Messages in this thread | | | Date | Wed, 27 Mar 2019 10:57:49 +0100 | From | Jiri Pirko <> | Subject | Re: [PATCH net-next v5 07/22] ethtool: netlink bitset handling |
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Tue, Mar 26, 2019 at 06:59:32PM CET, mkubecek@suse.cz wrote: >On Tue, Mar 26, 2019 at 04:59:11PM +0100, Jiri Pirko wrote: >> 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? > >I suppose it could if other netlink based APIs would be interested in >using it. The only ethtool specific part is the support for "legacy >style names" (fixed size strings) but that is something I'm not really >happy about. Perhaps it's time to return to the original idea of >supporting only arrays of (char *) and creating them around existing >fixed size ones.
Wait, could you please describe this more?
> >> 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. > >That would be similar to compact form but it would introduce the >interleaving and extra struct nlattr header for each block. I don't >think it would make things easier.
I'm just trying to figure out if it would be possible to use existing building block instead of introducing new ones....
> >The verbose form is meant to allow requests like > > ethtool -K eth0 tx-vlan-stag-hw-insert on > ethtool -s eth0 advertise 1000baseT/Full off > >without either keeping the table of available flags in sync between >kernel and userspace (all userspace users of the API) or having to ask >for the list first (in case of one shot requests as above; long running >tools like "ethtool --monitor" or config management daemons would keep >the tables and use compact form).
Okay, I have to go over those patches but this smells.
> >Michal
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