From: "David S. Miller" <davem@dm.cobaltmicro.com>
To: alan@cymru.net
Cc: Geert.Uytterhoeven@cs.kuleuven.ac.be,
Paul.Mackerras@cs.anu.edu.au, linuxppc-dev@lists.linuxppc.org,
linux-m68k@lists.linux-m68k.org, VANDROVE@vc.cvut.cz
Subject: Re: TCPv4 checksum errors
Date: Wed, 23 Dec 1998 23:36:53 -0800 [thread overview]
Message-ID: <199812240736.XAA06955@dm.cobaltmicro.com> (raw)
In-Reply-To: <199812232158.VAA21083@snowcrash.cymru.net> (message from Alan Cox on Wed, 23 Dec 1998 21:58:04 +0000 (GMT))
From: Alan Cox <alan@cymru.net>
Date: Wed, 23 Dec 1998 21:58:04 +0000 (GMT)
The classic bad packet error is a frame that ends up with
checksum =FFFF end around carry left =1
I challenge you to generate a packet which will create this condition,
it is impossible as far as I have tried....
However, I'm very very interested in being proved wrong. Because if I
am, then every single checksum implementation in the kernel would need
to be fixed and we should therefore settle this asap.
Instead of tiring one's brain like I did, to find if the case even
exists, better would probably be to put a piece of debugging code
which checked for this condition and printed out a nice message and
dumped the packet contents when triggered.
Later,
David S. Miller
davem@dm.cobaltmicro.com
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next prev parent reply other threads:[~1998-12-24 7:36 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
1998-12-21 21:49 TCPv4 checksum errors Geert Uytterhoeven
1998-12-22 3:07 ` Paul Mackerras
1998-12-22 7:21 ` Martin Costabel
1998-12-22 9:21 ` Geert Uytterhoeven
1998-12-22 9:35 ` David S. Miller
1998-12-22 10:01 ` Geert Uytterhoeven
1998-12-22 10:11 ` David S. Miller
1998-12-22 10:38 ` Geert Uytterhoeven
1998-12-22 10:13 ` Arno Griffioen
1998-12-23 9:14 ` Geert Uytterhoeven
1998-12-23 13:23 ` Gabriel Paubert
1998-12-23 21:58 ` Alan Cox
1998-12-24 7:36 ` David S. Miller [this message]
1998-12-28 9:20 ` Andreas Schwab
1998-12-28 13:04 ` Alan Cox
1998-12-28 13:12 ` Andreas Schwab
1998-12-24 3:57 ` Paul Mackerras
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