# -*- coding: utf-8 -*- # Copyright 2016 OpenMarket Ltd # Copyright 2018 New Vector Ltd # Copyright 2019 The Matrix.org Foundation C.I.C. # # 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 abc import logging from six.moves import http_client from twisted.internet import defer from synapse import types from synapse.api.constants import EventTypes, Membership from synapse.api.errors import AuthError, Codes, SynapseError from synapse.types import RoomID, UserID from synapse.util.async_helpers import Linearizer from synapse.util.distributor import user_joined_room, user_left_room from ._base import BaseHandler logger = logging.getLogger(__name__) class RoomMemberHandler(object): # TODO(paul): This handler currently contains a messy conflation of # low-level API that works on UserID objects and so on, and REST-level # API that takes ID strings and returns pagination chunks. These concerns # ought to be separated out a lot better. __metaclass__ = abc.ABCMeta def __init__(self, hs): """ Args: hs (synapse.server.HomeServer): """ self.hs = hs self.store = hs.get_datastore() self.auth = hs.get_auth() self.state_handler = hs.get_state_handler() self.config = hs.config self.federation_handler = hs.get_handlers().federation_handler self.directory_handler = hs.get_handlers().directory_handler self.identity_handler = hs.get_handlers().identity_handler self.registration_handler = hs.get_registration_handler() self.profile_handler = hs.get_profile_handler() self.event_creation_handler = hs.get_event_creation_handler() self.member_linearizer = Linearizer(name="member") self.clock = hs.get_clock() self.spam_checker = hs.get_spam_checker() self.third_party_event_rules = hs.get_third_party_event_rules() self._server_notices_mxid = self.config.server_notices_mxid self._enable_lookup = hs.config.enable_3pid_lookup self.allow_per_room_profiles = self.config.allow_per_room_profiles # This is only used to get at ratelimit function, and # maybe_kick_guest_users. It's fine there are multiple of these as # it doesn't store state. self.base_handler = BaseHandler(hs) @abc.abstractmethod def _remote_join(self, requester, remote_room_hosts, room_id, user, content): """Try and join a room that this server is not in Args: requester (Requester) remote_room_hosts (list[str]): List of servers that can be used to join via. room_id (str): Room that we are trying to join user (UserID): User who is trying to join content (dict): A dict that should be used as the content of the join event. Returns: Deferred """ raise NotImplementedError() @abc.abstractmethod def _remote_reject_invite(self, requester, remote_room_hosts, room_id, target): """Attempt to reject an invite for a room this server is not in. If we fail to do so we locally mark the invite as rejected. Args: requester (Requester) remote_room_hosts (list[str]): List of servers to use to try and reject invite room_id (str) target (UserID): The user rejecting the invite Returns: Deferred[dict]: A dictionary to be returned to the client, may include event_id etc, or nothing if we locally rejected """ raise NotImplementedError() @abc.abstractmethod def _user_joined_room(self, target, room_id): """Notifies distributor on master process that the user has joined the room. Args: target (UserID) room_id (str) Returns: Deferred|None """ raise NotImplementedError() @abc.abstractmethod def _user_left_room(self, target, room_id): """Notifies distributor on master process that the user has left the room. Args: target (UserID) room_id (str) Returns: Deferred|None """ raise NotImplementedError() @defer.inlineCallbacks def _local_membership_update( self, requester, target, room_id, membership, prev_events_and_hashes, txn_id=None, ratelimit=True, content=None, require_consent=True, ): user_id = target.to_string() if content is None: content = {} content["membership"] = membership if requester.is_guest: content["kind"] = "guest" event, context = yield self.event_creation_handler.create_event( requester, { "type": EventTypes.Member, "content": content, "room_id": room_id, "sender": requester.user.to_string(), "state_key": user_id, # For backwards compatibility: "membership": membership, }, token_id=requester.access_token_id, txn_id=txn_id, prev_events_and_hashes=prev_events_and_hashes, require_consent=require_consent, ) # Check if this event matches the previous membership event for the user. duplicate = yield self.event_creation_handler.deduplicate_state_event( event, context ) if duplicate is not None: # Discard the new event since this membership change is a no-op. return duplicate yield self.event_creation_handler.handle_new_client_event( requester, event, context, extra_users=[target], ratelimit=ratelimit ) prev_state_ids = yield context.get_prev_state_ids(self.store) prev_member_event_id = prev_state_ids.get((EventTypes.Member, user_id), None) if event.membership == Membership.JOIN: # Only fire user_joined_room if the user has actually joined the # room. Don't bother if the user is just changing their profile # info. newly_joined = True if prev_member_event_id: prev_member_event = yield self.store.get_event(prev_member_event_id) newly_joined = prev_member_event.membership != Membership.JOIN if newly_joined: yield self._user_joined_room(target, room_id) elif event.membership == Membership.LEAVE: if prev_member_event_id: prev_member_event = yield self.store.get_event(prev_member_event_id) if prev_member_event.membership == Membership.JOIN: yield self._user_left_room(target, room_id) return event @defer.inlineCallbacks def copy_room_tags_and_direct_to_room(self, old_room_id, new_room_id, user_id): """Copies the tags and direct room state from one room to another. Args: old_room_id (str) new_room_id (str) user_id (str) Returns: Deferred[None] """ logger.info( "### Copying room tags and direct room state from %s to %s for %s", old_room_id, new_room_id, user_id, ) # Retrieve user account data for predecessor room user_account_data, _ = yield self.store.get_account_data_for_user(user_id) # Copy direct message state if applicable direct_rooms = user_account_data.get("m.direct", {}) logger.info("### Found direct rooms: %s", direct_rooms) # Check which key this room is under if isinstance(direct_rooms, dict): for key, room_id_list in direct_rooms.items(): if old_room_id in room_id_list and new_room_id not in room_id_list: # Add new room_id to this key logger.info("### Appending %s to %s", new_room_id, key) direct_rooms[key].append(new_room_id) # Save back to user's m.direct account data logger.info("### Saving account data") yield self.store.add_account_data_for_user( user_id, "m.direct", direct_rooms ) break # Copy room tags if applicable logger.info("### Copying room tags") room_tags = yield self.store.get_tags_for_room(user_id, old_room_id) logger.info("### Got tags for old room id %s: %s", old_room_id, room_tags) # Copy each room tag to the new room for tag, tag_content in room_tags.items(): logger.info( "### Adding tag %s with content %s to %s", tag, tag_content, new_room_id ) yield self.store.add_tag_to_room(user_id, new_room_id, tag, tag_content) @defer.inlineCallbacks def update_membership( self, requester, target, room_id, action, txn_id=None, remote_room_hosts=None, third_party_signed=None, ratelimit=True, content=None, require_consent=True, ): key = (room_id,) with (yield self.member_linearizer.queue(key)): result = yield self._update_membership( requester, target, room_id, action, txn_id=txn_id, remote_room_hosts=remote_room_hosts, third_party_signed=third_party_signed, ratelimit=ratelimit, content=content, require_consent=require_consent, ) return result @defer.inlineCallbacks def _update_membership( self, requester, target, room_id, action, txn_id=None, remote_room_hosts=None, third_party_signed=None, ratelimit=True, content=None, require_consent=True, ): content_specified = bool(content) if content is None: content = {} else: # We do a copy here as we potentially change some keys # later on. content = dict(content) if not self.allow_per_room_profiles: # Strip profile data, knowing that new profile data will be added to the # event's content in event_creation_handler.create_event() using the target's # global profile. content.pop("displayname", None) content.pop("avatar_url", None) effective_membership_state = action if action in ["kick", "unban"]: effective_membership_state = "leave" # if this is a join with a 3pid signature, we may need to turn a 3pid # invite into a normal invite before we can handle the join. if third_party_signed is not None: yield self.federation_handler.exchange_third_party_invite( third_party_signed["sender"], target.to_string(), room_id, third_party_signed, ) if not remote_room_hosts: remote_room_hosts = [] if effective_membership_state not in ("leave", "ban"): is_blocked = yield self.store.is_room_blocked(room_id) if is_blocked: raise SynapseError(403, "This room has been blocked on this server") if effective_membership_state == Membership.INVITE: # block any attempts to invite the server notices mxid if target.to_string() == self._server_notices_mxid: raise SynapseError(http_client.FORBIDDEN, "Cannot invite this user") block_invite = False if ( self._server_notices_mxid is not None and requester.user.to_string() == self._server_notices_mxid ): # allow the server notices mxid to send invites is_requester_admin = True else: is_requester_admin = yield self.auth.is_server_admin(requester.user) if not is_requester_admin: if self.config.block_non_admin_invites: logger.info( "Blocking invite: user is not admin and non-admin " "invites disabled" ) block_invite = True if not self.spam_checker.user_may_invite( requester.user.to_string(), target.to_string(), room_id ): logger.info("Blocking invite due to spam checker") block_invite = True if block_invite: raise SynapseError(403, "Invites have been disabled on this server") prev_events_and_hashes = yield self.store.get_prev_events_for_room(room_id) latest_event_ids = (event_id for (event_id, _, _) in prev_events_and_hashes) current_state_ids = yield self.state_handler.get_current_state_ids( room_id, latest_event_ids=latest_event_ids ) # TODO: Refactor into dictionary of explicitly allowed transitions # between old and new state, with specific error messages for some # transitions and generic otherwise old_state_id = current_state_ids.get((EventTypes.Member, target.to_string())) if old_state_id: old_state = yield self.store.get_event(old_state_id, allow_none=True) old_membership = old_state.content.get("membership") if old_state else None if action == "unban" and old_membership != "ban": raise SynapseError( 403, "Cannot unban user who was not banned" " (membership=%s)" % old_membership, errcode=Codes.BAD_STATE, ) if old_membership == "ban" and action != "unban": raise SynapseError( 403, "Cannot %s user who was banned" % (action,), errcode=Codes.BAD_STATE, ) if old_state: same_content = content == old_state.content same_membership = old_membership == effective_membership_state same_sender = requester.user.to_string() == old_state.sender if same_sender and same_membership and same_content: return old_state if old_membership in ["ban", "leave"] and action == "kick": raise AuthError(403, "The target user is not in the room") # we don't allow people to reject invites to the server notice # room, but they can leave it once they are joined. if ( old_membership == Membership.INVITE and effective_membership_state == Membership.LEAVE ): is_blocked = yield self._is_server_notice_room(room_id) if is_blocked: raise SynapseError( http_client.FORBIDDEN, "You cannot reject this invite", errcode=Codes.CANNOT_LEAVE_SERVER_NOTICE_ROOM, ) else: if action == "kick": raise AuthError(403, "The target user is not in the room") is_host_in_room = yield self._is_host_in_room(current_state_ids) if effective_membership_state == Membership.JOIN: if requester.is_guest: guest_can_join = yield self._can_guest_join(current_state_ids) if not guest_can_join: # This should be an auth check, but guests are a local concept, # so don't really fit into the general auth process. raise AuthError(403, "Guest access not allowed") # Copy over direct message status and room tags if this is a join # on an upgraded room # Check if this is an upgraded room predecessor = yield self.store.get_room_predecessor(room_id) logger.info("###! Predecessor for %s: %s", room_id, predecessor) if predecessor: # It is an upgraded room. Copy over old tags self.copy_room_tags_and_direct_to_room( predecessor["room_id"], room_id, requester.user.to_string() ) # Copy over push rules yield self.store.copy_push_rules_from_room_to_room_for_user( predecessor["room_id"], room_id, requester.user.to_string() ) if not is_host_in_room: inviter = yield self._get_inviter(target.to_string(), room_id) if inviter and not self.hs.is_mine(inviter): remote_room_hosts.append(inviter.domain) content["membership"] = Membership.JOIN profile = self.profile_handler if not content_specified: content["displayname"] = yield profile.get_displayname(target) content["avatar_url"] = yield profile.get_avatar_url(target) if requester.is_guest: content["kind"] = "guest" ret = yield self._remote_join( requester, remote_room_hosts, room_id, target, content ) return ret elif effective_membership_state == Membership.LEAVE: if not is_host_in_room: # perhaps we've been invited inviter = yield self._get_inviter(target.to_string(), room_id) if not inviter: raise SynapseError(404, "Not a known room") if self.hs.is_mine(inviter): # the inviter was on our server, but has now left. Carry on # with the normal rejection codepath. # # This is a bit of a hack, because the room might still be # active on other servers. pass else: # send the rejection to the inviter's HS. remote_room_hosts = remote_room_hosts + [inviter.domain] res = yield self._remote_reject_invite( requester, remote_room_hosts, room_id, target ) return res res = yield self._local_membership_update( requester=requester, target=target, room_id=room_id, membership=effective_membership_state, txn_id=txn_id, ratelimit=ratelimit, prev_events_and_hashes=prev_events_and_hashes, content=content, require_consent=require_consent, ) return res @defer.inlineCallbacks def send_membership_event(self, requester, event, context, ratelimit=True): """ Change the membership status of a user in a room. Args: requester (Requester): The local user who requested the membership event. If None, certain checks, like whether this homeserver can act as the sender, will be skipped. event (SynapseEvent): The membership event. context: The context of the event. ratelimit (bool): Whether to rate limit this request. Raises: SynapseError if there was a problem changing the membership. """ target_user = UserID.from_string(event.state_key) room_id = event.room_id if requester is not None: sender = UserID.from_string(event.sender) assert ( sender == requester.user ), "Sender (%s) must be same as requester (%s)" % (sender, requester.user) assert self.hs.is_mine(sender), "Sender must be our own: %s" % (sender,) else: requester = types.create_requester(target_user) prev_event = yield self.event_creation_handler.deduplicate_state_event( event, context ) if prev_event is not None: return prev_state_ids = yield context.get_prev_state_ids(self.store) if event.membership == Membership.JOIN: if requester.is_guest: guest_can_join = yield self._can_guest_join(prev_state_ids) if not guest_can_join: # This should be an auth check, but guests are a local concept, # so don't really fit into the general auth process. raise AuthError(403, "Guest access not allowed") if event.membership not in (Membership.LEAVE, Membership.BAN): is_blocked = yield self.store.is_room_blocked(room_id) if is_blocked: raise SynapseError(403, "This room has been blocked on this server") yield self.event_creation_handler.handle_new_client_event( requester, event, context, extra_users=[target_user], ratelimit=ratelimit ) prev_member_event_id = prev_state_ids.get( (EventTypes.Member, event.state_key), None ) if event.membership == Membership.JOIN: # Only fire user_joined_room if the user has actually joined the # room. Don't bother if the user is just changing their profile # info. newly_joined = True if prev_member_event_id: prev_member_event = yield self.store.get_event(prev_member_event_id) newly_joined = prev_member_event.membership != Membership.JOIN if newly_joined: yield self._user_joined_room(target_user, room_id) elif event.membership == Membership.LEAVE: if prev_member_event_id: prev_member_event = yield self.store.get_event(prev_member_event_id) if prev_member_event.membership == Membership.JOIN: yield self._user_left_room(target_user, room_id) @defer.inlineCallbacks def _can_guest_join(self, current_state_ids): """ Returns whether a guest can join a room based on its current state. """ guest_access_id = current_state_ids.get((EventTypes.GuestAccess, ""), None) if not guest_access_id: return False guest_access = yield self.store.get_event(guest_access_id) return ( guest_access and guest_access.content and "guest_access" in guest_access.content and guest_access.content["guest_access"] == "can_join" ) @defer.inlineCallbacks def lookup_room_alias(self, room_alias): """ Get the room ID associated with a room alias. Args: room_alias (RoomAlias): The alias to look up. Returns: A tuple of: The room ID as a RoomID object. Hosts likely to be participating in the room ([str]). Raises: SynapseError if room alias could not be found. """ directory_handler = self.directory_handler mapping = yield directory_handler.get_association(room_alias) if not mapping: raise SynapseError(404, "No such room alias") room_id = mapping["room_id"] servers = mapping["servers"] # put the server which owns the alias at the front of the server list. if room_alias.domain in servers: servers.remove(room_alias.domain) servers.insert(0, room_alias.domain) return RoomID.from_string(room_id), servers @defer.inlineCallbacks def _get_inviter(self, user_id, room_id): invite = yield self.store.get_invite_for_user_in_room( user_id=user_id, room_id=room_id ) if invite: return UserID.from_string(invite.sender) @defer.inlineCallbacks def do_3pid_invite( self, room_id, inviter, medium, address, id_server, requester, txn_id, id_access_token=None, ): if self.config.block_non_admin_invites: is_requester_admin = yield self.auth.is_server_admin(requester.user) if not is_requester_admin: raise SynapseError( 403, "Invites have been disabled on this server", Codes.FORBIDDEN ) # We need to rate limit *before* we send out any 3PID invites, so we # can't just rely on the standard ratelimiting of events. yield self.base_handler.ratelimit(requester) can_invite = yield self.third_party_event_rules.check_threepid_can_be_invited( medium, address, room_id ) if not can_invite: raise SynapseError( 403, "This third-party identifier can not be invited in this room", Codes.FORBIDDEN, ) if not self._enable_lookup: raise SynapseError( 403, "Looking up third-party identifiers is denied from this server" ) invitee = yield self.identity_handler.lookup_3pid( id_server, medium, address, id_access_token ) if invitee: yield self.update_membership( requester, UserID.from_string(invitee), room_id, "invite", txn_id=txn_id ) else: yield self._make_and_store_3pid_invite( requester, id_server, medium, address, room_id, inviter, txn_id=txn_id, id_access_token=id_access_token, ) @defer.inlineCallbacks def _make_and_store_3pid_invite( self, requester, id_server, medium, address, room_id, user, txn_id, id_access_token=None, ): room_state = yield self.state_handler.get_current_state(room_id) inviter_display_name = "" inviter_avatar_url = "" member_event = room_state.get((EventTypes.Member, user.to_string())) if member_event: inviter_display_name = member_event.content.get("displayname", "") inviter_avatar_url = member_event.content.get("avatar_url", "") # if user has no display name, default to their MXID if not inviter_display_name: inviter_display_name = user.to_string() canonical_room_alias = "" canonical_alias_event = room_state.get((EventTypes.CanonicalAlias, "")) if canonical_alias_event: canonical_room_alias = canonical_alias_event.content.get("alias", "") room_name = "" room_name_event = room_state.get((EventTypes.Name, "")) if room_name_event: room_name = room_name_event.content.get("name", "") room_join_rules = "" join_rules_event = room_state.get((EventTypes.JoinRules, "")) if join_rules_event: room_join_rules = join_rules_event.content.get("join_rule", "") room_avatar_url = "" room_avatar_event = room_state.get((EventTypes.RoomAvatar, "")) if room_avatar_event: room_avatar_url = room_avatar_event.content.get("url", "") token, public_keys, fallback_public_key, display_name = ( yield self.identity_handler.ask_id_server_for_third_party_invite( requester=requester, id_server=id_server, medium=medium, address=address, room_id=room_id, inviter_user_id=user.to_string(), room_alias=canonical_room_alias, room_avatar_url=room_avatar_url, room_join_rules=room_join_rules, room_name=room_name, inviter_display_name=inviter_display_name, inviter_avatar_url=inviter_avatar_url, id_access_token=id_access_token, ) ) yield self.event_creation_handler.create_and_send_nonmember_event( requester, { "type": EventTypes.ThirdPartyInvite, "content": { "display_name": display_name, "public_keys": public_keys, # For backwards compatibility: "key_validity_url": fallback_public_key["key_validity_url"], "public_key": fallback_public_key["public_key"], }, "room_id": room_id, "sender": user.to_string(), "state_key": token, }, ratelimit=False, txn_id=txn_id, ) @defer.inlineCallbacks def _is_host_in_room(self, current_state_ids): # Have we just created the room, and is this about to be the very # first member event? create_event_id = current_state_ids.get(("m.room.create", "")) if len(current_state_ids) == 1 and create_event_id: # We can only get here if we're in the process of creating the room return True for etype, state_key in current_state_ids: if etype != EventTypes.Member or not self.hs.is_mine_id(state_key): continue event_id = current_state_ids[(etype, state_key)] event = yield self.store.get_event(event_id, allow_none=True) if not event: continue if event.membership == Membership.JOIN: return True return False @defer.inlineCallbacks def _is_server_notice_room(self, room_id): if self._server_notices_mxid is None: return False user_ids = yield self.store.get_users_in_room(room_id) return self._server_notices_mxid in user_ids class RoomMemberMasterHandler(RoomMemberHandler): def __init__(self, hs): super(RoomMemberMasterHandler, self).__init__(hs) self.distributor = hs.get_distributor() self.distributor.declare("user_joined_room") self.distributor.declare("user_left_room") @defer.inlineCallbacks def _is_remote_room_too_complex(self, room_id, remote_room_hosts): """ Check if complexity of a remote room is too great. Args: room_id (str) remote_room_hosts (list[str]) Returns: bool of whether the complexity is too great, or None if unable to be fetched """ max_complexity = self.hs.config.limit_remote_rooms.complexity complexity = yield self.federation_handler.get_room_complexity( remote_room_hosts, room_id ) if complexity: return complexity["v1"] > max_complexity return None @defer.inlineCallbacks def _is_local_room_too_complex(self, room_id): """ Check if the complexity of a local room is too great. Args: room_id (str) Returns: bool """ max_complexity = self.hs.config.limit_remote_rooms.complexity complexity = yield self.store.get_room_complexity(room_id) return complexity["v1"] > max_complexity @defer.inlineCallbacks def _remote_join(self, requester, remote_room_hosts, room_id, user, content): """Implements RoomMemberHandler._remote_join """ # filter ourselves out of remote_room_hosts: do_invite_join ignores it # and if it is the only entry we'd like to return a 404 rather than a # 500. remote_room_hosts = [ host for host in remote_room_hosts if host != self.hs.hostname ] if len(remote_room_hosts) == 0: raise SynapseError(404, "No known servers") if self.hs.config.limit_remote_rooms.enabled: # Fetch the room complexity too_complex = yield self._is_remote_room_too_complex( room_id, remote_room_hosts ) if too_complex is True: raise SynapseError( code=400, msg=self.hs.config.limit_remote_rooms.complexity_error, errcode=Codes.RESOURCE_LIMIT_EXCEEDED, ) # We don't do an auth check if we are doing an invite # join dance for now, since we're kinda implicitly checking # that we are allowed to join when we decide whether or not we # need to do the invite/join dance. yield self.federation_handler.do_invite_join( remote_room_hosts, room_id, user.to_string(), content ) yield self._user_joined_room(user, room_id) # Check the room we just joined wasn't too large, if we didn't fetch the # complexity of it before. if self.hs.config.limit_remote_rooms.enabled: if too_complex is False: # We checked, and we're under the limit. return # Check again, but with the local state events too_complex = yield self._is_local_room_too_complex(room_id) if too_complex is False: # We're under the limit. return # The room is too large. Leave. requester = types.create_requester(user, None, False, None) yield self.update_membership( requester=requester, target=user, room_id=room_id, action="leave" ) raise SynapseError( code=400, msg=self.hs.config.limit_remote_rooms.complexity_error, errcode=Codes.RESOURCE_LIMIT_EXCEEDED, ) @defer.inlineCallbacks def _remote_reject_invite(self, requester, remote_room_hosts, room_id, target): """Implements RoomMemberHandler._remote_reject_invite """ fed_handler = self.federation_handler try: ret = yield fed_handler.do_remotely_reject_invite( remote_room_hosts, room_id, target.to_string() ) return ret except Exception as e: # if we were unable to reject the exception, just mark # it as rejected on our end and plough ahead. # # The 'except' clause is very broad, but we need to # capture everything from DNS failures upwards # logger.warning("Failed to reject invite: %s", e) yield self.store.locally_reject_invite(target.to_string(), room_id) return {} def _user_joined_room(self, target, room_id): """Implements RoomMemberHandler._user_joined_room """ return user_joined_room(self.distributor, target, room_id) def _user_left_room(self, target, room_id): """Implements RoomMemberHandler._user_left_room """ return user_left_room(self.distributor, target, room_id) @defer.inlineCallbacks def forget(self, user, room_id): user_id = user.to_string() member = yield self.state_handler.get_current_state( room_id=room_id, event_type=EventTypes.Member, state_key=user_id ) membership = member.membership if member else None if membership is not None and membership not in [ Membership.LEAVE, Membership.BAN, ]: raise SynapseError(400, "User %s in room %s" % (user_id, room_id)) if membership: yield self.store.forget(user_id, room_id)