bonding driver - how to recognize the active slave

Hi,
Is there any way to know who is the active slave in active-passive mode?

Is there any indication for that in netdevice flags? Or some other way?
(I would like to get in my network interface driver which can be a slave of the bonding interface)

I saw that there is the flag IFF_SLAVE_INACTIVE but it is not used as far as I can see.

Thanks, Erez