Re: [PATCH v5 2/4] cfg80211: allow usermode to query wiphy specific regdom

[Johannes Berg <johannes@sipsolutions.net>]

On Sun, 2014-11-30 at 14:26 +0200, Arik Nemtsov wrote:

> I think Johannes' point was that it's easy to overrun the message size
> if there are a lot of wiphys.

Yes.

> So I'll simply add an iterator over all wiphys in "iw reg get" and
> kernel-mode will only return a single regdomain in each GET_REG
> invocation.

Err, there's such a thing built into netlink already - just support
dumpit instead of doit :)
iw will have to fall back to doit for older kernels though I guess.

> About the "--all" suggestion - I think it's fine to not have backward
> compatibility in the output of "iw reg get"? So we can just output the
> global first, and then output private regdoms for all wiphys that have
> them.
> 
> Does that sound ok?

Yeah I wasn't taking about the iw display, and adding --all there
doesn't help for what I was concerned about.

> Well you have to give a wiphy-idx in order to get a private regdom in
> the first place. And only new userspace will add a wiphy-idx in the
> first place..

Are you sure about the last part though? wpa_supplicant often passed a
netdev index instead of a wiphy index for example, so I could imagine it
passing a wiphy index here even though it was previously ignored?

If it didn't though then I think there's no problem, there shouldn't
really be any userspace other than wpa_s and iw for this I guess/hope.

johannes