# -*- coding: utf-8 -*- # Copyright 2015 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. from twisted.internet import defer from synapse.api.errors import SynapseError from synapse.types import UserID, RoomID class Filtering(object): def __init__(self, hs): super(Filtering, self).__init__() self.store = hs.get_datastore() def get_user_filter(self, user_localpart, filter_id): return self.store.get_user_filter(user_localpart, filter_id) def add_user_filter(self, user_localpart, user_filter): self._check_valid_filter(user_filter) return self.store.add_user_filter(user_localpart, user_filter) def filter_public_user_data(self, events, user, filter_id): return self._filter_on_key( events, user, filter_id, ["public_user_data"] ) def filter_private_user_data(self, events, user, filter_id): return self._filter_on_key( events, user, filter_id, ["private_user_data"] ) def filter_room_state(self, events, user, filter_id): return self._filter_on_key( events, user, filter_id, ["room", "state"] ) def filter_room_events(self, events, user, filter_id): return self._filter_on_key( events, user, filter_id, ["room", "events"] ) def filter_room_ephemeral(self, events, user, filter_id): return self._filter_on_key( events, user, filter_id, ["room", "ephemeral"] ) # TODO(paul): surely we should probably add a delete_user_filter or # replace_user_filter at some point? There's no REST API specified for # them however @defer.inlineCallbacks def _filter_on_key(self, events, user, filter_id, keys): filter_json = yield self.get_user_filter(user.localpart, filter_id) if not filter_json: defer.returnValue(events) try: # extract the right definition from the filter definition = filter_json for key in keys: definition = definition[key] defer.returnValue(self._filter_with_definition(events, definition)) except KeyError: # return all events if definition isn't specified. defer.returnValue(events) def _filter_with_definition(self, events, definition): return [e for e in events if self._passes_definition(definition, e)] def _passes_definition(self, definition, event): """Check if the event passes through the given definition. Args: definition(dict): The definition to check against. event(Event): The event to check. Returns: True if the event passes through the filter. """ # Algorithm notes: # For each key in the definition, check the event meets the criteria: # * For types: Literal match or prefix match (if ends with wildcard) # * For senders/rooms: Literal match only # * "not_" checks take presedence (e.g. if "m.*" is in both 'types' # and 'not_types' then it is treated as only being in 'not_types') # room checks if hasattr(event, "room_id"): room_id = event.room_id allow_rooms = definition["rooms"] if "rooms" in definition else None reject_rooms = ( definition["not_rooms"] if "not_rooms" in definition else None ) if reject_rooms and room_id in reject_rooms: return False if allow_rooms and room_id not in allow_rooms: return False # sender checks if hasattr(event, "sender"): # Should we be including event.state_key for some event types? sender = event.sender allow_senders = ( definition["senders"] if "senders" in definition else None ) reject_senders = ( definition["not_senders"] if "not_senders" in definition else None ) if reject_senders and sender in reject_senders: return False if allow_senders and sender not in allow_senders: return False # type checks if "not_types" in definition: for def_type in definition["not_types"]: if self._event_matches_type(event, def_type): return False if "types" in definition: included = False for def_type in definition["types"]: if self._event_matches_type(event, def_type): included = True break if not included: return False return True def _event_matches_type(self, event, def_type): if def_type.endswith("*"): type_prefix = def_type[:-1] return event.type.startswith(type_prefix) else: return event.type == def_type def _check_valid_filter(self, user_filter): """Check if the provided filter is valid. This inspects all definitions contained within the filter. Args: user_filter(dict): The filter Raises: SynapseError: If the filter is not valid. """ # NB: Filters are the complete json blobs. "Definitions" are an # individual top-level key e.g. public_user_data. Filters are made of # many definitions. top_level_definitions = [ "public_user_data", "private_user_data", "server_data" ] room_level_definitions = [ "state", "events", "ephemeral" ] for key in top_level_definitions: if key in user_filter: self._check_definition(user_filter[key]) if "room" in user_filter: for key in room_level_definitions: if key in user_filter["room"]: self._check_definition(user_filter["room"][key]) def _check_definition(self, definition): """Check if the provided definition is valid. This inspects not only the types but also the values to make sure they make sense. Args: definition(dict): The filter definition Raises: SynapseError: If there was a problem with this definition. """ # NB: Filters are the complete json blobs. "Definitions" are an # individual top-level key e.g. public_user_data. Filters are made of # many definitions. if type(definition) != dict: raise SynapseError( 400, "Expected JSON object, not %s" % (definition,) ) # check rooms are valid room IDs room_id_keys = ["rooms", "not_rooms"] for key in room_id_keys: if key in definition: if type(definition[key]) != list: raise SynapseError(400, "Expected %s to be a list." % key) for room_id in definition[key]: RoomID.from_string(room_id) # check senders are valid user IDs user_id_keys = ["senders", "not_senders"] for key in user_id_keys: if key in definition: if type(definition[key]) != list: raise SynapseError(400, "Expected %s to be a list." % key) for user_id in definition[key]: UserID.from_string(user_id) # TODO: We don't limit event type values but we probably should... # check types are valid event types event_keys = ["types", "not_types"] for key in event_keys: if key in definition: if type(definition[key]) != list: raise SynapseError(400, "Expected %s to be a list." % key) for event_type in definition[key]: if not isinstance(event_type, basestring): raise SynapseError(400, "Event type should be a string") try: event_format = definition["format"] if event_format not in ["federation", "events"]: raise SynapseError(400, "Invalid format: %s" % (event_format,)) except KeyError: pass # format is optional try: event_select_list = definition["select"] for select_key in event_select_list: if select_key not in ["event_id", "origin_server_ts", "thread_id", "content", "content.body"]: raise SynapseError(400, "Bad select: %s" % (select_key,)) except KeyError: pass # select is optional if ("bundle_updates" in definition and type(definition["bundle_updates"]) != bool): raise SynapseError(400, "Bad bundle_updates: expected bool.")