Yggdrasil demo updates ("Bare QUIC")

Squashed commit of the following:

commit 86c2388e13ffdbabdd50cea205652dccc40e1860
Merge: b0a3ee6c f5e7e751
Author: Neil Alexander <neilalexander@users.noreply.github.com>
Date:   Thu Jul 16 13:47:10 2020 +0100

    Merge branch 'master' into neilalexander/yggbarequic

commit b0a3ee6c5c
Author: Neil Alexander <neilalexander@users.noreply.github.com>
Date:   Thu Jul 16 13:42:22 2020 +0100

    Add support for broadcasting wake-up EDUs to known hosts

commit 8a5c2020b3
Author: Neil Alexander <neilalexander@users.noreply.github.com>
Date:   Thu Jul 16 13:42:10 2020 +0100

    Bare QUIC demo working

commit d3939b3d65
Author: Neil Alexander <neilalexander@users.noreply.github.com>
Date:   Wed Jul 15 11:42:43 2020 +0100

    Support bare Yggdrasil sessions with encrypted QUIC

build/gobind/monolith.go

@@ -3,7 +3,6 @@ package gobind
 import (
 	"context"
 	"crypto/tls"
-	"encoding/hex"
 	"fmt"
 	"net"
 	"net/http"
@@ -25,7 +24,6 @@ import (
 	"github.com/matrix-org/dendrite/userapi"
 	"github.com/matrix-org/gomatrixserverlib"
 	"github.com/sirupsen/logrus"
-	"github.com/yggdrasil-network/yggdrasil-go/src/crypto"
 	"go.uber.org/atomic"
 )
 
@@ -169,33 +167,6 @@ func (m *DendriteMonolith) Start() {
 		base.UseHTTPAPIs,
 	)
 
-	ygg.NewSession = func(serverName gomatrixserverlib.ServerName) {
-		logrus.Infof("Found new session %q", serverName)
-		time.Sleep(time.Second * 3)
-		req := &api.PerformServersAliveRequest{
-			Servers: []gomatrixserverlib.ServerName{serverName},
-		}
-		res := &api.PerformServersAliveResponse{}
-		if err := fsAPI.PerformServersAlive(context.TODO(), req, res); err != nil {
-			logrus.WithError(err).Warn("Failed to notify server alive due to new session")
-		}
-	}
-
-	ygg.NotifyLinkNew(func(_ crypto.BoxPubKey, sigPubKey crypto.SigPubKey, linkType, remote string) {
-		serverName := hex.EncodeToString(sigPubKey[:])
-		logrus.Infof("Found new peer %q", serverName)
-		time.Sleep(time.Second * 3)
-		req := &api.PerformServersAliveRequest{
-			Servers: []gomatrixserverlib.ServerName{
-				gomatrixserverlib.ServerName(serverName),
-			},
-		}
-		res := &api.PerformServersAliveResponse{}
-		if err := fsAPI.PerformServersAlive(context.TODO(), req, res); err != nil {
-			logrus.WithError(err).Warn("Failed to notify server alive due to new session")
-		}
-	})
-
 	// Build both ends of a HTTP multiplex.
 	m.httpServer = &http.Server{
 		Addr:         ":0",
@@ -209,28 +180,22 @@ func (m *DendriteMonolith) Start() {
 		Handler: base.BaseMux,
 	}
 
-	m.Resume()
-}
-
-func (m *DendriteMonolith) Resume() {
-	logrus.Info("Resuming monolith")
-	if listener, err := net.Listen("tcp", "localhost:65432"); err == nil {
-		m.listener = listener
-	}
-	if m.yggListening.CAS(false, true) {
-		go func() {
-			m.logger.Info("Listening on ", m.YggdrasilNode.DerivedServerName())
-			m.logger.Fatal(m.httpServer.Serve(m.YggdrasilNode))
-			m.yggListening.Store(false)
-		}()
-	}
-	if m.httpListening.CAS(false, true) {
-		go func() {
-			m.logger.Info("Listening on ", m.BaseURL())
-			m.logger.Fatal(m.httpServer.Serve(m.listener))
-			m.httpListening.Store(false)
-		}()
-	}
+	go func() {
+		logger.Info("Listening on ", ygg.DerivedServerName())
+		logger.Fatal(httpServer.Serve(ygg))
+	}()
+	go func() {
+		logger.Info("Listening on ", m.BaseURL())
+		logger.Fatal(httpServer.Serve(m.listener))
+	}()
+	go func() {
+		logrus.Info("Sending wake-up message to known nodes")
+		req := &api.PerformBroadcastEDURequest{}
+		res := &api.PerformBroadcastEDUResponse{}
+		if err := fsAPI.PerformBroadcastEDU(context.TODO(), req, res); err != nil {
+			logrus.WithError(err).Error("Failed to send wake-up message to known nodes")
+		}
+	}()
 }
 
 func (m *DendriteMonolith) Suspend() {

cmd/dendrite-demo-yggdrasil/main.go

@@ -17,7 +17,6 @@ package main
 import (
 	"context"
 	"crypto/tls"
-	"encoding/hex"
 	"flag"
 	"fmt"
 	"net"
@@ -42,7 +41,6 @@ import (
 	"github.com/matrix-org/dendrite/roomserver"
 	"github.com/matrix-org/dendrite/userapi"
 	"github.com/matrix-org/gomatrixserverlib"
-	"github.com/yggdrasil-network/yggdrasil-go/src/crypto"
 
 	"github.com/sirupsen/logrus"
 )
@@ -158,31 +156,6 @@ func main() {
 		base.UseHTTPAPIs,
 	)
 
-	ygg.NewSession = func(serverName gomatrixserverlib.ServerName) {
-		logrus.Infof("Found new session %q", serverName)
-		req := &api.PerformServersAliveRequest{
-			Servers: []gomatrixserverlib.ServerName{serverName},
-		}
-		res := &api.PerformServersAliveResponse{}
-		if err := fsAPI.PerformServersAlive(context.TODO(), req, res); err != nil {
-			logrus.WithError(err).Warn("Failed to notify server alive due to new session")
-		}
-	}
-
-	ygg.NotifyLinkNew(func(_ crypto.BoxPubKey, sigPubKey crypto.SigPubKey, linkType, remote string) {
-		serverName := hex.EncodeToString(sigPubKey[:])
-		logrus.Infof("Found new peer %q", serverName)
-		req := &api.PerformServersAliveRequest{
-			Servers: []gomatrixserverlib.ServerName{
-				gomatrixserverlib.ServerName(serverName),
-			},
-		}
-		res := &api.PerformServersAliveResponse{}
-		if err := fsAPI.PerformServersAlive(context.TODO(), req, res); err != nil {
-			logrus.WithError(err).Warn("Failed to notify server alive due to new session")
-		}
-	})
-
 	// Build both ends of a HTTP multiplex.
 	httpServer := &http.Server{
 		Addr:         ":0",
@@ -205,6 +178,14 @@ func main() {
 		logrus.Info("Listening on ", httpBindAddr)
 		logrus.Fatal(http.ListenAndServe(httpBindAddr, base.BaseMux))
 	}()
+	go func() {
+		logrus.Info("Sending wake-up message to known nodes")
+		req := &api.PerformBroadcastEDURequest{}
+		res := &api.PerformBroadcastEDUResponse{}
+		if err := fsAPI.PerformBroadcastEDU(context.TODO(), req, res); err != nil {
+			logrus.WithError(err).Error("Failed to send wake-up message to known nodes")
+		}
+	}()
 
 	select {}
 }

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

@@ -1,35 +1,13 @@
 package yggconn
 
 import (
-	"context"
-	"crypto/ed25519"
-	"encoding/hex"
-	"fmt"
-	"net"
 	"net/http"
-	"strings"
 	"time"
 
-	"github.com/matrix-org/dendrite/cmd/dendrite-demo-yggdrasil/convert"
 	"github.com/matrix-org/dendrite/internal/setup"
 	"github.com/matrix-org/gomatrixserverlib"
 )
 
-func (n *Node) yggdialer(_, address string) (net.Conn, error) {
-	tokens := strings.Split(address, ":")
-	raw, err := hex.DecodeString(tokens[0])
-	if err != nil {
-		return nil, fmt.Errorf("hex.DecodeString: %w", err)
-	}
-	converted := convert.Ed25519PublicKeyToCurve25519(ed25519.PublicKey(raw))
-	convhex := hex.EncodeToString(converted)
-	return n.Dial("curve25519", convhex)
-}
-
-func (n *Node) yggdialerctx(ctx context.Context, network, address string) (net.Conn, error) {
-	return n.yggdialer(network, address)
-}
-
 type yggroundtripper struct {
 	inner *http.Transport
 }
@@ -49,7 +27,7 @@ func (n *Node) CreateClient(
 				TLSHandshakeTimeout:   20 * time.Second,
 				ResponseHeaderTimeout: 10 * time.Second,
 				IdleConnTimeout:       60 * time.Second,
-				DialContext:           n.yggdialerctx,
+				DialContext:           n.DialerContext,
 			},
 		},
 	)
@@ -66,7 +44,8 @@ func (n *Node) CreateFederationClient(
 				TLSHandshakeTimeout:   20 * time.Second,
 				ResponseHeaderTimeout: 10 * time.Second,
 				IdleConnTimeout:       60 * time.Second,
-				DialContext:           n.yggdialerctx,
+				DialContext:           n.DialerContext,
+				TLSClientConfig:       n.tlsConfig,
 			},
 		},
 	)

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

@@ -20,6 +20,7 @@ import (
 	"crypto/tls"
 	"encoding/hex"
 	"encoding/json"
+	"errors"
 	"fmt"
 	"io/ioutil"
 	"log"
@@ -33,9 +34,7 @@ import (
 	"github.com/matrix-org/dendrite/cmd/dendrite-demo-yggdrasil/convert"
 	"github.com/matrix-org/gomatrixserverlib"
 
-	yggdrasiladmin "github.com/yggdrasil-network/yggdrasil-go/src/admin"
 	yggdrasilconfig "github.com/yggdrasil-network/yggdrasil-go/src/config"
-	"github.com/yggdrasil-network/yggdrasil-go/src/crypto"
 	yggdrasilmulticast "github.com/yggdrasil-network/yggdrasil-go/src/multicast"
 	"github.com/yggdrasil-network/yggdrasil-go/src/yggdrasil"
 
@@ -46,10 +45,8 @@ type Node struct {
 	core       *yggdrasil.Core
 	config     *yggdrasilconfig.NodeConfig
 	state      *yggdrasilconfig.NodeState
-	admin      *yggdrasiladmin.AdminSocket
 	multicast  *yggdrasilmulticast.Multicast
 	log        *gologme.Logger
-	packetConn *yggdrasil.PacketConn
 	listener   quic.Listener
 	tlsConfig  *tls.Config
 	quicConfig *quic.Config
@@ -58,15 +55,10 @@ type Node struct {
 	NewSession func(remote gomatrixserverlib.ServerName)
 }
 
-func (n *Node) BuildName() string {
-	return "dendrite"
-}
-
-func (n *Node) BuildVersion() string {
-	return "dev"
-}
-
 func (n *Node) Dialer(_, address string) (net.Conn, error) {
+	if len(n.core.GetSwitchPeers()) == 0 {
+		return nil, errors.New("no peer connections available")
+	}
 	tokens := strings.Split(address, ":")
 	raw, err := hex.DecodeString(tokens[0])
 	if err != nil {
@@ -86,12 +78,10 @@ func Setup(instanceName, storageDirectory string) (*Node, error) {
 	n := &Node{
 		core:      &yggdrasil.Core{},
 		config:    yggdrasilconfig.GenerateConfig(),
-		admin:     &yggdrasiladmin.AdminSocket{},
 		multicast: &yggdrasilmulticast.Multicast{},
 		log:       gologme.New(os.Stdout, "YGG ", log.Flags()),
 		incoming:  make(chan QUICStream),
 	}
-	n.core.SetBuildInfo(n)
 
 	yggfile := fmt.Sprintf("%s/%s-yggdrasil.conf", storageDirectory, instanceName)
 	if _, err := os.Stat(yggfile); !os.IsNotExist(err) {
@@ -132,20 +122,22 @@ func Setup(instanceName, storageDirectory string) (*Node, error) {
 		panic(err)
 	}
 
-	n.packetConn = n.core.PacketConn()
 	n.tlsConfig = n.generateTLSConfig()
 	n.quicConfig = &quic.Config{
 		MaxIncomingStreams:    0,
 		MaxIncomingUniStreams: 0,
 		KeepAlive:             true,
-		MaxIdleTimeout:        time.Minute * 15,
-		HandshakeTimeout:      time.Second * 15,
+		MaxIdleTimeout:        time.Minute * 30,
+		HandshakeTimeout:      time.Second * 30,
 	}
 
 	n.log.Println("Public curve25519:", n.core.EncryptionPublicKey())
 	n.log.Println("Public ed25519:", n.core.SigningPublicKey())
 
-	go n.listenFromYgg()
+	go func() {
+		time.Sleep(time.Second)
+		n.listenFromYgg()
+	}()
 
 	return n, nil
 }
@@ -193,9 +185,11 @@ func (n *Node) KnownNodes() []gomatrixserverlib.ServerName {
 	nodemap := map[string]struct{}{
 		"b5ae50589e50991dd9dd7d59c5c5f7a4521e8da5b603b7f57076272abc58b374": struct{}{},
 	}
-	for _, peer := range n.core.GetSwitchPeers() {
-		nodemap[hex.EncodeToString(peer.SigningKey[:])] = struct{}{}
-	}
+	/*
+		for _, peer := range n.core.GetSwitchPeers() {
+			nodemap[hex.EncodeToString(peer.SigningKey[:])] = struct{}{}
+		}
+	*/
 	n.sessions.Range(func(_, v interface{}) bool {
 		session, ok := v.(quic.Session)
 		if !ok {
@@ -266,11 +260,3 @@ func (n *Node) SetStaticPeer(uri string) error {
 	}
 	return nil
 }
-
-func (n *Node) NotifyLinkNew(f func(boxPubKey crypto.BoxPubKey, sigPubKey crypto.SigPubKey, linkType, remote string)) {
-	n.core.NotifyLinkNew(f)
-}
-
-func (n *Node) NotifyLinkGone(f func(boxPubKey crypto.BoxPubKey, sigPubKey crypto.SigPubKey, linkType, remote string)) {
-	n.core.NotifyLinkGone(f)
-}

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

@@ -24,19 +24,19 @@ import (
 	"encoding/hex"
 	"encoding/pem"
 	"errors"
+	"fmt"
 	"math/big"
 	"net"
 	"time"
 
 	"github.com/lucas-clemente/quic-go"
-	"github.com/matrix-org/gomatrixserverlib"
 	"github.com/yggdrasil-network/yggdrasil-go/src/crypto"
 )
 
 func (n *Node) listenFromYgg() {
 	var err error
 	n.listener, err = quic.Listen(
-		n.packetConn, // yggdrasil.PacketConn
+		n.core,       // yggdrasil.PacketConn
 		n.tlsConfig,  // TLS config
 		n.quicConfig, // QUIC config
 	)
@@ -45,24 +45,25 @@ func (n *Node) listenFromYgg() {
 	}
 
 	for {
+		n.log.Infoln("Waiting to accept QUIC sessions")
 		session, err := n.listener.Accept(context.TODO())
 		if err != nil {
 			n.log.Println("n.listener.Accept:", err)
 			return
 		}
-		go n.listenFromQUIC(session)
+		if len(session.ConnectionState().PeerCertificates) != 1 {
+			_ = session.CloseWithError(0, "expected a peer certificate")
+			continue
+		}
+		address := session.ConnectionState().PeerCertificates[0].Subject.CommonName
+		n.log.Infoln("Accepted connection from", address)
+		go n.listenFromQUIC(session, address)
 	}
 }
 
-func (n *Node) listenFromQUIC(session quic.Session) {
-	n.sessions.Store(session.RemoteAddr().String(), session)
-	defer n.sessions.Delete(session.RemoteAddr())
-	if n.NewSession != nil {
-		if len(session.ConnectionState().PeerCertificates) == 1 {
-			subjectName := session.ConnectionState().PeerCertificates[0].Subject.CommonName
-			go n.NewSession(gomatrixserverlib.ServerName(subjectName))
-		}
-	}
+func (n *Node) listenFromQUIC(session quic.Session, address string) {
+	n.sessions.Store(address, session)
+	defer n.sessions.Delete(address)
 	for {
 		st, err := session.AcceptStream(context.TODO())
 		if err != nil {
@@ -107,10 +108,23 @@ func (n *Node) DialContext(ctx context.Context, network, address string) (net.Co
 		}
 		var pubKey crypto.BoxPubKey
 		copy(pubKey[:], dest)
+		nodeID := crypto.GetNodeID(&pubKey)
+		nodeMask := &crypto.NodeID{}
+		for i := range nodeMask {
+			nodeMask[i] = 0xFF
+		}
+
+		fmt.Println("Resolving coords")
+		coords, err := n.core.Resolve(nodeID, nodeMask)
+		if err != nil {
+			return nil, fmt.Errorf("n.core.Resolve: %w", err)
+		}
+		fmt.Println("Found coords:", coords)
+		fmt.Println("Dialling")
 
 		session, err = quic.Dial(
-			n.packetConn, // yggdrasil.PacketConn
-			&pubKey,      // dial address
+			n.core,       // yggdrasil.PacketConn
+			coords,       // dial address
 			address,      // dial SNI
 			n.tlsConfig,  // TLS config
 			n.quicConfig, // QUIC config
@@ -119,7 +133,8 @@ func (n *Node) DialContext(ctx context.Context, network, address string) (net.Co
 			n.log.Println("n.dialer.DialContext:", err)
 			return nil, err
 		}
-		go n.listenFromQUIC(session)
+		fmt.Println("Dial OK")
+		go n.listenFromQUIC(session, address)
 	}
 	st, err := session.OpenStream()
 	if err != nil {
@@ -157,5 +172,9 @@ func (n *Node) generateTLSConfig() *tls.Config {
 		Certificates:       []tls.Certificate{tlsCert},
 		NextProtos:         []string{"quic-matrix-ygg"},
 		InsecureSkipVerify: true,
+		ClientAuth:         tls.RequireAnyClientCert,
+		GetClientCertificate: func(info *tls.CertificateRequestInfo) (*tls.Certificate, error) {
+			return &tlsCert, nil
+		},
 	}
 }

federationsender/api/api.go

@@ -42,6 +42,12 @@ type FederationSenderInternalAPI interface {
 		request *PerformServersAliveRequest,
 		response *PerformServersAliveResponse,
 	) error
+	// Broadcasts an EDU to all servers in rooms we are joined to.
+	PerformBroadcastEDU(
+		ctx context.Context,
+		request *PerformBroadcastEDURequest,
+		response *PerformBroadcastEDUResponse,
+	) error
 }
 
 type PerformDirectoryLookupRequest struct {
@@ -91,3 +97,9 @@ type QueryJoinedHostServerNamesInRoomRequest struct {
 type QueryJoinedHostServerNamesInRoomResponse struct {
 	ServerNames []gomatrixserverlib.ServerName `json:"server_names"`
 }
+
+type PerformBroadcastEDURequest struct {
+}
+
+type PerformBroadcastEDUResponse struct {
+}

federationsender/internal/perform.go

@@ -308,3 +308,25 @@ func (r *FederationSenderInternalAPI) PerformServersAlive(
 
 	return nil
 }
+
+// PerformServersAlive implements api.FederationSenderInternalAPI
+func (r *FederationSenderInternalAPI) PerformBroadcastEDU(
+	ctx context.Context,
+	request *api.PerformBroadcastEDURequest,
+	response *api.PerformBroadcastEDUResponse,
+) (err error) {
+	destinations, err := r.db.GetAllJoinedHosts(ctx)
+	if err != nil {
+		return fmt.Errorf("r.db.GetAllJoinedHosts: %w", err)
+	}
+
+	edu := &gomatrixserverlib.EDU{
+		Type:   "org.matrix.dendrite.wakeup",
+		Origin: string(r.cfg.Matrix.ServerName),
+	}
+	if err = r.queues.SendEDU(edu, r.cfg.Matrix.ServerName, destinations); err != nil {
+		return fmt.Errorf("r.queues.SendEDU: %w", err)
+	}
+
+	return nil
+}

federationsender/inthttp/client.go

@@ -19,6 +19,7 @@ const (
 	FederationSenderPerformJoinRequestPath            = "/federationsender/performJoinRequest"
 	FederationSenderPerformLeaveRequestPath           = "/federationsender/performLeaveRequest"
 	FederationSenderPerformServersAlivePath           = "/federationsender/performServersAlive"
+	FederationSenderPerformBroadcastEDUPath           = "/federationsender/performBroadcastEDU"
 )
 
 // NewFederationSenderClient creates a FederationSenderInternalAPI implemented by talking to a HTTP POST API.
@@ -105,3 +106,16 @@ func (h *httpFederationSenderInternalAPI) PerformDirectoryLookup(
 	apiURL := h.federationSenderURL + FederationSenderPerformDirectoryLookupRequestPath
 	return httputil.PostJSON(ctx, span, h.httpClient, apiURL, request, response)
 }
+
+// Handle an instruction to broadcast an EDU to all servers in rooms we are joined to.
+func (h *httpFederationSenderInternalAPI) PerformBroadcastEDU(
+	ctx context.Context,
+	request *api.PerformBroadcastEDURequest,
+	response *api.PerformBroadcastEDUResponse,
+) error {
+	span, ctx := opentracing.StartSpanFromContext(ctx, "PerformBroadcastEDU")
+	defer span.Finish()
+
+	apiURL := h.federationSenderURL + FederationSenderPerformBroadcastEDUPath
+	return httputil.PostJSON(ctx, span, h.httpClient, apiURL, request, response)
+}

federationsender/inthttp/server.go

@@ -76,4 +76,17 @@ func AddRoutes(intAPI api.FederationSenderInternalAPI, internalAPIMux *mux.Route
 			return util.JSONResponse{Code: http.StatusOK, JSON: &response}
 		}),
 	)
+	internalAPIMux.Handle(FederationSenderPerformBroadcastEDUPath,
+		httputil.MakeInternalAPI("PerformBroadcastEDU", func(req *http.Request) util.JSONResponse {
+			var request api.PerformBroadcastEDURequest
+			var response api.PerformBroadcastEDUResponse
+			if err := json.NewDecoder(req.Body).Decode(&request); err != nil {
+				return util.MessageResponse(http.StatusBadRequest, err.Error())
+			}
+			if err := intAPI.PerformBroadcastEDU(req.Context(), &request, &response); err != nil {
+				return util.ErrorResponse(err)
+			}
+			return util.JSONResponse{Code: http.StatusOK, JSON: &response}
+		}),
+	)
 }

federationsender/storage/interface.go

@@ -26,6 +26,7 @@ type Database interface {
 	internal.PartitionStorer
 	UpdateRoom(ctx context.Context, roomID, oldEventID, newEventID string, addHosts []types.JoinedHost, removeHosts []string) (joinedHosts []types.JoinedHost, err error)
 	GetJoinedHosts(ctx context.Context, roomID string) ([]types.JoinedHost, error)
+	GetAllJoinedHosts(ctx context.Context) ([]gomatrixserverlib.ServerName, error)
 	StoreJSON(ctx context.Context, js string) (int64, error)
 	AssociatePDUWithDestination(ctx context.Context, transactionID gomatrixserverlib.TransactionID, serverName gomatrixserverlib.ServerName, nids []int64) error
 	GetNextTransactionPDUs(ctx context.Context, serverName gomatrixserverlib.ServerName, limit int) (gomatrixserverlib.TransactionID, []*gomatrixserverlib.HeaderedEvent, error)

federationsender/storage/postgres/joined_hosts_table.go

@@ -57,10 +57,14 @@ const selectJoinedHostsSQL = "" +
 	"SELECT event_id, server_name FROM federationsender_joined_hosts" +
 	" WHERE room_id = $1"
 
+const selectAllJoinedHostsSQL = "" +
+	"SELECT DISTINCT server_name FROM federationsender_joined_hosts"
+
 type joinedHostsStatements struct {
-	insertJoinedHostsStmt *sql.Stmt
-	deleteJoinedHostsStmt *sql.Stmt
-	selectJoinedHostsStmt *sql.Stmt
+	insertJoinedHostsStmt    *sql.Stmt
+	deleteJoinedHostsStmt    *sql.Stmt
+	selectJoinedHostsStmt    *sql.Stmt
+	selectAllJoinedHostsStmt *sql.Stmt
 }
 
 func (s *joinedHostsStatements) prepare(db *sql.DB) (err error) {
@@ -77,6 +81,9 @@ func (s *joinedHostsStatements) prepare(db *sql.DB) (err error) {
 	if s.selectJoinedHostsStmt, err = db.Prepare(selectJoinedHostsSQL); err != nil {
 		return
 	}
+	if s.selectAllJoinedHostsStmt, err = db.Prepare(selectAllJoinedHostsSQL); err != nil {
+		return
+	}
 	return
 }
 
@@ -112,6 +119,27 @@ func (s *joinedHostsStatements) selectJoinedHosts(
 	return joinedHostsFromStmt(ctx, s.selectJoinedHostsStmt, roomID)
 }
 
+func (s *joinedHostsStatements) selectAllJoinedHosts(
+	ctx context.Context,
+) ([]gomatrixserverlib.ServerName, error) {
+	rows, err := s.selectAllJoinedHostsStmt.QueryContext(ctx)
+	if err != nil {
+		return nil, err
+	}
+	defer internal.CloseAndLogIfError(ctx, rows, "selectAllJoinedHosts: rows.close() failed")
+
+	var result []gomatrixserverlib.ServerName
+	for rows.Next() {
+		var serverName string
+		if err = rows.Scan(&serverName); err != nil {
+			return nil, err
+		}
+		result = append(result, gomatrixserverlib.ServerName(serverName))
+	}
+
+	return result, rows.Err()
+}
+
 func joinedHostsFromStmt(
 	ctx context.Context, stmt *sql.Stmt, roomID string,
 ) ([]types.JoinedHost, error) {

federationsender/storage/postgres/storage.go

@@ -134,6 +134,13 @@ func (d *Database) GetJoinedHosts(
 	return d.selectJoinedHosts(ctx, roomID)
 }
 
+// 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) {
+	return d.selectAllJoinedHosts(ctx)
+}
+
 // StoreJSON adds a JSON blob into the queue JSON table and returns
 // a NID. The NID will then be used when inserting the per-destination
 // metadata entries.

federationsender/storage/sqlite3/joined_hosts_table.go

@@ -56,10 +56,14 @@ const selectJoinedHostsSQL = "" +
 	"SELECT event_id, server_name FROM federationsender_joined_hosts" +
 	" WHERE room_id = $1"
 
+const selectAllJoinedHostsSQL = "" +
+	"SELECT DISTINCT server_name FROM federationsender_joined_hosts"
+
 type joinedHostsStatements struct {
-	insertJoinedHostsStmt *sql.Stmt
-	deleteJoinedHostsStmt *sql.Stmt
-	selectJoinedHostsStmt *sql.Stmt
+	insertJoinedHostsStmt    *sql.Stmt
+	deleteJoinedHostsStmt    *sql.Stmt
+	selectJoinedHostsStmt    *sql.Stmt
+	selectAllJoinedHostsStmt *sql.Stmt
 }
 
 func (s *joinedHostsStatements) prepare(db *sql.DB) (err error) {
@@ -76,6 +80,9 @@ func (s *joinedHostsStatements) prepare(db *sql.DB) (err error) {
 	if s.selectJoinedHostsStmt, err = db.Prepare(selectJoinedHostsSQL); err != nil {
 		return
 	}
+	if s.selectAllJoinedHostsStmt, err = db.Prepare(selectAllJoinedHostsSQL); err != nil {
+		return
+	}
 	return
 }
 
@@ -115,6 +122,27 @@ func (s *joinedHostsStatements) selectJoinedHosts(
 	return joinedHostsFromStmt(ctx, s.selectJoinedHostsStmt, roomID)
 }
 
+func (s *joinedHostsStatements) selectAllJoinedHosts(
+	ctx context.Context,
+) ([]gomatrixserverlib.ServerName, error) {
+	rows, err := s.selectAllJoinedHostsStmt.QueryContext(ctx)
+	if err != nil {
+		return nil, err
+	}
+	defer internal.CloseAndLogIfError(ctx, rows, "selectAllJoinedHosts: rows.close() failed")
+
+	var result []gomatrixserverlib.ServerName
+	for rows.Next() {
+		var serverName string
+		if err = rows.Scan(&serverName); err != nil {
+			return nil, err
+		}
+		result = append(result, gomatrixserverlib.ServerName(serverName))
+	}
+
+	return result, rows.Err()
+}
+
 func joinedHostsFromStmt(
 	ctx context.Context, stmt *sql.Stmt, roomID string,
 ) ([]types.JoinedHost, error) {

federationsender/storage/sqlite3/storage.go

@@ -145,6 +145,13 @@ func (d *Database) GetJoinedHosts(
 	return d.selectJoinedHosts(ctx, roomID)
 }
 
+// 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) {
+	return d.selectAllJoinedHosts(ctx)
+}
+
 // StoreJSON adds a JSON blob into the queue JSON table and returns
 // a NID. The NID will then be used when inserting the per-destination
 // metadata entries.

go.mod

@@ -36,7 +36,7 @@ require (
 	github.com/uber-go/atomic v1.3.0 // indirect
 	github.com/uber/jaeger-client-go v2.15.0+incompatible
 	github.com/uber/jaeger-lib v1.5.0
-	github.com/yggdrasil-network/yggdrasil-go v0.3.15-0.20200713083728-5a765b33d55b
+	github.com/yggdrasil-network/yggdrasil-go v0.3.15-0.20200715104113-1046b00c3be3
 	go.uber.org/atomic v1.4.0
 	golang.org/x/crypto v0.0.0-20200423211502-4bdfaf469ed5
 	gopkg.in/h2non/bimg.v1 v1.0.18

go.sum

@@ -652,8 +652,8 @@ github.com/xdg/scram v0.0.0-20180814205039-7eeb5667e42c/go.mod h1:lB8K/P019DLNhe
 github.com/xdg/stringprep v1.0.0/go.mod h1:Jhud4/sHMO4oL310DaZAKk9ZaJ08SJfe+sJh0HrGL1Y=
 github.com/xordataexchange/crypt v0.0.3-0.20170626215501-b2862e3d0a77/go.mod h1:aYKd//L2LvnjZzWKhF00oedf4jCCReLcmhLdhm1A27Q=
 github.com/yggdrasil-network/yggdrasil-extras v0.0.0-20200525205615-6c8a4a2e8855/go.mod h1:xQdsh08Io6nV4WRnOVTe6gI8/2iTvfLDQ0CYa5aMt+I=
-github.com/yggdrasil-network/yggdrasil-go v0.3.15-0.20200713083728-5a765b33d55b h1:py36vWqSnHIQ2DQ9gC0jbkiFd9OCTQX01PdYJ7KmaQE=
-github.com/yggdrasil-network/yggdrasil-go v0.3.15-0.20200713083728-5a765b33d55b/go.mod h1:d+Nz6SPeG6kmeSPFL0cvfWfgwEql75fUnZiAONgvyBE=
+github.com/yggdrasil-network/yggdrasil-go v0.3.15-0.20200715104113-1046b00c3be3 h1:teLoIJgPHysREs8P6GlcS/PgaU9W9+GQndikFCQ1lY0=
+github.com/yggdrasil-network/yggdrasil-go v0.3.15-0.20200715104113-1046b00c3be3/go.mod h1:d+Nz6SPeG6kmeSPFL0cvfWfgwEql75fUnZiAONgvyBE=
 go.opencensus.io v0.18.0/go.mod h1:vKdFvxhtzZ9onBp9VKHK8z/sRpBMnKAsufL7wlDrCOA=
 go.opencensus.io v0.21.0/go.mod h1:mSImk1erAIZhrmZN+AvHh14ztQfjbGwt4TtuofqLduU=
 go.opencensus.io v0.22.1/go.mod h1:Ap50jQcDJrx6rB6VgeeFPtuPIf3wMRvRfrfYDO6+BmA=