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