[Cbe-oss-dev] [PATCH] PS3: gelic: ignore scan info from zero SSID beacons

[Masakazu Mokuno]

On Wed, 12 Mar 2008 09:25:10 +0100
Johannes Berg <johannes at sipsolutions.net> wrote:

> 
> > > Does this problem apply to probe responses as well?  (Do probe
> > > responses from hidden SSID APs still exclude the SSID?  I would
> > > guess not.)
> > 
> > There has been a problem in parsing IEs, so if the received probe
> > responses include zero length IEs, they also suffer this bug.
> > 
> > > As long as you can still associate w/ hidden SSID APs, I don't see
> > > a big problem.  Even if you can't, no information for those APs is
> > > probably better than bad information, no?
> > 
> > I was anxious that the userland apps or the users may get confused.  Any
> > other thing harmful is not found.
> > OK, I withdraw this patch.
> 
> I think John actually meant that it would be better to have the patch
> in. How does a "bad" scan result look like?

Usually the zero length IE, the SSID element, is the first one of IE
list, all information in the successor elements is lost. What we can see
is bssid.

The current firmware gives the following result.  The Corega (00:0A:79)
AP was the one which sent zero length SSID if it was in hidden SSID mode.

> iwlist wlan0 scanning
> wlan0     Scan completed :
>           Cell 01 - Address: 00:06:25:C6:B9:A7
>                     ESSID:"planexuser"
>                     Channel=1
>                     Bit Rates:1 Mb/s; 2 Mb/s; 5.5 Mb/s; 6 Mb/s; 9 Mb/s
>                               11 Mb/s; 12 Mb/s; 18 Mb/s; 24 Mb/s; 36 Mb/s
>                               48 Mb/s; 54 Mb/s
>                     Encryption key:on
>                     Mode:Master
>                     Signal level=100/100  
>                     IE: IEEE 802.11i/WPA2 Version 1
>                         Group Cipher : CCMP
>                         Pairwise Ciphers (1) : CCMP
>                         Authentication Suites (1) : PSK
>           Cell 02 - Address: 00:0A:79:A5:D2:E2
>                     ESSID:""
>                     Channel:0
>                     Encryption key:on
>                     Mode:Master
>                     Signal level=100/100  


With fixed firmware:

> wlan0     Scan completed :
>           Cell 01 - Address: 00:06:25:C6:B9:A7
>                     ESSID:"planexuser"
>                     Channel=1
>                     Bit Rates:1 Mb/s; 2 Mb/s; 5.5 Mb/s; 6 Mb/s; 9 Mb/s
>                               11 Mb/s; 12 Mb/s; 18 Mb/s; 24 Mb/s; 36 Mb/s
>                               48 Mb/s; 54 Mb/s
>                     Encryption key:on
>                     Mode:Master
>                     Signal level=100/100  
>                     IE: IEEE 802.11i/WPA2 Version 1
>                         Group Cipher : CCMP
>                         Pairwise Ciphers (1) : CCMP
>                         Authentication Suites (1) : PSK
>           Cell 02 - Address: 00:0A:79:A5:D2:E2
>                     ESSID:""
>                     Channel:1
>                     Bit Rates:1 Mb/s; 2 Mb/s; 5.5 Mb/s; 11 Mb/s; 6 Mb/s
>                               9 Mb/s; 12 Mb/s; 18 Mb/s; 24 Mb/s; 36 Mb/s
>                               48 Mb/s; 54 Mb/s
>                     Encryption key:on
>                     Mode:Master
>                     Signal level=100/100  
>                     IE: IEEE 802.11i/WPA2 Version 1
>                         Group Cipher : CCMP
>                         Pairwise Ciphers (1) : CCMP
>                         Authentication Suites (1) : PSK
> 


-- 
Masakazu MOKUNO