wpa_supplicant does not work properly with some USB adapters on WinXP

Jouni Malinen jkmaline
Tue Aug 22 06:39:37 PDT 2006

On Tue, Aug 22, 2006 at 10:57:41AM +0300, Adrian Nistor wrote:
> The idea to do the SELECTs in the opposite order and keep an
> InstanceName-to-GUID mapping is great. It will decrease the number of WMI
> calls per event and save a lot of time as WMI is notably slow.

I think I'll keep it, but..

> I could not find any relevant documentation regarding the source of the
> InstanceName from WMI. I did some investigation and found the weird
> behaviour regarding USB adapters I described in the previous mail (it can be
> seen also in the log file I sent). In the process, I also found that the
> InstanceName matches the Name from the Win32_PNPEntity instead.

That's getting somewhat complex. Well, I can easily add the use on
Win32_PnPEntity, but it sounds like that is not enough. There needs to
be code for re-doing this whenever the adapter addition notification is
received. Since ndis_events.exe can be made to receive this, it should
be possible to take care of all this complexity there. Though, the
current model of filtering all notifications based on a fixed interface
name is not going to work..

If the only thing changing is a number in the end of string, that can be
handled relatively easily by using LIKE 'prefix%' type matching. In
addition, I don't know whether Win32_PnPEntity is guaranteed to include
all network adapters, so it might be good to default to using Name from
Win32_NetworkAdapter and only replace it if a better candidate is found
from Win32_PnPEntity. I really love WMI.. This has almost convinced me
to write an own protocol driver for getting these events in a sane way..

Jouni Malinen                                            PGP id EFC895FA

More information about the Hostap mailing list