From mboxrd@z Thu Jan 1 00:00:00 1970 From: Florian Westphal Subject: Re: [patch net-next 2/3] netfilter: ip6_tables: use reasm skb for matching Date: Wed, 6 Nov 2013 15:33:49 +0100 Message-ID: <20131106143349.GF15370@breakpoint.cc> References: <1383649333-6321-1-git-send-email-jiri@resnulli.us> <1383649333-6321-3-git-send-email-jiri@resnulli.us> <20131105133205.GC15370@breakpoint.cc> <20131105134118.GA5818@macbook.localnet> <20131105150115.GB2438@minipsycho.orion> <20131105181633.GA7435@macbook.localnet> <20131106141845.GC2458@minipsycho.orion> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Patrick McHardy , Florian Westphal , netdev@vger.kernel.org, davem@davemloft.net, pablo@netfilter.org, netfilter-devel@vger.kernel.org, yoshfuji@linux-ipv6.org, kadlec@blackhole.kfki.hu, mleitner@redhat.com, kuznet@ms2.inr.ac.ru, jmorris@namei.org, wensong@linux-vs.org, horms@verge.net.au, ja@ssi.bg, edumazet@google.com, pshelar@nicira.com, jasowang@redhat.com, alexander.h.duyck@intel.com, coreteam@netfilter.org To: Jiri Pirko Return-path: Received: from Chamillionaire.breakpoint.cc ([80.244.247.6]:52993 "EHLO Chamillionaire.breakpoint.cc" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932208Ab3KFOeK (ORCPT ); Wed, 6 Nov 2013 09:34:10 -0500 Content-Disposition: inline In-Reply-To: <20131106141845.GC2458@minipsycho.orion> Sender: netfilter-devel-owner@vger.kernel.org List-ID: Jiri Pirko wrote: > >> >So if someone wants to change this, simply *only* pass the reassembled > >> >packet through the netfilter hooks and drop the fragments, as in IPv4. > >> > >> This is unfortunatelly not possible because in forwarding use case, the > >> fragments have to be send out as they come in. > > > >No, the IPv6 NAT patches fixed that, we still do proper refragmentation > >and we still respect the original fragment sizes, thus are not responsible > >for potentially exceeding the PMTU on the following path. > > Can you please point where this is done. Where the original fragment > sizes are stored and in which code are they restored? Thanks. Patrick is probably talking about commit 4cdd34084d539c758d00c5dc7bf95db2e4f2bc70 (netfilter: nf_conntrack_ipv6: improve fragmentation handling) which introduces 'frag_max_size' in inet6_skb_parm struct.