diff options
| -rw-r--r-- | changelog.d/7066.bugfix | 1 | ||||
| -rw-r--r-- | synapse/handlers/message.py | 2 | ||||
| -rw-r--r-- | synapse/visibility.py | 65 |
3 files changed, 37 insertions, 31 deletions
diff --git a/changelog.d/7066.bugfix b/changelog.d/7066.bugfix new file mode 100644 index 0000000000..94bb096287 --- /dev/null +++ b/changelog.d/7066.bugfix @@ -0,0 +1 @@ +Fix a bug that would cause Synapse to respond with an error about event visibility if a client tried to request the state of a room at a given token. diff --git a/synapse/handlers/message.py b/synapse/handlers/message.py index 0c84c6cec4..b743fc2dcc 100644 --- a/synapse/handlers/message.py +++ b/synapse/handlers/message.py @@ -160,7 +160,7 @@ class MessageHandler(object): raise NotFoundError("Can't find event for token %s" % (at_token,)) visible_events = yield filter_events_for_client( - self.storage, user_id, last_events, apply_retention_policies=False + self.storage, user_id, last_events, filter_send_to_client=False ) event = last_events[0] diff --git a/synapse/visibility.py b/synapse/visibility.py index a48a4f3dfe..bab41182b9 100644 --- a/synapse/visibility.py +++ b/synapse/visibility.py @@ -49,7 +49,7 @@ def filter_events_for_client( events, is_peeking=False, always_include_ids=frozenset(), - apply_retention_policies=True, + filter_send_to_client=True, ): """ Check which events a user is allowed to see. If the user can see the event but its @@ -65,10 +65,9 @@ def filter_events_for_client( events always_include_ids (set(event_id)): set of event ids to specifically include (unless sender is ignored) - apply_retention_policies (bool): Whether to filter out events that's older than - allowed by the room's retention policy. Useful when this function is called - to e.g. check whether a user should be allowed to see the state at a given - event rather than to know if it should send an event to a user's client(s). + filter_send_to_client (bool): Whether we're checking an event that's going to be + sent to a client. This might not always be the case since this function can + also be called to check whether a user can see the state at a given point. Returns: Deferred[list[synapse.events.EventBase]] @@ -96,7 +95,7 @@ def filter_events_for_client( erased_senders = yield storage.main.are_users_erased((e.sender for e in events)) - if apply_retention_policies: + if filter_send_to_client: room_ids = {e.room_id for e in events} retention_policies = {} @@ -119,30 +118,36 @@ def filter_events_for_client( the original event if they can see it as normal. """ - if event.type == "org.matrix.dummy_event": - return None - - if not event.is_state() and event.sender in ignore_list: - return None - - # Until MSC2261 has landed we can't redact malicious alias events, so for - # now we temporarily filter out m.room.aliases entirely to mitigate - # abuse, while we spec a better solution to advertising aliases - # on rooms. - if event.type == EventTypes.Aliases: - return None - - # Don't try to apply the room's retention policy if the event is a state event, as - # MSC1763 states that retention is only considered for non-state events. - if apply_retention_policies and not event.is_state(): - retention_policy = retention_policies[event.room_id] - max_lifetime = retention_policy.get("max_lifetime") - - if max_lifetime is not None: - oldest_allowed_ts = storage.main.clock.time_msec() - max_lifetime - - if event.origin_server_ts < oldest_allowed_ts: - return None + # Only run some checks if these events aren't about to be sent to clients. This is + # because, if this is not the case, we're probably only checking if the users can + # see events in the room at that point in the DAG, and that shouldn't be decided + # on those checks. + if filter_send_to_client: + if event.type == "org.matrix.dummy_event": + return None + + if not event.is_state() and event.sender in ignore_list: + return None + + # Until MSC2261 has landed we can't redact malicious alias events, so for + # now we temporarily filter out m.room.aliases entirely to mitigate + # abuse, while we spec a better solution to advertising aliases + # on rooms. + if event.type == EventTypes.Aliases: + return None + + # Don't try to apply the room's retention policy if the event is a state + # event, as MSC1763 states that retention is only considered for non-state + # events. + if not event.is_state(): + retention_policy = retention_policies[event.room_id] + max_lifetime = retention_policy.get("max_lifetime") + + if max_lifetime is not None: + oldest_allowed_ts = storage.main.clock.time_msec() - max_lifetime + + if event.origin_server_ts < oldest_allowed_ts: + return None if event.event_id in always_include_ids: return event |