[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_filter.c b/net/ipv4/netfilter/iptable_filter.c
index 3b43ca0..69f3d7e 100644
--- a/net/ipv4/netfilter/iptable_filter.c
+++ b/net/ipv4/netfilter/iptable_filter.c
@@ -28,7 +28,7 @@
 	struct ipt_replace repl;
 	struct ipt_standard entries[3];
 	struct ipt_error term;
-} initial_table __initdata = {
+} initial_table __net_initdata = {
 	.repl = {
 		.name = "filter",
 		.valid_hooks = FILTER_VALID_HOOKS,
@@ -53,14 +53,13 @@
 	.term = IPT_ERROR_INIT,			/* ERROR */
 };
 
-static struct xt_table __packet_filter = {
+static struct xt_table packet_filter = {
 	.name		= "filter",
 	.valid_hooks	= FILTER_VALID_HOOKS,
 	.lock		= RW_LOCK_UNLOCKED,
 	.me		= THIS_MODULE,
 	.af		= AF_INET,
 };
-static struct xt_table *packet_filter;
 
 /* The work comes in here from netfilter.c. */
 static unsigned int
@@ -70,7 +69,7 @@
 	 const struct net_device *out,
 	 int (*okfn)(struct sk_buff *))
 {
-	return ipt_do_table(skb, hook, in, out, packet_filter);
+	return ipt_do_table(skb, hook, in, out, init_net.ipv4.iptable_filter);
 }
 
 static unsigned int
@@ -89,7 +88,7 @@
 		return NF_ACCEPT;
 	}
 
-	return ipt_do_table(skb, hook, in, out, packet_filter);
+	return ipt_do_table(skb, hook, in, out, init_net.ipv4.iptable_filter);
 }
 
 static struct nf_hook_ops ipt_ops[] __read_mostly = {
@@ -120,6 +119,26 @@
 static int forward = NF_ACCEPT;
 module_param(forward, bool, 0000);
 
+static int __net_init iptable_filter_net_init(struct net *net)
+{
+	/* Register table */
+	net->ipv4.iptable_filter =
+		ipt_register_table(net, &packet_filter, &initial_table.repl);
+	if (IS_ERR(net->ipv4.iptable_filter))
+		return PTR_ERR(net->ipv4.iptable_filter);
+	return 0;
+}
+
+static void __net_exit iptable_filter_net_exit(struct net *net)
+{
+	ipt_unregister_table(net->ipv4.iptable_filter);
+}
+
+static struct pernet_operations iptable_filter_net_ops = {
+	.init = iptable_filter_net_init,
+	.exit = iptable_filter_net_exit,
+};
+
 static int __init iptable_filter_init(void)
 {
 	int ret;
@@ -132,11 +151,9 @@
 	/* Entry 1 is the FORWARD hook */
 	initial_table.entries[1].target.verdict = -forward - 1;
 
-	/* Register table */
-	packet_filter = ipt_register_table(&init_net, &__packet_filter,
-					   &initial_table.repl);
-	if (IS_ERR(packet_filter))
-		return PTR_ERR(packet_filter);
+	ret = register_pernet_subsys(&iptable_filter_net_ops);
+	if (ret < 0)
+		return ret;
 
 	/* Register hooks */
 	ret = nf_register_hooks(ipt_ops, ARRAY_SIZE(ipt_ops));
@@ -146,14 +163,14 @@
 	return ret;
 
  cleanup_table:
-	ipt_unregister_table(packet_filter);
+	unregister_pernet_subsys(&iptable_filter_net_ops);
 	return ret;
 }
 
 static void __exit iptable_filter_fini(void)
 {
 	nf_unregister_hooks(ipt_ops, ARRAY_SIZE(ipt_ops));
-	ipt_unregister_table(packet_filter);
+	unregister_pernet_subsys(&iptable_filter_net_ops);
 }
 
 module_init(iptable_filter_init);