Subject: Re: softmac: semantics of SIOCSIWFREQ

From: Johannes Berg <[email-masked]>
Date: Mon, 17 Apr 2006 20:48:10 +0200

On Mon, 2006-04-17 at 09:37 -0700, Jean Tourrilhes wrote:

> 	Usually no, but...
> 	If you are in managed mode, SIOCSIWFREQ usually should return
> an error, because it is not allowed.

Ok.

> 	If you are in ad-hoc mode, SIOCSIWFREQ is used if a IBSS needs
> to be created. After scanning is done, if you did not find any
> network, you will create your own, and you will use the frequency that
> was set. You should never return an error.

Right. Well it should return an error if it is 'associated' in ad-hoc
mode too, no?

> 	The struct iw_scan_req has all the goodies you need to control
> scanning.

Right, so that's just a matter of using a different call to say where to
scan. Gotcha. IOW -- those people that want wardriving should use kismet
or whatever and properly control the driver via the iw_scan_req.

> 	The IW_FREQ_FIXED is mostly use for SIOCGIWFREQ, when
> getting. It tells you if the frequency was set by the user or
> automatically picked as the result of scanning.

Ah, but in which case is it set by the user? And is that 'fixed' then?

> 	I don't think any driver/hardware has the ability to set the
> frequency to auto, so IW_FREQ_FIXED is the default.

What would 'auto' be?

> 	It's because softmac only implements managed mode.

We might do some sort of ad-hoc client-only with Pete's patch, but we'll
never do master or wds I think.

> 	I've heard the call, I'll try to find some time for that.

Oh I was more thinking that I myself could add it somewhere after all
our discussion. If you do that, even better, but with the things we have
discussed already I can definitely help out.

johannes