Return-Path: Message-ID: <4F8ED1D0.1070401@sipsolutions.net> Date: Wed, 18 Apr 2012 07:38:08 -0700 From: Johannes Berg MIME-Version: 1.0 To: Andrei Emeltchenko , Marcel Holtmann , linux-bluetooth@vger.kernel.org, linux-wireless@vger.kernel.org Subject: Re: [RFCv1] mac80211: Adds Software / Virtual AMP 80211 References: <1334059909-20513-1-git-send-email-Andrei.Emeltchenko.news@gmail.com> <1334059909-20513-2-git-send-email-Andrei.Emeltchenko.news@gmail.com> <4F846257.1060807@sipsolutions.net> <1334092668.16897.54.camel@aeonflux> <4F84A422.3030900@sipsolutions.net> <4F84A52A.7050905@sipsolutions.net> <20120411071119.GC17779@aemeltch-MOBL1> <1334714611.3725.34.camel@jlt3.sipsolutions.net> <20120418121551.GE19228@aemeltch-MOBL1> In-Reply-To: <20120418121551.GE19228@aemeltch-MOBL1> Content-Type: text/plain; charset=ISO-8859-1; format=flowed List-ID: On 4/18/2012 5:15 AM, Andrei Emeltchenko wrote: >> It's never in your best interest to run one supplicant per virtual >> interface, you want to run one per piece of hardware so it can >> coordinate between virtual interfaces. > > Do I understand it right that virtual interfaces are like separate devices from > user point of view? If I create virtual interface and assign MAC I can > transfer data through it without affecting other interfaces? Then > wpa_supplicant does not need to know about it at all. No, this is incorrect. If one device wants to connect on one channel, the other typically has to use the same channel. If one device wants to scan, the other will be affected. Some hardware may support switching around between two channels, but might also support more than 2 virtual interfaces, so again they won't be independent. Therefore, you need something managing all this concurrency. This is in a small part the driver which will enforce restrictions (it will reject new impossible things), but mostly the supplicant which can make policy decisions about which usage should win. johannes