diff options
Diffstat (limited to 'synapse/handlers/federation.py')
| -rw-r--r-- | synapse/handlers/federation.py | 237 |
1 files changed, 179 insertions, 58 deletions
diff --git a/synapse/handlers/federation.py b/synapse/handlers/federation.py index 8197b60b76..9a5e726533 100644 --- a/synapse/handlers/federation.py +++ b/synapse/handlers/federation.py @@ -42,6 +42,7 @@ from twisted.internet import defer from synapse import event_auth from synapse.api.constants import ( + EventContentFields, EventTypes, Membership, RejectedReason, @@ -108,21 +109,33 @@ soft_failed_event_counter = Counter( ) -@attr.s(slots=True) +@attr.s(slots=True, frozen=True, auto_attribs=True) class _NewEventInfo: """Holds information about a received event, ready for passing to _auth_and_persist_events Attributes: event: the received event - state: the state at that event + state: the state at that event, according to /state_ids from a remote + homeserver. Only populated for backfilled events which are going to be a + new backwards extremity. + + claimed_auth_event_map: a map of (type, state_key) => event for the event's + claimed auth_events. + + This can include events which have not yet been persisted, in the case that + we are backfilling a batch of events. + + Note: May be incomplete: if we were unable to find all of the claimed auth + events. Also, treat the contents with caution: the events might also have + been rejected, might not yet have been authorized themselves, or they might + be in the wrong room. - auth_events: the auth_event map for that event """ - event = attr.ib(type=EventBase) - state = attr.ib(type=Optional[Sequence[EventBase]], default=None) - auth_events = attr.ib(type=Optional[MutableStateMap[EventBase]], default=None) + event: EventBase + state: Optional[Sequence[EventBase]] + claimed_auth_event_map: StateMap[EventBase] class FederationHandler(BaseHandler): @@ -262,7 +275,12 @@ class FederationHandler(BaseHandler): state = None - # Get missing pdus if necessary. + # Check that the event passes auth based on the state at the event. This is + # done for events that are to be added to the timeline (non-outliers). + # + # Get missing pdus if necessary: + # - Fetching any missing prev events to fill in gaps in the graph + # - Fetching state if we have a hole in the graph if not pdu.internal_metadata.is_outlier(): # We only backfill backwards to the min depth. min_depth = await self.get_min_depth_for_context(pdu.room_id) @@ -432,6 +450,13 @@ class FederationHandler(BaseHandler): affected=event_id, ) + # A second round of checks for all events. Check that the event passes auth + # based on `auth_events`, this allows us to assert that the event would + # have been allowed at some point. If an event passes this check its OK + # for it to be used as part of a returned `/state` request, as either + # a) we received the event as part of the original join and so trust it, or + # b) we'll do a state resolution with existing state before it becomes + # part of the "current state", which adds more protection. await self._process_received_pdu(origin, pdu, state=state) async def _get_missing_events_for_pdu( @@ -889,6 +914,79 @@ class FederationHandler(BaseHandler): "resync_device_due_to_pdu", self._resync_device, event.sender ) + await self._handle_marker_event(origin, event) + + async def _handle_marker_event(self, origin: str, marker_event: EventBase): + """Handles backfilling the insertion event when we receive a marker + event that points to one. + + Args: + origin: Origin of the event. Will be called to get the insertion event + marker_event: The event to process + """ + + if marker_event.type != EventTypes.MSC2716_MARKER: + # Not a marker event + return + + if marker_event.rejected_reason is not None: + # Rejected event + return + + # Skip processing a marker event if the room version doesn't + # support it. + room_version = await self.store.get_room_version(marker_event.room_id) + if not room_version.msc2716_historical: + return + + logger.debug("_handle_marker_event: received %s", marker_event) + + insertion_event_id = marker_event.content.get( + EventContentFields.MSC2716_MARKER_INSERTION + ) + + if insertion_event_id is None: + # Nothing to retrieve then (invalid marker) + return + + logger.debug( + "_handle_marker_event: backfilling insertion event %s", insertion_event_id + ) + + await self._get_events_and_persist( + origin, + marker_event.room_id, + [insertion_event_id], + ) + + insertion_event = await self.store.get_event( + insertion_event_id, allow_none=True + ) + if insertion_event is None: + logger.warning( + "_handle_marker_event: server %s didn't return insertion event %s for marker %s", + origin, + insertion_event_id, + marker_event.event_id, + ) + return + + logger.debug( + "_handle_marker_event: succesfully backfilled insertion event %s from marker event %s", + insertion_event, + marker_event, + ) + + await self.store.insert_insertion_extremity( + insertion_event_id, marker_event.room_id + ) + + logger.debug( + "_handle_marker_event: insertion extremity added for %s from marker event %s", + insertion_event, + marker_event, + ) + async def _resync_device(self, sender: str) -> None: """We have detected that the device list for the given user may be out of sync, so we try and resync them. @@ -1000,7 +1098,7 @@ class FederationHandler(BaseHandler): _NewEventInfo( event=ev, state=events_to_state[e_id], - auth_events={ + claimed_auth_event_map={ ( auth_events[a_id].type, auth_events[a_id].state_key, @@ -1057,9 +1155,19 @@ class FederationHandler(BaseHandler): async def _maybe_backfill_inner( self, room_id: str, current_depth: int, limit: int ) -> bool: - extremities = await self.store.get_oldest_events_with_depth_in_room(room_id) + oldest_events_with_depth = ( + await self.store.get_oldest_event_ids_with_depth_in_room(room_id) + ) + insertion_events_to_be_backfilled = ( + await self.store.get_insertion_event_backwards_extremities_in_room(room_id) + ) + logger.debug( + "_maybe_backfill_inner: extremities oldest_events_with_depth=%s insertion_events_to_be_backfilled=%s", + oldest_events_with_depth, + insertion_events_to_be_backfilled, + ) - if not extremities: + if not oldest_events_with_depth and not insertion_events_to_be_backfilled: logger.debug("Not backfilling as no extremeties found.") return False @@ -1089,10 +1197,12 @@ class FederationHandler(BaseHandler): # state *before* the event, ignoring the special casing certain event # types have. - forward_events = await self.store.get_successor_events(list(extremities)) + forward_event_ids = await self.store.get_successor_events( + list(oldest_events_with_depth) + ) extremities_events = await self.store.get_events( - forward_events, + forward_event_ids, redact_behaviour=EventRedactBehaviour.AS_IS, get_prev_content=False, ) @@ -1106,10 +1216,19 @@ class FederationHandler(BaseHandler): redact=False, check_history_visibility_only=True, ) + logger.debug( + "_maybe_backfill_inner: filtered_extremities %s", filtered_extremities + ) - if not filtered_extremities: + if not filtered_extremities and not insertion_events_to_be_backfilled: return False + extremities = { + **oldest_events_with_depth, + # TODO: insertion_events_to_be_backfilled is currently skipping the filtered_extremities checks + **insertion_events_to_be_backfilled, + } + # Check if we reached a point where we should start backfilling. sorted_extremeties_tuple = sorted(extremities.items(), key=lambda e: -int(e[1])) max_depth = sorted_extremeties_tuple[0][1] @@ -2208,7 +2327,7 @@ class FederationHandler(BaseHandler): event: EventBase, context: EventContext, state: Optional[Iterable[EventBase]] = None, - auth_events: Optional[MutableStateMap[EventBase]] = None, + claimed_auth_event_map: Optional[StateMap[EventBase]] = None, backfilled: bool = False, ) -> None: """ @@ -2220,17 +2339,18 @@ class FederationHandler(BaseHandler): context: The event context. - NB that this function potentially modifies it. state: The state events used to check the event for soft-fail. If this is not provided the current state events will be used. - auth_events: - Map from (event_type, state_key) to event - Normally, our calculated auth_events based on the state of the room - at the event's position in the DAG, though occasionally (eg if the - event is an outlier), may be the auth events claimed by the remote - server. + claimed_auth_event_map: + A map of (type, state_key) => event for the event's claimed auth_events. + Possibly incomplete, and possibly including events that are not yet + persisted, or authed, or in the right room. + + Only populated where we may not already have persisted these events - + for example, when populating outliers. + backfilled: True if the event was backfilled. """ context = await self._check_event_auth( @@ -2238,7 +2358,7 @@ class FederationHandler(BaseHandler): event, context, state=state, - auth_events=auth_events, + claimed_auth_event_map=claimed_auth_event_map, backfilled=backfilled, ) @@ -2302,7 +2422,7 @@ class FederationHandler(BaseHandler): event, res, state=ev_info.state, - auth_events=ev_info.auth_events, + claimed_auth_event_map=ev_info.claimed_auth_event_map, backfilled=backfilled, ) return res @@ -2568,7 +2688,7 @@ class FederationHandler(BaseHandler): event: EventBase, context: EventContext, state: Optional[Iterable[EventBase]] = None, - auth_events: Optional[MutableStateMap[EventBase]] = None, + claimed_auth_event_map: Optional[StateMap[EventBase]] = None, backfilled: bool = False, ) -> EventContext: """ @@ -2580,21 +2700,19 @@ class FederationHandler(BaseHandler): context: The event context. - NB that this function potentially modifies it. state: The state events used to check the event for soft-fail. If this is not provided the current state events will be used. - auth_events: - Map from (event_type, state_key) to event - Normally, our calculated auth_events based on the state of the room - at the event's position in the DAG, though occasionally (eg if the - event is an outlier), may be the auth events claimed by the remote - server. + claimed_auth_event_map: + A map of (type, state_key) => event for the event's claimed auth_events. + Possibly incomplete, and possibly including events that are not yet + persisted, or authed, or in the right room. - Also NB that this function adds entries to it. + Only populated where we may not already have persisted these events - + for example, when populating outliers, or the state for a backwards + extremity. - If this is not provided, it is calculated from the previous state IDs. backfilled: True if the event was backfilled. Returns: @@ -2603,7 +2721,12 @@ class FederationHandler(BaseHandler): room_version = await self.store.get_room_version_id(event.room_id) room_version_obj = KNOWN_ROOM_VERSIONS[room_version] - if not auth_events: + if claimed_auth_event_map: + # if we have a copy of the auth events from the event, use that as the + # basis for auth. + auth_events = claimed_auth_event_map + else: + # otherwise, we calculate what the auth events *should* be, and use that prev_state_ids = await context.get_prev_state_ids() auth_events_ids = self._event_auth_handler.compute_auth_events( event, prev_state_ids, for_verification=True @@ -2611,18 +2734,11 @@ class FederationHandler(BaseHandler): auth_events_x = await self.store.get_events(auth_events_ids) auth_events = {(e.type, e.state_key): e for e in auth_events_x.values()} - # This is a hack to fix some old rooms where the initial join event - # didn't reference the create event in its auth events. - if event.type == EventTypes.Member and not event.auth_event_ids(): - if len(event.prev_event_ids()) == 1 and event.depth < 5: - c = await self.store.get_event( - event.prev_event_ids()[0], allow_none=True - ) - if c and c.type == EventTypes.Create: - auth_events[(c.type, c.state_key)] = c - try: - context = await self._update_auth_events_and_context_for_auth( + ( + context, + auth_events_for_auth, + ) = await self._update_auth_events_and_context_for_auth( origin, event, context, auth_events ) except Exception: @@ -2635,9 +2751,10 @@ class FederationHandler(BaseHandler): "Ignoring failure and continuing processing of event.", event.event_id, ) + auth_events_for_auth = auth_events try: - event_auth.check(room_version_obj, event, auth_events=auth_events) + event_auth.check(room_version_obj, event, auth_events=auth_events_for_auth) except AuthError as e: logger.warning("Failed auth resolution for %r because %s", event, e) context.rejected = RejectedReason.AUTH_ERROR @@ -2662,8 +2779,8 @@ class FederationHandler(BaseHandler): origin: str, event: EventBase, context: EventContext, - auth_events: MutableStateMap[EventBase], - ) -> EventContext: + input_auth_events: StateMap[EventBase], + ) -> Tuple[EventContext, StateMap[EventBase]]: """Helper for _check_event_auth. See there for docs. Checks whether a given event has the expected auth events. If it @@ -2680,7 +2797,7 @@ class FederationHandler(BaseHandler): event: context: - auth_events: + input_auth_events: Map from (event_type, state_key) to event Normally, our calculated auth_events based on the state of the room @@ -2688,11 +2805,12 @@ class FederationHandler(BaseHandler): event is an outlier), may be the auth events claimed by the remote server. - Also NB that this function adds entries to it. - Returns: - updated context + updated context, updated auth event map """ + # take a copy of input_auth_events before we modify it. + auth_events: MutableStateMap[EventBase] = dict(input_auth_events) + event_auth_events = set(event.auth_event_ids()) # missing_auth is the set of the event's auth_events which we don't yet have @@ -2721,7 +2839,7 @@ class FederationHandler(BaseHandler): # The other side isn't around or doesn't implement the # endpoint, so lets just bail out. logger.info("Failed to get event auth from remote: %s", e1) - return context + return context, auth_events seen_remotes = await self.store.have_seen_events( event.room_id, [e.event_id for e in remote_auth_chain] @@ -2752,7 +2870,10 @@ class FederationHandler(BaseHandler): await self.state_handler.compute_event_context(e) ) await self._auth_and_persist_event( - origin, e, missing_auth_event_context, auth_events=auth + origin, + e, + missing_auth_event_context, + claimed_auth_event_map=auth, ) if e.event_id in event_auth_events: @@ -2770,14 +2891,14 @@ class FederationHandler(BaseHandler): # obviously be empty # (b) alternatively, why don't we do it earlier? logger.info("Skipping auth_event fetch for outlier") - return context + return context, auth_events different_auth = event_auth_events.difference( e.event_id for e in auth_events.values() ) if not different_auth: - return context + return context, auth_events logger.info( "auth_events refers to events which are not in our calculated auth " @@ -2803,7 +2924,7 @@ class FederationHandler(BaseHandler): # XXX: should we reject the event in this case? It feels like we should, # but then shouldn't we also do so if we've failed to fetch any of the # auth events? - return context + return context, auth_events # now we state-resolve between our own idea of the auth events, and the remote's # idea of them. @@ -2833,7 +2954,7 @@ class FederationHandler(BaseHandler): event, context, auth_events ) - return context + return context, auth_events async def _update_context_for_auth_events( self, event: EventBase, context: EventContext, auth_events: StateMap[EventBase] |