Re: [RFC][IPSEC]: tunnel mode processing

[jamal <hadi@cyberus.ca>]

On Fri, 2006-01-09 at 14:07 +1000, Herbert Xu wrote:
> On Thu, Aug 31, 2006 at 08:55:27PM -0400, jamal wrote:
> > 
> > Would it be reasonable to do a check so that incase a skb->dst doesnt
> > exist, the inner headers values can be used i.e something along 
> > xfrm4_tunnel_output()::
> 
> If you didn't care what values they were, couldn't you just stuff some
> bogus dst into the skb? 

That bogus dst is NULL ;->

> If this packet is going somewhere you're going
> to have a dst one way or another :)

If i was going to use routing/layer 3, then true. At the pktgen level
"somewhere" is just "shove down the ether". Actually (i havent thought
clearly about this) wouldnt a bump in the wire implementation aka
bridging level also not care about route details? 
Note: This does not absolve the need for a secure ipid or a proper ttl.

> Also, the IPID is only generated if DF is not set on the packet.
> Otherwise this path is already as fast as it can be.

In the case of traffic generation, if i could shave even more cycles the
better since i want to generate high speed. In this case the cycles
would be in creating a fake dst and attaching it some fake values.

I do agree that it is an awkward way of achieving my goals - but i dont
know of a clever way to do it ;->

cheers,
jamal