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Diffstat (limited to 'pyload/lib/mod_pywebsocket/handshake/_base.py')
| -rw-r--r-- | pyload/lib/mod_pywebsocket/handshake/_base.py | 226 |
1 files changed, 226 insertions, 0 deletions
diff --git a/pyload/lib/mod_pywebsocket/handshake/_base.py b/pyload/lib/mod_pywebsocket/handshake/_base.py new file mode 100644 index 000000000..e5c94ca90 --- /dev/null +++ b/pyload/lib/mod_pywebsocket/handshake/_base.py @@ -0,0 +1,226 @@ +# Copyright 2012, 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. + + +"""Common functions and exceptions used by WebSocket opening handshake +processors. +""" + + +from mod_pywebsocket import common +from mod_pywebsocket import http_header_util + + +class AbortedByUserException(Exception): + """Exception for aborting a connection intentionally. + + If this exception is raised in do_extra_handshake handler, the connection + will be abandoned. No other WebSocket or HTTP(S) handler will be invoked. + + If this exception is raised in transfer_data_handler, the connection will + be closed without closing handshake. No other WebSocket or HTTP(S) handler + will be invoked. + """ + + pass + + +class HandshakeException(Exception): + """This exception will be raised when an error occurred while processing + WebSocket initial handshake. + """ + + def __init__(self, name, status=None): + super(HandshakeException, self).__init__(name) + self.status = status + + +class VersionException(Exception): + """This exception will be raised when a version of client request does not + match with version the server supports. + """ + + def __init__(self, name, supported_versions=''): + """Construct an instance. + + Args: + supported_version: a str object to show supported hybi versions. + (e.g. '8, 13') + """ + super(VersionException, self).__init__(name) + self.supported_versions = supported_versions + + +def get_default_port(is_secure): + if is_secure: + return common.DEFAULT_WEB_SOCKET_SECURE_PORT + else: + return common.DEFAULT_WEB_SOCKET_PORT + + +def validate_subprotocol(subprotocol, hixie): + """Validate a value in the Sec-WebSocket-Protocol field. + + See + - RFC 6455: Section 4.1., 4.2.2., and 4.3. + - HyBi 00: Section 4.1. Opening handshake + + Args: + hixie: if True, checks if characters in subprotocol are in range + between U+0020 and U+007E. It's required by HyBi 00 but not by + RFC 6455. + """ + + if not subprotocol: + raise HandshakeException('Invalid subprotocol name: empty') + if hixie: + # Parameter should be in the range U+0020 to U+007E. + for c in subprotocol: + if not 0x20 <= ord(c) <= 0x7e: + raise HandshakeException( + 'Illegal character in subprotocol name: %r' % c) + else: + # Parameter should be encoded HTTP token. + state = http_header_util.ParsingState(subprotocol) + token = http_header_util.consume_token(state) + rest = http_header_util.peek(state) + # If |rest| is not None, |subprotocol| is not one token or invalid. If + # |rest| is None, |token| must not be None because |subprotocol| is + # concatenation of |token| and |rest| and is not None. + if rest is not None: + raise HandshakeException('Invalid non-token string in subprotocol ' + 'name: %r' % rest) + + +def parse_host_header(request): + fields = request.headers_in['Host'].split(':', 1) + if len(fields) == 1: + return fields[0], get_default_port(request.is_https()) + try: + return fields[0], int(fields[1]) + except ValueError, e: + raise HandshakeException('Invalid port number format: %r' % e) + + +def format_header(name, value): + return '%s: %s\r\n' % (name, value) + + +def build_location(request): + """Build WebSocket location for request.""" + location_parts = [] + if request.is_https(): + location_parts.append(common.WEB_SOCKET_SECURE_SCHEME) + else: + location_parts.append(common.WEB_SOCKET_SCHEME) + location_parts.append('://') + host, port = parse_host_header(request) + connection_port = request.connection.local_addr[1] + if port != connection_port: + raise HandshakeException('Header/connection port mismatch: %d/%d' % + (port, connection_port)) + location_parts.append(host) + if (port != get_default_port(request.is_https())): + location_parts.append(':') + location_parts.append(str(port)) + location_parts.append(request.uri) + return ''.join(location_parts) + + +def get_mandatory_header(request, key): + value = request.headers_in.get(key) + if value is None: + raise HandshakeException('Header %s is not defined' % key) + return value + + +def validate_mandatory_header(request, key, expected_value, fail_status=None): + value = get_mandatory_header(request, key) + + if value.lower() != expected_value.lower(): + raise HandshakeException( + 'Expected %r for header %s but found %r (case-insensitive)' % + (expected_value, key, value), status=fail_status) + + +def check_request_line(request): + # 5.1 1. The three character UTF-8 string "GET". + # 5.1 2. A UTF-8-encoded U+0020 SPACE character (0x20 byte). + if request.method != 'GET': + raise HandshakeException('Method is not GET: %r' % request.method) + + if request.protocol != 'HTTP/1.1': + raise HandshakeException('Version is not HTTP/1.1: %r' % + request.protocol) + + +def check_header_lines(request, mandatory_headers): + check_request_line(request) + + # The expected field names, and the meaning of their corresponding + # values, are as follows. + # |Upgrade| and |Connection| + for key, expected_value in mandatory_headers: + validate_mandatory_header(request, key, expected_value) + + +def parse_token_list(data): + """Parses a header value which follows 1#token and returns parsed elements + as a list of strings. + + Leading LWSes must be trimmed. + """ + + state = http_header_util.ParsingState(data) + + token_list = [] + + while True: + token = http_header_util.consume_token(state) + if token is not None: + token_list.append(token) + + http_header_util.consume_lwses(state) + + if http_header_util.peek(state) is None: + break + + if not http_header_util.consume_string(state, ','): + raise HandshakeException( + 'Expected a comma but found %r' % http_header_util.peek(state)) + + http_header_util.consume_lwses(state) + + if len(token_list) == 0: + raise HandshakeException('No valid token found') + + return token_list + + +# vi:sts=4 sw=4 et |