How to capture data-link layer on ipad with wireshark

Hello,

i've managed to capture on a macbook traffic from an ipad (with a virtual interface mounted thanks to xcode) but it's layer 4 (fake Ethernet capture). I've also managed to capture layer 2 from the macbook after editing preferences on the wifi interface.

But i fail to modify preferences on the rvi0 interface.

Is it possible?

Thank you.