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=-5.5 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 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 5B96FC433DF for ; Fri, 31 Jul 2020 17:19:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 44A102074B for ; Fri, 31 Jul 2020 17:19:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732872AbgGaRTN (ORCPT ); Fri, 31 Jul 2020 13:19:13 -0400 Received: from correo.us.es ([193.147.175.20]:35300 "EHLO mail.us.es" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732970AbgGaRTM (ORCPT ); Fri, 31 Jul 2020 13:19:12 -0400 Received: from antivirus1-rhel7.int (unknown [192.168.2.11]) by mail.us.es (Postfix) with ESMTP id 8331E172C9B for ; Fri, 31 Jul 2020 19:19:09 +0200 (CEST) Received: from antivirus1-rhel7.int (localhost [127.0.0.1]) by antivirus1-rhel7.int (Postfix) with ESMTP id 7365ADA903 for ; Fri, 31 Jul 2020 19:19:09 +0200 (CEST) Received: by antivirus1-rhel7.int (Postfix, from userid 99) id 700F7DA902; Fri, 31 Jul 2020 19:19:09 +0200 (CEST) Received: from antivirus1-rhel7.int (localhost [127.0.0.1]) by antivirus1-rhel7.int (Postfix) with ESMTP id 13CA1DA73F; Fri, 31 Jul 2020 19:19:07 +0200 (CEST) Received: from 192.168.1.97 (192.168.1.97) by antivirus1-rhel7.int (F-Secure/fsigk_smtp/550/antivirus1-rhel7.int); Fri, 31 Jul 2020 19:19:07 +0200 (CEST) X-Virus-Status: clean(F-Secure/fsigk_smtp/550/antivirus1-rhel7.int) Received: from us.es (unknown [90.77.255.23]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) (Authenticated sender: 1984lsi) by entrada.int (Postfix) with ESMTPSA id DA17D4265A2F; Fri, 31 Jul 2020 19:19:06 +0200 (CEST) Date: Fri, 31 Jul 2020 19:19:06 +0200 X-SMTPAUTHUS: auth mail.us.es From: Pablo Neira Ayuso To: Eric Garver , Phil Sutter , "Jose M. Guisado Gomez" , netfilter-devel@vger.kernel.org Subject: Re: [PATCH nft v2 1/1] src: enable output with "nft --echo --json" and nftables syntax Message-ID: <20200731171906.GA15741@salvia> References: <20200730195337.3627-1-guigom@riseup.net> <20200731000020.4230-2-guigom@riseup.net> <20200731092212.GA1850@salvia> <20200731123342.GF13697@orbyte.nwl.cc> <20200731125825.GA12545@salvia> <20200731134828.GG13697@orbyte.nwl.cc> <20200731141742.so3oklljvtuad2cl@egarver> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200731141742.so3oklljvtuad2cl@egarver> User-Agent: Mutt/1.10.1 (2018-07-13) X-Virus-Scanned: ClamAV using ClamSMTP Sender: netfilter-devel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netfilter-devel@vger.kernel.org On Fri, Jul 31, 2020 at 10:17:42AM -0400, Eric Garver wrote: > On Fri, Jul 31, 2020 at 03:48:28PM +0200, Phil Sutter wrote: > > On Fri, Jul 31, 2020 at 02:58:25PM +0200, Pablo Neira Ayuso wrote: > > > On Fri, Jul 31, 2020 at 02:33:42PM +0200, Phil Sutter wrote: [...] > > I'm assuming scripts will work directly with the Python data structures > > that are later passed to libnftables as JSON. If they want to change a > > rule, e.g. add a statement, it is no use if other statements disappear > > or new ones are added by the commit->retrieve action. > > > > Maybe Eric can shed some light on how Firewalld uses echo mode and > > whether my concerns are relevant or not. > > How it stands today is exactly as you described above. firewalld relies > on the output (--echo) being in the same order as the input. At the > time, and I think still today, this was the _only_ way to reliably get > the rule handles. It's mostly due to the fact that input != output. > > In the past we discussed allowing a user defined cookie/handle. This > would allow applications to perform in a write only manner. They would > not need to parse back the JSON since they already know the > cookie/handle. IMO, this would be ideal for firewalld's use case. The question is: Is this patch breaking anything in firewalld? And if so, what is it breaking? I don't find a good reason why maintaining two different codepaths for --json --echo in the codebase is needed. Thanks.