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The idea here being that the directory server shouldn't advertise rooms to a requesting server is the requesting server would not be allowed to join or participate in the room. <!-- Fixes: # <!-- --> <!-- Supersedes: # <!-- --> <!-- Follows: # <!-- --> <!-- Part of: # <!-- --> Base: `develop` <!-- git-stack-base-branch:develop --> <!-- This pull request is commit-by-commit review friendly. <!-- --> <!-- This pull request is intended for commit-by-commit review. <!-- --> Original commit schedule, with full messages: <ol> <li> Pass `from_federation_origin` down into room list retrieval code </li> <li> Don't cache /publicRooms response for inbound federated requests </li> <li> fixup! Don't cache /publicRooms response for inbound federated requests </li> <li> Cap the number of /publicRooms entries to 100 </li> <li> Simplify code now that you can't request unlimited rooms </li> <li> Filter out rooms from federated requests that don't have the correct ACL </li> <li> Request a handful more when filtering ACLs so that we can try to avoid shortchanging the requester </li> </ol> --------- Signed-off-by: Olivier Wilkinson (reivilibre) <oliverw@matrix.org>
622 lines
23 KiB
Python
622 lines
23 KiB
Python
#
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# This file is licensed under the Affero General Public License (AGPL) version 3.
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#
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# Copyright (C) 2023 New Vector, Ltd
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#
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# This program is free software: you can redistribute it and/or modify
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# it under the terms of the GNU Affero General Public License as
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# published by the Free Software Foundation, either version 3 of the
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# License, or (at your option) any later version.
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#
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# See the GNU Affero General Public License for more details:
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# <https://www.gnu.org/licenses/agpl-3.0.html>.
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#
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# Originally licensed under the Apache License, Version 2.0:
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# <http://www.apache.org/licenses/LICENSE-2.0>.
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#
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# [This file includes modifications made by New Vector Limited]
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#
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#
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import logging
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from typing import TYPE_CHECKING, Any, List, Optional, Tuple
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import attr
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import msgpack
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from unpaddedbase64 import decode_base64, encode_base64
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from synapse.api.constants import (
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EventContentFields,
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EventTypes,
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GuestAccess,
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HistoryVisibility,
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JoinRules,
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PublicRoomsFilterFields,
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)
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from synapse.api.errors import (
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Codes,
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HttpResponseException,
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RequestSendFailed,
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SynapseError,
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)
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from synapse.storage.databases.main.room import LargestRoomStats
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from synapse.types import JsonDict, JsonMapping, ThirdPartyInstanceID
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from synapse.util.caches.descriptors import _CacheContext, cached
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from synapse.util.caches.response_cache import ResponseCache
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if TYPE_CHECKING:
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from synapse.server import HomeServer
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logger = logging.getLogger(__name__)
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REMOTE_ROOM_LIST_POLL_INTERVAL = 60 * 1000
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# This is used to indicate we should only return rooms published to the main list.
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EMPTY_THIRD_PARTY_ID = ThirdPartyInstanceID(None, None)
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# Maximum number of local public rooms returned over the CS or SS API
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MAX_PUBLIC_ROOMS_IN_RESPONSE = 100
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class RoomListHandler:
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def __init__(self, hs: "HomeServer"):
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self.store = hs.get_datastores().main
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self._storage_controllers = hs.get_storage_controllers()
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self.hs = hs
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self.enable_room_list_search = hs.config.roomdirectory.enable_room_list_search
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self.response_cache: ResponseCache[
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Tuple[Optional[int], Optional[str], Optional[ThirdPartyInstanceID]]
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] = ResponseCache(hs.get_clock(), "room_list")
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self.remote_response_cache: ResponseCache[
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Tuple[str, Optional[int], Optional[str], bool, Optional[str]]
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] = ResponseCache(hs.get_clock(), "remote_room_list", timeout_ms=30 * 1000)
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async def get_local_public_room_list(
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self,
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limit: Optional[int] = None,
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since_token: Optional[str] = None,
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search_filter: Optional[dict] = None,
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network_tuple: Optional[ThirdPartyInstanceID] = EMPTY_THIRD_PARTY_ID,
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from_federation_origin: Optional[str] = None,
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) -> JsonDict:
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"""Generate a local public room list.
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There are multiple different lists: the main one plus one per third
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party network. A client can ask for a specific list or to return all.
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Args:
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limit
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since_token
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search_filter
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network_tuple: Which public list to use.
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This can be (None, None) to indicate the main list, or a particular
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appservice and network id to use an appservice specific one.
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Setting to None returns all public rooms across all lists.
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from_federation_origin: the server name of the requester, or None
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if the request is not from federation.
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"""
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if not self.enable_room_list_search:
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return {"chunk": [], "total_room_count_estimate": 0}
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logger.info(
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"Getting public room list: limit=%r, since=%r, search=%r, network=%r",
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limit,
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since_token,
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bool(search_filter),
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network_tuple,
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)
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capped_limit: int = (
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MAX_PUBLIC_ROOMS_IN_RESPONSE
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if limit is None or limit > MAX_PUBLIC_ROOMS_IN_RESPONSE
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else limit
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)
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if search_filter or from_federation_origin is not None:
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# We explicitly don't bother caching searches or requests for
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# appservice specific lists.
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# We also don't bother caching requests from federated homeservers.
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logger.debug("Bypassing cache as search or federation request.")
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return await self._get_public_room_list(
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capped_limit,
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since_token,
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search_filter,
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network_tuple=network_tuple,
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from_federation_origin=from_federation_origin,
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)
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key = (capped_limit, since_token, network_tuple)
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return await self.response_cache.wrap(
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key,
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self._get_public_room_list,
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capped_limit,
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since_token,
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network_tuple=network_tuple,
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from_federation_origin=from_federation_origin,
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)
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async def _get_public_room_list(
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self,
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limit: int,
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since_token: Optional[str] = None,
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search_filter: Optional[dict] = None,
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network_tuple: Optional[ThirdPartyInstanceID] = EMPTY_THIRD_PARTY_ID,
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from_federation_origin: Optional[str] = None,
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) -> JsonDict:
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"""Generate a public room list.
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Args:
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limit: Maximum amount of rooms to return.
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since_token:
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search_filter: Dictionary to filter rooms by.
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network_tuple: Which public list to use.
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This can be (None, None) to indicate the main list, or a particular
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appservice and network id to use an appservice specific one.
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Setting to None returns all public rooms across all lists.
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from_federation_origin: the server name of the requester, or None
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if the request is not from federation.
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"""
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# Pagination tokens work by storing the room ID sent in the last batch,
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# plus the direction (forwards or backwards). Next batch tokens always
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# go forwards, prev batch tokens always go backwards.
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if since_token:
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batch_token = RoomListNextBatch.from_token(since_token)
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bounds: Optional[Tuple[int, str]] = (
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batch_token.last_joined_members,
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batch_token.last_room_id,
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)
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forwards = batch_token.direction_is_forward
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has_batch_token = True
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else:
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bounds = None
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forwards = True
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has_batch_token = False
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if from_federation_origin is None:
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# Client-Server API:
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# we request one more than wanted to see if there are more pages to come
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probing_limit = limit + 1
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else:
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# Federation API:
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# we request a handful more in case any get filtered out by ACLs
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# as a best easy effort attempt to return the full number of entries
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# specified by `limit`.
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probing_limit = limit + 10
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results = await self.store.get_largest_public_rooms(
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network_tuple,
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search_filter,
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probing_limit,
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bounds=bounds,
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forwards=forwards,
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ignore_non_federatable=from_federation_origin is not None,
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)
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def build_room_entry(room: LargestRoomStats) -> JsonDict:
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entry = {
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"room_id": room.room_id,
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"name": room.name,
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"topic": room.topic,
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"canonical_alias": room.canonical_alias,
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"num_joined_members": room.joined_members,
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"avatar_url": room.avatar,
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"world_readable": room.history_visibility
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== HistoryVisibility.WORLD_READABLE,
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"guest_can_join": room.guest_access == "can_join",
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"join_rule": room.join_rules,
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"room_type": room.room_type,
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}
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# Filter out Nones – rather omit the field altogether
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return {k: v for k, v in entry.items() if v is not None}
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# Build a list of up to `limit` entries.
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room_entries: List[JsonDict] = []
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rooms_iterator = results if forwards else reversed(results)
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# Track the first and last 'considered' rooms so that we can provide correct
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# next_batch/prev_batch tokens.
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# This is needed because the loop might finish early when
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# `len(room_entries) >= limit` and we might be left with rooms we didn't
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# 'consider' (iterate over) and we should save those rooms for the next
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# batch.
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first_considered_room: Optional[LargestRoomStats] = None
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last_considered_room: Optional[LargestRoomStats] = None
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cut_off_due_to_limit: bool = False
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for room_result in rooms_iterator:
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if len(room_entries) >= limit:
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cut_off_due_to_limit = True
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break
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if first_considered_room is None:
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first_considered_room = room_result
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last_considered_room = room_result
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if from_federation_origin is not None:
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# If this is a federated request, apply server ACLs if the room has any set
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acl_evaluator = (
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await self._storage_controllers.state.get_server_acl_for_room(
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room_result.room_id
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)
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)
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if acl_evaluator is not None:
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if not acl_evaluator.server_matches_acl_event(
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from_federation_origin
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):
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# the requesting server is ACL blocked by the room,
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# don't show in directory
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continue
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room_entries.append(build_room_entry(room_result))
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if not forwards:
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# If we are paginating backwards, we still return the chunk in
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# biggest-first order, so reverse again.
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room_entries.reverse()
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# Swap the order of first/last considered rooms.
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first_considered_room, last_considered_room = (
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last_considered_room,
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first_considered_room,
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)
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response: JsonDict = {
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"chunk": room_entries,
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}
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num_results = len(results)
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more_to_come_from_database = num_results == probing_limit
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if forwards and has_batch_token:
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# If there was a token given then we assume that there
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# must be previous results, even if there were no results in this batch.
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if first_considered_room is not None:
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response["prev_batch"] = RoomListNextBatch(
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last_joined_members=first_considered_room.joined_members,
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last_room_id=first_considered_room.room_id,
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direction_is_forward=False,
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).to_token()
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else:
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# If we didn't find any results this time,
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# we don't have an actual room ID to put in the token.
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# But since `first_considered_room` is None, we know that we have
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# reached the end of the results.
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# So we can use a token of (0, empty room ID) to paginate from the end
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# next time.
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response["prev_batch"] = RoomListNextBatch(
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last_joined_members=0,
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last_room_id="",
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direction_is_forward=False,
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).to_token()
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if num_results > 0:
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assert first_considered_room is not None
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assert last_considered_room is not None
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if forwards:
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if more_to_come_from_database or cut_off_due_to_limit:
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response["next_batch"] = RoomListNextBatch(
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last_joined_members=last_considered_room.joined_members,
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last_room_id=last_considered_room.room_id,
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direction_is_forward=True,
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).to_token()
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else: # backwards
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if has_batch_token:
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response["next_batch"] = RoomListNextBatch(
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last_joined_members=last_considered_room.joined_members,
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last_room_id=last_considered_room.room_id,
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direction_is_forward=True,
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).to_token()
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if more_to_come_from_database or cut_off_due_to_limit:
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response["prev_batch"] = RoomListNextBatch(
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last_joined_members=first_considered_room.joined_members,
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last_room_id=first_considered_room.room_id,
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direction_is_forward=False,
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).to_token()
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# We can't efficiently count the total number of rooms that are not
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# blocked by ACLs, but this is just an estimate so that should be
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# good enough.
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response["total_room_count_estimate"] = await self.store.count_public_rooms(
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network_tuple,
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ignore_non_federatable=from_federation_origin is not None,
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search_filter=search_filter,
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)
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return response
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@cached(num_args=1, cache_context=True)
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async def generate_room_entry(
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self,
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room_id: str,
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num_joined_users: int,
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cache_context: _CacheContext,
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with_alias: bool = True,
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allow_private: bool = False,
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) -> Optional[JsonMapping]:
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"""Returns the entry for a room
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Args:
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room_id: The room's ID.
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num_joined_users: Number of users in the room.
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cache_context: Information for cached responses.
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with_alias: Whether to return the room's aliases in the result.
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allow_private: Whether invite-only rooms should be shown.
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Returns:
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Returns a room entry as a dictionary, or None if this
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room was determined not to be shown publicly.
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"""
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result = {"room_id": room_id, "num_joined_members": num_joined_users}
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if with_alias:
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aliases = await self.store.get_aliases_for_room(
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room_id, on_invalidate=cache_context.invalidate
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)
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if aliases:
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result["aliases"] = aliases
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current_state_ids = await self._storage_controllers.state.get_current_state_ids(
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room_id, on_invalidate=cache_context.invalidate
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)
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if not current_state_ids:
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# We're not in the room, so may as well bail out here.
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return result
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event_map = await self.store.get_events(
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[
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event_id
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for key, event_id in current_state_ids.items()
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if key[0]
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in (
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EventTypes.Create,
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EventTypes.JoinRules,
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EventTypes.Name,
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EventTypes.Topic,
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EventTypes.CanonicalAlias,
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EventTypes.RoomHistoryVisibility,
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EventTypes.GuestAccess,
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"m.room.avatar",
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)
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]
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)
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current_state = {(ev.type, ev.state_key): ev for ev in event_map.values()}
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# Double check that this is actually a public room.
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join_rules_event = current_state.get((EventTypes.JoinRules, ""))
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if join_rules_event:
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join_rule = join_rules_event.content.get("join_rule", None)
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if not allow_private and join_rule and join_rule != JoinRules.PUBLIC:
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return None
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# Return whether this room is open to federation users or not
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create_event = current_state[EventTypes.Create, ""]
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result["m.federate"] = create_event.content.get(
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EventContentFields.FEDERATE, True
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)
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name_event = current_state.get((EventTypes.Name, ""))
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if name_event:
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name = name_event.content.get("name", None)
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if name:
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result["name"] = name
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topic_event = current_state.get((EventTypes.Topic, ""))
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if topic_event:
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topic = topic_event.content.get("topic", None)
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if topic:
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result["topic"] = topic
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canonical_event = current_state.get((EventTypes.CanonicalAlias, ""))
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if canonical_event:
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canonical_alias = canonical_event.content.get("alias", None)
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if canonical_alias:
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result["canonical_alias"] = canonical_alias
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visibility_event = current_state.get((EventTypes.RoomHistoryVisibility, ""))
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visibility = None
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if visibility_event:
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visibility = visibility_event.content.get("history_visibility", None)
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result["world_readable"] = visibility == HistoryVisibility.WORLD_READABLE
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guest_event = current_state.get((EventTypes.GuestAccess, ""))
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guest = None
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if guest_event:
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guest = guest_event.content.get(EventContentFields.GUEST_ACCESS)
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result["guest_can_join"] = guest == GuestAccess.CAN_JOIN
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avatar_event = current_state.get(("m.room.avatar", ""))
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if avatar_event:
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avatar_url = avatar_event.content.get("url", None)
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if avatar_url:
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result["avatar_url"] = avatar_url
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return result
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async def get_remote_public_room_list(
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self,
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server_name: str,
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limit: Optional[int] = None,
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since_token: Optional[str] = None,
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search_filter: Optional[dict] = None,
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include_all_networks: bool = False,
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third_party_instance_id: Optional[str] = None,
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) -> JsonDict:
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"""Get the public room list from remote server
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Raises:
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SynapseError
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"""
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if not self.enable_room_list_search:
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return {"chunk": [], "total_room_count_estimate": 0}
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if search_filter:
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# Searching across federation is defined in MSC2197.
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# However, the remote homeserver may or may not actually support it.
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# So we first try an MSC2197 remote-filtered search, then fall back
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# to a locally-filtered search if we must.
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try:
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res = await self._get_remote_list_cached(
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server_name,
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limit=limit,
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since_token=since_token,
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include_all_networks=include_all_networks,
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third_party_instance_id=third_party_instance_id,
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search_filter=search_filter,
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)
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return res
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except HttpResponseException as hre:
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syn_err = hre.to_synapse_error()
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if hre.code in (404, 405) or syn_err.errcode in (
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Codes.UNRECOGNIZED,
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Codes.NOT_FOUND,
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):
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logger.debug("Falling back to locally-filtered /publicRooms")
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else:
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# Not an error that should trigger a fallback.
|
||
raise SynapseError(502, "Failed to fetch room list")
|
||
except RequestSendFailed:
|
||
# Not an error that should trigger a fallback.
|
||
raise SynapseError(502, "Failed to fetch room list")
|
||
|
||
# if we reach this point, then we fall back to the situation where
|
||
# we currently don't support searching across federation, so we have
|
||
# to do it manually without pagination
|
||
limit = None
|
||
since_token = None
|
||
|
||
try:
|
||
res = await self._get_remote_list_cached(
|
||
server_name,
|
||
limit=limit,
|
||
since_token=since_token,
|
||
include_all_networks=include_all_networks,
|
||
third_party_instance_id=third_party_instance_id,
|
||
)
|
||
except (RequestSendFailed, HttpResponseException):
|
||
raise SynapseError(502, "Failed to fetch room list")
|
||
|
||
if search_filter:
|
||
res = {
|
||
"chunk": [
|
||
entry
|
||
for entry in list(res.get("chunk", []))
|
||
if _matches_room_entry(entry, search_filter)
|
||
]
|
||
}
|
||
|
||
return res
|
||
|
||
async def _get_remote_list_cached(
|
||
self,
|
||
server_name: str,
|
||
limit: Optional[int] = None,
|
||
since_token: Optional[str] = None,
|
||
search_filter: Optional[dict] = None,
|
||
include_all_networks: bool = False,
|
||
third_party_instance_id: Optional[str] = None,
|
||
) -> JsonDict:
|
||
"""Wrapper around FederationClient.get_public_rooms that caches the
|
||
result.
|
||
"""
|
||
|
||
repl_layer = self.hs.get_federation_client()
|
||
if search_filter:
|
||
# We can't cache when asking for search
|
||
return await repl_layer.get_public_rooms(
|
||
server_name,
|
||
limit=limit,
|
||
since_token=since_token,
|
||
search_filter=search_filter,
|
||
include_all_networks=include_all_networks,
|
||
third_party_instance_id=third_party_instance_id,
|
||
)
|
||
|
||
key = (
|
||
server_name,
|
||
limit,
|
||
since_token,
|
||
include_all_networks,
|
||
third_party_instance_id,
|
||
)
|
||
return await self.remote_response_cache.wrap(
|
||
key,
|
||
repl_layer.get_public_rooms,
|
||
server_name,
|
||
limit=limit,
|
||
since_token=since_token,
|
||
search_filter=search_filter,
|
||
include_all_networks=include_all_networks,
|
||
third_party_instance_id=third_party_instance_id,
|
||
)
|
||
|
||
|
||
@attr.s(slots=True, frozen=True, auto_attribs=True)
|
||
class RoomListNextBatch:
|
||
last_joined_members: int # The count to get rooms after/before
|
||
last_room_id: str # The room_id to get rooms after/before
|
||
direction_is_forward: bool # True if this is a next_batch, false if prev_batch
|
||
|
||
KEY_DICT = {
|
||
"last_joined_members": "m",
|
||
"last_room_id": "r",
|
||
"direction_is_forward": "d",
|
||
}
|
||
|
||
REVERSE_KEY_DICT = {v: k for k, v in KEY_DICT.items()}
|
||
|
||
@classmethod
|
||
def from_token(cls, token: str) -> "RoomListNextBatch":
|
||
decoded = msgpack.loads(decode_base64(token), raw=False)
|
||
return RoomListNextBatch(
|
||
**{cls.REVERSE_KEY_DICT[key]: val for key, val in decoded.items()}
|
||
)
|
||
|
||
def to_token(self) -> str:
|
||
return encode_base64(
|
||
msgpack.dumps(
|
||
{self.KEY_DICT[key]: val for key, val in attr.asdict(self).items()}
|
||
)
|
||
)
|
||
|
||
def copy_and_replace(self, **kwds: Any) -> "RoomListNextBatch":
|
||
return attr.evolve(self, **kwds)
|
||
|
||
|
||
def _matches_room_entry(room_entry: JsonDict, search_filter: dict) -> bool:
|
||
"""Determines whether the given search filter matches a room entry returned over
|
||
federation.
|
||
|
||
Only used if the remote server does not support MSC2197 remote-filtered search, and
|
||
hence does not support MSC3827 filtering of `/publicRooms` by room type either.
|
||
|
||
In this case, we cannot apply the `room_type` filter since no `room_type` field is
|
||
returned.
|
||
"""
|
||
if search_filter and search_filter.get(
|
||
PublicRoomsFilterFields.GENERIC_SEARCH_TERM, None
|
||
):
|
||
generic_search_term = search_filter[
|
||
PublicRoomsFilterFields.GENERIC_SEARCH_TERM
|
||
].upper()
|
||
if generic_search_term in room_entry.get("name", "").upper():
|
||
return True
|
||
elif generic_search_term in room_entry.get("topic", "").upper():
|
||
return True
|
||
elif generic_search_term in room_entry.get("canonical_alias", "").upper():
|
||
return True
|
||
else:
|
||
return True
|
||
|
||
return False
|