Re: [PATCH net-next] {ipv4,xfrm}: Introduce xfrm_tunnel_notifier for xfrm tunnel mode callback

[Steffen Klassert <steffen.klassert@secunet.com>]

On Tue, Aug 27, 2013 at 09:29:40AM +0800, Fan Du wrote:
> On 2013年08月27日 04:21, David Miller wrote:
> >
> >I don't understand why VTI doesn't need to propagate a PMTU update via
> >ipv4_update_pmtu().  Why is it different from a real xfrm_tunnel?
>   ^^^^^^^^^^^^^^^^
> 
> A IPsec protected packet is first handled by protocol handlers, e.g AH/ESP,
> to check packet authentication or encryption rightness. PMTU update is taken
> care of in this stage by protocol error handler.
> 
> Then the packet is rearranged properly depending on whether it's transport
> mode or tunnel mode packed by mode "input" handler. The VTI handler code
> takes effects in this stage in tunnel mode only. So it neither need propagate
> PMTU, as it has already been done if necessary, nor the VTI handler is
> qualified as a xfrm_tunnel.
> 

I think you are right here, please update your commit message with
the above informations. I'd take this into ipsec-next and update
the the ipv6 vti patch according to your changes if David does not
mind.