diff options
Diffstat (limited to 'synapse/handlers/federation.py')
| -rw-r--r-- | synapse/handlers/federation.py | 395 |
1 files changed, 280 insertions, 115 deletions
diff --git a/synapse/handlers/federation.py b/synapse/handlers/federation.py index 0ebf0fd188..45d955e6f5 100644 --- a/synapse/handlers/federation.py +++ b/synapse/handlers/federation.py @@ -18,7 +18,6 @@ import itertools import logging -import sys import six from six import iteritems, itervalues @@ -69,6 +68,27 @@ from ._base import BaseHandler logger = logging.getLogger(__name__) +def shortstr(iterable, maxitems=5): + """If iterable has maxitems or fewer, return the stringification of a list + containing those items. + + Otherwise, return the stringification of a a list with the first maxitems items, + followed by "...". + + Args: + iterable (Iterable): iterable to truncate + maxitems (int): number of items to return before truncating + + Returns: + unicode + """ + + items = list(itertools.islice(iterable, maxitems + 1)) + if len(items) <= maxitems: + return str(items) + return u"[" + u", ".join(repr(r) for r in items[:maxitems]) + u", ...]" + + class FederationHandler(BaseHandler): """Handles events that originated from federation. Responsible for: @@ -85,7 +105,7 @@ class FederationHandler(BaseHandler): self.hs = hs - self.store = hs.get_datastore() + self.store = hs.get_datastore() # type: synapse.storage.DataStore self.federation_client = hs.get_federation_client() self.state_handler = hs.get_state_handler() self.server_name = hs.hostname @@ -114,9 +134,8 @@ class FederationHandler(BaseHandler): self._room_pdu_linearizer = Linearizer("fed_room_pdu") @defer.inlineCallbacks - @log_function def on_receive_pdu( - self, origin, pdu, get_missing=True, sent_to_us_directly=False, + self, origin, pdu, sent_to_us_directly=False, ): """ Process a PDU received via a federation /send/ transaction, or via backfill of missing prev_events @@ -125,14 +144,23 @@ class FederationHandler(BaseHandler): origin (str): server which initiated the /send/ transaction. Will be used to fetch missing events or state. pdu (FrozenEvent): received PDU - get_missing (bool): True if we should fetch missing prev_events + sent_to_us_directly (bool): True if this event was pushed to us; False if + we pulled it as the result of a missing prev_event. Returns (Deferred): completes with None """ + room_id = pdu.room_id + event_id = pdu.event_id + + logger.info( + "[%s %s] handling received PDU: %s", + room_id, event_id, pdu, + ) + # We reprocess pdus when we have seen them only as outliers existing = yield self.store.get_event( - pdu.event_id, + event_id, allow_none=True, allow_rejected=True, ) @@ -147,7 +175,7 @@ class FederationHandler(BaseHandler): ) ) if already_seen: - logger.debug("Already seen pdu %s", pdu.event_id) + logger.debug("[%s %s]: Already seen pdu", room_id, event_id) return # do some initial sanity-checking of the event. In particular, make @@ -156,6 +184,7 @@ class FederationHandler(BaseHandler): try: self._sanity_check_event(pdu) except SynapseError as err: + logger.warn("[%s %s] Received event failed sanity checks", room_id, event_id) raise FederationError( "ERROR", err.code, @@ -165,10 +194,12 @@ class FederationHandler(BaseHandler): # If we are currently in the process of joining this room, then we # queue up events for later processing. - if pdu.room_id in self.room_queues: - logger.info("Ignoring PDU %s for room %s from %s for now; join " - "in progress", pdu.event_id, pdu.room_id, origin) - self.room_queues[pdu.room_id].append((pdu, origin)) + if room_id in self.room_queues: + logger.info( + "[%s %s] Queuing PDU from %s for now: join in progress", + room_id, event_id, origin, + ) + self.room_queues[room_id].append((pdu, origin)) return # If we're no longer in the room just ditch the event entirely. This @@ -179,7 +210,7 @@ class FederationHandler(BaseHandler): # we should check if we *are* in fact in the room. If we are then we # can magically rejoin the room. is_in_room = yield self.auth.check_host_in_room( - pdu.room_id, + room_id, self.server_name ) if not is_in_room: @@ -188,8 +219,8 @@ class FederationHandler(BaseHandler): ) if was_in_room: logger.info( - "Ignoring PDU %s for room %s from %s as we've left the room!", - pdu.event_id, pdu.room_id, origin, + "[%s %s] Ignoring PDU from %s as we've left the room", + room_id, event_id, origin, ) defer.returnValue(None) @@ -204,8 +235,8 @@ class FederationHandler(BaseHandler): ) logger.debug( - "_handle_new_pdu min_depth for %s: %d", - pdu.room_id, min_depth + "[%s %s] min_depth: %d", + room_id, event_id, min_depth, ) prevs = {e_id for e_id, _ in pdu.prev_events} @@ -218,17 +249,18 @@ class FederationHandler(BaseHandler): # send to the clients. pdu.internal_metadata.outlier = True elif min_depth and pdu.depth > min_depth: - if get_missing and prevs - seen: + missing_prevs = prevs - seen + if sent_to_us_directly and missing_prevs: # If we're missing stuff, ensure we only fetch stuff one # at a time. logger.info( - "Acquiring lock for room %r to fetch %d missing events: %r...", - pdu.room_id, len(prevs - seen), list(prevs - seen)[:5], + "[%s %s] Acquiring room lock to fetch %d missing prev_events: %s", + room_id, event_id, len(missing_prevs), shortstr(missing_prevs), ) with (yield self._room_pdu_linearizer.queue(pdu.room_id)): logger.info( - "Acquired lock for room %r to fetch %d missing events", - pdu.room_id, len(prevs - seen), + "[%s %s] Acquired room lock to fetch %d missing prev_events", + room_id, event_id, len(missing_prevs), ) yield self._get_missing_events_for_pdu( @@ -241,69 +273,150 @@ class FederationHandler(BaseHandler): if not prevs - seen: logger.info( - "Found all missing prev events for %s", pdu.event_id + "[%s %s] Found all missing prev_events", + room_id, event_id, ) - elif prevs - seen: + elif missing_prevs: logger.info( - "Not fetching %d missing events for room %r,event %s: %r...", - len(prevs - seen), pdu.room_id, pdu.event_id, - list(prevs - seen)[:5], + "[%s %s] Not recursively fetching %d missing prev_events: %s", + room_id, event_id, len(missing_prevs), shortstr(missing_prevs), ) - if sent_to_us_directly and prevs - seen: - # If they have sent it to us directly, and the server - # isn't telling us about the auth events that it's - # made a message referencing, we explode - raise FederationError( - "ERROR", - 403, - ( - "Your server isn't divulging details about prev_events " - "referenced in this event." - ), - affected=pdu.event_id, - ) - elif prevs - seen: - # Calculate the state of the previous events, and - # de-conflict them to find the current state. - state_groups = [] + if prevs - seen: + # We've still not been able to get all of the prev_events for this event. + # + # In this case, we need to fall back to asking another server in the + # federation for the state at this event. That's ok provided we then + # resolve the state against other bits of the DAG before using it (which + # will ensure that you can't just take over a room by sending an event, + # withholding its prev_events, and declaring yourself to be an admin in + # the subsequent state request). + # + # Now, if we're pulling this event as a missing prev_event, then clearly + # this event is not going to become the only forward-extremity and we are + # guaranteed to resolve its state against our existing forward + # extremities, so that should be fine. + # + # On the other hand, if this event was pushed to us, it is possible for + # it to become the only forward-extremity in the room, and we would then + # trust its state to be the state for the whole room. This is very bad. + # Further, if the event was pushed to us, there is no excuse for us not to + # have all the prev_events. We therefore reject any such events. + # + # XXX this really feels like it could/should be merged with the above, + # but there is an interaction with min_depth that I'm not really + # following. + + if sent_to_us_directly: + logger.warn( + "[%s %s] Failed to fetch %d prev events: rejecting", + room_id, event_id, len(prevs - seen), + ) + raise FederationError( + "ERROR", + 403, + ( + "Your server isn't divulging details about prev_events " + "referenced in this event." + ), + affected=pdu.event_id, + ) + + # Calculate the state after each of the previous events, and + # resolve them to find the correct state at the current event. auth_chains = set() + event_map = { + event_id: pdu, + } try: # Get the state of the events we know about - ours = yield self.store.get_state_groups(pdu.room_id, list(seen)) - state_groups.append(ours) + ours = yield self.store.get_state_groups_ids(room_id, seen) + + # state_maps is a list of mappings from (type, state_key) to event_id + # type: list[dict[tuple[str, str], str]] + state_maps = list(ours.values()) + + # we don't need this any more, let's delete it. + del ours # Ask the remote server for the states we don't # know about for p in prevs - seen: - state, got_auth_chain = ( - yield self.federation_client.get_state_for_room( - origin, pdu.room_id, p - ) + logger.info( + "[%s %s] Requesting state at missing prev_event %s", + room_id, event_id, p, ) - auth_chains.update(got_auth_chain) - state_group = {(x.type, x.state_key): x.event_id for x in state} - state_groups.append(state_group) + + with logcontext.nested_logging_context(p): + # note that if any of the missing prevs share missing state or + # auth events, the requests to fetch those events are deduped + # by the get_pdu_cache in federation_client. + remote_state, got_auth_chain = ( + yield self.federation_client.get_state_for_room( + origin, room_id, p, + ) + ) + + # we want the state *after* p; get_state_for_room returns the + # state *before* p. + remote_event = yield self.federation_client.get_pdu( + [origin], p, outlier=True, + ) + + if remote_event is None: + raise Exception( + "Unable to get missing prev_event %s" % (p, ) + ) + + if remote_event.is_state(): + remote_state.append(remote_event) + + # XXX hrm I'm not convinced that duplicate events will compare + # for equality, so I'm not sure this does what the author + # hoped. + auth_chains.update(got_auth_chain) + + remote_state_map = { + (x.type, x.state_key): x.event_id for x in remote_state + } + state_maps.append(remote_state_map) + + for x in remote_state: + event_map[x.event_id] = x # Resolve any conflicting state + @defer.inlineCallbacks def fetch(ev_ids): - return self.store.get_events( - ev_ids, get_prev_content=False, check_redacted=False + fetched = yield self.store.get_events( + ev_ids, get_prev_content=False, check_redacted=False, ) + # add any events we fetch here to the `event_map` so that we + # can use them to build the state event list below. + event_map.update(fetched) + defer.returnValue(fetched) - room_version = yield self.store.get_room_version(pdu.room_id) + room_version = yield self.store.get_room_version(room_id) state_map = yield resolve_events_with_factory( - room_version, state_groups, {pdu.event_id: pdu}, fetch + room_version, state_maps, event_map, fetch, ) - state = (yield self.store.get_events(state_map.values())).values() + # we need to give _process_received_pdu the actual state events + # rather than event ids, so generate that now. + state = [ + event_map[e] for e in six.itervalues(state_map) + ] auth_chain = list(auth_chains) except Exception: + logger.warn( + "[%s %s] Error attempting to resolve state at missing " + "prev_events", + room_id, event_id, exc_info=True, + ) raise FederationError( "ERROR", 403, "We can't get valid state history.", - affected=pdu.event_id, + affected=event_id, ) yield self._process_received_pdu( @@ -322,15 +435,16 @@ class FederationHandler(BaseHandler): prevs (set(str)): List of event ids which we are missing min_depth (int): Minimum depth of events to return. """ - # We recalculate seen, since it may have changed. + + room_id = pdu.room_id + event_id = pdu.event_id + seen = yield self.store.have_seen_events(prevs) if not prevs - seen: return - latest = yield self.store.get_latest_event_ids_in_room( - pdu.room_id - ) + latest = yield self.store.get_latest_event_ids_in_room(room_id) # We add the prev events that we have seen to the latest # list to ensure the remote server doesn't give them to us @@ -338,8 +452,8 @@ class FederationHandler(BaseHandler): latest |= seen logger.info( - "Missing %d events for room %r pdu %s: %r...", - len(prevs - seen), pdu.room_id, pdu.event_id, list(prevs - seen)[:5] + "[%s %s]: Requesting %d prev_events: %s", + room_id, event_id, len(prevs - seen), shortstr(prevs - seen) ) # XXX: we set timeout to 10s to help workaround @@ -360,49 +474,88 @@ class FederationHandler(BaseHandler): # apparently. # # see https://github.com/matrix-org/synapse/pull/1744 + # + # ---- + # + # Update richvdh 2018/09/18: There are a number of problems with timing this + # request out agressively on the client side: + # + # - it plays badly with the server-side rate-limiter, which starts tarpitting you + # if you send too many requests at once, so you end up with the server carefully + # working through the backlog of your requests, which you have already timed + # out. + # + # - for this request in particular, we now (as of + # https://github.com/matrix-org/synapse/pull/3456) reject any PDUs where the + # server can't produce a plausible-looking set of prev_events - so we becone + # much more likely to reject the event. + # + # - contrary to what it says above, we do *not* fall back to fetching fresh state + # for the room if get_missing_events times out. Rather, we give up processing + # the PDU whose prevs we are missing, which then makes it much more likely that + # we'll end up back here for the *next* PDU in the list, which exacerbates the + # problem. + # + # - the agressive 10s timeout was introduced to deal with incoming federation + # requests taking 8 hours to process. It's not entirely clear why that was going + # on; certainly there were other issues causing traffic storms which are now + # resolved, and I think in any case we may be more sensible about our locking + # now. We're *certainly* more sensible about our logging. + # + # All that said: Let's try increasing the timout to 60s and see what happens. missing_events = yield self.federation_client.get_missing_events( origin, - pdu.room_id, + room_id, earliest_events_ids=list(latest), latest_events=[pdu], limit=10, min_depth=min_depth, - timeout=10000, + timeout=60000, ) logger.info( - "Got %d events: %r...", - len(missing_events), [e.event_id for e in missing_events[:5]] + "[%s %s]: Got %d prev_events: %s", + room_id, event_id, len(missing_events), shortstr(missing_events), ) # We want to sort these by depth so we process them and # tell clients about them in order. missing_events.sort(key=lambda x: x.depth) - for e in missing_events: - logger.info("Handling found event %s", e.event_id) - try: - yield self.on_receive_pdu( - origin, - e, - get_missing=False - ) - except FederationError as e: - if e.code == 403: - logger.warn("Event %s failed history check.") - else: - raise + for ev in missing_events: + logger.info( + "[%s %s] Handling received prev_event %s", + room_id, event_id, ev.event_id, + ) + with logcontext.nested_logging_context(ev.event_id): + try: + yield self.on_receive_pdu( + origin, + ev, + sent_to_us_directly=False, + ) + except FederationError as e: + if e.code == 403: + logger.warn( + "[%s %s] Received prev_event %s failed history check.", + room_id, event_id, ev.event_id, + ) + else: + raise - @log_function @defer.inlineCallbacks - def _process_received_pdu(self, origin, pdu, state, auth_chain): + def _process_received_pdu(self, origin, event, state, auth_chain): """ Called when we have a new pdu. We need to do auth checks and put it through the StateHandler. """ - event = pdu + room_id = event.room_id + event_id = event.event_id - logger.debug("Processing event: %s", event) + logger.debug( + "[%s %s] Processing event: %s", + room_id, event_id, event, + ) # FIXME (erikj): Awful hack to make the case where we are not currently # in the room work @@ -411,15 +564,16 @@ class FederationHandler(BaseHandler): # event. if state and auth_chain and not event.internal_metadata.is_outlier(): is_in_room = yield self.auth.check_host_in_room( - event.room_id, + room_id, self.server_name ) else: is_in_room = True + if not is_in_room: logger.info( - "Got event for room we're not in: %r %r", - event.room_id, event.event_id + "[%s %s] Got event for room we're not in", + room_id, event_id, ) try: @@ -431,7 +585,7 @@ class FederationHandler(BaseHandler): "ERROR", e.code, e.msg, - affected=event.event_id, + affected=event_id, ) else: @@ -464,6 +618,10 @@ class FederationHandler(BaseHandler): }) seen_ids.add(e.event_id) + logger.info( + "[%s %s] persisting newly-received auth/state events %s", + room_id, event_id, [e["event"].event_id for e in event_infos] + ) yield self._handle_new_events(origin, event_infos) try: @@ -480,12 +638,12 @@ class FederationHandler(BaseHandler): affected=event.event_id, ) - room = yield self.store.get_room(event.room_id) + room = yield self.store.get_room(room_id) if not room: try: yield self.store.store_room( - room_id=event.room_id, + room_id=room_id, room_creator_user_id="", is_public=False, ) @@ -513,7 +671,7 @@ class FederationHandler(BaseHandler): if newly_joined: user = UserID.from_string(event.state_key) - yield self.user_joined_room(user, event.room_id) + yield self.user_joined_room(user, room_id) @log_function @defer.inlineCallbacks @@ -594,7 +752,7 @@ class FederationHandler(BaseHandler): required_auth = set( a_id - for event in events + state_events.values() + auth_events.values() + for event in events + list(state_events.values()) + list(auth_events.values()) for a_id, _ in event.auth_events ) auth_events.update({ @@ -802,7 +960,7 @@ class FederationHandler(BaseHandler): ) continue except NotRetryingDestination as e: - logger.info(e.message) + logger.info(str(e)) continue except FederationDeniedError as e: logger.info(e) @@ -1027,7 +1185,8 @@ class FederationHandler(BaseHandler): try: logger.info("Processing queued PDU %s which was received " "while we were joining %s", p.event_id, p.room_id) - yield self.on_receive_pdu(origin, p) + with logcontext.nested_logging_context(p.event_id): + yield self.on_receive_pdu(origin, p, sent_to_us_directly=True) except Exception as e: logger.warn( "Error handling queued PDU %s from %s: %s", @@ -1358,7 +1517,7 @@ class FederationHandler(BaseHandler): ) if state_groups: - _, state = state_groups.items().pop() + _, state = list(state_groups.items()).pop() results = state if event.is_state(): @@ -1430,12 +1589,10 @@ class FederationHandler(BaseHandler): else: defer.returnValue(None) - @log_function def get_min_depth_for_context(self, context): return self.store.get_min_depth(context) @defer.inlineCallbacks - @log_function def _handle_new_event(self, origin, event, state=None, auth_events=None, backfilled=False): context = yield self._prep_event( @@ -1444,6 +1601,9 @@ class FederationHandler(BaseHandler): auth_events=auth_events, ) + # reraise does not allow inlineCallbacks to preserve the stacktrace, so we + # hack around with a try/finally instead. + success = False try: if not event.internal_metadata.is_outlier() and not backfilled: yield self.action_generator.handle_push_actions_for_event( @@ -1454,15 +1614,13 @@ class FederationHandler(BaseHandler): [(event, context)], backfilled=backfilled, ) - except: # noqa: E722, as we reraise the exception this is fine. - tp, value, tb = sys.exc_info() - - logcontext.run_in_background( - self.store.remove_push_actions_from_staging, - event.event_id, - ) - - six.reraise(tp, value, tb) + success = True + finally: + if not success: + logcontext.run_in_background( + self.store.remove_push_actions_from_staging, + event.event_id, + ) defer.returnValue(context) @@ -1475,15 +1633,22 @@ class FederationHandler(BaseHandler): Notifies about the events where appropriate. """ - contexts = yield logcontext.make_deferred_yieldable(defer.gatherResults( - [ - logcontext.run_in_background( - self._prep_event, + + @defer.inlineCallbacks + def prep(ev_info): + event = ev_info["event"] + with logcontext.nested_logging_context(suffix=event.event_id): + res = yield self._prep_event( origin, - ev_info["event"], + event, state=ev_info.get("state"), auth_events=ev_info.get("auth_events"), ) + defer.returnValue(res) + + contexts = yield logcontext.make_deferred_yieldable(defer.gatherResults( + [ + logcontext.run_in_background(prep, ev_info) for ev_info in event_infos ], consumeErrors=True, )) @@ -1635,8 +1800,8 @@ class FederationHandler(BaseHandler): ) except AuthError as e: logger.warn( - "Rejecting %s because %s", - event.event_id, e.msg + "[%s %s] Rejecting: %s", + event.room_id, event.event_id, e.msg ) context.rejected = RejectedReason.AUTH_ERROR @@ -1831,7 +1996,7 @@ class FederationHandler(BaseHandler): room_version = yield self.store.get_room_version(event.room_id) - new_state = self.state_handler.resolve_events( + new_state = yield self.state_handler.resolve_events( room_version, [list(local_view.values()), list(remote_view.values())], event |