# -*- coding: utf-8 -*- # Copyright 2018 New Vector 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 six import iteritems from twisted.internet import defer from synapse.api.constants import ( EventTypes, ServerNoticeLimitReached, ServerNoticeMsgType, ) from synapse.api.errors import AuthError, ResourceLimitError, SynapseError from synapse.server_notices.server_notices_manager import SERVER_NOTICE_ROOM_TAG logger = logging.getLogger(__name__) class ResourceLimitsServerNotices(object): """ Keeps track of whether the server has reached it's resource limit and ensures that the client is kept up to date. """ def __init__(self, hs): """ Args: hs (synapse.server.HomeServer): """ self._server_notices_manager = hs.get_server_notices_manager() self._store = hs.get_datastore() self._auth = hs.get_auth() self._config = hs.config self._resouce_limited = False self._message_handler = hs.get_message_handler() self._state = hs.get_state_handler() @defer.inlineCallbacks def maybe_send_server_notice_to_user(self, user_id): """Check if we need to send a notice to this user, this will be true in two cases. 1. The server has reached its limit does not reflect this 2. The room state indicates that the server has reached its limit when actually the server is fine Args: user_id (str): user to check Returns: Deferred """ if self._config.hs_disabled is True: return if self._config.limit_usage_by_mau is False: return timestamp = yield self._store.user_last_seen_monthly_active(user_id) if timestamp is None: # This user will be blocked from receiving the notice anyway. # In practice, not sure we can ever get here return # Determine current state of room room_id = yield self._server_notices_manager.get_notice_room_for_user(user_id) if not room_id: logger.warn("Failed to get server notices room") return yield self._check_and_set_tags(user_id, room_id) currently_blocked, ref_events = yield self._is_room_currently_blocked(room_id) try: # Normally should always pass in user_id if you have it, but in # this case are checking what would happen to other users if they # were to arrive. try: yield self._auth.check_auth_blocking() is_auth_blocking = False except ResourceLimitError as e: is_auth_blocking = True event_content = e.msg event_limit_type = e.limit_type if currently_blocked and not is_auth_blocking: # Room is notifying of a block, when it ought not to be. # Remove block notification content = { "pinned": ref_events } yield self._server_notices_manager.send_notice( user_id, content, EventTypes.Pinned, '', ) elif not currently_blocked and is_auth_blocking: # Room is not notifying of a block, when it ought to be. # Add block notification content = { 'body': event_content, 'msgtype': ServerNoticeMsgType, 'server_notice_type': ServerNoticeLimitReached, 'admin_uri': self._config.admin_uri, 'limit_type': event_limit_type } event = yield self._server_notices_manager.send_notice( user_id, content, EventTypes.Message, ) content = { "pinned": [ event.event_id, ] } yield self._server_notices_manager.send_notice( user_id, content, EventTypes.Pinned, '', ) except SynapseError as e: logger.error("Error sending resource limits server notice: %s", e) @defer.inlineCallbacks def _check_and_set_tags(self, user_id, room_id): """ Since server notices rooms were originally not with tags, important to check that tags have been set correctly Args: user_id(str): the user in question room_id(str): the server notices room for that user """ tags = yield self._store.get_tags_for_user(user_id) server_notices_tags = tags.get(room_id) need_to_set_tag = True if server_notices_tags: if server_notices_tags.get(SERVER_NOTICE_ROOM_TAG): # tag already present, nothing to do here need_to_set_tag = False if need_to_set_tag: yield self._store.add_tag_to_room( user_id, room_id, SERVER_NOTICE_ROOM_TAG, None ) @defer.inlineCallbacks def _is_room_currently_blocked(self, room_id): """ Determines if the room is currently blocked Args: room_id(str): The room id of the server notices room Returns: bool: Is the room currently blocked list: The list of pinned events that are unrelated to limit blocking This list can be used as a convenience in the case where the block is to be lifted and the remaining pinned event references need to be preserved """ currently_blocked = False pinned_state_event = None try: pinned_state_event = yield self._state.get_current_state( room_id, event_type=EventTypes.Pinned ) except AuthError: # The user has yet to join the server notices room pass referenced_events = [] if pinned_state_event is not None: referenced_events = list(pinned_state_event.content.get('pinned', [])) events = yield self._store.get_events(referenced_events) for event_id, event in iteritems(events): if event.type != EventTypes.Message: continue if event.content.get("msgtype") == ServerNoticeMsgType: currently_blocked = True # remove event in case we need to disable blocking later on. if event_id in referenced_events: referenced_events.remove(event.event_id) defer.returnValue((currently_blocked, referenced_events))