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 <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index a26e2d2..0ffcd07 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -4307,6 +4307,12 @@
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 @@
__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 @@
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 @@
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 @@
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 @@
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 @@
tcp_enter_quickack_mode(sk);
inet_csk_schedule_ack(sk);
drop:
- __kfree_skb(skb);
+ tcp_drop(sk, skb);
return;
}
@@ -5233,7 +5240,7 @@
return true;
discard:
- __kfree_skb(skb);
+ tcp_drop(sk, skb);
return false;
}
@@ -5451,7 +5458,7 @@
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 @@
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 @@
if (!queued) {
discard:
- __kfree_skb(skb);
+ tcp_drop(sk, skb);
}
return 0;
}