Skip site navigation (1)Skip section navigation (2)
Date:      Sun, 23 Jan 2000 08:32:34 -0800
From:      Alfred Perlstein <bright@wintelcom.net>
To:        Richard Steenbergen <ras@above.net>
Cc:        freebsd-security@FreeBSD.ORG
Subject:   Re: stream.c
Message-ID:  <20000123083234.N26520@fw.wintelcom.net>
In-Reply-To: <20000123102829.C18349@above.net>; from ras@above.net on Sun, Jan 23, 2000 at 10:28:30AM -0500
References:  <20000123102829.C18349@above.net>

next in thread | previous in thread | raw e-mail | index | archive | help
* Richard Steenbergen <ras@above.net> [000123 07:53] wrote:
> 
> The correct "sorta-fix" is to rate limit the number of dropwithreset's per
> second, else kick them down to straight drop. I believe this has been done
> effectively in http://www.freebsd.org/~alfred/tcp_fix.diff (though I
> question what its aimed to be accomplished with that checksum work :P).

The idea is to reduce the amount of time spent doing checksums on invalid
packets, why checksum if the destination port isn't open or no such
connection is open?

Unfortunatly even after moving the checksum quite far into tcp_input's
path it still seems pretty easy to eat all CPU on a box, in fact I
didn't notice any improvement at all.

Maybe i'm missing something, those interested can have a try at:
http://www.freebsd.org/~alfred/tcp_fix_untested.diff

maybe someone can tell me what i'm screwing up.

> yada yada hope this helps someone, I'm so sick of stream.c its not even
> funny.

:)

-- 
-Alfred Perlstein - [bright@wintelcom.net|alfred@freebsd.org]


To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe freebsd-security" in the body of the message




Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20000123083234.N26520>