p2p: skip nodes with node.nr label when selecting relay peer

disco/peer.go

@@ -1,5 +1,7 @@
 package disco
 
+import "strings"
+
 type PeerID string
 
 func (id PeerID) String() string {
@@ -17,3 +19,21 @@ func (id PeerID) Len() byte {
 func (id PeerID) Bytes() []byte {
 	return []byte(id)
 }
+
+type Labels []string
+
+func (ls Labels) Get(key string) (string, bool) {
+	for _, l := range ls {
+		kv := strings.Split(l, "=")
+		if len(kv) == 2 {
+			if kv[0] == key {
+				return kv[1], true
+			}
+			continue
+		}
+		if kv[0] == key {
+			return "", true
+		}
+	}
+	return "", false
+}

p2p/conn.go

@@ -270,8 +270,12 @@ func (c *PacketConn) relayPeer(peerID disco.PeerID) disco.PeerID {
 		if meta == nil {
 			continue
 		}
+		if _, ok := disco.Labels(meta["label"]).Get("node.nr"); ok {
+			// can not as relay peer when `node.nr` label is present
+			continue
+		}
 		peerNAT := disco.NATType(meta.Get("nat"))
-		if peerNAT == disco.Easy || peerNAT == disco.IP4 {
+		if peerNAT == disco.Easy || peerNAT == disco.IP4 || peerNAT == disco.IP46 {
 			return p.PeerID
 		}
 	}