1 /*
2 * Copyright (c) 2011 Patrick McHardy <kaber@trash.net>
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License version 2 as
6 * published by the Free Software Foundation.
7 *
8 * Based on Rusty Russell's IPv4 NAT code. Development of IPv6 NAT
9 * funded by Astaro.
10 */
11
12 #include <linux/module.h>
13 #include <linux/netfilter.h>
14 #include <linux/netfilter_ipv6.h>
15 #include <linux/netfilter_ipv6/ip6_tables.h>
16 #include <linux/ipv6.h>
17 #include <net/ipv6.h>
18
19 #include <net/netfilter/nf_nat.h>
20 #include <net/netfilter/nf_nat_core.h>
21 #include <net/netfilter/nf_nat_l3proto.h>
22
23 static int __net_init ip6table_nat_table_init(struct net *net);
24
25 static const struct xt_table nf_nat_ipv6_table = {
26 .name = "nat",
27 .valid_hooks = (1 << NF_INET_PRE_ROUTING) |
28 (1 << NF_INET_POST_ROUTING) |
29 (1 << NF_INET_LOCAL_OUT) |
30 (1 << NF_INET_LOCAL_IN),
31 .me = THIS_MODULE,
32 .af = NFPROTO_IPV6,
33 .table_init = ip6table_nat_table_init,
34 };
35
ip6table_nat_do_chain(void * priv,struct sk_buff * skb,const struct nf_hook_state * state)36 static unsigned int ip6table_nat_do_chain(void *priv,
37 struct sk_buff *skb,
38 const struct nf_hook_state *state)
39 {
40 return ip6t_do_table(skb, state, state->net->ipv6.ip6table_nat);
41 }
42
43 static const struct nf_hook_ops nf_nat_ipv6_ops[] = {
44 {
45 .hook = ip6table_nat_do_chain,
46 .pf = NFPROTO_IPV6,
47 .hooknum = NF_INET_PRE_ROUTING,
48 .priority = NF_IP6_PRI_NAT_DST,
49 },
50 {
51 .hook = ip6table_nat_do_chain,
52 .pf = NFPROTO_IPV6,
53 .hooknum = NF_INET_POST_ROUTING,
54 .priority = NF_IP6_PRI_NAT_SRC,
55 },
56 {
57 .hook = ip6table_nat_do_chain,
58 .pf = NFPROTO_IPV6,
59 .hooknum = NF_INET_LOCAL_OUT,
60 .priority = NF_IP6_PRI_NAT_DST,
61 },
62 {
63 .hook = ip6table_nat_do_chain,
64 .pf = NFPROTO_IPV6,
65 .hooknum = NF_INET_LOCAL_IN,
66 .priority = NF_IP6_PRI_NAT_SRC,
67 },
68 };
69
ip6t_nat_register_lookups(struct net * net)70 static int ip6t_nat_register_lookups(struct net *net)
71 {
72 int i, ret;
73
74 for (i = 0; i < ARRAY_SIZE(nf_nat_ipv6_ops); i++) {
75 ret = nf_nat_l3proto_ipv6_register_fn(net, &nf_nat_ipv6_ops[i]);
76 if (ret) {
77 while (i)
78 nf_nat_l3proto_ipv6_unregister_fn(net, &nf_nat_ipv6_ops[--i]);
79
80 return ret;
81 }
82 }
83
84 return 0;
85 }
86
ip6t_nat_unregister_lookups(struct net * net)87 static void ip6t_nat_unregister_lookups(struct net *net)
88 {
89 int i;
90
91 for (i = 0; i < ARRAY_SIZE(nf_nat_ipv6_ops); i++)
92 nf_nat_l3proto_ipv6_unregister_fn(net, &nf_nat_ipv6_ops[i]);
93 }
94
ip6table_nat_table_init(struct net * net)95 static int __net_init ip6table_nat_table_init(struct net *net)
96 {
97 struct ip6t_replace *repl;
98 int ret;
99
100 if (net->ipv6.ip6table_nat)
101 return 0;
102
103 repl = ip6t_alloc_initial_table(&nf_nat_ipv6_table);
104 if (repl == NULL)
105 return -ENOMEM;
106 ret = ip6t_register_table(net, &nf_nat_ipv6_table, repl,
107 NULL, &net->ipv6.ip6table_nat);
108 if (ret < 0) {
109 kfree(repl);
110 return ret;
111 }
112
113 ret = ip6t_nat_register_lookups(net);
114 if (ret < 0) {
115 ip6t_unregister_table(net, net->ipv6.ip6table_nat, NULL);
116 net->ipv6.ip6table_nat = NULL;
117 }
118 kfree(repl);
119 return ret;
120 }
121
ip6table_nat_net_exit(struct net * net)122 static void __net_exit ip6table_nat_net_exit(struct net *net)
123 {
124 if (!net->ipv6.ip6table_nat)
125 return;
126 ip6t_nat_unregister_lookups(net);
127 ip6t_unregister_table(net, net->ipv6.ip6table_nat, NULL);
128 net->ipv6.ip6table_nat = NULL;
129 }
130
131 static struct pernet_operations ip6table_nat_net_ops = {
132 .exit = ip6table_nat_net_exit,
133 };
134
ip6table_nat_init(void)135 static int __init ip6table_nat_init(void)
136 {
137 int ret = register_pernet_subsys(&ip6table_nat_net_ops);
138
139 if (ret)
140 return ret;
141
142 ret = ip6table_nat_table_init(&init_net);
143 if (ret)
144 unregister_pernet_subsys(&ip6table_nat_net_ops);
145 return ret;
146 }
147
ip6table_nat_exit(void)148 static void __exit ip6table_nat_exit(void)
149 {
150 unregister_pernet_subsys(&ip6table_nat_net_ops);
151 }
152
153 module_init(ip6table_nat_init);
154 module_exit(ip6table_nat_exit);
155
156 MODULE_LICENSE("GPL");
157
