Retrieving device type

Hi, gr-osmosdr is great at abstracting the device type, but now I find myself wishing to de-abstract. For instance: HackRF has large DC offset, so I'd like the option to switch in a DC blocking filter when using that source. RTL dongles can't support more than 2.4Msps reliably, so I'd like to be able to cope accordingly at initialization time. Is there a good way to retrieve, say, a string descriptor telling me which particular source I'm using? --n