MatrixSynapse/synapse/api/filtering.py

256 lines
9.6 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(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", "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 Filter(object):
def __init__(self, filter_json):
self.filter_json = filter_json
def timeline_limit(self):
return self.filter_json.get("room", {}).get("timeline", {}).get("limit", 10)
def presence_limit(self):
return self.filter_json.get("presence", {}).get("limit", 10)
def ephemeral_limit(self):
return self.filter_json.get("room", {}).get("ephemeral", {}).get("limit", 10)
def filter_presence(self, events):
return self._filter_on_key(events, ["presence"])
def filter_room_state(self, events):
return self._filter_on_key(events, ["room", "state"])
def filter_room_timeline(self, events):
return self._filter_on_key(events, ["room", "timeline"])
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 the filter definition
Args:
definition(dict): The filter definition to check against
event(dict or Event): The event to check
Returns:
True if the event passes the filter in the definition
"""
if type(event) is dict:
room_id = event.get("room_id")
sender = event.get("sender")
event_type = event["type"]
else:
room_id = getattr(event, "room_id", None)
sender = getattr(event, "sender", None)
event_type = event.type
return self._event_passes_definition(
definition, room_id, sender, event_type
)
def _event_passes_definition(self, definition, room_id, sender,
event_type):
"""Check if the event passes through the given definition.
Args:
definition(dict): The definition to check against.
room_id(str): The id of the room this event is in or None.
sender(str): The sender of the event
event_type(str): The type of the event.
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 room_id is not None:
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 sender is not None:
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_type, def_type):
return False
if "types" in definition:
included = False
for def_type in definition["types"]:
if self._event_matches_type(event_type, def_type):
included = True
break
if not included:
return False
return True
def _event_matches_type(self, event_type, def_type):
if def_type.endswith("*"):
type_prefix = def_type[:-1]
return event_type.startswith(type_prefix)
else:
return event_type == def_type