[NETFILTER]: ip_tables: per-netns FILTER, MANGLE, RAW

Now, iptables show and configure different set of rules in different
netnss'. Filtering decisions are still made by consulting only
init_net's set.

Changes are identical except naming so no splitting.

P.S.: one need to remove init_net checks in nf_sockopt.c and inet_create()
      to see the effect.

Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/netfilter/iptable_mangle.c b/net/ipv4/netfilter/iptable_mangle.c
index 292f2ed..c55a210 100644
--- a/net/ipv4/netfilter/iptable_mangle.c
+++ b/net/ipv4/netfilter/iptable_mangle.c
@@ -33,7 +33,7 @@
 	struct ipt_replace repl;
 	struct ipt_standard entries[5];
 	struct ipt_error term;
-} initial_table __initdata = {
+} initial_table __net_initdata = {
 	.repl = {
 		.name = "mangle",
 		.valid_hooks = MANGLE_VALID_HOOKS,
@@ -64,14 +64,13 @@
 	.term = IPT_ERROR_INIT,			/* ERROR */
 };
 
-static struct xt_table __packet_mangler = {
+static struct xt_table packet_mangler = {
 	.name		= "mangle",
 	.valid_hooks	= MANGLE_VALID_HOOKS,
 	.lock		= RW_LOCK_UNLOCKED,
 	.me		= THIS_MODULE,
 	.af		= AF_INET,
 };
-static struct xt_table *packet_mangler;
 
 /* The work comes in here from netfilter.c. */
 static unsigned int
@@ -81,7 +80,7 @@
 	 const struct net_device *out,
 	 int (*okfn)(struct sk_buff *))
 {
-	return ipt_do_table(skb, hook, in, out, packet_mangler);
+	return ipt_do_table(skb, hook, in, out, init_net.ipv4.iptable_mangle);
 }
 
 static unsigned int
@@ -113,7 +112,7 @@
 	daddr = iph->daddr;
 	tos = iph->tos;
 
-	ret = ipt_do_table(skb, hook, in, out, packet_mangler);
+	ret = ipt_do_table(skb, hook, in, out, init_net.ipv4.iptable_mangle);
 	/* Reroute for ANY change. */
 	if (ret != NF_DROP && ret != NF_STOLEN && ret != NF_QUEUE) {
 		iph = ip_hdr(skb);
@@ -167,15 +166,33 @@
 	},
 };
 
+static int __net_init iptable_mangle_net_init(struct net *net)
+{
+	/* Register table */
+	net->ipv4.iptable_mangle =
+		ipt_register_table(net, &packet_mangler, &initial_table.repl);
+	if (IS_ERR(net->ipv4.iptable_mangle))
+		return PTR_ERR(net->ipv4.iptable_mangle);
+	return 0;
+}
+
+static void __net_exit iptable_mangle_net_exit(struct net *net)
+{
+	ipt_unregister_table(net->ipv4.iptable_mangle);
+}
+
+static struct pernet_operations iptable_mangle_net_ops = {
+	.init = iptable_mangle_net_init,
+	.exit = iptable_mangle_net_exit,
+};
+
 static int __init iptable_mangle_init(void)
 {
 	int ret;
 
-	/* Register table */
-	packet_mangler = ipt_register_table(&init_net, &__packet_mangler,
-					    &initial_table.repl);
-	if (IS_ERR(packet_mangler))
-		return PTR_ERR(packet_mangler);
+	ret = register_pernet_subsys(&iptable_mangle_net_ops);
+	if (ret < 0)
+		return ret;
 
 	/* Register hooks */
 	ret = nf_register_hooks(ipt_ops, ARRAY_SIZE(ipt_ops));
@@ -185,14 +202,14 @@
 	return ret;
 
  cleanup_table:
-	ipt_unregister_table(packet_mangler);
+	unregister_pernet_subsys(&iptable_mangle_net_ops);
 	return ret;
 }
 
 static void __exit iptable_mangle_fini(void)
 {
 	nf_unregister_hooks(ipt_ops, ARRAY_SIZE(ipt_ops));
-	ipt_unregister_table(packet_mangler);
+	unregister_pernet_subsys(&iptable_mangle_net_ops);
 }
 
 module_init(iptable_mangle_init);