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[VLAN]: Fix promiscous/allmulti synchronization races

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The set_multicast_list function may be called without holding the rtnl
mutex, resulting in races when changing the underlying device's promiscous
and allmulti state. Use the change_rx_mode hook, which is always invoked
under the rtnl.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Patrick McHardy 2007-07-14 18:52:56 -07:00 committed by David S. Miller
parent a0a400d79e
commit 6c78dcbd47
4 changed files with 22 additions and 20 deletions
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2
include/linux/if_vlan.h
View file

@ -132,8 +132,6 @@ struct vlan_dev_info {
* made, in order to feed the right changes down
* to the real hardware...
*/
int old_allmulti; /* similar to above. */
int old_promiscuity; /* similar to above. */
struct net_device *real_dev; /* the underlying device/interface */
unsigned char real_dev_addr[ETH_ALEN];
struct proc_dir_entry *dent; /* Holds the proc data */

1
net/8021q/vlan.c
View file

@ -373,6 +373,7 @@ void vlan_setup(struct net_device *new_dev)
new_dev->open = vlan_dev_open;
new_dev->stop = vlan_dev_stop;
new_dev->set_multicast_list = vlan_dev_set_multicast_list;
new_dev->change_rx_flags = vlan_change_rx_flags;
new_dev->destructor = free_netdev;
new_dev->do_ioctl = vlan_dev_ioctl;

1
net/8021q/vlan.h
View file

@ -69,6 +69,7 @@ int vlan_dev_set_vlan_flag(const struct net_device *dev,
u32 flag, short flag_val);
void vlan_dev_get_realdev_name(const struct net_device *dev, char *result);
void vlan_dev_get_vid(const struct net_device *dev, unsigned short *result);
void vlan_change_rx_flags(struct net_device *dev, int change);
void vlan_dev_set_multicast_list(struct net_device *vlan_dev);
int vlan_check_real_dev(struct net_device *real_dev, unsigned short vlan_id);

38
net/8021q/vlan_dev.c
View file

@ -712,6 +712,11 @@ int vlan_dev_open(struct net_device *dev)
}
memcpy(vlan->real_dev_addr, real_dev->dev_addr, ETH_ALEN);
if (dev->flags & IFF_ALLMULTI)
dev_set_allmulti(real_dev, 1);
if (dev->flags & IFF_PROMISC)
dev_set_promiscuity(real_dev, 1);
return 0;
}
@ -721,6 +726,11 @@ int vlan_dev_stop(struct net_device *dev)
vlan_flush_mc_list(dev);
if (dev->flags & IFF_ALLMULTI)
dev_set_allmulti(real_dev, -1);
if (dev->flags & IFF_PROMISC)
dev_set_promiscuity(real_dev, -1);
if (compare_ether_addr(dev->dev_addr, real_dev->dev_addr))
dev_unicast_delete(real_dev, dev->dev_addr, dev->addr_len);
@ -754,34 +764,26 @@ int vlan_dev_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
return err;
}
void vlan_change_rx_flags(struct net_device *dev, int change)
{
struct net_device *real_dev = VLAN_DEV_INFO(dev)->real_dev;
if (change & IFF_ALLMULTI)
dev_set_allmulti(real_dev, dev->flags & IFF_ALLMULTI ? 1 : -1);
if (change & IFF_PROMISC)
dev_set_promiscuity(real_dev, dev->flags & IFF_PROMISC ? 1 : -1);
}
/** Taken from Gleb + Lennert's VLAN code, and modified... */
void vlan_dev_set_multicast_list(struct net_device *vlan_dev)
{
struct dev_mc_list *dmi;
struct net_device *real_dev;
int inc;
if (vlan_dev && (vlan_dev->priv_flags & IFF_802_1Q_VLAN)) {
/* Then it's a real vlan device, as far as we can tell.. */
real_dev = VLAN_DEV_INFO(vlan_dev)->real_dev;
/* compare the current promiscuity to the last promisc we had.. */
inc = vlan_dev->promiscuity - VLAN_DEV_INFO(vlan_dev)->old_promiscuity;
if (inc) {
printk(KERN_INFO "%s: dev_set_promiscuity(master, %d)\n",
vlan_dev->name, inc);
dev_set_promiscuity(real_dev, inc); /* found in dev.c */
VLAN_DEV_INFO(vlan_dev)->old_promiscuity = vlan_dev->promiscuity;
}
inc = vlan_dev->allmulti - VLAN_DEV_INFO(vlan_dev)->old_allmulti;
if (inc) {
printk(KERN_INFO "%s: dev_set_allmulti(master, %d)\n",
vlan_dev->name, inc);
dev_set_allmulti(real_dev, inc); /* dev.c */
VLAN_DEV_INFO(vlan_dev)->old_allmulti = vlan_dev->allmulti;
}
/* looking for addresses to add to master's list */
for (dmi = vlan_dev->mc_list; dmi != NULL; dmi = dmi->next) {
if (vlan_should_add_mc(dmi, VLAN_DEV_INFO(vlan_dev)->old_mc_list)) {