From ee80fbf301adac644d0c9465194a7ec87bcd4a07 Mon Sep 17 00:00:00 2001 From: Daniel Borkmann Date: Fri, 19 Apr 2013 06:12:29 +0000 Subject: [PATCH] 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 Signed-off-by: David S. Miller --- net/packet/af_packet.c | 37 ++++++++++++++++--------------------- net/packet/internal.h | 3 +-- 2 files changed, 17 insertions(+), 23 deletions(-) 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 @@ 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 @@ drop: 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; 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 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; -- 2.7.4