Re: [patch] vlan Q in Q

Alex Zeffertt wrote:
> For the sake of completeness I've made a proper (?) patch which supports Q in Q.
> I've taken out my unrelated changes discussed previously in this thread.
> 
> The changes needed were:
> 
> 1.	Remove the ability to disable the addition/stripping of tags on tx/rx.
> 	I.e. remove the REORDER flag.
> 
> 2.	for non hw/accel real_devs use real_dev->hard_header and
> 	real_dev->rebuild_header.
> 
> 3.	for non hw/accel real_devs *always* encapsulate on tx and *always* strip
> 	on rx.
> 
> 4.	proc files modified to reflect changes
> 
> 
> This patch is against linux-2.4.25
> 
> NB:
> 
> i)	This patch will break any code that opens raw sockets on vlan devices
> 	and is writes tagged frames to that device.  Such frames will become
> 	double tagged.  Any such code will need to be modified to write untagged
> 	frames instead, or use the real_dev.

This may be fine, but I think we may want a socket flag that allows backwards
compat.

> ii)	This patch will also break any code that reads raw sockets on vlan
> 	devices and expects to see vlan tags in the frames it reads.  Basically
> 	this patch makes eth0.N look *exactly* like any other ethernet device to
> 	the networking stack and all other users of the device.

I haven't looked at the patch, but I don't like this change.  If nothing else,
it is a performance hit to reorder the header.

Why do you need to remove the REORDER flag?  (If you need it always enabled on
your box, then just make sure it is always set..)

> 
> Alex
> 
> 
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-- 
Ben Greear <[email protected]>
Candela Technologies Inc  http://www.candelatech.com