Messages in this thread | | | Subject | Re: [PATCH net-next v6 06/15] ethtool: netlink bitset handling | From | Johannes Berg <> | Date | Thu, 04 Jul 2019 14:07:16 +0200 |
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On Wed, 2019-07-03 at 16:37 +0200, Jiri Pirko wrote: > Wed, Jul 03, 2019 at 03:44:57PM CEST, johannes@sipsolutions.net wrote: > > On Wed, 2019-07-03 at 13:49 +0200, Jiri Pirko wrote: > > > > > > > +Value and mask must have length at least ETHTOOL_A_BITSET_SIZE bits rounded up > > > > +to a multiple of 32 bits. They consist of 32-bit words in host byte order, > > > > > > Looks like the blocks are similar to NLA_BITFIELD32. Why don't you user > > > nested array of NLA_BITFIELD32 instead? > > > > That would seem kind of awkward to use, IMHO. > > > > Perhaps better to make some kind of generic "arbitrary size bitfield" > > attribute type? > > Yep, I believe I was trying to make this point during bitfield32 > discussion, failed apparently. So if we have "NLA_BITFIELD" with > arbitrary size, that sounds good to me.
I guess it could be the same way - just have the content be
u32 value[N]; u32 select[N];
where N = nla_len(attr) / 8
That'd be compatible with NLA_BITFIELD32, and we could basically change all occurrences of NLA_BITFIELD32 to NLA_BITFIELD, and have NLA_BITFIELD take something like a "max_bit" for the .len field or something like that? And an entry in the validation union to point to a "u32 *mask" instead of the current validation_data that just points to a single u32 mask...
So overall seems like a pretty simple extension to NLA_BITFIELD32 that handles NLA_BITFIELD32 as a special case with simply .len=32.
(len is a 16-bit field, but a 64k bitmap should be sufficient I hope?)
johannes
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