dendrite/roomserver/internal/input/input_events.go
Neil Alexander a763cbb0e1
Roomserver/federation input refactor (#2104)
* Put federation client functions into their own file

* Look for missing auth events in RS input

* Remove retrieveMissingAuthEvents from federation API

* Logging

* Sorta transplanted the code over

* Use event origin failing all else

* Don't get stuck on mutexes:

* Add verifier

* Don't mark state events with zero snapshot NID as not existing

* Check missing state if not an outlier before storing the event

* Reject instead of soft-fail, don't copy roominfo so much

* Use synchronous contexts, limit time to fetch missing events

* Clean up some commented out bits

* Simplify `/send` endpoint significantly

* Submit async

* Report errors on sending to RS input

* Set max payload in NATS to 16MB

* Tweak metrics

* Add `workerForRoom` for tidiness

* Try skipping unmarshalling errors for RespMissingEvents

* Track missing prev events separately to avoid calculating state when not possible

* Tweak logic around checking missing state

* Care about state when checking missing prev events

* Don't check missing state for create events

* Try that again

* Handle create events better

* Send create room events as new

* Use given event kind when sending auth/state events

* Revert "Use given event kind when sending auth/state events"

This reverts commit 089d64d271.

* Only search for missing prev events or state for new events

* Tweaks

* We only have missing prev if we don't supply state

* Room version tweaks

* Allow async inputs again

* Apply backpressure to consumers/synchronous requests to hopefully stop things being overwhelmed

* Set timeouts on roomserver input tasks (need to decide what timeout makes sense)

* Use work queue policy, deliver all on restart

* Reduce chance of duplicates being sent by NATS

* Limit the number of servers we attempt to reduce backpressure

* Some review comment fixes

* Tidy up a couple things

* Don't limit servers, randomise order using map

* Some context refactoring

* Update gmsl

* Don't resend create events

* Set stateIDs length correctly or else the roomserver thinks there are missing events when there aren't

* Exclude our own servername

* Try backing off servers

* Make excluding self behaviour optional

* Exclude self from g_m_e

* Update sytest-whitelist

* Update consumers for the roomserver output stream

* Remember to send outliers for state returned from /gme

* Make full HTTP tests less upsetti

* Remove 'If a device list update goes missing, the server resyncs on the next one' from the sytest blacklist

* Remove debugging test

* Fix blacklist again, remove unnecessary duplicate context

* Clearer contexts, don't use background in case there's something happening there

* Don't queue up events more than once in memory

* Correctly identify create events when checking for state

* Fill in gaps again in /gme code

* Remove `AuthEventIDs` from `InputRoomEvent`

* Remove stray field

Co-authored-by: Kegan Dougal <kegan@matrix.org>
2022-01-27 14:29:14 +00:00

494 lines
18 KiB
Go

// Copyright 2017 Vector Creations Ltd
// Copyright 2018 New Vector Ltd
// Copyright 2019-2020 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.
package input
import (
"bytes"
"context"
"fmt"
"time"
fedapi "github.com/matrix-org/dendrite/federationapi/api"
"github.com/matrix-org/dendrite/internal"
"github.com/matrix-org/dendrite/internal/eventutil"
"github.com/matrix-org/dendrite/roomserver/api"
"github.com/matrix-org/dendrite/roomserver/internal/helpers"
"github.com/matrix-org/dendrite/roomserver/state"
"github.com/matrix-org/dendrite/roomserver/types"
"github.com/matrix-org/gomatrixserverlib"
"github.com/matrix-org/util"
"github.com/prometheus/client_golang/prometheus"
"github.com/sirupsen/logrus"
)
func init() {
prometheus.MustRegister(processRoomEventDuration)
}
// TODO: Does this value make sense?
const MaximumProcessingTime = time.Minute * 2
var processRoomEventDuration = prometheus.NewHistogramVec(
prometheus.HistogramOpts{
Namespace: "dendrite",
Subsystem: "roomserver",
Name: "processroomevent_duration_millis",
Help: "How long it takes the roomserver to process an event",
Buckets: []float64{ // milliseconds
5, 10, 25, 50, 75, 100, 250, 500,
1000, 2000, 3000, 4000, 5000, 6000,
7000, 8000, 9000, 10000, 15000, 20000,
},
},
[]string{"room_id"},
)
// processRoomEvent can only be called once at a time
//
// TODO(#375): This should be rewritten to allow concurrent calls. The
// difficulty is in ensuring that we correctly annotate events with the correct
// state deltas when sending to kafka streams
// TODO: Break up function - we should probably do transaction ID checks before calling this.
// nolint:gocyclo
func (r *Inputer) processRoomEvent(
inctx context.Context,
input *api.InputRoomEvent,
) (err error) {
select {
case <-inctx.Done():
// Before we do anything, make sure the context hasn't expired for this pending task.
// If it has then we'll give up straight away — it's probably a synchronous input
// request and the caller has already given up, but the inbox task was still queued.
return context.DeadlineExceeded
default:
}
// Wrap the context with a time limit. We'll allow no more than MaximumProcessingTime for
// everything that we need to do for this event, or it's possible that we could end up wedging
// the roomserver for a very long time.
var cancel context.CancelFunc
ctx, cancel := context.WithTimeout(inctx, MaximumProcessingTime)
defer cancel()
// Measure how long it takes to process this event.
started := time.Now()
defer func() {
timetaken := time.Since(started)
processRoomEventDuration.With(prometheus.Labels{
"room_id": input.Event.RoomID(),
}).Observe(float64(timetaken.Milliseconds()))
}()
// Parse and validate the event JSON
headered := input.Event
event := headered.Unwrap()
logger := util.GetLogger(ctx).WithFields(logrus.Fields{
"event_id": event.EventID(),
"room_id": event.RoomID(),
"type": event.Type(),
})
// if we have already got this event then do not process it again, if the input kind is an outlier.
// Outliers contain no extra information which may warrant a re-processing.
if input.Kind == api.KindOutlier {
evs, err2 := r.DB.EventsFromIDs(ctx, []string{event.EventID()})
if err2 == nil && len(evs) == 1 {
// check hash matches if we're on early room versions where the event ID was a random string
idFormat, err2 := headered.RoomVersion.EventIDFormat()
if err2 == nil {
switch idFormat {
case gomatrixserverlib.EventIDFormatV1:
if bytes.Equal(event.EventReference().EventSHA256, evs[0].EventReference().EventSHA256) {
logger.Debugf("Already processed event; ignoring")
return nil
}
default:
logger.Debugf("Already processed event; ignoring")
return nil
}
}
}
}
missingRes := &api.QueryMissingAuthPrevEventsResponse{}
serverRes := &fedapi.QueryJoinedHostServerNamesInRoomResponse{}
if event.Type() != gomatrixserverlib.MRoomCreate || !event.StateKeyEquals("") {
missingReq := &api.QueryMissingAuthPrevEventsRequest{
RoomID: event.RoomID(),
AuthEventIDs: event.AuthEventIDs(),
PrevEventIDs: event.PrevEventIDs(),
}
if err = r.Queryer.QueryMissingAuthPrevEvents(ctx, missingReq, missingRes); err != nil {
return fmt.Errorf("r.Queryer.QueryMissingAuthPrevEvents: %w", err)
}
}
if len(missingRes.MissingAuthEventIDs) > 0 || len(missingRes.MissingPrevEventIDs) > 0 {
serverReq := &fedapi.QueryJoinedHostServerNamesInRoomRequest{
RoomID: event.RoomID(),
ExcludeSelf: true,
}
if err = r.FSAPI.QueryJoinedHostServerNamesInRoom(ctx, serverReq, serverRes); err != nil {
return fmt.Errorf("r.FSAPI.QueryJoinedHostServerNamesInRoom: %w", err)
}
}
if input.Origin != "" {
serverRes.ServerNames = append(serverRes.ServerNames, input.Origin)
}
// First of all, check that the auth events of the event are known.
// If they aren't then we will ask the federation API for them.
isRejected := false
authEvents := gomatrixserverlib.NewAuthEvents(nil)
knownEvents := map[string]*types.Event{}
if err = r.fetchAuthEvents(ctx, logger, headered, &authEvents, knownEvents, serverRes.ServerNames); err != nil {
return fmt.Errorf("r.checkForMissingAuthEvents: %w", err)
}
// Check if the event is allowed by its auth events. If it isn't then
// we consider the event to be "rejected" — it will still be persisted.
var rejectionErr error
if rejectionErr = gomatrixserverlib.Allowed(event, &authEvents); rejectionErr != nil {
isRejected = true
logger.WithError(rejectionErr).Warnf("Event %s rejected", event.EventID())
}
// Accumulate the auth event NIDs.
authEventIDs := event.AuthEventIDs()
authEventNIDs := make([]types.EventNID, 0, len(authEventIDs))
for _, authEventID := range authEventIDs {
if _, ok := knownEvents[authEventID]; !ok {
return fmt.Errorf("missing auth event %s", authEventID)
}
authEventNIDs = append(authEventNIDs, knownEvents[authEventID].EventNID)
}
var softfail bool
if input.Kind == api.KindNew {
// Check that the event passes authentication checks based on the
// current room state.
softfail, err = helpers.CheckForSoftFail(ctx, r.DB, headered, input.StateEventIDs)
if err != nil {
logger.WithError(err).Info("Error authing soft-failed event")
}
}
// At this point we are checking whether we know all of the prev events, and
// if we know the state before the prev events. This is necessary before we
// try to do `calculateAndSetState` on the event later, otherwise it will fail
// with missing event NIDs. If there's anything missing then we'll go and fetch
// the prev events and state from the federation. Note that we only do this if
// we weren't already told what the state before the event should be — if the
// HasState option was set and a state set was provided (as is the case in a
// typical federated room join) then we won't bother trying to fetch prev events
// because we may not be allowed to see them and we have no choice but to trust
// the state event IDs provided to us in the join instead.
missingPrev := !input.HasState && len(missingRes.MissingPrevEventIDs) > 0
if missingPrev && input.Kind == api.KindNew {
// Don't do this for KindOld events, otherwise old events that we fetch
// to satisfy missing prev events/state will end up recursively calling
// processRoomEvent.
if len(serverRes.ServerNames) > 0 {
missingState := missingStateReq{
origin: input.Origin,
inputer: r,
queryer: r.Queryer,
db: r.DB,
federation: r.FSAPI,
keys: r.KeyRing,
roomsMu: internal.NewMutexByRoom(),
servers: map[gomatrixserverlib.ServerName]struct{}{},
hadEvents: map[string]bool{},
haveEvents: map[string]*gomatrixserverlib.HeaderedEvent{},
}
for _, serverName := range serverRes.ServerNames {
missingState.servers[serverName] = struct{}{}
}
if err = missingState.processEventWithMissingState(ctx, event, headered.RoomVersion); err != nil {
isRejected = true
rejectionErr = fmt.Errorf("missingState.processEventWithMissingState: %w", err)
} else {
missingPrev = false
}
} else {
isRejected = true
rejectionErr = fmt.Errorf("missing prev events and no other servers to ask")
}
}
// Store the event.
_, _, stateAtEvent, redactionEvent, redactedEventID, err := r.DB.StoreEvent(ctx, event, authEventNIDs, isRejected)
if err != nil {
return fmt.Errorf("r.DB.StoreEvent: %w", err)
}
// if storing this event results in it being redacted then do so.
if !isRejected && redactedEventID == event.EventID() {
r, rerr := eventutil.RedactEvent(redactionEvent, event)
if rerr != nil {
return fmt.Errorf("eventutil.RedactEvent: %w", rerr)
}
event = r
}
// For outliers we can stop after we've stored the event itself as it
// doesn't have any associated state to store and we don't need to
// notify anyone about it.
if input.Kind == api.KindOutlier {
logger.Debug("Stored outlier")
return nil
}
roomInfo, err := r.DB.RoomInfo(ctx, event.RoomID())
if err != nil {
return fmt.Errorf("r.DB.RoomInfo: %w", err)
}
if roomInfo == nil {
return fmt.Errorf("r.DB.RoomInfo missing for room %s", event.RoomID())
}
if !missingPrev && stateAtEvent.BeforeStateSnapshotNID == 0 {
// We haven't calculated a state for this event yet.
// Lets calculate one.
err = r.calculateAndSetState(ctx, input, roomInfo, &stateAtEvent, event, isRejected)
if err != nil {
return fmt.Errorf("r.calculateAndSetState: %w", err)
}
}
// We stop here if the event is rejected: We've stored it but won't update forward extremities or notify anyone about it.
if isRejected || softfail {
logger.WithError(rejectionErr).WithField("soft_fail", softfail).Debug("Stored rejected event")
return rejectionErr
}
switch input.Kind {
case api.KindNew:
if err = r.updateLatestEvents(
ctx, // context
roomInfo, // room info for the room being updated
stateAtEvent, // state at event (below)
event, // event
input.SendAsServer, // send as server
input.TransactionID, // transaction ID
input.HasState, // rewrites state?
); err != nil {
return fmt.Errorf("r.updateLatestEvents: %w", err)
}
case api.KindOld:
err = r.WriteOutputEvents(event.RoomID(), []api.OutputEvent{
{
Type: api.OutputTypeOldRoomEvent,
OldRoomEvent: &api.OutputOldRoomEvent{
Event: headered,
},
},
})
if err != nil {
return fmt.Errorf("r.WriteOutputEvents (old): %w", err)
}
}
// processing this event resulted in an event (which may not be the one we're processing)
// being redacted. We are guaranteed to have both sides (the redaction/redacted event),
// so notify downstream components to redact this event - they should have it if they've
// been tracking our output log.
if redactedEventID != "" {
err = r.WriteOutputEvents(event.RoomID(), []api.OutputEvent{
{
Type: api.OutputTypeRedactedEvent,
RedactedEvent: &api.OutputRedactedEvent{
RedactedEventID: redactedEventID,
RedactedBecause: redactionEvent.Headered(headered.RoomVersion),
},
},
})
if err != nil {
return fmt.Errorf("r.WriteOutputEvents (redactions): %w", err)
}
}
// Update the extremities of the event graph for the room
return nil
}
// fetchAuthEvents will check to see if any of the
// auth events specified by the given event are unknown. If they are
// then we will go off and request them from the federation and then
// store them in the database. By the time this function ends, either
// we've failed to retrieve the auth chain altogether (in which case
// an error is returned) or we've successfully retrieved them all and
// they are now in the database.
func (r *Inputer) fetchAuthEvents(
ctx context.Context,
logger *logrus.Entry,
event *gomatrixserverlib.HeaderedEvent,
auth *gomatrixserverlib.AuthEvents,
known map[string]*types.Event,
servers []gomatrixserverlib.ServerName,
) error {
unknown := map[string]struct{}{}
authEventIDs := event.AuthEventIDs()
if len(authEventIDs) == 0 {
return nil
}
for _, authEventID := range authEventIDs {
authEvents, err := r.DB.EventsFromIDs(ctx, []string{authEventID})
if err != nil || len(authEvents) == 0 || authEvents[0].Event == nil {
unknown[authEventID] = struct{}{}
continue
}
ev := authEvents[0]
known[authEventID] = &ev // don't take the pointer of the iterated event
if err = auth.AddEvent(ev.Event); err != nil {
return fmt.Errorf("auth.AddEvent: %w", err)
}
}
// If there are no missing auth events then there is nothing more
// to do — we've loaded everything that we need.
if len(unknown) == 0 {
return nil
}
var err error
var res gomatrixserverlib.RespEventAuth
var found bool
for _, serverName := range servers {
// Request the entire auth chain for the event in question. This should
// contain all of the auth events — including ones that we already know —
// so we'll need to filter through those in the next section.
res, err = r.FSAPI.GetEventAuth(ctx, serverName, event.RoomVersion, event.RoomID(), event.EventID())
if err != nil {
logger.WithError(err).Warnf("Failed to get event auth from federation for %q: %s", event.EventID(), err)
continue
}
found = true
break
}
if !found {
return fmt.Errorf("no servers provided event auth for event ID %q, tried servers %v", event.EventID(), servers)
}
for _, authEvent := range gomatrixserverlib.ReverseTopologicalOrdering(
res.AuthEvents,
gomatrixserverlib.TopologicalOrderByAuthEvents,
) {
// If we already know about this event from the database then we don't
// need to store it again or do anything further with it, so just skip
// over it rather than wasting cycles.
if ev, ok := known[authEvent.EventID()]; ok && ev != nil {
continue
}
// Check the signatures of the event.
// TODO: It really makes sense for the federation API to be doing this,
// because then it can attempt another server if one serves up an event
// with an invalid signature. For now this will do.
if err := authEvent.VerifyEventSignatures(ctx, r.FSAPI.KeyRing()); err != nil {
return fmt.Errorf("event.VerifyEventSignatures: %w", err)
}
// In order to store the new auth event, we need to know its auth chain
// as NIDs for the `auth_event_nids` column. Let's see if we can find those.
authEventNIDs := make([]types.EventNID, 0, len(authEvent.AuthEventIDs()))
for _, eventID := range authEvent.AuthEventIDs() {
knownEvent, ok := known[eventID]
if !ok {
return fmt.Errorf("missing auth event %s for %s", eventID, authEvent.EventID())
}
authEventNIDs = append(authEventNIDs, knownEvent.EventNID)
}
// Let's take a note of the fact that we now know about this event.
if err := auth.AddEvent(authEvent); err != nil {
return fmt.Errorf("auth.AddEvent: %w", err)
}
// Check if the auth event should be rejected.
isRejected := false
if err := gomatrixserverlib.Allowed(authEvent, auth); err != nil {
isRejected = true
logger.WithError(err).Warnf("Auth event %s rejected", authEvent.EventID())
}
// Finally, store the event in the database.
eventNID, _, _, _, _, err := r.DB.StoreEvent(ctx, authEvent, authEventNIDs, isRejected)
if err != nil {
return fmt.Errorf("r.DB.StoreEvent: %w", err)
}
// Now we know about this event, it was stored and the signatures were OK.
known[authEvent.EventID()] = &types.Event{
EventNID: eventNID,
Event: authEvent,
}
}
return nil
}
func (r *Inputer) calculateAndSetState(
ctx context.Context,
input *api.InputRoomEvent,
roomInfo *types.RoomInfo,
stateAtEvent *types.StateAtEvent,
event *gomatrixserverlib.Event,
isRejected bool,
) error {
var err error
roomState := state.NewStateResolution(r.DB, roomInfo)
if input.HasState && !isRejected {
// Check here if we think we're in the room already.
stateAtEvent.Overwrite = true
var joinEventNIDs []types.EventNID
// Request join memberships only for local users only.
if joinEventNIDs, err = r.DB.GetMembershipEventNIDsForRoom(ctx, roomInfo.RoomNID, true, true); err == nil {
// If we have no local users that are joined to the room then any state about
// the room that we have is quite possibly out of date. Therefore in that case
// we should overwrite it rather than merge it.
stateAtEvent.Overwrite = len(joinEventNIDs) == 0
}
// We've been told what the state at the event is so we don't need to calculate it.
// Check that those state events are in the database and store the state.
var entries []types.StateEntry
if entries, err = r.DB.StateEntriesForEventIDs(ctx, input.StateEventIDs); err != nil {
return fmt.Errorf("r.DB.StateEntriesForEventIDs: %w", err)
}
entries = types.DeduplicateStateEntries(entries)
if stateAtEvent.BeforeStateSnapshotNID, err = r.DB.AddState(ctx, roomInfo.RoomNID, nil, entries); err != nil {
return fmt.Errorf("r.DB.AddState: %w", err)
}
} else {
stateAtEvent.Overwrite = false
// We haven't been told what the state at the event is so we need to calculate it from the prev_events
if stateAtEvent.BeforeStateSnapshotNID, err = roomState.CalculateAndStoreStateBeforeEvent(ctx, event, isRejected); err != nil {
return fmt.Errorf("roomState.CalculateAndStoreStateBeforeEvent: %w", err)
}
}
err = r.DB.SetState(ctx, stateAtEvent.EventNID, stateAtEvent.BeforeStateSnapshotNID)
if err != nil {
return fmt.Errorf("r.DB.SetState: %w", err)
}
return nil
}