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9#include <linux/module.h>
10#include <linux/netfilter.h>
11#include <linux/netfilter_ipv6.h>
12#include <linux/netfilter_ipv6/ip6_tables.h>
13#include <linux/ipv6.h>
14#include <net/ipv6.h>
15
16#include <net/netfilter/nf_nat.h>
17
18struct ip6table_nat_pernet {
19 struct nf_hook_ops *nf_nat_ops;
20};
21
22static unsigned int ip6table_nat_net_id __read_mostly;
23
24static const struct xt_table nf_nat_ipv6_table = {
25 .name = "nat",
26 .valid_hooks = (1 << NF_INET_PRE_ROUTING) |
27 (1 << NF_INET_POST_ROUTING) |
28 (1 << NF_INET_LOCAL_OUT) |
29 (1 << NF_INET_LOCAL_IN),
30 .me = THIS_MODULE,
31 .af = NFPROTO_IPV6,
32};
33
34static unsigned int ip6table_nat_do_chain(void *priv,
35 struct sk_buff *skb,
36 const struct nf_hook_state *state)
37{
38 return ip6t_do_table(skb, state, priv);
39}
40
41static const struct nf_hook_ops nf_nat_ipv6_ops[] = {
42 {
43 .hook = ip6table_nat_do_chain,
44 .pf = NFPROTO_IPV6,
45 .hooknum = NF_INET_PRE_ROUTING,
46 .priority = NF_IP6_PRI_NAT_DST,
47 },
48 {
49 .hook = ip6table_nat_do_chain,
50 .pf = NFPROTO_IPV6,
51 .hooknum = NF_INET_POST_ROUTING,
52 .priority = NF_IP6_PRI_NAT_SRC,
53 },
54 {
55 .hook = ip6table_nat_do_chain,
56 .pf = NFPROTO_IPV6,
57 .hooknum = NF_INET_LOCAL_OUT,
58 .priority = NF_IP6_PRI_NAT_DST,
59 },
60 {
61 .hook = ip6table_nat_do_chain,
62 .pf = NFPROTO_IPV6,
63 .hooknum = NF_INET_LOCAL_IN,
64 .priority = NF_IP6_PRI_NAT_SRC,
65 },
66};
67
68static int ip6t_nat_register_lookups(struct net *net)
69{
70 struct ip6table_nat_pernet *xt_nat_net;
71 struct nf_hook_ops *ops;
72 struct xt_table *table;
73 int i, ret;
74
75 table = xt_find_table(net, NFPROTO_IPV6, "nat");
76 if (WARN_ON_ONCE(!table))
77 return -ENOENT;
78
79 xt_nat_net = net_generic(net, ip6table_nat_net_id);
80 ops = kmemdup(nf_nat_ipv6_ops, sizeof(nf_nat_ipv6_ops), GFP_KERNEL);
81 if (!ops)
82 return -ENOMEM;
83
84 for (i = 0; i < ARRAY_SIZE(nf_nat_ipv6_ops); i++) {
85 ops[i].priv = table;
86 ret = nf_nat_ipv6_register_fn(net, &ops[i]);
87 if (ret) {
88 while (i)
89 nf_nat_ipv6_unregister_fn(net, &ops[--i]);
90
91 kfree(ops);
92 return ret;
93 }
94 }
95
96 xt_nat_net->nf_nat_ops = ops;
97 return 0;
98}
99
100static void ip6t_nat_unregister_lookups(struct net *net)
101{
102 struct ip6table_nat_pernet *xt_nat_net = net_generic(net, ip6table_nat_net_id);
103 struct nf_hook_ops *ops = xt_nat_net->nf_nat_ops;
104 int i;
105
106 if (!ops)
107 return;
108
109 for (i = 0; i < ARRAY_SIZE(nf_nat_ipv6_ops); i++)
110 nf_nat_ipv6_unregister_fn(net, &ops[i]);
111
112 kfree(ops);
113}
114
115static int ip6table_nat_table_init(struct net *net)
116{
117 struct ip6t_replace *repl;
118 int ret;
119
120 repl = ip6t_alloc_initial_table(&nf_nat_ipv6_table);
121 if (repl == NULL)
122 return -ENOMEM;
123 ret = ip6t_register_table(net, &nf_nat_ipv6_table, repl,
124 NULL);
125 if (ret < 0) {
126 kfree(repl);
127 return ret;
128 }
129
130 ret = ip6t_nat_register_lookups(net);
131 if (ret < 0)
132 ip6t_unregister_table_exit(net, "nat");
133
134 kfree(repl);
135 return ret;
136}
137
138static void __net_exit ip6table_nat_net_pre_exit(struct net *net)
139{
140 ip6t_nat_unregister_lookups(net);
141}
142
143static void __net_exit ip6table_nat_net_exit(struct net *net)
144{
145 ip6t_unregister_table_exit(net, "nat");
146}
147
148static struct pernet_operations ip6table_nat_net_ops = {
149 .pre_exit = ip6table_nat_net_pre_exit,
150 .exit = ip6table_nat_net_exit,
151 .id = &ip6table_nat_net_id,
152 .size = sizeof(struct ip6table_nat_pernet),
153};
154
155static int __init ip6table_nat_init(void)
156{
157 int ret = xt_register_template(&nf_nat_ipv6_table,
158 ip6table_nat_table_init);
159
160 if (ret < 0)
161 return ret;
162
163 ret = register_pernet_subsys(&ip6table_nat_net_ops);
164 if (ret)
165 xt_unregister_template(&nf_nat_ipv6_table);
166
167 return ret;
168}
169
170static void __exit ip6table_nat_exit(void)
171{
172 unregister_pernet_subsys(&ip6table_nat_net_ops);
173 xt_unregister_template(&nf_nat_ipv6_table);
174}
175
176module_init(ip6table_nat_init);
177module_exit(ip6table_nat_exit);
178
179MODULE_LICENSE("GPL");
180
