netdev - Re: IPv6-UDP 0x0000 checksum

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Message-ID: <1485441942.5145.131.camel@edumazet-glaptop3.roam.corp.google.com>
Date:   Thu, 26 Jan 2017 06:45:42 -0800
From:   Eric Dumazet <eric.dumazet@...il.com>
To:     Johannes Berg <johannes@...solutions.net>
Cc:     netdev@...r.kernel.org,
        linux-wireless <linux-wireless@...r.kernel.org>
Subject: Re: IPv6-UDP 0x0000 checksum

On Thu, 2017-01-26 at 14:49 +0100, Johannes Berg wrote:

> Oops, sorry - receive. We can only indicate "CHECKSUM_UNNECESSARY",
> nothing more advanced right now, but right now we'd indicate that if
> the packet had 0x0000 in the checksum field, but should've had 0xffff.
> 
> On TX I believe we actually do in HW exactly what your patch just did.

Can you describe the visible effects of this problem ?

Is that because of a conversion we might do later to CHECKSUM_COMPLETE ?