libip6t_NETMAP.c revision cccfff9309743f173c504dd265fae173caa5b47f 
1/*
2 * Copyright (c) 2011 Patrick McHardy <kaber@trash.net>
3 *
4 * Based on Svenning Soerensen's IPv4 NETMAP target. Development of IPv6 NAT
5 * funded by Astaro.
6 */
7
8#include <stdio.h>
9#include <netdb.h>
10#include <string.h>
11#include <stdlib.h>
12#include <getopt.h>
13#include <xtables.h>
14#include <libiptc/libip6tc.h>
15#include <linux/netfilter/nf_nat.h>
16
17#define MODULENAME "NETMAP"
18
19enum {
20	O_TO = 0,
21};
22
23static const struct xt_option_entry NETMAP_opts[] = {
24	{.name = "to", .id = O_TO, .type = XTTYPE_HOSTMASK,
25	 .flags = XTOPT_MAND},
26	XTOPT_TABLEEND,
27};
28
29static void NETMAP_help(void)
30{
31	printf(MODULENAME" target options:\n"
32	       "  --%s address[/mask]\n"
33	       "				Network address to map to.\n\n",
34	       NETMAP_opts[0].name);
35}
36
37static void NETMAP_parse(struct xt_option_call *cb)
38{
39	struct nf_nat_range *range = cb->data;
40	unsigned int i;
41
42	xtables_option_parse(cb);
43	range->flags |= NF_NAT_RANGE_MAP_IPS;
44	for (i = 0; i < 4; i++) {
45		range->min_addr.ip6[i] = cb->val.haddr.ip6[i] &
46					 cb->val.hmask.ip6[i];
47		range->max_addr.ip6[i] = range->min_addr.ip6[i] |
48					 ~cb->val.hmask.ip6[i];
49	}
50}
51
52static void NETMAP_print(const void *ip, const struct xt_entry_target *target,
53                         int numeric)
54{
55	const struct nf_nat_range *r = (const void *)target->data;
56	struct in6_addr a;
57	unsigned int i;
58	int bits;
59
60	a = r->min_addr.in6;
61	printf("%s", xtables_ip6addr_to_numeric(&a));
62	for (i = 0; i < 4; i++)
63		a.s6_addr32[i] = ~(r->min_addr.ip6[i] ^ r->max_addr.ip6[i]);
64	bits = xtables_ip6mask_to_cidr(&a);
65	if (bits < 0)
66		printf("/%s", xtables_ip6addr_to_numeric(&a));
67	else
68		printf("/%d", bits);
69}
70
71static void NETMAP_save(const void *ip, const struct xt_entry_target *target)
72{
73	printf(" --%s ", NETMAP_opts[0].name);
74	NETMAP_print(ip, target, 0);
75}
76
77static struct xtables_target netmap_tg_reg = {
78	.name		= MODULENAME,
79	.version	= XTABLES_VERSION,
80	.family		= NFPROTO_IPV6,
81	.size		= XT_ALIGN(sizeof(struct nf_nat_range)),
82	.userspacesize	= XT_ALIGN(sizeof(struct nf_nat_range)),
83	.help		= NETMAP_help,
84	.x6_parse	= NETMAP_parse,
85	.print		= NETMAP_print,
86	.save		= NETMAP_save,
87	.x6_options	= NETMAP_opts,
88};
89
90void _init(void)
91{
92	xtables_register_target(&netmap_tg_reg);
93}
94