Detect unknown remote devices and mark cache as stale (#6776)

We just mark the fact that the cache may be stale in the database for
now.
This commit is contained in:
Erik Johnston 2020-01-28 14:43:21 +00:00 committed by GitHub
parent a8ce7aeb43
commit e17a110661
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6 changed files with 126 additions and 8 deletions

1
changelog.d/6776.misc Normal file
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@ -0,0 +1 @@
Detect unknown remote devices and mark cache as stale.

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@ -14,6 +14,7 @@
# limitations under the License.
import logging
from typing import Any, Dict
from canonicaljson import json
@ -65,6 +66,9 @@ class DeviceMessageHandler(object):
logger.warning("Request for keys for non-local user %s", user_id)
raise SynapseError(400, "Not a user here")
if not by_device:
continue
messages_by_device = {
device_id: {
"content": message_content,
@ -73,9 +77,12 @@ class DeviceMessageHandler(object):
}
for device_id, message_content in by_device.items()
}
if messages_by_device:
local_messages[user_id] = messages_by_device
yield self._check_for_unknown_devices(
message_type, sender_user_id, by_device
)
stream_id = yield self.store.add_messages_from_remote_to_device_inbox(
origin, message_id, local_messages
)
@ -84,6 +91,52 @@ class DeviceMessageHandler(object):
"to_device_key", stream_id, users=local_messages.keys()
)
@defer.inlineCallbacks
def _check_for_unknown_devices(
self,
message_type: str,
sender_user_id: str,
by_device: Dict[str, Dict[str, Any]],
):
"""Checks inbound device messages for unkown remote devices, and if
found marks the remote cache for the user as stale.
"""
if message_type != "m.room_key_request":
return
# Get the sending device IDs
requesting_device_ids = set()
for message_content in by_device.values():
device_id = message_content.get("requesting_device_id")
requesting_device_ids.add(device_id)
# Check if we are tracking the devices of the remote user.
room_ids = yield self.store.get_rooms_for_user(sender_user_id)
if not room_ids:
logger.info(
"Received device message from remote device we don't"
" share a room with: %s %s",
sender_user_id,
requesting_device_ids,
)
return
# If we are tracking check that we know about the sending
# devices.
cached_devices = yield self.store.get_cached_devices_for_user(sender_user_id)
unknown_devices = requesting_device_ids - set(cached_devices)
if unknown_devices:
logger.info(
"Received device message from remote device not in our cache: %s %s",
sender_user_id,
unknown_devices,
)
yield self.store.mark_remote_user_device_cache_as_stale(sender_user_id)
# TODO: Poke something to start trying to refetch user's
# keys.
@defer.inlineCallbacks
def send_device_message(self, sender_user_id, message_type, messages):
set_tag("number_of_messages", len(messages))

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@ -742,6 +742,26 @@ class FederationHandler(BaseHandler):
user = UserID.from_string(event.state_key)
await self.user_joined_room(user, room_id)
# For encrypted messages we check that we know about the sending device,
# if we don't then we mark the device cache for that user as stale.
if event.type == EventTypes.Encryption:
device_id = event.content.get("device_id")
if device_id is not None:
cached_devices = await self.store.get_cached_devices_for_user(
event.sender
)
if device_id not in cached_devices:
logger.info(
"Received event from remote device not in our cache: %s %s",
event.sender,
device_id,
)
await self.store.mark_remote_user_device_cache_as_stale(
event.sender
)
# TODO: Poke something to start trying to refetch user's
# keys.
@log_function
async def backfill(self, dest, room_id, limit, extremities):
""" Trigger a backfill request to `dest` for the given `room_id`

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@ -72,6 +72,6 @@ class SlavedDeviceStore(EndToEndKeyWorkerStore, DeviceWorkerStore, BaseSlavedSto
destination, token
)
self._get_cached_devices_for_user.invalidate((user_id,))
self.get_cached_devices_for_user.invalidate((user_id,))
self._get_cached_user_device.invalidate_many((user_id,))
self.get_device_list_last_stream_id_for_remote.invalidate((user_id,))

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@ -457,7 +457,7 @@ class DeviceWorkerStore(SQLBaseStore):
device = yield self._get_cached_user_device(user_id, device_id)
results.setdefault(user_id, {})[device_id] = device
else:
results[user_id] = yield self._get_cached_devices_for_user(user_id)
results[user_id] = yield self.get_cached_devices_for_user(user_id)
set_tag("in_cache", results)
set_tag("not_in_cache", user_ids_not_in_cache)
@ -475,12 +475,12 @@ class DeviceWorkerStore(SQLBaseStore):
return db_to_json(content)
@cachedInlineCallbacks()
def _get_cached_devices_for_user(self, user_id):
def get_cached_devices_for_user(self, user_id):
devices = yield self.db.simple_select_list(
table="device_lists_remote_cache",
keyvalues={"user_id": user_id},
retcols=("device_id", "content"),
desc="_get_cached_devices_for_user",
desc="get_cached_devices_for_user",
)
return {
device["device_id"]: db_to_json(device["content"]) for device in devices
@ -641,6 +641,18 @@ class DeviceWorkerStore(SQLBaseStore):
return results
def mark_remote_user_device_cache_as_stale(self, user_id: str):
"""Records that the server has reason to believe the cache of the devices
for the remote users is out of date.
"""
return self.db.simple_upsert(
table="device_lists_remote_resync",
keyvalues={"user_id": user_id},
values={},
insertion_values={"added_ts": self._clock.time_msec()},
desc="make_remote_user_device_cache_as_stale",
)
class DeviceBackgroundUpdateStore(SQLBaseStore):
def __init__(self, database: Database, db_conn, hs):
@ -887,7 +899,7 @@ class DeviceStore(DeviceWorkerStore, DeviceBackgroundUpdateStore):
)
txn.call_after(self._get_cached_user_device.invalidate, (user_id, device_id))
txn.call_after(self._get_cached_devices_for_user.invalidate, (user_id,))
txn.call_after(self.get_cached_devices_for_user.invalidate, (user_id,))
txn.call_after(
self.get_device_list_last_stream_id_for_remote.invalidate, (user_id,)
)
@ -902,6 +914,13 @@ class DeviceStore(DeviceWorkerStore, DeviceBackgroundUpdateStore):
lock=False,
)
# If we're replacing the remote user's device list cache presumably
# we've done a full resync, so we remove the entry that says we need
# to resync
self.db.simple_delete_txn(
txn, table="device_lists_remote_resync", keyvalues={"user_id": user_id},
)
def update_remote_device_list_cache(self, user_id, devices, stream_id):
"""Replace the entire cache of the remote user's devices.
@ -942,7 +961,7 @@ class DeviceStore(DeviceWorkerStore, DeviceBackgroundUpdateStore):
],
)
txn.call_after(self._get_cached_devices_for_user.invalidate, (user_id,))
txn.call_after(self.get_cached_devices_for_user.invalidate, (user_id,))
txn.call_after(self._get_cached_user_device.invalidate_many, (user_id,))
txn.call_after(
self.get_device_list_last_stream_id_for_remote.invalidate, (user_id,)

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@ -0,0 +1,25 @@
/* Copyright 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.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
-- Records whether the server thinks that the remote users cached device lists
-- may be out of date (e.g. if we have received a to device message from a
-- device we don't know about).
CREATE TABLE IF NOT EXISTS device_lists_remote_resync (
user_id TEXT NOT NULL,
added_ts BIGINT NOT NULL
);
CREATE UNIQUE INDEX device_lists_remote_resync_idx ON device_lists_remote_resync (user_id);
CREATE INDEX device_lists_remote_resync_ts_idx ON device_lists_remote_resync (added_ts);