[NETNS]: Make icmpv6_sk per namespace.

All preparations are done. Now just add a hook to perform an
initialization on namespace startup and replace icmpv6_sk macro with
proper inline call.  Actual namespace the packet belongs too will be
passed later along with the one for the routing.
Signed-off-by: Denis V. Lunev <den@openvz.org>
Acked-by: Daniel Lezcano <dlezcano@fr.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/netns/ipv6.h

@@ -36,5 +36,6 @@ struct netns_ipv6 {
 	struct xt_table		*ip6table_mangle;
 	struct xt_table		*ip6table_raw;
 #endif
+	struct sock		**icmp_sk;
 };
 #endif

net/ipv6/icmp.c

@@ -80,8 +80,10 @@ EXPORT_SYMBOL(icmpv6msg_statistics);
  *
  *	On SMP we have one ICMP socket per-cpu.
  */
-static struct sock **__icmpv6_sk = NULL;
-#define icmpv6_sk	(__icmpv6_sk[smp_processor_id()])
+static inline struct sock *icmpv6_sk(struct net *net)
+{
+	return net->ipv6.icmp_sk[smp_processor_id()];
+}
 
 static int icmpv6_rcv(struct sk_buff *skb);
 
@@ -389,7 +391,7 @@ void icmpv6_send(struct sk_buff *skb, int type, int code, __u32 info,
 	fl.fl_icmp_code = code;
 	security_skb_classify_flow(skb, &fl);
 
-	sk = icmpv6_sk;
+	sk = icmpv6_sk(&init_net);
 	np = inet6_sk(sk);
 
 	if (icmpv6_xmit_lock(sk))
@@ -535,7 +537,7 @@ static void icmpv6_echo_reply(struct sk_buff *skb)
 	fl.fl_icmp_type = ICMPV6_ECHO_REPLY;
 	security_skb_classify_flow(skb, &fl);
 
-	sk = icmpv6_sk;
+	sk = icmpv6_sk(&init_net);
 	np = inet6_sk(sk);
 
 	if (icmpv6_xmit_lock(sk))
@@ -780,13 +782,14 @@ static int icmpv6_rcv(struct sk_buff *skb)
  */
 static struct lock_class_key icmpv6_socket_sk_dst_lock_key;
 
-int __init icmpv6_init(void)
+static int __net_init icmpv6_sk_init(struct net *net)
 {
 	struct sock *sk;
 	int err, i, j;
 
-	__icmpv6_sk = kzalloc(nr_cpu_ids * sizeof(struct sock *), GFP_KERNEL);
-	if (__icmpv6_sk == NULL)
+	net->ipv6.icmp_sk =
+		kzalloc(nr_cpu_ids * sizeof(struct sock *), GFP_KERNEL);
+	if (net->ipv6.icmp_sk == NULL)
 		return -ENOMEM;
 
 	for_each_possible_cpu(i) {
@@ -801,8 +804,8 @@ int __init icmpv6_init(void)
 			goto fail;
 		}
 
-		__icmpv6_sk[i] = sk = sock->sk;
-		sk_change_net(sk, &init_net);
+		net->ipv6.icmp_sk[i] = sk = sock->sk;
+		sk_change_net(sk, net);
 
 		sk->sk_allocation = GFP_ATOMIC;
 		/*
@@ -822,33 +825,56 @@ int __init icmpv6_init(void)
 
 		sk->sk_prot->unhash(sk);
 	}
-
-
-	if (inet6_add_protocol(&icmpv6_protocol, IPPROTO_ICMPV6) < 0) {
-		printk(KERN_ERR "Failed to register ICMP6 protocol\n");
-		err = -EAGAIN;
-		goto fail;
-	}
-
 	return 0;
 
  fail:
 	for (j = 0; j < i; j++)
-		sk_release_kernel(__icmpv6_sk[j]);
-
+		sk_release_kernel(net->ipv6.icmp_sk[j]);
+	kfree(net->ipv6.icmp_sk);
 	return err;
 }
 
-void icmpv6_cleanup(void)
+static void __net_exit icmpv6_sk_exit(struct net *net)
 {
 	int i;
 
 	for_each_possible_cpu(i) {
-		sk_release_kernel(__icmpv6_sk[i]);
+		sk_release_kernel(net->ipv6.icmp_sk[i]);
 	}
+	kfree(net->ipv6.icmp_sk);
+}
+
+static struct pernet_operations __net_initdata icmpv6_sk_ops = {
+       .init = icmpv6_sk_init,
+       .exit = icmpv6_sk_exit,
+};
+
+int __init icmpv6_init(void)
+{
+	int err;
+
+	err = register_pernet_subsys(&icmpv6_sk_ops);
+	if (err < 0)
+		return err;
+
+	err = -EAGAIN;
+	if (inet6_add_protocol(&icmpv6_protocol, IPPROTO_ICMPV6) < 0)
+		goto fail;
+	return 0;
+
+fail:
+	printk(KERN_ERR "Failed to register ICMP6 protocol\n");
+	unregister_pernet_subsys(&icmpv6_sk_ops);
+	return err;
+}
+
+void __exit icmpv6_cleanup(void)
+{
+	unregister_pernet_subsys(&icmpv6_sk_ops);
 	inet6_del_protocol(&icmpv6_protocol, IPPROTO_ICMPV6);
 }
 
+
 static const struct icmp6_err {
 	int err;
 	int fatal;