Re: [PATCH] Add sk_mark route lookup support for IPv4 listening sockets, and for IPv4 multicast forwarding

[steve@chygwyn.com]

Hi,

On Wed, Oct 14, 2009 at 02:04:37PM +0300, Atis Elsts wrote:
> On Wednesday 14 October 2009 12:27:43 steve@chygwyn.com wrote:
> >
> > The mark is supposed to be a generic thing, not just for routing
> > lookups, it can be used for classification, etc as well. 
> 
> In general, sounds like a good idea, but IMHO exactly this could be a problem.
> skb->mark is already used for a lot of things. What if I am setting the mark 
> by a firewall rule in prerouting chain, and matching it by a postrouting 
> rule? If routing lookup was changing the mark, then my setup would break.
>
Yes, thats exactly why I said that it should default to the current
behaviour.
 
> Perhaps one more field could be added dst_entry? The field would be filled 
> from route's table (if "setmark" for that route was specified). The use of 
> that field would be similar to tclassid (e.g matching in firewall), except 
> that it would also be used in routing lookups, if set.
>
Yes, I think that we are both thinking along the same lines. There
must obviously be a default "don't touch" setting,

Steve.