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/af_packet.c b/net/packet/af_packet.c
index ba8309a..dd5cd49 100644
--- a/net/packet/af_packet.c
+++ b/net/packet/af_packet.c
@@ -528,7 +528,7 @@
p1->hdrlen = po->tp_hdrlen;
p1->version = po->tp_version;
p1->last_kactive_blk_num = 0;
- po->stats_u.stats3.tp_freeze_q_cnt = 0;
+ po->stats.stats3.tp_freeze_q_cnt = 0;
if (req_u->req3.tp_retire_blk_tov)
p1->retire_blk_tov = req_u->req3.tp_retire_blk_tov;
else
@@ -696,7 +696,7 @@
struct tpacket3_hdr *last_pkt;
struct tpacket_hdr_v1 *h1 = &pbd1->hdr.bh1;
- if (po->stats.tp_drops)
+ if (po->stats.stats3.tp_drops)
status |= TP_STATUS_LOSING;
last_pkt = (struct tpacket3_hdr *)pkc1->prev;
@@ -801,7 +801,7 @@
struct packet_sock *po)
{
pkc->reset_pending_on_curr_blk = 1;
- po->stats_u.stats3.tp_freeze_q_cnt++;
+ po->stats.stats3.tp_freeze_q_cnt++;
}
#define TOTAL_PKT_LEN_INCL_ALIGN(length) (ALIGN((length), V3_ALIGNMENT))
@@ -1687,7 +1687,7 @@
nf_reset(skb);
spin_lock(&sk->sk_receive_queue.lock);
- po->stats.tp_packets++;
+ po->stats.stats1.tp_packets++;
skb->dropcount = atomic_read(&sk->sk_drops);
__skb_queue_tail(&sk->sk_receive_queue, skb);
spin_unlock(&sk->sk_receive_queue.lock);
@@ -1696,7 +1696,7 @@
drop_n_acct:
spin_lock(&sk->sk_receive_queue.lock);
- po->stats.tp_drops++;
+ po->stats.stats1.tp_drops++;
atomic_inc(&sk->sk_drops);
spin_unlock(&sk->sk_receive_queue.lock);
@@ -1796,10 +1796,10 @@
* Anyways, moving it for V1/V2 only as V3 doesn't need this
* at packet level.
*/
- if (po->stats.tp_drops)
+ if (po->stats.stats1.tp_drops)
status |= TP_STATUS_LOSING;
}
- po->stats.tp_packets++;
+ po->stats.stats1.tp_packets++;
if (copy_skb) {
status |= TP_STATUS_COPY;
__skb_queue_tail(&sk->sk_receive_queue, copy_skb);
@@ -1898,7 +1898,7 @@
return 0;
ring_is_full:
- po->stats.tp_drops++;
+ po->stats.stats1.tp_drops++;
spin_unlock(&sk->sk_receive_queue.lock);
sk->sk_data_ready(sk, 0);
@@ -3247,8 +3247,7 @@
struct sock *sk = sock->sk;
struct packet_sock *po = pkt_sk(sk);
void *data = &val;
- struct tpacket_stats st;
- union tpacket_stats_u st_u;
+ union tpacket_stats_u st;
if (level != SOL_PACKET)
return -ENOPROTOOPT;
@@ -3262,22 +3261,18 @@
switch (optname) {
case PACKET_STATISTICS:
spin_lock_bh(&sk->sk_receive_queue.lock);
+ memcpy(&st, &po->stats, sizeof(st));
+ memset(&po->stats, 0, sizeof(po->stats));
+ spin_unlock_bh(&sk->sk_receive_queue.lock);
+
if (po->tp_version == TPACKET_V3) {
lv = sizeof(struct tpacket_stats_v3);
- memcpy(&st_u.stats3, &po->stats,
- sizeof(struct tpacket_stats));
- st_u.stats3.tp_freeze_q_cnt =
- po->stats_u.stats3.tp_freeze_q_cnt;
- st_u.stats3.tp_packets += po->stats.tp_drops;
- data = &st_u.stats3;
+ data = &st.stats3;
} else {
lv = sizeof(struct tpacket_stats);
- st = po->stats;
- st.tp_packets += st.tp_drops;
- data = &st;
+ data = &st.stats1;
}
- memset(&po->stats, 0, sizeof(st));
- spin_unlock_bh(&sk->sk_receive_queue.lock);
+
break;
case PACKET_AUXDATA:
val = po->auxdata;
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;