6 files changed, 153 insertions, 2 deletions

diff --git a/drivers/net/ipvlan/ipvlan_main.c b/drivers/net/ipvlan/ipvlan_main.c
index 618ed88fad0f..e4141d62b5c3 100644
--- a/drivers/net/ipvlan/ipvlan_main.c
+++ b/drivers/net/ipvlan/ipvlan_main.c
@@ -824,6 +824,33 @@ static int ipvlan_addr6_event(struct notifier_block *unused,
         return NOTIFY_OK;
 }
 
+static int ipvlan_addr6_validator_event(struct notifier_block *unused,
+                                        unsigned long event, void *ptr)
+{
+        struct in6_validator_info *i6vi = (struct in6_validator_info *)ptr;
+        struct net_device *dev = (struct net_device *)i6vi->i6vi_dev->dev;
+        struct ipvl_dev *ipvlan = netdev_priv(dev);
+
+        /* FIXME IPv6 autoconf calls us from bh without RTNL */
+        if (in_softirq())
+                return NOTIFY_DONE;
+
+        if (!netif_is_ipvlan(dev))
+                return NOTIFY_DONE;
+
+        if (!ipvlan || !ipvlan->port)
+                return NOTIFY_DONE;
+
+        switch (event) {
+        case NETDEV_UP:
+                if (ipvlan_addr_busy(ipvlan->port, &i6vi->i6vi_addr, true))
+                        return notifier_from_errno(-EADDRINUSE);
+                break;
+        }
+
+        return NOTIFY_OK;
+}
+
 static int ipvlan_add_addr4(struct ipvl_dev *ipvlan, struct in_addr *ip4_addr)
 {
         if (ipvlan_addr_busy(ipvlan->port, ip4_addr, false)) {
@@ -871,10 +898,37 @@ static int ipvlan_addr4_event(struct notifier_block *unused,
         return NOTIFY_OK;
 }
 
+static int ipvlan_addr4_validator_event(struct notifier_block *unused,
+                                        unsigned long event, void *ptr)
+{
+        struct in_validator_info *ivi = (struct in_validator_info *)ptr;
+        struct net_device *dev = (struct net_device *)ivi->ivi_dev->dev;
+        struct ipvl_dev *ipvlan = netdev_priv(dev);
+
+        if (!netif_is_ipvlan(dev))
+                return NOTIFY_DONE;
+
+        if (!ipvlan || !ipvlan->port)
+                return NOTIFY_DONE;
+
+        switch (event) {
+        case NETDEV_UP:
+                if (ipvlan_addr_busy(ipvlan->port, &ivi->ivi_addr, false))
+                        return notifier_from_errno(-EADDRINUSE);
+                break;
+        }
+
+        return NOTIFY_OK;
+}
+
 static struct notifier_block ipvlan_addr4_notifier_block __read_mostly = {
         .notifier_call = ipvlan_addr4_event,
 };
 
+static struct notifier_block ipvlan_addr4_vtor_notifier_block __read_mostly = {
+        .notifier_call = ipvlan_addr4_validator_event,
+};
+
 static struct notifier_block ipvlan_notifier_block __read_mostly = {
         .notifier_call = ipvlan_device_event,
 };
@@ -883,6 +937,10 @@ static struct notifier_block ipvlan_addr6_notifier_block __read_mostly = {
         .notifier_call = ipvlan_addr6_event,
 };
 
+static struct notifier_block ipvlan_addr6_vtor_notifier_block __read_mostly = {
+        .notifier_call = ipvlan_addr6_validator_event,
+};
+
 static void ipvlan_ns_exit(struct net *net)
 {
         struct ipvlan_netns *vnet = net_generic(net, ipvlan_netid);
@@ -907,7 +965,10 @@ static int __init ipvlan_init_module(void)
         ipvlan_init_secret();
         register_netdevice_notifier(&ipvlan_notifier_block);
         register_inet6addr_notifier(&ipvlan_addr6_notifier_block);
+        register_inet6addr_validator_notifier(
+            &ipvlan_addr6_vtor_notifier_block);
         register_inetaddr_notifier(&ipvlan_addr4_notifier_block);
+        register_inetaddr_validator_notifier(&ipvlan_addr4_vtor_notifier_block);
 
         err = register_pernet_subsys(&ipvlan_net_ops);
         if (err < 0)
@@ -922,7 +983,11 @@ static int __init ipvlan_init_module(void)
         return 0;
 error:
         unregister_inetaddr_notifier(&ipvlan_addr4_notifier_block);
+        unregister_inetaddr_validator_notifier(
+            &ipvlan_addr4_vtor_notifier_block);
         unregister_inet6addr_notifier(&ipvlan_addr6_notifier_block);
+        unregister_inet6addr_validator_notifier(
+            &ipvlan_addr6_vtor_notifier_block);
         unregister_netdevice_notifier(&ipvlan_notifier_block);
         return err;
 }
@@ -933,7 +998,11 @@ static void __exit ipvlan_cleanup_module(void)
         unregister_pernet_subsys(&ipvlan_net_ops);
         unregister_netdevice_notifier(&ipvlan_notifier_block);
         unregister_inetaddr_notifier(&ipvlan_addr4_notifier_block);
+        unregister_inetaddr_validator_notifier(
+            &ipvlan_addr4_vtor_notifier_block);
         unregister_inet6addr_notifier(&ipvlan_addr6_notifier_block);
+        unregister_inet6addr_validator_notifier(
+            &ipvlan_addr6_vtor_notifier_block);
 }
 
 module_init(ipvlan_init_module);
diff --git a/include/linux/inetdevice.h b/include/linux/inetdevice.h
index a2e9d6ea1349..e7c04c4e4bcd 100644
--- a/include/linux/inetdevice.h
+++ b/include/linux/inetdevice.h
@@ -150,8 +150,15 @@ struct in_ifaddr {
         unsigned long           ifa_tstamp; /* updated timestamp */
 };
 
+struct in_validator_info {
+        __be32                  ivi_addr;
+        struct in_device        *ivi_dev;
+};
+
 int register_inetaddr_notifier(struct notifier_block *nb);
 int unregister_inetaddr_notifier(struct notifier_block *nb);
+int register_inetaddr_validator_notifier(struct notifier_block *nb);
+int unregister_inetaddr_validator_notifier(struct notifier_block *nb);
 
 void inet_netconf_notify_devconf(struct net *net, int event, int type,
                                  int ifindex, struct ipv4_devconf *devconf);
diff --git a/include/net/addrconf.h b/include/net/addrconf.h
index b43a4eec3cec..d0889cb50172 100644
--- a/include/net/addrconf.h
+++ b/include/net/addrconf.h
@@ -48,11 +48,15 @@ struct prefix_info {
         struct in6_addr         prefix;
 };
 
-
 #include <linux/netdevice.h>
 #include <net/if_inet6.h>
 #include <net/ipv6.h>
 
+struct in6_validator_info {
+        struct in6_addr         i6vi_addr;
+        struct inet6_dev        *i6vi_dev;
+};
+
 #define IN6_ADDR_HSIZE_SHIFT    4
 #define IN6_ADDR_HSIZE          (1 << IN6_ADDR_HSIZE_SHIFT)
 
@@ -278,6 +282,10 @@ int register_inet6addr_notifier(struct notifier_block *nb);
 int unregister_inet6addr_notifier(struct notifier_block *nb);
 int inet6addr_notifier_call_chain(unsigned long val, void *v);
 
+int register_inet6addr_validator_notifier(struct notifier_block *nb);
+int unregister_inet6addr_validator_notifier(struct notifier_block *nb);
+int inet6addr_validator_notifier_call_chain(unsigned long val, void *v);
+
 void inet6_netconf_notify_devconf(struct net *net, int event, int type,
                                   int ifindex, struct ipv6_devconf *devconf);
 
diff --git a/net/ipv4/devinet.c b/net/ipv4/devinet.c
index df14815a3b8c..a7dd088d5fc9 100644
--- a/net/ipv4/devinet.c
+++ b/net/ipv4/devinet.c
@@ -176,6 +176,7 @@ EXPORT_SYMBOL(__ip_dev_find);
 static void rtmsg_ifa(int event, struct in_ifaddr *, struct nlmsghdr *, u32);
 
 static BLOCKING_NOTIFIER_HEAD(inetaddr_chain);
+static BLOCKING_NOTIFIER_HEAD(inetaddr_validator_chain);
 static void inet_del_ifa(struct in_device *in_dev, struct in_ifaddr **ifap,
                          int destroy);
 #ifdef CONFIG_SYSCTL
@@ -441,6 +442,8 @@ static int __inet_insert_ifa(struct in_ifaddr *ifa, struct nlmsghdr *nlh,
 {
         struct in_device *in_dev = ifa->ifa_dev;
         struct in_ifaddr *ifa1, **ifap, **last_primary;
+        struct in_validator_info ivi;
+        int ret;
 
         ASSERT_RTNL();
 
@@ -471,6 +474,23 @@ static int __inet_insert_ifa(struct in_ifaddr *ifa, struct nlmsghdr *nlh,
                 }
         }
 
+        /* Allow any devices that wish to register ifaddr validtors to weigh
+         * in now, before changes are committed.  The rntl lock is serializing
+         * access here, so the state should not change between a validator call
+         * and a final notify on commit.  This isn't invoked on promotion under
+         * the assumption that validators are checking the address itself, and
+         * not the flags.
+         */
+        ivi.ivi_addr = ifa->ifa_address;
+        ivi.ivi_dev = ifa->ifa_dev;
+        ret = blocking_notifier_call_chain(&inetaddr_validator_chain,
+                                           NETDEV_UP, &ivi);
+        ret = notifier_to_errno(ret);
+        if (ret) {
+                inet_free_ifa(ifa);
+                return ret;
+        }
+
         if (!(ifa->ifa_flags & IFA_F_SECONDARY)) {
                 prandom_seed((__force u32) ifa->ifa_local);
                 ifap = last_primary;
@@ -1356,6 +1376,19 @@ int unregister_inetaddr_notifier(struct notifier_block *nb)
 }
 EXPORT_SYMBOL(unregister_inetaddr_notifier);
 
+int register_inetaddr_validator_notifier(struct notifier_block *nb)
+{
+        return blocking_notifier_chain_register(&inetaddr_validator_chain, nb);
+}
+EXPORT_SYMBOL(register_inetaddr_validator_notifier);
+
+int unregister_inetaddr_validator_notifier(struct notifier_block *nb)
+{
+        return blocking_notifier_chain_unregister(&inetaddr_validator_chain,
+            nb);
+}
+EXPORT_SYMBOL(unregister_inetaddr_validator_notifier);
+
 /* Rename ifa_labels for a device name change. Make some effort to preserve
  * existing alias numbering and to create unique labels if possible.
 */
diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index 25443fd946a8..0aa36b093013 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -963,6 +963,7 @@ ipv6_add_addr(struct inet6_dev *idev, const struct in6_addr *addr,
         struct net *net = dev_net(idev->dev);
         struct inet6_ifaddr *ifa = NULL;
         struct rt6_info *rt;
+        struct in6_validator_info i6vi;
         unsigned int hash;
         int err = 0;
         int addr_type = ipv6_addr_type(addr);
@@ -974,6 +975,9 @@ ipv6_add_addr(struct inet6_dev *idev, const struct in6_addr *addr,
                 return ERR_PTR(-EADDRNOTAVAIL);
 
         rcu_read_lock_bh();
+
+        in6_dev_hold(idev);
+
         if (idev->dead) {
                 err = -ENODEV;                  /*XXX*/
                 goto out2;
@@ -984,6 +988,17 @@ ipv6_add_addr(struct inet6_dev *idev, const struct in6_addr *addr,
                 goto out2;
         }
 
+        i6vi.i6vi_addr = *addr;
+        i6vi.i6vi_dev = idev;
+        rcu_read_unlock_bh();
+
+        err = inet6addr_validator_notifier_call_chain(NETDEV_UP, &i6vi);
+
+        rcu_read_lock_bh();
+        err = notifier_to_errno(err);
+        if (err)
+                goto out2;
+
         spin_lock(&addrconf_hash_lock);
 
         /* Ignore adding duplicate addresses on an interface */
@@ -1034,7 +1049,6 @@ ipv6_add_addr(struct inet6_dev *idev, const struct in6_addr *addr,
         ifa->rt = rt;
 
         ifa->idev = idev;
-        in6_dev_hold(idev);
         /* For caller */
         in6_ifa_hold(ifa);
 
@@ -1062,6 +1076,7 @@ out2:
                 inet6addr_notifier_call_chain(NETDEV_UP, ifa);
         else {
                 kfree(ifa);
+                in6_dev_put(idev);
                 ifa = ERR_PTR(err);
         }
 
diff --git a/net/ipv6/addrconf_core.c b/net/ipv6/addrconf_core.c
index bfa941fc1165..9e3488d50b15 100644
--- a/net/ipv6/addrconf_core.c
+++ b/net/ipv6/addrconf_core.c
@@ -88,6 +88,7 @@ int __ipv6_addr_type(const struct in6_addr *addr)
 EXPORT_SYMBOL(__ipv6_addr_type);
 
 static ATOMIC_NOTIFIER_HEAD(inet6addr_chain);
+static ATOMIC_NOTIFIER_HEAD(inet6addr_validator_chain);
 
 int register_inet6addr_notifier(struct notifier_block *nb)
 {
@@ -107,6 +108,24 @@ int inet6addr_notifier_call_chain(unsigned long val, void *v)
 }
 EXPORT_SYMBOL(inet6addr_notifier_call_chain);
 
+int register_inet6addr_validator_notifier(struct notifier_block *nb)
+{
+        return atomic_notifier_chain_register(&inet6addr_validator_chain, nb);
+}
+EXPORT_SYMBOL(register_inet6addr_validator_notifier);
+
+int unregister_inet6addr_validator_notifier(struct notifier_block *nb)
+{
+        return atomic_notifier_chain_unregister(&inet6addr_validator_chain, nb);
+}
+EXPORT_SYMBOL(unregister_inet6addr_validator_notifier);
+
+int inet6addr_validator_notifier_call_chain(unsigned long val, void *v)
+{
+        return atomic_notifier_call_chain(&inet6addr_validator_chain, val, v);
+}
+EXPORT_SYMBOL(inet6addr_validator_notifier_call_chain);
+
 static int eafnosupport_ipv6_dst_lookup(struct net *net, struct sock *u1,
                                         struct dst_entry **u2,
                                         struct flowi6 *u3)