Mirrors
/
synapse-old
mirror of https://github.com/matrix-org/synapse.git
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity
synapse-old/synapse/visibility.py

383 lines
13 KiB
Python
Raw Blame History

# -*- coding: utf-8 -*-
# Copyright 2014 - 2016 OpenMarket Ltd
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
import logging
import operator
from six import iteritems, itervalues
from six.moves import map
from twisted.internet import defer
from synapse.api.constants import EventTypes, Membership
from synapse.events.utils import prune_event
from synapse.types import get_domain_from_id
from synapse.util.logcontext import make_deferred_yieldable, preserve_fn
logger = logging.getLogger(__name__)
VISIBILITY_PRIORITY = (
"world_readable",
"shared",
"invited",
"joined",
)
MEMBERSHIP_PRIORITY = (
Membership.JOIN,
Membership.INVITE,
Membership.KNOCK,
Membership.LEAVE,
Membership.BAN,
)
@defer.inlineCallbacks
def filter_events_for_client(store, user_id, events, is_peeking=False,
always_include_ids=frozenset()):
"""
Check which events a user is allowed to see
Args:
store (synapse.storage.DataStore): our datastore (can also be a worker
store)
user_id(str): user id to be checked
events(list[synapse.events.EventBase]): sequence of events to be checked
is_peeking(bool): should be True if:
* the user is not currently a member of the room, and:
* the user has not been a member of the room since the given
events
always_include_ids (set(event_id)): set of event ids to specifically
include (unless sender is ignored)
Returns:
Deferred[list[synapse.events.EventBase]]
"""
types = (
(EventTypes.RoomHistoryVisibility, ""),
(EventTypes.Member, user_id),
)
event_id_to_state = yield store.get_state_for_events(
frozenset(e.event_id for e in events),
types=types,
)
forgotten = yield make_deferred_yieldable(defer.gatherResults([
defer.maybeDeferred(
preserve_fn(store.who_forgot_in_room),
room_id,
)
for room_id in frozenset(e.room_id for e in events)
], consumeErrors=True))
# Set of membership event_ids that have been forgotten
event_id_forgotten = frozenset(
row["event_id"] for rows in forgotten for row in rows
)
ignore_dict_content = yield store.get_global_account_data_by_type_for_user(
"m.ignored_user_list", user_id,
)
# FIXME: This will explode if people upload something incorrect.
ignore_list = frozenset(
ignore_dict_content.get("ignored_users", {}).keys()
if ignore_dict_content else []
)
erased_senders = yield store.are_users_erased((e.sender for e in events))
def allowed(event):
"""
Args:
event (synapse.events.EventBase): event to check
Returns:
None|EventBase:
None if the user cannot see this event at all
a redacted copy of the event if they can only see a redacted
version
the original event if they can see it as normal.
"""
if not event.is_state() and event.sender in ignore_list:
return None
if event.event_id in always_include_ids:
return event
state = event_id_to_state[event.event_id]
# get the room_visibility at the time of the event.
visibility_event = state.get((EventTypes.RoomHistoryVisibility, ""), None)
if visibility_event:
visibility = visibility_event.content.get("history_visibility", "shared")
else:
visibility = "shared"
if visibility not in VISIBILITY_PRIORITY:
visibility = "shared"
# Always allow history visibility events on boundaries. This is done
# by setting the effective visibility to the least restrictive
# of the old vs new.
if event.type == EventTypes.RoomHistoryVisibility:
prev_content = event.unsigned.get("prev_content", {})
prev_visibility = prev_content.get("history_visibility", None)
if prev_visibility not in VISIBILITY_PRIORITY:
prev_visibility = "shared"
new_priority = VISIBILITY_PRIORITY.index(visibility)
old_priority = VISIBILITY_PRIORITY.index(prev_visibility)
if old_priority < new_priority:
visibility = prev_visibility
# likewise, if the event is the user's own membership event, use
# the 'most joined' membership
membership = None
if event.type == EventTypes.Member and event.state_key == user_id:
membership = event.content.get("membership", None)
if membership not in MEMBERSHIP_PRIORITY:
membership = "leave"
prev_content = event.unsigned.get("prev_content", {})
prev_membership = prev_content.get("membership", None)
if prev_membership not in MEMBERSHIP_PRIORITY:
prev_membership = "leave"
# Always allow the user to see their own leave events, otherwise
# they won't see the room disappear if they reject the invite
if membership == "leave" and (
prev_membership == "join" or prev_membership == "invite"
):
return event
new_priority = MEMBERSHIP_PRIORITY.index(membership)
old_priority = MEMBERSHIP_PRIORITY.index(prev_membership)
if old_priority < new_priority:
membership = prev_membership
# otherwise, get the user's membership at the time of the event.
if membership is None:
membership_event = state.get((EventTypes.Member, user_id), None)
if membership_event:
# XXX why do we do this?
# https://github.com/matrix-org/synapse/issues/3350
if membership_event.event_id not in event_id_forgotten:
membership = membership_event.membership
# if the user was a member of the room at the time of the event,
# they can see it.
if membership == Membership.JOIN:
return event
# otherwise, it depends on the room visibility.
if visibility == "joined":
# we weren't a member at the time of the event, so we can't
# see this event.
return None
elif visibility == "invited":
# user can also see the event if they were *invited* at the time
# of the event.
return (
event if membership == Membership.INVITE else None
)
elif visibility == "shared" and is_peeking:
# if the visibility is shared, users cannot see the event unless
# they have *subequently* joined the room (or were members at the
# time, of course)
#
# XXX: if the user has subsequently joined and then left again,
# ideally we would share history up to the point they left. But
# we don't know when they left. We just treat it as though they
# never joined, and restrict access.
return None
# the visibility is either shared or world_readable, and the user was
# not a member at the time. We allow it, provided the original sender
# has not requested their data to be erased, in which case, we return
# a redacted version.
if erased_senders[event.sender]:
return prune_event(event)
return event
# check each event: gives an iterable[None|EventBase]
filtered_events = map(allowed, events)
# remove the None entries
filtered_events = filter(operator.truth, filtered_events)
# we turn it into a list before returning it.
defer.returnValue(list(filtered_events))
@defer.inlineCallbacks
def filter_events_for_server(store, server_name, events):
# Whatever else we do, we need to check for senders which have requested
# erasure of their data.
erased_senders = yield store.are_users_erased(
e.sender for e in events,
)
def redact_disallowed(event, state):
# if the sender has been gdpr17ed, always return a redacted
# copy of the event.
if erased_senders[event.sender]:
logger.info(
"Sender of %s has been erased, redacting",
event.event_id,
)
return prune_event(event)
# state will be None if we decided we didn't need to filter by
# room membership.
if not state:
return event
history = state.get((EventTypes.RoomHistoryVisibility, ''), None)
if history:
visibility = history.content.get("history_visibility", "shared")
if visibility in ["invited", "joined"]:
# We now loop through all state events looking for
# membership states for the requesting server to determine
# if the server is either in the room or has been invited
# into the room.
for ev in itervalues(state):
if ev.type != EventTypes.Member:
continue
try:
domain = get_domain_from_id(ev.state_key)
except Exception:
continue
if domain != server_name:
continue
memtype = ev.membership
if memtype == Membership.JOIN:
return event
elif memtype == Membership.INVITE:
if visibility == "invited":
return event
else:
# server has no users in the room: redact
return prune_event(event)
return event
# Next lets check to see if all the events have a history visibility
# of "shared" or "world_readable". If thats the case then we don't
# need to check membership (as we know the server is in the room).
event_to_state_ids = yield store.get_state_ids_for_events(
frozenset(e.event_id for e in events),
types=(
(EventTypes.RoomHistoryVisibility, ""),
)
)
visibility_ids = set()
for sids in itervalues(event_to_state_ids):
hist = sids.get((EventTypes.RoomHistoryVisibility, ""))
if hist:
visibility_ids.add(hist)
# If we failed to find any history visibility events then the default
# is "shared" visiblity.
if not visibility_ids:
all_open = True
else:
event_map = yield store.get_events(visibility_ids)
all_open = all(
e.content.get("history_visibility") in (None, "shared", "world_readable")
for e in itervalues(event_map)
)
if all_open:
# all the history_visibility state affecting these events is open, so
# we don't need to filter by membership state. We *do* need to check
# for user erasure, though.
if erased_senders:
events = [
redact_disallowed(e, None)
for e in events
]
defer.returnValue(events)
# Ok, so we're dealing with events that have non-trivial visibility
# rules, so we need to also get the memberships of the room.
# first, for each event we're wanting to return, get the event_ids
# of the history vis and membership state at those events.
event_to_state_ids = yield store.get_state_ids_for_events(
frozenset(e.event_id for e in events),
types=(
(EventTypes.RoomHistoryVisibility, ""),
(EventTypes.Member, None),
)
)
# We only want to pull out member events that correspond to the
# server's domain.
#
# event_to_state_ids contains lots of duplicates, so it turns out to be
# cheaper to build a complete set of unique
# ((type, state_key), event_id) tuples, and then filter out the ones we
# don't want.
#
state_key_to_event_id_set = {
e
for key_to_eid in itervalues(event_to_state_ids)
for e in key_to_eid.items()
}
def include(typ, state_key):
if typ != EventTypes.Member:
return True
# we avoid using get_domain_from_id here for efficiency.
idx = state_key.find(":")
if idx == -1:
return False
return state_key[idx + 1:] == server_name
event_map = yield store.get_events([
e_id
for key, e_id in state_key_to_event_id_set
if include(key[0], key[1])
])
event_to_state = {
e_id: {
key: event_map[inner_e_id]
for key, inner_e_id in iteritems(key_to_eid)
if inner_e_id in event_map
}
for e_id, key_to_eid in iteritems(event_to_state_ids)
}
defer.returnValue([
redact_disallowed(e, event_to_state[e.event_id])
for e in events
])
Reference in New Issue View Git Blame Copy Permalink