Hi,
On Thu, 22 Sep 2016 19:40:15 -0400 Jamal Hadi Salim <j...@mojatatu.com> wrote:
> On 16-09-22 09:21 AM, Shmulik Ladkani wrote:
> > From: Shmulik Ladkani <shmulik.ladk...@gmail.com>
> >
> > Up until now, 'action mirred' supported only egress actions (either
> > TCA_EGRESS_REDIR or TCA_EGRESS_MIRROR).
> >
> > This patch implements the corresponding ingress actions
> > TCA_INGRESS_REDIR and TCA_INGRESS_MIRROR.
> >
> > This allows attaching filters whose target is to hand matching skbs into
> > the rx processing of a specified device.
>
> Thank you for doing this. There was something that made me remove
> initial support for this feature - I am blanking out right now but
> will find my notes and give more details.
Thanks Jamal, appreciate any details.
Was wondering why it's missing, googled a bit with no meaningful
results, so speculated the following:
Some time long ago, initial 'mirred' purpose was to facilitate ifb.
Therefore 'egress redirect' was implemented. Jamal probably left the
'ingress' support for a later time :)
One interesting usecase for 'ingress redirect' is creating "rx bouncing"
construct (like macvlan/macvtap/ipvlan) but applied according to custom
logic.
> It may be around preventing loops maybe.
Could be, but personally, I treat these constructs as (powerful)
building blocks, and "with great power comes great responsibility".
Even today, one may create loops using existing 'egress redirect',
e.g. this rediculously errorneous construct:
# ip l add v0 type veth peer name v0p
# tc filter add dev v0p parent ffff: basic \
action mirred egress redirect dev v0
Regards,
Shmulik
