Re: Passive Scanning not supported?

On Tue, 2006-07-25 at 12:53 +0200, Thomas King wrote:
> Hi all,
> I try to do passive scanning with ipw2200-1.1.3, however, it looks like it 
> doesn't work. I wrote a small program using the Wireless Tools version 
> 29-pre10 (beta). I set the scan_type in the iw_scan_req 
> struct to IW_SCAN_TYPE_PASSIVE and link this struct to the iwreq struct. The 
> iwreq struct is then used by the iw_set_ext function. However, if I invoke the 
> passive scanning program I see a Probe Request packet on the channel from the 
> machine that is supposed to do a passive scan.

Did you set IW_SCAN_THIS_ESSID? If so, ipw2200 will think you want an
active scan for this ssid even if IW_SCAN_TYPE_PASSIVE is provided.

> I think the reason for this is that in the ipw_wx_set_scan function there is 
> no distiction between active and passive scanning because 
> ipw_request_direct_scan is invoked. Ipw_wx_set_scan is more or less directly 
> called by the iw_set_ext function.

ipw_request_scan() performs the scan request to the firmware. Currently
if STA is not in monitor mode or roaming, it will do an active broadcast
scan. While from your description, if IW_SCAN_TYPE_PASSIVE is given, we
should actually do a passive scan (IPW_SCAN_PASSIVE_FULL_DWELL_SCAN).

Would you like to provide a patch to fix that? And try to see if the
probe request frames are not actually sent out by the card.

Thanks,
-yi

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