libip6t_mh.c revision 5d9678ad3eabc34ac40dfe055d7f6a8e44445a5a 
1/* Shared library add-on to ip6tables to add mobility header support. */
2/*
3 * Copyright (C)2006 USAGI/WIDE Project
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License version 2 as
7 * published by the Free Software Foundation.
8 *
9 * Author:
10 *	Masahide NAKAMURA @USAGI <masahide.nakamura.cz@hitachi.com>
11 *
12 * Based on libip6t_{icmpv6,udp}.c
13 */
14#include <stdio.h>
15#include <netdb.h>
16#include <string.h>
17#include <stdlib.h>
18#include <getopt.h>
19#include <xtables.h>
20#include <linux/netfilter_ipv6/ip6_tables.h>
21#include <linux/netfilter_ipv6/ip6t_mh.h>
22
23struct mh_name {
24	const char *name;
25	u_int8_t type;
26};
27
28static const struct mh_name mh_names[] = {
29	{ "binding-refresh-request", 0, },
30	/* Alias */ { "brr", 0, },
31	{ "home-test-init", 1, },
32	/* Alias */ { "hoti", 1, },
33	{ "careof-test-init", 2, },
34	/* Alias */ { "coti", 2, },
35	{ "home-test", 3, },
36	/* Alias */ { "hot", 3, },
37	{ "careof-test", 4, },
38	/* Alias */ { "cot", 4, },
39	{ "binding-update", 5, },
40	/* Alias */ { "bu", 5, },
41	{ "binding-acknowledgement", 6, },
42	/* Alias */ { "ba", 6, },
43	{ "binding-error", 7, },
44	/* Alias */ { "be", 7, },
45};
46
47static void print_types_all(void)
48{
49	unsigned int i;
50	printf("Valid MH types:");
51
52	for (i = 0; i < sizeof(mh_names)/sizeof(struct mh_name); i++) {
53		if (i && mh_names[i].type == mh_names[i-1].type)
54			printf(" (%s)", mh_names[i].name);
55		else
56			printf("\n%s", mh_names[i].name);
57	}
58	printf("\n");
59}
60
61static void mh_help(void)
62{
63	printf(
64"mh match options:\n"
65"[!] --mh-type type[:type]	match mh type\n");
66	print_types_all();
67}
68
69static void mh_init(struct xt_entry_match *m)
70{
71	struct ip6t_mh *mhinfo = (struct ip6t_mh *)m->data;
72
73	mhinfo->types[1] = 0xFF;
74}
75
76static unsigned int name_to_type(const char *name)
77{
78	int namelen = strlen(name);
79	unsigned int limit = sizeof(mh_names)/sizeof(struct mh_name);
80	unsigned int match = limit;
81	unsigned int i;
82
83	for (i = 0; i < limit; i++) {
84		if (strncasecmp(mh_names[i].name, name, namelen) == 0) {
85			int len = strlen(mh_names[i].name);
86			if (match == limit || len == namelen)
87				match = i;
88		}
89	}
90
91	if (match != limit) {
92		return mh_names[match].type;
93	} else {
94		unsigned int number;
95
96		if (string_to_number(name, 0, 255, &number) == -1)
97			exit_error(PARAMETER_PROBLEM,
98				   "Invalid MH type `%s'\n", name);
99		return number;
100	}
101}
102
103static void parse_mh_types(const char *mhtype, u_int8_t *types)
104{
105	char *buffer;
106	char *cp;
107
108	buffer = strdup(mhtype);
109	if ((cp = strchr(buffer, ':')) == NULL)
110		types[0] = types[1] = name_to_type(buffer);
111	else {
112		*cp = '\0';
113		cp++;
114
115		types[0] = buffer[0] ? name_to_type(buffer) : 0;
116		types[1] = cp[0] ? name_to_type(cp) : 0xFF;
117
118		if (types[0] > types[1])
119			exit_error(PARAMETER_PROBLEM,
120				   "Invalid MH type range (min > max)");
121	}
122	free(buffer);
123}
124
125#define MH_TYPES 0x01
126
127static int mh_parse(int c, char **argv, int invert, unsigned int *flags,
128                    const void *entry, struct xt_entry_match **match)
129{
130	struct ip6t_mh *mhinfo = (struct ip6t_mh *)(*match)->data;
131
132	switch (c) {
133	case '1':
134		if (*flags & MH_TYPES)
135			exit_error(PARAMETER_PROBLEM,
136				   "Only one `--mh-type' allowed");
137		check_inverse(optarg, &invert, &optind, 0);
138		parse_mh_types(argv[optind-1], mhinfo->types);
139		if (invert)
140			mhinfo->invflags |= IP6T_MH_INV_TYPE;
141		*flags |= MH_TYPES;
142		break;
143
144	default:
145		return 0;
146	}
147
148	return 1;
149}
150
151static const char *type_to_name(u_int8_t type)
152{
153	unsigned int i;
154
155	for (i = 0; i < sizeof(mh_names)/sizeof(struct mh_name); i++) {
156		if (mh_names[i].type == type)
157			return mh_names[i].name;
158	}
159
160	return NULL;
161}
162
163static void print_type(u_int8_t type, int numeric)
164{
165	const char *name;
166	if (numeric || !(name = type_to_name(type)))
167		printf("%u", type);
168	else
169		printf("%s", name);
170}
171
172static void print_types(u_int8_t min, u_int8_t max, int invert, int numeric)
173{
174	const char *inv = invert ? "!" : "";
175
176	if (min != 0 || max != 0xFF || invert) {
177		if (min == max) {
178			printf("%s", inv);
179			print_type(min, numeric);
180		} else {
181			printf("%s", inv);
182			print_type(min, numeric);
183			printf(":");
184			print_type(max, numeric);
185		}
186		printf(" ");
187	}
188}
189
190static void mh_print(const void *ip, const struct xt_entry_match *match,
191                     int numeric)
192{
193	const struct ip6t_mh *mhinfo = (struct ip6t_mh *)match->data;
194
195	printf("mh ");
196	print_types(mhinfo->types[0], mhinfo->types[1],
197		    mhinfo->invflags & IP6T_MH_INV_TYPE,
198		    numeric);
199	if (mhinfo->invflags & ~IP6T_MH_INV_MASK)
200		printf("Unknown invflags: 0x%X ",
201		       mhinfo->invflags & ~IP6T_MH_INV_MASK);
202}
203
204static void mh_save(const void *ip, const struct xt_entry_match *match)
205{
206	const struct ip6t_mh *mhinfo = (struct ip6t_mh *)match->data;
207
208	if (mhinfo->types[0] == 0 && mhinfo->types[1] == 0xFF)
209		return;
210
211	if (mhinfo->invflags & IP6T_MH_INV_TYPE)
212		printf("! ");
213
214	if (mhinfo->types[0] != mhinfo->types[1])
215		printf("--mh-type %u:%u ", mhinfo->types[0], mhinfo->types[1]);
216	else
217		printf("--mh-type %u ", mhinfo->types[0]);
218}
219
220static const struct option mh_opts[] = {
221	{ "mh-type", 1, NULL, '1' },
222	{ .name = NULL }
223};
224
225static struct xtables_match mh_mt6_reg = {
226	.name		= "mh",
227	.version	= XTABLES_VERSION,
228	.family		= NFPROTO_IPV6,
229	.size		= XT_ALIGN(sizeof(struct ip6t_mh)),
230	.userspacesize	= XT_ALIGN(sizeof(struct ip6t_mh)),
231	.help		= mh_help,
232	.init		= mh_init,
233	.parse		= mh_parse,
234	.print		= mh_print,
235	.save		= mh_save,
236	.extra_opts	= mh_opts,
237};
238
239void _init(void)
240{
241	xtables_register_match(&mh_mt6_reg);
242}
243