From 094714725481da5cfbeaa9e4c713633f3fd0dcc4 Mon Sep 17 00:00:00 2001
From: Markus Stenberg <markus.stenberg@iki.fi>
Date: Wed, 19 Feb 2014 19:21:40 +0200
Subject: mdnsresponder: [PATCH] Binding IPv6 sockets to interface

Due to link-local addresses, otherwise responses may wind up in wrong
places and mdnsd is quite confused.

---
 .../patches/003-ipv6-bind-to-interface.patch       |   22 ++++++++++++++++++++
 1 file changed, 22 insertions(+)

--- mDNSResponder-544.source/mDNSPosix/mDNSPosix.c	2013-12-14 22:54:24.000000000 +0200
+++ mDNSResponder-544/mDNSPosix/mDNSPosix.c	2014-02-19 18:59:55.000000000 +0200
@@ -784,6 +784,17 @@
             if (err < 0) { err = errno; perror("setsockopt - IPV6_MULTICAST_HOPS"); }
         }
 
+#ifdef __linux__
+#ifdef SO_BINDTODEVICE
+        if (err == 0)
+        {
+            char ifname[IFNAMSIZ];
+            if (if_indextoname(interfaceIndex, ifname))
+                err = setsockopt(*sktPtr, SOL_SOCKET, SO_BINDTODEVICE, ifname, strlen(ifname));
+        }
+#endif /* SO_BINDTODEVICE */
+#endif /* __linux__ */
+
         // And start listening for packets
         if (err == 0)
         {