From patchwork Sat Nov 21 06:28:17 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eyal Birger X-Patchwork-Id: 11923225 X-Patchwork-Delegate: kuba@kernel.org 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=-15.8 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 9D622C388F9 for ; Sat, 21 Nov 2020 06:33:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 553C122226 for ; Sat, 21 Nov 2020 06:33:29 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="sLZEVhLh" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726058AbgKUG24 (ORCPT ); Sat, 21 Nov 2020 01:28:56 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39584 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725958AbgKUG24 (ORCPT ); Sat, 21 Nov 2020 01:28:56 -0500 Received: from mail-wr1-x435.google.com (mail-wr1-x435.google.com [IPv6:2a00:1450:4864:20::435]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 57464C0613CF for ; Fri, 20 Nov 2020 22:28:53 -0800 (PST) Received: by mail-wr1-x435.google.com with SMTP id s8so13037790wrw.10 for ; Fri, 20 Nov 2020 22:28:53 -0800 (PST) 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=1/xlmPnAKQeD0cO6ZV0O9++jY/BgRGkHW+yfYnnb42o=; b=sLZEVhLh13Xyma6RisAtbnnbcE93Pa/Uzus+9+W8Tm1mTxicts8CTH4Xmb55Cbi/Zu 7AvD8FanTRvO8BX9SuY6KH/nCvuu3JnpV2LE6tOVfakY8w5kKINUhUAbJmlbl2J7PV/c tKadQoXHxbYa8r21JPKFLTFuRIuK6r4kpFBEy3w6oO9OnycTt5EIcpqXHUlgSDN+fy9H YetHxT56qk/pHb1DDh6V8/7vsndFSn2MmampAoetVVsxmsK9kdiFkPVyn+giqiis4p2B ZAn/LOl/DQliryW+DYOKScJXVoE3Oj8LKznlV1Bdc6zmIr+P7hbhRvUbs8IimeRx4bVd UdCw== 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=1/xlmPnAKQeD0cO6ZV0O9++jY/BgRGkHW+yfYnnb42o=; b=jLwskkw+HO9nyDUiTjDR8biGwAZs1y6Ue/2Jo9llAAJzUbE8shQ7B/GefDEYuBcIWK v+c7JGENe7qFWF5sx/5SxFb+Nnc3Ml7nwRR6+dWMFwWnMyAECQjOdJyWycn+7xk864kc rtL8E7Q6AJgBV8c6L8TudwHsX3g0qVdcj9l/2yzi+IZWVBmOmEQzq1DlxpqtJyWeS4mA tyJDRPhYt/6OIkYkuj4QOMU2Wl0cPZNf3gQjx1Nlk+aCD9gEXxKKtMvH5Ta/D0yd5o0u pMZgnplLzO9nULPJZm845605/XVOQHEfHv+4yoJ9yhjTjka8um4tbii0NBGC9oupLqie iwDA== X-Gm-Message-State: AOAM533/hhHaZexVALSXB+gbkBPR5WDN9Dwvaarr3Yi+mbkKCICNf/lL g7F1vnUfxuvU3Gd3MeEaVu4= X-Google-Smtp-Source: ABdhPJzW2n2eggfHNxFKJy63ASVi3G5ofepsougxqsvz+bzu9mcrACfenwanSuvqgBTyzzI4k1mbBA== X-Received: by 2002:adf:8366:: with SMTP id 93mr19664327wrd.321.1605940131181; Fri, 20 Nov 2020 22:28:51 -0800 (PST) Received: from localhost.localdomain ([213.57.166.51]) by smtp.gmail.com with ESMTPSA id q66sm6852043wme.6.2020.11.20.22.28.49 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 20 Nov 2020 22:28:50 -0800 (PST) From: Eyal Birger To: willemdebruijn.kernel@gmail.com, davem@davemloft.net, kuba@kernel.org Cc: Jason@zx2c4.com, netdev@vger.kernel.org, xie.he.0141@gmail.com, Eyal Birger Subject: [net,v2] net/packet: fix packet receive on L3 devices without visible hard header Date: Sat, 21 Nov 2020 08:28:17 +0200 Message-Id: <20201121062817.3178900-1-eyal.birger@gmail.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org In the patchset merged by commit b9fcf0a0d826 ("Merge branch 'support-AF_PACKET-for-layer-3-devices'") L3 devices which did not have header_ops were given one for the purpose of protocol parsing on af_packet transmit path. That change made af_packet receive path regard these devices as having a visible L3 header and therefore aligned incoming skb->data to point to the skb's mac_header. Some devices, such as ipip, xfrmi, and others, do not reset their mac_header prior to ingress and therefore their incoming packets became malformed. Ideally these devices would reset their mac headers, or af_packet would be able to rely on dev->hard_header_len being 0 for such cases, but it seems this is not the case. Fix by changing af_packet RX ll visibility criteria to include the existence of a '.create()' header operation, which is used when creating a device hard header - via dev_hard_header() - by upper layers, and does not exist in these L3 devices. As this predicate may be useful in other situations, add it as a common dev_has_header() helper in netdevice.h. Fixes: b9fcf0a0d826 ("Merge branch 'support-AF_PACKET-for-layer-3-devices'") Signed-off-by: Eyal Birger Acked-by: Jason A. Donenfeld Acked-by: Willem de Bruijn --- v2: - add common dev_has_header() helper as suggested by Willem de Bruijn --- include/linux/netdevice.h | 5 +++++ net/packet/af_packet.c | 18 +++++++++--------- 2 files changed, 14 insertions(+), 9 deletions(-) diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index 964b494b0e8d..fa275a054f46 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -3137,6 +3137,11 @@ static inline bool dev_validate_header(const struct net_device *dev, return false; } +static inline bool dev_has_header(const struct net_device *dev) +{ + return dev->header_ops && dev->header_ops->create; +} + typedef int gifconf_func_t(struct net_device * dev, char __user * bufptr, int len, int size); int register_gifconf(unsigned int family, gifconf_func_t *gifconf); diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c index cefbd50c1090..7a18ffff8551 100644 --- a/net/packet/af_packet.c +++ b/net/packet/af_packet.c @@ -93,8 +93,8 @@ /* Assumptions: - - If the device has no dev->header_ops, there is no LL header visible - above the device. In this case, its hard_header_len should be 0. + - If the device has no dev->header_ops->create, there is no LL header + visible above the device. In this case, its hard_header_len should be 0. The device may prepend its own header internally. In this case, its needed_headroom should be set to the space needed for it to add its internal header. @@ -108,26 +108,26 @@ On receive: ----------- -Incoming, dev->header_ops != NULL +Incoming, dev_has_header(dev) == true mac_header -> ll header data -> data -Outgoing, dev->header_ops != NULL +Outgoing, dev_has_header(dev) == true mac_header -> ll header data -> ll header -Incoming, dev->header_ops == NULL +Incoming, dev_has_header(dev) == false mac_header -> data However drivers often make it point to the ll header. This is incorrect because the ll header should be invisible to us. data -> data -Outgoing, dev->header_ops == NULL +Outgoing, dev_has_header(dev) == false mac_header -> data. ll header is invisible to us. data -> data Resume - If dev->header_ops == NULL we are unable to restore the ll header, + If dev_has_header(dev) == false we are unable to restore the ll header, because it is invisible to us. @@ -2069,7 +2069,7 @@ static int packet_rcv(struct sk_buff *skb, struct net_device *dev, skb->dev = dev; - if (dev->header_ops) { + if (dev_has_header(dev)) { /* The device has an explicit notion of ll header, * exported to higher levels. * @@ -2198,7 +2198,7 @@ static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev, if (!net_eq(dev_net(dev), sock_net(sk))) goto drop; - if (dev->header_ops) { + if (dev_has_header(dev)) { if (sk->sk_type != SOCK_DGRAM) skb_push(skb, skb->data - skb_mac_header(skb)); else if (skb->pkt_type == PACKET_OUTGOING) {