Initial Store & Forward Implementation (#2917)

This adds store & forward relays into dendrite for p2p.
A few things have changed:
- new relay api serves new http endpoints for s&f federation
- updated outbound federation queueing which will attempt to forward
using s&f if appropriate
- database entries to track s&f relays for other nodes

.gitignore

@@ -56,6 +56,7 @@ dendrite.yaml
 
 # Database files
 *.db
+*.db-journal
 
 # Log files
 *.log*

build/gobind-pinecone/monolith.go

@@ -41,13 +41,16 @@ import (
 	"github.com/matrix-org/dendrite/cmd/dendrite-demo-yggdrasil/signing"
 	"github.com/matrix-org/dendrite/federationapi"
 	"github.com/matrix-org/dendrite/federationapi/api"
+	"github.com/matrix-org/dendrite/federationapi/producers"
 	"github.com/matrix-org/dendrite/internal/httputil"
 	"github.com/matrix-org/dendrite/keyserver"
+	"github.com/matrix-org/dendrite/relayapi"
+	relayServerAPI "github.com/matrix-org/dendrite/relayapi/api"
 	"github.com/matrix-org/dendrite/roomserver"
 	"github.com/matrix-org/dendrite/setup"
 	"github.com/matrix-org/dendrite/setup/base"
 	"github.com/matrix-org/dendrite/setup/config"
-	"github.com/matrix-org/dendrite/setup/process"
+	"github.com/matrix-org/dendrite/setup/jetstream"
 	"github.com/matrix-org/dendrite/test"
 	"github.com/matrix-org/dendrite/userapi"
 	userapiAPI "github.com/matrix-org/dendrite/userapi/api"
@@ -67,24 +70,27 @@ import (
 )
 
 const (
-	PeerTypeRemote    = pineconeRouter.PeerTypeRemote
-	PeerTypeMulticast = pineconeRouter.PeerTypeMulticast
-	PeerTypeBluetooth = pineconeRouter.PeerTypeBluetooth
-	PeerTypeBonjour   = pineconeRouter.PeerTypeBonjour
+	PeerTypeRemote           = pineconeRouter.PeerTypeRemote
+	PeerTypeMulticast        = pineconeRouter.PeerTypeMulticast
+	PeerTypeBluetooth        = pineconeRouter.PeerTypeBluetooth
+	PeerTypeBonjour          = pineconeRouter.PeerTypeBonjour
+	relayServerRetryInterval = time.Second * 30
 )
 
 type DendriteMonolith struct {
-	logger            logrus.Logger
-	PineconeRouter    *pineconeRouter.Router
-	PineconeMulticast *pineconeMulticast.Multicast
-	PineconeQUIC      *pineconeSessions.Sessions
-	PineconeManager   *pineconeConnections.ConnectionManager
-	StorageDirectory  string
-	CacheDirectory    string
-	listener          net.Listener
-	httpServer        *http.Server
-	processContext    *process.ProcessContext
-	userAPI           userapiAPI.UserInternalAPI
+	logger              logrus.Logger
+	baseDendrite        *base.BaseDendrite
+	PineconeRouter      *pineconeRouter.Router
+	PineconeMulticast   *pineconeMulticast.Multicast
+	PineconeQUIC        *pineconeSessions.Sessions
+	PineconeManager     *pineconeConnections.ConnectionManager
+	StorageDirectory    string
+	CacheDirectory      string
+	listener            net.Listener
+	httpServer          *http.Server
+	userAPI             userapiAPI.UserInternalAPI
+	federationAPI       api.FederationInternalAPI
+	relayServersQueried map[gomatrixserverlib.ServerName]bool
 }
 
 func (m *DendriteMonolith) PublicKey() string {
@@ -326,6 +332,7 @@ func (m *DendriteMonolith) Start() {
 	cfg.FederationAPI.Database.ConnectionString = config.DataSource(fmt.Sprintf("file:%s-federationsender.db", filepath.Join(m.StorageDirectory, prefix)))
 	cfg.MediaAPI.BasePath = config.Path(filepath.Join(m.CacheDirectory, "media"))
 	cfg.MediaAPI.AbsBasePath = config.Path(filepath.Join(m.CacheDirectory, "media"))
+	cfg.RelayAPI.Database.ConnectionString = config.DataSource(fmt.Sprintf("file:%s-relayapi.db", filepath.Join(m.StorageDirectory, prefix)))
 	cfg.MSCs.MSCs = []string{"msc2836", "msc2946"}
 	cfg.ClientAPI.RegistrationDisabled = false
 	cfg.ClientAPI.OpenRegistrationWithoutVerificationEnabled = true
@@ -335,9 +342,9 @@ func (m *DendriteMonolith) Start() {
 		panic(err)
 	}
 
-	base := base.NewBaseDendrite(cfg, "Monolith")
+	base := base.NewBaseDendrite(cfg, "Monolith", base.DisableMetrics)
+	m.baseDendrite = base
 	base.ConfigureAdminEndpoints()
-	defer base.Close() // nolint: errcheck
 
 	federation := conn.CreateFederationClient(base, m.PineconeQUIC)
 
@@ -346,11 +353,11 @@ func (m *DendriteMonolith) Start() {
 
 	rsAPI := roomserver.NewInternalAPI(base)
 
-	fsAPI := federationapi.NewInternalAPI(
+	m.federationAPI = federationapi.NewInternalAPI(
 		base, federation, rsAPI, base.Caches, keyRing, true,
 	)
 
-	keyAPI := keyserver.NewInternalAPI(base, &base.Cfg.KeyServer, fsAPI, rsAPI)
+	keyAPI := keyserver.NewInternalAPI(base, &base.Cfg.KeyServer, m.federationAPI, rsAPI)
 	m.userAPI = userapi.NewInternalAPI(base, &cfg.UserAPI, cfg.Derived.ApplicationServices, keyAPI, rsAPI, base.PushGatewayHTTPClient())
 	keyAPI.SetUserAPI(m.userAPI)
 
@@ -358,10 +365,24 @@ func (m *DendriteMonolith) Start() {
 
 	// The underlying roomserver implementation needs to be able to call the fedsender.
 	// This is different to rsAPI which can be the http client which doesn't need this dependency
-	rsAPI.SetFederationAPI(fsAPI, keyRing)
+	rsAPI.SetFederationAPI(m.federationAPI, keyRing)
 
 	userProvider := users.NewPineconeUserProvider(m.PineconeRouter, m.PineconeQUIC, m.userAPI, federation)
-	roomProvider := rooms.NewPineconeRoomProvider(m.PineconeRouter, m.PineconeQUIC, fsAPI, federation)
+	roomProvider := rooms.NewPineconeRoomProvider(m.PineconeRouter, m.PineconeQUIC, m.federationAPI, federation)
+
+	js, _ := base.NATS.Prepare(base.ProcessContext, &base.Cfg.Global.JetStream)
+	producer := &producers.SyncAPIProducer{
+		JetStream:              js,
+		TopicReceiptEvent:      base.Cfg.Global.JetStream.Prefixed(jetstream.OutputReceiptEvent),
+		TopicSendToDeviceEvent: base.Cfg.Global.JetStream.Prefixed(jetstream.OutputSendToDeviceEvent),
+		TopicTypingEvent:       base.Cfg.Global.JetStream.Prefixed(jetstream.OutputTypingEvent),
+		TopicPresenceEvent:     base.Cfg.Global.JetStream.Prefixed(jetstream.OutputPresenceEvent),
+		TopicDeviceListUpdate:  base.Cfg.Global.JetStream.Prefixed(jetstream.InputDeviceListUpdate),
+		TopicSigningKeyUpdate:  base.Cfg.Global.JetStream.Prefixed(jetstream.InputSigningKeyUpdate),
+		Config:                 &base.Cfg.FederationAPI,
+		UserAPI:                m.userAPI,
+	}
+	relayAPI := relayapi.NewRelayInternalAPI(base, federation, rsAPI, keyRing, producer)
 
 	monolith := setup.Monolith{
 		Config:    base.Cfg,
@@ -370,10 +391,11 @@ func (m *DendriteMonolith) Start() {
 		KeyRing:   keyRing,
 
 		AppserviceAPI:            asAPI,
-		FederationAPI:            fsAPI,
+		FederationAPI:            m.federationAPI,
 		RoomserverAPI:            rsAPI,
 		UserAPI:                  m.userAPI,
 		KeyAPI:                   keyAPI,
+		RelayAPI:                 relayAPI,
 		ExtPublicRoomsProvider:   roomProvider,
 		ExtUserDirectoryProvider: userProvider,
 	}
@@ -411,8 +433,6 @@ func (m *DendriteMonolith) Start() {
 		Handler: h2c.NewHandler(pMux, h2s),
 	}
 
-	m.processContext = base.ProcessContext
-
 	go func() {
 		m.logger.Info("Listening on ", cfg.Global.ServerName)
 
@@ -420,7 +440,7 @@ func (m *DendriteMonolith) Start() {
 		case net.ErrClosed, http.ErrServerClosed:
 			m.logger.Info("Stopped listening on ", cfg.Global.ServerName)
 		default:
-			m.logger.Fatal(err)
+			m.logger.Error("Stopped listening on ", cfg.Global.ServerName)
 		}
 	}()
 	go func() {
@@ -430,33 +450,44 @@ func (m *DendriteMonolith) Start() {
 		case net.ErrClosed, http.ErrServerClosed:
 			m.logger.Info("Stopped listening on ", cfg.Global.ServerName)
 		default:
-			m.logger.Fatal(err)
+			m.logger.Error("Stopped listening on ", cfg.Global.ServerName)
 		}
 	}()
 
 	go func(ch <-chan pineconeEvents.Event) {
 		eLog := logrus.WithField("pinecone", "events")
+		stopRelayServerSync := make(chan bool)
+
+		relayRetriever := RelayServerRetriever{
+			Context:             context.Background(),
+			ServerName:          gomatrixserverlib.ServerName(m.PineconeRouter.PublicKey().String()),
+			FederationAPI:       m.federationAPI,
+			relayServersQueried: make(map[gomatrixserverlib.ServerName]bool),
+			RelayAPI:            monolith.RelayAPI,
+			running:             *atomic.NewBool(false),
+		}
+		relayRetriever.InitializeRelayServers(eLog)
 
 		for event := range ch {
 			switch e := event.(type) {
 			case pineconeEvents.PeerAdded:
+				if !relayRetriever.running.Load() {
+					go relayRetriever.SyncRelayServers(stopRelayServerSync)
+				}
 			case pineconeEvents.PeerRemoved:
-			case pineconeEvents.TreeParentUpdate:
-			case pineconeEvents.SnakeDescUpdate:
-			case pineconeEvents.TreeRootAnnUpdate:
-			case pineconeEvents.SnakeEntryAdded:
-			case pineconeEvents.SnakeEntryRemoved:
+				if relayRetriever.running.Load() && m.PineconeRouter.TotalPeerCount() == 0 {
+					stopRelayServerSync <- true
+				}
 			case pineconeEvents.BroadcastReceived:
-				eLog.Info("Broadcast received from: ", e.PeerID)
+				// eLog.Info("Broadcast received from: ", e.PeerID)
 
 				req := &api.PerformWakeupServersRequest{
 					ServerNames: []gomatrixserverlib.ServerName{gomatrixserverlib.ServerName(e.PeerID)},
 				}
 				res := &api.PerformWakeupServersResponse{}
-				if err := fsAPI.PerformWakeupServers(base.Context(), req, res); err != nil {
-					logrus.WithError(err).Error("Failed to wakeup destination", e.PeerID)
+				if err := m.federationAPI.PerformWakeupServers(base.Context(), req, res); err != nil {
+					eLog.WithError(err).Error("Failed to wakeup destination", e.PeerID)
 				}
-			case pineconeEvents.BandwidthReport:
 			default:
 			}
 		}
@@ -464,12 +495,106 @@ func (m *DendriteMonolith) Start() {
 }
 
 func (m *DendriteMonolith) Stop() {
-	m.processContext.ShutdownDendrite()
+	m.baseDendrite.Close()
+	m.baseDendrite.WaitForShutdown()
 	_ = m.listener.Close()
 	m.PineconeMulticast.Stop()
 	_ = m.PineconeQUIC.Close()
 	_ = m.PineconeRouter.Close()
-	m.processContext.WaitForComponentsToFinish()
+}
+
+type RelayServerRetriever struct {
+	Context             context.Context
+	ServerName          gomatrixserverlib.ServerName
+	FederationAPI       api.FederationInternalAPI
+	RelayAPI            relayServerAPI.RelayInternalAPI
+	relayServersQueried map[gomatrixserverlib.ServerName]bool
+	queriedServersMutex sync.Mutex
+	running             atomic.Bool
+}
+
+func (m *RelayServerRetriever) InitializeRelayServers(eLog *logrus.Entry) {
+	request := api.P2PQueryRelayServersRequest{Server: gomatrixserverlib.ServerName(m.ServerName)}
+	response := api.P2PQueryRelayServersResponse{}
+	err := m.FederationAPI.P2PQueryRelayServers(m.Context, &request, &response)
+	if err != nil {
+		eLog.Warnf("Failed obtaining list of this node's relay servers: %s", err.Error())
+	}
+	for _, server := range response.RelayServers {
+		m.relayServersQueried[server] = false
+	}
+
+	eLog.Infof("Registered relay servers: %v", response.RelayServers)
+}
+
+func (m *RelayServerRetriever) SyncRelayServers(stop <-chan bool) {
+	defer m.running.Store(false)
+
+	t := time.NewTimer(relayServerRetryInterval)
+	for {
+		relayServersToQuery := []gomatrixserverlib.ServerName{}
+		func() {
+			m.queriedServersMutex.Lock()
+			defer m.queriedServersMutex.Unlock()
+			for server, complete := range m.relayServersQueried {
+				if !complete {
+					relayServersToQuery = append(relayServersToQuery, server)
+				}
+			}
+		}()
+		if len(relayServersToQuery) == 0 {
+			// All relay servers have been synced.
+			return
+		}
+		m.queryRelayServers(relayServersToQuery)
+		t.Reset(relayServerRetryInterval)
+
+		select {
+		case <-stop:
+			if !t.Stop() {
+				<-t.C
+			}
+			return
+		case <-t.C:
+		}
+	}
+}
+
+func (m *RelayServerRetriever) GetQueriedServerStatus() map[gomatrixserverlib.ServerName]bool {
+	m.queriedServersMutex.Lock()
+	defer m.queriedServersMutex.Unlock()
+
+	result := map[gomatrixserverlib.ServerName]bool{}
+	for server, queried := range m.relayServersQueried {
+		result[server] = queried
+	}
+	return result
+}
+
+func (m *RelayServerRetriever) queryRelayServers(relayServers []gomatrixserverlib.ServerName) {
+	logrus.Info("querying relay servers for any available transactions")
+	for _, server := range relayServers {
+		userID, err := gomatrixserverlib.NewUserID("@user:"+string(m.ServerName), false)
+		if err != nil {
+			return
+		}
+		err = m.RelayAPI.PerformRelayServerSync(context.Background(), *userID, server)
+		if err == nil {
+			func() {
+				m.queriedServersMutex.Lock()
+				defer m.queriedServersMutex.Unlock()
+				m.relayServersQueried[server] = true
+			}()
+			// TODO : What happens if your relay receives new messages after this point?
+			// Should you continue to check with them, or should they try and contact you?
+			// They could send a "new_async_events" message your way maybe?
+			// Then you could mark them as needing to be queried again.
+			// What if you miss this message?
+			// Maybe you should try querying them again after a certain period of time as a backup?
+		} else {
+			logrus.Errorf("Failed querying relay server: %s", err.Error())
+		}
+	}
 }
 
 const MaxFrameSize = types.MaxFrameSize

build/gobind-pinecone/monolith_test.go

@@ -0,0 +1,198 @@
+// Copyright 2022 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 gobind
+
+import (
+	"context"
+	"fmt"
+	"net"
+	"testing"
+	"time"
+
+	"github.com/matrix-org/dendrite/federationapi/api"
+	relayServerAPI "github.com/matrix-org/dendrite/relayapi/api"
+	"github.com/matrix-org/gomatrixserverlib"
+	"github.com/sirupsen/logrus"
+	"github.com/stretchr/testify/assert"
+	"gotest.tools/v3/poll"
+)
+
+var TestBuf = []byte{0, 1, 2, 3, 4, 5, 6, 7, 8, 9}
+
+type TestNetConn struct {
+	net.Conn
+	shouldFail bool
+}
+
+func (t *TestNetConn) Read(b []byte) (int, error) {
+	if t.shouldFail {
+		return 0, fmt.Errorf("Failed")
+	} else {
+		n := copy(b, TestBuf)
+		return n, nil
+	}
+}
+
+func (t *TestNetConn) Write(b []byte) (int, error) {
+	if t.shouldFail {
+		return 0, fmt.Errorf("Failed")
+	} else {
+		return len(b), nil
+	}
+}
+
+func (t *TestNetConn) Close() error {
+	if t.shouldFail {
+		return fmt.Errorf("Failed")
+	} else {
+		return nil
+	}
+}
+
+func TestConduitStoresPort(t *testing.T) {
+	conduit := Conduit{port: 7}
+	assert.Equal(t, 7, conduit.Port())
+}
+
+func TestConduitRead(t *testing.T) {
+	conduit := Conduit{conn: &TestNetConn{}}
+	b := make([]byte, len(TestBuf))
+	bytes, err := conduit.Read(b)
+	assert.NoError(t, err)
+	assert.Equal(t, len(TestBuf), bytes)
+	assert.Equal(t, TestBuf, b)
+}
+
+func TestConduitReadCopy(t *testing.T) {
+	conduit := Conduit{conn: &TestNetConn{}}
+	result, err := conduit.ReadCopy()
+	assert.NoError(t, err)
+	assert.Equal(t, TestBuf, result)
+}
+
+func TestConduitWrite(t *testing.T) {
+	conduit := Conduit{conn: &TestNetConn{}}
+	bytes, err := conduit.Write(TestBuf)
+	assert.NoError(t, err)
+	assert.Equal(t, len(TestBuf), bytes)
+}
+
+func TestConduitClose(t *testing.T) {
+	conduit := Conduit{conn: &TestNetConn{}}
+	err := conduit.Close()
+	assert.NoError(t, err)
+	assert.True(t, conduit.closed.Load())
+}
+
+func TestConduitReadClosed(t *testing.T) {
+	conduit := Conduit{conn: &TestNetConn{}}
+	err := conduit.Close()
+	assert.NoError(t, err)
+	b := make([]byte, len(TestBuf))
+	_, err = conduit.Read(b)
+	assert.Error(t, err)
+}
+
+func TestConduitReadCopyClosed(t *testing.T) {
+	conduit := Conduit{conn: &TestNetConn{}}
+	err := conduit.Close()
+	assert.NoError(t, err)
+	_, err = conduit.ReadCopy()
+	assert.Error(t, err)
+}
+
+func TestConduitWriteClosed(t *testing.T) {
+	conduit := Conduit{conn: &TestNetConn{}}
+	err := conduit.Close()
+	assert.NoError(t, err)
+	_, err = conduit.Write(TestBuf)
+	assert.Error(t, err)
+}
+
+func TestConduitReadCopyFails(t *testing.T) {
+	conduit := Conduit{conn: &TestNetConn{shouldFail: true}}
+	_, err := conduit.ReadCopy()
+	assert.Error(t, err)
+}
+
+var testRelayServers = []gomatrixserverlib.ServerName{"relay1", "relay2"}
+
+type FakeFedAPI struct {
+	api.FederationInternalAPI
+}
+
+func (f *FakeFedAPI) P2PQueryRelayServers(ctx context.Context, req *api.P2PQueryRelayServersRequest, res *api.P2PQueryRelayServersResponse) error {
+	res.RelayServers = testRelayServers
+	return nil
+}
+
+type FakeRelayAPI struct {
+	relayServerAPI.RelayInternalAPI
+}
+
+func (r *FakeRelayAPI) PerformRelayServerSync(ctx context.Context, userID gomatrixserverlib.UserID, relayServer gomatrixserverlib.ServerName) error {
+	return nil
+}
+
+func TestRelayRetrieverInitialization(t *testing.T) {
+	retriever := RelayServerRetriever{
+		Context:             context.Background(),
+		ServerName:          "server",
+		relayServersQueried: make(map[gomatrixserverlib.ServerName]bool),
+		FederationAPI:       &FakeFedAPI{},
+		RelayAPI:            &FakeRelayAPI{},
+	}
+
+	retriever.InitializeRelayServers(logrus.WithField("test", "relay"))
+	relayServers := retriever.GetQueriedServerStatus()
+	assert.Equal(t, 2, len(relayServers))
+}
+
+func TestRelayRetrieverSync(t *testing.T) {
+	retriever := RelayServerRetriever{
+		Context:             context.Background(),
+		ServerName:          "server",
+		relayServersQueried: make(map[gomatrixserverlib.ServerName]bool),
+		FederationAPI:       &FakeFedAPI{},
+		RelayAPI:            &FakeRelayAPI{},
+	}
+
+	retriever.InitializeRelayServers(logrus.WithField("test", "relay"))
+	relayServers := retriever.GetQueriedServerStatus()
+	assert.Equal(t, 2, len(relayServers))
+
+	stopRelayServerSync := make(chan bool)
+	go retriever.SyncRelayServers(stopRelayServerSync)
+
+	check := func(log poll.LogT) poll.Result {
+		relayServers := retriever.GetQueriedServerStatus()
+		for _, queried := range relayServers {
+			if !queried {
+				return poll.Continue("waiting for all servers to be queried")
+			}
+		}
+
+		stopRelayServerSync <- true
+		return poll.Success()
+	}
+	poll.WaitOn(t, check, poll.WithTimeout(5*time.Second), poll.WithDelay(100*time.Millisecond))
+}
+
+func TestMonolithStarts(t *testing.T) {
+	monolith := DendriteMonolith{}
+	monolith.Start()
+	monolith.PublicKey()
+	monolith.Stop()
+}

cmd/dendrite-demo-pinecone/ARCHITECTURE.md

@@ -0,0 +1,59 @@
+## Relay Server Architecture
+
+Relay Servers function similar to the way physical mail drop boxes do. 
+A node can have many associated relay servers. Matrix events can be sent to them instead of to the destination node, and the destination node will eventually retrieve them from the relay server. 
+Nodes that want to send events to an offline node need to know what relay servers are associated with their intended destination. 
+Currently this is manually configured in the dendrite database. In the future this information could be configurable in the app and shared automatically via other means.
+
+Currently events are sent as complete Matrix Transactions. 
+Transactions include a list of PDUs, (which contain, among other things, lists of authorization events, previous events, and signatures) a list of EDUs, and other information about the transaction. 
+There is no additional information sent along with the transaction other than what is typically added to them during Matrix federation today. 
+In the future this will probably need to change in order to handle more complex room state resolution during p2p usage.
+
+### Relay Server Architecture
+
+```
+                     0                            +--------------------+
+ +----------------------------------------+       |     P2P Node A     |
+ |             Relay Server               |       |     +--------+     |
+ |                                        |       |     | Client |     |
+ |                 +--------------------+ |       |     +--------+     |
+ |                 |  Relay Server API  | |       |          |         |
+ |                 |                    | |       |          V         |
+ |  .--------.   2 |   +-------------+  | |   1   |   +------------+   |
+ | |`--------`| <----- |  Forwarder  | <------------- | Homeserver |   |
+ | | Database |    |   +-------------+  | |       |   +------------+   |
+ | `----------`    |                    | |       +--------------------+
+ |       ^         |                    | |       
+ |       |     4   |   +-------------+  | |  
+ |       `------------ |  Retriever  | <------.   +--------------------+
+ |                 |   +-------------+  | |   |   |     P2P Node B     |
+ |                 |                    | |   |   |     +--------+     |
+ |                 +--------------------+ |   |   |     | Client |     |
+ |                                        |   |   |     +--------+     |
+ +----------------------------------------+   |   |          |         |
+                                              |   |          V         |
+                                            3 |   |   +------------+   |
+                                              `------ | Homeserver |   |
+                                                  |   +------------+   |
+                                                  +--------------------+
+```
+
+-   0: This relay server is currently only acting on behalf of `P2P Node B`. It will only receive, and later forward events that are destined for `P2P Node B`.
+-   1: When `P2P Node A` fails sending directly to `P2P Node B` (after a configurable number of attempts), it checks for any known relay servers associated with `P2P Node B` and sends to all of them.
+    - If sending to any of the relay servers succeeds, that transaction is considered to be successfully sent.      
+-   2: The relay server `forwarder` stores the transaction json in its database and marks it as destined for `P2P Node B`.
+-   3: When `P2P Node B` comes online, it queries all its relay servers for any missed messages.
+-   4: The relay server `retriever` will look in its database for any transactions that are destined for `P2P Node B` and returns them one at a time.
+
+For now, it is important that we don’t design out a hybrid approach of having both sender-side and recipient-side relay servers. 
+Both approaches make sense and determining which makes for a better experience depends on the use case.
+
+#### Sender-Side Relay Servers
+
+If we are running around truly ad-hoc, and I don't know when or where you will be able to pick up messages, then having a sender designated server makes sense to give things the best chance at making their way to the destination. 
+But in order to achieve this, you are either relying on p2p presence broadcasts for the relay to know when to try forwarding (which means you are in a pretty small network), or the relay just keeps on periodically attempting to forward to the destination which will lead to a lot of extra traffic on the network.
+
+#### Recipient-Side Relay Servers
+
+If we have agreed to some static relay server before going off and doing other things, or if we are talking about more global p2p federation, then having a recipient designated relay server can cut down on redundant traffic since it will sit there idle until the recipient pulls events from it.

cmd/dendrite-demo-pinecone/README.md

@@ -24,3 +24,42 @@ Then point your favourite Matrix client to  the homeserver URL`http://localhost:
 If your peering connection is operational then you should see a `Connected TCP:` line in the log output. If not then try a different peer.
 
 Once logged in, you should be able to open the room directory or join a room by its ID.
+
+## Store & Forward Relays
+
+To test out the store & forward relay functionality, you need a minimum of 3 instances. 
+One instance will act as the relay, and the other two instances will be the users trying to communicate.
+Then you can send messages between the two nodes and watch as the relay is used if the receiving node is offline.
+
+### Launching the Nodes
+
+Relay Server:
+```
+go run cmd/dendrite-demo-pinecone/main.go -dir relay/ -listen "[::]:49000"
+```
+
+Node 1:
+```
+go run cmd/dendrite-demo-pinecone/main.go -dir node-1/ -peer "[::]:49000" -port 8007
+```
+
+Node 2:
+```
+go run cmd/dendrite-demo-pinecone/main.go -dir node-2/ -peer "[::]:49000" -port 8009
+```
+
+### Database Setup
+
+At the moment, the database must be manually configured.
+For both `Node 1` and `Node 2` add the following entries to their respective `relay_server` table in the federationapi database:
+```
+server_name: {node_1_public_key}, relay_server_name: {relay_public_key}
+server_name: {node_2_public_key}, relay_server_name: {relay_public_key}
+```
+
+After editing the database you will need to relaunch the nodes for the changes to be picked up by dendrite.
+
+### Testing
+
+Now you can run two separate instances of element and connect them to `Node 1` and `Node 2`.
+You can shutdown one of the nodes and continue sending messages. If you wait long enough, the message will be sent to the relay server. (you can see this in the log output of the relay server) 

cmd/dendrite-demo-pinecone/main.go

@@ -38,16 +38,21 @@ import (
 	"github.com/matrix-org/dendrite/cmd/dendrite-demo-yggdrasil/signing"
 	"github.com/matrix-org/dendrite/federationapi"
 	"github.com/matrix-org/dendrite/federationapi/api"
+	"github.com/matrix-org/dendrite/federationapi/producers"
 	"github.com/matrix-org/dendrite/internal"
 	"github.com/matrix-org/dendrite/internal/httputil"
 	"github.com/matrix-org/dendrite/keyserver"
+	"github.com/matrix-org/dendrite/relayapi"
+	relayServerAPI "github.com/matrix-org/dendrite/relayapi/api"
 	"github.com/matrix-org/dendrite/roomserver"
 	"github.com/matrix-org/dendrite/setup"
 	"github.com/matrix-org/dendrite/setup/base"
 	"github.com/matrix-org/dendrite/setup/config"
+	"github.com/matrix-org/dendrite/setup/jetstream"
 	"github.com/matrix-org/dendrite/test"
 	"github.com/matrix-org/dendrite/userapi"
 	"github.com/matrix-org/gomatrixserverlib"
+	"go.uber.org/atomic"
 
 	pineconeConnections "github.com/matrix-org/pinecone/connections"
 	pineconeMulticast "github.com/matrix-org/pinecone/multicast"
@@ -66,6 +71,8 @@ var (
 	instanceDir    = flag.String("dir", ".", "the directory to store the databases in (if --config not specified)")
 )
 
+const relayServerRetryInterval = time.Second * 30
+
 // nolint:gocyclo
 func main() {
 	flag.Parse()
@@ -139,6 +146,7 @@ func main() {
 		cfg.RoomServer.Database.ConnectionString = config.DataSource(fmt.Sprintf("file:%s-roomserver.db", filepath.Join(*instanceDir, *instanceName)))
 		cfg.KeyServer.Database.ConnectionString = config.DataSource(fmt.Sprintf("file:%s-keyserver.db", filepath.Join(*instanceDir, *instanceName)))
 		cfg.FederationAPI.Database.ConnectionString = config.DataSource(fmt.Sprintf("file:%s-federationapi.db", filepath.Join(*instanceDir, *instanceName)))
+		cfg.RelayAPI.Database.ConnectionString = config.DataSource(fmt.Sprintf("file:%s-relayapi.db", filepath.Join(*instanceDir, *instanceName)))
 		cfg.MSCs.MSCs = []string{"msc2836", "msc2946"}
 		cfg.MSCs.Database.ConnectionString = config.DataSource(fmt.Sprintf("file:%s-mscs.db", filepath.Join(*instanceDir, *instanceName)))
 		cfg.ClientAPI.RegistrationDisabled = false
@@ -224,6 +232,20 @@ func main() {
 	userProvider := users.NewPineconeUserProvider(pRouter, pQUIC, userAPI, federation)
 	roomProvider := rooms.NewPineconeRoomProvider(pRouter, pQUIC, fsAPI, federation)
 
+	js, _ := base.NATS.Prepare(base.ProcessContext, &base.Cfg.Global.JetStream)
+	producer := &producers.SyncAPIProducer{
+		JetStream:              js,
+		TopicReceiptEvent:      base.Cfg.Global.JetStream.Prefixed(jetstream.OutputReceiptEvent),
+		TopicSendToDeviceEvent: base.Cfg.Global.JetStream.Prefixed(jetstream.OutputSendToDeviceEvent),
+		TopicTypingEvent:       base.Cfg.Global.JetStream.Prefixed(jetstream.OutputTypingEvent),
+		TopicPresenceEvent:     base.Cfg.Global.JetStream.Prefixed(jetstream.OutputPresenceEvent),
+		TopicDeviceListUpdate:  base.Cfg.Global.JetStream.Prefixed(jetstream.InputDeviceListUpdate),
+		TopicSigningKeyUpdate:  base.Cfg.Global.JetStream.Prefixed(jetstream.InputSigningKeyUpdate),
+		Config:                 &base.Cfg.FederationAPI,
+		UserAPI:                userAPI,
+	}
+	relayAPI := relayapi.NewRelayInternalAPI(base, federation, rsAPI, keyRing, producer)
+
 	monolith := setup.Monolith{
 		Config:    base.Cfg,
 		Client:    conn.CreateClient(base, pQUIC),
@@ -235,6 +257,7 @@ func main() {
 		RoomserverAPI:            rsAPI,
 		UserAPI:                  userAPI,
 		KeyAPI:                   keyAPI,
+		RelayAPI:                 relayAPI,
 		ExtPublicRoomsProvider:   roomProvider,
 		ExtUserDirectoryProvider: userProvider,
 	}
@@ -305,27 +328,38 @@ func main() {
 
 	go func(ch <-chan pineconeEvents.Event) {
 		eLog := logrus.WithField("pinecone", "events")
+		relayServerSyncRunning := atomic.NewBool(false)
+		stopRelayServerSync := make(chan bool)
+
+		m := RelayServerRetriever{
+			Context:             context.Background(),
+			ServerName:          gomatrixserverlib.ServerName(pRouter.PublicKey().String()),
+			FederationAPI:       fsAPI,
+			RelayServersQueried: make(map[gomatrixserverlib.ServerName]bool),
+			RelayAPI:            monolith.RelayAPI,
+		}
+		m.InitializeRelayServers(eLog)
 
 		for event := range ch {
 			switch e := event.(type) {
 			case pineconeEvents.PeerAdded:
+				if !relayServerSyncRunning.Load() {
+					go m.syncRelayServers(stopRelayServerSync, *relayServerSyncRunning)
+				}
 			case pineconeEvents.PeerRemoved:
-			case pineconeEvents.TreeParentUpdate:
-			case pineconeEvents.SnakeDescUpdate:
-			case pineconeEvents.TreeRootAnnUpdate:
-			case pineconeEvents.SnakeEntryAdded:
-			case pineconeEvents.SnakeEntryRemoved:
+				if relayServerSyncRunning.Load() && pRouter.TotalPeerCount() == 0 {
+					stopRelayServerSync <- true
+				}
 			case pineconeEvents.BroadcastReceived:
-				eLog.Info("Broadcast received from: ", e.PeerID)
+				// eLog.Info("Broadcast received from: ", e.PeerID)
 
 				req := &api.PerformWakeupServersRequest{
 					ServerNames: []gomatrixserverlib.ServerName{gomatrixserverlib.ServerName(e.PeerID)},
 				}
 				res := &api.PerformWakeupServersResponse{}
 				if err := fsAPI.PerformWakeupServers(base.Context(), req, res); err != nil {
-					logrus.WithError(err).Error("Failed to wakeup destination", e.PeerID)
+					eLog.WithError(err).Error("Failed to wakeup destination", e.PeerID)
 				}
-			case pineconeEvents.BandwidthReport:
 			default:
 			}
 		}
@@ -333,3 +367,78 @@ func main() {
 
 	base.WaitForShutdown()
 }
+
+type RelayServerRetriever struct {
+	Context             context.Context
+	ServerName          gomatrixserverlib.ServerName
+	FederationAPI       api.FederationInternalAPI
+	RelayServersQueried map[gomatrixserverlib.ServerName]bool
+	RelayAPI            relayServerAPI.RelayInternalAPI
+}
+
+func (m *RelayServerRetriever) InitializeRelayServers(eLog *logrus.Entry) {
+	request := api.P2PQueryRelayServersRequest{Server: gomatrixserverlib.ServerName(m.ServerName)}
+	response := api.P2PQueryRelayServersResponse{}
+	err := m.FederationAPI.P2PQueryRelayServers(m.Context, &request, &response)
+	if err != nil {
+		eLog.Warnf("Failed obtaining list of this node's relay servers: %s", err.Error())
+	}
+	for _, server := range response.RelayServers {
+		m.RelayServersQueried[server] = false
+	}
+
+	eLog.Infof("Registered relay servers: %v", response.RelayServers)
+}
+
+func (m *RelayServerRetriever) syncRelayServers(stop <-chan bool, running atomic.Bool) {
+	defer running.Store(false)
+
+	t := time.NewTimer(relayServerRetryInterval)
+	for {
+		relayServersToQuery := []gomatrixserverlib.ServerName{}
+		for server, complete := range m.RelayServersQueried {
+			if !complete {
+				relayServersToQuery = append(relayServersToQuery, server)
+			}
+		}
+		if len(relayServersToQuery) == 0 {
+			// All relay servers have been synced.
+			return
+		}
+		m.queryRelayServers(relayServersToQuery)
+		t.Reset(relayServerRetryInterval)
+
+		select {
+		case <-stop:
+			// We have been asked to stop syncing, drain the timer and return.
+			if !t.Stop() {
+				<-t.C
+			}
+			return
+		case <-t.C:
+			// The timer has expired. Continue to the next loop iteration.
+		}
+	}
+}
+
+func (m *RelayServerRetriever) queryRelayServers(relayServers []gomatrixserverlib.ServerName) {
+	logrus.Info("querying relay servers for any available transactions")
+	for _, server := range relayServers {
+		userID, err := gomatrixserverlib.NewUserID("@user:"+string(m.ServerName), false)
+		if err != nil {
+			return
+		}
+		err = m.RelayAPI.PerformRelayServerSync(context.Background(), *userID, server)
+		if err == nil {
+			m.RelayServersQueried[server] = true
+			// TODO : What happens if your relay receives new messages after this point?
+			// Should you continue to check with them, or should they try and contact you?
+			// They could send a "new_async_events" message your way maybe?
+			// Then you could mark them as needing to be queried again.
+			// What if you miss this message?
+			// Maybe you should try querying them again after a certain period of time as a backup?
+		} else {
+			logrus.Errorf("Failed querying relay server: %s", err.Error())
+		}
+	}
+}

federationapi/api/api.go

@@ -18,6 +18,7 @@ type FederationInternalAPI interface {
 	gomatrixserverlib.KeyDatabase
 	ClientFederationAPI
 	RoomserverFederationAPI
+	P2PFederationAPI
 
 	QueryServerKeys(ctx context.Context, request *QueryServerKeysRequest, response *QueryServerKeysResponse) error
 	LookupServerKeys(ctx context.Context, s gomatrixserverlib.ServerName, keyRequests map[gomatrixserverlib.PublicKeyLookupRequest]gomatrixserverlib.Timestamp) ([]gomatrixserverlib.ServerKeys, error)
@@ -30,7 +31,6 @@ type FederationInternalAPI interface {
 		request *PerformBroadcastEDURequest,
 		response *PerformBroadcastEDUResponse,
 	) error
-
 	PerformWakeupServers(
 		ctx context.Context,
 		request *PerformWakeupServersRequest,
@@ -71,6 +71,15 @@ type RoomserverFederationAPI interface {
 	LookupMissingEvents(ctx context.Context, origin, s gomatrixserverlib.ServerName, roomID string, missing gomatrixserverlib.MissingEvents, roomVersion gomatrixserverlib.RoomVersion) (res gomatrixserverlib.RespMissingEvents, err error)
 }
 
+type P2PFederationAPI interface {
+	// Relay Server sync api used in the pinecone demos.
+	P2PQueryRelayServers(
+		ctx context.Context,
+		request *P2PQueryRelayServersRequest,
+		response *P2PQueryRelayServersResponse,
+	) error
+}
+
 // KeyserverFederationAPI is a subset of gomatrixserverlib.FederationClient functions which the keyserver
 // implements as proxy calls, with built-in backoff/retries/etc. Errors returned from functions in
 // this interface are of type FederationClientError
@@ -82,6 +91,7 @@ type KeyserverFederationAPI interface {
 
 // an interface for gmsl.FederationClient - contains functions called by federationapi only.
 type FederationClient interface {
+	P2PFederationClient
 	gomatrixserverlib.KeyClient
 	SendTransaction(ctx context.Context, t gomatrixserverlib.Transaction) (res gomatrixserverlib.RespSend, err error)
 
@@ -110,6 +120,11 @@ type FederationClient interface {
 	LookupMissingEvents(ctx context.Context, origin, s gomatrixserverlib.ServerName, roomID string, missing gomatrixserverlib.MissingEvents, roomVersion gomatrixserverlib.RoomVersion) (res gomatrixserverlib.RespMissingEvents, err error)
 }
 
+type P2PFederationClient interface {
+	P2PSendTransactionToRelay(ctx context.Context, u gomatrixserverlib.UserID, t gomatrixserverlib.Transaction, forwardingServer gomatrixserverlib.ServerName) (res gomatrixserverlib.EmptyResp, err error)
+	P2PGetTransactionFromRelay(ctx context.Context, u gomatrixserverlib.UserID, prev gomatrixserverlib.RelayEntry, relayServer gomatrixserverlib.ServerName) (res gomatrixserverlib.RespGetRelayTransaction, err error)
+}
+
 // FederationClientError is returned from FederationClient methods in the event of a problem.
 type FederationClientError struct {
 	Err         string
@@ -233,3 +248,11 @@ type InputPublicKeysRequest struct {
 
 type InputPublicKeysResponse struct {
 }
+
+type P2PQueryRelayServersRequest struct {
+	Server gomatrixserverlib.ServerName
+}
+
+type P2PQueryRelayServersResponse struct {
+	RelayServers []gomatrixserverlib.ServerName
+}

federationapi/federationapi.go

@@ -113,7 +113,10 @@ func NewInternalAPI(
 		_ = federationDB.RemoveAllServersFromBlacklist()
 	}
 
-	stats := statistics.NewStatistics(federationDB, cfg.FederationMaxRetries+1)
+	stats := statistics.NewStatistics(
+		federationDB,
+		cfg.FederationMaxRetries+1,
+		cfg.P2PFederationRetriesUntilAssumedOffline+1)
 
 	js, nats := base.NATS.Prepare(base.ProcessContext, &cfg.Matrix.JetStream)
 

federationapi/internal/api.go

@@ -109,13 +109,14 @@ func NewFederationInternalAPI(
 
 func (a *FederationInternalAPI) isBlacklistedOrBackingOff(s gomatrixserverlib.ServerName) (*statistics.ServerStatistics, error) {
 	stats := a.statistics.ForServer(s)
-	until, blacklisted := stats.BackoffInfo()
-	if blacklisted {
+	if stats.Blacklisted() {
 		return stats, &api.FederationClientError{
 			Blacklisted: true,
 		}
 	}
+
 	now := time.Now()
+	until := stats.BackoffInfo()
 	if until != nil && now.Before(*until) {
 		return stats, &api.FederationClientError{
 			RetryAfter: time.Until(*until),
@@ -163,7 +164,7 @@ func (a *FederationInternalAPI) doRequestIfNotBackingOffOrBlacklisted(
 			RetryAfter:  retryAfter,
 		}
 	}
-	stats.Success()
+	stats.Success(statistics.SendDirect)
 	return res, nil
 }
 
@@ -171,7 +172,7 @@ func (a *FederationInternalAPI) doRequestIfNotBlacklisted(
 	s gomatrixserverlib.ServerName, request func() (interface{}, error),
 ) (interface{}, error) {
 	stats := a.statistics.ForServer(s)
-	if _, blacklisted := stats.BackoffInfo(); blacklisted {
+	if blacklisted := stats.Blacklisted(); blacklisted {
 		return stats, &api.FederationClientError{
 			Err:         fmt.Sprintf("server %q is blacklisted", s),
 			Blacklisted: true,

federationapi/internal/federationclient_test.go

@@ -0,0 +1,202 @@
+// Copyright 2022 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"
+	"fmt"
+	"testing"
+
+	"github.com/matrix-org/dendrite/federationapi/queue"
+	"github.com/matrix-org/dendrite/federationapi/statistics"
+	"github.com/matrix-org/dendrite/setup/config"
+	"github.com/matrix-org/dendrite/setup/process"
+	"github.com/matrix-org/dendrite/test"
+	"github.com/matrix-org/gomatrixserverlib"
+	"github.com/stretchr/testify/assert"
+)
+
+const (
+	FailuresUntilAssumedOffline = 3
+	FailuresUntilBlacklist      = 8
+)
+
+func (t *testFedClient) QueryKeys(ctx context.Context, origin, s gomatrixserverlib.ServerName, keys map[string][]string) (gomatrixserverlib.RespQueryKeys, error) {
+	t.queryKeysCalled = true
+	if t.shouldFail {
+		return gomatrixserverlib.RespQueryKeys{}, fmt.Errorf("Failure")
+	}
+	return gomatrixserverlib.RespQueryKeys{}, nil
+}
+
+func (t *testFedClient) ClaimKeys(ctx context.Context, origin, s gomatrixserverlib.ServerName, oneTimeKeys map[string]map[string]string) (gomatrixserverlib.RespClaimKeys, error) {
+	t.claimKeysCalled = true
+	if t.shouldFail {
+		return gomatrixserverlib.RespClaimKeys{}, fmt.Errorf("Failure")
+	}
+	return gomatrixserverlib.RespClaimKeys{}, nil
+}
+
+func TestFederationClientQueryKeys(t *testing.T) {
+	testDB := test.NewInMemoryFederationDatabase()
+
+	cfg := config.FederationAPI{
+		Matrix: &config.Global{
+			SigningIdentity: gomatrixserverlib.SigningIdentity{
+				ServerName: "server",
+			},
+		},
+	}
+	fedClient := &testFedClient{}
+	stats := statistics.NewStatistics(testDB, FailuresUntilBlacklist, FailuresUntilAssumedOffline)
+	queues := queue.NewOutgoingQueues(
+		testDB, process.NewProcessContext(),
+		false,
+		cfg.Matrix.ServerName, fedClient, nil, &stats,
+		nil,
+	)
+	fedapi := FederationInternalAPI{
+		db:         testDB,
+		cfg:        &cfg,
+		statistics: &stats,
+		federation: fedClient,
+		queues:     queues,
+	}
+	_, err := fedapi.QueryKeys(context.Background(), "origin", "server", nil)
+	assert.Nil(t, err)
+	assert.True(t, fedClient.queryKeysCalled)
+}
+
+func TestFederationClientQueryKeysBlacklisted(t *testing.T) {
+	testDB := test.NewInMemoryFederationDatabase()
+	testDB.AddServerToBlacklist("server")
+
+	cfg := config.FederationAPI{
+		Matrix: &config.Global{
+			SigningIdentity: gomatrixserverlib.SigningIdentity{
+				ServerName: "server",
+			},
+		},
+	}
+	fedClient := &testFedClient{}
+	stats := statistics.NewStatistics(testDB, FailuresUntilBlacklist, FailuresUntilAssumedOffline)
+	queues := queue.NewOutgoingQueues(
+		testDB, process.NewProcessContext(),
+		false,
+		cfg.Matrix.ServerName, fedClient, nil, &stats,
+		nil,
+	)
+	fedapi := FederationInternalAPI{
+		db:         testDB,
+		cfg:        &cfg,
+		statistics: &stats,
+		federation: fedClient,
+		queues:     queues,
+	}
+	_, err := fedapi.QueryKeys(context.Background(), "origin", "server", nil)
+	assert.NotNil(t, err)
+	assert.False(t, fedClient.queryKeysCalled)
+}
+
+func TestFederationClientQueryKeysFailure(t *testing.T) {
+	testDB := test.NewInMemoryFederationDatabase()
+
+	cfg := config.FederationAPI{
+		Matrix: &config.Global{
+			SigningIdentity: gomatrixserverlib.SigningIdentity{
+				ServerName: "server",
+			},
+		},
+	}
+	fedClient := &testFedClient{shouldFail: true}
+	stats := statistics.NewStatistics(testDB, FailuresUntilBlacklist, FailuresUntilAssumedOffline)
+	queues := queue.NewOutgoingQueues(
+		testDB, process.NewProcessContext(),
+		false,
+		cfg.Matrix.ServerName, fedClient, nil, &stats,
+		nil,
+	)
+	fedapi := FederationInternalAPI{
+		db:         testDB,
+		cfg:        &cfg,
+		statistics: &stats,
+		federation: fedClient,
+		queues:     queues,
+	}
+	_, err := fedapi.QueryKeys(context.Background(), "origin", "server", nil)
+	assert.NotNil(t, err)
+	assert.True(t, fedClient.queryKeysCalled)
+}
+
+func TestFederationClientClaimKeys(t *testing.T) {
+	testDB := test.NewInMemoryFederationDatabase()
+
+	cfg := config.FederationAPI{
+		Matrix: &config.Global{
+			SigningIdentity: gomatrixserverlib.SigningIdentity{
+				ServerName: "server",
+			},
+		},
+	}
+	fedClient := &testFedClient{}
+	stats := statistics.NewStatistics(testDB, FailuresUntilBlacklist, FailuresUntilAssumedOffline)
+	queues := queue.NewOutgoingQueues(
+		testDB, process.NewProcessContext(),
+		false,
+		cfg.Matrix.ServerName, fedClient, nil, &stats,
+		nil,
+	)
+	fedapi := FederationInternalAPI{
+		db:         testDB,
+		cfg:        &cfg,
+		statistics: &stats,
+		federation: fedClient,
+		queues:     queues,
+	}
+	_, err := fedapi.ClaimKeys(context.Background(), "origin", "server", nil)
+	assert.Nil(t, err)
+	assert.True(t, fedClient.claimKeysCalled)
+}
+
+func TestFederationClientClaimKeysBlacklisted(t *testing.T) {
+	testDB := test.NewInMemoryFederationDatabase()
+	testDB.AddServerToBlacklist("server")
+
+	cfg := config.FederationAPI{
+		Matrix: &config.Global{
+			SigningIdentity: gomatrixserverlib.SigningIdentity{
+				ServerName: "server",
+			},
+		},
+	}
+	fedClient := &testFedClient{}
+	stats := statistics.NewStatistics(testDB, FailuresUntilBlacklist, FailuresUntilAssumedOffline)
+	queues := queue.NewOutgoingQueues(
+		testDB, process.NewProcessContext(),
+		false,
+		cfg.Matrix.ServerName, fedClient, nil, &stats,
+		nil,
+	)
+	fedapi := FederationInternalAPI{
+		db:         testDB,
+		cfg:        &cfg,
+		statistics: &stats,
+		federation: fedClient,
+		queues:     queues,
+	}
+	_, err := fedapi.ClaimKeys(context.Background(), "origin", "server", nil)
+	assert.NotNil(t, err)
+	assert.False(t, fedClient.claimKeysCalled)
+}

federationapi/internal/perform.go

@@ -14,6 +14,7 @@ import (
 
 	"github.com/matrix-org/dendrite/federationapi/api"
 	"github.com/matrix-org/dendrite/federationapi/consumers"
+	"github.com/matrix-org/dendrite/federationapi/statistics"
 	roomserverAPI "github.com/matrix-org/dendrite/roomserver/api"
 	"github.com/matrix-org/dendrite/roomserver/version"
 )
@@ -24,6 +25,10 @@ func (r *FederationInternalAPI) PerformDirectoryLookup(
 	request *api.PerformDirectoryLookupRequest,
 	response *api.PerformDirectoryLookupResponse,
 ) (err error) {
+	if !r.shouldAttemptDirectFederation(request.ServerName) {
+		return fmt.Errorf("relay servers have no meaningful response for directory lookup.")
+	}
+
 	dir, err := r.federation.LookupRoomAlias(
 		ctx,
 		r.cfg.Matrix.ServerName,
@@ -36,7 +41,7 @@ func (r *FederationInternalAPI) PerformDirectoryLookup(
 	}
 	response.RoomID = dir.RoomID
 	response.ServerNames = dir.Servers
-	r.statistics.ForServer(request.ServerName).Success()
+	r.statistics.ForServer(request.ServerName).Success(statistics.SendDirect)
 	return nil
 }
 
@@ -144,6 +149,10 @@ func (r *FederationInternalAPI) performJoinUsingServer(
 	supportedVersions []gomatrixserverlib.RoomVersion,
 	unsigned map[string]interface{},
 ) error {
+	if !r.shouldAttemptDirectFederation(serverName) {
+		return fmt.Errorf("relay servers have no meaningful response for join.")
+	}
+
 	_, origin, err := r.cfg.Matrix.SplitLocalID('@', userID)
 	if err != nil {
 		return err
@@ -164,7 +173,7 @@ func (r *FederationInternalAPI) performJoinUsingServer(
 		r.statistics.ForServer(serverName).Failure()
 		return fmt.Errorf("r.federation.MakeJoin: %w", err)
 	}
-	r.statistics.ForServer(serverName).Success()
+	r.statistics.ForServer(serverName).Success(statistics.SendDirect)
 
 	// Set all the fields to be what they should be, this should be a no-op
 	// but it's possible that the remote server returned us something "odd"
@@ -219,7 +228,7 @@ func (r *FederationInternalAPI) performJoinUsingServer(
 		r.statistics.ForServer(serverName).Failure()
 		return fmt.Errorf("r.federation.SendJoin: %w", err)
 	}
-	r.statistics.ForServer(serverName).Success()
+	r.statistics.ForServer(serverName).Success(statistics.SendDirect)
 
 	// If the remote server returned an event in the "event" key of
 	// the send_join request then we should use that instead. It may
@@ -407,6 +416,10 @@ func (r *FederationInternalAPI) performOutboundPeekUsingServer(
 	serverName gomatrixserverlib.ServerName,
 	supportedVersions []gomatrixserverlib.RoomVersion,
 ) error {
+	if !r.shouldAttemptDirectFederation(serverName) {
+		return fmt.Errorf("relay servers have no meaningful response for outbound peek.")
+	}
+
 	// create a unique ID for this peek.
 	// for now we just use the room ID again. In future, if we ever
 	// support concurrent peeks to the same room with different filters
@@ -446,7 +459,7 @@ func (r *FederationInternalAPI) performOutboundPeekUsingServer(
 		r.statistics.ForServer(serverName).Failure()
 		return fmt.Errorf("r.federation.Peek: %w", err)
 	}
-	r.statistics.ForServer(serverName).Success()
+	r.statistics.ForServer(serverName).Success(statistics.SendDirect)
 
 	// Work out if we support the room version that has been supplied in
 	// the peek response.
@@ -516,6 +529,10 @@ func (r *FederationInternalAPI) PerformLeave(
 	// Try each server that we were provided until we land on one that
 	// successfully completes the make-leave send-leave dance.
 	for _, serverName := range request.ServerNames {
+		if !r.shouldAttemptDirectFederation(serverName) {
+			continue
+		}
+
 		// Try to perform a make_leave using the information supplied in the
 		// request.
 		respMakeLeave, err := r.federation.MakeLeave(
@@ -585,7 +602,7 @@ func (r *FederationInternalAPI) PerformLeave(
 			continue
 		}
 
-		r.statistics.ForServer(serverName).Success()
+		r.statistics.ForServer(serverName).Success(statistics.SendDirect)
 		return nil
 	}
 
@@ -616,6 +633,12 @@ func (r *FederationInternalAPI) PerformInvite(
 		return fmt.Errorf("gomatrixserverlib.SplitID: %w", err)
 	}
 
+	// TODO (devon): This should be allowed via a relay. Currently only transactions
+	// can be sent to relays. Would need to extend relays to handle invites.
+	if !r.shouldAttemptDirectFederation(destination) {
+		return fmt.Errorf("relay servers have no meaningful response for invite.")
+	}
+
 	logrus.WithFields(logrus.Fields{
 		"event_id":     request.Event.EventID(),
 		"user_id":      *request.Event.StateKey(),
@@ -682,12 +705,8 @@ func (r *FederationInternalAPI) PerformWakeupServers(
 
 func (r *FederationInternalAPI) MarkServersAlive(destinations []gomatrixserverlib.ServerName) {
 	for _, srv := range destinations {
-		// Check the statistics cache for the blacklist status to prevent hitting
-		// the database unnecessarily.
-		if r.queues.IsServerBlacklisted(srv) {
-			_ = r.db.RemoveServerFromBlacklist(srv)
-		}
-		r.queues.RetryServer(srv)
+		wasBlacklisted := r.statistics.ForServer(srv).MarkServerAlive()
+		r.queues.RetryServer(srv, wasBlacklisted)
 	}
 }
 
@@ -719,7 +738,9 @@ func sanityCheckAuthChain(authChain []*gomatrixserverlib.Event) error {
 	return fmt.Errorf("auth chain response is missing m.room.create event")
 }
 
-func setDefaultRoomVersionFromJoinEvent(joinEvent gomatrixserverlib.EventBuilder) gomatrixserverlib.RoomVersion {
+func setDefaultRoomVersionFromJoinEvent(
+	joinEvent gomatrixserverlib.EventBuilder,
+) gomatrixserverlib.RoomVersion {
 	// if auth events are not event references we know it must be v3+
 	// we have to do these shenanigans to satisfy sytest, specifically for:
 	// "Outbound federation rejects m.room.create events with an unknown room version"
@@ -802,3 +823,31 @@ func federatedAuthProvider(
 		return returning, nil
 	}
 }
+
+// P2PQueryRelayServers implements api.FederationInternalAPI
+func (r *FederationInternalAPI) P2PQueryRelayServers(
+	ctx context.Context,
+	request *api.P2PQueryRelayServersRequest,
+	response *api.P2PQueryRelayServersResponse,
+) error {
+	logrus.Infof("Getting relay servers for: %s", request.Server)
+	relayServers, err := r.db.P2PGetRelayServersForServer(ctx, request.Server)
+	if err != nil {
+		return err
+	}
+
+	response.RelayServers = relayServers
+	return nil
+}
+
+func (r *FederationInternalAPI) shouldAttemptDirectFederation(
+	destination gomatrixserverlib.ServerName,
+) bool {
+	var shouldRelay bool
+	stats := r.statistics.ForServer(destination)
+	if stats.AssumedOffline() && len(stats.KnownRelayServers()) > 0 {
+		shouldRelay = true
+	}
+
+	return !shouldRelay
+}

federationapi/internal/perform_test.go

@@ -0,0 +1,190 @@
+// Copyright 2022 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"
+	"testing"
+
+	"github.com/matrix-org/dendrite/federationapi/api"
+	"github.com/matrix-org/dendrite/federationapi/queue"
+	"github.com/matrix-org/dendrite/federationapi/statistics"
+	"github.com/matrix-org/dendrite/setup/config"
+	"github.com/matrix-org/dendrite/setup/process"
+	"github.com/matrix-org/dendrite/test"
+	"github.com/matrix-org/gomatrixserverlib"
+	"github.com/stretchr/testify/assert"
+)
+
+type testFedClient struct {
+	api.FederationClient
+	queryKeysCalled bool
+	claimKeysCalled bool
+	shouldFail      bool
+}
+
+func (t *testFedClient) LookupRoomAlias(ctx context.Context, origin, s gomatrixserverlib.ServerName, roomAlias string) (res gomatrixserverlib.RespDirectory, err error) {
+	return gomatrixserverlib.RespDirectory{}, nil
+}
+
+func TestPerformWakeupServers(t *testing.T) {
+	testDB := test.NewInMemoryFederationDatabase()
+
+	server := gomatrixserverlib.ServerName("wakeup")
+	testDB.AddServerToBlacklist(server)
+	testDB.SetServerAssumedOffline(context.Background(), server)
+	blacklisted, err := testDB.IsServerBlacklisted(server)
+	assert.NoError(t, err)
+	assert.True(t, blacklisted)
+	offline, err := testDB.IsServerAssumedOffline(context.Background(), server)
+	assert.NoError(t, err)
+	assert.True(t, offline)
+
+	cfg := config.FederationAPI{
+		Matrix: &config.Global{
+			SigningIdentity: gomatrixserverlib.SigningIdentity{
+				ServerName: "relay",
+			},
+		},
+	}
+	fedClient := &testFedClient{}
+	stats := statistics.NewStatistics(testDB, FailuresUntilBlacklist, FailuresUntilAssumedOffline)
+	queues := queue.NewOutgoingQueues(
+		testDB, process.NewProcessContext(),
+		false,
+		cfg.Matrix.ServerName, fedClient, nil, &stats,
+		nil,
+	)
+	fedAPI := NewFederationInternalAPI(
+		testDB, &cfg, nil, fedClient, &stats, nil, queues, nil,
+	)
+
+	req := api.PerformWakeupServersRequest{
+		ServerNames: []gomatrixserverlib.ServerName{server},
+	}
+	res := api.PerformWakeupServersResponse{}
+	err = fedAPI.PerformWakeupServers(context.Background(), &req, &res)
+	assert.NoError(t, err)
+
+	blacklisted, err = testDB.IsServerBlacklisted(server)
+	assert.NoError(t, err)
+	assert.False(t, blacklisted)
+	offline, err = testDB.IsServerAssumedOffline(context.Background(), server)
+	assert.NoError(t, err)
+	assert.False(t, offline)
+}
+
+func TestQueryRelayServers(t *testing.T) {
+	testDB := test.NewInMemoryFederationDatabase()
+
+	server := gomatrixserverlib.ServerName("wakeup")
+	relayServers := []gomatrixserverlib.ServerName{"relay1", "relay2"}
+	err := testDB.P2PAddRelayServersForServer(context.Background(), server, relayServers)
+	assert.NoError(t, err)
+
+	cfg := config.FederationAPI{
+		Matrix: &config.Global{
+			SigningIdentity: gomatrixserverlib.SigningIdentity{
+				ServerName: "relay",
+			},
+		},
+	}
+	fedClient := &testFedClient{}
+	stats := statistics.NewStatistics(testDB, FailuresUntilBlacklist, FailuresUntilAssumedOffline)
+	queues := queue.NewOutgoingQueues(
+		testDB, process.NewProcessContext(),
+		false,
+		cfg.Matrix.ServerName, fedClient, nil, &stats,
+		nil,
+	)
+	fedAPI := NewFederationInternalAPI(
+		testDB, &cfg, nil, fedClient, &stats, nil, queues, nil,
+	)
+
+	req := api.P2PQueryRelayServersRequest{
+		Server: server,
+	}
+	res := api.P2PQueryRelayServersResponse{}
+	err = fedAPI.P2PQueryRelayServers(context.Background(), &req, &res)
+	assert.NoError(t, err)
+
+	assert.Equal(t, len(relayServers), len(res.RelayServers))
+}
+
+func TestPerformDirectoryLookup(t *testing.T) {
+	testDB := test.NewInMemoryFederationDatabase()
+
+	cfg := config.FederationAPI{
+		Matrix: &config.Global{
+			SigningIdentity: gomatrixserverlib.SigningIdentity{
+				ServerName: "relay",
+			},
+		},
+	}
+	fedClient := &testFedClient{}
+	stats := statistics.NewStatistics(testDB, FailuresUntilBlacklist, FailuresUntilAssumedOffline)
+	queues := queue.NewOutgoingQueues(
+		testDB, process.NewProcessContext(),
+		false,
+		cfg.Matrix.ServerName, fedClient, nil, &stats,
+		nil,
+	)
+	fedAPI := NewFederationInternalAPI(
+		testDB, &cfg, nil, fedClient, &stats, nil, queues, nil,
+	)
+
+	req := api.PerformDirectoryLookupRequest{
+		RoomAlias:  "room",
+		ServerName: "server",
+	}
+	res := api.PerformDirectoryLookupResponse{}
+	err := fedAPI.PerformDirectoryLookup(context.Background(), &req, &res)
+	assert.NoError(t, err)
+}
+
+func TestPerformDirectoryLookupRelaying(t *testing.T) {
+	testDB := test.NewInMemoryFederationDatabase()
+
+	server := gomatrixserverlib.ServerName("wakeup")
+	testDB.SetServerAssumedOffline(context.Background(), server)
+	testDB.P2PAddRelayServersForServer(context.Background(), server, []gomatrixserverlib.ServerName{"relay"})
+
+	cfg := config.FederationAPI{
+		Matrix: &config.Global{
+			SigningIdentity: gomatrixserverlib.SigningIdentity{
+				ServerName: server,
+			},
+		},
+	}
+	fedClient := &testFedClient{}
+	stats := statistics.NewStatistics(testDB, FailuresUntilBlacklist, FailuresUntilAssumedOffline)
+	queues := queue.NewOutgoingQueues(
+		testDB, process.NewProcessContext(),
+		false,
+		cfg.Matrix.ServerName, fedClient, nil, &stats,
+		nil,
+	)
+	fedAPI := NewFederationInternalAPI(
+		testDB, &cfg, nil, fedClient, &stats, nil, queues, nil,
+	)
+
+	req := api.PerformDirectoryLookupRequest{
+		RoomAlias:  "room",
+		ServerName: server,
+	}
+	res := api.PerformDirectoryLookupResponse{}
+	err := fedAPI.PerformDirectoryLookup(context.Background(), &req, &res)
+	assert.Error(t, err)
+}

federationapi/inthttp/client.go

@@ -24,6 +24,7 @@ const (
 	FederationAPIPerformOutboundPeekRequestPath    = "/federationapi/performOutboundPeekRequest"
 	FederationAPIPerformBroadcastEDUPath           = "/federationapi/performBroadcastEDU"
 	FederationAPIPerformWakeupServers              = "/federationapi/performWakeupServers"
+	FederationAPIQueryRelayServers                 = "/federationapi/queryRelayServers"
 
 	FederationAPIGetUserDevicesPath      = "/federationapi/client/getUserDevices"
 	FederationAPIClaimKeysPath           = "/federationapi/client/claimKeys"
@@ -510,3 +511,14 @@ func (h *httpFederationInternalAPI) QueryPublicKeys(
 		h.httpClient, ctx, request, response,
 	)
 }
+
+func (h *httpFederationInternalAPI) P2PQueryRelayServers(
+	ctx context.Context,
+	request *api.P2PQueryRelayServersRequest,
+	response *api.P2PQueryRelayServersResponse,
+) error {
+	return httputil.CallInternalRPCAPI(
+		"QueryRelayServers", h.federationAPIURL+FederationAPIQueryRelayServers,
+		h.httpClient, ctx, request, response,
+	)
+}

federationapi/queue/destinationqueue.go

@@ -29,7 +29,7 @@ import (
 	fedapi "github.com/matrix-org/dendrite/federationapi/api"
 	"github.com/matrix-org/dendrite/federationapi/statistics"
 	"github.com/matrix-org/dendrite/federationapi/storage"
-	"github.com/matrix-org/dendrite/federationapi/storage/shared"
+	"github.com/matrix-org/dendrite/federationapi/storage/shared/receipt"
 	"github.com/matrix-org/dendrite/roomserver/api"
 	"github.com/matrix-org/dendrite/setup/process"
 )
@@ -70,7 +70,7 @@ type destinationQueue struct {
 // Send event adds the 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) sendEvent(event *gomatrixserverlib.HeaderedEvent, receipt *shared.Receipt) {
+func (oq *destinationQueue) sendEvent(event *gomatrixserverlib.HeaderedEvent, dbReceipt *receipt.Receipt) {
 	if event == nil {
 		logrus.Errorf("attempt to send nil PDU with destination %q", oq.destination)
 		return
@@ -84,8 +84,8 @@ func (oq *destinationQueue) sendEvent(event *gomatrixserverlib.HeaderedEvent, re
 		oq.pendingMutex.Lock()
 		if len(oq.pendingPDUs) < maxPDUsInMemory {
 			oq.pendingPDUs = append(oq.pendingPDUs, &queuedPDU{
-				pdu:     event,
-				receipt: receipt,
+				pdu:       event,
+				dbReceipt: dbReceipt,
 			})
 		} else {
 			oq.overflowed.Store(true)
@@ -101,7 +101,7 @@ func (oq *destinationQueue) sendEvent(event *gomatrixserverlib.HeaderedEvent, re
 // 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 events to that destination.
-func (oq *destinationQueue) sendEDU(event *gomatrixserverlib.EDU, receipt *shared.Receipt) {
+func (oq *destinationQueue) sendEDU(event *gomatrixserverlib.EDU, dbReceipt *receipt.Receipt) {
 	if event == nil {
 		logrus.Errorf("attempt to send nil EDU with destination %q", oq.destination)
 		return
@@ -115,8 +115,8 @@ func (oq *destinationQueue) sendEDU(event *gomatrixserverlib.EDU, receipt *share
 		oq.pendingMutex.Lock()
 		if len(oq.pendingEDUs) < maxEDUsInMemory {
 			oq.pendingEDUs = append(oq.pendingEDUs, &queuedEDU{
-				edu:     event,
-				receipt: receipt,
+				edu:       event,
+				dbReceipt: dbReceipt,
 			})
 		} else {
 			oq.overflowed.Store(true)
@@ -210,10 +210,10 @@ func (oq *destinationQueue) getPendingFromDatabase() {
 	gotPDUs := map[string]struct{}{}
 	gotEDUs := map[string]struct{}{}
 	for _, pdu := range oq.pendingPDUs {
-		gotPDUs[pdu.receipt.String()] = struct{}{}
+		gotPDUs[pdu.dbReceipt.String()] = struct{}{}
 	}
 	for _, edu := range oq.pendingEDUs {
-		gotEDUs[edu.receipt.String()] = struct{}{}
+		gotEDUs[edu.dbReceipt.String()] = struct{}{}
 	}
 
 	overflowed := false
@@ -371,7 +371,7 @@ func (oq *destinationQueue) backgroundSend() {
 
 		// If we have pending PDUs or EDUs then construct a transaction.
 		// Try sending the next transaction and see what happens.
-		terr := oq.nextTransaction(toSendPDUs, toSendEDUs)
+		terr, sendMethod := oq.nextTransaction(toSendPDUs, toSendEDUs)
 		if terr != nil {
 			// We failed to send the transaction. Mark it as a failure.
 			_, blacklisted := oq.statistics.Failure()
@@ -388,18 +388,19 @@ func (oq *destinationQueue) backgroundSend() {
 				return
 			}
 		} else {
-			oq.handleTransactionSuccess(pduCount, eduCount)
+			oq.handleTransactionSuccess(pduCount, eduCount, sendMethod)
 		}
 	}
 }
 
 // nextTransaction creates a new transaction from the pending event
 // queue and sends it.
-// Returns an error if the transaction wasn't sent.
+// Returns an error if the transaction wasn't sent. And whether the success
+// was to a relay server or not.
 func (oq *destinationQueue) nextTransaction(
 	pdus []*queuedPDU,
 	edus []*queuedEDU,
-) error {
+) (err error, sendMethod statistics.SendMethod) {
 	// Create the transaction.
 	t, pduReceipts, eduReceipts := oq.createTransaction(pdus, edus)
 	logrus.WithField("server_name", oq.destination).Debugf("Sending transaction %q containing %d PDUs, %d EDUs", t.TransactionID, len(t.PDUs), len(t.EDUs))
@@ -407,7 +408,37 @@ func (oq *destinationQueue) nextTransaction(
 	// Try to send the transaction to the destination server.
 	ctx, cancel := context.WithTimeout(oq.process.Context(), time.Minute*5)
 	defer cancel()
-	_, err := oq.client.SendTransaction(ctx, t)
+
+	relayServers := oq.statistics.KnownRelayServers()
+	if oq.statistics.AssumedOffline() && len(relayServers) > 0 {
+		sendMethod = statistics.SendViaRelay
+		relaySuccess := false
+		logrus.Infof("Sending to relay servers: %v", relayServers)
+		// TODO : how to pass through actual userID here?!?!?!?!
+		userID, userErr := gomatrixserverlib.NewUserID("@user:"+string(oq.destination), false)
+		if userErr != nil {
+			return userErr, sendMethod
+		}
+
+		// Attempt sending to each known relay server.
+		for _, relayServer := range relayServers {
+			_, relayErr := oq.client.P2PSendTransactionToRelay(ctx, *userID, t, relayServer)
+			if relayErr != nil {
+				err = relayErr
+			} else {
+				// If sending to one of the relay servers succeeds, consider the send successful.
+				relaySuccess = true
+			}
+		}
+
+		// Clear the error if sending to any of the relay servers succeeded.
+		if relaySuccess {
+			err = nil
+		}
+	} else {
+		sendMethod = statistics.SendDirect
+		_, err = oq.client.SendTransaction(ctx, t)
+	}
 	switch errResponse := err.(type) {
 	case nil:
 		// Clean up the transaction in the database.
@@ -427,7 +458,7 @@ func (oq *destinationQueue) nextTransaction(
 		oq.transactionIDMutex.Lock()
 		oq.transactionID = ""
 		oq.transactionIDMutex.Unlock()
-		return nil
+		return nil, sendMethod
 	case gomatrix.HTTPError:
 		// Report that we failed to send the transaction and we
 		// will retry again, subject to backoff.
@@ -437,13 +468,13 @@ func (oq *destinationQueue) nextTransaction(
 		// to a 400-ish error
 		code := errResponse.Code
 		logrus.Debug("Transaction failed with HTTP", code)
-		return err
+		return err, sendMethod
 	default:
 		logrus.WithFields(logrus.Fields{
 			"destination":   oq.destination,
 			logrus.ErrorKey: err,
 		}).Debugf("Failed to send transaction %q", t.TransactionID)
-		return err
+		return err, sendMethod
 	}
 }
 
@@ -453,7 +484,7 @@ func (oq *destinationQueue) nextTransaction(
 func (oq *destinationQueue) createTransaction(
 	pdus []*queuedPDU,
 	edus []*queuedEDU,
-) (gomatrixserverlib.Transaction, []*shared.Receipt, []*shared.Receipt) {
+) (gomatrixserverlib.Transaction, []*receipt.Receipt, []*receipt.Receipt) {
 	// If there's no projected transaction ID then generate one. If
 	// the transaction succeeds then we'll set it back to "" so that
 	// we generate a new one next time. If it fails, we'll preserve
@@ -474,8 +505,8 @@ func (oq *destinationQueue) createTransaction(
 	t.OriginServerTS = gomatrixserverlib.AsTimestamp(time.Now())
 	t.TransactionID = oq.transactionID
 
-	var pduReceipts []*shared.Receipt
-	var eduReceipts []*shared.Receipt
+	var pduReceipts []*receipt.Receipt
+	var eduReceipts []*receipt.Receipt
 
 	// Go through PDUs that we retrieved from the database, if any,
 	// and add them into the transaction.
@@ -487,7 +518,7 @@ func (oq *destinationQueue) createTransaction(
 		// Append the JSON of the event, since this is a json.RawMessage type in the
 		// gomatrixserverlib.Transaction struct
 		t.PDUs = append(t.PDUs, pdu.pdu.JSON())
-		pduReceipts = append(pduReceipts, pdu.receipt)
+		pduReceipts = append(pduReceipts, pdu.dbReceipt)
 	}
 
 	// Do the same for pending EDUS in the queue.
@@ -497,7 +528,7 @@ func (oq *destinationQueue) createTransaction(
 			continue
 		}
 		t.EDUs = append(t.EDUs, *edu.edu)
-		eduReceipts = append(eduReceipts, edu.receipt)
+		eduReceipts = append(eduReceipts, edu.dbReceipt)
 	}
 
 	return t, pduReceipts, eduReceipts
@@ -530,10 +561,11 @@ func (oq *destinationQueue) blacklistDestination() {
 
 // handleTransactionSuccess updates the cached event queues as well as the success and
 // backoff information for this server.
-func (oq *destinationQueue) handleTransactionSuccess(pduCount int, eduCount int) {
+func (oq *destinationQueue) handleTransactionSuccess(pduCount int, eduCount int, sendMethod statistics.SendMethod) {
 	// If we successfully sent the transaction then clear out
 	// the pending events and EDUs, and wipe our transaction ID.
-	oq.statistics.Success()
+
+	oq.statistics.Success(sendMethod)
 	oq.pendingMutex.Lock()
 	defer oq.pendingMutex.Unlock()
 

federationapi/queue/queue.go

@@ -30,7 +30,7 @@ import (
 	fedapi "github.com/matrix-org/dendrite/federationapi/api"
 	"github.com/matrix-org/dendrite/federationapi/statistics"
 	"github.com/matrix-org/dendrite/federationapi/storage"
-	"github.com/matrix-org/dendrite/federationapi/storage/shared"
+	"github.com/matrix-org/dendrite/federationapi/storage/shared/receipt"
 	"github.com/matrix-org/dendrite/roomserver/api"
 	"github.com/matrix-org/dendrite/setup/process"
 )
@@ -138,13 +138,13 @@ func NewOutgoingQueues(
 }
 
 type queuedPDU struct {
-	receipt *shared.Receipt
-	pdu     *gomatrixserverlib.HeaderedEvent
+	dbReceipt *receipt.Receipt
+	pdu       *gomatrixserverlib.HeaderedEvent
 }
 
 type queuedEDU struct {
-	receipt *shared.Receipt
-	edu     *gomatrixserverlib.EDU
+	dbReceipt *receipt.Receipt
+	edu       *gomatrixserverlib.EDU
 }
 
 func (oqs *OutgoingQueues) getQueue(destination gomatrixserverlib.ServerName) *destinationQueue {
@@ -374,24 +374,13 @@ func (oqs *OutgoingQueues) SendEDU(
 	return nil
 }
 
-// IsServerBlacklisted returns whether or not the provided server is currently
-// blacklisted.
-func (oqs *OutgoingQueues) IsServerBlacklisted(srv gomatrixserverlib.ServerName) bool {
-	return oqs.statistics.ForServer(srv).Blacklisted()
-}
-
 // RetryServer attempts to resend events to the given server if we had given up.
-func (oqs *OutgoingQueues) RetryServer(srv gomatrixserverlib.ServerName) {
+func (oqs *OutgoingQueues) RetryServer(srv gomatrixserverlib.ServerName, wasBlacklisted bool) {
 	if oqs.disabled {
 		return
 	}
 
-	serverStatistics := oqs.statistics.ForServer(srv)
-	forceWakeup := serverStatistics.Blacklisted()
-	serverStatistics.RemoveBlacklist()
-	serverStatistics.ClearBackoff()
-
 	if queue := oqs.getQueue(srv); queue != nil {
-		queue.wakeQueueIfEventsPending(forceWakeup)
+		queue.wakeQueueIfEventsPending(wasBlacklisted)
 	}
 }

federationapi/queue/queue_test.go

@@ -18,7 +18,6 @@ import (
 	"context"
 	"encoding/json"
 	"fmt"
-	"sync"
 	"testing"
 	"time"
 
@@ -26,13 +25,11 @@ import (
 	"gotest.tools/v3/poll"
 
 	"github.com/matrix-org/gomatrixserverlib"
-	"github.com/pkg/errors"
 	"github.com/stretchr/testify/assert"
 
 	"github.com/matrix-org/dendrite/federationapi/api"
 	"github.com/matrix-org/dendrite/federationapi/statistics"
 	"github.com/matrix-org/dendrite/federationapi/storage"
-	"github.com/matrix-org/dendrite/federationapi/storage/shared"
 	rsapi "github.com/matrix-org/dendrite/roomserver/api"
 	"github.com/matrix-org/dendrite/setup/config"
 	"github.com/matrix-org/dendrite/setup/process"
@@ -57,7 +54,7 @@ func mustCreateFederationDatabase(t *testing.T, dbType test.DBType, realDatabase
 		}
 	} else {
 		// Fake Database
-		db := createDatabase()
+		db := test.NewInMemoryFederationDatabase()
 		b := struct {
 			ProcessContext *process.ProcessContext
 		}{ProcessContext: process.NewProcessContext()}
@@ -65,220 +62,6 @@ func mustCreateFederationDatabase(t *testing.T, dbType test.DBType, realDatabase
 	}
 }
 
-func createDatabase() storage.Database {
-	return &fakeDatabase{
-		pendingPDUServers:  make(map[gomatrixserverlib.ServerName]struct{}),
-		pendingEDUServers:  make(map[gomatrixserverlib.ServerName]struct{}),
-		blacklistedServers: make(map[gomatrixserverlib.ServerName]struct{}),
-		pendingPDUs:        make(map[*shared.Receipt]*gomatrixserverlib.HeaderedEvent),
-		pendingEDUs:        make(map[*shared.Receipt]*gomatrixserverlib.EDU),
-		associatedPDUs:     make(map[gomatrixserverlib.ServerName]map[*shared.Receipt]struct{}),
-		associatedEDUs:     make(map[gomatrixserverlib.ServerName]map[*shared.Receipt]struct{}),
-	}
-}
-
-type fakeDatabase struct {
-	storage.Database
-	dbMutex            sync.Mutex
-	pendingPDUServers  map[gomatrixserverlib.ServerName]struct{}
-	pendingEDUServers  map[gomatrixserverlib.ServerName]struct{}
-	blacklistedServers map[gomatrixserverlib.ServerName]struct{}
-	pendingPDUs        map[*shared.Receipt]*gomatrixserverlib.HeaderedEvent
-	pendingEDUs        map[*shared.Receipt]*gomatrixserverlib.EDU
-	associatedPDUs     map[gomatrixserverlib.ServerName]map[*shared.Receipt]struct{}
-	associatedEDUs     map[gomatrixserverlib.ServerName]map[*shared.Receipt]struct{}
-}
-
-var nidMutex sync.Mutex
-var nid = int64(0)
-
-func (d *fakeDatabase) StoreJSON(ctx context.Context, js string) (*shared.Receipt, error) {
-	d.dbMutex.Lock()
-	defer d.dbMutex.Unlock()
-
-	var event gomatrixserverlib.HeaderedEvent
-	if err := json.Unmarshal([]byte(js), &event); err == nil {
-		nidMutex.Lock()
-		defer nidMutex.Unlock()
-		nid++
-		receipt := shared.NewReceipt(nid)
-		d.pendingPDUs[&receipt] = &event
-		return &receipt, nil
-	}
-
-	var edu gomatrixserverlib.EDU
-	if err := json.Unmarshal([]byte(js), &edu); err == nil {
-		nidMutex.Lock()
-		defer nidMutex.Unlock()
-		nid++
-		receipt := shared.NewReceipt(nid)
-		d.pendingEDUs[&receipt] = &edu
-		return &receipt, nil
-	}
-
-	return nil, errors.New("Failed to determine type of json to store")
-}
-
-func (d *fakeDatabase) GetPendingPDUs(ctx context.Context, serverName gomatrixserverlib.ServerName, limit int) (pdus map[*shared.Receipt]*gomatrixserverlib.HeaderedEvent, err error) {
-	d.dbMutex.Lock()
-	defer d.dbMutex.Unlock()
-
-	pduCount := 0
-	pdus = make(map[*shared.Receipt]*gomatrixserverlib.HeaderedEvent)
-	if receipts, ok := d.associatedPDUs[serverName]; ok {
-		for receipt := range receipts {
-			if event, ok := d.pendingPDUs[receipt]; ok {
-				pdus[receipt] = event
-				pduCount++
-				if pduCount == limit {
-					break
-				}
-			}
-		}
-	}
-	return pdus, nil
-}
-
-func (d *fakeDatabase) GetPendingEDUs(ctx context.Context, serverName gomatrixserverlib.ServerName, limit int) (edus map[*shared.Receipt]*gomatrixserverlib.EDU, err error) {
-	d.dbMutex.Lock()
-	defer d.dbMutex.Unlock()
-
-	eduCount := 0
-	edus = make(map[*shared.Receipt]*gomatrixserverlib.EDU)
-	if receipts, ok := d.associatedEDUs[serverName]; ok {
-		for receipt := range receipts {
-			if event, ok := d.pendingEDUs[receipt]; ok {
-				edus[receipt] = event
-				eduCount++
-				if eduCount == limit {
-					break
-				}
-			}
-		}
-	}
-	return edus, nil
-}
-
-func (d *fakeDatabase) AssociatePDUWithDestinations(ctx context.Context, destinations map[gomatrixserverlib.ServerName]struct{}, receipt *shared.Receipt) error {
-	d.dbMutex.Lock()
-	defer d.dbMutex.Unlock()
-
-	if _, ok := d.pendingPDUs[receipt]; ok {
-		for destination := range destinations {
-			if _, ok := d.associatedPDUs[destination]; !ok {
-				d.associatedPDUs[destination] = make(map[*shared.Receipt]struct{})
-			}
-			d.associatedPDUs[destination][receipt] = struct{}{}
-		}
-
-		return nil
-	} else {
-		return errors.New("PDU doesn't exist")
-	}
-}
-
-func (d *fakeDatabase) AssociateEDUWithDestinations(ctx context.Context, destinations map[gomatrixserverlib.ServerName]struct{}, receipt *shared.Receipt, eduType string, expireEDUTypes map[string]time.Duration) error {
-	d.dbMutex.Lock()
-	defer d.dbMutex.Unlock()
-
-	if _, ok := d.pendingEDUs[receipt]; ok {
-		for destination := range destinations {
-			if _, ok := d.associatedEDUs[destination]; !ok {
-				d.associatedEDUs[destination] = make(map[*shared.Receipt]struct{})
-			}
-			d.associatedEDUs[destination][receipt] = struct{}{}
-		}
-
-		return nil
-	} else {
-		return errors.New("EDU doesn't exist")
-	}
-}
-
-func (d *fakeDatabase) CleanPDUs(ctx context.Context, serverName gomatrixserverlib.ServerName, receipts []*shared.Receipt) error {
-	d.dbMutex.Lock()
-	defer d.dbMutex.Unlock()
-
-	if pdus, ok := d.associatedPDUs[serverName]; ok {
-		for _, receipt := range receipts {
-			delete(pdus, receipt)
-		}
-	}
-
-	return nil
-}
-
-func (d *fakeDatabase) CleanEDUs(ctx context.Context, serverName gomatrixserverlib.ServerName, receipts []*shared.Receipt) error {
-	d.dbMutex.Lock()
-	defer d.dbMutex.Unlock()
-
-	if edus, ok := d.associatedEDUs[serverName]; ok {
-		for _, receipt := range receipts {
-			delete(edus, receipt)
-		}
-	}
-
-	return nil
-}
-
-func (d *fakeDatabase) GetPendingPDUServerNames(ctx context.Context) ([]gomatrixserverlib.ServerName, error) {
-	d.dbMutex.Lock()
-	defer d.dbMutex.Unlock()
-
-	servers := []gomatrixserverlib.ServerName{}
-	for server := range d.pendingPDUServers {
-		servers = append(servers, server)
-	}
-	return servers, nil
-}
-
-func (d *fakeDatabase) GetPendingEDUServerNames(ctx context.Context) ([]gomatrixserverlib.ServerName, error) {
-	d.dbMutex.Lock()
-	defer d.dbMutex.Unlock()
-
-	servers := []gomatrixserverlib.ServerName{}
-	for server := range d.pendingEDUServers {
-		servers = append(servers, server)
-	}
-	return servers, nil
-}
-
-func (d *fakeDatabase) AddServerToBlacklist(serverName gomatrixserverlib.ServerName) error {
-	d.dbMutex.Lock()
-	defer d.dbMutex.Unlock()
-
-	d.blacklistedServers[serverName] = struct{}{}
-	return nil
-}
-
-func (d *fakeDatabase) RemoveServerFromBlacklist(serverName gomatrixserverlib.ServerName) error {
-	d.dbMutex.Lock()
-	defer d.dbMutex.Unlock()
-
-	delete(d.blacklistedServers, serverName)
-	return nil
-}
-
-func (d *fakeDatabase) RemoveAllServersFromBlacklist() error {
-	d.dbMutex.Lock()
-	defer d.dbMutex.Unlock()
-
-	d.blacklistedServers = make(map[gomatrixserverlib.ServerName]struct{})
-	return nil
-}
-
-func (d *fakeDatabase) IsServerBlacklisted(serverName gomatrixserverlib.ServerName) (bool, error) {
-	d.dbMutex.Lock()
-	defer d.dbMutex.Unlock()
-
-	isBlacklisted := false
-	if _, ok := d.blacklistedServers[serverName]; ok {
-		isBlacklisted = true
-	}
-
-	return isBlacklisted, nil
-}
-
 type stubFederationRoomServerAPI struct {
 	rsapi.FederationRoomserverAPI
 }
@@ -290,8 +73,10 @@ func (r *stubFederationRoomServerAPI) QueryServerBannedFromRoom(ctx context.Cont
 
 type stubFederationClient struct {
 	api.FederationClient
-	shouldTxSucceed bool
-	txCount         atomic.Uint32
+	shouldTxSucceed      bool
+	shouldTxRelaySucceed bool
+	txCount              atomic.Uint32
+	txRelayCount         atomic.Uint32
 }
 
 func (f *stubFederationClient) SendTransaction(ctx context.Context, t gomatrixserverlib.Transaction) (res gomatrixserverlib.RespSend, err error) {
@@ -304,6 +89,16 @@ func (f *stubFederationClient) SendTransaction(ctx context.Context, t gomatrixse
 	return gomatrixserverlib.RespSend{}, result
 }
 
+func (f *stubFederationClient) P2PSendTransactionToRelay(ctx context.Context, u gomatrixserverlib.UserID, t gomatrixserverlib.Transaction, forwardingServer gomatrixserverlib.ServerName) (res gomatrixserverlib.EmptyResp, err error) {
+	var result error
+	if !f.shouldTxRelaySucceed {
+		result = fmt.Errorf("relay transaction failed")
+	}
+
+	f.txRelayCount.Add(1)
+	return gomatrixserverlib.EmptyResp{}, result
+}
+
 func mustCreatePDU(t *testing.T) *gomatrixserverlib.HeaderedEvent {
 	t.Helper()
 	content := `{"type":"m.room.message"}`
@@ -319,15 +114,18 @@ func mustCreateEDU(t *testing.T) *gomatrixserverlib.EDU {
 	return &gomatrixserverlib.EDU{Type: gomatrixserverlib.MTyping}
 }
 
-func testSetup(failuresUntilBlacklist uint32, shouldTxSucceed bool, t *testing.T, dbType test.DBType, realDatabase bool) (storage.Database, *stubFederationClient, *OutgoingQueues, *process.ProcessContext, func()) {
+func testSetup(failuresUntilBlacklist uint32, failuresUntilAssumedOffline uint32, shouldTxSucceed bool, shouldTxRelaySucceed bool, t *testing.T, dbType test.DBType, realDatabase bool) (storage.Database, *stubFederationClient, *OutgoingQueues, *process.ProcessContext, func()) {
 	db, processContext, close := mustCreateFederationDatabase(t, dbType, realDatabase)
 
 	fc := &stubFederationClient{
-		shouldTxSucceed: shouldTxSucceed,
-		txCount:         *atomic.NewUint32(0),
+		shouldTxSucceed:      shouldTxSucceed,
+		shouldTxRelaySucceed: shouldTxRelaySucceed,
+		txCount:              *atomic.NewUint32(0),
+		txRelayCount:         *atomic.NewUint32(0),
 	}
 	rs := &stubFederationRoomServerAPI{}
-	stats := statistics.NewStatistics(db, failuresUntilBlacklist)
+
+	stats := statistics.NewStatistics(db, failuresUntilBlacklist, failuresUntilAssumedOffline)
 	signingInfo := []*gomatrixserverlib.SigningIdentity{
 		{
 			KeyID:      "ed21019:auto",
@@ -344,7 +142,7 @@ func TestSendPDUOnSuccessRemovedFromDB(t *testing.T) {
 	t.Parallel()
 	failuresUntilBlacklist := uint32(16)
 	destination := gomatrixserverlib.ServerName("remotehost")
-	db, fc, queues, pc, close := testSetup(failuresUntilBlacklist, true, t, test.DBTypeSQLite, false)
+	db, fc, queues, pc, close := testSetup(failuresUntilBlacklist, failuresUntilBlacklist+1, true, false, t, test.DBTypeSQLite, false)
 	defer close()
 	defer func() {
 		pc.ShutdownDendrite()
@@ -373,7 +171,7 @@ func TestSendEDUOnSuccessRemovedFromDB(t *testing.T) {
 	t.Parallel()
 	failuresUntilBlacklist := uint32(16)
 	destination := gomatrixserverlib.ServerName("remotehost")
-	db, fc, queues, pc, close := testSetup(failuresUntilBlacklist, true, t, test.DBTypeSQLite, false)
+	db, fc, queues, pc, close := testSetup(failuresUntilBlacklist, failuresUntilBlacklist+1, true, false, t, test.DBTypeSQLite, false)
 	defer close()
 	defer func() {
 		pc.ShutdownDendrite()
@@ -402,7 +200,7 @@ func TestSendPDUOnFailStoredInDB(t *testing.T) {
 	t.Parallel()
 	failuresUntilBlacklist := uint32(16)
 	destination := gomatrixserverlib.ServerName("remotehost")
-	db, fc, queues, pc, close := testSetup(failuresUntilBlacklist, false, t, test.DBTypeSQLite, false)
+	db, fc, queues, pc, close := testSetup(failuresUntilBlacklist, failuresUntilBlacklist+1, false, false, t, test.DBTypeSQLite, false)
 	defer close()
 	defer func() {
 		pc.ShutdownDendrite()
@@ -432,7 +230,7 @@ func TestSendEDUOnFailStoredInDB(t *testing.T) {
 	t.Parallel()
 	failuresUntilBlacklist := uint32(16)
 	destination := gomatrixserverlib.ServerName("remotehost")
-	db, fc, queues, pc, close := testSetup(failuresUntilBlacklist, false, t, test.DBTypeSQLite, false)
+	db, fc, queues, pc, close := testSetup(failuresUntilBlacklist, failuresUntilBlacklist+1, false, false, t, test.DBTypeSQLite, false)
 	defer close()
 	defer func() {
 		pc.ShutdownDendrite()
@@ -462,7 +260,7 @@ func TestSendPDUAgainDoesntInterruptBackoff(t *testing.T) {
 	t.Parallel()
 	failuresUntilBlacklist := uint32(16)
 	destination := gomatrixserverlib.ServerName("remotehost")
-	db, fc, queues, pc, close := testSetup(failuresUntilBlacklist, false, t, test.DBTypeSQLite, false)
+	db, fc, queues, pc, close := testSetup(failuresUntilBlacklist, failuresUntilBlacklist+1, false, false, t, test.DBTypeSQLite, false)
 	defer close()
 	defer func() {
 		pc.ShutdownDendrite()
@@ -513,7 +311,7 @@ func TestSendEDUAgainDoesntInterruptBackoff(t *testing.T) {
 	t.Parallel()
 	failuresUntilBlacklist := uint32(16)
 	destination := gomatrixserverlib.ServerName("remotehost")
-	db, fc, queues, pc, close := testSetup(failuresUntilBlacklist, false, t, test.DBTypeSQLite, false)
+	db, fc, queues, pc, close := testSetup(failuresUntilBlacklist, failuresUntilBlacklist+1, false, false, t, test.DBTypeSQLite, false)
 	defer close()
 	defer func() {
 		pc.ShutdownDendrite()
@@ -564,7 +362,7 @@ func TestSendPDUMultipleFailuresBlacklisted(t *testing.T) {
 	t.Parallel()
 	failuresUntilBlacklist := uint32(2)
 	destination := gomatrixserverlib.ServerName("remotehost")
-	db, fc, queues, pc, close := testSetup(failuresUntilBlacklist, false, t, test.DBTypeSQLite, false)
+	db, fc, queues, pc, close := testSetup(failuresUntilBlacklist, failuresUntilBlacklist+1, false, false, t, test.DBTypeSQLite, false)
 	defer close()
 	defer func() {
 		pc.ShutdownDendrite()
@@ -596,7 +394,7 @@ func TestSendEDUMultipleFailuresBlacklisted(t *testing.T) {
 	t.Parallel()
 	failuresUntilBlacklist := uint32(2)
 	destination := gomatrixserverlib.ServerName("remotehost")
-	db, fc, queues, pc, close := testSetup(failuresUntilBlacklist, false, t, test.DBTypeSQLite, false)
+	db, fc, queues, pc, close := testSetup(failuresUntilBlacklist, failuresUntilBlacklist+1, false, false, t, test.DBTypeSQLite, false)
 	defer close()
 	defer func() {
 		pc.ShutdownDendrite()
@@ -628,7 +426,7 @@ func TestSendPDUBlacklistedWithPriorExternalFailure(t *testing.T) {
 	t.Parallel()
 	failuresUntilBlacklist := uint32(2)
 	destination := gomatrixserverlib.ServerName("remotehost")
-	db, fc, queues, pc, close := testSetup(failuresUntilBlacklist, false, t, test.DBTypeSQLite, false)
+	db, fc, queues, pc, close := testSetup(failuresUntilBlacklist, failuresUntilBlacklist+1, false, false, t, test.DBTypeSQLite, false)
 	defer close()
 	defer func() {
 		pc.ShutdownDendrite()
@@ -662,7 +460,7 @@ func TestSendEDUBlacklistedWithPriorExternalFailure(t *testing.T) {
 	t.Parallel()
 	failuresUntilBlacklist := uint32(2)
 	destination := gomatrixserverlib.ServerName("remotehost")
-	db, fc, queues, pc, close := testSetup(failuresUntilBlacklist, false, t, test.DBTypeSQLite, false)
+	db, fc, queues, pc, close := testSetup(failuresUntilBlacklist, failuresUntilBlacklist+1, false, false, t, test.DBTypeSQLite, false)
 	defer close()
 	defer func() {
 		pc.ShutdownDendrite()
@@ -696,7 +494,7 @@ func TestRetryServerSendsPDUSuccessfully(t *testing.T) {
 	t.Parallel()
 	failuresUntilBlacklist := uint32(1)
 	destination := gomatrixserverlib.ServerName("remotehost")
-	db, fc, queues, pc, close := testSetup(failuresUntilBlacklist, false, t, test.DBTypeSQLite, false)
+	db, fc, queues, pc, close := testSetup(failuresUntilBlacklist, failuresUntilBlacklist+1, false, false, t, test.DBTypeSQLite, false)
 	defer close()
 	defer func() {
 		pc.ShutdownDendrite()
@@ -730,8 +528,8 @@ func TestRetryServerSendsPDUSuccessfully(t *testing.T) {
 	poll.WaitOn(t, checkBlacklisted, poll.WithTimeout(5*time.Second), poll.WithDelay(100*time.Millisecond))
 
 	fc.shouldTxSucceed = true
-	db.RemoveServerFromBlacklist(destination)
-	queues.RetryServer(destination)
+	wasBlacklisted := dest.statistics.MarkServerAlive()
+	queues.RetryServer(destination, wasBlacklisted)
 	checkRetry := func(log poll.LogT) poll.Result {
 		data, dbErr := db.GetPendingPDUs(pc.Context(), destination, 100)
 		assert.NoError(t, dbErr)
@@ -747,7 +545,7 @@ func TestRetryServerSendsEDUSuccessfully(t *testing.T) {
 	t.Parallel()
 	failuresUntilBlacklist := uint32(1)
 	destination := gomatrixserverlib.ServerName("remotehost")
-	db, fc, queues, pc, close := testSetup(failuresUntilBlacklist, false, t, test.DBTypeSQLite, false)
+	db, fc, queues, pc, close := testSetup(failuresUntilBlacklist, failuresUntilBlacklist+1, false, false, t, test.DBTypeSQLite, false)
 	defer close()
 	defer func() {
 		pc.ShutdownDendrite()
@@ -781,8 +579,8 @@ func TestRetryServerSendsEDUSuccessfully(t *testing.T) {
 	poll.WaitOn(t, checkBlacklisted, poll.WithTimeout(5*time.Second), poll.WithDelay(100*time.Millisecond))
 
 	fc.shouldTxSucceed = true
-	db.RemoveServerFromBlacklist(destination)
-	queues.RetryServer(destination)
+	wasBlacklisted := dest.statistics.MarkServerAlive()
+	queues.RetryServer(destination, wasBlacklisted)
 	checkRetry := func(log poll.LogT) poll.Result {
 		data, dbErr := db.GetPendingEDUs(pc.Context(), destination, 100)
 		assert.NoError(t, dbErr)
@@ -801,7 +599,7 @@ func TestSendPDUBatches(t *testing.T) {
 
 	// test.WithAllDatabases(t, func(t *testing.T, dbType test.DBType) {
 	// db, fc, queues, pc, close := testSetup(failuresUntilBlacklist, true, t, dbType, true)
-	db, fc, queues, pc, close := testSetup(failuresUntilBlacklist, true, t, test.DBTypeSQLite, false)
+	db, fc, queues, pc, close := testSetup(failuresUntilBlacklist, failuresUntilBlacklist+1, true, false, t, test.DBTypeSQLite, false)
 	defer close()
 	defer func() {
 		pc.ShutdownDendrite()
@@ -845,7 +643,7 @@ func TestSendEDUBatches(t *testing.T) {
 
 	// test.WithAllDatabases(t, func(t *testing.T, dbType test.DBType) {
 	// db, fc, queues, pc, close := testSetup(failuresUntilBlacklist, true, t, dbType, true)
-	db, fc, queues, pc, close := testSetup(failuresUntilBlacklist, true, t, test.DBTypeSQLite, false)
+	db, fc, queues, pc, close := testSetup(failuresUntilBlacklist, failuresUntilBlacklist+1, true, false, t, test.DBTypeSQLite, false)
 	defer close()
 	defer func() {
 		pc.ShutdownDendrite()
@@ -889,7 +687,7 @@ func TestSendPDUAndEDUBatches(t *testing.T) {
 
 	// test.WithAllDatabases(t, func(t *testing.T, dbType test.DBType) {
 	// db, fc, queues, pc, close := testSetup(failuresUntilBlacklist, true, t, dbType, true)
-	db, fc, queues, pc, close := testSetup(failuresUntilBlacklist, true, t, test.DBTypeSQLite, false)
+	db, fc, queues, pc, close := testSetup(failuresUntilBlacklist, failuresUntilBlacklist+1, true, false, t, test.DBTypeSQLite, false)
 	defer close()
 	defer func() {
 		pc.ShutdownDendrite()
@@ -940,7 +738,7 @@ func TestExternalFailureBackoffDoesntStartQueue(t *testing.T) {
 	t.Parallel()
 	failuresUntilBlacklist := uint32(16)
 	destination := gomatrixserverlib.ServerName("remotehost")
-	db, fc, queues, pc, close := testSetup(failuresUntilBlacklist, true, t, test.DBTypeSQLite, false)
+	db, fc, queues, pc, close := testSetup(failuresUntilBlacklist, failuresUntilBlacklist+1, true, false, t, test.DBTypeSQLite, false)
 	defer close()
 	defer func() {
 		pc.ShutdownDendrite()
@@ -978,7 +776,7 @@ func TestQueueInteractsWithRealDatabasePDUAndEDU(t *testing.T) {
 	destination := gomatrixserverlib.ServerName("remotehost")
 	destinations := map[gomatrixserverlib.ServerName]struct{}{destination: {}}
 	test.WithAllDatabases(t, func(t *testing.T, dbType test.DBType) {
-		db, fc, queues, pc, close := testSetup(failuresUntilBlacklist, false, t, dbType, true)
+		db, fc, queues, pc, close := testSetup(failuresUntilBlacklist, failuresUntilBlacklist+1, false, false, t, dbType, true)
 		// NOTE : These defers aren't called if go test is killed so the dbs may not get cleaned up.
 		defer close()
 		defer func() {
@@ -1023,8 +821,8 @@ func TestQueueInteractsWithRealDatabasePDUAndEDU(t *testing.T) {
 		poll.WaitOn(t, checkBlacklisted, poll.WithTimeout(10*time.Second), poll.WithDelay(100*time.Millisecond))
 
 		fc.shouldTxSucceed = true
-		db.RemoveServerFromBlacklist(destination)
-		queues.RetryServer(destination)
+		wasBlacklisted := dest.statistics.MarkServerAlive()
+		queues.RetryServer(destination, wasBlacklisted)
 		checkRetry := func(log poll.LogT) poll.Result {
 			pduData, dbErrPDU := db.GetPendingPDUs(pc.Context(), destination, 200)
 			assert.NoError(t, dbErrPDU)
@@ -1038,3 +836,147 @@ func TestQueueInteractsWithRealDatabasePDUAndEDU(t *testing.T) {
 		poll.WaitOn(t, checkRetry, poll.WithTimeout(10*time.Second), poll.WithDelay(100*time.Millisecond))
 	})
 }
+
+func TestSendPDUMultipleFailuresAssumedOffline(t *testing.T) {
+	t.Parallel()
+	failuresUntilBlacklist := uint32(7)
+	failuresUntilAssumedOffline := uint32(2)
+	destination := gomatrixserverlib.ServerName("remotehost")
+	db, fc, queues, pc, close := testSetup(failuresUntilBlacklist, failuresUntilAssumedOffline, false, false, t, test.DBTypeSQLite, false)
+	defer close()
+	defer func() {
+		pc.ShutdownDendrite()
+		<-pc.WaitForShutdown()
+	}()
+
+	ev := mustCreatePDU(t)
+	err := queues.SendEvent(ev, "localhost", []gomatrixserverlib.ServerName{destination})
+	assert.NoError(t, err)
+
+	check := func(log poll.LogT) poll.Result {
+		if fc.txCount.Load() == failuresUntilAssumedOffline {
+			data, dbErr := db.GetPendingPDUs(pc.Context(), destination, 100)
+			assert.NoError(t, dbErr)
+			if len(data) == 1 {
+				if val, _ := db.IsServerAssumedOffline(context.Background(), destination); val {
+					return poll.Success()
+				}
+				return poll.Continue("waiting for server to be assumed offline")
+			}
+			return poll.Continue("waiting for event to be added to database. Currently present PDU: %d", len(data))
+		}
+		return poll.Continue("waiting for more send attempts before checking database. Currently %d", fc.txCount.Load())
+	}
+	poll.WaitOn(t, check, poll.WithTimeout(5*time.Second), poll.WithDelay(100*time.Millisecond))
+}
+
+func TestSendEDUMultipleFailuresAssumedOffline(t *testing.T) {
+	t.Parallel()
+	failuresUntilBlacklist := uint32(7)
+	failuresUntilAssumedOffline := uint32(2)
+	destination := gomatrixserverlib.ServerName("remotehost")
+	db, fc, queues, pc, close := testSetup(failuresUntilBlacklist, failuresUntilAssumedOffline, false, false, t, test.DBTypeSQLite, false)
+	defer close()
+	defer func() {
+		pc.ShutdownDendrite()
+		<-pc.WaitForShutdown()
+	}()
+
+	ev := mustCreateEDU(t)
+	err := queues.SendEDU(ev, "localhost", []gomatrixserverlib.ServerName{destination})
+	assert.NoError(t, err)
+
+	check := func(log poll.LogT) poll.Result {
+		if fc.txCount.Load() == failuresUntilAssumedOffline {
+			data, dbErr := db.GetPendingEDUs(pc.Context(), destination, 100)
+			assert.NoError(t, dbErr)
+			if len(data) == 1 {
+				if val, _ := db.IsServerAssumedOffline(context.Background(), destination); val {
+					return poll.Success()
+				}
+				return poll.Continue("waiting for server to be assumed offline")
+			}
+			return poll.Continue("waiting for event to be added to database. Currently present EDU: %d", len(data))
+		}
+		return poll.Continue("waiting for more send attempts before checking database. Currently %d", fc.txCount.Load())
+	}
+	poll.WaitOn(t, check, poll.WithTimeout(5*time.Second), poll.WithDelay(100*time.Millisecond))
+}
+
+func TestSendPDUOnRelaySuccessRemovedFromDB(t *testing.T) {
+	t.Parallel()
+	failuresUntilBlacklist := uint32(16)
+	failuresUntilAssumedOffline := uint32(1)
+	destination := gomatrixserverlib.ServerName("remotehost")
+	db, fc, queues, pc, close := testSetup(failuresUntilBlacklist, failuresUntilAssumedOffline, false, true, t, test.DBTypeSQLite, false)
+	defer close()
+	defer func() {
+		pc.ShutdownDendrite()
+		<-pc.WaitForShutdown()
+	}()
+
+	relayServers := []gomatrixserverlib.ServerName{"relayserver"}
+	queues.statistics.ForServer(destination).AddRelayServers(relayServers)
+
+	ev := mustCreatePDU(t)
+	err := queues.SendEvent(ev, "localhost", []gomatrixserverlib.ServerName{destination})
+	assert.NoError(t, err)
+
+	check := func(log poll.LogT) poll.Result {
+		if fc.txCount.Load() == 1 {
+			if fc.txRelayCount.Load() == 1 {
+				data, dbErr := db.GetPendingPDUs(pc.Context(), destination, 100)
+				assert.NoError(t, dbErr)
+				if len(data) == 0 {
+					return poll.Success()
+				}
+				return poll.Continue("waiting for event to be removed from database. Currently present PDU: %d", len(data))
+			}
+			return poll.Continue("waiting for more relay send attempts before checking database. Currently %d", fc.txRelayCount.Load())
+		}
+		return poll.Continue("waiting for more send attempts before checking database. Currently %d", fc.txCount.Load())
+	}
+	poll.WaitOn(t, check, poll.WithTimeout(5*time.Second), poll.WithDelay(100*time.Millisecond))
+
+	assumedOffline, _ := db.IsServerAssumedOffline(context.Background(), destination)
+	assert.Equal(t, true, assumedOffline)
+}
+
+func TestSendEDUOnRelaySuccessRemovedFromDB(t *testing.T) {
+	t.Parallel()
+	failuresUntilBlacklist := uint32(16)
+	failuresUntilAssumedOffline := uint32(1)
+	destination := gomatrixserverlib.ServerName("remotehost")
+	db, fc, queues, pc, close := testSetup(failuresUntilBlacklist, failuresUntilAssumedOffline, false, true, t, test.DBTypeSQLite, false)
+	defer close()
+	defer func() {
+		pc.ShutdownDendrite()
+		<-pc.WaitForShutdown()
+	}()
+
+	relayServers := []gomatrixserverlib.ServerName{"relayserver"}
+	queues.statistics.ForServer(destination).AddRelayServers(relayServers)
+
+	ev := mustCreateEDU(t)
+	err := queues.SendEDU(ev, "localhost", []gomatrixserverlib.ServerName{destination})
+	assert.NoError(t, err)
+
+	check := func(log poll.LogT) poll.Result {
+		if fc.txCount.Load() == 1 {
+			if fc.txRelayCount.Load() == 1 {
+				data, dbErr := db.GetPendingEDUs(pc.Context(), destination, 100)
+				assert.NoError(t, dbErr)
+				if len(data) == 0 {
+					return poll.Success()
+				}
+				return poll.Continue("waiting for event to be removed from database. Currently present EDU: %d", len(data))
+			}
+			return poll.Continue("waiting for more relay send attempts before checking database. Currently %d", fc.txRelayCount.Load())
+		}
+		return poll.Continue("waiting for more send attempts before checking database. Currently %d", fc.txCount.Load())
+	}
+	poll.WaitOn(t, check, poll.WithTimeout(5*time.Second), poll.WithDelay(100*time.Millisecond))
+
+	assumedOffline, _ := db.IsServerAssumedOffline(context.Background(), destination)
+	assert.Equal(t, true, assumedOffline)
+}

federationapi/routing/profile_test.go

@@ -0,0 +1,94 @@
+// Copyright 2022 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 routing_test
+
+import (
+	"context"
+	"encoding/hex"
+	"io"
+	"net/http/httptest"
+	"net/url"
+	"testing"
+
+	"github.com/gorilla/mux"
+	"github.com/matrix-org/dendrite/cmd/dendrite-demo-yggdrasil/signing"
+	fedAPI "github.com/matrix-org/dendrite/federationapi"
+	fedInternal "github.com/matrix-org/dendrite/federationapi/internal"
+	"github.com/matrix-org/dendrite/federationapi/routing"
+	"github.com/matrix-org/dendrite/internal/httputil"
+	"github.com/matrix-org/dendrite/test"
+	"github.com/matrix-org/dendrite/test/testrig"
+	userAPI "github.com/matrix-org/dendrite/userapi/api"
+	"github.com/matrix-org/gomatrixserverlib"
+	"github.com/stretchr/testify/assert"
+	"golang.org/x/crypto/ed25519"
+)
+
+type fakeUserAPI struct {
+	userAPI.FederationUserAPI
+}
+
+func (u *fakeUserAPI) QueryProfile(ctx context.Context, req *userAPI.QueryProfileRequest, res *userAPI.QueryProfileResponse) error {
+	return nil
+}
+
+func TestHandleQueryProfile(t *testing.T) {
+	test.WithAllDatabases(t, func(t *testing.T, dbType test.DBType) {
+		base, close := testrig.CreateBaseDendrite(t, dbType)
+		defer close()
+
+		fedMux := mux.NewRouter().SkipClean(true).PathPrefix(httputil.PublicFederationPathPrefix).Subrouter().UseEncodedPath()
+		base.PublicFederationAPIMux = fedMux
+		base.Cfg.FederationAPI.Matrix.SigningIdentity.ServerName = testOrigin
+		base.Cfg.FederationAPI.Matrix.Metrics.Enabled = false
+		fedClient := fakeFedClient{}
+		serverKeyAPI := &signing.YggdrasilKeys{}
+		keyRing := serverKeyAPI.KeyRing()
+		fedapi := fedAPI.NewInternalAPI(base, &fedClient, nil, nil, keyRing, true)
+		userapi := fakeUserAPI{}
+		r, ok := fedapi.(*fedInternal.FederationInternalAPI)
+		if !ok {
+			panic("This is a programming error.")
+		}
+		routing.Setup(base, nil, r, keyRing, &fedClient, &userapi, nil, &base.Cfg.MSCs, nil, nil)
+
+		handler := fedMux.Get(routing.QueryProfileRouteName).GetHandler().ServeHTTP
+		_, sk, _ := ed25519.GenerateKey(nil)
+		keyID := signing.KeyID
+		pk := sk.Public().(ed25519.PublicKey)
+		serverName := gomatrixserverlib.ServerName(hex.EncodeToString(pk))
+		req := gomatrixserverlib.NewFederationRequest("GET", serverName, testOrigin, "/query/profile?user_id="+url.QueryEscape("@user:"+string(testOrigin)))
+		type queryContent struct{}
+		content := queryContent{}
+		err := req.SetContent(content)
+		if err != nil {
+			t.Fatalf("Error: %s", err.Error())
+		}
+		req.Sign(serverName, gomatrixserverlib.KeyID(keyID), sk)
+		httpReq, err := req.HTTPRequest()
+		if err != nil {
+			t.Fatalf("Error: %s", err.Error())
+		}
+		// vars := map[string]string{"room_alias": "#room:server"}
+		w := httptest.NewRecorder()
+		// httpReq = mux.SetURLVars(httpReq, vars)
+		handler(w, httpReq)
+
+		res := w.Result()
+		data, _ := io.ReadAll(res.Body)
+		println(string(data))
+		assert.Equal(t, 200, res.StatusCode)
+	})
+}

federationapi/routing/query_test.go

@@ -0,0 +1,94 @@
+// Copyright 2022 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 routing_test
+
+import (
+	"context"
+	"encoding/hex"
+	"io"
+	"net/http/httptest"
+	"net/url"
+	"testing"
+
+	"github.com/gorilla/mux"
+	"github.com/matrix-org/dendrite/cmd/dendrite-demo-yggdrasil/signing"
+	fedAPI "github.com/matrix-org/dendrite/federationapi"
+	fedclient "github.com/matrix-org/dendrite/federationapi/api"
+	fedInternal "github.com/matrix-org/dendrite/federationapi/internal"
+	"github.com/matrix-org/dendrite/federationapi/routing"
+	"github.com/matrix-org/dendrite/internal/httputil"
+	"github.com/matrix-org/dendrite/test"
+	"github.com/matrix-org/dendrite/test/testrig"
+	"github.com/matrix-org/gomatrixserverlib"
+	"github.com/stretchr/testify/assert"
+	"golang.org/x/crypto/ed25519"
+)
+
+type fakeFedClient struct {
+	fedclient.FederationClient
+}
+
+func (f *fakeFedClient) LookupRoomAlias(ctx context.Context, origin, s gomatrixserverlib.ServerName, roomAlias string) (res gomatrixserverlib.RespDirectory, err error) {
+	return
+}
+
+func TestHandleQueryDirectory(t *testing.T) {
+	test.WithAllDatabases(t, func(t *testing.T, dbType test.DBType) {
+		base, close := testrig.CreateBaseDendrite(t, dbType)
+		defer close()
+
+		fedMux := mux.NewRouter().SkipClean(true).PathPrefix(httputil.PublicFederationPathPrefix).Subrouter().UseEncodedPath()
+		base.PublicFederationAPIMux = fedMux
+		base.Cfg.FederationAPI.Matrix.SigningIdentity.ServerName = testOrigin
+		base.Cfg.FederationAPI.Matrix.Metrics.Enabled = false
+		fedClient := fakeFedClient{}
+		serverKeyAPI := &signing.YggdrasilKeys{}
+		keyRing := serverKeyAPI.KeyRing()
+		fedapi := fedAPI.NewInternalAPI(base, &fedClient, nil, nil, keyRing, true)
+		userapi := fakeUserAPI{}
+		r, ok := fedapi.(*fedInternal.FederationInternalAPI)
+		if !ok {
+			panic("This is a programming error.")
+		}
+		routing.Setup(base, nil, r, keyRing, &fedClient, &userapi, nil, &base.Cfg.MSCs, nil, nil)
+
+		handler := fedMux.Get(routing.QueryDirectoryRouteName).GetHandler().ServeHTTP
+		_, sk, _ := ed25519.GenerateKey(nil)
+		keyID := signing.KeyID
+		pk := sk.Public().(ed25519.PublicKey)
+		serverName := gomatrixserverlib.ServerName(hex.EncodeToString(pk))
+		req := gomatrixserverlib.NewFederationRequest("GET", serverName, testOrigin, "/query/directory?room_alias="+url.QueryEscape("#room:server"))
+		type queryContent struct{}
+		content := queryContent{}
+		err := req.SetContent(content)
+		if err != nil {
+			t.Fatalf("Error: %s", err.Error())
+		}
+		req.Sign(serverName, gomatrixserverlib.KeyID(keyID), sk)
+		httpReq, err := req.HTTPRequest()
+		if err != nil {
+			t.Fatalf("Error: %s", err.Error())
+		}
+		// vars := map[string]string{"room_alias": "#room:server"}
+		w := httptest.NewRecorder()
+		// httpReq = mux.SetURLVars(httpReq, vars)
+		handler(w, httpReq)
+
+		res := w.Result()
+		data, _ := io.ReadAll(res.Body)
+		println(string(data))
+		assert.Equal(t, 200, res.StatusCode)
+	})
+}

federationapi/routing/routing.go

@@ -41,6 +41,12 @@ import (
 	"github.com/sirupsen/logrus"
 )
 
+const (
+	SendRouteName           = "Send"
+	QueryDirectoryRouteName = "QueryDirectory"
+	QueryProfileRouteName   = "QueryProfile"
+)
+
 // Setup registers HTTP handlers with the given ServeMux.
 // The provided publicAPIMux MUST have `UseEncodedPath()` enabled or else routes will incorrectly
 // path unescape twice (once from the router, once from MakeFedAPI). We need to have this enabled
@@ -68,7 +74,7 @@ func Setup(
 
 	if base.EnableMetrics {
 		prometheus.MustRegister(
-			pduCountTotal, eduCountTotal,
+			internal.PDUCountTotal, internal.EDUCountTotal,
 		)
 	}
 
@@ -138,7 +144,7 @@ func Setup(
 				cfg, rsAPI, keyAPI, keys, federation, mu, servers, producer,
 			)
 		},
-	)).Methods(http.MethodPut, http.MethodOptions)
+	)).Methods(http.MethodPut, http.MethodOptions).Name(SendRouteName)
 
 	v1fedmux.Handle("/invite/{roomID}/{eventID}", MakeFedAPI(
 		"federation_invite", cfg.Matrix.ServerName, cfg.Matrix.IsLocalServerName, keys, wakeup,
@@ -248,7 +254,7 @@ func Setup(
 				httpReq, federation, cfg, rsAPI, fsAPI,
 			)
 		},
-	)).Methods(http.MethodGet)
+	)).Methods(http.MethodGet).Name(QueryDirectoryRouteName)
 
 	v1fedmux.Handle("/query/profile", MakeFedAPI(
 		"federation_query_profile", cfg.Matrix.ServerName, cfg.Matrix.IsLocalServerName, keys, wakeup,
@@ -257,7 +263,7 @@ func Setup(
 				httpReq, userAPI, cfg,
 			)
 		},
-	)).Methods(http.MethodGet)
+	)).Methods(http.MethodGet).Name(QueryProfileRouteName)
 
 	v1fedmux.Handle("/user/devices/{userID}", MakeFedAPI(
 		"federation_user_devices", cfg.Matrix.ServerName, cfg.Matrix.IsLocalServerName, keys, wakeup,

federationapi/routing/send.go

@@ -17,26 +17,20 @@ package routing
 import (
 	"context"
 	"encoding/json"
-	"fmt"
 	"net/http"
 	"sync"
 	"time"
 
-	"github.com/getsentry/sentry-go"
 	"github.com/matrix-org/gomatrixserverlib"
 	"github.com/matrix-org/util"
-	"github.com/prometheus/client_golang/prometheus"
-	"github.com/sirupsen/logrus"
 
 	"github.com/matrix-org/dendrite/clientapi/jsonerror"
 	federationAPI "github.com/matrix-org/dendrite/federationapi/api"
 	"github.com/matrix-org/dendrite/federationapi/producers"
-	"github.com/matrix-org/dendrite/federationapi/types"
 	"github.com/matrix-org/dendrite/internal"
 	keyapi "github.com/matrix-org/dendrite/keyserver/api"
 	"github.com/matrix-org/dendrite/roomserver/api"
 	"github.com/matrix-org/dendrite/setup/config"
-	syncTypes "github.com/matrix-org/dendrite/syncapi/types"
 )
 
 const (
@@ -56,26 +50,6 @@ const (
 	MetricsWorkMissingPrevEvents = "missing_prev_events"
 )
 
-var (
-	pduCountTotal = prometheus.NewCounterVec(
-		prometheus.CounterOpts{
-			Namespace: "dendrite",
-			Subsystem: "federationapi",
-			Name:      "recv_pdus",
-			Help:      "Number of incoming PDUs from remote servers with labels for success",
-		},
-		[]string{"status"}, // 'success' or 'total'
-	)
-	eduCountTotal = prometheus.NewCounter(
-		prometheus.CounterOpts{
-			Namespace: "dendrite",
-			Subsystem: "federationapi",
-			Name:      "recv_edus",
-			Help:      "Number of incoming EDUs from remote servers",
-		},
-	)
-)
-
 var inFlightTxnsPerOrigin sync.Map // transaction ID -> chan util.JSONResponse
 
 // Send implements /_matrix/federation/v1/send/{txnID}
@@ -123,18 +97,6 @@ func Send(
 	defer close(ch)
 	defer inFlightTxnsPerOrigin.Delete(index)
 
-	t := txnReq{
-		rsAPI:                  rsAPI,
-		keys:                   keys,
-		ourServerName:          cfg.Matrix.ServerName,
-		federation:             federation,
-		servers:                servers,
-		keyAPI:                 keyAPI,
-		roomsMu:                mu,
-		producer:               producer,
-		inboundPresenceEnabled: cfg.Matrix.Presence.EnableInbound,
-	}
-
 	var txnEvents struct {
 		PDUs []json.RawMessage       `json:"pdus"`
 		EDUs []gomatrixserverlib.EDU `json:"edus"`
@@ -155,16 +117,23 @@ func Send(
 		}
 	}
 
-	// TODO: Really we should have a function to convert FederationRequest to txnReq
-	t.PDUs = txnEvents.PDUs
-	t.EDUs = txnEvents.EDUs
-	t.Origin = request.Origin()
-	t.TransactionID = txnID
-	t.Destination = cfg.Matrix.ServerName
+	t := internal.NewTxnReq(
+		rsAPI,
+		keyAPI,
+		cfg.Matrix.ServerName,
+		keys,
+		mu,
+		producer,
+		cfg.Matrix.Presence.EnableInbound,
+		txnEvents.PDUs,
+		txnEvents.EDUs,
+		request.Origin(),
+		txnID,
+		cfg.Matrix.ServerName)
 
 	util.GetLogger(httpReq.Context()).Debugf("Received transaction %q from %q containing %d PDUs, %d EDUs", txnID, request.Origin(), len(t.PDUs), len(t.EDUs))
 
-	resp, jsonErr := t.processTransaction(httpReq.Context())
+	resp, jsonErr := t.ProcessTransaction(httpReq.Context())
 	if jsonErr != nil {
 		util.GetLogger(httpReq.Context()).WithField("jsonErr", jsonErr).Error("t.processTransaction failed")
 		return *jsonErr
@@ -181,283 +150,3 @@ func Send(
 	ch <- res
 	return res
 }
-
-type txnReq struct {
-	gomatrixserverlib.Transaction
-	rsAPI                  api.FederationRoomserverAPI
-	keyAPI                 keyapi.FederationKeyAPI
-	ourServerName          gomatrixserverlib.ServerName
-	keys                   gomatrixserverlib.JSONVerifier
-	federation             txnFederationClient
-	roomsMu                *internal.MutexByRoom
-	servers                federationAPI.ServersInRoomProvider
-	producer               *producers.SyncAPIProducer
-	inboundPresenceEnabled bool
-}
-
-// A subset of FederationClient functionality that txn requires. Useful for testing.
-type txnFederationClient interface {
-	LookupState(ctx context.Context, origin, s gomatrixserverlib.ServerName, roomID string, eventID string, roomVersion gomatrixserverlib.RoomVersion) (
-		res gomatrixserverlib.RespState, err error,
-	)
-	LookupStateIDs(ctx context.Context, origin, s gomatrixserverlib.ServerName, roomID string, eventID string) (res gomatrixserverlib.RespStateIDs, err error)
-	GetEvent(ctx context.Context, origin, s gomatrixserverlib.ServerName, eventID string) (res gomatrixserverlib.Transaction, err error)
-	LookupMissingEvents(ctx context.Context, origin, s gomatrixserverlib.ServerName, roomID string, missing gomatrixserverlib.MissingEvents,
-		roomVersion gomatrixserverlib.RoomVersion) (res gomatrixserverlib.RespMissingEvents, err error)
-}
-
-func (t *txnReq) processTransaction(ctx context.Context) (*gomatrixserverlib.RespSend, *util.JSONResponse) {
-	var wg sync.WaitGroup
-	wg.Add(1)
-	go func() {
-		defer wg.Done()
-		t.processEDUs(ctx)
-	}()
-
-	results := make(map[string]gomatrixserverlib.PDUResult)
-	roomVersions := make(map[string]gomatrixserverlib.RoomVersion)
-	getRoomVersion := func(roomID string) gomatrixserverlib.RoomVersion {
-		if v, ok := roomVersions[roomID]; ok {
-			return v
-		}
-		verReq := api.QueryRoomVersionForRoomRequest{RoomID: roomID}
-		verRes := api.QueryRoomVersionForRoomResponse{}
-		if err := t.rsAPI.QueryRoomVersionForRoom(ctx, &verReq, &verRes); err != nil {
-			util.GetLogger(ctx).WithError(err).Debug("Transaction: Failed to query room version for room", verReq.RoomID)
-			return ""
-		}
-		roomVersions[roomID] = verRes.RoomVersion
-		return verRes.RoomVersion
-	}
-
-	for _, pdu := range t.PDUs {
-		pduCountTotal.WithLabelValues("total").Inc()
-		var header struct {
-			RoomID string `json:"room_id"`
-		}
-		if err := json.Unmarshal(pdu, &header); err != nil {
-			util.GetLogger(ctx).WithError(err).Debug("Transaction: Failed to extract room ID from event")
-			// We don't know the event ID at this point so we can't return the
-			// failure in the PDU results
-			continue
-		}
-		roomVersion := getRoomVersion(header.RoomID)
-		event, err := gomatrixserverlib.NewEventFromUntrustedJSON(pdu, roomVersion)
-		if err != nil {
-			if _, ok := err.(gomatrixserverlib.BadJSONError); ok {
-				// Room version 6 states that homeservers should strictly enforce canonical JSON
-				// on PDUs.
-				//
-				// This enforces that the entire transaction is rejected if a single bad PDU is
-				// sent. It is unclear if this is the correct behaviour or not.
-				//
-				// See https://github.com/matrix-org/synapse/issues/7543
-				return nil, &util.JSONResponse{
-					Code: 400,
-					JSON: jsonerror.BadJSON("PDU contains bad JSON"),
-				}
-			}
-			util.GetLogger(ctx).WithError(err).Debugf("Transaction: Failed to parse event JSON of event %s", string(pdu))
-			continue
-		}
-		if event.Type() == gomatrixserverlib.MRoomCreate && event.StateKeyEquals("") {
-			continue
-		}
-		if api.IsServerBannedFromRoom(ctx, t.rsAPI, event.RoomID(), t.Origin) {
-			results[event.EventID()] = gomatrixserverlib.PDUResult{
-				Error: "Forbidden by server ACLs",
-			}
-			continue
-		}
-		if err = event.VerifyEventSignatures(ctx, t.keys); err != nil {
-			util.GetLogger(ctx).WithError(err).Debugf("Transaction: Couldn't validate signature of event %q", event.EventID())
-			results[event.EventID()] = gomatrixserverlib.PDUResult{
-				Error: err.Error(),
-			}
-			continue
-		}
-
-		// 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
-		if err = api.SendEvents(
-			ctx,
-			t.rsAPI,
-			api.KindNew,
-			[]*gomatrixserverlib.HeaderedEvent{
-				event.Headered(roomVersion),
-			},
-			t.Destination,
-			t.Origin,
-			api.DoNotSendToOtherServers,
-			nil,
-			true,
-		); err != nil {
-			util.GetLogger(ctx).WithError(err).Errorf("Transaction: Couldn't submit event %q to input queue: %s", event.EventID(), err)
-			results[event.EventID()] = gomatrixserverlib.PDUResult{
-				Error: err.Error(),
-			}
-			continue
-		}
-
-		results[event.EventID()] = gomatrixserverlib.PDUResult{}
-		pduCountTotal.WithLabelValues("success").Inc()
-	}
-
-	wg.Wait()
-	return &gomatrixserverlib.RespSend{PDUs: results}, nil
-}
-
-// nolint:gocyclo
-func (t *txnReq) processEDUs(ctx context.Context) {
-	for _, e := range t.EDUs {
-		eduCountTotal.Inc()
-		switch e.Type {
-		case gomatrixserverlib.MTyping:
-			// https://matrix.org/docs/spec/server_server/latest#typing-notifications
-			var typingPayload struct {
-				RoomID string `json:"room_id"`
-				UserID string `json:"user_id"`
-				Typing bool   `json:"typing"`
-			}
-			if err := json.Unmarshal(e.Content, &typingPayload); err != nil {
-				util.GetLogger(ctx).WithError(err).Debug("Failed to unmarshal typing event")
-				continue
-			}
-			if _, serverName, err := gomatrixserverlib.SplitID('@', typingPayload.UserID); err != nil {
-				continue
-			} else if serverName == t.ourServerName {
-				continue
-			} else if serverName != t.Origin {
-				continue
-			}
-			if err := t.producer.SendTyping(ctx, typingPayload.UserID, typingPayload.RoomID, typingPayload.Typing, 30*1000); err != nil {
-				util.GetLogger(ctx).WithError(err).Error("Failed to send typing event to JetStream")
-			}
-		case gomatrixserverlib.MDirectToDevice:
-			// https://matrix.org/docs/spec/server_server/r0.1.3#m-direct-to-device-schema
-			var directPayload gomatrixserverlib.ToDeviceMessage
-			if err := json.Unmarshal(e.Content, &directPayload); err != nil {
-				util.GetLogger(ctx).WithError(err).Debug("Failed to unmarshal send-to-device events")
-				continue
-			}
-			if _, serverName, err := gomatrixserverlib.SplitID('@', directPayload.Sender); err != nil {
-				continue
-			} else if serverName == t.ourServerName {
-				continue
-			} else if serverName != t.Origin {
-				continue
-			}
-			for userID, byUser := range directPayload.Messages {
-				for deviceID, message := range byUser {
-					// TODO: check that the user and the device actually exist here
-					if err := t.producer.SendToDevice(ctx, directPayload.Sender, userID, deviceID, directPayload.Type, message); err != nil {
-						sentry.CaptureException(err)
-						util.GetLogger(ctx).WithError(err).WithFields(logrus.Fields{
-							"sender":    directPayload.Sender,
-							"user_id":   userID,
-							"device_id": deviceID,
-						}).Error("Failed to send send-to-device event to JetStream")
-					}
-				}
-			}
-		case gomatrixserverlib.MDeviceListUpdate:
-			if err := t.producer.SendDeviceListUpdate(ctx, e.Content, t.Origin); err != nil {
-				sentry.CaptureException(err)
-				util.GetLogger(ctx).WithError(err).Error("failed to InputDeviceListUpdate")
-			}
-		case gomatrixserverlib.MReceipt:
-			// https://matrix.org/docs/spec/server_server/r0.1.4#receipts
-			payload := map[string]types.FederationReceiptMRead{}
-
-			if err := json.Unmarshal(e.Content, &payload); err != nil {
-				util.GetLogger(ctx).WithError(err).Debug("Failed to unmarshal receipt event")
-				continue
-			}
-
-			for roomID, receipt := range payload {
-				for userID, mread := range receipt.User {
-					_, domain, err := gomatrixserverlib.SplitID('@', userID)
-					if err != nil {
-						util.GetLogger(ctx).WithError(err).Debug("Failed to split domain from receipt event sender")
-						continue
-					}
-					if t.Origin != domain {
-						util.GetLogger(ctx).Debugf("Dropping receipt event where sender domain (%q) doesn't match origin (%q)", domain, t.Origin)
-						continue
-					}
-					if err := t.processReceiptEvent(ctx, userID, roomID, "m.read", mread.Data.TS, mread.EventIDs); err != nil {
-						util.GetLogger(ctx).WithError(err).WithFields(logrus.Fields{
-							"sender":  t.Origin,
-							"user_id": userID,
-							"room_id": roomID,
-							"events":  mread.EventIDs,
-						}).Error("Failed to send receipt event to JetStream")
-						continue
-					}
-				}
-			}
-		case types.MSigningKeyUpdate:
-			if err := t.producer.SendSigningKeyUpdate(ctx, e.Content, t.Origin); err != nil {
-				sentry.CaptureException(err)
-				logrus.WithError(err).Errorf("Failed to process signing key update")
-			}
-		case gomatrixserverlib.MPresence:
-			if t.inboundPresenceEnabled {
-				if err := t.processPresence(ctx, e); err != nil {
-					logrus.WithError(err).Errorf("Failed to process presence update")
-				}
-			}
-		default:
-			util.GetLogger(ctx).WithField("type", e.Type).Debug("Unhandled EDU")
-		}
-	}
-}
-
-// processPresence handles m.receipt events
-func (t *txnReq) processPresence(ctx context.Context, e gomatrixserverlib.EDU) error {
-	payload := types.Presence{}
-	if err := json.Unmarshal(e.Content, &payload); err != nil {
-		return err
-	}
-	for _, content := range payload.Push {
-		if _, serverName, err := gomatrixserverlib.SplitID('@', content.UserID); err != nil {
-			continue
-		} else if serverName == t.ourServerName {
-			continue
-		} else if serverName != t.Origin {
-			continue
-		}
-		presence, ok := syncTypes.PresenceFromString(content.Presence)
-		if !ok {
-			continue
-		}
-		if err := t.producer.SendPresence(ctx, content.UserID, presence, content.StatusMsg, content.LastActiveAgo); err != nil {
-			return err
-		}
-	}
-	return nil
-}
-
-// processReceiptEvent sends receipt events to JetStream
-func (t *txnReq) processReceiptEvent(ctx context.Context,
-	userID, roomID, receiptType string,
-	timestamp gomatrixserverlib.Timestamp,
-	eventIDs []string,
-) error {
-	if _, serverName, err := gomatrixserverlib.SplitID('@', userID); err != nil {
-		return nil
-	} else if serverName == t.ourServerName {
-		return nil
-	} else if serverName != t.Origin {
-		return nil
-	}
-	// store every event
-	for _, eventID := range eventIDs {
-		if err := t.producer.SendReceipt(ctx, userID, roomID, eventID, receiptType, timestamp); err != nil {
-			return fmt.Errorf("unable to set receipt event: %w", err)
-		}
-	}
-
-	return nil
-}

federationapi/routing/send_test.go

@@ -1,552 +1,87 @@
-package routing
+// Copyright 2022 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 routing_test
 
 import (
-	"context"
+	"encoding/hex"
 	"encoding/json"
-	"fmt"
+	"net/http/httptest"
 	"testing"
-	"time"
 
-	"github.com/matrix-org/dendrite/internal"
-	"github.com/matrix-org/dendrite/roomserver/api"
+	"github.com/gorilla/mux"
+	"github.com/matrix-org/dendrite/cmd/dendrite-demo-yggdrasil/signing"
+	fedAPI "github.com/matrix-org/dendrite/federationapi"
+	fedInternal "github.com/matrix-org/dendrite/federationapi/internal"
+	"github.com/matrix-org/dendrite/federationapi/routing"
+	"github.com/matrix-org/dendrite/internal/httputil"
 	"github.com/matrix-org/dendrite/test"
+	"github.com/matrix-org/dendrite/test/testrig"
 	"github.com/matrix-org/gomatrixserverlib"
+	"github.com/stretchr/testify/assert"
+	"golang.org/x/crypto/ed25519"
 )
 
 const (
-	testOrigin      = gomatrixserverlib.ServerName("kaer.morhen")
-	testDestination = gomatrixserverlib.ServerName("white.orchard")
+	testOrigin = gomatrixserverlib.ServerName("kaer.morhen")
 )
 
-var (
-	testRoomVersion = gomatrixserverlib.RoomVersionV1
-	testData        = []json.RawMessage{
-		[]byte(`{"auth_events":[],"content":{"creator":"@userid:kaer.morhen"},"depth":0,"event_id":"$0ok8ynDp7kjc95e3:kaer.morhen","hashes":{"sha256":"17kPoH+h0Dk4Omn7Sus0qMb6+oGcf+CZFEgDhv7UKWs"},"origin":"kaer.morhen","origin_server_ts":0,"prev_events":[],"prev_state":[],"room_id":"!roomid:kaer.morhen","sender":"@userid:kaer.morhen","signatures":{"kaer.morhen":{"ed25519:auto":"jP4a04f5/F10Pw95FPpdCyKAO44JOwUQ/MZOOeA/RTU1Dn+AHPMzGSaZnuGjRr/xQuADt+I3ctb5ZQfLKNzHDw"}},"state_key":"","type":"m.room.create"}`),
-		[]byte(`{"auth_events":[["$0ok8ynDp7kjc95e3:kaer.morhen",{"sha256":"sWCi6Ckp9rDimQON+MrUlNRkyfZ2tjbPbWfg2NMB18Q"}]],"content":{"membership":"join"},"depth":1,"event_id":"$LEwEu0kxrtu5fOiS:kaer.morhen","hashes":{"sha256":"B7M88PhXf3vd1LaFtjQutFu4x/w7fHD28XKZ4sAsJTo"},"origin":"kaer.morhen","origin_server_ts":0,"prev_events":[["$0ok8ynDp7kjc95e3:kaer.morhen",{"sha256":"sWCi6Ckp9rDimQON+MrUlNRkyfZ2tjbPbWfg2NMB18Q"}]],"prev_state":[],"room_id":"!roomid:kaer.morhen","sender":"@userid:kaer.morhen","signatures":{"kaer.morhen":{"ed25519:auto":"p2vqmuJn7ZBRImctSaKbXCAxCcBlIjPH9JHte1ouIUGy84gpu4eLipOvSBCLL26hXfC0Zrm4WUto6Hr+ohdrCg"}},"state_key":"@userid:kaer.morhen","type":"m.room.member"}`),
-		[]byte(`{"auth_events":[["$0ok8ynDp7kjc95e3:kaer.morhen",{"sha256":"sWCi6Ckp9rDimQON+MrUlNRkyfZ2tjbPbWfg2NMB18Q"}],["$LEwEu0kxrtu5fOiS:kaer.morhen",{"sha256":"1aKajq6DWHru1R1HJjvdWMEavkJJHGaTmPvfuERUXaA"}]],"content":{"join_rule":"public"},"depth":2,"event_id":"$SMHlqUrNhhBBRLeN:kaer.morhen","hashes":{"sha256":"vIuJQvmMjrGxshAkj1SXe0C4RqvMbv4ZADDw9pFCWqQ"},"origin":"kaer.morhen","origin_server_ts":0,"prev_events":[["$LEwEu0kxrtu5fOiS:kaer.morhen",{"sha256":"1aKajq6DWHru1R1HJjvdWMEavkJJHGaTmPvfuERUXaA"}]],"prev_state":[],"room_id":"!roomid:kaer.morhen","sender":"@userid:kaer.morhen","signatures":{"kaer.morhen":{"ed25519:auto":"hBMsb3Qppo3RaqqAl4JyTgaiWEbW5hlckATky6PrHun+F3YM203TzG7w9clwuQU5F5pZoB1a6nw+to0hN90FAw"}},"state_key":"","type":"m.room.join_rules"}`),
-		[]byte(`{"auth_events":[["$0ok8ynDp7kjc95e3:kaer.morhen",{"sha256":"sWCi6Ckp9rDimQON+MrUlNRkyfZ2tjbPbWfg2NMB18Q"}],["$LEwEu0kxrtu5fOiS:kaer.morhen",{"sha256":"1aKajq6DWHru1R1HJjvdWMEavkJJHGaTmPvfuERUXaA"}]],"content":{"history_visibility":"shared"},"depth":3,"event_id":"$6F1yGIbO0J7TM93h:kaer.morhen","hashes":{"sha256":"Mr23GKSlZW7UCCYLgOWawI2Sg6KIoMjUWO2TDenuOgw"},"origin":"kaer.morhen","origin_server_ts":0,"prev_events":[["$SMHlqUrNhhBBRLeN:kaer.morhen",{"sha256":"SylzE8U02I+6eyEHgL+FlU0L5YdqrVp8OOlxKS9VQW0"}]],"prev_state":[],"room_id":"!roomid:kaer.morhen","sender":"@userid:kaer.morhen","signatures":{"kaer.morhen":{"ed25519:auto":"sHLKrFI3hKGrEJfpMVZSDS3LvLasQsy50CTsOwru9XTVxgRsPo6wozNtRVjxo1J3Rk18RC9JppovmQ5VR5EcDw"}},"state_key":"","type":"m.room.history_visibility"}`),
-		[]byte(`{"auth_events":[["$0ok8ynDp7kjc95e3:kaer.morhen",{"sha256":"sWCi6Ckp9rDimQON+MrUlNRkyfZ2tjbPbWfg2NMB18Q"}],["$LEwEu0kxrtu5fOiS:kaer.morhen",{"sha256":"1aKajq6DWHru1R1HJjvdWMEavkJJHGaTmPvfuERUXaA"}]],"content":{"ban":50,"events":null,"events_default":0,"invite":0,"kick":50,"redact":50,"state_default":50,"users":null,"users_default":0},"depth":4,"event_id":"$UKNe10XzYzG0TeA9:kaer.morhen","hashes":{"sha256":"ngbP3yja9U5dlckKerUs/fSOhtKxZMCVvsfhPURSS28"},"origin":"kaer.morhen","origin_server_ts":0,"prev_events":[["$6F1yGIbO0J7TM93h:kaer.morhen",{"sha256":"A4CucrKSoWX4IaJXhq02mBg1sxIyZEftbC+5p3fZAvk"}]],"prev_state":[],"room_id":"!roomid:kaer.morhen","sender":"@userid:kaer.morhen","signatures":{"kaer.morhen":{"ed25519:auto":"zOmwlP01QL3yFchzuR9WHvogOoBZA3oVtNIF3lM0ZfDnqlSYZB9sns27G/4HVq0k7alaK7ZE3oGoCrVnMkPNCw"}},"state_key":"","type":"m.room.power_levels"}`),
-		// messages
-		[]byte(`{"auth_events":[["$0ok8ynDp7kjc95e3:kaer.morhen",{"sha256":"sWCi6Ckp9rDimQON+MrUlNRkyfZ2tjbPbWfg2NMB18Q"}],["$LEwEu0kxrtu5fOiS:kaer.morhen",{"sha256":"1aKajq6DWHru1R1HJjvdWMEavkJJHGaTmPvfuERUXaA"}]],"content":{"body":"Test Message"},"depth":5,"event_id":"$gl2T9l3qm0kUbiIJ:kaer.morhen","hashes":{"sha256":"Qx3nRMHLDPSL5hBAzuX84FiSSP0K0Kju2iFoBWH4Za8"},"origin":"kaer.morhen","origin_server_ts":0,"prev_events":[["$UKNe10XzYzG0TeA9:kaer.morhen",{"sha256":"KtSRyMjt0ZSjsv2koixTRCxIRCGoOp6QrKscsW97XRo"}]],"room_id":"!roomid:kaer.morhen","sender":"@userid:kaer.morhen","signatures":{"kaer.morhen":{"ed25519:auto":"sqDgv3EG7ml5VREzmT9aZeBpS4gAPNIaIeJOwqjDhY0GPU/BcpX5wY4R7hYLrNe5cChgV+eFy/GWm1Zfg5FfDg"}},"type":"m.room.message"}`),
-		[]byte(`{"auth_events":[["$0ok8ynDp7kjc95e3:kaer.morhen",{"sha256":"sWCi6Ckp9rDimQON+MrUlNRkyfZ2tjbPbWfg2NMB18Q"}],["$LEwEu0kxrtu5fOiS:kaer.morhen",{"sha256":"1aKajq6DWHru1R1HJjvdWMEavkJJHGaTmPvfuERUXaA"}]],"content":{"body":"Test Message"},"depth":6,"event_id":"$MYSbs8m4rEbsCWXD:kaer.morhen","hashes":{"sha256":"kgbYM7v4Ud2YaBsjBTolM4ySg6rHcJNYI6nWhMSdFUA"},"origin":"kaer.morhen","origin_server_ts":0,"prev_events":[["$gl2T9l3qm0kUbiIJ:kaer.morhen",{"sha256":"C/rD04h9wGxRdN2G/IBfrgoE1UovzLZ+uskwaKZ37/Q"}]],"room_id":"!roomid:kaer.morhen","sender":"@userid:kaer.morhen","signatures":{"kaer.morhen":{"ed25519:auto":"x0UoKh968jj/F5l1/R7Ew0T6CTKuew3PLNHASNxqck/bkNe8yYQiDHXRr+kZxObeqPZZTpaF1+EI+bLU9W8GDQ"}},"type":"m.room.message"}`),
-		[]byte(`{"auth_events":[["$0ok8ynDp7kjc95e3:kaer.morhen",{"sha256":"sWCi6Ckp9rDimQON+MrUlNRkyfZ2tjbPbWfg2NMB18Q"}],["$LEwEu0kxrtu5fOiS:kaer.morhen",{"sha256":"1aKajq6DWHru1R1HJjvdWMEavkJJHGaTmPvfuERUXaA"}]],"content":{"body":"Test Message"},"depth":7,"event_id":"$N5x9WJkl9ClPrAEg:kaer.morhen","hashes":{"sha256":"FWM8oz4yquTunRZ67qlW2gzPDzdWfBP6RPHXhK1I/x8"},"origin":"kaer.morhen","origin_server_ts":0,"prev_events":[["$MYSbs8m4rEbsCWXD:kaer.morhen",{"sha256":"fatqgW+SE8mb2wFn3UN+drmluoD4UJ/EcSrL6Ur9q1M"}]],"room_id":"!roomid:kaer.morhen","sender":"@userid:kaer.morhen","signatures":{"kaer.morhen":{"ed25519:auto":"Y+LX/xcyufoXMOIoqQBNOzy6lZfUGB1ffgXIrSugk6obMiyAsiRejHQN/pciZXsHKxMJLYRFAz4zSJoS/LGPAA"}},"type":"m.room.message"}`),
-	}
-	testEvents      = []*gomatrixserverlib.HeaderedEvent{}
-	testStateEvents = make(map[gomatrixserverlib.StateKeyTuple]*gomatrixserverlib.HeaderedEvent)
-)
+type sendContent struct {
+	PDUs []json.RawMessage       `json:"pdus"`
+	EDUs []gomatrixserverlib.EDU `json:"edus"`
+}
 
-func init() {
-	for _, j := range testData {
-		e, err := gomatrixserverlib.NewEventFromTrustedJSON(j, false, testRoomVersion)
+func TestHandleSend(t *testing.T) {
+	test.WithAllDatabases(t, func(t *testing.T, dbType test.DBType) {
+		base, close := testrig.CreateBaseDendrite(t, dbType)
+		defer close()
+
+		fedMux := mux.NewRouter().SkipClean(true).PathPrefix(httputil.PublicFederationPathPrefix).Subrouter().UseEncodedPath()
+		base.PublicFederationAPIMux = fedMux
+		base.Cfg.FederationAPI.Matrix.SigningIdentity.ServerName = testOrigin
+		base.Cfg.FederationAPI.Matrix.Metrics.Enabled = false
+		fedapi := fedAPI.NewInternalAPI(base, nil, nil, nil, nil, true)
+		serverKeyAPI := &signing.YggdrasilKeys{}
+		keyRing := serverKeyAPI.KeyRing()
+		r, ok := fedapi.(*fedInternal.FederationInternalAPI)
+		if !ok {
+			panic("This is a programming error.")
+		}
+		routing.Setup(base, nil, r, keyRing, nil, nil, nil, &base.Cfg.MSCs, nil, nil)
+
+		handler := fedMux.Get(routing.SendRouteName).GetHandler().ServeHTTP
+		_, sk, _ := ed25519.GenerateKey(nil)
+		keyID := signing.KeyID
+		pk := sk.Public().(ed25519.PublicKey)
+		serverName := gomatrixserverlib.ServerName(hex.EncodeToString(pk))
+		req := gomatrixserverlib.NewFederationRequest("PUT", serverName, testOrigin, "/send/1234")
+		content := sendContent{}
+		err := req.SetContent(content)
 		if err != nil {
-			panic("cannot load test data: " + err.Error())
+			t.Fatalf("Error: %s", err.Error())
 		}
-		h := e.Headered(testRoomVersion)
-		testEvents = append(testEvents, h)
-		if e.StateKey() != nil {
-			testStateEvents[gomatrixserverlib.StateKeyTuple{
-				EventType: e.Type(),
-				StateKey:  *e.StateKey(),
-			}] = h
+		req.Sign(serverName, gomatrixserverlib.KeyID(keyID), sk)
+		httpReq, err := req.HTTPRequest()
+		if err != nil {
+			t.Fatalf("Error: %s", err.Error())
 		}
-	}
+		vars := map[string]string{"txnID": "1234"}
+		w := httptest.NewRecorder()
+		httpReq = mux.SetURLVars(httpReq, vars)
+		handler(w, httpReq)
+
+		res := w.Result()
+		assert.Equal(t, 200, res.StatusCode)
+	})
 }
-
-type testRoomserverAPI struct {
-	api.RoomserverInternalAPITrace
-	inputRoomEvents           []api.InputRoomEvent
-	queryStateAfterEvents     func(*api.QueryStateAfterEventsRequest) api.QueryStateAfterEventsResponse
-	queryEventsByID           func(req *api.QueryEventsByIDRequest) api.QueryEventsByIDResponse
-	queryLatestEventsAndState func(*api.QueryLatestEventsAndStateRequest) api.QueryLatestEventsAndStateResponse
-}
-
-func (t *testRoomserverAPI) InputRoomEvents(
-	ctx context.Context,
-	request *api.InputRoomEventsRequest,
-	response *api.InputRoomEventsResponse,
-) error {
-	t.inputRoomEvents = append(t.inputRoomEvents, request.InputRoomEvents...)
-	for _, ire := range request.InputRoomEvents {
-		fmt.Println("InputRoomEvents: ", ire.Event.EventID())
-	}
-	return nil
-}
-
-// Query the latest events and state for a room from the room server.
-func (t *testRoomserverAPI) QueryLatestEventsAndState(
-	ctx context.Context,
-	request *api.QueryLatestEventsAndStateRequest,
-	response *api.QueryLatestEventsAndStateResponse,
-) error {
-	r := t.queryLatestEventsAndState(request)
-	response.RoomExists = r.RoomExists
-	response.RoomVersion = testRoomVersion
-	response.LatestEvents = r.LatestEvents
-	response.StateEvents = r.StateEvents
-	response.Depth = r.Depth
-	return nil
-}
-
-// Query the state after a list of events in a room from the room server.
-func (t *testRoomserverAPI) QueryStateAfterEvents(
-	ctx context.Context,
-	request *api.QueryStateAfterEventsRequest,
-	response *api.QueryStateAfterEventsResponse,
-) error {
-	response.RoomVersion = testRoomVersion
-	res := t.queryStateAfterEvents(request)
-	response.PrevEventsExist = res.PrevEventsExist
-	response.RoomExists = res.RoomExists
-	response.StateEvents = res.StateEvents
-	return nil
-}
-
-// Query a list of events by event ID.
-func (t *testRoomserverAPI) QueryEventsByID(
-	ctx context.Context,
-	request *api.QueryEventsByIDRequest,
-	response *api.QueryEventsByIDResponse,
-) error {
-	res := t.queryEventsByID(request)
-	response.Events = res.Events
-	return nil
-}
-
-// Query if a server is joined to a room
-func (t *testRoomserverAPI) QueryServerJoinedToRoom(
-	ctx context.Context,
-	request *api.QueryServerJoinedToRoomRequest,
-	response *api.QueryServerJoinedToRoomResponse,
-) error {
-	response.RoomExists = true
-	response.IsInRoom = true
-	return nil
-}
-
-// Asks for the room version for a given room.
-func (t *testRoomserverAPI) QueryRoomVersionForRoom(
-	ctx context.Context,
-	request *api.QueryRoomVersionForRoomRequest,
-	response *api.QueryRoomVersionForRoomResponse,
-) error {
-	response.RoomVersion = testRoomVersion
-	return nil
-}
-
-func (t *testRoomserverAPI) QueryServerBannedFromRoom(
-	ctx context.Context, req *api.QueryServerBannedFromRoomRequest, res *api.QueryServerBannedFromRoomResponse,
-) error {
-	res.Banned = false
-	return nil
-}
-
-type txnFedClient struct {
-	state            map[string]gomatrixserverlib.RespState    // event_id to response
-	stateIDs         map[string]gomatrixserverlib.RespStateIDs // event_id to response
-	getEvent         map[string]gomatrixserverlib.Transaction  // event_id to response
-	getMissingEvents func(gomatrixserverlib.MissingEvents) (res gomatrixserverlib.RespMissingEvents, err error)
-}
-
-func (c *txnFedClient) LookupState(ctx context.Context, origin, s gomatrixserverlib.ServerName, roomID string, eventID string, roomVersion gomatrixserverlib.RoomVersion) (
-	res gomatrixserverlib.RespState, err error,
-) {
-	fmt.Println("testFederationClient.LookupState", eventID)
-	r, ok := c.state[eventID]
-	if !ok {
-		err = fmt.Errorf("txnFedClient: no /state for event %s", eventID)
-		return
-	}
-	res = r
-	return
-}
-func (c *txnFedClient) LookupStateIDs(ctx context.Context, origin, s gomatrixserverlib.ServerName, roomID string, eventID string) (res gomatrixserverlib.RespStateIDs, err error) {
-	fmt.Println("testFederationClient.LookupStateIDs", eventID)
-	r, ok := c.stateIDs[eventID]
-	if !ok {
-		err = fmt.Errorf("txnFedClient: no /state_ids for event %s", eventID)
-		return
-	}
-	res = r
-	return
-}
-func (c *txnFedClient) GetEvent(ctx context.Context, origin, s gomatrixserverlib.ServerName, eventID string) (res gomatrixserverlib.Transaction, err error) {
-	fmt.Println("testFederationClient.GetEvent", eventID)
-	r, ok := c.getEvent[eventID]
-	if !ok {
-		err = fmt.Errorf("txnFedClient: no /event for event ID %s", eventID)
-		return
-	}
-	res = r
-	return
-}
-func (c *txnFedClient) LookupMissingEvents(ctx context.Context, origin, s gomatrixserverlib.ServerName, roomID string, missing gomatrixserverlib.MissingEvents,
-	roomVersion gomatrixserverlib.RoomVersion) (res gomatrixserverlib.RespMissingEvents, err error) {
-	return c.getMissingEvents(missing)
-}
-
-func mustCreateTransaction(rsAPI api.FederationRoomserverAPI, fedClient txnFederationClient, pdus []json.RawMessage) *txnReq {
-	t := &txnReq{
-		rsAPI:      rsAPI,
-		keys:       &test.NopJSONVerifier{},
-		federation: fedClient,
-		roomsMu:    internal.NewMutexByRoom(),
-	}
-	t.PDUs = pdus
-	t.Origin = testOrigin
-	t.TransactionID = gomatrixserverlib.TransactionID(fmt.Sprintf("%d", time.Now().UnixNano()))
-	t.Destination = testDestination
-	return t
-}
-
-func mustProcessTransaction(t *testing.T, txn *txnReq, pdusWithErrors []string) {
-	res, err := txn.processTransaction(context.Background())
-	if err != nil {
-		t.Errorf("txn.processTransaction returned an error: %v", err)
-		return
-	}
-	if len(res.PDUs) != len(txn.PDUs) {
-		t.Errorf("txn.processTransaction did not return results for all PDUs, got %d want %d", len(res.PDUs), len(txn.PDUs))
-		return
-	}
-NextPDU:
-	for eventID, result := range res.PDUs {
-		if result.Error == "" {
-			continue
-		}
-		for _, eventIDWantError := range pdusWithErrors {
-			if eventID == eventIDWantError {
-				break NextPDU
-			}
-		}
-		t.Errorf("txn.processTransaction PDU %s returned an error %s", eventID, result.Error)
-	}
-}
-
-/*
-func fromStateTuples(tuples []gomatrixserverlib.StateKeyTuple, omitTuples []gomatrixserverlib.StateKeyTuple) (result []*gomatrixserverlib.HeaderedEvent) {
-NextTuple:
-	for _, t := range tuples {
-		for _, o := range omitTuples {
-			if t == o {
-				break NextTuple
-			}
-		}
-		h, ok := testStateEvents[t]
-		if ok {
-			result = append(result, h)
-		}
-	}
-	return
-}
-*/
-
-func assertInputRoomEvents(t *testing.T, got []api.InputRoomEvent, want []*gomatrixserverlib.HeaderedEvent) {
-	for _, g := range got {
-		fmt.Println("GOT ", g.Event.EventID())
-	}
-	if len(got) != len(want) {
-		t.Errorf("wrong number of InputRoomEvents: got %d want %d", len(got), len(want))
-		return
-	}
-	for i := range got {
-		if got[i].Event.EventID() != want[i].EventID() {
-			t.Errorf("InputRoomEvents[%d] got %s want %s", i, got[i].Event.EventID(), want[i].EventID())
-		}
-	}
-}
-
-// The purpose of this test is to check that receiving an event over federation for which we have the prev_events works correctly, and passes it on
-// to the roomserver. It's the most basic test possible.
-func TestBasicTransaction(t *testing.T) {
-	rsAPI := &testRoomserverAPI{}
-	pdus := []json.RawMessage{
-		testData[len(testData)-1], // a message event
-	}
-	txn := mustCreateTransaction(rsAPI, &txnFedClient{}, pdus)
-	mustProcessTransaction(t, txn, nil)
-	assertInputRoomEvents(t, rsAPI.inputRoomEvents, []*gomatrixserverlib.HeaderedEvent{testEvents[len(testEvents)-1]})
-}
-
-// The purpose of this test is to check that if the event received fails auth checks the event is still sent to the roomserver
-// as it does the auth check.
-func TestTransactionFailAuthChecks(t *testing.T) {
-	rsAPI := &testRoomserverAPI{}
-	pdus := []json.RawMessage{
-		testData[len(testData)-1], // a message event
-	}
-	txn := mustCreateTransaction(rsAPI, &txnFedClient{}, pdus)
-	mustProcessTransaction(t, txn, []string{})
-	// expect message to be sent to the roomserver
-	assertInputRoomEvents(t, rsAPI.inputRoomEvents, []*gomatrixserverlib.HeaderedEvent{testEvents[len(testEvents)-1]})
-}
-
-// The purpose of this test is to make sure that when an event is received for which we do not know the prev_events,
-// we request them from /get_missing_events. It works by setting PrevEventsExist=false in the roomserver query response,
-// resulting in a call to /get_missing_events which returns the missing prev event. Both events should be processed in
-// topological order and sent to the roomserver.
-/*
-func TestTransactionFetchMissingPrevEvents(t *testing.T) {
-	haveEvent := testEvents[len(testEvents)-3]
-	prevEvent := testEvents[len(testEvents)-2]
-	inputEvent := testEvents[len(testEvents)-1]
-
-	var rsAPI *testRoomserverAPI // ref here so we can refer to inputRoomEvents inside these functions
-	rsAPI = &testRoomserverAPI{
-		queryEventsByID: func(req *api.QueryEventsByIDRequest) api.QueryEventsByIDResponse {
-			res := api.QueryEventsByIDResponse{}
-			for _, ev := range testEvents {
-				for _, id := range req.EventIDs {
-					if ev.EventID() == id {
-						res.Events = append(res.Events, ev)
-					}
-				}
-			}
-			return res
-		},
-		queryStateAfterEvents: func(req *api.QueryStateAfterEventsRequest) api.QueryStateAfterEventsResponse {
-			return api.QueryStateAfterEventsResponse{
-				PrevEventsExist: true,
-				StateEvents:     testEvents[:5],
-			}
-		},
-		queryMissingAuthPrevEvents: func(req *api.QueryMissingAuthPrevEventsRequest) api.QueryMissingAuthPrevEventsResponse {
-			missingPrevEvent := []string{"missing_prev_event"}
-			if len(req.PrevEventIDs) == 1 {
-				switch req.PrevEventIDs[0] {
-				case haveEvent.EventID():
-					missingPrevEvent = []string{}
-				case prevEvent.EventID():
-					// we only have this event if we've been send prevEvent
-					if len(rsAPI.inputRoomEvents) == 1 && rsAPI.inputRoomEvents[0].Event.EventID() == prevEvent.EventID() {
-						missingPrevEvent = []string{}
-					}
-				}
-			}
-
-			return api.QueryMissingAuthPrevEventsResponse{
-				RoomExists:          true,
-				MissingAuthEventIDs: []string{},
-				MissingPrevEventIDs: missingPrevEvent,
-			}
-		},
-		queryLatestEventsAndState: func(req *api.QueryLatestEventsAndStateRequest) api.QueryLatestEventsAndStateResponse {
-			return api.QueryLatestEventsAndStateResponse{
-				RoomExists: true,
-				Depth:      haveEvent.Depth(),
-				LatestEvents: []gomatrixserverlib.EventReference{
-					haveEvent.EventReference(),
-				},
-				StateEvents: fromStateTuples(req.StateToFetch, nil),
-			}
-		},
-	}
-
-	cli := &txnFedClient{
-		getMissingEvents: func(missing gomatrixserverlib.MissingEvents) (res gomatrixserverlib.RespMissingEvents, err error) {
-			if !reflect.DeepEqual(missing.EarliestEvents, []string{haveEvent.EventID()}) {
-				t.Errorf("call to /get_missing_events wrong earliest events: got %v want %v", missing.EarliestEvents, haveEvent.EventID())
-			}
-			if !reflect.DeepEqual(missing.LatestEvents, []string{inputEvent.EventID()}) {
-				t.Errorf("call to /get_missing_events wrong latest events: got %v want %v", missing.LatestEvents, inputEvent.EventID())
-			}
-			return gomatrixserverlib.RespMissingEvents{
-				Events: []*gomatrixserverlib.Event{
-					prevEvent.Unwrap(),
-				},
-			}, nil
-		},
-	}
-
-	pdus := []json.RawMessage{
-		inputEvent.JSON(),
-	}
-	txn := mustCreateTransaction(rsAPI, cli, pdus)
-	mustProcessTransaction(t, txn, nil)
-	assertInputRoomEvents(t, rsAPI.inputRoomEvents, []*gomatrixserverlib.HeaderedEvent{prevEvent, inputEvent})
-}
-
-// The purpose of this test is to check that when there are missing prev_events and we still haven't been able to fill
-// in the hole with /get_missing_events that the state BEFORE the events we want to persist is fetched via /state_ids
-// and /event. It works by setting PrevEventsExist=false in the roomserver query response, resulting in
-// a call to /get_missing_events which returns 1 out of the 2 events it needs to fill in the gap. Synapse and Dendrite
-// both give up after 1x /get_missing_events call, relying on requesting the state AFTER the missing event in order to
-// continue. The DAG looks something like:
-// FE           GME    TXN
-//  A ---> B ---> C ---> D
-// TXN=event in the txn, GME=response to /get_missing_events, FE=roomserver's forward extremity. Should result in:
-// - /state_ids?event=B is requested, then /event/B to get the state AFTER B. B is a state event.
-// - state resolution is done to check C is allowed.
-// This results in B being sent as an outlier FIRST, then C,D.
-func TestTransactionFetchMissingStateByStateIDs(t *testing.T) {
-	eventA := testEvents[len(testEvents)-5]
-	// this is also len(testEvents)-4
-	eventB := testStateEvents[gomatrixserverlib.StateKeyTuple{
-		EventType: gomatrixserverlib.MRoomPowerLevels,
-		StateKey:  "",
-	}]
-	eventC := testEvents[len(testEvents)-3]
-	eventD := testEvents[len(testEvents)-2]
-	fmt.Println("a:", eventA.EventID())
-	fmt.Println("b:", eventB.EventID())
-	fmt.Println("c:", eventC.EventID())
-	fmt.Println("d:", eventD.EventID())
-	var rsAPI *testRoomserverAPI
-	rsAPI = &testRoomserverAPI{
-		queryStateAfterEvents: func(req *api.QueryStateAfterEventsRequest) api.QueryStateAfterEventsResponse {
-			omitTuples := []gomatrixserverlib.StateKeyTuple{
-				{
-					EventType: gomatrixserverlib.MRoomPowerLevels,
-					StateKey:  "",
-				},
-			}
-			askingForEvent := req.PrevEventIDs[0]
-			haveEventB := false
-			haveEventC := false
-			for _, ev := range rsAPI.inputRoomEvents {
-				switch ev.Event.EventID() {
-				case eventB.EventID():
-					haveEventB = true
-					omitTuples = nil // include event B now
-				case eventC.EventID():
-					haveEventC = true
-				}
-			}
-			prevEventExists := false
-			if askingForEvent == eventC.EventID() {
-				prevEventExists = haveEventC
-			} else if askingForEvent == eventB.EventID() {
-				prevEventExists = haveEventB
-			}
-			var stateEvents []*gomatrixserverlib.HeaderedEvent
-			if prevEventExists {
-				stateEvents = fromStateTuples(req.StateToFetch, omitTuples)
-			}
-			return api.QueryStateAfterEventsResponse{
-				PrevEventsExist: prevEventExists,
-				RoomExists:      true,
-				StateEvents:     stateEvents,
-			}
-		},
-
-		queryMissingAuthPrevEvents: func(req *api.QueryMissingAuthPrevEventsRequest) api.QueryMissingAuthPrevEventsResponse {
-			askingForEvent := req.PrevEventIDs[0]
-			haveEventB := false
-			haveEventC := false
-			for _, ev := range rsAPI.inputRoomEvents {
-				switch ev.Event.EventID() {
-				case eventB.EventID():
-					haveEventB = true
-				case eventC.EventID():
-					haveEventC = true
-				}
-			}
-			prevEventExists := false
-			if askingForEvent == eventC.EventID() {
-				prevEventExists = haveEventC
-			} else if askingForEvent == eventB.EventID() {
-				prevEventExists = haveEventB
-			}
-
-			var missingPrevEvent []string
-			if !prevEventExists {
-				missingPrevEvent = []string{"test"}
-			}
-
-			return api.QueryMissingAuthPrevEventsResponse{
-				RoomExists:          true,
-				MissingAuthEventIDs: []string{},
-				MissingPrevEventIDs: missingPrevEvent,
-			}
-		},
-
-		queryLatestEventsAndState: func(req *api.QueryLatestEventsAndStateRequest) api.QueryLatestEventsAndStateResponse {
-			omitTuples := []gomatrixserverlib.StateKeyTuple{
-				{EventType: gomatrixserverlib.MRoomPowerLevels, StateKey: ""},
-			}
-			return api.QueryLatestEventsAndStateResponse{
-				RoomExists: true,
-				Depth:      eventA.Depth(),
-				LatestEvents: []gomatrixserverlib.EventReference{
-					eventA.EventReference(),
-				},
-				StateEvents: fromStateTuples(req.StateToFetch, omitTuples),
-			}
-		},
-		queryEventsByID: func(req *api.QueryEventsByIDRequest) api.QueryEventsByIDResponse {
-			var res api.QueryEventsByIDResponse
-			fmt.Println("queryEventsByID ", req.EventIDs)
-			for _, wantEventID := range req.EventIDs {
-				for _, ev := range testStateEvents {
-					// roomserver is missing the power levels event unless it's been sent to us recently as an outlier
-					if wantEventID == eventB.EventID() {
-						fmt.Println("Asked for pl event")
-						for _, inEv := range rsAPI.inputRoomEvents {
-							fmt.Println("recv ", inEv.Event.EventID())
-							if inEv.Event.EventID() == wantEventID {
-								res.Events = append(res.Events, inEv.Event)
-								break
-							}
-						}
-						continue
-					}
-					if ev.EventID() == wantEventID {
-						res.Events = append(res.Events, ev)
-					}
-				}
-			}
-			return res
-		},
-	}
-	// /state_ids for event B returns every state event but B (it's the state before)
-	var authEventIDs []string
-	var stateEventIDs []string
-	for _, ev := range testStateEvents {
-		if ev.EventID() == eventB.EventID() {
-			continue
-		}
-		// state res checks what auth events you give it, and this isn't a valid auth event
-		if ev.Type() != gomatrixserverlib.MRoomHistoryVisibility {
-			authEventIDs = append(authEventIDs, ev.EventID())
-		}
-		stateEventIDs = append(stateEventIDs, ev.EventID())
-	}
-	cli := &txnFedClient{
-		stateIDs: map[string]gomatrixserverlib.RespStateIDs{
-			eventB.EventID(): {
-				StateEventIDs: stateEventIDs,
-				AuthEventIDs:  authEventIDs,
-			},
-		},
-		// /event for event B returns it
-		getEvent: map[string]gomatrixserverlib.Transaction{
-			eventB.EventID(): {
-				PDUs: []json.RawMessage{
-					eventB.JSON(),
-				},
-			},
-		},
-		// /get_missing_events should be done exactly once
-		getMissingEvents: func(missing gomatrixserverlib.MissingEvents) (res gomatrixserverlib.RespMissingEvents, err error) {
-			if !reflect.DeepEqual(missing.EarliestEvents, []string{eventA.EventID()}) {
-				t.Errorf("call to /get_missing_events wrong earliest events: got %v want %v", missing.EarliestEvents, eventA.EventID())
-			}
-			if !reflect.DeepEqual(missing.LatestEvents, []string{eventD.EventID()}) {
-				t.Errorf("call to /get_missing_events wrong latest events: got %v want %v", missing.LatestEvents, eventD.EventID())
-			}
-			// just return event C, not event B so /state_ids logic kicks in as there will STILL be missing prev_events
-			return gomatrixserverlib.RespMissingEvents{
-				Events: []*gomatrixserverlib.Event{
-					eventC.Unwrap(),
-				},
-			}, nil
-		},
-	}
-
-	pdus := []json.RawMessage{
-		eventD.JSON(),
-	}
-	txn := mustCreateTransaction(rsAPI, cli, pdus)
-	mustProcessTransaction(t, txn, nil)
-	assertInputRoomEvents(t, rsAPI.inputRoomEvents, []*gomatrixserverlib.HeaderedEvent{eventB, eventC, eventD})
-}
-*/

federationapi/statistics/statistics.go

@@ -1,6 +1,7 @@
 package statistics
 
 import (
+	"context"
 	"math"
 	"math/rand"
 	"sync"
@@ -28,14 +29,24 @@ type Statistics struct {
 	// just blacklist the host altogether? The backoff is exponential,
 	// so the max time here to attempt is 2**failures seconds.
 	FailuresUntilBlacklist uint32
+
+	// How many times should we tolerate consecutive failures before we
+	// mark the destination as offline. At this point we should attempt
+	// to send messages to the user's async relay servers if we know them.
+	FailuresUntilAssumedOffline uint32
 }
 
-func NewStatistics(db storage.Database, failuresUntilBlacklist uint32) Statistics {
+func NewStatistics(
+	db storage.Database,
+	failuresUntilBlacklist uint32,
+	failuresUntilAssumedOffline uint32,
+) Statistics {
 	return Statistics{
-		DB:                     db,
-		FailuresUntilBlacklist: failuresUntilBlacklist,
-		backoffTimers:          make(map[gomatrixserverlib.ServerName]*time.Timer),
-		servers:                make(map[gomatrixserverlib.ServerName]*ServerStatistics),
+		DB:                          db,
+		FailuresUntilBlacklist:      failuresUntilBlacklist,
+		FailuresUntilAssumedOffline: failuresUntilAssumedOffline,
+		backoffTimers:               make(map[gomatrixserverlib.ServerName]*time.Timer),
+		servers:                     make(map[gomatrixserverlib.ServerName]*ServerStatistics),
 	}
 }
 
@@ -50,8 +61,9 @@ func (s *Statistics) ForServer(serverName gomatrixserverlib.ServerName) *ServerS
 	if !found {
 		s.mutex.Lock()
 		server = &ServerStatistics{
-			statistics: s,
-			serverName: serverName,
+			statistics:        s,
+			serverName:        serverName,
+			knownRelayServers: []gomatrixserverlib.ServerName{},
 		}
 		s.servers[serverName] = server
 		s.mutex.Unlock()
@@ -61,24 +73,49 @@ func (s *Statistics) ForServer(serverName gomatrixserverlib.ServerName) *ServerS
 		} else {
 			server.blacklisted.Store(blacklisted)
 		}
+		assumedOffline, err := s.DB.IsServerAssumedOffline(context.Background(), serverName)
+		if err != nil {
+			logrus.WithError(err).Errorf("Failed to get assumed offline entry %q", serverName)
+		} else {
+			server.assumedOffline.Store(assumedOffline)
+		}
+
+		knownRelayServers, err := s.DB.P2PGetRelayServersForServer(context.Background(), serverName)
+		if err != nil {
+			logrus.WithError(err).Errorf("Failed to get relay server list for %q", serverName)
+		} else {
+			server.relayMutex.Lock()
+			server.knownRelayServers = knownRelayServers
+			server.relayMutex.Unlock()
+		}
 	}
 	return server
 }
 
+type SendMethod uint8
+
+const (
+	SendDirect SendMethod = iota
+	SendViaRelay
+)
+
 // ServerStatistics contains information about our interactions with a
 // remote federated host, e.g. how many times we were successful, how
 // many times we failed etc. It also manages the backoff time and black-
 // listing a remote host if it remains uncooperative.
 type ServerStatistics struct {
-	statistics      *Statistics                  //
-	serverName      gomatrixserverlib.ServerName //
-	blacklisted     atomic.Bool                  // is the node blacklisted
-	backoffStarted  atomic.Bool                  // is the backoff started
-	backoffUntil    atomic.Value                 // time.Time until this backoff interval ends
-	backoffCount    atomic.Uint32                // number of times BackoffDuration has been called
-	successCounter  atomic.Uint32                // how many times have we succeeded?
-	backoffNotifier func()                       // notifies destination queue when backoff completes
-	notifierMutex   sync.Mutex
+	statistics        *Statistics                  //
+	serverName        gomatrixserverlib.ServerName //
+	blacklisted       atomic.Bool                  // is the node blacklisted
+	assumedOffline    atomic.Bool                  // is the node assumed to be offline
+	backoffStarted    atomic.Bool                  // is the backoff started
+	backoffUntil      atomic.Value                 // time.Time until this backoff interval ends
+	backoffCount      atomic.Uint32                // number of times BackoffDuration has been called
+	successCounter    atomic.Uint32                // how many times have we succeeded?
+	backoffNotifier   func()                       // notifies destination queue when backoff completes
+	notifierMutex     sync.Mutex
+	knownRelayServers []gomatrixserverlib.ServerName
+	relayMutex        sync.Mutex
 }
 
 const maxJitterMultiplier = 1.4
@@ -113,13 +150,19 @@ func (s *ServerStatistics) AssignBackoffNotifier(notifier func()) {
 // attempt, which increases the sent counter and resets the idle and
 // failure counters. If a host was blacklisted at this point then
 // we will unblacklist it.
-func (s *ServerStatistics) Success() {
+// `relay` specifies whether the success was to the actual destination
+// or one of their relay servers.
+func (s *ServerStatistics) Success(method SendMethod) {
 	s.cancel()
 	s.backoffCount.Store(0)
-	s.successCounter.Inc()
-	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)
+	// NOTE : Sending to the final destination vs. a relay server has
+	// slightly different semantics.
+	if method == SendDirect {
+		s.successCounter.Inc()
+		if s.blacklisted.Load() && 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)
+			}
 		}
 	}
 }
@@ -139,7 +182,18 @@ func (s *ServerStatistics) Failure() (time.Time, bool) {
 	// start a goroutine which will wait out the backoff and
 	// unset the backoffStarted flag when done.
 	if s.backoffStarted.CompareAndSwap(false, true) {
-		if s.backoffCount.Inc() >= s.statistics.FailuresUntilBlacklist {
+		backoffCount := s.backoffCount.Inc()
+
+		if backoffCount >= s.statistics.FailuresUntilAssumedOffline {
+			s.assumedOffline.CompareAndSwap(false, true)
+			if s.statistics.DB != nil {
+				if err := s.statistics.DB.SetServerAssumedOffline(context.Background(), s.serverName); err != nil {
+					logrus.WithError(err).Errorf("Failed to set %q as assumed offline", s.serverName)
+				}
+			}
+		}
+
+		if backoffCount >= s.statistics.FailuresUntilBlacklist {
 			s.blacklisted.Store(true)
 			if s.statistics.DB != nil {
 				if err := s.statistics.DB.AddServerToBlacklist(s.serverName); err != nil {
@@ -157,13 +211,21 @@ func (s *ServerStatistics) Failure() (time.Time, bool) {
 		s.backoffUntil.Store(until)
 
 		s.statistics.backoffMutex.Lock()
-		defer s.statistics.backoffMutex.Unlock()
 		s.statistics.backoffTimers[s.serverName] = time.AfterFunc(time.Until(until), s.backoffFinished)
+		s.statistics.backoffMutex.Unlock()
 	}
 
 	return s.backoffUntil.Load().(time.Time), false
 }
 
+// MarkServerAlive removes the assumed offline and blacklisted statuses from this server.
+// Returns whether the server was blacklisted before this point.
+func (s *ServerStatistics) MarkServerAlive() bool {
+	s.removeAssumedOffline()
+	wasBlacklisted := s.removeBlacklist()
+	return wasBlacklisted
+}
+
 // ClearBackoff stops the backoff timer for this destination if it is running
 // and removes the timer from the backoffTimers map.
 func (s *ServerStatistics) ClearBackoff() {
@@ -191,13 +253,13 @@ func (s *ServerStatistics) backoffFinished() {
 }
 
 // BackoffInfo returns information about the current or previous backoff.
-// Returns the last backoffUntil time and whether the server is currently blacklisted or not.
-func (s *ServerStatistics) BackoffInfo() (*time.Time, bool) {
+// Returns the last backoffUntil time.
+func (s *ServerStatistics) BackoffInfo() *time.Time {
 	until, ok := s.backoffUntil.Load().(time.Time)
 	if ok {
-		return &until, s.blacklisted.Load()
+		return &until
 	}
-	return nil, s.blacklisted.Load()
+	return nil
 }
 
 // Blacklisted returns true if the server is blacklisted and false
@@ -206,10 +268,33 @@ func (s *ServerStatistics) Blacklisted() bool {
 	return s.blacklisted.Load()
 }
 
-// RemoveBlacklist removes the blacklisted status from the server.
-func (s *ServerStatistics) RemoveBlacklist() {
+// AssumedOffline returns true if the server is assumed offline and false
+// otherwise.
+func (s *ServerStatistics) AssumedOffline() bool {
+	return s.assumedOffline.Load()
+}
+
+// removeBlacklist removes the blacklisted status from the server.
+// Returns whether the server was blacklisted.
+func (s *ServerStatistics) removeBlacklist() bool {
+	var wasBlacklisted bool
+
+	if s.Blacklisted() {
+		wasBlacklisted = true
+		_ = s.statistics.DB.RemoveServerFromBlacklist(s.serverName)
+	}
 	s.cancel()
 	s.backoffCount.Store(0)
+
+	return wasBlacklisted
+}
+
+// removeAssumedOffline removes the assumed offline status from the server.
+func (s *ServerStatistics) removeAssumedOffline() {
+	if s.AssumedOffline() {
+		_ = s.statistics.DB.RemoveServerAssumedOffline(context.Background(), s.serverName)
+	}
+	s.assumedOffline.Store(false)
 }
 
 // SuccessCount returns the number of successful requests. This is
@@ -217,3 +302,46 @@ func (s *ServerStatistics) RemoveBlacklist() {
 func (s *ServerStatistics) SuccessCount() uint32 {
 	return s.successCounter.Load()
 }
+
+// KnownRelayServers returns the list of relay servers associated with this
+// server.
+func (s *ServerStatistics) KnownRelayServers() []gomatrixserverlib.ServerName {
+	s.relayMutex.Lock()
+	defer s.relayMutex.Unlock()
+	return s.knownRelayServers
+}
+
+func (s *ServerStatistics) AddRelayServers(relayServers []gomatrixserverlib.ServerName) {
+	seenSet := make(map[gomatrixserverlib.ServerName]bool)
+	uniqueList := []gomatrixserverlib.ServerName{}
+	for _, srv := range relayServers {
+		if seenSet[srv] {
+			continue
+		}
+		seenSet[srv] = true
+		uniqueList = append(uniqueList, srv)
+	}
+
+	err := s.statistics.DB.P2PAddRelayServersForServer(context.Background(), s.serverName, uniqueList)
+	if err != nil {
+		logrus.WithError(err).Errorf("Failed to add relay servers for %q. Servers: %v", s.serverName, uniqueList)
+		return
+	}
+
+	for _, newServer := range uniqueList {
+		alreadyKnown := false
+		knownRelayServers := s.KnownRelayServers()
+		for _, srv := range knownRelayServers {
+			if srv == newServer {
+				alreadyKnown = true
+			}
+		}
+		if !alreadyKnown {
+			{
+				s.relayMutex.Lock()
+				s.knownRelayServers = append(s.knownRelayServers, newServer)
+				s.relayMutex.Unlock()
+			}
+		}
+	}
+}

federationapi/statistics/statistics_test.go

@@ -4,17 +4,26 @@ import (
 	"math"
 	"testing"
 	"time"
+
+	"github.com/matrix-org/dendrite/test"
+	"github.com/matrix-org/gomatrixserverlib"
+	"github.com/stretchr/testify/assert"
+)
+
+const (
+	FailuresUntilAssumedOffline = 3
+	FailuresUntilBlacklist      = 8
 )
 
 func TestBackoff(t *testing.T) {
-	stats := NewStatistics(nil, 7)
+	stats := NewStatistics(nil, FailuresUntilBlacklist, FailuresUntilAssumedOffline)
 	server := ServerStatistics{
 		statistics: &stats,
 		serverName: "test.com",
 	}
 
 	// Start by checking that counting successes works.
-	server.Success()
+	server.Success(SendDirect)
 	if successes := server.SuccessCount(); successes != 1 {
 		t.Fatalf("Expected success count 1, got %d", successes)
 	}
@@ -31,9 +40,8 @@ func TestBackoff(t *testing.T) {
 		// side effects since a backoff is already in progress. If it does
 		// then we'll fail.
 		until, blacklisted := server.Failure()
-
-		// Get the duration.
-		_, blacklist := server.BackoffInfo()
+		blacklist := server.Blacklisted()
+		assumedOffline := server.AssumedOffline()
 		duration := time.Until(until)
 
 		// Unset the backoff, or otherwise our next call will think that
@@ -41,16 +49,43 @@ func TestBackoff(t *testing.T) {
 		server.cancel()
 		server.backoffStarted.Store(false)
 
+		if i >= stats.FailuresUntilAssumedOffline {
+			if !assumedOffline {
+				t.Fatalf("Backoff %d should have resulted in assuming the destination was offline but didn't", i)
+			}
+		}
+
+		// Check if we should be assumed offline by now.
+		if i >= stats.FailuresUntilAssumedOffline {
+			if !assumedOffline {
+				t.Fatalf("Backoff %d should have resulted in assumed offline but didn't", i)
+			} else {
+				t.Logf("Backoff %d is assumed offline as expected", i)
+			}
+		} else {
+			if assumedOffline {
+				t.Fatalf("Backoff %d should not have resulted in assumed offline but did", i)
+			} else {
+				t.Logf("Backoff %d is not assumed offline as expected", i)
+			}
+		}
+
 		// 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 if blacklist != blacklisted {
-				t.Fatalf("BackoffInfo and Failure returned different blacklist values")
+				t.Fatalf("Blacklisted and Failure returned different blacklist values")
 			} else {
 				t.Logf("Backoff %d is blacklisted as expected", i)
 				continue
 			}
+		} else {
+			if blacklist {
+				t.Fatalf("Backoff %d should not have resulted in blacklist but did", i)
+			} else {
+				t.Logf("Backoff %d is not blacklisted as expected", i)
+			}
 		}
 
 		// Check if the duration is what we expect.
@@ -69,3 +104,14 @@ func TestBackoff(t *testing.T) {
 		}
 	}
 }
+
+func TestRelayServersListing(t *testing.T) {
+	stats := NewStatistics(test.NewInMemoryFederationDatabase(), FailuresUntilBlacklist, FailuresUntilAssumedOffline)
+	server := ServerStatistics{statistics: &stats}
+	server.AddRelayServers([]gomatrixserverlib.ServerName{"relay1", "relay1", "relay2"})
+	relayServers := server.KnownRelayServers()
+	assert.Equal(t, []gomatrixserverlib.ServerName{"relay1", "relay2"}, relayServers)
+	server.AddRelayServers([]gomatrixserverlib.ServerName{"relay1", "relay1", "relay2"})
+	relayServers = server.KnownRelayServers()
+	assert.Equal(t, []gomatrixserverlib.ServerName{"relay1", "relay2"}, relayServers)
+}

federationapi/storage/interface.go

@@ -20,11 +20,12 @@ import (
 
 	"github.com/matrix-org/gomatrixserverlib"
 
-	"github.com/matrix-org/dendrite/federationapi/storage/shared"
+	"github.com/matrix-org/dendrite/federationapi/storage/shared/receipt"
 	"github.com/matrix-org/dendrite/federationapi/types"
 )
 
 type Database interface {
+	P2PDatabase
 	gomatrixserverlib.KeyDatabase
 
 	UpdateRoom(ctx context.Context, roomID string, addHosts []types.JoinedHost, removeHosts []string, purgeRoomFirst bool) (joinedHosts []types.JoinedHost, err error)
@@ -34,16 +35,16 @@ type Database interface {
 	// GetJoinedHostsForRooms returns the complete set of servers in the rooms given.
 	GetJoinedHostsForRooms(ctx context.Context, roomIDs []string, excludeSelf, excludeBlacklisted bool) ([]gomatrixserverlib.ServerName, error)
 
-	StoreJSON(ctx context.Context, js string) (*shared.Receipt, error)
+	StoreJSON(ctx context.Context, js string) (*receipt.Receipt, error)
 
-	GetPendingPDUs(ctx context.Context, serverName gomatrixserverlib.ServerName, limit int) (pdus map[*shared.Receipt]*gomatrixserverlib.HeaderedEvent, err error)
-	GetPendingEDUs(ctx context.Context, serverName gomatrixserverlib.ServerName, limit int) (edus map[*shared.Receipt]*gomatrixserverlib.EDU, err error)
+	GetPendingPDUs(ctx context.Context, serverName gomatrixserverlib.ServerName, limit int) (pdus map[*receipt.Receipt]*gomatrixserverlib.HeaderedEvent, err error)
+	GetPendingEDUs(ctx context.Context, serverName gomatrixserverlib.ServerName, limit int) (edus map[*receipt.Receipt]*gomatrixserverlib.EDU, err error)
 
-	AssociatePDUWithDestinations(ctx context.Context, destinations map[gomatrixserverlib.ServerName]struct{}, receipt *shared.Receipt) error
-	AssociateEDUWithDestinations(ctx context.Context, destinations map[gomatrixserverlib.ServerName]struct{}, receipt *shared.Receipt, eduType string, expireEDUTypes map[string]time.Duration) error
+	AssociatePDUWithDestinations(ctx context.Context, destinations map[gomatrixserverlib.ServerName]struct{}, dbReceipt *receipt.Receipt) error
+	AssociateEDUWithDestinations(ctx context.Context, destinations map[gomatrixserverlib.ServerName]struct{}, dbReceipt *receipt.Receipt, eduType string, expireEDUTypes map[string]time.Duration) error
 
-	CleanPDUs(ctx context.Context, serverName gomatrixserverlib.ServerName, receipts []*shared.Receipt) error
-	CleanEDUs(ctx context.Context, serverName gomatrixserverlib.ServerName, receipts []*shared.Receipt) error
+	CleanPDUs(ctx context.Context, serverName gomatrixserverlib.ServerName, receipts []*receipt.Receipt) error
+	CleanEDUs(ctx context.Context, serverName gomatrixserverlib.ServerName, receipts []*receipt.Receipt) error
 
 	GetPendingPDUServerNames(ctx context.Context) ([]gomatrixserverlib.ServerName, error)
 	GetPendingEDUServerNames(ctx context.Context) ([]gomatrixserverlib.ServerName, error)
@@ -54,6 +55,18 @@ type Database interface {
 	RemoveAllServersFromBlacklist() error
 	IsServerBlacklisted(serverName gomatrixserverlib.ServerName) (bool, error)
 
+	// Adds the server to the list of assumed offline servers.
+	// If the server already exists in the table, nothing happens and returns success.
+	SetServerAssumedOffline(ctx context.Context, serverName gomatrixserverlib.ServerName) error
+	// Removes the server from the list of assumed offline servers.
+	// If the server doesn't exist in the table, nothing happens and returns success.
+	RemoveServerAssumedOffline(ctx context.Context, serverName gomatrixserverlib.ServerName) error
+	// Purges all entries from the assumed offline table.
+	RemoveAllServersAssumedOffline(ctx context.Context) error
+	// Gets whether the provided server is present in the table.
+	// If it is present, returns true. If not, returns false.
+	IsServerAssumedOffline(ctx context.Context, serverName gomatrixserverlib.ServerName) (bool, error)
+
 	AddOutboundPeek(ctx context.Context, serverName gomatrixserverlib.ServerName, roomID, peekID string, renewalInterval int64) error
 	RenewOutboundPeek(ctx context.Context, serverName gomatrixserverlib.ServerName, roomID, peekID string, renewalInterval int64) error
 	GetOutboundPeek(ctx context.Context, serverName gomatrixserverlib.ServerName, roomID, peekID string) (*types.OutboundPeek, error)
@@ -74,3 +87,21 @@ type Database interface {
 
 	PurgeRoom(ctx context.Context, roomID string) error
 }
+
+type P2PDatabase interface {
+	// Stores the given list of servers as relay servers for the provided destination server.
+	// Providing duplicates will only lead to a single entry and won't lead to an error.
+	P2PAddRelayServersForServer(ctx context.Context, serverName gomatrixserverlib.ServerName, relayServers []gomatrixserverlib.ServerName) error
+
+	// Get the list of relay servers associated with the provided destination server.
+	// If no entry exists in the table, an empty list is returned and does not result in an error.
+	P2PGetRelayServersForServer(ctx context.Context, serverName gomatrixserverlib.ServerName) ([]gomatrixserverlib.ServerName, error)
+
+	// Deletes any entries for the provided destination server that match the provided relayServers list.
+	// If any of the provided servers don't match an entry, nothing happens and no error is returned.
+	P2PRemoveRelayServersForServer(ctx context.Context, serverName gomatrixserverlib.ServerName, relayServers []gomatrixserverlib.ServerName) error
+
+	// Deletes all entries for the provided destination server.
+	// If the destination server doesn't exist in the table, nothing happens and no error is returned.
+	P2PRemoveAllRelayServersForServer(ctx context.Context, serverName gomatrixserverlib.ServerName) error
+}

federationapi/storage/postgres/assumed_offline_table.go

@@ -0,0 +1,107 @@
+// Copyright 2022 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"
+
+	"github.com/matrix-org/dendrite/internal/sqlutil"
+	"github.com/matrix-org/gomatrixserverlib"
+)
+
+const assumedOfflineSchema = `
+CREATE TABLE IF NOT EXISTS federationsender_assumed_offline(
+    -- The assumed offline server name
+	server_name TEXT PRIMARY KEY NOT NULL
+);
+`
+
+const insertAssumedOfflineSQL = "" +
+	"INSERT INTO federationsender_assumed_offline (server_name) VALUES ($1)" +
+	" ON CONFLICT DO NOTHING"
+
+const selectAssumedOfflineSQL = "" +
+	"SELECT server_name FROM federationsender_assumed_offline WHERE server_name = $1"
+
+const deleteAssumedOfflineSQL = "" +
+	"DELETE FROM federationsender_assumed_offline WHERE server_name = $1"
+
+const deleteAllAssumedOfflineSQL = "" +
+	"TRUNCATE federationsender_assumed_offline"
+
+type assumedOfflineStatements struct {
+	db                          *sql.DB
+	insertAssumedOfflineStmt    *sql.Stmt
+	selectAssumedOfflineStmt    *sql.Stmt
+	deleteAssumedOfflineStmt    *sql.Stmt
+	deleteAllAssumedOfflineStmt *sql.Stmt
+}
+
+func NewPostgresAssumedOfflineTable(db *sql.DB) (s *assumedOfflineStatements, err error) {
+	s = &assumedOfflineStatements{
+		db: db,
+	}
+	_, err = db.Exec(assumedOfflineSchema)
+	if err != nil {
+		return
+	}
+
+	return s, sqlutil.StatementList{
+		{&s.insertAssumedOfflineStmt, insertAssumedOfflineSQL},
+		{&s.selectAssumedOfflineStmt, selectAssumedOfflineSQL},
+		{&s.deleteAssumedOfflineStmt, deleteAssumedOfflineSQL},
+		{&s.deleteAllAssumedOfflineStmt, deleteAllAssumedOfflineSQL},
+	}.Prepare(db)
+}
+
+func (s *assumedOfflineStatements) InsertAssumedOffline(
+	ctx context.Context, txn *sql.Tx, serverName gomatrixserverlib.ServerName,
+) error {
+	stmt := sqlutil.TxStmt(txn, s.insertAssumedOfflineStmt)
+	_, err := stmt.ExecContext(ctx, serverName)
+	return err
+}
+
+func (s *assumedOfflineStatements) SelectAssumedOffline(
+	ctx context.Context, txn *sql.Tx, serverName gomatrixserverlib.ServerName,
+) (bool, error) {
+	stmt := sqlutil.TxStmt(txn, s.selectAssumedOfflineStmt)
+	res, err := stmt.QueryContext(ctx, serverName)
+	if err != nil {
+		return false, err
+	}
+	defer res.Close() // nolint:errcheck
+	// The query will return the server name if the server is assume offline, and
+	// will return no rows if not. By calling Next, we find out if a row was
+	// returned or not - we don't care about the value itself.
+	return res.Next(), nil
+}
+
+func (s *assumedOfflineStatements) DeleteAssumedOffline(
+	ctx context.Context, txn *sql.Tx, serverName gomatrixserverlib.ServerName,
+) error {
+	stmt := sqlutil.TxStmt(txn, s.deleteAssumedOfflineStmt)
+	_, err := stmt.ExecContext(ctx, serverName)
+	return err
+}
+
+func (s *assumedOfflineStatements) DeleteAllAssumedOffline(
+	ctx context.Context, txn *sql.Tx,
+) error {
+	stmt := sqlutil.TxStmt(txn, s.deleteAllAssumedOfflineStmt)
+	_, err := stmt.ExecContext(ctx)
+	return err
+}

federationapi/storage/postgres/relay_servers_table.go

@@ -0,0 +1,137 @@
+// Copyright 2022 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"
+
+	"github.com/lib/pq"
+	"github.com/matrix-org/dendrite/internal"
+	"github.com/matrix-org/dendrite/internal/sqlutil"
+	"github.com/matrix-org/gomatrixserverlib"
+)
+
+const relayServersSchema = `
+CREATE TABLE IF NOT EXISTS federationsender_relay_servers (
+	-- The destination server name
+	server_name TEXT NOT NULL,
+	-- The relay server name for a given destination
+	relay_server_name TEXT NOT NULL,
+	UNIQUE (server_name, relay_server_name)
+);
+
+CREATE INDEX IF NOT EXISTS federationsender_relay_servers_server_name_idx
+	ON federationsender_relay_servers (server_name);
+`
+
+const insertRelayServersSQL = "" +
+	"INSERT INTO federationsender_relay_servers (server_name, relay_server_name) VALUES ($1, $2)" +
+	" ON CONFLICT DO NOTHING"
+
+const selectRelayServersSQL = "" +
+	"SELECT relay_server_name FROM federationsender_relay_servers WHERE server_name = $1"
+
+const deleteRelayServersSQL = "" +
+	"DELETE FROM federationsender_relay_servers WHERE server_name = $1 AND relay_server_name = ANY($2)"
+
+const deleteAllRelayServersSQL = "" +
+	"DELETE FROM federationsender_relay_servers WHERE server_name = $1"
+
+type relayServersStatements struct {
+	db                        *sql.DB
+	insertRelayServersStmt    *sql.Stmt
+	selectRelayServersStmt    *sql.Stmt
+	deleteRelayServersStmt    *sql.Stmt
+	deleteAllRelayServersStmt *sql.Stmt
+}
+
+func NewPostgresRelayServersTable(db *sql.DB) (s *relayServersStatements, err error) {
+	s = &relayServersStatements{
+		db: db,
+	}
+	_, err = db.Exec(relayServersSchema)
+	if err != nil {
+		return
+	}
+
+	return s, sqlutil.StatementList{
+		{&s.insertRelayServersStmt, insertRelayServersSQL},
+		{&s.selectRelayServersStmt, selectRelayServersSQL},
+		{&s.deleteRelayServersStmt, deleteRelayServersSQL},
+		{&s.deleteAllRelayServersStmt, deleteAllRelayServersSQL},
+	}.Prepare(db)
+}
+
+func (s *relayServersStatements) InsertRelayServers(
+	ctx context.Context,
+	txn *sql.Tx,
+	serverName gomatrixserverlib.ServerName,
+	relayServers []gomatrixserverlib.ServerName,
+) error {
+	for _, relayServer := range relayServers {
+		stmt := sqlutil.TxStmt(txn, s.insertRelayServersStmt)
+		if _, err := stmt.ExecContext(ctx, serverName, relayServer); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func (s *relayServersStatements) SelectRelayServers(
+	ctx context.Context,
+	txn *sql.Tx,
+	serverName gomatrixserverlib.ServerName,
+) ([]gomatrixserverlib.ServerName, error) {
+	stmt := sqlutil.TxStmt(txn, s.selectRelayServersStmt)
+	rows, err := stmt.QueryContext(ctx, serverName)
+	if err != nil {
+		return nil, err
+	}
+	defer internal.CloseAndLogIfError(ctx, rows, "SelectRelayServers: rows.close() failed")
+
+	var result []gomatrixserverlib.ServerName
+	for rows.Next() {
+		var relayServer string
+		if err = rows.Scan(&relayServer); err != nil {
+			return nil, err
+		}
+		result = append(result, gomatrixserverlib.ServerName(relayServer))
+	}
+	return result, nil
+}
+
+func (s *relayServersStatements) DeleteRelayServers(
+	ctx context.Context,
+	txn *sql.Tx,
+	serverName gomatrixserverlib.ServerName,
+	relayServers []gomatrixserverlib.ServerName,
+) error {
+	stmt := sqlutil.TxStmt(txn, s.deleteRelayServersStmt)
+	_, err := stmt.ExecContext(ctx, serverName, pq.Array(relayServers))
+	return err
+}
+
+func (s *relayServersStatements) DeleteAllRelayServers(
+	ctx context.Context,
+	txn *sql.Tx,
+	serverName gomatrixserverlib.ServerName,
+) error {
+	stmt := sqlutil.TxStmt(txn, s.deleteAllRelayServersStmt)
+	if _, err := stmt.ExecContext(ctx, serverName); err != nil {
+		return err
+	}
+	return nil
+}

federationapi/storage/postgres/storage.go

@@ -62,6 +62,14 @@ func NewDatabase(base *base.BaseDendrite, dbProperties *config.DatabaseOptions,
 	if err != nil {
 		return nil, err
 	}
+	assumedOffline, err := NewPostgresAssumedOfflineTable(d.db)
+	if err != nil {
+		return nil, err
+	}
+	relayServers, err := NewPostgresRelayServersTable(d.db)
+	if err != nil {
+		return nil, err
+	}
 	inboundPeeks, err := NewPostgresInboundPeeksTable(d.db)
 	if err != nil {
 		return nil, err
@@ -104,6 +112,8 @@ func NewDatabase(base *base.BaseDendrite, dbProperties *config.DatabaseOptions,
 		FederationQueueEDUs:      queueEDUs,
 		FederationQueueJSON:      queueJSON,
 		FederationBlacklist:      blacklist,
+		FederationAssumedOffline: assumedOffline,
+		FederationRelayServers:   relayServers,
 		FederationInboundPeeks:   inboundPeeks,
 		FederationOutboundPeeks:  outboundPeeks,
 		NotaryServerKeysJSON:     notaryJSON,

federationapi/storage/shared/receipt/receipt.go

@@ -0,0 +1,42 @@
+// Copyright 2023 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.
+// A Receipt contains the NIDs of a call to GetNextTransactionPDUs/EDUs.
+// We don't actually export the NIDs but we need the caller to be able
+// to pass them back so that we can clean up if the transaction sends
+// successfully.
+
+package receipt
+
+import "fmt"
+
+// Receipt is a wrapper type used to represent a nid that corresponds to a unique row entry
+// in some database table.
+// The internal nid value cannot be modified after a Receipt has been created.
+// This guarantees a receipt will always refer to the same table entry that it was created
+// to represent.
+type Receipt struct {
+	nid int64
+}
+
+func NewReceipt(nid int64) Receipt {
+	return Receipt{nid: nid}
+}
+
+func (r *Receipt) GetNID() int64 {
+	return r.nid
+}
+
+func (r *Receipt) String() string {
+	return fmt.Sprintf("%d", r.nid)
+}

federationapi/storage/shared/storage.go

@@ -20,6 +20,7 @@ import (
 	"fmt"
 	"time"
 
+	"github.com/matrix-org/dendrite/federationapi/storage/shared/receipt"
 	"github.com/matrix-org/dendrite/federationapi/storage/tables"
 	"github.com/matrix-org/dendrite/federationapi/types"
 	"github.com/matrix-org/dendrite/internal/caching"
@@ -37,6 +38,8 @@ type Database struct {
 	FederationQueueJSON      tables.FederationQueueJSON
 	FederationJoinedHosts    tables.FederationJoinedHosts
 	FederationBlacklist      tables.FederationBlacklist
+	FederationAssumedOffline tables.FederationAssumedOffline
+	FederationRelayServers   tables.FederationRelayServers
 	FederationOutboundPeeks  tables.FederationOutboundPeeks
 	FederationInboundPeeks   tables.FederationInboundPeeks
 	NotaryServerKeysJSON     tables.FederationNotaryServerKeysJSON
@@ -44,22 +47,6 @@ type Database struct {
 	ServerSigningKeys        tables.FederationServerSigningKeys
 }
 
-// An Receipt contains the NIDs of a call to GetNextTransactionPDUs/EDUs.
-// We don't actually export the NIDs but we need the caller to be able
-// to pass them back so that we can clean up if the transaction sends
-// successfully.
-type Receipt struct {
-	nid int64
-}
-
-func NewReceipt(nid int64) Receipt {
-	return Receipt{nid: nid}
-}
-
-func (r *Receipt) String() string {
-	return fmt.Sprintf("%d", r.nid)
-}
-
 // UpdateRoom updates the joined hosts for a room and returns what the joined
 // hosts were before the update, or nil if this was a duplicate message.
 // This is called when we receive a message from kafka, so we pass in
@@ -113,11 +100,18 @@ func (d *Database) GetJoinedHosts(
 // GetAllJoinedHosts returns the currently joined hosts for
 // all rooms known to the federation sender.
 // Returns an error if something goes wrong.
-func (d *Database) GetAllJoinedHosts(ctx context.Context) ([]gomatrixserverlib.ServerName, error) {
+func (d *Database) GetAllJoinedHosts(
+	ctx context.Context,
+) ([]gomatrixserverlib.ServerName, error) {
 	return d.FederationJoinedHosts.SelectAllJoinedHosts(ctx)
 }
 
-func (d *Database) GetJoinedHostsForRooms(ctx context.Context, roomIDs []string, excludeSelf, excludeBlacklisted bool) ([]gomatrixserverlib.ServerName, error) {
+func (d *Database) GetJoinedHostsForRooms(
+	ctx context.Context,
+	roomIDs []string,
+	excludeSelf,
+	excludeBlacklisted bool,
+) ([]gomatrixserverlib.ServerName, error) {
 	servers, err := d.FederationJoinedHosts.SelectJoinedHostsForRooms(ctx, roomIDs, excludeBlacklisted)
 	if err != nil {
 		return nil, err
@@ -139,7 +133,7 @@ func (d *Database) GetJoinedHostsForRooms(ctx context.Context, roomIDs []string,
 // metadata entries.
 func (d *Database) StoreJSON(
 	ctx context.Context, js string,
-) (*Receipt, error) {
+) (*receipt.Receipt, error) {
 	var nid int64
 	var err error
 	_ = d.Writer.Do(d.DB, nil, func(txn *sql.Tx) error {
@@ -149,18 +143,21 @@ func (d *Database) StoreJSON(
 	if err != nil {
 		return nil, fmt.Errorf("d.insertQueueJSON: %w", err)
 	}
-	return &Receipt{
-		nid: nid,
-	}, nil
+	newReceipt := receipt.NewReceipt(nid)
+	return &newReceipt, nil
 }
 
-func (d *Database) AddServerToBlacklist(serverName gomatrixserverlib.ServerName) error {
+func (d *Database) AddServerToBlacklist(
+	serverName gomatrixserverlib.ServerName,
+) error {
 	return d.Writer.Do(d.DB, nil, func(txn *sql.Tx) error {
 		return d.FederationBlacklist.InsertBlacklist(context.TODO(), txn, serverName)
 	})
 }
 
-func (d *Database) RemoveServerFromBlacklist(serverName gomatrixserverlib.ServerName) error {
+func (d *Database) RemoveServerFromBlacklist(
+	serverName gomatrixserverlib.ServerName,
+) error {
 	return d.Writer.Do(d.DB, nil, func(txn *sql.Tx) error {
 		return d.FederationBlacklist.DeleteBlacklist(context.TODO(), txn, serverName)
 	})
@@ -172,51 +169,166 @@ func (d *Database) RemoveAllServersFromBlacklist() error {
 	})
 }
 
-func (d *Database) IsServerBlacklisted(serverName gomatrixserverlib.ServerName) (bool, error) {
+func (d *Database) IsServerBlacklisted(
+	serverName gomatrixserverlib.ServerName,
+) (bool, error) {
 	return d.FederationBlacklist.SelectBlacklist(context.TODO(), nil, serverName)
 }
 
-func (d *Database) AddOutboundPeek(ctx context.Context, serverName gomatrixserverlib.ServerName, roomID, peekID string, renewalInterval int64) error {
+func (d *Database) SetServerAssumedOffline(
+	ctx context.Context,
+	serverName gomatrixserverlib.ServerName,
+) error {
+	return d.Writer.Do(d.DB, nil, func(txn *sql.Tx) error {
+		return d.FederationAssumedOffline.InsertAssumedOffline(ctx, txn, serverName)
+	})
+}
+
+func (d *Database) RemoveServerAssumedOffline(
+	ctx context.Context,
+	serverName gomatrixserverlib.ServerName,
+) error {
+	return d.Writer.Do(d.DB, nil, func(txn *sql.Tx) error {
+		return d.FederationAssumedOffline.DeleteAssumedOffline(ctx, txn, serverName)
+	})
+}
+
+func (d *Database) RemoveAllServersAssumedOffline(
+	ctx context.Context,
+) error {
+	return d.Writer.Do(d.DB, nil, func(txn *sql.Tx) error {
+		return d.FederationAssumedOffline.DeleteAllAssumedOffline(ctx, txn)
+	})
+}
+
+func (d *Database) IsServerAssumedOffline(
+	ctx context.Context,
+	serverName gomatrixserverlib.ServerName,
+) (bool, error) {
+	return d.FederationAssumedOffline.SelectAssumedOffline(ctx, nil, serverName)
+}
+
+func (d *Database) P2PAddRelayServersForServer(
+	ctx context.Context,
+	serverName gomatrixserverlib.ServerName,
+	relayServers []gomatrixserverlib.ServerName,
+) error {
+	return d.Writer.Do(d.DB, nil, func(txn *sql.Tx) error {
+		return d.FederationRelayServers.InsertRelayServers(ctx, txn, serverName, relayServers)
+	})
+}
+
+func (d *Database) P2PGetRelayServersForServer(
+	ctx context.Context,
+	serverName gomatrixserverlib.ServerName,
+) ([]gomatrixserverlib.ServerName, error) {
+	return d.FederationRelayServers.SelectRelayServers(ctx, nil, serverName)
+}
+
+func (d *Database) P2PRemoveRelayServersForServer(
+	ctx context.Context,
+	serverName gomatrixserverlib.ServerName,
+	relayServers []gomatrixserverlib.ServerName,
+) error {
+	return d.Writer.Do(d.DB, nil, func(txn *sql.Tx) error {
+		return d.FederationRelayServers.DeleteRelayServers(ctx, txn, serverName, relayServers)
+	})
+}
+
+func (d *Database) P2PRemoveAllRelayServersForServer(
+	ctx context.Context,
+	serverName gomatrixserverlib.ServerName,
+) error {
+	return d.Writer.Do(d.DB, nil, func(txn *sql.Tx) error {
+		return d.FederationRelayServers.DeleteAllRelayServers(ctx, txn, serverName)
+	})
+}
+
+func (d *Database) AddOutboundPeek(
+	ctx context.Context,
+	serverName gomatrixserverlib.ServerName,
+	roomID string,
+	peekID string,
+	renewalInterval int64,
+) error {
 	return d.Writer.Do(d.DB, nil, func(txn *sql.Tx) error {
 		return d.FederationOutboundPeeks.InsertOutboundPeek(ctx, txn, serverName, roomID, peekID, renewalInterval)
 	})
 }
 
-func (d *Database) RenewOutboundPeek(ctx context.Context, serverName gomatrixserverlib.ServerName, roomID, peekID string, renewalInterval int64) error {
+func (d *Database) RenewOutboundPeek(
+	ctx context.Context,
+	serverName gomatrixserverlib.ServerName,
+	roomID string,
+	peekID string,
+	renewalInterval int64,
+) error {
 	return d.Writer.Do(d.DB, nil, func(txn *sql.Tx) error {
 		return d.FederationOutboundPeeks.RenewOutboundPeek(ctx, txn, serverName, roomID, peekID, renewalInterval)
 	})
 }
 
-func (d *Database) GetOutboundPeek(ctx context.Context, serverName gomatrixserverlib.ServerName, roomID, peekID string) (*types.OutboundPeek, error) {
+func (d *Database) GetOutboundPeek(
+	ctx context.Context,
+	serverName gomatrixserverlib.ServerName,
+	roomID,
+	peekID string,
+) (*types.OutboundPeek, error) {
 	return d.FederationOutboundPeeks.SelectOutboundPeek(ctx, nil, serverName, roomID, peekID)
 }
 
-func (d *Database) GetOutboundPeeks(ctx context.Context, roomID string) ([]types.OutboundPeek, error) {
+func (d *Database) GetOutboundPeeks(
+	ctx context.Context,
+	roomID string,
+) ([]types.OutboundPeek, error) {
 	return d.FederationOutboundPeeks.SelectOutboundPeeks(ctx, nil, roomID)
 }
 
-func (d *Database) AddInboundPeek(ctx context.Context, serverName gomatrixserverlib.ServerName, roomID, peekID string, renewalInterval int64) error {
+func (d *Database) AddInboundPeek(
+	ctx context.Context,
+	serverName gomatrixserverlib.ServerName,
+	roomID string,
+	peekID string,
+	renewalInterval int64,
+) error {
 	return d.Writer.Do(d.DB, nil, func(txn *sql.Tx) error {
 		return d.FederationInboundPeeks.InsertInboundPeek(ctx, txn, serverName, roomID, peekID, renewalInterval)
 	})
 }
 
-func (d *Database) RenewInboundPeek(ctx context.Context, serverName gomatrixserverlib.ServerName, roomID, peekID string, renewalInterval int64) error {
+func (d *Database) RenewInboundPeek(
+	ctx context.Context,
+	serverName gomatrixserverlib.ServerName,
+	roomID string,
+	peekID string,
+	renewalInterval int64,
+) error {
 	return d.Writer.Do(d.DB, nil, func(txn *sql.Tx) error {
 		return d.FederationInboundPeeks.RenewInboundPeek(ctx, txn, serverName, roomID, peekID, renewalInterval)
 	})
 }
 
-func (d *Database) GetInboundPeek(ctx context.Context, serverName gomatrixserverlib.ServerName, roomID, peekID string) (*types.InboundPeek, error) {
+func (d *Database) GetInboundPeek(
+	ctx context.Context,
+	serverName gomatrixserverlib.ServerName,
+	roomID string,
+	peekID string,
+) (*types.InboundPeek, error) {
 	return d.FederationInboundPeeks.SelectInboundPeek(ctx, nil, serverName, roomID, peekID)
 }
 
-func (d *Database) GetInboundPeeks(ctx context.Context, roomID string) ([]types.InboundPeek, error) {
+func (d *Database) GetInboundPeeks(
+	ctx context.Context,
+	roomID string,
+) ([]types.InboundPeek, error) {
 	return d.FederationInboundPeeks.SelectInboundPeeks(ctx, nil, roomID)
 }
 
-func (d *Database) UpdateNotaryKeys(ctx context.Context, serverName gomatrixserverlib.ServerName, serverKeys gomatrixserverlib.ServerKeys) error {
+func (d *Database) UpdateNotaryKeys(
+	ctx context.Context,
+	serverName gomatrixserverlib.ServerName,
+	serverKeys gomatrixserverlib.ServerKeys,
+) error {
 	return d.Writer.Do(d.DB, nil, func(txn *sql.Tx) error {
 		validUntil := serverKeys.ValidUntilTS
 		// Servers MUST use the lesser of this field and 7 days into the future when determining if a key is valid.
@@ -251,7 +363,9 @@ func (d *Database) UpdateNotaryKeys(ctx context.Context, serverName gomatrixserv
 }
 
 func (d *Database) GetNotaryKeys(
-	ctx context.Context, serverName gomatrixserverlib.ServerName, optKeyIDs []gomatrixserverlib.KeyID,
+	ctx context.Context,
+	serverName gomatrixserverlib.ServerName,
+	optKeyIDs []gomatrixserverlib.KeyID,
 ) (sks []gomatrixserverlib.ServerKeys, err error) {
 	err = d.Writer.Do(d.DB, nil, func(txn *sql.Tx) error {
 		sks, err = d.NotaryServerKeysMetadata.SelectKeys(ctx, txn, serverName, optKeyIDs)

federationapi/storage/shared/storage_edus.go

@@ -22,6 +22,7 @@ import (
 	"fmt"
 	"time"
 
+	"github.com/matrix-org/dendrite/federationapi/storage/shared/receipt"
 	"github.com/matrix-org/gomatrixserverlib"
 )
 
@@ -41,7 +42,7 @@ var defaultExpireEDUTypes = map[string]time.Duration{
 func (d *Database) AssociateEDUWithDestinations(
 	ctx context.Context,
 	destinations map[gomatrixserverlib.ServerName]struct{},
-	receipt *Receipt,
+	dbReceipt *receipt.Receipt,
 	eduType string,
 	expireEDUTypes map[string]time.Duration,
 ) error {
@@ -62,12 +63,12 @@ func (d *Database) AssociateEDUWithDestinations(
 		var err error
 		for destination := range destinations {
 			err = d.FederationQueueEDUs.InsertQueueEDU(
-				ctx,         // context
-				txn,         // SQL transaction
-				eduType,     // EDU type for coalescing
-				destination, // destination server name
-				receipt.nid, // NID from the federationapi_queue_json table
-				expiresAt,   // The timestamp this EDU will expire
+				ctx,                // context
+				txn,                // SQL transaction
+				eduType,            // EDU type for coalescing
+				destination,        // destination server name
+				dbReceipt.GetNID(), // NID from the federationapi_queue_json table
+				expiresAt,          // The timestamp this EDU will expire
 			)
 		}
 		return err
@@ -81,10 +82,10 @@ func (d *Database) GetPendingEDUs(
 	serverName gomatrixserverlib.ServerName,
 	limit int,
 ) (
-	edus map[*Receipt]*gomatrixserverlib.EDU,
+	edus map[*receipt.Receipt]*gomatrixserverlib.EDU,
 	err error,
 ) {
-	edus = make(map[*Receipt]*gomatrixserverlib.EDU)
+	edus = make(map[*receipt.Receipt]*gomatrixserverlib.EDU)
 	err = d.Writer.Do(d.DB, nil, func(txn *sql.Tx) error {
 		nids, err := d.FederationQueueEDUs.SelectQueueEDUs(ctx, txn, serverName, limit)
 		if err != nil {
@@ -94,7 +95,8 @@ func (d *Database) GetPendingEDUs(
 		retrieve := make([]int64, 0, len(nids))
 		for _, nid := range nids {
 			if edu, ok := d.Cache.GetFederationQueuedEDU(nid); ok {
-				edus[&Receipt{nid}] = edu
+				newReceipt := receipt.NewReceipt(nid)
+				edus[&newReceipt] = edu
 			} else {
 				retrieve = append(retrieve, nid)
 			}
@@ -110,7 +112,8 @@ func (d *Database) GetPendingEDUs(
 			if err := json.Unmarshal(blob, &event); err != nil {
 				return fmt.Errorf("json.Unmarshal: %w", err)
 			}
-			edus[&Receipt{nid}] = &event
+			newReceipt := receipt.NewReceipt(nid)
+			edus[&newReceipt] = &event
 			d.Cache.StoreFederationQueuedEDU(nid, &event)
 		}
 
@@ -124,7 +127,7 @@ func (d *Database) GetPendingEDUs(
 func (d *Database) CleanEDUs(
 	ctx context.Context,
 	serverName gomatrixserverlib.ServerName,
-	receipts []*Receipt,
+	receipts []*receipt.Receipt,
 ) error {
 	if len(receipts) == 0 {
 		return errors.New("expected receipt")
@@ -132,7 +135,7 @@ func (d *Database) CleanEDUs(
 
 	nids := make([]int64, len(receipts))
 	for i := range receipts {
-		nids[i] = receipts[i].nid
+		nids[i] = receipts[i].GetNID()
 	}
 
 	return d.Writer.Do(d.DB, nil, func(txn *sql.Tx) error {

federationapi/storage/shared/storage_pdus.go

@@ -21,6 +21,7 @@ import (
 	"errors"
 	"fmt"
 
+	"github.com/matrix-org/dendrite/federationapi/storage/shared/receipt"
 	"github.com/matrix-org/gomatrixserverlib"
 )
 
@@ -30,17 +31,17 @@ import (
 func (d *Database) AssociatePDUWithDestinations(
 	ctx context.Context,
 	destinations map[gomatrixserverlib.ServerName]struct{},
-	receipt *Receipt,
+	dbReceipt *receipt.Receipt,
 ) error {
 	return d.Writer.Do(d.DB, nil, func(txn *sql.Tx) error {
 		var err error
 		for destination := range destinations {
 			err = d.FederationQueuePDUs.InsertQueuePDU(
-				ctx,         // context
-				txn,         // SQL transaction
-				"",          // transaction ID
-				destination, // destination server name
-				receipt.nid, // NID from the federationapi_queue_json table
+				ctx,                // context
+				txn,                // SQL transaction
+				"",                 // transaction ID
+				destination,        // destination server name
+				dbReceipt.GetNID(), // NID from the federationapi_queue_json table
 			)
 		}
 		return err
@@ -54,7 +55,7 @@ func (d *Database) GetPendingPDUs(
 	serverName gomatrixserverlib.ServerName,
 	limit int,
 ) (
-	events map[*Receipt]*gomatrixserverlib.HeaderedEvent,
+	events map[*receipt.Receipt]*gomatrixserverlib.HeaderedEvent,
 	err error,
 ) {
 	// Strictly speaking this doesn't need to be using the writer
@@ -62,7 +63,7 @@ func (d *Database) GetPendingPDUs(
 	// a guarantee of transactional isolation, it's actually useful
 	// to know in SQLite mode that nothing else is trying to modify
 	// the database.
-	events = make(map[*Receipt]*gomatrixserverlib.HeaderedEvent)
+	events = make(map[*receipt.Receipt]*gomatrixserverlib.HeaderedEvent)
 	err = d.Writer.Do(d.DB, nil, func(txn *sql.Tx) error {
 		nids, err := d.FederationQueuePDUs.SelectQueuePDUs(ctx, txn, serverName, limit)
 		if err != nil {
@@ -72,7 +73,8 @@ func (d *Database) GetPendingPDUs(
 		retrieve := make([]int64, 0, len(nids))
 		for _, nid := range nids {
 			if event, ok := d.Cache.GetFederationQueuedPDU(nid); ok {
-				events[&Receipt{nid}] = event
+				newReceipt := receipt.NewReceipt(nid)
+				events[&newReceipt] = event
 			} else {
 				retrieve = append(retrieve, nid)
 			}
@@ -88,7 +90,8 @@ func (d *Database) GetPendingPDUs(
 			if err := json.Unmarshal(blob, &event); err != nil {
 				return fmt.Errorf("json.Unmarshal: %w", err)
 			}
-			events[&Receipt{nid}] = &event
+			newReceipt := receipt.NewReceipt(nid)
+			events[&newReceipt] = &event
 			d.Cache.StoreFederationQueuedPDU(nid, &event)
 		}
 
@@ -103,7 +106,7 @@ func (d *Database) GetPendingPDUs(
 func (d *Database) CleanPDUs(
 	ctx context.Context,
 	serverName gomatrixserverlib.ServerName,
-	receipts []*Receipt,
+	receipts []*receipt.Receipt,
 ) error {
 	if len(receipts) == 0 {
 		return errors.New("expected receipt")
@@ -111,7 +114,7 @@ func (d *Database) CleanPDUs(
 
 	nids := make([]int64, len(receipts))
 	for i := range receipts {
-		nids[i] = receipts[i].nid
+		nids[i] = receipts[i].GetNID()
 	}
 
 	return d.Writer.Do(d.DB, nil, func(txn *sql.Tx) error {

federationapi/storage/sqlite3/assumed_offline_table.go

@@ -0,0 +1,107 @@
+// Copyright 2022 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"
+
+	"github.com/matrix-org/dendrite/internal/sqlutil"
+	"github.com/matrix-org/gomatrixserverlib"
+)
+
+const assumedOfflineSchema = `
+CREATE TABLE IF NOT EXISTS federationsender_assumed_offline(
+    -- The assumed offline server name
+	server_name TEXT PRIMARY KEY NOT NULL
+);
+`
+
+const insertAssumedOfflineSQL = "" +
+	"INSERT INTO federationsender_assumed_offline (server_name) VALUES ($1)" +
+	" ON CONFLICT DO NOTHING"
+
+const selectAssumedOfflineSQL = "" +
+	"SELECT server_name FROM federationsender_assumed_offline WHERE server_name = $1"
+
+const deleteAssumedOfflineSQL = "" +
+	"DELETE FROM federationsender_assumed_offline WHERE server_name = $1"
+
+const deleteAllAssumedOfflineSQL = "" +
+	"DELETE FROM federationsender_assumed_offline"
+
+type assumedOfflineStatements struct {
+	db                          *sql.DB
+	insertAssumedOfflineStmt    *sql.Stmt
+	selectAssumedOfflineStmt    *sql.Stmt
+	deleteAssumedOfflineStmt    *sql.Stmt
+	deleteAllAssumedOfflineStmt *sql.Stmt
+}
+
+func NewSQLiteAssumedOfflineTable(db *sql.DB) (s *assumedOfflineStatements, err error) {
+	s = &assumedOfflineStatements{
+		db: db,
+	}
+	_, err = db.Exec(assumedOfflineSchema)
+	if err != nil {
+		return
+	}
+
+	return s, sqlutil.StatementList{
+		{&s.insertAssumedOfflineStmt, insertAssumedOfflineSQL},
+		{&s.selectAssumedOfflineStmt, selectAssumedOfflineSQL},
+		{&s.deleteAssumedOfflineStmt, deleteAssumedOfflineSQL},
+		{&s.deleteAllAssumedOfflineStmt, deleteAllAssumedOfflineSQL},
+	}.Prepare(db)
+}
+
+func (s *assumedOfflineStatements) InsertAssumedOffline(
+	ctx context.Context, txn *sql.Tx, serverName gomatrixserverlib.ServerName,
+) error {
+	stmt := sqlutil.TxStmt(txn, s.insertAssumedOfflineStmt)
+	_, err := stmt.ExecContext(ctx, serverName)
+	return err
+}
+
+func (s *assumedOfflineStatements) SelectAssumedOffline(
+	ctx context.Context, txn *sql.Tx, serverName gomatrixserverlib.ServerName,
+) (bool, error) {
+	stmt := sqlutil.TxStmt(txn, s.selectAssumedOfflineStmt)
+	res, err := stmt.QueryContext(ctx, serverName)
+	if err != nil {
+		return false, err
+	}
+	defer res.Close() // nolint:errcheck
+	// The query will return the server name if the server is assume offline, and
+	// will return no rows if not. By calling Next, we find out if a row was
+	// returned or not - we don't care about the value itself.
+	return res.Next(), nil
+}
+
+func (s *assumedOfflineStatements) DeleteAssumedOffline(
+	ctx context.Context, txn *sql.Tx, serverName gomatrixserverlib.ServerName,
+) error {
+	stmt := sqlutil.TxStmt(txn, s.deleteAssumedOfflineStmt)
+	_, err := stmt.ExecContext(ctx, serverName)
+	return err
+}
+
+func (s *assumedOfflineStatements) DeleteAllAssumedOffline(
+	ctx context.Context, txn *sql.Tx,
+) error {
+	stmt := sqlutil.TxStmt(txn, s.deleteAllAssumedOfflineStmt)
+	_, err := stmt.ExecContext(ctx)
+	return err
+}

federationapi/storage/sqlite3/relay_servers_table.go

@@ -0,0 +1,148 @@
+// Copyright 2022 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"
+	"strings"
+
+	"github.com/matrix-org/dendrite/internal"
+	"github.com/matrix-org/dendrite/internal/sqlutil"
+	"github.com/matrix-org/gomatrixserverlib"
+)
+
+const relayServersSchema = `
+CREATE TABLE IF NOT EXISTS federationsender_relay_servers (
+	-- The destination server name
+	server_name TEXT NOT NULL,
+	-- The relay server name for a given destination
+	relay_server_name TEXT NOT NULL,
+	UNIQUE (server_name, relay_server_name)
+);
+
+CREATE INDEX IF NOT EXISTS federationsender_relay_servers_server_name_idx
+	ON federationsender_relay_servers (server_name);
+`
+
+const insertRelayServersSQL = "" +
+	"INSERT INTO federationsender_relay_servers (server_name, relay_server_name) VALUES ($1, $2)" +
+	" ON CONFLICT DO NOTHING"
+
+const selectRelayServersSQL = "" +
+	"SELECT relay_server_name FROM federationsender_relay_servers WHERE server_name = $1"
+
+const deleteRelayServersSQL = "" +
+	"DELETE FROM federationsender_relay_servers WHERE server_name = $1 AND relay_server_name IN ($2)"
+
+const deleteAllRelayServersSQL = "" +
+	"DELETE FROM federationsender_relay_servers WHERE server_name = $1"
+
+type relayServersStatements struct {
+	db                     *sql.DB
+	insertRelayServersStmt *sql.Stmt
+	selectRelayServersStmt *sql.Stmt
+	// deleteRelayServersStmt    *sql.Stmt - prepared at runtime due to variadic
+	deleteAllRelayServersStmt *sql.Stmt
+}
+
+func NewSQLiteRelayServersTable(db *sql.DB) (s *relayServersStatements, err error) {
+	s = &relayServersStatements{
+		db: db,
+	}
+	_, err = db.Exec(relayServersSchema)
+	if err != nil {
+		return
+	}
+
+	return s, sqlutil.StatementList{
+		{&s.insertRelayServersStmt, insertRelayServersSQL},
+		{&s.selectRelayServersStmt, selectRelayServersSQL},
+		{&s.deleteAllRelayServersStmt, deleteAllRelayServersSQL},
+	}.Prepare(db)
+}
+
+func (s *relayServersStatements) InsertRelayServers(
+	ctx context.Context,
+	txn *sql.Tx,
+	serverName gomatrixserverlib.ServerName,
+	relayServers []gomatrixserverlib.ServerName,
+) error {
+	for _, relayServer := range relayServers {
+		stmt := sqlutil.TxStmt(txn, s.insertRelayServersStmt)
+		if _, err := stmt.ExecContext(ctx, serverName, relayServer); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func (s *relayServersStatements) SelectRelayServers(
+	ctx context.Context,
+	txn *sql.Tx,
+	serverName gomatrixserverlib.ServerName,
+) ([]gomatrixserverlib.ServerName, error) {
+	stmt := sqlutil.TxStmt(txn, s.selectRelayServersStmt)
+	rows, err := stmt.QueryContext(ctx, serverName)
+	if err != nil {
+		return nil, err
+	}
+	defer internal.CloseAndLogIfError(ctx, rows, "SelectRelayServers: rows.close() failed")
+
+	var result []gomatrixserverlib.ServerName
+	for rows.Next() {
+		var relayServer string
+		if err = rows.Scan(&relayServer); err != nil {
+			return nil, err
+		}
+		result = append(result, gomatrixserverlib.ServerName(relayServer))
+	}
+	return result, nil
+}
+
+func (s *relayServersStatements) DeleteRelayServers(
+	ctx context.Context,
+	txn *sql.Tx,
+	serverName gomatrixserverlib.ServerName,
+	relayServers []gomatrixserverlib.ServerName,
+) error {
+	deleteSQL := strings.Replace(deleteRelayServersSQL, "($2)", sqlutil.QueryVariadicOffset(len(relayServers), 1), 1)
+	deleteStmt, err := s.db.Prepare(deleteSQL)
+	if err != nil {
+		return err
+	}
+
+	stmt := sqlutil.TxStmt(txn, deleteStmt)
+	params := make([]interface{}, len(relayServers)+1)
+	params[0] = serverName
+	for i, v := range relayServers {
+		params[i+1] = v
+	}
+
+	_, err = stmt.ExecContext(ctx, params...)
+	return err
+}
+
+func (s *relayServersStatements) DeleteAllRelayServers(
+	ctx context.Context,
+	txn *sql.Tx,
+	serverName gomatrixserverlib.ServerName,
+) error {
+	stmt := sqlutil.TxStmt(txn, s.deleteAllRelayServersStmt)
+	if _, err := stmt.ExecContext(ctx, serverName); err != nil {
+		return err
+	}
+	return nil
+}

federationapi/storage/sqlite3/storage.go

@@ -1,5 +1,4 @@
-// Copyright 2017-2018 New Vector Ltd
-// Copyright 2019-2020 The Matrix.org Foundation C.I.C.
+// Copyright 2022 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.
@@ -61,6 +60,14 @@ func NewDatabase(base *base.BaseDendrite, dbProperties *config.DatabaseOptions,
 	if err != nil {
 		return nil, err
 	}
+	assumedOffline, err := NewSQLiteAssumedOfflineTable(d.db)
+	if err != nil {
+		return nil, err
+	}
+	relayServers, err := NewSQLiteRelayServersTable(d.db)
+	if err != nil {
+		return nil, err
+	}
 	outboundPeeks, err := NewSQLiteOutboundPeeksTable(d.db)
 	if err != nil {
 		return nil, err
@@ -103,6 +110,8 @@ func NewDatabase(base *base.BaseDendrite, dbProperties *config.DatabaseOptions,
 		FederationQueueEDUs:      queueEDUs,
 		FederationQueueJSON:      queueJSON,
 		FederationBlacklist:      blacklist,
+		FederationAssumedOffline: assumedOffline,
+		FederationRelayServers:   relayServers,
 		FederationOutboundPeeks:  outboundPeeks,
 		FederationInboundPeeks:   inboundPeeks,
 		NotaryServerKeysJSON:     notaryKeys,

federationapi/storage/storage_test.go

@@ -6,14 +6,13 @@ import (
 	"testing"
 	"time"
 
-	"github.com/matrix-org/gomatrixserverlib"
-	"github.com/matrix-org/util"
-	"github.com/stretchr/testify/assert"
-
 	"github.com/matrix-org/dendrite/federationapi/storage"
 	"github.com/matrix-org/dendrite/setup/config"
 	"github.com/matrix-org/dendrite/test"
 	"github.com/matrix-org/dendrite/test/testrig"
+	"github.com/matrix-org/gomatrixserverlib"
+	"github.com/matrix-org/util"
+	"github.com/stretchr/testify/assert"
 )
 
 func mustCreateFederationDatabase(t *testing.T, dbType test.DBType) (storage.Database, func()) {
@@ -246,3 +245,99 @@ func TestInboundPeeking(t *testing.T) {
 		assert.ElementsMatch(t, gotPeekIDs, peekIDs)
 	})
 }
+
+func TestServersAssumedOffline(t *testing.T) {
+	server1 := gomatrixserverlib.ServerName("server1")
+	server2 := gomatrixserverlib.ServerName("server2")
+
+	test.WithAllDatabases(t, func(t *testing.T, dbType test.DBType) {
+		db, closeDB := mustCreateFederationDatabase(t, dbType)
+		defer closeDB()
+
+		// Set server1 & server2 as assumed offline.
+		err := db.SetServerAssumedOffline(context.Background(), server1)
+		assert.Nil(t, err)
+		err = db.SetServerAssumedOffline(context.Background(), server2)
+		assert.Nil(t, err)
+
+		// Ensure both servers are assumed offline.
+		isOffline, err := db.IsServerAssumedOffline(context.Background(), server1)
+		assert.Nil(t, err)
+		assert.True(t, isOffline)
+		isOffline, err = db.IsServerAssumedOffline(context.Background(), server2)
+		assert.Nil(t, err)
+		assert.True(t, isOffline)
+
+		// Set server1 as not assumed offline.
+		err = db.RemoveServerAssumedOffline(context.Background(), server1)
+		assert.Nil(t, err)
+
+		// Ensure both servers have correct state.
+		isOffline, err = db.IsServerAssumedOffline(context.Background(), server1)
+		assert.Nil(t, err)
+		assert.False(t, isOffline)
+		isOffline, err = db.IsServerAssumedOffline(context.Background(), server2)
+		assert.Nil(t, err)
+		assert.True(t, isOffline)
+
+		// Re-set server1 as assumed offline.
+		err = db.SetServerAssumedOffline(context.Background(), server1)
+		assert.Nil(t, err)
+
+		// Ensure server1 is assumed offline.
+		isOffline, err = db.IsServerAssumedOffline(context.Background(), server1)
+		assert.Nil(t, err)
+		assert.True(t, isOffline)
+
+		err = db.RemoveAllServersAssumedOffline(context.Background())
+		assert.Nil(t, err)
+
+		// Ensure both servers have correct state.
+		isOffline, err = db.IsServerAssumedOffline(context.Background(), server1)
+		assert.Nil(t, err)
+		assert.False(t, isOffline)
+		isOffline, err = db.IsServerAssumedOffline(context.Background(), server2)
+		assert.Nil(t, err)
+		assert.False(t, isOffline)
+	})
+}
+
+func TestRelayServersStored(t *testing.T) {
+	server := gomatrixserverlib.ServerName("server")
+	relayServer1 := gomatrixserverlib.ServerName("relayserver1")
+	relayServer2 := gomatrixserverlib.ServerName("relayserver2")
+
+	test.WithAllDatabases(t, func(t *testing.T, dbType test.DBType) {
+		db, closeDB := mustCreateFederationDatabase(t, dbType)
+		defer closeDB()
+
+		err := db.P2PAddRelayServersForServer(context.Background(), server, []gomatrixserverlib.ServerName{relayServer1})
+		assert.Nil(t, err)
+
+		relayServers, err := db.P2PGetRelayServersForServer(context.Background(), server)
+		assert.Nil(t, err)
+		assert.Equal(t, relayServer1, relayServers[0])
+
+		err = db.P2PRemoveRelayServersForServer(context.Background(), server, []gomatrixserverlib.ServerName{relayServer1})
+		assert.Nil(t, err)
+
+		relayServers, err = db.P2PGetRelayServersForServer(context.Background(), server)
+		assert.Nil(t, err)
+		assert.Zero(t, len(relayServers))
+
+		err = db.P2PAddRelayServersForServer(context.Background(), server, []gomatrixserverlib.ServerName{relayServer1, relayServer2})
+		assert.Nil(t, err)
+
+		relayServers, err = db.P2PGetRelayServersForServer(context.Background(), server)
+		assert.Nil(t, err)
+		assert.Equal(t, relayServer1, relayServers[0])
+		assert.Equal(t, relayServer2, relayServers[1])
+
+		err = db.P2PRemoveAllRelayServersForServer(context.Background(), server)
+		assert.Nil(t, err)
+
+		relayServers, err = db.P2PGetRelayServersForServer(context.Background(), server)
+		assert.Nil(t, err)
+		assert.Zero(t, len(relayServers))
+	})
+}

federationapi/storage/tables/interface.go

@@ -49,6 +49,19 @@ type FederationQueueJSON interface {
 	SelectQueueJSON(ctx context.Context, txn *sql.Tx, jsonNIDs []int64) (map[int64][]byte, error)
 }
 
+type FederationQueueTransactions interface {
+	InsertQueueTransaction(ctx context.Context, txn *sql.Tx, transactionID gomatrixserverlib.TransactionID, serverName gomatrixserverlib.ServerName, nid int64) error
+	DeleteQueueTransactions(ctx context.Context, txn *sql.Tx, serverName gomatrixserverlib.ServerName, jsonNIDs []int64) error
+	SelectQueueTransactions(ctx context.Context, txn *sql.Tx, serverName gomatrixserverlib.ServerName, limit int) ([]int64, error)
+	SelectQueueTransactionCount(ctx context.Context, txn *sql.Tx, serverName gomatrixserverlib.ServerName) (int64, error)
+}
+
+type FederationTransactionJSON interface {
+	InsertTransactionJSON(ctx context.Context, txn *sql.Tx, json string) (int64, error)
+	DeleteTransactionJSON(ctx context.Context, txn *sql.Tx, nids []int64) error
+	SelectTransactionJSON(ctx context.Context, txn *sql.Tx, jsonNIDs []int64) (map[int64][]byte, error)
+}
+
 type FederationJoinedHosts interface {
 	InsertJoinedHosts(ctx context.Context, txn *sql.Tx, roomID, eventID string, serverName gomatrixserverlib.ServerName) error
 	DeleteJoinedHosts(ctx context.Context, txn *sql.Tx, eventIDs []string) error
@@ -66,6 +79,20 @@ type FederationBlacklist interface {
 	DeleteAllBlacklist(ctx context.Context, txn *sql.Tx) error
 }
 
+type FederationAssumedOffline interface {
+	InsertAssumedOffline(ctx context.Context, txn *sql.Tx, serverName gomatrixserverlib.ServerName) error
+	SelectAssumedOffline(ctx context.Context, txn *sql.Tx, serverName gomatrixserverlib.ServerName) (bool, error)
+	DeleteAssumedOffline(ctx context.Context, txn *sql.Tx, serverName gomatrixserverlib.ServerName) error
+	DeleteAllAssumedOffline(ctx context.Context, txn *sql.Tx) error
+}
+
+type FederationRelayServers interface {
+	InsertRelayServers(ctx context.Context, txn *sql.Tx, serverName gomatrixserverlib.ServerName, relayServers []gomatrixserverlib.ServerName) error
+	SelectRelayServers(ctx context.Context, txn *sql.Tx, serverName gomatrixserverlib.ServerName) ([]gomatrixserverlib.ServerName, error)
+	DeleteRelayServers(ctx context.Context, txn *sql.Tx, serverName gomatrixserverlib.ServerName, relayServers []gomatrixserverlib.ServerName) error
+	DeleteAllRelayServers(ctx context.Context, txn *sql.Tx, serverName gomatrixserverlib.ServerName) error
+}
+
 type FederationOutboundPeeks interface {
 	InsertOutboundPeek(ctx context.Context, txn *sql.Tx, serverName gomatrixserverlib.ServerName, roomID, peekID string, renewalInterval int64) (err error)
 	RenewOutboundPeek(ctx context.Context, txn *sql.Tx, serverName gomatrixserverlib.ServerName, roomID, peekID string, renewalInterval int64) (err error)

federationapi/storage/tables/relay_servers_table_test.go

@@ -0,0 +1,224 @@
+package tables_test
+
+import (
+	"context"
+	"database/sql"
+	"testing"
+
+	"github.com/matrix-org/dendrite/federationapi/storage/postgres"
+	"github.com/matrix-org/dendrite/federationapi/storage/sqlite3"
+	"github.com/matrix-org/dendrite/federationapi/storage/tables"
+	"github.com/matrix-org/dendrite/internal/sqlutil"
+	"github.com/matrix-org/dendrite/setup/config"
+	"github.com/matrix-org/dendrite/test"
+	"github.com/matrix-org/gomatrixserverlib"
+	"github.com/stretchr/testify/assert"
+)
+
+const (
+	server1 = "server1"
+	server2 = "server2"
+	server3 = "server3"
+	server4 = "server4"
+)
+
+type RelayServersDatabase struct {
+	DB     *sql.DB
+	Writer sqlutil.Writer
+	Table  tables.FederationRelayServers
+}
+
+func mustCreateRelayServersTable(
+	t *testing.T,
+	dbType test.DBType,
+) (database RelayServersDatabase, close func()) {
+	t.Helper()
+	connStr, close := test.PrepareDBConnectionString(t, dbType)
+	db, err := sqlutil.Open(&config.DatabaseOptions{
+		ConnectionString: config.DataSource(connStr),
+	}, sqlutil.NewExclusiveWriter())
+	assert.NoError(t, err)
+	var tab tables.FederationRelayServers
+	switch dbType {
+	case test.DBTypePostgres:
+		tab, err = postgres.NewPostgresRelayServersTable(db)
+		assert.NoError(t, err)
+	case test.DBTypeSQLite:
+		tab, err = sqlite3.NewSQLiteRelayServersTable(db)
+		assert.NoError(t, err)
+	}
+	assert.NoError(t, err)
+
+	database = RelayServersDatabase{
+		DB:     db,
+		Writer: sqlutil.NewDummyWriter(),
+		Table:  tab,
+	}
+	return database, close
+}
+
+func Equal(a, b []gomatrixserverlib.ServerName) bool {
+	if len(a) != len(b) {
+		return false
+	}
+	for i, v := range a {
+		if v != b[i] {
+			return false
+		}
+	}
+	return true
+}
+
+func TestShouldInsertRelayServers(t *testing.T) {
+	ctx := context.Background()
+	test.WithAllDatabases(t, func(t *testing.T, dbType test.DBType) {
+		db, close := mustCreateRelayServersTable(t, dbType)
+		defer close()
+		expectedRelayServers := []gomatrixserverlib.ServerName{server2, server3}
+
+		err := db.Table.InsertRelayServers(ctx, nil, server1, expectedRelayServers)
+		if err != nil {
+			t.Fatalf("Failed inserting transaction: %s", err.Error())
+		}
+
+		relayServers, err := db.Table.SelectRelayServers(ctx, nil, server1)
+		if err != nil {
+			t.Fatalf("Failed retrieving relay servers for %s: %s", relayServers, err.Error())
+		}
+
+		if !Equal(relayServers, expectedRelayServers) {
+			t.Fatalf("Expected: %v \nActual: %v", expectedRelayServers, relayServers)
+		}
+	})
+}
+
+func TestShouldInsertRelayServersWithDuplicates(t *testing.T) {
+	ctx := context.Background()
+	test.WithAllDatabases(t, func(t *testing.T, dbType test.DBType) {
+		db, close := mustCreateRelayServersTable(t, dbType)
+		defer close()
+		insertRelayServers := []gomatrixserverlib.ServerName{server2, server2, server2, server3, server2}
+		expectedRelayServers := []gomatrixserverlib.ServerName{server2, server3}
+
+		err := db.Table.InsertRelayServers(ctx, nil, server1, insertRelayServers)
+		if err != nil {
+			t.Fatalf("Failed inserting transaction: %s", err.Error())
+		}
+
+		// Insert the same list again, this shouldn't fail and should have no effect.
+		err = db.Table.InsertRelayServers(ctx, nil, server1, insertRelayServers)
+		if err != nil {
+			t.Fatalf("Failed inserting transaction: %s", err.Error())
+		}
+
+		relayServers, err := db.Table.SelectRelayServers(ctx, nil, server1)
+		if err != nil {
+			t.Fatalf("Failed retrieving relay servers for %s: %s", relayServers, err.Error())
+		}
+
+		if !Equal(relayServers, expectedRelayServers) {
+			t.Fatalf("Expected: %v \nActual: %v", expectedRelayServers, relayServers)
+		}
+	})
+}
+
+func TestShouldGetRelayServersUnknownDestination(t *testing.T) {
+	ctx := context.Background()
+	test.WithAllDatabases(t, func(t *testing.T, dbType test.DBType) {
+		db, close := mustCreateRelayServersTable(t, dbType)
+		defer close()
+
+		// Query relay servers for a destination that doesn't exist in the table.
+		relayServers, err := db.Table.SelectRelayServers(ctx, nil, server1)
+		if err != nil {
+			t.Fatalf("Failed retrieving relay servers for %s: %s", relayServers, err.Error())
+		}
+
+		if !Equal(relayServers, []gomatrixserverlib.ServerName{}) {
+			t.Fatalf("Expected: %v \nActual: %v", []gomatrixserverlib.ServerName{}, relayServers)
+		}
+	})
+}
+
+func TestShouldDeleteCorrectRelayServers(t *testing.T) {
+	ctx := context.Background()
+	test.WithAllDatabases(t, func(t *testing.T, dbType test.DBType) {
+		db, close := mustCreateRelayServersTable(t, dbType)
+		defer close()
+		relayServers1 := []gomatrixserverlib.ServerName{server2, server3}
+		relayServers2 := []gomatrixserverlib.ServerName{server1, server3, server4}
+
+		err := db.Table.InsertRelayServers(ctx, nil, server1, relayServers1)
+		if err != nil {
+			t.Fatalf("Failed inserting transaction: %s", err.Error())
+		}
+		err = db.Table.InsertRelayServers(ctx, nil, server2, relayServers2)
+		if err != nil {
+			t.Fatalf("Failed inserting transaction: %s", err.Error())
+		}
+
+		err = db.Table.DeleteRelayServers(ctx, nil, server1, []gomatrixserverlib.ServerName{server2})
+		if err != nil {
+			t.Fatalf("Failed deleting relay servers for %s: %s", server1, err.Error())
+		}
+		err = db.Table.DeleteRelayServers(ctx, nil, server2, []gomatrixserverlib.ServerName{server1, server4})
+		if err != nil {
+			t.Fatalf("Failed deleting relay servers for %s: %s", server2, err.Error())
+		}
+
+		expectedRelayServers := []gomatrixserverlib.ServerName{server3}
+		relayServers, err := db.Table.SelectRelayServers(ctx, nil, server1)
+		if err != nil {
+			t.Fatalf("Failed retrieving relay servers for %s: %s", relayServers, err.Error())
+		}
+		if !Equal(relayServers, expectedRelayServers) {
+			t.Fatalf("Expected: %v \nActual: %v", expectedRelayServers, relayServers)
+		}
+		relayServers, err = db.Table.SelectRelayServers(ctx, nil, server2)
+		if err != nil {
+			t.Fatalf("Failed retrieving relay servers for %s: %s", relayServers, err.Error())
+		}
+		if !Equal(relayServers, expectedRelayServers) {
+			t.Fatalf("Expected: %v \nActual: %v", expectedRelayServers, relayServers)
+		}
+	})
+}
+
+func TestShouldDeleteAllRelayServers(t *testing.T) {
+	ctx := context.Background()
+	test.WithAllDatabases(t, func(t *testing.T, dbType test.DBType) {
+		db, close := mustCreateRelayServersTable(t, dbType)
+		defer close()
+		expectedRelayServers := []gomatrixserverlib.ServerName{server2, server3}
+
+		err := db.Table.InsertRelayServers(ctx, nil, server1, expectedRelayServers)
+		if err != nil {
+			t.Fatalf("Failed inserting transaction: %s", err.Error())
+		}
+		err = db.Table.InsertRelayServers(ctx, nil, server2, expectedRelayServers)
+		if err != nil {
+			t.Fatalf("Failed inserting transaction: %s", err.Error())
+		}
+
+		err = db.Table.DeleteAllRelayServers(ctx, nil, server1)
+		if err != nil {
+			t.Fatalf("Failed deleting relay servers for %s: %s", server1, err.Error())
+		}
+
+		expectedRelayServers1 := []gomatrixserverlib.ServerName{}
+		relayServers, err := db.Table.SelectRelayServers(ctx, nil, server1)
+		if err != nil {
+			t.Fatalf("Failed retrieving relay servers for %s: %s", relayServers, err.Error())
+		}
+		if !Equal(relayServers, expectedRelayServers1) {
+			t.Fatalf("Expected: %v \nActual: %v", expectedRelayServers1, relayServers)
+		}
+		relayServers, err = db.Table.SelectRelayServers(ctx, nil, server2)
+		if err != nil {
+			t.Fatalf("Failed retrieving relay servers for %s: %s", relayServers, err.Error())
+		}
+		if !Equal(relayServers, expectedRelayServers) {
+			t.Fatalf("Expected: %v \nActual: %v", expectedRelayServers, relayServers)
+		}
+	})
+}

go.mod

@@ -22,9 +22,9 @@ require (
 	github.com/matrix-org/dugong v0.0.0-20210921133753-66e6b1c67e2e
 	github.com/matrix-org/go-sqlite3-js v0.0.0-20220419092513-28aa791a1c91
 	github.com/matrix-org/gomatrix v0.0.0-20220926102614-ceba4d9f7530
-	github.com/matrix-org/gomatrixserverlib v0.0.0-20230119151039-d8748f6d5dc8
-	github.com/matrix-org/pinecone v0.0.0-20221118192051-fef26631b847
-	github.com/matrix-org/util v0.0.0-20200807132607-55161520e1d4
+	github.com/matrix-org/gomatrixserverlib v0.0.0-20230119205614-cb888d80b00f
+	github.com/matrix-org/pinecone v0.11.1-0.20230111184901-61850f0e63cb
+	github.com/matrix-org/util v0.0.0-20221111132719-399730281e66
 	github.com/mattn/go-sqlite3 v1.14.15
 	github.com/nats-io/nats-server/v2 v2.9.8
 	github.com/nats-io/nats.go v1.20.0
@@ -37,17 +37,17 @@ require (
 	github.com/prometheus/client_golang v1.13.0
 	github.com/sirupsen/logrus v1.9.0
 	github.com/stretchr/testify v1.8.1
-	github.com/tidwall/gjson v1.14.3
+	github.com/tidwall/gjson v1.14.4
 	github.com/tidwall/sjson v1.2.5
 	github.com/uber/jaeger-client-go v2.30.0+incompatible
 	github.com/uber/jaeger-lib v2.4.1+incompatible
 	github.com/yggdrasil-network/yggdrasil-go v0.4.6
 	go.uber.org/atomic v1.10.0
-	golang.org/x/crypto v0.1.0
+	golang.org/x/crypto v0.5.0
 	golang.org/x/image v0.1.0
 	golang.org/x/mobile v0.0.0-20221020085226-b36e6246172e
-	golang.org/x/net v0.1.0
-	golang.org/x/term v0.1.0
+	golang.org/x/net v0.5.0
+	golang.org/x/term v0.4.0
 	gopkg.in/h2non/bimg.v1 v1.1.9
 	gopkg.in/yaml.v2 v2.4.0
 	gotest.tools/v3 v3.4.0
@@ -119,12 +119,12 @@ require (
 	github.com/prometheus/procfs v0.8.0 // indirect
 	github.com/remyoudompheng/bigfft v0.0.0-20220927061507-ef77025ab5aa // indirect
 	github.com/tidwall/match v1.1.1 // indirect
-	github.com/tidwall/pretty v1.2.0 // indirect
+	github.com/tidwall/pretty v1.2.1 // indirect
 	go.etcd.io/bbolt v1.3.6 // indirect
 	golang.org/x/exp v0.0.0-20221031165847-c99f073a8326 // indirect
 	golang.org/x/mod v0.6.0 // indirect
-	golang.org/x/sys v0.1.0 // indirect
-	golang.org/x/text v0.4.0 // indirect
+	golang.org/x/sys v0.4.0 // indirect
+	golang.org/x/text v0.6.0 // indirect
 	golang.org/x/time v0.1.0 // indirect
 	golang.org/x/tools v0.2.0 // indirect
 	google.golang.org/protobuf v1.28.1 // indirect

go.sum

@@ -348,16 +348,12 @@ github.com/matrix-org/go-sqlite3-js v0.0.0-20220419092513-28aa791a1c91 h1:s7fexw
 github.com/matrix-org/go-sqlite3-js v0.0.0-20220419092513-28aa791a1c91/go.mod h1:e+cg2q7C7yE5QnAXgzo512tgFh1RbQLC0+jozuegKgo=
 github.com/matrix-org/gomatrix v0.0.0-20220926102614-ceba4d9f7530 h1:kHKxCOLcHH8r4Fzarl4+Y3K5hjothkVW5z7T1dUM11U=
 github.com/matrix-org/gomatrix v0.0.0-20220926102614-ceba4d9f7530/go.mod h1:/gBX06Kw0exX1HrwmoBibFA98yBk/jxKpGVeyQbff+s=
-github.com/matrix-org/gomatrixserverlib v0.0.0-20230105074811-965b10ae73ab h1:ChaQdT2mpxMm3GRXNOZzLDQ/wOnlKZ8o60LmZGOjdj8=
-github.com/matrix-org/gomatrixserverlib v0.0.0-20230105074811-965b10ae73ab/go.mod h1:Mtifyr8q8htcBeugvlDnkBcNUy5LO8OzUoplAf1+mb4=
-github.com/matrix-org/gomatrixserverlib v0.0.0-20230119135050-7da03ab58f45 h1:zGrmcm2M4F4f+zk5JXAkw3oHa/zXhOh5XVGBdl7GdPo=
-github.com/matrix-org/gomatrixserverlib v0.0.0-20230119135050-7da03ab58f45/go.mod h1:Mtifyr8q8htcBeugvlDnkBcNUy5LO8OzUoplAf1+mb4=
-github.com/matrix-org/gomatrixserverlib v0.0.0-20230119151039-d8748f6d5dc8 h1:P7me2oCmksST9B4+1I1nA+XrnDQwIqAWmy6ntQrXwc8=
-github.com/matrix-org/gomatrixserverlib v0.0.0-20230119151039-d8748f6d5dc8/go.mod h1:Mtifyr8q8htcBeugvlDnkBcNUy5LO8OzUoplAf1+mb4=
-github.com/matrix-org/pinecone v0.0.0-20221118192051-fef26631b847 h1:auIBCi7gfZuvztD0aPr1G/J5Ya5vWr79M/+TJqwD/JM=
-github.com/matrix-org/pinecone v0.0.0-20221118192051-fef26631b847/go.mod h1:F3GHppRuHCTDeoOmmgjZMeJdbql91+RSGGsATWfC7oc=
-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/matrix-org/gomatrixserverlib v0.0.0-20230119205614-cb888d80b00f h1:niRWEVkeeekpjxwnMhKn8PD0PUloDsNXP8W+Ez/co/M=
+github.com/matrix-org/gomatrixserverlib v0.0.0-20230119205614-cb888d80b00f/go.mod h1:Mtifyr8q8htcBeugvlDnkBcNUy5LO8OzUoplAf1+mb4=
+github.com/matrix-org/pinecone v0.11.1-0.20230111184901-61850f0e63cb h1:2L+ltfNKab56FoBBqAvbBLjoAbxwwoZie+B8d+Mp3JI=
+github.com/matrix-org/pinecone v0.11.1-0.20230111184901-61850f0e63cb/go.mod h1:F3GHppRuHCTDeoOmmgjZMeJdbql91+RSGGsATWfC7oc=
+github.com/matrix-org/util v0.0.0-20221111132719-399730281e66 h1:6z4KxomXSIGWqhHcfzExgkH3Z3UkIXry4ibJS4Aqz2Y=
+github.com/matrix-org/util v0.0.0-20221111132719-399730281e66/go.mod h1:iBI1foelCqA09JJgPV0FYz4qA5dUXYOxMi57FxKBdd4=
 github.com/mattn/go-isatty v0.0.12/go.mod h1:cbi8OIDigv2wuxKPP5vlRcQ1OAZbq2CE4Kysco4FUpU=
 github.com/mattn/go-isatty v0.0.16 h1:bq3VjFmv/sOjHtdEhmkEV4x1AJtvUvOJ2PFAZ5+peKQ=
 github.com/mattn/go-isatty v0.0.16/go.mod h1:kYGgaQfpe5nmfYZH+SKPsOc2e4SrIfOl2e/yFXSvRLM=
@@ -494,12 +490,13 @@ github.com/stretchr/testify v1.8.0/go.mod h1:yNjHg4UonilssWZ8iaSj1OCr/vHnekPRkoO
 github.com/stretchr/testify v1.8.1 h1:w7B6lhMri9wdJUVmEZPGGhZzrYTPvgJArz7wNPgYKsk=
 github.com/stretchr/testify v1.8.1/go.mod h1:w2LPCIKwWwSfY2zedu0+kehJoqGctiVI29o6fzry7u4=
 github.com/tidwall/gjson v1.14.2/go.mod h1:/wbyibRr2FHMks5tjHJ5F8dMZh3AcwJEMf5vlfC0lxk=
-github.com/tidwall/gjson v1.14.3 h1:9jvXn7olKEHU1S9vwoMGliaT8jq1vJ7IH/n9zD9Dnlw=
-github.com/tidwall/gjson v1.14.3/go.mod h1:/wbyibRr2FHMks5tjHJ5F8dMZh3AcwJEMf5vlfC0lxk=
+github.com/tidwall/gjson v1.14.4 h1:uo0p8EbA09J7RQaflQ1aBRffTR7xedD2bcIVSYxLnkM=
+github.com/tidwall/gjson v1.14.4/go.mod h1:/wbyibRr2FHMks5tjHJ5F8dMZh3AcwJEMf5vlfC0lxk=
 github.com/tidwall/match v1.1.1 h1:+Ho715JplO36QYgwN9PGYNhgZvoUSc9X2c80KVTi+GA=
 github.com/tidwall/match v1.1.1/go.mod h1:eRSPERbgtNPcGhD8UCthc6PmLEQXEWd3PRB5JTxsfmM=
-github.com/tidwall/pretty v1.2.0 h1:RWIZEg2iJ8/g6fDDYzMpobmaoGh5OLl4AXtGUGPcqCs=
 github.com/tidwall/pretty v1.2.0/go.mod h1:ITEVvHYasfjBbM0u2Pg8T2nJnzm8xPwvNhhsoaGGjNU=
+github.com/tidwall/pretty v1.2.1 h1:qjsOFOWWQl+N3RsoF5/ssm1pHmJJwhjlSbZ51I6wMl4=
+github.com/tidwall/pretty v1.2.1/go.mod h1:ITEVvHYasfjBbM0u2Pg8T2nJnzm8xPwvNhhsoaGGjNU=
 github.com/tidwall/sjson v1.2.5 h1:kLy8mja+1c9jlljvWTlSazM7cKDRfJuR/bOJhcY5NcY=
 github.com/tidwall/sjson v1.2.5/go.mod h1:Fvgq9kS/6ociJEDnK0Fk1cpYF4FIW6ZF7LAe+6jwd28=
 github.com/tinylib/msgp v1.0.2/go.mod h1:+d+yLhGm8mzTaHzB+wgMYrodPfmZrzkirds8fDWklFE=
@@ -543,8 +540,8 @@ golang.org/x/crypto v0.0.0-20200622213623-75b288015ac9/go.mod h1:LzIPMQfyMNhhGPh
 golang.org/x/crypto v0.0.0-20210314154223-e6e6c4f2bb5b/go.mod h1:T9bdIzuCu7OtxOm1hfPfRQxPLYneinmdGuTeoZ9dtd4=
 golang.org/x/crypto v0.0.0-20210421170649-83a5a9bb288b/go.mod h1:T9bdIzuCu7OtxOm1hfPfRQxPLYneinmdGuTeoZ9dtd4=
 golang.org/x/crypto v0.0.0-20210921155107-089bfa567519/go.mod h1:GvvjBRRGRdwPK5ydBHafDWAxML/pGHZbMvKqRZ5+Abc=
-golang.org/x/crypto v0.1.0 h1:MDRAIl0xIo9Io2xV565hzXHw3zVseKrJKodhohM5CjU=
-golang.org/x/crypto v0.1.0/go.mod h1:RecgLatLF4+eUMCP1PoPZQb+cVrJcOPbHkTkbkB9sbw=
+golang.org/x/crypto v0.5.0 h1:U/0M97KRkSFvyD/3FSmdP5W5swImpNgle/EHFhOsQPE=
+golang.org/x/crypto v0.5.0/go.mod h1:NK/OQwhpMQP3MwtdjgLlYHnH9ebylxKWv3e0fK+mkQU=
 golang.org/x/exp v0.0.0-20180321215751-8460e604b9de/go.mod h1:CJ0aWSM057203Lf6IL+f9T1iT9GByDxfZKAQTCR3kQA=
 golang.org/x/exp v0.0.0-20180807140117-3d87b88a115f/go.mod h1:CJ0aWSM057203Lf6IL+f9T1iT9GByDxfZKAQTCR3kQA=
 golang.org/x/exp v0.0.0-20190121172915-509febef88a4/go.mod h1:CJ0aWSM057203Lf6IL+f9T1iT9GByDxfZKAQTCR3kQA=
@@ -625,8 +622,8 @@ golang.org/x/net v0.0.0-20210525063256-abc453219eb5/go.mod h1:9nx3DQGgdP8bBQD5qx
 golang.org/x/net v0.0.0-20220127200216-cd36cc0744dd/go.mod h1:CfG3xpIq0wQ8r1q4Su4UZFWDARRcnwPjda9FqA0JpMk=
 golang.org/x/net v0.0.0-20220225172249-27dd8689420f/go.mod h1:CfG3xpIq0wQ8r1q4Su4UZFWDARRcnwPjda9FqA0JpMk=
 golang.org/x/net v0.0.0-20220722155237-a158d28d115b/go.mod h1:XRhObCWvk6IyKnWLug+ECip1KBveYUHfp+8e9klMJ9c=
-golang.org/x/net v0.1.0 h1:hZ/3BUoy5aId7sCpA/Tc5lt8DkFgdVS2onTpJsZ/fl0=
-golang.org/x/net v0.1.0/go.mod h1:Cx3nUiGt4eDBEyega/BKRp+/AlGL8hYe7U9odMt2Cco=
+golang.org/x/net v0.5.0 h1:GyT4nK/YDHSqa1c4753ouYCDajOYKTja9Xb/OHtgvSw=
+golang.org/x/net v0.5.0/go.mod h1:DivGGAXEgPSlEBzxGzZI+ZLohi+xUj054jfeKui00ws=
 golang.org/x/oauth2 v0.0.0-20180821212333-d2e6202438be/go.mod h1:N/0e6XlmueqKjAGxoOufVs8QHGRruUQn6yWY3a++T0U=
 golang.org/x/oauth2 v0.0.0-20190226205417-e64efc72b421/go.mod h1:gOpvHmFTYa4IltrdGE7lF6nIHvwfUNPOp7c8zoXwtLw=
 golang.org/x/oauth2 v0.0.0-20190604053449-0f29369cfe45/go.mod h1:gOpvHmFTYa4IltrdGE7lF6nIHvwfUNPOp7c8zoXwtLw=
@@ -701,12 +698,12 @@ golang.org/x/sys v0.0.0-20220715151400-c0bba94af5f8/go.mod h1:oPkhp1MJrh7nUepCBc
 golang.org/x/sys v0.0.0-20220722155257-8c9f86f7a55f/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.0.0-20220811171246-fbc7d0a398ab/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.0.0-20221010170243-090e33056c14/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
-golang.org/x/sys v0.1.0 h1:kunALQeHf1/185U1i0GOB/fy1IPRDDpuoOOqRReG57U=
-golang.org/x/sys v0.1.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/sys v0.4.0 h1:Zr2JFtRQNX3BCZ8YtxRE9hNJYC8J6I1MVbMg6owUp18=
+golang.org/x/sys v0.4.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/term v0.0.0-20201126162022-7de9c90e9dd1/go.mod h1:bj7SfCRtBDWHUb9snDiAeCFNEtKQo2Wmx5Cou7ajbmo=
 golang.org/x/term v0.0.0-20210927222741-03fcf44c2211/go.mod h1:jbD1KX2456YbFQfuXm/mYQcufACuNUgVhRMnK/tPxf8=
-golang.org/x/term v0.1.0 h1:g6Z6vPFA9dYBAF7DWcH6sCcOntplXsDKcliusYijMlw=
-golang.org/x/term v0.1.0/go.mod h1:jbD1KX2456YbFQfuXm/mYQcufACuNUgVhRMnK/tPxf8=
+golang.org/x/term v0.4.0 h1:O7UWfv5+A2qiuulQk30kVinPoMtoIPeVaKLEgLpVkvg=
+golang.org/x/term v0.4.0/go.mod h1:9P2UbLfCdcvo3p/nzKvsmas4TnlujnuoV9hGgYzW1lQ=
 golang.org/x/text v0.0.0-20170915032832-14c0d48ead0c/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
 golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
 golang.org/x/text v0.3.1-0.20180807135948-17ff2d5776d2/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
@@ -714,8 +711,9 @@ golang.org/x/text v0.3.2/go.mod h1:bEr9sfX3Q8Zfm5fL9x+3itogRgK3+ptLWKqgva+5dAk=
 golang.org/x/text v0.3.3/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
 golang.org/x/text v0.3.6/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
 golang.org/x/text v0.3.7/go.mod h1:u+2+/6zg+i71rQMx5EYifcz6MCKuco9NR6JIITiCfzQ=
-golang.org/x/text v0.4.0 h1:BrVqGRd7+k1DiOgtnFvAkoQEWQvBc25ouMJM6429SFg=
 golang.org/x/text v0.4.0/go.mod h1:mrYo+phRRbMaCq/xk9113O4dZlRixOauAjOtrjsXDZ8=
+golang.org/x/text v0.6.0 h1:3XmdazWV+ubf7QgHSTWeykHOci5oeekaGJBLkrkaw4k=
+golang.org/x/text v0.6.0/go.mod h1:mrYo+phRRbMaCq/xk9113O4dZlRixOauAjOtrjsXDZ8=
 golang.org/x/time v0.0.0-20181108054448-85acf8d2951c/go.mod h1:tRJNPiyCQ0inRvYxbN9jk5I+vvW/OXSQhTDSoE431IQ=
 golang.org/x/time v0.0.0-20190308202827-9d24e82272b4/go.mod h1:tRJNPiyCQ0inRvYxbN9jk5I+vvW/OXSQhTDSoE431IQ=
 golang.org/x/time v0.0.0-20191024005414-555d28b269f0/go.mod h1:tRJNPiyCQ0inRvYxbN9jk5I+vvW/OXSQhTDSoE431IQ=

internal/log.go

@@ -101,6 +101,8 @@ func SetupPprof() {
 
 // SetupStdLogging configures the logging format to standard output. Typically, it is called when the config is not yet loaded.
 func SetupStdLogging() {
+	levelLogAddedMu.Lock()
+	defer levelLogAddedMu.Unlock()
 	logrus.SetReportCaller(true)
 	logrus.SetFormatter(&utcFormatter{
 		&logrus.TextFormatter{

internal/log_unix.go

@@ -32,6 +32,8 @@ import (
 // If something fails here it means that the logging was improperly configured,
 // so we just exit with the error
 func SetupHookLogging(hooks []config.LogrusHook, componentName string) {
+	levelLogAddedMu.Lock()
+	defer levelLogAddedMu.Unlock()
 	for _, hook := range hooks {
 		// Check we received a proper logging level
 		level, err := logrus.ParseLevel(hook.Level)
@@ -85,8 +87,6 @@ func checkSyslogHookParams(params map[string]interface{}) {
 }
 
 func setupStdLogHook(level logrus.Level) {
-	levelLogAddedMu.Lock()
-	defer levelLogAddedMu.Unlock()
 	if stdLevelLogAdded[level] {
 		return
 	}

internal/transactionrequest.go

@@ -0,0 +1,356 @@
+// Copyright 2022 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"
+	"encoding/json"
+	"fmt"
+	"sync"
+
+	"github.com/getsentry/sentry-go"
+	"github.com/matrix-org/dendrite/clientapi/jsonerror"
+	"github.com/matrix-org/dendrite/federationapi/producers"
+	"github.com/matrix-org/dendrite/federationapi/types"
+	keyapi "github.com/matrix-org/dendrite/keyserver/api"
+	"github.com/matrix-org/dendrite/roomserver/api"
+	syncTypes "github.com/matrix-org/dendrite/syncapi/types"
+	"github.com/matrix-org/gomatrixserverlib"
+	"github.com/matrix-org/util"
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/sirupsen/logrus"
+)
+
+var (
+	PDUCountTotal = prometheus.NewCounterVec(
+		prometheus.CounterOpts{
+			Namespace: "dendrite",
+			Subsystem: "federationapi",
+			Name:      "recv_pdus",
+			Help:      "Number of incoming PDUs from remote servers with labels for success",
+		},
+		[]string{"status"}, // 'success' or 'total'
+	)
+	EDUCountTotal = prometheus.NewCounter(
+		prometheus.CounterOpts{
+			Namespace: "dendrite",
+			Subsystem: "federationapi",
+			Name:      "recv_edus",
+			Help:      "Number of incoming EDUs from remote servers",
+		},
+	)
+)
+
+type TxnReq struct {
+	gomatrixserverlib.Transaction
+	rsAPI                  api.FederationRoomserverAPI
+	keyAPI                 keyapi.FederationKeyAPI
+	ourServerName          gomatrixserverlib.ServerName
+	keys                   gomatrixserverlib.JSONVerifier
+	roomsMu                *MutexByRoom
+	producer               *producers.SyncAPIProducer
+	inboundPresenceEnabled bool
+}
+
+func NewTxnReq(
+	rsAPI api.FederationRoomserverAPI,
+	keyAPI keyapi.FederationKeyAPI,
+	ourServerName gomatrixserverlib.ServerName,
+	keys gomatrixserverlib.JSONVerifier,
+	roomsMu *MutexByRoom,
+	producer *producers.SyncAPIProducer,
+	inboundPresenceEnabled bool,
+	pdus []json.RawMessage,
+	edus []gomatrixserverlib.EDU,
+	origin gomatrixserverlib.ServerName,
+	transactionID gomatrixserverlib.TransactionID,
+	destination gomatrixserverlib.ServerName,
+) TxnReq {
+	t := TxnReq{
+		rsAPI:                  rsAPI,
+		keyAPI:                 keyAPI,
+		ourServerName:          ourServerName,
+		keys:                   keys,
+		roomsMu:                roomsMu,
+		producer:               producer,
+		inboundPresenceEnabled: inboundPresenceEnabled,
+	}
+
+	t.PDUs = pdus
+	t.EDUs = edus
+	t.Origin = origin
+	t.TransactionID = transactionID
+	t.Destination = destination
+
+	return t
+}
+
+func (t *TxnReq) ProcessTransaction(ctx context.Context) (*gomatrixserverlib.RespSend, *util.JSONResponse) {
+	var wg sync.WaitGroup
+	wg.Add(1)
+	go func() {
+		defer wg.Done()
+		if t.producer != nil {
+			t.processEDUs(ctx)
+		}
+	}()
+
+	results := make(map[string]gomatrixserverlib.PDUResult)
+	roomVersions := make(map[string]gomatrixserverlib.RoomVersion)
+	getRoomVersion := func(roomID string) gomatrixserverlib.RoomVersion {
+		if v, ok := roomVersions[roomID]; ok {
+			return v
+		}
+		verReq := api.QueryRoomVersionForRoomRequest{RoomID: roomID}
+		verRes := api.QueryRoomVersionForRoomResponse{}
+		if err := t.rsAPI.QueryRoomVersionForRoom(ctx, &verReq, &verRes); err != nil {
+			util.GetLogger(ctx).WithError(err).Debug("Transaction: Failed to query room version for room", verReq.RoomID)
+			return ""
+		}
+		roomVersions[roomID] = verRes.RoomVersion
+		return verRes.RoomVersion
+	}
+
+	for _, pdu := range t.PDUs {
+		PDUCountTotal.WithLabelValues("total").Inc()
+		var header struct {
+			RoomID string `json:"room_id"`
+		}
+		if err := json.Unmarshal(pdu, &header); err != nil {
+			util.GetLogger(ctx).WithError(err).Debug("Transaction: Failed to extract room ID from event")
+			// We don't know the event ID at this point so we can't return the
+			// failure in the PDU results
+			continue
+		}
+		roomVersion := getRoomVersion(header.RoomID)
+		event, err := gomatrixserverlib.NewEventFromUntrustedJSON(pdu, roomVersion)
+		if err != nil {
+			if _, ok := err.(gomatrixserverlib.BadJSONError); ok {
+				// Room version 6 states that homeservers should strictly enforce canonical JSON
+				// on PDUs.
+				//
+				// This enforces that the entire transaction is rejected if a single bad PDU is
+				// sent. It is unclear if this is the correct behaviour or not.
+				//
+				// See https://github.com/matrix-org/synapse/issues/7543
+				return nil, &util.JSONResponse{
+					Code: 400,
+					JSON: jsonerror.BadJSON("PDU contains bad JSON"),
+				}
+			}
+			util.GetLogger(ctx).WithError(err).Debugf("Transaction: Failed to parse event JSON of event %s", string(pdu))
+			continue
+		}
+		if event.Type() == gomatrixserverlib.MRoomCreate && event.StateKeyEquals("") {
+			continue
+		}
+		if api.IsServerBannedFromRoom(ctx, t.rsAPI, event.RoomID(), t.Origin) {
+			results[event.EventID()] = gomatrixserverlib.PDUResult{
+				Error: "Forbidden by server ACLs",
+			}
+			continue
+		}
+		if err = event.VerifyEventSignatures(ctx, t.keys); err != nil {
+			util.GetLogger(ctx).WithError(err).Debugf("Transaction: Couldn't validate signature of event %q", event.EventID())
+			results[event.EventID()] = gomatrixserverlib.PDUResult{
+				Error: err.Error(),
+			}
+			continue
+		}
+
+		// 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
+		if err = api.SendEvents(
+			ctx,
+			t.rsAPI,
+			api.KindNew,
+			[]*gomatrixserverlib.HeaderedEvent{
+				event.Headered(roomVersion),
+			},
+			t.Destination,
+			t.Origin,
+			api.DoNotSendToOtherServers,
+			nil,
+			true,
+		); err != nil {
+			util.GetLogger(ctx).WithError(err).Errorf("Transaction: Couldn't submit event %q to input queue: %s", event.EventID(), err)
+			results[event.EventID()] = gomatrixserverlib.PDUResult{
+				Error: err.Error(),
+			}
+			continue
+		}
+
+		results[event.EventID()] = gomatrixserverlib.PDUResult{}
+		PDUCountTotal.WithLabelValues("success").Inc()
+	}
+
+	wg.Wait()
+	return &gomatrixserverlib.RespSend{PDUs: results}, nil
+}
+
+// nolint:gocyclo
+func (t *TxnReq) processEDUs(ctx context.Context) {
+	for _, e := range t.EDUs {
+		EDUCountTotal.Inc()
+		switch e.Type {
+		case gomatrixserverlib.MTyping:
+			// https://matrix.org/docs/spec/server_server/latest#typing-notifications
+			var typingPayload struct {
+				RoomID string `json:"room_id"`
+				UserID string `json:"user_id"`
+				Typing bool   `json:"typing"`
+			}
+			if err := json.Unmarshal(e.Content, &typingPayload); err != nil {
+				util.GetLogger(ctx).WithError(err).Debug("Failed to unmarshal typing event")
+				continue
+			}
+			if _, serverName, err := gomatrixserverlib.SplitID('@', typingPayload.UserID); err != nil {
+				continue
+			} else if serverName == t.ourServerName {
+				continue
+			} else if serverName != t.Origin {
+				continue
+			}
+			if err := t.producer.SendTyping(ctx, typingPayload.UserID, typingPayload.RoomID, typingPayload.Typing, 30*1000); err != nil {
+				util.GetLogger(ctx).WithError(err).Error("Failed to send typing event to JetStream")
+			}
+		case gomatrixserverlib.MDirectToDevice:
+			// https://matrix.org/docs/spec/server_server/r0.1.3#m-direct-to-device-schema
+			var directPayload gomatrixserverlib.ToDeviceMessage
+			if err := json.Unmarshal(e.Content, &directPayload); err != nil {
+				util.GetLogger(ctx).WithError(err).Debug("Failed to unmarshal send-to-device events")
+				continue
+			}
+			if _, serverName, err := gomatrixserverlib.SplitID('@', directPayload.Sender); err != nil {
+				continue
+			} else if serverName == t.ourServerName {
+				continue
+			} else if serverName != t.Origin {
+				continue
+			}
+			for userID, byUser := range directPayload.Messages {
+				for deviceID, message := range byUser {
+					// TODO: check that the user and the device actually exist here
+					if err := t.producer.SendToDevice(ctx, directPayload.Sender, userID, deviceID, directPayload.Type, message); err != nil {
+						sentry.CaptureException(err)
+						util.GetLogger(ctx).WithError(err).WithFields(logrus.Fields{
+							"sender":    directPayload.Sender,
+							"user_id":   userID,
+							"device_id": deviceID,
+						}).Error("Failed to send send-to-device event to JetStream")
+					}
+				}
+			}
+		case gomatrixserverlib.MDeviceListUpdate:
+			if err := t.producer.SendDeviceListUpdate(ctx, e.Content, t.Origin); err != nil {
+				sentry.CaptureException(err)
+				util.GetLogger(ctx).WithError(err).Error("failed to InputDeviceListUpdate")
+			}
+		case gomatrixserverlib.MReceipt:
+			// https://matrix.org/docs/spec/server_server/r0.1.4#receipts
+			payload := map[string]types.FederationReceiptMRead{}
+
+			if err := json.Unmarshal(e.Content, &payload); err != nil {
+				util.GetLogger(ctx).WithError(err).Debug("Failed to unmarshal receipt event")
+				continue
+			}
+
+			for roomID, receipt := range payload {
+				for userID, mread := range receipt.User {
+					_, domain, err := gomatrixserverlib.SplitID('@', userID)
+					if err != nil {
+						util.GetLogger(ctx).WithError(err).Debug("Failed to split domain from receipt event sender")
+						continue
+					}
+					if t.Origin != domain {
+						util.GetLogger(ctx).Debugf("Dropping receipt event where sender domain (%q) doesn't match origin (%q)", domain, t.Origin)
+						continue
+					}
+					if err := t.processReceiptEvent(ctx, userID, roomID, "m.read", mread.Data.TS, mread.EventIDs); err != nil {
+						util.GetLogger(ctx).WithError(err).WithFields(logrus.Fields{
+							"sender":  t.Origin,
+							"user_id": userID,
+							"room_id": roomID,
+							"events":  mread.EventIDs,
+						}).Error("Failed to send receipt event to JetStream")
+						continue
+					}
+				}
+			}
+		case types.MSigningKeyUpdate:
+			if err := t.producer.SendSigningKeyUpdate(ctx, e.Content, t.Origin); err != nil {
+				sentry.CaptureException(err)
+				logrus.WithError(err).Errorf("Failed to process signing key update")
+			}
+		case gomatrixserverlib.MPresence:
+			if t.inboundPresenceEnabled {
+				if err := t.processPresence(ctx, e); err != nil {
+					logrus.WithError(err).Errorf("Failed to process presence update")
+				}
+			}
+		default:
+			util.GetLogger(ctx).WithField("type", e.Type).Debug("Unhandled EDU")
+		}
+	}
+}
+
+// processPresence handles m.receipt events
+func (t *TxnReq) processPresence(ctx context.Context, e gomatrixserverlib.EDU) error {
+	payload := types.Presence{}
+	if err := json.Unmarshal(e.Content, &payload); err != nil {
+		return err
+	}
+	for _, content := range payload.Push {
+		if _, serverName, err := gomatrixserverlib.SplitID('@', content.UserID); err != nil {
+			continue
+		} else if serverName == t.ourServerName {
+			continue
+		} else if serverName != t.Origin {
+			continue
+		}
+		presence, ok := syncTypes.PresenceFromString(content.Presence)
+		if !ok {
+			continue
+		}
+		if err := t.producer.SendPresence(ctx, content.UserID, presence, content.StatusMsg, content.LastActiveAgo); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+// processReceiptEvent sends receipt events to JetStream
+func (t *TxnReq) processReceiptEvent(ctx context.Context,
+	userID, roomID, receiptType string,
+	timestamp gomatrixserverlib.Timestamp,
+	eventIDs []string,
+) error {
+	if _, serverName, err := gomatrixserverlib.SplitID('@', userID); err != nil {
+		return nil
+	} else if serverName == t.ourServerName {
+		return nil
+	} else if serverName != t.Origin {
+		return nil
+	}
+	// store every event
+	for _, eventID := range eventIDs {
+		if err := t.producer.SendReceipt(ctx, userID, roomID, eventID, receiptType, timestamp); err != nil {
+			return fmt.Errorf("unable to set receipt event: %w", err)
+		}
+	}
+
+	return nil
+}

internal/transactionrequest_test.go

@@ -0,0 +1,820 @@
+// Copyright 2022 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"
+	"encoding/json"
+	"fmt"
+	"strconv"
+	"testing"
+	"time"
+
+	"github.com/matrix-org/dendrite/federationapi/producers"
+	keyAPI "github.com/matrix-org/dendrite/keyserver/api"
+	rsAPI "github.com/matrix-org/dendrite/roomserver/api"
+	"github.com/matrix-org/dendrite/setup/config"
+	"github.com/matrix-org/dendrite/setup/jetstream"
+	"github.com/matrix-org/dendrite/setup/process"
+	"github.com/matrix-org/dendrite/syncapi/types"
+	"github.com/matrix-org/dendrite/test"
+	"github.com/matrix-org/gomatrixserverlib"
+	"github.com/nats-io/nats.go"
+	"github.com/stretchr/testify/assert"
+	"go.uber.org/atomic"
+	"gotest.tools/v3/poll"
+)
+
+const (
+	testOrigin      = gomatrixserverlib.ServerName("kaer.morhen")
+	testDestination = gomatrixserverlib.ServerName("white.orchard")
+)
+
+var (
+	invalidSignatures = json.RawMessage(`{"auth_events":["$x4MKEPRSF6OGlo0qpnsP3BfSmYX5HhVlykOsQH3ECyg","$BcEcbZnlFLB5rxSNSZNBn6fO3jU/TKAJ79wfKyCQLiU"],"content":{"body":"Test Message"},"depth":3917,"hashes":{"sha256":"cNAWtlHIegrji0mMA6x1rhpYCccY8W1NsWZqSpJFhjs"},"origin":"localhost","origin_server_ts":0,"prev_events":["$4GDB0bVjkWwS3G4noUZCq5oLWzpBYpwzdMcf7gj24CI"],"room_id":"!roomid:localishhost","sender":"@userid:localhost","signatures":{"localhost":{"ed2559:auto":"NKym6Kcy3u9mGUr21Hjfe3h7DfDilDhN5PqztT0QZ4NTZ+8Y7owseLolQVXp+TvNjecvzdDywsXXVvGiaQiWAQ"}},"type":"m.room.member"}`)
+	testData          = []json.RawMessage{
+		[]byte(`{"auth_events":[],"content":{"creator":"@userid:kaer.morhen"},"depth":0,"event_id":"$0ok8ynDp7kjc95e3:kaer.morhen","hashes":{"sha256":"17kPoH+h0Dk4Omn7Sus0qMb6+oGcf+CZFEgDhv7UKWs"},"origin":"kaer.morhen","origin_server_ts":0,"prev_events":[],"prev_state":[],"room_id":"!roomid:kaer.morhen","sender":"@userid:kaer.morhen","signatures":{"kaer.morhen":{"ed25519:auto":"jP4a04f5/F10Pw95FPpdCyKAO44JOwUQ/MZOOeA/RTU1Dn+AHPMzGSaZnuGjRr/xQuADt+I3ctb5ZQfLKNzHDw"}},"state_key":"","type":"m.room.create"}`),
+		[]byte(`{"auth_events":[["$0ok8ynDp7kjc95e3:kaer.morhen",{"sha256":"sWCi6Ckp9rDimQON+MrUlNRkyfZ2tjbPbWfg2NMB18Q"}]],"content":{"membership":"join"},"depth":1,"event_id":"$LEwEu0kxrtu5fOiS:kaer.morhen","hashes":{"sha256":"B7M88PhXf3vd1LaFtjQutFu4x/w7fHD28XKZ4sAsJTo"},"origin":"kaer.morhen","origin_server_ts":0,"prev_events":[["$0ok8ynDp7kjc95e3:kaer.morhen",{"sha256":"sWCi6Ckp9rDimQON+MrUlNRkyfZ2tjbPbWfg2NMB18Q"}]],"prev_state":[],"room_id":"!roomid:kaer.morhen","sender":"@userid:kaer.morhen","signatures":{"kaer.morhen":{"ed25519:auto":"p2vqmuJn7ZBRImctSaKbXCAxCcBlIjPH9JHte1ouIUGy84gpu4eLipOvSBCLL26hXfC0Zrm4WUto6Hr+ohdrCg"}},"state_key":"@userid:kaer.morhen","type":"m.room.member"}`),
+		[]byte(`{"auth_events":[["$0ok8ynDp7kjc95e3:kaer.morhen",{"sha256":"sWCi6Ckp9rDimQON+MrUlNRkyfZ2tjbPbWfg2NMB18Q"}],["$LEwEu0kxrtu5fOiS:kaer.morhen",{"sha256":"1aKajq6DWHru1R1HJjvdWMEavkJJHGaTmPvfuERUXaA"}]],"content":{"join_rule":"public"},"depth":2,"event_id":"$SMHlqUrNhhBBRLeN:kaer.morhen","hashes":{"sha256":"vIuJQvmMjrGxshAkj1SXe0C4RqvMbv4ZADDw9pFCWqQ"},"origin":"kaer.morhen","origin_server_ts":0,"prev_events":[["$LEwEu0kxrtu5fOiS:kaer.morhen",{"sha256":"1aKajq6DWHru1R1HJjvdWMEavkJJHGaTmPvfuERUXaA"}]],"prev_state":[],"room_id":"!roomid:kaer.morhen","sender":"@userid:kaer.morhen","signatures":{"kaer.morhen":{"ed25519:auto":"hBMsb3Qppo3RaqqAl4JyTgaiWEbW5hlckATky6PrHun+F3YM203TzG7w9clwuQU5F5pZoB1a6nw+to0hN90FAw"}},"state_key":"","type":"m.room.join_rules"}`),
+		[]byte(`{"auth_events":[["$0ok8ynDp7kjc95e3:kaer.morhen",{"sha256":"sWCi6Ckp9rDimQON+MrUlNRkyfZ2tjbPbWfg2NMB18Q"}],["$LEwEu0kxrtu5fOiS:kaer.morhen",{"sha256":"1aKajq6DWHru1R1HJjvdWMEavkJJHGaTmPvfuERUXaA"}]],"content":{"history_visibility":"shared"},"depth":3,"event_id":"$6F1yGIbO0J7TM93h:kaer.morhen","hashes":{"sha256":"Mr23GKSlZW7UCCYLgOWawI2Sg6KIoMjUWO2TDenuOgw"},"origin":"kaer.morhen","origin_server_ts":0,"prev_events":[["$SMHlqUrNhhBBRLeN:kaer.morhen",{"sha256":"SylzE8U02I+6eyEHgL+FlU0L5YdqrVp8OOlxKS9VQW0"}]],"prev_state":[],"room_id":"!roomid:kaer.morhen","sender":"@userid:kaer.morhen","signatures":{"kaer.morhen":{"ed25519:auto":"sHLKrFI3hKGrEJfpMVZSDS3LvLasQsy50CTsOwru9XTVxgRsPo6wozNtRVjxo1J3Rk18RC9JppovmQ5VR5EcDw"}},"state_key":"","type":"m.room.history_visibility"}`),
+		[]byte(`{"auth_events":[["$0ok8ynDp7kjc95e3:kaer.morhen",{"sha256":"sWCi6Ckp9rDimQON+MrUlNRkyfZ2tjbPbWfg2NMB18Q"}],["$LEwEu0kxrtu5fOiS:kaer.morhen",{"sha256":"1aKajq6DWHru1R1HJjvdWMEavkJJHGaTmPvfuERUXaA"}]],"content":{"ban":50,"events":null,"events_default":0,"invite":0,"kick":50,"redact":50,"state_default":50,"users":null,"users_default":0},"depth":4,"event_id":"$UKNe10XzYzG0TeA9:kaer.morhen","hashes":{"sha256":"ngbP3yja9U5dlckKerUs/fSOhtKxZMCVvsfhPURSS28"},"origin":"kaer.morhen","origin_server_ts":0,"prev_events":[["$6F1yGIbO0J7TM93h:kaer.morhen",{"sha256":"A4CucrKSoWX4IaJXhq02mBg1sxIyZEftbC+5p3fZAvk"}]],"prev_state":[],"room_id":"!roomid:kaer.morhen","sender":"@userid:kaer.morhen","signatures":{"kaer.morhen":{"ed25519:auto":"zOmwlP01QL3yFchzuR9WHvogOoBZA3oVtNIF3lM0ZfDnqlSYZB9sns27G/4HVq0k7alaK7ZE3oGoCrVnMkPNCw"}},"state_key":"","type":"m.room.power_levels"}`),
+		// messages
+		[]byte(`{"auth_events":[["$0ok8ynDp7kjc95e3:kaer.morhen",{"sha256":"sWCi6Ckp9rDimQON+MrUlNRkyfZ2tjbPbWfg2NMB18Q"}],["$LEwEu0kxrtu5fOiS:kaer.morhen",{"sha256":"1aKajq6DWHru1R1HJjvdWMEavkJJHGaTmPvfuERUXaA"}]],"content":{"body":"Test Message"},"depth":5,"event_id":"$gl2T9l3qm0kUbiIJ:kaer.morhen","hashes":{"sha256":"Qx3nRMHLDPSL5hBAzuX84FiSSP0K0Kju2iFoBWH4Za8"},"origin":"kaer.morhen","origin_server_ts":0,"prev_events":[["$UKNe10XzYzG0TeA9:kaer.morhen",{"sha256":"KtSRyMjt0ZSjsv2koixTRCxIRCGoOp6QrKscsW97XRo"}]],"room_id":"!roomid:kaer.morhen","sender":"@userid:kaer.morhen","signatures":{"kaer.morhen":{"ed25519:auto":"sqDgv3EG7ml5VREzmT9aZeBpS4gAPNIaIeJOwqjDhY0GPU/BcpX5wY4R7hYLrNe5cChgV+eFy/GWm1Zfg5FfDg"}},"type":"m.room.message"}`),
+		[]byte(`{"auth_events":[["$0ok8ynDp7kjc95e3:kaer.morhen",{"sha256":"sWCi6Ckp9rDimQON+MrUlNRkyfZ2tjbPbWfg2NMB18Q"}],["$LEwEu0kxrtu5fOiS:kaer.morhen",{"sha256":"1aKajq6DWHru1R1HJjvdWMEavkJJHGaTmPvfuERUXaA"}]],"content":{"body":"Test Message"},"depth":6,"event_id":"$MYSbs8m4rEbsCWXD:kaer.morhen","hashes":{"sha256":"kgbYM7v4Ud2YaBsjBTolM4ySg6rHcJNYI6nWhMSdFUA"},"origin":"kaer.morhen","origin_server_ts":0,"prev_events":[["$gl2T9l3qm0kUbiIJ:kaer.morhen",{"sha256":"C/rD04h9wGxRdN2G/IBfrgoE1UovzLZ+uskwaKZ37/Q"}]],"room_id":"!roomid:kaer.morhen","sender":"@userid:kaer.morhen","signatures":{"kaer.morhen":{"ed25519:auto":"x0UoKh968jj/F5l1/R7Ew0T6CTKuew3PLNHASNxqck/bkNe8yYQiDHXRr+kZxObeqPZZTpaF1+EI+bLU9W8GDQ"}},"type":"m.room.message"}`),
+		[]byte(`{"auth_events":[["$0ok8ynDp7kjc95e3:kaer.morhen",{"sha256":"sWCi6Ckp9rDimQON+MrUlNRkyfZ2tjbPbWfg2NMB18Q"}],["$LEwEu0kxrtu5fOiS:kaer.morhen",{"sha256":"1aKajq6DWHru1R1HJjvdWMEavkJJHGaTmPvfuERUXaA"}]],"content":{"body":"Test Message"},"depth":7,"event_id":"$N5x9WJkl9ClPrAEg:kaer.morhen","hashes":{"sha256":"FWM8oz4yquTunRZ67qlW2gzPDzdWfBP6RPHXhK1I/x8"},"origin":"kaer.morhen","origin_server_ts":0,"prev_events":[["$MYSbs8m4rEbsCWXD:kaer.morhen",{"sha256":"fatqgW+SE8mb2wFn3UN+drmluoD4UJ/EcSrL6Ur9q1M"}]],"room_id":"!roomid:kaer.morhen","sender":"@userid:kaer.morhen","signatures":{"kaer.morhen":{"ed25519:auto":"Y+LX/xcyufoXMOIoqQBNOzy6lZfUGB1ffgXIrSugk6obMiyAsiRejHQN/pciZXsHKxMJLYRFAz4zSJoS/LGPAA"}},"type":"m.room.message"}`),
+	}
+	testEvent       = []byte(`{"auth_events":["$x4MKEPRSF6OGlo0qpnsP3BfSmYX5HhVlykOsQH3ECyg","$BcEcbZnlFLB5rxSNSZNBn6fO3jU/TKAJ79wfKyCQLiU"],"content":{"body":"Test Message"},"depth":3917,"hashes":{"sha256":"cNAWtlHIegrji0mMA6x1rhpYCccY8W1NsWZqSpJFhjs"},"origin":"localhost","origin_server_ts":0,"prev_events":["$4GDB0bVjkWwS3G4noUZCq5oLWzpBYpwzdMcf7gj24CI"],"room_id":"!roomid:localhost","sender":"@userid:localhost","signatures":{"localhost":{"ed25519:auto":"NKym6Kcy3u9mGUr21Hjfe3h7DfDilDhN5PqztT0QZ4NTZ+8Y7owseLolQVXp+TvNjecvzdDywsXXVvGiuQiWAQ"}},"type":"m.room.message"}`)
+	testRoomVersion = gomatrixserverlib.RoomVersionV1
+	testEvents      = []*gomatrixserverlib.HeaderedEvent{}
+	testStateEvents = make(map[gomatrixserverlib.StateKeyTuple]*gomatrixserverlib.HeaderedEvent)
+)
+
+type FakeRsAPI struct {
+	rsAPI.RoomserverInternalAPI
+	shouldFailQuery  bool
+	bannedFromRoom   bool
+	shouldEventsFail bool
+}
+
+func (r *FakeRsAPI) QueryRoomVersionForRoom(
+	ctx context.Context,
+	req *rsAPI.QueryRoomVersionForRoomRequest,
+	res *rsAPI.QueryRoomVersionForRoomResponse,
+) error {
+	if r.shouldFailQuery {
+		return fmt.Errorf("Failure")
+	}
+	res.RoomVersion = gomatrixserverlib.RoomVersionV10
+	return nil
+}
+
+func (r *FakeRsAPI) QueryServerBannedFromRoom(
+	ctx context.Context,
+	req *rsAPI.QueryServerBannedFromRoomRequest,
+	res *rsAPI.QueryServerBannedFromRoomResponse,
+) error {
+	if r.bannedFromRoom {
+		res.Banned = true
+	} else {
+		res.Banned = false
+	}
+	return nil
+}
+
+func (r *FakeRsAPI) InputRoomEvents(
+	ctx context.Context,
+	req *rsAPI.InputRoomEventsRequest,
+	res *rsAPI.InputRoomEventsResponse,
+) error {
+	if r.shouldEventsFail {
+		return fmt.Errorf("Failure")
+	}
+	return nil
+}
+
+func TestEmptyTransactionRequest(t *testing.T) {
+	txn := NewTxnReq(&FakeRsAPI{}, nil, "ourserver", nil, nil, nil, false, []json.RawMessage{}, []gomatrixserverlib.EDU{}, "", "", "")
+	txnRes, jsonRes := txn.ProcessTransaction(context.Background())
+
+	assert.Nil(t, jsonRes)
+	assert.Zero(t, len(txnRes.PDUs))
+}
+
+func TestProcessTransactionRequestPDU(t *testing.T) {
+	keyRing := &test.NopJSONVerifier{}
+	txn := NewTxnReq(&FakeRsAPI{}, nil, "ourserver", keyRing, nil, nil, false, []json.RawMessage{testEvent}, []gomatrixserverlib.EDU{}, "", "", "")
+	txnRes, jsonRes := txn.ProcessTransaction(context.Background())
+
+	assert.Nil(t, jsonRes)
+	assert.Equal(t, 1, len(txnRes.PDUs))
+	for _, result := range txnRes.PDUs {
+		assert.Empty(t, result.Error)
+	}
+}
+
+func TestProcessTransactionRequestPDUs(t *testing.T) {
+	keyRing := &test.NopJSONVerifier{}
+	txn := NewTxnReq(&FakeRsAPI{}, nil, "ourserver", keyRing, nil, nil, false, append(testData, testEvent), []gomatrixserverlib.EDU{}, "", "", "")
+	txnRes, jsonRes := txn.ProcessTransaction(context.Background())
+
+	assert.Nil(t, jsonRes)
+	assert.Equal(t, 1, len(txnRes.PDUs))
+	for _, result := range txnRes.PDUs {
+		assert.Empty(t, result.Error)
+	}
+}
+
+func TestProcessTransactionRequestBadPDU(t *testing.T) {
+	pdu := json.RawMessage("{\"room_id\":\"asdf\"}")
+	pdu2 := json.RawMessage("\"roomid\":\"asdf\"")
+	keyRing := &test.NopJSONVerifier{}
+	txn := NewTxnReq(&FakeRsAPI{}, nil, "ourserver", keyRing, nil, nil, false, []json.RawMessage{pdu, pdu2, testEvent}, []gomatrixserverlib.EDU{}, "", "", "")
+	txnRes, jsonRes := txn.ProcessTransaction(context.Background())
+
+	assert.Nil(t, jsonRes)
+	assert.Equal(t, 1, len(txnRes.PDUs))
+	for _, result := range txnRes.PDUs {
+		assert.Empty(t, result.Error)
+	}
+}
+
+func TestProcessTransactionRequestPDUQueryFailure(t *testing.T) {
+	keyRing := &test.NopJSONVerifier{}
+	txn := NewTxnReq(&FakeRsAPI{shouldFailQuery: true}, nil, "ourserver", keyRing, nil, nil, false, []json.RawMessage{testEvent}, []gomatrixserverlib.EDU{}, "", "", "")
+	txnRes, jsonRes := txn.ProcessTransaction(context.Background())
+
+	assert.Nil(t, jsonRes)
+	assert.Zero(t, len(txnRes.PDUs))
+}
+
+func TestProcessTransactionRequestPDUBannedFromRoom(t *testing.T) {
+	keyRing := &test.NopJSONVerifier{}
+	txn := NewTxnReq(&FakeRsAPI{bannedFromRoom: true}, nil, "ourserver", keyRing, nil, nil, false, []json.RawMessage{testEvent}, []gomatrixserverlib.EDU{}, "", "", "")
+	txnRes, jsonRes := txn.ProcessTransaction(context.Background())
+
+	assert.Nil(t, jsonRes)
+	assert.Equal(t, 1, len(txnRes.PDUs))
+	for _, result := range txnRes.PDUs {
+		assert.NotEmpty(t, result.Error)
+	}
+}
+
+func TestProcessTransactionRequestPDUInvalidSignature(t *testing.T) {
+	keyRing := &test.NopJSONVerifier{}
+	txn := NewTxnReq(&FakeRsAPI{}, nil, "ourserver", keyRing, nil, nil, false, []json.RawMessage{invalidSignatures}, []gomatrixserverlib.EDU{}, "", "", "")
+	txnRes, jsonRes := txn.ProcessTransaction(context.Background())
+
+	assert.Nil(t, jsonRes)
+	assert.Equal(t, 1, len(txnRes.PDUs))
+	for _, result := range txnRes.PDUs {
+		assert.NotEmpty(t, result.Error)
+	}
+}
+
+func TestProcessTransactionRequestPDUSendFail(t *testing.T) {
+	keyRing := &test.NopJSONVerifier{}
+	txn := NewTxnReq(&FakeRsAPI{shouldEventsFail: true}, nil, "ourserver", keyRing, nil, nil, false, []json.RawMessage{testEvent}, []gomatrixserverlib.EDU{}, "", "", "")
+	txnRes, jsonRes := txn.ProcessTransaction(context.Background())
+
+	assert.Nil(t, jsonRes)
+	assert.Equal(t, 1, len(txnRes.PDUs))
+	for _, result := range txnRes.PDUs {
+		assert.NotEmpty(t, result.Error)
+	}
+}
+
+func createTransactionWithEDU(ctx *process.ProcessContext, edus []gomatrixserverlib.EDU) (TxnReq, nats.JetStreamContext, *config.Dendrite) {
+	cfg := &config.Dendrite{}
+	cfg.Defaults(config.DefaultOpts{
+		Generate:   true,
+		Monolithic: true,
+	})
+	cfg.Global.JetStream.InMemory = true
+	natsInstance := &jetstream.NATSInstance{}
+	js, _ := natsInstance.Prepare(ctx, &cfg.Global.JetStream)
+	producer := &producers.SyncAPIProducer{
+		JetStream:              js,
+		TopicReceiptEvent:      cfg.Global.JetStream.Prefixed(jetstream.OutputReceiptEvent),
+		TopicSendToDeviceEvent: cfg.Global.JetStream.Prefixed(jetstream.OutputSendToDeviceEvent),
+		TopicTypingEvent:       cfg.Global.JetStream.Prefixed(jetstream.OutputTypingEvent),
+		TopicPresenceEvent:     cfg.Global.JetStream.Prefixed(jetstream.OutputPresenceEvent),
+		TopicDeviceListUpdate:  cfg.Global.JetStream.Prefixed(jetstream.InputDeviceListUpdate),
+		TopicSigningKeyUpdate:  cfg.Global.JetStream.Prefixed(jetstream.InputSigningKeyUpdate),
+		Config:                 &cfg.FederationAPI,
+		UserAPI:                nil,
+	}
+	keyRing := &test.NopJSONVerifier{}
+	txn := NewTxnReq(&FakeRsAPI{}, nil, "ourserver", keyRing, nil, producer, true, []json.RawMessage{}, edus, "kaer.morhen", "", "ourserver")
+	return txn, js, cfg
+}
+
+func TestProcessTransactionRequestEDUTyping(t *testing.T) {
+	var err error
+	roomID := "!roomid:kaer.morhen"
+	userID := "@userid:kaer.morhen"
+	typing := true
+	edu := gomatrixserverlib.EDU{Type: "m.typing"}
+	if edu.Content, err = json.Marshal(map[string]interface{}{
+		"room_id": roomID,
+		"user_id": userID,
+		"typing":  typing,
+	}); err != nil {
+		t.Errorf("failed to marshal EDU JSON")
+	}
+	badEDU := gomatrixserverlib.EDU{Type: "m.typing"}
+	badEDU.Content = gomatrixserverlib.RawJSON("badjson")
+	edus := []gomatrixserverlib.EDU{badEDU, edu}
+
+	ctx := process.NewProcessContext()
+	defer ctx.ShutdownDendrite()
+	txn, js, cfg := createTransactionWithEDU(ctx, edus)
+	received := atomic.NewBool(false)
+	onMessage := func(ctx context.Context, msgs []*nats.Msg) bool {
+		msg := msgs[0] // Guaranteed to exist if onMessage is called
+		room := msg.Header.Get(jetstream.RoomID)
+		assert.Equal(t, roomID, room)
+		user := msg.Header.Get(jetstream.UserID)
+		assert.Equal(t, userID, user)
+		typ, parseErr := strconv.ParseBool(msg.Header.Get("typing"))
+		if parseErr != nil {
+			return true
+		}
+		assert.Equal(t, typing, typ)
+
+		received.Store(true)
+		return true
+	}
+	err = jetstream.JetStreamConsumer(
+		ctx.Context(), js, cfg.Global.JetStream.Prefixed(jetstream.OutputTypingEvent),
+		cfg.Global.JetStream.Durable("TestTypingConsumer"), 1,
+		onMessage, nats.DeliverAll(), nats.ManualAck(),
+	)
+	assert.Nil(t, err)
+
+	txnRes, jsonRes := txn.ProcessTransaction(ctx.Context())
+	assert.Nil(t, jsonRes)
+	assert.Zero(t, len(txnRes.PDUs))
+
+	check := func(log poll.LogT) poll.Result {
+		if received.Load() {
+			return poll.Success()
+		}
+		return poll.Continue("waiting for events to be processed")
+	}
+	poll.WaitOn(t, check, poll.WithTimeout(2*time.Second), poll.WithDelay(10*time.Millisecond))
+}
+
+func TestProcessTransactionRequestEDUToDevice(t *testing.T) {
+	var err error
+	sender := "@userid:kaer.morhen"
+	messageID := "$x4MKEPRSF6OGlo0qpnsP3BfSmYX5HhVlykOsQH3ECyg"
+	msgType := "m.dendrite.test"
+	edu := gomatrixserverlib.EDU{Type: "m.direct_to_device"}
+	if edu.Content, err = json.Marshal(map[string]interface{}{
+		"sender":     sender,
+		"type":       msgType,
+		"message_id": messageID,
+		"messages": map[string]interface{}{
+			"@alice:example.org": map[string]interface{}{
+				"IWHQUZUIAH": map[string]interface{}{
+					"algorithm":   "m.megolm.v1.aes-sha2",
+					"room_id":     "!Cuyf34gef24t:localhost",
+					"session_id":  "X3lUlvLELLYxeTx4yOVu6UDpasGEVO0Jbu+QFnm0cKQ",
+					"session_key": "AgAAAADxKHa9uFxcXzwYoNueL5Xqi69IkD4sni8LlfJL7qNBEY...",
+				},
+			},
+		},
+	}); err != nil {
+		t.Errorf("failed to marshal EDU JSON")
+	}
+	badEDU := gomatrixserverlib.EDU{Type: "m.direct_to_device"}
+	badEDU.Content = gomatrixserverlib.RawJSON("badjson")
+	edus := []gomatrixserverlib.EDU{badEDU, edu}
+
+	ctx := process.NewProcessContext()
+	defer ctx.ShutdownDendrite()
+	txn, js, cfg := createTransactionWithEDU(ctx, edus)
+	received := atomic.NewBool(false)
+	onMessage := func(ctx context.Context, msgs []*nats.Msg) bool {
+		msg := msgs[0] // Guaranteed to exist if onMessage is called
+
+		var output types.OutputSendToDeviceEvent
+		if err = json.Unmarshal(msg.Data, &output); err != nil {
+			// If the message was invalid, log it and move on to the next message in the stream
+			println(err.Error())
+			return true
+		}
+		assert.Equal(t, sender, output.Sender)
+		assert.Equal(t, msgType, output.Type)
+
+		received.Store(true)
+		return true
+	}
+	err = jetstream.JetStreamConsumer(
+		ctx.Context(), js, cfg.Global.JetStream.Prefixed(jetstream.OutputSendToDeviceEvent),
+		cfg.Global.JetStream.Durable("TestToDevice"), 1,
+		onMessage, nats.DeliverAll(), nats.ManualAck(),
+	)
+	assert.Nil(t, err)
+
+	txnRes, jsonRes := txn.ProcessTransaction(ctx.Context())
+	assert.Nil(t, jsonRes)
+	assert.Zero(t, len(txnRes.PDUs))
+
+	check := func(log poll.LogT) poll.Result {
+		if received.Load() {
+			return poll.Success()
+		}
+		return poll.Continue("waiting for events to be processed")
+	}
+	poll.WaitOn(t, check, poll.WithTimeout(2*time.Second), poll.WithDelay(10*time.Millisecond))
+}
+
+func TestProcessTransactionRequestEDUDeviceListUpdate(t *testing.T) {
+	var err error
+	deviceID := "QBUAZIFURK"
+	userID := "@john:example.com"
+	edu := gomatrixserverlib.EDU{Type: "m.device_list_update"}
+	if edu.Content, err = json.Marshal(map[string]interface{}{
+		"device_display_name": "Mobile",
+		"device_id":           deviceID,
+		"key":                 "value",
+		"keys": map[string]interface{}{
+			"algorithms": []string{
+				"m.olm.v1.curve25519-aes-sha2",
+				"m.megolm.v1.aes-sha2",
+			},
+			"device_id": "JLAFKJWSCS",
+			"keys": map[string]interface{}{
+				"curve25519:JLAFKJWSCS": "3C5BFWi2Y8MaVvjM8M22DBmh24PmgR0nPvJOIArzgyI",
+				"ed25519:JLAFKJWSCS":    "lEuiRJBit0IG6nUf5pUzWTUEsRVVe/HJkoKuEww9ULI",
+			},
+			"signatures": map[string]interface{}{
+				"@alice:example.com": map[string]interface{}{
+					"ed25519:JLAFKJWSCS": "dSO80A01XiigH3uBiDVx/EjzaoycHcjq9lfQX0uWsqxl2giMIiSPR8a4d291W1ihKJL/a+myXS367WT6NAIcBA",
+				},
+			},
+			"user_id": "@alice:example.com",
+		},
+		"prev_id": []int{
+			5,
+		},
+		"stream_id": 6,
+		"user_id":   userID,
+	}); err != nil {
+		t.Errorf("failed to marshal EDU JSON")
+	}
+	badEDU := gomatrixserverlib.EDU{Type: "m.device_list_update"}
+	badEDU.Content = gomatrixserverlib.RawJSON("badjson")
+	edus := []gomatrixserverlib.EDU{badEDU, edu}
+
+	ctx := process.NewProcessContext()
+	defer ctx.ShutdownDendrite()
+	txn, js, cfg := createTransactionWithEDU(ctx, edus)
+	received := atomic.NewBool(false)
+	onMessage := func(ctx context.Context, msgs []*nats.Msg) bool {
+		msg := msgs[0] // Guaranteed to exist if onMessage is called
+
+		var output gomatrixserverlib.DeviceListUpdateEvent
+		if err = json.Unmarshal(msg.Data, &output); err != nil {
+			// If the message was invalid, log it and move on to the next message in the stream
+			println(err.Error())
+			return true
+		}
+		assert.Equal(t, userID, output.UserID)
+		assert.Equal(t, deviceID, output.DeviceID)
+
+		received.Store(true)
+		return true
+	}
+	err = jetstream.JetStreamConsumer(
+		ctx.Context(), js, cfg.Global.JetStream.Prefixed(jetstream.InputDeviceListUpdate),
+		cfg.Global.JetStream.Durable("TestDeviceListUpdate"), 1,
+		onMessage, nats.DeliverAll(), nats.ManualAck(),
+	)
+	assert.Nil(t, err)
+
+	txnRes, jsonRes := txn.ProcessTransaction(ctx.Context())
+	assert.Nil(t, jsonRes)
+	assert.Zero(t, len(txnRes.PDUs))
+
+	check := func(log poll.LogT) poll.Result {
+		if received.Load() {
+			return poll.Success()
+		}
+		return poll.Continue("waiting for events to be processed")
+	}
+	poll.WaitOn(t, check, poll.WithTimeout(2*time.Second), poll.WithDelay(10*time.Millisecond))
+}
+
+func TestProcessTransactionRequestEDUReceipt(t *testing.T) {
+	var err error
+	roomID := "!some_room:example.org"
+	edu := gomatrixserverlib.EDU{Type: "m.receipt"}
+	if edu.Content, err = json.Marshal(map[string]interface{}{
+		roomID: map[string]interface{}{
+			"m.read": map[string]interface{}{
+				"@john:kaer.morhen": map[string]interface{}{
+					"data": map[string]interface{}{
+						"ts": 1533358089009,
+					},
+					"event_ids": []string{
+						"$read_this_event:matrix.org",
+					},
+				},
+			},
+		},
+	}); err != nil {
+		t.Errorf("failed to marshal EDU JSON")
+	}
+	badEDU := gomatrixserverlib.EDU{Type: "m.receipt"}
+	badEDU.Content = gomatrixserverlib.RawJSON("badjson")
+	badUser := gomatrixserverlib.EDU{Type: "m.receipt"}
+	if badUser.Content, err = json.Marshal(map[string]interface{}{
+		roomID: map[string]interface{}{
+			"m.read": map[string]interface{}{
+				"johnkaer.morhen": map[string]interface{}{
+					"data": map[string]interface{}{
+						"ts": 1533358089009,
+					},
+					"event_ids": []string{
+						"$read_this_event:matrix.org",
+					},
+				},
+			},
+		},
+	}); err != nil {
+		t.Errorf("failed to marshal EDU JSON")
+	}
+	badDomain := gomatrixserverlib.EDU{Type: "m.receipt"}
+	if badDomain.Content, err = json.Marshal(map[string]interface{}{
+		roomID: map[string]interface{}{
+			"m.read": map[string]interface{}{
+				"@john:bad.domain": map[string]interface{}{
+					"data": map[string]interface{}{
+						"ts": 1533358089009,
+					},
+					"event_ids": []string{
+						"$read_this_event:matrix.org",
+					},
+				},
+			},
+		},
+	}); err != nil {
+		t.Errorf("failed to marshal EDU JSON")
+	}
+	edus := []gomatrixserverlib.EDU{badEDU, badUser, edu}
+
+	ctx := process.NewProcessContext()
+	defer ctx.ShutdownDendrite()
+	txn, js, cfg := createTransactionWithEDU(ctx, edus)
+	received := atomic.NewBool(false)
+	onMessage := func(ctx context.Context, msgs []*nats.Msg) bool {
+		msg := msgs[0] // Guaranteed to exist if onMessage is called
+
+		var output types.OutputReceiptEvent
+		output.RoomID = msg.Header.Get(jetstream.RoomID)
+		assert.Equal(t, roomID, output.RoomID)
+
+		received.Store(true)
+		return true
+	}
+	err = jetstream.JetStreamConsumer(
+		ctx.Context(), js, cfg.Global.JetStream.Prefixed(jetstream.OutputReceiptEvent),
+		cfg.Global.JetStream.Durable("TestReceipt"), 1,
+		onMessage, nats.DeliverAll(), nats.ManualAck(),
+	)
+	assert.Nil(t, err)
+
+	txnRes, jsonRes := txn.ProcessTransaction(ctx.Context())
+	assert.Nil(t, jsonRes)
+	assert.Zero(t, len(txnRes.PDUs))
+
+	check := func(log poll.LogT) poll.Result {
+		if received.Load() {
+			return poll.Success()
+		}
+		return poll.Continue("waiting for events to be processed")
+	}
+	poll.WaitOn(t, check, poll.WithTimeout(2*time.Second), poll.WithDelay(10*time.Millisecond))
+}
+
+func TestProcessTransactionRequestEDUSigningKeyUpdate(t *testing.T) {
+	var err error
+	edu := gomatrixserverlib.EDU{Type: "m.signing_key_update"}
+	if edu.Content, err = json.Marshal(map[string]interface{}{}); err != nil {
+		t.Errorf("failed to marshal EDU JSON")
+	}
+	badEDU := gomatrixserverlib.EDU{Type: "m.signing_key_update"}
+	badEDU.Content = gomatrixserverlib.RawJSON("badjson")
+	edus := []gomatrixserverlib.EDU{badEDU, edu}
+
+	ctx := process.NewProcessContext()
+	defer ctx.ShutdownDendrite()
+	txn, js, cfg := createTransactionWithEDU(ctx, edus)
+	received := atomic.NewBool(false)
+	onMessage := func(ctx context.Context, msgs []*nats.Msg) bool {
+		msg := msgs[0] // Guaranteed to exist if onMessage is called
+
+		var output keyAPI.CrossSigningKeyUpdate
+		if err = json.Unmarshal(msg.Data, &output); err != nil {
+			// If the message was invalid, log it and move on to the next message in the stream
+			println(err.Error())
+			return true
+		}
+
+		received.Store(true)
+		return true
+	}
+	err = jetstream.JetStreamConsumer(
+		ctx.Context(), js, cfg.Global.JetStream.Prefixed(jetstream.InputSigningKeyUpdate),
+		cfg.Global.JetStream.Durable("TestSigningKeyUpdate"), 1,
+		onMessage, nats.DeliverAll(), nats.ManualAck(),
+	)
+	assert.Nil(t, err)
+
+	txnRes, jsonRes := txn.ProcessTransaction(ctx.Context())
+	assert.Nil(t, jsonRes)
+	assert.Zero(t, len(txnRes.PDUs))
+
+	check := func(log poll.LogT) poll.Result {
+		if received.Load() {
+			return poll.Success()
+		}
+		return poll.Continue("waiting for events to be processed")
+	}
+	poll.WaitOn(t, check, poll.WithTimeout(2*time.Second), poll.WithDelay(10*time.Millisecond))
+}
+
+func TestProcessTransactionRequestEDUPresence(t *testing.T) {
+	var err error
+	userID := "@john:kaer.morhen"
+	presence := "online"
+	edu := gomatrixserverlib.EDU{Type: "m.presence"}
+	if edu.Content, err = json.Marshal(map[string]interface{}{
+		"push": []map[string]interface{}{{
+			"currently_active": true,
+			"last_active_ago":  5000,
+			"presence":         presence,
+			"status_msg":       "Making cupcakes",
+			"user_id":          userID,
+		}},
+	}); err != nil {
+		t.Errorf("failed to marshal EDU JSON")
+	}
+	badEDU := gomatrixserverlib.EDU{Type: "m.presence"}
+	badEDU.Content = gomatrixserverlib.RawJSON("badjson")
+	edus := []gomatrixserverlib.EDU{badEDU, edu}
+
+	ctx := process.NewProcessContext()
+	defer ctx.ShutdownDendrite()
+	txn, js, cfg := createTransactionWithEDU(ctx, edus)
+	received := atomic.NewBool(false)
+	onMessage := func(ctx context.Context, msgs []*nats.Msg) bool {
+		msg := msgs[0] // Guaranteed to exist if onMessage is called
+
+		userIDRes := msg.Header.Get(jetstream.UserID)
+		presenceRes := msg.Header.Get("presence")
+		assert.Equal(t, userID, userIDRes)
+		assert.Equal(t, presence, presenceRes)
+
+		received.Store(true)
+		return true
+	}
+	err = jetstream.JetStreamConsumer(
+		ctx.Context(), js, cfg.Global.JetStream.Prefixed(jetstream.OutputPresenceEvent),
+		cfg.Global.JetStream.Durable("TestPresence"), 1,
+		onMessage, nats.DeliverAll(), nats.ManualAck(),
+	)
+	assert.Nil(t, err)
+
+	txnRes, jsonRes := txn.ProcessTransaction(ctx.Context())
+	assert.Nil(t, jsonRes)
+	assert.Zero(t, len(txnRes.PDUs))
+
+	check := func(log poll.LogT) poll.Result {
+		if received.Load() {
+			return poll.Success()
+		}
+		return poll.Continue("waiting for events to be processed")
+	}
+	poll.WaitOn(t, check, poll.WithTimeout(2*time.Second), poll.WithDelay(10*time.Millisecond))
+}
+
+func TestProcessTransactionRequestEDUUnhandled(t *testing.T) {
+	var err error
+	edu := gomatrixserverlib.EDU{Type: "m.unhandled"}
+	if edu.Content, err = json.Marshal(map[string]interface{}{}); err != nil {
+		t.Errorf("failed to marshal EDU JSON")
+	}
+
+	ctx := process.NewProcessContext()
+	defer ctx.ShutdownDendrite()
+	txn, _, _ := createTransactionWithEDU(ctx, []gomatrixserverlib.EDU{edu})
+	txnRes, jsonRes := txn.ProcessTransaction(ctx.Context())
+
+	assert.Nil(t, jsonRes)
+	assert.Zero(t, len(txnRes.PDUs))
+}
+
+func init() {
+	for _, j := range testData {
+		e, err := gomatrixserverlib.NewEventFromTrustedJSON(j, false, testRoomVersion)
+		if err != nil {
+			panic("cannot load test data: " + err.Error())
+		}
+		h := e.Headered(testRoomVersion)
+		testEvents = append(testEvents, h)
+		if e.StateKey() != nil {
+			testStateEvents[gomatrixserverlib.StateKeyTuple{
+				EventType: e.Type(),
+				StateKey:  *e.StateKey(),
+			}] = h
+		}
+	}
+}
+
+type testRoomserverAPI struct {
+	rsAPI.RoomserverInternalAPITrace
+	inputRoomEvents           []rsAPI.InputRoomEvent
+	queryStateAfterEvents     func(*rsAPI.QueryStateAfterEventsRequest) rsAPI.QueryStateAfterEventsResponse
+	queryEventsByID           func(req *rsAPI.QueryEventsByIDRequest) rsAPI.QueryEventsByIDResponse
+	queryLatestEventsAndState func(*rsAPI.QueryLatestEventsAndStateRequest) rsAPI.QueryLatestEventsAndStateResponse
+}
+
+func (t *testRoomserverAPI) InputRoomEvents(
+	ctx context.Context,
+	request *rsAPI.InputRoomEventsRequest,
+	response *rsAPI.InputRoomEventsResponse,
+) error {
+	t.inputRoomEvents = append(t.inputRoomEvents, request.InputRoomEvents...)
+	for _, ire := range request.InputRoomEvents {
+		fmt.Println("InputRoomEvents: ", ire.Event.EventID())
+	}
+	return nil
+}
+
+// Query the latest events and state for a room from the room server.
+func (t *testRoomserverAPI) QueryLatestEventsAndState(
+	ctx context.Context,
+	request *rsAPI.QueryLatestEventsAndStateRequest,
+	response *rsAPI.QueryLatestEventsAndStateResponse,
+) error {
+	r := t.queryLatestEventsAndState(request)
+	response.RoomExists = r.RoomExists
+	response.RoomVersion = testRoomVersion
+	response.LatestEvents = r.LatestEvents
+	response.StateEvents = r.StateEvents
+	response.Depth = r.Depth
+	return nil
+}
+
+// Query the state after a list of events in a room from the room server.
+func (t *testRoomserverAPI) QueryStateAfterEvents(
+	ctx context.Context,
+	request *rsAPI.QueryStateAfterEventsRequest,
+	response *rsAPI.QueryStateAfterEventsResponse,
+) error {
+	response.RoomVersion = testRoomVersion
+	res := t.queryStateAfterEvents(request)
+	response.PrevEventsExist = res.PrevEventsExist
+	response.RoomExists = res.RoomExists
+	response.StateEvents = res.StateEvents
+	return nil
+}
+
+// Query a list of events by event ID.
+func (t *testRoomserverAPI) QueryEventsByID(
+	ctx context.Context,
+	request *rsAPI.QueryEventsByIDRequest,
+	response *rsAPI.QueryEventsByIDResponse,
+) error {
+	res := t.queryEventsByID(request)
+	response.Events = res.Events
+	return nil
+}
+
+// Query if a server is joined to a room
+func (t *testRoomserverAPI) QueryServerJoinedToRoom(
+	ctx context.Context,
+	request *rsAPI.QueryServerJoinedToRoomRequest,
+	response *rsAPI.QueryServerJoinedToRoomResponse,
+) error {
+	response.RoomExists = true
+	response.IsInRoom = true
+	return nil
+}
+
+// Asks for the room version for a given room.
+func (t *testRoomserverAPI) QueryRoomVersionForRoom(
+	ctx context.Context,
+	request *rsAPI.QueryRoomVersionForRoomRequest,
+	response *rsAPI.QueryRoomVersionForRoomResponse,
+) error {
+	response.RoomVersion = testRoomVersion
+	return nil
+}
+
+func (t *testRoomserverAPI) QueryServerBannedFromRoom(
+	ctx context.Context, req *rsAPI.QueryServerBannedFromRoomRequest, res *rsAPI.QueryServerBannedFromRoomResponse,
+) error {
+	res.Banned = false
+	return nil
+}
+
+func mustCreateTransaction(rsAPI rsAPI.FederationRoomserverAPI, pdus []json.RawMessage) *TxnReq {
+	t := NewTxnReq(
+		rsAPI,
+		nil,
+		"",
+		&test.NopJSONVerifier{},
+		NewMutexByRoom(),
+		nil,
+		false,
+		pdus,
+		nil,
+		testOrigin,
+		gomatrixserverlib.TransactionID(fmt.Sprintf("%d", time.Now().UnixNano())),
+		testDestination)
+	t.PDUs = pdus
+	t.Origin = testOrigin
+	t.TransactionID = gomatrixserverlib.TransactionID(fmt.Sprintf("%d", time.Now().UnixNano()))
+	t.Destination = testDestination
+	return &t
+}
+
+func mustProcessTransaction(t *testing.T, txn *TxnReq, pdusWithErrors []string) {
+	res, err := txn.ProcessTransaction(context.Background())
+	if err != nil {
+		t.Errorf("txn.processTransaction returned an error: %v", err)
+		return
+	}
+	if len(res.PDUs) != len(txn.PDUs) {
+		t.Errorf("txn.processTransaction did not return results for all PDUs, got %d want %d", len(res.PDUs), len(txn.PDUs))
+		return
+	}
+NextPDU:
+	for eventID, result := range res.PDUs {
+		if result.Error == "" {
+			continue
+		}
+		for _, eventIDWantError := range pdusWithErrors {
+			if eventID == eventIDWantError {
+				break NextPDU
+			}
+		}
+		t.Errorf("txn.processTransaction PDU %s returned an error %s", eventID, result.Error)
+	}
+}
+
+func assertInputRoomEvents(t *testing.T, got []rsAPI.InputRoomEvent, want []*gomatrixserverlib.HeaderedEvent) {
+	for _, g := range got {
+		fmt.Println("GOT ", g.Event.EventID())
+	}
+	if len(got) != len(want) {
+		t.Errorf("wrong number of InputRoomEvents: got %d want %d", len(got), len(want))
+		return
+	}
+	for i := range got {
+		if got[i].Event.EventID() != want[i].EventID() {
+			t.Errorf("InputRoomEvents[%d] got %s want %s", i, got[i].Event.EventID(), want[i].EventID())
+		}
+	}
+}
+
+// The purpose of this test is to check that receiving an event over federation for which we have the prev_events works correctly, and passes it on
+// to the roomserver. It's the most basic test possible.
+func TestBasicTransaction(t *testing.T) {
+	rsAPI := &testRoomserverAPI{}
+	pdus := []json.RawMessage{
+		testData[len(testData)-1], // a message event
+	}
+	txn := mustCreateTransaction(rsAPI, pdus)
+	mustProcessTransaction(t, txn, nil)
+	assertInputRoomEvents(t, rsAPI.inputRoomEvents, []*gomatrixserverlib.HeaderedEvent{testEvents[len(testEvents)-1]})
+}
+
+// The purpose of this test is to check that if the event received fails auth checks the event is still sent to the roomserver
+// as it does the auth check.
+func TestTransactionFailAuthChecks(t *testing.T) {
+	rsAPI := &testRoomserverAPI{}
+	pdus := []json.RawMessage{
+		testData[len(testData)-1], // a message event
+	}
+	txn := mustCreateTransaction(rsAPI, pdus)
+	mustProcessTransaction(t, txn, []string{})
+	// expect message to be sent to the roomserver
+	assertInputRoomEvents(t, rsAPI.inputRoomEvents, []*gomatrixserverlib.HeaderedEvent{testEvents[len(testEvents)-1]})
+}

mediaapi/routing/routing.go

@@ -108,13 +108,16 @@ func makeDownloadAPI(
 	activeRemoteRequests *types.ActiveRemoteRequests,
 	activeThumbnailGeneration *types.ActiveThumbnailGeneration,
 ) http.HandlerFunc {
-	counterVec := promauto.NewCounterVec(
-		prometheus.CounterOpts{
-			Name: name,
-			Help: "Total number of media_api requests for either thumbnails or full downloads",
-		},
-		[]string{"code"},
-	)
+	var counterVec *prometheus.CounterVec
+	if cfg.Matrix.Metrics.Enabled {
+		counterVec = promauto.NewCounterVec(
+			prometheus.CounterOpts{
+				Name: name,
+				Help: "Total number of media_api requests for either thumbnails or full downloads",
+			},
+			[]string{"code"},
+		)
+	}
 	httpHandler := func(w http.ResponseWriter, req *http.Request) {
 		req = util.RequestWithLogging(req)
 
@@ -166,5 +169,12 @@ func makeDownloadAPI(
 			vars["downloadName"],
 		)
 	}
-	return promhttp.InstrumentHandlerCounter(counterVec, http.HandlerFunc(httpHandler))
+
+	var handlerFunc http.HandlerFunc
+	if counterVec != nil {
+		handlerFunc = promhttp.InstrumentHandlerCounter(counterVec, http.HandlerFunc(httpHandler))
+	} else {
+		handlerFunc = http.HandlerFunc(httpHandler)
+	}
+	return handlerFunc
 }

relayapi/api/api.go

@@ -0,0 +1,56 @@
+// Copyright 2022 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 api
+
+import (
+	"context"
+
+	"github.com/matrix-org/gomatrixserverlib"
+)
+
+// RelayInternalAPI is used to query information from the relay server.
+type RelayInternalAPI interface {
+	RelayServerAPI
+
+	// Retrieve from external relay server all transactions stored for us and process them.
+	PerformRelayServerSync(
+		ctx context.Context,
+		userID gomatrixserverlib.UserID,
+		relayServer gomatrixserverlib.ServerName,
+	) error
+}
+
+// RelayServerAPI exposes the store & query transaction functionality of a relay server.
+type RelayServerAPI interface {
+	// Store transactions for forwarding to the destination at a later time.
+	PerformStoreTransaction(
+		ctx context.Context,
+		transaction gomatrixserverlib.Transaction,
+		userID gomatrixserverlib.UserID,
+	) error
+
+	// Obtain the oldest stored transaction for the specified userID.
+	QueryTransactions(
+		ctx context.Context,
+		userID gomatrixserverlib.UserID,
+		previousEntry gomatrixserverlib.RelayEntry,
+	) (QueryRelayTransactionsResponse, error)
+}
+
+type QueryRelayTransactionsResponse struct {
+	Transaction   gomatrixserverlib.Transaction `json:"transaction"`
+	EntryID       int64                         `json:"entry_id"`
+	EntriesQueued bool                          `json:"entries_queued"`
+}

relayapi/internal/api.go

@@ -0,0 +1,53 @@
+// Copyright 2022 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 (
+	fedAPI "github.com/matrix-org/dendrite/federationapi/api"
+	"github.com/matrix-org/dendrite/federationapi/producers"
+	"github.com/matrix-org/dendrite/relayapi/storage"
+	rsAPI "github.com/matrix-org/dendrite/roomserver/api"
+	"github.com/matrix-org/gomatrixserverlib"
+)
+
+type RelayInternalAPI struct {
+	db                     storage.Database
+	fedClient              fedAPI.FederationClient
+	rsAPI                  rsAPI.RoomserverInternalAPI
+	keyRing                *gomatrixserverlib.KeyRing
+	producer               *producers.SyncAPIProducer
+	presenceEnabledInbound bool
+	serverName             gomatrixserverlib.ServerName
+}
+
+func NewRelayInternalAPI(
+	db storage.Database,
+	fedClient fedAPI.FederationClient,
+	rsAPI rsAPI.RoomserverInternalAPI,
+	keyRing *gomatrixserverlib.KeyRing,
+	producer *producers.SyncAPIProducer,
+	presenceEnabledInbound bool,
+	serverName gomatrixserverlib.ServerName,
+) *RelayInternalAPI {
+	return &RelayInternalAPI{
+		db:                     db,
+		fedClient:              fedClient,
+		rsAPI:                  rsAPI,
+		keyRing:                keyRing,
+		producer:               producer,
+		presenceEnabledInbound: presenceEnabledInbound,
+		serverName:             serverName,
+	}
+}

relayapi/internal/perform.go

@@ -0,0 +1,141 @@
+// Copyright 2022 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"
+
+	"github.com/matrix-org/dendrite/federationapi/storage/shared/receipt"
+	"github.com/matrix-org/dendrite/internal"
+	"github.com/matrix-org/dendrite/relayapi/api"
+	"github.com/matrix-org/gomatrixserverlib"
+	"github.com/sirupsen/logrus"
+)
+
+// PerformRelayServerSync implements api.RelayInternalAPI
+func (r *RelayInternalAPI) PerformRelayServerSync(
+	ctx context.Context,
+	userID gomatrixserverlib.UserID,
+	relayServer gomatrixserverlib.ServerName,
+) error {
+	// Providing a default RelayEntry (EntryID = 0) is done to ask the relay if there are any
+	// transactions available for this node.
+	prevEntry := gomatrixserverlib.RelayEntry{}
+	asyncResponse, err := r.fedClient.P2PGetTransactionFromRelay(ctx, userID, prevEntry, relayServer)
+	if err != nil {
+		logrus.Errorf("P2PGetTransactionFromRelay: %s", err.Error())
+		return err
+	}
+	r.processTransaction(&asyncResponse.Txn)
+
+	prevEntry = gomatrixserverlib.RelayEntry{EntryID: asyncResponse.EntryID}
+	for asyncResponse.EntriesQueued {
+		// There are still more entries available for this node from the relay.
+		logrus.Infof("Retrieving next entry from relay, previous: %v", prevEntry)
+		asyncResponse, err = r.fedClient.P2PGetTransactionFromRelay(ctx, userID, prevEntry, relayServer)
+		prevEntry = gomatrixserverlib.RelayEntry{EntryID: asyncResponse.EntryID}
+		if err != nil {
+			logrus.Errorf("P2PGetTransactionFromRelay: %s", err.Error())
+			return err
+		}
+		r.processTransaction(&asyncResponse.Txn)
+	}
+
+	return nil
+}
+
+// PerformStoreTransaction implements api.RelayInternalAPI
+func (r *RelayInternalAPI) PerformStoreTransaction(
+	ctx context.Context,
+	transaction gomatrixserverlib.Transaction,
+	userID gomatrixserverlib.UserID,
+) error {
+	logrus.Warnf("Storing transaction for %v", userID)
+	receipt, err := r.db.StoreTransaction(ctx, transaction)
+	if err != nil {
+		logrus.Errorf("db.StoreTransaction: %s", err.Error())
+		return err
+	}
+	err = r.db.AssociateTransactionWithDestinations(
+		ctx,
+		map[gomatrixserverlib.UserID]struct{}{
+			userID: {},
+		},
+		transaction.TransactionID,
+		receipt)
+
+	return err
+}
+
+// QueryTransactions implements api.RelayInternalAPI
+func (r *RelayInternalAPI) QueryTransactions(
+	ctx context.Context,
+	userID gomatrixserverlib.UserID,
+	previousEntry gomatrixserverlib.RelayEntry,
+) (api.QueryRelayTransactionsResponse, error) {
+	logrus.Infof("QueryTransactions for %s", userID.Raw())
+	if previousEntry.EntryID > 0 {
+		logrus.Infof("Cleaning previous entry (%v) from db for %s",
+			previousEntry.EntryID,
+			userID.Raw(),
+		)
+		prevReceipt := receipt.NewReceipt(previousEntry.EntryID)
+		err := r.db.CleanTransactions(ctx, userID, []*receipt.Receipt{&prevReceipt})
+		if err != nil {
+			logrus.Errorf("db.CleanTransactions: %s", err.Error())
+			return api.QueryRelayTransactionsResponse{}, err
+		}
+	}
+
+	transaction, receipt, err := r.db.GetTransaction(ctx, userID)
+	if err != nil {
+		logrus.Errorf("db.GetTransaction: %s", err.Error())
+		return api.QueryRelayTransactionsResponse{}, err
+	}
+
+	response := api.QueryRelayTransactionsResponse{}
+	if transaction != nil && receipt != nil {
+		logrus.Infof("Obtained transaction (%v) for %s", transaction.TransactionID, userID.Raw())
+		response.Transaction = *transaction
+		response.EntryID = receipt.GetNID()
+		response.EntriesQueued = true
+	} else {
+		logrus.Infof("No more entries in the queue for %s", userID.Raw())
+		response.EntryID = 0
+		response.EntriesQueued = false
+	}
+
+	return response, nil
+}
+
+func (r *RelayInternalAPI) processTransaction(txn *gomatrixserverlib.Transaction) {
+	logrus.Warn("Processing transaction from relay server")
+	mu := internal.NewMutexByRoom()
+	t := internal.NewTxnReq(
+		r.rsAPI,
+		nil,
+		r.serverName,
+		r.keyRing,
+		mu,
+		r.producer,
+		r.presenceEnabledInbound,
+		txn.PDUs,
+		txn.EDUs,
+		txn.Origin,
+		txn.TransactionID,
+		txn.Destination)
+
+	t.ProcessTransaction(context.TODO())
+}

relayapi/internal/perform_test.go

@@ -0,0 +1,121 @@
+// Copyright 2022 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"
+	"fmt"
+	"testing"
+
+	fedAPI "github.com/matrix-org/dendrite/federationapi/api"
+	"github.com/matrix-org/dendrite/internal/sqlutil"
+	"github.com/matrix-org/dendrite/relayapi/storage/shared"
+	"github.com/matrix-org/dendrite/test"
+	"github.com/matrix-org/gomatrixserverlib"
+	"github.com/stretchr/testify/assert"
+)
+
+type testFedClient struct {
+	fedAPI.FederationClient
+	shouldFail bool
+	queryCount uint
+	queueDepth uint
+}
+
+func (f *testFedClient) P2PGetTransactionFromRelay(
+	ctx context.Context,
+	u gomatrixserverlib.UserID,
+	prev gomatrixserverlib.RelayEntry,
+	relayServer gomatrixserverlib.ServerName,
+) (res gomatrixserverlib.RespGetRelayTransaction, err error) {
+	f.queryCount++
+	if f.shouldFail {
+		return res, fmt.Errorf("Error")
+	}
+
+	res = gomatrixserverlib.RespGetRelayTransaction{
+		Txn:     gomatrixserverlib.Transaction{},
+		EntryID: 0,
+	}
+	if f.queueDepth > 0 {
+		res.EntriesQueued = true
+	} else {
+		res.EntriesQueued = false
+	}
+	f.queueDepth -= 1
+
+	return
+}
+
+func TestPerformRelayServerSync(t *testing.T) {
+	testDB := test.NewInMemoryRelayDatabase()
+	db := shared.Database{
+		Writer:         sqlutil.NewDummyWriter(),
+		RelayQueue:     testDB,
+		RelayQueueJSON: testDB,
+	}
+
+	userID, err := gomatrixserverlib.NewUserID("@local:domain", false)
+	assert.Nil(t, err, "Invalid userID")
+
+	fedClient := &testFedClient{}
+	relayAPI := NewRelayInternalAPI(
+		&db, fedClient, nil, nil, nil, false, "",
+	)
+
+	err = relayAPI.PerformRelayServerSync(context.Background(), *userID, gomatrixserverlib.ServerName("relay"))
+	assert.NoError(t, err)
+}
+
+func TestPerformRelayServerSyncFedError(t *testing.T) {
+	testDB := test.NewInMemoryRelayDatabase()
+	db := shared.Database{
+		Writer:         sqlutil.NewDummyWriter(),
+		RelayQueue:     testDB,
+		RelayQueueJSON: testDB,
+	}
+
+	userID, err := gomatrixserverlib.NewUserID("@local:domain", false)
+	assert.Nil(t, err, "Invalid userID")
+
+	fedClient := &testFedClient{shouldFail: true}
+	relayAPI := NewRelayInternalAPI(
+		&db, fedClient, nil, nil, nil, false, "",
+	)
+
+	err = relayAPI.PerformRelayServerSync(context.Background(), *userID, gomatrixserverlib.ServerName("relay"))
+	assert.Error(t, err)
+}
+
+func TestPerformRelayServerSyncRunsUntilQueueEmpty(t *testing.T) {
+	testDB := test.NewInMemoryRelayDatabase()
+	db := shared.Database{
+		Writer:         sqlutil.NewDummyWriter(),
+		RelayQueue:     testDB,
+		RelayQueueJSON: testDB,
+	}
+
+	userID, err := gomatrixserverlib.NewUserID("@local:domain", false)
+	assert.Nil(t, err, "Invalid userID")
+
+	fedClient := &testFedClient{queueDepth: 2}
+	relayAPI := NewRelayInternalAPI(
+		&db, fedClient, nil, nil, nil, false, "",
+	)
+
+	err = relayAPI.PerformRelayServerSync(context.Background(), *userID, gomatrixserverlib.ServerName("relay"))
+	assert.NoError(t, err)
+	assert.Equal(t, uint(3), fedClient.queryCount)
+}

relayapi/relayapi.go

@@ -0,0 +1,74 @@
+// Copyright 2022 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 relayapi
+
+import (
+	"github.com/matrix-org/dendrite/federationapi/producers"
+	"github.com/matrix-org/dendrite/relayapi/api"
+	"github.com/matrix-org/dendrite/relayapi/internal"
+	"github.com/matrix-org/dendrite/relayapi/routing"
+	"github.com/matrix-org/dendrite/relayapi/storage"
+	rsAPI "github.com/matrix-org/dendrite/roomserver/api"
+	"github.com/matrix-org/dendrite/setup/base"
+	"github.com/matrix-org/gomatrixserverlib"
+	"github.com/sirupsen/logrus"
+)
+
+// AddPublicRoutes sets up and registers HTTP handlers on the base API muxes for the FederationAPI component.
+func AddPublicRoutes(
+	base *base.BaseDendrite,
+	keyRing gomatrixserverlib.JSONVerifier,
+	relayAPI api.RelayInternalAPI,
+) {
+	fedCfg := &base.Cfg.FederationAPI
+
+	relay, ok := relayAPI.(*internal.RelayInternalAPI)
+	if !ok {
+		panic("relayapi.AddPublicRoutes called with a RelayInternalAPI impl which was not " +
+			"RelayInternalAPI. This is a programming error.")
+	}
+
+	routing.Setup(
+		base.PublicFederationAPIMux,
+		fedCfg,
+		relay,
+		keyRing,
+	)
+}
+
+func NewRelayInternalAPI(
+	base *base.BaseDendrite,
+	fedClient *gomatrixserverlib.FederationClient,
+	rsAPI rsAPI.RoomserverInternalAPI,
+	keyRing *gomatrixserverlib.KeyRing,
+	producer *producers.SyncAPIProducer,
+) api.RelayInternalAPI {
+	cfg := &base.Cfg.RelayAPI
+
+	relayDB, err := storage.NewDatabase(base, &cfg.Database, base.Caches, base.Cfg.Global.IsLocalServerName)
+	if err != nil {
+		logrus.WithError(err).Panic("failed to connect to relay db")
+	}
+
+	return internal.NewRelayInternalAPI(
+		relayDB,
+		fedClient,
+		rsAPI,
+		keyRing,
+		producer,
+		base.Cfg.Global.Presence.EnableInbound,
+		base.Cfg.Global.ServerName,
+	)
+}

relayapi/relayapi_test.go

@@ -0,0 +1,154 @@
+// Copyright 2022 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 relayapi_test
+
+import (
+	"crypto/ed25519"
+	"encoding/hex"
+	"encoding/json"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+
+	"github.com/gorilla/mux"
+	"github.com/matrix-org/dendrite/cmd/dendrite-demo-yggdrasil/signing"
+	"github.com/matrix-org/dendrite/relayapi"
+	"github.com/matrix-org/dendrite/test"
+	"github.com/matrix-org/dendrite/test/testrig"
+	"github.com/matrix-org/gomatrixserverlib"
+	"github.com/stretchr/testify/assert"
+)
+
+func TestCreateNewRelayInternalAPI(t *testing.T) {
+	test.WithAllDatabases(t, func(t *testing.T, dbType test.DBType) {
+		base, close := testrig.CreateBaseDendrite(t, dbType)
+		defer close()
+
+		relayAPI := relayapi.NewRelayInternalAPI(base, nil, nil, nil, nil)
+		assert.NotNil(t, relayAPI)
+	})
+}
+
+func TestCreateRelayInternalInvalidDatabasePanics(t *testing.T) {
+	test.WithAllDatabases(t, func(t *testing.T, dbType test.DBType) {
+		base, close := testrig.CreateBaseDendrite(t, dbType)
+		if dbType == test.DBTypeSQLite {
+			base.Cfg.RelayAPI.Database.ConnectionString = "file:"
+		} else {
+			base.Cfg.RelayAPI.Database.ConnectionString = "test"
+		}
+		defer close()
+
+		assert.Panics(t, func() {
+			relayapi.NewRelayInternalAPI(base, nil, nil, nil, nil)
+		})
+	})
+}
+
+func TestCreateInvalidRelayPublicRoutesPanics(t *testing.T) {
+	test.WithAllDatabases(t, func(t *testing.T, dbType test.DBType) {
+		base, close := testrig.CreateBaseDendrite(t, dbType)
+		defer close()
+
+		assert.Panics(t, func() {
+			relayapi.AddPublicRoutes(base, nil, nil)
+		})
+	})
+}
+
+func createGetRelayTxnHTTPRequest(serverName gomatrixserverlib.ServerName, userID string) *http.Request {
+	_, sk, _ := ed25519.GenerateKey(nil)
+	keyID := signing.KeyID
+	pk := sk.Public().(ed25519.PublicKey)
+	origin := gomatrixserverlib.ServerName(hex.EncodeToString(pk))
+	req := gomatrixserverlib.NewFederationRequest("GET", origin, serverName, "/_matrix/federation/v1/relay_txn/"+userID)
+	content := gomatrixserverlib.RelayEntry{EntryID: 0}
+	req.SetContent(content)
+	req.Sign(origin, gomatrixserverlib.KeyID(keyID), sk)
+	httpreq, _ := req.HTTPRequest()
+	vars := map[string]string{"userID": userID}
+	httpreq = mux.SetURLVars(httpreq, vars)
+	return httpreq
+}
+
+type sendRelayContent struct {
+	PDUs []json.RawMessage       `json:"pdus"`
+	EDUs []gomatrixserverlib.EDU `json:"edus"`
+}
+
+func createSendRelayTxnHTTPRequest(serverName gomatrixserverlib.ServerName, txnID string, userID string) *http.Request {
+	_, sk, _ := ed25519.GenerateKey(nil)
+	keyID := signing.KeyID
+	pk := sk.Public().(ed25519.PublicKey)
+	origin := gomatrixserverlib.ServerName(hex.EncodeToString(pk))
+	req := gomatrixserverlib.NewFederationRequest("PUT", origin, serverName, "/_matrix/federation/v1/send_relay/"+txnID+"/"+userID)
+	content := sendRelayContent{}
+	req.SetContent(content)
+	req.Sign(origin, gomatrixserverlib.KeyID(keyID), sk)
+	httpreq, _ := req.HTTPRequest()
+	vars := map[string]string{"userID": userID, "txnID": txnID}
+	httpreq = mux.SetURLVars(httpreq, vars)
+	return httpreq
+}
+
+func TestCreateRelayPublicRoutes(t *testing.T) {
+	test.WithAllDatabases(t, func(t *testing.T, dbType test.DBType) {
+		base, close := testrig.CreateBaseDendrite(t, dbType)
+		defer close()
+
+		relayAPI := relayapi.NewRelayInternalAPI(base, nil, nil, nil, nil)
+		assert.NotNil(t, relayAPI)
+
+		serverKeyAPI := &signing.YggdrasilKeys{}
+		keyRing := serverKeyAPI.KeyRing()
+		relayapi.AddPublicRoutes(base, keyRing, relayAPI)
+
+		testCases := []struct {
+			name            string
+			req             *http.Request
+			wantCode        int
+			wantJoinedRooms []string
+		}{
+			{
+				name:     "relay_txn invalid user id",
+				req:      createGetRelayTxnHTTPRequest(base.Cfg.Global.ServerName, "user:local"),
+				wantCode: 400,
+			},
+			{
+				name:     "relay_txn valid user id",
+				req:      createGetRelayTxnHTTPRequest(base.Cfg.Global.ServerName, "@user:local"),
+				wantCode: 200,
+			},
+			{
+				name:     "send_relay invalid user id",
+				req:      createSendRelayTxnHTTPRequest(base.Cfg.Global.ServerName, "123", "user:local"),
+				wantCode: 400,
+			},
+			{
+				name:     "send_relay valid user id",
+				req:      createSendRelayTxnHTTPRequest(base.Cfg.Global.ServerName, "123", "@user:local"),
+				wantCode: 200,
+			},
+		}
+
+		for _, tc := range testCases {
+			w := httptest.NewRecorder()
+			base.PublicFederationAPIMux.ServeHTTP(w, tc.req)
+			if w.Code != tc.wantCode {
+				t.Fatalf("%s: got HTTP %d want %d", tc.name, w.Code, tc.wantCode)
+			}
+		}
+	})
+}

relayapi/routing/relaytxn.go

@@ -0,0 +1,74 @@
+// Copyright 2022 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 routing
+
+import (
+	"encoding/json"
+	"net/http"
+
+	"github.com/matrix-org/dendrite/clientapi/jsonerror"
+	"github.com/matrix-org/dendrite/relayapi/api"
+	"github.com/matrix-org/gomatrixserverlib"
+	"github.com/matrix-org/util"
+	"github.com/sirupsen/logrus"
+)
+
+type RelayTransactionResponse struct {
+	Transaction   gomatrixserverlib.Transaction `json:"transaction"`
+	EntryID       int64                         `json:"entry_id,omitempty"`
+	EntriesQueued bool                          `json:"entries_queued"`
+}
+
+// GetTransactionFromRelay implements /_matrix/federation/v1/relay_txn/{userID}
+// This endpoint can be extracted into a separate relay server service.
+func GetTransactionFromRelay(
+	httpReq *http.Request,
+	fedReq *gomatrixserverlib.FederationRequest,
+	relayAPI api.RelayInternalAPI,
+	userID gomatrixserverlib.UserID,
+) util.JSONResponse {
+	logrus.Infof("Handling relay_txn for %s", userID.Raw())
+
+	previousEntry := gomatrixserverlib.RelayEntry{}
+	if err := json.Unmarshal(fedReq.Content(), &previousEntry); err != nil {
+		return util.JSONResponse{
+			Code: http.StatusInternalServerError,
+			JSON: jsonerror.BadJSON("invalid json provided"),
+		}
+	}
+	if previousEntry.EntryID < 0 {
+		return util.JSONResponse{
+			Code: http.StatusInternalServerError,
+			JSON: jsonerror.BadJSON("Invalid entry id provided. Must be >= 0."),
+		}
+	}
+	logrus.Infof("Previous entry provided: %v", previousEntry.EntryID)
+
+	response, err := relayAPI.QueryTransactions(httpReq.Context(), userID, previousEntry)
+	if err != nil {
+		return util.JSONResponse{
+			Code: http.StatusInternalServerError,
+		}
+	}
+
+	return util.JSONResponse{
+		Code: http.StatusOK,
+		JSON: RelayTransactionResponse{
+			Transaction:   response.Transaction,
+			EntryID:       response.EntryID,
+			EntriesQueued: response.EntriesQueued,
+		},
+	}
+}

relayapi/routing/relaytxn_test.go

@@ -0,0 +1,220 @@
+// Copyright 2022 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 routing_test
+
+import (
+	"context"
+	"net/http"
+	"testing"
+
+	"github.com/matrix-org/dendrite/internal/sqlutil"
+	"github.com/matrix-org/dendrite/relayapi/internal"
+	"github.com/matrix-org/dendrite/relayapi/routing"
+	"github.com/matrix-org/dendrite/relayapi/storage/shared"
+	"github.com/matrix-org/dendrite/test"
+	"github.com/matrix-org/gomatrixserverlib"
+	"github.com/stretchr/testify/assert"
+)
+
+func createQuery(
+	userID gomatrixserverlib.UserID,
+	prevEntry gomatrixserverlib.RelayEntry,
+) gomatrixserverlib.FederationRequest {
+	var federationPathPrefixV1 = "/_matrix/federation/v1"
+	path := federationPathPrefixV1 + "/relay_txn/" + userID.Raw()
+	request := gomatrixserverlib.NewFederationRequest("GET", userID.Domain(), "relay", path)
+	request.SetContent(prevEntry)
+
+	return request
+}
+
+func TestGetEmptyDatabaseReturnsNothing(t *testing.T) {
+	testDB := test.NewInMemoryRelayDatabase()
+	db := shared.Database{
+		Writer:         sqlutil.NewDummyWriter(),
+		RelayQueue:     testDB,
+		RelayQueueJSON: testDB,
+	}
+	httpReq := &http.Request{}
+	userID, err := gomatrixserverlib.NewUserID("@local:domain", false)
+	assert.NoError(t, err, "Invalid userID")
+
+	transaction := createTransaction()
+
+	_, err = db.StoreTransaction(context.Background(), transaction)
+	assert.NoError(t, err, "Failed to store transaction")
+
+	relayAPI := internal.NewRelayInternalAPI(
+		&db, nil, nil, nil, nil, false, "",
+	)
+
+	request := createQuery(*userID, gomatrixserverlib.RelayEntry{})
+	response := routing.GetTransactionFromRelay(httpReq, &request, relayAPI, *userID)
+	assert.Equal(t, http.StatusOK, response.Code)
+
+	jsonResponse := response.JSON.(routing.RelayTransactionResponse)
+	assert.Equal(t, false, jsonResponse.EntriesQueued)
+	assert.Equal(t, gomatrixserverlib.Transaction{}, jsonResponse.Transaction)
+
+	count, err := db.GetTransactionCount(context.Background(), *userID)
+	assert.NoError(t, err)
+	assert.Zero(t, count)
+}
+
+func TestGetInvalidPrevEntryFails(t *testing.T) {
+	testDB := test.NewInMemoryRelayDatabase()
+	db := shared.Database{
+		Writer:         sqlutil.NewDummyWriter(),
+		RelayQueue:     testDB,
+		RelayQueueJSON: testDB,
+	}
+	httpReq := &http.Request{}
+	userID, err := gomatrixserverlib.NewUserID("@local:domain", false)
+	assert.NoError(t, err, "Invalid userID")
+
+	transaction := createTransaction()
+
+	_, err = db.StoreTransaction(context.Background(), transaction)
+	assert.NoError(t, err, "Failed to store transaction")
+
+	relayAPI := internal.NewRelayInternalAPI(
+		&db, nil, nil, nil, nil, false, "",
+	)
+
+	request := createQuery(*userID, gomatrixserverlib.RelayEntry{EntryID: -1})
+	response := routing.GetTransactionFromRelay(httpReq, &request, relayAPI, *userID)
+	assert.Equal(t, http.StatusInternalServerError, response.Code)
+}
+
+func TestGetReturnsSavedTransaction(t *testing.T) {
+	testDB := test.NewInMemoryRelayDatabase()
+	db := shared.Database{
+		Writer:         sqlutil.NewDummyWriter(),
+		RelayQueue:     testDB,
+		RelayQueueJSON: testDB,
+	}
+	httpReq := &http.Request{}
+	userID, err := gomatrixserverlib.NewUserID("@local:domain", false)
+	assert.NoError(t, err, "Invalid userID")
+
+	transaction := createTransaction()
+	receipt, err := db.StoreTransaction(context.Background(), transaction)
+	assert.NoError(t, err, "Failed to store transaction")
+
+	err = db.AssociateTransactionWithDestinations(
+		context.Background(),
+		map[gomatrixserverlib.UserID]struct{}{
+			*userID: {},
+		},
+		transaction.TransactionID,
+		receipt)
+	assert.NoError(t, err, "Failed to associate transaction with user")
+
+	relayAPI := internal.NewRelayInternalAPI(
+		&db, nil, nil, nil, nil, false, "",
+	)
+
+	request := createQuery(*userID, gomatrixserverlib.RelayEntry{})
+	response := routing.GetTransactionFromRelay(httpReq, &request, relayAPI, *userID)
+	assert.Equal(t, http.StatusOK, response.Code)
+
+	jsonResponse := response.JSON.(routing.RelayTransactionResponse)
+	assert.True(t, jsonResponse.EntriesQueued)
+	assert.Equal(t, transaction, jsonResponse.Transaction)
+
+	// And once more to clear the queue
+	request = createQuery(*userID, gomatrixserverlib.RelayEntry{EntryID: jsonResponse.EntryID})
+	response = routing.GetTransactionFromRelay(httpReq, &request, relayAPI, *userID)
+	assert.Equal(t, http.StatusOK, response.Code)
+
+	jsonResponse = response.JSON.(routing.RelayTransactionResponse)
+	assert.False(t, jsonResponse.EntriesQueued)
+	assert.Equal(t, gomatrixserverlib.Transaction{}, jsonResponse.Transaction)
+
+	count, err := db.GetTransactionCount(context.Background(), *userID)
+	assert.NoError(t, err)
+	assert.Zero(t, count)
+}
+
+func TestGetReturnsMultipleSavedTransactions(t *testing.T) {
+	testDB := test.NewInMemoryRelayDatabase()
+	db := shared.Database{
+		Writer:         sqlutil.NewDummyWriter(),
+		RelayQueue:     testDB,
+		RelayQueueJSON: testDB,
+	}
+	httpReq := &http.Request{}
+	userID, err := gomatrixserverlib.NewUserID("@local:domain", false)
+	assert.NoError(t, err, "Invalid userID")
+
+	transaction := createTransaction()
+	receipt, err := db.StoreTransaction(context.Background(), transaction)
+	assert.NoError(t, err, "Failed to store transaction")
+
+	err = db.AssociateTransactionWithDestinations(
+		context.Background(),
+		map[gomatrixserverlib.UserID]struct{}{
+			*userID: {},
+		},
+		transaction.TransactionID,
+		receipt)
+	assert.NoError(t, err, "Failed to associate transaction with user")
+
+	transaction2 := createTransaction()
+	receipt2, err := db.StoreTransaction(context.Background(), transaction2)
+	assert.NoError(t, err, "Failed to store transaction")
+
+	err = db.AssociateTransactionWithDestinations(
+		context.Background(),
+		map[gomatrixserverlib.UserID]struct{}{
+			*userID: {},
+		},
+		transaction2.TransactionID,
+		receipt2)
+	assert.NoError(t, err, "Failed to associate transaction with user")
+
+	relayAPI := internal.NewRelayInternalAPI(
+		&db, nil, nil, nil, nil, false, "",
+	)
+
+	request := createQuery(*userID, gomatrixserverlib.RelayEntry{})
+	response := routing.GetTransactionFromRelay(httpReq, &request, relayAPI, *userID)
+	assert.Equal(t, http.StatusOK, response.Code)
+
+	jsonResponse := response.JSON.(routing.RelayTransactionResponse)
+	assert.True(t, jsonResponse.EntriesQueued)
+	assert.Equal(t, transaction, jsonResponse.Transaction)
+
+	request = createQuery(*userID, gomatrixserverlib.RelayEntry{EntryID: jsonResponse.EntryID})
+	response = routing.GetTransactionFromRelay(httpReq, &request, relayAPI, *userID)
+	assert.Equal(t, http.StatusOK, response.Code)
+
+	jsonResponse = response.JSON.(routing.RelayTransactionResponse)
+	assert.True(t, jsonResponse.EntriesQueued)
+	assert.Equal(t, transaction2, jsonResponse.Transaction)
+
+	// And once more to clear the queue
+	request = createQuery(*userID, gomatrixserverlib.RelayEntry{EntryID: jsonResponse.EntryID})
+	response = routing.GetTransactionFromRelay(httpReq, &request, relayAPI, *userID)
+	assert.Equal(t, http.StatusOK, response.Code)
+
+	jsonResponse = response.JSON.(routing.RelayTransactionResponse)
+	assert.False(t, jsonResponse.EntriesQueued)
+	assert.Equal(t, gomatrixserverlib.Transaction{}, jsonResponse.Transaction)
+
+	count, err := db.GetTransactionCount(context.Background(), *userID)
+	assert.NoError(t, err)
+	assert.Zero(t, count)
+}

relayapi/routing/routing.go

@@ -0,0 +1,123 @@
+// Copyright 2022 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 routing
+
+import (
+	"fmt"
+	"net/http"
+	"time"
+
+	"github.com/getsentry/sentry-go"
+	"github.com/gorilla/mux"
+	"github.com/matrix-org/dendrite/clientapi/jsonerror"
+	"github.com/matrix-org/dendrite/internal/httputil"
+	relayInternal "github.com/matrix-org/dendrite/relayapi/internal"
+	"github.com/matrix-org/dendrite/setup/config"
+	"github.com/matrix-org/gomatrixserverlib"
+	"github.com/matrix-org/util"
+)
+
+// Setup registers HTTP handlers with the given ServeMux.
+// The provided publicAPIMux MUST have `UseEncodedPath()` enabled or else routes will incorrectly
+// path unescape twice (once from the router, once from MakeRelayAPI). We need to have this enabled
+// so we can decode paths like foo/bar%2Fbaz as [foo, bar/baz] - by default it will decode to [foo, bar, baz]
+//
+// Due to Setup being used to call many other functions, a gocyclo nolint is
+// applied:
+// nolint: gocyclo
+func Setup(
+	fedMux *mux.Router,
+	cfg *config.FederationAPI,
+	relayAPI *relayInternal.RelayInternalAPI,
+	keys gomatrixserverlib.JSONVerifier,
+) {
+	v1fedmux := fedMux.PathPrefix("/v1").Subrouter()
+
+	v1fedmux.Handle("/send_relay/{txnID}/{userID}", MakeRelayAPI(
+		"send_relay_transaction", "", cfg.Matrix.IsLocalServerName, keys,
+		func(httpReq *http.Request, request *gomatrixserverlib.FederationRequest, vars map[string]string) util.JSONResponse {
+			userID, err := gomatrixserverlib.NewUserID(vars["userID"], false)
+			if err != nil {
+				return util.JSONResponse{
+					Code: http.StatusBadRequest,
+					JSON: jsonerror.InvalidUsername("Username was invalid"),
+				}
+			}
+			return SendTransactionToRelay(
+				httpReq, request, relayAPI, gomatrixserverlib.TransactionID(vars["txnID"]),
+				*userID,
+			)
+		},
+	)).Methods(http.MethodPut, http.MethodOptions)
+
+	v1fedmux.Handle("/relay_txn/{userID}", MakeRelayAPI(
+		"get_relay_transaction", "", cfg.Matrix.IsLocalServerName, keys,
+		func(httpReq *http.Request, request *gomatrixserverlib.FederationRequest, vars map[string]string) util.JSONResponse {
+			userID, err := gomatrixserverlib.NewUserID(vars["userID"], false)
+			if err != nil {
+				return util.JSONResponse{
+					Code: http.StatusBadRequest,
+					JSON: jsonerror.InvalidUsername("Username was invalid"),
+				}
+			}
+			return GetTransactionFromRelay(httpReq, request, relayAPI, *userID)
+		},
+	)).Methods(http.MethodGet, http.MethodOptions)
+}
+
+// MakeRelayAPI makes an http.Handler that checks matrix relay authentication.
+func MakeRelayAPI(
+	metricsName string, serverName gomatrixserverlib.ServerName,
+	isLocalServerName func(gomatrixserverlib.ServerName) bool,
+	keyRing gomatrixserverlib.JSONVerifier,
+	f func(*http.Request, *gomatrixserverlib.FederationRequest, map[string]string) util.JSONResponse,
+) http.Handler {
+	h := func(req *http.Request) util.JSONResponse {
+		fedReq, errResp := gomatrixserverlib.VerifyHTTPRequest(
+			req, time.Now(), serverName, isLocalServerName, keyRing,
+		)
+		if fedReq == nil {
+			return errResp
+		}
+		// add the user to Sentry, if enabled
+		hub := sentry.GetHubFromContext(req.Context())
+		if hub != nil {
+			hub.Scope().SetTag("origin", string(fedReq.Origin()))
+			hub.Scope().SetTag("uri", fedReq.RequestURI())
+		}
+		defer func() {
+			if r := recover(); r != nil {
+				if hub != nil {
+					hub.CaptureException(fmt.Errorf("%s panicked", req.URL.Path))
+				}
+				// re-panic to return the 500
+				panic(r)
+			}
+		}()
+		vars, err := httputil.URLDecodeMapValues(mux.Vars(req))
+		if err != nil {
+			return util.MatrixErrorResponse(400, "M_UNRECOGNISED", "badly encoded query params")
+		}
+
+		jsonRes := f(req, fedReq, vars)
+		// do not log 4xx as errors as they are client fails, not server fails
+		if hub != nil && jsonRes.Code >= 500 {
+			hub.Scope().SetExtra("response", jsonRes)
+			hub.CaptureException(fmt.Errorf("%s returned HTTP %d", req.URL.Path, jsonRes.Code))
+		}
+		return jsonRes
+	}
+	return httputil.MakeExternalAPI(metricsName, h)
+}

relayapi/routing/sendrelay.go

@@ -0,0 +1,77 @@
+// Copyright 2022 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 routing
+
+import (
+	"encoding/json"
+	"net/http"
+
+	"github.com/matrix-org/dendrite/clientapi/jsonerror"
+	"github.com/matrix-org/dendrite/relayapi/api"
+	"github.com/matrix-org/gomatrixserverlib"
+	"github.com/matrix-org/util"
+	"github.com/sirupsen/logrus"
+)
+
+// SendTransactionToRelay implements PUT /_matrix/federation/v1/relay_txn/{txnID}/{userID}
+// This endpoint can be extracted into a separate relay server service.
+func SendTransactionToRelay(
+	httpReq *http.Request,
+	fedReq *gomatrixserverlib.FederationRequest,
+	relayAPI api.RelayInternalAPI,
+	txnID gomatrixserverlib.TransactionID,
+	userID gomatrixserverlib.UserID,
+) util.JSONResponse {
+	var txnEvents struct {
+		PDUs []json.RawMessage       `json:"pdus"`
+		EDUs []gomatrixserverlib.EDU `json:"edus"`
+	}
+
+	if err := json.Unmarshal(fedReq.Content(), &txnEvents); err != nil {
+		logrus.Info("The request body could not be decoded into valid JSON." + err.Error())
+		return util.JSONResponse{
+			Code: http.StatusBadRequest,
+			JSON: jsonerror.NotJSON("The request body could not be decoded into valid JSON." + err.Error()),
+		}
+	}
+
+	// Transactions are limited in size; they can have at most 50 PDUs and 100 EDUs.
+	// https://matrix.org/docs/spec/server_server/latest#transactions
+	if len(txnEvents.PDUs) > 50 || len(txnEvents.EDUs) > 100 {
+		return util.JSONResponse{
+			Code: http.StatusBadRequest,
+			JSON: jsonerror.BadJSON("max 50 pdus / 100 edus"),
+		}
+	}
+
+	t := gomatrixserverlib.Transaction{}
+	t.PDUs = txnEvents.PDUs
+	t.EDUs = txnEvents.EDUs
+	t.Origin = fedReq.Origin()
+	t.TransactionID = txnID
+	t.Destination = userID.Domain()
+
+	util.GetLogger(httpReq.Context()).Warnf("Received transaction %q from %q containing %d PDUs, %d EDUs", txnID, fedReq.Origin(), len(t.PDUs), len(t.EDUs))
+
+	err := relayAPI.PerformStoreTransaction(httpReq.Context(), t, userID)
+	if err != nil {
+		return util.JSONResponse{
+			Code: http.StatusInternalServerError,
+			JSON: jsonerror.BadJSON("could not store the transaction for forwarding"),
+		}
+	}
+
+	return util.JSONResponse{Code: 200}
+}

relayapi/routing/sendrelay_test.go

@@ -0,0 +1,209 @@
+// Copyright 2022 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 routing_test
+
+import (
+	"context"
+	"encoding/json"
+	"net/http"
+	"testing"
+
+	"github.com/matrix-org/dendrite/internal/sqlutil"
+	"github.com/matrix-org/dendrite/relayapi/internal"
+	"github.com/matrix-org/dendrite/relayapi/routing"
+	"github.com/matrix-org/dendrite/relayapi/storage/shared"
+	"github.com/matrix-org/dendrite/test"
+	"github.com/matrix-org/gomatrixserverlib"
+	"github.com/stretchr/testify/assert"
+)
+
+const (
+	testOrigin = gomatrixserverlib.ServerName("kaer.morhen")
+)
+
+func createTransaction() gomatrixserverlib.Transaction {
+	txn := gomatrixserverlib.Transaction{}
+	txn.PDUs = []json.RawMessage{
+		[]byte(`{"auth_events":[["$0ok8ynDp7kjc95e3:kaer.morhen",{"sha256":"sWCi6Ckp9rDimQON+MrUlNRkyfZ2tjbPbWfg2NMB18Q"}],["$LEwEu0kxrtu5fOiS:kaer.morhen",{"sha256":"1aKajq6DWHru1R1HJjvdWMEavkJJHGaTmPvfuERUXaA"}]],"content":{"body":"Test Message"},"depth":5,"event_id":"$gl2T9l3qm0kUbiIJ:kaer.morhen","hashes":{"sha256":"Qx3nRMHLDPSL5hBAzuX84FiSSP0K0Kju2iFoBWH4Za8"},"origin":"kaer.morhen","origin_server_ts":0,"prev_events":[["$UKNe10XzYzG0TeA9:kaer.morhen",{"sha256":"KtSRyMjt0ZSjsv2koixTRCxIRCGoOp6QrKscsW97XRo"}]],"room_id":"!roomid:kaer.morhen","sender":"@userid:kaer.morhen","signatures":{"kaer.morhen":{"ed25519:auto":"sqDgv3EG7ml5VREzmT9aZeBpS4gAPNIaIeJOwqjDhY0GPU/BcpX5wY4R7hYLrNe5cChgV+eFy/GWm1Zfg5FfDg"}},"type":"m.room.message"}`),
+	}
+	txn.Origin = testOrigin
+	return txn
+}
+
+func createFederationRequest(
+	userID gomatrixserverlib.UserID,
+	txnID gomatrixserverlib.TransactionID,
+	origin gomatrixserverlib.ServerName,
+	destination gomatrixserverlib.ServerName,
+	content interface{},
+) gomatrixserverlib.FederationRequest {
+	var federationPathPrefixV1 = "/_matrix/federation/v1"
+	path := federationPathPrefixV1 + "/send_relay/" + string(txnID) + "/" + userID.Raw()
+	request := gomatrixserverlib.NewFederationRequest("PUT", origin, destination, path)
+	request.SetContent(content)
+
+	return request
+}
+
+func TestForwardEmptyReturnsOk(t *testing.T) {
+	testDB := test.NewInMemoryRelayDatabase()
+	db := shared.Database{
+		Writer:         sqlutil.NewDummyWriter(),
+		RelayQueue:     testDB,
+		RelayQueueJSON: testDB,
+	}
+	httpReq := &http.Request{}
+	userID, err := gomatrixserverlib.NewUserID("@local:domain", false)
+	assert.NoError(t, err, "Invalid userID")
+
+	txn := createTransaction()
+	request := createFederationRequest(*userID, txn.TransactionID, txn.Origin, txn.Destination, txn)
+
+	relayAPI := internal.NewRelayInternalAPI(
+		&db, nil, nil, nil, nil, false, "",
+	)
+
+	response := routing.SendTransactionToRelay(httpReq, &request, relayAPI, "1", *userID)
+
+	assert.Equal(t, 200, response.Code)
+}
+
+func TestForwardBadJSONReturnsError(t *testing.T) {
+	testDB := test.NewInMemoryRelayDatabase()
+	db := shared.Database{
+		Writer:         sqlutil.NewDummyWriter(),
+		RelayQueue:     testDB,
+		RelayQueueJSON: testDB,
+	}
+	httpReq := &http.Request{}
+	userID, err := gomatrixserverlib.NewUserID("@local:domain", false)
+	assert.NoError(t, err, "Invalid userID")
+
+	type BadData struct {
+		Field bool `json:"pdus"`
+	}
+	content := BadData{
+		Field: false,
+	}
+	txn := createTransaction()
+	request := createFederationRequest(*userID, txn.TransactionID, txn.Origin, txn.Destination, content)
+
+	relayAPI := internal.NewRelayInternalAPI(
+		&db, nil, nil, nil, nil, false, "",
+	)
+
+	response := routing.SendTransactionToRelay(httpReq, &request, relayAPI, "1", *userID)
+
+	assert.NotEqual(t, 200, response.Code)
+}
+
+func TestForwardTooManyPDUsReturnsError(t *testing.T) {
+	testDB := test.NewInMemoryRelayDatabase()
+	db := shared.Database{
+		Writer:         sqlutil.NewDummyWriter(),
+		RelayQueue:     testDB,
+		RelayQueueJSON: testDB,
+	}
+	httpReq := &http.Request{}
+	userID, err := gomatrixserverlib.NewUserID("@local:domain", false)
+	assert.NoError(t, err, "Invalid userID")
+
+	type BadData struct {
+		Field []json.RawMessage `json:"pdus"`
+	}
+	content := BadData{
+		Field: []json.RawMessage{},
+	}
+	for i := 0; i < 51; i++ {
+		content.Field = append(content.Field, []byte{})
+	}
+	assert.Greater(t, len(content.Field), 50)
+
+	txn := createTransaction()
+	request := createFederationRequest(*userID, txn.TransactionID, txn.Origin, txn.Destination, content)
+
+	relayAPI := internal.NewRelayInternalAPI(
+		&db, nil, nil, nil, nil, false, "",
+	)
+
+	response := routing.SendTransactionToRelay(httpReq, &request, relayAPI, "1", *userID)
+
+	assert.NotEqual(t, 200, response.Code)
+}
+
+func TestForwardTooManyEDUsReturnsError(t *testing.T) {
+	testDB := test.NewInMemoryRelayDatabase()
+	db := shared.Database{
+		Writer:         sqlutil.NewDummyWriter(),
+		RelayQueue:     testDB,
+		RelayQueueJSON: testDB,
+	}
+	httpReq := &http.Request{}
+	userID, err := gomatrixserverlib.NewUserID("@local:domain", false)
+	assert.NoError(t, err, "Invalid userID")
+
+	type BadData struct {
+		Field []gomatrixserverlib.EDU `json:"edus"`
+	}
+	content := BadData{
+		Field: []gomatrixserverlib.EDU{},
+	}
+	for i := 0; i < 101; i++ {
+		content.Field = append(content.Field, gomatrixserverlib.EDU{Type: gomatrixserverlib.MTyping})
+	}
+	assert.Greater(t, len(content.Field), 100)
+
+	txn := createTransaction()
+	request := createFederationRequest(*userID, txn.TransactionID, txn.Origin, txn.Destination, content)
+
+	relayAPI := internal.NewRelayInternalAPI(
+		&db, nil, nil, nil, nil, false, "",
+	)
+
+	response := routing.SendTransactionToRelay(httpReq, &request, relayAPI, "1", *userID)
+
+	assert.NotEqual(t, 200, response.Code)
+}
+
+func TestUniqueTransactionStoredInDatabase(t *testing.T) {
+	testDB := test.NewInMemoryRelayDatabase()
+	db := shared.Database{
+		Writer:         sqlutil.NewDummyWriter(),
+		RelayQueue:     testDB,
+		RelayQueueJSON: testDB,
+	}
+	httpReq := &http.Request{}
+	userID, err := gomatrixserverlib.NewUserID("@local:domain", false)
+	assert.NoError(t, err, "Invalid userID")
+
+	txn := createTransaction()
+	request := createFederationRequest(*userID, txn.TransactionID, txn.Origin, txn.Destination, txn)
+
+	relayAPI := internal.NewRelayInternalAPI(
+		&db, nil, nil, nil, nil, false, "",
+	)
+
+	response := routing.SendTransactionToRelay(
+		httpReq, &request, relayAPI, txn.TransactionID, *userID)
+	transaction, _, err := db.GetTransaction(context.Background(), *userID)
+	assert.NoError(t, err, "Failed retrieving transaction")
+
+	transactionCount, err := db.GetTransactionCount(context.Background(), *userID)
+	assert.NoError(t, err, "Failed retrieving transaction count")
+
+	assert.Equal(t, 200, response.Code)
+	assert.Equal(t, int64(1), transactionCount)
+	assert.Equal(t, txn.TransactionID, transaction.TransactionID)
+}

relayapi/storage/interface.go

@@ -0,0 +1,47 @@
+// Copyright 2022 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 storage
+
+import (
+	"context"
+
+	"github.com/matrix-org/dendrite/federationapi/storage/shared/receipt"
+	"github.com/matrix-org/gomatrixserverlib"
+)
+
+type Database interface {
+	// Adds a new transaction to the queue json table.
+	// Adding a duplicate transaction will result in a new row being added and a new unique nid.
+	// return: unique nid representing this entry.
+	StoreTransaction(ctx context.Context, txn gomatrixserverlib.Transaction) (*receipt.Receipt, error)
+
+	// Adds a new transaction_id: server_name mapping with associated json table nid to the queue
+	// entry table for each provided destination.
+	AssociateTransactionWithDestinations(ctx context.Context, destinations map[gomatrixserverlib.UserID]struct{}, transactionID gomatrixserverlib.TransactionID, dbReceipt *receipt.Receipt) error
+
+	// Removes every server_name: receipt pair provided from the queue entries table.
+	// Will then remove every entry for each receipt provided from the queue json table.
+	// If any of the entries don't exist in either table, nothing will happen for that entry and
+	// an error will not be generated.
+	CleanTransactions(ctx context.Context, userID gomatrixserverlib.UserID, receipts []*receipt.Receipt) error
+
+	// Gets the oldest transaction for the provided server_name.
+	// If no transactions exist, returns nil and no error.
+	GetTransaction(ctx context.Context, userID gomatrixserverlib.UserID) (*gomatrixserverlib.Transaction, *receipt.Receipt, error)
+
+	// Gets the number of transactions being stored for the provided server_name.
+	// If the server doesn't exist in the database then 0 is returned with no error.
+	GetTransactionCount(ctx context.Context, userID gomatrixserverlib.UserID) (int64, error)
+}

relayapi/storage/postgres/relay_queue_json_table.go

@@ -0,0 +1,113 @@
+// Copyright 2022 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"
+
+	"github.com/lib/pq"
+	"github.com/matrix-org/dendrite/internal"
+	"github.com/matrix-org/dendrite/internal/sqlutil"
+)
+
+const relayQueueJSONSchema = `
+-- The relayapi_queue_json table contains event contents that
+-- we are storing for future forwarding. 
+CREATE TABLE IF NOT EXISTS relayapi_queue_json (
+	-- The JSON NID. This allows cross-referencing to find the JSON blob.
+	json_nid BIGSERIAL,
+	-- The JSON body. Text so that we preserve UTF-8.
+	json_body TEXT NOT NULL
+);
+
+CREATE UNIQUE INDEX IF NOT EXISTS relayapi_queue_json_json_nid_idx
+	ON relayapi_queue_json (json_nid);
+`
+
+const insertQueueJSONSQL = "" +
+	"INSERT INTO relayapi_queue_json (json_body)" +
+	" VALUES ($1)" +
+	" RETURNING json_nid"
+
+const deleteQueueJSONSQL = "" +
+	"DELETE FROM relayapi_queue_json WHERE json_nid = ANY($1)"
+
+const selectQueueJSONSQL = "" +
+	"SELECT json_nid, json_body FROM relayapi_queue_json" +
+	" WHERE json_nid = ANY($1)"
+
+type relayQueueJSONStatements struct {
+	db             *sql.DB
+	insertJSONStmt *sql.Stmt
+	deleteJSONStmt *sql.Stmt
+	selectJSONStmt *sql.Stmt
+}
+
+func NewPostgresRelayQueueJSONTable(db *sql.DB) (s *relayQueueJSONStatements, err error) {
+	s = &relayQueueJSONStatements{
+		db: db,
+	}
+	_, err = s.db.Exec(relayQueueJSONSchema)
+	if err != nil {
+		return
+	}
+
+	return s, sqlutil.StatementList{
+		{&s.insertJSONStmt, insertQueueJSONSQL},
+		{&s.deleteJSONStmt, deleteQueueJSONSQL},
+		{&s.selectJSONStmt, selectQueueJSONSQL},
+	}.Prepare(db)
+}
+
+func (s *relayQueueJSONStatements) InsertQueueJSON(
+	ctx context.Context, txn *sql.Tx, json string,
+) (int64, error) {
+	stmt := sqlutil.TxStmt(txn, s.insertJSONStmt)
+	var lastid int64
+	if err := stmt.QueryRowContext(ctx, json).Scan(&lastid); err != nil {
+		return 0, err
+	}
+	return lastid, nil
+}
+
+func (s *relayQueueJSONStatements) DeleteQueueJSON(
+	ctx context.Context, txn *sql.Tx, nids []int64,
+) error {
+	stmt := sqlutil.TxStmt(txn, s.deleteJSONStmt)
+	_, err := stmt.ExecContext(ctx, pq.Int64Array(nids))
+	return err
+}
+
+func (s *relayQueueJSONStatements) SelectQueueJSON(
+	ctx context.Context, txn *sql.Tx, jsonNIDs []int64,
+) (map[int64][]byte, error) {
+	blobs := map[int64][]byte{}
+	stmt := sqlutil.TxStmt(txn, s.selectJSONStmt)
+	rows, err := stmt.QueryContext(ctx, pq.Int64Array(jsonNIDs))
+	if err != nil {
+		return nil, err
+	}
+	defer internal.CloseAndLogIfError(ctx, rows, "selectJSON: rows.close() failed")
+	for rows.Next() {
+		var nid int64
+		var blob []byte
+		if err = rows.Scan(&nid, &blob); err != nil {
+			return nil, err
+		}
+		blobs[nid] = blob
+	}
+	return blobs, err
+}

relayapi/storage/postgres/relay_queue_table.go

@@ -0,0 +1,156 @@
+// Copyright 2022 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"
+
+	"github.com/lib/pq"
+	"github.com/matrix-org/dendrite/internal"
+	"github.com/matrix-org/dendrite/internal/sqlutil"
+	"github.com/matrix-org/gomatrixserverlib"
+)
+
+const relayQueueSchema = `
+CREATE TABLE IF NOT EXISTS relayapi_queue (
+	-- The transaction ID that was generated before persisting the event.
+	transaction_id TEXT NOT NULL,
+	-- The destination server that we will send the event to.
+	server_name TEXT NOT NULL,
+	-- The JSON NID from the relayapi_queue_json table.
+	json_nid BIGINT NOT NULL
+);
+
+CREATE UNIQUE INDEX IF NOT EXISTS relayapi_queue_queue_json_nid_idx
+	ON relayapi_queue (json_nid, server_name);
+CREATE INDEX IF NOT EXISTS relayapi_queue_json_nid_idx
+	ON relayapi_queue (json_nid);
+CREATE INDEX IF NOT EXISTS relayapi_queue_server_name_idx
+	ON relayapi_queue (server_name);
+`
+
+const insertQueueEntrySQL = "" +
+	"INSERT INTO relayapi_queue (transaction_id, server_name, json_nid)" +
+	" VALUES ($1, $2, $3)"
+
+const deleteQueueEntriesSQL = "" +
+	"DELETE FROM relayapi_queue WHERE server_name = $1 AND json_nid = ANY($2)"
+
+const selectQueueEntriesSQL = "" +
+	"SELECT json_nid FROM relayapi_queue" +
+	" WHERE server_name = $1" +
+	" ORDER BY json_nid" +
+	" LIMIT $2"
+
+const selectQueueEntryCountSQL = "" +
+	"SELECT COUNT(*) FROM relayapi_queue" +
+	" WHERE server_name = $1"
+
+type relayQueueStatements struct {
+	db                        *sql.DB
+	insertQueueEntryStmt      *sql.Stmt
+	deleteQueueEntriesStmt    *sql.Stmt
+	selectQueueEntriesStmt    *sql.Stmt
+	selectQueueEntryCountStmt *sql.Stmt
+}
+
+func NewPostgresRelayQueueTable(
+	db *sql.DB,
+) (s *relayQueueStatements, err error) {
+	s = &relayQueueStatements{
+		db: db,
+	}
+	_, err = s.db.Exec(relayQueueSchema)
+	if err != nil {
+		return
+	}
+
+	return s, sqlutil.StatementList{
+		{&s.insertQueueEntryStmt, insertQueueEntrySQL},
+		{&s.deleteQueueEntriesStmt, deleteQueueEntriesSQL},
+		{&s.selectQueueEntriesStmt, selectQueueEntriesSQL},
+		{&s.selectQueueEntryCountStmt, selectQueueEntryCountSQL},
+	}.Prepare(db)
+}
+
+func (s *relayQueueStatements) InsertQueueEntry(
+	ctx context.Context,
+	txn *sql.Tx,
+	transactionID gomatrixserverlib.TransactionID,
+	serverName gomatrixserverlib.ServerName,
+	nid int64,
+) error {
+	stmt := sqlutil.TxStmt(txn, s.insertQueueEntryStmt)
+	_, err := stmt.ExecContext(
+		ctx,
+		transactionID, // the transaction ID that we initially attempted
+		serverName,    // destination server name
+		nid,           // JSON blob NID
+	)
+	return err
+}
+
+func (s *relayQueueStatements) DeleteQueueEntries(
+	ctx context.Context,
+	txn *sql.Tx,
+	serverName gomatrixserverlib.ServerName,
+	jsonNIDs []int64,
+) error {
+	stmt := sqlutil.TxStmt(txn, s.deleteQueueEntriesStmt)
+	_, err := stmt.ExecContext(ctx, serverName, pq.Int64Array(jsonNIDs))
+	return err
+}
+
+func (s *relayQueueStatements) SelectQueueEntries(
+	ctx context.Context,
+	txn *sql.Tx,
+	serverName gomatrixserverlib.ServerName,
+	limit int,
+) ([]int64, error) {
+	stmt := sqlutil.TxStmt(txn, s.selectQueueEntriesStmt)
+	rows, err := stmt.QueryContext(ctx, serverName, limit)
+	if err != nil {
+		return nil, err
+	}
+	defer internal.CloseAndLogIfError(ctx, rows, "queueFromStmt: rows.close() failed")
+	var result []int64
+	for rows.Next() {
+		var nid int64
+		if err = rows.Scan(&nid); err != nil {
+			return nil, err
+		}
+		result = append(result, nid)
+	}
+
+	return result, rows.Err()
+}
+
+func (s *relayQueueStatements) SelectQueueEntryCount(
+	ctx context.Context,
+	txn *sql.Tx,
+	serverName gomatrixserverlib.ServerName,
+) (int64, error) {
+	var count int64
+	stmt := sqlutil.TxStmt(txn, s.selectQueueEntryCountStmt)
+	err := stmt.QueryRowContext(ctx, serverName).Scan(&count)
+	if err == sql.ErrNoRows {
+		// It's acceptable for there to be no rows referencing a given
+		// JSON NID but it's not an error condition. Just return as if
+		// there's a zero count.
+		return 0, nil
+	}
+	return count, err
+}

relayapi/storage/postgres/storage.go

@@ -0,0 +1,64 @@
+// Copyright 2022 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 (
+	"database/sql"
+
+	"github.com/matrix-org/dendrite/internal/caching"
+	"github.com/matrix-org/dendrite/internal/sqlutil"
+	"github.com/matrix-org/dendrite/relayapi/storage/shared"
+	"github.com/matrix-org/dendrite/setup/base"
+	"github.com/matrix-org/dendrite/setup/config"
+	"github.com/matrix-org/gomatrixserverlib"
+)
+
+// Database stores information needed by the relayapi
+type Database struct {
+	shared.Database
+	db     *sql.DB
+	writer sqlutil.Writer
+}
+
+// NewDatabase opens a new database
+func NewDatabase(
+	base *base.BaseDendrite,
+	dbProperties *config.DatabaseOptions,
+	cache caching.FederationCache,
+	isLocalServerName func(gomatrixserverlib.ServerName) bool,
+) (*Database, error) {
+	var d Database
+	var err error
+	if d.db, d.writer, err = base.DatabaseConnection(dbProperties, sqlutil.NewDummyWriter()); err != nil {
+		return nil, err
+	}
+	queue, err := NewPostgresRelayQueueTable(d.db)
+	if err != nil {
+		return nil, err
+	}
+	queueJSON, err := NewPostgresRelayQueueJSONTable(d.db)
+	if err != nil {
+		return nil, err
+	}
+	d.Database = shared.Database{
+		DB:                d.db,
+		IsLocalServerName: isLocalServerName,
+		Cache:             cache,
+		Writer:            d.writer,
+		RelayQueue:        queue,
+		RelayQueueJSON:    queueJSON,
+	}
+	return &d, nil
+}

relayapi/storage/shared/storage.go

@@ -0,0 +1,170 @@
+// Copyright 2022 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 shared
+
+import (
+	"context"
+	"database/sql"
+	"encoding/json"
+	"fmt"
+
+	"github.com/matrix-org/dendrite/federationapi/storage/shared/receipt"
+	"github.com/matrix-org/dendrite/internal/caching"
+	"github.com/matrix-org/dendrite/internal/sqlutil"
+	"github.com/matrix-org/dendrite/relayapi/storage/tables"
+	"github.com/matrix-org/gomatrixserverlib"
+)
+
+type Database struct {
+	DB                *sql.DB
+	IsLocalServerName func(gomatrixserverlib.ServerName) bool
+	Cache             caching.FederationCache
+	Writer            sqlutil.Writer
+	RelayQueue        tables.RelayQueue
+	RelayQueueJSON    tables.RelayQueueJSON
+}
+
+func (d *Database) StoreTransaction(
+	ctx context.Context,
+	transaction gomatrixserverlib.Transaction,
+) (*receipt.Receipt, error) {
+	var err error
+	jsonTransaction, err := json.Marshal(transaction)
+	if err != nil {
+		return nil, fmt.Errorf("failed to marshal: %w", err)
+	}
+
+	var nid int64
+	_ = d.Writer.Do(d.DB, nil, func(txn *sql.Tx) error {
+		nid, err = d.RelayQueueJSON.InsertQueueJSON(ctx, txn, string(jsonTransaction))
+		return err
+	})
+	if err != nil {
+		return nil, fmt.Errorf("d.insertQueueJSON: %w", err)
+	}
+
+	newReceipt := receipt.NewReceipt(nid)
+	return &newReceipt, nil
+}
+
+func (d *Database) AssociateTransactionWithDestinations(
+	ctx context.Context,
+	destinations map[gomatrixserverlib.UserID]struct{},
+	transactionID gomatrixserverlib.TransactionID,
+	dbReceipt *receipt.Receipt,
+) error {
+	err := d.Writer.Do(d.DB, nil, func(txn *sql.Tx) error {
+		var lastErr error
+		for destination := range destinations {
+			destination := destination
+			err := d.RelayQueue.InsertQueueEntry(
+				ctx,
+				txn,
+				transactionID,
+				destination.Domain(),
+				dbReceipt.GetNID(),
+			)
+			if err != nil {
+				lastErr = fmt.Errorf("d.insertQueueEntry: %w", err)
+			}
+		}
+		return lastErr
+	})
+
+	return err
+}
+
+func (d *Database) CleanTransactions(
+	ctx context.Context,
+	userID gomatrixserverlib.UserID,
+	receipts []*receipt.Receipt,
+) error {
+	nids := make([]int64, len(receipts))
+	for i, dbReceipt := range receipts {
+		nids[i] = dbReceipt.GetNID()
+	}
+
+	err := d.Writer.Do(d.DB, nil, func(txn *sql.Tx) error {
+		deleteEntryErr := d.RelayQueue.DeleteQueueEntries(ctx, txn, userID.Domain(), nids)
+		// TODO : If there are still queue entries for any of these nids for other destinations
+		// then we shouldn't delete the json entries.
+		// But this can't happen with the current api design.
+		// There will only ever be one server entry for each nid since each call to send_relay
+		// only accepts a single server name and inside there we create a new json entry.
+		// So for multiple destinations we would call send_relay multiple times and have multiple
+		// json entries of the same transaction.
+		//
+		// TLDR; this works as expected right now but can easily be optimised in the future.
+		deleteJSONErr := d.RelayQueueJSON.DeleteQueueJSON(ctx, txn, nids)
+
+		if deleteEntryErr != nil {
+			return fmt.Errorf("d.deleteQueueEntries: %w", deleteEntryErr)
+		}
+		if deleteJSONErr != nil {
+			return fmt.Errorf("d.deleteQueueJSON: %w", deleteJSONErr)
+		}
+		return nil
+	})
+
+	return err
+}
+
+func (d *Database) GetTransaction(
+	ctx context.Context,
+	userID gomatrixserverlib.UserID,
+) (*gomatrixserverlib.Transaction, *receipt.Receipt, error) {
+	entriesRequested := 1
+	nids, err := d.RelayQueue.SelectQueueEntries(ctx, nil, userID.Domain(), entriesRequested)
+	if err != nil {
+		return nil, nil, fmt.Errorf("d.SelectQueueEntries: %w", err)
+	}
+	if len(nids) == 0 {
+		return nil, nil, nil
+	}
+	firstNID := nids[0]
+
+	txns := map[int64][]byte{}
+	err = d.Writer.Do(d.DB, nil, func(txn *sql.Tx) error {
+		txns, err = d.RelayQueueJSON.SelectQueueJSON(ctx, txn, nids)
+		return err
+	})
+	if err != nil {
+		return nil, nil, fmt.Errorf("d.SelectQueueJSON: %w", err)
+	}
+
+	transaction := &gomatrixserverlib.Transaction{}
+	if _, ok := txns[firstNID]; !ok {
+		return nil, nil, fmt.Errorf("Failed retrieving json blob for transaction: %d", firstNID)
+	}
+
+	err = json.Unmarshal(txns[firstNID], transaction)
+	if err != nil {
+		return nil, nil, fmt.Errorf("Unmarshal transaction: %w", err)
+	}
+
+	newReceipt := receipt.NewReceipt(firstNID)
+	return transaction, &newReceipt, nil
+}
+
+func (d *Database) GetTransactionCount(
+	ctx context.Context,
+	userID gomatrixserverlib.UserID,
+) (int64, error) {
+	count, err := d.RelayQueue.SelectQueueEntryCount(ctx, nil, userID.Domain())
+	if err != nil {
+		return 0, fmt.Errorf("d.SelectQueueEntryCount: %w", err)
+	}
+	return count, nil
+}

relayapi/storage/sqlite3/relay_queue_json_table.go

@@ -0,0 +1,137 @@
+// Copyright 2022 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"
+	"fmt"
+	"strings"
+
+	"github.com/matrix-org/dendrite/internal"
+	"github.com/matrix-org/dendrite/internal/sqlutil"
+)
+
+const relayQueueJSONSchema = `
+-- The relayapi_queue_json table contains event contents that
+-- we are storing for future forwarding. 
+CREATE TABLE IF NOT EXISTS relayapi_queue_json (
+	-- The JSON NID. This allows cross-referencing to find the JSON blob.
+	json_nid INTEGER PRIMARY KEY AUTOINCREMENT,
+	-- The JSON body. Text so that we preserve UTF-8.
+	json_body TEXT NOT NULL
+);
+
+CREATE UNIQUE INDEX IF NOT EXISTS relayapi_queue_json_json_nid_idx
+	ON relayapi_queue_json (json_nid);
+`
+
+const insertQueueJSONSQL = "" +
+	"INSERT INTO relayapi_queue_json (json_body)" +
+	" VALUES ($1)"
+
+const deleteQueueJSONSQL = "" +
+	"DELETE FROM relayapi_queue_json WHERE json_nid IN ($1)"
+
+const selectQueueJSONSQL = "" +
+	"SELECT json_nid, json_body FROM relayapi_queue_json" +
+	" WHERE json_nid IN ($1)"
+
+type relayQueueJSONStatements struct {
+	db             *sql.DB
+	insertJSONStmt *sql.Stmt
+	//deleteJSONStmt *sql.Stmt - prepared at runtime due to variadic
+	//selectJSONStmt *sql.Stmt - prepared at runtime due to variadic
+}
+
+func NewSQLiteRelayQueueJSONTable(db *sql.DB) (s *relayQueueJSONStatements, err error) {
+	s = &relayQueueJSONStatements{
+		db: db,
+	}
+	_, err = db.Exec(relayQueueJSONSchema)
+	if err != nil {
+		return
+	}
+
+	return s, sqlutil.StatementList{
+		{&s.insertJSONStmt, insertQueueJSONSQL},
+	}.Prepare(db)
+}
+
+func (s *relayQueueJSONStatements) InsertQueueJSON(
+	ctx context.Context, txn *sql.Tx, json string,
+) (lastid int64, err error) {
+	stmt := sqlutil.TxStmt(txn, s.insertJSONStmt)
+	res, err := stmt.ExecContext(ctx, json)
+	if err != nil {
+		return 0, fmt.Errorf("stmt.QueryContext: %w", err)
+	}
+	lastid, err = res.LastInsertId()
+	if err != nil {
+		return 0, fmt.Errorf("res.LastInsertId: %w", err)
+	}
+	return
+}
+
+func (s *relayQueueJSONStatements) DeleteQueueJSON(
+	ctx context.Context, txn *sql.Tx, nids []int64,
+) error {
+	deleteSQL := strings.Replace(deleteQueueJSONSQL, "($1)", sqlutil.QueryVariadic(len(nids)), 1)
+	deleteStmt, err := txn.Prepare(deleteSQL)
+	if err != nil {
+		return fmt.Errorf("s.deleteQueueJSON s.db.Prepare: %w", err)
+	}
+
+	iNIDs := make([]interface{}, len(nids))
+	for k, v := range nids {
+		iNIDs[k] = v
+	}
+
+	stmt := sqlutil.TxStmt(txn, deleteStmt)
+	_, err = stmt.ExecContext(ctx, iNIDs...)
+	return err
+}
+
+func (s *relayQueueJSONStatements) SelectQueueJSON(
+	ctx context.Context, txn *sql.Tx, jsonNIDs []int64,
+) (map[int64][]byte, error) {
+	selectSQL := strings.Replace(selectQueueJSONSQL, "($1)", sqlutil.QueryVariadic(len(jsonNIDs)), 1)
+	selectStmt, err := txn.Prepare(selectSQL)
+	if err != nil {
+		return nil, fmt.Errorf("s.selectQueueJSON s.db.Prepare: %w", err)
+	}
+
+	iNIDs := make([]interface{}, len(jsonNIDs))
+	for k, v := range jsonNIDs {
+		iNIDs[k] = v
+	}
+
+	blobs := map[int64][]byte{}
+	stmt := sqlutil.TxStmt(txn, selectStmt)
+	rows, err := stmt.QueryContext(ctx, iNIDs...)
+	if err != nil {
+		return nil, fmt.Errorf("s.selectQueueJSON stmt.QueryContext: %w", err)
+	}
+	defer internal.CloseAndLogIfError(ctx, rows, "selectQueueJSON: rows.close() failed")
+	for rows.Next() {
+		var nid int64
+		var blob []byte
+		if err = rows.Scan(&nid, &blob); err != nil {
+			return nil, fmt.Errorf("s.selectQueueJSON rows.Scan: %w", err)
+		}
+		blobs[nid] = blob
+	}
+	return blobs, err
+}

relayapi/storage/sqlite3/relay_queue_table.go

@@ -0,0 +1,168 @@
+// Copyright 2022 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"
+	"fmt"
+	"strings"
+
+	"github.com/matrix-org/dendrite/internal"
+	"github.com/matrix-org/dendrite/internal/sqlutil"
+	"github.com/matrix-org/gomatrixserverlib"
+)
+
+const relayQueueSchema = `
+CREATE TABLE IF NOT EXISTS relayapi_queue (
+	-- The transaction ID that was generated before persisting the event.
+	transaction_id TEXT NOT NULL,
+	-- The domain part of the user ID the m.room.member event is for.
+	server_name TEXT NOT NULL,
+	-- The JSON NID from the relayapi_queue_json table.
+	json_nid BIGINT NOT NULL
+);
+
+CREATE UNIQUE INDEX IF NOT EXISTS relayapi_queue_queue_json_nid_idx
+	ON relayapi_queue (json_nid, server_name);
+CREATE INDEX IF NOT EXISTS relayapi_queue_json_nid_idx
+	ON relayapi_queue (json_nid);
+CREATE INDEX IF NOT EXISTS relayapi_queue_server_name_idx
+	ON relayapi_queue (server_name);
+`
+
+const insertQueueEntrySQL = "" +
+	"INSERT INTO relayapi_queue (transaction_id, server_name, json_nid)" +
+	" VALUES ($1, $2, $3)"
+
+const deleteQueueEntriesSQL = "" +
+	"DELETE FROM relayapi_queue WHERE server_name = $1 AND json_nid IN ($2)"
+
+const selectQueueEntriesSQL = "" +
+	"SELECT json_nid FROM relayapi_queue" +
+	" WHERE server_name = $1" +
+	" ORDER BY json_nid" +
+	" LIMIT $2"
+
+const selectQueueEntryCountSQL = "" +
+	"SELECT COUNT(*) FROM relayapi_queue" +
+	" WHERE server_name = $1"
+
+type relayQueueStatements struct {
+	db                        *sql.DB
+	insertQueueEntryStmt      *sql.Stmt
+	selectQueueEntriesStmt    *sql.Stmt
+	selectQueueEntryCountStmt *sql.Stmt
+	// deleteQueueEntriesStmt *sql.Stmt - prepared at runtime due to variadic
+}
+
+func NewSQLiteRelayQueueTable(
+	db *sql.DB,
+) (s *relayQueueStatements, err error) {
+	s = &relayQueueStatements{
+		db: db,
+	}
+	_, err = db.Exec(relayQueueSchema)
+	if err != nil {
+		return
+	}
+
+	return s, sqlutil.StatementList{
+		{&s.insertQueueEntryStmt, insertQueueEntrySQL},
+		{&s.selectQueueEntriesStmt, selectQueueEntriesSQL},
+		{&s.selectQueueEntryCountStmt, selectQueueEntryCountSQL},
+	}.Prepare(db)
+}
+
+func (s *relayQueueStatements) InsertQueueEntry(
+	ctx context.Context,
+	txn *sql.Tx,
+	transactionID gomatrixserverlib.TransactionID,
+	serverName gomatrixserverlib.ServerName,
+	nid int64,
+) error {
+	stmt := sqlutil.TxStmt(txn, s.insertQueueEntryStmt)
+	_, err := stmt.ExecContext(
+		ctx,
+		transactionID, // the transaction ID that we initially attempted
+		serverName,    // destination server name
+		nid,           // JSON blob NID
+	)
+	return err
+}
+
+func (s *relayQueueStatements) DeleteQueueEntries(
+	ctx context.Context,
+	txn *sql.Tx,
+	serverName gomatrixserverlib.ServerName,
+	jsonNIDs []int64,
+) error {
+	deleteSQL := strings.Replace(deleteQueueEntriesSQL, "($2)", sqlutil.QueryVariadicOffset(len(jsonNIDs), 1), 1)
+	deleteStmt, err := txn.Prepare(deleteSQL)
+	if err != nil {
+		return fmt.Errorf("s.deleteQueueEntries s.db.Prepare: %w", err)
+	}
+
+	params := make([]interface{}, len(jsonNIDs)+1)
+	params[0] = serverName
+	for k, v := range jsonNIDs {
+		params[k+1] = v
+	}
+
+	stmt := sqlutil.TxStmt(txn, deleteStmt)
+	_, err = stmt.ExecContext(ctx, params...)
+	return err
+}
+
+func (s *relayQueueStatements) SelectQueueEntries(
+	ctx context.Context,
+	txn *sql.Tx,
+	serverName gomatrixserverlib.ServerName,
+	limit int,
+) ([]int64, error) {
+	stmt := sqlutil.TxStmt(txn, s.selectQueueEntriesStmt)
+	rows, err := stmt.QueryContext(ctx, serverName, limit)
+	if err != nil {
+		return nil, err
+	}
+	defer internal.CloseAndLogIfError(ctx, rows, "queueFromStmt: rows.close() failed")
+	var result []int64
+	for rows.Next() {
+		var nid int64
+		if err = rows.Scan(&nid); err != nil {
+			return nil, err
+		}
+		result = append(result, nid)
+	}
+
+	return result, rows.Err()
+}
+
+func (s *relayQueueStatements) SelectQueueEntryCount(
+	ctx context.Context,
+	txn *sql.Tx,
+	serverName gomatrixserverlib.ServerName,
+) (int64, error) {
+	var count int64
+	stmt := sqlutil.TxStmt(txn, s.selectQueueEntryCountStmt)
+	err := stmt.QueryRowContext(ctx, serverName).Scan(&count)
+	if err == sql.ErrNoRows {
+		// It's acceptable for there to be no rows referencing a given
+		// JSON NID but it's not an error condition. Just return as if
+		// there's a zero count.
+		return 0, nil
+	}
+	return count, err
+}

relayapi/storage/sqlite3/storage.go

@@ -0,0 +1,64 @@
+// Copyright 2022 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 (
+	"database/sql"
+
+	"github.com/matrix-org/dendrite/internal/caching"
+	"github.com/matrix-org/dendrite/internal/sqlutil"
+	"github.com/matrix-org/dendrite/relayapi/storage/shared"
+	"github.com/matrix-org/dendrite/setup/base"
+	"github.com/matrix-org/dendrite/setup/config"
+	"github.com/matrix-org/gomatrixserverlib"
+)
+
+// Database stores information needed by the federation sender
+type Database struct {
+	shared.Database
+	db     *sql.DB
+	writer sqlutil.Writer
+}
+
+// NewDatabase opens a new database
+func NewDatabase(
+	base *base.BaseDendrite,
+	dbProperties *config.DatabaseOptions,
+	cache caching.FederationCache,
+	isLocalServerName func(gomatrixserverlib.ServerName) bool,
+) (*Database, error) {
+	var d Database
+	var err error
+	if d.db, d.writer, err = base.DatabaseConnection(dbProperties, sqlutil.NewExclusiveWriter()); err != nil {
+		return nil, err
+	}
+	queue, err := NewSQLiteRelayQueueTable(d.db)
+	if err != nil {
+		return nil, err
+	}
+	queueJSON, err := NewSQLiteRelayQueueJSONTable(d.db)
+	if err != nil {
+		return nil, err
+	}
+	d.Database = shared.Database{
+		DB:                d.db,
+		IsLocalServerName: isLocalServerName,
+		Cache:             cache,
+		Writer:            d.writer,
+		RelayQueue:        queue,
+		RelayQueueJSON:    queueJSON,
+	}
+	return &d, nil
+}

relayapi/storage/storage.go

@@ -0,0 +1,46 @@
+// Copyright 2022 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.
+
+//go:build !wasm
+// +build !wasm
+
+package storage
+
+import (
+	"fmt"
+
+	"github.com/matrix-org/dendrite/internal/caching"
+	"github.com/matrix-org/dendrite/relayapi/storage/postgres"
+	"github.com/matrix-org/dendrite/relayapi/storage/sqlite3"
+	"github.com/matrix-org/dendrite/setup/base"
+	"github.com/matrix-org/dendrite/setup/config"
+	"github.com/matrix-org/gomatrixserverlib"
+)
+
+// NewDatabase opens a new database
+func NewDatabase(
+	base *base.BaseDendrite,
+	dbProperties *config.DatabaseOptions,
+	cache caching.FederationCache,
+	isLocalServerName func(gomatrixserverlib.ServerName) bool,
+) (Database, error) {
+	switch {
+	case dbProperties.ConnectionString.IsSQLite():
+		return sqlite3.NewDatabase(base, dbProperties, cache, isLocalServerName)
+	case dbProperties.ConnectionString.IsPostgres():
+		return postgres.NewDatabase(base, dbProperties, cache, isLocalServerName)
+	default:
+		return nil, fmt.Errorf("unexpected database type")
+	}
+}

relayapi/storage/tables/interface.go

@@ -0,0 +1,66 @@
+// Copyright 2022 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 tables
+
+import (
+	"context"
+	"database/sql"
+
+	"github.com/matrix-org/gomatrixserverlib"
+)
+
+// RelayQueue table contains a mapping of server name to transaction id and the corresponding nid.
+// These are the transactions being stored for the given destination server.
+// The nids correspond to entries in the RelayQueueJSON table.
+type RelayQueue interface {
+	// Adds a new transaction_id: server_name mapping with associated json table nid to the table.
+	// Will ensure only one transaction id is present for each server_name: nid mapping.
+	// Adding duplicates will silently do nothing.
+	InsertQueueEntry(ctx context.Context, txn *sql.Tx, transactionID gomatrixserverlib.TransactionID, serverName gomatrixserverlib.ServerName, nid int64) error
+
+	// Removes multiple entries from the table corresponding the the list of nids provided.
+	// If any of the provided nids don't match a row in the table, that deletion is considered
+	// successful.
+	DeleteQueueEntries(ctx context.Context, txn *sql.Tx, serverName gomatrixserverlib.ServerName, jsonNIDs []int64) error
+
+	// Get a list of nids associated with the provided server name.
+	// Returns up to `limit` nids. The entries are returned oldest first.
+	// Will return an empty list if no matches were found.
+	SelectQueueEntries(ctx context.Context, txn *sql.Tx, serverName gomatrixserverlib.ServerName, limit int) ([]int64, error)
+
+	// Get the number of entries in the table associated with the provided server name.
+	// If there are no matching rows, a count of 0 is returned with err set to nil.
+	SelectQueueEntryCount(ctx context.Context, txn *sql.Tx, serverName gomatrixserverlib.ServerName) (int64, error)
+}
+
+// RelayQueueJSON table contains a map of nid to the raw transaction json.
+type RelayQueueJSON interface {
+	// Adds a new transaction to the table.
+	// Adding a duplicate transaction will result in a new row being added and a new unique nid.
+	// return: unique nid representing this entry.
+	InsertQueueJSON(ctx context.Context, txn *sql.Tx, json string) (int64, error)
+
+	// Removes multiple nids from the table.
+	// If any of the provided nids don't match a row in the table, that deletion is considered
+	// successful.
+	DeleteQueueJSON(ctx context.Context, txn *sql.Tx, nids []int64) error
+
+	// Get the transaction json corresponding to the provided nids.
+	// Will return a partial result containing any matching nid from the table.
+	// Will return an empty map if no matches were found.
+	// It is the caller's responsibility to deal with the results appropriately.
+	// return: map indexed by nid of each matching transaction json.
+	SelectQueueJSON(ctx context.Context, txn *sql.Tx, jsonNIDs []int64) (map[int64][]byte, error)
+}

relayapi/storage/tables/relay_queue_json_table_test.go

@@ -0,0 +1,173 @@
+// Copyright 2022 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 tables_test
+
+import (
+	"context"
+	"database/sql"
+	"encoding/json"
+	"testing"
+
+	"github.com/matrix-org/dendrite/internal/sqlutil"
+	"github.com/matrix-org/dendrite/relayapi/storage/postgres"
+	"github.com/matrix-org/dendrite/relayapi/storage/sqlite3"
+	"github.com/matrix-org/dendrite/relayapi/storage/tables"
+	"github.com/matrix-org/dendrite/setup/config"
+	"github.com/matrix-org/dendrite/test"
+	"github.com/matrix-org/gomatrixserverlib"
+	"github.com/stretchr/testify/assert"
+)
+
+const (
+	testOrigin = gomatrixserverlib.ServerName("kaer.morhen")
+)
+
+func mustCreateTransaction() gomatrixserverlib.Transaction {
+	txn := gomatrixserverlib.Transaction{}
+	txn.PDUs = []json.RawMessage{
+		[]byte(`{"auth_events":[["$0ok8ynDp7kjc95e3:kaer.morhen",{"sha256":"sWCi6Ckp9rDimQON+MrUlNRkyfZ2tjbPbWfg2NMB18Q"}],["$LEwEu0kxrtu5fOiS:kaer.morhen",{"sha256":"1aKajq6DWHru1R1HJjvdWMEavkJJHGaTmPvfuERUXaA"}]],"content":{"body":"Test Message"},"depth":5,"event_id":"$gl2T9l3qm0kUbiIJ:kaer.morhen","hashes":{"sha256":"Qx3nRMHLDPSL5hBAzuX84FiSSP0K0Kju2iFoBWH4Za8"},"origin":"kaer.morhen","origin_server_ts":0,"prev_events":[["$UKNe10XzYzG0TeA9:kaer.morhen",{"sha256":"KtSRyMjt0ZSjsv2koixTRCxIRCGoOp6QrKscsW97XRo"}]],"room_id":"!roomid:kaer.morhen","sender":"@userid:kaer.morhen","signatures":{"kaer.morhen":{"ed25519:auto":"sqDgv3EG7ml5VREzmT9aZeBpS4gAPNIaIeJOwqjDhY0GPU/BcpX5wY4R7hYLrNe5cChgV+eFy/GWm1Zfg5FfDg"}},"type":"m.room.message"}`),
+	}
+	txn.Origin = testOrigin
+
+	return txn
+}
+
+type RelayQueueJSONDatabase struct {
+	DB     *sql.DB
+	Writer sqlutil.Writer
+	Table  tables.RelayQueueJSON
+}
+
+func mustCreateQueueJSONTable(
+	t *testing.T,
+	dbType test.DBType,
+) (database RelayQueueJSONDatabase, close func()) {
+	t.Helper()
+	connStr, close := test.PrepareDBConnectionString(t, dbType)
+	db, err := sqlutil.Open(&config.DatabaseOptions{
+		ConnectionString: config.DataSource(connStr),
+	}, sqlutil.NewExclusiveWriter())
+	assert.NoError(t, err)
+	var tab tables.RelayQueueJSON
+	switch dbType {
+	case test.DBTypePostgres:
+		tab, err = postgres.NewPostgresRelayQueueJSONTable(db)
+		assert.NoError(t, err)
+	case test.DBTypeSQLite:
+		tab, err = sqlite3.NewSQLiteRelayQueueJSONTable(db)
+		assert.NoError(t, err)
+	}
+	assert.NoError(t, err)
+
+	database = RelayQueueJSONDatabase{
+		DB:     db,
+		Writer: sqlutil.NewDummyWriter(),
+		Table:  tab,
+	}
+	return database, close
+}
+
+func TestShoudInsertTransaction(t *testing.T) {
+	ctx := context.Background()
+	test.WithAllDatabases(t, func(t *testing.T, dbType test.DBType) {
+		db, close := mustCreateQueueJSONTable(t, dbType)
+		defer close()
+
+		transaction := mustCreateTransaction()
+		tx, err := json.Marshal(transaction)
+		if err != nil {
+			t.Fatalf("Invalid transaction: %s", err.Error())
+		}
+
+		_, err = db.Table.InsertQueueJSON(ctx, nil, string(tx))
+		if err != nil {
+			t.Fatalf("Failed inserting transaction: %s", err.Error())
+		}
+	})
+}
+
+func TestShouldRetrieveInsertedTransaction(t *testing.T) {
+	ctx := context.Background()
+	test.WithAllDatabases(t, func(t *testing.T, dbType test.DBType) {
+		db, close := mustCreateQueueJSONTable(t, dbType)
+		defer close()
+
+		transaction := mustCreateTransaction()
+		tx, err := json.Marshal(transaction)
+		if err != nil {
+			t.Fatalf("Invalid transaction: %s", err.Error())
+		}
+
+		nid, err := db.Table.InsertQueueJSON(ctx, nil, string(tx))
+		if err != nil {
+			t.Fatalf("Failed inserting transaction: %s", err.Error())
+		}
+
+		var storedJSON map[int64][]byte
+		_ = db.Writer.Do(db.DB, nil, func(txn *sql.Tx) error {
+			storedJSON, err = db.Table.SelectQueueJSON(ctx, txn, []int64{nid})
+			return err
+		})
+		if err != nil {
+			t.Fatalf("Failed retrieving transaction: %s", err.Error())
+		}
+
+		assert.Equal(t, 1, len(storedJSON))
+
+		var storedTx gomatrixserverlib.Transaction
+		json.Unmarshal(storedJSON[1], &storedTx)
+
+		assert.Equal(t, transaction, storedTx)
+	})
+}
+
+func TestShouldDeleteTransaction(t *testing.T) {
+	ctx := context.Background()
+	test.WithAllDatabases(t, func(t *testing.T, dbType test.DBType) {
+		db, close := mustCreateQueueJSONTable(t, dbType)
+		defer close()
+
+		transaction := mustCreateTransaction()
+		tx, err := json.Marshal(transaction)
+		if err != nil {
+			t.Fatalf("Invalid transaction: %s", err.Error())
+		}
+
+		nid, err := db.Table.InsertQueueJSON(ctx, nil, string(tx))
+		if err != nil {
+			t.Fatalf("Failed inserting transaction: %s", err.Error())
+		}
+
+		storedJSON := map[int64][]byte{}
+		_ = db.Writer.Do(db.DB, nil, func(txn *sql.Tx) error {
+			err = db.Table.DeleteQueueJSON(ctx, txn, []int64{nid})
+			return err
+		})
+		if err != nil {
+			t.Fatalf("Failed deleting transaction: %s", err.Error())
+		}
+
+		storedJSON = map[int64][]byte{}
+		_ = db.Writer.Do(db.DB, nil, func(txn *sql.Tx) error {
+			storedJSON, err = db.Table.SelectQueueJSON(ctx, txn, []int64{nid})
+			return err
+		})
+		if err != nil {
+			t.Fatalf("Failed retrieving transaction: %s", err.Error())
+		}
+
+		assert.Equal(t, 0, len(storedJSON))
+	})
+}

relayapi/storage/tables/relay_queue_table_test.go

@@ -0,0 +1,229 @@
+// Copyright 2022 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 tables_test
+
+import (
+	"context"
+	"database/sql"
+	"fmt"
+	"testing"
+	"time"
+
+	"github.com/matrix-org/dendrite/internal/sqlutil"
+	"github.com/matrix-org/dendrite/relayapi/storage/postgres"
+	"github.com/matrix-org/dendrite/relayapi/storage/sqlite3"
+	"github.com/matrix-org/dendrite/relayapi/storage/tables"
+	"github.com/matrix-org/dendrite/setup/config"
+	"github.com/matrix-org/dendrite/test"
+	"github.com/matrix-org/gomatrixserverlib"
+	"github.com/stretchr/testify/assert"
+)
+
+type RelayQueueDatabase struct {
+	DB     *sql.DB
+	Writer sqlutil.Writer
+	Table  tables.RelayQueue
+}
+
+func mustCreateQueueTable(
+	t *testing.T,
+	dbType test.DBType,
+) (database RelayQueueDatabase, close func()) {
+	t.Helper()
+	connStr, close := test.PrepareDBConnectionString(t, dbType)
+	db, err := sqlutil.Open(&config.DatabaseOptions{
+		ConnectionString: config.DataSource(connStr),
+	}, sqlutil.NewExclusiveWriter())
+	assert.NoError(t, err)
+	var tab tables.RelayQueue
+	switch dbType {
+	case test.DBTypePostgres:
+		tab, err = postgres.NewPostgresRelayQueueTable(db)
+		assert.NoError(t, err)
+	case test.DBTypeSQLite:
+		tab, err = sqlite3.NewSQLiteRelayQueueTable(db)
+		assert.NoError(t, err)
+	}
+	assert.NoError(t, err)
+
+	database = RelayQueueDatabase{
+		DB:     db,
+		Writer: sqlutil.NewDummyWriter(),
+		Table:  tab,
+	}
+	return database, close
+}
+
+func TestShoudInsertQueueTransaction(t *testing.T) {
+	ctx := context.Background()
+	test.WithAllDatabases(t, func(t *testing.T, dbType test.DBType) {
+		db, close := mustCreateQueueTable(t, dbType)
+		defer close()
+
+		transactionID := gomatrixserverlib.TransactionID(fmt.Sprintf("%d", time.Now().UnixNano()))
+		serverName := gomatrixserverlib.ServerName("domain")
+		nid := int64(1)
+		err := db.Table.InsertQueueEntry(ctx, nil, transactionID, serverName, nid)
+		if err != nil {
+			t.Fatalf("Failed inserting transaction: %s", err.Error())
+		}
+	})
+}
+
+func TestShouldRetrieveInsertedQueueTransaction(t *testing.T) {
+	ctx := context.Background()
+	test.WithAllDatabases(t, func(t *testing.T, dbType test.DBType) {
+		db, close := mustCreateQueueTable(t, dbType)
+		defer close()
+
+		transactionID := gomatrixserverlib.TransactionID(fmt.Sprintf("%d", time.Now().UnixNano()))
+		serverName := gomatrixserverlib.ServerName("domain")
+		nid := int64(1)
+
+		err := db.Table.InsertQueueEntry(ctx, nil, transactionID, serverName, nid)
+		if err != nil {
+			t.Fatalf("Failed inserting transaction: %s", err.Error())
+		}
+
+		retrievedNids, err := db.Table.SelectQueueEntries(ctx, nil, serverName, 10)
+		if err != nil {
+			t.Fatalf("Failed retrieving transaction: %s", err.Error())
+		}
+
+		assert.Equal(t, nid, retrievedNids[0])
+		assert.Equal(t, 1, len(retrievedNids))
+	})
+}
+
+func TestShouldRetrieveOldestInsertedQueueTransaction(t *testing.T) {
+	ctx := context.Background()
+	test.WithAllDatabases(t, func(t *testing.T, dbType test.DBType) {
+		db, close := mustCreateQueueTable(t, dbType)
+		defer close()
+
+		transactionID := gomatrixserverlib.TransactionID(fmt.Sprintf("%d", time.Now().UnixNano()))
+		serverName := gomatrixserverlib.ServerName("domain")
+		nid := int64(2)
+		err := db.Table.InsertQueueEntry(ctx, nil, transactionID, serverName, nid)
+		if err != nil {
+			t.Fatalf("Failed inserting transaction: %s", err.Error())
+		}
+
+		transactionID = gomatrixserverlib.TransactionID(fmt.Sprintf("%d", time.Now().UnixNano()))
+		serverName = gomatrixserverlib.ServerName("domain")
+		oldestNID := int64(1)
+		err = db.Table.InsertQueueEntry(ctx, nil, transactionID, serverName, oldestNID)
+		if err != nil {
+			t.Fatalf("Failed inserting transaction: %s", err.Error())
+		}
+
+		retrievedNids, err := db.Table.SelectQueueEntries(ctx, nil, serverName, 1)
+		if err != nil {
+			t.Fatalf("Failed retrieving transaction: %s", err.Error())
+		}
+
+		assert.Equal(t, oldestNID, retrievedNids[0])
+		assert.Equal(t, 1, len(retrievedNids))
+
+		retrievedNids, err = db.Table.SelectQueueEntries(ctx, nil, serverName, 10)
+		if err != nil {
+			t.Fatalf("Failed retrieving transaction: %s", err.Error())
+		}
+
+		assert.Equal(t, oldestNID, retrievedNids[0])
+		assert.Equal(t, nid, retrievedNids[1])
+		assert.Equal(t, 2, len(retrievedNids))
+	})
+}
+
+func TestShouldDeleteQueueTransaction(t *testing.T) {
+	ctx := context.Background()
+	test.WithAllDatabases(t, func(t *testing.T, dbType test.DBType) {
+		db, close := mustCreateQueueTable(t, dbType)
+		defer close()
+
+		transactionID := gomatrixserverlib.TransactionID(fmt.Sprintf("%d", time.Now().UnixNano()))
+		serverName := gomatrixserverlib.ServerName("domain")
+		nid := int64(1)
+
+		err := db.Table.InsertQueueEntry(ctx, nil, transactionID, serverName, nid)
+		if err != nil {
+			t.Fatalf("Failed inserting transaction: %s", err.Error())
+		}
+
+		_ = db.Writer.Do(db.DB, nil, func(txn *sql.Tx) error {
+			err = db.Table.DeleteQueueEntries(ctx, txn, serverName, []int64{nid})
+			return err
+		})
+		if err != nil {
+			t.Fatalf("Failed deleting transaction: %s", err.Error())
+		}
+
+		count, err := db.Table.SelectQueueEntryCount(ctx, nil, serverName)
+		if err != nil {
+			t.Fatalf("Failed retrieving transaction count: %s", err.Error())
+		}
+		assert.Equal(t, int64(0), count)
+	})
+}
+
+func TestShouldDeleteOnlySpecifiedQueueTransaction(t *testing.T) {
+	ctx := context.Background()
+	test.WithAllDatabases(t, func(t *testing.T, dbType test.DBType) {
+		db, close := mustCreateQueueTable(t, dbType)
+		defer close()
+
+		transactionID := gomatrixserverlib.TransactionID(fmt.Sprintf("%d", time.Now().UnixNano()))
+		serverName := gomatrixserverlib.ServerName("domain")
+		nid := int64(1)
+		transactionID2 := gomatrixserverlib.TransactionID(fmt.Sprintf("%d2", time.Now().UnixNano()))
+		serverName2 := gomatrixserverlib.ServerName("domain2")
+		nid2 := int64(2)
+		transactionID3 := gomatrixserverlib.TransactionID(fmt.Sprintf("%d3", time.Now().UnixNano()))
+
+		err := db.Table.InsertQueueEntry(ctx, nil, transactionID, serverName, nid)
+		if err != nil {
+			t.Fatalf("Failed inserting transaction: %s", err.Error())
+		}
+		err = db.Table.InsertQueueEntry(ctx, nil, transactionID2, serverName2, nid)
+		if err != nil {
+			t.Fatalf("Failed inserting transaction: %s", err.Error())
+		}
+		err = db.Table.InsertQueueEntry(ctx, nil, transactionID3, serverName, nid2)
+		if err != nil {
+			t.Fatalf("Failed inserting transaction: %s", err.Error())
+		}
+
+		_ = db.Writer.Do(db.DB, nil, func(txn *sql.Tx) error {
+			err = db.Table.DeleteQueueEntries(ctx, txn, serverName, []int64{nid})
+			return err
+		})
+		if err != nil {
+			t.Fatalf("Failed deleting transaction: %s", err.Error())
+		}
+
+		count, err := db.Table.SelectQueueEntryCount(ctx, nil, serverName)
+		if err != nil {
+			t.Fatalf("Failed retrieving transaction count: %s", err.Error())
+		}
+		assert.Equal(t, int64(1), count)
+
+		count, err = db.Table.SelectQueueEntryCount(ctx, nil, serverName2)
+		if err != nil {
+			t.Fatalf("Failed retrieving transaction count: %s", err.Error())
+		}
+		assert.Equal(t, int64(1), count)
+	})
+}

setup/base/base.go

@@ -595,6 +595,12 @@ func (b *BaseDendrite) WaitForShutdown() {
 			logrus.Warnf("failed to flush all Sentry events!")
 		}
 	}
+	if b.Fulltext != nil {
+		err := b.Fulltext.Close()
+		if err != nil {
+			logrus.Warnf("failed to close full text search!")
+		}
+	}
 
 	logrus.Warnf("Dendrite is exiting now")
 }

setup/config/config.go

@@ -62,6 +62,7 @@ type Dendrite struct {
 	RoomServer    RoomServer    `yaml:"room_server"`
 	SyncAPI       SyncAPI       `yaml:"sync_api"`
 	UserAPI       UserAPI       `yaml:"user_api"`
+	RelayAPI      RelayAPI      `yaml:"relay_api"`
 
 	MSCs MSCs `yaml:"mscs"`
 
@@ -349,6 +350,7 @@ func (c *Dendrite) Defaults(opts DefaultOpts) {
 	c.SyncAPI.Defaults(opts)
 	c.UserAPI.Defaults(opts)
 	c.AppServiceAPI.Defaults(opts)
+	c.RelayAPI.Defaults(opts)
 	c.MSCs.Defaults(opts)
 	c.Wiring()
 }
@@ -361,7 +363,7 @@ func (c *Dendrite) Verify(configErrs *ConfigErrors, isMonolith bool) {
 		&c.Global, &c.ClientAPI, &c.FederationAPI,
 		&c.KeyServer, &c.MediaAPI, &c.RoomServer,
 		&c.SyncAPI, &c.UserAPI,
-		&c.AppServiceAPI, &c.MSCs,
+		&c.AppServiceAPI, &c.RelayAPI, &c.MSCs,
 	} {
 		c.Verify(configErrs, isMonolith)
 	}
@@ -377,6 +379,7 @@ func (c *Dendrite) Wiring() {
 	c.SyncAPI.Matrix = &c.Global
 	c.UserAPI.Matrix = &c.Global
 	c.AppServiceAPI.Matrix = &c.Global
+	c.RelayAPI.Matrix = &c.Global
 	c.MSCs.Matrix = &c.Global
 
 	c.ClientAPI.Derived = &c.Derived

setup/config/config_federationapi.go

@@ -18,6 +18,12 @@ type FederationAPI struct {
 	// The default value is 16 if not specified, which is circa 18 hours.
 	FederationMaxRetries uint32 `yaml:"send_max_retries"`
 
+	// P2P Feature: How many consecutive failures that we should tolerate when
+	// sending federation requests to a specific server until we should assume they
+	// are offline. If we assume they are offline then we will attempt to send
+	// messages to their relay server if we know of one that is appropriate.
+	P2PFederationRetriesUntilAssumedOffline uint32 `yaml:"p2p_retries_until_assumed_offline"`
+
 	// 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"`
@@ -43,6 +49,7 @@ func (c *FederationAPI) Defaults(opts DefaultOpts) {
 		c.Database.Defaults(10)
 	}
 	c.FederationMaxRetries = 16
+	c.P2PFederationRetriesUntilAssumedOffline = 2
 	c.DisableTLSValidation = false
 	c.DisableHTTPKeepalives = false
 	if opts.Generate {

setup/config/config_relayapi.go

@@ -0,0 +1,52 @@
+// Copyright 2022 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 config
+
+type RelayAPI struct {
+	Matrix *Global `yaml:"-"`
+
+	InternalAPI InternalAPIOptions `yaml:"internal_api,omitempty"`
+	ExternalAPI ExternalAPIOptions `yaml:"external_api,omitempty"`
+
+	// The database stores information used by the relay queue to
+	// forward transactions to remote servers.
+	Database DatabaseOptions `yaml:"database,omitempty"`
+}
+
+func (c *RelayAPI) Defaults(opts DefaultOpts) {
+	if !opts.Monolithic {
+		c.InternalAPI.Listen = "http://localhost:7775"
+		c.InternalAPI.Connect = "http://localhost:7775"
+		c.ExternalAPI.Listen = "http://[::]:8075"
+		c.Database.Defaults(10)
+	}
+	if opts.Generate {
+		if !opts.Monolithic {
+			c.Database.ConnectionString = "file:relayapi.db"
+		}
+	}
+}
+
+func (c *RelayAPI) Verify(configErrs *ConfigErrors, isMonolith bool) {
+	if isMonolith { // polylith required configs below
+		return
+	}
+	if c.Matrix.DatabaseOptions.ConnectionString == "" {
+		checkNotEmpty(configErrs, "relay_api.database.connection_string", string(c.Database.ConnectionString))
+	}
+	checkURL(configErrs, "relay_api.external_api.listen", string(c.ExternalAPI.Listen))
+	checkURL(configErrs, "relay_api.internal_api.listen", string(c.InternalAPI.Listen))
+	checkURL(configErrs, "relay_api.internal_api.connect", string(c.InternalAPI.Connect))
+}

setup/config/config_test.go

@@ -20,11 +20,12 @@ import (
 	"testing"
 
 	"github.com/matrix-org/gomatrixserverlib"
+	"github.com/sirupsen/logrus"
 	"gopkg.in/yaml.v2"
 )
 
 func TestLoadConfigRelative(t *testing.T) {
-	_, err := loadConfig("/my/config/dir", []byte(testConfig),
+	cfg, err := loadConfig("/my/config/dir", []byte(testConfig),
 		mockReadFile{
 			"/my/config/dir/matrix_key.pem": testKey,
 			"/my/config/dir/tls_cert.pem":   testCert,
@@ -34,6 +35,15 @@ func TestLoadConfigRelative(t *testing.T) {
 	if err != nil {
 		t.Error("failed to load config:", err)
 	}
+
+	configErrors := &ConfigErrors{}
+	cfg.Verify(configErrors, false)
+	if len(*configErrors) > 0 {
+		for _, err := range *configErrors {
+			logrus.Errorf("Configuration error: %s", err)
+		}
+		t.Error("configuration verification failed")
+	}
 }
 
 const testConfig = `
@@ -68,6 +78,8 @@ global:
     display_name: "Server alerts"
     avatar: ""
     room_name: "Server Alerts"	
+  jetstream:
+    addresses: ["test"]
 app_service_api:
   internal_api:
     listen: http://localhost:7777
@@ -84,7 +96,7 @@ client_api:
     connect: http://localhost:7771
   external_api:
     listen: http://[::]:8071
-  registration_disabled: false
+  registration_disabled: true
   registration_shared_secret: ""
   enable_registration_captcha: false
   recaptcha_public_key: ""
@@ -112,6 +124,8 @@ federation_api:
     connect: http://localhost:7772
   external_api:
     listen: http://[::]:8072
+  database:
+    connection_string: file:federationapi.db
 key_server:
   internal_api:
     listen: http://localhost:7779
@@ -194,6 +208,17 @@ user_api:
     max_open_conns: 100
     max_idle_conns: 2
     conn_max_lifetime: -1
+relay_api:
+  internal_api:
+    listen: http://localhost:7775
+    connect: http://localhost:7775
+  external_api:
+    listen: http://[::]:8075
+  database:
+    connection_string: file:relayapi.db
+mscs:
+  database:
+    connection_string: file:mscs.db
 tracing:
   enabled: false
   jaeger:

setup/monolith.go

@@ -23,6 +23,8 @@ import (
 	"github.com/matrix-org/dendrite/internal/transactions"
 	keyAPI "github.com/matrix-org/dendrite/keyserver/api"
 	"github.com/matrix-org/dendrite/mediaapi"
+	"github.com/matrix-org/dendrite/relayapi"
+	relayAPI "github.com/matrix-org/dendrite/relayapi/api"
 	roomserverAPI "github.com/matrix-org/dendrite/roomserver/api"
 	"github.com/matrix-org/dendrite/setup/base"
 	"github.com/matrix-org/dendrite/setup/config"
@@ -44,6 +46,7 @@ type Monolith struct {
 	RoomserverAPI roomserverAPI.RoomserverInternalAPI
 	UserAPI       userapi.UserInternalAPI
 	KeyAPI        keyAPI.KeyInternalAPI
+	RelayAPI      relayAPI.RelayInternalAPI
 
 	// Optional
 	ExtPublicRoomsProvider   api.ExtraPublicRoomsProvider
@@ -71,4 +74,8 @@ func (m *Monolith) AddAllPublicRoutes(base *base.BaseDendrite) {
 	syncapi.AddPublicRoutes(
 		base, m.UserAPI, m.RoomserverAPI, m.KeyAPI,
 	)
+
+	if m.RelayAPI != nil {
+		relayapi.AddPublicRoutes(base, m.KeyRing, m.RelayAPI)
+	}
 }

test/db.go

@@ -101,7 +101,6 @@ func currentUser() string {
 // Returns the connection string to use and a close function which must be called when the test finishes.
 // Calling this function twice will return the same database, which will have data from previous tests
 // unless close() is called.
-// TODO: namespace for concurrent package tests
 func PrepareDBConnectionString(t *testing.T, dbType DBType) (connStr string, close func()) {
 	if dbType == DBTypeSQLite {
 		// this will be made in the t.TempDir, which is unique per test

test/memory_federation_db.go

@@ -0,0 +1,488 @@
+// Copyright 2022 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 test
+
+import (
+	"context"
+	"encoding/json"
+	"errors"
+	"sync"
+	"time"
+
+	"github.com/matrix-org/dendrite/federationapi/storage/shared/receipt"
+	"github.com/matrix-org/dendrite/federationapi/types"
+	"github.com/matrix-org/gomatrixserverlib"
+)
+
+var nidMutex sync.Mutex
+var nid = int64(0)
+
+type InMemoryFederationDatabase struct {
+	dbMutex            sync.Mutex
+	pendingPDUServers  map[gomatrixserverlib.ServerName]struct{}
+	pendingEDUServers  map[gomatrixserverlib.ServerName]struct{}
+	blacklistedServers map[gomatrixserverlib.ServerName]struct{}
+	assumedOffline     map[gomatrixserverlib.ServerName]struct{}
+	pendingPDUs        map[*receipt.Receipt]*gomatrixserverlib.HeaderedEvent
+	pendingEDUs        map[*receipt.Receipt]*gomatrixserverlib.EDU
+	associatedPDUs     map[gomatrixserverlib.ServerName]map[*receipt.Receipt]struct{}
+	associatedEDUs     map[gomatrixserverlib.ServerName]map[*receipt.Receipt]struct{}
+	relayServers       map[gomatrixserverlib.ServerName][]gomatrixserverlib.ServerName
+}
+
+func NewInMemoryFederationDatabase() *InMemoryFederationDatabase {
+	return &InMemoryFederationDatabase{
+		pendingPDUServers:  make(map[gomatrixserverlib.ServerName]struct{}),
+		pendingEDUServers:  make(map[gomatrixserverlib.ServerName]struct{}),
+		blacklistedServers: make(map[gomatrixserverlib.ServerName]struct{}),
+		assumedOffline:     make(map[gomatrixserverlib.ServerName]struct{}),
+		pendingPDUs:        make(map[*receipt.Receipt]*gomatrixserverlib.HeaderedEvent),
+		pendingEDUs:        make(map[*receipt.Receipt]*gomatrixserverlib.EDU),
+		associatedPDUs:     make(map[gomatrixserverlib.ServerName]map[*receipt.Receipt]struct{}),
+		associatedEDUs:     make(map[gomatrixserverlib.ServerName]map[*receipt.Receipt]struct{}),
+		relayServers:       make(map[gomatrixserverlib.ServerName][]gomatrixserverlib.ServerName),
+	}
+}
+
+func (d *InMemoryFederationDatabase) StoreJSON(
+	ctx context.Context,
+	js string,
+) (*receipt.Receipt, error) {
+	d.dbMutex.Lock()
+	defer d.dbMutex.Unlock()
+
+	var event gomatrixserverlib.HeaderedEvent
+	if err := json.Unmarshal([]byte(js), &event); err == nil {
+		nidMutex.Lock()
+		defer nidMutex.Unlock()
+		nid++
+		newReceipt := receipt.NewReceipt(nid)
+		d.pendingPDUs[&newReceipt] = &event
+		return &newReceipt, nil
+	}
+
+	var edu gomatrixserverlib.EDU
+	if err := json.Unmarshal([]byte(js), &edu); err == nil {
+		nidMutex.Lock()
+		defer nidMutex.Unlock()
+		nid++
+		newReceipt := receipt.NewReceipt(nid)
+		d.pendingEDUs[&newReceipt] = &edu
+		return &newReceipt, nil
+	}
+
+	return nil, errors.New("Failed to determine type of json to store")
+}
+
+func (d *InMemoryFederationDatabase) GetPendingPDUs(
+	ctx context.Context,
+	serverName gomatrixserverlib.ServerName,
+	limit int,
+) (pdus map[*receipt.Receipt]*gomatrixserverlib.HeaderedEvent, err error) {
+	d.dbMutex.Lock()
+	defer d.dbMutex.Unlock()
+
+	pduCount := 0
+	pdus = make(map[*receipt.Receipt]*gomatrixserverlib.HeaderedEvent)
+	if receipts, ok := d.associatedPDUs[serverName]; ok {
+		for dbReceipt := range receipts {
+			if event, ok := d.pendingPDUs[dbReceipt]; ok {
+				pdus[dbReceipt] = event
+				pduCount++
+				if pduCount == limit {
+					break
+				}
+			}
+		}
+	}
+	return pdus, nil
+}
+
+func (d *InMemoryFederationDatabase) GetPendingEDUs(
+	ctx context.Context,
+	serverName gomatrixserverlib.ServerName,
+	limit int,
+) (edus map[*receipt.Receipt]*gomatrixserverlib.EDU, err error) {
+	d.dbMutex.Lock()
+	defer d.dbMutex.Unlock()
+
+	eduCount := 0
+	edus = make(map[*receipt.Receipt]*gomatrixserverlib.EDU)
+	if receipts, ok := d.associatedEDUs[serverName]; ok {
+		for dbReceipt := range receipts {
+			if event, ok := d.pendingEDUs[dbReceipt]; ok {
+				edus[dbReceipt] = event
+				eduCount++
+				if eduCount == limit {
+					break
+				}
+			}
+		}
+	}
+	return edus, nil
+}
+
+func (d *InMemoryFederationDatabase) AssociatePDUWithDestinations(
+	ctx context.Context,
+	destinations map[gomatrixserverlib.ServerName]struct{},
+	dbReceipt *receipt.Receipt,
+) error {
+	d.dbMutex.Lock()
+	defer d.dbMutex.Unlock()
+
+	if _, ok := d.pendingPDUs[dbReceipt]; ok {
+		for destination := range destinations {
+			if _, ok := d.associatedPDUs[destination]; !ok {
+				d.associatedPDUs[destination] = make(map[*receipt.Receipt]struct{})
+			}
+			d.associatedPDUs[destination][dbReceipt] = struct{}{}
+		}
+
+		return nil
+	} else {
+		return errors.New("PDU doesn't exist")
+	}
+}
+
+func (d *InMemoryFederationDatabase) AssociateEDUWithDestinations(
+	ctx context.Context,
+	destinations map[gomatrixserverlib.ServerName]struct{},
+	dbReceipt *receipt.Receipt,
+	eduType string,
+	expireEDUTypes map[string]time.Duration,
+) error {
+	d.dbMutex.Lock()
+	defer d.dbMutex.Unlock()
+
+	if _, ok := d.pendingEDUs[dbReceipt]; ok {
+		for destination := range destinations {
+			if _, ok := d.associatedEDUs[destination]; !ok {
+				d.associatedEDUs[destination] = make(map[*receipt.Receipt]struct{})
+			}
+			d.associatedEDUs[destination][dbReceipt] = struct{}{}
+		}
+
+		return nil
+	} else {
+		return errors.New("EDU doesn't exist")
+	}
+}
+
+func (d *InMemoryFederationDatabase) CleanPDUs(
+	ctx context.Context,
+	serverName gomatrixserverlib.ServerName,
+	receipts []*receipt.Receipt,
+) error {
+	d.dbMutex.Lock()
+	defer d.dbMutex.Unlock()
+
+	if pdus, ok := d.associatedPDUs[serverName]; ok {
+		for _, dbReceipt := range receipts {
+			delete(pdus, dbReceipt)
+		}
+	}
+
+	return nil
+}
+
+func (d *InMemoryFederationDatabase) CleanEDUs(
+	ctx context.Context,
+	serverName gomatrixserverlib.ServerName,
+	receipts []*receipt.Receipt,
+) error {
+	d.dbMutex.Lock()
+	defer d.dbMutex.Unlock()
+
+	if edus, ok := d.associatedEDUs[serverName]; ok {
+		for _, dbReceipt := range receipts {
+			delete(edus, dbReceipt)
+		}
+	}
+
+	return nil
+}
+
+func (d *InMemoryFederationDatabase) GetPendingPDUCount(
+	ctx context.Context,
+	serverName gomatrixserverlib.ServerName,
+) (int64, error) {
+	d.dbMutex.Lock()
+	defer d.dbMutex.Unlock()
+
+	var count int64
+	if pdus, ok := d.associatedPDUs[serverName]; ok {
+		count = int64(len(pdus))
+	}
+	return count, nil
+}
+
+func (d *InMemoryFederationDatabase) GetPendingEDUCount(
+	ctx context.Context,
+	serverName gomatrixserverlib.ServerName,
+) (int64, error) {
+	d.dbMutex.Lock()
+	defer d.dbMutex.Unlock()
+
+	var count int64
+	if edus, ok := d.associatedEDUs[serverName]; ok {
+		count = int64(len(edus))
+	}
+	return count, nil
+}
+
+func (d *InMemoryFederationDatabase) GetPendingPDUServerNames(
+	ctx context.Context,
+) ([]gomatrixserverlib.ServerName, error) {
+	d.dbMutex.Lock()
+	defer d.dbMutex.Unlock()
+
+	servers := []gomatrixserverlib.ServerName{}
+	for server := range d.pendingPDUServers {
+		servers = append(servers, server)
+	}
+	return servers, nil
+}
+
+func (d *InMemoryFederationDatabase) GetPendingEDUServerNames(
+	ctx context.Context,
+) ([]gomatrixserverlib.ServerName, error) {
+	d.dbMutex.Lock()
+	defer d.dbMutex.Unlock()
+
+	servers := []gomatrixserverlib.ServerName{}
+	for server := range d.pendingEDUServers {
+		servers = append(servers, server)
+	}
+	return servers, nil
+}
+
+func (d *InMemoryFederationDatabase) AddServerToBlacklist(
+	serverName gomatrixserverlib.ServerName,
+) error {
+	d.dbMutex.Lock()
+	defer d.dbMutex.Unlock()
+
+	d.blacklistedServers[serverName] = struct{}{}
+	return nil
+}
+
+func (d *InMemoryFederationDatabase) RemoveServerFromBlacklist(
+	serverName gomatrixserverlib.ServerName,
+) error {
+	d.dbMutex.Lock()
+	defer d.dbMutex.Unlock()
+
+	delete(d.blacklistedServers, serverName)
+	return nil
+}
+
+func (d *InMemoryFederationDatabase) RemoveAllServersFromBlacklist() error {
+	d.dbMutex.Lock()
+	defer d.dbMutex.Unlock()
+
+	d.blacklistedServers = make(map[gomatrixserverlib.ServerName]struct{})
+	return nil
+}
+
+func (d *InMemoryFederationDatabase) IsServerBlacklisted(
+	serverName gomatrixserverlib.ServerName,
+) (bool, error) {
+	d.dbMutex.Lock()
+	defer d.dbMutex.Unlock()
+
+	isBlacklisted := false
+	if _, ok := d.blacklistedServers[serverName]; ok {
+		isBlacklisted = true
+	}
+
+	return isBlacklisted, nil
+}
+
+func (d *InMemoryFederationDatabase) SetServerAssumedOffline(
+	ctx context.Context,
+	serverName gomatrixserverlib.ServerName,
+) error {
+	d.dbMutex.Lock()
+	defer d.dbMutex.Unlock()
+
+	d.assumedOffline[serverName] = struct{}{}
+	return nil
+}
+
+func (d *InMemoryFederationDatabase) RemoveServerAssumedOffline(
+	ctx context.Context,
+	serverName gomatrixserverlib.ServerName,
+) error {
+	d.dbMutex.Lock()
+	defer d.dbMutex.Unlock()
+
+	delete(d.assumedOffline, serverName)
+	return nil
+}
+
+func (d *InMemoryFederationDatabase) RemoveAllServersAssumedOffine(
+	ctx context.Context,
+) error {
+	d.dbMutex.Lock()
+	defer d.dbMutex.Unlock()
+
+	d.assumedOffline = make(map[gomatrixserverlib.ServerName]struct{})
+	return nil
+}
+
+func (d *InMemoryFederationDatabase) IsServerAssumedOffline(
+	ctx context.Context,
+	serverName gomatrixserverlib.ServerName,
+) (bool, error) {
+	d.dbMutex.Lock()
+	defer d.dbMutex.Unlock()
+
+	assumedOffline := false
+	if _, ok := d.assumedOffline[serverName]; ok {
+		assumedOffline = true
+	}
+
+	return assumedOffline, nil
+}
+
+func (d *InMemoryFederationDatabase) P2PGetRelayServersForServer(
+	ctx context.Context,
+	serverName gomatrixserverlib.ServerName,
+) ([]gomatrixserverlib.ServerName, error) {
+	d.dbMutex.Lock()
+	defer d.dbMutex.Unlock()
+
+	knownRelayServers := []gomatrixserverlib.ServerName{}
+	if relayServers, ok := d.relayServers[serverName]; ok {
+		knownRelayServers = relayServers
+	}
+
+	return knownRelayServers, nil
+}
+
+func (d *InMemoryFederationDatabase) P2PAddRelayServersForServer(
+	ctx context.Context,
+	serverName gomatrixserverlib.ServerName,
+	relayServers []gomatrixserverlib.ServerName,
+) error {
+	d.dbMutex.Lock()
+	defer d.dbMutex.Unlock()
+
+	if knownRelayServers, ok := d.relayServers[serverName]; ok {
+		for _, relayServer := range relayServers {
+			alreadyKnown := false
+			for _, knownRelayServer := range knownRelayServers {
+				if relayServer == knownRelayServer {
+					alreadyKnown = true
+				}
+			}
+			if !alreadyKnown {
+				d.relayServers[serverName] = append(d.relayServers[serverName], relayServer)
+			}
+		}
+	} else {
+		d.relayServers[serverName] = relayServers
+	}
+
+	return nil
+}
+
+func (d *InMemoryFederationDatabase) FetchKeys(ctx context.Context, requests map[gomatrixserverlib.PublicKeyLookupRequest]gomatrixserverlib.Timestamp) (map[gomatrixserverlib.PublicKeyLookupRequest]gomatrixserverlib.PublicKeyLookupResult, error) {
+	return nil, nil
+}
+
+func (d *InMemoryFederationDatabase) FetcherName() string {
+	return ""
+}
+
+func (d *InMemoryFederationDatabase) StoreKeys(ctx context.Context, results map[gomatrixserverlib.PublicKeyLookupRequest]gomatrixserverlib.PublicKeyLookupResult) error {
+	return nil
+}
+
+func (d *InMemoryFederationDatabase) UpdateRoom(ctx context.Context, roomID string, addHosts []types.JoinedHost, removeHosts []string, purgeRoomFirst bool) (joinedHosts []types.JoinedHost, err error) {
+	return nil, nil
+}
+
+func (d *InMemoryFederationDatabase) GetJoinedHosts(ctx context.Context, roomID string) ([]types.JoinedHost, error) {
+	return nil, nil
+}
+
+func (d *InMemoryFederationDatabase) GetAllJoinedHosts(ctx context.Context) ([]gomatrixserverlib.ServerName, error) {
+	return nil, nil
+}
+
+func (d *InMemoryFederationDatabase) GetJoinedHostsForRooms(ctx context.Context, roomIDs []string, excludeSelf, excludeBlacklisted bool) ([]gomatrixserverlib.ServerName, error) {
+	return nil, nil
+}
+
+func (d *InMemoryFederationDatabase) RemoveAllServersAssumedOffline(ctx context.Context) error {
+	return nil
+}
+
+func (d *InMemoryFederationDatabase) P2PRemoveRelayServersForServer(ctx context.Context, serverName gomatrixserverlib.ServerName, relayServers []gomatrixserverlib.ServerName) error {
+	return nil
+}
+
+func (d *InMemoryFederationDatabase) P2PRemoveAllRelayServersForServer(ctx context.Context, serverName gomatrixserverlib.ServerName) error {
+	return nil
+}
+
+func (d *InMemoryFederationDatabase) AddOutboundPeek(ctx context.Context, serverName gomatrixserverlib.ServerName, roomID, peekID string, renewalInterval int64) error {
+	return nil
+}
+
+func (d *InMemoryFederationDatabase) RenewOutboundPeek(ctx context.Context, serverName gomatrixserverlib.ServerName, roomID, peekID string, renewalInterval int64) error {
+	return nil
+}
+
+func (d *InMemoryFederationDatabase) GetOutboundPeek(ctx context.Context, serverName gomatrixserverlib.ServerName, roomID, peekID string) (*types.OutboundPeek, error) {
+	return nil, nil
+}
+
+func (d *InMemoryFederationDatabase) GetOutboundPeeks(ctx context.Context, roomID string) ([]types.OutboundPeek, error) {
+	return nil, nil
+}
+
+func (d *InMemoryFederationDatabase) AddInboundPeek(ctx context.Context, serverName gomatrixserverlib.ServerName, roomID, peekID string, renewalInterval int64) error {
+	return nil
+}
+
+func (d *InMemoryFederationDatabase) RenewInboundPeek(ctx context.Context, serverName gomatrixserverlib.ServerName, roomID, peekID string, renewalInterval int64) error {
+	return nil
+}
+
+func (d *InMemoryFederationDatabase) GetInboundPeek(ctx context.Context, serverName gomatrixserverlib.ServerName, roomID, peekID string) (*types.InboundPeek, error) {
+	return nil, nil
+}
+
+func (d *InMemoryFederationDatabase) GetInboundPeeks(ctx context.Context, roomID string) ([]types.InboundPeek, error) {
+	return nil, nil
+}
+
+func (d *InMemoryFederationDatabase) UpdateNotaryKeys(ctx context.Context, serverName gomatrixserverlib.ServerName, serverKeys gomatrixserverlib.ServerKeys) error {
+	return nil
+}
+
+func (d *InMemoryFederationDatabase) GetNotaryKeys(ctx context.Context, serverName gomatrixserverlib.ServerName, optKeyIDs []gomatrixserverlib.KeyID) ([]gomatrixserverlib.ServerKeys, error) {
+	return nil, nil
+}
+
+func (d *InMemoryFederationDatabase) DeleteExpiredEDUs(ctx context.Context) error {
+	return nil
+}
+
+func (d *InMemoryFederationDatabase) PurgeRoom(ctx context.Context, roomID string) error {
+	return nil
+}

test/memory_relay_db.go

@@ -0,0 +1,140 @@
+// Copyright 2022 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 test
+
+import (
+	"context"
+	"database/sql"
+	"encoding/json"
+	"sync"
+
+	"github.com/matrix-org/gomatrixserverlib"
+)
+
+type InMemoryRelayDatabase struct {
+	nid          int64
+	nidMutex     sync.Mutex
+	transactions map[int64]json.RawMessage
+	associations map[gomatrixserverlib.ServerName][]int64
+}
+
+func NewInMemoryRelayDatabase() *InMemoryRelayDatabase {
+	return &InMemoryRelayDatabase{
+		nid:          1,
+		nidMutex:     sync.Mutex{},
+		transactions: make(map[int64]json.RawMessage),
+		associations: make(map[gomatrixserverlib.ServerName][]int64),
+	}
+}
+
+func (d *InMemoryRelayDatabase) InsertQueueEntry(
+	ctx context.Context,
+	txn *sql.Tx,
+	transactionID gomatrixserverlib.TransactionID,
+	serverName gomatrixserverlib.ServerName,
+	nid int64,
+) error {
+	if _, ok := d.associations[serverName]; !ok {
+		d.associations[serverName] = []int64{}
+	}
+	d.associations[serverName] = append(d.associations[serverName], nid)
+	return nil
+}
+
+func (d *InMemoryRelayDatabase) DeleteQueueEntries(
+	ctx context.Context,
+	txn *sql.Tx,
+	serverName gomatrixserverlib.ServerName,
+	jsonNIDs []int64,
+) error {
+	for _, nid := range jsonNIDs {
+		for index, associatedNID := range d.associations[serverName] {
+			if associatedNID == nid {
+				d.associations[serverName] = append(d.associations[serverName][:index], d.associations[serverName][index+1:]...)
+			}
+		}
+	}
+
+	return nil
+}
+
+func (d *InMemoryRelayDatabase) SelectQueueEntries(
+	ctx context.Context,
+	txn *sql.Tx, serverName gomatrixserverlib.ServerName,
+	limit int,
+) ([]int64, error) {
+	results := []int64{}
+	resultCount := limit
+	if limit > len(d.associations[serverName]) {
+		resultCount = len(d.associations[serverName])
+	}
+	if resultCount > 0 {
+		for i := 0; i < resultCount; i++ {
+			results = append(results, d.associations[serverName][i])
+		}
+	}
+
+	return results, nil
+}
+
+func (d *InMemoryRelayDatabase) SelectQueueEntryCount(
+	ctx context.Context,
+	txn *sql.Tx,
+	serverName gomatrixserverlib.ServerName,
+) (int64, error) {
+	return int64(len(d.associations[serverName])), nil
+}
+
+func (d *InMemoryRelayDatabase) InsertQueueJSON(
+	ctx context.Context,
+	txn *sql.Tx,
+	json string,
+) (int64, error) {
+	d.nidMutex.Lock()
+	defer d.nidMutex.Unlock()
+
+	nid := d.nid
+	d.transactions[nid] = []byte(json)
+	d.nid++
+
+	return nid, nil
+}
+
+func (d *InMemoryRelayDatabase) DeleteQueueJSON(
+	ctx context.Context,
+	txn *sql.Tx,
+	nids []int64,
+) error {
+	for _, nid := range nids {
+		delete(d.transactions, nid)
+	}
+
+	return nil
+}
+
+func (d *InMemoryRelayDatabase) SelectQueueJSON(
+	ctx context.Context,
+	txn *sql.Tx,
+	jsonNIDs []int64,
+) (map[int64][]byte, error) {
+	result := make(map[int64][]byte)
+	for _, nid := range jsonNIDs {
+		if transaction, ok := d.transactions[nid]; ok {
+			result[nid] = transaction
+		}
+	}
+
+	return result, nil
+}

test/testrig/base.go

@@ -67,9 +67,10 @@ func CreateBaseDendrite(t *testing.T, dbType test.DBType) (*base.BaseDendrite, f
 	case test.DBTypeSQLite:
 		cfg.Defaults(config.DefaultOpts{
 			Generate:   true,
-			Monolithic: false, // because we need a database per component
+			Monolithic: true,
 		})
 		cfg.Global.ServerName = "test"
+
 		// use a distinct prefix else concurrent postgres/sqlite runs will clash since NATS will use
 		// the file system event with InMemory=true :(
 		cfg.Global.JetStream.TopicPrefix = fmt.Sprintf("Test_%d_", dbType)
@@ -83,6 +84,7 @@ func CreateBaseDendrite(t *testing.T, dbType test.DBType) (*base.BaseDendrite, f
 		cfg.RoomServer.Database.ConnectionString = config.DataSource(filepath.Join("file://", tempDir, "roomserver.db"))
 		cfg.SyncAPI.Database.ConnectionString = config.DataSource(filepath.Join("file://", tempDir, "syncapi.db"))
 		cfg.UserAPI.AccountDatabase.ConnectionString = config.DataSource(filepath.Join("file://", tempDir, "userapi.db"))
+		cfg.RelayAPI.Database.ConnectionString = config.DataSource(filepath.Join("file://", tempDir, "relayapi.db"))
 
 		base := base.NewBaseDendrite(&cfg, "Test", base.DisableMetrics)
 		return base, func() {