From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED,USER_AGENT_NEOMUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 94817C5CFEB for ; Mon, 9 Jul 2018 20:27:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2B97C2087C for ; Mon, 9 Jul 2018 20:27:46 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2B97C2087C Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=strlen.de Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933096AbeGIU1k (ORCPT ); Mon, 9 Jul 2018 16:27:40 -0400 Received: from Chamillionaire.breakpoint.cc ([146.0.238.67]:35358 "EHLO Chamillionaire.breakpoint.cc" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932686AbeGIU1i (ORCPT ); Mon, 9 Jul 2018 16:27:38 -0400 Received: from fw by Chamillionaire.breakpoint.cc with local (Exim 4.89) (envelope-from ) id 1fcckn-0003cA-OF; Mon, 09 Jul 2018 22:27:25 +0200 Date: Mon, 9 Jul 2018 22:27:25 +0200 From: Florian Westphal To: Pablo Neira Ayuso Cc: Florian Westphal , Arnd Bergmann , Jozsef Kadlecsik , "David S. Miller" , =?iso-8859-15?Q?M=E1t=E9?= Eckl , Fernando Fernandez Mancera , "Pablo M. Bermudo Garay" , Felix Fietkau , netfilter-devel@vger.kernel.org, coreteam@netfilter.org, Networking , Linux Kernel Mailing List Subject: Re: [PATCH] netfilter: conntrack: add weak IPV6 dependency Message-ID: <20180709202725.d2fgn5p26whfrvfn@breakpoint.cc> References: <20180706130005.3640993-1-arnd@arndb.de> <20180706135516.viz6pjtkdmcoqq2l@breakpoint.cc> <20180706150037.knqt736uq6uyh3bs@breakpoint.cc> <20180706183548.hk7jwobomkqdccs5@breakpoint.cc> <20180709165050.uuglk24ctiezhnye@salvia> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180709165050.uuglk24ctiezhnye@salvia> User-Agent: NeoMutt/20170113 (1.7.2) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Pablo Neira Ayuso wrote: > On Fri, Jul 06, 2018 at 08:35:48PM +0200, Florian Westphal wrote: > > Florian Westphal wrote: > > > Arnd Bergmann wrote: > > > > and that resulted in a new build failure: > > > > > > > > net/netfilter/nf_conntrack_proto.o:(.rodata+0x788): undefined > > > > reference to `nf_conntrack_l4proto_icmpv6' > > > > net/ipv6/netfilter/nf_conntrack_reasm.o: In function `nf_ct_frag6_expire': > > > > nf_conntrack_reasm.c:(.text+0x2320): undefined reference to > > > > `ip6_expire_frag_queue' > > > > net/ipv6/netfilter/nf_conntrack_reasm.o: In function `nf_ct_frag6_init': > > > > nf_conntrack_reasm.c:(.text+0x2384): undefined reference to `ip6_frag_init' > > > > nf_conntrack_reasm.c:(.text+0x2394): undefined reference to `ip6_frag_init' > > > > nf_conntrack_reasm.c:(.text+0x2398): undefined reference to `ip6_rhash_params' > > > > net/ipv6/netfilter/nf_conntrack_reasm.o: In function `nf_ct_frag6_expire': > > > > nf_conntrack_reasm.c:(.text+0x10bc): undefined reference to > > > > `ip6_expire_frag_queue' > > > > > > > > I don't think we can get CONFIG_NF_DEFRAG_IPV6=y to work with IPV6=m. > > > > > > Yes, not with current implementation, but I still don't think this > > > is unavoidable. > > > > > > In case this is urgent I'm fine with the patch that adds the dependency, > > > otherwise I'd like to try and disentangle nf_conntrack_reasm and ipv6. > > > > This links fine for me with IPV6=m: > > > > Pablo, do you think this is too ugly? > > Well, yes... > > > It requires some copypastry from ipv6 defrag into nfct ipv6 defrag > > to avoid the link errors outlined above. > > This is a bit of a regression I think. nf_defrag_ipv6 has always depended on ipv6. Previously dependency chain is nf_conntrack_ipv6 -> ipv6 +-----> nf_defrag_ipv6 > ipv6 +-----> nf_conntrack new dependency chain is: nf_conntrack --> nf_defrag_ipv6 --> ipv6 The alternate fix is the one from Arnd to disallow NF_CONNTRACK=y IPV6=m > While I think a bit of demodularization is fine, if things like this > start to kick in, it's probably good if we go make a step back... If you want to revert, ok. It will prevent all l4 unification patches plus any attempt to get rid of the nf_hook for defrag too however so I do not like it. > Let me know, thanks. Yet another alternative would be to remove the nf_conntrack -> nf_defrag_ipv6 dependency, e.g. by adding a new rcu-protected function pointer. nf_conntrack, when ipv6 conntrack is requested, would check if its null, and, if so, issue request_module() for ipv6 defrag before failing the request. However, I find it even more ugly than my patch.