From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751854AbaBLINv (ORCPT ); Wed, 12 Feb 2014 03:13:51 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:50044 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751676AbaBLINq (ORCPT ); Wed, 12 Feb 2014 03:13:46 -0500 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "David S. Miller" Date: Wed, 12 Feb 2014 08:10:12 +0000 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.2 12/79] vlan: Fix header ops passthru when doing TX VLAN offload. In-Reply-To: X-SA-Exim-Connect-IP: 91.84.160.45 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.2.55-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: "David S. Miller" [ Upstream commit 2205369a314e12fcec4781cc73ac9c08fc2b47de ] When the vlan code detects that the real device can do TX VLAN offloads in hardware, it tries to arrange for the real device's header_ops to be invoked directly. But it does so illegally, by simply hooking the real device's header_ops up to the VLAN device. This doesn't work because we will end up invoking a set of header_ops routines which expect a device type which matches the real device, but will see a VLAN device instead. Fix this by providing a pass-thru set of header_ops which will arrange to pass the proper real device instead. To facilitate this add a dev_rebuild_header(). There are implementations which provide a ->cache and ->create but not a ->rebuild (f.e. PLIP). So we need a helper function just like dev_hard_header() to avoid crashes. Use this helper in the one existing place where the header_ops->rebuild was being invoked, the neighbour code. With lots of help from Florian Westphal. Signed-off-by: David S. Miller Signed-off-by: Ben Hutchings --- include/linux/netdevice.h | 9 +++++++++ net/8021q/vlan_dev.c | 18 +++++++++++++++++- 2 files changed, 26 insertions(+), 1 deletion(-) diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index 8c43fd1..4b04097 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -1719,6 +1719,15 @@ static inline int dev_parse_header(const struct sk_buff *skb, return dev->header_ops->parse(skb, haddr); } +static inline int dev_rebuild_header(struct sk_buff *skb) +{ + const struct net_device *dev = skb->dev; + + if (!dev->header_ops || !dev->header_ops->rebuild) + return 0; + return dev->header_ops->rebuild(skb); +} + typedef int gifconf_func_t(struct net_device * dev, char __user * bufptr, int len); extern int register_gifconf(unsigned int family, gifconf_func_t * gifconf); static inline int unregister_gifconf(unsigned int family) diff --git a/net/8021q/vlan_dev.c b/net/8021q/vlan_dev.c index b40d3da..48a62d8 100644 --- a/net/8021q/vlan_dev.c +++ b/net/8021q/vlan_dev.c @@ -522,6 +522,22 @@ static const struct header_ops vlan_header_ops = { .parse = eth_header_parse, }; +static int vlan_passthru_hard_header(struct sk_buff *skb, struct net_device *dev, + unsigned short type, + const void *daddr, const void *saddr, + unsigned int len) +{ + struct net_device *real_dev = vlan_dev_info(dev)->real_dev; + + return dev_hard_header(skb, real_dev, type, daddr, saddr, len); +} + +static const struct header_ops vlan_passthru_header_ops = { + .create = vlan_passthru_hard_header, + .rebuild = dev_rebuild_header, + .parse = eth_header_parse, +}; + static const struct net_device_ops vlan_netdev_ops; static int vlan_dev_init(struct net_device *dev) @@ -561,7 +577,7 @@ static int vlan_dev_init(struct net_device *dev) dev->needed_headroom = real_dev->needed_headroom; if (real_dev->features & NETIF_F_HW_VLAN_TX) { - dev->header_ops = real_dev->header_ops; + dev->header_ops = &vlan_passthru_header_ops; dev->hard_header_len = real_dev->hard_header_len; } else { dev->header_ops = &vlan_header_ops;