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tcp: fix handling of TCP RST segments missing timestamps

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A TCP RST segment should be processed even it is missing TCP
timestamps.

Reported by:		dmgk@, kevans@
Reviewed by:		rscheff@, dmgk@
Sponsored by:		Netflix, Inc.
MFC after:		3 days
Differential Revision:	https://reviews.freebsd.org/D28143
This commit is contained in:
Michael Tuexen 2021-01-13 23:43:40 +01:00
parent 03cab14ea3
commit cc3c34859e
3 changed files with 21 additions and 10 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

21
sys/netinet/tcp_input.c
View File

@ -1692,16 +1692,25 @@ tcp_do_segment(struct mbuf *m, struct tcphdr *th, struct socket *so,
/*
* If timestamps were negotiated during SYN/ACK and a
* segment without a timestamp is received, silently drop
* the segment.
* the segment, unless it is a RST segment.
* See section 3.2 of RFC 7323.
*/
if ((tp->t_flags & TF_RCVD_TSTMP) && !(to.to_flags & TOF_TS)) {
if ((s = tcp_log_addrs(inc, th, NULL, NULL))) {
log(LOG_DEBUG, "%s; %s: Timestamp missing, "
"segment silently dropped\n", s, __func__);
free(s, M_TCPLOG);
if ((thflags & TH_RST) != 0) {
if ((s = tcp_log_addrs(inc, th, NULL, NULL))) {
log(LOG_DEBUG, "%s; %s: Timestamp missing, "
"segment processed normally\n",
s, __func__);
free(s, M_TCPLOG);
}
} else {
if ((s = tcp_log_addrs(inc, th, NULL, NULL))) {
log(LOG_DEBUG, "%s; %s: Timestamp missing, "
"segment silently dropped\n", s, __func__);
free(s, M_TCPLOG);
}
goto drop;
}
goto drop;
}
/*
* If timestamps were not negotiated during SYN/ACK and a

5
sys/netinet/tcp_stacks/bbr.c
View File

@ -11463,10 +11463,11 @@ bbr_do_segment_nounlock(struct mbuf *m, struct tcphdr *th, struct socket *so,
/*
* If timestamps were negotiated during SYN/ACK and a
* segment without a timestamp is received, silently drop
* the segment.
* the segment, unless it is a RST segment.
* See section 3.2 of RFC 7323.
*/
if ((tp->t_flags & TF_RCVD_TSTMP) && !(to.to_flags & TOF_TS)) {
if ((tp->t_flags & TF_RCVD_TSTMP) && !(to.to_flags & TOF_TS) &&
((thflags & TH_RST) == 0)) {
retval = 0;
goto done_with_input;
}

5
sys/netinet/tcp_stacks/rack.c
View File

@ -10879,10 +10879,11 @@ rack_do_segment_nounlock(struct mbuf *m, struct tcphdr *th, struct socket *so,
/*
* If timestamps were negotiated during SYN/ACK and a
* segment without a timestamp is received, silently drop
* the segment.
* the segment, unless it is a RST segment.
* See section 3.2 of RFC 7323.
*/
if ((tp->t_flags & TF_RCVD_TSTMP) && !(to.to_flags & TOF_TS)) {
if ((tp->t_flags & TF_RCVD_TSTMP) && !(to.to_flags & TOF_TS) &&
((thflags & TH_RST) == 0)) {
way_out = 5;
retval = 0;
goto done_with_input;