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Sorta transplanted the code over

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This commit is contained in:
Neil Alexander 2021-12-15 13:59:58 +00:00
parent 69111355d0
commit 2203dd9d8a
No known key found for this signature in database
GPG key ID: A02A2019A2BB0944
22 changed files with 1111 additions and 778 deletions
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1
clientapi/routing/createroom.go
View file

@ -462,6 +462,7 @@ func createRoom(
AuthEvents: accumulated,
},
ev.Headered(roomVersion),
cfg.Matrix.ServerName,
nil,
); err != nil {
util.GetLogger(req.Context()).WithError(err).Error("SendEventWithState failed")

1
clientapi/routing/membership.go
View file

@ -109,6 +109,7 @@ func sendMembership(ctx context.Context, accountDB accounts.Database, device *us
roomserverAPI.KindNew,
[]*gomatrixserverlib.HeaderedEvent{event.Event.Headered(roomVer)},
cfg.Matrix.ServerName,
cfg.Matrix.ServerName,
nil,
); err != nil {
util.GetLogger(ctx).WithError(err).Error("SendEvents failed")

4
clientapi/routing/profile.go
View file

@ -169,7 +169,7 @@ func SetAvatarURL(
return jsonerror.InternalServerError()
}
if err := api.SendEvents(req.Context(), rsAPI, api.KindNew, events, cfg.Matrix.ServerName, nil); err != nil {
if err := api.SendEvents(req.Context(), rsAPI, api.KindNew, events, cfg.Matrix.ServerName, cfg.Matrix.ServerName, nil); err != nil {
util.GetLogger(req.Context()).WithError(err).Error("SendEvents failed")
return jsonerror.InternalServerError()
}
@ -286,7 +286,7 @@ func SetDisplayName(
return jsonerror.InternalServerError()
}
if err := api.SendEvents(req.Context(), rsAPI, api.KindNew, events, cfg.Matrix.ServerName, nil); err != nil {
if err := api.SendEvents(req.Context(), rsAPI, api.KindNew, events, cfg.Matrix.ServerName, cfg.Matrix.ServerName, nil); err != nil {
util.GetLogger(req.Context()).WithError(err).Error("SendEvents failed")
return jsonerror.InternalServerError()
}

2
clientapi/routing/redaction.go
View file

@ -120,7 +120,7 @@ func SendRedaction(
JSON: jsonerror.NotFound("Room does not exist"),
}
}
if err = roomserverAPI.SendEvents(context.Background(), rsAPI, roomserverAPI.KindNew, []*gomatrixserverlib.HeaderedEvent{e}, cfg.Matrix.ServerName, nil); err != nil {
if err = roomserverAPI.SendEvents(context.Background(), rsAPI, roomserverAPI.KindNew, []*gomatrixserverlib.HeaderedEvent{e}, cfg.Matrix.ServerName, cfg.Matrix.ServerName, nil); err != nil {
util.GetLogger(req.Context()).WithError(err).Errorf("failed to SendEvents")
return jsonerror.InternalServerError()
}

1
clientapi/routing/sendevent.go
View file

@ -121,6 +121,7 @@ func SendEvent(
e.Headered(verRes.RoomVersion),
},
cfg.Matrix.ServerName,
cfg.Matrix.ServerName,
txnAndSessionID,
); err != nil {
util.GetLogger(req.Context()).WithError(err).Error("SendEvents failed")

1
clientapi/threepid/invites.go
View file

@ -366,6 +366,7 @@ func emit3PIDInviteEvent(
event.Headered(queryRes.RoomVersion),
},
cfg.Matrix.ServerName,
cfg.Matrix.ServerName,
nil,
)
}

1
federationapi/api/api.go
View file

@ -24,6 +24,7 @@ type FederationClient interface {
MSC2946Spaces(ctx context.Context, dst gomatrixserverlib.ServerName, roomID string, r gomatrixserverlib.MSC2946SpacesRequest) (res gomatrixserverlib.MSC2946SpacesResponse, err error)
LookupServerKeys(ctx context.Context, s gomatrixserverlib.ServerName, keyRequests map[gomatrixserverlib.PublicKeyLookupRequest]gomatrixserverlib.Timestamp) ([]gomatrixserverlib.ServerKeys, error)
GetEventAuth(ctx context.Context, s gomatrixserverlib.ServerName, roomID, eventID string) (res gomatrixserverlib.RespEventAuth, err error)
LookupMissingEvents(ctx context.Context, s gomatrixserverlib.ServerName, roomID string, missing gomatrixserverlib.MissingEvents, roomVersion gomatrixserverlib.RoomVersion) (res gomatrixserverlib.RespMissingEvents, err error)
}
// FederationClientError is returned from FederationClient methods in the event of a problem.

15
federationapi/internal/federationclient.go
View file

@ -106,6 +106,21 @@ func (a *FederationInternalAPI) LookupStateIDs(
return ires.(gomatrixserverlib.RespStateIDs), nil
}
func (a *FederationInternalAPI) LookupMissingEvents(
ctx context.Context, s gomatrixserverlib.ServerName, roomID string,
missing gomatrixserverlib.MissingEvents, roomVersion gomatrixserverlib.RoomVersion,
) (res gomatrixserverlib.RespMissingEvents, err error) {
ctx, cancel := context.WithTimeout(ctx, time.Second*30)
defer cancel()
ires, err := a.doRequest(s, func() (interface{}, error) {
return a.federation.LookupMissingEvents(ctx, s, roomID, missing, roomVersion)
})
if err != nil {
return gomatrixserverlib.RespMissingEvents{}, err
}
return ires.(gomatrixserverlib.RespMissingEvents), nil
}
func (a *FederationInternalAPI) GetEvent(
ctx context.Context, s gomatrixserverlib.ServerName, eventID string,
) (res gomatrixserverlib.Transaction, err error) {

2
federationapi/internal/perform.go
View file

@ -249,6 +249,7 @@ func (r *FederationInternalAPI) performJoinUsingServer(
roomserverAPI.KindNew,
respState,
event.Headered(respMakeJoin.RoomVersion),
serverName,
nil,
); err != nil {
logrus.WithFields(logrus.Fields{
@ -430,6 +431,7 @@ func (r *FederationInternalAPI) performOutboundPeekUsingServer(
roomserverAPI.KindNew,
&respState,
respPeek.LatestEvent.Headered(respPeek.RoomVersion),
serverName,
nil,
); err != nil {
return fmt.Errorf("r.producer.SendEventWithState: %w", err)

35
federationapi/inthttp/client.go
View file

@ -32,6 +32,7 @@ const (
FederationAPIBackfillPath = "/federationapi/client/backfill"
FederationAPILookupStatePath = "/federationapi/client/lookupState"
FederationAPILookupStateIDsPath = "/federationapi/client/lookupStateIDs"
FederationAPILookupMissingEventsPath = "/federationapi/client/lookupMissingEvents"
FederationAPIGetEventPath = "/federationapi/client/getEvent"
FederationAPILookupServerKeysPath = "/federationapi/client/lookupServerKeys"
FederationAPIEventRelationshipsPath = "/federationapi/client/msc2836eventRelationships"
@ -354,6 +355,40 @@ func (h *httpFederationInternalAPI) LookupStateIDs(
return *response.Res, nil
}
type lookupMissingEvents struct {
S gomatrixserverlib.ServerName
RoomID string
Missing gomatrixserverlib.MissingEvents
RoomVersion gomatrixserverlib.RoomVersion
Res *gomatrixserverlib.RespMissingEvents
Err *api.FederationClientError
}
func (h *httpFederationInternalAPI) LookupMissingEvents(
ctx context.Context, s gomatrixserverlib.ServerName, roomID string,
missing gomatrixserverlib.MissingEvents, roomVersion gomatrixserverlib.RoomVersion,
) (gomatrixserverlib.RespMissingEvents, error) {
span, ctx := opentracing.StartSpanFromContext(ctx, "LookupMissingEvents")
defer span.Finish()
request := lookupMissingEvents{
S: s,
RoomID: roomID,
Missing: missing,
RoomVersion: roomVersion,
}
var response lookupMissingEvents
apiURL := h.federationAPIURL + FederationAPILookupMissingEventsPath
err := httputil.PostJSON(ctx, span, h.httpClient, apiURL, &request, &response)
if err != nil {
return gomatrixserverlib.RespMissingEvents{}, err
}
if response.Err != nil {
return gomatrixserverlib.RespMissingEvents{}, response.Err
}
return *response.Res, nil
}
type getEvent struct {
S gomatrixserverlib.ServerName
EventID string

22
federationapi/inthttp/server.go
View file

@ -241,6 +241,28 @@ func AddRoutes(intAPI api.FederationInternalAPI, internalAPIMux *mux.Router) {
return util.JSONResponse{Code: http.StatusOK, JSON: request}
}),
)
internalAPIMux.Handle(
FederationAPILookupMissingEventsPath,
httputil.MakeInternalAPI("LookupMissingEvents", func(req *http.Request) util.JSONResponse {
var request lookupMissingEvents
if err := json.NewDecoder(req.Body).Decode(&request); err != nil {
return util.MessageResponse(http.StatusBadRequest, err.Error())
}
res, err := intAPI.LookupMissingEvents(req.Context(), request.S, request.RoomID, request.Missing, request.RoomVersion)
if err != nil {
ferr, ok := err.(*api.FederationClientError)
if ok {
request.Err = ferr
} else {
request.Err = &api.FederationClientError{
Err: err.Error(),
}
}
}
request.Res = &res
return util.JSONResponse{Code: http.StatusOK, JSON: request}
}),
)
internalAPIMux.Handle(
FederationAPIGetEventPath,
httputil.MakeInternalAPI("GetEvent", func(req *http.Request) util.JSONResponse {

726
federationapi/routing/send.go
View file

@ -17,7 +17,6 @@ package routing
import (
"context"
"encoding/json"
"errors"
"fmt"
"net/http"
"sync"
@ -201,8 +200,6 @@ func Send(
eduAPI: eduAPI,
keys: keys,
federation: federation,
hadEvents: make(map[string]bool),
haveEvents: make(map[string]*gomatrixserverlib.HeaderedEvent),
servers: servers,
keyAPI: keyAPI,
roomsMu: mu,
@ -263,22 +260,8 @@ type txnReq struct {
keys gomatrixserverlib.JSONVerifier
federation txnFederationClient
roomsMu *internal.MutexByRoom
// something that can tell us about which servers are in a room right now
servers federationAPI.ServersInRoomProvider
// a list of events from the auth and prev events which we already had
hadEvents map[string]bool
hadEventsMutex sync.Mutex
// local cache of events for auth checks, etc - this may include events
// which the roomserver is unaware of.
haveEvents map[string]*gomatrixserverlib.HeaderedEvent
haveEventsMutex sync.Mutex
work string // metrics
}
func (t *txnReq) hadEvent(eventID string, had bool) {
t.hadEventsMutex.Lock()
defer t.hadEventsMutex.Unlock()
t.hadEvents[eventID] = had
work string
}
// A subset of FederationClient functionality that txn requires. Useful for testing.
@ -440,22 +423,8 @@ func (t *inputWorker) run() {
type roomNotFoundError struct {
roomID string
}
type verifySigError struct {
eventID string
err error
}
type missingPrevEventsError struct {
eventID string
err error
}
func (e roomNotFoundError) Error() string { return fmt.Sprintf("room %q not found", e.roomID) }
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)
}
func (t *txnReq) processEDUs(ctx context.Context) {
for _, e := range t.EDUs {
@ -599,28 +568,7 @@ func (t *txnReq) processDeviceListUpdate(ctx context.Context, e gomatrixserverli
}
}
func (t *txnReq) getServers(ctx context.Context, roomID string, event *gomatrixserverlib.Event) []gomatrixserverlib.ServerName {
// The server that sent us the event should be sufficient to tell us about missing
// prev and auth events.
servers := []gomatrixserverlib.ServerName{t.Origin}
// If the event origin is different to the transaction origin then we can use
// this as a last resort. The origin server that created the event would have
// had to know the auth and prev events.
if event != nil {
if origin := event.Origin(); origin != t.Origin {
servers = append(servers, origin)
}
}
// If a specific room-to-server provider exists then use that. This will primarily
// be used for the P2P demos.
if t.servers != nil {
servers = append(servers, t.servers.GetServersForRoom(ctx, roomID, event)...)
}
return servers
}
func (t *txnReq) processEvent(ctx context.Context, e *gomatrixserverlib.Event) error {
logger := util.GetLogger(ctx).WithField("event_id", e.EventID()).WithField("room_id", e.RoomID())
t.work = "" // reset from previous event
// Ask the roomserver if we know about the room and/or if we're joined
@ -648,30 +596,14 @@ func (t *txnReq) processEvent(ctx context.Context, e *gomatrixserverlib.Event) e
// before the roomserver tries to work out
stateReq := api.QueryMissingAuthPrevEventsRequest{
RoomID: e.RoomID(),
AuthEventIDs: e.AuthEventIDs(),
PrevEventIDs: e.PrevEventIDs(),
AuthEventIDs: nil, //e.AuthEventIDs(),
PrevEventIDs: nil, //e.PrevEventIDs(),
}
var stateResp api.QueryMissingAuthPrevEventsResponse
if err := t.rsAPI.QueryMissingAuthPrevEvents(ctx, &stateReq, &stateResp); err != nil {
return fmt.Errorf("t.rsAPI.QueryMissingAuthPrevEvents: %w", err)
}
// Prepare a map of all the events we already had before this point, so
// that we don't send them to the roomserver again.
for _, eventID := range append(e.AuthEventIDs(), e.PrevEventIDs()...) {
t.hadEvent(eventID, true)
}
for _, eventID := range append(stateResp.MissingAuthEventIDs, stateResp.MissingPrevEventIDs...) {
t.hadEvent(eventID, false)
}
if len(stateResp.MissingPrevEventIDs) > 0 {
t.work = MetricsWorkMissingPrevEvents
logger.Infof("Event refers to %d unknown prev_events", len(stateResp.MissingPrevEventIDs))
return t.processEventWithMissingState(ctx, e, stateResp.RoomVersion)
}
t.work = MetricsWorkDirect
// pass the event to the roomserver which will do auth checks
// If the event fail auth checks, gmsl.NotAllowed error will be returned which we be silently
// discarded by the caller of this function
@ -682,656 +614,8 @@ func (t *txnReq) processEvent(ctx context.Context, e *gomatrixserverlib.Event) e
[]*gomatrixserverlib.HeaderedEvent{
e.Headered(stateResp.RoomVersion),
},
api.DoNotSendToOtherServers,
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 *txnReq) 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()
err = api.SendEventWithState(
context.Background(),
t.rsAPI,
api.KindOld,
resolvedState,
backwardsExtremity.Headered(roomVersion),
hadEvents,
)
if err != nil {
return fmt.Errorf("api.SendEventWithState: %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.
headeredNewEvents := make([]*gomatrixserverlib.HeaderedEvent, len(newEvents))
for i, newEvent := range newEvents {
headeredNewEvents[i] = newEvent.Headered(roomVersion)
}
if err = api.SendEvents(
context.Background(),
t.rsAPI,
api.KindOld,
append(headeredNewEvents, e.Headered(roomVersion)),
api.DoNotSendToOtherServers,
nil,
); err != nil {
return fmt.Errorf("api.SendEvents: %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 *txnReq) 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 *txnReq) 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 *txnReq) lookupStateAfterEventLocally(ctx context.Context, roomID, eventID string) *gomatrixserverlib.RespState {
var res api.QueryStateAfterEventsResponse
err := t.rsAPI.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(), true)
}
// 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.rsAPI.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(), true)
}
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 *txnReq) 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 *txnReq) 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 *txnReq) 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.rsAPI.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, true)
}
var missingResp *gomatrixserverlib.RespMissingEvents
servers := t.getServers(ctx, e.RoomID(), e)
for _, server := range 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(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,
api.DoNotSendToOtherServers,
nil,
)
return nil, missingPrevEventsError{
eventID: e.EventID(),
err: err,
}
}
return newEvents, nil
}
func (t *txnReq) 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 *txnReq) 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.rsAPI.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(), true)
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 *txnReq) 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 *txnReq) lookupEvent(ctx context.Context, roomVersion gomatrixserverlib.RoomVersion, roomID, 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.rsAPI.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
servers := t.getServers(ctx, roomID, nil)
for _, serverName := range 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(servers))
return nil, fmt.Errorf("wasn't able to find event via %d server(s)", len(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
}

2
federationapi/routing/send_test.go
View file

@ -244,8 +244,6 @@ func mustCreateTransaction(rsAPI api.RoomserverInternalAPI, fedClient txnFederat
eduAPI: &testEDUProducer{},
keys: &test.NopJSONVerifier{},
federation: fedClient,
haveEvents: make(map[string]*gomatrixserverlib.HeaderedEvent),
hadEvents: make(map[string]bool),
roomsMu: internal.NewMutexByRoom(),
}
t.PDUs = pdus

3
federationapi/routing/threepid.go
View file

@ -89,7 +89,7 @@ func CreateInvitesFrom3PIDInvites(
}
// Send all the events
if err := api.SendEvents(req.Context(), rsAPI, api.KindNew, evs, cfg.Matrix.ServerName, nil); err != nil {
if err := api.SendEvents(req.Context(), rsAPI, api.KindNew, evs, "TODO", cfg.Matrix.ServerName, nil); err != nil {
util.GetLogger(req.Context()).WithError(err).Error("SendEvents failed")
return jsonerror.InternalServerError()
}
@ -178,6 +178,7 @@ func ExchangeThirdPartyInvite(
[]*gomatrixserverlib.HeaderedEvent{
signedEvent.Event.Headered(verRes.RoomVersion),
},
request.Origin(),
cfg.Matrix.ServerName,
nil,
); err != nil {

2
roomserver/api/input.go
View file

@ -54,6 +54,8 @@ type InputRoomEvent struct {
Kind Kind `json:"kind"`
// The event JSON for the event to add.
Event *gomatrixserverlib.HeaderedEvent `json:"event"`
// Which server told us about this event.
Origin gomatrixserverlib.ServerName `json:"origin"`
// List of state event IDs that authenticate this event.
// These are likely derived from the "auth_events" JSON key of the event.
// But can be different because the "auth_events" key can be incomplete or wrong.

16
roomserver/api/wrapper.go
View file

@ -22,10 +22,15 @@ import (
"github.com/matrix-org/util"
)
type RoomEventInputter interface {
InputRoomEvents(context.Context, *InputRoomEventsRequest, *InputRoomEventsResponse)
}
// SendEvents to the roomserver The events are written with KindNew.
func SendEvents(
ctx context.Context, rsAPI RoomserverInternalAPI,
ctx context.Context, rsAPI RoomEventInputter,
kind Kind, events []*gomatrixserverlib.HeaderedEvent,
origin gomatrixserverlib.ServerName,
sendAsServer gomatrixserverlib.ServerName, txnID *TransactionID,
) error {
ires := make([]InputRoomEvent, len(events))
@ -33,6 +38,7 @@ func SendEvents(
ires[i] = InputRoomEvent{
Kind: kind,
Event: event,
Origin: origin,
AuthEventIDs: event.AuthEventIDs(),
SendAsServer: string(sendAsServer),
TransactionID: txnID,
@ -45,9 +51,9 @@ func SendEvents(
// with the state at the event as KindOutlier before it. Will not send any event that is
// marked as `true` in haveEventIDs.
func SendEventWithState(
ctx context.Context, rsAPI RoomserverInternalAPI, kind Kind,
ctx context.Context, rsAPI RoomEventInputter, kind Kind,
state *gomatrixserverlib.RespState, event *gomatrixserverlib.HeaderedEvent,
haveEventIDs map[string]bool,
origin gomatrixserverlib.ServerName, haveEventIDs map[string]bool,
) error {
outliers, err := state.Events()
if err != nil {
@ -62,6 +68,7 @@ func SendEventWithState(
ires = append(ires, InputRoomEvent{
Kind: KindOutlier,
Event: outlier.Headered(event.RoomVersion),
Origin: origin,
AuthEventIDs: outlier.AuthEventIDs(),
})
}
@ -74,6 +81,7 @@ func SendEventWithState(
ires = append(ires, InputRoomEvent{
Kind: kind,
Event: event,
Origin: origin,
AuthEventIDs: event.AuthEventIDs(),
HasState: true,
StateEventIDs: stateEventIDs,
@ -84,7 +92,7 @@ func SendEventWithState(
// SendInputRoomEvents to the roomserver.
func SendInputRoomEvents(
ctx context.Context, rsAPI RoomserverInternalAPI, ires []InputRoomEvent,
ctx context.Context, rsAPI RoomEventInputter, ires []InputRoomEvent,
) error {
request := InputRoomEventsRequest{InputRoomEvents: ires}
var response InputRoomEventsResponse

1
roomserver/internal/api.go
View file

@ -92,6 +92,7 @@ func (r *RoomserverInternalAPI) SetFederationAPI(fsAPI fsAPI.FederationInternalA
FSAPI: fsAPI,
KeyRing: keyRing,
ACLs: r.ServerACLs,
Queryer: r.Queryer,
}
r.Inviter = &perform.Inviter{
DB: r.DB,

3
roomserver/internal/input/input.go
View file

@ -27,6 +27,7 @@ import (
"github.com/matrix-org/dendrite/internal/hooks"
"github.com/matrix-org/dendrite/roomserver/acls"
"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/prometheus/client_golang/prometheus"
@ -50,6 +51,8 @@ type Inputer struct {
ACLs *acls.ServerACLs
OutputRoomEventTopic string
workers sync.Map // room ID -> *inputWorker
Queryer *query.Queryer
}
type inputTask struct {

316
roomserver/internal/input/input_events.go
View file

@ -23,6 +23,7 @@ import (
"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"
@ -76,6 +77,11 @@ func (r *Inputer) processRoomEvent(
// 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.
@ -88,23 +94,35 @@ func (r *Inputer) processRoomEvent(
switch idFormat {
case gomatrixserverlib.EventIDFormatV1:
if bytes.Equal(event.EventReference().EventSHA256, evs[0].EventReference().EventSHA256) {
util.GetLogger(ctx).WithField("event_id", event.EventID()).Infof("Already processed event; ignoring")
logger.Debugf("Already processed event; ignoring")
return event.EventID(), nil
}
default:
util.GetLogger(ctx).WithField("event_id", event.EventID()).Infof("Already processed event; ignoring")
logger.Debugf("Already processed event; ignoring")
return event.EventID(), nil
}
}
}
}
missingReq := &api.QueryMissingAuthPrevEventsRequest{
RoomID: event.RoomID(),
AuthEventIDs: event.AuthEventIDs(),
PrevEventIDs: event.PrevEventIDs(),
}
missingRes := &api.QueryMissingAuthPrevEventsResponse{}
if event.Type() != gomatrixserverlib.MRoomCreate {
if err = r.Queryer.QueryMissingAuthPrevEvents(ctx, missingReq, missingRes); err != nil {
return "", fmt.Errorf("r.Queryer.QueryMissingAuthPrevEvents: %w", err)
}
}
// 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)
knownAuthEvents := map[string]types.Event{}
if err = r.checkForMissingAuthEvents(ctx, input.Event, &authEvents, knownAuthEvents); err != nil {
knownEvents := map[string]*types.Event{}
if err = r.checkForMissingAuthEvents(ctx, logger, input.Event, &authEvents, knownEvents); err != nil {
return "", fmt.Errorf("r.checkForMissingAuthEvents: %w", err)
}
@ -113,14 +131,14 @@ func (r *Inputer) processRoomEvent(
var rejectionErr error
if rejectionErr = gomatrixserverlib.Allowed(event, &authEvents); rejectionErr != nil {
isRejected = true
logrus.WithError(rejectionErr).Warnf("Event %s rejected", event.EventID())
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 {
authEventNIDs = append(authEventNIDs, knownAuthEvents[authEventID].EventNID)
authEventNIDs = append(authEventNIDs, knownEvents[authEventID].EventNID)
}
var softfail bool
@ -129,11 +147,7 @@ func (r *Inputer) processRoomEvent(
// current room state.
softfail, err = helpers.CheckForSoftFail(ctx, r.DB, headered, input.StateEventIDs)
if err != nil {
logrus.WithFields(logrus.Fields{
"event_id": event.EventID(),
"type": event.Type(),
"room": event.RoomID(),
}).WithError(err).Info("Error authing soft-failed event")
logger.WithError(err).Info("Error authing soft-failed event")
}
}
@ -156,12 +170,7 @@ func (r *Inputer) processRoomEvent(
// doesn't have any associated state to store and we don't need to
// notify anyone about it.
if input.Kind == api.KindOutlier {
logrus.WithFields(logrus.Fields{
"event_id": event.EventID(),
"type": event.Type(),
"room": event.RoomID(),
"sender": event.Sender(),
}).Debug("Stored outlier")
logger.Debug("Stored outlier")
return event.EventID(), nil
}
@ -173,6 +182,27 @@ func (r *Inputer) processRoomEvent(
return "", fmt.Errorf("r.DB.RoomInfo missing for room %s", event.RoomID())
}
if input.Origin == "" {
return "", fmt.Errorf("expected an origin")
}
if len(missingRes.MissingPrevEventIDs) > 0 {
missingState := missingStateReq{
origin: input.Origin,
inputer: r,
queryer: r.Queryer,
db: r.DB,
federation: r.FSAPI,
roomsMu: internal.NewMutexByRoom(),
servers: []gomatrixserverlib.ServerName{input.Origin},
hadEvents: map[string]bool{},
haveEvents: map[string]*gomatrixserverlib.HeaderedEvent{},
}
if err = missingState.processEventWithMissingState(ctx, input.Event.Unwrap(), roomInfo.RoomVersion); err != nil {
return "", fmt.Errorf("r.checkForMissingPrevEvents: %w", err)
}
}
if stateAtEvent.BeforeStateSnapshotNID == 0 {
// We haven't calculated a state for this event yet.
// Lets calculate one.
@ -184,13 +214,7 @@ func (r *Inputer) processRoomEvent(
// 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 {
logrus.WithFields(logrus.Fields{
"event_id": event.EventID(),
"type": event.Type(),
"room": event.RoomID(),
"soft_fail": softfail,
"sender": event.Sender(),
}).Debug("Stored rejected event")
logger.WithField("soft_fail", softfail).Debug("Stored rejected event")
return event.EventID(), rejectionErr
}
@ -246,9 +270,10 @@ func (r *Inputer) processRoomEvent(
func (r *Inputer) checkForMissingAuthEvents(
ctx context.Context,
logger *logrus.Entry,
event *gomatrixserverlib.HeaderedEvent,
auth *gomatrixserverlib.AuthEvents,
known map[string]types.Event,
known map[string]*types.Event,
) error {
authEventIDs := event.AuthEventIDs()
if len(authEventIDs) == 0 {
@ -263,7 +288,8 @@ func (r *Inputer) checkForMissingAuthEvents(
}
for _, event := range authEvents {
if event.Event != nil {
known[event.EventID()] = event
ev := event // don't take the address of the iterated value
known[event.EventID()] = &ev
if err = auth.AddEvent(event.Event); err != nil {
return fmt.Errorf("auth.AddEvent: %w", err)
}
@ -273,7 +299,7 @@ func (r *Inputer) checkForMissingAuthEvents(
}
if len(unknown) > 0 {
logrus.Printf("XXX: There are %d missing auth events", len(unknown))
logger.Printf("XXX: There are %d missing auth events", len(unknown))
serverReq := &fedapi.QueryJoinedHostServerNamesInRoomRequest{
RoomID: event.RoomID(),
@ -283,22 +309,22 @@ func (r *Inputer) checkForMissingAuthEvents(
return fmt.Errorf("r.FSAPI.QueryJoinedHostServerNamesInRoom: %w", err)
}
logrus.Printf("XXX: Asking servers %+v", serverRes.ServerNames)
logger.Printf("XXX: Asking servers %+v", serverRes.ServerNames)
var res gomatrixserverlib.RespEventAuth
var found bool
for _, serverName := range serverRes.ServerNames {
res, err = r.FSAPI.GetEventAuth(ctx, serverName, event.RoomID(), event.EventID())
if err != nil {
logrus.WithError(err).Warnf("Failed to get event auth from federation for %q: %s", event.EventID(), err)
logger.WithError(err).Warnf("Failed to get event auth from federation for %q: %s", event.EventID(), err)
continue
}
logrus.Printf("XXX: Server %q provided us with %d auth events", serverName, len(res.AuthEvents))
logger.Printf("XXX: Server %q provided us with %d auth events", serverName, len(res.AuthEvents))
found = true
break
}
if !found {
logrus.Printf("XXX: None of the %d servers provided us with auth events", len(serverRes.ServerNames))
logger.Printf("XXX: None of the %d servers provided us with auth events", len(serverRes.ServerNames))
return fmt.Errorf("no servers provided event auth")
}
@ -332,7 +358,7 @@ func (r *Inputer) checkForMissingAuthEvents(
}
// Let's take a note of the fact that we now know about this event.
known[event.EventID()] = types.Event{}
known[event.EventID()] = nil
if err := auth.AddEvent(event); err != nil {
return fmt.Errorf("auth.AddEvent: %w", err)
}
@ -341,7 +367,7 @@ func (r *Inputer) checkForMissingAuthEvents(
isRejected := false
if err := gomatrixserverlib.Allowed(event, auth); err != nil {
isRejected = true
logrus.WithError(err).Warnf("Auth event %s rejected", event.EventID())
logger.WithError(err).Warnf("Auth event %s rejected", event.EventID())
}
// Finally, store the event in the database.
@ -351,7 +377,7 @@ func (r *Inputer) checkForMissingAuthEvents(
}
// Now we know about this event, too.
known[event.EventID()] = types.Event{
known[event.EventID()] = &types.Event{
EventNID: eventNID,
Event: event,
}
@ -361,6 +387,228 @@ func (r *Inputer) checkForMissingAuthEvents(
return nil
}
/*
func (r *Inputer) checkForMissingPrevEvents(
ctx context.Context,
logger *logrus.Entry,
event *gomatrixserverlib.HeaderedEvent,
roomInfo *types.RoomInfo,
known map[string]*types.Event,
) error {
prevStates := map[string]*types.StateAtEvent{}
prevEventIDs := event.PrevEventIDs()
if len(prevEventIDs) == 0 && event.Type() != gomatrixserverlib.MRoomCreate {
return fmt.Errorf("expected to find some prev events for event type %q", event.Type())
}
for _, eventID := range prevEventIDs {
state, err := r.DB.StateAtEventIDs(ctx, []string{eventID})
if err != nil {
if _, ok := err.(types.MissingEventError); ok {
continue
}
return fmt.Errorf("r.DB.StateAtEventIDs: %w", err)
}
if len(state) == 1 {
prevStates[eventID] = &state[0]
continue
}
}
// If we know all of the states of the previous events then there is nothing more to
// do here, as the state across them will be resolved later.
if len(prevStates) == len(prevEventIDs) {
return nil
}
if r.FSAPI == nil {
return fmt.Errorf("cannot satisfy missing events without federation")
}
// Ask the federation API which servers we should ask. In theory the roomserver
// doesn't need the help of the federation API to do this because we already know
// all of the membership states, it's just that the federation API tracks this in
// a table for this purpose. TODO: Work out what makes most sense here.
serverReq := &fedapi.QueryJoinedHostServerNamesInRoomRequest{
RoomID: event.RoomID(),
}
serverRes := &fedapi.QueryJoinedHostServerNamesInRoomResponse{}
if err := r.FSAPI.QueryJoinedHostServerNamesInRoom(ctx, serverReq, serverRes); err != nil {
return fmt.Errorf("r.FSAPI.QueryJoinedHostServerNamesInRoom: %w", err)
}
// 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 := r.getMissingEvents(ctx, logger, event, roomInfo, serverRes.ServerNames, known)
if err != nil {
return err
}
if len(newEvents) == 0 {
return fmt.Errorf("/get_missing_events returned no new events")
}
return nil
}
func (r *Inputer) getMissingEvents(
ctx context.Context,
logger *logrus.Entry,
event *gomatrixserverlib.HeaderedEvent,
roomInfo *types.RoomInfo,
servers []gomatrixserverlib.ServerName,
known map[string]*types.Event,
) (newEvents []*gomatrixserverlib.Event, err error) {
logger.Printf("XXX: get_missing_events called")
needed := gomatrixserverlib.StateNeededForAuth([]*gomatrixserverlib.Event{event.Unwrap()})
// Ask the roomserver for our current forward extremities. These will form
// the "earliest" part of the `/get_missing_events` request.
req := &api.QueryLatestEventsAndStateRequest{
RoomID: event.RoomID(),
StateToFetch: needed.Tuples(),
}
res := &api.QueryLatestEventsAndStateResponse{}
if err = r.Queryer.QueryLatestEventsAndState(ctx, req, res); err != nil {
logger.WithError(err).Warn("Failed to query latest events")
return nil, err
}
// Accumulate the event IDs of our forward extremities for use in the request.
latestEvents := make([]string, len(res.LatestEvents))
for i := range res.LatestEvents {
latestEvents[i] = res.LatestEvents[i].EventID
}
var missingResp *gomatrixserverlib.RespMissingEvents
for _, server := range servers {
logger.Printf("XXX: Calling /get_missing_events via %q", server)
var m gomatrixserverlib.RespMissingEvents
if m, err = r.FSAPI.LookupMissingEvents(ctx, server, event.RoomID(), gomatrixserverlib.MissingEvents{
Limit: 20,
EarliestEvents: latestEvents,
LatestEvents: []string{event.EventID()},
}, event.RoomVersion); err == nil {
missingResp = &m
break
} else if errors.Is(err, context.DeadlineExceeded) {
break
}
}
if missingResp == nil {
return nil, fmt.Errorf("/get_missing_events failed via all candidate servers")
}
if len(missingResp.Events) == 0 {
return nil, fmt.Errorf("/get_missing_events returned no events")
}
// 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.Printf("XXX: get_missing_events returned %d events", len(missingResp.Events))
newEvents = gomatrixserverlib.ReverseTopologicalOrdering(
missingResp.Events,
gomatrixserverlib.TopologicalOrderByPrevEvents,
)
for _, pe := range event.PrevEventIDs() {
hasPrevEvent := false
for _, ev := range newEvents {
if ev.EventID() == pe {
hasPrevEvent = true
break
}
}
if !hasPrevEvent {
logger.Errorf("Prev event %q is still missing after /get_missing_events", pe)
}
}
backwardExtremity := newEvents[0]
fastForwardEvents := newEvents[1:]
// Do we know about the state of the backward extremity already?
if _, err := r.DB.StateAtEventIDs(ctx, []string{backwardExtremity.EventID()}); err == nil {
// Yes, we do, so we don't need to store that event.
} else {
// No, we don't, so let's go find it.
// r.FSAPI.LookupStateIDs()
}
for _, ev := range fastForwardEvents {
if _, err := r.processRoomEvent(ctx, &api.InputRoomEvent{
Kind: api.KindOld,
Event: ev.Headered(event.RoomVersion),
AuthEventIDs: ev.AuthEventIDs(),
}); err != nil {
return nil, fmt.Errorf("r.processRoomEvent (prev event): %w", err)
}
}
return newEvents, nil
}
func (r *Inputer) lookupStateBeforeEvent(
ctx context.Context,
logger *logrus.Entry,
event *gomatrixserverlib.HeaderedEvent,
roomInfo *types.RoomInfo,
servers []gomatrixserverlib.ServerName,
) error {
knownPrevStates := map[string]types.StateAtEvent{}
unknownPrevStates := map[string]struct{}{}
neededStateEvents := map[string]struct{}{}
for _, prevEventID := range event.PrevEventIDs() {
if state, err := r.DB.StateAtEventIDs(ctx, []string{prevEventID}); err == nil && len(state) == 1 {
knownPrevStates[prevEventID] = state[0]
} else {
unknownPrevStates[prevEventID] = struct{}{}
}
}
for prevEventID := range unknownPrevStates {
stateIDs, err := r.FSAPI.LookupStateIDs(ctx, "TODO: SERVER", event.RoomID(), prevEventID)
if err != nil {
return fmt.Errorf("r.FSAPI.LookupStateIDs: %w", err)
}
events, err := r.DB.EventsFromIDs(ctx, stateIDs.StateEventIDs)
if err != nil {
return fmt.Errorf("r.DB.EventsFromIDs: %w", err)
}
for i, eventID := range stateIDs.StateEventIDs {
if events[i].Event == nil || events[i].EventNID == 0 {
neededStateEvents[eventID] = struct{}{}
}
}
if len(neededStateEvents) > (len(stateIDs.StateEventIDs) / 2) {
// More than 50% of the state events are missing, so let's just
// call `/state` instead of fetching the events individually.
state, err := r.FSAPI.LookupState(ctx, "", event.RoomID(), prevEventID, roomInfo.RoomVersion)
if err != nil {
return fmt.Errorf("r.FSAPI.LookupState: %w", err)
}
knownPrevStates[prevEventID] = types.StateAtEvent{
StateEntry: types.StateEntry{},
}
}
}
return nil
}
*/
func (r *Inputer) calculateAndSetState(
ctx context.Context,
input *api.InputRoomEvent,

708
roomserver/internal/input/input_missing.go Normal file
View file

@ -0,0 +1,708 @@
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()
err = api.SendEventWithState(
context.Background(),
t.inputer,
api.KindOld,
resolvedState,
backwardsExtremity.Headered(roomVersion),
t.origin,
hadEvents,
)
if err != nil {
return fmt.Errorf("api.SendEventWithState: %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.
headeredNewEvents := make([]*gomatrixserverlib.HeaderedEvent, len(newEvents))
for i, newEvent := range newEvents {
headeredNewEvents[i] = newEvent.Headered(roomVersion)
}
if err = api.SendEvents(
context.Background(),
t.inputer,
api.KindOld,
append(headeredNewEvents, e.Headered(roomVersion)),
t.origin,
api.DoNotSendToOtherServers,
nil,
); err != nil {
return fmt.Errorf("api.SendEvents: %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(), true)
}
// 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(), true)
}
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, true)
}
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(), true)
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, roomID, 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, had bool) {
t.hadEventsMutex.Lock()
defer t.hadEventsMutex.Unlock()
t.hadEvents[eventID] = had
}
type roomNotFoundError struct {
roomID string
}
type verifySigError struct {
eventID string
err error
}
type missingPrevEventsError struct {
eventID string
err error
}
func (e roomNotFoundError) Error() string { return fmt.Sprintf("room %q not found", e.roomID) }
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)
}

1
roomserver/internal/perform/perform_invite.go
View file

@ -172,6 +172,7 @@ func (r *Inviter) PerformInvite(
{
Kind: api.KindNew,
Event: event,
Origin: event.Origin(),
AuthEventIDs: event.AuthEventIDs(),
SendAsServer: req.SendAsServer,
},

4
roomserver/roomserver_test.go
View file

@ -189,7 +189,7 @@ func mustSendEvents(t *testing.T, ver gomatrixserverlib.RoomVersion, events []js
t.Helper()
rsAPI, dp := mustCreateRoomserverAPI(t)
hevents := mustLoadRawEvents(t, ver, events)
if err := api.SendEvents(ctx, rsAPI, api.KindNew, hevents, testOrigin, nil); err != nil {
if err := api.SendEvents(ctx, rsAPI, api.KindNew, hevents, testOrigin, testOrigin, nil); err != nil {
t.Errorf("failed to SendEvents: %s", err)
}
return rsAPI, dp, hevents
@ -335,7 +335,7 @@ func TestOutputRewritesState(t *testing.T) {
deleteDatabase()
rsAPI, producer := mustCreateRoomserverAPI(t)
defer deleteDatabase()
err := api.SendEvents(context.Background(), rsAPI, api.KindNew, originalEvents, testOrigin, nil)
err := api.SendEvents(context.Background(), rsAPI, api.KindNew, originalEvents, testOrigin, testOrigin, nil)
if err != nil {
t.Fatalf("failed to send original events: %s", err)
}