Hi,
On Wed, 2018-07-25 at 13:56 +0200, Jiri Pirko wrote:
> Tue, Jul 24, 2018 at 10:06:39PM CEST, pab...@redhat.com wrote:
> > Only cls_bpf and act_bpf can safely use such value. If a generic
> > action is configured by user space to return TC_ACT_REDIRECT,
> > the usually visible behavior is passing the skb up the stack - as
> > for unknown action, but, with complex configuration, more random
> > results can be obtained.
> >
> > This patch forcefully converts TC_ACT_REDIRECT to TC_ACT_UNSPEC
> > at action init time, making the kernel behavior more consistent.
> >
> > v1 -> v3: use TC_ACT_UNSPEC instead of a newly definied act value
> >
> > Signed-off-by: Paolo Abeni <pab...@redhat.com>
> > ---
> > net/sched/act_api.c | 5 +++++
> > 1 file changed, 5 insertions(+)
> >
> > diff --git a/net/sched/act_api.c b/net/sched/act_api.c
> > index 148a89ab789b..24b5534967fe 100644
> > --- a/net/sched/act_api.c
> > +++ b/net/sched/act_api.c
> > @@ -895,6 +895,11 @@ struct tc_action *tcf_action_init_1(struct net *net,
> > struct tcf_proto *tp,
> > }
> > }
> >
> > + if (a->tcfa_action == TC_ACT_REDIRECT) {
> > + net_warn_ratelimited("TC_ACT_REDIRECT can't be used directly");
>
> Can't you push this warning through extack?
>
> But, wouldn't it be more appropriate to fail here? User is passing
> invalid configuration....
Jiri, Jamal, thank you for the feedback.
Please allow me to answer both of you here, since you raised similar
concers.
I thought about rejecting the action, but that change of behavior could
break some users, as currently most kind of invalid tcfa_action values
are simply accepted.
If there is consensus about it, I can simply fail.
Thanks,
Paolo
