kernel: add a bridge feature for filtering BPDU packets on ports

[Andre Heider]

On 28/09/2021 09:54, Andre Heider wrote:

[...]

> But if I now switch back to what I thought was a known working version, 
> it still doesn't work. So maybe it's something different entirely, like 
> a race condition or order of setting up things that doesn't hit on every 
> boot?

Updated again to current master without reverts. Problem exists after 
boot, and it turns out hairpin_mode wasn't set for both APs.

After:
echo "1" > /sys/class/net/$nacmaster/brport/hairpin_mode
echo "1" > /sys/class/net/$bgnmaster/brport/hairpin_mode

It starts working again!

Cheers,
Andre