ipv4: New multicast-all socket option

After some discussion offline with Christoph Lameter and David Stevens
regarding multicast behaviour in Linux, I'm submitting a slightly
modified patch from the one Christoph submitted earlier.

This patch provides a new socket option IP_MULTICAST_ALL.

In this case, default behaviour is _unchanged_ from the current
Linux standard. The socket option is set by default to provide
original behaviour. Sockets wishing to receive data only from
multicast groups they join explicitly will need to clear this
socket option.

Signed-off-by: Nivedita Singhvi <niv@us.ibm.com>
Signed-off-by: Christoph Lameter<cl@linux.com>
Acked-by: David Stevens <dlstevens@us.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 2 insertions, 1 deletions

diff --git a/include/net/inet_sock.h b/include/net/inet_sock.h
index de0ecc71cf03..20a6957af870 100644
--- a/include/net/inet_sock.h
+++ b/include/net/inet_sock.h
@@ -130,7 +130,8 @@ struct inet_sock {
                                 freebind:1,
                                 hdrincl:1,
                                 mc_loop:1,
-                                transparent:1;
+                                transparent:1,
+                                mc_all:1;
         int                     mc_index;
         __be32                  mc_addr;
         struct ip_mc_socklist   *mc_list;