From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933510Ab1LFPFt (ORCPT ); Tue, 6 Dec 2011 10:05:49 -0500 Received: from ffm.saftware.de ([83.141.3.46]:34167 "EHLO ffm.saftware.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933409Ab1LFPFs (ORCPT ); Tue, 6 Dec 2011 10:05:48 -0500 Message-ID: <4EDE2F49.3030108@linuxtv.org> Date: Tue, 06 Dec 2011 16:05:45 +0100 From: Andreas Oberritter User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:8.0) Gecko/20111124 Thunderbird/8.0 MIME-Version: 1.0 To: =?UTF-8?B?UsOpbWkgRGVuaXMtQ291cm1vbnQ=?= CC: linux-media@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [RFC] vtunerc: virtual DVB device - is it ok to NACK driver because of worrying about possible misusage? References: <4EDE1733.8060409@redhat.com> <4EDE1D57.90307@linuxtv.org> <201112061619.31357.remi@remlab.net> In-Reply-To: <201112061619.31357.remi@remlab.net> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 06.12.2011 15:19, Rémi Denis-Courmont wrote: > Le mardi 6 décembre 2011 15:49:11 Andreas Oberritter, vous avez écrit : >> You don't need to wait for write-only operations. Basically all demux >> ioctls are write-only. Since vtunerc is using dvb-core's software demux >> *locally*, errors for invalid arguments etc. will be returned as usual. > > That's a limitation, not a feature. You misunderstood. > You should not transmit unwanted programs over the network, nor copy them to > kernel space. I agree. And nobody said that this would happen. The software demux receives pre-filtered data. Still the ioctls are local. Just a trigger to start or stop filters needs to be sent to the remote demux, just like a register setting would be needed for a local hardware demux.