libip6t_icmp6.c revision e37d45ce390c2f5a7f1e64742b9100ecef0def54 
1#include <stdint.h>
2#include <stdio.h>
3#include <string.h>
4#include <xtables.h>
5#include <limits.h> /* INT_MAX in ip6_tables.h */
6#include <linux/netfilter_ipv6/ip6_tables.h>
7
8enum {
9	O_ICMPV6_TYPE = 0,
10};
11
12struct icmpv6_names {
13	const char *name;
14	uint8_t type;
15	uint8_t code_min, code_max;
16};
17
18static const struct icmpv6_names icmpv6_codes[] = {
19	{ "destination-unreachable", 1, 0, 0xFF },
20	{   "no-route", 1, 0, 0 },
21	{   "communication-prohibited", 1, 1, 1 },
22	{   "address-unreachable", 1, 3, 3 },
23	{   "port-unreachable", 1, 4, 4 },
24
25	{ "packet-too-big", 2, 0, 0xFF },
26
27	{ "time-exceeded", 3, 0, 0xFF },
28	/* Alias */ { "ttl-exceeded", 3, 0, 0xFF },
29	{   "ttl-zero-during-transit", 3, 0, 0 },
30	{   "ttl-zero-during-reassembly", 3, 1, 1 },
31
32	{ "parameter-problem", 4, 0, 0xFF },
33	{   "bad-header", 4, 0, 0 },
34	{   "unknown-header-type", 4, 1, 1 },
35	{   "unknown-option", 4, 2, 2 },
36
37	{ "echo-request", 128, 0, 0xFF },
38	/* Alias */ { "ping", 128, 0, 0xFF },
39
40	{ "echo-reply", 129, 0, 0xFF },
41	/* Alias */ { "pong", 129, 0, 0xFF },
42
43	{ "router-solicitation", 133, 0, 0xFF },
44
45	{ "router-advertisement", 134, 0, 0xFF },
46
47	{ "neighbour-solicitation", 135, 0, 0xFF },
48	/* Alias */ { "neighbor-solicitation", 135, 0, 0xFF },
49
50	{ "neighbour-advertisement", 136, 0, 0xFF },
51	/* Alias */ { "neighbor-advertisement", 136, 0, 0xFF },
52
53	{ "redirect", 137, 0, 0xFF },
54
55};
56
57static void
58print_icmpv6types(void)
59{
60	unsigned int i;
61	printf("Valid ICMPv6 Types:");
62
63	for (i = 0; i < ARRAY_SIZE(icmpv6_codes); ++i) {
64		if (i && icmpv6_codes[i].type == icmpv6_codes[i-1].type) {
65			if (icmpv6_codes[i].code_min == icmpv6_codes[i-1].code_min
66			    && (icmpv6_codes[i].code_max
67				== icmpv6_codes[i-1].code_max))
68				printf(" (%s)", icmpv6_codes[i].name);
69			else
70				printf("\n   %s", icmpv6_codes[i].name);
71		}
72		else
73			printf("\n%s", icmpv6_codes[i].name);
74	}
75	printf("\n");
76}
77
78static void icmp6_help(void)
79{
80	printf(
81"icmpv6 match options:\n"
82"[!] --icmpv6-type typename	match icmpv6 type\n"
83"				(or numeric type or type/code)\n");
84	print_icmpv6types();
85}
86
87static const struct xt_option_entry icmp6_opts[] = {
88	{.name = "icmpv6-type", .id = O_ICMPV6_TYPE, .type = XTTYPE_STRING,
89	 .flags = XTOPT_MAND | XTOPT_INVERT},
90	XTOPT_TABLEEND,
91};
92
93static void
94parse_icmpv6(const char *icmpv6type, uint8_t *type, uint8_t code[])
95{
96	static const unsigned int limit = ARRAY_SIZE(icmpv6_codes);
97	unsigned int match = limit;
98	unsigned int i;
99
100	for (i = 0; i < limit; i++) {
101		if (strncasecmp(icmpv6_codes[i].name, icmpv6type, strlen(icmpv6type))
102		    == 0) {
103			if (match != limit)
104				xtables_error(PARAMETER_PROBLEM,
105					   "Ambiguous ICMPv6 type `%s':"
106					   " `%s' or `%s'?",
107					   icmpv6type,
108					   icmpv6_codes[match].name,
109					   icmpv6_codes[i].name);
110			match = i;
111		}
112	}
113
114	if (match != limit) {
115		*type = icmpv6_codes[match].type;
116		code[0] = icmpv6_codes[match].code_min;
117		code[1] = icmpv6_codes[match].code_max;
118	} else {
119		char *slash;
120		char buffer[strlen(icmpv6type) + 1];
121		unsigned int number;
122
123		strcpy(buffer, icmpv6type);
124		slash = strchr(buffer, '/');
125
126		if (slash)
127			*slash = '\0';
128
129		if (!xtables_strtoui(buffer, NULL, &number, 0, UINT8_MAX))
130			xtables_error(PARAMETER_PROBLEM,
131				   "Invalid ICMPv6 type `%s'\n", buffer);
132		*type = number;
133		if (slash) {
134			if (!xtables_strtoui(slash+1, NULL, &number, 0, UINT8_MAX))
135				xtables_error(PARAMETER_PROBLEM,
136					   "Invalid ICMPv6 code `%s'\n",
137					   slash+1);
138			code[0] = code[1] = number;
139		} else {
140			code[0] = 0;
141			code[1] = 0xFF;
142		}
143	}
144}
145
146static void icmp6_init(struct xt_entry_match *m)
147{
148	struct ip6t_icmp *icmpv6info = (struct ip6t_icmp *)m->data;
149
150	icmpv6info->code[1] = 0xFF;
151}
152
153static void icmp6_parse(struct xt_option_call *cb)
154{
155	struct ip6t_icmp *icmpv6info = cb->data;
156
157	xtables_option_parse(cb);
158	parse_icmpv6(cb->arg, &icmpv6info->type, icmpv6info->code);
159	if (cb->invert)
160		icmpv6info->invflags |= IP6T_ICMP_INV;
161}
162
163static void print_icmpv6type(uint8_t type,
164			   uint8_t code_min, uint8_t code_max,
165			   int invert,
166			   int numeric)
167{
168	if (!numeric) {
169		unsigned int i;
170
171		for (i = 0; i < ARRAY_SIZE(icmpv6_codes); ++i)
172			if (icmpv6_codes[i].type == type
173			    && icmpv6_codes[i].code_min == code_min
174			    && icmpv6_codes[i].code_max == code_max)
175				break;
176
177		if (i != ARRAY_SIZE(icmpv6_codes)) {
178			printf(" %s%s",
179			       invert ? "!" : "",
180			       icmpv6_codes[i].name);
181			return;
182		}
183	}
184
185	if (invert)
186		printf(" !");
187
188	printf("type %u", type);
189	if (code_min == code_max)
190		printf(" code %u", code_min);
191	else if (code_min != 0 || code_max != 0xFF)
192		printf(" codes %u-%u", code_min, code_max);
193}
194
195static void icmp6_print(const void *ip, const struct xt_entry_match *match,
196                        int numeric)
197{
198	const struct ip6t_icmp *icmpv6 = (struct ip6t_icmp *)match->data;
199
200	printf(" ipv6-icmp");
201	print_icmpv6type(icmpv6->type, icmpv6->code[0], icmpv6->code[1],
202		       icmpv6->invflags & IP6T_ICMP_INV,
203		       numeric);
204
205	if (icmpv6->invflags & ~IP6T_ICMP_INV)
206		printf(" Unknown invflags: 0x%X",
207		       icmpv6->invflags & ~IP6T_ICMP_INV);
208}
209
210static void icmp6_save(const void *ip, const struct xt_entry_match *match)
211{
212	const struct ip6t_icmp *icmpv6 = (struct ip6t_icmp *)match->data;
213
214	if (icmpv6->invflags & IP6T_ICMP_INV)
215		printf(" !");
216
217	printf(" --icmpv6-type %u", icmpv6->type);
218	if (icmpv6->code[0] != 0 || icmpv6->code[1] != 0xFF)
219		printf("/%u", icmpv6->code[0]);
220}
221
222static struct xtables_match icmp6_mt6_reg = {
223	.name 		= "icmp6",
224	.version 	= XTABLES_VERSION,
225	.family		= NFPROTO_IPV6,
226	.size		= XT_ALIGN(sizeof(struct ip6t_icmp)),
227	.userspacesize	= XT_ALIGN(sizeof(struct ip6t_icmp)),
228	.help		= icmp6_help,
229	.init		= icmp6_init,
230	.print		= icmp6_print,
231	.save		= icmp6_save,
232	.x6_parse	= icmp6_parse,
233	.x6_options	= icmp6_opts,
234};
235
236void _init(void)
237{
238	xtables_register_match(&icmp6_mt6_reg);
239}
240