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=-5.3 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A, 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 13749C433DB for ; Mon, 29 Mar 2021 12:43:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D7CE361934 for ; Mon, 29 Mar 2021 12:43:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231384AbhC2MnC (ORCPT ); Mon, 29 Mar 2021 08:43:02 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:21290 "EHLO mx0b-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231400AbhC2Mmc (ORCPT ); Mon, 29 Mar 2021 08:42:32 -0400 Received: from pps.filterd (m0098421.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.43/8.16.0.43) with SMTP id 12TCXX4i184245; Mon, 29 Mar 2021 08:42:06 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ibm.com; h=subject : to : cc : references : from : message-id : date : mime-version : in-reply-to : content-type : content-transfer-encoding; s=pp1; bh=h1zE9n5c0hlt1PROjfx0pTaVLD/oTEhrqI+hnRec3y0=; b=V/T0NNOUMIPft/bmPZBq+/Kt53pNUMREcobwRGkOxQwHJWswm1FyeTO91JCF6fzqe+09 d0Sl53hBlTMN6qGfXR7J1z4GrDI+m5WHOoakjUBbOIlBXC3zRgwyw6HB+M8VmcLN65Tm 1Vhtw4WRU6wRU9zJCIrNa6oGsgt8rl1zCbBIHD+VF6+qgajVAoFJJ4TOterjdEYNdB/Y SRP+HomKXKv7mLTczRbZlOuMCoSI3YT9zng6wPM08BaNawIjSbzljdj1NkjjE9FluxBJ x6WK8EqLH7hAAVKd6ZdMVRF7E8FuM7l6hxf6M9FxAECyvsoee56vcGb4R7qoM3yJ7D5X Mg== Received: from pps.reinject (localhost [127.0.0.1]) by mx0a-001b2d01.pphosted.com with ESMTP id 37jpbvaand-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Mon, 29 Mar 2021 08:42:06 -0400 Received: from m0098421.ppops.net (m0098421.ppops.net [127.0.0.1]) by pps.reinject (8.16.0.43/8.16.0.43) with SMTP id 12TCXbir184598; Mon, 29 Mar 2021 08:42:06 -0400 Received: from ppma03ams.nl.ibm.com (62.31.33a9.ip4.static.sl-reverse.com [169.51.49.98]) by mx0a-001b2d01.pphosted.com with ESMTP id 37jpbvaamf-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Mon, 29 Mar 2021 08:42:05 -0400 Received: from pps.filterd (ppma03ams.nl.ibm.com [127.0.0.1]) by ppma03ams.nl.ibm.com (8.16.0.43/8.16.0.43) with SMTP id 12TCMi8v012170; Mon, 29 Mar 2021 12:42:04 GMT Received: from b06cxnps3075.portsmouth.uk.ibm.com (d06relay10.portsmouth.uk.ibm.com [9.149.109.195]) by ppma03ams.nl.ibm.com with ESMTP id 37hvb89t2a-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Mon, 29 Mar 2021 12:42:04 +0000 Received: from b06wcsmtp001.portsmouth.uk.ibm.com (b06wcsmtp001.portsmouth.uk.ibm.com [9.149.105.160]) by b06cxnps3075.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 12TCg1Cs28180932 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Mon, 29 Mar 2021 12:42:01 GMT Received: from b06wcsmtp001.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 468E2A4065; Mon, 29 Mar 2021 12:42:01 +0000 (GMT) Received: from b06wcsmtp001.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id B5EA0A405F; Mon, 29 Mar 2021 12:41:59 +0000 (GMT) Received: from [9.145.24.127] (unknown [9.145.24.127]) by b06wcsmtp001.portsmouth.uk.ibm.com (Postfix) with ESMTP; Mon, 29 Mar 2021 12:41:59 +0000 (GMT) Subject: Re: [PATCH net v2] net: Reset MAC header for direct packet transmission To: Eric Dumazet , Kurt Kanzenbach Cc: "David S. Miller" , Jakub Kicinski , Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Antoine Tenart , Wei Wang , Cong Wang , Taehee Yoo , Jesper Dangaard Brouer , Sebastian Andrzej Siewior , Willem de Bruijn , netdev References: <20210329071716.12235-1-kurt@linutronix.de> <878s661cc2.fsf@kurt> From: Julian Wiedmann Message-ID: Date: Mon, 29 Mar 2021 14:41:59 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.8.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-TM-AS-GCONF: 00 X-Proofpoint-GUID: 6_aepRK3ZuMlbSUF2Fw5k4iNirvcjpKj X-Proofpoint-ORIG-GUID: JMlNIpVc6D4lj3hdsWQiIITskVe7zf34 X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.369,18.0.761 definitions=2021-03-29_08:2021-03-26,2021-03-29 signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 phishscore=0 mlxscore=0 suspectscore=0 priorityscore=1501 malwarescore=0 clxscore=1011 spamscore=0 lowpriorityscore=0 bulkscore=0 impostorscore=0 adultscore=0 mlxlogscore=999 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2103250000 definitions=main-2103290097 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On 29.03.21 14:13, Eric Dumazet wrote: > On Mon, Mar 29, 2021 at 12:30 PM Kurt Kanzenbach wrote: >> >> On Mon Mar 29 2021, Eric Dumazet wrote: >>> Note that last year, I addressed the issue differently in commit >>> 96cc4b69581db68efc9749ef32e9cf8e0160c509 >>> ("macvlan: do not assume mac_header is set in macvlan_broadcast()") >>> (amended with commit 1712b2fff8c682d145c7889d2290696647d82dab >>> "macvlan: use skb_reset_mac_header() in macvlan_queue_xmit()") >>> >>> My reasoning was that in TX path, when ndo_start_xmit() is called, MAC >>> header is essentially skb->data, >>> so I was hoping to _remove_ skb_reset_mac_header(skb) eventually from >>> the fast path (aka __dev_queue_xmit), >>> because most drivers do not care about MAC header, they just use skb->data. >>> >>> I understand it is more difficult to review drivers instead of just >>> adding more code in __dev_direct_xmit() >>> >>> In hsr case, I do not really see why the existing check can not be >>> simply reworked ? >> >> It can be reworked, no problem. I just thought it might be better to add >> it to the generic code just in case there are more drivers suffering >> from the issue. > > Note that I have a similar issue pending in ipvlan. > > Still, I think I prefer the non easy way to not add more stuff in fast path. > Can we apply this fix (and propagate it to stable), and then remove the skb_reset_mac_header() from _both_ xmit paths through net-next?