Hello,
On Tue, Aug 4, 2020 at 10:39 PM satish dhote <sdhote...@gmail.com> wrote:
>
> Hi Team,
>
> I have a question regarding tc filter behavior. I tried to look
> for the answer over the web and netdev FAQ but didn't get the
> answer. Hence I'm looking for your help.
>
> I added ingress qdisc for interface enp0s25 and then configured the
> tc filter as shown below, but after adding filters I realize that
> rule is reflected as a result of both ingress and egress filter
> command? Is this the expected behaviour? or a bug? Why should the
> same filter be reflected in both ingress and egress path?
I am not very sure but I am feeling this is a bug. Let's Cc Daniel who
introduced this.
With the introduction of clsact qdisc, the keywords "ingress" and
"egress" were introduced too to match clsact qdisc. However, its
major/minor handle is kinda confusing:
TC_H_MAKE(TC_H_CLSACT, TC_H_MIN_INGRESS);
TC_H_MAKE(TC_H_CLSACT, TC_H_MIN_EGRESS);
#define TC_H_CLSACT TC_H_INGRESS
They could match the ingress qdisc (ffff:) too.
>
> I understand that policy is always configured for ingress traffic,
> so I believe that filters should not be reflected with egress.
> Behaviour is same when I offloaded ovs flow to the tc software
> datapath.
I believe so too, otherwise it would be too confusing to users.
If you are able to test kernel patch, does the following one-line
change fix this problem? If not, I will try it on my side.
diff --git a/net/sched/sch_ingress.c b/net/sched/sch_ingress.c
index 84838128b9c5..4d9c1bb15545 100644
--- a/net/sched/sch_ingress.c
+++ b/net/sched/sch_ingress.c
@@ -49,7 +49,7 @@ static struct tcf_block *ingress_tcf_block(struct
Qdisc *sch, unsigned long cl,
{
struct ingress_sched_data *q = qdisc_priv(sch);
- return q->block;
+ return cl == 0 ? q->block : NULL;
}
static void clsact_chain_head_change(struct tcf_proto *tp_head, void *priv)
Thanks.
