mirror of
https://github.com/matrix-org/dendrite.git
synced 2024-11-23 14:51:56 -06:00
707 lines
26 KiB
Go
707 lines
26 KiB
Go
package input
|
|
|
|
import (
|
|
"context"
|
|
"errors"
|
|
"fmt"
|
|
"sync"
|
|
|
|
fedapi "github.com/matrix-org/dendrite/federationapi/api"
|
|
"github.com/matrix-org/dendrite/internal"
|
|
"github.com/matrix-org/dendrite/roomserver/api"
|
|
"github.com/matrix-org/dendrite/roomserver/internal/query"
|
|
"github.com/matrix-org/dendrite/roomserver/storage"
|
|
"github.com/matrix-org/gomatrixserverlib"
|
|
"github.com/matrix-org/util"
|
|
"github.com/sirupsen/logrus"
|
|
)
|
|
|
|
type missingStateReq struct {
|
|
origin gomatrixserverlib.ServerName
|
|
db storage.Database
|
|
inputer *Inputer
|
|
queryer *query.Queryer
|
|
keys gomatrixserverlib.JSONVerifier
|
|
federation fedapi.FederationInternalAPI
|
|
roomsMu *internal.MutexByRoom
|
|
servers []gomatrixserverlib.ServerName
|
|
hadEvents map[string]bool
|
|
hadEventsMutex sync.Mutex
|
|
haveEvents map[string]*gomatrixserverlib.HeaderedEvent
|
|
haveEventsMutex sync.Mutex
|
|
}
|
|
|
|
func (t *missingStateReq) processEventWithMissingState(
|
|
ctx context.Context, e *gomatrixserverlib.Event, roomVersion gomatrixserverlib.RoomVersion,
|
|
) error {
|
|
// We are missing the previous events for this events.
|
|
// This means that there is a gap in our view of the history of the
|
|
// room. There two ways that we can handle such a gap:
|
|
// 1) We can fill in the gap using /get_missing_events
|
|
// 2) We can leave the gap and request the state of the room at
|
|
// this event from the remote server using either /state_ids
|
|
// or /state.
|
|
// Synapse will attempt to do 1 and if that fails or if the gap is
|
|
// too large then it will attempt 2.
|
|
// Synapse will use /state_ids if possible since usually the state
|
|
// is largely unchanged and it is more efficient to fetch a list of
|
|
// event ids and then use /event to fetch the individual events.
|
|
// However not all version of synapse support /state_ids so you may
|
|
// need to fallback to /state.
|
|
|
|
// Attempt to fill in the gap using /get_missing_events
|
|
// This will either:
|
|
// - fill in the gap completely then process event `e` returning no backwards extremity
|
|
// - fail to fill in the gap and tell us to terminate the transaction err=not nil
|
|
// - fail to fill in the gap and tell us to fetch state at the new backwards extremity, and to not terminate the transaction
|
|
newEvents, err := t.getMissingEvents(ctx, e, roomVersion)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
if len(newEvents) == 0 {
|
|
return nil
|
|
}
|
|
|
|
backwardsExtremity := newEvents[0]
|
|
newEvents = newEvents[1:]
|
|
|
|
type respState struct {
|
|
// A snapshot is considered trustworthy if it came from our own roomserver.
|
|
// That's because the state will have been through state resolution once
|
|
// already in QueryStateAfterEvent.
|
|
trustworthy bool
|
|
*gomatrixserverlib.RespState
|
|
}
|
|
|
|
// at this point we know we're going to have a gap: we need to work out the room state at the new backwards extremity.
|
|
// Therefore, we cannot just query /state_ids with this event to get the state before. Instead, we need to query
|
|
// the state AFTER all the prev_events for this event, then apply state resolution to that to get the state before the event.
|
|
var states []*respState
|
|
for _, prevEventID := range backwardsExtremity.PrevEventIDs() {
|
|
// Look up what the state is after the backward extremity. This will either
|
|
// come from the roomserver, if we know all the required events, or it will
|
|
// come from a remote server via /state_ids if not.
|
|
prevState, trustworthy, lerr := t.lookupStateAfterEvent(ctx, roomVersion, backwardsExtremity.RoomID(), prevEventID)
|
|
if lerr != nil {
|
|
util.GetLogger(ctx).WithError(lerr).Errorf("Failed to lookup state after prev_event: %s", prevEventID)
|
|
return lerr
|
|
}
|
|
// Append the state onto the collected state. We'll run this through the
|
|
// state resolution next.
|
|
states = append(states, &respState{trustworthy, prevState})
|
|
}
|
|
|
|
// Now that we have collected all of the state from the prev_events, we'll
|
|
// run the state through the appropriate state resolution algorithm for the
|
|
// room if needed. This does a couple of things:
|
|
// 1. Ensures that the state is deduplicated fully for each state-key tuple
|
|
// 2. Ensures that we pick the latest events from both sets, in the case that
|
|
// one of the prev_events is quite a bit older than the others
|
|
resolvedState := &gomatrixserverlib.RespState{}
|
|
switch len(states) {
|
|
case 0:
|
|
extremityIsCreate := backwardsExtremity.Type() == gomatrixserverlib.MRoomCreate && backwardsExtremity.StateKeyEquals("")
|
|
if !extremityIsCreate {
|
|
// There are no previous states and this isn't the beginning of the
|
|
// room - this is an error condition!
|
|
util.GetLogger(ctx).Errorf("Failed to lookup any state after prev_events")
|
|
return fmt.Errorf("expected %d states but got %d", len(backwardsExtremity.PrevEventIDs()), len(states))
|
|
}
|
|
case 1:
|
|
// There's only one previous state - if it's trustworthy (came from a
|
|
// local state snapshot which will already have been through state res),
|
|
// use it as-is. There's no point in resolving it again.
|
|
if states[0].trustworthy {
|
|
resolvedState = states[0].RespState
|
|
break
|
|
}
|
|
// Otherwise, if it isn't trustworthy (came from federation), run it through
|
|
// state resolution anyway for safety, in case there are duplicates.
|
|
fallthrough
|
|
default:
|
|
respStates := make([]*gomatrixserverlib.RespState, len(states))
|
|
for i := range states {
|
|
respStates[i] = states[i].RespState
|
|
}
|
|
// There's more than one previous state - run them all through state res
|
|
t.roomsMu.Lock(e.RoomID())
|
|
resolvedState, err = t.resolveStatesAndCheck(ctx, roomVersion, respStates, backwardsExtremity)
|
|
t.roomsMu.Unlock(e.RoomID())
|
|
if err != nil {
|
|
util.GetLogger(ctx).WithError(err).Errorf("Failed to resolve state conflicts for event %s", backwardsExtremity.EventID())
|
|
return err
|
|
}
|
|
}
|
|
|
|
// First of all, send the backward extremity into the roomserver with the
|
|
// newly resolved state. This marks the "oldest" point in the backfill and
|
|
// sets the baseline state for any new events after this. We'll make a
|
|
// copy of the hadEvents map so that it can be taken downstream without
|
|
// worrying about concurrent map reads/writes, since t.hadEvents is meant
|
|
// to be protected by a mutex.
|
|
hadEvents := map[string]bool{}
|
|
t.hadEventsMutex.Lock()
|
|
for k, v := range t.hadEvents {
|
|
hadEvents[k] = v
|
|
}
|
|
t.hadEventsMutex.Unlock()
|
|
|
|
stateIDs := make([]string, len(resolvedState.StateEvents))
|
|
for _, event := range resolvedState.StateEvents {
|
|
stateIDs = append(stateIDs, event.EventID())
|
|
}
|
|
|
|
err = t.inputer.processRoomEvent(ctx, &api.InputRoomEvent{
|
|
Kind: api.KindOld,
|
|
Event: backwardsExtremity.Headered(roomVersion),
|
|
Origin: t.origin,
|
|
AuthEventIDs: backwardsExtremity.AuthEventIDs(),
|
|
HasState: true,
|
|
StateEventIDs: stateIDs,
|
|
SendAsServer: api.DoNotSendToOtherServers,
|
|
})
|
|
if err != nil {
|
|
return fmt.Errorf("t.inputer.processRoomEvent: %w", err)
|
|
}
|
|
|
|
// Then send all of the newer backfilled events, of which will all be newer
|
|
// than the backward extremity, into the roomserver without state. This way
|
|
// they will automatically fast-forward based on the room state at the
|
|
// extremity in the last step.
|
|
for _, newEvent := range newEvents {
|
|
err = t.inputer.processRoomEvent(ctx, &api.InputRoomEvent{
|
|
Kind: api.KindOld,
|
|
Event: newEvent.Headered(roomVersion),
|
|
Origin: t.origin,
|
|
AuthEventIDs: backwardsExtremity.AuthEventIDs(),
|
|
SendAsServer: api.DoNotSendToOtherServers,
|
|
})
|
|
if err != nil {
|
|
return fmt.Errorf("t.inputer.processRoomEvent: %w", err)
|
|
}
|
|
}
|
|
|
|
return nil
|
|
}
|
|
|
|
// lookupStateAfterEvent returns the room state after `eventID`, which is the state before eventID with the state of `eventID` (if it's a state event)
|
|
// added into the mix.
|
|
func (t *missingStateReq) lookupStateAfterEvent(ctx context.Context, roomVersion gomatrixserverlib.RoomVersion, roomID, eventID string) (*gomatrixserverlib.RespState, bool, error) {
|
|
// try doing all this locally before we resort to querying federation
|
|
respState := t.lookupStateAfterEventLocally(ctx, roomID, eventID)
|
|
if respState != nil {
|
|
return respState, true, nil
|
|
}
|
|
|
|
respState, err := t.lookupStateBeforeEvent(ctx, roomVersion, roomID, eventID)
|
|
if err != nil {
|
|
return nil, false, fmt.Errorf("t.lookupStateBeforeEvent: %w", err)
|
|
}
|
|
|
|
// fetch the event we're missing and add it to the pile
|
|
h, err := t.lookupEvent(ctx, roomVersion, roomID, eventID, false)
|
|
switch err.(type) {
|
|
case verifySigError:
|
|
return respState, false, nil
|
|
case nil:
|
|
// do nothing
|
|
default:
|
|
return nil, false, fmt.Errorf("t.lookupEvent: %w", err)
|
|
}
|
|
h = t.cacheAndReturn(h)
|
|
if h.StateKey() != nil {
|
|
addedToState := false
|
|
for i := range respState.StateEvents {
|
|
se := respState.StateEvents[i]
|
|
if se.Type() == h.Type() && se.StateKeyEquals(*h.StateKey()) {
|
|
respState.StateEvents[i] = h.Unwrap()
|
|
addedToState = true
|
|
break
|
|
}
|
|
}
|
|
if !addedToState {
|
|
respState.StateEvents = append(respState.StateEvents, h.Unwrap())
|
|
}
|
|
}
|
|
|
|
return respState, false, nil
|
|
}
|
|
|
|
func (t *missingStateReq) cacheAndReturn(ev *gomatrixserverlib.HeaderedEvent) *gomatrixserverlib.HeaderedEvent {
|
|
t.haveEventsMutex.Lock()
|
|
defer t.haveEventsMutex.Unlock()
|
|
if cached, exists := t.haveEvents[ev.EventID()]; exists {
|
|
return cached
|
|
}
|
|
t.haveEvents[ev.EventID()] = ev
|
|
return ev
|
|
}
|
|
|
|
func (t *missingStateReq) lookupStateAfterEventLocally(ctx context.Context, roomID, eventID string) *gomatrixserverlib.RespState {
|
|
var res api.QueryStateAfterEventsResponse
|
|
err := t.queryer.QueryStateAfterEvents(ctx, &api.QueryStateAfterEventsRequest{
|
|
RoomID: roomID,
|
|
PrevEventIDs: []string{eventID},
|
|
}, &res)
|
|
if err != nil || !res.PrevEventsExist {
|
|
util.GetLogger(ctx).WithField("room_id", roomID).WithError(err).Warnf("failed to query state after %s locally, prev exists=%v", eventID, res.PrevEventsExist)
|
|
return nil
|
|
}
|
|
stateEvents := make([]*gomatrixserverlib.HeaderedEvent, len(res.StateEvents))
|
|
for i, ev := range res.StateEvents {
|
|
// set the event from the haveEvents cache - this means we will share pointers with other prev_event branches for this
|
|
// processEvent request, which is better for memory.
|
|
stateEvents[i] = t.cacheAndReturn(ev)
|
|
t.hadEvent(ev.EventID())
|
|
}
|
|
// we should never access res.StateEvents again so we delete it here to make GC faster
|
|
res.StateEvents = nil
|
|
|
|
var authEvents []*gomatrixserverlib.Event
|
|
missingAuthEvents := map[string]bool{}
|
|
for _, ev := range stateEvents {
|
|
t.haveEventsMutex.Lock()
|
|
for _, ae := range ev.AuthEventIDs() {
|
|
if aev, ok := t.haveEvents[ae]; ok {
|
|
authEvents = append(authEvents, aev.Unwrap())
|
|
} else {
|
|
missingAuthEvents[ae] = true
|
|
}
|
|
}
|
|
t.haveEventsMutex.Unlock()
|
|
}
|
|
// QueryStateAfterEvents does not return the auth events, so fetch them now. We know the roomserver has them else it wouldn't
|
|
// have stored the event.
|
|
if len(missingAuthEvents) > 0 {
|
|
var missingEventList []string
|
|
for evID := range missingAuthEvents {
|
|
missingEventList = append(missingEventList, evID)
|
|
}
|
|
queryReq := api.QueryEventsByIDRequest{
|
|
EventIDs: missingEventList,
|
|
}
|
|
util.GetLogger(ctx).WithField("count", len(missingEventList)).Infof("Fetching missing auth events")
|
|
var queryRes api.QueryEventsByIDResponse
|
|
if err = t.queryer.QueryEventsByID(ctx, &queryReq, &queryRes); err != nil {
|
|
return nil
|
|
}
|
|
for i, ev := range queryRes.Events {
|
|
authEvents = append(authEvents, t.cacheAndReturn(queryRes.Events[i]).Unwrap())
|
|
t.hadEvent(ev.EventID())
|
|
}
|
|
queryRes.Events = nil
|
|
}
|
|
|
|
return &gomatrixserverlib.RespState{
|
|
StateEvents: gomatrixserverlib.UnwrapEventHeaders(stateEvents),
|
|
AuthEvents: authEvents,
|
|
}
|
|
}
|
|
|
|
// lookuptStateBeforeEvent returns the room state before the event e, which is just /state_ids and/or /state depending on what
|
|
// the server supports.
|
|
func (t *missingStateReq) lookupStateBeforeEvent(ctx context.Context, roomVersion gomatrixserverlib.RoomVersion, roomID, eventID string) (
|
|
*gomatrixserverlib.RespState, error) {
|
|
|
|
// Attempt to fetch the missing state using /state_ids and /events
|
|
return t.lookupMissingStateViaStateIDs(ctx, roomID, eventID, roomVersion)
|
|
}
|
|
|
|
func (t *missingStateReq) resolveStatesAndCheck(ctx context.Context, roomVersion gomatrixserverlib.RoomVersion, states []*gomatrixserverlib.RespState, backwardsExtremity *gomatrixserverlib.Event) (*gomatrixserverlib.RespState, error) {
|
|
var authEventList []*gomatrixserverlib.Event
|
|
var stateEventList []*gomatrixserverlib.Event
|
|
for _, state := range states {
|
|
authEventList = append(authEventList, state.AuthEvents...)
|
|
stateEventList = append(stateEventList, state.StateEvents...)
|
|
}
|
|
resolvedStateEvents, err := gomatrixserverlib.ResolveConflicts(roomVersion, stateEventList, authEventList)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
// apply the current event
|
|
retryAllowedState:
|
|
if err = checkAllowedByState(backwardsExtremity, resolvedStateEvents); err != nil {
|
|
switch missing := err.(type) {
|
|
case gomatrixserverlib.MissingAuthEventError:
|
|
h, err2 := t.lookupEvent(ctx, roomVersion, backwardsExtremity.RoomID(), missing.AuthEventID, true)
|
|
switch err2.(type) {
|
|
case verifySigError:
|
|
return &gomatrixserverlib.RespState{
|
|
AuthEvents: authEventList,
|
|
StateEvents: resolvedStateEvents,
|
|
}, nil
|
|
case nil:
|
|
// do nothing
|
|
default:
|
|
return nil, fmt.Errorf("missing auth event %s and failed to look it up: %w", missing.AuthEventID, err2)
|
|
}
|
|
util.GetLogger(ctx).Infof("fetched event %s", missing.AuthEventID)
|
|
resolvedStateEvents = append(resolvedStateEvents, h.Unwrap())
|
|
goto retryAllowedState
|
|
default:
|
|
}
|
|
return nil, err
|
|
}
|
|
return &gomatrixserverlib.RespState{
|
|
AuthEvents: authEventList,
|
|
StateEvents: resolvedStateEvents,
|
|
}, nil
|
|
}
|
|
|
|
func (t *missingStateReq) getMissingEvents(ctx context.Context, e *gomatrixserverlib.Event, roomVersion gomatrixserverlib.RoomVersion) (newEvents []*gomatrixserverlib.Event, err error) {
|
|
logger := util.GetLogger(ctx).WithField("event_id", e.EventID()).WithField("room_id", e.RoomID())
|
|
needed := gomatrixserverlib.StateNeededForAuth([]*gomatrixserverlib.Event{e})
|
|
// query latest events (our trusted forward extremities)
|
|
req := api.QueryLatestEventsAndStateRequest{
|
|
RoomID: e.RoomID(),
|
|
StateToFetch: needed.Tuples(),
|
|
}
|
|
var res api.QueryLatestEventsAndStateResponse
|
|
if err = t.queryer.QueryLatestEventsAndState(ctx, &req, &res); err != nil {
|
|
logger.WithError(err).Warn("Failed to query latest events")
|
|
return nil, err
|
|
}
|
|
latestEvents := make([]string, len(res.LatestEvents))
|
|
for i, ev := range res.LatestEvents {
|
|
latestEvents[i] = res.LatestEvents[i].EventID
|
|
t.hadEvent(ev.EventID)
|
|
}
|
|
|
|
var missingResp *gomatrixserverlib.RespMissingEvents
|
|
for _, server := range t.servers {
|
|
var m gomatrixserverlib.RespMissingEvents
|
|
if m, err = t.federation.LookupMissingEvents(ctx, server, e.RoomID(), gomatrixserverlib.MissingEvents{
|
|
Limit: 20,
|
|
// The latest event IDs that the sender already has. These are skipped when retrieving the previous events of latest_events.
|
|
EarliestEvents: latestEvents,
|
|
// The event IDs to retrieve the previous events for.
|
|
LatestEvents: []string{e.EventID()},
|
|
}, roomVersion); err == nil {
|
|
missingResp = &m
|
|
break
|
|
} else {
|
|
logger.WithError(err).Errorf("%s pushed us an event but %q did not respond to /get_missing_events", t.origin, server)
|
|
if errors.Is(err, context.DeadlineExceeded) {
|
|
break
|
|
}
|
|
}
|
|
}
|
|
|
|
if missingResp == nil {
|
|
logger.WithError(err).Errorf(
|
|
"%s pushed us an event but %d server(s) couldn't give us details about prev_events via /get_missing_events - dropping this event until it can",
|
|
t.origin, len(t.servers),
|
|
)
|
|
return nil, missingPrevEventsError{
|
|
eventID: e.EventID(),
|
|
err: err,
|
|
}
|
|
}
|
|
|
|
// security: how we handle failures depends on whether or not this event will become the new forward extremity for the room.
|
|
// There's 2 scenarios to consider:
|
|
// - Case A: We got pushed an event and are now fetching missing prev_events. (isInboundTxn=true)
|
|
// - Case B: We are fetching missing prev_events already and now fetching some more (isInboundTxn=false)
|
|
// In Case B, we know for sure that the event we are currently processing will not become the new forward extremity for the room,
|
|
// as it was called in response to an inbound txn which had it as a prev_event.
|
|
// In Case A, the event is a forward extremity, and could eventually become the _only_ forward extremity in the room. This is bad
|
|
// because it means we would trust the state at that event to be the state for the entire room, and allows rooms to be hijacked.
|
|
// https://github.com/matrix-org/synapse/pull/3456
|
|
// https://github.com/matrix-org/synapse/blob/229eb81498b0fe1da81e9b5b333a0285acde9446/synapse/handlers/federation.py#L335
|
|
// For now, we do not allow Case B, so reject the event.
|
|
logger.Infof("get_missing_events returned %d events", len(missingResp.Events))
|
|
|
|
// Make sure events from the missingResp are using the cache - missing events
|
|
// will be added and duplicates will be removed.
|
|
for i, ev := range missingResp.Events {
|
|
missingResp.Events[i] = t.cacheAndReturn(ev.Headered(roomVersion)).Unwrap()
|
|
}
|
|
|
|
// topologically sort and sanity check that we are making forward progress
|
|
newEvents = gomatrixserverlib.ReverseTopologicalOrdering(missingResp.Events, gomatrixserverlib.TopologicalOrderByPrevEvents)
|
|
shouldHaveSomeEventIDs := e.PrevEventIDs()
|
|
hasPrevEvent := false
|
|
Event:
|
|
for _, pe := range shouldHaveSomeEventIDs {
|
|
for _, ev := range newEvents {
|
|
if ev.EventID() == pe {
|
|
hasPrevEvent = true
|
|
break Event
|
|
}
|
|
}
|
|
}
|
|
if !hasPrevEvent {
|
|
err = fmt.Errorf("called /get_missing_events but server %s didn't return any prev_events with IDs %v", t.origin, shouldHaveSomeEventIDs)
|
|
logger.WithError(err).Errorf(
|
|
"%s pushed us an event but couldn't give us details about prev_events via /get_missing_events - dropping this event until it can",
|
|
t.origin,
|
|
)
|
|
return nil, missingPrevEventsError{
|
|
eventID: e.EventID(),
|
|
err: err,
|
|
}
|
|
}
|
|
|
|
return newEvents, nil
|
|
}
|
|
|
|
func (t *missingStateReq) lookupMissingStateViaState(ctx context.Context, roomID, eventID string, roomVersion gomatrixserverlib.RoomVersion) (
|
|
respState *gomatrixserverlib.RespState, err error) {
|
|
state, err := t.federation.LookupState(ctx, t.origin, roomID, eventID, roomVersion)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
// Check that the returned state is valid.
|
|
if err := state.Check(ctx, t.keys, nil); err != nil {
|
|
return nil, err
|
|
}
|
|
// Cache the results of this state lookup and deduplicate anything we already
|
|
// have in the cache, freeing up memory.
|
|
for i, ev := range state.AuthEvents {
|
|
state.AuthEvents[i] = t.cacheAndReturn(ev.Headered(roomVersion)).Unwrap()
|
|
}
|
|
for i, ev := range state.StateEvents {
|
|
state.StateEvents[i] = t.cacheAndReturn(ev.Headered(roomVersion)).Unwrap()
|
|
}
|
|
return &state, nil
|
|
}
|
|
|
|
func (t *missingStateReq) lookupMissingStateViaStateIDs(ctx context.Context, roomID, eventID string, roomVersion gomatrixserverlib.RoomVersion) (
|
|
*gomatrixserverlib.RespState, error) {
|
|
util.GetLogger(ctx).WithField("room_id", roomID).Infof("lookupMissingStateViaStateIDs %s", eventID)
|
|
// fetch the state event IDs at the time of the event
|
|
stateIDs, err := t.federation.LookupStateIDs(ctx, t.origin, roomID, eventID)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
// work out which auth/state IDs are missing
|
|
wantIDs := append(stateIDs.StateEventIDs, stateIDs.AuthEventIDs...)
|
|
missing := make(map[string]bool)
|
|
var missingEventList []string
|
|
t.haveEventsMutex.Lock()
|
|
for _, sid := range wantIDs {
|
|
if _, ok := t.haveEvents[sid]; !ok {
|
|
if !missing[sid] {
|
|
missing[sid] = true
|
|
missingEventList = append(missingEventList, sid)
|
|
}
|
|
}
|
|
}
|
|
t.haveEventsMutex.Unlock()
|
|
|
|
// fetch as many as we can from the roomserver
|
|
queryReq := api.QueryEventsByIDRequest{
|
|
EventIDs: missingEventList,
|
|
}
|
|
var queryRes api.QueryEventsByIDResponse
|
|
if err = t.queryer.QueryEventsByID(ctx, &queryReq, &queryRes); err != nil {
|
|
return nil, err
|
|
}
|
|
for i, ev := range queryRes.Events {
|
|
queryRes.Events[i] = t.cacheAndReturn(queryRes.Events[i])
|
|
t.hadEvent(ev.EventID())
|
|
evID := queryRes.Events[i].EventID()
|
|
if missing[evID] {
|
|
delete(missing, evID)
|
|
}
|
|
}
|
|
queryRes.Events = nil // allow it to be GCed
|
|
|
|
concurrentRequests := 8
|
|
missingCount := len(missing)
|
|
util.GetLogger(ctx).WithField("room_id", roomID).WithField("event_id", eventID).Infof("lookupMissingStateViaStateIDs missing %d/%d events", missingCount, len(wantIDs))
|
|
|
|
// If over 50% of the auth/state events from /state_ids are missing
|
|
// then we'll just call /state instead, otherwise we'll just end up
|
|
// hammering the remote side with /event requests unnecessarily.
|
|
if missingCount > concurrentRequests && missingCount > len(wantIDs)/2 {
|
|
util.GetLogger(ctx).WithFields(logrus.Fields{
|
|
"missing": missingCount,
|
|
"event_id": eventID,
|
|
"room_id": roomID,
|
|
"total_state": len(stateIDs.StateEventIDs),
|
|
"total_auth_events": len(stateIDs.AuthEventIDs),
|
|
}).Info("Fetching all state at event")
|
|
return t.lookupMissingStateViaState(ctx, roomID, eventID, roomVersion)
|
|
}
|
|
|
|
if missingCount > 0 {
|
|
util.GetLogger(ctx).WithFields(logrus.Fields{
|
|
"missing": missingCount,
|
|
"event_id": eventID,
|
|
"room_id": roomID,
|
|
"total_state": len(stateIDs.StateEventIDs),
|
|
"total_auth_events": len(stateIDs.AuthEventIDs),
|
|
"concurrent_requests": concurrentRequests,
|
|
}).Info("Fetching missing state at event")
|
|
|
|
// Create a queue containing all of the missing event IDs that we want
|
|
// to retrieve.
|
|
pending := make(chan string, missingCount)
|
|
for missingEventID := range missing {
|
|
pending <- missingEventID
|
|
}
|
|
close(pending)
|
|
|
|
// Define how many workers we should start to do this.
|
|
if missingCount < concurrentRequests {
|
|
concurrentRequests = missingCount
|
|
}
|
|
|
|
// Create the wait group.
|
|
var fetchgroup sync.WaitGroup
|
|
fetchgroup.Add(concurrentRequests)
|
|
|
|
// This is the only place where we'll write to t.haveEvents from
|
|
// multiple goroutines, and everywhere else is blocked on this
|
|
// synchronous function anyway.
|
|
var haveEventsMutex sync.Mutex
|
|
|
|
// Define what we'll do in order to fetch the missing event ID.
|
|
fetch := func(missingEventID string) {
|
|
var h *gomatrixserverlib.HeaderedEvent
|
|
h, err = t.lookupEvent(ctx, roomVersion, roomID, missingEventID, false)
|
|
switch err.(type) {
|
|
case verifySigError:
|
|
return
|
|
case nil:
|
|
break
|
|
default:
|
|
util.GetLogger(ctx).WithFields(logrus.Fields{
|
|
"event_id": missingEventID,
|
|
"room_id": roomID,
|
|
}).Info("Failed to fetch missing event")
|
|
return
|
|
}
|
|
haveEventsMutex.Lock()
|
|
t.cacheAndReturn(h)
|
|
haveEventsMutex.Unlock()
|
|
}
|
|
|
|
// Create the worker.
|
|
worker := func(ch <-chan string) {
|
|
defer fetchgroup.Done()
|
|
for missingEventID := range ch {
|
|
fetch(missingEventID)
|
|
}
|
|
}
|
|
|
|
// Start the workers.
|
|
for i := 0; i < concurrentRequests; i++ {
|
|
go worker(pending)
|
|
}
|
|
|
|
// Wait for the workers to finish.
|
|
fetchgroup.Wait()
|
|
}
|
|
|
|
resp, err := t.createRespStateFromStateIDs(stateIDs)
|
|
return resp, err
|
|
}
|
|
|
|
func (t *missingStateReq) createRespStateFromStateIDs(stateIDs gomatrixserverlib.RespStateIDs) (
|
|
*gomatrixserverlib.RespState, error) { // nolint:unparam
|
|
t.haveEventsMutex.Lock()
|
|
defer t.haveEventsMutex.Unlock()
|
|
|
|
// create a RespState response using the response to /state_ids as a guide
|
|
respState := gomatrixserverlib.RespState{}
|
|
|
|
for i := range stateIDs.StateEventIDs {
|
|
ev, ok := t.haveEvents[stateIDs.StateEventIDs[i]]
|
|
if !ok {
|
|
logrus.Warnf("Missing state event in createRespStateFromStateIDs: %s", stateIDs.StateEventIDs[i])
|
|
continue
|
|
}
|
|
respState.StateEvents = append(respState.StateEvents, ev.Unwrap())
|
|
}
|
|
for i := range stateIDs.AuthEventIDs {
|
|
ev, ok := t.haveEvents[stateIDs.AuthEventIDs[i]]
|
|
if !ok {
|
|
logrus.Warnf("Missing auth event in createRespStateFromStateIDs: %s", stateIDs.AuthEventIDs[i])
|
|
continue
|
|
}
|
|
respState.AuthEvents = append(respState.AuthEvents, ev.Unwrap())
|
|
}
|
|
// We purposefully do not do auth checks on the returned events, as they will still
|
|
// be processed in the exact same way, just as a 'rejected' event
|
|
// TODO: Add a field to HeaderedEvent to indicate if the event is rejected.
|
|
return &respState, nil
|
|
}
|
|
|
|
func (t *missingStateReq) lookupEvent(ctx context.Context, roomVersion gomatrixserverlib.RoomVersion, _, missingEventID string, localFirst bool) (*gomatrixserverlib.HeaderedEvent, error) {
|
|
if localFirst {
|
|
// fetch from the roomserver
|
|
queryReq := api.QueryEventsByIDRequest{
|
|
EventIDs: []string{missingEventID},
|
|
}
|
|
var queryRes api.QueryEventsByIDResponse
|
|
if err := t.queryer.QueryEventsByID(ctx, &queryReq, &queryRes); err != nil {
|
|
util.GetLogger(ctx).Warnf("Failed to query roomserver for missing event %s: %s - falling back to remote", missingEventID, err)
|
|
} else if len(queryRes.Events) == 1 {
|
|
return queryRes.Events[0], nil
|
|
}
|
|
}
|
|
var event *gomatrixserverlib.Event
|
|
found := false
|
|
for _, serverName := range t.servers {
|
|
txn, err := t.federation.GetEvent(ctx, serverName, missingEventID)
|
|
if err != nil || len(txn.PDUs) == 0 {
|
|
util.GetLogger(ctx).WithError(err).WithField("event_id", missingEventID).Warn("Failed to get missing /event for event ID")
|
|
if errors.Is(err, context.DeadlineExceeded) {
|
|
break
|
|
}
|
|
continue
|
|
}
|
|
event, err = gomatrixserverlib.NewEventFromUntrustedJSON(txn.PDUs[0], roomVersion)
|
|
if err != nil {
|
|
util.GetLogger(ctx).WithError(err).WithField("event_id", missingEventID).Warnf("Transaction: Failed to parse event JSON of event")
|
|
continue
|
|
}
|
|
found = true
|
|
break
|
|
}
|
|
if !found {
|
|
util.GetLogger(ctx).WithField("event_id", missingEventID).Warnf("Failed to get missing /event for event ID from %d server(s)", len(t.servers))
|
|
return nil, fmt.Errorf("wasn't able to find event via %d server(s)", len(t.servers))
|
|
}
|
|
if err := event.VerifyEventSignatures(ctx, t.keys); err != nil {
|
|
util.GetLogger(ctx).WithError(err).Warnf("Transaction: Couldn't validate signature of event %q", event.EventID())
|
|
return nil, verifySigError{event.EventID(), err}
|
|
}
|
|
return t.cacheAndReturn(event.Headered(roomVersion)), nil
|
|
}
|
|
|
|
func checkAllowedByState(e *gomatrixserverlib.Event, stateEvents []*gomatrixserverlib.Event) error {
|
|
authUsingState := gomatrixserverlib.NewAuthEvents(nil)
|
|
for i := range stateEvents {
|
|
err := authUsingState.AddEvent(stateEvents[i])
|
|
if err != nil {
|
|
return err
|
|
}
|
|
}
|
|
return gomatrixserverlib.Allowed(e, &authUsingState)
|
|
}
|
|
|
|
func (t *missingStateReq) hadEvent(eventID string) {
|
|
t.hadEventsMutex.Lock()
|
|
defer t.hadEventsMutex.Unlock()
|
|
t.hadEvents[eventID] = true
|
|
}
|
|
|
|
type verifySigError struct {
|
|
eventID string
|
|
err error
|
|
}
|
|
type missingPrevEventsError struct {
|
|
eventID string
|
|
err error
|
|
}
|
|
|
|
func (e verifySigError) Error() string {
|
|
return fmt.Sprintf("unable to verify signature of event %q: %s", e.eventID, e.err)
|
|
}
|
|
func (e missingPrevEventsError) Error() string {
|
|
return fmt.Sprintf("unable to get prev_events for event %q: %s", e.eventID, e.err)
|
|
}
|