Re: Linville's L2 rant... -- Re: PATCH Fix bonding active-backup behavior for VLAN interfaces

[Christophe Devriese <Christophe.Devriese@eurid.eu>]

On Tuesday 01 August 2006 19:21, you wrote:
> John W. Linville wrote:
> >>>I'm just not sure that cleverness is worth the headache, especially
> >>>since the most clever things usually only work by accident...
> >>
> >>Or, work by solid, modular design and small tweaks!
> >
> > Point taken.  But stashing little hacks in the networking core for
> > specific virtual drivers isn't totally modular either.  And even if
> > it were, "modular design" probably belongs on the list of "things
> > that can be taken too far", like "everything in userland", "never
> > use ioctl", and "microkernels are superior". :-)
>
> To be honest, I'm not over-joyed to see bridging hooks included
> in the VLAN code..but if that is what it takes to get bridging
> and VLANs to play well and be flexible, I think it is a fair price.
>
> It certainly wouldn't hurt to have someone take a holistic view of the
> various L2 device interactions.  Just documenting current functionality
> on, say, the netdev wiki would be a good first step.

Ultimate flexibility could be provided by making the netif_rx routine (and the 
others, including vlan etc), a "virtual" routine.

That way a list of "filters" could be defined that allow any processing to be 
done on the packet before it is handed of to the linux kernel's higher 
layers, including not delivering it on that interface, or delivering it on 
another interface.

This would allow very complex implementations including stuff like a 
high-level l2 bridge, with vlan support, and a number of protocols like rstp, 
pvst+, ... with relatively simple code, that could be isolated from the main 
kernel.

Would anyone be interested in signing off on such a patch ? (which basically 
creates netif_rx and vlan_acc_netif_rx lists in the net_device structure, and 
then modify bridging and bonding drivers to just use this) 

Regards,

Christophe