diff options
Diffstat (limited to 'synapse/visibility.py')
| -rw-r--r-- | synapse/visibility.py | 159 |
1 files changed, 157 insertions, 2 deletions
diff --git a/synapse/visibility.py b/synapse/visibility.py index 015c2bab37..ba0499a022 100644 --- a/synapse/visibility.py +++ b/synapse/visibility.py @@ -12,14 +12,18 @@ # 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. -import itertools + import logging import operator +from six import iteritems, itervalues +from six.moves import map + 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 from synapse.util.logcontext import make_deferred_yieldable, preserve_fn logger = logging.getLogger(__name__) @@ -218,10 +222,161 @@ def filter_events_for_client(store, user_id, events, is_peeking=False, return event # check each event: gives an iterable[None|EventBase] - filtered_events = itertools.imap(allowed, events) + filtered_events = map(allowed, events) # remove the None entries filtered_events = filter(operator.truth, filtered_events) # we turn it into a list before returning it. defer.returnValue(list(filtered_events)) + + +@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, + ) + + 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=( + (EventTypes.RoomHistoryVisibility, ""), + ) + ) + + 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), + ) + ) + + # 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 + ]) |