1 files changed, 154 insertions, 0 deletions
diff --git a/net/ipv4/netfilter/iptable_nat.c b/net/ipv4/netfilter/iptable_nat.c
new file mode 100644
index 000000000..0d4d9cdf9
--- /dev/null
+++ b/net/ipv4/netfilter/iptable_nat.c
@@ -0,0 +1,154 @@
+/* (C) 1999-2001 Paul `Rusty' Russell
+ * (C) 2002-2006 Netfilter Core Team <coreteam@netfilter.org>
+ * (C) 2011 Patrick McHardy <kaber@trash.net>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/module.h>
+#include <linux/netfilter.h>
+#include <linux/netfilter_ipv4.h>
+#include <linux/netfilter_ipv4/ip_tables.h>
+#include <linux/ip.h>
+#include <net/ip.h>
+
+#include <net/netfilter/nf_nat.h>
+#include <net/netfilter/nf_nat_core.h>
+#include <net/netfilter/nf_nat_l3proto.h>
+
+static const struct xt_table nf_nat_ipv4_table = {
+	.name		= "nat",
+	.valid_hooks	= (1 << NF_INET_PRE_ROUTING) |
+			  (1 << NF_INET_POST_ROUTING) |
+			  (1 << NF_INET_LOCAL_OUT) |
+			  (1 << NF_INET_LOCAL_IN),
+	.me		= THIS_MODULE,
+	.af		= NFPROTO_IPV4,
+};
+
+static unsigned int iptable_nat_do_chain(const struct nf_hook_ops *ops,
+					 struct sk_buff *skb,
+					 const struct nf_hook_state *state,
+					 struct nf_conn *ct)
+{
+	struct net *net = nf_ct_net(ct);
+
+	return ipt_do_table(skb, ops->hooknum, state, net->ipv4.nat_table);
+}
+
+static unsigned int iptable_nat_ipv4_fn(const struct nf_hook_ops *ops,
+					struct sk_buff *skb,
+					const struct nf_hook_state *state)
+{
+	return nf_nat_ipv4_fn(ops, skb, state, iptable_nat_do_chain);
+}
+
+static unsigned int iptable_nat_ipv4_in(const struct nf_hook_ops *ops,
+					struct sk_buff *skb,
+					const struct nf_hook_state *state)
+{
+	return nf_nat_ipv4_in(ops, skb, state, iptable_nat_do_chain);
+}
+
+static unsigned int iptable_nat_ipv4_out(const struct nf_hook_ops *ops,
+					 struct sk_buff *skb,
+					 const struct nf_hook_state *state)
+{
+	return nf_nat_ipv4_out(ops, skb, state, iptable_nat_do_chain);
+}
+
+static unsigned int iptable_nat_ipv4_local_fn(const struct nf_hook_ops *ops,
+					      struct sk_buff *skb,
+					      const struct nf_hook_state *state)
+{
+	return nf_nat_ipv4_local_fn(ops, skb, state, iptable_nat_do_chain);
+}
+
+static struct nf_hook_ops nf_nat_ipv4_ops[] __read_mostly = {
+	/* Before packet filtering, change destination */
+	{
+		.hook		= iptable_nat_ipv4_in,
+		.owner		= THIS_MODULE,
+		.pf		= NFPROTO_IPV4,
+		.hooknum	= NF_INET_PRE_ROUTING,
+		.priority	= NF_IP_PRI_NAT_DST,
+	},
+	/* After packet filtering, change source */
+	{
+		.hook		= iptable_nat_ipv4_out,
+		.owner		= THIS_MODULE,
+		.pf		= NFPROTO_IPV4,
+		.hooknum	= NF_INET_POST_ROUTING,
+		.priority	= NF_IP_PRI_NAT_SRC,
+	},
+	/* Before packet filtering, change destination */
+	{
+		.hook		= iptable_nat_ipv4_local_fn,
+		.owner		= THIS_MODULE,
+		.pf		= NFPROTO_IPV4,
+		.hooknum	= NF_INET_LOCAL_OUT,
+		.priority	= NF_IP_PRI_NAT_DST,
+	},
+	/* After packet filtering, change source */
+	{
+		.hook		= iptable_nat_ipv4_fn,
+		.owner		= THIS_MODULE,
+		.pf		= NFPROTO_IPV4,
+		.hooknum	= NF_INET_LOCAL_IN,
+		.priority	= NF_IP_PRI_NAT_SRC,
+	},
+};
+
+static int __net_init iptable_nat_net_init(struct net *net)
+{
+	struct ipt_replace *repl;
+
+	repl = ipt_alloc_initial_table(&nf_nat_ipv4_table);
+	if (repl == NULL)
+		return -ENOMEM;
+	net->ipv4.nat_table = ipt_register_table(net, &nf_nat_ipv4_table, repl);
+	kfree(repl);
+	return PTR_ERR_OR_ZERO(net->ipv4.nat_table);
+}
+
+static void __net_exit iptable_nat_net_exit(struct net *net)
+{
+	ipt_unregister_table(net, net->ipv4.nat_table);
+}
+
+static struct pernet_operations iptable_nat_net_ops = {
+	.init	= iptable_nat_net_init,
+	.exit	= iptable_nat_net_exit,
+};
+
+static int __init iptable_nat_init(void)
+{
+	int err;
+
+	err = register_pernet_subsys(&iptable_nat_net_ops);
+	if (err < 0)
+		goto err1;
+
+	err = nf_register_hooks(nf_nat_ipv4_ops, ARRAY_SIZE(nf_nat_ipv4_ops));
+	if (err < 0)
+		goto err2;
+	return 0;
+
+err2:
+	unregister_pernet_subsys(&iptable_nat_net_ops);
+err1:
+	return err;
+}
+
+static void __exit iptable_nat_exit(void)
+{
+	nf_unregister_hooks(nf_nat_ipv4_ops, ARRAY_SIZE(nf_nat_ipv4_ops));
+	unregister_pernet_subsys(&iptable_nat_net_ops);
+}
+
+module_init(iptable_nat_init);
+module_exit(iptable_nat_exit);
+
+MODULE_LICENSE("GPL");