1/*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (C) 2000 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 *	$KAME: scope6.c,v 1.10 2000/07/24 13:29:31 itojun Exp $
32 */
33
34#include <sys/cdefs.h>
35__FBSDID("$FreeBSD$");
36
37#include <sys/param.h>
38#include <sys/malloc.h>
39#include <sys/mbuf.h>
40#include <sys/socket.h>
41#include <sys/sockio.h>
42#include <sys/systm.h>
43#include <sys/queue.h>
44#include <sys/sysctl.h>
45#include <sys/syslog.h>
46
47#include <net/if.h>
48#include <net/if_var.h>
49#include <net/vnet.h>
50
51#include <netinet/in.h>
52
53#include <netinet/ip6.h>
54#include <netinet6/in6_var.h>
55#include <netinet6/ip6_var.h>
56#include <netinet6/scope6_var.h>
57
58#ifdef ENABLE_DEFAULT_SCOPE
59VNET_DEFINE(int, ip6_use_defzone) = 1;
60#else
61VNET_DEFINE(int, ip6_use_defzone) = 0;
62#endif
63VNET_DEFINE(int, deembed_scopeid) = 1;
64SYSCTL_DECL(_net_inet6_ip6);
65SYSCTL_INT(_net_inet6_ip6, OID_AUTO, deembed_scopeid, CTLFLAG_VNET | CTLFLAG_RW,
66    &VNET_NAME(deembed_scopeid), 0,
67    "Extract embedded zone ID and set it to sin6_scope_id in sockaddr_in6.");
68
69/*
70 * The scope6_lock protects the global sid default stored in
71 * sid_default below.
72 */
73static struct mtx scope6_lock;
74#define	SCOPE6_LOCK_INIT()	mtx_init(&scope6_lock, "scope6_lock", NULL, MTX_DEF)
75#define	SCOPE6_LOCK()		mtx_lock(&scope6_lock)
76#define	SCOPE6_UNLOCK()		mtx_unlock(&scope6_lock)
77#define	SCOPE6_LOCK_ASSERT()	mtx_assert(&scope6_lock, MA_OWNED)
78
79VNET_DEFINE_STATIC(struct scope6_id, sid_default);
80#define	V_sid_default			VNET(sid_default)
81
82#define SID(ifp) \
83	(((struct in6_ifextra *)(ifp)->if_afdata[AF_INET6])->scope6_id)
84
85static int	scope6_get(struct ifnet *, struct scope6_id *);
86static int	scope6_set(struct ifnet *, struct scope6_id *);
87
88void
89scope6_init(void)
90{
91
92	bzero(&V_sid_default, sizeof(V_sid_default));
93
94	if (!IS_DEFAULT_VNET(curvnet))
95		return;
96
97	SCOPE6_LOCK_INIT();
98}
99
100struct scope6_id *
101scope6_ifattach(struct ifnet *ifp)
102{
103	struct scope6_id *sid;
104
105	sid = malloc(sizeof(*sid), M_IFADDR, M_WAITOK | M_ZERO);
106	/*
107	 * XXX: IPV6_ADDR_SCOPE_xxx macros are not standard.
108	 * Should we rather hardcode here?
109	 */
110	sid->s6id_list[IPV6_ADDR_SCOPE_INTFACELOCAL] = ifp->if_index;
111	sid->s6id_list[IPV6_ADDR_SCOPE_LINKLOCAL] = ifp->if_index;
112	return (sid);
113}
114
115void
116scope6_ifdetach(struct scope6_id *sid)
117{
118
119	free(sid, M_IFADDR);
120}
121
122int
123scope6_ioctl(u_long cmd, caddr_t data, struct ifnet *ifp)
124{
125	struct in6_ifreq *ifr;
126
127	if (ifp->if_afdata[AF_INET6] == NULL)
128		return (EPFNOSUPPORT);
129
130	ifr = (struct in6_ifreq *)data;
131	switch (cmd) {
132	case SIOCSSCOPE6:
133		return (scope6_set(ifp,
134		    (struct scope6_id *)ifr->ifr_ifru.ifru_scope_id));
135	case SIOCGSCOPE6:
136		return (scope6_get(ifp,
137		    (struct scope6_id *)ifr->ifr_ifru.ifru_scope_id));
138	case SIOCGSCOPE6DEF:
139		return (scope6_get_default(
140		    (struct scope6_id *)ifr->ifr_ifru.ifru_scope_id));
141	default:
142		return (EOPNOTSUPP);
143	}
144}
145
146static int
147scope6_set(struct ifnet *ifp, struct scope6_id *idlist)
148{
149	int i;
150	int error = 0;
151	struct scope6_id *sid = NULL;
152
153	IF_AFDATA_WLOCK(ifp);
154	sid = SID(ifp);
155
156	if (!sid) {	/* paranoid? */
157		IF_AFDATA_WUNLOCK(ifp);
158		return (EINVAL);
159	}
160
161	/*
162	 * XXX: We need more consistency checks of the relationship among
163	 * scopes (e.g. an organization should be larger than a site).
164	 */
165
166	/*
167	 * TODO(XXX): after setting, we should reflect the changes to
168	 * interface addresses, routing table entries, PCB entries...
169	 */
170
171	for (i = 0; i < 16; i++) {
172		if (idlist->s6id_list[i] &&
173		    idlist->s6id_list[i] != sid->s6id_list[i]) {
174			/*
175			 * An interface zone ID must be the corresponding
176			 * interface index by definition.
177			 */
178			if (i == IPV6_ADDR_SCOPE_INTFACELOCAL &&
179			    idlist->s6id_list[i] != ifp->if_index) {
180				IF_AFDATA_WUNLOCK(ifp);
181				return (EINVAL);
182			}
183
184			if (i == IPV6_ADDR_SCOPE_LINKLOCAL &&
185			    idlist->s6id_list[i] > V_if_index) {
186				/*
187				 * XXX: theoretically, there should be no
188				 * relationship between link IDs and interface
189				 * IDs, but we check the consistency for
190				 * safety in later use.
191				 */
192				IF_AFDATA_WUNLOCK(ifp);
193				return (EINVAL);
194			}
195
196			/*
197			 * XXX: we must need lots of work in this case,
198			 * but we simply set the new value in this initial
199			 * implementation.
200			 */
201			sid->s6id_list[i] = idlist->s6id_list[i];
202		}
203	}
204	IF_AFDATA_WUNLOCK(ifp);
205
206	return (error);
207}
208
209static int
210scope6_get(struct ifnet *ifp, struct scope6_id *idlist)
211{
212	struct epoch_tracker et;
213	struct scope6_id *sid;
214
215	/* We only need to lock the interface's afdata for SID() to work. */
216	NET_EPOCH_ENTER(et);
217	sid = SID(ifp);
218	if (sid == NULL) {	/* paranoid? */
219		NET_EPOCH_EXIT(et);
220		return (EINVAL);
221	}
222
223	*idlist = *sid;
224
225	NET_EPOCH_EXIT(et);
226	return (0);
227}
228
229/*
230 * Get a scope of the address. Node-local, link-local, site-local or global.
231 */
232int
233in6_addrscope(const struct in6_addr *addr)
234{
235
236	if (IN6_IS_ADDR_MULTICAST(addr)) {
237		/*
238		 * Addresses with reserved value F must be treated as
239		 * global multicast addresses.
240		 */
241		if (IPV6_ADDR_MC_SCOPE(addr) == 0x0f)
242			return (IPV6_ADDR_SCOPE_GLOBAL);
243		return (IPV6_ADDR_MC_SCOPE(addr));
244	}
245	if (IN6_IS_ADDR_LINKLOCAL(addr) ||
246	    IN6_IS_ADDR_LOOPBACK(addr))
247		return (IPV6_ADDR_SCOPE_LINKLOCAL);
248	if (IN6_IS_ADDR_SITELOCAL(addr))
249		return (IPV6_ADDR_SCOPE_SITELOCAL);
250	return (IPV6_ADDR_SCOPE_GLOBAL);
251}
252
253/*
254 * ifp - note that this might be NULL
255 */
256
257void
258scope6_setdefault(struct ifnet *ifp)
259{
260
261	/*
262	 * Currently, this function just sets the default "interfaces"
263	 * and "links" according to the given interface.
264	 * We might eventually have to separate the notion of "link" from
265	 * "interface" and provide a user interface to set the default.
266	 */
267	SCOPE6_LOCK();
268	if (ifp) {
269		V_sid_default.s6id_list[IPV6_ADDR_SCOPE_INTFACELOCAL] =
270			ifp->if_index;
271		V_sid_default.s6id_list[IPV6_ADDR_SCOPE_LINKLOCAL] =
272			ifp->if_index;
273	} else {
274		V_sid_default.s6id_list[IPV6_ADDR_SCOPE_INTFACELOCAL] = 0;
275		V_sid_default.s6id_list[IPV6_ADDR_SCOPE_LINKLOCAL] = 0;
276	}
277	SCOPE6_UNLOCK();
278}
279
280int
281scope6_get_default(struct scope6_id *idlist)
282{
283
284	SCOPE6_LOCK();
285	*idlist = V_sid_default;
286	SCOPE6_UNLOCK();
287
288	return (0);
289}
290
291u_int32_t
292scope6_addr2default(struct in6_addr *addr)
293{
294	u_int32_t id;
295
296	/*
297	 * special case: The loopback address should be considered as
298	 * link-local, but there's no ambiguity in the syntax.
299	 */
300	if (IN6_IS_ADDR_LOOPBACK(addr))
301		return (0);
302
303	/*
304	 * XXX: 32-bit read is atomic on all our platforms, is it OK
305	 * not to lock here?
306	 */
307	SCOPE6_LOCK();
308	id = V_sid_default.s6id_list[in6_addrscope(addr)];
309	SCOPE6_UNLOCK();
310	return (id);
311}
312
313/*
314 * Validate the specified scope zone ID in the sin6_scope_id field.  If the ID
315 * is unspecified (=0), needs to be specified, and the default zone ID can be
316 * used, the default value will be used.
317 * This routine then generates the kernel-internal form: if the address scope
318 * of is interface-local or link-local, embed the interface index in the
319 * address.
320 */
321int
322sa6_embedscope(struct sockaddr_in6 *sin6, int defaultok)
323{
324	u_int32_t zoneid;
325
326	if ((zoneid = sin6->sin6_scope_id) == 0 && defaultok)
327		zoneid = scope6_addr2default(&sin6->sin6_addr);
328
329	if (zoneid != 0 &&
330	    (IN6_IS_SCOPE_LINKLOCAL(&sin6->sin6_addr) ||
331	    IN6_IS_ADDR_MC_INTFACELOCAL(&sin6->sin6_addr))) {
332		/*
333		 * At this moment, we only check interface-local and
334		 * link-local scope IDs, and use interface indices as the
335		 * zone IDs assuming a one-to-one mapping between interfaces
336		 * and links.
337		 */
338		if (V_if_index < zoneid || ifnet_byindex(zoneid) == NULL)
339			return (ENXIO);
340
341		/* XXX assignment to 16bit from 32bit variable */
342		sin6->sin6_addr.s6_addr16[1] = htons(zoneid & 0xffff);
343		sin6->sin6_scope_id = 0;
344	}
345
346	return 0;
347}
348
349/*
350 * generate standard sockaddr_in6 from embedded form.
351 */
352int
353sa6_recoverscope(struct sockaddr_in6 *sin6)
354{
355	char ip6buf[INET6_ADDRSTRLEN];
356	u_int32_t zoneid;
357
358	if (IN6_IS_SCOPE_LINKLOCAL(&sin6->sin6_addr) ||
359	    IN6_IS_ADDR_MC_INTFACELOCAL(&sin6->sin6_addr)) {
360		/*
361		 * KAME assumption: link id == interface id
362		 */
363		zoneid = ntohs(sin6->sin6_addr.s6_addr16[1]);
364		if (zoneid) {
365			/* sanity check */
366			if (V_if_index < zoneid)
367				return (ENXIO);
368#if 0
369			/* XXX: Disabled due to possible deadlock. */
370			if (!ifnet_byindex(zoneid))
371				return (ENXIO);
372#endif
373			if (sin6->sin6_scope_id != 0 &&
374			    zoneid != sin6->sin6_scope_id) {
375				log(LOG_NOTICE,
376				    "%s: embedded scope mismatch: %s%%%d. "
377				    "sin6_scope_id was overridden\n", __func__,
378				    ip6_sprintf(ip6buf, &sin6->sin6_addr),
379				    sin6->sin6_scope_id);
380			}
381			sin6->sin6_addr.s6_addr16[1] = 0;
382			sin6->sin6_scope_id = zoneid;
383		}
384	}
385
386	return 0;
387}
388
389/*
390 * Determine the appropriate scope zone ID for in6 and ifp.  If ret_id is
391 * non NULL, it is set to the zone ID.  If the zone ID needs to be embedded
392 * in the in6_addr structure, in6 will be modified.
393 *
394 * ret_id - unnecessary?
395 */
396int
397in6_setscope(struct in6_addr *in6, struct ifnet *ifp, u_int32_t *ret_id)
398{
399	int scope;
400	u_int32_t zoneid = 0;
401	struct scope6_id *sid;
402
403	/*
404	 * special case: the loopback address can only belong to a loopback
405	 * interface.
406	 */
407	if (IN6_IS_ADDR_LOOPBACK(in6)) {
408		if (!(ifp->if_flags & IFF_LOOPBACK))
409			return (EINVAL);
410	} else {
411		scope = in6_addrscope(in6);
412		if (scope == IPV6_ADDR_SCOPE_INTFACELOCAL ||
413		    scope == IPV6_ADDR_SCOPE_LINKLOCAL) {
414			/*
415			 * Currently we use interface indices as the
416			 * zone IDs for interface-local and link-local
417			 * scopes.
418			 */
419			zoneid = ifp->if_index;
420			in6->s6_addr16[1] = htons(zoneid & 0xffff); /* XXX */
421		} else if (scope != IPV6_ADDR_SCOPE_GLOBAL) {
422			struct epoch_tracker et;
423
424			NET_EPOCH_ENTER(et);
425			sid = SID(ifp);
426			zoneid = sid->s6id_list[scope];
427			NET_EPOCH_EXIT(et);
428		}
429	}
430
431	if (ret_id != NULL)
432		*ret_id = zoneid;
433
434	return (0);
435}
436
437/*
438 * Just clear the embedded scope identifier.  Return 0 if the original address
439 * is intact; return non 0 if the address is modified.
440 */
441int
442in6_clearscope(struct in6_addr *in6)
443{
444	int modified = 0;
445
446	if (IN6_IS_SCOPE_LINKLOCAL(in6) || IN6_IS_ADDR_MC_INTFACELOCAL(in6)) {
447		if (in6->s6_addr16[1] != 0)
448			modified = 1;
449		in6->s6_addr16[1] = 0;
450	}
451
452	return (modified);
453}
454
455/*
456 * Return the scope identifier or zero.
457 */
458uint16_t
459in6_getscope(const struct in6_addr *in6)
460{
461
462	if (IN6_IS_SCOPE_LINKLOCAL(in6) || IN6_IS_ADDR_MC_INTFACELOCAL(in6))
463		return (in6->s6_addr16[1]);
464
465	return (0);
466}
467
468/*
469 * Return pointer to ifnet structure, corresponding to the zone id of
470 * link-local scope.
471 */
472struct ifnet*
473in6_getlinkifnet(uint32_t zoneid)
474{
475
476	return (ifnet_byindex((u_short)zoneid));
477}
478
479/*
480 * Return zone id for the specified scope.
481 */
482uint32_t
483in6_getscopezone(const struct ifnet *ifp, int scope)
484{
485
486	if (scope == IPV6_ADDR_SCOPE_INTFACELOCAL ||
487	    scope == IPV6_ADDR_SCOPE_LINKLOCAL)
488		return (ifp->if_index);
489	if (scope >= 0 && scope < IPV6_ADDR_SCOPES_COUNT)
490		return (SID(ifp)->s6id_list[scope]);
491	return (0);
492}
493
494/*
495 * Extracts scope from adddress @dst, stores cleared address
496 * inside @dst and zone inside @scopeid
497 */
498void
499in6_splitscope(const struct in6_addr *src, struct in6_addr *dst,
500    uint32_t *scopeid)
501{
502	uint32_t zoneid;
503
504	*dst = *src;
505	zoneid = ntohs(in6_getscope(dst));
506	in6_clearscope(dst);
507	*scopeid = zoneid;
508}
509
510/*
511 * This function is for checking sockaddr_in6 structure passed
512 * from the application level (usually).
513 *
514 * sin6_scope_id should be set for link-local unicast, link-local and
515 * interface-local  multicast addresses.
516 *
517 * If it is zero, then look into default zone ids. If default zone id is
518 * not set or disabled, then return error.
519 */
520int
521sa6_checkzone(struct sockaddr_in6 *sa6)
522{
523	int scope;
524
525	scope = in6_addrscope(&sa6->sin6_addr);
526	if (scope == IPV6_ADDR_SCOPE_GLOBAL)
527		return (sa6->sin6_scope_id ? EINVAL: 0);
528	if (IN6_IS_ADDR_MULTICAST(&sa6->sin6_addr) &&
529	    scope != IPV6_ADDR_SCOPE_LINKLOCAL &&
530	    scope != IPV6_ADDR_SCOPE_INTFACELOCAL) {
531		if (sa6->sin6_scope_id == 0 && V_ip6_use_defzone != 0)
532			sa6->sin6_scope_id = V_sid_default.s6id_list[scope];
533		return (0);
534	}
535	/*
536	 * Since ::1 address always configured on the lo0, we can
537	 * automatically set its zone id, when it is not specified.
538	 * Return error, when specified zone id doesn't match with
539	 * actual value.
540	 */
541	if (IN6_IS_ADDR_LOOPBACK(&sa6->sin6_addr)) {
542		if (sa6->sin6_scope_id == 0)
543			sa6->sin6_scope_id = in6_getscopezone(V_loif, scope);
544		else if (sa6->sin6_scope_id != in6_getscopezone(V_loif, scope))
545			return (EADDRNOTAVAIL);
546	}
547	/* XXX: we can validate sin6_scope_id here */
548	if (sa6->sin6_scope_id != 0)
549		return (0);
550	if (V_ip6_use_defzone != 0)
551		sa6->sin6_scope_id = V_sid_default.s6id_list[scope];
552	/* Return error if we can't determine zone id */
553	return (sa6->sin6_scope_id ? 0: EADDRNOTAVAIL);
554}
555
556/*
557 * This function is similar to sa6_checkzone, but it uses given ifp
558 * to initialize sin6_scope_id.
559 */
560int
561sa6_checkzone_ifp(struct ifnet *ifp, struct sockaddr_in6 *sa6)
562{
563	int scope;
564
565	scope = in6_addrscope(&sa6->sin6_addr);
566	if (scope == IPV6_ADDR_SCOPE_LINKLOCAL ||
567	    scope == IPV6_ADDR_SCOPE_INTFACELOCAL) {
568		if (sa6->sin6_scope_id == 0) {
569			sa6->sin6_scope_id = in6_getscopezone(ifp, scope);
570			return (0);
571		} else if (sa6->sin6_scope_id != in6_getscopezone(ifp, scope))
572			return (EADDRNOTAVAIL);
573	}
574	return (sa6_checkzone(sa6));
575}
576
577
578