tcp: add OFO snmp counters
Add three SNMP TCP counters, to better track TCP behavior
at global stage (netstat -s), when packets are received
Out Of Order (OFO)
TCPOFOQueue : Number of packets queued in OFO queue
TCPOFODrop : Number of packets meant to be queued in OFO
but dropped because socket rcvbuf limit hit.
TCPOFOMerge : Number of packets in OFO that were merged with
other packets.
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 055ac49..cc4e12f 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -4397,8 +4397,8 @@
TCP_ECN_check_ce(tp, skb);
- if (tcp_try_rmem_schedule(sk, skb->truesize)) {
- /* TODO: should increment a counter */
+ if (unlikely(tcp_try_rmem_schedule(sk, skb->truesize))) {
+ NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPOFODROP);
__kfree_skb(skb);
return;
}
@@ -4407,6 +4407,7 @@
tp->pred_flags = 0;
inet_csk_schedule_ack(sk);
+ NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPOFOQUEUE);
SOCK_DEBUG(sk, "out of order segment: rcv_next %X seq %X - %X\n",
tp->rcv_nxt, TCP_SKB_CB(skb)->seq, TCP_SKB_CB(skb)->end_seq);
@@ -4460,6 +4461,7 @@
if (skb1 && before(seq, TCP_SKB_CB(skb1)->end_seq)) {
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);
skb = NULL;
tcp_dsack_set(sk, seq, end_seq);
@@ -4498,6 +4500,7 @@
__skb_unlink(skb1, &tp->out_of_order_queue);
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);
}