twisted/words/protocols/jabber/component.py

   1 # -*- test-case-name: twisted.words.test.test_jabbercomponent -*-
   2 #
   3 # Copyright (c) Twisted Matrix Laboratories.
   4 # See LICENSE for details.
   5
   6 """
   7 External server-side components.
   8
   9 Most Jabber server implementations allow for add-on components that act as a
  10 seperate entity on the Jabber network, but use the server-to-server
  11 functionality of a regular Jabber IM server. These so-called 'external
  12 components' are connected to the Jabber server using the Jabber Component
  13 Protocol as defined in U{JEP-0114<http://www.jabber.org/jeps/jep-0114.html>}.
  14
  15 This module allows for writing external server-side component by assigning one
  16 or more services implementing L{ijabber.IService} up to L{ServiceManager}. The
  17 ServiceManager connects to the Jabber server and is responsible for the
  18 corresponding XML stream.
  19 """
  20
  21 from zope.interface import implements
  22
  23 from twisted.application import service
  24 from twisted.internet import defer
  25 from twisted.python import log
  26 from twisted.words.xish import domish
  27 from twisted.words.protocols.jabber import error, ijabber, jstrports, xmlstream
  28 from twisted.words.protocols.jabber.jid import internJID as JID
  29
  30 NS_COMPONENT_ACCEPT = 'jabber:component:accept'
  31
  32 def componentFactory(componentid, password):
  33     """
  34     XML stream factory for external server-side components.
  35
  36     @param componentid: JID of the component.
  37     @type componentid: C{unicode}
  38     @param password: password used to authenticate to the server.
  39     @type password: C{str}
  40     """
  41     a = ConnectComponentAuthenticator(componentid, password)
  42     return xmlstream.XmlStreamFactory(a)
  43
  44 class ComponentInitiatingInitializer(object):
  45     """
  46     External server-side component authentication initializer for the
  47     initiating entity.
  48
  49     @ivar xmlstream: XML stream between server and component.
  50     @type xmlstream: L{xmlstream.XmlStream}
  51     """
  52
  53     def __init__(self, xs):
  54         self.xmlstream = xs
  55         self._deferred = None
  56
  57     def initialize(self):
  58         xs = self.xmlstream
  59         hs = domish.Element((self.xmlstream.namespace, "handshake"))
  60         hs.addContent(xmlstream.hashPassword(xs.sid,
  61                                              unicode(xs.authenticator.password)))
  62
  63         # Setup observer to watch for handshake result
  64         xs.addOnetimeObserver("/handshake", self._cbHandshake)
  65         xs.send(hs)
  66         self._deferred = defer.Deferred()
  67         return self._deferred
  68
  69     def _cbHandshake(self, _):
  70         # we have successfully shaken hands and can now consider this
  71         # entity to represent the component JID.
  72         self.xmlstream.thisEntity = self.xmlstream.otherEntity
  73         self._deferred.callback(None)
  74
  75
  76
  77 class ConnectComponentAuthenticator(xmlstream.ConnectAuthenticator):
  78     """
  79     Authenticator to permit an XmlStream to authenticate against a Jabber
  80     server as an external component (where the Authenticator is initiating the
  81     stream).
  82     """
  83     namespace = NS_COMPONENT_ACCEPT
  84
  85     def __init__(self, componentjid, password):
  86         """
  87         @type componentjid: C{str}
  88         @param componentjid: Jabber ID that this component wishes to bind to.
  89
  90         @type password: C{str}
  91         @param password: Password/secret this component uses to authenticate.
  92         """
  93         # Note that we are sending 'to' our desired component JID.
  94         xmlstream.ConnectAuthenticator.__init__(self, componentjid)
  95         self.password = password
  96
  97     def associateWithStream(self, xs):
  98         xs.version = (0, 0)
  99         xmlstream.ConnectAuthenticator.associateWithStream(self, xs)
 100
 101         xs.initializers = [ComponentInitiatingInitializer(xs)]
 102
 103
 104
 105 class ListenComponentAuthenticator(xmlstream.ListenAuthenticator):
 106     """
 107     Authenticator for accepting components.
 108
 109     @since: 8.2
 110     @ivar secret: The shared secret used to authorized incoming component
 111                   connections.
 112     @type secret: C{unicode}.
 113     """
 114
 115     namespace = NS_COMPONENT_ACCEPT
 116
 117     def __init__(self, secret):
 118         self.secret = secret
 119         xmlstream.ListenAuthenticator.__init__(self)
 120
 121
 122     def associateWithStream(self, xs):
 123         """
 124         Associate the authenticator with a stream.
 125
 126         This sets the stream's version to 0.0, because the XEP-0114 component
 127         protocol was not designed for XMPP 1.0.
 128         """
 129         xs.version = (0, 0)
 130         xmlstream.ListenAuthenticator.associateWithStream(self, xs)
 131
 132
 133     def streamStarted(self, rootElement):
 134         """
 135         Called by the stream when it has started.
 136
 137         This examines the default namespace of the incoming stream and whether
 138         there is a requested hostname for the component. Then it generates a
 139         stream identifier, sends a response header and adds an observer for
 140         the first incoming element, triggering L{onElement}.
 141         """
 142
 143         xmlstream.ListenAuthenticator.streamStarted(self, rootElement)
 144
 145         if rootElement.defaultUri != self.namespace:
 146             exc = error.StreamError('invalid-namespace')
 147             self.xmlstream.sendStreamError(exc)
 148             return
 149
 150         # self.xmlstream.thisEntity is set to the address the component
 151         # wants to assume.
 152         if not self.xmlstream.thisEntity:
 153             exc = error.StreamError('improper-addressing')
 154             self.xmlstream.sendStreamError(exc)
 155             return
 156
 157         self.xmlstream.sendHeader()
 158         self.xmlstream.addOnetimeObserver('/*', self.onElement)
 159
 160
 161     def onElement(self, element):
 162         """
 163         Called on incoming XML Stanzas.
 164
 165         The very first element received should be a request for handshake.
 166         Otherwise, the stream is dropped with a 'not-authorized' error. If a
 167         handshake request was received, the hash is extracted and passed to
 168         L{onHandshake}.
 169         """
 170         if (element.uri, element.name) == (self.namespace, 'handshake'):
 171             self.onHandshake(unicode(element))
 172         else:
 173             exc = error.StreamError('not-authorized')
 174             self.xmlstream.sendStreamError(exc)
 175
 176
 177     def onHandshake(self, handshake):
 178         """
 179         Called upon receiving the handshake request.
 180
 181         This checks that the given hash in C{handshake} is equal to a
 182         calculated hash, responding with a handshake reply or a stream error.
 183         If the handshake was ok, the stream is authorized, and  XML Stanzas may
 184         be exchanged.
 185         """
 186         calculatedHash = xmlstream.hashPassword(self.xmlstream.sid,
 187                                                 unicode(self.secret))
 188         if handshake != calculatedHash:
 189             exc = error.StreamError('not-authorized', text='Invalid hash')
 190             self.xmlstream.sendStreamError(exc)
 191         else:
 192             self.xmlstream.send('<handshake/>')
 193             self.xmlstream.dispatch(self.xmlstream,
 194                                     xmlstream.STREAM_AUTHD_EVENT)
 195
 196
 197
 198 class Service(service.Service):
 199     """
 200     External server-side component service.
 201     """
 202
 203     implements(ijabber.IService)
 204
 205     def componentConnected(self, xs):
 206         pass
 207
 208     def componentDisconnected(self):
 209         pass
 210
 211     def transportConnected(self, xs):
 212         pass
 213
 214     def send(self, obj):
 215         """
 216         Send data over service parent's XML stream.
 217
 218         @note: L{ServiceManager} maintains a queue for data sent using this
 219         method when there is no current established XML stream. This data is
 220         then sent as soon as a new stream has been established and initialized.
 221         Subsequently, L{componentConnected} will be called again. If this
 222         queueing is not desired, use C{send} on the XmlStream object (passed to
 223         L{componentConnected}) directly.
 224
 225         @param obj: data to be sent over the XML stream. This is usually an
 226         object providing L{domish.IElement}, or serialized XML. See
 227         L{xmlstream.XmlStream} for details.
 228         """
 229
 230         self.parent.send(obj)
 231
 232 class ServiceManager(service.MultiService):
 233     """
 234     Business logic representing a managed component connection to a Jabber
 235     router.
 236
 237     This service maintains a single connection to a Jabber router and provides
 238     facilities for packet routing and transmission. Business logic modules are
 239     services implementing L{ijabber.IService} (like subclasses of L{Service}), and
 240     added as sub-service.
 241     """
 242
 243     def __init__(self, jid, password):
 244         service.MultiService.__init__(self)
 245
 246         # Setup defaults
 247         self.jabberId = jid
 248         self.xmlstream = None
 249
 250         # Internal buffer of packets
 251         self._packetQueue = []
 252
 253         # Setup the xmlstream factory
 254         self._xsFactory = componentFactory(self.jabberId, password)
 255
 256         # Register some lambda functions to keep the self.xmlstream var up to
 257         # date
 258         self._xsFactory.addBootstrap(xmlstream.STREAM_CONNECTED_EVENT,
 259                                      self._connected)
 260         self._xsFactory.addBootstrap(xmlstream.STREAM_AUTHD_EVENT, self._authd)
 261         self._xsFactory.addBootstrap(xmlstream.STREAM_END_EVENT,
 262                                      self._disconnected)
 263
 264         # Map addBootstrap and removeBootstrap to the underlying factory -- is
 265         # this right? I have no clue...but it'll work for now, until i can
 266         # think about it more.
 267         self.addBootstrap = self._xsFactory.addBootstrap
 268         self.removeBootstrap = self._xsFactory.removeBootstrap
 269
 270     def getFactory(self):
 271         return self._xsFactory
 272
 273     def _connected(self, xs):
 274         self.xmlstream = xs
 275         for c in self:
 276             if ijabber.IService.providedBy(c):
 277                 c.transportConnected(xs)
 278
 279     def _authd(self, xs):
 280         # Flush all pending packets
 281         for p in self._packetQueue:
 282             self.xmlstream.send(p)
 283         self._packetQueue = []
 284
 285         # Notify all child services which implement the IService interface
 286         for c in self:
 287             if ijabber.IService.providedBy(c):
 288                 c.componentConnected(xs)
 289
 290     def _disconnected(self, _):
 291         self.xmlstream = None
 292
 293         # Notify all child services which implement
 294         # the IService interface
 295         for c in self:
 296             if ijabber.IService.providedBy(c):
 297                 c.componentDisconnected()
 298
 299     def send(self, obj):
 300         """
 301         Send data over the XML stream.
 302
 303         When there is no established XML stream, the data is queued and sent
 304         out when a new XML stream has been established and initialized.
 305
 306         @param obj: data to be sent over the XML stream. This is usually an
 307         object providing L{domish.IElement}, or serialized XML. See
 308         L{xmlstream.XmlStream} for details.
 309         """
 310
 311         if self.xmlstream != None:
 312             self.xmlstream.send(obj)
 313         else:
 314             self._packetQueue.append(obj)
 315
 316 def buildServiceManager(jid, password, strport):
 317     """
 318     Constructs a pre-built L{ServiceManager}, using the specified strport
 319     string.
 320     """
 321
 322     svc = ServiceManager(jid, password)
 323     client_svc = jstrports.client(strport, svc.getFactory())
 324     client_svc.setServiceParent(svc)
 325     return svc
 326
 327
 328
 329 class Router(object):
 330     """
 331     XMPP Server's Router.
 332
 333     A router connects the different components of the XMPP service and routes
 334     messages between them based on the given routing table.
 335
 336     Connected components are trusted to have correct addressing in the
 337     stanzas they offer for routing.
 338
 339     A route destination of C{None} adds a default route. Traffic for which no
 340     specific route exists, will be routed to this default route.
 341
 342     @since: 8.2
 343     @ivar routes: Routes based on the host part of JIDs. Maps host names to the
 344                   L{EventDispatcher<utility.EventDispatcher>}s that should
 345                   receive the traffic. A key of C{None} means the default
 346                   route.
 347     @type routes: C{dict}
 348     """
 349
 350     def __init__(self):
 351         self.routes = {}
 352
 353
 354     def addRoute(self, destination, xs):
 355         """
 356         Add a new route.
 357
 358         The passed XML Stream C{xs} will have an observer for all stanzas
 359         added to route its outgoing traffic. In turn, traffic for
 360         C{destination} will be passed to this stream.
 361
 362         @param destination: Destination of the route to be added as a host name
 363                             or C{None} for the default route.
 364         @type destination: C{str} or C{NoneType}.
 365         @param xs: XML Stream to register the route for.
 366         @type xs: L{EventDispatcher<utility.EventDispatcher>}.
 367         """
 368         self.routes[destination] = xs
 369         xs.addObserver('/*', self.route)
 370
 371
 372     def removeRoute(self, destination, xs):
 373         """
 374         Remove a route.
 375
 376         @param destination: Destination of the route that should be removed.
 377         @type destination: C{str}.
 378         @param xs: XML Stream to remove the route for.
 379         @type xs: L{EventDispatcher<utility.EventDispatcher>}.
 380         """
 381         xs.removeObserver('/*', self.route)
 382         if (xs == self.routes[destination]):
 383             del self.routes[destination]
 384
 385
 386     def route(self, stanza):
 387         """
 388         Route a stanza.
 389
 390         @param stanza: The stanza to be routed.
 391         @type stanza: L{domish.Element}.
 392         """
 393         destination = JID(stanza['to'])
 394
 395         log.msg("Routing to %s: %r" % (destination.full(), stanza.toXml()))
 396
 397         if destination.host in self.routes:
 398             self.routes[destination.host].send(stanza)
 399         else:
 400             self.routes[None].send(stanza)
 401
 402
 403
 404 class XMPPComponentServerFactory(xmlstream.XmlStreamServerFactory):
 405     """
 406     XMPP Component Server factory.
 407
 408     This factory accepts XMPP external component connections and makes
 409     the router service route traffic for a component's bound domain
 410     to that component.
 411
 412     @since: 8.2
 413     """
 414
 415     logTraffic = False
 416
 417     def __init__(self, router, secret='secret'):
 418         self.router = router
 419         self.secret = secret
 420
 421         def authenticatorFactory():
 422             return ListenComponentAuthenticator(self.secret)
 423
 424         xmlstream.XmlStreamServerFactory.__init__(self, authenticatorFactory)
 425         self.addBootstrap(xmlstream.STREAM_CONNECTED_EVENT,
 426                           self.onConnectionMade)
 427         self.addBootstrap(xmlstream.STREAM_AUTHD_EVENT,
 428                           self.onAuthenticated)
 429
 430         self.serial = 0
 431
 432
 433     def onConnectionMade(self, xs):
 434         """
 435         Called when a component connection was made.
 436
 437         This enables traffic debugging on incoming streams.
 438         """
 439         xs.serial = self.serial
 440         self.serial += 1
 441
 442         def logDataIn(buf):
 443             log.msg("RECV (%d): %r" % (xs.serial, buf))
 444
 445         def logDataOut(buf):
 446             log.msg("SEND (%d): %r" % (xs.serial, buf))
 447
 448         if self.logTraffic:
 449             xs.rawDataInFn = logDataIn
 450             xs.rawDataOutFn = logDataOut
 451
 452         xs.addObserver(xmlstream.STREAM_ERROR_EVENT, self.onError)
 453
 454
 455     def onAuthenticated(self, xs):
 456         """
 457         Called when a component has succesfully authenticated.
 458
 459         Add the component to the routing table and establish a handler
 460         for a closed connection.
 461         """
 462         destination = xs.thisEntity.host
 463
 464         self.router.addRoute(destination, xs)
 465         xs.addObserver(xmlstream.STREAM_END_EVENT, self.onConnectionLost, 0,
 466                                                    destination, xs)
 467
 468
 469     def onError(self, reason):
 470         log.err(reason, "Stream Error")
 471
 472
 473     def onConnectionLost(self, destination, xs, reason):
 474         self.router.removeRoute(destination, xs)