[PATCH] Treat '' in SSIDs param of DBus Interface.Scan as a request for braodcast scan.

[Dan Williams]

On Fri, 2010-10-08 at 08:39 -0700, Daniel Kurtz wrote:
> Dan:
> To put it another way, this patch adds a feature that allows
> simultaneous active scanning for both broadcast SSID, and a list of
> specific SSIDs.  This is useful when searching for available networks,
> including some known hidden SSIDs, that only respond to directed
> ProbeRequests.
> 
> 
> Not sending an explicit SSIDs field with a Scan request is merely a
> shortcut for requesting a ProbeRequests with SSID=''.  This patch
> allows the caller to request this explicitly.

Fair enough.

Dan

> 
> Blaise:
> Thanks for the info.  I guess you are literally answering Dan's
> question: "Does not sending any SSIDs somehow not work?"
> 
> 
> -Dan
> 
> On Thu, Oct 7, 2010 at 9:15 AM, Blaise Gassend
> <blaise at willowgarage.com> wrote:
>         On Wed, Oct 6, 2010 at 11:06 PM, Dan Williams
>         <dcbw at redhat.com> wrote:
>         
>         > On Wed, 2010-10-06 at 15:46 -0700, Daniel Kurtz wrote:
>         >> This patch changes wpa_supplicant policy for handling '' in
>         SSIDs field of Interface.SSID DBus message.
>         >> It treats '' (zero-length) SSID as a request for a
>         broadcast scan, instead of ignoring it.
>         >
>         > Does not sending any SSIDs somehow not work?  This seems
>         like a pretty
>         > big kludge.  The behavior should be that if no SSID property
>         is sent,
>         > then no specific scan is performed.  A zero-length SSID
>         should actually
>         > be rejected with an error.
>         
>         
>         If I recall, iw's scan command sends an empty SSID when no
>         ssid is
>         explicitely specified. A while ago iwlagn was not doing the
>         broadcast
>         scan if the empty ssid wasn't there. However, I believe that
>         was a
>         bug, and it has been corrected in recent versions of iwlagn.