From 493488d8a5f180be9f45cd674e5b96223b2f7bde Mon Sep 17 00:00:00 2001 From: Brendan Abolivier Date: Fri, 21 Oct 2022 14:12:56 +0100 Subject: [PATCH] Implement MSC3912: Relation-based redactions --- synapse/config/experimental.py | 3 ++ synapse/handlers/message.py | 47 +++++++++++++---- synapse/handlers/relations.py | 56 ++++++++++++++++++++- synapse/rest/client/room.py | 55 ++++++++++++++------ synapse/storage/databases/main/relations.py | 38 ++++++++++++++ 5 files changed, 175 insertions(+), 24 deletions(-) diff --git a/synapse/config/experimental.py b/synapse/config/experimental.py index 4009add01db0..95df14ada621 100644 --- a/synapse/config/experimental.py +++ b/synapse/config/experimental.py @@ -125,3 +125,6 @@ def read_config(self, config: JsonDict, **kwargs: Any) -> None: self.msc3886_endpoint: Optional[str] = experimental.get( "msc3886_endpoint", None ) + + # MSC3912: Relation-based redactions. + self.msc3912_enabled: bool = experimental.get("msc3912_enabled", False) diff --git a/synapse/handlers/message.py b/synapse/handlers/message.py index 15b828dd742d..de257b1bb21e 100644 --- a/synapse/handlers/message.py +++ b/synapse/handlers/message.py @@ -877,6 +877,36 @@ async def deduplicate_state_event( return prev_event return None + async def get_event_from_transaction( + self, + requester: Requester, + txn_id: str, + room_id: str, + ) -> Optional[EventBase]: + """For the given transaction ID and room ID, check if there is a matching event. + If so, fetch it and return it. + + Args: + requester: The requester making the request in the context of which we want + to fetch the event. + txn_id: The transaction ID. + room_id: The room ID. + + Returns: + An event if one could be found, None otherwise. + """ + if requester.access_token_id: + existing_event_id = await self.store.get_event_id_from_transaction_id( + room_id, + requester.user.to_string(), + requester.access_token_id, + txn_id, + ) + if existing_event_id: + return await self.store.get_event(existing_event_id) + + return None + async def create_and_send_nonmember_event( self, requester: Requester, @@ -956,18 +986,17 @@ async def create_and_send_nonmember_event( # extremities to pile up, which in turn leads to state resolution # taking longer. async with self.limiter.queue(event_dict["room_id"]): - if txn_id and requester.access_token_id: - existing_event_id = await self.store.get_event_id_from_transaction_id( - event_dict["room_id"], - requester.user.to_string(), - requester.access_token_id, - txn_id, + if txn_id: + event = await self.get_event_from_transaction( + requester, txn_id, event_dict["room_id"] ) - if existing_event_id: - event = await self.store.get_event(existing_event_id) + if event: # we know it was persisted, so must have a stream ordering assert event.internal_metadata.stream_ordering - return event, event.internal_metadata.stream_ordering + return ( + event, + event.internal_metadata.stream_ordering, + ) event, context = await self.create_event( requester, diff --git a/synapse/handlers/relations.py b/synapse/handlers/relations.py index 0a0c6d938e12..8e71dda970c0 100644 --- a/synapse/handlers/relations.py +++ b/synapse/handlers/relations.py @@ -17,7 +17,7 @@ import attr -from synapse.api.constants import RelationTypes +from synapse.api.constants import EventTypes, RelationTypes from synapse.api.errors import SynapseError from synapse.events import EventBase, relation_from_event from synapse.logging.opentracing import trace @@ -75,6 +75,7 @@ def __init__(self, hs: "HomeServer"): self._clock = hs.get_clock() self._event_handler = hs.get_event_handler() self._event_serializer = hs.get_event_client_serializer() + self._event_creation_handler = hs.get_event_creation_handler() async def get_relations( self, @@ -205,6 +206,59 @@ async def get_relations_for_event( return related_events, next_token + async def redact_events_related_to( + self, + requester: Requester, + event_id: str, + initial_redaction_event: EventBase, + relation_types: List[str], + ) -> None: + """Redacts all events related to the given event ID with one of the given + relation types. + + This method is expected to be called when redacting the event referred to by + the given event ID. + + If an event cannot be redacted (e.g. because of insufficient permissions), log + the error and try to redact the next one. + + Args: + requester: The requester to redact events on behalf of. + event_id: The event IDs to look and redact relations of. + initial_redaction_event: The redaction for the event referred to by + event_id. + relation_types: The types of relations to look for. + + Raises: + ShadowBanError if the requester is shadow-banned + """ + related_event_ids = ( + await self._main_store.get_all_relations_for_event_with_types( + event_id, relation_types + ) + ) + + for related_event_id in related_event_ids: + try: + await self._event_creation_handler.create_and_send_nonmember_event( + requester, + { + "type": EventTypes.Redaction, + "content": initial_redaction_event.content, + "room_id": initial_redaction_event.room_id, + "sender": requester.user.to_string(), + "redacts": related_event_id, + }, + ratelimit=False, + ) + except SynapseError as e: + logger.warning( + "Failed to redact event %s (related to event %s): %s", + related_event_id, + event_id, + e.msg, + ) + async def get_annotations_for_event( self, event_id: str, diff --git a/synapse/rest/client/room.py b/synapse/rest/client/room.py index 01e507996339..2373bba22cb1 100644 --- a/synapse/rest/client/room.py +++ b/synapse/rest/client/room.py @@ -1029,6 +1029,8 @@ def __init__(self, hs: "HomeServer"): super().__init__(hs) self.event_creation_handler = hs.get_event_creation_handler() self.auth = hs.get_auth() + self._relation_handler = hs.get_relations_handler() + self._msc3912_enabled = hs.config.experimental.msc3912_enabled def register(self, http_server: HttpServer) -> None: PATTERNS = "/rooms/(?P[^/]*)/redact/(?P[^/]*)" @@ -1045,20 +1047,45 @@ async def on_POST( content = parse_json_object_from_request(request) try: - ( - event, - _, - ) = await self.event_creation_handler.create_and_send_nonmember_event( - requester, - { - "type": EventTypes.Redaction, - "content": content, - "room_id": room_id, - "sender": requester.user.to_string(), - "redacts": event_id, - }, - txn_id=txn_id, - ) + with_relations = None + if self._msc3912_enabled and "org.matrix.msc3912.with_relations" in content: + with_relations = content["org.matrix.msc3912.with_relations"] + del content["org.matrix.msc3912.with_relations"] + + # Check if there's an existing event for this transaction now (even though + # create_and_send_nonmember_event also does it) because, if there's one, + # then we want to skip the call to redact_events_related_to. + event = None + if txn_id: + event = await self.event_creation_handler.get_event_from_transaction( + requester, txn_id, room_id + ) + + if event is None: + ( + event, + _, + ) = await self.event_creation_handler.create_and_send_nonmember_event( + requester, + { + "type": EventTypes.Redaction, + "content": content, + "room_id": room_id, + "sender": requester.user.to_string(), + "redacts": event_id, + }, + txn_id=txn_id, + ) + + if with_relations: + run_in_background( + self._relation_handler.redact_events_related_to, + requester=requester, + event_id=event_id, + initial_redaction_event=event, + relation_types=with_relations, + ) + event_id = event.event_id except ShadowBanError: event_id = "$" + random_string(43) diff --git a/synapse/storage/databases/main/relations.py b/synapse/storage/databases/main/relations.py index 1de62ee9dfba..df2dc3f3f84d 100644 --- a/synapse/storage/databases/main/relations.py +++ b/synapse/storage/databases/main/relations.py @@ -295,6 +295,44 @@ def _get_recent_references_for_event_txn( "get_recent_references_for_event", _get_recent_references_for_event_txn ) + async def get_all_relations_for_event_with_types( + self, + event_id: str, + relation_types: List[str], + ) -> List[str]: + """Get the event IDs of all events that have a relation to the given event with + one of the given relation types. + + Args: + event_id: The event for which to look for related events. + relation_types: The types of relations to look for. + + Returns: + A list of the IDs of the events that relate to the given event with one of + the given relation types. + """ + + def get_all_relation_ids_for_event_with_types_txn( + txn: LoggingTransaction, + ) -> List[str]: + sql = """ + SELECT event_id FROM event_relations + WHERE + relates_to_id = ? + AND relation_type IN (%s) + """ % ( + ",".join(["?" for _ in relation_types]), + ) + + txn.execute(sql, [event_id] + relation_types) + + return [row[0] for row in txn] + + return await self.db_pool.runInteraction( + desc="get_all_relation_ids_for_event_with_types", + func=get_all_relation_ids_for_event_with_types_txn, + ) + async def event_includes_relation(self, event_id: str) -> bool: """Check if the given event relates to another event.