Hi Jouni,<br><br><div class="gmail_quote">On Tue, Nov 29, 2011 at 7:20 PM, Jouni Malinen <span dir="ltr"><<a href="mailto:j@w1.fi">j@w1.fi</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;">
<div class="im">On Tue, Nov 29, 2011 at 05:36:26PM +0100, Vitaly Wool wrote:<br>
> I've been struggling to get my prototype P2P device to work with Samsung<br>
> Galaxy SII. The connection establishment kept failing with WPS_FAILURE and<br>
> it turned out to be due to overlap detected:<br>
><br>
> 01-03 01:27:26.140 E/wpa_supplicant( 2455): WPS: Requested UUID -<br>
> hexdump(len=16): 22 21 02 03 04 05 06 07 08 09 1a 1b 1c 1d 1e 1f<br>
> 01-03 01:27:26.140 D/wpa_supplicant( 2455): WPS: Consider PBC session with<br>
> 06:46:65:d3:4a:54<br>
> 01-03 01:27:26.140 E/wpa_supplicant( 2455): WPS: UUID-E - hexdump(len=16):<br>
> 22 21 02 03 04 05 06 07 08 09 0a 0b 0c 0d 0e 0f<br>
> 01-03 01:27:26.140 D/wpa_supplicant( 2455): WPS: New Enrollee<br>
> 01-03 01:27:26.140 D/wpa_supplicant( 2455): WPS: 2 active PBC session(s)<br>
> found<br>
> 01-03 01:27:26.140 D/wpa_supplicant( 2455): WPS: PBC overlap - deny PBC<br>
> negotiation<br>
<br>
</div>Argh.. Is that the way this device works with a deployed software? That<br>
is a known bug in that specific WPS implementation and I was hoping that<br>
it would never get released in a real end user product.<br>
<br>
This is so broken on multiple levels.. Those UUIDs are supposed to be<br>
unique for each device (good luck with those hardcoded values being<br>
unique) and only a single UUID can be used by the device, but this<br>
device is using two different ones..<br>
<div class="im"><br>
> So Galaxy changes UUID for PBC negotiation but the thing is, it could have<br>
> been considered to be the same session because the MAC address is the same.<br>
<br>
</div>Well, yes, it could have, but this is so horribly broken that I would<br>
like to just not allow it to use PBC.<br></blockquote><div><br></div><div>Right, but OTOH, if we have this overlap detection skipping mechanism is present in wpa_supplicant, let's either use it or drop it. I'd suggest that we used it, maybe under a configuration option of some kind, maybe producing warning messages in logs but still.</div>
<div> </div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;">
<div class="im"><br>
> There is a mechanism to do so for P2P connections in wpa_supplicant but it<br>
> doesn't work because P2P MAC address is not passed over<br>
> to wps_registrar_skip_overlap(). This patch adds that and also fixes the<br>
> PBC session removal after the negotiation (the current version leaves the<br>
> session in the list if it doesn't match UUID, I suggest that we remove all<br>
> sessions for the given MAC).<br>
<br>
</div>Could you please confirm that you are seeing this broken behavior with a<br>
deployed end user product and there are large number of those deployed?<br>
I don't think I would agree with all these changes since they break the<br>
way PBC overlap detection is supposed to work. If this bad behavior<br>
shows up in huge number of end user devices, it may be justifiable to<br>
add a workaround for it, but I want to limit the scope of how far the<br>
workaround goes in disabling overlap detection.<br>
<span class="HOEnZb"><font color="#888888"><br></font></span></blockquote><div><br></div><div>This broken behavior is seen with Samsung Galaxy SII, which is one of the top 5 smartphone bestsellers all over the world, and it's gotten all the latest updates. I'm not 100% sure yet but it looks like LG970 has gotten the same problem, so it's fair to say that all the Wi-Fi Direct enabled smartphones currently widely available on the market have got this problem.</div>
<div><br></div><div>Thanks,</div><div> Vitaly</div></div>