Re: [RFC PATCH] Fix false positives in can_checksum_protocol()

On Mon, 2015-09-28 at 12:37 -0700, Tom Herbert wrote:

I think it's easier to just call skb_checksum_help from the driver
when the packet is actually sent to the device (should be no cost for
late binding).

That's true for checksum. Not for things like TSO though, and I wonder
if it's worth keeping it simple and doing it *all* in
.ndo_features_check()? 

quoted

Note that 'seeded with an IPv[46] pseudo header' isn't quite
sufficient. Some hardware like 8139cp is explicitly told to do a UDP or
a TCP checksum with a bit in the descriptor, so any UDP-like or TCP
-like checksum works out fine.

UDP or TCP can be determined from csum_offset, e.g. 16=>TCP 6=>UDP

Kind of. There'll be false positives there too, though. That was
actually the basis of my first attempt to address this, at
http://lists.openwall.net/netdev/2013/01/14/36

-- 
dwmw2