USB support

[Dan Williams]

On Tue, 2008-07-01 at 15:56 -0400, Stuffed Crust wrote:
> On Tue, Jul 01, 2008 at 12:35:21PM -0400, Pavel Roskin wrote:
> > Once approach would be to start with linux-wlan-ng and clean it up.
> > It's a lot of work, but you would have a working driver at every point.
> 
> This isn't as bad as it sounds, as most of the crap in the wlan-ng stack 
> is due to how it interacts with userspace, and most of that was set up 
> assuming that tertiary(ie firmware-based) AP mode was being used.  The 
> so-called HostAP mode works fine on USB devices.
> 
> Wlan-ng's packet paths are pretty straightforard, and can easily be 
> ported to net80211.  The real work comes from bolting up the mac80211 
> configuration interface, and from that perspective, you're writing a 
> whole new driver anyway.

Ugh.  I looked into just doing that, and it didn't look very nice.  I
think there's just too much cruft between p80211 and linux-wlan-ng to
try porting linux-wlan-ng over.  At the end of the day, it's probably
about the same amount of work, and if that's true, I'd personally rather
have a clean mac80211 driver.

The appeal of porting to hostap was the ability to re-use constants and
some of the hfa code.  Not sure how feasible that would be.  But the
benefit of that is likely outweighed by the locking issues and
synchronous command nature of hostap which would be probably be a bitch
to fit the USB stuff into.  The locking required to do that seems
difficult to get right.

Dan