From patchwork Mon Sep 28 12:56:43 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Xie He X-Patchwork-Id: 289485 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=-12.6 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_GIT autolearn=unavailable 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 6CE6CC2D0A8 for ; Mon, 28 Sep 2020 12:57:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2C6A8206D9 for ; Mon, 28 Sep 2020 12:57:03 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="K2BpzpUG" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726727AbgI1M5B (ORCPT ); Mon, 28 Sep 2020 08:57:01 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54030 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726656AbgI1M47 (ORCPT ); Mon, 28 Sep 2020 08:56:59 -0400 Received: from mail-pg1-x542.google.com (mail-pg1-x542.google.com [IPv6:2607:f8b0:4864:20::542]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5EE21C061755; Mon, 28 Sep 2020 05:56:59 -0700 (PDT) Received: by mail-pg1-x542.google.com with SMTP id 197so805215pge.8; Mon, 28 Sep 2020 05:56:59 -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=mRYM/ijXhKyqcG0hlYbKfkBIgPJZyqY3iZRUkY2MEAM=; b=K2BpzpUGM5K+keY0Wj/FUqJFwjDK4osnAOoEiEuSAPpmlaLnAbYQXKAPpBKZNmme8g +NlzUyroaDHcu7YqhUBU98qKgvzFk0YFmyvZe2n3+teCxbuLgA1yafjqlG0/FwM7g2h+ iNcsaNiFdiwz/Al92fAhMcyFwBvREAJizcJvg8tRYYqG++NAMdxWh4nMdf4pUGr/ieIW 4p5euwrO5Aqdz/OB/hQc36kmoQOKYV17caUlmaIZ24ucWie72p0/nvLmdYHEK77cMwbi poMiwhK2/mT7L6isHqNUbHFTrUksqZxV+V49W7rwV3qfgf2Kg9vKlpduqPIyNErsyqA5 mJ/Q== 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=mRYM/ijXhKyqcG0hlYbKfkBIgPJZyqY3iZRUkY2MEAM=; b=AaCXnG+q9MQqVm4iocn0nDud7YZ3CWcpItDp29hGifNovKp8+X5a2c80vnlG+7oxQA tGdxTO5AXYvhbWNf4cWCq+WGqCTjNQ8uQR4I4/IkyxfxtYJnpJiEc+YticFpbZ1y7I7b Mnb6zTLtlBbHRMIrHH+LmyzlI94JAZIka3eFejC1IzsYEOWcP5pQTQ0unRTliYNdtXd9 rN15OvnOllY9uE0M4uIBpFVwDjhKy85RX6ezqV4+G7CvM7UoABPzTtd2BL3CWwU0G58p P6PKSg2O/y7xBuAIgG42HKuGonXdIXsaNHQ2mA1muNX+8fjbONVkriFSk3c4ZSBlTp6t +uRg== X-Gm-Message-State: AOAM533RbQUAXm9LvZ2q6Tarw7tIaX30teqmI6DbD851tIve7fW2s4Ml 0n9GFZVRf9lmrgCvgZYV2QE= X-Google-Smtp-Source: ABdhPJwx5YX5q+hrrI/wiwlHvD8cQ+jpbLwTzMvdZp15W0n7M8nFP3RT+BaViMrLdTfrhwji76axGg== X-Received: by 2002:aa7:941a:0:b029:142:2501:35d1 with SMTP id x26-20020aa7941a0000b0290142250135d1mr1279322pfo.49.1601297818865; Mon, 28 Sep 2020 05:56:58 -0700 (PDT) Received: from shane-XPS-13-9380.hsd1.ca.comcast.net ([2601:646:8800:1c00:1405:efe3:1493:1a47]) by smtp.gmail.com with ESMTPSA id b2sm1686819pfp.3.2020.09.28.05.56.56 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 28 Sep 2020 05:56:58 -0700 (PDT) From: Xie He To: "David S. Miller" , Jakub Kicinski , netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Krzysztof Halasa Cc: Xie He Subject: [PATCH net-next] drivers/net/wan/hdlc_fr: Correctly handle special skb->protocol values Date: Mon, 28 Sep 2020 05:56:43 -0700 Message-Id: <20200928125643.396575-1-xie.he.0141@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 The fr_hard_header function is used to prepend the header to skbs before transmission. It is used in 3 situations: 1) When a control packet is generated internally in this driver; 2) When a user sends an skb on an Ethernet-emulating PVC device; 3) When a user sends an skb on a normal PVC device. These 3 situations need to be handled differently by fr_hard_header. Different headers should be prepended to the skb in different situations. Currently fr_hard_header distinguishes these 3 situations using skb->protocol. For situation 1 and 2, a special skb->protocol value will be assigned before calling fr_hard_header, so that it can recognize these 2 situations. All skb->protocol values other than these special ones are treated by fr_hard_header as situation 3. However, it is possible that in situation 3, the user sends an skb with one of the special skb->protocol values. In this case, fr_hard_header would incorrectly treat it as situation 1 or 2. This patch tries to solve this issue by using skb->dev instead of skb->protocol to distinguish between these 3 situations. For situation 1, skb->dev would be NULL; for situation 2, skb->dev->type would be ARPHRD_ETHER; and for situation 3, skb->dev->type would be ARPHRD_DLCI. This way fr_hard_header would be able to distinguish these 3 situations correctly regardless what skb->protocol value the user tries to use in situation 3. Cc: Krzysztof Halasa Signed-off-by: Xie He --- drivers/net/wan/hdlc_fr.c | 98 ++++++++++++++++++++------------------- 1 file changed, 51 insertions(+), 47 deletions(-) diff --git a/drivers/net/wan/hdlc_fr.c b/drivers/net/wan/hdlc_fr.c index d6cfd51613ed..3a44dad87602 100644 --- a/drivers/net/wan/hdlc_fr.c +++ b/drivers/net/wan/hdlc_fr.c @@ -273,63 +273,69 @@ static inline struct net_device **get_dev_p(struct pvc_device *pvc, static int fr_hard_header(struct sk_buff **skb_p, u16 dlci) { - u16 head_len; struct sk_buff *skb = *skb_p; - switch (skb->protocol) { - case cpu_to_be16(NLPID_CCITT_ANSI_LMI): - head_len = 4; - skb_push(skb, head_len); - skb->data[3] = NLPID_CCITT_ANSI_LMI; - break; - - case cpu_to_be16(NLPID_CISCO_LMI): - head_len = 4; - skb_push(skb, head_len); - skb->data[3] = NLPID_CISCO_LMI; - break; - - case cpu_to_be16(ETH_P_IP): - head_len = 4; - skb_push(skb, head_len); - skb->data[3] = NLPID_IP; - break; - - case cpu_to_be16(ETH_P_IPV6): - head_len = 4; - skb_push(skb, head_len); - skb->data[3] = NLPID_IPV6; - break; - - case cpu_to_be16(ETH_P_802_3): - head_len = 10; - if (skb_headroom(skb) < head_len) { - struct sk_buff *skb2 = skb_realloc_headroom(skb, - head_len); + if (!skb->dev) { /* Control packets */ + switch (dlci) { + case LMI_CCITT_ANSI_DLCI: + skb_push(skb, 4); + skb->data[3] = NLPID_CCITT_ANSI_LMI; + break; + + case LMI_CISCO_DLCI: + skb_push(skb, 4); + skb->data[3] = NLPID_CISCO_LMI; + break; + + default: + return -EINVAL; + } + + } else if (skb->dev->type == ARPHRD_DLCI) { + switch (skb->protocol) { + case htons(ETH_P_IP): + skb_push(skb, 4); + skb->data[3] = NLPID_IP; + break; + + case htons(ETH_P_IPV6): + skb_push(skb, 4); + skb->data[3] = NLPID_IPV6; + break; + + default: + skb_push(skb, 10); + skb->data[3] = FR_PAD; + skb->data[4] = NLPID_SNAP; + /* OUI 00-00-00 indicates an Ethertype follows */ + skb->data[5] = 0x00; + skb->data[6] = 0x00; + skb->data[7] = 0x00; + /* This should be an Ethertype: */ + *(__be16 *)(skb->data + 8) = skb->protocol; + } + + } else if (skb->dev->type == ARPHRD_ETHER) { + if (skb_headroom(skb) < 10) { + struct sk_buff *skb2 = skb_realloc_headroom(skb, 10); if (!skb2) return -ENOBUFS; dev_kfree_skb(skb); skb = *skb_p = skb2; } - skb_push(skb, head_len); + skb_push(skb, 10); skb->data[3] = FR_PAD; skb->data[4] = NLPID_SNAP; - skb->data[5] = FR_PAD; + /* OUI 00-80-C2 stands for the 802.1 organization */ + skb->data[5] = 0x00; skb->data[6] = 0x80; skb->data[7] = 0xC2; + /* PID 00-07 stands for Ethernet frames without FCS */ skb->data[8] = 0x00; - skb->data[9] = 0x07; /* bridged Ethernet frame w/out FCS */ - break; + skb->data[9] = 0x07; - default: - head_len = 10; - skb_push(skb, head_len); - skb->data[3] = FR_PAD; - skb->data[4] = NLPID_SNAP; - skb->data[5] = FR_PAD; - skb->data[6] = FR_PAD; - skb->data[7] = FR_PAD; - *(__be16*)(skb->data + 8) = skb->protocol; + } else { + return -EINVAL; } dlci_to_q922(skb->data, dlci); @@ -425,8 +431,8 @@ static netdev_tx_t pvc_xmit(struct sk_buff *skb, struct net_device *dev) skb_put(skb, pad); memset(skb->data + len, 0, pad); } - skb->protocol = cpu_to_be16(ETH_P_802_3); } + skb->dev = dev; if (!fr_hard_header(&skb, pvc->dlci)) { dev->stats.tx_bytes += skb->len; dev->stats.tx_packets++; @@ -494,10 +500,8 @@ static void fr_lmi_send(struct net_device *dev, int fullrep) memset(skb->data, 0, len); skb_reserve(skb, 4); if (lmi == LMI_CISCO) { - skb->protocol = cpu_to_be16(NLPID_CISCO_LMI); fr_hard_header(&skb, LMI_CISCO_DLCI); } else { - skb->protocol = cpu_to_be16(NLPID_CCITT_ANSI_LMI); fr_hard_header(&skb, LMI_CCITT_ANSI_DLCI); } data = skb_tail_pointer(skb);