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Date: Sun, 25 Jan 2004 13:13:28 -0600 (CST)
From: Mike Silbersack <silby@silby.com>
To: Robert Watson <rwatson@freebsd.org>
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cc: Max Laier <max@love2party.net>
cc: hackers@freebsd.org
Subject: Re: XL driver checksum producing corrupted but checksum-correct
 packets
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On Sat, 24 Jan 2004, Robert Watson wrote:

> To pick up the corrupted packet on the machine where the corruption is
> occurring, you might want to try hooking up the UDP checksum drop case to
> BPF_MTAP() for a special BPF device or rule, or have it spit them into a
> raw socket (probably easier).

He said that the packet's checksum passes, but it is corrupt, so this
won't work.

I suppose that one thing we could do in the long run to help detect this
sort of corruption would be to import OpenBSD's TCP MD5 support and ensure
that packets which fail the md5 or fail the checksum are logged so that
they can be investigated.

Of course, that's adding data to the packet, and heisenberg wouldn't be
too happy about that. :)

Mike "Silby" Silbersack