From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jouni Malinen Subject: Re: [GIT]: Networking (WEXT events and 64/32 compat) Date: Thu, 18 Sep 2008 15:13:10 -0700 Message-ID: <20080918221309.GA22034@hostap.isc.org> References: <20080908.204323.04156464.davem@davemloft.net> <20080909040525.GA26151@hostap.isc.org> <20080917191128.GA23239@hostap.isc.org> <20080917.131133.135282530.davem@davemloft.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: j@w1.fi, jouni.malinen@atheros.com, alex.williamson@hp.com, torvalds@linux-foundation.org, akpm@linux-foundation.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org To: David Miller Return-path: Received: from hostap.isc.org ([149.20.54.63]:35404 "EHLO hostap.isc.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755018AbYIRWYp (ORCPT ); Thu, 18 Sep 2008 18:24:45 -0400 Content-Disposition: inline In-Reply-To: <20080917.131133.135282530.davem@davemloft.net> Sender: netdev-owner@vger.kernel.org List-ID: On Wed, Sep 17, 2008 at 01:11:33PM -0700, David Miller wrote: > Moving to a new event with a strictly sized datastructure, instead of > one that has variable sized members like pointers and crap which are > impossible to compat layer'ify, is indeed my preference. > > But in that case, we might as well make nl80211 usable instead. Would you be fine with continuing to use IFLA_WIRELESS for this or should we reserve a new identifier for the nl80211 case? I'm assuming that the base mechanism would continue to remain as a broadcast rtnetlink message and the main difference to WEXT is in defining all events as data with fixed size fields instead of C structures. IFLA_WIRELESS messages start with two fixed size fields (16-bit len and cmd) which would allow us to reserve a new cmd value for nl80211 messaages and then we could even share the helper functions in wireless/wext.c and just replace wireless_send_event() with a new function that generates the new event type. As a first porting step, wireless_send_event() could be extended to send both messages so that we do not need to modify all drivers to use the new mechanism in the beginning (and the old WEXT events would continue to be available for anyone who uses 32/32-bit or 64/64-bit kernel/userspace). As far as userspace is concerned, I would assume apps would eventually start moving to using the new events. As an example, wpa_supplicant has support for using either WEXT or nl80211 (though, this is still using WEXT for places that nl80211 does not support yet) and I would likely leave the WEXT case as-is and modify nl80211 interface to use only the new event messages. -- Jouni Malinen PGP id EFC895FA