From mboxrd@z Thu Jan  1 00:00:00 1970
From: Edward Cree <ecree@solarflare.com>
Subject: Re: [PATCH net-next 6/8] net: gre: Implement LCO for GRE over IPv4
Date: Mon, 11 Jan 2016 19:02:51 +0000
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Cc: David Laight <David.Laight@aculab.com>,
	David Miller <davem@davemloft.net>,
	"netdev@vger.kernel.org" <netdev@vger.kernel.org>,
	"linux-net-drivers@solarflare.com" <linux-net-drivers@solarflare.com>,
	"tom@herbertland.com" <tom@herbertland.com>
To: Alexander Duyck <alexander.duyck@gmail.com>
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On 11/01/16 18:39, Alexander Duyck wrote:
> On Mon, Jan 11, 2016 at 5:21 AM, Edward Cree <ecree@solarflare.com> wrote:
>> csum_fold complements, so if the sum comes to (say) 0x1fffe, it will return ~0xffff which is 0.
>>
>> Next version of patch will mangle 0 for both branches.
> Actually you may want to go the other way on that.  If they weren't
> flipping the checksum value for GRE before why should we start doing
> that now?  I'm pretty sure the checksum mangling is a very UDP centric
> thing.  There is no need to introduce it to other protocols.
Good catch, you're quite right.

-ed