Return-path: Received: from crystal.sipsolutions.net ([195.210.38.204]:45145 "EHLO sipsolutions.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756894AbYDALrA (ORCPT ); Tue, 1 Apr 2008 07:47:00 -0400 Subject: Re: mac80211 MLME scanning - BSS list trouble From: Johannes Berg To: Tomas Winkler Cc: linux-wireless , Luis Carlos Cobo , Javier Cardona , Jiri Benc , Michael Wu , Jouni Malinen , Bill Moss , Daniel Drake , Dan Williams , Vladimir Koutny , John Linville In-Reply-To: <1ba2fa240803310710w24a057j7687411cb20985db@mail.gmail.com> (sfid-20080331_151036_058996_694F6D84) References: <1206865999.22530.187.camel@johannes.berg> <1ba2fa240803310710w24a057j7687411cb20985db@mail.gmail.com> (sfid-20080331_151036_058996_694F6D84) Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="=-giKjmk9sXKEovoBretF1" Date: Mon, 31 Mar 2008 20:40:40 +0200 Message-Id: <1206988840.5143.5.camel@johannes.berg> (sfid-20080401_124723_517033_FDA0BA48) Mime-Version: 1.0 Sender: linux-wireless-owner@vger.kernel.org List-ID: --=-giKjmk9sXKEovoBretF1 Content-Type: text/plain Content-Transfer-Encoding: quoted-printable > > The second problem is the one Bill Moss and Vladimir Koutny were runni= ng > > into. As soon as we receive a probe response from a BSS, we never agai= n > > update it from beacons, hence userspace can never find an AP during > > passive scanning if we've seen that BSSID before during an active scan= . [...] > For example WMM parameters are not present in beacon but are present > in probe response. > What is needed here is being selective what is updated and what not. > What is for sure you need at least one probe response before you can asso= ciate. Hm, isn't that particular information also contained in association responses? I don't think receiving probe responses is really required, which IEs do you have in mind that aren't also part of the association exchange? It does seem that the current code is not correct if we allow going from "have IE" to "don't have IE" when updating from beacons, but I don't see why probe responses should actually be required, and we certainly do not try to enforce that. In any case, do you have any idea how to fix this problem? Simply update things selectively? Do you want to take over handling it? :) Also, I'm not sure why it shows up with iwlwifi but no other hardware, does iwlwifi filter out probe responses if it got a beacon for the same BSSID or something like that? johannes --=-giKjmk9sXKEovoBretF1 Content-Type: application/pgp-signature; name=signature.asc Content-Description: This is a digitally signed message part -----BEGIN PGP SIGNATURE----- Comment: Johannes Berg (powerbook) iQIVAwUAR/EwJqVg1VMiehFYAQK2+RAAwsJcHagto1nLL6kYq52zo1knIsrk/3nL 7lGCwZIJoXw99PU6ZGT95dRyQ21TlAk7lPCcm/xgu2hakeLStKub2yX7G/iW1oL+ Q21msyfzx3OyLV+AT+/OlwNUvvetUOG35c96xg3yVcyt1TWOjt85Rf8gPbsd+0QF bSbEt81S+YeYm/iDRS01maNX/fB+mgo3IrcvJkdB+pHMwnNg6qgx0uaQ8K0hvBYI H4I0Zn9FUZFX9E8jcg6uFqkafCw2pRBYaxZ4Kr36R5noiWU8V7R64tDtqFlkttsx NNiZgZHfLwt7fEv37zv4fdGyIMguZimNE/mLqIHOGEs3XkQD3/Trdx/kizKt84a9 580YMHorLvIxOc9PvFHKGPN65xqaLQENeV/hNCGqFLMcFsvxap0Cv4PtcVfeaqg2 09xVuY6fA3L3g4a5E9Oy2ZoHrxInbX6sJjT0qLpC0wyq2A4BsqxkQcoESSlO7mNH fWnfVhiAU3GPw8DDk0guC/lvfWc5pDXwZsaqU7I2A7cMviSrF5gP8kYvR2nO7ocu zMEdfq5e7v84R0+tIiXEsOt+RmE7HG/IPQGHhw5Q8CYO6ZqyojZjvK+YTYLPFQyI LJ/Mab5tlAfhKq8UvbQpMj2TzMYbNu4D2ysTVztsoxNXp4/2DCotBGP5/GrzPbEd 4zlwaGhvK1o= =3wot -----END PGP SIGNATURE----- --=-giKjmk9sXKEovoBretF1--