From 2ab0b021f153f527aa40080fe6e522df3ff976bc Mon Sep 17 00:00:00 2001 From: Richard van der Hoff <1389908+richvdh@users.noreply.github.com> Date: Thu, 9 Jul 2020 10:40:19 +0100 Subject: Generate real events when we reject invites (#7804) Fixes #2181. The basic premise is that, when we fail to reject an invite via the remote server, we can generate our own out-of-band leave event and persist it as an outlier, so that we have something to send to the client. --- synapse/handlers/message.py | 23 ++-- synapse/handlers/room_member.py | 194 ++++++++++++++++++++--------- synapse/handlers/room_member_worker.py | 17 +-- synapse/replication/http/membership.py | 92 ++++---------- synapse/storage/data_stores/main/events.py | 20 --- synapse/storage/persist_events.py | 6 - 6 files changed, 183 insertions(+), 169 deletions(-) (limited to 'synapse') diff --git a/synapse/handlers/message.py b/synapse/handlers/message.py index 665ad19b5d..da206e1ec1 100644 --- a/synapse/handlers/message.py +++ b/synapse/handlers/message.py @@ -15,7 +15,7 @@ # See the License for the specific language governing permissions and # limitations under the License. import logging -from typing import Optional, Tuple +from typing import TYPE_CHECKING, Optional, Tuple from canonicaljson import encode_canonical_json, json @@ -55,6 +55,9 @@ from synapse.visibility import filter_events_for_client from ._base import BaseHandler +if TYPE_CHECKING: + from synapse.server import HomeServer + logger = logging.getLogger(__name__) @@ -349,7 +352,7 @@ _DUMMY_EVENT_ROOM_EXCLUSION_EXPIRY = 7 * 24 * 60 * 60 * 1000 class EventCreationHandler(object): - def __init__(self, hs): + def __init__(self, hs: "HomeServer"): self.hs = hs self.auth = hs.get_auth() self.store = hs.get_datastore() @@ -814,11 +817,17 @@ class EventCreationHandler(object): 403, "This event is not allowed in this context", Codes.FORBIDDEN ) - try: - await self.auth.check_from_context(room_version, event, context) - except AuthError as err: - logger.warning("Denying new event %r because %s", event, err) - raise err + if event.internal_metadata.is_out_of_band_membership(): + # the only sort of out-of-band-membership events we expect to see here + # are invite rejections we have generated ourselves. + assert event.type == EventTypes.Member + assert event.content["membership"] == Membership.LEAVE + else: + try: + await self.auth.check_from_context(room_version, event, context) + except AuthError as err: + logger.warning("Denying new event %r because %s", event, err) + raise err # Ensure that we can round trip before trying to persist in db try: diff --git a/synapse/handlers/room_member.py b/synapse/handlers/room_member.py index 27c479da9e..178d7db94e 100644 --- a/synapse/handlers/room_member.py +++ b/synapse/handlers/room_member.py @@ -1,7 +1,5 @@ # -*- coding: utf-8 -*- -# Copyright 2016 OpenMarket Ltd -# Copyright 2018 New Vector Ltd -# Copyright 2019 The Matrix.org Foundation C.I.C. +# Copyright 2016-2020 The Matrix.org Foundation C.I.C. # # Licensed under the Apache License, Version 2.0 (the "License"); # you may not use this file except in compliance with the License. @@ -18,17 +16,21 @@ import abc import logging from http import HTTPStatus -from typing import Dict, Iterable, List, Optional, Tuple +from typing import Dict, Iterable, List, Optional, Tuple, Union + +from unpaddedbase64 import encode_base64 from synapse import types -from synapse.api.constants import EventTypes, Membership +from synapse.api.constants import MAX_DEPTH, EventTypes, Membership from synapse.api.errors import AuthError, Codes, SynapseError +from synapse.api.room_versions import EventFormatVersions +from synapse.crypto.event_signing import compute_event_reference_hash from synapse.events import EventBase +from synapse.events.builder import create_local_event_from_event_dict from synapse.events.snapshot import EventContext -from synapse.replication.http.membership import ( - ReplicationLocallyRejectInviteRestServlet, -) -from synapse.types import Collection, Requester, RoomAlias, RoomID, UserID +from synapse.events.validator import EventValidator +from synapse.storage.roommember import RoomsForUser +from synapse.types import Collection, JsonDict, Requester, RoomAlias, RoomID, UserID from synapse.util.async_helpers import Linearizer from synapse.util.distributor import user_joined_room, user_left_room @@ -74,10 +76,6 @@ class RoomMemberHandler(object): ) if self._is_on_event_persistence_instance: self.persist_event_storage = hs.get_storage().persistence - else: - self._locally_reject_client = ReplicationLocallyRejectInviteRestServlet.make_client( - hs - ) # This is only used to get at ratelimit function, and # maybe_kick_guest_users. It's fine there are multiple of these as @@ -105,46 +103,28 @@ class RoomMemberHandler(object): raise NotImplementedError() @abc.abstractmethod - async def _remote_reject_invite( + async def remote_reject_invite( self, + invite_event_id: str, + txn_id: Optional[str], requester: Requester, - remote_room_hosts: List[str], - room_id: str, - target: UserID, - content: dict, + content: JsonDict, ) -> Tuple[Optional[str], int]: - """Attempt to reject an invite for a room this server is not in. If we - fail to do so we locally mark the invite as rejected. + """ + Rejects an out-of-band invite we have received from a remote server Args: - requester - remote_room_hosts: List of servers to use to try and reject invite - room_id - target: The user rejecting the invite - content: The content for the rejection event + invite_event_id: ID of the invite to be rejected + txn_id: optional transaction ID supplied by the client + requester: user making the rejection request, according to the access token + content: additional content to include in the rejection event. + Normally an empty dict. Returns: - A dictionary to be returned to the client, may - include event_id etc, or nothing if we locally rejected + event id, stream_id of the leave event """ raise NotImplementedError() - async def locally_reject_invite(self, user_id: str, room_id: str) -> int: - """Mark the invite has having been rejected even though we failed to - create a leave event for it. - """ - if self._is_on_event_persistence_instance: - return await self.persist_event_storage.locally_reject_invite( - user_id, room_id - ) - else: - result = await self._locally_reject_client( - instance_name=self._event_stream_writer_instance, - user_id=user_id, - room_id=room_id, - ) - return result["stream_id"] - @abc.abstractmethod async def _user_joined_room(self, target: UserID, room_id: str) -> None: """Notifies distributor on master process that the user has joined the @@ -485,11 +465,17 @@ class RoomMemberHandler(object): elif effective_membership_state == Membership.LEAVE: if not is_host_in_room: # perhaps we've been invited - inviter = await self._get_inviter(target.to_string(), room_id) - if not inviter: + invite = await self.store.get_invite_for_local_user_in_room( + user_id=target.to_string(), room_id=room_id + ) # type: Optional[RoomsForUser] + if not invite: raise SynapseError(404, "Not a known room") - if self.hs.is_mine(inviter): + logger.info( + "%s rejects invite to %s from %s", target, room_id, invite.sender + ) + + if self.hs.is_mine_id(invite.sender): # the inviter was on our server, but has now left. Carry on # with the normal rejection codepath. # @@ -497,10 +483,10 @@ class RoomMemberHandler(object): # active on other servers. pass else: - # send the rejection to the inviter's HS. - remote_room_hosts = remote_room_hosts + [inviter.domain] - return await self._remote_reject_invite( - requester, remote_room_hosts, room_id, target, content, + # send the rejection to the inviter's HS (with fallback to + # local event) + return await self.remote_reject_invite( + invite.event_id, txn_id, requester, content, ) return await self._local_membership_update( @@ -1014,33 +1000,119 @@ class RoomMemberMasterHandler(RoomMemberHandler): return event_id, stream_id - async def _remote_reject_invite( + async def remote_reject_invite( self, + invite_event_id: str, + txn_id: Optional[str], requester: Requester, - remote_room_hosts: List[str], - room_id: str, - target: UserID, - content: dict, + content: JsonDict, ) -> Tuple[Optional[str], int]: - """Implements RoomMemberHandler._remote_reject_invite """ + Rejects an out-of-band invite received from a remote user + + Implements RoomMemberHandler.remote_reject_invite + """ + invite_event = await self.store.get_event(invite_event_id) + room_id = invite_event.room_id + target_user = invite_event.state_key + + # first of all, try doing a rejection via the inviting server fed_handler = self.federation_handler try: + inviter_id = UserID.from_string(invite_event.sender) event, stream_id = await fed_handler.do_remotely_reject_invite( - remote_room_hosts, room_id, target.to_string(), content=content, + [inviter_id.domain], room_id, target_user, content=content ) return event.event_id, stream_id except Exception as e: - # if we were unable to reject the exception, just mark - # it as rejected on our end and plough ahead. + # if we were unable to reject the invite, we will generate our own + # leave event. # # The 'except' clause is very broad, but we need to # capture everything from DNS failures upwards # logger.warning("Failed to reject invite: %s", e) - stream_id = await self.locally_reject_invite(target.to_string(), room_id) - return None, stream_id + return await self._locally_reject_invite( + invite_event, txn_id, requester, content + ) + + async def _locally_reject_invite( + self, + invite_event: EventBase, + txn_id: Optional[str], + requester: Requester, + content: JsonDict, + ) -> Tuple[str, int]: + """Generate a local invite rejection + + This is called after we fail to reject an invite via a remote server. It + generates an out-of-band membership event locally. + + Args: + invite_event: the invite to be rejected + txn_id: optional transaction ID supplied by the client + requester: user making the rejection request, according to the access token + content: additional content to include in the rejection event. + Normally an empty dict. + """ + + room_id = invite_event.room_id + target_user = invite_event.state_key + room_version = await self.store.get_room_version(room_id) + + content["membership"] = Membership.LEAVE + + # the auth events for the new event are the same as that of the invite, plus + # the invite itself. + # + # the prev_events are just the invite. + invite_hash = invite_event.event_id # type: Union[str, Tuple] + if room_version.event_format == EventFormatVersions.V1: + alg, h = compute_event_reference_hash(invite_event) + invite_hash = (invite_event.event_id, {alg: encode_base64(h)}) + + auth_events = invite_event.auth_events + (invite_hash,) + prev_events = (invite_hash,) + + # we cap depth of generated events, to ensure that they are not + # rejected by other servers (and so that they can be persisted in + # the db) + depth = min(invite_event.depth + 1, MAX_DEPTH) + + event_dict = { + "depth": depth, + "auth_events": auth_events, + "prev_events": prev_events, + "type": EventTypes.Member, + "room_id": room_id, + "sender": target_user, + "content": content, + "state_key": target_user, + } + + event = create_local_event_from_event_dict( + clock=self.clock, + hostname=self.hs.hostname, + signing_key=self.hs.signing_key, + room_version=room_version, + event_dict=event_dict, + ) + event.internal_metadata.outlier = True + event.internal_metadata.out_of_band_membership = True + if txn_id is not None: + event.internal_metadata.txn_id = txn_id + if requester.access_token_id is not None: + event.internal_metadata.token_id = requester.access_token_id + + EventValidator().validate_new(event, self.config) + + context = await self.state_handler.compute_event_context(event) + context.app_service = requester.app_service + stream_id = await self.event_creation_handler.handle_new_client_event( + requester, event, context, extra_users=[UserID.from_string(target_user)], + ) + return event.event_id, stream_id async def _user_joined_room(self, target: UserID, room_id: str) -> None: """Implements RoomMemberHandler._user_joined_room diff --git a/synapse/handlers/room_member_worker.py b/synapse/handlers/room_member_worker.py index 02e0c4103d..ac03f15166 100644 --- a/synapse/handlers/room_member_worker.py +++ b/synapse/handlers/room_member_worker.py @@ -61,21 +61,22 @@ class RoomMemberWorkerHandler(RoomMemberHandler): return ret["event_id"], ret["stream_id"] - async def _remote_reject_invite( + async def remote_reject_invite( self, + invite_event_id: str, + txn_id: Optional[str], requester: Requester, - remote_room_hosts: List[str], - room_id: str, - target: UserID, content: dict, ) -> Tuple[Optional[str], int]: - """Implements RoomMemberHandler._remote_reject_invite + """ + Rejects an out-of-band invite received from a remote user + + Implements RoomMemberHandler.remote_reject_invite """ ret = await self._remote_reject_client( + invite_event_id=invite_event_id, + txn_id=txn_id, requester=requester, - remote_room_hosts=remote_room_hosts, - room_id=room_id, - user_id=target.to_string(), content=content, ) return ret["event_id"], ret["stream_id"] diff --git a/synapse/replication/http/membership.py b/synapse/replication/http/membership.py index a7174c4a8f..63ef6eb7be 100644 --- a/synapse/replication/http/membership.py +++ b/synapse/replication/http/membership.py @@ -14,11 +14,11 @@ # limitations under the License. import logging -from typing import TYPE_CHECKING +from typing import TYPE_CHECKING, Optional from synapse.http.servlet import parse_json_object_from_request from synapse.replication.http._base import ReplicationEndpoint -from synapse.types import Requester, UserID +from synapse.types import JsonDict, Requester, UserID from synapse.util.distributor import user_joined_room, user_left_room if TYPE_CHECKING: @@ -88,49 +88,54 @@ class ReplicationRemoteJoinRestServlet(ReplicationEndpoint): class ReplicationRemoteRejectInviteRestServlet(ReplicationEndpoint): - """Rejects the invite for the user and room. + """Rejects an out-of-band invite we have received from a remote server Request format: - POST /_synapse/replication/remote_reject_invite/:room_id/:user_id + POST /_synapse/replication/remote_reject_invite/:event_id { + "txn_id": ..., "requester": ..., - "remote_room_hosts": [...], "content": { ... } } """ NAME = "remote_reject_invite" - PATH_ARGS = ("room_id", "user_id") + PATH_ARGS = ("invite_event_id",) - def __init__(self, hs): + def __init__(self, hs: "HomeServer"): super(ReplicationRemoteRejectInviteRestServlet, self).__init__(hs) - self.federation_handler = hs.get_handlers().federation_handler self.store = hs.get_datastore() self.clock = hs.get_clock() self.member_handler = hs.get_room_member_handler() @staticmethod - def _serialize_payload(requester, room_id, user_id, remote_room_hosts, content): + def _serialize_payload( # type: ignore + invite_event_id: str, + txn_id: Optional[str], + requester: Requester, + content: JsonDict, + ): """ Args: - requester(Requester) - room_id (str) - user_id (str) - remote_room_hosts (list[str]): Servers to try and reject via + invite_event_id: ID of the invite to be rejected + txn_id: optional transaction ID supplied by the client + requester: user making the rejection request, according to the access token + content: additional content to include in the rejection event. + Normally an empty dict. """ return { + "txn_id": txn_id, "requester": requester.serialize(), - "remote_room_hosts": remote_room_hosts, "content": content, } - async def _handle_request(self, request, room_id, user_id): + async def _handle_request(self, request, invite_event_id): content = parse_json_object_from_request(request) - remote_room_hosts = content["remote_room_hosts"] + txn_id = content["txn_id"] event_content = content["content"] requester = Requester.deserialize(self.store, content["requester"]) @@ -138,60 +143,14 @@ class ReplicationRemoteRejectInviteRestServlet(ReplicationEndpoint): if requester.user: request.authenticated_entity = requester.user.to_string() - logger.info("remote_reject_invite: %s out of room: %s", user_id, room_id) - - try: - event, stream_id = await self.federation_handler.do_remotely_reject_invite( - remote_room_hosts, room_id, user_id, event_content, - ) - event_id = event.event_id - except Exception as e: - # if we were unable to reject the exception, just mark - # it as rejected on our end and plough ahead. - # - # The 'except' clause is very broad, but we need to - # capture everything from DNS failures upwards - # - logger.warning("Failed to reject invite: %s", e) - - stream_id = await self.member_handler.locally_reject_invite( - user_id, room_id - ) - event_id = None + # hopefully we're now on the master, so this won't recurse! + event_id, stream_id = await self.member_handler.remote_reject_invite( + invite_event_id, txn_id, requester, event_content, + ) return 200, {"event_id": event_id, "stream_id": stream_id} -class ReplicationLocallyRejectInviteRestServlet(ReplicationEndpoint): - """Rejects the invite for the user and room locally. - - Request format: - - POST /_synapse/replication/locally_reject_invite/:room_id/:user_id - - {} - """ - - NAME = "locally_reject_invite" - PATH_ARGS = ("room_id", "user_id") - - def __init__(self, hs: "HomeServer"): - super().__init__(hs) - - self.member_handler = hs.get_room_member_handler() - - @staticmethod - def _serialize_payload(room_id, user_id): - return {} - - async def _handle_request(self, request, room_id, user_id): - logger.info("locally_reject_invite: %s out of room: %s", user_id, room_id) - - stream_id = await self.member_handler.locally_reject_invite(user_id, room_id) - - return 200, {"stream_id": stream_id} - - class ReplicationUserJoinedLeftRoomRestServlet(ReplicationEndpoint): """Notifies that a user has joined or left the room @@ -245,4 +204,3 @@ def register_servlets(hs, http_server): ReplicationRemoteJoinRestServlet(hs).register(http_server) ReplicationRemoteRejectInviteRestServlet(hs).register(http_server) ReplicationUserJoinedLeftRoomRestServlet(hs).register(http_server) - ReplicationLocallyRejectInviteRestServlet(hs).register(http_server) diff --git a/synapse/storage/data_stores/main/events.py b/synapse/storage/data_stores/main/events.py index a18317366c..230fb5cd7f 100644 --- a/synapse/storage/data_stores/main/events.py +++ b/synapse/storage/data_stores/main/events.py @@ -1541,23 +1541,3 @@ class PersistEventsStore: if not ev.internal_metadata.is_outlier() ], ) - - async def locally_reject_invite(self, user_id: str, room_id: str) -> int: - """Mark the invite has having been rejected even though we failed to - create a leave event for it. - """ - - def f(txn, stream_ordering): - # Clear this entry from `local_current_membership`. - # Ideally we'd point to a leave event, but we don't have one, so - # nevermind. - self.db.simple_delete_txn( - txn, - table="local_current_membership", - keyvalues={"room_id": room_id, "user_id": user_id}, - ) - - with self._stream_id_gen.get_next() as stream_ordering: - await self.db.runInteraction("locally_reject_invite", f, stream_ordering) - - return stream_ordering diff --git a/synapse/storage/persist_events.py b/synapse/storage/persist_events.py index ec894a91cb..fa46041676 100644 --- a/synapse/storage/persist_events.py +++ b/synapse/storage/persist_events.py @@ -783,9 +783,3 @@ class EventsPersistenceStorage(object): for user_id in left_users: await self.main_store.mark_remote_user_device_list_as_unsubscribed(user_id) - - async def locally_reject_invite(self, user_id: str, room_id: str) -> int: - """Mark the invite has having been rejected even though we failed to - create a leave event for it. - """ - return await self.persist_events_store.locally_reject_invite(user_id, room_id) -- cgit 1.4.1