User reported problems with driver_madwifi/driver_ipw

Jouni Malinen jkmaline
Sun Mar 6 11:17:34 PST 2005

On Mon, Feb 21, 2005 at 12:13:22PM -0800, Jouni Malinen wrote:

> On Fri, Feb 18, 2005 at 10:38:23AM -0500, Kyle McMartin wrote:
> > I'm the maintainer of the Debian packages of wpa_supplicant. A few users
> > reported needing the following patches to associate with open access points
> > using wpa_supplicant. However, this morning, some other users have
> > reported that the patch to driver_ipw breaks association with /ALL/
> > access points, and only reverting the patch fixes things. Do you think this
> > is plausible, or just a case of a problem on the users end?

> I do not have a test setup with ipw2100 or ipw2200, so the part about
> driver_ipw.c is somewhat less clear to me.

I managed to do a quick test with both ipw2100 and ipw2200 and here are
the results:

ipw2100 v1.0.5
- plaintext & WPA-PSK/CCMP worked with and without this patch
- roaming from plaintext to WPA-PSK was broken with this patch
  (worked without)

ipw2200 v1.0.1
- plaintext failed without this patch; worked with this patch
- WPA-PSK/CCMP worked with and without this patch
- roaming from plaintext to WPA-PSK was broken with this patch
- roaming to WPA-PSK worked after plaintext conf (which itself did not
  associated successfully) without this patch

In other words, these drivers behave differently and this patch is not
acceptable way of fixing the issue. In case of ipw2100, there does not
seem to be an issue in associating with plaintext in the first place and
in case of ipw2200, this patch allows plaintext association, but breaks
roaming (also for ipw2100).

As far as I can tell, this is likely to require a change in the driver
for a clean fix. The problem is that when set_wpa(drv, 0) is used to
disable WPA mode, scan results do not include wpa_ie. This makes finding
a WPA enabled AP impossible. However, since ipw2200 did not associate
with the plaintext AP without this patch, the driver would need to be
modified to allow this association without disabling WPA support in scan

ipw2100 seemed to allow association to a plaintext AP even in "WPA
mode". If the driver wants to disable association based on Privacy bit,
it needs to separate configuration for these two things: 1) WPA on/off
(mainly for scan results, I would assume; could be hardcoded to be on)
and 2) privacy on/off.

Jouni Malinen                                            PGP id EFC895FA

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