git: a8e817cf5c9c - main - tcp: stop doing superfluous work after sending RST

The branch main has been updated by rscheff:

URL: https://cgit.FreeBSD.org/src/commit/?id=a8e817cf5c9c6e34357e0c078a256e2526b9da53

commit a8e817cf5c9c6e34357e0c078a256e2526b9da53
Author:     Richard Scheffenegger <rscheff@FreeBSD.org>
AuthorDate: 2024-02-10 09:24:10 +0000
Commit:     Richard Scheffenegger <rscheff@FreeBSD.org>
CommitDate: 2024-02-10 09:25:02 +0000

    tcp: stop doing superfluous work after sending RST
    
    When sending a RST control segment in tcp_output() it
    means we are in TCPS_CLOSED state, called from tcp_drop().
    Once the RST is sent, don't call tcp_timer_activate() or
    update anything in tcpcb, since that will go away shortly.
    
    PR:                     276761
    Provided by:            glebius
    Reviewed By:            glebius, tuexen, #transport
    Sponsored by:           NetApp, Inc.
    Differential Revision:  https://reviews.freebsd.org/D43808
---
 sys/netinet/tcp_output.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/sys/netinet/tcp_output.c b/sys/netinet/tcp_output.c
index 50dc05e9c55a..26a8ed70ceff 100644
--- a/sys/netinet/tcp_output.c
+++ b/sys/netinet/tcp_output.c
@@ -1516,9 +1516,13 @@ out:
 		tcp_account_for_send(tp, len, (tp->snd_nxt != tp->snd_max), 0, hw_tls);
 	/*
 	 * In transmit state, time the transmission and arrange for
-	 * the retransmit.  In persist state, just set snd_max.
+	 * the retransmit.  In persist state, just set snd_max.  In a closed
+	 * state just return.
 	 */
-	if ((tp->t_flags & TF_FORCEDATA) == 0 ||
+	if (flags & TH_RST) {
+		TCPSTAT_INC(tcps_sndtotal);
+		return (0);
+	} else if ((tp->t_flags & TF_FORCEDATA) == 0 ||
 	    !tcp_timer_active(tp, TT_PERSIST)) {
 		tcp_seq startseq = tp->snd_nxt;