From 3fa37a345226c42db412ae952fba12800338c41f Mon Sep 17 00:00:00 2001
From: Cyril Fougeray <cyril.fougeray@gmail.com>
Date: Tue, 11 Aug 2020 15:04:54 +0200
Subject: [PATCH 1/2] Added parsing of IPv6 addresses for incomming mDNS
 requests

---
 p2p/discovery/mdns.go | 29 ++++++++++++++++++++++-------
 1 file changed, 22 insertions(+), 7 deletions(-)

diff --git a/p2p/discovery/mdns.go b/p2p/discovery/mdns.go
index 18a139b907..94fed3d310 100644
--- a/p2p/discovery/mdns.go
+++ b/p2p/discovery/mdns.go
@@ -157,7 +157,7 @@ func (m *mdnsService) pollForEntries(ctx context.Context) {
 }
 
 func (m *mdnsService) handleEntry(e *mdns.ServiceEntry) {
-	log.Debugf("Handling MDNS entry: %s:%d %s", e.AddrV4, e.Port, e.Info)
+	log.Debugf("Handling MDNS entry: [IPv4 %s][IPv6 %s]:%d %s", e.AddrV4, e.AddrV6, e.Port, e.Info)
 	mpeer, err := peer.IDB58Decode(e.Info)
 	if err != nil {
 		log.Warning("Error parsing peer ID from mdns entry: ", err)
@@ -169,12 +169,27 @@ func (m *mdnsService) handleEntry(e *mdns.ServiceEntry) {
 		return
 	}
 
-	maddr, err := manet.FromNetAddr(&net.TCPAddr{
-		IP:   e.AddrV4,
-		Port: e.Port,
-	})
-	if err != nil {
-		log.Warning("Error parsing multiaddr from mdns entry: ", err)
+	var maddr ma.Multiaddr
+	if e.AddrV4 != nil {
+		maddr, err = manet.FromNetAddr(&net.TCPAddr{
+			IP:   e.AddrV4,
+			Port: e.Port,
+		})
+		if err != nil {
+			log.Warning("Error parsing multiaddr from mdns entry: ", err)
+			return
+		}
+	} else if e.AddrV6 != nil {
+		maddr, err = manet.FromNetAddr(&net.TCPAddr{
+			IP:   e.AddrV6,
+			Port: e.Port,
+		})
+		if err != nil {
+			log.Warning("Error parsing multiaddr from mdns entry: ", err)
+			return
+		}
+	} else {
+		log.Warning("Error parsing multiaddr from mdns entry: no IP address found")
 		return
 	}
 

From 16d314cf300ca99f71b196fb8321992838f92884 Mon Sep 17 00:00:00 2001
From: Cyril Fougeray <cyril.fougeray@gmail.com>
Date: Thu, 20 Aug 2020 18:36:07 +0200
Subject: [PATCH 2/2] Deduplicating code when parsing ipv4/ipv6 address; from
 the comment on the PR

---
 p2p/discovery/mdns.go | 29 ++++++++++++-----------------
 1 file changed, 12 insertions(+), 17 deletions(-)

diff --git a/p2p/discovery/mdns.go b/p2p/discovery/mdns.go
index 94fed3d310..bccc9e6d21 100644
--- a/p2p/discovery/mdns.go
+++ b/p2p/discovery/mdns.go
@@ -169,30 +169,25 @@ func (m *mdnsService) handleEntry(e *mdns.ServiceEntry) {
 		return
 	}
 
-	var maddr ma.Multiaddr
+	var addr net.IP
 	if e.AddrV4 != nil {
-		maddr, err = manet.FromNetAddr(&net.TCPAddr{
-			IP:   e.AddrV4,
-			Port: e.Port,
-		})
-		if err != nil {
-			log.Warning("Error parsing multiaddr from mdns entry: ", err)
-			return
-		}
+		addr = e.AddrV4
 	} else if e.AddrV6 != nil {
-		maddr, err = manet.FromNetAddr(&net.TCPAddr{
-			IP:   e.AddrV6,
-			Port: e.Port,
-		})
-		if err != nil {
-			log.Warning("Error parsing multiaddr from mdns entry: ", err)
-			return
-		}
+		addr = e.AddrV6
 	} else {
 		log.Warning("Error parsing multiaddr from mdns entry: no IP address found")
 		return
 	}
 
+	maddr, err := manet.FromNetAddr(&net.TCPAddr{
+		IP:   addr,
+		Port: e.Port,
+	})
+	if err != nil {
+		log.Warning("Error parsing multiaddr from mdns entry: ", err)
+		return
+	}
+
 	pi := peer.AddrInfo{
 		ID:    mpeer,
 		Addrs: []ma.Multiaddr{maddr},