1 /* (C) 1999-2001 Paul `Rusty' Russell
2 * (C) 2002-2006 Netfilter Core Team <coreteam@netfilter.org>
3 * (C) 2011 Patrick McHardy <kaber@trash.net>
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License version 2 as
7 * published by the Free Software Foundation.
10 #include <linux/module.h>
11 #include <linux/netfilter.h>
12 #include <linux/netfilter_ipv4.h>
13 #include <linux/netfilter_ipv4/ip_tables.h>
17 #include <net/netfilter/nf_nat.h>
18 #include <net/netfilter/nf_nat_core.h>
19 #include <net/netfilter/nf_nat_l3proto.h>
21 static int __net_init iptable_nat_table_init(struct net *net);
23 static const struct xt_table nf_nat_ipv4_table = {
25 .valid_hooks = (1 << NF_INET_PRE_ROUTING) |
26 (1 << NF_INET_POST_ROUTING) |
27 (1 << NF_INET_LOCAL_OUT) |
28 (1 << NF_INET_LOCAL_IN),
31 .table_init = iptable_nat_table_init,
34 static unsigned int iptable_nat_do_chain(void *priv,
36 const struct nf_hook_state *state,
39 return ipt_do_table(skb, state, state->net->ipv4.nat_table);
42 static unsigned int iptable_nat_ipv4_fn(void *priv,
44 const struct nf_hook_state *state)
46 return nf_nat_ipv4_fn(priv, skb, state, iptable_nat_do_chain);
49 static unsigned int iptable_nat_ipv4_in(void *priv,
51 const struct nf_hook_state *state)
53 return nf_nat_ipv4_in(priv, skb, state, iptable_nat_do_chain);
56 static unsigned int iptable_nat_ipv4_out(void *priv,
58 const struct nf_hook_state *state)
60 return nf_nat_ipv4_out(priv, skb, state, iptable_nat_do_chain);
63 static unsigned int iptable_nat_ipv4_local_fn(void *priv,
65 const struct nf_hook_state *state)
67 return nf_nat_ipv4_local_fn(priv, skb, state, iptable_nat_do_chain);
70 static struct nf_hook_ops nf_nat_ipv4_ops[] __read_mostly = {
71 /* Before packet filtering, change destination */
73 .hook = iptable_nat_ipv4_in,
75 .hooknum = NF_INET_PRE_ROUTING,
76 .priority = NF_IP_PRI_NAT_DST,
78 /* After packet filtering, change source */
80 .hook = iptable_nat_ipv4_out,
82 .hooknum = NF_INET_POST_ROUTING,
83 .priority = NF_IP_PRI_NAT_SRC,
85 /* Before packet filtering, change destination */
87 .hook = iptable_nat_ipv4_local_fn,
89 .hooknum = NF_INET_LOCAL_OUT,
90 .priority = NF_IP_PRI_NAT_DST,
92 /* After packet filtering, change source */
94 .hook = iptable_nat_ipv4_fn,
96 .hooknum = NF_INET_LOCAL_IN,
97 .priority = NF_IP_PRI_NAT_SRC,
101 static int __net_init iptable_nat_table_init(struct net *net)
103 struct ipt_replace *repl;
106 if (net->ipv4.nat_table)
109 repl = ipt_alloc_initial_table(&nf_nat_ipv4_table);
112 ret = ipt_register_table(net, &nf_nat_ipv4_table, repl,
113 nf_nat_ipv4_ops, &net->ipv4.nat_table);
118 static void __net_exit iptable_nat_net_exit(struct net *net)
120 if (!net->ipv4.nat_table)
122 ipt_unregister_table(net, net->ipv4.nat_table, nf_nat_ipv4_ops);
123 net->ipv4.nat_table = NULL;
126 static struct pernet_operations iptable_nat_net_ops = {
127 .exit = iptable_nat_net_exit,
130 static int __init iptable_nat_init(void)
132 int ret = register_pernet_subsys(&iptable_nat_net_ops);
137 ret = iptable_nat_table_init(&init_net);
139 unregister_pernet_subsys(&iptable_nat_net_ops);
143 static void __exit iptable_nat_exit(void)
145 unregister_pernet_subsys(&iptable_nat_net_ops);
148 module_init(iptable_nat_init);
149 module_exit(iptable_nat_exit);
151 MODULE_LICENSE("GPL");