git: bb9dcbf1a243 - stable/13 - tcp: stop spurious rescue retransmissions and potential asserts

[Richard Scheffenegger]

The branch stable/13 has been updated by rscheff:

URL: https://cgit.FreeBSD.org/src/commit/?id=bb9dcbf1a243ac92855c0109fd922c2ba60eb691

commit bb9dcbf1a243ac92855c0109fd922c2ba60eb691
Author:     Richard Scheffenegger <rscheff at FreeBSD.org>
AuthorDate: 2021-04-28 12:56:14 +0000
Commit:     Richard Scheffenegger <rscheff at FreeBSD.org>
CommitDate: 2021-05-01 08:26:53 +0000

    tcp: stop spurious rescue retransmissions and potential asserts
    
    Reported by: pho@
    MFC after: 3 days
    Reviewed By: tuexen, #transport
    Sponsored by: NetApp, Inc.
    Differential Revision: https://reviews.freebsd.org/D29970
    
    (cherry picked from commit 48be5b976e34022862da3be69350d60e969d39e5)
---
 sys/netinet/tcp_input.c | 1 +
 sys/netinet/tcp_sack.c  | 4 +++-
 2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/sys/netinet/tcp_input.c b/sys/netinet/tcp_input.c
index 9905fc01ced8..eec722d8097e 100644
--- a/sys/netinet/tcp_input.c
+++ b/sys/netinet/tcp_input.c
@@ -510,6 +510,7 @@ cc_post_recovery(struct tcpcb *tp, struct tcphdr *th)
 	}
 	/* XXXLAS: EXIT_RECOVERY ? */
 	tp->t_bytes_acked = 0;
+	tp->sackhint.delivered_data = 0;
 	tp->sackhint.prr_out = 0;
 }
 
diff --git a/sys/netinet/tcp_sack.c b/sys/netinet/tcp_sack.c
index 40d63bd3832f..9187a9fc66d8 100644
--- a/sys/netinet/tcp_sack.c
+++ b/sys/netinet/tcp_sack.c
@@ -866,9 +866,11 @@ tcp_sack_partialack(struct tcpcb *tp, struct tcphdr *th)
 		tcp_seq highdata = tp->snd_max;
 		if (tp->t_flags & TF_SENTFIN)
 			highdata--;
-		if (th->th_ack != highdata)
+		if (th->th_ack != highdata) {
+			tp->snd_fack = th->th_ack;
 			(void)tcp_sackhole_insert(tp, SEQ_MAX(th->th_ack,
 			    highdata - maxseg), highdata, NULL);
+		}
 	}
 	(void) tp->t_fb->tfb_tcp_output(tp);
 }