tcp: consolidate SYNACK RTT sampling

[cascardo/linux.git] / net / ipv4 / tcp_input.c

diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 28af45a..b531710 100644 (file)
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -2853,6 +2853,17 @@ static inline void tcp_ack_update_rtt(struct sock *sk, const int flag,
                tcp_ack_no_tstamp(sk, seq_rtt, flag);
 }
 
+/* Compute time elapsed between (last) SYNACK and the ACK completing 3WHS. */
+static void tcp_synack_rtt_meas(struct sock *sk, struct request_sock *req)
+{
+       struct tcp_sock *tp = tcp_sk(sk);
+       s32 seq_rtt = -1;
+
+       if (tp->lsndtime && !tp->total_retrans)
+               seq_rtt = tcp_time_stamp - tp->lsndtime;
+       tcp_ack_update_rtt(sk, FLAG_SYN_ACKED, seq_rtt);
+}
+
 static void tcp_cong_avoid(struct sock *sk, u32 ack, u32 in_flight)
 {
        const struct inet_connection_sock *icsk = inet_csk(sk);
@@ -5624,9 +5635,7 @@ int tcp_rcv_state_process(struct sock *sk, struct sk_buff *skb,
                 * so release it.
                 */
                if (req) {
-                       tcp_synack_rtt_meas(sk, req);
                        tp->total_retrans = req->num_retrans;
-
                        reqsk_fastopen_remove(sk, req, false);
                } else {
                        /* Make sure socket is routed, for correct metrics. */
@@ -5651,6 +5660,7 @@ int tcp_rcv_state_process(struct sock *sk, struct sk_buff *skb,
                tp->snd_una = TCP_SKB_CB(skb)->ack_seq;
                tp->snd_wnd = ntohs(th->window) << tp->rx_opt.snd_wscale;
                tcp_init_wl(tp, TCP_SKB_CB(skb)->seq);
+               tcp_synack_rtt_meas(sk, req);
 
                if (tp->rx_opt.tstamp_ok)
                        tp->advmss -= TCPOLEN_TSTAMP_ALIGNED;