summaryrefslogtreecommitdiffstats
path: root/extensions/libip6t_rt.c
blob: b5f54eee0d9838ae8cddbae698c539b29e81aaf1 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
/* Shared library add-on to ip6tables to add Routing header support. */
#include <stdio.h>
#include <netdb.h>
#include <string.h>
#include <stdlib.h>
#include <getopt.h>
#include <errno.h>
#include <ip6tables.h>
/*#include <linux/in6.h>*/
#include <linux/netfilter_ipv6/ip6t_rt.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <arpa/inet.h>
                                        
/*#define DEBUG	1*/

/* Function which prints out usage message. */
static void rt_help(void)
{
	printf(
"rt match options:\n"
" --rt-type [!] type            match the type\n"
" --rt-segsleft [!] num[:num]   match the Segments Left field (range)\n"
" --rt-len [!] length           total length of this header\n"
" --rt-0-res                    check the reserved filed, too (type 0)\n"
" --rt-0-addrs ADDR[,ADDR...]   Type=0 addresses (list, max: %d)\n"
" --rt-0-not-strict             List of Type=0 addresses not a strict list\n",
IP6T_RT_HOPS);
}

static const struct option rt_opts[] = {
	{ "rt-type", 1, NULL, '1' },
	{ "rt-segsleft", 1, NULL, '2' },
	{ "rt-len", 1, NULL, '3' },
	{ "rt-0-res", 0, NULL, '4' },
	{ "rt-0-addrs", 1, NULL, '5' },
	{ "rt-0-not-strict", 0, NULL, '6' },
	{ .name = NULL }
};

static u_int32_t
parse_rt_num(const char *idstr, const char *typestr)
{
	unsigned long int id;
	char* ep;

	id =  strtoul(idstr,&ep,0) ;

	if ( idstr == ep ) {
		exit_error(PARAMETER_PROBLEM,
			   "RT no valid digits in %s `%s'", typestr, idstr);
	}
	if ( id == ULONG_MAX  && errno == ERANGE ) {
		exit_error(PARAMETER_PROBLEM,
			   "%s `%s' specified too big: would overflow",
			   typestr, idstr);
	}	
	if ( *idstr != '\0'  && *ep != '\0' ) {
		exit_error(PARAMETER_PROBLEM,
			   "RT error parsing %s `%s'", typestr, idstr);
	}
	return (u_int32_t) id;
}

static void
parse_rt_segsleft(const char *idstring, u_int32_t *ids)
{
	char *buffer;
	char *cp;

	buffer = strdup(idstring);
	if ((cp = strchr(buffer, ':')) == NULL)
		ids[0] = ids[1] = parse_rt_num(buffer,"segsleft");
	else {
		*cp = '\0';
		cp++;

		ids[0] = buffer[0] ? parse_rt_num(buffer,"segsleft") : 0;
		ids[1] = cp[0] ? parse_rt_num(cp,"segsleft") : 0xFFFFFFFF;
	}
	free(buffer);
}

static char *
addr_to_numeric(const struct in6_addr *addrp)
{
	static char buf[50+1];
	return (char *)inet_ntop(AF_INET6, addrp, buf, sizeof(buf));
}

static struct in6_addr *
numeric_to_addr(const char *num)
{
	static struct in6_addr ap;
	int err;

	if ((err=inet_pton(AF_INET6, num, &ap)) == 1)
		return &ap;
#ifdef DEBUG
	fprintf(stderr, "\nnumeric2addr: %d\n", err);
#endif
        exit_error(PARAMETER_PROBLEM, "bad address: %s", num);

	return (struct in6_addr *)NULL;
}


static int
parse_addresses(const char *addrstr, struct in6_addr *addrp)
{
        char *buffer, *cp, *next;
        unsigned int i;
	
	buffer = strdup(addrstr);
        if (!buffer) exit_error(OTHER_PROBLEM, "strdup failed");
			
        for (cp=buffer, i=0; cp && i<IP6T_RT_HOPS; cp=next,i++)
        {
                next=strchr(cp, ',');
                if (next) *next++='\0';
		memcpy(&(addrp[i]), numeric_to_addr(cp), sizeof(struct in6_addr));
#if DEBUG
		printf("addr str: %s\n", cp);
		printf("addr ip6: %s\n", addr_to_numeric((numeric_to_addr(cp))));
		printf("addr [%d]: %s\n", i, addr_to_numeric(&(addrp[i])));
#endif
	}
        if (cp) exit_error(PARAMETER_PROBLEM, "too many addresses specified");

	free(buffer);

#if DEBUG
	printf("addr nr: %d\n", i);
#endif

	return i;
}

/* Initialize the match. */
static void rt_init(struct xt_entry_match *m)
{
	struct ip6t_rt *rtinfo = (struct ip6t_rt *)m->data;

	rtinfo->rt_type = 0x0L;
	rtinfo->segsleft[0] = 0x0L;
	rtinfo->segsleft[1] = 0xFFFFFFFF;
	rtinfo->hdrlen = 0;
	rtinfo->flags = 0;
	rtinfo->invflags = 0;
	rtinfo->addrnr = 0;
}

/* Function which parses command options; returns true if it
   ate an option */
static int rt_parse(int c, char **argv, int invert, unsigned int *flags,
                    const void *entry, struct xt_entry_match **match)
{
	struct ip6t_rt *rtinfo = (struct ip6t_rt *)(*match)->data;

	switch (c) {
	case '1':
		if (*flags & IP6T_RT_TYP)
			exit_error(PARAMETER_PROBLEM,
				   "Only one `--rt-type' allowed");
		check_inverse(optarg, &invert, &optind, 0);
		rtinfo->rt_type = parse_rt_num(argv[optind-1], "type");
		if (invert)
			rtinfo->invflags |= IP6T_RT_INV_TYP;
		rtinfo->flags |= IP6T_RT_TYP;
		*flags |= IP6T_RT_TYP;
		break;
	case '2':
		if (*flags & IP6T_RT_SGS)
			exit_error(PARAMETER_PROBLEM,
				   "Only one `--rt-segsleft' allowed");
		check_inverse(optarg, &invert, &optind, 0);
		parse_rt_segsleft(argv[optind-1], rtinfo->segsleft);
		if (invert)
			rtinfo->invflags |= IP6T_RT_INV_SGS;
		rtinfo->flags |= IP6T_RT_SGS;
		*flags |= IP6T_RT_SGS;
		break;
	case '3':
		if (*flags & IP6T_RT_LEN)
			exit_error(PARAMETER_PROBLEM,
				   "Only one `--rt-len' allowed");
		check_inverse(optarg, &invert, &optind, 0);
		rtinfo->hdrlen = parse_rt_num(argv[optind-1], "length");
		if (invert)
			rtinfo->invflags |= IP6T_RT_INV_LEN;
		rtinfo->flags |= IP6T_RT_LEN;
		*flags |= IP6T_RT_LEN;
		break;
	case '4':
		if (*flags & IP6T_RT_RES)
			exit_error(PARAMETER_PROBLEM,
				   "Only one `--rt-0-res' allowed");
		if ( !(*flags & IP6T_RT_TYP) || (rtinfo->rt_type != 0) || (rtinfo->invflags & IP6T_RT_INV_TYP) )
			exit_error(PARAMETER_PROBLEM,
				   "`--rt-type 0' required before `--rt-0-res'");
		rtinfo->flags |= IP6T_RT_RES;
		*flags |= IP6T_RT_RES;
		break;
	case '5':
		if (*flags & IP6T_RT_FST)
			exit_error(PARAMETER_PROBLEM,
				   "Only one `--rt-0-addrs' allowed");
		if ( !(*flags & IP6T_RT_TYP) || (rtinfo->rt_type != 0) || (rtinfo->invflags & IP6T_RT_INV_TYP) )
			exit_error(PARAMETER_PROBLEM,
				   "`--rt-type 0' required before `--rt-0-addrs'");
		check_inverse(optarg, &invert, &optind, 0);
		if (invert)
			exit_error(PARAMETER_PROBLEM,
				   " '!' not allowed with `--rt-0-addrs'");
		rtinfo->addrnr = parse_addresses(argv[optind-1], rtinfo->addrs);
		rtinfo->flags |= IP6T_RT_FST;
		*flags |= IP6T_RT_FST;
		break;
	case '6':
		if (*flags & IP6T_RT_FST_NSTRICT)
			exit_error(PARAMETER_PROBLEM,
				   "Only one `--rt-0-not-strict' allowed");
		if ( !(*flags & IP6T_RT_FST) )
			exit_error(PARAMETER_PROBLEM,
				   "`--rt-0-addr ...' required before `--rt-0-not-strict'");
		rtinfo->flags |= IP6T_RT_FST_NSTRICT;
		*flags |= IP6T_RT_FST_NSTRICT;
		break;
	default:
		return 0;
	}

	return 1;
}

static void
print_nums(const char *name, u_int32_t min, u_int32_t max,
	    int invert)
{
	const char *inv = invert ? "!" : "";

	if (min != 0 || max != 0xFFFFFFFF || invert) {
		printf("%s", name);
		if (min == max) {
			printf(":%s", inv);
			printf("%u", min);
		} else {
			printf("s:%s", inv);
			printf("%u",min);
			printf(":");
			printf("%u",max);
		}
		printf(" ");
	}
}

static void
print_addresses(unsigned int addrnr, struct in6_addr *addrp)
{
	unsigned int i;

	for(i=0; i<addrnr; i++){
		printf("%s%c", addr_to_numeric(&(addrp[i])), (i!=addrnr-1)?',':' ');
	}
}

/* Prints out the union ip6t_matchinfo. */
static void rt_print(const void *ip, const struct xt_entry_match *match,
                     int numeric)
{
	const struct ip6t_rt *rtinfo = (struct ip6t_rt *)match->data;

	printf("rt ");
	if (rtinfo->flags & IP6T_RT_TYP)
	    printf("type:%s%d ", rtinfo->invflags & IP6T_RT_INV_TYP ? "!" : "",
		    rtinfo->rt_type);
	print_nums("segsleft", rtinfo->segsleft[0], rtinfo->segsleft[1],
		    rtinfo->invflags & IP6T_RT_INV_SGS);
	if (rtinfo->flags & IP6T_RT_LEN) {
		printf("length");
		printf(":%s", rtinfo->invflags & IP6T_RT_INV_LEN ? "!" : "");
		printf("%u", rtinfo->hdrlen);
		printf(" ");
	}
	if (rtinfo->flags & IP6T_RT_RES) printf("reserved ");
	if (rtinfo->flags & IP6T_RT_FST) printf("0-addrs ");
	print_addresses(rtinfo->addrnr, (struct in6_addr *)rtinfo->addrs);
	if (rtinfo->flags & IP6T_RT_FST_NSTRICT) printf("0-not-strict ");
	if (rtinfo->invflags & ~IP6T_RT_INV_MASK)
		printf("Unknown invflags: 0x%X ",
		       rtinfo->invflags & ~IP6T_RT_INV_MASK);
}

/* Saves the union ip6t_matchinfo in parsable form to stdout. */
static void rt_save(const void *ip, const struct xt_entry_match *match)
{
	const struct ip6t_rt *rtinfo = (struct ip6t_rt *)match->data;

	if (rtinfo->flags & IP6T_RT_TYP) {
		printf("--rt-type %s%u ", 
			(rtinfo->invflags & IP6T_RT_INV_TYP) ? "! " : "", 
			rtinfo->rt_type);
	}

	if (!(rtinfo->segsleft[0] == 0
	    && rtinfo->segsleft[1] == 0xFFFFFFFF)) {
		printf("--rt-segsleft %s", 
			(rtinfo->invflags & IP6T_RT_INV_SGS) ? "! " : "");
		if (rtinfo->segsleft[0]
		    != rtinfo->segsleft[1])
			printf("%u:%u ",
			       rtinfo->segsleft[0],
			       rtinfo->segsleft[1]);
		else
			printf("%u ",
			       rtinfo->segsleft[0]);
	}

	if (rtinfo->flags & IP6T_RT_LEN) {
		printf("--rt-len %s%u ", 
			(rtinfo->invflags & IP6T_RT_INV_LEN) ? "! " : "", 
			rtinfo->hdrlen);
	}

	if (rtinfo->flags & IP6T_RT_RES) printf("--rt-0-res ");
	if (rtinfo->flags & IP6T_RT_FST) printf("--rt-0-addrs ");
	print_addresses(rtinfo->addrnr, (struct in6_addr *)rtinfo->addrs);
	if (rtinfo->flags & IP6T_RT_FST_NSTRICT) printf("--rt-0-not-strict ");

}

static struct xtables_match rt_mt6_reg = {
	.name		= "rt",
	.version	= XTABLES_VERSION,
	.family		= PF_INET6,
	.size		= XT_ALIGN(sizeof(struct ip6t_rt)),
	.userspacesize	= XT_ALIGN(sizeof(struct ip6t_rt)),
	.help		= rt_help,
	.init		= rt_init,
	.parse		= rt_parse,
	.print		= rt_print,
	.save		= rt_save,
	.extra_opts	= rt_opts,
};

void
_init(void)
{
	xtables_register_match(&rt_mt6_reg);
}