. + _RECV_SIZE = 4096 + + def __init__(self, socket): + self._socket = socket + + self._logger = get_class_logger(self) + + self._deflater = _Deflater(zlib.MAX_WBITS) + self._inflater = _Inflater(zlib.MAX_WBITS) + + def recv(self, size): + """Receives data from the socket specified on the construction up + to the specified size. Once any data is available, returns it even + if it's smaller than the specified size. + """ + + # TODO(tyoshino): Allow call with size=0. It should block until any + # decompressed data is available. + if size <= 0: + raise Exception('Non-positive size passed') + while True: + data = self._inflater.decompress(size) + if len(data) != 0: + return data + + read_data = self._socket.recv(DeflateSocket._RECV_SIZE) + if not read_data: + return b'' + self._inflater.append(read_data) + + def sendall(self, bytes): + self.send(bytes) + + def send(self, bytes): + self._socket.sendall(self._deflater.compress_and_flush(bytes)) + return len(bytes) + + +# vi:sts=4 sw=4 et |