Introduced new XEP-0009 into develop.

1 files changed, 752 insertions, 0 deletions

diff --git a/sleekxmpp/plugins/xep_0009/remote.py b/sleekxmpp/plugins/xep_0009/remote.py
new file mode 100644
index 00000000..bd931c0c
--- /dev/null
+++ b/sleekxmpp/plugins/xep_0009/remote.py
@@ -0,0 +1,752 @@
+"""
+    SleekXMPP: The Sleek XMPP Library
+    Copyright (C) 2011 Nathanael C. Fritz, Dann Martens (TOMOTON).
+    This file is part of SleekXMPP.
+
+    See the file LICENSE for copying permission.
+"""
+
+from binding import py2xml, xml2py, xml2fault, fault2xml
+from threading import RLock
+import abc
+import inspect
+import logging
+import sleekxmpp
+import sys
+import threading
+import traceback
+
+
+
+log = logging.getLogger(__name__)
+
+
+
+def _intercept(method, name, public):
+    def _resolver(instance, *args, **kwargs):
+        log.debug("Locally calling %s.%s with arguments %s." % (instance.FQN(), method.__name__, args))
+        try: 
+            value = method(instance, *args, **kwargs)
+            if value == NotImplemented:
+                raise InvocationException("Local handler does not implement %s.%s!" % (instance.FQN(), method.__name__))            
+            return value
+        except InvocationException:
+            raise
+        except Exception as e:
+            raise InvocationException("A problem occured calling %s.%s!" % (instance.FQN(), method.__name__), e)
+    _resolver._rpc = public
+    _resolver._rpc_name = method.__name__ if name is None else name
+    return _resolver
+
+def remote(function_argument, public = True):
+    '''
+    Decorator for methods which are remotely callable. This decorator
+    works in conjunction with classes which extend ABC Endpoint.
+    Example:
+    
+        @remote
+        def remote_method(arg1, arg2)
+    
+    Arguments:
+        function_argument -- a stand-in for either the actual method
+            OR a new name (string) for the method. In that case the
+            method is considered mapped:
+            Example:
+            
+            @remote("new_name")
+            def remote_method(arg1, arg2)
+            
+        public -- A flag which indicates if this method should be part
+            of the known dictionary of remote methods. Defaults to True.
+            Example:
+            
+            @remote(False)
+            def remote_method(arg1, arg2)
+            
+    Note: renaming and revising (public vs. private) can be combined.
+    Example:
+    
+            @remote("new_name", False)
+            def remote_method(arg1, arg2)
+    '''
+    if hasattr(function_argument, '__call__'):
+        return _intercept(function_argument, None, public)
+    else:        
+        if not isinstance(function_argument, basestring):
+            if not isinstance(function_argument, bool):                
+                raise Exception('Expected an RPC method name or visibility modifier!')
+            else:
+                def _wrap_revised(function):
+                    function = _intercept(function, None, function_argument)
+                    return function
+                return _wrap_revised                
+        def _wrap_remapped(function):
+            function = _intercept(function, function_argument, public)
+            return function
+        return _wrap_remapped
+    
+    
+    
+class ACL:
+    '''
+    An Access Control List (ACL) is a list of rules, which are evaluated
+    in order until a match is found. The policy of the matching rule
+    is then applied.
+
+    Rules are 3-tuples, consisting of a policy enumerated type, a JID
+    expression and a RCP resource expression.
+
+    Examples:
+    [ (ACL.ALLOW, '*', '*') ] allow everyone everything, no restrictions
+    [ (ACL.DENY, '*', '*') ] deny everyone everything, no restrictions
+    [ (ACL.ALLOW, 'test@xmpp.org/unit', 'test.*'),
+      (ACL.DENY, '*', '*') ] deny everyone everything, except named
+        JID, which is allowed access to endpoint 'test' only.
+    
+    The use of wildcards is allowed in expressions, as follows:
+    '*' everyone, or everything (= all endpoints and methods)
+    'test@xmpp.org/*' every JID regardless of JID resource
+    '*@xmpp.org/rpc' every JID from domain xmpp.org with JID res 'rpc'
+    'frank@*' every 'frank', regardless of domain or JID res
+    'system.*' all methods of endpoint 'system'
+    '*.reboot' all methods reboot regardless of endpoint
+    '''
+    ALLOW = True
+    DENY = False
+    
+    @classmethod
+    def check(cls, rules, jid, resource):
+        if rules is None:
+            return cls.DENY                  # No rules means no access!
+        for rule in rules:
+            policy = cls._check(rule, jid, resource)
+            if policy is not None:
+                return policy        
+        return cls.DENY   # By default if not rule matches, deny access.
+    
+    @classmethod
+    def _check(cls, rule, jid, resource):
+        if cls._match(jid, rule[1]) and cls._match(resource, rule[2]):
+            return rule[0]
+        else:
+            return None
+
+    @classmethod
+    def _next_token(cls, expression, index):
+        new_index = expression.find('*', index)
+        if new_index == 0:
+            return ''
+        else:
+            if new_index == -1:
+                return expression[index : ]                
+            else:
+                return expression[index : new_index]
+
+    @classmethod
+    def _match(cls, value, expression):  
+        #! print "_match [VALUE] %s [EXPR] %s" % (value, expression)      
+        index = 0
+        position = 0
+        while index < len(expression):
+            token = cls._next_token(expression, index)
+            #! print "[TOKEN] '%s'" % token
+            size = len(token)
+            if size > 0:
+                token_index = value.find(token, position)
+                if token_index == -1:
+                    return False
+                else:
+                    #! print "[INDEX-OF] %s" % token_index
+                    position = token_index + len(token)
+                pass
+            if size == 0:
+                index += 1
+            else:
+                index += size
+        #! print "index %s position %s" % (index, position)
+        return True
+
+ANY_ALL = [ (ACL.ALLOW, '*', '*') ]
+
+
+
+class RemoteException(Exception):
+    '''
+    Base exception for RPC. This exception is raised when a problem
+    occurs in the network layer.
+    '''
+    
+    def __init__(self, message="", cause=None):
+        '''
+        Initializes a new RemoteException.
+        
+        Arguments:
+            message -- The message accompanying this exception.
+            cause -- The underlying cause of this exception.
+        '''        
+        self._message = message
+        self._cause = cause  
+        pass 
+
+    def __str__(self):
+        return repr(self._message)
+
+    def get_message(self):
+        return self._message
+
+    def get_cause(self):
+        return self._cause
+
+
+
+class InvocationException(RemoteException):
+    '''
+    Exception raised when a problem occurs during the remote invocation
+    of a method. 
+    '''
+    pass
+
+
+
+class AuthorizationException(RemoteException):
+    '''
+    Exception raised when the caller is not authorized to invoke the
+    remote method.
+    '''
+    pass
+
+
+
+class TimeoutException(Exception):
+    '''
+    Exception raised when the synchronous execution of a method takes
+    longer than the given threshold because an underlying asynchronous
+    reply did not arrive in time.
+    '''
+    pass 
+
+
+
+class Callback(object):
+    '''
+    A base class for callback handlers. 
+    '''
+    __metaclass__ = abc.ABCMeta
+    
+    
+    @abc.abstractproperty
+    def set_value(self, value):
+        return NotImplemented
+    
+    @abc.abstractproperty
+    def cancel_with_error(self, exception):
+        return NotImplemented
+
+
+
+class Future(Callback):
+    '''
+    Represents the result of an asynchronous computation.
+    '''
+    
+    def __init__(self):
+        '''
+        Initializes a new Future.
+        '''
+        self._value = None
+        self._exception = None        
+        self._event = threading.Event()
+        pass
+    
+    def set_value(self, value):
+        '''
+        Sets the value of this Future. Once the value is set, a caller
+        blocked on get_value will be able to continue.
+        '''
+        self._value = value
+        self._event.set()
+        
+    def get_value(self, timeout=None):
+        '''
+        Gets the value of this Future. This call will block until
+        the result is available, or until an optional timeout expires.
+        When this Future is cancelled with an error,  
+        
+        Arguments:
+            timeout -- The maximum waiting time to obtain the value.
+        '''
+        self._event.wait(timeout)
+        if self._exception:
+            raise self._exception
+        if not self._event.is_set():
+            raise TimeoutException
+        return self._value
+    
+    def is_done(self):
+        '''
+        Returns true if a value has been returned.
+        '''
+        return self._event.is_set()
+
+    def cancel_with_error(self, exception):
+        '''
+        Cancels the Future because of an error. Once cancelled, a 
+        caller blocked on get_value will be able to continue.
+        '''
+        self._exception = exception     
+        self._event.set()      
+
+
+        
+class Endpoint(object):
+    '''
+    The Endpoint class is an abstract base class for all objects
+    participating in an RPC-enabled XMPP network.
+    
+    A user subclassing this class is required to implement the method:
+        FQN(self) 
+    where FQN stands for Fully Qualified Name, an unambiguous name 
+    which specifies which object an RPC call refers to. It is the 
+    first part in a RPC method name '<fqn>.<method>'.
+    '''
+    __metaclass__ = abc.ABCMeta
+
+
+    def __init__(self, session, target_jid):
+        '''
+        Initialize a new Endpoint. This constructor should never be
+        invoked by a user, instead it will be called by the factories
+        which instantiate the RPC-enabled objects, of which only
+        the classes are provided by the user. 
+        
+        Arguments:
+            session -- An RPC session instance.
+            target_jid -- the identity of the remote XMPP entity.
+        '''
+        self.session = session
+        self.target_jid = target_jid
+        
+    @abc.abstractproperty
+    def FQN(self):
+        return NotImplemented
+    
+    def get_methods(self):
+        '''
+        Returns a dictionary of all RPC method names provided by this
+        class. This method returns the actual  method names as found
+        in the class definition which have been decorated with:
+        
+            @remote
+            def some_rpc_method(arg1, arg2)
+        
+        
+        Unless:
+            (1) the name has been remapped, in which case the new
+                name will be returned.
+                
+                    @remote("new_name")
+                    def some_rpc_method(arg1, arg2)
+                
+            (2) the method is set to hidden
+            
+                    @remote(False)
+                    def some_hidden_method(arg1, arg2)
+        '''
+        result = dict()
+        for function in dir(self):
+            test_attr = getattr(self, function, None)
+            try:
+                if test_attr._rpc:
+                    result[test_attr._rpc_name] = test_attr
+            except Exception:
+                pass
+        return result     
+
+
+
+class Proxy(Endpoint):
+    '''
+    Implementation of the Proxy pattern which is intended to wrap
+    around Endpoints in order to intercept calls, marshall them and
+    forward them to the remote object.
+    '''
+
+    def __init__(self, endpoint, callback = None):
+        '''
+        Initializes a new Proxy.
+        
+        Arguments:
+            endpoint -- The endpoint which is proxified.
+        '''
+        self._endpoint = endpoint
+        self._callback = callback
+        
+    def __getattribute__(self, name, *args):
+        if name in ('__dict__', '_endpoint', 'async', '_callback'):
+            return object.__getattribute__(self, name)
+        else:
+            attribute = self._endpoint.__getattribute__(name)
+            if hasattr(attribute, '__call__'):
+                try:
+                    if attribute._rpc:
+                        def _remote_call(*args, **kwargs): 
+                            log.debug("Remotely calling '%s.%s' with arguments %s." % (self._endpoint.FQN(), attribute._rpc_name, args))
+                            return self._endpoint.session._call_remote(self._endpoint.target_jid, "%s.%s" % (self._endpoint.FQN(), attribute._rpc_name), self._callback, *args, **kwargs)
+                        return _remote_call
+                except:
+                    pass   # If the attribute doesn't exist, don't care! 
+            return attribute
+    
+    def async(self, callback):        
+        return Proxy(self._endpoint, callback)
+               
+    def get_endpoint(self):
+        '''
+        Returns the proxified endpoint.
+        '''
+        return self._endpoint
+        
+    def FQN(self):
+        return self._endpoint.FQN()
+
+
+
+class JabberRPCEntry(object):
+    
+    
+    def __init__(self, endpoint_FQN, call):
+        self._endpoint_FQN = endpoint_FQN
+        self._call = call
+
+    def call_method(self, args):
+        return_value = self._call(*args)
+        if return_value is None:
+            return return_value
+        else:
+            return self._return(return_value)
+        
+    def get_endpoint_FQN(self):
+        return self._endpoint_FQN
+
+    def _return(self, *args):
+        return args
+    
+    
+    
+class RemoteSession(object):
+    '''
+    A context object for a Jabber-RPC session. 
+    '''
+    
+            
+    def __init__(self, client, session_close_callback):
+        '''
+        Initializes a new RPC session.
+        
+        Arguments:
+            client -- The SleekXMPP client associated with this session.
+            session_close_callback -- A callback called when the 
+                session is closed.
+        '''
+        self._client = client
+        self._session_close_callback = session_close_callback
+        self._event = threading.Event()
+        self._entries = {}
+        self._callbacks = {}
+        self._acls = {}
+        self._lock = RLock()
+            
+    def _wait(self):
+        self._event.wait()
+    
+    def _notify(self, event):
+        log.debug("RPC Session as %s started." % self._client.boundjid.full)
+        self._client.sendPresence()
+        self._event.set()
+        pass
+        
+    def _register_call(self, endpoint, method, name=None):
+        '''
+        Registers a method from an endpoint as remotely callable.
+        '''
+        if name is None:
+            name = method.__name__
+        key = "%s.%s" % (endpoint, name)
+        log.debug("Registering call handler for %s (%s)." % (key, method))
+        with self._lock:
+            if self._entries.has_key(key):
+                raise KeyError("A handler for %s has already been regisered!" % endpoint)
+            self._entries[key] = JabberRPCEntry(endpoint, method)
+        return key
+
+    def _register_acl(self, endpoint, acl):
+        log.debug("Registering ACL %s for endpoint %s." % (repr(acl), endpoint))
+        with self._lock:
+            self._acls[endpoint] = acl
+
+    def _register_callback(self, pid, callback):
+        with self._lock:
+            self._callbacks[pid] = callback
+            
+    def forget_callback(self, callback):        
+        with self._lock:
+            pid = self._find_key(self._callbacks, callback)
+            if pid is not None:
+                del self._callback[pid]
+            else:
+                raise ValueError("Unknown callback!")
+        pass
+    
+    def _find_key(self, dict, value):
+        """return the key of dictionary dic given the value"""
+        search = [k for k, v in dict.iteritems() if v == value]
+        if len(search) == 0:
+            return None
+        else:
+            return search[0]
+    
+    def _unregister_call(self, key):
+        #removes the registered call
+        with self._lock:
+            if self._entries[key]:
+                del self._entries[key]
+            else:
+                raise ValueError()
+        
+    def new_proxy(self, target_jid, endpoint_cls):
+        '''
+        Instantiates a new proxy object, which proxies to a remote
+        endpoint. This method uses a class reference without 
+        constructor arguments to instantiate the proxy.
+        
+        Arguments:
+            target_jid -- the XMPP entity ID hosting the endpoint.
+            endpoint_cls -- The remote (duck) type.
+        '''
+        try:            
+            argspec = inspect.getargspec(endpoint_cls.__init__)
+            args = [None] * (len(argspec[0]) - 1)
+            result = endpoint_cls(*args)
+            Endpoint.__init__(result, self, target_jid)
+            return Proxy(result)
+        except:
+            traceback.print_exc(file=sys.stdout)
+    
+    def new_handler(self, acl, handler_cls, *args, **kwargs):
+        '''
+        Instantiates a new handler object, which is called remotely
+        by others. The user can control the effect of the call by
+        implementing the remote method in the local endpoint class. The
+        returned reference can be called locally and will behave as a
+        regular instance.
+        
+        Arguments:
+            acl -- Access control list (see ACL class)
+            handler_clss -- The local (duck) type.
+            *args -- Constructor arguments for the local type.
+            **kwargs -- Constructor keyworded arguments for the local
+                type.
+        '''
+        argspec = inspect.getargspec(handler_cls.__init__)
+        base_argspec = inspect.getargspec(Endpoint.__init__)
+        if(argspec == base_argspec):
+            result = handler_cls(self, self._client.boundjid.full)
+        else:
+            result = handler_cls(*args, **kwargs)
+            Endpoint.__init__(result, self, self._client.boundjid.full)
+        method_dict = result.get_methods()
+        for method_name, method in method_dict.iteritems():
+            #!!! self._client.plugin['xep_0009'].register_call(result.FQN(), method, method_name)        
+            self._register_call(result.FQN(), method, method_name)
+        self._register_acl(result.FQN(), acl)
+        return result
+                         
+#    def is_available(self, targetCls, pto):
+#        return self._client.is_available(pto)
+
+    def _call_remote(self, pto, pmethod, callback, *arguments):
+        iq = self._client.plugin['xep_0009'].make_iq_method_call(pto, pmethod, py2xml(*arguments))
+        pid = iq['id']
+        if callback is None:
+            future = Future()
+            self._register_callback(pid, future)
+            iq.send()
+            return future.get_value(30)            
+        else:
+            print "[RemoteSession] _call_remote %s" % callback
+            self._register_callback(pid, callback)
+            iq.send()
+        
+    def close(self):
+        '''
+        Closes this session.
+        '''
+        self._client.disconnect(False)
+        self._session_close_callback()
+                      
+    def _on_jabber_rpc_method_call(self, iq):
+        iq.enable('rpc_query')
+        params = iq['rpc_query']['method_call']['params']
+        args = xml2py(params)
+        pmethod = iq['rpc_query']['method_call']['method_name']
+        try:
+            with self._lock:
+                entry = self._entries[pmethod]
+                rules = self._acls[entry.get_endpoint_FQN()]
+            if ACL.check(rules, iq['from'], pmethod):
+                return_value = entry.call_method(args)
+            else:
+                raise AuthorizationException("Unauthorized access to %s from %s!" % (pmethod, iq['from']))
+            if return_value is None:
+                return_value = ()
+            response = self._client.plugin['xep_0009'].make_iq_method_response(iq['id'], iq['from'], py2xml(*return_value))
+            response.send()
+        except InvocationException as ie:
+            fault = dict()
+            fault['code'] = 500
+            fault['string'] = ie.get_message()
+            self._client.plugin['xep_0009']._send_fault(iq, fault2xml(fault))
+        except AuthorizationException as ae:
+            log.error(ae.get_message())
+            error = self._client.plugin['xep_0009']._forbidden(iq)
+            error.send()                                            
+        except Exception as e:            
+            if isinstance(e, KeyError):
+                log.error("No handler available for %s!" % pmethod)
+                error = self._client.plugin['xep_0009']._item_not_found(iq)
+            else:
+                traceback.print_exc(file=sys.stderr)
+                log.error("An unexpected problem occurred invoking method %s!" % pmethod)
+                error = self._client.plugin['xep_0009']._undefined_condition(iq) 
+            #! print "[REMOTE.PY] _handle_remote_procedure_call AN ERROR SHOULD BE SENT NOW %s " % e
+            error.send()
+
+    def _on_jabber_rpc_method_response(self, iq):
+        iq.enable('rpc_query')
+        args = xml2py(iq['rpc_query']['method_response']['params'])
+        pid = iq['id']
+        with self._lock:
+            callback = self._callbacks[pid]
+            del self._callbacks[pid]
+        if(len(args) > 0):
+            callback.set_value(args[0])
+        else:
+            callback.set_value(None)
+        pass        
+
+    def _on_jabber_rpc_method_response2(self, iq):
+        iq.enable('rpc_query')
+        if iq['rpc_query']['method_response']['fault'] is not None:
+            self._on_jabber_rpc_method_fault(iq)
+        else:
+            args = xml2py(iq['rpc_query']['method_response']['params'])
+            pid = iq['id']
+            with self._lock:
+                callback = self._callbacks[pid]
+                del self._callbacks[pid]
+            if(len(args) > 0):
+                callback.set_value(args[0])
+            else:
+                callback.set_value(None)
+            pass    
+
+    def _on_jabber_rpc_method_fault(self, iq):
+        iq.enable('rpc_query')
+        fault = xml2fault(iq['rpc_query']['method_response']['fault'])
+        pid = iq['id']      
+        with self._lock:
+            callback = self._callbacks[pid]
+            del self._callbacks[pid]
+        e = {
+             500: InvocationException 
+        }[fault['code']](fault['string'])
+        callback.cancel_with_error(e)    
+
+    def _on_jabber_rpc_error(self, iq):
+        pid = iq['id']
+        pmethod = self._client.plugin['xep_0009']._extract_method(iq['rpc_query'])
+        code = iq['error']['code']        
+        type = iq['error']['type']
+        condition = iq['error']['condition']
+        #! print("['REMOTE.PY']._BINDING_handle_remote_procedure_error -> ERROR! ERROR! ERROR! Condition is '%s'" % condition)
+        with self._lock:
+            callback = self._callbacks[pid]
+            del self._callbacks[pid]
+        e = { 
+            'item-not-found': RemoteException("No remote handler available for %s at %s!" % (pmethod, iq['from'])),
+            'forbidden': AuthorizationException("Forbidden to invoke remote handler for %s at %s!" % (pmethod, iq['from'])),
+            'undefined-condition': RemoteException("An unexpected problem occured trying to invoke %s at %s!" % (pmethod, iq['from'])),            
+        }[condition]
+        if e is None:
+            RemoteException("An unexpected exception occurred at %s!" % iq['from'])
+        callback.cancel_with_error(e)
+
+
+
+class Remote(object):
+    '''
+    Bootstrap class for Jabber-RPC sessions. New sessions are openend
+    with an existing XMPP client, or one is instantiated on demand.
+    '''
+    _instance = None
+    _sessions = dict()
+    _lock = threading.RLock()
+    
+    @classmethod
+    def new_session_with_client(cls, client, callback=None):
+        '''
+        Opens a new session with a given client.
+        
+        Arguments:
+            client -- An XMPP client.
+            callback -- An optional callback which can be used to track
+                the starting state of the session.
+        '''
+        with Remote._lock:       
+            if(client.boundjid.bare in cls._sessions):
+                raise RemoteException("There already is a session associated with these credentials!")
+            else:
+                cls._sessions[client.boundjid.bare] = client;
+        def _session_close_callback():
+            with Remote._lock:
+                del cls._sessions[client.boundjid.bare]
+        result = RemoteSession(client, _session_close_callback)        
+        client.plugin['xep_0009'].xmpp.add_event_handler('jabber_rpc_method_call', result._on_jabber_rpc_method_call)
+        client.plugin['xep_0009'].xmpp.add_event_handler('jabber_rpc_method_response', result._on_jabber_rpc_method_response)
+        client.plugin['xep_0009'].xmpp.add_event_handler('jabber_rpc_method_fault', result._on_jabber_rpc_method_fault)        
+        client.plugin['xep_0009'].xmpp.add_event_handler('jabber_rpc_error', result._on_jabber_rpc_error)
+        if callback is None:
+            start_event_handler = result._notify        
+        else:
+            start_event_handler = callback        
+        client.add_event_handler("session_start", start_event_handler)        
+        if client.connect():
+            client.process(threaded=True)
+        else:
+            raise RemoteException("Could not connect to XMPP server!")
+        pass    
+        if callback is None:
+            result._wait()
+        return result
+
+    @classmethod
+    def new_session(cls, jid, password, callback=None):
+        '''
+        Opens a new session and instantiates a new XMPP client.
+        
+        Arguments:
+            jid -- The XMPP JID for logging in.
+            password -- The password for logging in.
+            callback -- An optional callback which can be used to track
+                the starting state of the session.            
+        '''        
+        client = sleekxmpp.ClientXMPP(jid, password)
+        #? Register plug-ins.        
+        client.registerPlugin('xep_0004') # Data Forms
+        client.registerPlugin('xep_0009') # Jabber-RPC
+        client.registerPlugin('xep_0030') # Service Discovery
+        client.registerPlugin('xep_0060') # PubSub
+        client.registerPlugin('xep_0199') # XMPP Ping      
+        return cls.new_session_with_client(client, callback) 
+
+    
\ No newline at end of file