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/*
* Copyright (c) 2011 Patrick McHardy <kaber@trash.net>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* Based on Svenning Soerensen's IPv4 NETMAP target. Development of IPv6
* NAT funded by Astaro.
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/ipv6.h>
#include <linux/netfilter.h>
#include <linux/netfilter_ipv6.h>
#include <linux/netfilter/x_tables.h>
#include <net/netfilter/nf_nat.h>
static unsigned int
netmap_tg6(struct sk_buff *skb, const struct xt_action_param *par)
{
const struct nf_nat_range *range = par->targinfo;
struct nf_nat_range newrange;
struct nf_conn *ct;
enum ip_conntrack_info ctinfo;
union nf_inet_addr new_addr, netmask;
unsigned int i;
ct = nf_ct_get(skb, &ctinfo);
for (i = 0; i < ARRAY_SIZE(range->min_addr.ip6); i++)
netmask.ip6[i] = ~(range->min_addr.ip6[i] ^
range->max_addr.ip6[i]);
if (par->hooknum == NF_INET_PRE_ROUTING ||
par->hooknum == NF_INET_LOCAL_OUT)
new_addr.in6 = ipv6_hdr(skb)->daddr;
else
new_addr.in6 = ipv6_hdr(skb)->saddr;
for (i = 0; i < ARRAY_SIZE(new_addr.ip6); i++) {
new_addr.ip6[i] &= ~netmask.ip6[i];
new_addr.ip6[i] |= range->min_addr.ip6[i] &
netmask.ip6[i];
}
newrange.flags = range->flags | NF_NAT_RANGE_MAP_IPS;
newrange.min_addr = new_addr;
newrange.max_addr = new_addr;
newrange.min_proto = range->min_proto;
newrange.max_proto = range->max_proto;
return nf_nat_setup_info(ct, &newrange, HOOK2MANIP(par->hooknum));
}
static int netmap_tg6_checkentry(const struct xt_tgchk_param *par)
{
const struct nf_nat_range *range = par->targinfo;
if (!(range->flags & NF_NAT_RANGE_MAP_IPS))
return -EINVAL;
return 0;
}
static struct xt_target netmap_tg6_reg __read_mostly = {
.name = "NETMAP",
.family = NFPROTO_IPV6,
.target = netmap_tg6,
.targetsize = sizeof(struct nf_nat_range),
.table = "nat",
.hooks = (1 << NF_INET_PRE_ROUTING) |
(1 << NF_INET_POST_ROUTING) |
(1 << NF_INET_LOCAL_OUT) |
(1 << NF_INET_LOCAL_IN),
.checkentry = netmap_tg6_checkentry,
.me = THIS_MODULE,
};
static int __init netmap_tg6_init(void)
{
return xt_register_target(&netmap_tg6_reg);
}
static void netmap_tg6_exit(void)
{
xt_unregister_target(&netmap_tg6_reg);
}
module_init(netmap_tg6_init);
module_exit(netmap_tg6_exit);
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Xtables: 1:1 NAT mapping of IPv6 subnets");
MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
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