237 lines
		
	
	
		
			8.2 KiB
		
	
	
	
		
			Python
		
	
	
			
		
		
	
	
			237 lines
		
	
	
		
			8.2 KiB
		
	
	
	
		
			Python
		
	
	
| # -*- 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 preserve_fn, preserve_context_over_deferred
 | |
| 
 | |
| 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):
 | |
|     """ 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
 | |
|     """
 | |
|     forgotten = yield preserve_context_over_deferred(defer.gatherResults([
 | |
|         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
 | |
| 
 | |
|         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_clients_context(store, user_tuples, events, event_id_to_context):
 | |
|     user_ids = set(u[0] for u in user_tuples)
 | |
|     event_id_to_state = {}
 | |
|     for event_id, context in event_id_to_context.items():
 | |
|         state = yield store.get_events([
 | |
|             e_id
 | |
|             for key, e_id in context.current_state_ids.iteritems()
 | |
|             if key == (EventTypes.RoomHistoryVisibility, "")
 | |
|             or (key[0] == EventTypes.Member and key[1] in user_ids)
 | |
|         ])
 | |
|         event_id_to_state[event_id] = state
 | |
| 
 | |
|     res = yield filter_events_for_clients(
 | |
|         store, user_tuples, events, event_id_to_state
 | |
|     )
 | |
|     defer.returnValue(res)
 | |
| 
 | |
| 
 | |
| @defer.inlineCallbacks
 | |
| def filter_events_for_client(store, user_id, events, is_peeking=False):
 | |
|     """
 | |
|     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
 | |
|     )
 | |
|     defer.returnValue(res.get(user_id, []))
 |