#!/usr/bin/env python # # 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. # A copy of standalone.py with uneeded stuff removed # some logging methods removed # Added api attribute to request import BaseHTTPServer import CGIHTTPServer import SocketServer import base64 import httplib import logging import os import re import select import socket import sys import threading from mod_pywebsocket import common from mod_pywebsocket import dispatch from mod_pywebsocket import handshake from mod_pywebsocket import http_header_util from mod_pywebsocket import memorizingfile from mod_pywebsocket import util _DEFAULT_LOG_MAX_BYTES = 1024 * 256 _DEFAULT_LOG_BACKUP_COUNT = 5 _DEFAULT_REQUEST_QUEUE_SIZE = 128 # 1024 is practically large enough to contain WebSocket handshake lines. _MAX_MEMORIZED_LINES = 1024 # Constants for the --tls_module flag. _TLS_BY_STANDARD_MODULE = 'ssl' _TLS_BY_PYOPENSSL = 'pyopenssl' class _StandaloneConnection(object): """Mimic mod_python mp_conn.""" def __init__(self, request_handler): """Construct an instance. Args: request_handler: A WebSocketRequestHandler instance. """ self._request_handler = request_handler def get_local_addr(self): """Getter to mimic mp_conn.local_addr.""" return (self._request_handler.server.server_name, self._request_handler.server.server_port) local_addr = property(get_local_addr) def get_remote_addr(self): """Getter to mimic mp_conn.remote_addr. Setting the property in __init__ won't work because the request handler is not initialized yet there.""" return self._request_handler.client_address remote_addr = property(get_remote_addr) def write(self, data): """Mimic mp_conn.write().""" return self._request_handler.wfile.write(data) def read(self, length): """Mimic mp_conn.read().""" return self._request_handler.rfile.read(length) def get_memorized_lines(self): """Get memorized lines.""" return self._request_handler.rfile.get_memorized_lines() class _StandaloneRequest(object): """Mimic mod_python request.""" def __init__(self, request_handler, use_tls): """Construct an instance. Args: request_handler: A WebSocketRequestHandler instance. """ self._logger = util.get_class_logger(self) self._request_handler = request_handler self.connection = _StandaloneConnection(request_handler) self._use_tls = use_tls self.headers_in = request_handler.headers def get_uri(self): """Getter to mimic request.uri. This method returns the raw data at the Request-URI part of the Request-Line, while the uri method on the request object of mod_python returns the path portion after parsing the raw data. This behavior is kept for compatibility. """ return self._request_handler.path uri = property(get_uri) def get_unparsed_uri(self): """Getter to mimic request.unparsed_uri.""" return self._request_handler.path unparsed_uri = property(get_unparsed_uri) def get_method(self): """Getter to mimic request.method.""" return self._request_handler.command method = property(get_method) def get_protocol(self): """Getter to mimic request.protocol.""" return self._request_handler.request_version protocol = property(get_protocol) def is_https(self): """Mimic request.is_https().""" return self._use_tls def _drain_received_data(self): """Don't use this method from WebSocket handler. Drains unread data in the receive buffer. """ raw_socket = self._request_handler.connection drained_data = util.drain_received_data(raw_socket) if drained_data: self._logger.debug( 'Drained data following close frame: %r', drained_data) def _import_ssl(): global ssl try: import ssl return True except ImportError: return False def _import_pyopenssl(): global OpenSSL try: import OpenSSL.SSL return True except ImportError: return False class _StandaloneSSLConnection(object): """A wrapper class for OpenSSL.SSL.Connection to - provide makefile method which is not supported by the class - tweak shutdown method since OpenSSL.SSL.Connection.shutdown doesn't accept the "how" argument. - convert SysCallError exceptions that its recv method may raise into a return value of '', meaning EOF. We cannot overwrite the recv method on self._connection since it's immutable. """ _OVERRIDDEN_ATTRIBUTES = ['_connection', 'makefile', 'shutdown', 'recv'] def __init__(self, connection): self._connection = connection def __getattribute__(self, name): if name in _StandaloneSSLConnection._OVERRIDDEN_ATTRIBUTES: return object.__getattribute__(self, name) return self._connection.__getattribute__(name) def __setattr__(self, name, value): if name in _StandaloneSSLConnection._OVERRIDDEN_ATTRIBUTES: return object.__setattr__(self, name, value) return self._connection.__setattr__(name, value) def makefile(self, mode='r', bufsize=-1): return socket._fileobject(self, mode, bufsize) def shutdown(self, unused_how): self._connection.shutdown() def recv(self, bufsize, flags=0): if flags != 0: raise ValueError('Non-zero flags not allowed') try: return self._connection.recv(bufsize) except OpenSSL.SSL.SysCallError, (err, message): if err == -1: # Suppress "unexpected EOF" exception. See the OpenSSL document # for SSL_get_error. return '' raise def _alias_handlers(dispatcher, websock_handlers_map_file): """Set aliases specified in websock_handler_map_file in dispatcher. Args: dispatcher: dispatch.Dispatcher instance websock_handler_map_file: alias map file """ fp = open(websock_handlers_map_file) try: for line in fp: if line[0] == '#' or line.isspace(): continue m = re.match('(\S+)\s+(\S+)', line) if not m: logging.warning('Wrong format in map file:' + line) continue try: dispatcher.add_resource_path_alias( m.group(1), m.group(2)) except dispatch.DispatchException, e: logging.error(str(e)) finally: fp.close() class WebSocketServer(SocketServer.ThreadingMixIn, BaseHTTPServer.HTTPServer): """HTTPServer specialized for WebSocket.""" # Overrides SocketServer.ThreadingMixIn.daemon_threads daemon_threads = True # Overrides BaseHTTPServer.HTTPServer.allow_reuse_address allow_reuse_address = True def __init__(self, options): """Override SocketServer.TCPServer.__init__ to set SSL enabled socket object to self.socket before server_bind and server_activate, if necessary. """ # Removed dispatcher init here self._logger = logging.getLogger("log") self.request_queue_size = options.request_queue_size self.__ws_is_shut_down = threading.Event() self.__ws_serving = False SocketServer.BaseServer.__init__( self, (options.server_host, options.port), WebSocketRequestHandler) # Expose the options object to allow handler objects access it. We name # it with websocket_ prefix to avoid conflict. self.websocket_server_options = options self._create_sockets() self.server_bind() self.server_activate() def _create_sockets(self): self.server_name, self.server_port = self.server_address self._sockets = [] if not self.server_name: # On platforms that doesn't support IPv6, the first bind fails. # On platforms that supports IPv6 # - If it binds both IPv4 and IPv6 on call with AF_INET6, the # first bind succeeds and the second fails (we'll see 'Address # already in use' error). # - If it binds only IPv6 on call with AF_INET6, both call are # expected to succeed to listen both protocol. addrinfo_array = [ (socket.AF_INET6, socket.SOCK_STREAM, '', '', ''), (socket.AF_INET, socket.SOCK_STREAM, '', '', '')] else: addrinfo_array = socket.getaddrinfo(self.server_name, self.server_port, socket.AF_UNSPEC, socket.SOCK_STREAM, socket.IPPROTO_TCP) for addrinfo in addrinfo_array: family, socktype, proto, canonname, sockaddr = addrinfo try: socket_ = socket.socket(family, socktype) except Exception, e: self._logger.info('Skip by failure: %r', e) continue server_options = self.websocket_server_options if server_options.use_tls: # For the case of _HAS_OPEN_SSL, we do wrapper setup after # accept. if server_options.tls_module == _TLS_BY_STANDARD_MODULE: if server_options.tls_client_auth: if server_options.tls_client_cert_optional: client_cert_ = ssl.CERT_OPTIONAL else: client_cert_ = ssl.CERT_REQUIRED else: client_cert_ = ssl.CERT_NONE socket_ = ssl.wrap_socket(socket_, keyfile=server_options.private_key, certfile=server_options.certificate, ssl_version=ssl.PROTOCOL_SSLv23, ca_certs=server_options.tls_client_ca, cert_reqs=client_cert_, do_handshake_on_connect=False) self._sockets.append((socket_, addrinfo)) def server_bind(self): """Override SocketServer.TCPServer.server_bind to enable multiple sockets bind. """ failed_sockets = [] for socketinfo in self._sockets: socket_, addrinfo = socketinfo if self.allow_reuse_address: socket_.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1) try: socket_.bind(self.server_address) except Exception, e: self._logger.info('Skip by failure: %r', e) socket_.close() failed_sockets.append(socketinfo) if self.server_address[1] == 0: # The operating system assigns the actual port number for port # number 0. This case, the second and later sockets should use # the same port number. Also self.server_port is rewritten # because it is exported, and will be used by external code. self.server_address = ( self.server_name, socket_.getsockname()[1]) self.server_port = self.server_address[1] self._logger.info('Port %r is assigned', self.server_port) for socketinfo in failed_sockets: self._sockets.remove(socketinfo) def server_activate(self): """Override SocketServer.TCPServer.server_activate to enable multiple sockets listen. """ failed_sockets = [] for socketinfo in self._sockets: socket_, addrinfo = socketinfo self._logger.debug('Listen on: %r', addrinfo) try: socket_.listen(self.request_queue_size) except Exception, e: self._logger.info('Skip by failure: %r', e) socket_.close() failed_sockets.append(socketinfo) for socketinfo in failed_sockets: self._sockets.remove(socketinfo) if len(self._sockets) == 0: self._logger.critical( 'No sockets activated. Use info log level to see the reason.') def server_close(self): """Override SocketServer.TCPServer.server_close to enable multiple sockets close. """ for socketinfo in self._sockets: socket_, addrinfo = socketinfo self._logger.info('Close on: %r', addrinfo) socket_.close() def fileno(self): """Override SocketServer.TCPServer.fileno.""" self._logger.critical('Not supported: fileno') return self._sockets[0][0].fileno() def handle_error(self, request, client_address): """Override SocketServer.handle_error.""" self._logger.error( 'Exception in processing request from: %r\n%s', client_address, util.get_stack_trace()) # Note: client_address is a tuple. def get_request(self): """Override TCPServer.get_request to wrap OpenSSL.SSL.Connection object with _StandaloneSSLConnection to provide makefile method. We cannot substitute OpenSSL.SSL.Connection.makefile since it's readonly attribute. """ accepted_socket, client_address = self.socket.accept() server_options = self.websocket_server_options if server_options.use_tls: if server_options.tls_module == _TLS_BY_STANDARD_MODULE: try: accepted_socket.do_handshake() except ssl.SSLError, e: self._logger.debug('%r', e) raise # Print cipher in use. Handshake is done on accept. self._logger.debug('Cipher: %s', accepted_socket.cipher()) self._logger.debug('Client cert: %r', accepted_socket.getpeercert()) elif server_options.tls_module == _TLS_BY_PYOPENSSL: # We cannot print the cipher in use. pyOpenSSL doesn't provide # any method to fetch that. ctx = OpenSSL.SSL.Context(OpenSSL.SSL.SSLv23_METHOD) ctx.use_privatekey_file(server_options.private_key) ctx.use_certificate_file(server_options.certificate) def default_callback(conn, cert, errnum, errdepth, ok): return ok == 1 # See the OpenSSL document for SSL_CTX_set_verify. if server_options.tls_client_auth: verify_mode = OpenSSL.SSL.VERIFY_PEER if not server_options.tls_client_cert_optional: verify_mode |= OpenSSL.SSL.VERIFY_FAIL_IF_NO_PEER_CERT ctx.set_verify(verify_mode, default_callback) ctx.load_verify_locations(server_options.tls_client_ca, None) else: ctx.set_verify(OpenSSL.SSL.VERIFY_NONE, default_callback) accepted_socket = OpenSSL.SSL.Connection(ctx, accepted_socket) accepted_socket.set_accept_state() # Convert SSL related error into socket.error so that # SocketServer ignores them and keeps running. # # TODO(tyoshino): Convert all kinds of errors. try: accepted_socket.do_handshake() except OpenSSL.SSL.Error, e: # Set errno part to 1 (SSL_ERROR_SSL) like the ssl module # does. self._logger.debug('%r', e) raise socket.error(1, '%r' % e) cert = accepted_socket.get_peer_certificate() self._logger.debug('Client cert subject: %r', cert.get_subject().get_components()) accepted_socket = _StandaloneSSLConnection(accepted_socket) else: raise ValueError('No TLS support module is available') return accepted_socket, client_address def serve_forever(self, poll_interval=0.5): """Override SocketServer.BaseServer.serve_forever.""" self.__ws_serving = True self.__ws_is_shut_down.clear() handle_request = self.handle_request if hasattr(self, '_handle_request_noblock'): handle_request = self._handle_request_noblock else: self._logger.warning('Fallback to blocking request handler') try: while self.__ws_serving: r, w, e = select.select( [socket_[0] for socket_ in self._sockets], [], [], poll_interval) for socket_ in r: self.socket = socket_ handle_request() self.socket = None finally: self.__ws_is_shut_down.set() def shutdown(self): """Override SocketServer.BaseServer.shutdown.""" self.__ws_serving = False self.__ws_is_shut_down.wait() class WebSocketRequestHandler(CGIHTTPServer.CGIHTTPRequestHandler): """CGIHTTPRequestHandler specialized for WebSocket.""" # Use httplib.HTTPMessage instead of mimetools.Message. MessageClass = httplib.HTTPMessage def setup(self): """Override SocketServer.StreamRequestHandler.setup to wrap rfile with MemorizingFile. This method will be called by BaseRequestHandler's constructor before calling BaseHTTPRequestHandler.handle. BaseHTTPRequestHandler.handle will call BaseHTTPRequestHandler.handle_one_request and it will call WebSocketRequestHandler.parse_request. """ # Call superclass's setup to prepare rfile, wfile, etc. See setup # definition on the root class SocketServer.StreamRequestHandler to # understand what this does. CGIHTTPServer.CGIHTTPRequestHandler.setup(self) self.rfile = memorizingfile.MemorizingFile( self.rfile, max_memorized_lines=_MAX_MEMORIZED_LINES) def __init__(self, request, client_address, server): self._logger = util.get_class_logger(self) self._options = server.websocket_server_options # Overrides CGIHTTPServerRequestHandler.cgi_directories. self.cgi_directories = self._options.cgi_directories # Replace CGIHTTPRequestHandler.is_executable method. if self._options.is_executable_method is not None: self.is_executable = self._options.is_executable_method # OWN MODIFICATION # This actually calls BaseRequestHandler.__init__. try: CGIHTTPServer.CGIHTTPRequestHandler.__init__( self, request, client_address, server) except socket.error, e: # Broken pipe, let it pass errno = e.args[0] # errno on py < 2.6 if errno != 32: raise self._logger.debug("WS: Broken pipe") def parse_request(self): """Override BaseHTTPServer.BaseHTTPRequestHandler.parse_request. Return True to continue processing for HTTP(S), False otherwise. See BaseHTTPRequestHandler.handle_one_request method which calls this method to understand how the return value will be handled. """ # We hook parse_request method, but also call the original # CGIHTTPRequestHandler.parse_request since when we return False, # CGIHTTPRequestHandler.handle_one_request continues processing and # it needs variables set by CGIHTTPRequestHandler.parse_request. # # Variables set by this method will be also used by WebSocket request # handling (self.path, self.command, self.requestline, etc. See also # how _StandaloneRequest's members are implemented using these # attributes). ### Modified # Most True values converted into False if not CGIHTTPServer.CGIHTTPRequestHandler.parse_request(self): return False if self._options.use_basic_auth: auth = self.headers.getheader('Authorization') if auth != self._options.basic_auth_credential: self.send_response(401) self.send_header('WWW-Authenticate', 'Basic realm="Pywebsocket"') self.end_headers() self._logger.info('Request basic authentication') return True host, port, resource = http_header_util.parse_uri(self.path) if resource is None: self._logger.info('Invalid URI: %r', self.path) self._logger.info('Fallback to CGIHTTPRequestHandler') return False server_options = self.server.websocket_server_options if host is not None: validation_host = server_options.validation_host if validation_host is not None and host != validation_host: self._logger.info('Invalid host: %r (expected: %r)', host, validation_host) self._logger.info('Fallback to CGIHTTPRequestHandler') return False if port is not None: validation_port = server_options.validation_port if validation_port is not None and port != validation_port: self._logger.info('Invalid port: %r (expected: %r)', port, validation_port) self._logger.info('Fallback to CGIHTTPRequestHandler') return False self.path = resource request = _StandaloneRequest(self, self._options.use_tls) try: # Fallback to default http handler for request paths for which # we don't have request handlers. if not self._options.dispatcher.get_handler_suite(self.path): self._logger.info('No handler for resource: %r', self.path) self._logger.info('Fallback to CGIHTTPRequestHandler') return False except dispatch.DispatchException, e: self._logger.info('Dispatch failed for error: %s', e) self.send_error(e.status) return False # If any Exceptions without except clause setup (including # DispatchException) is raised below this point, it will be caught # and logged by WebSocketServer. try: try: handshake.do_handshake( request, self._options.dispatcher, allowDraft75=self._options.allow_draft75, strict=self._options.strict) except handshake.VersionException, e: self._logger.info('Handshake failed for version error: %s', e) self.send_response(common.HTTP_STATUS_BAD_REQUEST) self.send_header(common.SEC_WEBSOCKET_VERSION_HEADER, e.supported_versions) self.end_headers() return False except handshake.HandshakeException, e: # Handshake for ws(s) failed. self._logger.info('Handshake failed for error: %s', e) self.send_error(e.status) return False request._dispatcher = self._options.dispatcher self._options.dispatcher.transfer_data(request) except handshake.AbortedByUserException, e: self._logger.info('Aborted: %s', e) return False def log_request(self, code='-', size='-'): """Override BaseHTTPServer.log_request.""" self._logger.info('"%s" %s %s', self.requestline, str(code), str(size)) def log_error(self, *args): """Override BaseHTTPServer.log_error.""" # Despite the name, this method is for warnings than for errors. # For example, HTTP status code is logged by this method. self._logger.warning('%s - %s', self.address_string(), args[0] % args[1:]) def is_cgi(self): """Test whether self.path corresponds to a CGI script. Add extra check that self.path doesn't contains .. Also check if the file is a executable file or not. If the file is not executable, it is handled as static file or dir rather than a CGI script. """ if CGIHTTPServer.CGIHTTPRequestHandler.is_cgi(self): if '..' in self.path: return False # strip query parameter from request path resource_name = self.path.split('?', 2)[0] # convert resource_name into real path name in filesystem. scriptfile = self.translate_path(resource_name) if not os.path.isfile(scriptfile): return False if not self.is_executable(scriptfile): return False return True return False def _get_logger_from_class(c): return logging.getLogger('%s.%s' % (c.__module__, c.__name__)) def _configure_logging(options): logging.addLevelName(common.LOGLEVEL_FINE, 'FINE') logger = logging.getLogger() logger.setLevel(logging.getLevelName(options.log_level.upper())) if options.log_file: handler = logging.handlers.RotatingFileHandler( options.log_file, 'a', options.log_max, options.log_count) else: handler = logging.StreamHandler() formatter = logging.Formatter( '[%(asctime)s] [%(levelname)s] %(name)s: %(message)s') handler.setFormatter(formatter) logger.addHandler(handler) deflate_log_level_name = logging.getLevelName( options.deflate_log_level.upper()) _get_logger_from_class(util._Deflater).setLevel( deflate_log_level_name) _get_logger_from_class(util._Inflater).setLevel( deflate_log_level_name) class DefaultOptions: server_host = '' port = common.DEFAULT_WEB_SOCKET_PORT use_tls = False private_key = '' certificate = '' tls_client_ca = None tls_client_auth = False tls_client_cert_optional = False tls_module = _TLS_BY_STANDARD_MODULE dispatcher = None request_queue_size = _DEFAULT_REQUEST_QUEUE_SIZE use_basic_auth = False allow_draft75 = False strict = False validation_host = None validation_port = None cgi_directories = '' is_executable_method = False def import_ssl(): if _import_ssl(): return _TLS_BY_STANDARD_MODULE elif _import_pyopenssl(): return _TLS_BY_PYOPENSSL return False def _main(args=None): """You can call this function from your own program, but please note that this function has some side-effects that might affect your program. For example, util.wrap_popen3_for_win use in this method replaces implementation of os.popen3. """ options, args = _parse_args_and_config(args=args) os.chdir(options.document_root) _configure_logging(options) if options.allow_draft75: logging.warning('--allow_draft75 option is obsolete.') if options.strict: logging.warning('--strict option is obsolete.') # TODO(tyoshino): Clean up initialization of CGI related values. Move some # of code here to WebSocketRequestHandler class if it's better. options.cgi_directories = [] options.is_executable_method = None if options.cgi_paths: options.cgi_directories = options.cgi_paths.split(',') if sys.platform in ('cygwin', 'win32'): cygwin_path = None # For Win32 Python, it is expected that CYGWIN_PATH # is set to a directory of cygwin binaries. # For example, websocket_server.py in Chromium sets CYGWIN_PATH to # full path of third_party/cygwin/bin. if 'CYGWIN_PATH' in os.environ: cygwin_path = os.environ['CYGWIN_PATH'] util.wrap_popen3_for_win(cygwin_path) def __check_script(scriptpath): return util.get_script_interp(scriptpath, cygwin_path) options.is_executable_method = __check_script if options.use_tls: if options.tls_module is None: if _import_ssl(): options.tls_module = _TLS_BY_STANDARD_MODULE logging.debug('Using ssl module') elif _import_pyopenssl(): options.tls_module = _TLS_BY_PYOPENSSL logging.debug('Using pyOpenSSL module') else: logging.critical( 'TLS support requires ssl or pyOpenSSL module.') sys.exit(1) elif options.tls_module == _TLS_BY_STANDARD_MODULE: if not _import_ssl(): logging.critical('ssl module is not available') sys.exit(1) elif options.tls_module == _TLS_BY_PYOPENSSL: if not _import_pyopenssl(): logging.critical('pyOpenSSL module is not available') sys.exit(1) else: logging.critical('Invalid --tls-module option: %r', options.tls_module) sys.exit(1) if not options.private_key or not options.certificate: logging.critical( 'To use TLS, specify private_key and certificate.') sys.exit(1) if (options.tls_client_cert_optional and not options.tls_client_auth): logging.critical('Client authentication must be enabled to ' 'specify tls_client_cert_optional') sys.exit(1) else: if options.tls_module is not None: logging.critical('Use --tls-module option only together with ' '--use-tls option.') sys.exit(1) if options.tls_client_auth: logging.critical('TLS must be enabled for client authentication.') sys.exit(1) if options.tls_client_cert_optional: logging.critical('TLS must be enabled for client authentication.') sys.exit(1) if not options.scan_dir: options.scan_dir = options.websock_handlers if options.use_basic_auth: options.basic_auth_credential = 'Basic ' + base64.b64encode( options.basic_auth_credential) try: if options.thread_monitor_interval_in_sec > 0: # Run a thread monitor to show the status of server threads for # debugging. ThreadMonitor(options.thread_monitor_interval_in_sec).start() server = WebSocketServer(options) server.serve_forever() except Exception, e: logging.critical('mod_pywebsocket: %s' % e) logging.critical('mod_pywebsocket: %s' % util.get_stack_trace()) sys.exit(1) if __name__ == '__main__': _main(sys.argv[1:]) # vi:sts=4 sw=4 et