| Message ID | 1348369427-29563-1-git-send-email-ncardwell@google.com |
|---|---|
| State | Accepted, archived |
| Delegated to: | David Miller |
| Headers | show |
From: Neal Cardwell <ncardwell@google.com> Date: Sat, 22 Sep 2012 23:03:47 -0400 > When recording the number of SYNACK retransmits for servers using TCP > Fast Open, fix the code to ensure that we copy over the retransmit > count from the request_sock after we receive the ACK that completes > the 3-way handshake. > > The story here is similar to that of SYNACK RTT > measurements. Previously we were always doing this in > tcp_v4_syn_recv_sock(). However, for TCP Fast Open connections > tcp_v4_conn_req_fastopen() calls tcp_v4_syn_recv_sock() at the time we > receive the SYN. So for TFO we must copy the final SYNACK retransmit > count in tcp_rcv_state_process(). > > Note that copying over the SYNACK retransmit count will give us the > correct count since, as is mentioned in a comment in > tcp_retransmit_timer(), before we receive an ACK for our SYN-ACK a TFO > passive connection does not retransmit anything else (e.g., data or > FIN segments). > > Signed-off-by: Neal Cardwell <ncardwell@google.com> Applied, thanks Neal. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index 36e069a1..e037697 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -5985,6 +5985,8 @@ int tcp_rcv_state_process(struct sock *sk, struct sk_buff *skb, */ if (req) { tcp_synack_rtt_meas(sk, req); + tp->total_retrans = req->retrans; + reqsk_fastopen_remove(sk, req, false); } else { /* Make sure socket is routed, for
When recording the number of SYNACK retransmits for servers using TCP Fast Open, fix the code to ensure that we copy over the retransmit count from the request_sock after we receive the ACK that completes the 3-way handshake. The story here is similar to that of SYNACK RTT measurements. Previously we were always doing this in tcp_v4_syn_recv_sock(). However, for TCP Fast Open connections tcp_v4_conn_req_fastopen() calls tcp_v4_syn_recv_sock() at the time we receive the SYN. So for TFO we must copy the final SYNACK retransmit count in tcp_rcv_state_process(). Note that copying over the SYNACK retransmit count will give us the correct count since, as is mentioned in a comment in tcp_retransmit_timer(), before we receive an ACK for our SYN-ACK a TFO passive connection does not retransmit anything else (e.g., data or FIN segments). Signed-off-by: Neal Cardwell <ncardwell@google.com> --- net/ipv4/tcp_input.c | 2 ++ 1 files changed, 2 insertions(+), 0 deletions(-)