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checksum offload problem freebsd

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Andrew White

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Jan 16, 2012, 8:24:29 PM1/16/12
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Hi,

In trying to debug a problem a colleague has with Freebsd 8 and ipfilter 4.1.34, I came across a bug report in Freebsd


Where the last post suggests this is a checksum problem and has a suggested an 'untested' patch for ip_fil_freebsd.c.

Turning off rx checksum on fxp0 has indeed worked around the problem.

under freebsd 6 with 4.1.33 this hardware had no problem, I see some checksum changes in CVS between 4.1.34 and 4.1.33 , but I don't know the code to comment if these introduced the problem


Has anyone here experience with this problem ?

Thanks

Andrew

Andrew White

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Jan 17, 2012, 7:15:40 PM1/17/12
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Hi,

Another colleague has pointed out

if_fxp in FreeBSD 7/8 adds hardware checksum support for the 82559, but not on the pseudo header. This triggers a bug in ipfilter (where it incorrectly calculates the pseudo header checksum by itself), so the patch from the PR should actually work.

The reason why it worked in 6.4 is because 6.4 didn't support hardware checksumming on 82559 at all. 

With the patch applied from the PR, it now works as expected (freebsd 8.2 with ipfilter 1.4.34)

Can this patch be added to ipfilter upstream please ?

Thanks

Andrew

Darren Reed

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Jan 17, 2012, 9:16:57 PM1/17/12
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I'll get it sorted in the next day or so.

Darren

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