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authorEric Dumazet <eric.dumazet@gmail.com>2010-03-19 08:37:18 +0300
committerDavid S. Miller <davem@davemloft.net>2010-03-22 04:31:35 +0300
commit907cdda5205b012eec7513f66713749b293188c9 (patch)
tree0488e7282c2d3748d90f8ceca78a183f905c4167 /net/ipv4/tcp_minisocks.c
parent32a806c194ea112cfab00f558482dd97bee5e44e (diff)
downloadlinux-907cdda5205b012eec7513f66713749b293188c9.tar.xz
tcp: Add SNMP counter for DEFER_ACCEPT
Its currently hard to diagnose when ACK frames are dropped because an application set TCP_DEFER_ACCEPT on its listening socket. See http://bugzilla.kernel.org/show_bug.cgi?id=15507 This patch adds a SNMP value, named TCPDeferAcceptDrop netstat -s | grep TCPDeferAcceptDrop TCPDeferAcceptDrop: 0 This counter is incremented every time we drop a pure ACK frame received by a socket in SYN_RECV state because its SYNACK retrans count is lower than defer_accept value. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4/tcp_minisocks.c')
-rw-r--r--net/ipv4/tcp_minisocks.c1
1 files changed, 1 insertions, 0 deletions
diff --git a/net/ipv4/tcp_minisocks.c b/net/ipv4/tcp_minisocks.c
index 4199bc6915c5..32f96278a24a 100644
--- a/net/ipv4/tcp_minisocks.c
+++ b/net/ipv4/tcp_minisocks.c
@@ -671,6 +671,7 @@ struct sock *tcp_check_req(struct sock *sk, struct sk_buff *skb,
if (req->retrans < inet_csk(sk)->icsk_accept_queue.rskq_defer_accept &&
TCP_SKB_CB(skb)->end_seq == tcp_rsk(req)->rcv_isn + 1) {
inet_rsk(req)->acked = 1;
+ NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPDEFERACCEPTDROP);
return NULL;
}