From 4e97eb89e5ed4517e5967a49acf6db987bb96d51 Mon Sep 17 00:00:00 2001 From: Richard van der Hoff Date: Wed, 24 Jul 2019 22:45:35 +0100 Subject: [PATCH] Handle loops in redaction events --- synapse/storage/events_worker.py | 96 ++++++++++++-------------------- tests/storage/test_redaction.py | 70 +++++++++++++++++++++++ 2 files changed, 106 insertions(+), 60 deletions(-) diff --git a/synapse/storage/events_worker.py b/synapse/storage/events_worker.py index e15e7d86fe..c6fa7f82fd 100644 --- a/synapse/storage/events_worker.py +++ b/synapse/storage/events_worker.py @@ -483,7 +483,8 @@ class EventsWorkerStore(SQLBaseStore): if events_to_fetch: logger.debug("Also fetching redaction events %s", events_to_fetch) - result_map = {} + # build a map from event_id to EventBase + event_map = {} for event_id, row in fetched_events.items(): if not row: continue @@ -494,14 +495,37 @@ class EventsWorkerStore(SQLBaseStore): if not allow_rejected and rejected_reason: continue - cache_entry = yield self._get_event_from_row( - row["internal_metadata"], - row["json"], - row["redactions"], - rejected_reason=row["rejected_reason"], - format_version=row["format_version"], + d = json.loads(row["json"]) + internal_metadata = json.loads(row["internal_metadata"]) + + format_version = row["format_version"] + if format_version is None: + # This means that we stored the event before we had the concept + # of a event format version, so it must be a V1 event. + format_version = EventFormatVersions.V1 + + original_ev = event_type_from_format_version(format_version)( + event_dict=d, + internal_metadata_dict=internal_metadata, + rejected_reason=rejected_reason, ) + event_map[event_id] = original_ev + + # finally, we can decide whether each one nededs redacting, and build + # the cache entries. + result_map = {} + for event_id, original_ev in event_map.items(): + redactions = fetched_events[event_id]["redactions"] + redacted_event = self._maybe_redact_event_row( + original_ev, redactions, event_map + ) + + cache_entry = _EventCacheEntry( + event=original_ev, redacted_event=redacted_event + ) + + self._get_event_cache.prefill((event_id,), cache_entry) result_map[event_id] = cache_entry return result_map @@ -615,50 +639,7 @@ class EventsWorkerStore(SQLBaseStore): return event_dict - @defer.inlineCallbacks - def _get_event_from_row( - self, internal_metadata, js, redactions, format_version, rejected_reason=None - ): - """Parse an event row which has been read from the database - - Args: - internal_metadata (str): json-encoded internal_metadata column - js (str): json-encoded event body from event_json - redactions (list[str]): a list of the events which claim to have redacted - this event, from the redactions table - format_version: (str): the 'format_version' column - rejected_reason (str|None): the reason this event was rejected, if any - - Returns: - _EventCacheEntry - """ - with Measure(self._clock, "_get_event_from_row"): - d = json.loads(js) - internal_metadata = json.loads(internal_metadata) - - if format_version is None: - # This means that we stored the event before we had the concept - # of a event format version, so it must be a V1 event. - format_version = EventFormatVersions.V1 - - original_ev = event_type_from_format_version(format_version)( - event_dict=d, - internal_metadata_dict=internal_metadata, - rejected_reason=rejected_reason, - ) - - redacted_event = yield self._maybe_redact_event_row(original_ev, redactions) - - cache_entry = _EventCacheEntry( - event=original_ev, redacted_event=redacted_event - ) - - self._get_event_cache.prefill((original_ev.event_id,), cache_entry) - - return cache_entry - - @defer.inlineCallbacks - def _maybe_redact_event_row(self, original_ev, redactions): + def _maybe_redact_event_row(self, original_ev, redactions, event_map): """Given an event object and a list of possible redacting event ids, determine whether to honour any of those redactions and if so return a redacted event. @@ -666,6 +647,8 @@ class EventsWorkerStore(SQLBaseStore): Args: original_ev (EventBase): redactions (iterable[str]): list of event ids of potential redaction events + event_map (dict[str, EventBase]): other events which have been fetched, in + which we can look up the redaaction events. Map from event id to event. Returns: Deferred[EventBase|None]: if the event should be redacted, a pruned @@ -675,15 +658,9 @@ class EventsWorkerStore(SQLBaseStore): # we choose to ignore redactions of m.room.create events. return None - if original_ev.type == "m.room.redaction": - # ... and redaction events - return None - - redaction_map = yield self._get_events_from_cache_or_db(redactions) - for redaction_id in redactions: - redaction_entry = redaction_map.get(redaction_id) - if not redaction_entry: + redaction_event = event_map.get(redaction_id) + if not redaction_event or redaction_event.rejected_reason: # we don't have the redaction event, or the redaction event was not # authorized. logger.debug( @@ -693,7 +670,6 @@ class EventsWorkerStore(SQLBaseStore): ) continue - redaction_event = redaction_entry.event if redaction_event.room_id != original_ev.room_id: logger.debug( "%s was redacted by %s but redaction was in a different room!", diff --git a/tests/storage/test_redaction.py b/tests/storage/test_redaction.py index 8488b6edc8..d961b81d48 100644 --- a/tests/storage/test_redaction.py +++ b/tests/storage/test_redaction.py @@ -17,6 +17,8 @@ from mock import Mock +from twisted.internet import defer + from synapse.api.constants import EventTypes, Membership from synapse.api.room_versions import RoomVersions from synapse.types import RoomID, UserID @@ -216,3 +218,71 @@ class RedactionTestCase(unittest.HomeserverTestCase): }, event.unsigned["redacted_because"], ) + + def test_circular_redaction(self): + redaction_event_id1 = "$redaction1_id:test" + redaction_event_id2 = "$redaction2_id:test" + + class EventIdManglingBuilder: + def __init__(self, base_builder, event_id): + self._base_builder = base_builder + self._event_id = event_id + + @defer.inlineCallbacks + def build(self, prev_event_ids): + built_event = yield self._base_builder.build(prev_event_ids) + built_event.event_id = self._event_id + built_event._event_dict["event_id"] = self._event_id + return built_event + + @property + def room_id(self): + return self._base_builder.room_id + + event_1, context_1 = self.get_success( + self.event_creation_handler.create_new_client_event( + EventIdManglingBuilder( + self.event_builder_factory.for_room_version( + RoomVersions.V1, + { + "type": EventTypes.Redaction, + "sender": self.u_alice.to_string(), + "room_id": self.room1.to_string(), + "content": {"reason": "test"}, + "redacts": redaction_event_id2, + }, + ), + redaction_event_id1, + ) + ) + ) + + self.get_success(self.store.persist_event(event_1, context_1)) + + event_2, context_2 = self.get_success( + self.event_creation_handler.create_new_client_event( + EventIdManglingBuilder( + self.event_builder_factory.for_room_version( + RoomVersions.V1, + { + "type": EventTypes.Redaction, + "sender": self.u_alice.to_string(), + "room_id": self.room1.to_string(), + "content": {"reason": "test"}, + "redacts": redaction_event_id1, + }, + ), + redaction_event_id2, + ) + ) + ) + self.get_success(self.store.persist_event(event_2, context_2)) + + # fetch one of the redactions + fetched = self.get_success(self.store.get_event(redaction_event_id1)) + + # it should have been redacted + self.assertEqual(fetched.unsigned["redacted_by"], redaction_event_id2) + self.assertEqual( + fetched.unsigned["redacted_because"].event_id, redaction_event_id2 + )