From mboxrd@z Thu Jan 1 00:00:00 1970 From: Patrick McHardy Subject: Re: [RFC] netlink: add socket destruction notification Date: Mon, 09 Nov 2009 14:19:15 +0100 Message-ID: <4AF816D3.7000304@trash.net> References: <1254473048.3959.76.camel@johannes.local> <4AF43EF9.3020707@trash.net> <1257521204.29454.31.camel@johannes.local> <4AF442C2.9040704@trash.net> <1257762132.29454.161.camel@johannes.local> <4AF8122F.9060807@trash.net> <1257771787.29454.173.camel@johannes.local> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15 Content-Transfer-Encoding: 7bit Cc: netdev , Jouni Malinen , Thomas Graf To: Johannes Berg Return-path: Received: from stinky.trash.net ([213.144.137.162]:39368 "EHLO stinky.trash.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754730AbZKINTO (ORCPT ); Mon, 9 Nov 2009 08:19:14 -0500 In-Reply-To: <1257771787.29454.173.camel@johannes.local> Sender: netdev-owner@vger.kernel.org List-ID: Johannes Berg wrote: > On Mon, 2009-11-09 at 13:59 +0100, Patrick McHardy wrote: > >>> Thanks for the explanation. I think we'd need the second condition >>> removed, I don't see a reason to force a socket to not also have >>> multicast RX if it's used for any of the purposes we're looking at this >>> for. Guess we need to audit the callees to determine whether that's ok. >> I've already done that. Its currently only used by netfilter >> for which this change also makes sense. > > Cool, I arrived at that conclusion too, it seemed that it would > currently be somewhat strangely broken if you could add multicast groups > to those sockets used there. Not sure if you can though. I don't see anything preventing it. >>> Can you quickly explain the difference between release and destruct? >> release is called when the socket is closed, destruct is called >> once all references are gone. I think with the synchonous processing >> done nowadays they shouldn't make any difference, but release >> should be fine in either case. > > Ok, cool, thanks. Do you want me to send the change removing the > multicast check, or would you want to do that since you audited all the > netlink callers? Please go ahead. > Also, it's called URELEASE for unicast -- should we rename it to just > RELEASE? I think URELEASE is still fine since won't necessarily get called for sockets that are used for pure multicast reception when using setsockopt to bind to groups. I also have a cleanup patch removing unneccessary nlk->pid checks from netfilter which would clash with a rename :)