Re: [BUG] 2.6.29-rc* QinQ vlan trunking regression

David Miller
2009-03-05T03:53:56Z

From: Patrick McHardy <kaber@trash.net>
Date: Wed, 04 Mar 2009 12:45:33 +0100

> This is a bit tricky to fix since we actually need some valid
> ops before invoking ->init(). One way would be to move the compat
> ops initialization to a seperate function and have VLAN use it to
> switch its ops.

Mind if I push this into net-2.6?

vlan: Fix vlan-in-vlan crashes.

As analyzed by Patrick McHardy, vlan needs to reset it's
netdev_ops pointer in it's ->init() function but this
leaves the compat method pointers stale.

Add a netdev_resync_ops() and call it from the vlan code.

Signed-off-by: David S. Miller <davem@davemloft.net>
---
include/linux/netdevice.h | 1 +
net/8021q/vlan_dev.c | 1 +
net/core/dev.c | 54 +++++++++++++++++++++++++++-----------------
3 files changed, 35 insertions(+), 21 deletions(-)

diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index ec54785..6593667 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -1079,6 +1079,7 @@ extern void synchronize_net(void);
extern int register_netdevice_notifier(struct notifier_block *nb);
extern int unregister_netdevice_notifier(struct notifier_block *nb);
extern int init_dummy_netdev(struct net_device *dev);
+extern void netdev_resync_ops(struct net_device *dev);

extern int call_netdevice_notifiers(unsigned long val, struct net_device *dev);
extern struct net_device *dev_get_by_index(struct net *net, int ifindex);
diff --git a/net/8021q/vlan_dev.c b/net/8021q/vlan_dev.c
index 4a19acd..b6e1f9e 100644
--- a/net/8021q/vlan_dev.c
+++ b/net/8021q/vlan_dev.c
@@ -639,6 +639,7 @@ static int vlan_dev_init(struct net_device *dev)
dev->hard_header_len = real_dev->hard_header_len + VLAN_HLEN;
dev->netdev_ops = &vlan_netdev_ops;
}
+ netdev_resync_ops(dev);

if (is_vlan_dev(real_dev))
subclass = 1;
diff --git a/net/core/dev.c b/net/core/dev.c
index 9e4afe6..a06c6fa 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -4282,6 +4282,38 @@ unsigned long netdev_fix_features(unsigned long features, const char *name)
}
EXPORT_SYMBOL(netdev_fix_features);

+/* Some devices need to (re-)set their netdev_ops inside
+ * ->init() or similar. If that happens, we have to setup
+ * the compat pointers again.
+ */
+void netdev_resync_ops(struct net_device *dev)
+{
+#ifdef CONFIG_COMPAT_NET_DEV_OPS
+ const struct net_device_ops *ops = dev->netdev_ops;
+
+ dev->init = ops->ndo_init;
+ dev->uninit = ops->ndo_uninit;
+ dev->open = ops->ndo_open;
+ dev->change_rx_flags = ops->ndo_change_rx_flags;
+ dev->set_rx_mode = ops->ndo_set_rx_mode;
+ dev->set_multicast_list = ops->ndo_set_multicast_list;
+ dev->set_mac_address = ops->ndo_set_mac_address;
+ dev->validate_addr = ops->ndo_validate_addr;
+ dev->do_ioctl = ops->ndo_do_ioctl;
+ dev->set_config = ops->ndo_set_config;
+ dev->change_mtu = ops->ndo_change_mtu;
+ dev->tx_timeout = ops->ndo_tx_timeout;
+ dev->get_stats = ops->ndo_get_stats;
+ dev->vlan_rx_register = ops->ndo_vlan_rx_register;
+ dev->vlan_rx_add_vid = ops->ndo_vlan_rx_add_vid;
+ dev->vlan_rx_kill_vid = ops->ndo_vlan_rx_kill_vid;
+#ifdef CONFIG_NET_POLL_CONTROLLER
+ dev->poll_controller = ops->ndo_poll_controller;
+#endif
+#endif
+}
+EXPORT_SYMBOL(netdev_resync_ops);
+
/**
* register_netdevice - register a network device
* @dev: device to register
@@ -4326,27 +4358,7 @@ int register_netdevice(struct net_device *dev)
* This is temporary until all network devices are converted.
*/
if (dev->netdev_ops) {
- const struct net_device_ops *ops = dev->netdev_ops;
-
- dev->init = ops->ndo_init;
- dev->uninit = ops->ndo_uninit;
- dev->open = ops->ndo_open;
- dev->change_rx_flags = ops->ndo_change_rx_flags;
- dev->set_rx_mode = ops->ndo_set_rx_mode;
- dev->set_multicast_list = ops->ndo_set_multicast_list;
- dev->set_mac_address = ops->ndo_set_mac_address;
- dev->validate_addr = ops->ndo_validate_addr;
- dev->do_ioctl = ops->ndo_do_ioctl;
- dev->set_config = ops->ndo_set_config;
- dev->change_mtu = ops->ndo_change_mtu;
- dev->tx_timeout = ops->ndo_tx_timeout;
- dev->get_stats = ops->ndo_get_stats;
- dev->vlan_rx_register = ops->ndo_vlan_rx_register;
- dev->vlan_rx_add_vid = ops->ndo_vlan_rx_add_vid;
- dev->vlan_rx_kill_vid = ops->ndo_vlan_rx_kill_vid;
-#ifdef CONFIG_NET_POLL_CONTROLLER
- dev->poll_controller = ops->ndo_poll_controller;
-#endif
+ netdev_resync_ops(dev);
} else {
char drivername[64];
pr_info("%s (%s): not using net_device_ops yet\n",
--
1.6.2