[PATCH 3/3]: wpa_gui-qt4: use bss ctrl interface command to get scan results

Kel Modderman kel
Thu Jan 31 20:52:41 PST 2008

On Thursday 31 January 2008 13:39:09 Jouni Malinen wrote:
> On Thu, Jan 31, 2008 at 04:28:00AM +1000, Kel Modderman wrote:
> > Use new ctrl interface bss command get scan results for display iteratively.
> Thanks, applied. And this was also on my list yesterday if only I had
> had enough time.. Nice to get this cleanup into wpa_gui to get rid of
> the scan-results-do-not-fit-in-message issues.

This change has introduced a condition where in infinite loop of bss
ctrl interface commands are possible.

In a noisy environment, with a configuration that allows association to any
open access point, the "BSS next <bssid>" ctrl interface command may carry
on infinitely sometimes.

I could reproduce this by opening scan dialog. The environment contained
a reliable access point, a hidden access point on the fringe of acceptable
range from my location, and my hostapd access point which was on a put on
periodic loop with intervals of between 5 to 9 seconds to toggle
interface up/down. So there were a few bss's coming and going from scan

When the interface would attempt to connect with the hidden network that
occasionally popped in and out (but fail), the "bss next <bssid>" ctrl
interface command would continue in an infinite loop, wpa_gui process would
go out of control.

I have a two patch workaround for this problem, but I'm not sure if its the
best solution, you can decide:

1. introduce "bss count" ctrl interface command, that returns the number
   of bss's in scan results

2. wpa_gui: before attempting to iterate through scan results, get the number
   of bss's expected to be in scan results. Count each loop until we processed
   same number of bss's as expected than break from loop.

Will send each patch as a reply.

Thanks, Kel.

More information about the Hostap mailing list