# -*- coding: utf-8 -*- # Copyright 2014 - 2016 OpenMarket Ltd # # Licensed under the Apache License, Version 2.0 (the "License"); # you may not use this file except in compliance with the License. # You may obtain a copy of the License at # # http://www.apache.org/licenses/LICENSE-2.0 # # Unless required by applicable law or agreed to in writing, software # distributed under the License is distributed on an "AS IS" BASIS, # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. # See the License for the specific language governing permissions and # limitations under the License. from twisted.internet import defer from synapse.api.constants import Membership, EventTypes from synapse.util.logcontext import make_deferred_yieldable, preserve_fn import logging logger = logging.getLogger(__name__) VISIBILITY_PRIORITY = ( "world_readable", "shared", "invited", "joined", ) MEMBERSHIP_PRIORITY = ( Membership.JOIN, Membership.INVITE, Membership.KNOCK, Membership.LEAVE, Membership.BAN, ) @defer.inlineCallbacks def filter_events_for_clients(store, user_tuples, events, event_id_to_state, always_include_ids=frozenset()): """ Returns dict of user_id -> list of events that user is allowed to see. Args: user_tuples (str, bool): (user id, is_peeking) for each user to be checked. is_peeking should be true if: * the user is not currently a member of the room, and: * the user has not been a member of the room since the given events events ([synapse.events.EventBase]): list of events to filter always_include_ids (set(event_id)): set of event ids to specifically include (unless sender is ignored) """ forgotten = yield make_deferred_yieldable(defer.gatherResults([ defer.maybeDeferred( preserve_fn(store.who_forgot_in_room), room_id, ) for room_id in frozenset(e.room_id for e in events) ], consumeErrors=True)) # Set of membership event_ids that have been forgotten event_id_forgotten = frozenset( row["event_id"] for rows in forgotten for row in rows ) ignore_dict_content = yield store.get_global_account_data_by_type_for_users( "m.ignored_user_list", user_ids=[user_id for user_id, _ in user_tuples] ) # FIXME: This will explode if people upload something incorrect. ignore_dict = { user_id: frozenset( content.get("ignored_users", {}).keys() if content else [] ) for user_id, content in ignore_dict_content.items() } def allowed(event, user_id, is_peeking, ignore_list): """ Args: event (synapse.events.EventBase): event to check user_id (str) is_peeking (bool) ignore_list (list): list of users to ignore """ if not event.is_state() and event.sender in ignore_list: return False if event.event_id in always_include_ids: return True state = event_id_to_state[event.event_id] # get the room_visibility at the time of the event. visibility_event = state.get((EventTypes.RoomHistoryVisibility, ""), None) if visibility_event: visibility = visibility_event.content.get("history_visibility", "shared") else: visibility = "shared" if visibility not in VISIBILITY_PRIORITY: visibility = "shared" # if it was world_readable, it's easy: everyone can read it if visibility == "world_readable": return True # Always allow history visibility events on boundaries. This is done # by setting the effective visibility to the least restrictive # of the old vs new. if event.type == EventTypes.RoomHistoryVisibility: prev_content = event.unsigned.get("prev_content", {}) prev_visibility = prev_content.get("history_visibility", None) if prev_visibility not in VISIBILITY_PRIORITY: prev_visibility = "shared" new_priority = VISIBILITY_PRIORITY.index(visibility) old_priority = VISIBILITY_PRIORITY.index(prev_visibility) if old_priority < new_priority: visibility = prev_visibility # likewise, if the event is the user's own membership event, use # the 'most joined' membership membership = None if event.type == EventTypes.Member and event.state_key == user_id: membership = event.content.get("membership", None) if membership not in MEMBERSHIP_PRIORITY: membership = "leave" prev_content = event.unsigned.get("prev_content", {}) prev_membership = prev_content.get("membership", None) if prev_membership not in MEMBERSHIP_PRIORITY: prev_membership = "leave" # Always allow the user to see their own leave events, otherwise # they won't see the room disappear if they reject the invite if membership == "leave" and ( prev_membership == "join" or prev_membership == "invite" ): return True new_priority = MEMBERSHIP_PRIORITY.index(membership) old_priority = MEMBERSHIP_PRIORITY.index(prev_membership) if old_priority < new_priority: membership = prev_membership # otherwise, get the user's membership at the time of the event. if membership is None: membership_event = state.get((EventTypes.Member, user_id), None) if membership_event: if membership_event.event_id not in event_id_forgotten: membership = membership_event.membership # if the user was a member of the room at the time of the event, # they can see it. if membership == Membership.JOIN: return True if visibility == "joined": # we weren't a member at the time of the event, so we can't # see this event. return False elif visibility == "invited": # user can also see the event if they were *invited* at the time # of the event. return membership == Membership.INVITE else: # visibility is shared: user can also see the event if they have # become a member since the event # # XXX: if the user has subsequently joined and then left again, # ideally we would share history up to the point they left. But # we don't know when they left. return not is_peeking defer.returnValue({ user_id: [ event for event in events if allowed(event, user_id, is_peeking, ignore_dict.get(user_id, [])) ] for user_id, is_peeking in user_tuples }) @defer.inlineCallbacks def filter_events_for_client(store, user_id, events, is_peeking=False, always_include_ids=frozenset()): """ Check which events a user is allowed to see Args: user_id(str): user id to be checked events([synapse.events.EventBase]): list of events to be checked is_peeking(bool): should be True if: * the user is not currently a member of the room, and: * the user has not been a member of the room since the given events Returns: [synapse.events.EventBase] """ types = ( (EventTypes.RoomHistoryVisibility, ""), (EventTypes.Member, user_id), ) event_id_to_state = yield store.get_state_for_events( frozenset(e.event_id for e in events), types=types ) res = yield filter_events_for_clients( store, [(user_id, is_peeking)], events, event_id_to_state, always_include_ids=always_include_ids, ) defer.returnValue(res.get(user_id, []))