diff options
Diffstat (limited to 'synapse/visibility.py')
| -rw-r--r-- | synapse/visibility.py | 330 |
1 files changed, 229 insertions, 101 deletions
diff --git a/synapse/visibility.py b/synapse/visibility.py index c4dd9ae2c7..d4680863d3 100644 --- a/synapse/visibility.py +++ b/synapse/visibility.py @@ -13,14 +13,17 @@ # 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 +import logging +import operator -from synapse.util.logcontext import preserve_fn, preserve_context_over_deferred +from six import iteritems, itervalues +from six.moves import map -import logging +from twisted.internet import defer +from synapse.api.constants import EventTypes, Membership +from synapse.events.utils import prune_event +from synapse.types import get_domain_from_id logger = logging.getLogger(__name__) @@ -43,53 +46,66 @@ MEMBERSHIP_PRIORITY = ( @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. +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_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([ - 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)) + store (synapse.storage.DataStore): our datastore (can also be a worker + store) + user_id(str): user id to be checked + events(list[synapse.events.EventBase]): sequence 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 + always_include_ids (set(event_id)): set of event ids to specifically + include (unless sender is ignored) - # Set of membership event_ids that have been forgotten - event_id_forgotten = frozenset( - row["event_id"] for rows in forgotten for row in rows + Returns: + Deferred[list[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, ) - 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] + ignore_dict_content = yield store.get_global_account_data_by_type_for_user( + "m.ignored_user_list", user_id, ) # 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() - } + ignore_list = frozenset( + ignore_dict_content.get("ignored_users", {}).keys() + if ignore_dict_content else [] + ) + + erased_senders = yield store.are_users_erased((e.sender for e in events)) - def allowed(event, user_id, is_peeking, ignore_list): + def allowed(event): """ Args: event (synapse.events.EventBase): event to check - user_id (str) - is_peeking (bool) - ignore_list (list): list of users to ignore + + Returns: + None|EventBase: + None if the user cannot see this event at all + + a redacted copy of the event if they can only see a redacted + version + + the original event if they can see it as normal. """ if not event.is_state() and event.sender in ignore_list: - return False + return None + + if event.event_id in always_include_ids: + return event state = event_id_to_state[event.event_id] @@ -103,10 +119,6 @@ def filter_events_for_clients(store, user_tuples, events, event_id_to_state): 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. @@ -140,7 +152,7 @@ def filter_events_for_clients(store, user_tuples, events, event_id_to_state): if membership == "leave" and ( prev_membership == "join" or prev_membership == "invite" ): - return True + return event new_priority = MEMBERSHIP_PRIORITY.index(membership) old_priority = MEMBERSHIP_PRIORITY.index(prev_membership) @@ -151,87 +163,203 @@ def filter_events_for_clients(store, user_tuples, events, event_id_to_state): 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 + 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 + return event + + # otherwise, it depends on the room visibility. if visibility == "joined": # we weren't a member at the time of the event, so we can't # see this event. - return False + return None 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 + return ( + event if membership == Membership.INVITE else None + ) + + elif visibility == "shared" and is_peeking: + # if the visibility is shared, users cannot see the event unless + # they have *subequently* joined the room (or were members at the + # time, of course) # # 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 + # we don't know when they left. We just treat it as though they + # never joined, and restrict access. + return None - 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 - }) + # the visibility is either shared or world_readable, and the user was + # not a member at the time. We allow it, provided the original sender + # has not requested their data to be erased, in which case, we return + # a redacted version. + if erased_senders[event.sender]: + return prune_event(event) + return event -@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) + # check each event: gives an iterable[None|EventBase] + filtered_events = map(allowed, events) + # remove the None entries + filtered_events = filter(operator.truth, filtered_events) -@defer.inlineCallbacks -def filter_events_for_client(store, user_id, events, is_peeking=False): - """ - Check which events a user is allowed to see + # we turn it into a list before returning it. + defer.returnValue(list(filtered_events)) - 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), +@defer.inlineCallbacks +def filter_events_for_server(store, server_name, events): + # Whatever else we do, we need to check for senders which have requested + # erasure of their data. + erased_senders = yield store.are_users_erased( + e.sender for e in events, ) - event_id_to_state = yield store.get_state_for_events( + + def redact_disallowed(event, state): + # if the sender has been gdpr17ed, always return a redacted + # copy of the event. + if erased_senders[event.sender]: + logger.info( + "Sender of %s has been erased, redacting", + event.event_id, + ) + return prune_event(event) + + # state will be None if we decided we didn't need to filter by + # room membership. + if not state: + return event + + history = state.get((EventTypes.RoomHistoryVisibility, ''), None) + if history: + visibility = history.content.get("history_visibility", "shared") + if visibility in ["invited", "joined"]: + # We now loop through all state events looking for + # membership states for the requesting server to determine + # if the server is either in the room or has been invited + # into the room. + for ev in itervalues(state): + if ev.type != EventTypes.Member: + continue + try: + domain = get_domain_from_id(ev.state_key) + except Exception: + continue + + if domain != server_name: + continue + + memtype = ev.membership + if memtype == Membership.JOIN: + return event + elif memtype == Membership.INVITE: + if visibility == "invited": + return event + else: + # server has no users in the room: redact + return prune_event(event) + + return event + + # Next lets check to see if all the events have a history visibility + # of "shared" or "world_readable". If thats the case then we don't + # need to check membership (as we know the server is in the room). + event_to_state_ids = yield store.get_state_ids_for_events( frozenset(e.event_id for e in events), - types=types + types=( + (EventTypes.RoomHistoryVisibility, ""), + ) ) - res = yield filter_events_for_clients( - store, [(user_id, is_peeking)], events, event_id_to_state + + visibility_ids = set() + for sids in itervalues(event_to_state_ids): + hist = sids.get((EventTypes.RoomHistoryVisibility, "")) + if hist: + visibility_ids.add(hist) + + # If we failed to find any history visibility events then the default + # is "shared" visiblity. + if not visibility_ids: + all_open = True + else: + event_map = yield store.get_events(visibility_ids) + all_open = all( + e.content.get("history_visibility") in (None, "shared", "world_readable") + for e in itervalues(event_map) + ) + + if all_open: + # all the history_visibility state affecting these events is open, so + # we don't need to filter by membership state. We *do* need to check + # for user erasure, though. + if erased_senders: + events = [ + redact_disallowed(e, None) + for e in events + ] + + defer.returnValue(events) + + # Ok, so we're dealing with events that have non-trivial visibility + # rules, so we need to also get the memberships of the room. + + # first, for each event we're wanting to return, get the event_ids + # of the history vis and membership state at those events. + event_to_state_ids = yield store.get_state_ids_for_events( + frozenset(e.event_id for e in events), + types=( + (EventTypes.RoomHistoryVisibility, ""), + (EventTypes.Member, None), + ) ) - defer.returnValue(res.get(user_id, [])) + + # We only want to pull out member events that correspond to the + # server's domain. + # + # event_to_state_ids contains lots of duplicates, so it turns out to be + # cheaper to build a complete set of unique + # ((type, state_key), event_id) tuples, and then filter out the ones we + # don't want. + # + state_key_to_event_id_set = { + e + for key_to_eid in itervalues(event_to_state_ids) + for e in key_to_eid.items() + } + + def include(typ, state_key): + if typ != EventTypes.Member: + return True + + # we avoid using get_domain_from_id here for efficiency. + idx = state_key.find(":") + if idx == -1: + return False + return state_key[idx + 1:] == server_name + + event_map = yield store.get_events([ + e_id + for key, e_id in state_key_to_event_id_set + if include(key[0], key[1]) + ]) + + event_to_state = { + e_id: { + key: event_map[inner_e_id] + for key, inner_e_id in iteritems(key_to_eid) + if inner_e_id in event_map + } + for e_id, key_to_eid in iteritems(event_to_state_ids) + } + + defer.returnValue([ + redact_disallowed(e, event_to_state[e.event_id]) + for e in events + ]) |