// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (c) 2011 Patrick McHardy <[email protected]>
*
* Based on Rusty Russell's IPv4 NAT code. Development of IPv6 NAT
* funded by Astaro.
*/
#include <linux/module.h>
#include <linux/netfilter.h>
#include <linux/netfilter_ipv6.h>
#include <linux/netfilter_ipv6/ip6_tables.h>
#include <linux/ipv6.h>
#include <net/ipv6.h>
#include <net/netfilter/nf_nat.h>
struct ip6table_nat_pernet {
struct nf_hook_ops *nf_nat_ops;
};
static unsigned int ip6table_nat_net_id __read_mostly;
static const struct xt_table nf_nat_ipv6_table = {
.name = "nat",
.valid_hooks = (1 << NF_INET_PRE_ROUTING) |
(1 << NF_INET_POST_ROUTING) |
(1 << NF_INET_LOCAL_OUT) |
(1 << NF_INET_LOCAL_IN),
.me = THIS_MODULE,
.af = NFPROTO_IPV6,
};
static const struct nf_hook_ops nf_nat_ipv6_ops[] = {
{
.hook = ip6t_do_table,
.pf = NFPROTO_IPV6,
.hooknum = NF_INET_PRE_ROUTING,
.priority = NF_IP6_PRI_NAT_DST,
},
{
.hook = ip6t_do_table,
.pf = NFPROTO_IPV6,
.hooknum = NF_INET_POST_ROUTING,
.priority = NF_IP6_PRI_NAT_SRC,
},
{
.hook = ip6t_do_table,
.pf = NFPROTO_IPV6,
.hooknum = NF_INET_LOCAL_OUT,
.priority = NF_IP6_PRI_NAT_DST,
},
{
.hook = ip6t_do_table,
.pf = NFPROTO_IPV6,
.hooknum = NF_INET_LOCAL_IN,
.priority = NF_IP6_PRI_NAT_SRC,
},
};
static int ip6t_nat_register_lookups(struct net *net)
{
struct ip6table_nat_pernet *xt_nat_net;
struct nf_hook_ops *ops;
struct xt_table *table;
int i, ret;
table = xt_find_table(net, NFPROTO_IPV6, "nat");
if (WARN_ON_ONCE(!table))
return -ENOENT;
xt_nat_net = net_generic(net, ip6table_nat_net_id);
ops = kmemdup(nf_nat_ipv6_ops, sizeof(nf_nat_ipv6_ops), GFP_KERNEL);
if (!ops)
return -ENOMEM;
for (i = 0; i < ARRAY_SIZE(nf_nat_ipv6_ops); i++) {
ops[i].priv = table;
ret = nf_nat_ipv6_register_fn(net, &ops[i]);
if (ret) {
while (i)
nf_nat_ipv6_unregister_fn(net, &ops[--i]);
kfree(ops);
return ret;
}
}
xt_nat_net->nf_nat_ops = ops;
return 0;
}
static void ip6t_nat_unregister_lookups(struct net *net)
{
struct ip6table_nat_pernet *xt_nat_net = net_generic(net, ip6table_nat_net_id);
struct nf_hook_ops *ops = xt_nat_net->nf_nat_ops;
int i;
if (!ops)
return;
for (i = 0; i < ARRAY_SIZE(nf_nat_ipv6_ops); i++)
nf_nat_ipv6_unregister_fn(net, &ops[i]);
kfree(ops);
}
static int ip6table_nat_table_init(struct net *net)
{
struct ip6t_replace *repl;
int ret;
repl = ip6t_alloc_initial_table(&nf_nat_ipv6_table);
if (repl == NULL)
return -ENOMEM;
ret = ip6t_register_table(net, &nf_nat_ipv6_table, repl,
NULL);
if (ret < 0) {
kfree(repl);
return ret;
}
ret = ip6t_nat_register_lookups(net);
if (ret < 0)
ip6t_unregister_table_exit(net, "nat");
kfree(repl);
return ret;
}
static void __net_exit ip6table_nat_net_pre_exit(struct net *net)
{
ip6t_nat_unregister_lookups(net);
}
static void __net_exit ip6table_nat_net_exit(struct net *net)
{
ip6t_unregister_table_exit(net, "nat");
}
static struct pernet_operations ip6table_nat_net_ops = {
.pre_exit = ip6table_nat_net_pre_exit,
.exit = ip6table_nat_net_exit,
.id = &ip6table_nat_net_id,
.size = sizeof(struct ip6table_nat_pernet),
};
static int __init ip6table_nat_init(void)
{
int ret;
/* net->gen->ptr[ip6table_nat_net_id] must be allocated
* before calling ip6t_nat_register_lookups().
*/
ret = register_pernet_subsys(&ip6table_nat_net_ops);
if (ret < 0)
return ret;
ret = xt_register_template(&nf_nat_ipv6_table,
ip6table_nat_table_init);
if (ret)
unregister_pernet_subsys(&ip6table_nat_net_ops);
return ret;
}
static void __exit ip6table_nat_exit(void)
{
xt_unregister_template(&nf_nat_ipv6_table);
unregister_pernet_subsys(&ip6table_nat_net_ops);
}
module_init(ip6table_nat_init);
module_exit(ip6table_nat_exit);
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Ip6tables legacy nat table");