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.

diff --git a/sysdep/linux/netlink.c b/sysdep/linux/netlink.c
index 860c8601dbf9443184293692d8fa20b3baa80374..48dd8babb264a331c2fb2dfb7bed91c6dda8b587 100644 (file)
--- 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)