packet: account statistics only in tpacket_stats_u
Currently, packet_sock has a struct tpacket_stats stats member for
TPACKET_V1 and TPACKET_V2 statistic accounting, and with TPACKET_V3
``union tpacket_stats_u stats_u'' was introduced, where however only
statistics for TPACKET_V3 are held, and when copied to user space,
TPACKET_V3 does some hackery and access also tpacket_stats' stats,
although everything could have been done within the union itself.
Unify accounting within the tpacket_stats_u union so that we can
remove 8 bytes from packet_sock that are there unnecessary. Note that
even if we switch to TPACKET_V3 and would use non mmap(2)ed option,
this still works due to the union with same types + offsets, that are
exposed to the user space.
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/packet/internal.h b/net/packet/internal.h
index 650751b..c4e4b45 100644
--- a/net/packet/internal.h
+++ b/net/packet/internal.h
@@ -93,8 +93,7 @@
/* struct sock has to be the first member of packet_sock */
struct sock sk;
struct packet_fanout *fanout;
- struct tpacket_stats stats;
- union tpacket_stats_u stats_u;
+ union tpacket_stats_u stats;
struct packet_ring_buffer rx_ring;
struct packet_ring_buffer tx_ring;
int copy_thresh;
