diff options
| author | Randall Stewart <rrs@FreeBSD.org> | 2021-05-27 14:50:32 +0000 |
|---|---|---|
| committer | Randall Stewart <rrs@FreeBSD.org> | 2021-05-27 14:50:32 +0000 |
| commit | 8c69d988a8d32e53310c7b73ec8721b04b7249e6 (patch) | |
| tree | 6a37f20260a0afb70508726377aadb5b6b8a5103 /sys/netinet | |
| parent | 4cc8a9da491d10f1b4bad6a50730b67dd5e899c7 (diff) | |
| download | src-8c69d988a8d32e53310c7b73ec8721b04b7249e6.tar.gz src-8c69d988a8d32e53310c7b73ec8721b04b7249e6.zip | |
tcp: When we have an out-of-order FIN we do want to strip off the FIN bit.
The last set of commits fixed both a panic (in rack) and an ACK-war (in freebsd and bbr).
However there was a missing case, i.e. where we get an out-of-order FIN by itself.
In such a case we don't want to leave the FIN bit set, otherwise we will do the
wrong thing and ack the FIN incorrectly. Instead we need to go through the
tcp_reasm() code and that way the FIN will be stripped and all will be well.
Reviewed by: mtuexen,rscheff
Sponsored by: Netflix Inc
Differential Revision: https://reviews.freebsd.org/D30497
Diffstat (limited to 'sys/netinet')
| -rw-r--r-- | sys/netinet/tcp_input.c | 7 | ||||
| -rw-r--r-- | sys/netinet/tcp_stacks/bbr.c | 7 | ||||
| -rw-r--r-- | sys/netinet/tcp_stacks/rack.c | 7 |
3 files changed, 18 insertions, 3 deletions
diff --git a/sys/netinet/tcp_input.c b/sys/netinet/tcp_input.c index b9836a137608..1dab2e511d95 100644 --- a/sys/netinet/tcp_input.c +++ b/sys/netinet/tcp_input.c @@ -3191,7 +3191,12 @@ dodata: /* XXX */ * when trimming from the head. */ tcp_seq temp = save_start; - if (tlen) { + if (tlen || (th->th_seq != tp->rcv_nxt)) { + /* + * We add the th_seq != rcv_nxt to + * catch the case of a stand alone out + * of order FIN. + */ thflags = tcp_reass(tp, th, &temp, &tlen, m); tp->t_flags |= TF_ACKNOW; } diff --git a/sys/netinet/tcp_stacks/bbr.c b/sys/netinet/tcp_stacks/bbr.c index b2fc5c1f928e..5b97c3d7800f 100644 --- a/sys/netinet/tcp_stacks/bbr.c +++ b/sys/netinet/tcp_stacks/bbr.c @@ -8320,7 +8320,12 @@ bbr_process_data(struct mbuf *m, struct tcphdr *th, struct socket *so, * trimming from the head. */ tcp_seq temp = save_start; - if (tlen) { + if (tlen || (th->th_seq != tp->rcv_nxt)) { + /* + * We add the th_seq != rcv_nxt to + * catch the case of a stand alone out + * of order FIN. + */ thflags = tcp_reass(tp, th, &temp, &tlen, m); tp->t_flags |= TF_ACKNOW; } diff --git a/sys/netinet/tcp_stacks/rack.c b/sys/netinet/tcp_stacks/rack.c index b7e8c1578f2b..1db09e30d968 100644 --- a/sys/netinet/tcp_stacks/rack.c +++ b/sys/netinet/tcp_stacks/rack.c @@ -10235,7 +10235,12 @@ rack_process_data(struct mbuf *m, struct tcphdr *th, struct socket *so, * trimming from the head. */ tcp_seq temp = save_start; - if (tlen) { + if (tlen || (th->th_seq != tp->rcv_nxt)) { + /* + * We add the th_seq != rcv_nxt to + * catch the case of a stand alone out + * of order FIN. + */ thflags = tcp_reass(tp, th, &temp, &tlen, m); tp->t_flags |= TF_ACKNOW; } |