From 532182cd610782db8c18230c2747626562032205 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Fri, 1 Apr 2016 08:52:19 -0700 Subject: [PATCH] tcp: increment sk_drops for dropped rx packets Now ss can report sk_drops, we can instruct TCP to increment this per socket counter when it drops an incoming frame, to refine monitoring and debugging. Following patch takes care of listeners drops. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller --- include/net/sock.h | 7 +++++++ net/ipv4/tcp_input.c | 33 ++++++++++++++++++++------------- net/ipv4/tcp_ipv4.c | 1 + net/ipv6/tcp_ipv6.c | 1 + 4 files changed, 29 insertions(+), 13 deletions(-) diff --git a/include/net/sock.h b/include/net/sock.h index 7ad73db9dde2..310c4367ea83 100644 --- a/include/net/sock.h +++ b/include/net/sock.h @@ -2012,6 +2012,13 @@ sock_skb_set_dropcount(const struct sock *sk, struct sk_buff *skb) SOCK_SKB_CB(skb)->dropcount = atomic_read(&sk->sk_drops); } +static inline void sk_drops_add(struct sock *sk, const struct sk_buff *skb) +{ + int segs = max_t(u16, 1, skb_shinfo(skb)->gso_segs); + + atomic_add(segs, &sk->sk_drops); +} + void __sock_recv_timestamp(struct msghdr *msg, struct sock *sk, struct sk_buff *skb); void __sock_recv_wifi_status(struct msghdr *msg, struct sock *sk, diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index a26e2d262358..0ffcd07e3409 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -4307,6 +4307,12 @@ static bool tcp_try_coalesce(struct sock *sk, return true; } +static void tcp_drop(struct sock *sk, struct sk_buff *skb) +{ + sk_drops_add(sk, skb); + __kfree_skb(skb); +} + /* This one checks to see if we can put data from the * out_of_order queue into the receive_queue. */ @@ -4331,7 +4337,7 @@ static void tcp_ofo_queue(struct sock *sk) __skb_unlink(skb, &tp->out_of_order_queue); if (!after(TCP_SKB_CB(skb)->end_seq, tp->rcv_nxt)) { SOCK_DEBUG(sk, "ofo packet was already received\n"); - __kfree_skb(skb); + tcp_drop(sk, skb); continue; } SOCK_DEBUG(sk, "ofo requeuing : rcv_next %X seq %X - %X\n", @@ -4383,7 +4389,7 @@ static void tcp_data_queue_ofo(struct sock *sk, struct sk_buff *skb) if (unlikely(tcp_try_rmem_schedule(sk, skb, skb->truesize))) { NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPOFODROP); - __kfree_skb(skb); + tcp_drop(sk, skb); return; } @@ -4447,7 +4453,7 @@ static void tcp_data_queue_ofo(struct sock *sk, struct sk_buff *skb) if (!after(end_seq, TCP_SKB_CB(skb1)->end_seq)) { /* All the bits are present. Drop. */ NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPOFOMERGE); - __kfree_skb(skb); + tcp_drop(sk, skb); skb = NULL; tcp_dsack_set(sk, seq, end_seq); goto add_sack; @@ -4486,7 +4492,7 @@ static void tcp_data_queue_ofo(struct sock *sk, struct sk_buff *skb) tcp_dsack_extend(sk, TCP_SKB_CB(skb1)->seq, TCP_SKB_CB(skb1)->end_seq); NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPOFOMERGE); - __kfree_skb(skb1); + tcp_drop(sk, skb1); } add_sack: @@ -4569,12 +4575,13 @@ err: static void tcp_data_queue(struct sock *sk, struct sk_buff *skb) { struct tcp_sock *tp = tcp_sk(sk); - int eaten = -1; bool fragstolen = false; + int eaten = -1; - if (TCP_SKB_CB(skb)->seq == TCP_SKB_CB(skb)->end_seq) - goto drop; - + if (TCP_SKB_CB(skb)->seq == TCP_SKB_CB(skb)->end_seq) { + __kfree_skb(skb); + return; + } skb_dst_drop(skb); __skb_pull(skb, tcp_hdr(skb)->doff * 4); @@ -4656,7 +4663,7 @@ out_of_window: tcp_enter_quickack_mode(sk); inet_csk_schedule_ack(sk); drop: - __kfree_skb(skb); + tcp_drop(sk, skb); return; } @@ -5233,7 +5240,7 @@ syn_challenge: return true; discard: - __kfree_skb(skb); + tcp_drop(sk, skb); return false; } @@ -5451,7 +5458,7 @@ csum_error: TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_INERRS); discard: - __kfree_skb(skb); + tcp_drop(sk, skb); } EXPORT_SYMBOL(tcp_rcv_established); @@ -5682,7 +5689,7 @@ static int tcp_rcv_synsent_state_process(struct sock *sk, struct sk_buff *skb, TCP_DELACK_MAX, TCP_RTO_MAX); discard: - __kfree_skb(skb); + tcp_drop(sk, skb); return 0; } else { tcp_send_ack(sk); @@ -6043,7 +6050,7 @@ int tcp_rcv_state_process(struct sock *sk, struct sk_buff *skb) if (!queued) { discard: - __kfree_skb(skb); + tcp_drop(sk, skb); } return 0; } diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c index e5f924b29946..059a98f5e7e1 100644 --- a/net/ipv4/tcp_ipv4.c +++ b/net/ipv4/tcp_ipv4.c @@ -1694,6 +1694,7 @@ discard_it: return 0; discard_and_relse: + sk_drops_add(sk, skb); if (refcounted) sock_put(sk); goto discard_it; diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c index f0422e782731..5fa8fea394c9 100644 --- a/net/ipv6/tcp_ipv6.c +++ b/net/ipv6/tcp_ipv6.c @@ -1484,6 +1484,7 @@ discard_it: return 0; discard_and_relse: + sk_drops_add(sk, skb); if (refcounted) sock_put(sk); goto discard_it; -- 2.30.2