1/*-
2 * Copyright (C) 2000 WIDE Project.
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 * 3. Neither the name of the project nor the names of its contributors
14 *    may be used to endorse or promote products derived from this software
15 *    without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 *
29 *	$KAME: scope6.c,v 1.10 2000/07/24 13:29:31 itojun Exp $
30 */
31
32#include <sys/cdefs.h>
33__FBSDID("$FreeBSD$");
34
35#include <sys/param.h>
36#include <sys/malloc.h>
37#include <sys/mbuf.h>
38#include <sys/socket.h>
39#include <sys/sockio.h>
40#include <sys/systm.h>
41#include <sys/queue.h>
42#include <sys/sysctl.h>
43#include <sys/syslog.h>
44
45#include <net/if.h>
46#include <net/vnet.h>
47
48#include <netinet/in.h>
49
50#include <netinet/ip6.h>
51#include <netinet6/in6_var.h>
52#include <netinet6/ip6_var.h>
53#include <netinet6/scope6_var.h>
54
55#ifdef ENABLE_DEFAULT_SCOPE
56VNET_DEFINE(int, ip6_use_defzone) = 1;
57#else
58VNET_DEFINE(int, ip6_use_defzone) = 0;
59#endif
60VNET_DEFINE(int, deembed_scopeid) = 1;
61SYSCTL_DECL(_net_inet6_ip6);
62SYSCTL_VNET_INT(_net_inet6_ip6, OID_AUTO, deembed_scopeid, CTLFLAG_RW,
63    &VNET_NAME(deembed_scopeid), 0,
64    "Extract embedded zone ID and set it to sin6_scope_id in sockaddr_in6.");
65
66/*
67 * The scope6_lock protects the global sid default stored in
68 * sid_default below.
69 */
70static struct mtx scope6_lock;
71#define	SCOPE6_LOCK_INIT()	mtx_init(&scope6_lock, "scope6_lock", NULL, MTX_DEF)
72#define	SCOPE6_LOCK()		mtx_lock(&scope6_lock)
73#define	SCOPE6_UNLOCK()		mtx_unlock(&scope6_lock)
74#define	SCOPE6_LOCK_ASSERT()	mtx_assert(&scope6_lock, MA_OWNED)
75
76static VNET_DEFINE(struct scope6_id, sid_default);
77#define	V_sid_default			VNET(sid_default)
78
79#define SID(ifp) \
80	(((struct in6_ifextra *)(ifp)->if_afdata[AF_INET6])->scope6_id)
81
82static int	scope6_get(struct ifnet *, struct scope6_id *);
83static int	scope6_set(struct ifnet *, struct scope6_id *);
84
85void
86scope6_init(void)
87{
88
89	bzero(&V_sid_default, sizeof(V_sid_default));
90
91	if (!IS_DEFAULT_VNET(curvnet))
92		return;
93
94	SCOPE6_LOCK_INIT();
95}
96
97struct scope6_id *
98scope6_ifattach(struct ifnet *ifp)
99{
100	struct scope6_id *sid;
101
102	sid = (struct scope6_id *)malloc(sizeof(*sid), M_IFADDR, M_WAITOK);
103	bzero(sid, sizeof(*sid));
104
105	/*
106	 * XXX: IPV6_ADDR_SCOPE_xxx macros are not standard.
107	 * Should we rather hardcode here?
108	 */
109	sid->s6id_list[IPV6_ADDR_SCOPE_INTFACELOCAL] = ifp->if_index;
110	sid->s6id_list[IPV6_ADDR_SCOPE_LINKLOCAL] = ifp->if_index;
111#ifdef MULTI_SCOPE
112	/* by default, we don't care about scope boundary for these scopes. */
113	sid->s6id_list[IPV6_ADDR_SCOPE_SITELOCAL] = 1;
114	sid->s6id_list[IPV6_ADDR_SCOPE_ORGLOCAL] = 1;
115#endif
116
117	return sid;
118}
119
120void
121scope6_ifdetach(struct scope6_id *sid)
122{
123
124	free(sid, M_IFADDR);
125}
126
127int
128scope6_ioctl(u_long cmd, caddr_t data, struct ifnet *ifp)
129{
130	struct in6_ifreq *ifr;
131
132	if (ifp->if_afdata[AF_INET6] == NULL)
133		return (EPFNOSUPPORT);
134
135	ifr = (struct in6_ifreq *)data;
136	switch (cmd) {
137	case SIOCSSCOPE6:
138		return (scope6_set(ifp,
139		    (struct scope6_id *)ifr->ifr_ifru.ifru_scope_id));
140	case SIOCGSCOPE6:
141		return (scope6_get(ifp,
142		    (struct scope6_id *)ifr->ifr_ifru.ifru_scope_id));
143	case SIOCGSCOPE6DEF:
144		return (scope6_get_default(
145		    (struct scope6_id *)ifr->ifr_ifru.ifru_scope_id));
146	default:
147		return (EOPNOTSUPP);
148	}
149}
150
151static int
152scope6_set(struct ifnet *ifp, struct scope6_id *idlist)
153{
154	int i;
155	int error = 0;
156	struct scope6_id *sid = NULL;
157
158	IF_AFDATA_WLOCK(ifp);
159	sid = SID(ifp);
160
161	if (!sid) {	/* paranoid? */
162		IF_AFDATA_WUNLOCK(ifp);
163		return (EINVAL);
164	}
165
166	/*
167	 * XXX: We need more consistency checks of the relationship among
168	 * scopes (e.g. an organization should be larger than a site).
169	 */
170
171	/*
172	 * TODO(XXX): after setting, we should reflect the changes to
173	 * interface addresses, routing table entries, PCB entries...
174	 */
175
176	for (i = 0; i < 16; i++) {
177		if (idlist->s6id_list[i] &&
178		    idlist->s6id_list[i] != sid->s6id_list[i]) {
179			/*
180			 * An interface zone ID must be the corresponding
181			 * interface index by definition.
182			 */
183			if (i == IPV6_ADDR_SCOPE_INTFACELOCAL &&
184			    idlist->s6id_list[i] != ifp->if_index) {
185				IF_AFDATA_WUNLOCK(ifp);
186				return (EINVAL);
187			}
188
189			if (i == IPV6_ADDR_SCOPE_LINKLOCAL &&
190			    idlist->s6id_list[i] > V_if_index) {
191				/*
192				 * XXX: theoretically, there should be no
193				 * relationship between link IDs and interface
194				 * IDs, but we check the consistency for
195				 * safety in later use.
196				 */
197				IF_AFDATA_WUNLOCK(ifp);
198				return (EINVAL);
199			}
200
201			/*
202			 * XXX: we must need lots of work in this case,
203			 * but we simply set the new value in this initial
204			 * implementation.
205			 */
206			sid->s6id_list[i] = idlist->s6id_list[i];
207		}
208	}
209	IF_AFDATA_WUNLOCK(ifp);
210
211	return (error);
212}
213
214static int
215scope6_get(struct ifnet *ifp, struct scope6_id *idlist)
216{
217	struct scope6_id *sid;
218
219	/* We only need to lock the interface's afdata for SID() to work. */
220	IF_AFDATA_RLOCK(ifp);
221	sid = SID(ifp);
222	if (sid == NULL) {	/* paranoid? */
223		IF_AFDATA_RUNLOCK(ifp);
224		return (EINVAL);
225	}
226
227	*idlist = *sid;
228
229	IF_AFDATA_RUNLOCK(ifp);
230	return (0);
231}
232
233/*
234 * Get a scope of the address. Node-local, link-local, site-local or global.
235 */
236int
237in6_addrscope(struct in6_addr *addr)
238{
239	int scope;
240
241	if (addr->s6_addr[0] == 0xfe) {
242		scope = addr->s6_addr[1] & 0xc0;
243
244		switch (scope) {
245		case 0x80:
246			return IPV6_ADDR_SCOPE_LINKLOCAL;
247			break;
248		case 0xc0:
249			return IPV6_ADDR_SCOPE_SITELOCAL;
250			break;
251		default:
252			return IPV6_ADDR_SCOPE_GLOBAL; /* just in case */
253			break;
254		}
255	}
256
257
258	if (addr->s6_addr[0] == 0xff) {
259		scope = addr->s6_addr[1] & 0x0f;
260
261		/*
262		 * due to other scope such as reserved,
263		 * return scope doesn't work.
264		 */
265		switch (scope) {
266		case IPV6_ADDR_SCOPE_INTFACELOCAL:
267			return IPV6_ADDR_SCOPE_INTFACELOCAL;
268			break;
269		case IPV6_ADDR_SCOPE_LINKLOCAL:
270			return IPV6_ADDR_SCOPE_LINKLOCAL;
271			break;
272		case IPV6_ADDR_SCOPE_SITELOCAL:
273			return IPV6_ADDR_SCOPE_SITELOCAL;
274			break;
275		default:
276			return IPV6_ADDR_SCOPE_GLOBAL;
277			break;
278		}
279	}
280
281	/*
282	 * Regard loopback and unspecified addresses as global, since
283	 * they have no ambiguity.
284	 */
285	if (bcmp(&in6addr_loopback, addr, sizeof(*addr) - 1) == 0) {
286		if (addr->s6_addr[15] == 1) /* loopback */
287			return IPV6_ADDR_SCOPE_LINKLOCAL;
288		if (addr->s6_addr[15] == 0) /* unspecified */
289			return IPV6_ADDR_SCOPE_GLOBAL; /* XXX: correct? */
290	}
291
292	return IPV6_ADDR_SCOPE_GLOBAL;
293}
294
295/*
296 * ifp - note that this might be NULL
297 */
298
299void
300scope6_setdefault(struct ifnet *ifp)
301{
302
303	/*
304	 * Currently, this function just sets the default "interfaces"
305	 * and "links" according to the given interface.
306	 * We might eventually have to separate the notion of "link" from
307	 * "interface" and provide a user interface to set the default.
308	 */
309	SCOPE6_LOCK();
310	if (ifp) {
311		V_sid_default.s6id_list[IPV6_ADDR_SCOPE_INTFACELOCAL] =
312			ifp->if_index;
313		V_sid_default.s6id_list[IPV6_ADDR_SCOPE_LINKLOCAL] =
314			ifp->if_index;
315	} else {
316		V_sid_default.s6id_list[IPV6_ADDR_SCOPE_INTFACELOCAL] = 0;
317		V_sid_default.s6id_list[IPV6_ADDR_SCOPE_LINKLOCAL] = 0;
318	}
319	SCOPE6_UNLOCK();
320}
321
322int
323scope6_get_default(struct scope6_id *idlist)
324{
325
326	SCOPE6_LOCK();
327	*idlist = V_sid_default;
328	SCOPE6_UNLOCK();
329
330	return (0);
331}
332
333u_int32_t
334scope6_addr2default(struct in6_addr *addr)
335{
336	u_int32_t id;
337
338	/*
339	 * special case: The loopback address should be considered as
340	 * link-local, but there's no ambiguity in the syntax.
341	 */
342	if (IN6_IS_ADDR_LOOPBACK(addr))
343		return (0);
344
345	/*
346	 * XXX: 32-bit read is atomic on all our platforms, is it OK
347	 * not to lock here?
348	 */
349	SCOPE6_LOCK();
350	id = V_sid_default.s6id_list[in6_addrscope(addr)];
351	SCOPE6_UNLOCK();
352	return (id);
353}
354
355/*
356 * Validate the specified scope zone ID in the sin6_scope_id field.  If the ID
357 * is unspecified (=0), needs to be specified, and the default zone ID can be
358 * used, the default value will be used.
359 * This routine then generates the kernel-internal form: if the address scope
360 * of is interface-local or link-local, embed the interface index in the
361 * address.
362 */
363int
364sa6_embedscope(struct sockaddr_in6 *sin6, int defaultok)
365{
366	u_int32_t zoneid;
367
368	if ((zoneid = sin6->sin6_scope_id) == 0 && defaultok)
369		zoneid = scope6_addr2default(&sin6->sin6_addr);
370
371	if (zoneid != 0 &&
372	    (IN6_IS_SCOPE_LINKLOCAL(&sin6->sin6_addr) ||
373	    IN6_IS_ADDR_MC_INTFACELOCAL(&sin6->sin6_addr))) {
374		/*
375		 * At this moment, we only check interface-local and
376		 * link-local scope IDs, and use interface indices as the
377		 * zone IDs assuming a one-to-one mapping between interfaces
378		 * and links.
379		 */
380		if (V_if_index < zoneid || ifnet_byindex(zoneid) == NULL)
381			return (ENXIO);
382
383		/* XXX assignment to 16bit from 32bit variable */
384		sin6->sin6_addr.s6_addr16[1] = htons(zoneid & 0xffff);
385		sin6->sin6_scope_id = 0;
386	}
387
388	return 0;
389}
390
391/*
392 * generate standard sockaddr_in6 from embedded form.
393 */
394int
395sa6_recoverscope(struct sockaddr_in6 *sin6)
396{
397	char ip6buf[INET6_ADDRSTRLEN];
398	u_int32_t zoneid;
399
400	if (IN6_IS_SCOPE_LINKLOCAL(&sin6->sin6_addr) ||
401	    IN6_IS_ADDR_MC_INTFACELOCAL(&sin6->sin6_addr)) {
402		/*
403		 * KAME assumption: link id == interface id
404		 */
405		zoneid = ntohs(sin6->sin6_addr.s6_addr16[1]);
406		if (zoneid) {
407			/* sanity check */
408			if (V_if_index < zoneid)
409				return (ENXIO);
410#if 0
411			/* XXX: Disabled due to possible deadlock. */
412			if (!ifnet_byindex(zoneid))
413				return (ENXIO);
414#endif
415			if (sin6->sin6_scope_id != 0 &&
416			    zoneid != sin6->sin6_scope_id) {
417				log(LOG_NOTICE,
418				    "%s: embedded scope mismatch: %s%%%d. "
419				    "sin6_scope_id was overridden\n", __func__,
420				    ip6_sprintf(ip6buf, &sin6->sin6_addr),
421				    sin6->sin6_scope_id);
422			}
423			sin6->sin6_addr.s6_addr16[1] = 0;
424			sin6->sin6_scope_id = zoneid;
425		}
426	}
427
428	return 0;
429}
430
431/*
432 * Determine the appropriate scope zone ID for in6 and ifp.  If ret_id is
433 * non NULL, it is set to the zone ID.  If the zone ID needs to be embedded
434 * in the in6_addr structure, in6 will be modified.
435 *
436 * ret_id - unnecessary?
437 */
438int
439in6_setscope(struct in6_addr *in6, struct ifnet *ifp, u_int32_t *ret_id)
440{
441	int scope;
442	u_int32_t zoneid = 0;
443	struct scope6_id *sid;
444
445	/*
446	 * special case: the loopback address can only belong to a loopback
447	 * interface.
448	 */
449	if (IN6_IS_ADDR_LOOPBACK(in6)) {
450		if (!(ifp->if_flags & IFF_LOOPBACK))
451			return (EINVAL);
452	} else {
453		scope = in6_addrscope(in6);
454		if (scope == IPV6_ADDR_SCOPE_INTFACELOCAL ||
455		    scope == IPV6_ADDR_SCOPE_LINKLOCAL) {
456			/*
457			 * Currently we use interface indeces as the
458			 * zone IDs for interface-local and link-local
459			 * scopes.
460			 */
461			zoneid = ifp->if_index;
462			in6->s6_addr16[1] = htons(zoneid & 0xffff); /* XXX */
463		} else if (scope != IPV6_ADDR_SCOPE_GLOBAL) {
464			IF_AFDATA_RLOCK(ifp);
465			sid = SID(ifp);
466			zoneid = sid->s6id_list[scope];
467			IF_AFDATA_RUNLOCK(ifp);
468		}
469	}
470
471	if (ret_id != NULL)
472		*ret_id = zoneid;
473
474	return (0);
475}
476
477/*
478 * Just clear the embedded scope identifier.  Return 0 if the original address
479 * is intact; return non 0 if the address is modified.
480 */
481int
482in6_clearscope(struct in6_addr *in6)
483{
484	int modified = 0;
485
486	if (IN6_IS_SCOPE_LINKLOCAL(in6) || IN6_IS_ADDR_MC_INTFACELOCAL(in6)) {
487		if (in6->s6_addr16[1] != 0)
488			modified = 1;
489		in6->s6_addr16[1] = 0;
490	}
491
492	return (modified);
493}
494
495/*
496 * Return the scope identifier or zero.
497 */
498uint16_t
499in6_getscope(struct in6_addr *in6)
500{
501
502	if (IN6_IS_SCOPE_LINKLOCAL(in6) || IN6_IS_ADDR_MC_INTFACELOCAL(in6))
503		return (in6->s6_addr16[1]);
504
505	return (0);
506}
507