From e8665123679fdd01294cea097636a15e59312a12 Mon Sep 17 00:00:00 2001 From: Richard van der Hoff <1389908+richvdh@users.noreply.github.com> Date: Wed, 1 Jul 2020 16:41:19 +0100 Subject: Add early returns to `_check_for_soft_fail` (#7769) my editor was complaining about unset variables, so let's add some early returns to fix that and reduce indentation/cognitive load. --- changelog.d/7769.misc | 1 + synapse/handlers/federation.py | 119 +++++++++++++++++++---------------------- 2 files changed, 56 insertions(+), 64 deletions(-) create mode 100644 changelog.d/7769.misc diff --git a/changelog.d/7769.misc b/changelog.d/7769.misc new file mode 100644 index 0000000000..2e200286ce --- /dev/null +++ b/changelog.d/7769.misc @@ -0,0 +1 @@ +Add early returns to `_check_for_soft_fail`. diff --git a/synapse/handlers/federation.py b/synapse/handlers/federation.py index 8f0b9be791..fa5854578d 100644 --- a/synapse/handlers/federation.py +++ b/synapse/handlers/federation.py @@ -2061,76 +2061,67 @@ class FederationHandler(BaseHandler): # For new (non-backfilled and non-outlier) events we check if the event # passes auth based on the current state. If it doesn't then we # "soft-fail" the event. - do_soft_fail_check = not backfilled and not event.internal_metadata.is_outlier() - if do_soft_fail_check: - extrem_ids = await self.store.get_latest_event_ids_in_room(event.room_id) - - extrem_ids = set(extrem_ids) - prev_event_ids = set(event.prev_event_ids()) - - if extrem_ids == prev_event_ids: - # If they're the same then the current state is the same as the - # state at the event, so no point rechecking auth for soft fail. - do_soft_fail_check = False - - if do_soft_fail_check: - room_version = await self.store.get_room_version_id(event.room_id) - room_version_obj = KNOWN_ROOM_VERSIONS[room_version] - - # Calculate the "current state". - if state is not None: - # If we're explicitly given the state then we won't have all the - # prev events, and so we have a gap in the graph. In this case - # we want to be a little careful as we might have been down for - # a while and have an incorrect view of the current state, - # however we still want to do checks as gaps are easy to - # maliciously manufacture. - # - # So we use a "current state" that is actually a state - # resolution across the current forward extremities and the - # given state at the event. This should correctly handle cases - # like bans, especially with state res v2. + if backfilled or event.internal_metadata.is_outlier(): + return - state_sets = await self.state_store.get_state_groups( - event.room_id, extrem_ids - ) - state_sets = list(state_sets.values()) - state_sets.append(state) - current_state_ids = await self.state_handler.resolve_events( - room_version, state_sets, event - ) - current_state_ids = { - k: e.event_id for k, e in current_state_ids.items() - } - else: - current_state_ids = await self.state_handler.get_current_state_ids( - event.room_id, latest_event_ids=extrem_ids - ) + extrem_ids = await self.store.get_latest_event_ids_in_room(event.room_id) + extrem_ids = set(extrem_ids) + prev_event_ids = set(event.prev_event_ids()) - logger.debug( - "Doing soft-fail check for %s: state %s", - event.event_id, - current_state_ids, + if extrem_ids == prev_event_ids: + # If they're the same then the current state is the same as the + # state at the event, so no point rechecking auth for soft fail. + return + + room_version = await self.store.get_room_version_id(event.room_id) + room_version_obj = KNOWN_ROOM_VERSIONS[room_version] + + # Calculate the "current state". + if state is not None: + # If we're explicitly given the state then we won't have all the + # prev events, and so we have a gap in the graph. In this case + # we want to be a little careful as we might have been down for + # a while and have an incorrect view of the current state, + # however we still want to do checks as gaps are easy to + # maliciously manufacture. + # + # So we use a "current state" that is actually a state + # resolution across the current forward extremities and the + # given state at the event. This should correctly handle cases + # like bans, especially with state res v2. + + state_sets = await self.state_store.get_state_groups( + event.room_id, extrem_ids + ) + state_sets = list(state_sets.values()) + state_sets.append(state) + current_state_ids = await self.state_handler.resolve_events( + room_version, state_sets, event + ) + current_state_ids = {k: e.event_id for k, e in current_state_ids.items()} + else: + current_state_ids = await self.state_handler.get_current_state_ids( + event.room_id, latest_event_ids=extrem_ids ) - # Now check if event pass auth against said current state - auth_types = auth_types_for_event(event) - current_state_ids = [ - e for k, e in current_state_ids.items() if k in auth_types - ] + logger.debug( + "Doing soft-fail check for %s: state %s", event.event_id, current_state_ids, + ) - current_auth_events = await self.store.get_events(current_state_ids) - current_auth_events = { - (e.type, e.state_key): e for e in current_auth_events.values() - } + # Now check if event pass auth against said current state + auth_types = auth_types_for_event(event) + current_state_ids = [e for k, e in current_state_ids.items() if k in auth_types] - try: - event_auth.check( - room_version_obj, event, auth_events=current_auth_events - ) - except AuthError as e: - logger.warning("Soft-failing %r because %s", event, e) - event.internal_metadata.soft_failed = True + current_auth_events = await self.store.get_events(current_state_ids) + current_auth_events = { + (e.type, e.state_key): e for e in current_auth_events.values() + } + + try: + event_auth.check(room_version_obj, event, auth_events=current_auth_events) + except AuthError as e: + logger.warning("Soft-failing %r because %s", event, e) + event.internal_metadata.soft_failed = True async def on_query_auth( self, origin, event_id, room_id, remote_auth_chain, rejects, missing -- cgit 1.4.1