diff options
Diffstat (limited to 'synapse')
| -rw-r--r-- | synapse/events/__init__.py | 15 | ||||
| -rw-r--r-- | synapse/federation/sender/__init__.py | 39 |
2 files changed, 50 insertions, 4 deletions
diff --git a/synapse/events/__init__.py b/synapse/events/__init__.py index 9acb3c0cc4..3e4b4f0384 100644 --- a/synapse/events/__init__.py +++ b/synapse/events/__init__.py @@ -213,10 +213,17 @@ class _EventInternalMetadata: return self.outlier def is_out_of_band_membership(self) -> bool: - """Whether this is an out of band membership, like an invite or an invite - rejection. This is needed as those events are marked as outliers, but - they still need to be processed as if they're new events (e.g. updating - invite state in the database, relaying to clients, etc). + """Whether this event is an out-of-band membership. + + OOB memberships are a special case of outlier events: they are membership events + for federated rooms that we aren't full members. Examples include invites + received over federation, and rejections for such invites. + + The concept of an OOB membership is needed because these events need to be + processed as if they're new regular events (e.g. updating membership state in + the database, relaying to clients via /sync, etc) despite being outliers. + + See also https://matrix-org.github.io/synapse/develop/development/room-dag-concepts.html#out-of-band-membership-events. (Added in synapse 0.99.0, so may be unreliable for events received before that) """ diff --git a/synapse/federation/sender/__init__.py b/synapse/federation/sender/__init__.py index 30e2421efc..d795b7b26b 100644 --- a/synapse/federation/sender/__init__.py +++ b/synapse/federation/sender/__init__.py @@ -355,6 +355,45 @@ class FederationSender(AbstractFederationSender): if not is_mine and send_on_behalf_of is None: return + # We also want to not send out-of-band membership events. + # + # OOB memberships are used in three (and a half) situations: + # + # (1) invite events which we have received over federation. Those + # will have a `sender` on a different server, so will be + # skipped by the "is_mine" test above anyway. + # + # (2) rejections of invites to federated rooms - either remotely + # or locally generated. (Such rejections are normally + # created via federation, in which case the remote server is + # responsible for sending out the rejection. If that fails, + # we'll create a leave event locally, but that's only really + # for the benefit of the invited user - we don't have enough + # information to send it out over federation). + # + # (2a) rescinded knocks. These are identical to rejected invites. + # + # (3) knock events which we have sent over federation. As with + # invite rejections, the remote server should send them out to + # the federation. + # + # So, in all the above cases, we want to ignore such events. + # + # OOB memberships are always(?) outliers anyway, so if we *don't* + # ignore them, we'll get an exception further down when we try to + # fetch the membership list for the room. + # + # Arguably, we could equivalently ignore all outliers here, since + # in theory the only way for an outlier with a local `sender` to + # exist is by being an OOB membership (via one of (2), (2a) or (3) + # above). + # + if event.internal_metadata.is_out_of_band_membership(): + return + + # Finally, there are some other events that we should not send out + # until someone asks for them. They are explicitly flagged as such + # with `proactively_send: False`. if not event.internal_metadata.should_proactively_send(): return |