diff options
| author | Michael Tuexen <tuexen@FreeBSD.org> | 2026-04-17 07:11:41 +0000 |
|---|---|---|
| committer | Michael Tuexen <tuexen@FreeBSD.org> | 2026-04-17 07:11:41 +0000 |
| commit | 3a54aa3b0911bef15e014b8a8185e116efb0a918 (patch) | |
| tree | 9ee7ce905d34daea1b99ccfbc18a35b69ac5e466 | |
| parent | b3b23f284a67317309af7c30bb70d5f461f3f02f (diff) | |
tcp: use RFC 6191 for connection recycling in TIME-WAIT
Implement the criteria specified in RFC 6191 for recycling TCP
connections in TIME-WAIT.
Reviewed by: rscheff, Marius Halden
Sponsored by: Netflix, Inc.
Differential Revision: https://reviews.freebsd.org/D56321
| -rw-r--r-- | sys/netinet/tcp_timewait.c | 11 |
1 files changed, 8 insertions, 3 deletions
diff --git a/sys/netinet/tcp_timewait.c b/sys/netinet/tcp_timewait.c index 430e98910743..eaa2fa336a94 100644 --- a/sys/netinet/tcp_timewait.c +++ b/sys/netinet/tcp_timewait.c @@ -215,12 +215,17 @@ tcp_twcheck(struct inpcb *inp, struct tcpopt *to, struct tcphdr *th, /* * If a new connection request is received * while in TIME_WAIT, drop the old connection - * and start over if the sequence numbers - * are above the previous ones. + * and start over if allowed by RFC 6191. * Allow UDP port number changes in this case. */ if (((thflags & (TH_SYN | TH_ACK)) == TH_SYN) && - SEQ_GT(th->th_seq, tp->rcv_nxt)) { + ((((tp->t_flags & TF_RCVD_TSTMP) != 0) && + ((to->to_flags & TOF_TS) != 0) && + TSTMP_LT(tp->ts_recent, to->to_tsval)) || + (((tp->t_flags & TF_RCVD_TSTMP) == 0) && + ((to->to_flags & TOF_TS) != 0) && + (V_tcp_tolerate_missing_ts == 0)) || + SEQ_GT(th->th_seq, tp->rcv_nxt))) { /* * In case we can't upgrade our lock just pretend we have * lost this packet. |