operation of GO after group formation in p2p

Jouni Malinen j
Tue Jul 12 10:03:16 PDT 2011

On Thu, Jul 07, 2011 at 09:44:34AM +0800, ghj kevin wrote:
> I am studying on the src code of wpa_supplicant. I know that for
> nl80211 interface, the p2p state machine is implemented by supplicant.
> I have a question that, how does wpa_supplicant passes GO related
> parameters to driver after the completion of GO negotiation?

The network interface (or a newly added network interface if separate
interfaces are used for P2P groups) is set up in AP/GO mode and a Beacon
frame template is configured to enable AP-like functionality on the
interface at that point.

> In p2p listen, I noticed that the probe_req_report is called. But, in
> wpas_go_neg_completed(), how does the driver know that they are now a
> group owner and they should pass the probe req frame to supplicant?
> Or, after group formation, is the supplicant still resposible for
> buiding and sending probe response frame?

This depends on the driver. With the nl80211 interface, there has been
an assumption on Probe Request frames being processed completely in user
space, but other driver interfaces process them in the driver/firmware.
Similar design may already work with nl80211, but if not, it is likely
to be added eventually to enable drivers that need such behavior.
Jouni Malinen                                            PGP id EFC895FA

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