# -*- coding: utf-8 -*- # Copyright 2015, 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. from synapse.api.errors import SynapseError from synapse.storage.presence import UserPresenceState from synapse.types import UserID, RoomID from twisted.internet import defer import ujson as json class Filtering(object): def __init__(self, hs): super(Filtering, self).__init__() self.store = hs.get_datastore() @defer.inlineCallbacks def get_user_filter(self, user_localpart, filter_id): result = yield self.store.get_user_filter(user_localpart, filter_id) defer.returnValue(FilterCollection(result)) 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) # 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 def check_valid_filter(self, user_filter_json): """Check if the provided filter is valid. This inspects all definitions contained within the filter. Args: user_filter_json(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 = [ "presence", "account_data" ] room_level_definitions = [ "state", "timeline", "ephemeral", "account_data" ] for key in top_level_definitions: if key in user_filter_json: self._check_definition(user_filter_json[key]) if "room" in user_filter_json: self._check_definition_room_lists(user_filter_json["room"]) for key in room_level_definitions: if key in user_filter_json["room"]: self._check_definition(user_filter_json["room"][key]) if "event_fields" in user_filter_json: if type(user_filter_json["event_fields"]) != list: raise SynapseError(400, "event_fields must be a list of strings") for field in user_filter_json["event_fields"]: if not isinstance(field, basestring): raise SynapseError(400, "Event field must be a string") # Don't allow '\\' in event field filters. This makes matching # events a lot easier as we can then use a negative lookbehind # assertion to split '\.' If we allowed \\ then it would # incorrectly split '\\.' See synapse.events.utils.serialize_event if r'\\' in field: raise SynapseError( 400, r'The escape character \ cannot itself be escaped' ) def _check_definition_room_lists(self, definition): """Check that "rooms" and "not_rooms" are lists of room ids if they are present Args: definition(dict): The filter definition Raises: SynapseError: If there was a problem with this 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) 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,) ) self._check_definition_room_lists(definition) # 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") class FilterCollection(object): def __init__(self, filter_json): self._filter_json = filter_json room_filter_json = self._filter_json.get("room", {}) self._room_filter = Filter({ k: v for k, v in room_filter_json.items() if k in ("rooms", "not_rooms") }) self._room_timeline_filter = Filter(room_filter_json.get("timeline", {})) self._room_state_filter = Filter(room_filter_json.get("state", {})) self._room_ephemeral_filter = Filter(room_filter_json.get("ephemeral", {})) self._room_account_data = Filter(room_filter_json.get("account_data", {})) self._presence_filter = Filter(filter_json.get("presence", {})) self._account_data = Filter(filter_json.get("account_data", {})) self.include_leave = filter_json.get("room", {}).get( "include_leave", False ) self.event_fields = filter_json.get("event_fields", []) def __repr__(self): return "" % (json.dumps(self._filter_json),) def get_filter_json(self): return self._filter_json def timeline_limit(self): return self._room_timeline_filter.limit() def presence_limit(self): return self._presence_filter.limit() def ephemeral_limit(self): return self._room_ephemeral_filter.limit() def filter_presence(self, events): return self._presence_filter.filter(events) def filter_account_data(self, events): return self._account_data.filter(events) def filter_room_state(self, events): return self._room_state_filter.filter(self._room_filter.filter(events)) def filter_room_timeline(self, events): return self._room_timeline_filter.filter(self._room_filter.filter(events)) def filter_room_ephemeral(self, events): return self._room_ephemeral_filter.filter(self._room_filter.filter(events)) def filter_room_account_data(self, events): return self._room_account_data.filter(self._room_filter.filter(events)) def blocks_all_presence(self): return ( self._presence_filter.filters_all_types() or self._presence_filter.filters_all_senders() ) def blocks_all_room_ephemeral(self): return ( self._room_ephemeral_filter.filters_all_types() or self._room_ephemeral_filter.filters_all_senders() or self._room_ephemeral_filter.filters_all_rooms() ) def blocks_all_room_timeline(self): return ( self._room_timeline_filter.filters_all_types() or self._room_timeline_filter.filters_all_senders() or self._room_timeline_filter.filters_all_rooms() ) class Filter(object): def __init__(self, filter_json): self.filter_json = filter_json self.types = self.filter_json.get("types", None) self.not_types = self.filter_json.get("not_types", []) self.rooms = self.filter_json.get("rooms", None) self.not_rooms = self.filter_json.get("not_rooms", []) self.senders = self.filter_json.get("senders", None) self.not_senders = self.filter_json.get("not_senders", []) self.contains_url = self.filter_json.get("contains_url", None) def filters_all_types(self): return "*" in self.not_types def filters_all_senders(self): return "*" in self.not_senders def filters_all_rooms(self): return "*" in self.not_rooms def check(self, event): """Checks whether the filter matches the given event. Returns: bool: True if the event matches """ # We usually get the full "events" as dictionaries coming through, # except for presence which actually gets passed around as its own # namedtuple type. if isinstance(event, UserPresenceState): sender = event.user_id room_id = None ev_type = "m.presence" is_url = False else: sender = event.get("sender", None) if not sender: # Presence events have their 'sender' in content.user_id content = event.get("content") # account_data has been allowed to have non-dict content, so # check type first if isinstance(content, dict): sender = content.get("user_id") room_id = event.get("room_id", None) ev_type = event.get("type", None) is_url = "url" in event.get("content", {}) return self.check_fields( room_id, sender, ev_type, is_url, ) def check_fields(self, room_id, sender, event_type, contains_url): """Checks whether the filter matches the given event fields. Returns: bool: True if the event fields match """ literal_keys = { "rooms": lambda v: room_id == v, "senders": lambda v: sender == v, "types": lambda v: _matches_wildcard(event_type, v) } for name, match_func in literal_keys.items(): not_name = "not_%s" % (name,) disallowed_values = getattr(self, not_name) if any(map(match_func, disallowed_values)): return False allowed_values = getattr(self, name) if allowed_values is not None: if not any(map(match_func, allowed_values)): return False contains_url_filter = self.filter_json.get("contains_url") if contains_url_filter is not None: if contains_url_filter != contains_url: return False return True def filter_rooms(self, room_ids): """Apply the 'rooms' filter to a given list of rooms. Args: room_ids (list): A list of room_ids. Returns: list: A list of room_ids that match the filter """ room_ids = set(room_ids) disallowed_rooms = set(self.filter_json.get("not_rooms", [])) room_ids -= disallowed_rooms allowed_rooms = self.filter_json.get("rooms", None) if allowed_rooms is not None: room_ids &= set(allowed_rooms) return room_ids def filter(self, events): return filter(self.check, events) def limit(self): return self.filter_json.get("limit", 10) def _matches_wildcard(actual_value, filter_value): if filter_value.endswith("*"): type_prefix = filter_value[:-1] return actual_value.startswith(type_prefix) else: return actual_value == filter_value DEFAULT_FILTER_COLLECTION = FilterCollection({})