Re: [RFC net-next] net: dsa: add support for MC_DISABLED attribute

Vivien Didelot
2019-07-05T16:01:54Z

Hi Ido,

On Sun, 23 Jun 2019 07:09:52 +0000, Ido Schimmel <idosch@mellanox.com> wrote:
> > Russell, Ido, Florian, so far I understand that a multicast-unaware
> > bridge must flood unknown traffic everywhere (CPU included);
> > and a multicast-aware bridge must only flood its ports if their
> > mcast_flood is on, and known traffic targeting the bridge must be
> > offloaded accordingly. Do you guys agree with this?
>
> When multicast snooping is enabled unregistered multicast traffic should
> only be flooded to mrouter ports.

I've figured out that this is what I need to prevent the flooding of undesired
multicast traffic to the CPU port of the switch. The bridge itself has a
multicast_router attribute which can be disabled, that is when I should drop
unknown multicast traffic.

However with SWITCHDEV_ATTR_ID_BRIDGE_MROUTER implemented, this
attribute is always called with .mrouter=0, regardless the value of
/sys/class/net/br0/bridge/multicast_router. Do I miss something here?

Thanks,

Vivien