diff options
| -rw-r--r-- | changelog.d/12905.bugfix | 1 | ||||
| -rw-r--r-- | synapse/handlers/message.py | 114 | ||||
| -rw-r--r-- | synapse/handlers/sync.py | 27 | ||||
| -rw-r--r-- | synapse/storage/databases/main/state.py | 12 | ||||
| -rw-r--r-- | synapse/storage/databases/main/stream.py | 12 | ||||
| -rw-r--r-- | synapse/visibility.py | 28 |
6 files changed, 129 insertions, 65 deletions
diff --git a/changelog.d/12905.bugfix b/changelog.d/12905.bugfix new file mode 100644 index 0000000000..67e95d0398 --- /dev/null +++ b/changelog.d/12905.bugfix @@ -0,0 +1 @@ +Fix a bug introduced in Synapse 1.58.0 where `/sync` would fail if the most recent event in a room was a redaction of an event that has since been purged. diff --git a/synapse/handlers/message.py b/synapse/handlers/message.py index cf7c2d1979..ac911a2ddc 100644 --- a/synapse/handlers/message.py +++ b/synapse/handlers/message.py @@ -28,6 +28,7 @@ from synapse.api.constants import ( EventContentFields, EventTypes, GuestAccess, + HistoryVisibility, Membership, RelationTypes, UserTypes, @@ -66,7 +67,7 @@ from synapse.util import json_decoder, json_encoder, log_failure, unwrapFirstErr from synapse.util.async_helpers import Linearizer, gather_results from synapse.util.caches.expiringcache import ExpiringCache from synapse.util.metrics import measure_func -from synapse.visibility import filter_events_for_client +from synapse.visibility import get_effective_room_visibility_from_state if TYPE_CHECKING: from synapse.events.third_party_rules import ThirdPartyEventRules @@ -182,51 +183,31 @@ class MessageHandler: state_filter = state_filter or StateFilter.all() if at_token: - last_event = await self.store.get_last_event_in_room_before_stream_ordering( - room_id, - end_token=at_token.room_key, + last_event_id = ( + await self.store.get_last_event_in_room_before_stream_ordering( + room_id, + end_token=at_token.room_key, + ) ) - if not last_event: + if not last_event_id: raise NotFoundError("Can't find event for token %s" % (at_token,)) - # check whether the user is in the room at that time to determine - # whether they should be treated as peeking. - state_map = await self._state_storage_controller.get_state_for_event( - last_event.event_id, - StateFilter.from_types([(EventTypes.Member, user_id)]), - ) - - joined = False - membership_event = state_map.get((EventTypes.Member, user_id)) - if membership_event: - joined = membership_event.membership == Membership.JOIN - - is_peeking = not joined - - visible_events = await filter_events_for_client( - self._storage_controllers, - user_id, - [last_event], - filter_send_to_client=False, - is_peeking=is_peeking, - ) - - if visible_events: - room_state_events = ( - await self._state_storage_controller.get_state_for_events( - [last_event.event_id], state_filter=state_filter - ) - ) - room_state: Mapping[Any, EventBase] = room_state_events[ - last_event.event_id - ] - else: + if not await self._user_can_see_state_at_event( + user_id, room_id, last_event_id + ): raise AuthError( 403, "User %s not allowed to view events in room %s at token %s" % (user_id, room_id, at_token), ) + + room_state_events = ( + await self._state_storage_controller.get_state_for_events( + [last_event_id], state_filter=state_filter + ) + ) + room_state: Mapping[Any, EventBase] = room_state_events[last_event_id] else: ( membership, @@ -256,6 +237,65 @@ class MessageHandler: events = self._event_serializer.serialize_events(room_state.values(), now) return events + async def _user_can_see_state_at_event( + self, user_id: str, room_id: str, event_id: str + ) -> bool: + # check whether the user was in the room, and the history visibility, + # at that time. + state_map = await self._state_storage_controller.get_state_for_event( + event_id, + StateFilter.from_types( + [ + (EventTypes.Member, user_id), + (EventTypes.RoomHistoryVisibility, ""), + ] + ), + ) + + membership = None + membership_event = state_map.get((EventTypes.Member, user_id)) + if membership_event: + 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 + + # otherwise, it depends on the history visibility. + visibility = get_effective_room_visibility_from_state(state_map) + + if visibility == HistoryVisibility.JOINED: + # we weren't a member at the time of the event, so we can't see this event. + return False + + # otherwise *invited* is good enough + if membership == Membership.INVITE: + return True + + if visibility == HistoryVisibility.INVITED: + # we weren't invited, so we can't see this event. + return False + + if visibility == HistoryVisibility.WORLD_READABLE: + return True + + # So it's SHARED, and the user was not a member at the time. The user cannot + # see history, unless they have *subsequently* joined the room. + # + # 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. We just treat it as though they + # never joined, and restrict access. + + ( + current_membership, + _, + ) = await self.store.get_local_current_membership_for_user_in_room( + user_id, event_id + ) + return current_membership == Membership.JOIN + async def get_joined_members(self, requester: Requester, room_id: str) -> dict: """Get all the joined members in the room and their profile information. diff --git a/synapse/handlers/sync.py b/synapse/handlers/sync.py index b5859dcb28..a1d41358d9 100644 --- a/synapse/handlers/sync.py +++ b/synapse/handlers/sync.py @@ -621,21 +621,32 @@ class SyncHandler: ) async def get_state_after_event( - self, event: EventBase, state_filter: Optional[StateFilter] = None + self, event_id: str, state_filter: Optional[StateFilter] = None ) -> StateMap[str]: """ Get the room state after the given event Args: - event: event of interest + event_id: event of interest state_filter: The state filter used to fetch state from the database. """ state_ids = await self._state_storage_controller.get_state_ids_for_event( - event.event_id, state_filter=state_filter or StateFilter.all() + event_id, state_filter=state_filter or StateFilter.all() ) - if event.is_state(): + + # using get_metadata_for_events here (instead of get_event) sidesteps an issue + # with redactions: if `event_id` is a redaction event, and we don't have the + # original (possibly because it got purged), get_event will refuse to return + # the redaction event, which isn't terribly helpful here. + # + # (To be fair, in that case we could assume it's *not* a state event, and + # therefore we don't need to worry about it. But still, it seems cleaner just + # to pull the metadata.) + m = (await self.store.get_metadata_for_events([event_id]))[event_id] + if m.state_key is not None and m.rejection_reason is None: state_ids = dict(state_ids) - state_ids[(event.type, event.state_key)] = event.event_id + state_ids[(m.event_type, m.state_key)] = event_id + return state_ids async def get_state_at( @@ -654,14 +665,14 @@ class SyncHandler: # FIXME: This gets the state at the latest event before the stream ordering, # which might not be the same as the "current state" of the room at the time # of the stream token if there were multiple forward extremities at the time. - last_event = await self.store.get_last_event_in_room_before_stream_ordering( + last_event_id = await self.store.get_last_event_in_room_before_stream_ordering( room_id, end_token=stream_position.room_key, ) - if last_event: + if last_event_id: state = await self.get_state_after_event( - last_event, state_filter=state_filter or StateFilter.all() + last_event_id, state_filter=state_filter or StateFilter.all() ) else: diff --git a/synapse/storage/databases/main/state.py b/synapse/storage/databases/main/state.py index a07ad85582..3f2be3854b 100644 --- a/synapse/storage/databases/main/state.py +++ b/synapse/storage/databases/main/state.py @@ -54,6 +54,7 @@ class EventMetadata: room_id: str event_type: str state_key: Optional[str] + rejection_reason: Optional[str] def _retrieve_and_check_room_version(room_id: str, room_version_id: str) -> RoomVersion: @@ -167,17 +168,22 @@ class StateGroupWorkerStore(EventsWorkerStore, SQLBaseStore): ) sql = f""" - SELECT e.event_id, e.room_id, e.type, se.state_key FROM events AS e + SELECT e.event_id, e.room_id, e.type, se.state_key, r.reason + FROM events AS e LEFT JOIN state_events se USING (event_id) + LEFT JOIN rejections r USING (event_id) WHERE {clause} """ txn.execute(sql, args) return { event_id: EventMetadata( - room_id=room_id, event_type=event_type, state_key=state_key + room_id=room_id, + event_type=event_type, + state_key=state_key, + rejection_reason=rejection_reason, ) - for event_id, room_id, event_type, state_key in txn + for event_id, room_id, event_type, state_key, rejection_reason in txn } result_map: Dict[str, EventMetadata] = {} diff --git a/synapse/storage/databases/main/stream.py b/synapse/storage/databases/main/stream.py index 0e3a23a140..8e88784d3c 100644 --- a/synapse/storage/databases/main/stream.py +++ b/synapse/storage/databases/main/stream.py @@ -765,15 +765,16 @@ class StreamWorkerStore(EventsWorkerStore, SQLBaseStore): self, room_id: str, end_token: RoomStreamToken, - ) -> Optional[EventBase]: - """Returns the last event in a room at or before a stream ordering + ) -> Optional[str]: + """Returns the ID of the last event in a room at or before a stream ordering Args: room_id end_token: The token used to stream from Returns: - The most recent event. + The ID of the most recent event, or None if there are no events in the room + before this stream ordering. """ last_row = await self.get_room_event_before_stream_ordering( @@ -781,10 +782,7 @@ class StreamWorkerStore(EventsWorkerStore, SQLBaseStore): stream_ordering=end_token.stream, ) if last_row: - _, _, event_id = last_row - event = await self.get_event(event_id, get_prev_content=True) - return event - + return last_row[2] return None async def get_current_room_stream_token_for_room_id( diff --git a/synapse/visibility.py b/synapse/visibility.py index 97548c14e3..8aaa8c709f 100644 --- a/synapse/visibility.py +++ b/synapse/visibility.py @@ -162,16 +162,7 @@ async def filter_events_for_client( state = event_id_to_state[event.event_id] # get the room_visibility at the time of the event. - visibility_event = state.get(_HISTORY_VIS_KEY, None) - if visibility_event: - visibility = visibility_event.content.get( - "history_visibility", HistoryVisibility.SHARED - ) - else: - visibility = HistoryVisibility.SHARED - - if visibility not in VISIBILITY_PRIORITY: - visibility = HistoryVisibility.SHARED + visibility = get_effective_room_visibility_from_state(state) # Always allow history visibility events on boundaries. This is done # by setting the effective visibility to the least restrictive @@ -267,6 +258,23 @@ async def filter_events_for_client( return [ev for ev in filtered_events if ev] +def get_effective_room_visibility_from_state(state: StateMap[EventBase]) -> str: + """Get the actual history vis, from a state map including the history_visibility event + + Handles missing and invalid history visibility events. + """ + visibility_event = state.get(_HISTORY_VIS_KEY, None) + if not visibility_event: + return HistoryVisibility.SHARED + + visibility = visibility_event.content.get( + "history_visibility", HistoryVisibility.SHARED + ) + if visibility not in VISIBILITY_PRIORITY: + visibility = HistoryVisibility.SHARED + return visibility + + async def filter_events_for_server( storage: StorageControllers, server_name: str, |