2 files changed, 33 insertions, 41 deletions

diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index f8f76d6e21cb..e83852ab4dc8 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -493,15 +493,17 @@ static void addrconf_forward_change(struct net *net, __s32 newf)
         read_unlock(&dev_base_lock);
 }
 
-static void addrconf_fixup_forwarding(struct ctl_table *table, int *p, int old)
+static int addrconf_fixup_forwarding(struct ctl_table *table, int *p, int old)
 {
         struct net *net;
 
         net = (struct net *)table->extra2;
         if (p == &net->ipv6.devconf_dflt->forwarding)
-                return;
+                return 0;
+
+        if (!rtnl_trylock())
+                return -ERESTARTSYS;
 
-        rtnl_lock();
         if (p == &net->ipv6.devconf_all->forwarding) {
                 __s32 newf = net->ipv6.devconf_all->forwarding;
                 net->ipv6.devconf_dflt->forwarding = newf;
@@ -512,6 +514,7 @@ static void addrconf_fixup_forwarding(struct ctl_table *table, int *p, int old)
 
         if (*p)
                 rt6_purge_dflt_routers(net);
+        return 1;
 }
 #endif
 
@@ -2599,9 +2602,6 @@ static int addrconf_ifdown(struct net_device *dev, int how)
 
         ASSERT_RTNL();
 
-        if ((dev->flags & IFF_LOOPBACK) && how == 1)
-                how = 0;
-
         rt6_ifdown(net, dev);
         neigh_ifdown(&nd_tbl, dev);
 
@@ -3977,7 +3977,7 @@ int addrconf_sysctl_forward(ctl_table *ctl, int write, struct file * filp,
         ret = proc_dointvec(ctl, write, filp, buffer, lenp, ppos);
 
         if (write)
-                addrconf_fixup_forwarding(ctl, valp, val);
+                ret = addrconf_fixup_forwarding(ctl, valp, val);
         return ret;
 }
 
@@ -4013,8 +4013,7 @@ static int addrconf_sysctl_forward_strategy(ctl_table *table,
         }
 
         *valp = new;
-        addrconf_fixup_forwarding(table, valp, val);
-        return 1;
+        return addrconf_fixup_forwarding(table, valp, val);
 }
 
 static struct addrconf_sysctl_table
@@ -4440,25 +4439,6 @@ int unregister_inet6addr_notifier(struct notifier_block *nb)
 
 EXPORT_SYMBOL(unregister_inet6addr_notifier);
 
-static void addrconf_net_exit(struct net *net)
-{
-        struct net_device *dev;
-
-        rtnl_lock();
-        /* clean dev list */
-        for_each_netdev(net, dev) {
-                if (__in6_dev_get(dev) == NULL)
-                        continue;
-                addrconf_ifdown(dev, 1);
-        }
-        addrconf_ifdown(net->loopback_dev, 2);
-        rtnl_unlock();
-}
-
-static struct pernet_operations addrconf_net_ops = {
-        .exit = addrconf_net_exit,
-};
-
 /*
  *      Init / cleanup code
  */
@@ -4500,10 +4480,6 @@ int __init addrconf_init(void)
         if (err)
                 goto errlo;
 
-        err = register_pernet_device(&addrconf_net_ops);
-        if (err)
-                return err;
-
         register_netdevice_notifier(&ipv6_dev_notf);
 
         addrconf_verify(0);
@@ -4533,15 +4509,22 @@ errlo:
 void addrconf_cleanup(void)
 {
         struct inet6_ifaddr *ifa;
+        struct net_device *dev;
         int i;
 
         unregister_netdevice_notifier(&ipv6_dev_notf);
-        unregister_pernet_device(&addrconf_net_ops);
-
         unregister_pernet_subsys(&addrconf_ops);
 
         rtnl_lock();
 
+        /* clean dev list */
+        for_each_netdev(&init_net, dev) {
+                if (__in6_dev_get(dev) == NULL)
+                        continue;
+                addrconf_ifdown(dev, 1);
+        }
+        addrconf_ifdown(init_net.loopback_dev, 2);
+
         /*
          *      Check hash table.
          */
@@ -4562,6 +4545,4 @@ void addrconf_cleanup(void)
 
         del_timer(&addr_chk_timer);
         rtnl_unlock();
-
-        unregister_pernet_subsys(&addrconf_net_ops);
 }
diff --git a/net/ipv6/af_inet6.c b/net/ipv6/af_inet6.c
index fa2ac7ee662f..57b07da1212a 100644
--- a/net/ipv6/af_inet6.c
+++ b/net/ipv6/af_inet6.c
@@ -72,6 +72,10 @@ MODULE_LICENSE("GPL");
 static struct list_head inetsw6[SOCK_MAX];
 static DEFINE_SPINLOCK(inetsw6_lock);
 
+static int disable_ipv6 = 0;
+module_param_named(disable, disable_ipv6, int, 0);
+MODULE_PARM_DESC(disable, "Disable IPv6 such that it is non-functional");
+
 static __inline__ struct ipv6_pinfo *inet6_sk_generic(struct sock *sk)
 {
         const int offset = sk->sk_prot->obj_size - sizeof(struct ipv6_pinfo);
@@ -1001,10 +1005,21 @@ static int __init inet6_init(void)
 {
         struct sk_buff *dummy_skb;
         struct list_head *r;
-        int err;
+        int err = 0;
 
         BUILD_BUG_ON(sizeof(struct inet6_skb_parm) > sizeof(dummy_skb->cb));
 
+        /* Register the socket-side information for inet6_create.  */
+        for(r = &inetsw6[0]; r < &inetsw6[SOCK_MAX]; ++r)
+                INIT_LIST_HEAD(r);
+
+        if (disable_ipv6) {
+                printk(KERN_INFO
+                       "IPv6: Loaded, but administratively disabled, "
+                       "reboot required to enable\n");
+                goto out;
+        }
+
         err = proto_register(&tcpv6_prot, 1);
         if (err)
                 goto out;
@@ -1022,10 +1037,6 @@ static int __init inet6_init(void)
                 goto out_unregister_udplite_proto;
 
 
-        /* Register the socket-side information for inet6_create.  */
-        for(r = &inetsw6[0]; r < &inetsw6[SOCK_MAX]; ++r)
-                INIT_LIST_HEAD(r);
-
         /* We MUST register RAW sockets before we create the ICMP6,
          * IGMP6, or NDISC control sockets.
          */