LXR linux/net/ipv6/netfilter/ip6table

   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
  23static const struct xt_table nf_nat_ipv6_table = {
  24        .name           = "nat",
  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),
  29        .me             = THIS_MODULE,
  30        .af             = NFPROTO_IPV6,
  31};
  32
  33static unsigned int ip6table_nat_do_chain(const struct nf_hook_ops *ops,
  34                                          struct sk_buff *skb,
  35                                          const struct nf_hook_state *state,
  36                                          struct nf_conn *ct)
  37{
  38        struct net *net = nf_ct_net(ct);
  39
  40        return ip6t_do_table(skb, ops->hooknum, state, net->ipv6.ip6table_nat);
  41}
  42
  43static unsigned int ip6table_nat_fn(const struct nf_hook_ops *ops,
  44                                    struct sk_buff *skb,
  45                                    const struct nf_hook_state *state)
  46{
  47        return nf_nat_ipv6_fn(ops, skb, state, ip6table_nat_do_chain);
  48}
  49
  50static unsigned int ip6table_nat_in(const struct nf_hook_ops *ops,
  51                                    struct sk_buff *skb,
  52                                    const struct nf_hook_state *state)
  53{
  54        return nf_nat_ipv6_in(ops, skb, state, ip6table_nat_do_chain);
  55}
  56
  57static unsigned int ip6table_nat_out(const struct nf_hook_ops *ops,
  58                                     struct sk_buff *skb,
  59                                     const struct nf_hook_state *state)
  60{
  61        return nf_nat_ipv6_out(ops, skb, state, ip6table_nat_do_chain);
  62}
  63
  64static unsigned int ip6table_nat_local_fn(const struct nf_hook_ops *ops,
  65                                          struct sk_buff *skb,
  66                                          const struct nf_hook_state *state)
  67{
  68        return nf_nat_ipv6_local_fn(ops, skb, state, ip6table_nat_do_chain);
  69}
  70
  71static struct nf_hook_ops nf_nat_ipv6_ops[] __read_mostly = {
  72        /* Before packet filtering, change destination */
  73        {
  74                .hook           = ip6table_nat_in,
  75                .owner          = THIS_MODULE,
  76                .pf             = NFPROTO_IPV6,
  77                .hooknum        = NF_INET_PRE_ROUTING,
  78                .priority       = NF_IP6_PRI_NAT_DST,
  79        },
  80        /* After packet filtering, change source */
  81        {
  82                .hook           = ip6table_nat_out,
  83                .owner          = THIS_MODULE,
  84                .pf             = NFPROTO_IPV6,
  85                .hooknum        = NF_INET_POST_ROUTING,
  86                .priority       = NF_IP6_PRI_NAT_SRC,
  87        },
  88        /* Before packet filtering, change destination */
  89        {
  90                .hook           = ip6table_nat_local_fn,
  91                .owner          = THIS_MODULE,
  92                .pf             = NFPROTO_IPV6,
  93                .hooknum        = NF_INET_LOCAL_OUT,
  94                .priority       = NF_IP6_PRI_NAT_DST,
  95        },
  96        /* After packet filtering, change source */
  97        {
  98                .hook           = ip6table_nat_fn,
  99                .owner          = THIS_MODULE,
 100                .pf             = NFPROTO_IPV6,
 101                .hooknum        = NF_INET_LOCAL_IN,
 102                .priority       = NF_IP6_PRI_NAT_SRC,
 103        },
 104};
 105
 106static int __net_init ip6table_nat_net_init(struct net *net)
 107{
 108        struct ip6t_replace *repl;
 109
 110        repl = ip6t_alloc_initial_table(&nf_nat_ipv6_table);
 111        if (repl == NULL)
 112                return -ENOMEM;
 113        net->ipv6.ip6table_nat = ip6t_register_table(net, &nf_nat_ipv6_table, repl);
 114        kfree(repl);
 115        return PTR_ERR_OR_ZERO(net->ipv6.ip6table_nat);
 116}
 117
 118static void __net_exit ip6table_nat_net_exit(struct net *net)
 119{
 120        ip6t_unregister_table(net, net->ipv6.ip6table_nat);
 121}
 122
 123static struct pernet_operations ip6table_nat_net_ops = {
 124        .init   = ip6table_nat_net_init,
 125        .exit   = ip6table_nat_net_exit,
 126};
 127
 128static int __init ip6table_nat_init(void)
 129{
 130        int err;
 131
 132        err = register_pernet_subsys(&ip6table_nat_net_ops);
 133        if (err < 0)
 134                goto err1;
 135
 136        err = nf_register_hooks(nf_nat_ipv6_ops, ARRAY_SIZE(nf_nat_ipv6_ops));
 137        if (err < 0)
 138                goto err2;
 139        return 0;
 140
 141err2:
 142        unregister_pernet_subsys(&ip6table_nat_net_ops);
 143err1:
 144        return err;
 145}
 146
 147static void __exit ip6table_nat_exit(void)
 148{
 149        nf_unregister_hooks(nf_nat_ipv6_ops, ARRAY_SIZE(nf_nat_ipv6_ops));
 150        unregister_pernet_subsys(&ip6table_nat_net_ops);
 151}
 152
 153module_init(ip6table_nat_init);
 154module_exit(ip6table_nat_exit);
 155
 156MODULE_LICENSE("GPL");
 157