From 865077f1d1f4866ab874c56b70abbd426fedfb97 Mon Sep 17 00:00:00 2001 From: Amber Brown Date: Tue, 30 Jul 2019 02:47:27 +1000 Subject: Room Complexity Client Implementation (#5783) --- synapse/handlers/federation.py | 25 ++++++++++++ synapse/handlers/room_member.py | 84 +++++++++++++++++++++++++++++++++++++++-- 2 files changed, 105 insertions(+), 4 deletions(-) (limited to 'synapse/handlers') diff --git a/synapse/handlers/federation.py b/synapse/handlers/federation.py index 89b37dbc1c..10160bfe86 100644 --- a/synapse/handlers/federation.py +++ b/synapse/handlers/federation.py @@ -2796,3 +2796,28 @@ class FederationHandler(BaseHandler): ) else: return user_joined_room(self.distributor, user, room_id) + + @defer.inlineCallbacks + def get_room_complexity(self, remote_room_hosts, room_id): + """ + Fetch the complexity of a remote room over federation. + + Args: + remote_room_hosts (list[str]): The remote servers to ask. + room_id (str): The room ID to ask about. + + Returns: + Deferred[dict] or Deferred[None]: Dict contains the complexity + metric versions, while None means we could not fetch the complexity. + """ + + for host in remote_room_hosts: + res = yield self.federation_client.get_room_complexity(host, room_id) + + # We got a result, return it. + if res: + defer.returnValue(res) + + # We fell off the bottom, couldn't get the complexity from anyone. Oh + # well. + defer.returnValue(None) diff --git a/synapse/handlers/room_member.py b/synapse/handlers/room_member.py index baea08ddd0..249a6d9c5d 100644 --- a/synapse/handlers/room_member.py +++ b/synapse/handlers/room_member.py @@ -26,8 +26,7 @@ from unpaddedbase64 import decode_base64 from twisted.internet import defer -import synapse.server -import synapse.types +from synapse import types from synapse.api.constants import EventTypes, Membership from synapse.api.errors import AuthError, Codes, HttpResponseException, SynapseError from synapse.types import RoomID, UserID @@ -543,7 +542,7 @@ class RoomMemberHandler(object): ), "Sender (%s) must be same as requester (%s)" % (sender, requester.user) assert self.hs.is_mine(sender), "Sender must be our own: %s" % (sender,) else: - requester = synapse.types.create_requester(target_user) + requester = types.create_requester(target_user) prev_event = yield self.event_creation_handler.deduplicate_state_event( event, context @@ -945,6 +944,47 @@ class RoomMemberMasterHandler(RoomMemberHandler): self.distributor.declare("user_joined_room") self.distributor.declare("user_left_room") + @defer.inlineCallbacks + def _is_remote_room_too_complex(self, room_id, remote_room_hosts): + """ + Check if complexity of a remote room is too great. + + Args: + room_id (str) + remote_room_hosts (list[str]) + + Returns: bool of whether the complexity is too great, or None + if unable to be fetched + """ + max_complexity = self.hs.config.limit_remote_rooms.complexity + complexity = yield self.federation_handler.get_room_complexity( + remote_room_hosts, room_id + ) + + if complexity: + if complexity["v1"] > max_complexity: + return True + return False + return None + + @defer.inlineCallbacks + def _is_local_room_too_complex(self, room_id): + """ + Check if the complexity of a local room is too great. + + Args: + room_id (str) + + Returns: bool + """ + max_complexity = self.hs.config.limit_remote_rooms.complexity + complexity = yield self.store.get_room_complexity(room_id) + + if complexity["v1"] > max_complexity: + return True + + return False + @defer.inlineCallbacks def _remote_join(self, requester, remote_room_hosts, room_id, user, content): """Implements RoomMemberHandler._remote_join @@ -952,7 +992,6 @@ class RoomMemberMasterHandler(RoomMemberHandler): # filter ourselves out of remote_room_hosts: do_invite_join ignores it # and if it is the only entry we'd like to return a 404 rather than a # 500. - remote_room_hosts = [ host for host in remote_room_hosts if host != self.hs.hostname ] @@ -960,6 +999,18 @@ class RoomMemberMasterHandler(RoomMemberHandler): if len(remote_room_hosts) == 0: raise SynapseError(404, "No known servers") + if self.hs.config.limit_remote_rooms.enabled: + # Fetch the room complexity + too_complex = yield self._is_remote_room_too_complex( + room_id, remote_room_hosts + ) + if too_complex is True: + raise SynapseError( + code=400, + msg=self.hs.config.limit_remote_rooms.complexity_error, + errcode=Codes.RESOURCE_LIMIT_EXCEEDED, + ) + # We don't do an auth check if we are doing an invite # join dance for now, since we're kinda implicitly checking # that we are allowed to join when we decide whether or not we @@ -969,6 +1020,31 @@ class RoomMemberMasterHandler(RoomMemberHandler): ) yield self._user_joined_room(user, room_id) + # Check the room we just joined wasn't too large, if we didn't fetch the + # complexity of it before. + if self.hs.config.limit_remote_rooms.enabled: + if too_complex is False: + # We checked, and we're under the limit. + return + + # Check again, but with the local state events + too_complex = yield self._is_local_room_too_complex(room_id) + + if too_complex is False: + # We're under the limit. + return + + # The room is too large. Leave. + requester = types.create_requester(user, None, False, None) + yield self.update_membership( + requester=requester, target=user, room_id=room_id, action="leave" + ) + raise SynapseError( + code=400, + msg=self.hs.config.limit_remote_rooms.complexity_error, + errcode=Codes.RESOURCE_LIMIT_EXCEEDED, + ) + @defer.inlineCallbacks def _remote_reject_invite(self, requester, remote_room_hosts, room_id, target): """Implements RoomMemberHandler._remote_reject_invite -- cgit 1.4.1