From: Jamal Hadi Salim <jhs@mojatatu.com>
Date: Sun, 30 Apr 2017 10:28:39 -0400

Generic bitflags attribute content sent to the kernel by user.
With this type the user can either set or unset a flag in the
kernel.

You asked for feedback, here it is :-)

I think this is overengineered.

Just define a u32 for the value, and mask which defines which bits are
legitimate and defined.  Any bit outside of the legitimate mask must
be zero.

Simple.