Invites v2 endpoint (#952)

* Start converting v1 invite endpoint to v2

* Update gomatrixserverlib

* Early federationsender code for sending invites

* Sending invites sorta happens now

* Populate invite request with stripped state

* Remodel a bit, don't reflect received invites

* Handle invite_room_state

* Handle room versions a bit better

* Update gomatrixserverlib

* Tweak order in destinationQueue.next

* Revert check in processMessage

* Tweak federation sender destination queue code a bit

* Add comments

federationsender/consumers/roomserver.go

@@ -32,6 +32,7 @@ import (
 
 // OutputRoomEventConsumer consumes events that originated in the room server.
 type OutputRoomEventConsumer struct {
+	cfg                *config.Dendrite
 	roomServerConsumer *common.ContinualConsumer
 	db                 storage.Database
 	queues             *queue.OutgoingQueues
@@ -52,6 +53,7 @@ func NewOutputRoomEventConsumer(
 		PartitionStore: store,
 	}
 	s := &OutputRoomEventConsumer{
+		cfg:                cfg,
 		roomServerConsumer: &consumer,
 		db:                 store,
 		queues:             queues,
@@ -79,29 +81,48 @@ func (s *OutputRoomEventConsumer) onMessage(msg *sarama.ConsumerMessage) error {
 		log.WithError(err).Errorf("roomserver output log: message parse failure")
 		return nil
 	}
-	if output.Type != api.OutputTypeNewRoomEvent {
+
+	switch output.Type {
+	case api.OutputTypeNewRoomEvent:
+		ev := &output.NewRoomEvent.Event
+		log.WithFields(log.Fields{
+			"event_id":       ev.EventID(),
+			"room_id":        ev.RoomID(),
+			"send_as_server": output.NewRoomEvent.SendAsServer,
+		}).Info("received room event from roomserver")
+
+		if err := s.processMessage(*output.NewRoomEvent); err != nil {
+			// panic rather than continue with an inconsistent database
+			log.WithFields(log.Fields{
+				"event":      string(ev.JSON()),
+				"add":        output.NewRoomEvent.AddsStateEventIDs,
+				"del":        output.NewRoomEvent.RemovesStateEventIDs,
+				log.ErrorKey: err,
+			}).Panicf("roomserver output log: write room event failure")
+			return nil
+		}
+	case api.OutputTypeNewInviteEvent:
+		ev := &output.NewInviteEvent.Event
+		log.WithFields(log.Fields{
+			"event_id":  ev.EventID(),
+			"room_id":   ev.RoomID(),
+			"state_key": ev.StateKey(),
+		}).Info("received invite event from roomserver")
+
+		if err := s.processInvite(*output.NewInviteEvent); err != nil {
+			// panic rather than continue with an inconsistent database
+			log.WithFields(log.Fields{
+				"event":      string(ev.JSON()),
+				log.ErrorKey: err,
+			}).Panicf("roomserver output log: write invite event failure")
+			return nil
+		}
+	default:
 		log.WithField("type", output.Type).Debug(
 			"roomserver output log: ignoring unknown output type",
 		)
 		return nil
 	}
-	ev := &output.NewRoomEvent.Event
-	log.WithFields(log.Fields{
-		"event_id":       ev.EventID(),
-		"room_id":        ev.RoomID(),
-		"send_as_server": output.NewRoomEvent.SendAsServer,
-	}).Info("received event from roomserver")
-
-	if err := s.processMessage(*output.NewRoomEvent); err != nil {
-		// panic rather than continue with an inconsistent database
-		log.WithFields(log.Fields{
-			"event":      string(ev.JSON()),
-			log.ErrorKey: err,
-			"add":        output.NewRoomEvent.AddsStateEventIDs,
-			"del":        output.NewRoomEvent.RemovesStateEventIDs,
-		}).Panicf("roomserver output log: write event failure")
-		return nil
-	}
 
 	return nil
 }
@@ -159,6 +180,69 @@ func (s *OutputRoomEventConsumer) processMessage(ore api.OutputNewRoomEvent) err
 	)
 }
 
+// processInvite handles an invite event for sending over federation.
+func (s *OutputRoomEventConsumer) processInvite(oie api.OutputNewInviteEvent) error {
+	// Don't try to reflect and resend invites that didn't originate from us.
+	if s.cfg.Matrix.ServerName != oie.Event.Origin() {
+		return nil
+	}
+
+	// When sending a v2 invite, the inviting server should try and include
+	// a "stripped down" version of the room state. This is pretty much just
+	// enough information for the remote side to show something useful to the
+	// user, like the room name, aliases etc.
+	strippedState := []gomatrixserverlib.InviteV2StrippedState{}
+	stateWanted := []string{
+		gomatrixserverlib.MRoomName, gomatrixserverlib.MRoomCanonicalAlias,
+		gomatrixserverlib.MRoomAliases, gomatrixserverlib.MRoomJoinRules,
+	}
+
+	// For each of the state keys that we want to try and send, ask the
+	// roomserver if we have a state event for that room that matches the
+	// state key.
+	for _, wanted := range stateWanted {
+		queryReq := api.QueryLatestEventsAndStateRequest{
+			RoomID: oie.Event.RoomID(),
+			StateToFetch: []gomatrixserverlib.StateKeyTuple{
+				gomatrixserverlib.StateKeyTuple{
+					EventType: wanted,
+					StateKey:  "",
+				},
+			},
+		}
+		// If this fails then we just move onto the next event - we don't
+		// actually know at this point whether the room even has that type
+		// of state.
+		queryRes := api.QueryLatestEventsAndStateResponse{}
+		if err := s.query.QueryLatestEventsAndState(context.TODO(), &queryReq, &queryRes); err != nil {
+			log.WithFields(log.Fields{
+				"room_id":    queryReq.RoomID,
+				"event_type": wanted,
+			}).WithError(err).Info("couldn't find state to strip")
+			continue
+		}
+		// Append the stripped down copy of the state to our list.
+		for _, headeredEvent := range queryRes.StateEvents {
+			event := headeredEvent.Unwrap()
+			strippedState = append(strippedState, gomatrixserverlib.NewInviteV2StrippedState(&event))
+
+			log.WithFields(log.Fields{
+				"room_id":    queryReq.RoomID,
+				"event_type": event.Type(),
+			}).Info("adding stripped state")
+		}
+	}
+
+	// Build the invite request with the info we've got.
+	inviteReq, err := gomatrixserverlib.NewInviteV2Request(&oie.Event, strippedState)
+	if err != nil {
+		return fmt.Errorf("gomatrixserverlib.NewInviteV2Request: %w", err)
+	}
+
+	// Send the event.
+	return s.queues.SendInvite(&inviteReq)
+}
+
 // joinedHostsAtEvent works out a list of matrix servers that were joined to
 // the room at the event.
 // It is important to use the state at the event for sending messages because:

federationsender/queue/destinationqueue.go

@@ -24,6 +24,7 @@ import (
 	"github.com/matrix-org/gomatrixserverlib"
 	"github.com/matrix-org/util"
 	log "github.com/sirupsen/logrus"
+	"go.uber.org/atomic"
 )
 
 // destinationQueue is a queue of events for a single destination.
@@ -34,14 +35,15 @@ type destinationQueue struct {
 	client      *gomatrixserverlib.FederationClient
 	origin      gomatrixserverlib.ServerName
 	destination gomatrixserverlib.ServerName
-	// The running mutex protects running, sentCounter, lastTransactionIDs and
+	running     atomic.Bool
+	// The running mutex protects sentCounter, lastTransactionIDs and
 	// pendingEvents, pendingEDUs.
 	runningMutex       sync.Mutex
-	running            bool
 	sentCounter        int
 	lastTransactionIDs []gomatrixserverlib.TransactionID
 	pendingEvents      []*gomatrixserverlib.HeaderedEvent
 	pendingEDUs        []*gomatrixserverlib.EDU
+	pendingInvites     []*gomatrixserverlib.InviteV2Request
 }
 
 // Send event adds the event to the pending queue for the destination.
@@ -51,29 +53,43 @@ func (oq *destinationQueue) sendEvent(ev *gomatrixserverlib.HeaderedEvent) {
 	oq.runningMutex.Lock()
 	defer oq.runningMutex.Unlock()
 	oq.pendingEvents = append(oq.pendingEvents, ev)
-	if !oq.running {
-		oq.running = true
+	if !oq.running.Load() {
 		go oq.backgroundSend()
 	}
 }
 
 // sendEDU adds the EDU event to the pending queue for the destination.
 // If the queue is empty then it starts a background goroutine to
-// start sending event to that destination.
+// start sending events to that destination.
 func (oq *destinationQueue) sendEDU(e *gomatrixserverlib.EDU) {
 	oq.runningMutex.Lock()
 	defer oq.runningMutex.Unlock()
 	oq.pendingEDUs = append(oq.pendingEDUs, e)
-	if !oq.running {
-		oq.running = true
+	if !oq.running.Load() {
 		go oq.backgroundSend()
 	}
 }
 
+// sendInvite adds the invite event to the pending queue for the
+// destination. If the queue is empty then it starts a background
+// goroutine to start sending events to that destination.
+func (oq *destinationQueue) sendInvite(ev *gomatrixserverlib.InviteV2Request) {
+	oq.runningMutex.Lock()
+	defer oq.runningMutex.Unlock()
+	oq.pendingInvites = append(oq.pendingInvites, ev)
+	if !oq.running.Load() {
+		go oq.backgroundSend()
+	}
+}
+
+// backgroundSend is the worker goroutine for sending events.
 func (oq *destinationQueue) backgroundSend() {
+	oq.running.Store(true)
+	defer oq.running.Store(false)
+
 	for {
-		t := oq.next()
-		if t == nil {
+		transaction, invites := oq.nextTransaction(), oq.nextInvites()
+		if !transaction && !invites {
 			// If the queue is empty then stop processing for this destination.
 			// TODO: Remove this destination from the queue map.
 			return
@@ -81,29 +97,18 @@ func (oq *destinationQueue) backgroundSend() {
 
 		// TODO: handle retries.
 		// TODO: blacklist uncooperative servers.
-
-		util.GetLogger(context.TODO()).Infof("Sending transaction %q containing %d PDUs, %d EDUs", t.TransactionID, len(t.PDUs), len(t.EDUs))
-
-		_, err := oq.client.SendTransaction(context.TODO(), *t)
-		if err != nil {
-			log.WithFields(log.Fields{
-				"destination": oq.destination,
-				log.ErrorKey:  err,
-			}).Info("problem sending transaction")
-		}
 	}
 }
 
-// next creates a new transaction from the pending event queue
-// and flushes the queue.
-// Returns nil if the queue was empty.
-func (oq *destinationQueue) next() *gomatrixserverlib.Transaction {
+// nextTransaction creates a new transaction from the pending event
+// queue and sends it. Returns true if a transaction was sent or
+// false otherwise.
+func (oq *destinationQueue) nextTransaction() bool {
 	oq.runningMutex.Lock()
 	defer oq.runningMutex.Unlock()
 
 	if len(oq.pendingEvents) == 0 && len(oq.pendingEDUs) == 0 {
-		oq.running = false
-		return nil
+		return false
 	}
 
 	t := gomatrixserverlib.Transaction{
@@ -136,5 +141,46 @@ func (oq *destinationQueue) next() *gomatrixserverlib.Transaction {
 	oq.pendingEDUs = nil
 	oq.sentCounter += len(t.EDUs)
 
-	return &t
+	util.GetLogger(context.TODO()).Infof("Sending transaction %q containing %d PDUs, %d EDUs", t.TransactionID, len(t.PDUs), len(t.EDUs))
+
+	_, err := oq.client.SendTransaction(context.TODO(), t)
+	if err != nil {
+		log.WithFields(log.Fields{
+			"destination": oq.destination,
+			log.ErrorKey:  err,
+		}).Info("problem sending transaction")
+	}
+
+	return true
+}
+
+// nextInvite takes pending invite events from the queue and sends
+// them. Returns true if a transaction was sent or false otherwise.
+func (oq *destinationQueue) nextInvites() bool {
+	oq.runningMutex.Lock()
+	defer oq.runningMutex.Unlock()
+
+	if len(oq.pendingInvites) == 0 {
+		return false
+	}
+
+	for _, inviteReq := range oq.pendingInvites {
+		ev := inviteReq.Event()
+
+		if _, err := oq.client.SendInviteV2(
+			context.TODO(),
+			oq.destination,
+			*inviteReq,
+		); err != nil {
+			log.WithFields(log.Fields{
+				"event_id":    ev.EventID(),
+				"state_key":   ev.StateKey(),
+				"destination": oq.destination,
+			}).WithError(err).Error("failed to send invite")
+		}
+	}
+
+	oq.pendingInvites = nil
+
+	return true
 }

federationsender/queue/queue.go

@@ -80,6 +80,49 @@ func (oqs *OutgoingQueues) SendEvent(
 	return nil
 }
 
+// SendEvent sends an event to the destinations
+func (oqs *OutgoingQueues) SendInvite(
+	inviteReq *gomatrixserverlib.InviteV2Request,
+) error {
+	ev := inviteReq.Event()
+	stateKey := ev.StateKey()
+	if stateKey == nil {
+		log.WithFields(log.Fields{
+			"event_id": ev.EventID(),
+		}).Info("invite had no state key, dropping")
+		return nil
+	}
+
+	_, destination, err := gomatrixserverlib.SplitID('@', *stateKey)
+	if err != nil {
+		log.WithFields(log.Fields{
+			"event_id":  ev.EventID(),
+			"state_key": stateKey,
+		}).Info("failed to split destination from state key")
+		return nil
+	}
+
+	log.WithFields(log.Fields{
+		"event_id": ev.EventID(),
+	}).Info("Sending invite")
+
+	oqs.queuesMutex.Lock()
+	defer oqs.queuesMutex.Unlock()
+	oq := oqs.queues[destination]
+	if oq == nil {
+		oq = &destinationQueue{
+			origin:      oqs.origin,
+			destination: destination,
+			client:      oqs.client,
+		}
+		oqs.queues[destination] = oq
+	}
+
+	oq.sendInvite(inviteReq)
+
+	return nil
+}
+
 // SendEDU sends an EDU event to the destinations
 func (oqs *OutgoingQueues) SendEDU(
 	e *gomatrixserverlib.EDU, origin gomatrixserverlib.ServerName,