Mon, Mar 25, 2019 at 06:08:15PM CET, mkubecek@suse.cz wrote:

Declare attribute type constants and add helper functions to generate and
parse arbitrary length bit sets.

Hmm, this looks like a lot of work. Two things:
1) This is generic. Not really related to ethtool in any way. Could this
   be done in netlink common code?
2) Did you think about leveraging NLA_BITFIELD32? What I mean is this:
NEST_START
   NLA_BITFIELD32 index 0 (bit 0-31)
   NLA_BITFIELD32 index 1 (bit 32-63)
   NLA_BITFIELD32 index 2 (bit 64-95)
   NLA_BITFIELD32 index 3 (bit 96-127)
   ....
NEST_END
It is basically an array of NLA_BITFIELD32.