The branch main has been updated by rscheff: URL: https://cgit.FreeBSD.org/src/commit/?id=66605ff791b12a2c3bb4570379db0e14d29fca4c
commit 66605ff791b12a2c3bb4570379db0e14d29fca4c Author: Richard Scheffenegger <[email protected]> AuthorDate: 2022-07-14 00:49:10 +0000 Commit: Richard Scheffenegger <[email protected]> CommitDate: 2022-07-14 01:18:19 +0000 tcp: Undo the increase in sequence number by 1 due to the FIN flag in case of a transient error. If an error occurs while processing a TCP segment with some data and the FIN flag, the back out of the sequence number advance does not take into account the increase by 1 due to the FIN flag. Reviewed By: jch, gnn, #transport, tuexen Sponsored by: NetApp, Inc. Differential Revision: https://reviews.freebsd.org/D2970 --- sys/netinet/tcp_output.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/sys/netinet/tcp_output.c b/sys/netinet/tcp_output.c index cd6238f10401..d2f946034c60 100644 --- a/sys/netinet/tcp_output.c +++ b/sys/netinet/tcp_output.c @@ -1681,8 +1681,13 @@ timer: tp->sackhint.sack_bytes_rexmit -= len; KASSERT(tp->sackhint.sack_bytes_rexmit >= 0, ("sackhint bytes rtx >= 0")); - } else + KASSERT((flags & TH_FIN) == 0, + ("error while FIN with SACK rxmit")); + } else { tp->snd_nxt -= len; + if (flags & TH_FIN) + tp->snd_nxt--; + } } SOCKBUF_UNLOCK_ASSERT(&so->so_snd); /* Check gotos. */ switch (error) {
