Re: forged tsecr giving -ve numbers in rtt calculation causing retran
From: Richard Wendland (richard_at_starburst.demon.co.uk)
To: email@example.com (Mike Silbersack) Date: Tue, 20 Jan 2004 00:27:48 +0000 (GMT)
> Hm, wasn't this accounted for in rev 1.174 / 188.8.131.52? From Matt's
> commit log:
True. My notes must have been from an older version. Sorry.
> Of course, that doesn't account for other non-zero strange values. I
> guess the timestamp code needs a lot of work. :(
This does suggest Ken is seeing TSecr messed up in some other way than
I'd expect this to be a pretty rare event, and perhaps my suggestion
that the 64 sec TCPTV_REXMTMAX limit be implemented correctly is a
good enough solution on its own for a rare event. It should certainly
avoid the insane -450000000 tp->t_rxtcur Ken has seen. It's simple to
implement, does what was probably originally intended, and also protects
from bizarre problems with non-timestamp option SRTT calculation.
Full validation of TSecr would be nice, but perhaps excessive for
something that should not happen. A 64 second RTO may discourage such
-- Richard Wendland firstname.lastname@example.org _______________________________________________ email@example.com mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-net To unsubscribe, send any mail to "firstname.lastname@example.org"