# Copyright 2016-2020 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 import random from http import HTTPStatus from typing import TYPE_CHECKING, Iterable, List, Optional, Tuple from synapse import types from synapse.api.constants import AccountDataTypes, EventTypes, Membership from synapse.api.errors import ( AuthError, Codes, LimitExceededError, ShadowBanError, SynapseError, ) from synapse.api.ratelimiting import Ratelimiter from synapse.events import EventBase from synapse.events.snapshot import EventContext from synapse.types import JsonDict, Requester, RoomAlias, RoomID, StateMap, UserID from synapse.util.async_helpers import Linearizer from synapse.util.distributor import user_left_room from ._base import BaseHandler if TYPE_CHECKING: from synapse.server import HomeServer logger = logging.getLogger(__name__) class RoomMemberHandler(metaclass=abc.ABCMeta): # 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. def __init__(self, hs: "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_federation_handler() self.directory_handler = hs.get_directory_handler() self.identity_handler = hs.get_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.account_data_handler = hs.get_account_data_handler() self.event_auth_handler = hs.get_event_auth_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 self._join_rate_limiter_local = Ratelimiter( store=self.store, clock=self.clock, rate_hz=hs.config.ratelimiting.rc_joins_local.per_second, burst_count=hs.config.ratelimiting.rc_joins_local.burst_count, ) self._join_rate_limiter_remote = Ratelimiter( store=self.store, clock=self.clock, rate_hz=hs.config.ratelimiting.rc_joins_remote.per_second, burst_count=hs.config.ratelimiting.rc_joins_remote.burst_count, ) self._invites_per_room_limiter = Ratelimiter( store=self.store, clock=self.clock, rate_hz=hs.config.ratelimiting.rc_invites_per_room.per_second, burst_count=hs.config.ratelimiting.rc_invites_per_room.burst_count, ) self._invites_per_user_limiter = Ratelimiter( store=self.store, clock=self.clock, rate_hz=hs.config.ratelimiting.rc_invites_per_user.per_second, burst_count=hs.config.ratelimiting.rc_invites_per_user.burst_count, ) # 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 async def _remote_join( self, requester: Requester, remote_room_hosts: List[str], room_id: str, user: UserID, content: dict, ) -> Tuple[str, int]: """Try and join a room that this server is not in Args: requester remote_room_hosts: List of servers that can be used to join via. room_id: Room that we are trying to join user: User who is trying to join content: A dict that should be used as the content of the join event. """ raise NotImplementedError() @abc.abstractmethod async def remote_reject_invite( self, invite_event_id: str, txn_id: Optional[str], requester: Requester, content: JsonDict, ) -> Tuple[str, int]: """ Rejects an out-of-band invite we have received from a remote server Args: invite_event_id: ID of the invite to be rejected txn_id: optional transaction ID supplied by the client requester: user making the rejection request, according to the access token content: additional content to include in the rejection event. Normally an empty dict. Returns: event id, stream_id of the leave event """ raise NotImplementedError() @abc.abstractmethod async def _user_left_room(self, target: UserID, room_id: str) -> None: """Notifies distributor on master process that the user has left the room. Args: target room_id """ raise NotImplementedError() @abc.abstractmethod async def forget(self, user: UserID, room_id: str) -> None: raise NotImplementedError() async def ratelimit_multiple_invites( self, requester: Optional[Requester], room_id: Optional[str], n_invites: int, update: bool = True, ): """Ratelimit more than one invite sent by the given requester in the given room. Args: requester: The requester sending the invites. room_id: The room the invites are being sent in. n_invites: The amount of invites to ratelimit for. update: Whether to update the ratelimiter's cache. Raises: LimitExceededError: The requester can't send that many invites in the room. """ await self._invites_per_room_limiter.ratelimit( requester, room_id, update=update, n_actions=n_invites, ) async def ratelimit_invite( self, requester: Optional[Requester], room_id: Optional[str], invitee_user_id: str, ): """Ratelimit invites by room and by target user. If room ID is missing then we just rate limit by target user. """ if room_id: await self._invites_per_room_limiter.ratelimit(requester, room_id) await self._invites_per_user_limiter.ratelimit(requester, invitee_user_id) async def _local_membership_update( self, requester: Requester, target: UserID, room_id: str, membership: str, prev_event_ids: List[str], txn_id: Optional[str] = None, ratelimit: bool = True, content: Optional[dict] = None, require_consent: bool = True, ) -> Tuple[str, int]: user_id = target.to_string() if content is None: content = {} content["membership"] = membership if requester.is_guest: content["kind"] = "guest" # Check if we already have an event with a matching transaction ID. (We # do this check just before we persist an event as well, but may as well # do it up front for efficiency.) if txn_id and requester.access_token_id: existing_event_id = await self.store.get_event_id_from_transaction_id( room_id, requester.user.to_string(), requester.access_token_id, txn_id, ) if existing_event_id: event_pos = await self.store.get_position_for_event(existing_event_id) return existing_event_id, event_pos.stream event, context = await 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, }, txn_id=txn_id, prev_event_ids=prev_event_ids, require_consent=require_consent, ) prev_state_ids = await context.get_prev_state_ids() prev_member_event_id = prev_state_ids.get((EventTypes.Member, user_id), None) if event.membership == Membership.JOIN: newly_joined = True user_is_invited = False if prev_member_event_id: prev_member_event = await self.store.get_event(prev_member_event_id) newly_joined = prev_member_event.membership != Membership.JOIN user_is_invited = prev_member_event.membership == Membership.INVITE # If the member is not already in the room and is not accepting an invite, # check if they should be allowed access via membership in a space. if ( newly_joined and not user_is_invited and not await self.event_auth_handler.can_join_without_invite( prev_state_ids, event.room_version, user_id ) ): raise AuthError( 403, "You do not belong to any of the required spaces to join this room.", ) # Only rate-limit if the user actually joined the room, otherwise we'll end # up blocking profile updates. if newly_joined and ratelimit: time_now_s = self.clock.time() ( allowed, time_allowed, ) = await self._join_rate_limiter_local.can_do_action(requester) if not allowed: raise LimitExceededError( retry_after_ms=int(1000 * (time_allowed - time_now_s)) ) result_event = await self.event_creation_handler.handle_new_client_event( requester, event, context, extra_users=[target], ratelimit=ratelimit, ) if event.membership == Membership.LEAVE: if prev_member_event_id: prev_member_event = await self.store.get_event(prev_member_event_id) if prev_member_event.membership == Membership.JOIN: await self._user_left_room(target, room_id) # we know it was persisted, so should have a stream ordering assert result_event.internal_metadata.stream_ordering return result_event.event_id, result_event.internal_metadata.stream_ordering async def copy_room_tags_and_direct_to_room( self, old_room_id, new_room_id, user_id ) -> None: """Copies the tags and direct room state from one room to another. Args: old_room_id: The room ID of the old room. new_room_id: The room ID of the new room. user_id: The user's ID. """ # Retrieve user account data for predecessor room user_account_data, _ = await self.store.get_account_data_for_user(user_id) # Copy direct message state if applicable direct_rooms = user_account_data.get(AccountDataTypes.DIRECT, {}) # 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 direct_rooms[key].append(new_room_id) # Save back to user's m.direct account data await self.account_data_handler.add_account_data_for_user( user_id, AccountDataTypes.DIRECT, direct_rooms ) break # Copy room tags if applicable room_tags = await self.store.get_tags_for_room(user_id, old_room_id) # Copy each room tag to the new room for tag, tag_content in room_tags.items(): await self.account_data_handler.add_tag_to_room( user_id, new_room_id, tag, tag_content ) async def update_membership( self, requester: Requester, target: UserID, room_id: str, action: str, txn_id: Optional[str] = None, remote_room_hosts: Optional[List[str]] = None, third_party_signed: Optional[dict] = None, ratelimit: bool = True, content: Optional[dict] = None, require_consent: bool = True, ) -> Tuple[str, int]: """Update a user's membership in a room. Params: requester: The user who is performing the update. target: The user whose membership is being updated. room_id: The room ID whose membership is being updated. action: The membership change, see synapse.api.constants.Membership. txn_id: The transaction ID, if given. remote_room_hosts: Remote servers to send the update to. third_party_signed: Information from a 3PID invite. ratelimit: Whether to rate limit the request. content: The content of the created event. require_consent: Whether consent is required. Returns: A tuple of the new event ID and stream ID. Raises: ShadowBanError if a shadow-banned requester attempts to send an invite. """ if action == Membership.INVITE and requester.shadow_banned: # We randomly sleep a bit just to annoy the requester. await self.clock.sleep(random.randint(1, 10)) raise ShadowBanError() key = (room_id,) with (await self.member_linearizer.queue(key)): result = await self.update_membership_locked( 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 async def update_membership_locked( self, requester: Requester, target: UserID, room_id: str, action: str, txn_id: Optional[str] = None, remote_room_hosts: Optional[List[str]] = None, third_party_signed: Optional[dict] = None, ratelimit: bool = True, content: Optional[dict] = None, require_consent: bool = True, ) -> Tuple[str, int]: """Helper for update_membership. Assumes that the membership linearizer is already held for the room. """ 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) # allow the server notices mxid to set room-level profile is_requester_server_notices_user = ( self._server_notices_mxid is not None and requester.user.to_string() == self._server_notices_mxid ) if ( not self.allow_per_room_profiles and not is_requester_server_notices_user ) or requester.shadow_banned: # 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: await 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 = await 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: target_id = target.to_string() if ratelimit: await self.ratelimit_invite(requester, room_id, target_id) # block any attempts to invite the server notices mxid if target_id == self._server_notices_mxid: raise SynapseError(HTTPStatus.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 = await 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 await self.spam_checker.user_may_invite( requester.user.to_string(), target_id, 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") latest_event_ids = await self.store.get_prev_events_for_room(room_id) current_state_ids = await 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 = await 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: # duplicate event. # we know it was persisted, so must have a stream ordering. assert old_state.internal_metadata.stream_ordering return ( old_state.event_id, old_state.internal_metadata.stream_ordering, ) 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 = await self._is_server_notice_room(room_id) if is_blocked: raise SynapseError( HTTPStatus.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 = await self._is_host_in_room(current_state_ids) if effective_membership_state == Membership.JOIN: if requester.is_guest: guest_can_join = await 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") if not is_host_in_room: if ratelimit: time_now_s = self.clock.time() ( allowed, time_allowed, ) = await self._join_rate_limiter_remote.can_do_action( requester, ) if not allowed: raise LimitExceededError( retry_after_ms=int(1000 * (time_allowed - time_now_s)) ) inviter = await 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"] = await profile.get_displayname(target) content["avatar_url"] = await profile.get_avatar_url(target) if requester.is_guest: content["kind"] = "guest" remote_join_response = await self._remote_join( requester, remote_room_hosts, room_id, target, content ) return remote_join_response elif effective_membership_state == Membership.LEAVE: if not is_host_in_room: # perhaps we've been invited ( current_membership_type, current_membership_event_id, ) = await self.store.get_local_current_membership_for_user_in_room( target.to_string(), room_id ) if ( current_membership_type != Membership.INVITE or not current_membership_event_id ): logger.info( "%s sent a leave request to %s, but that is not an active room " "on this server, and there is no pending invite", target, room_id, ) raise SynapseError(404, "Not a known room") invite = await self.store.get_event(current_membership_event_id) logger.info( "%s rejects invite to %s from %s", target, room_id, invite.sender ) if not self.hs.is_mine_id(invite.sender): # send the rejection to the inviter's HS (with fallback to # local event) return await self.remote_reject_invite( invite.event_id, txn_id, requester, content, ) # the inviter was on our server, but has now left. Carry on # with the normal rejection codepath, which will also send the # rejection out to any other servers we believe are still in the room. # thanks to overzealous cleaning up of event_forward_extremities in # `delete_old_current_state_events`, it's possible to end up with no # forward extremities here. If that happens, let's just hang the # rejection off the invite event. # # see: https://github.com/matrix-org/synapse/issues/7139 if len(latest_event_ids) == 0: latest_event_ids = [invite.event_id] return await self._local_membership_update( requester=requester, target=target, room_id=room_id, membership=effective_membership_state, txn_id=txn_id, ratelimit=ratelimit, prev_event_ids=latest_event_ids, content=content, require_consent=require_consent, ) async def transfer_room_state_on_room_upgrade( self, old_room_id: str, room_id: str ) -> None: """Upon our server becoming aware of an upgraded room, either by upgrading a room ourselves or joining one, we can transfer over information from the previous room. Copies user state (tags/push rules) for every local user that was in the old room, as well as migrating the room directory state. Args: old_room_id: The ID of the old room room_id: The ID of the new room """ logger.info("Transferring room state from %s to %s", old_room_id, room_id) # Find all local users that were in the old room and copy over each user's state users = await self.store.get_users_in_room(old_room_id) await self.copy_user_state_on_room_upgrade(old_room_id, room_id, users) # Add new room to the room directory if the old room was there # Remove old room from the room directory old_room = await self.store.get_room(old_room_id) if old_room and old_room["is_public"]: await self.store.set_room_is_public(old_room_id, False) await self.store.set_room_is_public(room_id, True) # Transfer alias mappings in the room directory await self.store.update_aliases_for_room(old_room_id, room_id) # Check if any groups we own contain the predecessor room local_group_ids = await self.store.get_local_groups_for_room(old_room_id) for group_id in local_group_ids: # Add new the new room to those groups await self.store.add_room_to_group(group_id, room_id, old_room["is_public"]) # Remove the old room from those groups await self.store.remove_room_from_group(group_id, old_room_id) async def copy_user_state_on_room_upgrade( self, old_room_id: str, new_room_id: str, user_ids: Iterable[str] ) -> None: """Copy user-specific information when they join a new room when that new room is the result of a room upgrade Args: old_room_id: The ID of upgraded room new_room_id: The ID of the new room user_ids: User IDs to copy state for """ logger.debug( "Copying over room tags and push rules from %s to %s for users %s", old_room_id, new_room_id, user_ids, ) for user_id in user_ids: try: # It is an upgraded room. Copy over old tags await self.copy_room_tags_and_direct_to_room( old_room_id, new_room_id, user_id ) # Copy over push rules await self.store.copy_push_rules_from_room_to_room_for_user( old_room_id, new_room_id, user_id ) except Exception: logger.exception( "Error copying tags and/or push rules from rooms %s to %s for user %s. " "Skipping...", old_room_id, new_room_id, user_id, ) continue async def send_membership_event( self, requester: Optional[Requester], event: EventBase, context: EventContext, ratelimit: bool = True, ): """ Change the membership status of a user in a room. Args: 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: The membership event. context: The context of the event. ratelimit: 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_state_ids = await context.get_prev_state_ids() if event.membership == Membership.JOIN: if requester.is_guest: guest_can_join = await 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 = await self.store.is_room_blocked(room_id) if is_blocked: raise SynapseError(403, "This room has been blocked on this server") event = await 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.LEAVE: if prev_member_event_id: prev_member_event = await self.store.get_event(prev_member_event_id) if prev_member_event.membership == Membership.JOIN: await self._user_left_room(target_user, room_id) async def _can_guest_join(self, current_state_ids: StateMap[str]) -> bool: """ 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 = await self.store.get_event(guest_access_id) return bool( guest_access and guest_access.content and "guest_access" in guest_access.content and guest_access.content["guest_access"] == "can_join" ) async def lookup_room_alias( self, room_alias: RoomAlias ) -> Tuple[RoomID, List[str]]: """ Get the room ID associated with a room alias. Args: room_alias: 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 = await 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 async def _get_inviter(self, user_id: str, room_id: str) -> Optional[UserID]: invite = await self.store.get_invite_for_local_user_in_room( user_id=user_id, room_id=room_id ) if invite: return UserID.from_string(invite.sender) return None async def do_3pid_invite( self, room_id: str, inviter: UserID, medium: str, address: str, id_server: str, requester: Requester, txn_id: Optional[str], id_access_token: Optional[str] = None, ) -> int: """Invite a 3PID to a room. Args: room_id: The room to invite the 3PID to. inviter: The user sending the invite. medium: The 3PID's medium. address: The 3PID's address. id_server: The identity server to use. requester: The user making the request. txn_id: The transaction ID this is part of, or None if this is not part of a transaction. id_access_token: The optional identity server access token. Returns: The new stream ID. Raises: ShadowBanError if the requester has been shadow-banned. """ if self.config.block_non_admin_invites: is_requester_admin = await self.auth.is_server_admin(requester.user) if not is_requester_admin: raise SynapseError( 403, "Invites have been disabled on this server", Codes.FORBIDDEN ) if requester.shadow_banned: # We randomly sleep a bit just to annoy the requester. await self.clock.sleep(random.randint(1, 10)) raise ShadowBanError() # We need to rate limit *before* we send out any 3PID invites, so we # can't just rely on the standard ratelimiting of events. await self.base_handler.ratelimit(requester) can_invite = await 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 = await self.identity_handler.lookup_3pid( id_server, medium, address, id_access_token ) if invitee: # Note that update_membership with an action of "invite" can raise # a ShadowBanError, but this was done above already. _, stream_id = await self.update_membership( requester, UserID.from_string(invitee), room_id, "invite", txn_id=txn_id ) else: stream_id = await self._make_and_store_3pid_invite( requester, id_server, medium, address, room_id, inviter, txn_id=txn_id, id_access_token=id_access_token, ) return stream_id async def _make_and_store_3pid_invite( self, requester: Requester, id_server: str, medium: str, address: str, room_id: str, user: UserID, txn_id: Optional[str], id_access_token: Optional[str] = None, ) -> int: room_state = await 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, ) = await 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, ) ( event, stream_id, ) = await 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, ) return stream_id async def _is_host_in_room(self, current_state_ids: StateMap[str]) -> bool: # 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 = await self.store.get_event(event_id, allow_none=True) if not event: continue if event.membership == Membership.JOIN: return True return False async def _is_server_notice_room(self, room_id: str) -> bool: if self._server_notices_mxid is None: return False user_ids = await self.store.get_users_in_room(room_id) return self._server_notices_mxid in user_ids class RoomMemberMasterHandler(RoomMemberHandler): def __init__(self, hs: "HomeServer"): super().__init__(hs) self.distributor = hs.get_distributor() self.distributor.declare("user_left_room") self._server_name = hs.hostname async def _is_remote_room_too_complex( self, room_id: str, remote_room_hosts: List[str] ) -> Optional[bool]: """ Check if complexity of a remote room is too great. Args: room_id remote_room_hosts 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 = await self.federation_handler.get_room_complexity( remote_room_hosts, room_id ) if complexity: return complexity["v1"] > max_complexity return None async def _is_local_room_too_complex(self, room_id: str) -> bool: """ Check if the complexity of a local room is too great. Args: room_id: The room ID to check for complexity. """ max_complexity = self.hs.config.limit_remote_rooms.complexity complexity = await self.store.get_room_complexity(room_id) return complexity["v1"] > max_complexity async def _remote_join( self, requester: Requester, remote_room_hosts: List[str], room_id: str, user: UserID, content: dict, ) -> Tuple[str, int]: """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") check_complexity = self.hs.config.limit_remote_rooms.enabled if check_complexity and self.hs.config.limit_remote_rooms.admins_can_join: check_complexity = not await self.auth.is_server_admin(user) if check_complexity: # Fetch the room complexity too_complex = await 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. event_id, stream_id = await self.federation_handler.do_invite_join( remote_room_hosts, room_id, user.to_string(), content ) # Check the room we just joined wasn't too large, if we didn't fetch the # complexity of it before. if check_complexity: if too_complex is False: # We checked, and we're under the limit. return event_id, stream_id # Check again, but with the local state events too_complex = await self._is_local_room_too_complex(room_id) if too_complex is False: # We're under the limit. return event_id, stream_id # The room is too large. Leave. requester = types.create_requester( user, authenticated_entity=self._server_name ) await 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, ) return event_id, stream_id async def remote_reject_invite( self, invite_event_id: str, txn_id: Optional[str], requester: Requester, content: JsonDict, ) -> Tuple[str, int]: """ Rejects an out-of-band invite received from a remote user Implements RoomMemberHandler.remote_reject_invite """ invite_event = await self.store.get_event(invite_event_id) room_id = invite_event.room_id target_user = invite_event.state_key # first of all, try doing a rejection via the inviting server fed_handler = self.federation_handler try: inviter_id = UserID.from_string(invite_event.sender) event, stream_id = await fed_handler.do_remotely_reject_invite( [inviter_id.domain], room_id, target_user, content=content ) return event.event_id, stream_id except Exception as e: # if we were unable to reject the invite, we will generate our own # leave event. # # The 'except' clause is very broad, but we need to # capture everything from DNS failures upwards # logger.warning("Failed to reject invite: %s", e) return await self._generate_local_out_of_band_leave( invite_event, txn_id, requester, content ) async def _generate_local_out_of_band_leave( self, previous_membership_event: EventBase, txn_id: Optional[str], requester: Requester, content: JsonDict, ) -> Tuple[str, int]: """Generate a local leave event for a room This can be called after we e.g fail to reject an invite via a remote server. It generates an out-of-band membership event locally. Args: previous_membership_event: the previous membership event for this user txn_id: optional transaction ID supplied by the client requester: user making the request, according to the access token content: additional content to include in the leave event. Normally an empty dict. Returns: A tuple containing (event_id, stream_id of the leave event) """ room_id = previous_membership_event.room_id target_user = previous_membership_event.state_key content["membership"] = Membership.LEAVE event_dict = { "type": EventTypes.Member, "room_id": room_id, "sender": target_user, "content": content, "state_key": target_user, } # the auth events for the new event are the same as that of the previous event, plus # the event itself. # # the prev_events consist solely of the previous membership event. prev_event_ids = [previous_membership_event.event_id] auth_event_ids = previous_membership_event.auth_event_ids() + prev_event_ids event, context = await self.event_creation_handler.create_event( requester, event_dict, txn_id=txn_id, prev_event_ids=prev_event_ids, auth_event_ids=auth_event_ids, ) event.internal_metadata.outlier = True event.internal_metadata.out_of_band_membership = True result_event = await self.event_creation_handler.handle_new_client_event( requester, event, context, extra_users=[UserID.from_string(target_user)], ) # we know it was persisted, so must have a stream ordering assert result_event.internal_metadata.stream_ordering return result_event.event_id, result_event.internal_metadata.stream_ordering async def _user_left_room(self, target: UserID, room_id: str) -> None: """Implements RoomMemberHandler._user_left_room""" user_left_room(self.distributor, target, room_id) async def forget(self, user: UserID, room_id: str) -> None: user_id = user.to_string() member = await 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: await self.store.forget(user_id, room_id)