From patchwork Fri Jul 9 03:45:02 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hangbin Liu X-Patchwork-Id: 472233 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=-16.0 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, USER_AGENT_GIT autolearn=ham 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 2C02BC07E99 for ; Fri, 9 Jul 2021 03:45:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0F75561447 for ; Fri, 9 Jul 2021 03:45:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231162AbhGIDsB (ORCPT ); Thu, 8 Jul 2021 23:48:01 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56294 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230462AbhGIDsA (ORCPT ); Thu, 8 Jul 2021 23:48:00 -0400 Received: from mail-pl1-x631.google.com (mail-pl1-x631.google.com [IPv6:2607:f8b0:4864:20::631]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D489EC061574 for ; Thu, 8 Jul 2021 20:45:17 -0700 (PDT) Received: by mail-pl1-x631.google.com with SMTP id a14so4315322pls.4 for ; Thu, 08 Jul 2021 20:45:17 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=fbmnfWR0VTKmQQpdEmQlhSbIvju7GrnnFUQ9ku9gI2o=; b=VwFA4U3ilJVsy0iwd0+dncS7Hxp4ov8nHDX/Bjj1LzGKdoUyq9DLifdfXiPsJXclST ntAeB15MQF9KLkaBcUH4yBK7Qh/UKzb1mVynbyzCYWfS0ug0MUGO0dLVVpx/4zft/LBX podfAS2u7/y6TddQTEkz1irXhc/ToLCM87K1KQUE8o2psbIghkw8aBp1NF1GAaCm1O37 kAn55mau4iKwQA3+9ATEugVM5LlhSglE8Uvv9jtNQQMwH5oxTFuaDHra60MjSrrT+BwF HojqYSKnpMDfC8I8c3kJ4CO79/IaY58hhHG6Q0vsWvEsIbHmnTMKs6Tjs3G4Aagp/pH3 +75w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=fbmnfWR0VTKmQQpdEmQlhSbIvju7GrnnFUQ9ku9gI2o=; b=i4CKYTBpM1H9M7Mut/E1E0yQ2ytnlYn1skzSP2G78qZ4/ivbt3SXSIMcsTDi1mmMRG Qbpi/g4I12Y7pCni6rJvi1Hoppu2c6BX5h63Rd5SWMOLaJQ+HHEU0q3PPh5h/lGtV+// DZg25lXcLnO0j6lcodrX/uGXn22KukYhjI2lUjrHSxTcG4xs2eBsd3TtfDZWhl24lZnF NA9TOypNzaQEKwUO3SdP5e0mmPnzPrCWXBLSK4TCKMIqZLdj50G78N6rYd4ZPGuEAXOk HDaOyBFjvdfhpwLIvLugJp+bZsefJ/Imlo2xq+gT3kSsVK6yEuSYMm+DeD7tZpNiNTZK 2odQ== X-Gm-Message-State: AOAM531Qvwy1XcsmFzHLop6+w31ytiiQ1xgt4wqaSEc5Cdk9UHYEzk6i 9hgJsg/I+Fo/wGzELJZerB3YPmKLzZ81DN/H X-Google-Smtp-Source: ABdhPJzfPFqlP+jx5LjqMduq3q3zArMAI+FYyUc9Xhc3psNKGMbl1B043Qc3YIP0/s+ImZLWKuVpZg== X-Received: by 2002:a17:90a:4091:: with SMTP id l17mr35031320pjg.12.1625802317121; Thu, 08 Jul 2021 20:45:17 -0700 (PDT) Received: from Laptop-X1.redhat.com ([209.132.188.80]) by smtp.gmail.com with ESMTPSA id i27sm4940289pgl.78.2021.07.08.20.45.14 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 08 Jul 2021 20:45:16 -0700 (PDT) From: Hangbin Liu To: netdev@vger.kernel.org Cc: Vadim Fedorenko , Cong Wang , Jakub Kicinski , Greg KH , Hangbin Liu , Jianlin Shi Subject: [PATCH net] net: ip_tunnel: fix mtu calculation for ETHER tunnel devices Date: Fri, 9 Jul 2021 11:45:02 +0800 Message-Id: <20210709034502.1227174-1-liuhangbin@gmail.com> X-Mailer: git-send-email 2.31.1 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Commit 28e104d00281 ("net: ip_tunnel: fix mtu calculation") removed dev->hard_header_len subtraction when calculate MTU for tunnel devices as there is an overhead for device that has header_ops. But there are ETHER tunnel devices, like gre_tap or erspan, which don't have header_ops but set dev->hard_header_len during setup. This makes pkts greater than (MTU - ETH_HLEN) could not be xmited. Fix it by subtracting the ETHER tunnel devices' dev->hard_header_len for MTU calculation. Fixes: 28e104d00281 ("net: ip_tunnel: fix mtu calculation") Reported-by: Jianlin Shi Signed-off-by: Hangbin Liu --- net/ipv4/ip_tunnel.c | 18 +++++++++++++++--- 1 file changed, 15 insertions(+), 3 deletions(-) diff --git a/net/ipv4/ip_tunnel.c b/net/ipv4/ip_tunnel.c index f6cc26de5ed3..0dca00745ac3 100644 --- a/net/ipv4/ip_tunnel.c +++ b/net/ipv4/ip_tunnel.c @@ -317,7 +317,7 @@ static int ip_tunnel_bind_dev(struct net_device *dev) } dev->needed_headroom = t_hlen + hlen; - mtu -= t_hlen; + mtu -= t_hlen + (dev->type == ARPHRD_ETHER ? dev->hard_header_len : 0); if (mtu < IPV4_MIN_MTU) mtu = IPV4_MIN_MTU; @@ -348,6 +348,9 @@ static struct ip_tunnel *ip_tunnel_create(struct net *net, t_hlen = nt->hlen + sizeof(struct iphdr); dev->min_mtu = ETH_MIN_MTU; dev->max_mtu = IP_MAX_MTU - t_hlen; + if (dev->type == ARPHRD_ETHER) + dev->max_mtu -= dev->hard_header_len; + ip_tunnel_add(itn, nt); return nt; @@ -489,11 +492,14 @@ static int tnl_update_pmtu(struct net_device *dev, struct sk_buff *skb, tunnel_hlen = md ? tunnel_hlen : tunnel->hlen; pkt_size = skb->len - tunnel_hlen; + pkt_size -= dev->type == ARPHRD_ETHER ? dev->hard_header_len : 0; - if (df) + if (df) { mtu = dst_mtu(&rt->dst) - (sizeof(struct iphdr) + tunnel_hlen); - else + mtu -= dev->type == ARPHRD_ETHER ? dev->hard_header_len : 0; + } else { mtu = skb_valid_dst(skb) ? dst_mtu(skb_dst(skb)) : dev->mtu; + } if (skb_valid_dst(skb)) skb_dst_update_pmtu_no_confirm(skb, mtu); @@ -972,6 +978,9 @@ int __ip_tunnel_change_mtu(struct net_device *dev, int new_mtu, bool strict) int t_hlen = tunnel->hlen + sizeof(struct iphdr); int max_mtu = IP_MAX_MTU - t_hlen; + if (dev->type == ARPHRD_ETHER) + max_mtu -= dev->hard_header_len; + if (new_mtu < ETH_MIN_MTU) return -EINVAL; @@ -1149,6 +1158,9 @@ int ip_tunnel_newlink(struct net_device *dev, struct nlattr *tb[], if (tb[IFLA_MTU]) { unsigned int max = IP_MAX_MTU - (nt->hlen + sizeof(struct iphdr)); + if (dev->type == ARPHRD_ETHER) + max -= dev->hard_header_len; + mtu = clamp(dev->mtu, (unsigned int)ETH_MIN_MTU, max); }