af_packet: Teach to listen for multiple unicast addresses.

The the PACKET_ADD_MEMBERSHIP and the PACKET_DROP_MEMBERSHIP setsockopt
calls for af_packet already has all of the infrastructure needed to subscribe
to multiple mac addresses.  All that is missing is a flag to say that
the address we want to listen on is a unicast address.

So introduce PACKET_MR_UNICAST and wire it up to dev_unicast_add and
dev_unicast_delete.

Additionally I noticed that errors from dev_mc_add were not propagated
from packet_dev_mc so fix that.

Signed-off-by: Eric W. Biederman <ebiederm@aristanetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 1 insertions, 0 deletions

diff --git a/include/linux/if_packet.h b/include/linux/if_packet.h
index 5b2badeb9497..dea7d6b7cf98 100644
--- a/include/linux/if_packet.h
+++ b/include/linux/if_packet.h
@@ -145,5 +145,6 @@ struct packet_mreq
 #define PACKET_MR_MULTICAST     0
 #define PACKET_MR_PROMISC       1
 #define PACKET_MR_ALLMULTI      2
+#define PACKET_MR_UNICAST       3
 
 #endif