diff --git a/changelog.d/14404.misc b/changelog.d/14404.misc new file mode 100644 index 0000000000..b9ab525f2b --- /dev/null +++ b/changelog.d/14404.misc @@ -0,0 +1 @@ +Faster joins: filter out non local events when a room doesn't have its full state. diff --git a/synapse/federation/sender/per_destination_queue.py b/synapse/federation/sender/per_destination_queue.py index 084c45a95c..3ae5e8634c 100644 --- a/synapse/federation/sender/per_destination_queue.py +++ b/synapse/federation/sender/per_destination_queue.py @@ -505,6 +505,7 @@ class PerDestinationQueue: new_pdus = await filter_events_for_server( self._storage_controllers, self._destination, + self._server_name, new_pdus, redact=False, ) diff --git a/synapse/handlers/federation.py b/synapse/handlers/federation.py index 188f0956ef..d92582fd5c 100644 --- a/synapse/handlers/federation.py +++ b/synapse/handlers/federation.py @@ -379,6 +379,7 @@ class FederationHandler: filtered_extremities = await filter_events_for_server( self._storage_controllers, self.server_name, + self.server_name, events_to_check, redact=False, check_history_visibility_only=True, @@ -1231,7 +1232,9 @@ class FederationHandler: async def on_backfill_request( self, origin: str, room_id: str, pdu_list: List[str], limit: int ) -> List[EventBase]: - await self._event_auth_handler.assert_host_in_room(room_id, origin) + # We allow partially joined rooms since in this case we are filtering out + # non-local events in `filter_events_for_server`. + await self._event_auth_handler.assert_host_in_room(room_id, origin, True) # Synapse asks for 100 events per backfill request. Do not allow more. limit = min(limit, 100) @@ -1252,7 +1255,7 @@ class FederationHandler: ) events = await filter_events_for_server( - self._storage_controllers, origin, events + self._storage_controllers, origin, self.server_name, events ) return events @@ -1283,7 +1286,7 @@ class FederationHandler: await self._event_auth_handler.assert_host_in_room(event.room_id, origin) events = await filter_events_for_server( - self._storage_controllers, origin, [event] + self._storage_controllers, origin, self.server_name, [event] ) event = events[0] return event @@ -1296,7 +1299,9 @@ class FederationHandler: latest_events: List[str], limit: int, ) -> List[EventBase]: - await self._event_auth_handler.assert_host_in_room(room_id, origin) + # We allow partially joined rooms since in this case we are filtering out + # non-local events in `filter_events_for_server`. + await self._event_auth_handler.assert_host_in_room(room_id, origin, True) # Only allow up to 20 events to be retrieved per request. limit = min(limit, 20) @@ -1309,7 +1314,7 @@ class FederationHandler: ) missing_events = await filter_events_for_server( - self._storage_controllers, origin, missing_events + self._storage_controllers, origin, self.server_name, missing_events ) return missing_events diff --git a/synapse/visibility.py b/synapse/visibility.py index 40a9c5b53f..b443857571 100644 --- a/synapse/visibility.py +++ b/synapse/visibility.py @@ -563,7 +563,8 @@ def get_effective_room_visibility_from_state(state: StateMap[EventBase]) -> str: async def filter_events_for_server( storage: StorageControllers, - server_name: str, + target_server_name: str, + local_server_name: str, events: List[EventBase], redact: bool = True, check_history_visibility_only: bool = False, @@ -603,7 +604,7 @@ async def filter_events_for_server( # if the server is either in the room or has been invited # into the room. for ev in memberships.values(): - assert get_domain_from_id(ev.state_key) == server_name + assert get_domain_from_id(ev.state_key) == target_server_name memtype = ev.membership if memtype == Membership.JOIN: @@ -622,6 +623,24 @@ async def filter_events_for_server( # to no users having been erased. erased_senders = {} + # Filter out non-local events when we are in the middle of a partial join, since our servers + # list can be out of date and we could leak events to servers not in the room anymore. + # This can also be true for local events but we consider it to be an acceptable risk. + + # We do this check as a first step and before retrieving membership events because + # otherwise a room could be fully joined after we retrieve those, which would then bypass + # this check but would base the filtering on an outdated view of the membership events. + + partial_state_invisible_events = set() + if not check_history_visibility_only: + for e in events: + sender_domain = get_domain_from_id(e.sender) + if ( + sender_domain != local_server_name + and await storage.main.is_partial_state_room(e.room_id) + ): + partial_state_invisible_events.add(e) + # Let's check to see if all the events have a history visibility # of "shared" or "world_readable". If that's the case then we don't # need to check membership (as we know the server is in the room). @@ -636,7 +655,7 @@ async def filter_events_for_server( if event_to_history_vis[e.event_id] not in (HistoryVisibility.SHARED, HistoryVisibility.WORLD_READABLE) ], - server_name, + target_server_name, ) to_return = [] @@ -645,6 +664,10 @@ async def filter_events_for_server( visible = check_event_is_visible( event_to_history_vis[e.event_id], event_to_memberships.get(e.event_id, {}) ) + + if e in partial_state_invisible_events: + visible = False + if visible and not erased: to_return.append(e) elif redact: diff --git a/tests/test_visibility.py b/tests/test_visibility.py index c385b2f8d4..d0b9ad5454 100644 --- a/tests/test_visibility.py +++ b/tests/test_visibility.py @@ -61,7 +61,7 @@ class FilterEventsForServerTestCase(unittest.HomeserverTestCase): filtered = self.get_success( filter_events_for_server( - self._storage_controllers, "test_server", events_to_filter + self._storage_controllers, "test_server", "hs", events_to_filter ) ) @@ -83,7 +83,7 @@ class FilterEventsForServerTestCase(unittest.HomeserverTestCase): self.assertEqual( self.get_success( filter_events_for_server( - self._storage_controllers, "remote_hs", [outlier] + self._storage_controllers, "remote_hs", "hs", [outlier] ) ), [outlier], @@ -94,7 +94,7 @@ class FilterEventsForServerTestCase(unittest.HomeserverTestCase): filtered = self.get_success( filter_events_for_server( - self._storage_controllers, "remote_hs", [outlier, evt] + self._storage_controllers, "remote_hs", "local_hs", [outlier, evt] ) ) self.assertEqual(len(filtered), 2, f"expected 2 results, got: {filtered}") @@ -106,7 +106,7 @@ class FilterEventsForServerTestCase(unittest.HomeserverTestCase): # be redacted) filtered = self.get_success( filter_events_for_server( - self._storage_controllers, "other_server", [outlier, evt] + self._storage_controllers, "other_server", "local_hs", [outlier, evt] ) ) self.assertEqual(filtered[0], outlier) @@ -141,7 +141,7 @@ class FilterEventsForServerTestCase(unittest.HomeserverTestCase): # ... and the filtering happens. filtered = self.get_success( filter_events_for_server( - self._storage_controllers, "test_server", events_to_filter + self._storage_controllers, "test_server", "local_hs", events_to_filter ) )