view sat/plugins/plugin_xep_0280.py @ 3153:2c7b42f53e9a

core (xmpp): avoid starting several clients at the same time: a check is done to avoid running startConnection several times at once, which would lead to the creation of several SatXMPPEntity instances at the same time, resulting in many issues. If startConnection is called while a previous one is not finished yet, a CancelError is now raised.
author Goffi <goffi@goffi.org>
date Mon, 03 Feb 2020 13:46:24 +0100
parents 49962f9a238a
children dcebc585c29f
line wrap: on
line source

#!/usr/bin/env python3


# SAT plugin for managing xep-0280
# Copyright (C) 2009-2020 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 _, D_
from sat.core.log import getLogger

log = getLogger(__name__)
from sat.core import exceptions
from sat.core.constants import Const as C
from twisted.words.protocols.jabber.error import StanzaError
from twisted.internet import defer
from wokkel import disco, iwokkel
from zope.interface import implementer

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


PARAM_CATEGORY = "Misc"
PARAM_NAME = "carbon"
PARAM_LABEL = D_("Message carbons")
NS_CARBONS = "urn:xmpp:carbons:2"

PLUGIN_INFO = {
    C.PI_NAME: "XEP-0280 Plugin",
    C.PI_IMPORT_NAME: "XEP-0280",
    C.PI_TYPE: "XEP",
    C.PI_PROTOCOLS: ["XEP-0280"],
    C.PI_DEPENDENCIES: [],
    C.PI_MAIN: "XEP_0280",
    C.PI_HANDLER: "yes",
    C.PI_DESCRIPTION: D_("""Implementation of Message Carbons"""),
}


class XEP_0280(object):
    #  TODO: param is only checked at profile connection
    #       activate carbons on param change even after profile connection
    # TODO: chat state notifications are not handled yet (and potentially other XEPs?)

    params = """
    <params>
    <individual>
    <category name="{category_name}" label="{category_label}">
        <param name="{param_name}" label="{param_label}" value="true" type="bool" security="0" />
     </category>
    </individual>
    </params>
    """.format(
        category_name=PARAM_CATEGORY,
        category_label=D_(PARAM_CATEGORY),
        param_name=PARAM_NAME,
        param_label=PARAM_LABEL,
    )

    def __init__(self, host):
        log.info(_("Plugin XEP_0280 initialization"))
        self.host = host
        host.memory.updateParams(self.params)
        host.trigger.add("MessageReceived", self.messageReceivedTrigger, priority=200000)

    def getHandler(self, client):
        return XEP_0280_handler()

    def setPrivate(self, message_elt):
        """Add a <private/> element to a message

        this method is intented to be called on final domish.Element by other plugins
        (in particular end 2 end encryption plugins)
        @param message_elt(domish.Element): <message> stanza
        """
        if message_elt.name != "message":
            log.error("addPrivateElt must be used with <message> stanzas")
            return
        message_elt.addElement((NS_CARBONS, "private"))

    @defer.inlineCallbacks
    def profileConnected(self, client):
        """activate message carbons on connection if possible and activated in config"""
        activate = self.host.memory.getParamA(
            PARAM_NAME, PARAM_CATEGORY, profile_key=client.profile
        )
        if not activate:
            log.info(_("Not activating message carbons as requested in params"))
            return
        try:
            yield self.host.checkFeatures(client, (NS_CARBONS,))
        except exceptions.FeatureNotFound:
            log.warning(_("server doesn't handle message carbons"))
        else:
            log.info(_("message carbons available, enabling it"))
            iq_elt = client.IQ()
            iq_elt.addElement((NS_CARBONS, "enable"))
            try:
                yield iq_elt.send()
            except StanzaError as e:
                log.warning("Can't activate message carbons: {}".format(e))
            else:
                log.info(_("message carbons activated"))

    def messageReceivedTrigger(self, client, message_elt, post_treat):
        """get message and handle it if carbons namespace is present"""
        carbons_elt = None
        for e in message_elt.elements():
            if e.uri == NS_CARBONS:
                carbons_elt = e
                break

        if carbons_elt is None:
            # this is not a message carbons,
            # we continue normal behaviour
            return True

        if message_elt["from"] != client.jid.userhost():
            log.warning(
                "The message carbon received is not from our server, hack attempt?\n{xml}".format(
                    xml=message_elt.toXml()
                )
            )
            return
        forwarded_elt = next(carbons_elt.elements(C.NS_FORWARD, "forwarded"))
        cc_message_elt = next(forwarded_elt.elements(C.NS_CLIENT, "message"))

        # we replace the wrapping message with the CCed one
        # and continue the normal behaviour
        if carbons_elt.name == "received":
            message_elt["from"] = cc_message_elt["from"]
        elif carbons_elt.name == "sent":
            try:
                message_elt["to"] = cc_message_elt["to"]
            except KeyError:
                # we may not have "to" in case of message from ourself (from an other
                # device)
                pass
        else:
            log.warning(
                "invalid message carbons received:\n{xml}".format(
                    xml=message_elt.toXml()
                )
            )
            return False

        del message_elt.children[:]
        for c in cc_message_elt.children:
            message_elt.addChild(c)

        return True

@implementer(iwokkel.IDisco)
class XEP_0280_handler(XMPPHandler):

    def getDiscoInfo(self, requestor, target, nodeIdentifier=""):
        return [disco.DiscoFeature(NS_CARBONS)]

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