[PATCH dpdk v4] net: fix VLAN packet type

[Morten Brørup]

> From: David Marchand [mailto:david.marchand at redhat.com]
> Sent: Thursday, 30 April 2026 12.12
> 
> On Mon, 27 Apr 2026 at 17:53, Thomas Monjalon <thomas at monjalon.net>
> wrote:
> >
> > 27/04/2026 12:47, Robin Jarry:
> > > David Marchand, Apr 25, 2026 at 10:40:
> > > > On Thu, 23 Apr 2026 at 13:25, Robin Jarry <rjarry at redhat.com>
> wrote:
> > > > This is untested, but what do you think?
> > >
> > > That looks correct. But you don't impose a limit in the number of
> VLANs?
> > >
> > > I don't see any good reason to support more than 2 stacked tags.
> >
> > Look in the mailing list.
> > I remember it was to limit a risk of infinite loop.
> 
> Defensive programming (iiuc why it was introduced) seems a bad idea.
> It imposes a restriction for no good reason.
> The same can be achieved by checking the offset vs packet length
> (rte_pktmbuf_read), and no arbitrary limit needed.
> 
> I am for simply reverting the patch in LTS releases.
> We can come up with a new change in main for Gregory usecase, but it
> does not seem like something we want to backport in LTS.
> 

I just took a look at rte_net_get_ptype().

The MPLS parser is also broken.
It simply skips 5 MPLS labels without checking if they are MPLS labels at all.

And there's no PPPoE parser.