Re: NL80211_ATTR_PAD question

[Johannes Berg <johannes@sipsolutions.net>]

On Mon, 2016-06-13 at 21:25 +0200, Arend van Spriel wrote:
> 
> On 10-06-16 23:08, Johannes Berg wrote:
> > On Fri, 2016-06-10 at 12:47 -0700, Ben Greear wrote:
> > > I see this was added sometime recently:  NL80211_ATTR_PAD
> > > 
> > > If another enum member is added, should it replace the PAD enum?
> > 
> > No.
> > 
> > > At the least, I think we need some comments about how this is to
> > > be
> > > dealt with.
> > > 
> > 
> > You simply ignore it :)
> 
> So do you know why the caller of nla_put_u64_64bit() would need to
> specify the padattr. I mean, why is this not an generic attribute
> that
> netlink deals with internally. It has probably been discussed on the
> netdev list but I could not find the right thread.
> 

Netlink attribute numbers are always specific to the (generic) netlink
family used. There was a discussion about using the attribute number 0
since that's reserved, but unfortunately it's only reserved in *most*
families, some actually use it (despite that being broken with libnl.)

johannes