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ipv6: Use state_lock to protect ifa state

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This patch makes use of the new state_lock to synchronise between
updates to the ifa state.  This fixes the issue where a remotely
triggered address deletion (through DAD failure) coincides with a
local administrative address deletion, causing certain actions to
be performed twice incorrectly.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Herbert Xu 2010-05-18 15:54:18 -07:00 committed by David S. Miller
parent e9d3e08497
commit 4c5ff6a6fe
1 changed files with 23 additions and 4 deletions
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27
net/ipv6/addrconf.c
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@ -715,13 +715,20 @@ static void ipv6_del_addr(struct inet6_ifaddr *ifp)
{
struct inet6_ifaddr *ifa, *ifn;
struct inet6_dev *idev = ifp->idev;
int state;
int hash;
int deleted = 0, onlink = 0;
unsigned long expires = jiffies;
hash = ipv6_addr_hash(&ifp->addr);
spin_lock_bh(&ifp->state_lock);
state = ifp->state;
ifp->state = INET6_IFADDR_STATE_DEAD;
spin_unlock_bh(&ifp->state_lock);
if (state == INET6_IFADDR_STATE_DEAD)
goto out;
spin_lock_bh(&addrconf_hash_lock);
hlist_del_init_rcu(&ifp->addr_lst);
@ -819,6 +826,7 @@ static void ipv6_del_addr(struct inet6_ifaddr *ifp)
dst_release(&rt->u.dst);
}
out:
in6_ifa_put(ifp);
}
@ -2626,6 +2634,7 @@ static int addrconf_ifdown(struct net_device *dev, int how)
struct inet6_dev *idev;
struct inet6_ifaddr *ifa;
LIST_HEAD(keep_list);
int state;
ASSERT_RTNL();
@ -2666,7 +2675,6 @@ static int addrconf_ifdown(struct net_device *dev, int how)
ifa = list_first_entry(&idev->tempaddr_list,
struct inet6_ifaddr, tmp_list);
list_del(&ifa->tmp_list);
ifa->state = INET6_IFADDR_STATE_DEAD;
write_unlock_bh(&idev->lock);
spin_lock_bh(&ifa->lock);
@ -2704,23 +2712,34 @@ static int addrconf_ifdown(struct net_device *dev, int how)
/* Flag it for later restoration when link comes up */
ifa->flags |= IFA_F_TENTATIVE;
in6_ifa_hold(ifa);
write_unlock_bh(&idev->lock);
in6_ifa_hold(ifa);
} else {
list_del(&ifa->if_list);
ifa->state = INET6_IFADDR_STATE_DEAD;
write_unlock_bh(&idev->lock);
/* clear hash table */
spin_lock_bh(&addrconf_hash_lock);
hlist_del_init_rcu(&ifa->addr_lst);
spin_unlock_bh(&addrconf_hash_lock);
write_unlock_bh(&idev->lock);
spin_lock_bh(&ifa->state_lock);
state = ifa->state;
ifa->state = INET6_IFADDR_STATE_DEAD;
spin_unlock_bh(&ifa->state_lock);
if (state == INET6_IFADDR_STATE_DEAD)
goto put_ifa;
}
__ipv6_ifa_notify(RTM_DELADDR, ifa);
if (ifa->state == INET6_IFADDR_STATE_DEAD)
atomic_notifier_call_chain(&inet6addr_chain,
NETDEV_DOWN, ifa);
put_ifa:
in6_ifa_put(ifa);
write_lock_bh(&idev->lock);