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Commit ee80fbf3 authored by Daniel Borkmann's avatar Daniel Borkmann Committed by David S. Miller
Browse files

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: default avatarDaniel Borkmann <dborkman@redhat.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 0578edc5

net/packet/af_packet.c

+16 −21
Original line number Diff line number Diff line
@@ -528,7 +528,7 @@ static void init_prb_bdqc(struct packet_sock *po, 
	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 @@ static void prb_close_block(struct tpacket_kbdq_core *pkc1, 
	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 @@ static void prb_freeze_queue(struct tpacket_kbdq_core *pkc, 
				  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 @@ static int packet_rcv(struct sk_buff *skb, struct net_device *dev, 
	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 @@ static int packet_rcv(struct sk_buff *skb, struct net_device *dev, 


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 @@ static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev, 
	 * 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 @@ static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev, 
	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 @@ static int packet_getsockopt(struct socket *sock, int level, int optname, 
	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 @@ static int packet_getsockopt(struct socket *sock, int level, int optname, 
	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;

net/packet/internal.h

+1 −2
Original line number Diff line number Diff line
@@ -93,8 +93,7 @@ struct packet_sock { 
	/* 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;