Files
synapse/synapse/rest/client/mutual_rooms.py
2025-12-16 15:24:36 +00:00

146 lines
5.3 KiB
Python

#
# This file is licensed under the Affero General Public License (AGPL) version 3.
#
# Copyright 2020 Half-Shot
# Copyright (C) 2023 New Vector, Ltd
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU Affero General Public License as
# published by the Free Software Foundation, either version 3 of the
# License, or (at your option) any later version.
#
# See the GNU Affero General Public License for more details:
# <https://www.gnu.org/licenses/agpl-3.0.html>.
#
# Originally licensed under the Apache License, Version 2.0:
# <http://www.apache.org/licenses/LICENSE-2.0>.
#
# [This file includes modifications made by New Vector Limited]
#
#
import logging
from bisect import bisect
from http import HTTPStatus
from typing import TYPE_CHECKING
from unpaddedbase64 import decode_base64, encode_base64
from synapse.api.errors import Codes, SynapseError
from synapse.http.server import HttpServer
from synapse.http.servlet import RestServlet, parse_strings_from_args
from synapse.http.site import SynapseRequest
from synapse.types import JsonDict
from ._base import client_patterns
if TYPE_CHECKING:
from synapse.server import HomeServer
logger = logging.getLogger(__name__)
MUTUAL_ROOMS_BATCH_LIMIT = 100
def _parse_mutual_rooms_batch_token_args(args: dict[bytes, list[bytes]]) -> str | None:
from_batches = parse_strings_from_args(args, "from")
if not from_batches:
return None
if len(from_batches) > 1:
raise SynapseError(
HTTPStatus.BAD_REQUEST,
"Duplicate from query parameter",
errcode=Codes.INVALID_PARAM,
)
if from_batches[0]:
try:
return decode_base64(from_batches[0]).decode("utf-8")
except Exception:
raise SynapseError(
HTTPStatus.BAD_REQUEST,
"Malformed from token",
errcode=Codes.INVALID_PARAM,
)
return None
class UserMutualRoomsServlet(RestServlet):
"""
GET /uk.half-shot.msc2666/user/mutual_rooms?user_id={user_id}&from={token} HTTP/1.1
"""
PATTERNS = client_patterns(
"/uk.half-shot.msc2666/user/mutual_rooms$",
releases=(), # This is an unstable feature
)
def __init__(self, hs: "HomeServer"):
super().__init__()
self.auth = hs.get_auth()
self.store = hs.get_datastores().main
async def on_GET(self, request: SynapseRequest) -> tuple[int, JsonDict]:
# twisted.web.server.Request.args is incorrectly defined as Any | None
args: dict[bytes, list[bytes]] = request.args # type: ignore
user_ids = parse_strings_from_args(args, "user_id", required=True)
from_batch = _parse_mutual_rooms_batch_token_args(args)
if len(user_ids) > 1:
raise SynapseError(
HTTPStatus.BAD_REQUEST,
"Duplicate user_id query parameter",
errcode=Codes.INVALID_PARAM,
)
user_id = user_ids[0]
requester = await self.auth.get_user_by_req(request)
if user_id == requester.user.to_string():
raise SynapseError(
HTTPStatus.BAD_REQUEST,
"You cannot request a list of shared rooms with yourself",
errcode=Codes.UNKNOWN,
)
# Sort here instead of the database function, so that we don't expose
# clients to any unrelated changes to the sorting algorithm.
rooms = sorted(
await self.store.get_mutual_rooms_between_users(
frozenset((requester.user.to_string(), user_id))
)
)
if from_batch:
# A from_batch token was provided, so cut off any rooms where the ID is
# lower than or equal to the token. This method doesn't care whether the
# provided token room still exists, nor whether it's even a real room ID.
#
# However, if rooms with a lower ID are added after the token was issued,
# they will not be included until the client makes a new request without a
# from token. This is considered acceptable, as clients generally won't
# persist these results for long periods.
rooms = rooms[bisect(rooms, from_batch) :]
if len(rooms) <= MUTUAL_ROOMS_BATCH_LIMIT:
# We've reached the end of the list, don't return a batch token
return 200, {"joined": rooms}
rooms = rooms[:MUTUAL_ROOMS_BATCH_LIMIT]
# We use urlsafe unpadded base64 encoding for the batch token in order to
# handle funny room IDs in old pre-v12 rooms properly. We also truncate it
# to stay within the 255-character limit of opaque tokens.
next_batch = encode_base64(rooms[-1].encode("utf-8"), urlsafe=True)[:255]
# Due to the truncation, it is technically possible to have conflicting next
# batches by creating hundreds of rooms with the same 191 character prefix
# in the room ID. In the event that some silly user does that, don't let
# them paginate further.
if next_batch == from_batch:
return 200, {"joined": rooms}
return 200, {"joined": list(rooms), "next_batch": next_batch}
def register_servlets(hs: "HomeServer", http_server: HttpServer) -> None:
if hs.config.experimental.msc2666_enabled:
UserMutualRoomsServlet(hs).register(http_server)