hostapd :: Set attributes e.g. group id on created 4addr interfaces

[Robert White <rwhite@xxxxxxxxx>]

Howdy,

It'd be really nice if there was a global up-down hook or something in 
hostapd that would let me set the interface group ID when a station 
interface is created on a 4addr link.

I couldn't find a hook to invoke on device creation; and invoking a 
whole hook might be a little costly.

I don't see a lot of relevant properties to set but group ID is really 
helpful for firewall rules on transient interfaces. Since it can be done 
when doing an ip link add, I'd assume setting the simpler properties 
like this should be available at the API level.

So being able to set that property at a minimum during device creation 
would be really helpful, and there may be use cases for other things.

I don't have the necessary skill set with hostapd to submit a sample 
implementation at this time, so color me a demanding user (ha ha ha).