tcp: account SYN-ACK timeouts & retransmissions

Currently we don't increment SYN-ACK timeouts & retransmissions
although we do increment the same stats for SYN. We seem to have lost
the SYN-ACK accounting with the introduction of tcp_syn_recv_timer
(commit 2248761e in the netdev-vger-cvs tree).

This patch fixes this issue. In the process we also rename the v4/v6
syn/ack retransmit functions for clarity. We also add a new
request_socket operations (syn_ack_timeout) so we can keep code in
inet_connection_sock.c protocol agnostic.

Signed-off-by: Octavian Purdila <opurdila@ixiacom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 10 insertions, 2 deletions

diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index 1c832bf198b3..82f2dea0e39e 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -520,6 +520,13 @@ done:
         return err;
 }
 
+static int tcp_v6_rtx_synack(struct sock *sk, struct request_sock *req,
+                             struct request_values *rvp)
+{
+        TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_RETRANSSEGS);
+        return tcp_v6_send_synack(sk, req, rvp);
+}
+
 static inline void syn_flood_warning(struct sk_buff *skb)
 {
 #ifdef CONFIG_SYN_COOKIES
@@ -890,10 +897,11 @@ static int tcp_v6_inbound_md5_hash (struct sock *sk, struct sk_buff *skb)
 struct request_sock_ops tcp6_request_sock_ops __read_mostly = {
         .family         =       AF_INET6,
         .obj_size       =       sizeof(struct tcp6_request_sock),
-        .rtx_syn_ack    =       tcp_v6_send_synack,
+        .rtx_syn_ack    =       tcp_v6_rtx_synack,
         .send_ack       =       tcp_v6_reqsk_send_ack,
         .destructor     =       tcp_v6_reqsk_destructor,
-        .send_reset     =       tcp_v6_send_reset
+        .send_reset     =       tcp_v6_send_reset,
+        .syn_ack_timeout =      tcp_syn_ack_timeout,
 };
 
 #ifdef CONFIG_TCP_MD5SIG