diff options
| author | Yafang Shao | 2018-06-24 10:02:54 -0400 |
|---|---|---|
| committer | David S. Miller | 2018-06-26 11:49:08 +0900 |
| commit | fb223502ec0889444965f602f57b1f45f9e9845e (patch) | |
| tree | 08a4895a31a307722691a1f6abdb1e44c658dece /net | |
| parent | 7e55052783fd3a9202e9f7c4c480629a7270645f (diff) | |
tcp: add SNMP counter for zero-window drops
It will be helpful if we could display the drops due to zero window or no
enough window space.
So a new SNMP MIB entry is added to track this behavior.
This entry is named LINUX_MIB_TCPZEROWINDOWDROP and published in
/proc/net/netstat in TcpExt line as TCPZeroWindowDrop.
Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
| -rw-r--r-- | net/ipv4/proc.c | 1 | ||||
| -rw-r--r-- | net/ipv4/tcp_input.c | 8 |
2 files changed, 7 insertions, 2 deletions
diff --git a/net/ipv4/proc.c b/net/ipv4/proc.c index 77350c1256ce..225ef3433fe5 100644 --- a/net/ipv4/proc.c +++ b/net/ipv4/proc.c @@ -287,6 +287,7 @@ static const struct snmp_mib snmp4_net_list[] = { SNMP_MIB_ITEM("TCPDelivered", LINUX_MIB_TCPDELIVERED), SNMP_MIB_ITEM("TCPDeliveredCE", LINUX_MIB_TCPDELIVEREDCE), SNMP_MIB_ITEM("TCPAckCompressed", LINUX_MIB_TCPACKCOMPRESSED), + SNMP_MIB_ITEM("TCPZeroWindowDrop", LINUX_MIB_TCPZEROWINDOWDROP), SNMP_MIB_SENTINEL }; diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index 76ca88f63b70..9c5b3415413f 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -4668,8 +4668,10 @@ static void tcp_data_queue(struct sock *sk, struct sk_buff *skb) * Out of sequence packets to the out_of_order_queue. */ if (TCP_SKB_CB(skb)->seq == tp->rcv_nxt) { - if (tcp_receive_window(tp) == 0) + if (tcp_receive_window(tp) == 0) { + NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPZEROWINDOWDROP); goto out_of_window; + } /* Ok. In sequence. In window. */ queue_and_out: @@ -4735,8 +4737,10 @@ drop: /* If window is closed, drop tail of packet. But after * remembering D-SACK for its head made in previous line. */ - if (!tcp_receive_window(tp)) + if (!tcp_receive_window(tp)) { + NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPZEROWINDOWDROP); goto out_of_window; + } goto queue_and_out; } |