diff options
| author |   hugh <hugh@openbsd.org> | 1999-11-15 05:50:59 +0000 |
|---|---|---|
| committer | hugh <hugh@openbsd.org> | 1999-11-15 05:50:59 +0000 |
| commit | 20014d98fec8e465734b37b00b8822a6f58786e3 (patch) | |
| tree | 366eb1c42e54e1a8a6b15ad5add03f9410b05499 /sys/netinet/tcp_input.c | |
| parent | Consistify DHCP man page titles somewhat; d@, sebastion@irelandmail.com (diff) | |
| download | wireguard-openbsd-20014d98fec8e465734b37b00b8822a6f58786e3.tar.xz wireguard-openbsd-20014d98fec8e465734b37b00b8822a6f58786e3.zip | |
Fix tcp retransmit/persist timers, provos@ OK.
Adapted from NetBSD:
Fix a retransmission bug introduced by the Brakmo and Peterson
RTO estimation changes. Under some circumstances it would
return a value of 0, while the old Van Jacobson RTO code would
return a minimum of 3. This would result in 12 retransmissions,
each 1 second apart. This takes care of those instances, and
ensures that t_rttmin is used everywhere as a lower bound.
Diffstat (limited to 'sys/netinet/tcp_input.c')
| -rw-r--r-- | sys/netinet/tcp_input.c | 14 |
1 files changed, 10 insertions, 4 deletions
diff --git a/sys/netinet/tcp_input.c b/sys/netinet/tcp_input.c index 142452d0849..e2a6b6136d3 100644 --- a/sys/netinet/tcp_input.c +++ b/sys/netinet/tcp_input.c @@ -1,4 +1,4 @@ -/* $OpenBSD: tcp_input.c,v 1.50 1999/11/04 11:24:23 ho Exp $ */ +/* $OpenBSD: tcp_input.c,v 1.51 1999/11/15 05:50:59 hugh Exp $ */ /* $NetBSD: tcp_input.c,v 1.23 1996/02/13 23:43:44 christos Exp $ */ /* @@ -2551,6 +2551,7 @@ tcp_xmit_timer(tp, rtt) short rtt; { register short delta; + short rttmin; tcpstat.tcps_rttupdated++; --rtt; @@ -2603,8 +2604,11 @@ tcp_xmit_timer(tp, rtt) * statistical, we have to test that we don't drop below * the minimum feasible timer (which is 2 ticks). */ - TCPT_RANGESET(tp->t_rxtcur, TCP_REXMTVAL(tp), - rtt + 2, TCPTV_REXMTMAX); + if (tp->t_rttmin > rtt + 2) + rttmin = tp->t_rttmin; + else + rttmin = rtt + 2; + TCPT_RANGESET(tp->t_rxtcur, TCP_REXMTVAL(tp), rttmin, TCPTV_REXMTMAX); /* * We received an ack for a packet that wasn't retransmitted; @@ -2704,7 +2708,9 @@ tcp_mss(tp, offer) * is also a minimum value; this is subject to time. */ if (rt->rt_rmx.rmx_locks & RTV_RTT) - tp->t_rttmin = rtt / (RTM_RTTUNIT / PR_SLOWHZ); + TCPT_RANGESET(tp->t_rttmin, + rtt / (RTM_RTTUNIT / PR_SLOWHZ), + TCPTV_MIN, TCPTV_REXMTMAX); tp->t_srtt = rtt / (RTM_RTTUNIT / (PR_SLOWHZ * TCP_RTT_SCALE)); if (rt->rt_rmx.rmx_rttvar) tp->t_rttvar = rt->rt_rmx.rmx_rttvar / |