fix: filter out peers to be considered for circuit-relay (#1130)

Co-authored-by: Richard Ramos <info@richardramos.me>

waku/v2/node/wakunode2.go

@@ -893,13 +893,26 @@ func (w *WakuNode) findRelayNodes(ctx context.Context) {
 		rand.Shuffle(len(peers), func(i, j int) { peers[i], peers[j] = peers[j], peers[i] })
 
 		for _, p := range peers {
+			pENR, err := w.Host().Peerstore().(wps.WakuPeerstore).ENR(p.ID)
+			if err != nil {
+				w.log.Debug("could not get ENR for the peer, skipping for circuit-relay", zap.Stringer("peer", p.ID), zap.Error(err))
+				continue
+			}
+			rs, err := enr.RelayShardList(pENR.Record())
+			if err != nil || rs == nil {
+				w.log.Debug("could not get shard info for the peer from ENR, skipping for circuit-relay", zap.Stringer("peer", p.ID), zap.Error(err))
+				continue
+			}
+			if rs.ClusterID != w.ClusterID() {
+				w.log.Debug("clusterID mismatch for the peer, skipping for circuit-relay", zap.Stringer("peer", p.ID), zap.Error(err))
+				continue
+			}
 			info := w.Host().Peerstore().PeerInfo(p.ID)
 			supportedProtocols, err := w.Host().Peerstore().SupportsProtocols(p.ID, proto.ProtoIDv2Hop)
 			if err != nil {
 				w.log.Error("could not check supported protocols", zap.Error(err))
 				continue
 			}
-
 			if len(supportedProtocols) == 0 {
 				continue
 			}

waku/v2/service/common_discovery_service.go

@@ -20,6 +20,7 @@ type PeerData struct {
 type CommonDiscoveryService struct {
 	commonService     *CommonService
 	channel           chan PeerData
+	canWriteToChannel sync.Mutex
 }
 
 func NewCommonDiscoveryService() *CommonDiscoveryService {
@@ -42,7 +43,9 @@ func (sp *CommonDiscoveryService) Stop(stopFn func()) {
 		stopFn()
 		sp.WaitGroup().Wait() // waitgroup is waited here so that channel can be closed after all the go rountines have stopped in service.
 		// there is a wait in the CommonService too
+		sp.canWriteToChannel.Lock()
 		close(sp.channel)
+		sp.canWriteToChannel.Unlock()
 	})
 }
 func (sp *CommonDiscoveryService) GetListeningChan() <-chan PeerData {
@@ -52,6 +55,10 @@ func (sp *CommonDiscoveryService) PushToChan(data PeerData) bool {
 	if err := sp.ErrOnNotRunning(); err != nil {
 		return false
 	}
+
+	sp.canWriteToChannel.Lock()
+	defer sp.canWriteToChannel.Unlock()
+
 	select {
 	case sp.channel <- data:
 		return true