[patch] Set WPS/WSC IE for ProbeRequests via WEXT driver wrapper

Jouni Malinen j
Sat Oct 1 11:11:51 PDT 2011

On Tue, Sep 27, 2011 at 04:22:35PM +0300, Andriy Tkachuk wrote:
> you asked (in another mail) - "How would this be cleared?" The answer
> - exactly this way. I.e. on next scanning params->extra_ies will be
> reset (if it is not WPS) and correspondent ioctl will be called with
> empty value for GENIE (that might reset it). BTW, doesn't it work the
> same way in wpa_driver_wext_associate() for Open mode when we call
> wpa_driver_wext_set_gen_ie()?

Yes, this has somewhat similar issues in association. However, I'm more
worried about the extra IE being forgotten in the Probe Request frames
for the active PBC case.

> >From another side, I do agree that maybe we should call this only if
> wpa_supplicant is compiled with WPS support.

Well, WPS is not the only protocol using extra IEs in Probe Request
frames. The main problem here is that the WEXT behavior for SIOCSIWGENIE
is not clearly defined. This was added to be able to add WPA/RSN IE into
(Re)Association Request frames. The use of it in Probe Request frames
does not look that common based on the drivers that are included in the
upstream kernel.

In general, WEXT should not really be extended with new functionality or
modified in cases where there is risk of causing unexpected behavior
with some drivers. Is there any specific justification to not follow
that general principle with this change?

Jouni Malinen                                            PGP id EFC895FA

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