path: root/net
diff options
authorDavid S. Miller <davem@davemloft.net>2013-12-31 16:23:35 -0500
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2014-01-15 15:28:49 -0800
commitc726095ec74daabd48a9a4ed48d46304601017b4 (patch)
tree5455a5a161d1230c07e8e1c26b643a0497ab55a8 /net
parent05df3bfbc832046a774fce22654cc55260cd1583 (diff)
vlan: Fix header ops passthru when doing TX VLAN offload.
[ 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 <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'net')
2 files changed, 19 insertions, 2 deletions
diff --git a/net/8021q/vlan_dev.c b/net/8021q/vlan_dev.c
index 1cd3d2a406f..4af64afc702 100644
--- a/net/8021q/vlan_dev.c
+++ b/net/8021q/vlan_dev.c
@@ -549,6 +549,23 @@ 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 vlan_dev_priv *vlan = vlan_dev_priv(dev);
+ struct net_device *real_dev = vlan->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 struct device_type vlan_type = {
.name = "vlan",
@@ -592,7 +609,7 @@ static int vlan_dev_init(struct net_device *dev)
dev->needed_headroom = real_dev->needed_headroom;
if (real_dev->features & NETIF_F_HW_VLAN_CTAG_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;
diff --git a/net/core/neighbour.c b/net/core/neighbour.c
index 0034b611fa5..49aeab86f31 100644
--- a/net/core/neighbour.c
+++ b/net/core/neighbour.c
@@ -1274,7 +1274,7 @@ int neigh_compat_output(struct neighbour *neigh, struct sk_buff *skb)
if (dev_hard_header(skb, dev, ntohs(skb->protocol), NULL, NULL,
skb->len) < 0 &&
- dev->header_ops->rebuild(skb))
+ dev_rebuild_header(skb))
return 0;
return dev_queue_xmit(skb);