libip6t_REJECT.c revision b313d8f3f78c62cce930728bc9163ecf942c22e8 
1/* Shared library add-on to ip6tables to add customized REJECT support.
2 *
3 * (C) 2000 Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
4 *
5 * ported to IPv6 by Harald Welte <laforge@gnumonks.org>
6 *
7 */
8#include <stdio.h>
9#include <string.h>
10#include <xtables.h>
11#include <linux/netfilter_ipv6/ip6t_REJECT.h>
12
13struct reject_names {
14	const char *name;
15	const char *alias;
16	enum ip6t_reject_with with;
17	const char *desc;
18};
19
20enum {
21	O_REJECT_WITH = 0,
22};
23
24static const struct reject_names reject_table[] = {
25	{"icmp6-no-route", "no-route",
26		IP6T_ICMP6_NO_ROUTE, "ICMPv6 no route"},
27	{"icmp6-adm-prohibited", "adm-prohibited",
28		IP6T_ICMP6_ADM_PROHIBITED, "ICMPv6 administratively prohibited"},
29#if 0
30	{"icmp6-not-neighbor", "not-neighbor"},
31		IP6T_ICMP6_NOT_NEIGHBOR, "ICMPv6 not a neighbor"},
32#endif
33	{"icmp6-addr-unreachable", "addr-unreach",
34		IP6T_ICMP6_ADDR_UNREACH, "ICMPv6 address unreachable"},
35	{"icmp6-port-unreachable", "port-unreach",
36		IP6T_ICMP6_PORT_UNREACH, "ICMPv6 port unreachable"},
37	{"tcp-reset", "tcp-reset",
38		IP6T_TCP_RESET, "TCP RST packet"}
39};
40
41static void
42print_reject_types(void)
43{
44	unsigned int i;
45
46	printf("Valid reject types:\n");
47
48	for (i = 0; i < ARRAY_SIZE(reject_table); ++i) {
49		printf("    %-25s\t%s\n", reject_table[i].name, reject_table[i].desc);
50		printf("    %-25s\talias\n", reject_table[i].alias);
51	}
52	printf("\n");
53}
54
55static void REJECT_help(void)
56{
57	printf(
58"REJECT target options:\n"
59"--reject-with type              drop input packet and send back\n"
60"                                a reply packet according to type:\n");
61
62	print_reject_types();
63}
64
65static const struct xt_option_entry REJECT_opts[] = {
66	{.name = "reject-with", .id = O_REJECT_WITH, .type = XTTYPE_STRING},
67	XTOPT_TABLEEND,
68};
69
70static void REJECT_init(struct xt_entry_target *t)
71{
72	struct ip6t_reject_info *reject = (struct ip6t_reject_info *)t->data;
73
74	/* default */
75	reject->with = IP6T_ICMP6_PORT_UNREACH;
76
77}
78
79static void REJECT_parse(struct xt_option_call *cb)
80{
81	struct ip6t_reject_info *reject = cb->data;
82	unsigned int i;
83
84	xtables_option_parse(cb);
85	for (i = 0; i < ARRAY_SIZE(reject_table); ++i)
86		if (strncasecmp(reject_table[i].name,
87		      cb->arg, strlen(cb->arg)) == 0 ||
88		    strncasecmp(reject_table[i].alias,
89		      cb->arg, strlen(cb->arg)) == 0) {
90			reject->with = reject_table[i].with;
91			return;
92		}
93	xtables_error(PARAMETER_PROBLEM,
94		"unknown reject type \"%s\"", cb->arg);
95}
96
97static void REJECT_print(const void *ip, const struct xt_entry_target *target,
98                         int numeric)
99{
100	const struct ip6t_reject_info *reject
101		= (const struct ip6t_reject_info *)target->data;
102	unsigned int i;
103
104	for (i = 0; i < ARRAY_SIZE(reject_table); ++i)
105		if (reject_table[i].with == reject->with)
106			break;
107	printf(" reject-with %s", reject_table[i].name);
108}
109
110static void REJECT_save(const void *ip, const struct xt_entry_target *target)
111{
112	const struct ip6t_reject_info *reject
113		= (const struct ip6t_reject_info *)target->data;
114	unsigned int i;
115
116	for (i = 0; i < ARRAY_SIZE(reject_table); ++i)
117		if (reject_table[i].with == reject->with)
118			break;
119
120	printf(" --reject-with %s", reject_table[i].name);
121}
122
123static struct xtables_target reject_tg6_reg = {
124	.name = "REJECT",
125	.version	= XTABLES_VERSION,
126	.family		= NFPROTO_IPV6,
127	.size 		= XT_ALIGN(sizeof(struct ip6t_reject_info)),
128	.userspacesize 	= XT_ALIGN(sizeof(struct ip6t_reject_info)),
129	.help		= REJECT_help,
130	.init		= REJECT_init,
131	.print		= REJECT_print,
132	.save		= REJECT_save,
133	.x6_parse	= REJECT_parse,
134	.x6_options	= REJECT_opts,
135};
136
137void _init(void)
138{
139	xtables_register_target(&reject_tg6_reg);
140}
141