[pkg-wpa-devel] Maybe wpasupplicant just shouldn't roam at all..

[Joachim Breitner]

Hi,

Am Sonntag, den 02.04.2006, 22:12 +0200 schrieb Reinhard Tartler:
> On Sun, Apr 02, 2006 at 09:51:02PM +0200, Joachim Breitner wrote:
> > while thinking about the roaming issue, I came to a different
> > conclusion: wpasupplicant should not roam at all, strictly following the
> > unix paradigm of small tools doing their stuff good. The work on mode1
> > enables that. But let's start at the beginning.
> > 
> > Let's have a look at the wired world first.
> > 
> > Setup 1) ifupdown
> > Setup 2) ifupdown + ifplugd
> > Setup 3) ifupdown + ifplugd + guessnet
>  
> > IIRC, wpasupplicant is also important for 802.1X. So if some network
> > needs that, we use wpasupplicant in mode1. This is orthogonal to these
> > Setups, and wpasupplicant can stick to it's main task.
> 
> I agree with your analysis. I don't think that Setup 3) is the only way
> to a decent roaming configuration, but it is surely a decent roaming 
> solution.
I'd like to hear how you would solve this (independent of wpasupplicant)

> > Let's transfer this to the wireless world:
> > 
> > Setup 1) ifupdown
> > Setup 2) ifupdown + wifiroamd
> > Usually, you walk in and out of the range of your (currently only)
> > network. So we need something that detects the reaching and leaving of
> > the AP's range. Currently, I'm using wpasupplicant for that, I used to
> > use waproamd, but both are actually overkill - we just need the "is
> > there an AP with an essid that appears in /e/n/i, then ifup wifi0"
> > functionality and the "oh, signal level is zero, or low enough to
> > warrant a re-scan, so run ifdown wifi0 and start scanning again". Maybe
> > that part of the code can be put in a separate daemon, here dubbed
> > "wifiroamd"
> 
> Such a daemon shouldn't be that hard to write. In principle, you would
> only need to scan periodically (iwlist $IFACE scan). There is a corner
> case with hidden ssids, the daemon would have to scan for them actively.
> But I like the idea for such an scanning daemon. Heck, it wouldn't even
> need to be a daemon, rather a wifidetector: for use with an mapping
> script it would perhaps be easier if you could just have the command
> returning a string which identifies the detected location.
I don't think it should be a mapping script (we actually have that,
that's guessnet, see below). But the point is that this daemon should
work _before_ ifupdown. Think of it this way. We have not hardware that
tells us that we are plugged in, so we need something to replace that.
It should work very analogous to ifplugd, IMHO.

> > Setup 3) ifupdown + wifiroamd + guessnet

> Thank you very much for your post. I think the solution you presented
> here does integrate very well into ifupdown. Is there perhaps such a
> wifi detector already written?

Yes, wpasupplicant in old mode3, if you don't configure any encryption
options :-)
Or waproamd, if you don't configure any encryption options...

If someone likes to delete code, he could just take wpasupplicant (which
roamings abilities are proven, at least for my usage), and turn it into
a wifiroamd.

Greetings,
Joachim

-- 
Joachim "nomeata" Breitner
Debian Developer
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