Return-path: Received: from smtp.nokia.com ([192.100.122.233]:27428 "EHLO mgw-mx06.nokia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752828AbZAIMNJ (ORCPT ); Fri, 9 Jan 2009 07:13:09 -0500 To: "Ville Nuorvala" Cc: "Johannes Berg" , linux-wireless@vger.kernel.org, linville@tuxdriver.com Subject: Re: [PATCH] mac80211: Add IWSPY support to mac80211 stack References: <1230567920-16623-1-git-send-email-ville.nuorvala@gmail.com> <1230568151.3116.63.camel@johannes> <46fdfd70812291023q62f146edhbbfe7d9f9b9beb1f@mail.gmail.com> From: Kalle Valo Date: Fri, 09 Jan 2009 14:12:12 +0200 In-Reply-To: <46fdfd70812291023q62f146edhbbfe7d9f9b9beb1f@mail.gmail.com> (ext Ville Nuorvala's message of "Mon\, 29 Dec 2008 20\:23\:38 +0200") Message-ID: <87mye0oezn.fsf@nokia.com> (sfid-20090109_131315_112623_5422314D) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-wireless-owner@vger.kernel.org List-ID: "Ville Nuorvala" writes: > On Mon, Dec 29, 2008 at 6:29 PM, Johannes Berg > wrote: >> On Mon, 2008-12-29 at 18:25 +0200, Ville Nuorvala wrote: >>> The IWSPY ioctls and netlink events were supported in the old ieee80211 >>> stack. This patch adds them to mac80211. >> >> missing very long explanation as to why this is needed > > Hello Johannes, > > to my knowledge it is currently the only way to get a realtime > indication that the wireless link quality has changed, please correct > me if I'm wrong. Last fall there was a discussion about roaming in mac80211: http://markmail.org/message/ml4bjiyd6a26he6x So we are working on support for quality events, just a bit slowly :/ > Such a feature can be used as an early indication that the link is > going down, and may help prepare a vertical IP layer handover to for > example 3G or just another WLAN interface. I didn't even think about vertical handovers, thanks for pointing it out. I will keep this in mind. >> As far as I can tell, nobody uses iwspy support or could possibly want >> it the way it is done. > > The IOCTL interface is horrible, but it's already there and there is a > tool that supports it; iwspy. > > I'm not bringing any new functionality to the wireless stack, I'm just > reintroducing a feature that got lost when the wireless stack was > changed. I'm with Johannes here, let's forget iwspy and do it properly with nl80211. -- Kalle Valo