From patchwork Wed Nov 11 20:44:08 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexander Lobakin X-Patchwork-Id: 11898521 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=-3.9 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,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 30536C5517A for ; Wed, 11 Nov 2020 20:44:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C193D20797 for ; Wed, 11 Nov 2020 20:44:20 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=pm.me header.i=@pm.me header.b="bV+XkA5q" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726752AbgKKUoS (ORCPT ); Wed, 11 Nov 2020 15:44:18 -0500 Received: from mail2.protonmail.ch ([185.70.40.22]:36967 "EHLO mail2.protonmail.ch" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725900AbgKKUoR (ORCPT ); Wed, 11 Nov 2020 15:44:17 -0500 Date: Wed, 11 Nov 2020 20:44:08 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=pm.me; s=protonmail; t=1605127454; bh=cjnSs7ggKuxNW/h5Wnq+CXkLVSWDuqP6wXc3zMUiSOA=; h=Date:To:From:Cc:Reply-To:Subject:From; b=bV+XkA5q3D9jxeC3YIesV5yGTAjx3vv/JBTesm6v1zru4MyGkKBFRMZwfoyR3Hsz0 bZPrBmw5+eop5UT8vCChwTW/ieUzI6bcuLYm9JmVsw+DKmEhhHTnZvKjK9fxEzLC0g oUUQGUV6UwDiuEu8btxMUpK9AFoq/Lh704g7kql24ESVYGgYo6W0A5HaeeA7Kw0WD+ Tvv3Cxltp08zYm8QCum3dtkxvp/iILQSIURXfXiK4GEDbcbk0E8ox/D7C0qi9TUCF7 uj79/YbkeePMozxqVqHWaTP8ZyY5hwYja8m1QdGsEll/hi0XX/H/sC+Q4PBLe2hNCJ L2yYTnBXmQ4+A== To: "David S. Miller" , Jakub Kicinski From: Alexander Lobakin Cc: Alexey Kuznetsov , Hideaki YOSHIFUJI , Paolo Abeni , Willem de Bruijn , Steffen Klassert , Alexander Lobakin , Eric Dumazet , netdev@vger.kernel.org, linux-kernel@vger.kernel.org Reply-To: Alexander Lobakin Subject: [PATCH v5 net 0/2] net: udp: fix Fast/frag0 UDP GRO Message-ID: MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org While testing UDP GSO fraglists forwarding through driver that uses Fast GRO (via napi_gro_frags()), I was observing lots of out-of-order iperf packets: [ ID] Interval Transfer Bitrate Jitter [SUM] 0.0-40.0 sec 12106 datagrams received out-of-order Simple switch to napi_gro_receive() or any other method without frag0 shortcut completely resolved them. I've found two incorrect header accesses in GRO receive callback(s): - udp_hdr() (instead of udp_gro_udphdr()) that always points to junk in "fast" mode and could probably do this in "regular". This was the actual bug that caused all out-of-order delivers; - udp{4,6}_lib_lookup_skb() -> ip{,v6}_hdr() (instead of skb_gro_network_header()) that potentionally might return odd pointers in both modes. Each patch addresses one of these two issues. This doesn't cover a support for nested tunnels as it's out of the subject and requires more invasive changes. It will be handled separately in net-next series. Credits: Cc: Eric Dumazet Cc: Jakub Kicinski Cc: Willem de Bruijn Since v4 [0]: - split the fix into two logical ones (Willem); - replace ternaries with plain ifs to beautify the code (Jakub); - drop p->data part to reintroduce it later in abovementioned set. Since v3 [1]: - restore the original {,__}udp{4,6}_lib_lookup_skb() and use private versions of them inside GRO code (Willem). Since v2 [2]: - dropped redundant check introduced in v2 as it's performed right before (thanks to Eric); - udp_hdr() switched to data + off for skbs from list (also Eric); - fixed possible malfunction of {,__}udp{4,6}_lib_lookup_skb() with Fast/frag0 due to ip{,v6}_hdr() usage (Willem). Since v1 [3]: - added a NULL pointer check for "uh" as suggested by Willem. [0] https://lore.kernel.org/netdev/Ha2hou5eJPcblo4abjAqxZRzIl1RaLs2Hy0oOAgFs@cp4-web-036.plabs.ch [1] https://lore.kernel.org/netdev/MgZce9htmEtCtHg7pmWxXXfdhmQ6AHrnltXC41zOoo@cp7-web-042.plabs.ch [2] https://lore.kernel.org/netdev/0eaG8xtbtKY1dEKCTKUBubGiC9QawGgB3tVZtNqVdY@cp4-web-030.plabs.ch [3] https://lore.kernel.org/netdev/YazU6GEzBdpyZMDMwJirxDX7B4sualpDG68ADZYvJI@cp4-web-034.plabs.ch Alexander Lobakin (2): net: udp: fix UDP header access on Fast/frag0 UDP GRO net: udp: fix IP header access and skb lookup on Fast/frag0 UDP GRO net/ipv4/udp_offload.c | 19 ++++++++++++++++--- net/ipv6/udp_offload.c | 17 +++++++++++++++-- 2 files changed, 31 insertions(+), 5 deletions(-)