synapse-product/synapse/handlers/room_member.py
Brendan Abolivier a683028d81
Correctly ratelimit invites when creating a room (#9968)
* Correctly ratelimit invites when creating a room

Also allow ratelimiting for more than one action at a time.
2021-05-12 16:05:28 +02:00

1305 lines
49 KiB
Python

# 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)