rthdr.c revision 121472 
1/*	$KAME: rthdr.c,v 1.19 2003/06/06 10:48:51 itojun Exp $	*/
2
3/*
4 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of the project nor the names of its contributors
16 *    may be used to endorse or promote products derived from this software
17 *    without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 */
31
32#include <sys/cdefs.h>
33__FBSDID("$FreeBSD: head/lib/libc/net/rthdr.c 121472 2003-10-24 18:26:30Z ume $");
34
35#include <sys/param.h>
36#include <sys/types.h>
37#include <sys/socket.h>
38
39#include <netinet/in.h>
40#include <netinet/ip6.h>
41
42#include <string.h>
43#include <stdio.h>
44
45/*
46 * RFC2292 API
47 */
48
49size_t
50inet6_rthdr_space(type, seg)
51	int type, seg;
52{
53	switch (type) {
54	case IPV6_RTHDR_TYPE_0:
55		if (seg < 1 || seg > 23)
56			return (0);
57#ifdef COMPAT_RFC2292
58		return (CMSG_SPACE(sizeof(struct in6_addr) * (seg - 1) +
59		    sizeof(struct ip6_rthdr0)));
60#else
61		return (CMSG_SPACE(sizeof(struct in6_addr) * seg +
62		    sizeof(struct ip6_rthdr0)));
63#endif
64	default:
65		return (0);
66	}
67}
68
69struct cmsghdr *
70inet6_rthdr_init(bp, type)
71	void *bp;
72	int type;
73{
74	struct cmsghdr *ch = (struct cmsghdr *)bp;
75	struct ip6_rthdr *rthdr;
76
77	rthdr = (struct ip6_rthdr *)CMSG_DATA(ch);
78
79	ch->cmsg_level = IPPROTO_IPV6;
80	ch->cmsg_type = IPV6_RTHDR;
81
82	switch (type) {
83	case IPV6_RTHDR_TYPE_0:
84#ifdef COMPAT_RFC2292
85		ch->cmsg_len = CMSG_LEN(sizeof(struct ip6_rthdr0) -
86		    sizeof(struct in6_addr));
87#else
88		ch->cmsg_len = CMSG_LEN(sizeof(struct ip6_rthdr0));
89#endif
90
91		bzero(rthdr, sizeof(struct ip6_rthdr0));
92		rthdr->ip6r_type = IPV6_RTHDR_TYPE_0;
93		return (ch);
94	default:
95		return (NULL);
96	}
97}
98
99/* ARGSUSED */
100int
101inet6_rthdr_add(cmsg, addr, flags)
102	struct cmsghdr *cmsg;
103	const struct in6_addr *addr;
104	u_int flags;
105{
106	struct ip6_rthdr *rthdr;
107
108	rthdr = (struct ip6_rthdr *)CMSG_DATA(cmsg);
109
110	switch (rthdr->ip6r_type) {
111	case IPV6_RTHDR_TYPE_0:
112	{
113		struct ip6_rthdr0 *rt0 = (struct ip6_rthdr0 *)rthdr;
114		if (flags != IPV6_RTHDR_LOOSE && flags != IPV6_RTHDR_STRICT)
115			return (-1);
116		if (rt0->ip6r0_segleft == 23)
117			return (-1);
118
119#ifdef COMPAT_RFC1883		/* XXX */
120		if (flags == IPV6_RTHDR_STRICT) {
121			int c, b;
122			c = rt0->ip6r0_segleft / 8;
123			b = rt0->ip6r0_segleft % 8;
124			rt0->ip6r0_slmap[c] |= (1 << (7 - b));
125		}
126#else
127		if (flags != IPV6_RTHDR_LOOSE)
128			return (-1);
129#endif
130		rt0->ip6r0_segleft++;
131		bcopy(addr, (caddr_t)rt0 + ((rt0->ip6r0_len + 1) << 3),
132		    sizeof(struct in6_addr));
133		rt0->ip6r0_len += sizeof(struct in6_addr) >> 3;
134		cmsg->cmsg_len = CMSG_LEN((rt0->ip6r0_len + 1) << 3);
135		break;
136	}
137	default:
138		return (-1);
139	}
140
141	return (0);
142}
143
144/* ARGSUSED */
145int
146inet6_rthdr_lasthop(cmsg, flags)
147	struct cmsghdr *cmsg;
148	unsigned int flags;
149{
150	struct ip6_rthdr *rthdr;
151
152	rthdr = (struct ip6_rthdr *)CMSG_DATA(cmsg);
153
154	switch (rthdr->ip6r_type) {
155	case IPV6_RTHDR_TYPE_0:
156	{
157		struct ip6_rthdr0 *rt0 = (struct ip6_rthdr0 *)rthdr;
158#ifdef COMPAT_RFC1883		/* XXX */
159		if (flags != IPV6_RTHDR_LOOSE && flags != IPV6_RTHDR_STRICT)
160			return (-1);
161#endif /* COMPAT_RFC1883 */
162		if (rt0->ip6r0_segleft > 23)
163			return (-1);
164#ifdef COMPAT_RFC1883		/* XXX */
165		if (flags == IPV6_RTHDR_STRICT) {
166			int c, b;
167			c = rt0->ip6r0_segleft / 8;
168			b = rt0->ip6r0_segleft % 8;
169			rt0->ip6r0_slmap[c] |= (1 << (7 - b));
170		}
171#else
172		if (flags != IPV6_RTHDR_LOOSE)
173			return (-1);
174#endif /* COMPAT_RFC1883 */
175		break;
176	}
177	default:
178		return (-1);
179	}
180
181	return (0);
182}
183
184#if 0
185int
186inet6_rthdr_reverse(in, out)
187	const struct cmsghdr *in;
188	struct cmsghdr *out;
189{
190
191	return (-1);
192}
193#endif
194
195int
196inet6_rthdr_segments(cmsg)
197	const struct cmsghdr *cmsg;
198{
199	struct ip6_rthdr *rthdr;
200
201	rthdr = (struct ip6_rthdr *)CMSG_DATA(cmsg);
202
203	switch (rthdr->ip6r_type) {
204	case IPV6_RTHDR_TYPE_0:
205	{
206		struct ip6_rthdr0 *rt0 = (struct ip6_rthdr0 *)rthdr;
207
208		if (rt0->ip6r0_len % 2 || 46 < rt0->ip6r0_len)
209			return (-1);
210
211		return (rt0->ip6r0_len * 8) / sizeof(struct in6_addr);
212	}
213
214	default:
215		return (-1);
216	}
217}
218
219struct in6_addr *
220inet6_rthdr_getaddr(cmsg, idx)
221	struct cmsghdr *cmsg;
222	int idx;
223{
224	struct ip6_rthdr *rthdr;
225
226	rthdr = (struct ip6_rthdr *)CMSG_DATA(cmsg);
227
228	switch (rthdr->ip6r_type) {
229	case IPV6_RTHDR_TYPE_0:
230	{
231		struct ip6_rthdr0 *rt0 = (struct ip6_rthdr0 *)rthdr;
232		int naddr;
233
234		if (rt0->ip6r0_len % 2 || 46 < rt0->ip6r0_len)
235			return NULL;
236		naddr = (rt0->ip6r0_len * 8) / sizeof(struct in6_addr);
237		if (idx <= 0 || naddr < idx)
238			return NULL;
239#ifdef COMPAT_RFC2292
240		return (((struct in6_addr *)(rt0 + 1)) + idx - 1);
241#else
242		return (((struct in6_addr *)(rt0 + 1)) + idx);
243#endif
244	}
245
246	default:
247		return NULL;
248	}
249}
250
251int
252inet6_rthdr_getflags(cmsg, idx)
253	const struct cmsghdr *cmsg;
254	int idx;
255{
256	struct ip6_rthdr *rthdr;
257
258	rthdr = (struct ip6_rthdr *)CMSG_DATA(cmsg);
259
260	switch (rthdr->ip6r_type) {
261	case IPV6_RTHDR_TYPE_0:
262	{
263		struct ip6_rthdr0 *rt0 = (struct ip6_rthdr0 *)rthdr;
264		int naddr;
265
266		if (rt0->ip6r0_len % 2 || 46 < rt0->ip6r0_len)
267			return (-1);
268		naddr = (rt0->ip6r0_len * 8) / sizeof(struct in6_addr);
269		if (idx < 0 || naddr < idx)
270			return (-1);
271#ifdef COMPAT_RFC1883		/* XXX */
272		if (rt0->ip6r0_slmap[idx / 8] & (0x80 >> (idx % 8)))
273			return IPV6_RTHDR_STRICT;
274		else
275			return IPV6_RTHDR_LOOSE;
276#else
277		return IPV6_RTHDR_LOOSE;
278#endif /* COMPAT_RFC1883 */
279	}
280
281	default:
282		return (-1);
283	}
284}
285
286/*
287 * RFC3542 (2292bis) API
288 */
289
290socklen_t
291inet6_rth_space(int type, int segments)
292{
293	switch (type) {
294	case IPV6_RTHDR_TYPE_0:
295		return (((segments * 2) + 1) << 3);
296	default:
297		return (0);	/* type not suppported */
298	}
299}
300
301void *
302inet6_rth_init(void *bp, socklen_t bp_len, int type, int segments)
303{
304	struct ip6_rthdr *rth = (struct ip6_rthdr *)bp;
305	struct ip6_rthdr0 *rth0;
306
307	switch (type) {
308	case IPV6_RTHDR_TYPE_0:
309		/* length validation */
310		if (bp_len < inet6_rth_space(IPV6_RTHDR_TYPE_0, segments))
311			return (NULL);
312
313		memset(bp, 0, bp_len);
314		rth0 = (struct ip6_rthdr0 *)rth;
315		rth0->ip6r0_len = segments * 2;
316		rth0->ip6r0_type = IPV6_RTHDR_TYPE_0;
317		rth0->ip6r0_segleft = 0;
318		rth0->ip6r0_reserved = 0;
319		break;
320	default:
321		return (NULL);	/* type not supported */
322	}
323
324	return (bp);
325}
326
327int
328inet6_rth_add(void *bp, const struct in6_addr *addr)
329{
330	struct ip6_rthdr *rth = (struct ip6_rthdr *)bp;
331	struct ip6_rthdr0 *rth0;
332	struct in6_addr *nextaddr;
333
334	switch (rth->ip6r_type) {
335	case IPV6_RTHDR_TYPE_0:
336		rth0 = (struct ip6_rthdr0 *)rth;
337		nextaddr = (struct in6_addr *)(rth0 + 1) + rth0->ip6r0_segleft;
338		*nextaddr = *addr;
339		rth0->ip6r0_segleft++;
340		break;
341	default:
342		return (-1);	/* type not supported */
343	}
344
345	return (0);
346}
347
348int
349inet6_rth_reverse(const void *in, void *out)
350{
351	struct ip6_rthdr *rth_in = (struct ip6_rthdr *)in;
352	struct ip6_rthdr0 *rth0_in, *rth0_out;
353	int i, segments;
354
355	switch (rth_in->ip6r_type) {
356	case IPV6_RTHDR_TYPE_0:
357		rth0_in = (struct ip6_rthdr0 *)in;
358		rth0_out = (struct ip6_rthdr0 *)out;
359
360		/* parameter validation XXX too paranoid? */
361		if (rth0_in->ip6r0_len % 2)
362			return (-1);
363		segments = rth0_in->ip6r0_len / 2;
364
365		/* we can't use memcpy here, since in and out may overlap */
366		memmove((void *)rth0_out, (void *)rth0_in,
367			((rth0_in->ip6r0_len) + 1) << 3);
368		rth0_out->ip6r0_segleft = segments;
369
370		/* reverse the addresses */
371		for (i = 0; i < segments / 2; i++) {
372			struct in6_addr addr_tmp, *addr1, *addr2;
373
374			addr1 = (struct in6_addr *)(rth0_out + 1) + i;
375			addr2 = (struct in6_addr *)(rth0_out + 1) +
376				(segments - i - 1);
377			addr_tmp = *addr1;
378			*addr1 = *addr2;
379			*addr2 = addr_tmp;
380		}
381
382		break;
383	default:
384		return (-1);	/* type not supported */
385	}
386
387	return (0);
388}
389
390int
391inet6_rth_segments(const void *bp)
392{
393	struct ip6_rthdr *rh = (struct ip6_rthdr *)bp;
394	struct ip6_rthdr0 *rh0;
395	int addrs;
396
397	switch (rh->ip6r_type) {
398	case IPV6_RTHDR_TYPE_0:
399		rh0 = (struct ip6_rthdr0 *)bp;
400
401		/*
402		 * Validation for a type-0 routing header.
403		 * Is this too strict?
404		 */
405		if ((rh0->ip6r0_len % 2) != 0 ||
406		    (addrs = (rh0->ip6r0_len >> 1)) < rh0->ip6r0_segleft)
407			return (-1);
408
409		return (addrs);
410	default:
411		return (-1);	/* unknown type */
412	}
413}
414
415struct in6_addr *
416inet6_rth_getaddr(const void *bp, int idx)
417{
418	struct ip6_rthdr *rh = (struct ip6_rthdr *)bp;
419	struct ip6_rthdr0 *rh0;
420	int rthlen, addrs;
421
422	switch (rh->ip6r_type) {
423	case IPV6_RTHDR_TYPE_0:
424		 rh0 = (struct ip6_rthdr0 *)bp;
425		 rthlen = (rh0->ip6r0_len + 1) << 3;
426
427		/*
428		 * Validation for a type-0 routing header.
429		 * Is this too strict?
430		 */
431		if ((rthlen % 2) != 0 ||
432		    (addrs = (rthlen >> 1)) < rh0->ip6r0_segleft)
433			return (NULL);
434
435		if (idx < 0 || addrs <= idx)
436			return (NULL);
437
438		return (((struct in6_addr *)(rh0 + 1)) + idx);
439	default:
440		return (NULL);	/* unknown type */
441		break;
442	}
443}
444