From 16a3254c4cb592e7cfa3aea744e9fd58665d6367 Mon Sep 17 00:00:00 2001
From: Ondrej Zajicek <santiago@crfreenet.org>
Date: Tue, 31 Mar 2015 23:59:40 +0200
Subject: [PATCH] Understand IFF_MULTICAST flag on ifaces in Linux

Unfortunately, some interfaces support multicast but do not have
this flag set, so we use it only as a positive hint.

Thanks to Clint Armstrong for noticing the problem.
---
 sysdep/linux/netlink.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/sysdep/linux/netlink.c b/sysdep/linux/netlink.c
index 860c8601..48dd8bab 100644
--- a/sysdep/linux/netlink.c
+++ b/sysdep/linux/netlink.c
@@ -436,6 +436,9 @@ nl_parse_link(struct nlmsghdr *h, int scan)
       else
 	f.flags |= IF_MULTIACCESS;	/* NBMA */
 
+      if (fl & IFF_MULTICAST)
+	f.flags |= IF_MULTICAST;
+
       ifi = if_update(&f);
 
       if (!scan)