netdev - Re: [Patch net] net: invert the check of detecting hardware RX checksum fault

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Message-ID: <CAM_iQpXxc5BuC5m_Ut7DxPpkVgEgEmZc=D8=NjzMSfZxNw06EA@mail.gmail.com>
Date:   Fri, 16 Nov 2018 13:32:50 -0800
From:   Cong Wang <xiyou.wangcong@...il.com>
To:     Herbert Xu <herbert@...dor.apana.org.au>
Cc:     Linux Kernel Network Developers <netdev@...r.kernel.org>,
        Tom Herbert <tom@...bertland.com>,
        Eric Dumazet <edumazet@...gle.com>
Subject: Re: [Patch net] net: invert the check of detecting hardware RX
 checksum fault

On Fri, Nov 16, 2018 at 12:06 PM Cong Wang <xiyou.wangcong@...il.com> wrote:
>
> Hmm, now I see how it works. Actually it uses the differences between
> these two check's as the difference between hardware checksum with
> skb_checksum().
>

Well...

This is true only when there is a skb_checksum_init*() or
skb_checksum_validate*() prior to it, it seems not true for
nf_ip_checksum() where skb->csum is correctly set to pesudo header
checksum but there is no validation of the original skb->csum.
So this check should be still inverted there??

Or am I still missing anything here?