diff options
Diffstat (limited to 'synapse/federation/federation_server.py')
| -rw-r--r-- | synapse/federation/federation_server.py | 57 |
1 files changed, 40 insertions, 17 deletions
diff --git a/synapse/federation/federation_server.py b/synapse/federation/federation_server.py index bea7fd0b71..247ddc89d5 100644 --- a/synapse/federation/federation_server.py +++ b/synapse/federation/federation_server.py @@ -1,5 +1,6 @@ # -*- coding: utf-8 -*- # Copyright 2015, 2016 OpenMarket Ltd +# Copyright 2018 New Vector Ltd # # Licensed under the Apache License, Version 2.0 (the "License"); # you may not use this file except in compliance with the License. @@ -30,9 +31,10 @@ import synapse.metrics from synapse.types import get_domain_from_id from synapse.util import async from synapse.util.caches.response_cache import ResponseCache -from synapse.util.logcontext import make_deferred_yieldable, preserve_fn from synapse.util.logutils import log_function +from six import iteritems + # when processing incoming transactions, we try to handle multiple rooms in # parallel, up to this limit. TRANSACTION_CONCURRENCY_LIMIT = 10 @@ -65,7 +67,7 @@ class FederationServer(FederationBase): # We cache responses to state queries, as they take a while and often # come in waves. - self._state_resp_cache = ResponseCache(hs, timeout_ms=30000) + self._state_resp_cache = ResponseCache(hs, "state_resp", timeout_ms=30000) @defer.inlineCallbacks @log_function @@ -212,16 +214,17 @@ class FederationServer(FederationBase): if not in_room: raise AuthError(403, "Host not in room.") - result = self._state_resp_cache.get((room_id, event_id)) - if not result: - with (yield self._server_linearizer.queue((origin, room_id))): - d = self._state_resp_cache.set( - (room_id, event_id), - preserve_fn(self._on_context_state_request_compute)(room_id, event_id) - ) - resp = yield make_deferred_yieldable(d) - else: - resp = yield make_deferred_yieldable(result) + # we grab the linearizer to protect ourselves from servers which hammer + # us. In theory we might already have the response to this query + # in the cache so we could return it without waiting for the linearizer + # - but that's non-trivial to get right, and anyway somewhat defeats + # the point of the linearizer. + with (yield self._server_linearizer.queue((origin, room_id))): + resp = yield self._state_resp_cache.wrap( + (room_id, event_id), + self._on_context_state_request_compute, + room_id, event_id, + ) defer.returnValue((200, resp)) @@ -425,9 +428,9 @@ class FederationServer(FederationBase): "Claimed one-time-keys: %s", ",".join(( "%s for %s:%s" % (key_id, user_id, device_id) - for user_id, user_keys in json_result.iteritems() - for device_id, device_keys in user_keys.iteritems() - for key_id, _ in device_keys.iteritems() + for user_id, user_keys in iteritems(json_result) + for device_id, device_keys in iteritems(user_keys) + for key_id, _ in iteritems(device_keys) )), ) @@ -494,13 +497,33 @@ class FederationServer(FederationBase): def _handle_received_pdu(self, origin, pdu): """ Process a PDU received in a federation /send/ transaction. + If the event is invalid, then this method throws a FederationError. + (The error will then be logged and sent back to the sender (which + probably won't do anything with it), and other events in the + transaction will be processed as normal). + + It is likely that we'll then receive other events which refer to + this rejected_event in their prev_events, etc. When that happens, + we'll attempt to fetch the rejected event again, which will presumably + fail, so those second-generation events will also get rejected. + + Eventually, we get to the point where there are more than 10 events + between any new events and the original rejected event. Since we + only try to backfill 10 events deep on received pdu, we then accept the + new event, possibly introducing a discontinuity in the DAG, with new + forward extremities, so normal service is approximately returned, + until we try to backfill across the discontinuity. + Args: origin (str): server which sent the pdu pdu (FrozenEvent): received pdu Returns (Deferred): completes with None - Raises: FederationError if the signatures / hash do not match - """ + + Raises: FederationError if the signatures / hash do not match, or + if the event was unacceptable for any other reason (eg, too large, + too many prev_events, couldn't find the prev_events) + """ # check that it's actually being sent from a valid destination to # workaround bug #1753 in 0.18.5 and 0.18.6 if origin != get_domain_from_id(pdu.event_id): |