mirror of
https://git.anonymousland.org/anonymousland/synapse.git
synced 2024-12-11 04:14:19 -05:00
709 lines
21 KiB
Python
709 lines
21 KiB
Python
# -*- coding: utf-8 -*-
|
|
# Copyright 2018 New Vector 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 heapq
|
|
import itertools
|
|
import logging
|
|
from typing import (
|
|
Any,
|
|
Callable,
|
|
Dict,
|
|
Generator,
|
|
Iterable,
|
|
List,
|
|
Optional,
|
|
Sequence,
|
|
Set,
|
|
Tuple,
|
|
overload,
|
|
)
|
|
|
|
from typing_extensions import Literal
|
|
|
|
import synapse.state
|
|
from synapse import event_auth
|
|
from synapse.api.constants import EventTypes
|
|
from synapse.api.errors import AuthError
|
|
from synapse.api.room_versions import KNOWN_ROOM_VERSIONS
|
|
from synapse.events import EventBase
|
|
from synapse.types import MutableStateMap, StateMap
|
|
from synapse.util import Clock
|
|
|
|
logger = logging.getLogger(__name__)
|
|
|
|
|
|
# We want to await to the reactor occasionally during state res when dealing
|
|
# with large data sets, so that we don't exhaust the reactor. This is done by
|
|
# awaiting to reactor during loops every N iterations.
|
|
_AWAIT_AFTER_ITERATIONS = 100
|
|
|
|
|
|
async def resolve_events_with_store(
|
|
clock: Clock,
|
|
room_id: str,
|
|
room_version: str,
|
|
state_sets: Sequence[StateMap[str]],
|
|
event_map: Optional[Dict[str, EventBase]],
|
|
state_res_store: "synapse.state.StateResolutionStore",
|
|
) -> StateMap[str]:
|
|
"""Resolves the state using the v2 state resolution algorithm
|
|
|
|
Args:
|
|
clock
|
|
room_id: the room we are working in
|
|
room_version: The room version
|
|
state_sets: List of dicts of (type, state_key) -> event_id,
|
|
which are the different state groups to resolve.
|
|
event_map:
|
|
a dict from event_id to event, for any events that we happen to
|
|
have in flight (eg, those currently being persisted). This will be
|
|
used as a starting point fof finding the state we need; any missing
|
|
events will be requested via state_res_store.
|
|
|
|
If None, all events will be fetched via state_res_store.
|
|
|
|
state_res_store:
|
|
|
|
Returns:
|
|
A map from (type, state_key) to event_id.
|
|
"""
|
|
|
|
logger.debug("Computing conflicted state")
|
|
|
|
# We use event_map as a cache, so if its None we need to initialize it
|
|
if event_map is None:
|
|
event_map = {}
|
|
|
|
# First split up the un/conflicted state
|
|
unconflicted_state, conflicted_state = _seperate(state_sets)
|
|
|
|
if not conflicted_state:
|
|
return unconflicted_state
|
|
|
|
logger.debug("%d conflicted state entries", len(conflicted_state))
|
|
logger.debug("Calculating auth chain difference")
|
|
|
|
# Also fetch all auth events that appear in only some of the state sets'
|
|
# auth chains.
|
|
auth_diff = await _get_auth_chain_difference(state_sets, event_map, state_res_store)
|
|
|
|
full_conflicted_set = set(
|
|
itertools.chain(
|
|
itertools.chain.from_iterable(conflicted_state.values()), auth_diff
|
|
)
|
|
)
|
|
|
|
events = await state_res_store.get_events(
|
|
[eid for eid in full_conflicted_set if eid not in event_map],
|
|
allow_rejected=True,
|
|
)
|
|
event_map.update(events)
|
|
|
|
# everything in the event map should be in the right room
|
|
for event in event_map.values():
|
|
if event.room_id != room_id:
|
|
raise Exception(
|
|
"Attempting to state-resolve for room %s with event %s which is in %s"
|
|
% (room_id, event.event_id, event.room_id,)
|
|
)
|
|
|
|
full_conflicted_set = {eid for eid in full_conflicted_set if eid in event_map}
|
|
|
|
logger.debug("%d full_conflicted_set entries", len(full_conflicted_set))
|
|
|
|
# Get and sort all the power events (kicks/bans/etc)
|
|
power_events = (
|
|
eid for eid in full_conflicted_set if _is_power_event(event_map[eid])
|
|
)
|
|
|
|
sorted_power_events = await _reverse_topological_power_sort(
|
|
clock, room_id, power_events, event_map, state_res_store, full_conflicted_set
|
|
)
|
|
|
|
logger.debug("sorted %d power events", len(sorted_power_events))
|
|
|
|
# Now sequentially auth each one
|
|
resolved_state = await _iterative_auth_checks(
|
|
clock,
|
|
room_id,
|
|
room_version,
|
|
sorted_power_events,
|
|
unconflicted_state,
|
|
event_map,
|
|
state_res_store,
|
|
)
|
|
|
|
logger.debug("resolved power events")
|
|
|
|
# OK, so we've now resolved the power events. Now sort the remaining
|
|
# events using the mainline of the resolved power level.
|
|
|
|
set_power_events = set(sorted_power_events)
|
|
leftover_events = [
|
|
ev_id for ev_id in full_conflicted_set if ev_id not in set_power_events
|
|
]
|
|
|
|
logger.debug("sorting %d remaining events", len(leftover_events))
|
|
|
|
pl = resolved_state.get((EventTypes.PowerLevels, ""), None)
|
|
leftover_events = await _mainline_sort(
|
|
clock, room_id, leftover_events, pl, event_map, state_res_store
|
|
)
|
|
|
|
logger.debug("resolving remaining events")
|
|
|
|
resolved_state = await _iterative_auth_checks(
|
|
clock,
|
|
room_id,
|
|
room_version,
|
|
leftover_events,
|
|
resolved_state,
|
|
event_map,
|
|
state_res_store,
|
|
)
|
|
|
|
logger.debug("resolved")
|
|
|
|
# We make sure that unconflicted state always still applies.
|
|
resolved_state.update(unconflicted_state)
|
|
|
|
logger.debug("done")
|
|
|
|
return resolved_state
|
|
|
|
|
|
async def _get_power_level_for_sender(
|
|
room_id: str,
|
|
event_id: str,
|
|
event_map: Dict[str, EventBase],
|
|
state_res_store: "synapse.state.StateResolutionStore",
|
|
) -> int:
|
|
"""Return the power level of the sender of the given event according to
|
|
their auth events.
|
|
|
|
Args:
|
|
room_id
|
|
event_id
|
|
event_map
|
|
state_res_store
|
|
|
|
Returns:
|
|
The power level.
|
|
"""
|
|
event = await _get_event(room_id, event_id, event_map, state_res_store)
|
|
|
|
pl = None
|
|
for aid in event.auth_event_ids():
|
|
aev = await _get_event(
|
|
room_id, aid, event_map, state_res_store, allow_none=True
|
|
)
|
|
if aev and (aev.type, aev.state_key) == (EventTypes.PowerLevels, ""):
|
|
pl = aev
|
|
break
|
|
|
|
if pl is None:
|
|
# Couldn't find power level. Check if they're the creator of the room
|
|
for aid in event.auth_event_ids():
|
|
aev = await _get_event(
|
|
room_id, aid, event_map, state_res_store, allow_none=True
|
|
)
|
|
if aev and (aev.type, aev.state_key) == (EventTypes.Create, ""):
|
|
if aev.content.get("creator") == event.sender:
|
|
return 100
|
|
break
|
|
return 0
|
|
|
|
level = pl.content.get("users", {}).get(event.sender)
|
|
if level is None:
|
|
level = pl.content.get("users_default", 0)
|
|
|
|
if level is None:
|
|
return 0
|
|
else:
|
|
return int(level)
|
|
|
|
|
|
async def _get_auth_chain_difference(
|
|
state_sets: Sequence[StateMap[str]],
|
|
event_map: Dict[str, EventBase],
|
|
state_res_store: "synapse.state.StateResolutionStore",
|
|
) -> Set[str]:
|
|
"""Compare the auth chains of each state set and return the set of events
|
|
that only appear in some but not all of the auth chains.
|
|
|
|
Args:
|
|
state_sets
|
|
event_map
|
|
state_res_store
|
|
|
|
Returns:
|
|
Set of event IDs
|
|
"""
|
|
|
|
difference = await state_res_store.get_auth_chain_difference(
|
|
[set(state_set.values()) for state_set in state_sets]
|
|
)
|
|
|
|
return difference
|
|
|
|
|
|
def _seperate(
|
|
state_sets: Iterable[StateMap[str]],
|
|
) -> Tuple[StateMap[str], StateMap[Set[str]]]:
|
|
"""Return the unconflicted and conflicted state. This is different than in
|
|
the original algorithm, as this defines a key to be conflicted if one of
|
|
the state sets doesn't have that key.
|
|
|
|
Args:
|
|
state_sets
|
|
|
|
Returns:
|
|
A tuple of unconflicted and conflicted state. The conflicted state dict
|
|
is a map from type/state_key to set of event IDs
|
|
"""
|
|
unconflicted_state = {}
|
|
conflicted_state = {}
|
|
|
|
for key in set(itertools.chain.from_iterable(state_sets)):
|
|
event_ids = {state_set.get(key) for state_set in state_sets}
|
|
if len(event_ids) == 1:
|
|
unconflicted_state[key] = event_ids.pop()
|
|
else:
|
|
event_ids.discard(None)
|
|
conflicted_state[key] = event_ids
|
|
|
|
# mypy doesn't understand that discarding None above means that conflicted
|
|
# state is StateMap[Set[str]], not StateMap[Set[Optional[Str]]].
|
|
return unconflicted_state, conflicted_state # type: ignore
|
|
|
|
|
|
def _is_power_event(event: EventBase) -> bool:
|
|
"""Return whether or not the event is a "power event", as defined by the
|
|
v2 state resolution algorithm
|
|
|
|
Args:
|
|
event
|
|
|
|
Returns:
|
|
True if the event is a power event.
|
|
"""
|
|
if (event.type, event.state_key) in (
|
|
(EventTypes.PowerLevels, ""),
|
|
(EventTypes.JoinRules, ""),
|
|
(EventTypes.Create, ""),
|
|
):
|
|
return True
|
|
|
|
if event.type == EventTypes.Member:
|
|
if event.membership in ("leave", "ban"):
|
|
return event.sender != event.state_key
|
|
|
|
return False
|
|
|
|
|
|
async def _add_event_and_auth_chain_to_graph(
|
|
graph: Dict[str, Set[str]],
|
|
room_id: str,
|
|
event_id: str,
|
|
event_map: Dict[str, EventBase],
|
|
state_res_store: "synapse.state.StateResolutionStore",
|
|
auth_diff: Set[str],
|
|
) -> None:
|
|
"""Helper function for _reverse_topological_power_sort that add the event
|
|
and its auth chain (that is in the auth diff) to the graph
|
|
|
|
Args:
|
|
graph: A map from event ID to the events auth event IDs
|
|
room_id: the room we are working in
|
|
event_id: Event to add to the graph
|
|
event_map
|
|
state_res_store
|
|
auth_diff: Set of event IDs that are in the auth difference.
|
|
"""
|
|
|
|
state = [event_id]
|
|
while state:
|
|
eid = state.pop()
|
|
graph.setdefault(eid, set())
|
|
|
|
event = await _get_event(room_id, eid, event_map, state_res_store)
|
|
for aid in event.auth_event_ids():
|
|
if aid in auth_diff:
|
|
if aid not in graph:
|
|
state.append(aid)
|
|
|
|
graph.setdefault(eid, set()).add(aid)
|
|
|
|
|
|
async def _reverse_topological_power_sort(
|
|
clock: Clock,
|
|
room_id: str,
|
|
event_ids: Iterable[str],
|
|
event_map: Dict[str, EventBase],
|
|
state_res_store: "synapse.state.StateResolutionStore",
|
|
auth_diff: Set[str],
|
|
) -> List[str]:
|
|
"""Returns a list of the event_ids sorted by reverse topological ordering,
|
|
and then by power level and origin_server_ts
|
|
|
|
Args:
|
|
clock
|
|
room_id: the room we are working in
|
|
event_ids: The events to sort
|
|
event_map
|
|
state_res_store
|
|
auth_diff: Set of event IDs that are in the auth difference.
|
|
|
|
Returns:
|
|
The sorted list
|
|
"""
|
|
|
|
graph = {} # type: Dict[str, Set[str]]
|
|
for idx, event_id in enumerate(event_ids, start=1):
|
|
await _add_event_and_auth_chain_to_graph(
|
|
graph, room_id, event_id, event_map, state_res_store, auth_diff
|
|
)
|
|
|
|
# We await occasionally when we're working with large data sets to
|
|
# ensure that we don't block the reactor loop for too long.
|
|
if idx % _AWAIT_AFTER_ITERATIONS == 0:
|
|
await clock.sleep(0)
|
|
|
|
event_to_pl = {}
|
|
for idx, event_id in enumerate(graph, start=1):
|
|
pl = await _get_power_level_for_sender(
|
|
room_id, event_id, event_map, state_res_store
|
|
)
|
|
event_to_pl[event_id] = pl
|
|
|
|
# We await occasionally when we're working with large data sets to
|
|
# ensure that we don't block the reactor loop for too long.
|
|
if idx % _AWAIT_AFTER_ITERATIONS == 0:
|
|
await clock.sleep(0)
|
|
|
|
def _get_power_order(event_id):
|
|
ev = event_map[event_id]
|
|
pl = event_to_pl[event_id]
|
|
|
|
return -pl, ev.origin_server_ts, event_id
|
|
|
|
# Note: graph is modified during the sort
|
|
it = lexicographical_topological_sort(graph, key=_get_power_order)
|
|
sorted_events = list(it)
|
|
|
|
return sorted_events
|
|
|
|
|
|
async def _iterative_auth_checks(
|
|
clock: Clock,
|
|
room_id: str,
|
|
room_version: str,
|
|
event_ids: List[str],
|
|
base_state: StateMap[str],
|
|
event_map: Dict[str, EventBase],
|
|
state_res_store: "synapse.state.StateResolutionStore",
|
|
) -> MutableStateMap[str]:
|
|
"""Sequentially apply auth checks to each event in given list, updating the
|
|
state as it goes along.
|
|
|
|
Args:
|
|
clock
|
|
room_id
|
|
room_version
|
|
event_ids: Ordered list of events to apply auth checks to
|
|
base_state: The set of state to start with
|
|
event_map
|
|
state_res_store
|
|
|
|
Returns:
|
|
Returns the final updated state
|
|
"""
|
|
resolved_state = dict(base_state)
|
|
room_version_obj = KNOWN_ROOM_VERSIONS[room_version]
|
|
|
|
for idx, event_id in enumerate(event_ids, start=1):
|
|
event = event_map[event_id]
|
|
|
|
auth_events = {}
|
|
for aid in event.auth_event_ids():
|
|
ev = await _get_event(
|
|
room_id, aid, event_map, state_res_store, allow_none=True
|
|
)
|
|
|
|
if not ev:
|
|
logger.warning(
|
|
"auth_event id %s for event %s is missing", aid, event_id
|
|
)
|
|
else:
|
|
if ev.rejected_reason is None:
|
|
auth_events[(ev.type, ev.state_key)] = ev
|
|
|
|
for key in event_auth.auth_types_for_event(event):
|
|
if key in resolved_state:
|
|
ev_id = resolved_state[key]
|
|
ev = await _get_event(room_id, ev_id, event_map, state_res_store)
|
|
|
|
if ev.rejected_reason is None:
|
|
auth_events[key] = event_map[ev_id]
|
|
|
|
try:
|
|
event_auth.check(
|
|
room_version_obj,
|
|
event,
|
|
auth_events,
|
|
do_sig_check=False,
|
|
do_size_check=False,
|
|
)
|
|
|
|
resolved_state[(event.type, event.state_key)] = event_id
|
|
except AuthError:
|
|
pass
|
|
|
|
# We await occasionally when we're working with large data sets to
|
|
# ensure that we don't block the reactor loop for too long.
|
|
if idx % _AWAIT_AFTER_ITERATIONS == 0:
|
|
await clock.sleep(0)
|
|
|
|
return resolved_state
|
|
|
|
|
|
async def _mainline_sort(
|
|
clock: Clock,
|
|
room_id: str,
|
|
event_ids: List[str],
|
|
resolved_power_event_id: Optional[str],
|
|
event_map: Dict[str, EventBase],
|
|
state_res_store: "synapse.state.StateResolutionStore",
|
|
) -> List[str]:
|
|
"""Returns a sorted list of event_ids sorted by mainline ordering based on
|
|
the given event resolved_power_event_id
|
|
|
|
Args:
|
|
clock
|
|
room_id: room we're working in
|
|
event_ids: Events to sort
|
|
resolved_power_event_id: The final resolved power level event ID
|
|
event_map
|
|
state_res_store
|
|
|
|
Returns:
|
|
The sorted list
|
|
"""
|
|
if not event_ids:
|
|
# It's possible for there to be no event IDs here to sort, so we can
|
|
# skip calculating the mainline in that case.
|
|
return []
|
|
|
|
mainline = []
|
|
pl = resolved_power_event_id
|
|
idx = 0
|
|
while pl:
|
|
mainline.append(pl)
|
|
pl_ev = await _get_event(room_id, pl, event_map, state_res_store)
|
|
auth_events = pl_ev.auth_event_ids()
|
|
pl = None
|
|
for aid in auth_events:
|
|
ev = await _get_event(
|
|
room_id, aid, event_map, state_res_store, allow_none=True
|
|
)
|
|
if ev and (ev.type, ev.state_key) == (EventTypes.PowerLevels, ""):
|
|
pl = aid
|
|
break
|
|
|
|
# We await occasionally when we're working with large data sets to
|
|
# ensure that we don't block the reactor loop for too long.
|
|
if idx != 0 and idx % _AWAIT_AFTER_ITERATIONS == 0:
|
|
await clock.sleep(0)
|
|
|
|
idx += 1
|
|
|
|
mainline_map = {ev_id: i + 1 for i, ev_id in enumerate(reversed(mainline))}
|
|
|
|
event_ids = list(event_ids)
|
|
|
|
order_map = {}
|
|
for idx, ev_id in enumerate(event_ids, start=1):
|
|
depth = await _get_mainline_depth_for_event(
|
|
event_map[ev_id], mainline_map, event_map, state_res_store
|
|
)
|
|
order_map[ev_id] = (depth, event_map[ev_id].origin_server_ts, ev_id)
|
|
|
|
# We await occasionally when we're working with large data sets to
|
|
# ensure that we don't block the reactor loop for too long.
|
|
if idx % _AWAIT_AFTER_ITERATIONS == 0:
|
|
await clock.sleep(0)
|
|
|
|
event_ids.sort(key=lambda ev_id: order_map[ev_id])
|
|
|
|
return event_ids
|
|
|
|
|
|
async def _get_mainline_depth_for_event(
|
|
event: EventBase,
|
|
mainline_map: Dict[str, int],
|
|
event_map: Dict[str, EventBase],
|
|
state_res_store: "synapse.state.StateResolutionStore",
|
|
) -> int:
|
|
"""Get the mainline depths for the given event based on the mainline map
|
|
|
|
Args:
|
|
event
|
|
mainline_map: Map from event_id to mainline depth for events in the mainline.
|
|
event_map
|
|
state_res_store
|
|
|
|
Returns:
|
|
The mainline depth
|
|
"""
|
|
|
|
room_id = event.room_id
|
|
tmp_event = event # type: Optional[EventBase]
|
|
|
|
# We do an iterative search, replacing `event with the power level in its
|
|
# auth events (if any)
|
|
while tmp_event:
|
|
depth = mainline_map.get(event.event_id)
|
|
if depth is not None:
|
|
return depth
|
|
|
|
auth_events = tmp_event.auth_event_ids()
|
|
tmp_event = None
|
|
|
|
for aid in auth_events:
|
|
aev = await _get_event(
|
|
room_id, aid, event_map, state_res_store, allow_none=True
|
|
)
|
|
if aev and (aev.type, aev.state_key) == (EventTypes.PowerLevels, ""):
|
|
tmp_event = aev
|
|
break
|
|
|
|
# Didn't find a power level auth event, so we just return 0
|
|
return 0
|
|
|
|
|
|
@overload
|
|
async def _get_event(
|
|
room_id: str,
|
|
event_id: str,
|
|
event_map: Dict[str, EventBase],
|
|
state_res_store: "synapse.state.StateResolutionStore",
|
|
allow_none: Literal[False] = False,
|
|
) -> EventBase:
|
|
...
|
|
|
|
|
|
@overload
|
|
async def _get_event(
|
|
room_id: str,
|
|
event_id: str,
|
|
event_map: Dict[str, EventBase],
|
|
state_res_store: "synapse.state.StateResolutionStore",
|
|
allow_none: Literal[True],
|
|
) -> Optional[EventBase]:
|
|
...
|
|
|
|
|
|
async def _get_event(
|
|
room_id: str,
|
|
event_id: str,
|
|
event_map: Dict[str, EventBase],
|
|
state_res_store: "synapse.state.StateResolutionStore",
|
|
allow_none: bool = False,
|
|
) -> Optional[EventBase]:
|
|
"""Helper function to look up event in event_map, falling back to looking
|
|
it up in the store
|
|
|
|
Args:
|
|
room_id
|
|
event_id
|
|
event_map
|
|
state_res_store
|
|
allow_none: if the event is not found, return None rather than raising
|
|
an exception
|
|
|
|
Returns:
|
|
The event, or none if the event does not exist (and allow_none is True).
|
|
"""
|
|
if event_id not in event_map:
|
|
events = await state_res_store.get_events([event_id], allow_rejected=True)
|
|
event_map.update(events)
|
|
event = event_map.get(event_id)
|
|
|
|
if event is None:
|
|
if allow_none:
|
|
return None
|
|
raise Exception("Unknown event %s" % (event_id,))
|
|
|
|
if event.room_id != room_id:
|
|
raise Exception(
|
|
"In state res for room %s, event %s is in %s"
|
|
% (room_id, event_id, event.room_id)
|
|
)
|
|
return event
|
|
|
|
|
|
def lexicographical_topological_sort(
|
|
graph: Dict[str, Set[str]], key: Callable[[str], Any]
|
|
) -> Generator[str, None, None]:
|
|
"""Performs a lexicographic reverse topological sort on the graph.
|
|
|
|
This returns a reverse topological sort (i.e. if node A references B then B
|
|
appears before A in the sort), with ties broken lexicographically based on
|
|
return value of the `key` function.
|
|
|
|
NOTE: `graph` is modified during the sort.
|
|
|
|
Args:
|
|
graph: A representation of the graph where each node is a key in the
|
|
dict and its value are the nodes edges.
|
|
key: A function that takes a node and returns a value that is comparable
|
|
and used to order nodes
|
|
|
|
Yields:
|
|
The next node in the topological sort
|
|
"""
|
|
|
|
# Note, this is basically Kahn's algorithm except we look at nodes with no
|
|
# outgoing edges, c.f.
|
|
# https://en.wikipedia.org/wiki/Topological_sorting#Kahn's_algorithm
|
|
outdegree_map = graph
|
|
reverse_graph = {} # type: Dict[str, Set[str]]
|
|
|
|
# Lists of nodes with zero out degree. Is actually a tuple of
|
|
# `(key(node), node)` so that sorting does the right thing
|
|
zero_outdegree = []
|
|
|
|
for node, edges in graph.items():
|
|
if len(edges) == 0:
|
|
zero_outdegree.append((key(node), node))
|
|
|
|
reverse_graph.setdefault(node, set())
|
|
for edge in edges:
|
|
reverse_graph.setdefault(edge, set()).add(node)
|
|
|
|
# heapq is a built in implementation of a sorted queue.
|
|
heapq.heapify(zero_outdegree)
|
|
|
|
while zero_outdegree:
|
|
_, node = heapq.heappop(zero_outdegree)
|
|
|
|
for parent in reverse_graph[node]:
|
|
out = outdegree_map[parent]
|
|
out.discard(node)
|
|
if len(out) == 0:
|
|
heapq.heappush(zero_outdegree, (key(parent), parent))
|
|
|
|
yield node
|