synapse-product/synapse/handlers/devicemessage.py
Erik Johnston e17a110661
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.
2020-01-28 14:43:21 +00:00

193 lines
6.8 KiB
Python

# -*- coding: utf-8 -*-
# Copyright 2016 OpenMarket Ltd
#
# 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.
import logging
from typing import Any, Dict
from canonicaljson import json
from twisted.internet import defer
from synapse.api.errors import SynapseError
from synapse.logging.opentracing import (
get_active_span_text_map,
log_kv,
set_tag,
start_active_span,
)
from synapse.types import UserID, get_domain_from_id
from synapse.util.stringutils import random_string
logger = logging.getLogger(__name__)
class DeviceMessageHandler(object):
def __init__(self, hs):
"""
Args:
hs (synapse.server.HomeServer): server
"""
self.store = hs.get_datastore()
self.notifier = hs.get_notifier()
self.is_mine = hs.is_mine
self.federation = hs.get_federation_sender()
hs.get_federation_registry().register_edu_handler(
"m.direct_to_device", self.on_direct_to_device_edu
)
@defer.inlineCallbacks
def on_direct_to_device_edu(self, origin, content):
local_messages = {}
sender_user_id = content["sender"]
if origin != get_domain_from_id(sender_user_id):
logger.warning(
"Dropping device message from %r with spoofed sender %r",
origin,
sender_user_id,
)
message_type = content["type"]
message_id = content["message_id"]
for user_id, by_device in content["messages"].items():
# we use UserID.from_string to catch invalid user ids
if not self.is_mine(UserID.from_string(user_id)):
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,
"type": message_type,
"sender": sender_user_id,
}
for device_id, message_content in by_device.items()
}
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
)
self.notifier.on_new_event(
"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))
set_tag("sender", sender_user_id)
local_messages = {}
remote_messages = {}
for user_id, by_device in messages.items():
# we use UserID.from_string to catch invalid user ids
if self.is_mine(UserID.from_string(user_id)):
messages_by_device = {
device_id: {
"content": message_content,
"type": message_type,
"sender": sender_user_id,
}
for device_id, message_content in by_device.items()
}
if messages_by_device:
local_messages[user_id] = messages_by_device
else:
destination = get_domain_from_id(user_id)
remote_messages.setdefault(destination, {})[user_id] = by_device
message_id = random_string(16)
context = get_active_span_text_map()
remote_edu_contents = {}
for destination, messages in remote_messages.items():
with start_active_span("to_device_for_user"):
set_tag("destination", destination)
remote_edu_contents[destination] = {
"messages": messages,
"sender": sender_user_id,
"type": message_type,
"message_id": message_id,
"org.matrix.opentracing_context": json.dumps(context),
}
log_kv({"local_messages": local_messages})
stream_id = yield self.store.add_messages_to_device_inbox(
local_messages, remote_edu_contents
)
self.notifier.on_new_event(
"to_device_key", stream_id, users=local_messages.keys()
)
log_kv({"remote_messages": remote_messages})
for destination in remote_messages.keys():
# Enqueue a new federation transaction to send the new
# device messages to each remote destination.
self.federation.send_device_messages(destination)