Killing wpa_supplicant and wi-fi interface down problem

Jouni Malinen j
Tue Nov 18 06:06:43 PST 2008

On Tue, Nov 18, 2008 at 09:16:26AM +0530, Raghavendra wrote:

>    I totally agree with your point that it is better to put interface down, 
> when we kill wpa_supplicant. I my case I am using wpa_supplicant for 
> associating with the AP. I can not use this for scanning becoz of limitation 
> on the number of scan result it provides using control interface which is 
> max of 15 or 16 AP info.

If you are referring to the size limit on ctrl_iface messages and long
scan_results length, this has been resolved in v0.6.3 with the new BSS
command that can be used to fetch the scan results one by one (see
wpa_gui-qt4 for an example on how to use this to iterate through the
results and ctrl_iface.doxygen for documentation on the BSS command).

> Also I we want to set advnced configuration of 
> interface like setting power management, RTS, txpower, getting MAC of 
> interface...etc we need wi-fi interface up and wpa_supplicant does not 
> provide support for these feature.

You can set interface up before starting wpa_supplicant..

> So I would like to know is there a way by which I can disable putting 
> interface down, without changing wpa_supplicant code. I mean just by using 
> some config while enabling wpa_supplicant or I should change wpa_supplicant 
> code it self?

There is no support for this in the current version. I'm still not sure
I understood why exactly you would need to do this, so I don't see a
good reason to add it either. Anyway, it would be a trivial change in
driver_*.c to add parsing of a driver parameter that could be used to
implement this should there be a justifiable need for it.

Jouni Malinen                                            PGP id EFC895FA

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