MatrixSynapse/synapse/api/filtering.py

257 lines
8.7 KiB
Python

# -*- 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(FilterCollection)
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", "timeline", "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 FilterCollection(object):
def __init__(self, filter_json):
self.filter_json = filter_json
self.room_timeline_filter = Filter(
self.filter_json.get("room", {}).get("timeline", {})
)
self.room_state_filter = Filter(
self.filter_json.get("room", {}).get("state", {})
)
self.room_ephemeral_filter = Filter(
self.filter_json.get("room", {}).get("ephemeral", {})
)
self.presence_filter = Filter(
self.filter_json.get("presence", {})
)
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_room_state(self, events):
return self.room_state_filter.filter(events)
def filter_room_timeline(self, events):
return self.room_timeline_filter.filter(events)
def filter_room_ephemeral(self, events):
return self.room_ephemeral_filter.filter(events)
class Filter(object):
def __init__(self, filter_json):
self.filter_json = filter_json
def check(self, event):
"""Checks whether the filter matches the given event.
Returns:
bool: True if the event matches
"""
if isinstance(event, dict):
return self.check_fields(
event.get("room_id", None),
event.get("sender", None),
event.get("type", None),
)
else:
return self.check_fields(
getattr(event, "room_id", None),
getattr(event, "sender", None),
event.type,
)
def check_fields(self, room_id, sender, event_type):
"""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 = self.filter_json.get(not_name, [])
if any(map(match_func, disallowed_values)):
return False
allowed_values = self.filter_json.get(name, None)
if allowed_values is not None:
if not any(map(match_func, allowed_values)):
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