From patchwork Wed Apr 3 05:01:16 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Martin Schiller X-Patchwork-Id: 1075422 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming-netdev@ozlabs.org Delivered-To: patchwork-incoming-netdev@ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=netdev-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=dev.tdt.de Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 44YvGd66Krz9sP6 for ; Wed, 3 Apr 2019 16:07:53 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728748AbfDCFHt (ORCPT ); Wed, 3 Apr 2019 01:07:49 -0400 Received: from host-88-217-225-28.customer.m-online.net ([88.217.225.28]:40986 "EHLO mail.dev.tdt.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1728548AbfDCFHs (ORCPT ); Wed, 3 Apr 2019 01:07:48 -0400 Received: from localhost.localdomain (unknown [10.2.3.20]) by mail.dev.tdt.de (Postfix) with ESMTPSA id 56E0620B0D; Wed, 3 Apr 2019 05:01:28 +0000 (UTC) From: Martin Schiller To: andrew.hendry@gmail.com, davem@davemloft.net, khc@pm.waw.pl, isdn@linux-pingi.de Cc: edumazet@google.com, linux-x25@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Martin Schiller Subject: [PATCH 2/4] wan/hdlc_x25: fix skb handling Date: Wed, 3 Apr 2019 07:01:16 +0200 Message-Id: <20190403050118.12785-2-ms@dev.tdt.de> X-Mailer: git-send-email 2.11.0 In-Reply-To: <20190403050118.12785-1-ms@dev.tdt.de> References: <20190403050118.12785-1-ms@dev.tdt.de> X-Spam-Status: No, score=-1.0 required=5.0 tests=ALL_TRUSTED autolearn=ham autolearn_force=no version=3.4.2 X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on mail.dev.tdt.de Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org o call skb_reset_network_header() before hdlc->xmit() o change skb proto to HDLC (0x0019) before hdlc->xmit() o call dev_queue_xmit_nit() before hdlc->xmit() This changes make it possible to trace (tcpdump) outgoing layer2 (ETH_P_HDLC) packets o use a copy of the skb for lapb_data_request() This fixes the problem, that tracing layer3 (ETH_P_X25) packets results in a malformed first byte of the packets. Signed-off-by: Martin Schiller --- drivers/net/wan/hdlc_x25.c | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-) diff --git a/drivers/net/wan/hdlc_x25.c b/drivers/net/wan/hdlc_x25.c index e867638067a6..fb5ed6856be5 100644 --- a/drivers/net/wan/hdlc_x25.c +++ b/drivers/net/wan/hdlc_x25.c @@ -66,6 +66,7 @@ static int x25_data_indication(struct net_device *dev, struct sk_buff *skb) unsigned char *ptr; skb_push(skb, 1); + skb_reset_network_header(skb); if (skb_cow(skb, 1)) return NET_RX_DROP; @@ -82,6 +83,9 @@ static int x25_data_indication(struct net_device *dev, struct sk_buff *skb) static void x25_data_transmit(struct net_device *dev, struct sk_buff *skb) { hdlc_device *hdlc = dev_to_hdlc(dev); + skb_reset_network_header(skb); + skb->protocol = hdlc_type_trans(skb, dev); + dev_queue_xmit_nit(skb, dev); hdlc->xmit(skb, dev); /* Ignore return value :-( */ } @@ -89,16 +93,19 @@ static void x25_data_transmit(struct net_device *dev, struct sk_buff *skb) static netdev_tx_t x25_xmit(struct sk_buff *skb, struct net_device *dev) { + struct sk_buff *skbn; int result; /* X.25 to LAPB */ switch (skb->data[0]) { case X25_IFACE_DATA: /* Data to be transmitted */ - skb_pull(skb, 1); - if ((result = lapb_data_request(dev, skb)) != LAPB_OK) - dev_kfree_skb(skb); - return NETDEV_TX_OK; + skbn = skb_copy(skb, GFP_ATOMIC); + skb_pull(skbn, 1); + skb_reset_network_header(skbn); + if ((result = lapb_data_request(dev, skbn)) != LAPB_OK) + dev_kfree_skb(skbn); + break; case X25_IFACE_CONNECT: if ((result = lapb_connect_request(dev))!= LAPB_OK) {