Generalise _locally_reject_invite (#8751)

`_locally_reject_invite` generates an out-of-band membership event which can be passed to clients, but not other homeservers.

This is used when we fail to reject an invite over federation. If this happens, we instead just generate a leave event locally and send it down /sync, allowing clients to reject invites even if we can't reach the remote homeserver.

A similar flow needs to be put in place for rescinding knocks. If we're unable to contact any remote server from the room we've tried to knock on, we'd still like to generate and store the leave event locally. Hence the need to reuse, and thus generalise, this method.

Separated from #6739.
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Andrew Morgan 2020-11-16 15:37:36 +00:00 committed by GitHub
parent 791d7cd6f0
commit 4f76eef0e8
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2 changed files with 20 additions and 17 deletions

1
changelog.d/8751.misc Normal file
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@ -0,0 +1 @@
Generalise `RoomMemberHandler._locally_reject_invite` to apply to more flows than just invite.

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@ -1104,32 +1104,34 @@ class RoomMemberMasterHandler(RoomMemberHandler):
# #
logger.warning("Failed to reject invite: %s", e) logger.warning("Failed to reject invite: %s", e)
return await self._locally_reject_invite( return await self._generate_local_out_of_band_leave(
invite_event, txn_id, requester, content invite_event, txn_id, requester, content
) )
async def _locally_reject_invite( async def _generate_local_out_of_band_leave(
self, self,
invite_event: EventBase, previous_membership_event: EventBase,
txn_id: Optional[str], txn_id: Optional[str],
requester: Requester, requester: Requester,
content: JsonDict, content: JsonDict,
) -> Tuple[str, int]: ) -> Tuple[str, int]:
"""Generate a local invite rejection """Generate a local leave event for a room
This is called after we fail to reject an invite via a remote server. It This can be called after we e.g fail to reject an invite via a remote server.
generates an out-of-band membership event locally. It generates an out-of-band membership event locally.
Args: Args:
invite_event: the invite to be rejected previous_membership_event: the previous membership event for this user
txn_id: optional transaction ID supplied by the client txn_id: optional transaction ID supplied by the client
requester: user making the rejection request, according to the access token requester: user making the request, according to the access token
content: additional content to include in the rejection event. content: additional content to include in the leave event.
Normally an empty dict. Normally an empty dict.
"""
room_id = invite_event.room_id Returns:
target_user = invite_event.state_key A tuple containing (event_id, stream_id of the leave event)
"""
room_id = previous_membership_event.room_id
target_user = previous_membership_event.state_key
content["membership"] = Membership.LEAVE content["membership"] = Membership.LEAVE
@ -1141,12 +1143,12 @@ class RoomMemberMasterHandler(RoomMemberHandler):
"state_key": target_user, "state_key": target_user,
} }
# the auth events for the new event are the same as that of the invite, plus # the auth events for the new event are the same as that of the previous event, plus
# the invite itself. # the event itself.
# #
# the prev_events are just the invite. # the prev_events consist solely of the previous membership event.
prev_event_ids = [invite_event.event_id] prev_event_ids = [previous_membership_event.event_id]
auth_event_ids = invite_event.auth_event_ids() + prev_event_ids auth_event_ids = previous_membership_event.auth_event_ids() + prev_event_ids
event, context = await self.event_creation_handler.create_event( event, context = await self.event_creation_handler.create_event(
requester, requester,