Audit changes.

peer/multicast.go

@@ -26,11 +26,19 @@ var mcAddr = net.UDPAddrFromAddrPort(netip.AddrPortFrom(
 // RunMCWriter broadcasts a signed beacon on the local multicast group every
 // mcBroadcastInterval so that LAN peers can discover our WireGuard endpoint.
 func RunMCWriter(selfVPNIP netip.Addr, pubKey wgtypes.Key, wgPort uint16, signKey *[64]byte) {
+	for {
+		runMCWriterInner(selfVPNIP, pubKey, wgPort, signKey)
+		time.Sleep(mcErrorRetryInterval)
+	}
+}
+
+func runMCWriterInner(selfVPNIP netip.Addr, pubKey wgtypes.Key, wgPort uint16, signKey *[64]byte) {
 	conn, err := net.ListenMulticastUDP("udp", nil, mcAddr)
 	if err != nil {
 		log.Printf("[MCWriter] bind: %v", err)
 		return
 	}
+	defer conn.Close()
 
 	payload := buildBeacon(selfVPNIP, pubKey, wgPort)
 	signed := sign.Sign(nil, payload, signKey)
@@ -38,9 +46,11 @@ func RunMCWriter(selfVPNIP netip.Addr, pubKey wgtypes.Key, wgPort uint16, signKe
 	if _, err := conn.WriteToUDP(signed, mcAddr); err != nil {
 		log.Printf("[MCWriter] write: %v", err)
 	}
+
 	for range time.Tick(mcBroadcastInterval) {
 		if _, err := conn.WriteToUDP(signed, mcAddr); err != nil {
 			log.Printf("[MCWriter] write: %v", err)
+			return
 		}
 	}
 }