From e17a11066192354f6c6144135a14e7abe524f44c Mon Sep 17 00:00:00 2001 From: Erik Johnston Date: Tue, 28 Jan 2020 14:43:21 +0000 Subject: [PATCH] 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. --- changelog.d/6776.misc | 1 + synapse/handlers/devicemessage.py | 57 ++++++++++++++++++- synapse/handlers/federation.py | 20 +++++++ synapse/replication/slave/storage/devices.py | 2 +- synapse/storage/data_stores/main/devices.py | 29 ++++++++-- .../57/device_list_remote_cache_stale.sql | 25 ++++++++ 6 files changed, 126 insertions(+), 8 deletions(-) create mode 100644 changelog.d/6776.misc create mode 100644 synapse/storage/data_stores/main/schema/delta/57/device_list_remote_cache_stale.sql diff --git a/changelog.d/6776.misc b/changelog.d/6776.misc new file mode 100644 index 000000000..4f9a4ac7a --- /dev/null +++ b/changelog.d/6776.misc @@ -0,0 +1 @@ +Detect unknown remote devices and mark cache as stale. diff --git a/synapse/handlers/devicemessage.py b/synapse/handlers/devicemessage.py index 73b9e120f..5c5fe77be 100644 --- a/synapse/handlers/devicemessage.py +++ b/synapse/handlers/devicemessage.py @@ -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, @@ -73,8 +77,11 @@ class DeviceMessageHandler(object): } for device_id, message_content in by_device.items() } - if messages_by_device: - local_messages[user_id] = 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)) diff --git a/synapse/handlers/federation.py b/synapse/handlers/federation.py index 180f165a7..a67020a25 100644 --- a/synapse/handlers/federation.py +++ b/synapse/handlers/federation.py @@ -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` diff --git a/synapse/replication/slave/storage/devices.py b/synapse/replication/slave/storage/devices.py index dc625e0d7..1c77687ee 100644 --- a/synapse/replication/slave/storage/devices.py +++ b/synapse/replication/slave/storage/devices.py @@ -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,)) diff --git a/synapse/storage/data_stores/main/devices.py b/synapse/storage/data_stores/main/devices.py index f0a7962dd..30bf66b2b 100644 --- a/synapse/storage/data_stores/main/devices.py +++ b/synapse/storage/data_stores/main/devices.py @@ -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,) diff --git a/synapse/storage/data_stores/main/schema/delta/57/device_list_remote_cache_stale.sql b/synapse/storage/data_stores/main/schema/delta/57/device_list_remote_cache_stale.sql new file mode 100644 index 000000000..c3b6de209 --- /dev/null +++ b/synapse/storage/data_stores/main/schema/delta/57/device_list_remote_cache_stale.sql @@ -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);