From mboxrd@z Thu Jan 1 00:00:00 1970 From: Vlad Yasevich Subject: Re: [PATCH] make ipv4 multicast packets only get delivered to sockets that are joined to group Date: Thu, 14 Sep 2006 13:12:08 -0400 Message-ID: <1158253928.12479.3.camel@galen.zko.hp.com> References: Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Cc: netdev Return-path: Received: from atlrel6.hp.com ([156.153.255.205]:32958 "EHLO atlrel6.hp.com") by vger.kernel.org with ESMTP id S1750775AbWINRML (ORCPT ); Thu, 14 Sep 2006 13:12:11 -0400 To: David Stevens In-Reply-To: Sender: netdev-owner@vger.kernel.org List-Id: netdev.vger.kernel.org On Thu, 2006-09-14 at 08:39 -0700, David Stevens wrote: > Alexey Kuznetsov wrote on 09/14/2006 03:30:37 AM: > > > Hello! > > > > > No, it returns 1 (allow) if there are no filters to explicitly > > > filter it. I wrote that code. :-) > > > > I see. It did not behave this way old times. > > > > From your mails I understood that current behaviour matches another > > implementations (BSD whatever), is it true? > > Hi, Alexey, > > If you mean IPv6 code in current BSD derivatives, I don't know. > > The IPv6 behaviour was different from IPv4 on Linux and was changed for > compatibility with IPv4 (discussion on netdev agreed that binding > should determine socket delivery, not group membership, or simply > that there was no reason to be different from long-standing IPv4 > practice). > > The IPv4 code is that way for compatibility with everything else since > about ~4.3BSD (with the possible exception of Solaris 8, apparently). > > FWIW, I think Deering's original interpretation is correct. Adding > a multicast address to an interface by joining a group is little > different from adding a unicast address via SIOCSIFADDR, which > certainly does affect packets delivered to the machine and to any > INADDR_ANY-bound socket. Binding to the multicast address and not > INADDR_ANY will give you only packets for that group, if that's > what you want, just as in the unicast address-specific bind. > > +-DLS There was an IETF daft quite a while ago that proposed something similar to the patch that originated this thread. In case anyone is curious, here is the link: http://tools.ietf.org/wg/ipv6/draft-arunt-ipv6-multicast-filtering-rules-01.txt That work got a few positive comments, but didn't really go anywhere. -vlad