[NETNS]: Make icmp_sk per namespace.

All preparations are done. Now just add a hook to perform an
initialization on namespace startup and replace icmp_sk macro with
proper inline call.
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/ipv4.h

@@ -26,6 +26,8 @@ struct netns_ipv4 {
 	struct hlist_head	*fib_table_hash;
 	struct sock		*fibnl;
 
+	struct sock		**icmp_sk;
+
 	struct netns_frags	frags;
 #ifdef CONFIG_NETFILTER
 	struct xt_table		*iptable_filter;

net/ipv4/icmp.c

@@ -229,8 +229,10 @@ static const struct icmp_control icmp_pointers[NR_ICMP_TYPES+1];
  *
  *	On SMP we have one ICMP socket per-cpu.
  */
-static struct sock **__icmp_sk = NULL;
-#define icmp_sk		(__icmp_sk[smp_processor_id()])
+static struct sock *icmp_sk(struct net *net)
+{
+	return net->ipv4.icmp_sk[smp_processor_id()];
+}
 
 static inline int icmp_xmit_lock(struct sock *sk)
 {
@@ -349,7 +351,7 @@ static void icmp_push_reply(struct icmp_bxm *icmp_param,
 	struct sock *sk;
 	struct sk_buff *skb;
 
-	sk = icmp_sk;
+	sk = icmp_sk(rt->u.dst.dev->nd_net);
 	if (ip_append_data(sk, icmp_glue_bits, icmp_param,
 			   icmp_param->data_len+icmp_param->head_len,
 			   icmp_param->head_len,
@@ -378,10 +380,11 @@ static void icmp_push_reply(struct icmp_bxm *icmp_param,
 
 static void icmp_reply(struct icmp_bxm *icmp_param, struct sk_buff *skb)
 {
-	struct sock *sk = icmp_sk;
-	struct inet_sock *inet = inet_sk(sk);
 	struct ipcm_cookie ipc;
 	struct rtable *rt = (struct rtable *)skb->dst;
+	struct net *net = rt->u.dst.dev->nd_net;
+	struct sock *sk = icmp_sk(net);
+	struct inet_sock *inet = inet_sk(sk);
 	__be32 daddr;
 
 	if (ip_options_echo(&icmp_param->replyopts, skb))
@@ -407,7 +410,7 @@ static void icmp_reply(struct icmp_bxm *icmp_param, struct sk_buff *skb)
 						.tos = RT_TOS(ip_hdr(skb)->tos) } },
 				    .proto = IPPROTO_ICMP };
 		security_skb_classify_flow(skb, &fl);
-		if (ip_route_output_key(rt->u.dst.dev->nd_net, &rt, &fl))
+		if (ip_route_output_key(net, &rt, &fl))
 			goto out_unlock;
 	}
 	if (icmpv4_xrlim_allow(rt, icmp_param->data.icmph.type,
@@ -440,11 +443,12 @@ void icmp_send(struct sk_buff *skb_in, int type, int code, __be32 info)
 	__be32 saddr;
 	u8  tos;
 	struct net *net;
-	struct sock *sk = icmp_sk;
+	struct sock *sk;
 
 	if (!rt)
 		goto out;
 	net = rt->u.dst.dev->nd_net;
+	sk = icmp_sk(net);
 
 	/*
 	 *	Find the original header. It is expected to be valid, of course.
@@ -1142,22 +1146,23 @@ static const struct icmp_control icmp_pointers[NR_ICMP_TYPES + 1] = {
 	},
 };
 
-static void __exit icmp_exit(void)
+static void __net_exit icmp_sk_exit(struct net *net)
 {
 	int i;
 
 	for_each_possible_cpu(i)
-		sk_release_kernel(__icmp_sk[i]);
-	kfree(__icmp_sk);
-	__icmp_sk = NULL;
+		sk_release_kernel(net->ipv4.icmp_sk[i]);
+	kfree(net->ipv4.icmp_sk);
+	net->ipv4.icmp_sk = NULL;
 }
 
-int __init icmp_init(void)
+int __net_init icmp_sk_init(struct net *net)
 {
 	int i, err;
 
-	__icmp_sk = kzalloc(nr_cpu_ids * sizeof(struct sock *), GFP_KERNEL);
-	if (__icmp_sk == NULL)
+	net->ipv4.icmp_sk =
+		kzalloc(nr_cpu_ids * sizeof(struct sock *), GFP_KERNEL);
+	if (net->ipv4.icmp_sk == NULL)
 		return -ENOMEM;
 
 	for_each_possible_cpu(i) {
@@ -1169,8 +1174,8 @@ int __init icmp_init(void)
 		if (err < 0)
 			goto fail;
 
-		__icmp_sk[i] = sk = sock->sk;
-		sk_change_net(sk, &init_net);
+		net->ipv4.icmp_sk[i] = sk = sock->sk;
+		sk_change_net(sk, net);
 
 		sk->sk_allocation = GFP_ATOMIC;
 
@@ -1193,10 +1198,20 @@ int __init icmp_init(void)
 	return 0;
 
 fail:
-	icmp_exit();
+	icmp_sk_exit(net);
 	return err;
 }
 
+static struct pernet_operations __net_initdata icmp_sk_ops = {
+       .init = icmp_sk_init,
+       .exit = icmp_sk_exit,
+};
+
+int __init icmp_init(void)
+{
+	return register_pernet_device(&icmp_sk_ops);
+}
+
 EXPORT_SYMBOL(icmp_err_convert);
 EXPORT_SYMBOL(icmp_send);
 EXPORT_SYMBOL(icmp_statistics);