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 5AB96C433E0 for ; Wed, 20 May 2020 14:33:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2F1EF207D3 for ; Wed, 20 May 2020 14:33:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726829AbgETOdh (ORCPT ); Wed, 20 May 2020 10:33:37 -0400 Received: from correo.us.es ([193.147.175.20]:53524 "EHLO mail.us.es" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726691AbgETOdg (ORCPT ); Wed, 20 May 2020 10:33:36 -0400 Received: from antivirus1-rhel7.int (unknown [192.168.2.11]) by mail.us.es (Postfix) with ESMTP id C034F120832 for ; Wed, 20 May 2020 16:33:32 +0200 (CEST) Received: from antivirus1-rhel7.int (localhost [127.0.0.1]) by antivirus1-rhel7.int (Postfix) with ESMTP id B3A0FDA70F for ; Wed, 20 May 2020 16:33:32 +0200 (CEST) Received: by antivirus1-rhel7.int (Postfix, from userid 99) id A066CDA716; Wed, 20 May 2020 16:33:32 +0200 (CEST) Received: from antivirus1-rhel7.int (localhost [127.0.0.1]) by antivirus1-rhel7.int (Postfix) with ESMTP id AA720DA703; Wed, 20 May 2020 16:33:30 +0200 (CEST) Received: from 192.168.1.97 (192.168.1.97) by antivirus1-rhel7.int (F-Secure/fsigk_smtp/550/antivirus1-rhel7.int); Wed, 20 May 2020 16:33:30 +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 8C0EE42EF42B; Wed, 20 May 2020 16:33:30 +0200 (CEST) Date: Wed, 20 May 2020 16:33:30 +0200 X-SMTPAUTHUS: auth mail.us.es From: Pablo Neira Ayuso To: Edward Cree Cc: davem@davemloft.net, netdev@vger.kernel.org, netfilter-devel@vger.kernel.org, jiri@resnulli.us, kuba@kernel.org Subject: Re: [PATCH net-next v2] net: flow_offload: simplify hw stats check handling Message-ID: <20200520143330.GA23050@salvia> References: <20200519171923.GA16785@salvia> <6013b7ce-48c9-7169-c945-01b2226638e4@solarflare.com> <20200519173508.GA17141@salvia> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: 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 Tue, May 19, 2020 at 07:26:42PM +0100, Edward Cree wrote: > On 19/05/2020 18:35, Pablo Neira Ayuso wrote: [...] > > Netfilter is a client of this flow offload API, you have to test that > > your core updates do not break any of existing clients. > > Okay, but can we distinguish between "this needs to be tested with >  netfilter before it can be merged" and "this is breaking netfilter"? > Or do you have a specific reason why you think this is broken, beyond >  merely 'it isn't tested'? This breaks netfilter in two ways ! #1 Drivers calling flow_action_hw_stats_check() fall within the second branch (check_allow_bit is set on). } else if (check_allow_bit && @@ -340,11 +342,9 @@ __flow_action_hw_stats_check(const struct flow_action *action, return false; action_entry = flow_action_first_entry_get(action); - if (action_entry->hw_stats == FLOW_ACTION_HW_STATS_DONT_CARE) - return true; if (!check_allow_bit && - action_entry->hw_stats != FLOW_ACTION_HW_STATS_ANY) { + ~action_entry->hw_stats & FLOW_ACTION_HW_STATS_ANY) { NL_SET_ERR_MSG_MOD(extack, "Driver supports only default HW stats type \"any\""); return false; } else if (check_allow_bit && <------ HERE These drivers are not honoring the _DONT_CARE bit, __flow_action_hw_stats_check() with check_allow_bit set on does not honor the _DONT_CARE bit. #2 Your patch needs to update Netfilter to set hw_stats to FLOW_ACTION_HW_STATS_DONT_CARE explicitly.