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=-13.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 C1B58C56201 for ; Tue, 27 Oct 2020 00:02:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 77CD020773 for ; Tue, 27 Oct 2020 00:02:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1603756929; bh=4Z1v4TALYvmiM+Jr6MSJrRkQL695zKhyYfCzHBl4R6U=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=AaqyVdIqiWeOK/N4BkEaWcHxTNKmq+JmXOWVyVwm1x36lUZR6pqFl+AJGT2zZHrUc tjcinMpGbYqVSLxschmx3eB719z0CTjopCCV6xaG3qUaADz+bmq41GQfqlHYTE2TOg NzBwlzaQnbPFwMUuZfGvCvTDGt6eagAxDcP3rW8k= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2437420AbgJ0ACI (ORCPT ); Mon, 26 Oct 2020 20:02:08 -0400 Received: from mail.kernel.org ([198.145.29.99]:35780 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2411093AbgJZX4R (ORCPT ); Mon, 26 Oct 2020 19:56:17 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 585BC22284; Mon, 26 Oct 2020 23:56:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1603756577; bh=4Z1v4TALYvmiM+Jr6MSJrRkQL695zKhyYfCzHBl4R6U=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=o/2EdJr+eW4fh5YBRcQ8fVN9m20k3Fe6QMiREEMvTw4JUQSzGOJ+nY6VLo9uPc04C pbZQ7SwXPwrY3BsX6l9CosP1SjfSKerfVRVOaahTERK0QdpNRq2Gi+OhB51sh5zm8p xic/s/8DTZlz3/T5/qex7OkiYVHW3Cz7FB8vb4QA= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Xie He , Krzysztof Halasa , "David S . Miller" , Sasha Levin , netdev@vger.kernel.org Subject: [PATCH AUTOSEL 5.4 50/80] drivers/net/wan/hdlc_fr: Correctly handle special skb->protocol values Date: Mon, 26 Oct 2020 19:54:46 -0400 Message-Id: <20201026235516.1025100-50-sashal@kernel.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20201026235516.1025100-1-sashal@kernel.org> References: <20201026235516.1025100-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Xie He [ Upstream commit 8306266c1d51aac9aa7aa907fe99032a58c6382c ] 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 Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- 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 d6cfd51613ed8..3a44dad87602d 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); -- 2.25.1