Traffic direction within a bridge

Hi!

I’ve bridged the public interface and the private one, and I’d like to mark the traffic direction (upload / download) within the bridge using mangle to apply QoS policies later. I’ve tried using the public and private interfaces as source and dst in the mangle rule, as well as per source and dst port, but it doesn’t work.
How can I mark packets/connections per direction based within a bridge?

Thanks a lot!

use ‘in-bridge-port’ and ‘out-bridge-port’ parameters