1/*	$NetBSD: scope6.c,v 1.7 2009/03/15 21:26:09 cegger Exp $	*/
2/*	$KAME$	*/
3
4/*-
5 * Copyright (C) 2000 WIDE Project.
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 *    notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 *    notice, this list of conditions and the following disclaimer in the
15 *    documentation and/or other materials provided with the distribution.
16 * 3. Neither the name of the project nor the names of its contributors
17 *    may be used to endorse or promote products derived from this software
18 *    without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 * SUCH DAMAGE.
31 */
32
33#include <sys/cdefs.h>
34__KERNEL_RCSID(0, "$NetBSD: scope6.c,v 1.7 2009/03/15 21:26:09 cegger Exp $");
35
36#include <sys/param.h>
37#include <sys/malloc.h>
38#include <sys/mbuf.h>
39#include <sys/socket.h>
40#include <sys/systm.h>
41#include <sys/queue.h>
42#include <sys/syslog.h>
43
44#include <net/route.h>
45#include <net/if.h>
46
47#include <netinet/in.h>
48
49#include <netinet6/in6_var.h>
50#include <netinet6/scope6_var.h>
51
52#ifdef ENABLE_DEFAULT_SCOPE
53int ip6_use_defzone = 1;
54#else
55int ip6_use_defzone = 0;
56#endif
57
58static struct scope6_id sid_default;
59#define SID(ifp) \
60	(((struct in6_ifextra *)(ifp)->if_afdata[AF_INET6])->scope6_id)
61
62void
63scope6_init(void)
64{
65
66	memset(&sid_default, 0, sizeof(sid_default));
67}
68
69struct scope6_id *
70scope6_ifattach(struct ifnet *ifp)
71{
72	struct scope6_id *sid;
73
74	sid = (struct scope6_id *)malloc(sizeof(*sid), M_IFADDR, M_WAITOK);
75	memset(sid, 0, sizeof(*sid));
76
77	/*
78	 * XXX: IPV6_ADDR_SCOPE_xxx macros are not standard.
79	 * Should we rather hardcode here?
80	 */
81	sid->s6id_list[IPV6_ADDR_SCOPE_INTFACELOCAL] = ifp->if_index;
82	sid->s6id_list[IPV6_ADDR_SCOPE_LINKLOCAL] = ifp->if_index;
83#ifdef MULTI_SCOPE
84	/* by default, we don't care about scope boundary for these scopes. */
85	sid->s6id_list[IPV6_ADDR_SCOPE_SITELOCAL] = 1;
86	sid->s6id_list[IPV6_ADDR_SCOPE_ORGLOCAL] = 1;
87#endif
88
89	return sid;
90}
91
92void
93scope6_ifdetach(struct scope6_id *sid)
94{
95
96	free(sid, M_IFADDR);
97}
98
99int
100scope6_set(struct ifnet *ifp, const struct scope6_id *idlist)
101{
102	int i;
103	int error = 0;
104	struct scope6_id *sid = NULL;
105
106	sid = SID(ifp);
107
108	if (!sid)	/* paranoid? */
109		return (EINVAL);
110
111	/*
112	 * XXX: We need more consistency checks of the relationship among
113	 * scopes (e.g. an organization should be larger than a site).
114	 */
115
116	/*
117	 * TODO(XXX): after setting, we should reflect the changes to
118	 * interface addresses, routing table entries, PCB entries...
119	 */
120
121	for (i = 0; i < 16; i++) {
122		if (idlist->s6id_list[i] &&
123		    idlist->s6id_list[i] != sid->s6id_list[i]) {
124			/*
125			 * An interface zone ID must be the corresponding
126			 * interface index by definition.
127			 */
128			if (i == IPV6_ADDR_SCOPE_INTFACELOCAL &&
129			    idlist->s6id_list[i] != ifp->if_index)
130				return (EINVAL);
131
132			if (i == IPV6_ADDR_SCOPE_LINKLOCAL &&
133			    idlist->s6id_list[i] >= if_indexlim) {
134				/*
135				 * XXX: theoretically, there should be no
136				 * relationship between link IDs and interface
137				 * IDs, but we check the consistency for
138				 * safety in later use.
139				 */
140				return (EINVAL);
141			}
142
143			/*
144			 * XXX: we must need lots of work in this case,
145			 * but we simply set the new value in this initial
146			 * implementation.
147			 */
148			sid->s6id_list[i] = idlist->s6id_list[i];
149		}
150	}
151
152	return (error);
153}
154
155int
156scope6_get(const struct ifnet *ifp, struct scope6_id *idlist)
157{
158	/* We only need to lock the interface's afdata for SID() to work. */
159	const struct scope6_id *sid = SID(ifp);
160
161	if (sid == NULL)	/* paranoid? */
162		return EINVAL;
163
164	*idlist = *sid;
165
166	return 0;
167}
168
169/*
170 * Get a scope of the address. Interface-local, link-local, site-local
171 * or global.
172 */
173int
174in6_addrscope(const struct in6_addr *addr)
175{
176	int scope;
177
178	if (addr->s6_addr[0] == 0xfe) {
179		scope = addr->s6_addr[1] & 0xc0;
180
181		switch (scope) {
182		case 0x80:
183			return IPV6_ADDR_SCOPE_LINKLOCAL;
184			break;
185		case 0xc0:
186			return IPV6_ADDR_SCOPE_SITELOCAL;
187			break;
188		default:
189			return IPV6_ADDR_SCOPE_GLOBAL; /* just in case */
190			break;
191		}
192	}
193
194
195	if (addr->s6_addr[0] == 0xff) {
196		scope = addr->s6_addr[1] & 0x0f;
197
198		/*
199		 * due to other scope such as reserved,
200		 * return scope doesn't work.
201		 */
202		switch (scope) {
203		case IPV6_ADDR_SCOPE_INTFACELOCAL:
204			return IPV6_ADDR_SCOPE_INTFACELOCAL;
205			break;
206		case IPV6_ADDR_SCOPE_LINKLOCAL:
207			return IPV6_ADDR_SCOPE_LINKLOCAL;
208			break;
209		case IPV6_ADDR_SCOPE_SITELOCAL:
210			return IPV6_ADDR_SCOPE_SITELOCAL;
211			break;
212		default:
213			return IPV6_ADDR_SCOPE_GLOBAL;
214			break;
215		}
216	}
217
218	if (memcmp(&in6addr_loopback, addr, sizeof(*addr) - 1) == 0) {
219		if (addr->s6_addr[15] == 1) /* loopback */
220			return IPV6_ADDR_SCOPE_LINKLOCAL;
221		if (addr->s6_addr[15] == 0) {
222			/*
223			 * Regard the unspecified addresses as global,
224			 * since it has no ambiguity.
225			 * XXX: not sure if it's correct...
226			 */
227			return IPV6_ADDR_SCOPE_GLOBAL;
228		}
229	}
230
231	return IPV6_ADDR_SCOPE_GLOBAL;
232}
233
234/* note that ifp argument might be NULL */
235void
236scope6_setdefault(struct ifnet *ifp)
237{
238
239	/*
240	 * Currently, this function just sets the default "interfaces"
241	 * and "links" according to the given interface.
242	 * We might eventually have to separate the notion of "link" from
243	 * "interface" and provide a user interface to set the default.
244	 */
245	if (ifp) {
246		sid_default.s6id_list[IPV6_ADDR_SCOPE_INTFACELOCAL] =
247			ifp->if_index;
248		sid_default.s6id_list[IPV6_ADDR_SCOPE_LINKLOCAL] =
249			ifp->if_index;
250	} else {
251		sid_default.s6id_list[IPV6_ADDR_SCOPE_INTFACELOCAL] = 0;
252		sid_default.s6id_list[IPV6_ADDR_SCOPE_LINKLOCAL] = 0;
253	}
254}
255
256int
257scope6_get_default(struct scope6_id *idlist)
258{
259
260	*idlist = sid_default;
261
262	return (0);
263}
264
265uint32_t
266scope6_addr2default(const struct in6_addr *addr)
267{
268	uint32_t id;
269
270	/*
271	 * special case: The loopback address should be considered as
272	 * link-local, but there's no ambiguity in the syntax.
273	 */
274	if (IN6_IS_ADDR_LOOPBACK(addr))
275		return (0);
276
277	/*
278	 * XXX: 32-bit read is atomic on all our platforms, is it OK
279	 * not to lock here?
280	 */
281	id = sid_default.s6id_list[in6_addrscope(addr)];
282
283	return (id);
284}
285
286/*
287 * Validate the specified scope zone ID in the sin6_scope_id field.  If the ID
288 * is unspecified (=0), needs to be specified, and the default zone ID can be
289 * used, the default value will be used.
290 * This routine then generates the kernel-internal form: if the address scope
291 * of is interface-local or link-local, embed the interface index in the
292 * address.
293 */
294int
295sa6_embedscope(struct sockaddr_in6 *sin6, int defaultok)
296{
297	struct ifnet *ifp;
298	uint32_t zoneid;
299
300	if ((zoneid = sin6->sin6_scope_id) == 0 && defaultok)
301		zoneid = scope6_addr2default(&sin6->sin6_addr);
302
303	if (zoneid != 0 &&
304	    (IN6_IS_SCOPE_LINKLOCAL(&sin6->sin6_addr) ||
305	    IN6_IS_ADDR_MC_INTFACELOCAL(&sin6->sin6_addr))) {
306		/*
307		 * At this moment, we only check interface-local and
308		 * link-local scope IDs, and use interface indices as the
309		 * zone IDs assuming a one-to-one mapping between interfaces
310		 * and links.
311		 */
312		if (if_indexlim <= zoneid)
313			return (ENXIO);
314#ifdef __FreeBSD__
315		ifp = ifnet_byindex(zoneid);
316#else
317		ifp = ifindex2ifnet[zoneid];
318#endif
319		if (ifp == NULL) /* XXX: this can happen for some OS */
320			return (ENXIO);
321
322		/* XXX assignment to 16bit from 32bit variable */
323		sin6->sin6_addr.s6_addr16[1] = htons(zoneid & 0xffff);
324
325		sin6->sin6_scope_id = 0;
326	}
327
328	return 0;
329}
330
331struct sockaddr *
332sockaddr_in6_externalize(struct sockaddr *dst, socklen_t socklen,
333    const struct sockaddr *src)
334{
335	struct sockaddr_in6 *sin6;
336
337	sin6 = satosin6(sockaddr_copy(dst, socklen, src));
338
339	if (sin6 == NULL || sa6_recoverscope(sin6) != 0)
340		return NULL;
341
342	return dst;
343}
344
345/*
346 * generate standard sockaddr_in6 from embedded form.
347 */
348int
349sa6_recoverscope(struct sockaddr_in6 *sin6)
350{
351	uint32_t zoneid;
352
353	if (sin6->sin6_scope_id != 0) {
354		log(LOG_NOTICE,
355		    "sa6_recoverscope: assumption failure (non 0 ID): %s%%%d\n",
356		    ip6_sprintf(&sin6->sin6_addr), sin6->sin6_scope_id);
357		/* XXX: proceed anyway... */
358	}
359	if (IN6_IS_SCOPE_LINKLOCAL(&sin6->sin6_addr) ||
360	    IN6_IS_ADDR_MC_INTFACELOCAL(&sin6->sin6_addr)) {
361		/*
362		 * KAME assumption: link id == interface id
363		 */
364		zoneid = ntohs(sin6->sin6_addr.s6_addr16[1]);
365		if (zoneid) {
366			/* sanity check */
367			if (/* zoneid < 0 || */ if_indexlim <= zoneid)
368				return (ENXIO);
369#ifdef __FreeBSD__
370			if (!ifnet_byindex(zoneid))
371#else
372			if (!ifindex2ifnet[zoneid])
373#endif
374				return (ENXIO);
375			sin6->sin6_addr.s6_addr16[1] = 0;
376			sin6->sin6_scope_id = zoneid;
377		}
378	}
379
380	return 0;
381}
382
383int
384in6_setzoneid(struct in6_addr *in6, uint32_t zoneid)
385{
386	if (IN6_IS_SCOPE_EMBEDDABLE(in6))
387		in6->s6_addr16[1] = htons(zoneid & 0xffff); /* XXX */
388
389	return 0;
390}
391
392/*
393 * Determine the appropriate scope zone ID for in6 and ifp.  If ret_id is
394 * non NULL, it is set to the zone ID.  If the zone ID needs to be embedded
395 * in the in6_addr structure, in6 will be modified.
396 */
397int
398in6_setscope(struct in6_addr *in6, const struct ifnet *ifp, uint32_t *ret_id)
399{
400	int scope;
401	uint32_t zoneid = 0;
402	const struct scope6_id *sid = SID(ifp);
403
404#ifdef DIAGNOSTIC
405	if (sid == NULL) { /* should not happen */
406		panic("in6_setscope: scope array is NULL");
407		/* NOTREACHED */
408	}
409#endif
410
411	/*
412	 * special case: the loopback address can only belong to a loopback
413	 * interface.
414	 */
415	if (IN6_IS_ADDR_LOOPBACK(in6)) {
416		if (!(ifp->if_flags & IFF_LOOPBACK))
417			return (EINVAL);
418		else {
419			if (ret_id != NULL)
420				*ret_id = 0; /* there's no ambiguity */
421			return (0);
422		}
423	}
424
425	scope = in6_addrscope(in6);
426
427	if (!sid->s6id_list)
428		return 0;
429
430	switch (scope) {
431	case IPV6_ADDR_SCOPE_INTFACELOCAL: /* should be interface index */
432		zoneid = sid->s6id_list[IPV6_ADDR_SCOPE_INTFACELOCAL];
433		break;
434
435	case IPV6_ADDR_SCOPE_LINKLOCAL:
436		zoneid = sid->s6id_list[IPV6_ADDR_SCOPE_LINKLOCAL];
437		break;
438
439	case IPV6_ADDR_SCOPE_SITELOCAL:
440		zoneid = sid->s6id_list[IPV6_ADDR_SCOPE_SITELOCAL];
441		break;
442
443	case IPV6_ADDR_SCOPE_ORGLOCAL:
444		zoneid = sid->s6id_list[IPV6_ADDR_SCOPE_ORGLOCAL];
445		break;
446
447	default:
448		zoneid = 0;	/* XXX: treat as global. */
449		break;
450	}
451
452	if (ret_id != NULL)
453		*ret_id = zoneid;
454
455	return in6_setzoneid(in6, zoneid);
456}
457
458/*
459 * Just clear the embedded scope identifier.  Return 0 if the original address
460 * is intact; return non 0 if the address is modified.
461 */
462int
463in6_clearscope(struct in6_addr *in6)
464{
465	int modified = 0;
466
467	if (IN6_IS_SCOPE_LINKLOCAL(in6) || IN6_IS_ADDR_MC_INTFACELOCAL(in6)) {
468		if (in6->s6_addr16[1] != 0)
469			modified = 1;
470		in6->s6_addr16[1] = 0;
471	}
472
473	return (modified);
474}
475