/*

 * Copyright (c) 2011 Patrick McHardy <kaber@trash.net>

 *

 * Based on Svenning Soerensen's IPv4 NETMAP target. Development of IPv6 NAT

 * funded by Astaro.

 */

#include <stdio.h>

#include <netdb.h>

#include <string.h>

#include <stdlib.h>

#include <getopt.h>

#include <xtables.h>

#include <libiptc/libip6tc.h>

#include <linux/netfilter/nf_nat.h>

#define MODULENAME "NETMAP"

enum {

	O_TO = 0,

};

static const struct xt_option_entry NETMAP_opts[] = {

	{.name = "to", .id = O_TO, .type = XTTYPE_HOSTMASK,

	 .flags = XTOPT_MAND},

	XTOPT_TABLEEND,

};

static void NETMAP_help(void)

{

	printf(MODULENAME" target options:\n"

	       "  --%s address[/mask]\n"

	       "				Network address to map to.\n\n",

	       NETMAP_opts[0].name);

}

static void NETMAP_parse(struct xt_option_call *cb)

{

	struct nf_nat_range *range = cb->data;

	unsigned int i;

	xtables_option_parse(cb);

	range->flags |= NF_NAT_RANGE_MAP_IPS;

	for (i = 0; i < 4; i++) {

		range->min_addr.ip6[i] = cb->val.haddr.ip6[i] &

					 cb->val.hmask.ip6[i];

		range->max_addr.ip6[i] = range->min_addr.ip6[i] |

					 ~cb->val.hmask.ip6[i];

	}

}

static void __NETMAP_print(const void *ip, const struct xt_entry_target *target,

                           int numeric)

{

	const struct nf_nat_range *r = (const void *)target->data;

	struct in6_addr a;

	unsigned int i;

	int bits;

	a = r->min_addr.in6;

	printf("%s", xtables_ip6addr_to_numeric(&a);;

	for (i = 0; i < 4; i++)

		a.s6_addr32[i] = ~(r->min_addr.ip6[i] ^ r->max_addr.ip6[i]);

	bits = xtables_ip6mask_to_cidr(&a);

	if (bits < 0)

		printf("/%s", xtables_ip6addr_to_numeric(&a);;

	else

		printf("/%d", bits);

}

static void NETMAP_print(const void *ip, const struct xt_entry_target *target,

                           int numeric)

{

	printf(" to:");

	__NETMAP_print(ip, target, numeric);

}

static void NETMAP_save(const void *ip, const struct xt_entry_target *target)

{

	printf(" --%s ", NETMAP_opts[0].name);

	__NETMAP_print(ip, target, 0);

}

static struct xtables_target netmap_tg_reg = {

	.name		= MODULENAME,

	.version	= XTABLES_VERSION,

	.family		= NFPROTO_IPV6,

	.size		= XT_ALIGN(sizeof(struct nf_nat_range)),

	.userspacesize	= XT_ALIGN(sizeof(struct nf_nat_range)),

	.help		= NETMAP_help,

	.x6_parse	= NETMAP_parse,

	.print		= NETMAP_print,

	.save		= NETMAP_save,

	.x6_options	= NETMAP_opts,

};

void _init(void)

{

	xtables_register_target(&netmap_tg_reg);

}