probe request handling with driver_nl80211

Mail4Lior mail4lior at
Mon May 16 16:19:16 EDT 2011

On Mon, May 16, 2011 at 10:23 PM, Jouni Malinen <j at> wrote:
> On Tue, May 10, 2011 at 07:52:59PM +0300, Mail4Lior wrote:
>> I want to understand why the probe request frames are registered at
>> the wpa_supplicant only when the device is in listen mode?
> This is special functionality for P2P device discovery.
>> Which component(fw/driver/supplicant) will handle those probe in
>> active mode(the device in GO state)?
> That depends on the driver. Some drivers handle the Probe Request frames
> in firmware or kernel, others may use the AP code in
> hostapd/wpa_supplicant to process the frames.
>> If this response done by lower layers (driver/fw) how the information
>> element is passing to those layer, which API is used?
> That depends on the driver. Full Probe Request frame (and other
> management frames) may be delivered to hostapd/wpa_supplicant (e.g.,
> through monitor interface in case of mac80211) or
> EVENT_RX_PROBE_REQ/EVENT_RX_MGMT driver events may be used for this.

So if I understand correctly
1. The probe response in P2P GO is always built in the wpa_supplicant
when using nl80211 driver (the nl80211 driver doesn't have an API for
sending the Probe Response IE to kernel).
2. when using nl80211, the drive event EVENT_RX_MGMT is used for probe
request only at discovery stage(listen mode) the frame registration is
done only for this period.
3. The nl80211 driver interface is always use the monitor interface to
indicate/forward management packets to the supplicant . when not in
listen state

> --
> Jouni Malinen                                            PGP id EFC895FA
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