view src/plugins/plugin_xep_0115.py @ 2307:8fa7edd0da24

plugin Pubsub Hook: first draft: This new plugin allow to attach an external action to a Pubsub event (i.e. notification). Hook can be persitent accross restarts, or temporary (will be deleted on profile disconnection). Only Python files are handled for now. In the future, it may make sense to move hooks in a generic plugin which could be used by ad-hoc commands, messages, pubsub, etc.
author Goffi <goffi@goffi.org>
date Wed, 05 Jul 2017 15:05:47 +0200
parents a543eda2c923
children 8b37a62336c3
line wrap: on
line source

#!/usr/bin/env python2
# -*- coding: utf-8 -*-

# SAT plugin for managing xep-0115
# Copyright (C) 2009-2016 Jérôme Poisson (goffi@goffi.org)

# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU Affero General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.

# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU Affero General Public License for more details.

# You should have received a copy of the GNU Affero General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.

from sat.core.i18n import _
from sat.core.constants import Const as C
from sat.core.log import getLogger
log = getLogger(__name__)
from twisted.words.xish import domish
from twisted.words.protocols.jabber import jid
from twisted.internet import defer, error
from zope.interface import implements
from wokkel import disco, iwokkel

try:
    from twisted.words.protocols.xmlstream import XMPPHandler
except ImportError:
    from wokkel.subprotocols import XMPPHandler

PRESENCE = '/presence'
NS_ENTITY_CAPABILITY = 'http://jabber.org/protocol/caps'
NS_CAPS_OPTIMIZE = 'http://jabber.org/protocol/caps#optimize'
CAPABILITY_UPDATE = PRESENCE + '/c[@xmlns="' + NS_ENTITY_CAPABILITY + '"]'

PLUGIN_INFO = {
    C.PI_NAME: "XEP 0115 Plugin",
    C.PI_IMPORT_NAME: "XEP-0115",
    C.PI_TYPE: "XEP",
    C.PI_PROTOCOLS: ["XEP-0115"],
    C.PI_DEPENDENCIES: [],
    C.PI_MAIN: "XEP_0115",
    C.PI_HANDLER: "yes",
    C.PI_DESCRIPTION: _("""Implementation of entity capabilities""")
}


class XEP_0115(object):
    cap_hash = None  # capabilities hash is class variable as it is common to all profiles

    def __init__(self, host):
        log.info(_("Plugin XEP_0115 initialization"))
        self.host = host
        host.trigger.add("Disco handled", self._checkHash)
        host.trigger.add("Presence send", self._presenceTrigger)

    def getHandler(self, client):
        return XEP_0115_handler(self, client.profile)

    def _checkHash(self, disco_d, profile):
        client = self.host.getClient(profile)
        client.caps_optimize = None

        if XEP_0115.cap_hash is None:
            disco_d.addCallback(lambda dummy: self.host.hasFeature(client, NS_CAPS_OPTIMIZE))
            def updateOptimize(optimize):
                client.caps_optimize = optimize
                if optimize:
                    log.info(_("Caps optimisation enabled"))
                    client.caps_sent = False
                else:
                    log.warning(_("Caps optimisation not available"))
            disco_d.addCallback(updateOptimize)
            disco_d.addCallback(lambda dummy: self.recalculateHash(profile))
        return True

    def _presenceTrigger(self, client, obj):
        if XEP_0115.cap_hash is not None:
            if client.caps_optimize:
                if client.caps_sent:
                    return True
                client.caps_sent = True
            obj.addChild(XEP_0115.c_elt)
        return True

    @defer.inlineCallbacks
    def recalculateHash(self, profile):
        client = self.host.getClient(profile)
        _infos = yield client.discoHandler.info(client.jid, client.jid, '')
        disco_infos = disco.DiscoInfo()
        for item in _infos:
            disco_infos.append(item)
        cap_hash = self.host.memory.disco.generateHash(disco_infos)
        log.info("Our capability hash has been generated: [%s]" % cap_hash)
        log.debug("Generating capability domish.Element")
        c_elt = domish.Element((NS_ENTITY_CAPABILITY, 'c'))
        c_elt['hash'] = 'sha-1'
        c_elt['node'] = C.APP_URL
        c_elt['ver'] = cap_hash
        XEP_0115.cap_hash = cap_hash
        XEP_0115.c_elt = c_elt
        if client.caps_optimize:
            client.caps_sent = False
        if cap_hash not in self.host.memory.disco.hashes:
            self.host.memory.disco.hashes[cap_hash] = disco_infos
            self.host.memory.updateEntityData(client.jid, C.ENTITY_CAP_HASH, cap_hash, profile_key=profile)


class XEP_0115_handler(XMPPHandler):
    implements(iwokkel.IDisco)

    def __init__(self, plugin_parent, profile):
        self.plugin_parent = plugin_parent
        self.host = plugin_parent.host
        self.profile = profile

    def connectionInitialized(self):
        self.xmlstream.addObserver(CAPABILITY_UPDATE, self.update)

    def getDiscoInfo(self, requestor, target, nodeIdentifier=''):
        return [disco.DiscoFeature(NS_ENTITY_CAPABILITY), disco.DiscoFeature(NS_CAPS_OPTIMIZE)]

    def getDiscoItems(self, requestor, target, nodeIdentifier=''):
        return []

    def update(self, presence):
        """
        Manage the capabilities of the entity

        Check if we know the version of this capabilities and get the capabilities if necessary
        """
        from_jid = jid.JID(presence['from'])
        c_elem = presence.elements(NS_ENTITY_CAPABILITY, 'c').next()
        try:
            c_ver = c_elem['ver']
            c_hash = c_elem['hash']
            c_node = c_elem['node']
        except KeyError:
            log.warning(_(u'Received invalid capabilities tag: %s') % c_elem.toXml())
            return

        if c_ver in self.host.memory.disco.hashes:
            # we already know the hash, we update the jid entity
            log.debug(u"hash [%(hash)s] already in cache, updating entity [%(jid)s]" % {'hash': c_ver, 'jid': from_jid.full()})
            self.host.memory.updateEntityData(from_jid, C.ENTITY_CAP_HASH, c_ver, profile_key=self.profile)
            return

        if c_hash != 'sha-1': # unknown hash method
            log.warning(_(u'Unknown hash method for entity capabilities: [%(hash_method)s] (entity: %(jid)s, node: %(node)s)') % {'hash_method':c_hash, 'jid': from_jid, 'node': c_node})

        def cb(dummy):
            computed_hash = self.host.memory.getEntityDatum(from_jid, C.ENTITY_CAP_HASH, self.profile)
            if computed_hash != c_ver:
                log.warning(_(u'Computed hash differ from given hash:\ngiven: [%(given_hash)s]\ncomputed: [%(computed_hash)s]\n(entity: %(jid)s, node: %(node)s)') % {'given_hash':c_ver, 'computed_hash': computed_hash, 'jid': from_jid, 'node': c_node})

        def eb(failure):
            if isinstance(failure.value, error.ConnectionDone):
                return
            msg = failure.value.condition if hasattr(failure.value, 'condition') else failure.getErrorMessage()
            log.error(_(u"Couldn't retrieve disco info for {jid}: {error}").format(jid=from_jid.full(), error=msg))

        d = self.host.getDiscoInfos(self.parent, from_jid)
        d.addCallbacks(cb, eb)
        # TODO: me must manage the full algorithm described at XEP-0115 #5.4 part 3