""" SleekXMPP: The Sleek XMPP Library Copyright (C) 2010 Nathanael C. Fritz This file is part of SleekXMPP. See the file LICENSE for copying permission. """ from __future__ import with_statement, unicode_literals import copy import logging import socket as Socket import ssl import sys import threading import time import types try: import queue except ImportError: import Queue as queue from sleekxmpp.thirdparty.statemachine import StateMachine from sleekxmpp.xmlstream import Scheduler, tostring from sleekxmpp.xmlstream.stanzabase import StanzaBase, ET from sleekxmpp.xmlstream.handler import Waiter, XMLCallback from sleekxmpp.xmlstream.matcher import MatchXMLMask # In Python 2.x, file socket objects are broken. A patched socket # wrapper is provided for this case in filesocket.py. if sys.version_info < (3, 0): from sleekxmpp.xmlstream.filesocket import FileSocket, Socket26 # The time in seconds to wait before timing out waiting for response stanzas. RESPONSE_TIMEOUT = 10 # The number of threads to use to handle XML stream events. This is not the # same as the number of custom event handling threads. HANDLER_THREADS must # be at least 1. HANDLER_THREADS = 1 # Flag indicating if the SSL library is available for use. SSL_SUPPORT = True log = logging.getLogger(__name__) class RestartStream(Exception): """ Exception to restart stream processing, including resending the stream header. """ class XMLStream(object): """ An XML stream connection manager and event dispatcher. The XMLStream class abstracts away the issues of establishing a connection with a server and sending and receiving XML "stanzas". A stanza is a complete XML element that is a direct child of a root document element. Two streams are used, one for each communication direction, over the same socket. Once the connection is closed, both streams should be complete and valid XML documents. Three types of events are provided to manage the stream: Stream -- Triggered based on received stanzas, similar in concept to events in a SAX XML parser. Custom -- Triggered manually. Scheduled -- Triggered based on time delays. Typically, stanzas are first processed by a stream event handler which will then trigger custom events to continue further processing, especially since custom event handlers may run in individual threads. Attributes: address -- The hostname and port of the server. default_ns -- The default XML namespace that will be applied to all non-namespaced stanzas. event_queue -- A queue of stream, custom, and scheduled events to be processed. filesocket -- A filesocket created from the main connection socket. Required for ElementTree.iterparse. namespace_map -- Optional mapping of namespaces to namespace prefixes. scheduler -- A scheduler object for triggering events after a given period of time. send_queue -- A queue of stanzas to be sent on the stream. socket -- The connection to the server. ssl_support -- Indicates if a SSL library is available for use. ssl_version -- The version of the SSL protocol to use. Defaults to ssl.PROTOCOL_TLSv1. ca_certs -- File path to a CA certificate to verify the server's identity. state -- A state machine for managing the stream's connection state. stream_footer -- The start tag and any attributes for the stream's root element. stream_header -- The closing tag of the stream's root element. use_ssl -- Flag indicating if SSL should be used. use_tls -- Flag indicating if TLS should be used. stop -- threading Event used to stop all threads. auto_reconnect-- Flag to determine whether we auto reconnect. Methods: add_event_handler -- Add a handler for a custom event. add_handler -- Shortcut method for registerHandler. connect -- Connect to the given server. del_event_handler -- Remove a handler for a custom event. disconnect -- Disconnect from the server and terminate processing. event -- Trigger a custom event. get_id -- Return the current stream ID. incoming_filter -- Optionally filter stanzas before processing. new_id -- Generate a new, unique ID value. process -- Read XML stanzas from the stream and apply matching stream handlers. reconnect -- Reestablish a connection to the server. register_handler -- Add a handler for a stream event. register_stanza -- Add a new stanza object type that may appear as a direct child of the stream's root. remove_handler -- Remove a stream handler. remove_stanza -- Remove a stanza object type. schedule -- Schedule an event handler to execute after a given delay. send -- Send a stanza object on the stream. send_raw -- Send a raw string on the stream. send_xml -- Send an XML string on the stream. set_socket -- Set the stream's socket and generate a new filesocket. start_stream_handler -- Perform any stream initialization such as handshakes. start_tls -- Establish a TLS connection and restart the stream. """ def __init__(self, socket=None, host='', port=0): """ Establish a new XML stream. Arguments: socket -- Use an existing socket for the stream. Defaults to None to generate a new socket. host -- The name of the target server. Defaults to the empty string. port -- The port to use for the connection. Defaults to 0. """ # To comply with PEP8, method names now use underscores. # Deprecated method names are re-mapped for backwards compatibility. self.startTLS = self.start_tls self.registerStanza = self.register_stanza self.removeStanza = self.remove_stanza self.registerHandler = self.register_handler self.removeHandler = self.remove_handler self.setSocket = self.set_socket self.sendRaw = self.send_raw self.getId = self.get_id self.getNewId = self.new_id self.sendXML = self.send_xml self.ssl_support = SSL_SUPPORT self.ssl_version = ssl.PROTOCOL_TLSv1 self.ca_certs = None self.response_timeout = RESPONSE_TIMEOUT self.state = StateMachine(('disconnected', 'connected')) self.state._set_state('disconnected') self.address = (host, int(port)) self.filesocket = None self.set_socket(socket) if sys.version_info < (3, 0): self.socket_class = Socket26 else: self.socket_class = Socket.socket self.use_ssl = False self.use_tls = False self.default_ns = '' self.stream_header = "<stream>" self.stream_footer = "</stream>" self.stop = threading.Event() self.stream_end_event = threading.Event() self.stream_end_event.set() self.event_queue = queue.Queue() self.send_queue = queue.Queue() self.scheduler = Scheduler(self.event_queue, self.stop) self.namespace_map = {StanzaBase.xml_ns: 'xml'} self.__thread = {} self.__root_stanza = [] self.__handlers = [] self.__event_handlers = {} self.__event_handlers_lock = threading.Lock() self._id = 0 self._id_lock = threading.Lock() self.auto_reconnect = True self.is_client = False def new_id(self): """ Generate and return a new stream ID in hexadecimal form. Many stanzas, handlers, or matchers may require unique ID values. Using this method ensures that all new ID values are unique in this stream. """ with self._id_lock: self._id += 1 return self.get_id() def get_id(self): """ Return the current unique stream ID in hexadecimal form. """ return "%X" % self._id def connect(self, host='', port=0, use_ssl=False, use_tls=True, reattempt=True): """ Create a new socket and connect to the server. Setting reattempt to True will cause connection attempts to be made every second until a successful connection is established. Arguments: host -- The name of the desired server for the connection. port -- Port to connect to on the server. use_ssl -- Flag indicating if SSL should be used. use_tls -- Flag indicating if TLS should be used. reattempt -- Flag indicating if the socket should reconnect after disconnections. """ if host and port: self.address = (host, int(port)) self.is_client = True # Respect previous SSL and TLS usage directives. if use_ssl is not None: self.use_ssl = use_ssl if use_tls is not None: self.use_tls = use_tls # Repeatedly attempt to connect until a successful connection # is established. connected = self.state.transition('disconnected', 'connected', func=self._connect) while reattempt and not connected: connected = self.state.transition('disconnected', 'connected', func=self._connect) return connected def _connect(self): self.stop.clear() self.socket = self.socket_class(Socket.AF_INET, Socket.SOCK_STREAM) self.socket.settimeout(None) if self.use_ssl and self.ssl_support: log.debug("Socket Wrapped for SSL") if self.ca_certs is None: cert_policy = ssl.CERT_NONE else: cert_policy = ssl.CERT_REQUIRED ssl_socket = ssl.wrap_socket(self.socket, ca_certs=self.ca_certs, certs_reqs=cert_policy) if hasattr(self.socket, 'socket'): # We are using a testing socket, so preserve the top # layer of wrapping. self.socket.socket = ssl_socket else: self.socket = ssl_socket try: log.debug("Connecting to %s:%s" % self.address) self.socket.connect(self.address) self.set_socket(self.socket, ignore=True) #this event is where you should set your application state self.event("connected", direct=True) return True except Socket.error as serr: error_msg = "Could not connect to %s:%s. Socket Error #%s: %s" log.error(error_msg % (self.address[0], self.address[1], serr.errno, serr.strerror)) time.sleep(1) return False def disconnect(self, reconnect=False): """ Terminate processing and close the XML streams. Optionally, the connection may be reconnected and resume processing afterwards. Arguments: reconnect -- Flag indicating if the connection and processing should be restarted. Defaults to False. """ self.state.transition('connected', 'disconnected', wait=0.0, func=self._disconnect, args=(reconnect,)) def _disconnect(self, reconnect=False): # Send the end of stream marker. self.send_raw(self.stream_footer) # Wait for confirmation that the stream was # closed in the other direction. if not reconnect: self.auto_reconnect = False self.stream_end_event.wait(4) if not self.auto_reconnect: self.stop.set() try: self.socket.close() self.filesocket.close() self.socket.shutdown(Socket.SHUT_RDWR) except Socket.error as serr: pass finally: #clear your application state self.event("disconnected", direct=True) return True def reconnect(self): """ Reset the stream's state and reconnect to the server. """ log.debug("reconnecting...") self.state.transition('connected', 'disconnected', wait=2.0, func=self._disconnect, args=(True,)) log.debug("connecting...") return self.state.transition('disconnected', 'connected', wait=2.0, func=self._connect) def set_socket(self, socket, ignore=False): """ Set the socket to use for the stream. The filesocket will be recreated as well. Arguments: socket -- The new socket to use. ignore -- don't set the state """ self.socket = socket if socket is not None: # ElementTree.iterparse requires a file. # 0 buffer files have to be binary. # Use the correct fileobject type based on the Python # version to work around a broken implementation in # Python 2.x. if sys.version_info < (3, 0): self.filesocket = FileSocket(self.socket) else: self.filesocket = self.socket.makefile('rb', 0) if not ignore: self.state._set_state('connected') def start_tls(self): """ Perform handshakes for TLS. If the handshake is successful, the XML stream will need to be restarted. """ if self.ssl_support: log.info("Negotiating TLS") log.info("Using SSL version: %s" % str(self.ssl_version)) if self.ca_certs is None: cert_policy = ssl.CERT_NONE else: cert_policy = ssl.CERT_REQUIRED ssl_socket = ssl.wrap_socket(self.socket, ssl_version=self.ssl_version, do_handshake_on_connect=False, ca_certs=self.ca_certs, cert_reqs=cert_policy) if hasattr(self.socket, 'socket'): # We are using a testing socket, so preserve the top # layer of wrapping. self.socket.socket = ssl_socket else: self.socket = ssl_socket self.socket.do_handshake() self.set_socket(self.socket) return True else: log.warning("Tried to enable TLS, but ssl module not found.") return False def start_stream_handler(self, xml): """ Perform any initialization actions, such as handshakes, once the stream header has been sent. Meant to be overridden. """ pass def register_stanza(self, stanza_class): """ Add a stanza object class as a known root stanza. A root stanza is one that appears as a direct child of the stream's root element. Stanzas that appear as substanzas of a root stanza do not need to be registered here. That is done using register_stanza_plugin() from sleekxmpp.xmlstream.stanzabase. Stanzas that are not registered will not be converted into stanza objects, but may still be processed using handlers and matchers. Arguments: stanza_class -- The top-level stanza object's class. """ self.__root_stanza.append(stanza_class) def remove_stanza(self, stanza_class): """ Remove a stanza from being a known root stanza. A root stanza is one that appears as a direct child of the stream's root element. Stanzas that are not registered will not be converted into stanza objects, but may still be processed using handlers and matchers. """ del self.__root_stanza[stanza_class] def add_handler(self, mask, pointer, name=None, disposable=False, threaded=False, filter=False, instream=False): """ A shortcut method for registering a handler using XML masks. Arguments: mask -- An XML snippet matching the structure of the stanzas that will be passed to this handler. pointer -- The handler function itself. name -- A unique name for the handler. A name will be generated if one is not provided. disposable -- Indicates if the handler should be discarded after one use. threaded -- Deprecated. Remains for backwards compatibility. filter -- Deprecated. Remains for backwards compatibility. instream -- Indicates if the handler should execute during stream processing and not during normal event processing. """ # To prevent circular dependencies, we must load the matcher # and handler classes here. if name is None: name = 'add_handler_%s' % self.getNewId() self.registerHandler(XMLCallback(name, MatchXMLMask(mask), pointer, once=disposable, instream=instream)) def register_handler(self, handler, before=None, after=None): """ Add a stream event handler that will be executed when a matching stanza is received. Arguments: handler -- The handler object to execute. """ if handler.stream is None: self.__handlers.append(handler) handler.stream = self def remove_handler(self, name): """ Remove any stream event handlers with the given name. Arguments: name -- The name of the handler. """ idx = 0 for handler in self.__handlers: if handler.name == name: self.__handlers.pop(idx) return True idx += 1 return False def add_event_handler(self, name, pointer, threaded=False, disposable=False): """ Add a custom event handler that will be executed whenever its event is manually triggered. Arguments: name -- The name of the event that will trigger this handler. pointer -- The function to execute. threaded -- If set to True, the handler will execute in its own thread. Defaults to False. disposable -- If set to True, the handler will be discarded after one use. Defaults to False. """ if not name in self.__event_handlers: self.__event_handlers[name] = [] self.__event_handlers[name].append((pointer, threaded, disposable)) def del_event_handler(self, name, pointer): """ Remove a function as a handler for an event. Arguments: name -- The name of the event. pointer -- The function to remove as a handler. """ if not name in self.__event_handlers: return # Need to keep handlers that do not use # the given function pointer def filter_pointers(handler): return handler[0] != pointer self.__event_handlers[name] = filter(filter_pointers, self.__event_handlers[name]) def event_handled(self, name): """ Indicates if an event has any associated handlers. Returns the number of registered handlers. Arguments: name -- The name of the event to check. """ return len(self.__event_handlers.get(name, [])) def event(self, name, data={}, direct=False): """ Manually trigger a custom event. Arguments: name -- The name of the event to trigger. data -- Data that will be passed to each event handler. Defaults to an empty dictionary. direct -- Runs the event directly if True, skipping the event queue. All event handlers will run in the same thread. """ for handler in self.__event_handlers.get(name, []): if direct: try: handler[0](copy.copy(data)) except Exception as e: error_msg = 'Error processing event handler: %s' log.exception(error_msg % str(handler[0])) if hasattr(data, 'exception'): data.exception(e) else: self.event_queue.put(('event', handler, copy.copy(data))) if handler[2]: # If the handler is disposable, we will go ahead and # remove it now instead of waiting for it to be # processed in the queue. with self.__event_handlers_lock: try: h_index = self.__event_handlers[name].index(handler) self.__event_handlers[name].pop(h_index) except: pass def schedule(self, name, seconds, callback, args=None, kwargs=None, repeat=False): """ Schedule a callback function to execute after a given delay. Arguments: name -- A unique name for the scheduled callback. seconds -- The time in seconds to wait before executing. callback -- A pointer to the function to execute. args -- A tuple of arguments to pass to the function. kwargs -- A dictionary of keyword arguments to pass to the function. repeat -- Flag indicating if the scheduled event should be reset and repeat after executing. """ self.scheduler.add(name, seconds, callback, args, kwargs, repeat, qpointer=self.event_queue) def incoming_filter(self, xml): """ Filter incoming XML objects before they are processed. Possible uses include remapping namespaces, or correcting elements from sources with incorrect behavior. Meant to be overridden. """ return xml def send(self, data, mask=None, timeout=None): """ A wrapper for send_raw for sending stanza objects. May optionally block until an expected response is received. Arguments: data -- The stanza object to send on the stream. mask -- Deprecated. An XML snippet matching the structure of the expected response. Execution will block in this thread until the response is received or a timeout occurs. timeout -- Time in seconds to wait for a response before continuing. Defaults to RESPONSE_TIMEOUT. """ if timeout is None: timeout = self.response_timeout if hasattr(mask, 'xml'): mask = mask.xml data = str(data) if mask is not None: log.warning("Use of send mask waiters is deprecated.") wait_for = Waiter("SendWait_%s" % self.new_id(), MatchXMLMask(mask)) self.register_handler(wait_for) self.send_raw(data) if mask is not None: return wait_for.wait(timeout) def send_raw(self, data): """ Send raw data across the stream. Arguments: data -- Any string value. """ self.send_queue.put(data) return True def send_xml(self, data, mask=None, timeout=None): """ Send an XML object on the stream, and optionally wait for a response. Arguments: data -- The XML object to send on the stream. mask -- Deprecated. An XML snippet matching the structure of the expected response. Execution will block in this thread until the response is received or a timeout occurs. timeout -- Time in seconds to wait for a response before continuing. Defaults to RESPONSE_TIMEOUT. """ if timeout is None: timeout = self.response_timeout return self.send(tostring(data), mask, timeout) def process(self, threaded=True): """ Initialize the XML streams and begin processing events. The number of threads used for processing stream events is determined by HANDLER_THREADS. Arguments: threaded -- If threaded=True then event dispatcher will run in a separate thread, allowing for the stream to be used in the background for another application. Defaults to True. Event handlers and the send queue will be threaded regardless of this parameter's value. """ self._thread_excepthook() self.scheduler.process(threaded=True) def start_thread(name, target): self.__thread[name] = threading.Thread(name=name, target=target) self.__thread[name].daemon = True self.__thread[name].start() for t in range(0, HANDLER_THREADS): log.debug("Starting HANDLER THREAD") start_thread('stream_event_handler_%s' % t, self._event_runner) start_thread('send_thread', self._send_thread) if threaded: # Run the XML stream in the background for another application. start_thread('process', self._process) else: self._process() def _process(self): """ Start processing the XML streams. Processing will continue after any recoverable errors if reconnections are allowed. """ firstrun = True # The body of this loop will only execute once per connection. # Additional passes will be made only if an error occurs and # reconnecting is permitted. while firstrun or (self.auto_reconnect and not self.stop.isSet()): firstrun = False try: if self.is_client: self.send_raw(self.stream_header) # The call to self.__read_xml will block and prevent # the body of the loop from running until a disconnect # occurs. After any reconnection, the stream header will # be resent and processing will resume. while not self.stop.isSet() and self.__read_xml(): # Ensure the stream header is sent for any # new connections. if self.is_client: self.send_raw(self.stream_header) except KeyboardInterrupt: log.debug("Keyboard Escape Detected in _process") self.stop.set() except SystemExit: log.debug("SystemExit in _process") self.stop.set() except Socket.error: log.exception('Socket Error') except: if not self.stop.isSet(): log.exception('Connection error.') if not self.stop.isSet() and self.auto_reconnect: self.reconnect() else: self.disconnect() self.event_queue.put(('quit', None, None)) self.scheduler.run = False def __read_xml(self): """ Parse the incoming XML stream, raising stream events for each received stanza. """ depth = 0 root = None for (event, xml) in ET.iterparse(self.filesocket, (b'end', b'start')): if event == b'start': if depth == 0: # We have received the start of the root element. root = xml # Perform any stream initialization actions, such # as handshakes. self.stream_end_event.clear() self.start_stream_handler(root) depth += 1 if event == b'end': depth -= 1 if depth == 0: # The stream's root element has closed, # terminating the stream. log.debug("End of stream recieved") self.stream_end_event.set() return False elif depth == 1: # We only raise events for stanzas that are direct # children of the root element. try: self.__spawn_event(xml) except RestartStream: return True if root: # Keep the root element empty of children to # save on memory use. root.clear() log.debug("Ending read XML loop") def _build_stanza(self, xml, default_ns=None): """ Create a stanza object from a given XML object. If a specialized stanza type is not found for the XML, then a generic StanzaBase stanza will be returned. Arguments: xml -- The XML object to convert into a stanza object. default_ns -- Optional default namespace to use instead of the stream's current default namespace. """ if default_ns is None: default_ns = self.default_ns stanza_type = StanzaBase for stanza_class in self.__root_stanza: if xml.tag == "{%s}%s" % (default_ns, stanza_class.name): stanza_type = stanza_class break stanza = stanza_type(self, xml) return stanza def __spawn_event(self, xml): """ Analyze incoming XML stanzas and convert them into stanza objects if applicable and queue stream events to be processed by matching handlers. Arguments: xml -- The XML stanza to analyze. """ log.debug("RECV: %s" % tostring(xml, xmlns=self.default_ns, stream=self)) # Apply any preprocessing filters. xml = self.incoming_filter(xml) # Convert the raw XML object into a stanza object. If no registered # stanza type applies, a generic StanzaBase stanza will be used. stanza_type = StanzaBase for stanza_class in self.__root_stanza: if xml.tag == "{%s}%s" % (self.default_ns, stanza_class.name): stanza_type = stanza_class break stanza = stanza_type(self, xml) # Match the stanza against registered handlers. Handlers marked # to run "in stream" will be executed immediately; the rest will # be queued. unhandled = True for handler in self.__handlers: if handler.match(stanza): stanza_copy = stanza_type(self, copy.deepcopy(xml)) handler.prerun(stanza_copy) self.event_queue.put(('stanza', handler, stanza_copy)) try: if handler.check_delete(): self.__handlers.pop(self.__handlers.index(handler)) except: pass # not thread safe unhandled = False # Some stanzas require responses, such as Iq queries. A default # handler will be executed immediately for this case. if unhandled: stanza.unhandled() def _threaded_event_wrapper(self, func, args): """ Capture exceptions for event handlers that run in individual threads. Arguments: func -- The event handler to execute. args -- Arguments to the event handler. """ try: func(*args) except Exception as e: error_msg = 'Error processing event handler: %s' log.exception(error_msg % str(func)) if hasattr(args[0], 'exception'): args[0].exception(e) def _event_runner(self): """ Process the event queue and execute handlers. The number of event runner threads is controlled by HANDLER_THREADS. Stream event handlers will all execute in this thread. Custom event handlers may be spawned in individual threads. """ log.debug("Loading event runner") try: while not self.stop.isSet(): try: event = self.event_queue.get(True, timeout=5) except queue.Empty: event = None if event is None: continue etype, handler = event[0:2] args = event[2:] if etype == 'stanza': try: handler.run(args[0]) except Exception as e: error_msg = 'Error processing stream handler: %s' log.exception(error_msg % handler.name) args[0].exception(e) elif etype == 'schedule': try: log.debug(args) handler(*args[0]) except: log.exception('Error processing scheduled task') elif etype == 'event': func, threaded, disposable = handler try: if threaded: x = threading.Thread( name="Event_%s" % str(func), target=self._threaded_event_wrapper, args=(func, args)) x.start() else: func(*args) except Exception as e: error_msg = 'Error processing event handler: %s' log.exception(error_msg % str(func)) if hasattr(args[0], 'exception'): args[0].exception(e) elif etype == 'quit': log.debug("Quitting event runner thread") return False except KeyboardInterrupt: log.debug("Keyboard Escape Detected in _event_runner") self.disconnect() return except SystemExit: self.disconnect() self.event_queue.put(('quit', None, None)) return def _send_thread(self): """ Extract stanzas from the send queue and send them on the stream. """ try: while not self.stop.isSet(): try: data = self.send_queue.get(True, 1) except queue.Empty: continue log.debug("SEND: %s" % data) try: self.socket.send(data.encode('utf-8')) except: log.warning("Failed to send %s" % data) self.disconnect(self.auto_reconnect) except KeyboardInterrupt: log.debug("Keyboard Escape Detected in _send_thread") self.disconnect() return except SystemExit: self.disconnect() self.event_queue.put(('quit', None, None)) return def _thread_excepthook(self): """ If a threaded event handler raises an exception, there is no way to catch it except with an excepthook. Currently, each thread has its own excepthook, but ideally we could use the main sys.excepthook. Modifies threading.Thread to use sys.excepthook when an exception is not caught. """ init_old = threading.Thread.__init__ def init(self, *args, **kwargs): init_old(self, *args, **kwargs) run_old = self.run def run_with_except_hook(*args, **kw): try: run_old(*args, **kw) except (KeyboardInterrupt, SystemExit): raise except: sys.excepthook(*sys.exc_info()) self.run = run_with_except_hook threading.Thread.__init__ = init