1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Copyright (c) 2011 Patrick McHardy <kaber@trash.net> 4 * 5 * Based on Rusty Russell's IPv4 NAT code. Development of IPv6 NAT 6 * funded by Astaro. 7 */ 8 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 18 static int __net_init ip6table_nat_table_init(struct net *net); 19 20 static const struct xt_table nf_nat_ipv6_table = { 21 .name = "nat", 22 .valid_hooks = (1 << NF_INET_PRE_ROUTING) | 23 (1 << NF_INET_POST_ROUTING) | 24 (1 << NF_INET_LOCAL_OUT) | 25 (1 << NF_INET_LOCAL_IN), 26 .me = THIS_MODULE, 27 .af = NFPROTO_IPV6, 28 .table_init = ip6table_nat_table_init, 29 }; 30 31 static unsigned int ip6table_nat_do_chain(void *priv, 32 struct sk_buff *skb, 33 const struct nf_hook_state *state) 34 { 35 return ip6t_do_table(skb, state, state->net->ipv6.ip6table_nat); 36 } 37 38 static const struct nf_hook_ops nf_nat_ipv6_ops[] = { 39 { 40 .hook = ip6table_nat_do_chain, 41 .pf = NFPROTO_IPV6, 42 .hooknum = NF_INET_PRE_ROUTING, 43 .priority = NF_IP6_PRI_NAT_DST, 44 }, 45 { 46 .hook = ip6table_nat_do_chain, 47 .pf = NFPROTO_IPV6, 48 .hooknum = NF_INET_POST_ROUTING, 49 .priority = NF_IP6_PRI_NAT_SRC, 50 }, 51 { 52 .hook = ip6table_nat_do_chain, 53 .pf = NFPROTO_IPV6, 54 .hooknum = NF_INET_LOCAL_OUT, 55 .priority = NF_IP6_PRI_NAT_DST, 56 }, 57 { 58 .hook = ip6table_nat_do_chain, 59 .pf = NFPROTO_IPV6, 60 .hooknum = NF_INET_LOCAL_IN, 61 .priority = NF_IP6_PRI_NAT_SRC, 62 }, 63 }; 64 65 static int ip6t_nat_register_lookups(struct net *net) 66 { 67 int i, ret; 68 69 for (i = 0; i < ARRAY_SIZE(nf_nat_ipv6_ops); i++) { 70 ret = nf_nat_ipv6_register_fn(net, &nf_nat_ipv6_ops[i]); 71 if (ret) { 72 while (i) 73 nf_nat_ipv6_unregister_fn(net, &nf_nat_ipv6_ops[--i]); 74 75 return ret; 76 } 77 } 78 79 return 0; 80 } 81 82 static void ip6t_nat_unregister_lookups(struct net *net) 83 { 84 int i; 85 86 for (i = 0; i < ARRAY_SIZE(nf_nat_ipv6_ops); i++) 87 nf_nat_ipv6_unregister_fn(net, &nf_nat_ipv6_ops[i]); 88 } 89 90 static int __net_init ip6table_nat_table_init(struct net *net) 91 { 92 struct ip6t_replace *repl; 93 int ret; 94 95 if (net->ipv6.ip6table_nat) 96 return 0; 97 98 repl = ip6t_alloc_initial_table(&nf_nat_ipv6_table); 99 if (repl == NULL) 100 return -ENOMEM; 101 ret = ip6t_register_table(net, &nf_nat_ipv6_table, repl, 102 NULL, &net->ipv6.ip6table_nat); 103 if (ret < 0) { 104 kfree(repl); 105 return ret; 106 } 107 108 ret = ip6t_nat_register_lookups(net); 109 if (ret < 0) { 110 ip6t_unregister_table(net, net->ipv6.ip6table_nat, NULL); 111 net->ipv6.ip6table_nat = NULL; 112 } 113 kfree(repl); 114 return ret; 115 } 116 117 static void __net_exit ip6table_nat_net_pre_exit(struct net *net) 118 { 119 if (net->ipv6.ip6table_nat) 120 ip6t_nat_unregister_lookups(net); 121 } 122 123 static void __net_exit ip6table_nat_net_exit(struct net *net) 124 { 125 if (!net->ipv6.ip6table_nat) 126 return; 127 ip6t_unregister_table_exit(net, net->ipv6.ip6table_nat); 128 net->ipv6.ip6table_nat = NULL; 129 } 130 131 static struct pernet_operations ip6table_nat_net_ops = { 132 .pre_exit = ip6table_nat_net_pre_exit, 133 .exit = ip6table_nat_net_exit, 134 }; 135 136 static int __init ip6table_nat_init(void) 137 { 138 int ret = register_pernet_subsys(&ip6table_nat_net_ops); 139 140 if (ret) 141 return ret; 142 143 ret = ip6table_nat_table_init(&init_net); 144 if (ret) 145 unregister_pernet_subsys(&ip6table_nat_net_ops); 146 return ret; 147 } 148 149 static void __exit ip6table_nat_exit(void) 150 { 151 unregister_pernet_subsys(&ip6table_nat_net_ops); 152 } 153 154 module_init(ip6table_nat_init); 155 module_exit(ip6table_nat_exit); 156 157 MODULE_LICENSE("GPL"); 158