From mboxrd@z Thu Jan  1 00:00:00 1970
From: Edward Cree <ecree@solarflare.com>
Subject: Re: [PATCH v2 net-next 1/5] net: local checksum offload for
 encapsulation
Date: Thu, 7 Jan 2016 17:54:09 +0000
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	"Tom Herbert" <tom@herbertland.com>
To: David Laight <David.Laight@ACULAB.COM>,
	David Miller <davem@davemloft.net>
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On 07/01/16 17:22, David Laight wrote:
> Isn't it even simpler than that?
> The checksum of the inner packet (including its header) is ~0 (ie 0).
> So the checksum of the whole packet (for the outer header) is the same
> as that of the packet down to the start of the inner header.
Not quite.  The inner pseudo-header is included in the inner checksum
 calculation, but does not actually appear in the packet.  Thus the checksum
 of the inner packet is ~sum_of_inner_pseudo_header.

-ed