Re: [PATCH net-next v3 4/5] net/tc: introduce TC_ACT_REINJECT.

[Paolo Abeni <pabeni@redhat.com>]

Hi,

On Wed, 2018-07-25 at 08:16 -0400, Jamal Hadi Salim wrote:
> +Cc Shmulik
> 
> Paolo - please also run the tdc tests (and add anymore if you
> feel they dont do coverage to your changes)

I run successfully tdc tests on a patched before posting. I plan to
rerun them before posting the v4.

> On 24/07/18 04:06 PM, Paolo Abeni wrote:
> > This is similar TC_ACT_REDIRECT, but with a slightly different
> > semantic:
> > - on ingress the mirred skbs are passed to the target device
> > network stack without any additional check not scrubbing.
> > - the rcu-protected stats provided via the tcf_result struct
> >    are updated on error conditions.
> > 
> > This new tcfa_action value is not exposed to the user-space
> > and can be used only internally by clsact.
> > 
> > v1 -> v2: do not touch TC_ACT_REDIRECT code path, introduce
> >   a new action type instead
> > 
> > v2 -> v3:
> >   - rename the new action value TC_ACT_REINJECT, update the
> >     helper accordingly
> >   - take care of uncloned reinjected packets in XDP generic
> >     hook
> > 
> > Signed-off-by: Paolo Abeni <pabeni@redhat.com>
> > ---
> >   include/net/pkt_cls.h     |  3 +++
> >   include/net/sch_generic.h | 19 +++++++++++++++++++
> >   net/core/dev.c            |  6 +++++-
> >   3 files changed, 27 insertions(+), 1 deletion(-)
> > 
> > diff --git a/include/net/pkt_cls.h b/include/net/pkt_cls.h
> > index 2081e4219f81..36ccfe2a303a 100644
> > --- a/include/net/pkt_cls.h
> > +++ b/include/net/pkt_cls.h
> > @@ -7,6 +7,9 @@
> >   #include <net/sch_generic.h>
> >   #include <net/act_api.h>
> >   
> > +/* TC action not accessible from user space */
> > +#define TC_ACT_REINJECT		(TC_ACT_VALUE_MAX + 1)
> 
> Lets say in the future we add a new opcode.
> Will old kernel, new iproute2 (new value) work?

It will works as it currently does in similar situation: opcode unknown
to the kernel are treated as TC_ACT_UNSPEC even now. 

Cheers,

Paolo