Date: Fri, 1 Apr 2011 01:40:17 +0200 From: Stefan `Sec` Zehl <sec@42.org> To: John Baldwin <jhb@freebsd.org> Cc: freebsd-net@freebsd.org Subject: Re: The tale of a TCP bug Message-ID: <20110331234017.GC3308@ice.42.org> In-Reply-To: <201103300838.09608.jhb@freebsd.org> References: <4D8B99B4.4070404@FreeBSD.org> <201103281423.52202.jhb@freebsd.org> <20110328183810.GF23803@ice.42.org> <201103300838.09608.jhb@freebsd.org>
next in thread | previous in thread | raw e-mail | index | archive | help
On Wed, Mar 30, 2011 at 08:38 -0400, John Baldwin wrote:
> There is at least one case I know of related to a bug I reported earlier
> where a window probe from a remote connection can cause rcv_nxt to advance
> past rcv_adv by one. However, I think we want to know about those cases,
> and we should probably be treating rcv_adv - rcv_nxt as if it is zero in
> that case, not -1 (my patch in my original e-mail does just that in a
> different place in tcp_output() when we calculate the window "for real").
I've been running for about a day now with the committed patch and
adv_neg is still zero:
| ice:~>uptime; sysctl net.inet.tcp.adv_neg
| 1:36AM up 1 day, 4:52, 1 user, load averages: 0.12, 0.06, 0.05
| net.inet.tcp.adv_neg: 0
I'll of course monitor this value and report back if I ever see it
increase :-)
CU,
Sec
--
Diplomacy is the ability to tell a person to go to hell in such a nice way
that he or she looks forward to the trip.
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20110331234017.GC3308>