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synapse/synapse/handlers/directory.py
Patrick Cloke fe3941f6e3
Stop sending events when creating or deleting aliases ()
Stop sending events when creating or deleting associations (room aliases). Send an updated canonical alias event if one of the alt_aliases is deleted.
2020-02-18 07:29:44 -05:00

454 lines
16 KiB
Python

# -*- coding: utf-8 -*-
# Copyright 2014-2016 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.
import logging
import string
from twisted.internet import defer
from synapse.api.constants import MAX_ALIAS_LENGTH, EventTypes
from synapse.api.errors import (
AuthError,
CodeMessageException,
Codes,
NotFoundError,
StoreError,
SynapseError,
)
from synapse.types import RoomAlias, UserID, get_domain_from_id
from ._base import BaseHandler
logger = logging.getLogger(__name__)
class DirectoryHandler(BaseHandler):
def __init__(self, hs):
super(DirectoryHandler, self).__init__(hs)
self.state = hs.get_state_handler()
self.appservice_handler = hs.get_application_service_handler()
self.event_creation_handler = hs.get_event_creation_handler()
self.store = hs.get_datastore()
self.config = hs.config
self.enable_room_list_search = hs.config.enable_room_list_search
self.require_membership = hs.config.require_membership_for_aliases
self.federation = hs.get_federation_client()
hs.get_federation_registry().register_query_handler(
"directory", self.on_directory_query
)
self.spam_checker = hs.get_spam_checker()
@defer.inlineCallbacks
def _create_association(self, room_alias, room_id, servers=None, creator=None):
# general association creation for both human users and app services
for wchar in string.whitespace:
if wchar in room_alias.localpart:
raise SynapseError(400, "Invalid characters in room alias")
if not self.hs.is_mine(room_alias):
raise SynapseError(400, "Room alias must be local")
# TODO(erikj): Change this.
# TODO(erikj): Add transactions.
# TODO(erikj): Check if there is a current association.
if not servers:
users = yield self.state.get_current_users_in_room(room_id)
servers = set(get_domain_from_id(u) for u in users)
if not servers:
raise SynapseError(400, "Failed to get server list")
yield self.store.create_room_alias_association(
room_alias, room_id, servers, creator=creator
)
@defer.inlineCallbacks
def create_association(
self, requester, room_alias, room_id, servers=None, check_membership=True,
):
"""Attempt to create a new alias
Args:
requester (Requester)
room_alias (RoomAlias)
room_id (str)
servers (list[str]|None): List of servers that others servers
should try and join via
check_membership (bool): Whether to check if the user is in the room
before the alias can be set (if the server's config requires it).
Returns:
Deferred
"""
user_id = requester.user.to_string()
if len(room_alias.to_string()) > MAX_ALIAS_LENGTH:
raise SynapseError(
400,
"Can't create aliases longer than %s characters" % MAX_ALIAS_LENGTH,
Codes.INVALID_PARAM,
)
service = requester.app_service
if service:
if not service.is_interested_in_alias(room_alias.to_string()):
raise SynapseError(
400,
"This application service has not reserved this kind of alias.",
errcode=Codes.EXCLUSIVE,
)
else:
if self.require_membership and check_membership:
rooms_for_user = yield self.store.get_rooms_for_user(user_id)
if room_id not in rooms_for_user:
raise AuthError(
403, "You must be in the room to create an alias for it"
)
if not self.spam_checker.user_may_create_room_alias(user_id, room_alias):
raise AuthError(403, "This user is not permitted to create this alias")
if not self.config.is_alias_creation_allowed(
user_id, room_id, room_alias.to_string()
):
# Lets just return a generic message, as there may be all sorts of
# reasons why we said no. TODO: Allow configurable error messages
# per alias creation rule?
raise SynapseError(403, "Not allowed to create alias")
can_create = yield self.can_modify_alias(room_alias, user_id=user_id)
if not can_create:
raise AuthError(
400,
"This alias is reserved by an application service.",
errcode=Codes.EXCLUSIVE,
)
yield self._create_association(room_alias, room_id, servers, creator=user_id)
@defer.inlineCallbacks
def delete_association(self, requester, room_alias):
"""Remove an alias from the directory
(this is only meant for human users; AS users should call
delete_appservice_association)
Args:
requester (Requester):
room_alias (RoomAlias):
Returns:
Deferred[unicode]: room id that the alias used to point to
Raises:
NotFoundError: if the alias doesn't exist
AuthError: if the user doesn't have perms to delete the alias (ie, the user
is neither the creator of the alias, nor a server admin.
SynapseError: if the alias belongs to an AS
"""
user_id = requester.user.to_string()
try:
can_delete = yield self._user_can_delete_alias(room_alias, user_id)
except StoreError as e:
if e.code == 404:
raise NotFoundError("Unknown room alias")
raise
if not can_delete:
raise AuthError(403, "You don't have permission to delete the alias.")
can_delete = yield self.can_modify_alias(room_alias, user_id=user_id)
if not can_delete:
raise SynapseError(
400,
"This alias is reserved by an application service.",
errcode=Codes.EXCLUSIVE,
)
room_id = yield self._delete_association(room_alias)
try:
yield self._update_canonical_alias(
requester, requester.user.to_string(), room_id, room_alias
)
except AuthError as e:
logger.info("Failed to update alias events: %s", e)
return room_id
@defer.inlineCallbacks
def delete_appservice_association(self, service, room_alias):
if not service.is_interested_in_alias(room_alias.to_string()):
raise SynapseError(
400,
"This application service has not reserved this kind of alias",
errcode=Codes.EXCLUSIVE,
)
yield self._delete_association(room_alias)
@defer.inlineCallbacks
def _delete_association(self, room_alias):
if not self.hs.is_mine(room_alias):
raise SynapseError(400, "Room alias must be local")
room_id = yield self.store.delete_room_alias(room_alias)
return room_id
@defer.inlineCallbacks
def get_association(self, room_alias):
room_id = None
if self.hs.is_mine(room_alias):
result = yield self.get_association_from_room_alias(room_alias)
if result:
room_id = result.room_id
servers = result.servers
else:
try:
result = yield self.federation.make_query(
destination=room_alias.domain,
query_type="directory",
args={"room_alias": room_alias.to_string()},
retry_on_dns_fail=False,
ignore_backoff=True,
)
except CodeMessageException as e:
logging.warning("Error retrieving alias")
if e.code == 404:
result = None
else:
raise
if result and "room_id" in result and "servers" in result:
room_id = result["room_id"]
servers = result["servers"]
if not room_id:
raise SynapseError(
404,
"Room alias %s not found" % (room_alias.to_string(),),
Codes.NOT_FOUND,
)
users = yield self.state.get_current_users_in_room(room_id)
extra_servers = set(get_domain_from_id(u) for u in users)
servers = set(extra_servers) | set(servers)
# If this server is in the list of servers, return it first.
if self.server_name in servers:
servers = [self.server_name] + [s for s in servers if s != self.server_name]
else:
servers = list(servers)
return {"room_id": room_id, "servers": servers}
@defer.inlineCallbacks
def on_directory_query(self, args):
room_alias = RoomAlias.from_string(args["room_alias"])
if not self.hs.is_mine(room_alias):
raise SynapseError(400, "Room Alias is not hosted on this homeserver")
result = yield self.get_association_from_room_alias(room_alias)
if result is not None:
return {"room_id": result.room_id, "servers": result.servers}
else:
raise SynapseError(
404,
"Room alias %r not found" % (room_alias.to_string(),),
Codes.NOT_FOUND,
)
@defer.inlineCallbacks
def send_room_alias_update_event(self, requester, room_id):
aliases = yield self.store.get_aliases_for_room(room_id)
yield self.event_creation_handler.create_and_send_nonmember_event(
requester,
{
"type": EventTypes.Aliases,
"state_key": self.hs.hostname,
"room_id": room_id,
"sender": requester.user.to_string(),
"content": {"aliases": aliases},
},
ratelimit=False,
)
@defer.inlineCallbacks
def _update_canonical_alias(self, requester, user_id, room_id, room_alias):
"""
Send an updated canonical alias event if the removed alias was set as
the canonical alias or listed in the alt_aliases field.
"""
alias_event = yield self.state.get_current_state(
room_id, EventTypes.CanonicalAlias, ""
)
# There is no canonical alias, nothing to do.
if not alias_event:
return
# Obtain a mutable version of the event content.
content = dict(alias_event.content)
send_update = False
# Remove the alias property if it matches the removed alias.
alias_str = room_alias.to_string()
if alias_event.content.get("alias", "") == alias_str:
send_update = True
content.pop("alias", "")
# Filter alt_aliases for the removed alias.
alt_aliases = content.pop("alt_aliases", None)
# If the aliases are not a list (or not found) do not attempt to modify
# the list.
if isinstance(alt_aliases, list):
send_update = True
alt_aliases = [alias for alias in alt_aliases if alias != alias_str]
if alt_aliases:
content["alt_aliases"] = alt_aliases
if send_update:
yield self.event_creation_handler.create_and_send_nonmember_event(
requester,
{
"type": EventTypes.CanonicalAlias,
"state_key": "",
"room_id": room_id,
"sender": user_id,
"content": content,
},
ratelimit=False,
)
@defer.inlineCallbacks
def get_association_from_room_alias(self, room_alias):
result = yield self.store.get_association_from_room_alias(room_alias)
if not result:
# Query AS to see if it exists
as_handler = self.appservice_handler
result = yield as_handler.query_room_alias_exists(room_alias)
return result
def can_modify_alias(self, alias, user_id=None):
# Any application service "interested" in an alias they are regexing on
# can modify the alias.
# Users can only modify the alias if ALL the interested services have
# non-exclusive locks on the alias (or there are no interested services)
services = self.store.get_app_services()
interested_services = [
s for s in services if s.is_interested_in_alias(alias.to_string())
]
for service in interested_services:
if user_id == service.sender:
# this user IS the app service so they can do whatever they like
return defer.succeed(True)
elif service.is_exclusive_alias(alias.to_string()):
# another service has an exclusive lock on this alias.
return defer.succeed(False)
# either no interested services, or no service with an exclusive lock
return defer.succeed(True)
@defer.inlineCallbacks
def _user_can_delete_alias(self, alias, user_id):
creator = yield self.store.get_room_alias_creator(alias.to_string())
if creator is not None and creator == user_id:
return True
is_admin = yield self.auth.is_server_admin(UserID.from_string(user_id))
return is_admin
@defer.inlineCallbacks
def edit_published_room_list(self, requester, room_id, visibility):
"""Edit the entry of the room in the published room list.
requester
room_id (str)
visibility (str): "public" or "private"
"""
user_id = requester.user.to_string()
if not self.spam_checker.user_may_publish_room(user_id, room_id):
raise AuthError(
403, "This user is not permitted to publish rooms to the room list"
)
if requester.is_guest:
raise AuthError(403, "Guests cannot edit the published room list")
if visibility not in ["public", "private"]:
raise SynapseError(400, "Invalid visibility setting")
if visibility == "public" and not self.enable_room_list_search:
# The room list has been disabled.
raise AuthError(
403, "This user is not permitted to publish rooms to the room list"
)
room = yield self.store.get_room(room_id)
if room is None:
raise SynapseError(400, "Unknown room")
yield self.auth.check_can_change_room_list(room_id, requester.user)
making_public = visibility == "public"
if making_public:
room_aliases = yield self.store.get_aliases_for_room(room_id)
canonical_alias = yield self.store.get_canonical_alias_for_room(room_id)
if canonical_alias:
room_aliases.append(canonical_alias)
if not self.config.is_publishing_room_allowed(
user_id, room_id, room_aliases
):
# Lets just return a generic message, as there may be all sorts of
# reasons why we said no. TODO: Allow configurable error messages
# per alias creation rule?
raise SynapseError(403, "Not allowed to publish room")
yield self.store.set_room_is_public(room_id, making_public)
@defer.inlineCallbacks
def edit_published_appservice_room_list(
self, appservice_id, network_id, room_id, visibility
):
"""Add or remove a room from the appservice/network specific public
room list.
Args:
appservice_id (str): ID of the appservice that owns the list
network_id (str): The ID of the network the list is associated with
room_id (str)
visibility (str): either "public" or "private"
"""
if visibility not in ["public", "private"]:
raise SynapseError(400, "Invalid visibility setting")
yield self.store.set_room_is_public_appservice(
room_id, appservice_id, network_id, visibility == "public"
)