From d37bec73c909e7cb2930877f877e63dde9998d25 Mon Sep 17 00:00:00 2001
From: Asim <asim@chuhnk.me>
Date: Sun, 1 May 2016 19:45:12 +0100
Subject: [PATCH] Fix the udp6 binding error

---
 client.go | 27 +++++++++++++++++++++++++--
 server.go |  2 +-
 2 files changed, 26 insertions(+), 3 deletions(-)

diff --git a/client.go b/client.go
index b6d2ff1..24c1450 100644
--- a/client.go
+++ b/client.go
@@ -182,11 +182,11 @@ func newClient() (*client, error) {
 		return nil, fmt.Errorf("failed to bind to any unicast udp port")
 	}
 
-	mconn4, err := net.ListenMulticastUDP("udp4", nil, ipv4Addr)
+	mconn4, err := net.ListenUDP("udp4", mdnsWildcardAddrIPv4)
 	if err != nil {
 		log.Printf("[ERR] mdns: Failed to bind to udp4 port: %v", err)
 	}
-	mconn6, err := net.ListenMulticastUDP("udp6", nil, ipv6Addr)
+	mconn6, err := net.ListenUDP("udp6", mdnsWildcardAddrIPv6)
 	if err != nil {
 		log.Printf("[ERR] mdns: Failed to bind to udp6 port: %v", err)
 	}
@@ -195,6 +195,29 @@ func newClient() (*client, error) {
 		return nil, fmt.Errorf("failed to bind to any multicast udp port")
 	}
 
+	p1 := ipv4.NewPacketConn(mconn4)
+	p2 := ipv6.NewPacketConn(mconn6)
+
+	ifaces, err := net.Interfaces()
+	if err != nil {
+		return nil, err
+	}
+
+	var errCount1, errCount2 int
+
+	for _, iface := range ifaces {
+		if err := p1.JoinGroup(&iface, &net.UDPAddr{IP: mdnsGroupIPv4}); err != nil {
+			errCount1++
+		}
+		if err := p2.JoinGroup(&iface, &net.UDPAddr{IP: mdnsGroupIPv6}); err != nil {
+			errCount2++
+		}
+	}
+
+	if len(ifaces) == errCount1 && len(ifaces) == errCount2 {
+		return nil, fmt.Errorf("Failed to join multicast group on all interfaces!")
+	}
+
 	c := &client{
 		ipv4MulticastConn: mconn4,
 		ipv6MulticastConn: mconn6,
diff --git a/server.go b/server.go
index 4cde1a5..77ab248 100644
--- a/server.go
+++ b/server.go
@@ -23,7 +23,7 @@ var (
 		Port: 5353,
 	}
 	mdnsWildcardAddrIPv6 = &net.UDPAddr{
-		IP:   net.ParseIP("[ff02::]"),
+		IP:   net.ParseIP("ff02::"),
 		Port: 5353,
 	}