Merge branch 'master' into neilalexander/config

cmd/dendrite-demo-libp2p/main.go

@@ -75,7 +75,8 @@ func createFederationClient(
 		p2phttp.NewTransport(base.LibP2P, p2phttp.ProtocolOption("/matrix")),
 	)
 	return gomatrixserverlib.NewFederationClientWithTransport(
-		base.Base.Cfg.Global.ServerName, base.Base.Cfg.Global.KeyID, base.Base.Cfg.Global.PrivateKey, tr,
+		base.Base.Cfg.Global.ServerName, base.Base.Cfg.Global.KeyID,
+		base.Base.Cfg.Global.PrivateKey, true, tr,
 	)
 }
 
@@ -87,7 +88,7 @@ func createClient(
 		"matrix",
 		p2phttp.NewTransport(base.LibP2P, p2phttp.ProtocolOption("/matrix")),
 	)
-	return gomatrixserverlib.NewClientWithTransport(tr)
+	return gomatrixserverlib.NewClientWithTransport(true, tr)
 }
 
 func main() {

cmd/dendrite-demo-yggdrasil/yggconn/client.go

@@ -33,7 +33,7 @@ func (n *Node) CreateClient(
 			},
 		},
 	)
-	return gomatrixserverlib.NewClientWithTransport(tr)
+	return gomatrixserverlib.NewClientWithTransport(true, tr)
 }
 
 func (n *Node) CreateFederationClient(
@@ -54,6 +54,7 @@ func (n *Node) CreateFederationClient(
 		},
 	)
 	return gomatrixserverlib.NewFederationClientWithTransport(
-		base.Cfg.Global.ServerName, base.Cfg.Global.KeyID, base.Cfg.Global.PrivateKey, tr,
+		base.Cfg.Global.ServerName, base.Cfg.Global.KeyID,
+		base.Cfg.Global.PrivateKey, true, tr,
 	)
 }

cmd/dendrite-media-api-server/main.go

@@ -26,7 +26,7 @@ func main() {
 	defer base.Close() // nolint: errcheck
 
 	userAPI := base.UserAPIClient()
-	client := gomatrixserverlib.NewClient()
+	client := gomatrixserverlib.NewClient(cfg.FederationSender.DisableTLSValidation)
 
 	mediaapi.AddPublicRoutes(base.PublicAPIMux, &base.Cfg.MediaAPI, userAPI, client)
 

cmd/dendrite-monolith-server/main.go

@@ -132,7 +132,7 @@ func main() {
 		Config:        base.Cfg,
 		AccountDB:     accountDB,
 		DeviceDB:      deviceDB,
-		Client:        gomatrixserverlib.NewClient(),
+		Client:        gomatrixserverlib.NewClient(cfg.FederationSender.DisableTLSValidation),
 		FedClient:     federation,
 		KeyRing:       keyRing,
 		KafkaConsumer: base.KafkaConsumer,

cmd/dendritejs/main.go

@@ -139,16 +139,16 @@ func createFederationClient(cfg *config.Dendrite, node *go_http_js_libp2p.P2pLoc
 	tr := go_http_js_libp2p.NewP2pTransport(node)
 
 	fed := gomatrixserverlib.NewFederationClient(
-		cfg.Global.ServerName, cfg.Global.KeyID, cfg.Global.PrivateKey,
+		cfg.Global.ServerName, cfg.Global.KeyID, cfg.Global.PrivateKey, true,
 	)
-	fed.Client = *gomatrixserverlib.NewClientWithTransport(tr)
+	fed.Client = *gomatrixserverlib.NewClientWithTransport(true, tr)
 
 	return fed
 }
 
 func createClient(node *go_http_js_libp2p.P2pLocalNode) *gomatrixserverlib.Client {
 	tr := go_http_js_libp2p.NewP2pTransport(node)
-	return gomatrixserverlib.NewClientWithTransport(tr)
+	return gomatrixserverlib.NewClientWithTransport(true, tr)
 }
 
 func createP2PNode(privKey ed25519.PrivateKey) (serverName string, node *go_http_js_libp2p.P2pLocalNode) {

dendrite-config.yaml

@@ -27,6 +27,9 @@ matrix:
     #        public_key: l8Hft5qXKn1vfHrg3p4+W8gELQVo8N13JkluMfmn2sQ
     # Disables new users from registering (except via shared secrets)
     registration_disabled: false
+    # Whether to disable TLS certificate validation. Warning: this reduces federation
+    # security and should not be enabled in production!
+    federation_disable_tls_validation: false
 
 # The media repository config
 media:

federationapi/federationapi_test.go

@@ -44,7 +44,7 @@ func TestRoomsV3URLEscapeDoNot404(t *testing.T) {
 	defer cancel()
 	serverName := gomatrixserverlib.ServerName(strings.TrimPrefix(baseURL, "https://"))
 
-	fedCli := gomatrixserverlib.NewFederationClient(serverName, cfg.Global.KeyID, cfg.Global.PrivateKey)
+	fedCli := gomatrixserverlib.NewFederationClient(serverName, cfg.Global.KeyID, cfg.Global.PrivateKey, true)
 
 	testCases := []struct {
 		roomVer   gomatrixserverlib.RoomVersion

federationapi/routing/send.go

@@ -218,7 +218,9 @@ func (t *txnReq) processTransaction() (*gomatrixserverlib.RespSend, *util.JSONRe
 	}
 
 	t.processEDUs(t.EDUs)
-	util.GetLogger(t.context).Infof("Processed %d PDUs from transaction %q", len(results), t.TransactionID)
+	if c := len(results); c > 0 {
+		util.GetLogger(t.context).Infof("Processed %d PDUs from transaction %q", c, t.TransactionID)
+	}
 	return &gomatrixserverlib.RespSend{PDUs: results}, nil
 }
 
@@ -315,7 +317,7 @@ func (t *txnReq) processEDUs(edus []gomatrixserverlib.EDU) {
 		case gomatrixserverlib.MDeviceListUpdate:
 			t.processDeviceListUpdate(e)
 		default:
-			util.GetLogger(t.context).WithField("type", e.Type).Warn("unhandled edu")
+			util.GetLogger(t.context).WithField("type", e.Type).Debug("Unhandled EDU")
 		}
 	}
 }

federationsender/queue/destinationqueue.go

@@ -255,22 +255,20 @@ func (oq *destinationQueue) backgroundSend() {
 			// The worker is idle so stop the goroutine. It'll get
 			// restarted automatically the next time we have an event to
 			// send.
-			log.Infof("Queue %q has been idle for %s, going to sleep", oq.destination, queueIdleTimeout)
+			log.Debugf("Queue %q has been idle for %s, going to sleep", oq.destination, queueIdleTimeout)
 			return
 		}
 
 		// If we are backing off this server then wait for the
 		// backoff duration to complete first, or until explicitly
 		// told to retry.
-		if backoff, duration := oq.statistics.BackoffDuration(); backoff {
+		if _, giveUp := oq.statistics.BackoffIfRequired(oq.backingOff, oq.interruptBackoff); giveUp {
-			log.WithField("duration", duration).Infof("Backing off %s", oq.destination)
+			// It's been suggested that we should give up because the backoff
-			oq.backingOff.Store(true)
+			// has exceeded a maximum allowable value. Clean up the in-memory
-			select {
+			// buffers at this point. The PDU clean-up is already on a defer.
-			case <-time.After(duration):
+			oq.cleanPendingInvites()
-			case <-oq.interruptBackoff:
+			log.Warnf("Blacklisting %q due to exceeding backoff threshold", oq.destination)
-				log.Infof("Interrupting backoff for %q", oq.destination)
+			return
-			}
-			oq.backingOff.Store(false)
 		}
 
 		// If we have pending PDUs or EDUs then construct a transaction.
@@ -278,24 +276,8 @@ func (oq *destinationQueue) backgroundSend() {
 			// Try sending the next transaction and see what happens.
 			transaction, terr := oq.nextTransaction()
 			if terr != nil {
-				// We failed to send the transaction.
+				// We failed to send the transaction. Mark it as a failure.
-				if giveUp := oq.statistics.Failure(); giveUp {
+				oq.statistics.Failure()
-					// It's been suggested that we should give up because the backoff
-					// has exceeded a maximum allowable value. Clean up the in-memory
-					// buffers at this point. The PDU clean-up is already on a defer.
-					oq.cleanPendingInvites()
-					log.Infof("Blacklisting %q due to errors", oq.destination)
-					return
-				} else {
-					// We haven't been told to give up terminally yet but we still have
-					// PDUs waiting to be sent. By sending a message into the wake chan,
-					// the next loop iteration will try processing these PDUs again,
-					// subject to the backoff.
-					select {
-					case oq.notifyPDUs <- true:
-					default:
-					}
-				}
 			} else if transaction {
 				// If we successfully sent the transaction then clear out
 				// the pending events and EDUs, and wipe our transaction ID.
@@ -307,14 +289,8 @@ func (oq *destinationQueue) backgroundSend() {
 		if len(oq.pendingInvites) > 0 {
 			sent, ierr := oq.nextInvites(oq.pendingInvites)
 			if ierr != nil {
-				// We failed to send the transaction so increase the
+				// We failed to send the transaction. Mark it as a failure.
-				// backoff and give it another go shortly.
+				oq.statistics.Failure()
-				if giveUp := oq.statistics.Failure(); giveUp {
-					// It's been suggested that we should give up because
-					// the backoff has exceeded a maximum allowable value.
-					log.Infof("Blacklisting %q due to errors", oq.destination)
-					return
-				}
 			} else if sent > 0 {
 				// If we successfully sent the invites then clear out
 				// the pending invites.
@@ -414,7 +390,7 @@ func (oq *destinationQueue) nextTransaction() (bool, error) {
 		t.EDUs = append(t.EDUs, *edu)
 	}
 
-	logrus.WithField("server_name", oq.destination).Infof("Sending transaction %q containing %d PDUs, %d EDUs", t.TransactionID, len(t.PDUs), len(t.EDUs))
+	logrus.WithField("server_name", oq.destination).Debugf("Sending transaction %q containing %d PDUs, %d EDUs", t.TransactionID, len(t.PDUs), len(t.EDUs))
 
 	// Try to send the transaction to the destination server.
 	// TODO: we should check for 500-ish fails vs 400-ish here,

federationsender/queue/queue.go

@@ -136,7 +136,7 @@ func (oqs *OutgoingQueues) SendEvent(
 
 	log.WithFields(log.Fields{
 		"destinations": destinations, "event": ev.EventID(),
-	}).Info("Sending event")
+	}).Infof("Sending event")
 
 	headeredJSON, err := json.Marshal(ev)
 	if err != nil {

federationsender/statistics/statistics.go

@@ -65,8 +65,8 @@ type ServerStatistics struct {
 	statistics     *Statistics                  //
 	serverName     gomatrixserverlib.ServerName //
 	blacklisted    atomic.Bool                  // is the node blacklisted
-	backoffUntil   atomic.Value                 // time.Time to wait until before sending requests
+	backoffStarted atomic.Bool                  // is the backoff started
-	failCounter    atomic.Uint32                // how many times have we failed?
+	backoffCount   atomic.Uint32                // number of times BackoffDuration has been called
 	successCounter atomic.Uint32                // how many times have we succeeded?
 }
 
@@ -76,55 +76,67 @@ type ServerStatistics struct {
 // we will unblacklist it.
 func (s *ServerStatistics) Success() {
 	s.successCounter.Add(1)
-	s.failCounter.Store(0)
+	s.backoffStarted.Store(false)
+	s.backoffCount.Store(0)
 	s.blacklisted.Store(false)
+	if s.statistics.DB != nil {
 		if err := s.statistics.DB.RemoveServerFromBlacklist(s.serverName); err != nil {
 			logrus.WithError(err).Errorf("Failed to remove %q from blacklist", s.serverName)
 		}
 	}
+}
 
-// Failure marks a failure and works out when to backoff until. It
+// Failure marks a failure and starts backing off if needed.
-// returns true if the worker should give up altogether because of
+// The next call to BackoffIfRequired will do the right thing
-// too many consecutive failures. At this point the host is marked
+// after this.
-// as blacklisted.
+func (s *ServerStatistics) Failure() {
-func (s *ServerStatistics) Failure() bool {
+	if s.backoffStarted.CAS(false, true) {
-	// Increase the fail counter.
+		s.backoffCount.Store(0)
-	failCounter := s.failCounter.Add(1)
+	}
+}
 
-	// Check that we haven't failed more times than is acceptable.
+// BackoffIfRequired will block for as long as the current
-	if failCounter >= s.statistics.FailuresUntilBlacklist {
+// backoff requires, if needed. Otherwise it will do nothing.
+func (s *ServerStatistics) BackoffIfRequired(backingOff atomic.Bool, interrupt <-chan bool) (time.Duration, bool) {
+	if started := s.backoffStarted.Load(); !started {
+		return 0, false
+	}
+
+	// Work out how many times we've backed off so far.
+	count := s.backoffCount.Inc()
+	duration := time.Second * time.Duration(math.Exp2(float64(count)))
+
+	// Work out if we should be blacklisting at this point.
+	if count >= s.statistics.FailuresUntilBlacklist {
 		// We've exceeded the maximum amount of times we're willing
 		// to back off, which is probably in the region of hours by
 		// now. Mark the host as blacklisted and tell the caller to
 		// give up.
 		s.blacklisted.Store(true)
+		if s.statistics.DB != nil {
 			if err := s.statistics.DB.AddServerToBlacklist(s.serverName); err != nil {
 				logrus.WithError(err).Errorf("Failed to add %q to blacklist", s.serverName)
 			}
-		return true
+		}
+		return duration, true
 	}
 
-	// We're still under the threshold so work out the exponential
+	// Notify the destination queue that we're backing off now.
-	// backoff based on how many times we have failed already. The
+	backingOff.Store(true)
-	// worker goroutine will wait until this time before processing
+	defer backingOff.Store(false)
-	// anything from the queue.
+
-	backoffSeconds := time.Second * time.Duration(math.Exp2(float64(failCounter)))
+	// Work out how long we should be backing off for.
-	s.backoffUntil.Store(
+	logrus.Warnf("Backing off %q for %s", s.serverName, duration)
-		time.Now().Add(backoffSeconds),
+
-	)
+	// Wait for either an interruption or for the backoff to
-	return false
+	// complete.
+	select {
+	case <-interrupt:
+		logrus.Debugf("Interrupting backoff for %q", s.serverName)
+	case <-time.After(duration):
 	}
 
-// BackoffDuration returns both a bool stating whether to wait,
+	return duration, false
-// and then if true, a duration to wait for.
-func (s *ServerStatistics) BackoffDuration() (bool, time.Duration) {
-	backoff, until := false, time.Second
-	if b, ok := s.backoffUntil.Load().(time.Time); ok {
-		if b.After(time.Now()) {
-			backoff, until = true, time.Until(b)
-		}
-	}
-	return backoff, until
 }
 
 // Blacklisted returns true if the server is blacklisted and false

federationsender/statistics/statistics_test.go

@@ -0,0 +1,60 @@
+package statistics
+
+import (
+	"math"
+	"testing"
+	"time"
+
+	"go.uber.org/atomic"
+)
+
+func TestBackoff(t *testing.T) {
+	stats := Statistics{
+		FailuresUntilBlacklist: 5,
+	}
+	server := ServerStatistics{
+		statistics: &stats,
+		serverName: "test.com",
+	}
+
+	// Start by checking that counting successes works.
+	server.Success()
+	if successes := server.SuccessCount(); successes != 1 {
+		t.Fatalf("Expected success count 1, got %d", successes)
+	}
+
+	// Register a failure.
+	server.Failure()
+
+	t.Logf("Backoff counter: %d", server.backoffCount.Load())
+	backingOff := atomic.Bool{}
+
+	// Now we're going to simulate backing off a few times to see
+	// what happens.
+	for i := uint32(1); i <= 10; i++ {
+		// Interrupt the backoff - it doesn't really matter if it
+		// completes but we will find out how long the backoff should
+		// have been.
+		interrupt := make(chan bool, 1)
+		close(interrupt)
+
+		// Get the duration.
+		duration, blacklist := server.BackoffIfRequired(backingOff, interrupt)
+
+		// Check if we should be blacklisted by now.
+		if i > stats.FailuresUntilBlacklist {
+			if !blacklist {
+				t.Fatalf("Backoff %d should have resulted in blacklist but didn't", i)
+			} else {
+				t.Logf("Backoff %d is blacklisted as expected", i)
+				continue
+			}
+		}
+
+		// Check if the duration is what we expect.
+		t.Logf("Backoff %d is for %s", i, duration)
+		if wanted := time.Second * time.Duration(math.Exp2(float64(i))); !blacklist && duration != wanted {
+			t.Fatalf("Backoff %d should have been %s but was %s", i, wanted, duration)
+		}
+	}
+}

go.mod

@@ -23,9 +23,9 @@ require (
 	github.com/matrix-org/go-http-js-libp2p v0.0.0-20200518170932-783164aeeda4
 	github.com/matrix-org/go-sqlite3-js v0.0.0-20200522092705-bc8506ccbcf3
 	github.com/matrix-org/gomatrix v0.0.0-20190528120928-7df988a63f26
-	github.com/matrix-org/gomatrixserverlib v0.0.0-20200807122736-eb1a0b991914
+	github.com/matrix-org/gomatrixserverlib v0.0.0-20200807145008-79c173b65786
 	github.com/matrix-org/naffka v0.0.0-20200422140631-181f1ee7401f
-	github.com/matrix-org/util v0.0.0-20190711121626-527ce5ddefc7
+	github.com/matrix-org/util v0.0.0-20200807132607-55161520e1d4
 	github.com/mattn/go-sqlite3 v2.0.2+incompatible
 	github.com/nfnt/resize v0.0.0-20160724205520-891127d8d1b5
 	github.com/ngrok/sqlmw v0.0.0-20200129213757-d5c93a81bec6

go.sum

@@ -425,12 +425,14 @@ github.com/matrix-org/go-sqlite3-js v0.0.0-20200522092705-bc8506ccbcf3 h1:Yb+Wlf
 github.com/matrix-org/go-sqlite3-js v0.0.0-20200522092705-bc8506ccbcf3/go.mod h1:e+cg2q7C7yE5QnAXgzo512tgFh1RbQLC0+jozuegKgo=
 github.com/matrix-org/gomatrix v0.0.0-20190528120928-7df988a63f26 h1:Hr3zjRsq2bhrnp3Ky1qgx/fzCtCALOoGYylh2tpS9K4=
 github.com/matrix-org/gomatrix v0.0.0-20190528120928-7df988a63f26/go.mod h1:3fxX6gUjWyI/2Bt7J1OLhpCzOfO/bB3AiX0cJtEKud0=
-github.com/matrix-org/gomatrixserverlib v0.0.0-20200807122736-eb1a0b991914 h1:VSGCvSUB1/Y32F/JSjmTaIW9jr1BmBHEd0ok4AaT/lo=
+github.com/matrix-org/gomatrixserverlib v0.0.0-20200807145008-79c173b65786 h1:HQclx5J2CrCBqP88t5Di9IkVDJZn5+h4ZL48viY4FJ4=
-github.com/matrix-org/gomatrixserverlib v0.0.0-20200807122736-eb1a0b991914/go.mod h1:JsAzE1Ll3+gDWS9JSUHPJiiyAksvOOnGWF2nXdg4ZzU=
+github.com/matrix-org/gomatrixserverlib v0.0.0-20200807145008-79c173b65786/go.mod h1:JsAzE1Ll3+gDWS9JSUHPJiiyAksvOOnGWF2nXdg4ZzU=
 github.com/matrix-org/naffka v0.0.0-20200422140631-181f1ee7401f h1:pRz4VTiRCO4zPlEMc3ESdUOcW4PXHH4Kj+YDz1XyE+Y=
 github.com/matrix-org/naffka v0.0.0-20200422140631-181f1ee7401f/go.mod h1:y0oDTjZDv5SM9a2rp3bl+CU+bvTRINQsdb7YlDql5Go=
 github.com/matrix-org/util v0.0.0-20190711121626-527ce5ddefc7 h1:ntrLa/8xVzeSs8vHFHK25k0C+NV74sYMJnNSg5NoSRo=
 github.com/matrix-org/util v0.0.0-20190711121626-527ce5ddefc7/go.mod h1:vVQlW/emklohkZnOPwD3LrZUBqdfsbiyO3p1lNV8F6U=
+github.com/matrix-org/util v0.0.0-20200807132607-55161520e1d4 h1:eCEHXWDv9Rm335MSuB49mFUK44bwZPFSDde3ORE3syk=
+github.com/matrix-org/util v0.0.0-20200807132607-55161520e1d4/go.mod h1:vVQlW/emklohkZnOPwD3LrZUBqdfsbiyO3p1lNV8F6U=
 github.com/mattn/go-colorable v0.0.9/go.mod h1:9vuHe8Xs5qXnSaW/c/ABM9alt+Vo+STaOChaDxuIBZU=
 github.com/mattn/go-colorable v0.1.1 h1:G1f5SKeVxmagw/IyvzvtZE4Gybcc4Tr1tf7I8z0XgOg=
 github.com/mattn/go-colorable v0.1.1/go.mod h1:FuOcm+DKB9mbwrcAfNl7/TZVBZ6rcnceauSikq3lYCQ=

internal/config/config_federationsender.go

@@ -14,7 +14,11 @@ type FederationSender struct {
 	// tolerate when sending federation requests to a specific server. The backoff
 	// is 2**x seconds, so 1 = 2 seconds, 2 = 4 seconds, 3 = 8 seconds, etc.
 	// The default value is 16 if not specified, which is circa 18 hours.
-	FederationMaxRetries uint32 `yaml:"federation_max_retries"`
+	FederationMaxRetries uint32 `yaml:"send_max_retries"`
+
+	// FederationDisableTLSValidation disables the validation of X.509 TLS certs
+	// on remote federation endpoints. This is not recommended in production!
+	DisableTLSValidation bool `yaml:"disable_tls_validation"`
 
 	Proxy Proxy `yaml:"proxy_outbound"`
 }
@@ -26,6 +30,7 @@ func (c *FederationSender) Defaults() {
 	c.Database.ConnectionString = "file:federationsender.db"
 
 	c.FederationMaxRetries = 16
+	c.DisableTLSValidation = false
 
 	c.Proxy.Defaults()
 }

internal/setup/base.go

@@ -251,6 +251,7 @@ func (b *BaseDendrite) CreateAccountsDB() accounts.Database {
 func (b *BaseDendrite) CreateFederationClient() *gomatrixserverlib.FederationClient {
 	return gomatrixserverlib.NewFederationClient(
 		b.Cfg.Global.ServerName, b.Cfg.Global.KeyID, b.Cfg.Global.PrivateKey,
+		b.Cfg.FederationSender.DisableTLSValidation,
 	)
 }
 

keyserver/internal/device_list_update.go

@@ -23,7 +23,6 @@ import (
 	"time"
 
 	"github.com/matrix-org/dendrite/keyserver/api"
-	"github.com/matrix-org/dendrite/keyserver/producers"
 	"github.com/matrix-org/gomatrixserverlib"
 	"github.com/matrix-org/util"
 	"github.com/sirupsen/logrus"
@@ -65,7 +64,7 @@ type DeviceListUpdater struct {
 	mu            *sync.Mutex // protects UserIDToMutex
 
 	db          DeviceListUpdaterDatabase
-	producer    *producers.KeyChange
+	producer    KeyChangeProducer
 	fedClient   *gomatrixserverlib.FederationClient
 	workerChans []chan gomatrixserverlib.ServerName
 }
@@ -88,9 +87,14 @@ type DeviceListUpdaterDatabase interface {
 	PrevIDsExists(ctx context.Context, userID string, prevIDs []int) (bool, error)
 }
 
+// KeyChangeProducer is the interface for producers.KeyChange useful for testing.
+type KeyChangeProducer interface {
+	ProduceKeyChanges(keys []api.DeviceMessage) error
+}
+
 // NewDeviceListUpdater creates a new updater which fetches fresh device lists when they go stale.
 func NewDeviceListUpdater(
-	db DeviceListUpdaterDatabase, producer *producers.KeyChange, fedClient *gomatrixserverlib.FederationClient,
+	db DeviceListUpdaterDatabase, producer KeyChangeProducer, fedClient *gomatrixserverlib.FederationClient,
 	numWorkers int,
 ) *DeviceListUpdater {
 	return &DeviceListUpdater{
@@ -154,12 +158,17 @@ func (u *DeviceListUpdater) update(ctx context.Context, event gomatrixserverlib.
 	if err != nil {
 		return false, fmt.Errorf("failed to check prev IDs exist for %s (%s): %w", event.UserID, event.DeviceID, err)
 	}
+	// if this is the first time we're hearing about this user, sync the device list manually.
+	if len(event.PrevID) == 0 {
+		exists = false
+	}
 	util.GetLogger(ctx).WithFields(logrus.Fields{
 		"prev_ids_exist": exists,
 		"user_id":        event.UserID,
 		"device_id":      event.DeviceID,
 		"stream_id":      event.StreamID,
 		"prev_ids":       event.PrevID,
+		"display_name":   event.DeviceDisplayName,
 	}).Info("DeviceListUpdater.Update")
 
 	// if we haven't missed anything update the database and notify users
@@ -263,16 +272,17 @@ func (u *DeviceListUpdater) processServer(serverName gomatrixserverlib.ServerNam
 			hasFailures = true
 			continue
 		}
-		err = u.updateDeviceList(ctx, &res)
+		err = u.updateDeviceList(&res)
 		if err != nil {
-			logger.WithError(err).WithField("user_id", userID).Error("fetched device list but failed to store it")
+			logger.WithError(err).WithField("user_id", userID).Error("fetched device list but failed to store/emit it")
 			hasFailures = true
 		}
 	}
 	return hasFailures
 }
 
-func (u *DeviceListUpdater) updateDeviceList(ctx context.Context, res *gomatrixserverlib.RespUserDevices) error {
+func (u *DeviceListUpdater) updateDeviceList(res *gomatrixserverlib.RespUserDevices) error {
+	ctx := context.Background() // we've got the keys, don't time out when persisting them to the database.
 	keys := make([]api.DeviceMessage, len(res.Devices))
 	for i, device := range res.Devices {
 		keyJSON, err := json.Marshal(device.Keys)
@@ -292,7 +302,15 @@ func (u *DeviceListUpdater) updateDeviceList(ctx context.Context, res *gomatrixs
 	}
 	err := u.db.StoreRemoteDeviceKeys(ctx, keys)
 	if err != nil {
-		return err
+		return fmt.Errorf("failed to store remote device keys: %w", err)
 	}
-	return u.db.MarkDeviceListStale(ctx, res.UserID, false)
+	err = u.db.MarkDeviceListStale(ctx, res.UserID, false)
+	if err != nil {
+		return fmt.Errorf("failed to mark device list as fresh: %w", err)
+	}
+	err = u.producer.ProduceKeyChanges(keys)
+	if err != nil {
+		return fmt.Errorf("failed to emit key changes for fresh device list: %w", err)
+	}
+	return nil
 }

keyserver/internal/device_list_update_test.go

@@ -0,0 +1,242 @@
+// Copyright 2020 The Matrix.org Foundation C.I.C.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package internal
+
+import (
+	"context"
+	"crypto/ed25519"
+	"fmt"
+	"io/ioutil"
+	"net/http"
+	"net/url"
+	"reflect"
+	"strings"
+	"sync"
+	"testing"
+	"time"
+
+	"github.com/matrix-org/dendrite/keyserver/api"
+	"github.com/matrix-org/gomatrixserverlib"
+)
+
+var (
+	ctx = context.Background()
+)
+
+type mockKeyChangeProducer struct {
+	events []api.DeviceMessage
+}
+
+func (p *mockKeyChangeProducer) ProduceKeyChanges(keys []api.DeviceMessage) error {
+	p.events = append(p.events, keys...)
+	return nil
+}
+
+type mockDeviceListUpdaterDatabase struct {
+	staleUsers   map[string]bool
+	prevIDsExist func(string, []int) bool
+	storedKeys   []api.DeviceMessage
+}
+
+// StaleDeviceLists returns a list of user IDs ending with the domains provided who have stale device lists.
+// If no domains are given, all user IDs with stale device lists are returned.
+func (d *mockDeviceListUpdaterDatabase) StaleDeviceLists(ctx context.Context, domains []gomatrixserverlib.ServerName) ([]string, error) {
+	var result []string
+	for userID := range d.staleUsers {
+		_, remoteServer, err := gomatrixserverlib.SplitID('@', userID)
+		if err != nil {
+			return nil, err
+		}
+		if len(domains) == 0 {
+			result = append(result, userID)
+			continue
+		}
+		for _, d := range domains {
+			if remoteServer == d {
+				result = append(result, userID)
+				break
+			}
+		}
+	}
+	return result, nil
+}
+
+// MarkDeviceListStale sets the stale bit for this user to isStale.
+func (d *mockDeviceListUpdaterDatabase) MarkDeviceListStale(ctx context.Context, userID string, isStale bool) error {
+	d.staleUsers[userID] = isStale
+	return nil
+}
+
+// StoreRemoteDeviceKeys persists the given keys. Keys with the same user ID and device ID will be replaced. An empty KeyJSON removes the key
+// for this (user, device). Does not modify the stream ID for keys.
+func (d *mockDeviceListUpdaterDatabase) StoreRemoteDeviceKeys(ctx context.Context, keys []api.DeviceMessage) error {
+	d.storedKeys = append(d.storedKeys, keys...)
+	return nil
+}
+
+// PrevIDsExists returns true if all prev IDs exist for this user.
+func (d *mockDeviceListUpdaterDatabase) PrevIDsExists(ctx context.Context, userID string, prevIDs []int) (bool, error) {
+	return d.prevIDsExist(userID, prevIDs), nil
+}
+
+type roundTripper struct {
+	fn func(*http.Request) (*http.Response, error)
+}
+
+func (t *roundTripper) RoundTrip(req *http.Request) (*http.Response, error) {
+	return t.fn(req)
+}
+
+func newFedClient(tripper func(*http.Request) (*http.Response, error)) *gomatrixserverlib.FederationClient {
+	_, pkey, _ := ed25519.GenerateKey(nil)
+	fedClient := gomatrixserverlib.NewFederationClient(
+		gomatrixserverlib.ServerName("example.test"), gomatrixserverlib.KeyID("ed25519:test"), pkey, true,
+	)
+	fedClient.Client = *gomatrixserverlib.NewClientWithTransport(true, &roundTripper{tripper})
+	return fedClient
+}
+
+// Test that the device keys get persisted and emitted if we have the previous IDs.
+func TestUpdateHavePrevID(t *testing.T) {
+	db := &mockDeviceListUpdaterDatabase{
+		staleUsers: make(map[string]bool),
+		prevIDsExist: func(string, []int) bool {
+			return true
+		},
+	}
+	producer := &mockKeyChangeProducer{}
+	updater := NewDeviceListUpdater(db, producer, nil, 1)
+	event := gomatrixserverlib.DeviceListUpdateEvent{
+		DeviceDisplayName: "Foo Bar",
+		Deleted:           false,
+		DeviceID:          "FOO",
+		Keys:              []byte(`{"key":"value"}`),
+		PrevID:            []int{0},
+		StreamID:          1,
+		UserID:            "@alice:localhost",
+	}
+	err := updater.Update(ctx, event)
+	if err != nil {
+		t.Fatalf("Update returned an error: %s", err)
+	}
+	want := api.DeviceMessage{
+		StreamID: event.StreamID,
+		DeviceKeys: api.DeviceKeys{
+			DeviceID:    event.DeviceID,
+			DisplayName: event.DeviceDisplayName,
+			KeyJSON:     event.Keys,
+			UserID:      event.UserID,
+		},
+	}
+	if !reflect.DeepEqual(producer.events, []api.DeviceMessage{want}) {
+		t.Errorf("Update didn't produce correct event, got %v want %v", producer.events, want)
+	}
+	if !reflect.DeepEqual(db.storedKeys, []api.DeviceMessage{want}) {
+		t.Errorf("DB didn't store correct event, got %v want %v", db.storedKeys, want)
+	}
+	if db.staleUsers[event.UserID] {
+		t.Errorf("%s incorrectly marked as stale", event.UserID)
+	}
+}
+
+// Test that device keys are fetched from the remote server if we are missing prev IDs
+// and that the user's devices are marked as stale until it succeeds.
+func TestUpdateNoPrevID(t *testing.T) {
+	db := &mockDeviceListUpdaterDatabase{
+		staleUsers: make(map[string]bool),
+		prevIDsExist: func(string, []int) bool {
+			return false
+		},
+	}
+	producer := &mockKeyChangeProducer{}
+	remoteUserID := "@alice:example.somewhere"
+	var wg sync.WaitGroup
+	wg.Add(1)
+	keyJSON := `{"user_id":"` + remoteUserID + `","device_id":"JLAFKJWSCS","algorithms":["m.olm.v1.curve25519-aes-sha2","m.megolm.v1.aes-sha2"],"keys":{"curve25519:JLAFKJWSCS":"3C5BFWi2Y8MaVvjM8M22DBmh24PmgR0nPvJOIArzgyI","ed25519:JLAFKJWSCS":"lEuiRJBit0IG6nUf5pUzWTUEsRVVe/HJkoKuEww9ULI"},"signatures":{"` + remoteUserID + `":{"ed25519:JLAFKJWSCS":"dSO80A01XiigH3uBiDVx/EjzaoycHcjq9lfQX0uWsqxl2giMIiSPR8a4d291W1ihKJL/a+myXS367WT6NAIcBA"}}}`
+	fedClient := newFedClient(func(req *http.Request) (*http.Response, error) {
+		defer wg.Done()
+		if req.URL.Path != "/_matrix/federation/v1/user/devices/"+url.PathEscape(remoteUserID) {
+			return nil, fmt.Errorf("test: invalid path: %s", req.URL.Path)
+		}
+		return &http.Response{
+			StatusCode: 200,
+			Body: ioutil.NopCloser(strings.NewReader(`
+			{
+				"user_id": "` + remoteUserID + `",
+				"stream_id": 5,
+				"devices": [
+				  {
+					"device_id": "JLAFKJWSCS",
+					"keys": ` + keyJSON + `,
+					"device_display_name": "Mobile Phone"
+				  }
+				]
+			  }
+			`)),
+		}, nil
+	})
+	updater := NewDeviceListUpdater(db, producer, fedClient, 2)
+	if err := updater.Start(); err != nil {
+		t.Fatalf("failed to start updater: %s", err)
+	}
+	event := gomatrixserverlib.DeviceListUpdateEvent{
+		DeviceDisplayName: "Mobile Phone",
+		Deleted:           false,
+		DeviceID:          "another_device_id",
+		Keys:              []byte(`{"key":"value"}`),
+		PrevID:            []int{3},
+		StreamID:          4,
+		UserID:            remoteUserID,
+	}
+	err := updater.Update(ctx, event)
+	if err != nil {
+		t.Fatalf("Update returned an error: %s", err)
+	}
+	// At this point we show have this device list marked as stale and not store the keys or emitted anything
+	if !db.staleUsers[event.UserID] {
+		t.Errorf("%s not marked as stale", event.UserID)
+	}
+	if len(producer.events) > 0 {
+		t.Errorf("Update incorrect emitted %d device change events", len(producer.events))
+	}
+	if len(db.storedKeys) > 0 {
+		t.Errorf("Update incorrect stored %d device change events", len(db.storedKeys))
+	}
+	t.Log("waiting for /users/devices to be called...")
+	wg.Wait()
+	// wait a bit for db to be updated...
+	time.Sleep(100 * time.Millisecond)
+	want := api.DeviceMessage{
+		StreamID: 5,
+		DeviceKeys: api.DeviceKeys{
+			DeviceID:    "JLAFKJWSCS",
+			DisplayName: "Mobile Phone",
+			UserID:      remoteUserID,
+			KeyJSON:     []byte(keyJSON),
+		},
+	}
+	// Now we should have a fresh list and the keys and emitted something
+	if db.staleUsers[event.UserID] {
+		t.Errorf("%s still marked as stale", event.UserID)
+	}
+	if !reflect.DeepEqual(producer.events, []api.DeviceMessage{want}) {
+		t.Logf("len got %d len want %d", len(producer.events[0].KeyJSON), len(want.KeyJSON))
+		t.Errorf("Update didn't produce correct event, got %v want %v", producer.events, want)
+	}
+	if !reflect.DeepEqual(db.storedKeys, []api.DeviceMessage{want}) {
+		t.Errorf("DB didn't store correct event, got %v want %v", db.storedKeys, want)
+	}
+
+}

keyserver/internal/internal.go

@@ -250,10 +250,14 @@ func (a *KeyInternalAPI) QueryKeys(ctx context.Context, req *api.QueryKeysReques
 				if len(dk.KeyJSON) == 0 {
 					continue // don't include blank keys
 				}
-				// inject display name if known
+				// inject display name if known (either locally or remotely)
+				displayName := dk.DisplayName
+				if queryRes.DeviceInfo[dk.DeviceID].DisplayName != "" {
+					displayName = queryRes.DeviceInfo[dk.DeviceID].DisplayName
+				}
 				dk.KeyJSON, _ = sjson.SetBytes(dk.KeyJSON, "unsigned", struct {
 					DisplayName string `json:"device_display_name,omitempty"`
-				}{queryRes.DeviceInfo[dk.DeviceID].DisplayName})
+				}{displayName})
 				res.DeviceKeys[userID][dk.DeviceID] = dk.KeyJSON
 			}
 		} else {
@@ -261,12 +265,49 @@ func (a *KeyInternalAPI) QueryKeys(ctx context.Context, req *api.QueryKeysReques
 			domainToDeviceKeys[domain][userID] = append(domainToDeviceKeys[domain][userID], deviceIDs...)
 		}
 	}
-	// TODO: set device display names when they are known
+
+	// attempt to satisfy key queries from the local database first as we should get device updates pushed to us
+	domainToDeviceKeys = a.remoteKeysFromDatabase(ctx, res, domainToDeviceKeys)
+	if len(domainToDeviceKeys) == 0 {
+		return // nothing to query
+	}
 
 	// perform key queries for remote devices
 	a.queryRemoteKeys(ctx, req.Timeout, res, domainToDeviceKeys)
 }
 
+func (a *KeyInternalAPI) remoteKeysFromDatabase(
+	ctx context.Context, res *api.QueryKeysResponse, domainToDeviceKeys map[string]map[string][]string,
+) map[string]map[string][]string {
+	fetchRemote := make(map[string]map[string][]string)
+	for domain, userToDeviceMap := range domainToDeviceKeys {
+		for userID, deviceIDs := range userToDeviceMap {
+			keys, err := a.DB.DeviceKeysForUser(ctx, userID, deviceIDs)
+			// if we can't query the db or there are fewer keys than requested, fetch from remote.
+			// Likewise, we can't safely return keys from the db when all devices are requested as we don't
+			// know if one has just been added.
+			if len(deviceIDs) == 0 || err != nil || len(keys) < len(deviceIDs) {
+				if _, ok := fetchRemote[domain]; !ok {
+					fetchRemote[domain] = make(map[string][]string)
+				}
+				fetchRemote[domain][userID] = append(fetchRemote[domain][userID], deviceIDs...)
+				continue
+			}
+			if res.DeviceKeys[userID] == nil {
+				res.DeviceKeys[userID] = make(map[string]json.RawMessage)
+			}
+			for _, key := range keys {
+				// inject the display name
+				key.KeyJSON, _ = sjson.SetBytes(key.KeyJSON, "unsigned", struct {
+					DisplayName string `json:"device_display_name,omitempty"`
+				}{key.DisplayName})
+				res.DeviceKeys[userID][key.DeviceID] = key.KeyJSON
+			}
+		}
+	}
+	return fetchRemote
+}
+
 func (a *KeyInternalAPI) queryRemoteKeys(
 	ctx context.Context, timeout time.Duration, res *api.QueryKeysResponse, domainToDeviceKeys map[string]map[string][]string,
 ) {

keyserver/storage/postgres/device_keys_table.go

@@ -37,22 +37,23 @@ CREATE TABLE IF NOT EXISTS keyserver_device_keys (
 	-- required in the spec because in the event of a missed update the server fetches the entire
 	-- current set of keys rather than trying to 'fast-forward' or catchup missing stream IDs.
 	stream_id BIGINT NOT NULL,
+	display_name TEXT,
 	-- Clobber based on tuple of user/device.
     CONSTRAINT keyserver_device_keys_unique UNIQUE (user_id, device_id)
 );
 `
 
 const upsertDeviceKeysSQL = "" +
-	"INSERT INTO keyserver_device_keys (user_id, device_id, ts_added_secs, key_json, stream_id)" +
+	"INSERT INTO keyserver_device_keys (user_id, device_id, ts_added_secs, key_json, stream_id, display_name)" +
-	" VALUES ($1, $2, $3, $4, $5)" +
+	" VALUES ($1, $2, $3, $4, $5, $6)" +
 	" ON CONFLICT ON CONSTRAINT keyserver_device_keys_unique" +
-	" DO UPDATE SET key_json = $4, stream_id = $5"
+	" DO UPDATE SET key_json = $4, stream_id = $5, display_name = $6"
 
 const selectDeviceKeysSQL = "" +
-	"SELECT key_json, stream_id FROM keyserver_device_keys WHERE user_id=$1 AND device_id=$2"
+	"SELECT key_json, stream_id, display_name FROM keyserver_device_keys WHERE user_id=$1 AND device_id=$2"
 
 const selectBatchDeviceKeysSQL = "" +
-	"SELECT device_id, key_json, stream_id FROM keyserver_device_keys WHERE user_id=$1"
+	"SELECT device_id, key_json, stream_id, display_name FROM keyserver_device_keys WHERE user_id=$1"
 
 const selectMaxStreamForUserSQL = "" +
 	"SELECT MAX(stream_id) FROM keyserver_device_keys WHERE user_id=$1"
@@ -99,13 +100,17 @@ func (s *deviceKeysStatements) SelectDeviceKeysJSON(ctx context.Context, keys []
 	for i, key := range keys {
 		var keyJSONStr string
 		var streamID int
-		err := s.selectDeviceKeysStmt.QueryRowContext(ctx, key.UserID, key.DeviceID).Scan(&keyJSONStr, &streamID)
+		var displayName sql.NullString
+		err := s.selectDeviceKeysStmt.QueryRowContext(ctx, key.UserID, key.DeviceID).Scan(&keyJSONStr, &streamID, &displayName)
 		if err != nil && err != sql.ErrNoRows {
 			return err
 		}
 		// this will be '' when there is no device
 		keys[i].KeyJSON = []byte(keyJSONStr)
 		keys[i].StreamID = streamID
+		if displayName.Valid {
+			keys[i].DisplayName = displayName.String
+		}
 	}
 	return nil
 }
@@ -140,7 +145,7 @@ func (s *deviceKeysStatements) InsertDeviceKeys(ctx context.Context, txn *sql.Tx
 	for _, key := range keys {
 		now := time.Now().Unix()
 		_, err := txn.Stmt(s.upsertDeviceKeysStmt).ExecContext(
-			ctx, key.UserID, key.DeviceID, now, string(key.KeyJSON), key.StreamID,
+			ctx, key.UserID, key.DeviceID, now, string(key.KeyJSON), key.StreamID, key.DisplayName,
 		)
 		if err != nil {
 			return err
@@ -165,11 +170,15 @@ func (s *deviceKeysStatements) SelectBatchDeviceKeys(ctx context.Context, userID
 		dk.UserID = userID
 		var keyJSON string
 		var streamID int
-		if err := rows.Scan(&dk.DeviceID, &keyJSON, &streamID); err != nil {
+		var displayName sql.NullString
+		if err := rows.Scan(&dk.DeviceID, &keyJSON, &streamID, &displayName); err != nil {
 			return nil, err
 		}
 		dk.KeyJSON = []byte(keyJSON)
 		dk.StreamID = streamID
+		if displayName.Valid {
+			dk.DisplayName = displayName.String
+		}
 		// include the key if we want all keys (no device) or it was asked
 		if deviceIDMap[dk.DeviceID] || len(deviceIDs) == 0 {
 			result = append(result, dk)

keyserver/storage/postgres/stale_device_lists.go

@@ -0,0 +1,118 @@
+// Copyright 2020 The Matrix.org Foundation C.I.C.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package postgres
+
+import (
+	"context"
+	"database/sql"
+	"time"
+
+	"github.com/matrix-org/dendrite/internal"
+	"github.com/matrix-org/dendrite/keyserver/storage/tables"
+	"github.com/matrix-org/gomatrixserverlib"
+)
+
+var staleDeviceListsSchema = `
+-- Stores whether a user's device lists are stale or not.
+CREATE TABLE IF NOT EXISTS keyserver_stale_device_lists (
+    user_id TEXT PRIMARY KEY NOT NULL,
+	domain TEXT NOT NULL,
+	is_stale BOOLEAN NOT NULL,
+	ts_added_secs BIGINT NOT NULL
+);
+
+CREATE INDEX IF NOT EXISTS keyserver_stale_device_lists_idx ON keyserver_stale_device_lists (domain, is_stale);
+`
+
+const upsertStaleDeviceListSQL = "" +
+	"INSERT INTO keyserver_stale_device_lists (user_id, domain, is_stale, ts_added_secs)" +
+	" VALUES ($1, $2, $3, $4)" +
+	" ON CONFLICT (user_id)" +
+	" DO UPDATE SET is_stale = $3, ts_added_secs = $4"
+
+const selectStaleDeviceListsWithDomainsSQL = "" +
+	"SELECT user_id FROM keyserver_stale_device_lists WHERE is_stale = $1 AND domain = $2"
+
+const selectStaleDeviceListsSQL = "" +
+	"SELECT user_id FROM keyserver_stale_device_lists WHERE is_stale = $1"
+
+type staleDeviceListsStatements struct {
+	upsertStaleDeviceListStmt             *sql.Stmt
+	selectStaleDeviceListsWithDomainsStmt *sql.Stmt
+	selectStaleDeviceListsStmt            *sql.Stmt
+}
+
+func NewPostgresStaleDeviceListsTable(db *sql.DB) (tables.StaleDeviceLists, error) {
+	s := &staleDeviceListsStatements{}
+	_, err := db.Exec(staleDeviceListsSchema)
+	if err != nil {
+		return nil, err
+	}
+	if s.upsertStaleDeviceListStmt, err = db.Prepare(upsertStaleDeviceListSQL); err != nil {
+		return nil, err
+	}
+	if s.selectStaleDeviceListsStmt, err = db.Prepare(selectStaleDeviceListsSQL); err != nil {
+		return nil, err
+	}
+	if s.selectStaleDeviceListsWithDomainsStmt, err = db.Prepare(selectStaleDeviceListsWithDomainsSQL); err != nil {
+		return nil, err
+	}
+	return s, nil
+}
+
+func (s *staleDeviceListsStatements) InsertStaleDeviceList(ctx context.Context, userID string, isStale bool) error {
+	_, domain, err := gomatrixserverlib.SplitID('@', userID)
+	if err != nil {
+		return err
+	}
+	_, err = s.upsertStaleDeviceListStmt.ExecContext(ctx, userID, string(domain), isStale, time.Now().Unix())
+	return err
+}
+
+func (s *staleDeviceListsStatements) SelectUserIDsWithStaleDeviceLists(ctx context.Context, domains []gomatrixserverlib.ServerName) ([]string, error) {
+	// we only query for 1 domain or all domains so optimise for those use cases
+	if len(domains) == 0 {
+		rows, err := s.selectStaleDeviceListsStmt.QueryContext(ctx, true)
+		if err != nil {
+			return nil, err
+		}
+		return rowsToUserIDs(ctx, rows)
+	}
+	var result []string
+	for _, domain := range domains {
+		rows, err := s.selectStaleDeviceListsWithDomainsStmt.QueryContext(ctx, true, string(domain))
+		if err != nil {
+			return nil, err
+		}
+		userIDs, err := rowsToUserIDs(ctx, rows)
+		if err != nil {
+			return nil, err
+		}
+		result = append(result, userIDs...)
+	}
+	return result, nil
+}
+
+func rowsToUserIDs(ctx context.Context, rows *sql.Rows) (result []string, err error) {
+	defer internal.CloseAndLogIfError(ctx, rows, "closing rowsToUserIDs failed")
+	for rows.Next() {
+		var userID string
+		if err := rows.Scan(&userID); err != nil {
+			return nil, err
+		}
+		result = append(result, userID)
+	}
+	return result, rows.Err()
+}

keyserver/storage/postgres/storage.go

@@ -39,10 +39,15 @@ func NewDatabase(dbProperties *config.DatabaseOptions) (*shared.Database, error)
 	if err != nil {
 		return nil, err
 	}
+	sdl, err := NewPostgresStaleDeviceListsTable(db)
+	if err != nil {
+		return nil, err
+	}
 	return &shared.Database{
 		DB:                    db,
 		OneTimeKeysTable:      otk,
 		DeviceKeysTable:       dk,
 		KeyChangesTable:       kc,
+		StaleDeviceListsTable: sdl,
 	}, nil
 }

keyserver/storage/shared/storage.go

@@ -30,6 +30,7 @@ type Database struct {
 	OneTimeKeysTable      tables.OneTimeKeys
 	DeviceKeysTable       tables.DeviceKeys
 	KeyChangesTable       tables.KeyChanges
+	StaleDeviceListsTable tables.StaleDeviceLists
 }
 
 func (d *Database) ExistingOneTimeKeys(ctx context.Context, userID, deviceID string, keyIDsWithAlgorithms []string) (map[string]json.RawMessage, error) {
@@ -129,10 +130,10 @@ func (d *Database) KeyChanges(ctx context.Context, partition int32, fromOffset,
 // StaleDeviceLists returns a list of user IDs ending with the domains provided who have stale device lists.
 // If no domains are given, all user IDs with stale device lists are returned.
 func (d *Database) StaleDeviceLists(ctx context.Context, domains []gomatrixserverlib.ServerName) ([]string, error) {
-	return nil, nil // TODO
+	return d.StaleDeviceListsTable.SelectUserIDsWithStaleDeviceLists(ctx, domains)
 }
 
 // MarkDeviceListStale sets the stale bit for this user to isStale.
 func (d *Database) MarkDeviceListStale(ctx context.Context, userID string, isStale bool) error {
-	return nil // TODO
+	return d.StaleDeviceListsTable.InsertStaleDeviceList(ctx, userID, isStale)
 }

keyserver/storage/sqlite3/device_keys_table.go

@@ -34,22 +34,23 @@ CREATE TABLE IF NOT EXISTS keyserver_device_keys (
 	ts_added_secs BIGINT NOT NULL,
 	key_json TEXT NOT NULL,
 	stream_id BIGINT NOT NULL,
+	display_name TEXT,
 	-- Clobber based on tuple of user/device.
     UNIQUE (user_id, device_id)
 );
 `
 
 const upsertDeviceKeysSQL = "" +
-	"INSERT INTO keyserver_device_keys (user_id, device_id, ts_added_secs, key_json, stream_id)" +
+	"INSERT INTO keyserver_device_keys (user_id, device_id, ts_added_secs, key_json, stream_id, display_name)" +
-	" VALUES ($1, $2, $3, $4, $5)" +
+	" VALUES ($1, $2, $3, $4, $5, $6)" +
 	" ON CONFLICT (user_id, device_id)" +
-	" DO UPDATE SET key_json = $4, stream_id = $5"
+	" DO UPDATE SET key_json = $4, stream_id = $5, display_name = $6"
 
 const selectDeviceKeysSQL = "" +
-	"SELECT key_json, stream_id FROM keyserver_device_keys WHERE user_id=$1 AND device_id=$2"
+	"SELECT key_json, stream_id, display_name FROM keyserver_device_keys WHERE user_id=$1 AND device_id=$2"
 
 const selectBatchDeviceKeysSQL = "" +
-	"SELECT device_id, key_json, stream_id FROM keyserver_device_keys WHERE user_id=$1"
+	"SELECT device_id, key_json, stream_id, display_name FROM keyserver_device_keys WHERE user_id=$1"
 
 const selectMaxStreamForUserSQL = "" +
 	"SELECT MAX(stream_id) FROM keyserver_device_keys WHERE user_id=$1"
@@ -106,11 +107,15 @@ func (s *deviceKeysStatements) SelectBatchDeviceKeys(ctx context.Context, userID
 		dk.UserID = userID
 		var keyJSON string
 		var streamID int
-		if err := rows.Scan(&dk.DeviceID, &keyJSON, &streamID); err != nil {
+		var displayName sql.NullString
+		if err := rows.Scan(&dk.DeviceID, &keyJSON, &streamID, &displayName); err != nil {
 			return nil, err
 		}
 		dk.KeyJSON = []byte(keyJSON)
 		dk.StreamID = streamID
+		if displayName.Valid {
+			dk.DisplayName = displayName.String
+		}
 		// include the key if we want all keys (no device) or it was asked
 		if deviceIDMap[dk.DeviceID] || len(deviceIDs) == 0 {
 			result = append(result, dk)
@@ -123,13 +128,17 @@ func (s *deviceKeysStatements) SelectDeviceKeysJSON(ctx context.Context, keys []
 	for i, key := range keys {
 		var keyJSONStr string
 		var streamID int
-		err := s.selectDeviceKeysStmt.QueryRowContext(ctx, key.UserID, key.DeviceID).Scan(&keyJSONStr, &streamID)
+		var displayName sql.NullString
+		err := s.selectDeviceKeysStmt.QueryRowContext(ctx, key.UserID, key.DeviceID).Scan(&keyJSONStr, &streamID, &displayName)
 		if err != nil && err != sql.ErrNoRows {
 			return err
 		}
 		// this will be '' when there is no device
 		keys[i].KeyJSON = []byte(keyJSONStr)
 		keys[i].StreamID = streamID
+		if displayName.Valid {
+			keys[i].DisplayName = displayName.String
+		}
 	}
 	return nil
 }
@@ -171,7 +180,7 @@ func (s *deviceKeysStatements) InsertDeviceKeys(ctx context.Context, txn *sql.Tx
 		for _, key := range keys {
 			now := time.Now().Unix()
 			_, err := txn.Stmt(s.upsertDeviceKeysStmt).ExecContext(
-				ctx, key.UserID, key.DeviceID, now, string(key.KeyJSON), key.StreamID,
+				ctx, key.UserID, key.DeviceID, now, string(key.KeyJSON), key.StreamID, key.DisplayName,
 			)
 			if err != nil {
 				return err

keyserver/storage/sqlite3/one_time_keys_table.go

@@ -196,6 +196,9 @@ func (s *oneTimeKeysStatements) SelectAndDeleteOneTimeKey(
 		_, err = txn.StmtContext(ctx, s.deleteOneTimeKeyStmt).ExecContext(ctx, userID, deviceID, algorithm, keyID)
 		return err
 	})
+	if keyJSON == "" {
+		return nil, nil
+	}
 	return map[string]json.RawMessage{
 		algorithm + ":" + keyID: json.RawMessage(keyJSON),
 	}, err

keyserver/storage/sqlite3/stale_device_lists.go

@@ -0,0 +1,118 @@
+// Copyright 2020 The Matrix.org Foundation C.I.C.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package sqlite3
+
+import (
+	"context"
+	"database/sql"
+	"time"
+
+	"github.com/matrix-org/dendrite/internal"
+	"github.com/matrix-org/dendrite/keyserver/storage/tables"
+	"github.com/matrix-org/gomatrixserverlib"
+)
+
+var staleDeviceListsSchema = `
+-- Stores whether a user's device lists are stale or not.
+CREATE TABLE IF NOT EXISTS keyserver_stale_device_lists (
+    user_id TEXT PRIMARY KEY NOT NULL,
+	domain TEXT NOT NULL,
+	is_stale BOOLEAN NOT NULL,
+	ts_added_secs BIGINT NOT NULL
+);
+
+CREATE INDEX IF NOT EXISTS keyserver_stale_device_lists_idx ON keyserver_stale_device_lists (domain, is_stale);
+`
+
+const upsertStaleDeviceListSQL = "" +
+	"INSERT INTO keyserver_stale_device_lists (user_id, domain, is_stale, ts_added_secs)" +
+	" VALUES ($1, $2, $3, $4)" +
+	" ON CONFLICT (user_id)" +
+	" DO UPDATE SET is_stale = $3, ts_added_secs = $4"
+
+const selectStaleDeviceListsWithDomainsSQL = "" +
+	"SELECT user_id FROM keyserver_stale_device_lists WHERE is_stale = $1 AND domain = $2"
+
+const selectStaleDeviceListsSQL = "" +
+	"SELECT user_id FROM keyserver_stale_device_lists WHERE is_stale = $1"
+
+type staleDeviceListsStatements struct {
+	upsertStaleDeviceListStmt             *sql.Stmt
+	selectStaleDeviceListsWithDomainsStmt *sql.Stmt
+	selectStaleDeviceListsStmt            *sql.Stmt
+}
+
+func NewSqliteStaleDeviceListsTable(db *sql.DB) (tables.StaleDeviceLists, error) {
+	s := &staleDeviceListsStatements{}
+	_, err := db.Exec(staleDeviceListsSchema)
+	if err != nil {
+		return nil, err
+	}
+	if s.upsertStaleDeviceListStmt, err = db.Prepare(upsertStaleDeviceListSQL); err != nil {
+		return nil, err
+	}
+	if s.selectStaleDeviceListsStmt, err = db.Prepare(selectStaleDeviceListsSQL); err != nil {
+		return nil, err
+	}
+	if s.selectStaleDeviceListsWithDomainsStmt, err = db.Prepare(selectStaleDeviceListsWithDomainsSQL); err != nil {
+		return nil, err
+	}
+	return s, nil
+}
+
+func (s *staleDeviceListsStatements) InsertStaleDeviceList(ctx context.Context, userID string, isStale bool) error {
+	_, domain, err := gomatrixserverlib.SplitID('@', userID)
+	if err != nil {
+		return err
+	}
+	_, err = s.upsertStaleDeviceListStmt.ExecContext(ctx, userID, string(domain), isStale, time.Now().Unix())
+	return err
+}
+
+func (s *staleDeviceListsStatements) SelectUserIDsWithStaleDeviceLists(ctx context.Context, domains []gomatrixserverlib.ServerName) ([]string, error) {
+	// we only query for 1 domain or all domains so optimise for those use cases
+	if len(domains) == 0 {
+		rows, err := s.selectStaleDeviceListsStmt.QueryContext(ctx, true)
+		if err != nil {
+			return nil, err
+		}
+		return rowsToUserIDs(ctx, rows)
+	}
+	var result []string
+	for _, domain := range domains {
+		rows, err := s.selectStaleDeviceListsWithDomainsStmt.QueryContext(ctx, true, string(domain))
+		if err != nil {
+			return nil, err
+		}
+		userIDs, err := rowsToUserIDs(ctx, rows)
+		if err != nil {
+			return nil, err
+		}
+		result = append(result, userIDs...)
+	}
+	return result, nil
+}
+
+func rowsToUserIDs(ctx context.Context, rows *sql.Rows) (result []string, err error) {
+	defer internal.CloseAndLogIfError(ctx, rows, "closing rowsToUserIDs failed")
+	for rows.Next() {
+		var userID string
+		if err := rows.Scan(&userID); err != nil {
+			return nil, err
+		}
+		result = append(result, userID)
+	}
+	return result, rows.Err()
+}

keyserver/storage/sqlite3/storage.go

@@ -37,10 +37,15 @@ func NewDatabase(dbProperties *config.DatabaseOptions) (*shared.Database, error)
 	if err != nil {
 		return nil, err
 	}
+	sdl, err := NewSqliteStaleDeviceListsTable(db)
+	if err != nil {
+		return nil, err
+	}
 	return &shared.Database{
 		DB:                    db,
 		OneTimeKeysTable:      otk,
 		DeviceKeysTable:       dk,
 		KeyChangesTable:       kc,
+		StaleDeviceListsTable: sdl,
 	}, nil
 }

keyserver/storage/tables/interface.go

@@ -20,6 +20,7 @@ import (
 	"encoding/json"
 
 	"github.com/matrix-org/dendrite/keyserver/api"
+	"github.com/matrix-org/gomatrixserverlib"
 )
 
 type OneTimeKeys interface {
@@ -45,3 +46,8 @@ type KeyChanges interface {
 	// Results are exclusive of fromOffset and inclusive of toOffset. A toOffset of sarama.OffsetNewest means no upper offset.
 	SelectKeyChanges(ctx context.Context, partition int32, fromOffset, toOffset int64) (userIDs []string, latestOffset int64, err error)
 }
+
+type StaleDeviceLists interface {
+	InsertStaleDeviceList(ctx context.Context, userID string, isStale bool) error
+	SelectUserIDsWithStaleDeviceLists(ctx context.Context, domains []gomatrixserverlib.ServerName) ([]string, error)
+}

serverkeyapi/serverkeyapi_test.go

@@ -88,7 +88,7 @@ func TestMain(m *testing.M) {
 
 		// Create the federation client.
 		s.fedclient = gomatrixserverlib.NewFederationClientWithTransport(
-			s.config.Matrix.ServerName, serverKeyID, testPriv, transport,
+			s.config.Matrix.ServerName, serverKeyID, testPriv, true, transport,
 		)
 
 		// Finally, build the server key APIs.

syncapi/internal/keychange.go

@@ -46,6 +46,7 @@ func DeviceOTKCounts(ctx context.Context, keyAPI keyapi.KeyInternalAPI, userID,
 // DeviceListCatchup fills in the given response for the given user ID to bring it up-to-date with device lists. hasNew=true if the response
 // was filled in, else false if there are no new device list changes because there is nothing to catch up on. The response MUST
 // be already filled in with join/leave information.
+// nolint:gocyclo
 func DeviceListCatchup(
 	ctx context.Context, keyAPI keyapi.KeyInternalAPI, stateAPI currentstateAPI.CurrentStateInternalAPI,
 	userID string, res *types.Response, from, to types.StreamingToken,
@@ -68,22 +69,20 @@ func DeviceListCatchup(
 
 	var partition int32
 	var offset int64
+	partition = -1
+	offset = sarama.OffsetOldest
 	// Extract partition/offset from sync token
 	// TODO: In a world where keyserver is sharded there will be multiple partitions and hence multiple QueryKeyChanges to make.
 	logOffset := from.Log(DeviceListLogName)
 	if logOffset != nil {
 		partition = logOffset.Partition
 		offset = logOffset.Offset
-	} else {
-		partition = -1
-		offset = sarama.OffsetOldest
 	}
 	var toOffset int64
-	toLog := to.Log(DeviceListLogName)
-	if toLog != nil {
-		toOffset = toLog.Offset
-	} else {
 	toOffset = sarama.OffsetNewest
+	toLog := to.Log(DeviceListLogName)
+	if toLog != nil && toLog.Offset > 0 {
+		toOffset = toLog.Offset
 	}
 	var queryRes api.QueryKeyChangesResponse
 	keyAPI.QueryKeyChanges(ctx, &api.QueryKeyChangesRequest{
@@ -96,6 +95,10 @@ func DeviceListCatchup(
 		util.GetLogger(ctx).WithError(queryRes.Error).Error("QueryKeyChanges failed")
 		return hasNew, nil
 	}
+	util.GetLogger(ctx).Debugf(
+		"QueryKeyChanges request p=%d,off=%d,to=%d response p=%d off=%d uids=%v",
+		partition, offset, toOffset, queryRes.Partition, queryRes.Offset, queryRes.UserIDs,
+	)
 	userSet := make(map[string]bool)
 	for _, userID := range res.DeviceLists.Changed {
 		userSet[userID] = true
@@ -116,6 +119,13 @@ func DeviceListCatchup(
 			userSet[userID] = true
 		}
 	}
+	// set the new token
+	to.SetLog(DeviceListLogName, &types.LogPosition{
+		Partition: queryRes.Partition,
+		Offset:    queryRes.Offset,
+	})
+	res.NextBatch = to.String()
+
 	return hasNew, nil
 }
 

syncapi/types/types.go

@@ -112,6 +112,9 @@ type StreamingToken struct {
 }
 
 func (t *StreamingToken) SetLog(name string, lp *LogPosition) {
+	if t.logs == nil {
+		t.logs = make(map[string]*LogPosition)
+	}
 	t.logs[name] = lp
 }
 
@@ -173,12 +176,14 @@ func (t *StreamingToken) WithUpdates(other StreamingToken) (ret StreamingToken)
 		}
 		ret.Positions[i] = other.Positions[i]
 	}
+	ret.logs = make(map[string]*LogPosition)
 	for name := range t.logs {
 		otherLog := other.Log(name)
 		if otherLog == nil {
 			continue
 		}
-		t.logs[name] = otherLog
+		copy := *otherLog
+		ret.logs[name] = &copy
 	}
 	return ret
 }

sytest-whitelist

@@ -138,6 +138,7 @@ Users receive device_list updates for their own devices
 Get left notifs for other users in sync and /keys/changes when user leaves
 Local device key changes get to remote servers
 Local device key changes get to remote servers with correct prev_id
+#Server correctly handles incoming m.device_list_update
 Can add account data
 Can add account data to room
 Can get account data without syncing