linux-kernel - Re: attempt to scan fails (device busy) if essid/ssid was changed recently

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <1239110860.4084.0.camel@johannes.local>
Date:	Tue, 07 Apr 2009 15:27:40 +0200
From:	Johannes Berg <johannes@...solutions.net>
To:	Maxim Levitsky <maximlevitsky@...il.com>
Cc:	linux-wireless <linux-wireless@...r.kernel.org>,
	linux-kernel <linux-kernel@...r.kernel.org>
Subject: Re: attempt to scan fails (device busy) if essid/ssid was changed
 recently

On Tue, 2009-04-07 at 16:20 +0300, Maxim Levitsky wrote:

> > Of course, we can go back to dropping the scan request, but that
> > wouldn't be very nice.
> > 
> > Is this creating any problems?

> Yep, but dropping the request won't help ether.

Indeed.

> Problem is that wpa_supplicant will attempt to scan before association,
> scan fails (it doesn't know it is already running) thus it waits 10
> seconds. (I patched it to wait 2 seconds).
> 
> It happens if user first disconnects, and then reconnects to a network
> (typical test I do for time it takes to connect)
> 
> Now I patched it not to clear essid on disconnect, and this helped
> reduce connect times by about 2 seconds.
> 
> now it takes just 3~4 seconds to connect to open network, and ~6 seconds
> to WPA2 network.
> 
> (This is with patched dhclient, I reduced its timeouts, but this is
> another story.... it seems that first DHCPREQUEST never succeeds, and I
> tested this with 2 cards, and few wireless networks)

Have you tried with a new tree and wpa_supplicant's (from git) nl80211
driver? Might be a lot better.

johannes

Download attachment "signature.asc" of type "application/pgp-signature" (837 bytes)