Re: "hme" tcp4csum-rx breaks 'pf' redirection to 'ftp-proxy'

[Eduardo Horvath <eeh%NetBSD.org@localhost>]

On Mon, 14 Sep 2015, Greg Troxel wrote:

> (I used to have a sparc64 with qfe, but it broke.)
> 
> Have you convinced yourself that the interface works ok with rx checksum
> offloading when pf is not involved?
> 
> Over the years there have been multiple cases of "card X firmware Y is
> buggy with checksum offloading Z".  So this is not shocking.

HME is a really primitive MAC and doesn't have any firmware.  The rx 
checksum is simply the checksum of all the bytes in the ethernet packet.  
The driver needs to take that value and adjust it by whatever bytes in the 
packet should not be part of the checksum.

Having said that, I wouldn't be surprised if the h/w accellerated 
checksumming code in the driver was suffering from code rot.  You should 
test it without pf and make sure it's working properly.

Eduardo