595 lines
18 KiB
Python
595 lines
18 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 Dict, List, Optional, Tuple
|
|
|
|
from six import iteritems, itervalues
|
|
|
|
from twisted.internet import defer
|
|
|
|
import synapse.state
|
|
from synapse import event_auth
|
|
from synapse.api.constants import EventTypes
|
|
from synapse.api.errors import AuthError
|
|
from synapse.events import EventBase
|
|
|
|
logger = logging.getLogger(__name__)
|
|
|
|
|
|
@defer.inlineCallbacks
|
|
def resolve_events_with_store(
|
|
room_id: str,
|
|
room_version: str,
|
|
state_sets: List[Dict[Tuple[str, str], str]],
|
|
event_map: Optional[Dict[str, EventBase]],
|
|
state_res_store: "synapse.state.StateResolutionStore",
|
|
):
|
|
"""Resolves the state using the v2 state resolution algorithm
|
|
|
|
Args:
|
|
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:
|
|
Deferred[dict[(str, str), str]]:
|
|
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 = yield _get_auth_chain_difference(state_sets, event_map, state_res_store)
|
|
|
|
full_conflicted_set = set(
|
|
itertools.chain(
|
|
itertools.chain.from_iterable(itervalues(conflicted_state)), auth_diff
|
|
)
|
|
)
|
|
|
|
events = yield 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 = 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 = yield _reverse_topological_power_sort(
|
|
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 = yield _iterative_auth_checks(
|
|
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.
|
|
|
|
leftover_events = [
|
|
ev_id for ev_id in full_conflicted_set if ev_id not in sorted_power_events
|
|
]
|
|
|
|
logger.debug("sorting %d remaining events", len(leftover_events))
|
|
|
|
pl = resolved_state.get((EventTypes.PowerLevels, ""), None)
|
|
leftover_events = yield _mainline_sort(
|
|
room_id, leftover_events, pl, event_map, state_res_store
|
|
)
|
|
|
|
logger.debug("resolving remaining events")
|
|
|
|
resolved_state = yield _iterative_auth_checks(
|
|
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
|
|
|
|
|
|
@defer.inlineCallbacks
|
|
def _get_power_level_for_sender(room_id, event_id, event_map, state_res_store):
|
|
"""Return the power level of the sender of the given event according to
|
|
their auth events.
|
|
|
|
Args:
|
|
room_id (str)
|
|
event_id (str)
|
|
event_map (dict[str,FrozenEvent])
|
|
state_res_store (StateResolutionStore)
|
|
|
|
Returns:
|
|
Deferred[int]
|
|
"""
|
|
event = yield _get_event(room_id, event_id, event_map, state_res_store)
|
|
|
|
pl = None
|
|
for aid in event.auth_event_ids():
|
|
aev = yield _get_event(room_id, aid, event_map, state_res_store)
|
|
if (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 = yield _get_event(room_id, aid, event_map, state_res_store)
|
|
if (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)
|
|
|
|
|
|
@defer.inlineCallbacks
|
|
def _get_auth_chain_difference(state_sets, event_map, state_res_store):
|
|
"""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 (list)
|
|
event_map (dict[str,FrozenEvent])
|
|
state_res_store (StateResolutionStore)
|
|
|
|
Returns:
|
|
Deferred[set[str]]: Set of event IDs
|
|
"""
|
|
common = set(itervalues(state_sets[0])).intersection(
|
|
*(itervalues(s) for s in state_sets[1:])
|
|
)
|
|
|
|
auth_sets = []
|
|
for state_set in state_sets:
|
|
auth_ids = set(
|
|
eid
|
|
for key, eid in iteritems(state_set)
|
|
if (
|
|
key[0] in (EventTypes.Member, EventTypes.ThirdPartyInvite)
|
|
or key
|
|
in (
|
|
(EventTypes.PowerLevels, ""),
|
|
(EventTypes.Create, ""),
|
|
(EventTypes.JoinRules, ""),
|
|
)
|
|
)
|
|
and eid not in common
|
|
)
|
|
|
|
auth_chain = yield state_res_store.get_auth_chain(auth_ids)
|
|
auth_ids.update(auth_chain)
|
|
|
|
auth_sets.append(auth_ids)
|
|
|
|
intersection = set(auth_sets[0]).intersection(*auth_sets[1:])
|
|
union = set().union(*auth_sets)
|
|
|
|
return union - intersection
|
|
|
|
|
|
def _seperate(state_sets):
|
|
"""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 (list)
|
|
|
|
Returns:
|
|
tuple[dict, dict]: 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 = set(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
|
|
|
|
return unconflicted_state, conflicted_state
|
|
|
|
|
|
def _is_power_event(event):
|
|
"""Return whether or not the event is a "power event", as defined by the
|
|
v2 state resolution algorithm
|
|
|
|
Args:
|
|
event (FrozenEvent)
|
|
|
|
Returns:
|
|
boolean
|
|
"""
|
|
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
|
|
|
|
|
|
@defer.inlineCallbacks
|
|
def _add_event_and_auth_chain_to_graph(
|
|
graph, room_id, event_id, event_map, state_res_store, auth_diff
|
|
):
|
|
"""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 (dict[str, set[str]]): A map from event ID to the events auth
|
|
event IDs
|
|
room_id (str): the room we are working in
|
|
event_id (str): Event to add to the graph
|
|
event_map (dict[str,FrozenEvent])
|
|
state_res_store (StateResolutionStore)
|
|
auth_diff (set[str]): Set of event IDs that are in the auth difference.
|
|
"""
|
|
|
|
state = [event_id]
|
|
while state:
|
|
eid = state.pop()
|
|
graph.setdefault(eid, set())
|
|
|
|
event = yield _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)
|
|
|
|
|
|
@defer.inlineCallbacks
|
|
def _reverse_topological_power_sort(
|
|
room_id, event_ids, event_map, state_res_store, auth_diff
|
|
):
|
|
"""Returns a list of the event_ids sorted by reverse topological ordering,
|
|
and then by power level and origin_server_ts
|
|
|
|
Args:
|
|
room_id (str): the room we are working in
|
|
event_ids (list[str]): The events to sort
|
|
event_map (dict[str,FrozenEvent])
|
|
state_res_store (StateResolutionStore)
|
|
auth_diff (set[str]): Set of event IDs that are in the auth difference.
|
|
|
|
Returns:
|
|
Deferred[list[str]]: The sorted list
|
|
"""
|
|
|
|
graph = {}
|
|
for event_id in event_ids:
|
|
yield _add_event_and_auth_chain_to_graph(
|
|
graph, room_id, event_id, event_map, state_res_store, auth_diff
|
|
)
|
|
|
|
event_to_pl = {}
|
|
for event_id in graph:
|
|
pl = yield _get_power_level_for_sender(
|
|
room_id, event_id, event_map, state_res_store
|
|
)
|
|
event_to_pl[event_id] = pl
|
|
|
|
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
|
|
|
|
|
|
@defer.inlineCallbacks
|
|
def _iterative_auth_checks(
|
|
room_id, room_version, event_ids, base_state, event_map, state_res_store
|
|
):
|
|
"""Sequentially apply auth checks to each event in given list, updating the
|
|
state as it goes along.
|
|
|
|
Args:
|
|
room_id (str)
|
|
room_version (str)
|
|
event_ids (list[str]): Ordered list of events to apply auth checks to
|
|
base_state (dict[tuple[str, str], str]): The set of state to start with
|
|
event_map (dict[str,FrozenEvent])
|
|
state_res_store (StateResolutionStore)
|
|
|
|
Returns:
|
|
Deferred[dict[tuple[str, str], str]]: Returns the final updated state
|
|
"""
|
|
resolved_state = base_state.copy()
|
|
|
|
for event_id in event_ids:
|
|
event = event_map[event_id]
|
|
|
|
auth_events = {}
|
|
for aid in event.auth_event_ids():
|
|
ev = yield _get_event(room_id, aid, event_map, state_res_store)
|
|
|
|
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 = yield _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,
|
|
event,
|
|
auth_events,
|
|
do_sig_check=False,
|
|
do_size_check=False,
|
|
)
|
|
|
|
resolved_state[(event.type, event.state_key)] = event_id
|
|
except AuthError:
|
|
pass
|
|
|
|
return resolved_state
|
|
|
|
|
|
@defer.inlineCallbacks
|
|
def _mainline_sort(
|
|
room_id, event_ids, resolved_power_event_id, event_map, state_res_store
|
|
):
|
|
"""Returns a sorted list of event_ids sorted by mainline ordering based on
|
|
the given event resolved_power_event_id
|
|
|
|
Args:
|
|
room_id (str): room we're working in
|
|
event_ids (list[str]): Events to sort
|
|
resolved_power_event_id (str): The final resolved power level event ID
|
|
event_map (dict[str,FrozenEvent])
|
|
state_res_store (StateResolutionStore)
|
|
|
|
Returns:
|
|
Deferred[list[str]]: The sorted list
|
|
"""
|
|
mainline = []
|
|
pl = resolved_power_event_id
|
|
while pl:
|
|
mainline.append(pl)
|
|
pl_ev = yield _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 = yield _get_event(room_id, aid, event_map, state_res_store)
|
|
if (ev.type, ev.state_key) == (EventTypes.PowerLevels, ""):
|
|
pl = aid
|
|
break
|
|
|
|
mainline_map = {ev_id: i + 1 for i, ev_id in enumerate(reversed(mainline))}
|
|
|
|
event_ids = list(event_ids)
|
|
|
|
order_map = {}
|
|
for ev_id in event_ids:
|
|
depth = yield _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)
|
|
|
|
event_ids.sort(key=lambda ev_id: order_map[ev_id])
|
|
|
|
return event_ids
|
|
|
|
|
|
@defer.inlineCallbacks
|
|
def _get_mainline_depth_for_event(event, mainline_map, event_map, state_res_store):
|
|
"""Get the mainline depths for the given event based on the mainline map
|
|
|
|
Args:
|
|
event (FrozenEvent)
|
|
mainline_map (dict[str, int]): Map from event_id to mainline depth for
|
|
events in the mainline.
|
|
event_map (dict[str,FrozenEvent])
|
|
state_res_store (StateResolutionStore)
|
|
|
|
Returns:
|
|
Deferred[int]
|
|
"""
|
|
|
|
room_id = event.room_id
|
|
|
|
# We do an iterative search, replacing `event with the power level in its
|
|
# auth events (if any)
|
|
while event:
|
|
depth = mainline_map.get(event.event_id)
|
|
if depth is not None:
|
|
return depth
|
|
|
|
auth_events = event.auth_event_ids()
|
|
event = None
|
|
|
|
for aid in auth_events:
|
|
aev = yield _get_event(room_id, aid, event_map, state_res_store)
|
|
if (aev.type, aev.state_key) == (EventTypes.PowerLevels, ""):
|
|
event = aev
|
|
break
|
|
|
|
# Didn't find a power level auth event, so we just return 0
|
|
return 0
|
|
|
|
|
|
@defer.inlineCallbacks
|
|
def _get_event(room_id, event_id, event_map, state_res_store):
|
|
"""Helper function to look up event in event_map, falling back to looking
|
|
it up in the store
|
|
|
|
Args:
|
|
room_id (str)
|
|
event_id (str)
|
|
event_map (dict[str,FrozenEvent])
|
|
state_res_store (StateResolutionStore)
|
|
|
|
Returns:
|
|
Deferred[FrozenEvent]
|
|
"""
|
|
if event_id not in event_map:
|
|
events = yield state_res_store.get_events([event_id], allow_rejected=True)
|
|
event_map.update(events)
|
|
event = event_map[event_id]
|
|
assert event is not None
|
|
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, key):
|
|
"""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 (dict[str, set[str]]): A representation of the graph where each
|
|
node is a key in the dict and its value are the nodes edges.
|
|
key (func): A function that takes a node and returns a value that is
|
|
comparable and used to order nodes
|
|
|
|
Yields:
|
|
str: 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 = {}
|
|
|
|
# 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 iteritems(graph):
|
|
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
|