tcp: extract code to compute SYNACK RTT

In preparation for adding another spot where we compute the SYNACK
RTT, extract this code so that it can be shared.

Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 1 insertions, 3 deletions

diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index f3bfb8bbfdec..cfeeeb7fcf54 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -1348,9 +1348,7 @@ static struct sock * tcp_v6_syn_recv_sock(struct sock *sk, struct sk_buff *skb,
                 newtp->advmss = tcp_sk(sk)->rx_opt.user_mss;
 
         tcp_initialize_rcv_mss(newsk);
-        if (tcp_rsk(req)->snt_synack)
-                tcp_valid_rtt_meas(newsk,
-                    tcp_time_stamp - tcp_rsk(req)->snt_synack);
+        tcp_synack_rtt_meas(newsk, req);
         newtp->total_retrans = req->retrans;
 
         newinet->inet_daddr = newinet->inet_saddr = LOOPBACK4_IPV6;