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=-2.3 required=3.0 tests=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 B4720C3A5A6 for ; Fri, 30 Aug 2019 09:07:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 926D22343C for ; Fri, 30 Aug 2019 09:07:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727546AbfH3JHR (ORCPT ); Fri, 30 Aug 2019 05:07:17 -0400 Received: from correo.us.es ([193.147.175.20]:50468 "EHLO mail.us.es" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726480AbfH3JHR (ORCPT ); Fri, 30 Aug 2019 05:07:17 -0400 Received: from antivirus1-rhel7.int (unknown [192.168.2.11]) by mail.us.es (Postfix) with ESMTP id 94076E8626 for ; Fri, 30 Aug 2019 11:07:11 +0200 (CEST) Received: from antivirus1-rhel7.int (localhost [127.0.0.1]) by antivirus1-rhel7.int (Postfix) with ESMTP id 8283EFF2C8 for ; Fri, 30 Aug 2019 11:07:11 +0200 (CEST) Received: by antivirus1-rhel7.int (Postfix, from userid 99) id 7606CB8007; Fri, 30 Aug 2019 11:07:11 +0200 (CEST) Received: from antivirus1-rhel7.int (localhost [127.0.0.1]) by antivirus1-rhel7.int (Postfix) with ESMTP id 46DFADA72F; Fri, 30 Aug 2019 11:07:09 +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, 30 Aug 2019 11:07:09 +0200 (CEST) X-Virus-Status: clean(F-Secure/fsigk_smtp/550/antivirus1-rhel7.int) Received: from us.es (sys.soleta.eu [212.170.55.40]) (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 241F64265A5A; Fri, 30 Aug 2019 11:07:09 +0200 (CEST) Date: Fri, 30 Aug 2019 11:07:10 +0200 X-SMTPAUTHUS: auth mail.us.es From: Pablo Neira Ayuso To: Jakub Kicinski Cc: netfilter-devel@vger.kernel.org, davem@davemloft.net, netdev@vger.kernel.org, vishal@chelsio.com, saeedm@mellanox.com, jiri@resnulli.us Subject: Re: [PATCH 0/4 net-next] flow_offload: update mangle action representation Message-ID: <20190830090710.g7q2chf3qulfs5e4@salvia> References: <20190830005336.23604-1-pablo@netfilter.org> <20190829185448.0b502af8@cakuba.netronome.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190829185448.0b502af8@cakuba.netronome.com> User-Agent: NeoMutt/20170113 (1.7.2) 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 Thu, Aug 29, 2019 at 06:54:48PM -0700, Jakub Kicinski wrote: > On Fri, 30 Aug 2019 02:53:32 +0200, Pablo Neira Ayuso wrote: > > * Offsets do not need to be on the 32-bits boundaries anymore. This > > patchset adds front-end code to adjust the offset and length coming > > from the tc pedit representation, so drivers get an exact header field > > offset and length. > > But drivers use offsetof(start of field) to match headers, and I don't > see you changing that. So how does this work then? Drivers can only use offsetof() for fields that are on the 32-bits boundary. Before this patchset, if you want to mangle the destination port, then the driver needs to refer to the source port offset and the length is 4 bytes, so the mask is telling what needs to be mangled. After this patchset, the offset is set to the destination port, the length is set to 2-bytes, and the mask is telling what bytes of the destination port field you specifically want to update. It's just 100 LOC of preprocessing that is simplifying driver codebase. > Say - I want to change the second byte of an IPv4 address. Then, the front-end sets the offset to IPv4 address header field, and the mask tells what to update. > > * The front-end coalesces consecutive pedit actions into one single > > word, so drivers can mangle IPv6 and ethernet address fields in one > > single go. > > You still only coalesce up to 16 bytes, no? You only have to rise FLOW_ACTION_MANGLE_MAXLEN coming in this patch if you need more. I don't know of any packet field larger than 16 bytes. If there is a use-case for this, it should be easy to rise that definition. > As I said previously drivers will continue to implement mangle action > merge code if that's the case. It'd be nice if core did the coalescing, > and mark down first and last action, in case there is a setup cost for > rewrite group. In this patchset, the core front-end is doing the coalescing.