[ovs-dev] [PATCH 1/5] datapath: Use strip_vlan() for modify_vlan_tci().

[Jesse Gross]

On Thu, Jun 16, 2011 at 1:44 PM, Ben Pfaff <blp at nicira.com> wrote:
> On Thu, Jun 16, 2011 at 01:39:24PM -0700, Jesse Gross wrote:
>> By the way, my eventual plan is to convert the kernel actions to be
>> pure push/pop for vlan tags as I think that really is the correct
>> model and make userspace generate a pop and push pair to emulate the
>> OpenFlow set action if necessary.
>
> I agree that that is a better model.
>
> What about matching on more than one level of tag?

It's possible, though we'd have to pick some number of tags to match
on in a single pass.  We would have similar issues with MPLS as well.
I guess two tags is somewhat common in hardware.

Beyond that we'd need to do some form of resubmit.  That's obviously
possible with patch ports now but I wonder if there is a cleaner way
to do it for this particular use case.  The current reasons for using
patch ports are mostly due to artificial limitations so maybe once we
lift those we can improve the semantics.