fix: enr exceeds 300 bytes

waku/v2/node/localnode.go

@@ -6,8 +6,10 @@ import (
 	"encoding/binary"
 	"errors"
 	"math"
+	"math/rand"
 	"net"
 	"strconv"
+	"time"
 
 	"github.com/ethereum/go-ethereum/p2p/enode"
 	"github.com/ethereum/go-ethereum/p2p/enr"
@@ -24,6 +26,33 @@ func (w *WakuNode) newLocalnode(priv *ecdsa.PrivateKey) (*enode.LocalNode, error
 	return enode.NewLocalNode(db, priv), nil
 }
 
+func writeMultiaddressField(localnode *enode.LocalNode, addrAggr []ma.Multiaddr) (err error) {
+	defer func() {
+		if e := recover(); e != nil {
+			err = errors.New("could not write enr record")
+		}
+	}()
+
+	var fieldRaw []byte
+	for _, addr := range addrAggr {
+		maRaw := addr.Bytes()
+		maSize := make([]byte, 2)
+		binary.BigEndian.PutUint16(maSize, uint16(len(maRaw)))
+
+		fieldRaw = append(fieldRaw, maSize...)
+		fieldRaw = append(fieldRaw, maRaw...)
+	}
+
+	if len(fieldRaw) != 0 {
+		localnode.Set(enr.WithEntry(utils.MultiaddrENRField, fieldRaw))
+	}
+
+	// This is to trigger the signing record err due to exceeding 300bytes limit
+	_ = localnode.Node()
+
+	return nil
+}
+
 func (w *WakuNode) updateLocalNode(localnode *enode.LocalNode, multiaddrs []ma.Multiaddr, ipAddr *net.TCPAddr, udpPort uint, wakuFlags utils.WakuEnrBitfield, advertiseAddr *net.IP, shouldAutoUpdate bool, log *zap.Logger) error {
 	localnode.SetFallbackUDP(int(udpPort))
 	localnode.Set(enr.WithEntry(utils.WakuENRField, wakuFlags))
@@ -67,47 +96,37 @@ func (w *WakuNode) updateLocalNode(localnode *enode.LocalNode, multiaddrs []ma.M
 		}
 	}
 
-	// Adding extra multiaddresses. It will to add as many multiaddresses as possible
+	// Randomly shuffle multiaddresses
-	// without exceeding the enr max size of 300bytes
+	rand.Seed(time.Now().UnixNano())
-	var addrAggr []ma.Multiaddr
+	rand.Shuffle(len(multiaddrs), func(i, j int) { multiaddrs[i], multiaddrs[j] = multiaddrs[j], multiaddrs[i] })
+
+	// Adding extra multiaddresses. Should probably not exceed the enr max size of 300bytes
 	var err error
+	failedOnceWritingENR := false
+	couldWriteENRatLeastOnce := false
+	successIdx := -1
 	for i := len(multiaddrs) - 1; i >= 0; i-- {
-		addrAggr = append(addrAggr, multiaddrs[0:i]...)
+		err = writeMultiaddressField(localnode, multiaddrs[0:i])
-		err = func() (err error) {
-			defer func() {
-				if e := recover(); e != nil {
-					err = errors.New("could not write enr record")
-				}
-			}()
-
-			var fieldRaw []byte
-			for _, addr := range addrAggr {
-				maRaw := addr.Bytes()
-				maSize := make([]byte, 2)
-				binary.BigEndian.PutUint16(maSize, uint16(len(maRaw)))
-
-				fieldRaw = append(fieldRaw, maSize...)
-				fieldRaw = append(fieldRaw, maRaw...)
-			}
-
-			if len(fieldRaw) != 0 {
-				localnode.Set(enr.WithEntry(utils.MultiaddrENRField, fieldRaw))
-			}
-
-			// This is to trigger the signing record err due to exceeding 300bytes limit
-			_ = localnode.Node()
-
-			return nil
-		}()
-
 		if err == nil {
+			couldWriteENRatLeastOnce = true
+			successIdx = i
 			break
+		} else {
+			failedOnceWritingENR = true
 		}
 	}
 
-	// In case multiaddr could not be populated at all
+	if failedOnceWritingENR {
-	if err != nil {
+		if !couldWriteENRatLeastOnce {
-		localnode.Delete(enr.WithEntry(utils.MultiaddrENRField, struct{}{}))
+			// In case multiaddr could not be populated at all
+			localnode.Delete(enr.WithEntry(utils.MultiaddrENRField, struct{}{}))
+		} else {
+			// Could write a subset of multiaddresses but not all
+			err = writeMultiaddressField(localnode, multiaddrs[0:successIdx])
+			if err != nil {
+				return errors.New("could not write new ENR")
+			}
+		}
 	}
 
 	return nil

waku/v2/node/wakunode2.go

@@ -91,6 +91,7 @@ type WakuNode struct {
 	protocolEventSub       event.Subscription
 	identificationEventSub event.Subscription
 	addressChangesSub      event.Subscription
+	enrChangeCh            chan struct{}
 
 	keepAliveMutex sync.Mutex
 	keepAliveFails map[peer.ID]int
@@ -234,6 +235,8 @@ func New(opts ...WakuNodeOption) (*WakuNode, error) {
 		return nil, err
 	}
 
+	w.enrChangeCh = make(chan struct{}, 10)
+
 	if params.connStatusC != nil {
 		w.connStatusChan = params.connStatusC
 	}
@@ -253,6 +256,7 @@ func (w *WakuNode) watchMultiaddressChanges(ctx context.Context) {
 			return
 		case <-first:
 			w.log.Info("listening", logging.MultiAddrs("multiaddr", addrs...))
+			w.enrChangeCh <- struct{}{}
 		case <-w.addressChangesSub.Out():
 			newAddrs := w.ListenAddresses()
 			diff := false
@@ -270,6 +274,7 @@ func (w *WakuNode) watchMultiaddressChanges(ctx context.Context) {
 				addrs = newAddrs
 				w.log.Info("listening addresses update received", logging.MultiAddrs("multiaddr", addrs...))
 				_ = w.setupENR(ctx, addrs)
+				w.enrChangeCh <- struct{}{}
 			}
 		}
 	}
@@ -403,6 +408,8 @@ func (w *WakuNode) Stop() {
 
 	w.host.Close()
 
+	close(w.enrChangeCh)
+
 	w.wg.Wait()
 }
 
@@ -419,13 +426,12 @@ func (w *WakuNode) ID() string {
 func (w *WakuNode) watchENRChanges(ctx context.Context) {
 	defer w.wg.Done()
 
-	timer := time.NewTicker(1 * time.Second)
 	var prevNodeVal string
 	for {
 		select {
 		case <-ctx.Done():
 			return
-		case <-timer.C:
+		case <-w.enrChangeCh:
 			if w.localNode != nil {
 				currNodeVal := w.localNode.Node().String()
 				if prevNodeVal != currNodeVal {

waku/v2/utils/enr_test.go

@@ -4,8 +4,10 @@ import (
 	"encoding/binary"
 	"errors"
 	"math"
+	"math/rand"
 	"net"
 	"testing"
+	"time"
 
 	gcrypto "github.com/ethereum/go-ethereum/crypto"
 	"github.com/ethereum/go-ethereum/p2p/enode"
@@ -25,6 +27,33 @@ func TestEnodeToMultiAddr(t *testing.T) {
 	require.Equal(t, expectedMultiAddr, actualMultiAddr.String())
 }
 
+func writeMultiaddressField(localnode *enode.LocalNode, addrAggr []ma.Multiaddr) (err error) {
+	defer func() {
+		if e := recover(); e != nil {
+			err = errors.New("could not write enr record")
+		}
+	}()
+
+	var fieldRaw []byte
+	for _, addr := range addrAggr {
+		maRaw := addr.Bytes()
+		maSize := make([]byte, 2)
+		binary.BigEndian.PutUint16(maSize, uint16(len(maRaw)))
+
+		fieldRaw = append(fieldRaw, maSize...)
+		fieldRaw = append(fieldRaw, maRaw...)
+	}
+
+	if len(fieldRaw) != 0 {
+		localnode.Set(enr.WithEntry(MultiaddrENRField, fieldRaw))
+	}
+
+	// This is to trigger the signing record err due to exceeding 300bytes limit
+	_ = localnode.Node()
+
+	return nil
+}
+
 // TODO: this function is duplicated in localnode.go. Remove duplication
 func updateLocalNode(localnode *enode.LocalNode, multiaddrs []ma.Multiaddr, ipAddr *net.TCPAddr, udpPort uint, wakuFlags WakuEnrBitfield, advertiseAddr *net.IP, shouldAutoUpdate bool, log *zap.Logger) error {
 	localnode.SetFallbackUDP(int(udpPort))
@@ -69,45 +98,37 @@ func updateLocalNode(localnode *enode.LocalNode, multiaddrs []ma.Multiaddr, ipAd
 		}
 	}
 
-	var addrAggr []ma.Multiaddr
+	// Randomly shuffle multiaddresses
+	rand.Seed(time.Now().UnixNano())
+	rand.Shuffle(len(multiaddrs), func(i, j int) { multiaddrs[i], multiaddrs[j] = multiaddrs[j], multiaddrs[i] })
+
+	// Adding a single extra multiaddress. Should probably not exceed the enr max size of 300bytes
 	var err error
+	failedOnceWritingENR := false
+	couldWriteENRatLeastOnce := false
+	successIdx := -1
 	for i := len(multiaddrs) - 1; i >= 0; i-- {
-		addrAggr = append(addrAggr, multiaddrs[0:i]...)
+		err = writeMultiaddressField(localnode, multiaddrs[0:i])
-		err = func() (err error) {
-			defer func() {
-				if e := recover(); e != nil {
-					err = errors.New("could not write enr record")
-				}
-			}()
-
-			var fieldRaw []byte
-			for _, addr := range addrAggr {
-				maRaw := addr.Bytes()
-				maSize := make([]byte, 2)
-				binary.BigEndian.PutUint16(maSize, uint16(len(maRaw)))
-
-				fieldRaw = append(fieldRaw, maSize...)
-				fieldRaw = append(fieldRaw, maRaw...)
-			}
-
-			if len(fieldRaw) != 0 {
-				localnode.Set(enr.WithEntry(MultiaddrENRField, fieldRaw))
-			}
-
-			// This is to trigger the signing record err due to exceeding 300bytes limit
-			_ = localnode.Node()
-
-			return nil
-		}()
-
 		if err == nil {
+			couldWriteENRatLeastOnce = true
+			successIdx = i
 			break
+		} else {
+			failedOnceWritingENR = true
 		}
 	}
 
-	// In case multiaddr could not be populated at all
+	if failedOnceWritingENR {
-	if err != nil {
+		if !couldWriteENRatLeastOnce {
-		localnode.Delete(enr.WithEntry(MultiaddrENRField, struct{}{}))
+			// In case multiaddr could not be populated at all
+			localnode.Delete(enr.WithEntry(MultiaddrENRField, struct{}{}))
+		} else {
+			// Could write a subset of multiaddresses but not all
+			err = writeMultiaddressField(localnode, multiaddrs[0:successIdx])
+			if err != nil {
+				return errors.New("could not write new ENR")
+			}
+		}
 	}
 
 	return nil