Subject: Re: [RFC] SPD basic actions per netdev

From: Timo Teräs <[email-masked]>
Date: Thu, 01 Apr 2010 09:20:40 +0300

Herbert Xu wrote:
> On Thu, Apr 01, 2010 at 07:52:34AM +0300, Timo Teräs wrote:
>> IMHO, it's slightly confusing that in/fwd is split, but out is not.
>> But that's the way it works. If you now override the how interface
>> is checked for 'out' policy, it'll break current behaviour.
> 
> Unless I've misunderstood what his patch is trying to do, it would
> seem that out policies would be completely unchanged.
> 
> Forward policies are not used on output.

Oh, that right.

But my statement still holds. If iif/oif is swapped, it's changing
current semantics and can end up breaking setups. Both are still
valid for 'in' and 'fwd' policies too, right? What if I'm using
'in' policy to make sure that all stuff arriving via 'eth0' is
encrypted, but 'eth1' is trusted and does not need xfrm. This
would break.

I do like the idea very much. In fact I remember asking this exact
feature long time ago. But I think it should be done by explicitly
allowing user to specify both iif and oif; even if it's more
intrusive.