| Submitter | Yuchung Cheng |
|---|---|
| Date | Jan. 31, 2013, 7:16 p.m. |
| Message ID | <1359659806-29556-1-git-send-email-ycheng@google.com> |
| Download | mbox | patch |
| Permalink | /patch/217244/ |
| State | Accepted |
| Delegated to: | David Miller |
| Headers | show |
Comments
From: Yuchung Cheng <ycheng@google.com> Date: Thu, 31 Jan 2013 11:16:46 -0800 > On receiving the SYN-ACK, Fast Open checks icsk_retransmit for SYN > retransmission to detect SYN/data drops. But if F-RTO is disabled, > icsk_retransmit is reset at step D of tcp_fastretrans_alert() ( > under tcp_ack()) before tcp_rcv_fastopen_synack(). The fix is to use > total_retrans instead which accounts for SYN retransmission regardless > the use of F-RTO. > > Signed-off-by: Yuchung Cheng <ycheng@google.com> Applied, thanks. -- 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
Patch
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index 492c7cf..de52403 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -5647,8 +5647,7 @@ static bool tcp_rcv_fastopen_synack(struct sock *sk, struct sk_buff *synack, * the remote receives only the retransmitted (regular) SYNs: either * the original SYN-data or the corresponding SYN-ACK is lost. */ - syn_drop = (cookie->len <= 0 && data && - inet_csk(sk)->icsk_retransmits); + syn_drop = (cookie->len <= 0 && data && tp->total_retrans); tcp_fastopen_cache_set(sk, mss, cookie, syn_drop);
On receiving the SYN-ACK, Fast Open checks icsk_retransmit for SYN retransmission to detect SYN/data drops. But if F-RTO is disabled, icsk_retransmit is reset at step D of tcp_fastretrans_alert() ( under tcp_ack()) before tcp_rcv_fastopen_synack(). The fix is to use total_retrans instead which accounts for SYN retransmission regardless the use of F-RTO. Signed-off-by: Yuchung Cheng <ycheng@google.com> --- net/ipv4/tcp_input.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-)