From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752224Ab1LKSpg (ORCPT ); Sun, 11 Dec 2011 13:45:36 -0500 Received: from moutng.kundenserver.de ([212.227.17.8]:62060 "EHLO moutng.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752101Ab1LKSpe (ORCPT ); Sun, 11 Dec 2011 13:45:34 -0500 Message-ID: <4EE4FA4A.6030909@naiadhome.com> Date: Sun, 11 Dec 2011 18:45:30 +0000 From: Peter martin User-Agent: Mozilla/5.0 (Windows NT 6.1; rv:8.0) Gecko/20111105 Thunderbird/8.0 MIME-Version: 1.0 CC: 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: <20111202231909.1ca311e2@lxorguk.ukuu.org.uk> <4EDC9B17.2080701@gmail.com> <4EDD01BA.40208@redhat.com> <4EDD2C82.7040804@linuxtv.org> <20111206112153.GC17194@sirena.org.uk> <4EDE0427.2050307@linuxtv.org> <20111206141929.GE17731@opensource.wolfsonmicro.com> <4EDE2B3B.2080905@linuxtv.org> <20111207134848.GB18837@opensource.wolfsonmicro.com> <4EDF71AE.5070509@linuxtv.org> In-Reply-To: <4EDF71AE.5070509@linuxtv.org> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Provags-ID: V02:K0:c3/b8VrUoP4WGQPcbs6+CQOgqJ/kxPOVb1ZwIuropIP FcN2MzeQxfBOWgzTaTyXV045fZ/PHE2Sh4Nu+vXwC39HQMo39P nSWyvraCbgrX9bUZYq0QGQoNgcSOM/tir0ksidLtDHlHhH+MlH +c/fu16sWwwI7a6m15mZSryr3xz37d99/I5oq1sVjNwvuN6jN9 7jK9rcikNkgKgX3LhSde4E71SVAAaETml4SHO/q4/4obAvw3tU p9f9t2j6Q9mNvwU3qKzoU/dhXmd7fMyQ8B1MWLsId5fIM4pdJf JfsbpJ700cfNm/oqE5WOwcOruGJM09Ab+K5NztQkuSk/itsysF dtN1huPn2BnMAH4fHnWE= To: unlisted-recipients:; (no To-header on input) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org One thing I have not seen addressed here is security. I've had a brief scan of the code, but there does not appear to be any mechanism to authenticate/authorise remote access to the vtunerc devices. In a home entertainment environment, this is not too serious, but In a non-closed network, for example a commercial installation in a hotel, what is to stop a rogue client from accessing a tuner and potentially causing mischief by changing settings, More seriously pulling a full MPTS of decrypted content from a CI card, which would make content providers most unhappy! I don't know enough about kernel modules doing networking, but do the packets go through the iptables route, and do things like DSCP still get taken note of? vtunerc sounds like a neat idea, but I am worried by the back doors it opens up. Sorry if I've missed something obvious here! Pete Martin On 07/12/2011 14:01, Andreas Oberritter wrote: > On 07.12.2011 14:49, Mark Brown wrote: >> On Tue, Dec 06, 2011 at 03:48:27PM +0100, Andreas Oberritter wrote: >>> On 06.12.2011 15:19, Mark Brown wrote: >>>> Your assertatation that applications should ignore the underlying >>>> transport (which seems to be a big part of what you're saying) isn't >>>> entirely in line with reality. >>> Did you notice that we're talking about a very particular application? >> *sigh* >> >>> VoIP really is totally off-topic. The B in DVB stands for broadcast. >>> There's only one direction in which MPEG payload is to be sent (using >>> RTP for example). You can't just re-encode the data on the fly without >>> loss of information. >> This is pretty much exactly the case for VoIP some of the time (though >> obviously bidirectional use cases are rather common there's things like >> conferencing). I would really expect similar considerations to apply >> for video content as they certainly do in videoconferencing VoIP >> applications - if the application knows about the network it can tailor >> what it's doing to that network. >> >> For example, if it is using a network with a guaranteed bandwidth it can >> assume that bandwidth. If it knows something about the structure of the >> network it may be able to arrange to work around choke points. >> Depending on the situation even something lossy may be the answer - if >> it's the difference between working at all and not working then the cost >> may be worth it. > Once and for all: We have *not* discussed a generic video streaming > application. It's only, I repeat, only about accessing a remote DVB API > tuner *as if it was local*. No data received from a satellite, cable or > terrestrial DVB network shall be modified by this application! > > Virtually *every* user of it will use it in a LAN. > > It can't be so hard to understand. > -- > To unsubscribe from this list: send the line "unsubscribe linux-media" in > the body of a message tomajordomo@vger.kernel.org > More majordomo info athttp://vger.kernel.org/majordomo-info.html