From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.3 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_2 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B956FC4360C for ; Tue, 8 Oct 2019 22:16:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 873B32070B for ; Tue, 8 Oct 2019 22:16:00 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="PWAav7px" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725935AbfJHWP7 (ORCPT ); Tue, 8 Oct 2019 18:15:59 -0400 Received: from mail-pl1-f196.google.com ([209.85.214.196]:46700 "EHLO mail-pl1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725848AbfJHWP7 (ORCPT ); Tue, 8 Oct 2019 18:15:59 -0400 Received: by mail-pl1-f196.google.com with SMTP id q24so9601plr.13 for ; Tue, 08 Oct 2019 15:15:57 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=message-id:subject:from:to:date:in-reply-to:references:mime-version :content-transfer-encoding; bh=lT7q6Z4nn0a+mDA6l257fP8CWvqqcrjOaGrVwoUYlUU=; b=PWAav7pxBhlSTRlQmKmPvYYk8j0jbDDC4zr2P2Yh7yVNIOMZIVGnMpFioqyhHChvAF 3jpf3lWgE4KxFz886D1K0JsdozTAVUc+AB1Ls1piLl8Umjv1uyO7JYmmL48o1Myfltgj rSEsi93dYkVVgOhTu4mPkd+Sf3aBRgbTd205fdTSBxdB5mEasxc5cTUKxT+nzOKeAIxL Zc4wI3EEf2kQIg2jlqQwKwKtl7MQ3DSPXuWkRRQtaogCv7hyOvVQw2Sv24Pk1E81+lty qhux7TvLu8oK4cpMKitlx3hjX7SD/+bS28qGuffr5Aoszijqp7Zf81pBtctFnxWwp/d3 pOvA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:message-id:subject:from:to:date:in-reply-to :references:mime-version:content-transfer-encoding; bh=lT7q6Z4nn0a+mDA6l257fP8CWvqqcrjOaGrVwoUYlUU=; b=tHbuHpRKCcr55jRARUexZTyKrwiNyOoU/OgADDi8PLcDPtEzBVXgZ3kA3ThPzrHXIE H9T9KJV2Mzb+/M1DAfe6siaoxMro+TY3dC8x+eiJXN7I9P3WR95Fxy+F+g2We3KlrxeU LTLshnRnpEcuu7h6Cb8gWGSVssPl3goytOlojdMshZSwjy8B4eVjODx/+SXRhKYs8j02 MHfwU5KlkmYdm8sSeFcSW41NlxG4hUhscFE81t1fgHGvzZgDNpcyGGw96rUaCkb9mqOv 1aAC7FDOFWjDYVca1h9iNWVZGfuSM9LMZjYi5JBj5AQWz6Yh/hu2ZL0yuYLQ0XVJ1203 cwfA== X-Gm-Message-State: APjAAAVl9/nEMDhHb52zJ0vNuTzz00liDATbwUWJDwpsLOgN3e7C046m +KL06A8wMetMC9+ArNvTrnpgukRV X-Google-Smtp-Source: APXvYqx//PhQV1+cXg5GPVC9DrC8NGqDC3jxWKU/5ig21LB1VpwyOyakp/u+vtJfITsAfZ5dkhM87A== X-Received: by 2002:a17:902:b109:: with SMTP id q9mr37229598plr.306.1570572957283; Tue, 08 Oct 2019 15:15:57 -0700 (PDT) Received: from jprestwo-test.jf.intel.com ([134.134.139.76]) by smtp.googlemail.com with ESMTPSA id 4sm166688pja.29.2019.10.08.15.15.55 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Tue, 08 Oct 2019 15:15:55 -0700 (PDT) Message-ID: Subject: Re: [PATCH 1/2] nl80211: Add LIVE_ADDR_CHANGE feature From: James Prestwood To: Johannes Berg , linux-wireless@vger.kernel.org Date: Tue, 08 Oct 2019 15:13:30 -0700 In-Reply-To: <83bde7f521e636903b6b386faaa31b73479add8b.camel@sipsolutions.net> References: <20190913195908.7871-1-prestwoj@gmail.com> (sfid-20190913_220113_419728_36032050) <6c85d9b108825939afb84ebc8a708a211f7e2b98.camel@sipsolutions.net> <38c222129dd182de4c55e536a89eada7f58a1bf1.camel@gmail.com> (sfid-20190913_225826_111097_E5ED9AB1) <47aaaccf7d8fb58587f0cfbe38acd18e1420dc9a.camel@sipsolutions.net> (sfid-20190913_231625_014352_843A9715) <83bde7f521e636903b6b386faaa31b73479add8b.camel@sipsolutions.net> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.28.5-0ubuntu0.18.04.1 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-wireless-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org Hi Johannes, On Tue, 2019-10-01 at 11:14 +0200, Johannes Berg wrote: > Hi, > > > > > Because userspace needs to know if this is supported? > > > > IFF_LIVE_ADDR_CHANGE is a private flag... AFAIK userspace has > > > > no > > > > way of > > > > obtaining this. > > > > > > Oh, annoying. > > > > > > But that doesn't really mean that nl80211 is an appropriate place > > > to > > > advertise it, IMHO? > > > > The intention of the flag was not soley related to > > CMD_CONNECT/CMD_AUTHENTICATE. Its an indication that the > > hardware/driver supports a live address change. If you don't want > > it > > here could you suggest a better location for it? > > I guess RTNL would be the right place? This can hardly be specific to > wireless, the flag comes from elsewhere. I do see where your coming from, and maybe the answer is both RTNL and NL80211? In this context a NL80211 flag would mean something different than only putting a flag into RTNL. The NL80211 flag means this device supports changing the MAC while running and not offchannel/scanning. Which is what -EBUSY would mean in this context. Managing the offchannel/scanning work is only possible with a NL80211 application. An RTNL only application has no idea about scanning/offchannel work, so it has no way of knowing what -EBUSY means in the wireless device context, or a way to prevent this from happening (stopping scanning or offchannel before changing the MAC). Now, another example would be an RTNL application that only cares about non-wireless devices (like ethernet), and in this case it could benefit from some type of RTNL specific flag and not care about a NL80211 flag. Since there is no such application that cares about this RTNL flag (since it doesn't exist) I would say that adding NL80211 flag is the way to go. If someone wants to add an RTNL flag I would say that is appropriate too. But in terms of this feature, a NL80211 flag is really what fits best since the changes are wireless specific. Thanks, James > > johannes >