view src/memory/disco.py @ 2138:6e509ee853a8

plugin OTR, core; use of new sendMessage + OTR mini refactoring: - new client.sendMessage method is used instead of sendMessageToStream - client.feedback is used in OTR - OTR now add message processing hints and carbon private element as recommanded by XEP-0364. Explicit Message Encryption is still TODO - OTR use the new sendMessageFinish trigger, this has a number of advantages: * there is little risk that OTR is skipped by other plugins (they have to use client.sendMessage as recommanded) * being at the end of the chain, OTR can check and remove any HTML or other leaking elements * OTR doesn't have to skip other plugins anymore, this means that things like delivery receipts are now working with OTR (but because there is not full stanza encryption, they can leak metadata) * OTR can decide to follow storage hint by letting or deleting "history" key
author Goffi <goffi@goffi.org>
date Sun, 05 Feb 2017 15:00:01 +0100
parents efe31f0881fb
children a543eda2c923
line wrap: on
line source

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

# SAT: a jabber client
# 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 import exceptions
from sat.core.log import getLogger
log = getLogger(__name__)
from twisted.words.protocols.jabber import jid
from twisted.words.protocols.jabber.error import StanzaError
from twisted.internet import defer
from twisted.internet import reactor
from twisted.python import failure
from sat.core.constants import Const as C
from sat.tools import xml_tools
from sat.memory import persistent
from wokkel import disco
from base64 import b64encode
from hashlib import sha1


TIMEOUT = 15
CAP_HASH_ERROR = 'ERROR'

class HashGenerationError(Exception):
    pass


class ByteIdentity(object):
    """This class manage identity as bytes (needed for i;octet sort), it is used for the hash generation"""

    def __init__(self, identity, lang=None):
        assert isinstance(identity, disco.DiscoIdentity)
        self.category = identity.category.encode('utf-8')
        self.idType = identity.type.encode('utf-8')
        self.name = identity.name.encode('utf-8') if identity.name else ''
        self.lang = lang.encode('utf-8') if lang is not None else ''

    def __str__(self):
        return "%s/%s/%s/%s" % (self.category, self.idType, self.lang, self.name)


class HashManager(object):
    """map object which manage hashes

    persistent storage is update when a new hash is added
    """

    def __init__(self, persistent):
        self.hashes = {
            CAP_HASH_ERROR: disco.DiscoInfo(), # used when we can't get disco infos
            }
        self.persistent = persistent

    def __getitem__(self, key):
        return self.hashes[key]

    def __setitem__(self, hash_, disco_info):
        if hash_ in self.hashes:
            log.debug(u"ignoring hash set: it is already known")
            return
        self.hashes[hash_] = disco_info
        self.persistent[hash_] = disco_info.toElement().toXml()

    def __contains__(self, hash_):
        return self.hashes.__contains__(hash_)

    def load(self):
        def fillHashes(hashes):
            for hash_, xml in hashes.iteritems():
                element = xml_tools.ElementParser()(xml)
                self.hashes[hash_] = disco.DiscoInfo.fromElement(element)
            log.info(u"Disco hashes loaded")
        d = self.persistent.load()
        d.addCallback(fillHashes)
        return d


class Discovery(object):
    """ Manage capabilities of entities """

    def __init__(self, host):
        self.host = host
        # TODO: remove legacy hashes

    def load(self):
        """Load persistent hashes"""
        self.hashes = HashManager(persistent.PersistentDict("disco"))
        return self.hashes.load()

    @defer.inlineCallbacks
    def hasFeature(self, feature, jid_=None, profile=C.PROF_KEY_NONE):
        """Tell if an entity has the required feature

        @param feature: feature namespace
        @param jid_: jid of the target, or None for profile's server
        @param profile: %(doc_profile)s
        @return: a Deferred which fire a boolean (True if feature is available)
        """
        disco_infos = yield self.getInfos(jid_, profile)
        defer.returnValue(feature in disco_infos.features)

    @defer.inlineCallbacks
    def checkFeature(self, feature, jid_=None, profile=C.PROF_KEY_NONE):
        """Like hasFeature, but raise an exception is feature is not Found

        @param feature: feature namespace
        @param jid_: jid of the target, or None for profile's server
        @param profile: %(doc_profile)s

        @raise: exceptions.FeatureNotFound
        """
        disco_infos = yield self.getInfos(jid_, profile)
        if not feature in disco_infos.features:
            raise failure.Failure(exceptions.FeatureNotFound)

    @defer.inlineCallbacks
    def checkFeatures(self, features, jid_=None, identity=None, profile=C.PROF_KEY_NONE):
        """Like checkFeature, but check several features at once, and check also identity

        @param features(iterable[unicode]): features to check
        @param jid_(jid.JID): jid of the target, or None for profile's server
        @param identity(None, tuple(unicode, unicode): if not None, the entity must have an identity with this (category, type) tuple
        @param profile: %(doc_profile)s

        @raise: exceptions.FeatureNotFound
        """
        disco_infos = yield self.getInfos(jid_, profile)
        if not set(features).issubset(disco_infos.features):
            raise failure.Failure(exceptions.FeatureNotFound())

        if identity is not None and identity not in disco_infos.identities:
            raise failure.Failure(exceptions.FeatureNotFound())

    def getInfos(self, jid_=None, profile=C.PROF_KEY_NONE):
        """get disco infos from jid_, filling capability hash if needed

        @param jid_: jid of the target, or None for profile's server
        @param profile: %(doc_profile)s
        @return: a Deferred which fire disco.DiscoInfo
        """
        client = self.host.getClient(profile)
        if jid_ is None:
            jid_ = jid.JID(client.jid.host)
        try:
            cap_hash = self.host.memory.getEntityData(jid_, [C.ENTITY_CAP_HASH], client.profile)[C.ENTITY_CAP_HASH]
        except (KeyError, exceptions.UnknownEntityError):
            # capability hash is not available, we'll compute one
            def infosCb(disco_infos):
                cap_hash = self.generateHash(disco_infos)
                self.hashes[cap_hash] = disco_infos
                self.host.memory.updateEntityData(jid_, C.ENTITY_CAP_HASH, cap_hash, profile_key=client.profile)
                return disco_infos
            def infosEb(fail):
                if fail.check(defer.CancelledError):
                    reason = u"request time-out"
                else:
                    try:
                        reason = unicode(fail.value)
                    except AttributeError:
                        reason = unicode(fail)
                    log.warning(u"Error while requesting disco infos from {jid}: {reason}".format(jid=jid_.full(), reason=reason))
                self.host.memory.updateEntityData(jid_, C.ENTITY_CAP_HASH, CAP_HASH_ERROR, profile_key=client.profile)
                disco_infos = self.hashes[CAP_HASH_ERROR]
                return disco_infos
            d = client.disco.requestInfo(jid_)
            d.addCallback(infosCb)
            d.addErrback(infosEb)
            return d
        else:
            disco_infos = self.hashes[cap_hash]
            return defer.succeed(disco_infos)

    @defer.inlineCallbacks
    def getItems(self, jid_=None, nodeIdentifier='', profile=C.PROF_KEY_NONE):
        """get disco items from jid_, cache them for our own server

        @param jid_ (jid.JID): jid of the target, or None for profile's server
        @param nodeIdentifier (str): optional node identifier
        @param profile: %(doc_profile)s
        @return: a Deferred which fire disco.DiscoItems
        """
        client = self.host.getClient(profile)
        if jid_ is None:
            jid_ = jid.JID(client.jid.host)
            # we cache items only for our own server
            try:
                items = self.host.memory.getEntityData(jid_, ["DISCO_ITEMS"], client.profile)["DISCO_ITEMS"]
                log.debug(u"[%s] disco items are in cache" % jid_.full())
            except (KeyError, exceptions.UnknownEntityError):
                log.debug(u"Caching [%s] disco items" % jid_.full())
                items = yield client.disco.requestItems(jid_, nodeIdentifier)
                self.host.memory.updateEntityData(jid_, "DISCO_ITEMS", items, profile_key=client.profile)
        else:
            try:
                items = yield client.disco.requestItems(jid_, nodeIdentifier)
            except StanzaError as e:
                log.warning(u"Error while requesting items for {jid}: {reason}"
                    .format(jid=jid_.full(), reason=e.condition))
                items = disco.DiscoItems()

        defer.returnValue(items)


    def _infosEb(self, failure_, entity_jid):
        failure_.trap(StanzaError)
        log.warning(_(u"Error while requesting [%(jid)s]: %(error)s") % {'jid': entity_jid.full(),
                                                                    'error': failure_.getErrorMessage()})

    def findServiceEntities(self, category, type_, jid_=None, profile=C.PROF_KEY_NONE):
        """Return all available items of an entity which correspond to (category, type_)

        @param category: identity's category
        @param type_: identitiy's type
        @param jid_: the jid of the target server (None for profile's server)
        @param profile: %(doc_profile)s
        @return: a set of found entities
        @raise defer.CancelledError: the request timed out
        """
        found_entities = set()

        def infosCb(infos, entity_jid):
            if (category, type_) in infos.identities:
                found_entities.add(entity_jid)

        def gotItems(items):
            defers_list = []
            for item in items:
                info_d = self.getInfos(item.entity, profile)
                info_d.addCallbacks(infosCb, self._infosEb, [item.entity], None, [item.entity])
                defers_list.append(info_d)
            return defer.DeferredList(defers_list)

        d = self.getItems(jid_, profile=profile)
        d.addCallback(gotItems)
        d.addCallback(lambda dummy: found_entities)
        reactor.callLater(TIMEOUT, d.cancel) # FIXME: one bad service make a general timeout
        return d

    def findFeaturesSet(self, features, identity=None, jid_=None, profile=C.PROF_KEY_NONE):
        """Return entities (including jid_ and its items) offering features

        @param features: iterable of features which must be present
        @param identity(None, tuple(unicode, unicode)): if not None, accept only this (category/type) identity
        @param jid_: the jid of the target server (None for profile's server)
        @param profile: %(doc_profile)s
        @return: a set of found entities
        """
        client = self.host.getClient(profile)
        if jid_ is None:
            jid_ = jid.JID(client.jid.host)
        features = set(features)
        found_entities = set()

        def infosCb(infos, entity):
            if identity is not None and identity not in infos.identities:
                return
            if features.issubset(infos.features):
                found_entities.add(entity)

        def gotItems(items):
            defer_list = []
            for entity in [jid_] + [item.entity for item in items]:
                infos_d = self.getInfos(entity, profile)
                infos_d.addCallbacks(infosCb, self._infosEb, [entity], None, [entity])
                defer_list.append(infos_d)
            return defer.DeferredList(defer_list)

        d = self.getItems(jid_, profile=profile)
        d.addCallback(gotItems)
        d.addCallback(lambda dummy: found_entities)
        reactor.callLater(TIMEOUT, d.cancel) # FIXME: one bad service make a general timeout
        return d

    def generateHash(self, services):
        """ Generate a unique hash for given service

        hash algorithm is the one described in XEP-0115
        @param services: iterable of disco.DiscoIdentity/disco.DiscoFeature, as returned by discoHandler.info

        """
        s = []
        byte_identities = [ByteIdentity(service) for service in services if isinstance(service, disco.DiscoIdentity)]  # FIXME: lang must be managed here
        byte_identities.sort(key=lambda i: i.lang)
        byte_identities.sort(key=lambda i: i.idType)
        byte_identities.sort(key=lambda i: i.category)
        for identity in byte_identities:
            s.append(str(identity))
            s.append('<')
        byte_features = [service.encode('utf-8') for service in services if isinstance(service, disco.DiscoFeature)]
        byte_features.sort()  # XXX: the default sort has the same behaviour as the requested RFC 4790 i;octet sort
        for feature in byte_features:
            s.append(feature)
            s.append('<')
        #TODO: manage XEP-0128 data form here
        cap_hash = b64encode(sha1(''.join(s)).digest())
        log.debug(_(u'Capability hash generated: [%s]') % cap_hash)
        return cap_hash

    @defer.inlineCallbacks
    def _discoInfos(self, entity_jid_s, profile_key=C.PROF_KEY_NONE):
        """ Discovery method for the bridge
        @param entity_jid_s: entity we want to discover

        @return: list of tuples
        """
        profile = self.host.memory.getProfileName(profile_key)
        entity = jid.JID(entity_jid_s)
        disco_infos = yield self.getInfos(entity, profile)
        extensions = {}
        for form_type, form in disco_infos.extensions.items():
            fields = []
            for field in form.fieldList:
                data = {'type': field.fieldType}
                for attr in ('var', 'label', 'desc'):
                    value = getattr(field, attr)
                    if value is not None:
                        data[attr] = value

                values = [field.value] if field.value is not None else field.values
                fields.append((data, values))

            extensions[form_type or ""] = fields

        defer.returnValue((disco_infos.features,
            [(cat, type_, name or '') for (cat, type_), name in disco_infos.identities.items()],
            extensions))

    @defer.inlineCallbacks
    def _discoItems(self, entity_jid_s, profile_key=C.PROF_KEY_NONE):
        """ Discovery method for the bridge
        @param entity_jid_s: entity we want to discover

        @return: list of tuples"""
        profile = self.host.memory.getProfileName(profile_key)
        entity = jid.JID(entity_jid_s)
        disco_items = yield self.getItems(entity, profile=profile)
        try:
            ret = [(item.entity.full(), item.nodeIdentifier or '', item.name or '') for item in disco_items]
        except AttributeError:
            log.error(u"error while getting items from {entity}, it may result from invalid item(s)".format(entity=entity.full()))
            # second try by ignoring empty items
            ret = [(item.entity.full(), item.nodeIdentifier or '', item.name or '') for item in disco_items if item.entity]

        defer.returnValue(ret)