diff options
Diffstat (limited to 'synapse/api')
| -rw-r--r-- | synapse/api/filtering.py | 229 |
1 files changed, 229 insertions, 0 deletions
diff --git a/synapse/api/filtering.py b/synapse/api/filtering.py new file mode 100644 index 0000000000..4d570b74f8 --- /dev/null +++ b/synapse/api/filtering.py @@ -0,0 +1,229 @@ +# -*- 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 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): + result = self.store.get_user_filter(user_localpart, filter_id) + result.addCallback(Filter) + return 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 = [ + "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_json: + self._check_definition(user_filter_json[key]) + + if "room" in user_filter_json: + for key in room_level_definitions: + if key in user_filter_json["room"]: + self._check_definition(user_filter_json["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") + + if "format" in definition: + event_format = definition["format"] + if event_format not in ["federation", "events"]: + raise SynapseError(400, "Invalid format: %s" % (event_format,)) + + if "select" in definition: + 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,)) + + if ("bundle_updates" in definition and + type(definition["bundle_updates"]) != bool): + raise SynapseError(400, "Bad bundle_updates: expected bool.") + + +class Filter(object): + def __init__(self, filter_json): + self.filter_json = filter_json + + def filter_public_user_data(self, events): + return self._filter_on_key(events, ["public_user_data"]) + + def filter_private_user_data(self, events): + return self._filter_on_key(events, ["private_user_data"]) + + def filter_room_state(self, events): + return self._filter_on_key(events, ["room", "state"]) + + def filter_room_events(self, events): + return self._filter_on_key(events, ["room", "events"]) + + def filter_room_ephemeral(self, events): + return self._filter_on_key(events, ["room", "ephemeral"]) + + def _filter_on_key(self, events, keys): + filter_json = self.filter_json + if not filter_json: + return events + + try: + # extract the right definition from the filter + definition = filter_json + for key in keys: + definition = definition[key] + return self._filter_with_definition(events, definition) + except KeyError: + # return all events if definition isn't specified. + return 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.get("rooms", None) + reject_rooms = definition.get("not_rooms", 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.get("senders", None) + reject_senders = definition.get("not_senders", 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 |