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=-4.0 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no 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 A7988C433E1 for ; Sat, 25 Jul 2020 11:55:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 880BB206EB for ; Sat, 25 Jul 2020 11:55:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726618AbgGYLzq (ORCPT ); Sat, 25 Jul 2020 07:55:46 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49158 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726583AbgGYLzp (ORCPT ); Sat, 25 Jul 2020 07:55:45 -0400 Received: from orbyte.nwl.cc (orbyte.nwl.cc [IPv6:2001:41d0:e:133a::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8297FC0619D3 for ; Sat, 25 Jul 2020 04:55:45 -0700 (PDT) Received: from n0-1 by orbyte.nwl.cc with local (Exim 4.94) (envelope-from ) id 1jzImD-0003o5-VM; Sat, 25 Jul 2020 13:55:42 +0200 Date: Sat, 25 Jul 2020 13:55:41 +0200 From: Phil Sutter To: Pablo Neira Ayuso Cc: netfilter-devel@vger.kernel.org Subject: Re: [iptables PATCH 00/18] nft: Sorted chain listing et al. Message-ID: <20200725115541.GA13697@orbyte.nwl.cc> Mail-Followup-To: Phil Sutter , Pablo Neira Ayuso , netfilter-devel@vger.kernel.org References: <20200711101831.29506-1-phil@nwl.cc> <20200723122257.GA22824@salvia> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200723122257.GA22824@salvia> Sender: netfilter-devel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netfilter-devel@vger.kernel.org Hi Pablo, On Thu, Jul 23, 2020 at 02:22:57PM +0200, Pablo Neira Ayuso wrote: > On Sat, Jul 11, 2020 at 12:18:13PM +0200, Phil Sutter wrote: > > Work in this series centered around Harald's complaint about seemingly > > random custom chain ordering in iptables-nft-save output. nftables > > returns chains in the order they were created which differs from > > legacy iptables which sorts by name. > > > > The intuitive approach of simply sorting chains in tables' > > nftnl_chain_lists is problematic since base chains, which shall be > > dumped first, are contained in there as well. Patch 15 solves this by > > introducing a per-table array of nftnl_chain pointers to hold only base > > chains (the hook values determine the array index). The old > > nftnl_chain_list now contains merely non-base chains and is sorted upon > > population by the new nftnl_chain_list_add_sorted() function. > > > > Having dedicated slots for base chains allows for another neat trick, > > namely to create only immediately required base chains. Apart from the > > obvious case, where adding a rule to OUTPUT chain doesn't cause creation > > of INPUT or FORWARD chains, this means ruleset modifications can be > > avoided completely when listing, flushing or zeroing counters (unless > > chains exist). > > Patches from 1 to 7, they look good to me. Would it be possible to > apply these patches independently from this batch or they are a strong > dependency? I just pushed them after making sure they don't break any of the testsuites. Fingers crossed I didn't miss a detail which breaks without the other patches. :) > I think it's better if we go slightly different direction? > > https://patchwork.ozlabs.org/project/netfilter-devel/patch/20200723121553.7400-1-pablo@netfilter.org/ That's interesting. At least it would allow us to reorganize the cache-related data structures, e.g. move the nft_cache->table array items into nft_cache->table items. > Instead of adding more functions into libnftnl for specific list > handling, which are not used by nft, use linux list native handling. OK. > I think there is not need to cache the full nftnl_table object, > probably it should be even possible to just use it to collect the > attributes from the kernel to populate the nft_table object that I'm > proposing. Yes, for iptables-nft at least we should be completely fine with table name alone. > IIRC embedded people complained on the size of libnftnl, going this > direction I suggest, we can probably deprecated iterators for a number > of objects and get it slimmer in the midrun. OK. I'll keep that in mind. So I'll rework my changes based on your nft_table idea and introduce an nft_chain struct to be organized in a standard list_head list. This will allow me to perform the sorting in iptables-nft itself. Should I base this onto your nft_table patch (and exploit it a bit further) or keep them separate for now? Thanks, Phil