Function IOConnectCallStructMethod 

pub unsafe extern "C-unwind" fn IOConnectCallStructMethod(
    connection: mach_port_t,
    selector: u32,
    input_struct: *const c_void,
    input_struct_cnt: usize,
    output_struct: *mut c_void,
    output_struct_cnt: *mut usize,
) -> kern_return_t

Available on crate feature libc only.