Subject: Re: [PATCH v2 net-next 1/5] net: local checksum offload for encapsulation

From: Edward Cree <[email-masked]>
Date: Thu, 7 Jan 2016 17:54:09 +0000

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