[ovs-dev] [PATCH 0/3 v2.20] MPLS actions and matches

[Simon Horman]

On Thu, Feb 28, 2013 at 11:12:41AM +0000, Rajahalme, Jarno (NSN - FI/Espoo) wrote:
> On Feb 28, 2013, at 11:15 , ext Simon Horman wrote:
> > * Implement recirculation and a host of more sophisticated MPLS features
> >  including:
> >  - copy_ttl_in
> >  - copy_ttl_out
> >  - L3+ actions on MPLS frames (e.g. pop_mpls(0x800),set_ttl)
> >  - multi-level mpls_pop and mpls_push
> > * Other more specific datapath todo items listed in the changelog of
> >  "datapath: Add basic MPLS support to kernel"
> > 
> 
> Am I right in assuming that something like a "resubmit" action would be
> needed for recirculation in the kernel datapath? I have earlier
> implemented something like "recirculation" (as I understand it) with a
> special vport that provides it's output as input to the datapath. I.e., I
> have used the OVS_ACTION_ATTR_OUTPUT to implement "recirculation" with a
> "loopback vport". It would be nice to get rid of that with a more
> explicit mechanism.
> 
> Or have I completely misunderstood what you mean with recirculation here?

My current thought is that recirculation could be implemented using
a new action (I had in mind to call it "recirculate") as you suggest.
And I intend to try and implement that.

It is not entirely clear to me that is quite what Jesse has in mind
or that it will work as expected. We shall see.

However, what is clear to me is that if done correctly recirculation should
be a generic mechanism that can be used to solve a variety of problems.
Even though the problem I am focusing on solving relates to MPLS.