From e9e6aacfbe016922ed6a25071c0e9ce77334b4e8 Mon Sep 17 00:00:00 2001 From: reivilibre Date: Thu, 4 Aug 2022 15:27:04 +0000 Subject: [PATCH] Faster Room Joins: prevent Synapse from answering federated join requests for a room which it has not fully joined yet. (#13416) --- changelog.d/13416.misc | 1 + synapse/federation/federation_server.py | 17 +++++++++++++++++ synapse/handlers/federation.py | 17 +++++++++++++++++ 3 files changed, 35 insertions(+) create mode 100644 changelog.d/13416.misc diff --git a/changelog.d/13416.misc b/changelog.d/13416.misc new file mode 100644 index 000000000..2904e7337 --- /dev/null +++ b/changelog.d/13416.misc @@ -0,0 +1 @@ +Faster Room Joins: prevent Synapse from answering federated join requests for a room which it has not fully joined yet. \ No newline at end of file diff --git a/synapse/federation/federation_server.py b/synapse/federation/federation_server.py index 1d6013741..db4b83a50 100644 --- a/synapse/federation/federation_server.py +++ b/synapse/federation/federation_server.py @@ -843,8 +843,25 @@ class FederationServer(FederationBase): Codes.BAD_JSON, ) + # Note that get_room_version throws if the room does not exist here. room_version = await self.store.get_room_version(room_id) + if await self.store.is_partial_state_room(room_id): + # If our server is still only partially joined, we can't give a complete + # response to /send_join, /send_knock or /send_leave. + # This is because we will not be able to provide the server list (for partial + # joins) or the full state (for full joins). + # Return a 404 as we would if we weren't in the room at all. + logger.info( + f"Rejecting /send_{membership_type} to %s because it's a partial state room", + room_id, + ) + raise SynapseError( + 404, + f"Unable to handle /send_{membership_type} right now; this server is not fully joined.", + errcode=Codes.NOT_FOUND, + ) + if membership_type == Membership.KNOCK and not room_version.msc2403_knocking: raise SynapseError( 403, diff --git a/synapse/handlers/federation.py b/synapse/handlers/federation.py index 30f1585a8..504223674 100644 --- a/synapse/handlers/federation.py +++ b/synapse/handlers/federation.py @@ -754,6 +754,23 @@ class FederationHandler: # (and return a 404 otherwise) room_version = await self.store.get_room_version(room_id) + if await self.store.is_partial_state_room(room_id): + # If our server is still only partially joined, we can't give a complete + # response to /make_join, so return a 404 as we would if we weren't in the + # room at all. + # The main reason we can't respond properly is that we need to know about + # the auth events for the join event that we would return. + # We also should not bother entertaining the /make_join since we cannot + # handle the /send_join. + logger.info( + "Rejecting /make_join to %s because it's a partial state room", room_id + ) + raise SynapseError( + 404, + "Unable to handle /make_join right now; this server is not fully joined.", + errcode=Codes.NOT_FOUND, + ) + # now check that we are *still* in the room is_in_room = await self._event_auth_handler.check_host_in_room( room_id, self.server_name