xref: /freebsd/sys/netinet6/scope6.c (revision 4f6aec90ff8521301da9c6bc04310e1ab25a410c)
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/if_var.h>
47 #include <net/vnet.h>
48 
49 #include <netinet/in.h>
50 
51 #include <netinet/ip6.h>
52 #include <netinet6/in6_var.h>
53 #include <netinet6/ip6_var.h>
54 #include <netinet6/scope6_var.h>
55 
56 #ifdef ENABLE_DEFAULT_SCOPE
57 VNET_DEFINE(int, ip6_use_defzone) = 1;
58 #else
59 VNET_DEFINE(int, ip6_use_defzone) = 0;
60 #endif
61 VNET_DEFINE(int, deembed_scopeid) = 1;
62 SYSCTL_DECL(_net_inet6_ip6);
63 SYSCTL_VNET_INT(_net_inet6_ip6, OID_AUTO, deembed_scopeid, CTLFLAG_RW,
64     &VNET_NAME(deembed_scopeid), 0,
65     "Extract embedded zone ID and set it to sin6_scope_id in sockaddr_in6.");
66 
67 /*
68  * The scope6_lock protects the global sid default stored in
69  * sid_default below.
70  */
71 static struct mtx scope6_lock;
72 #define	SCOPE6_LOCK_INIT()	mtx_init(&scope6_lock, "scope6_lock", NULL, MTX_DEF)
73 #define	SCOPE6_LOCK()		mtx_lock(&scope6_lock)
74 #define	SCOPE6_UNLOCK()		mtx_unlock(&scope6_lock)
75 #define	SCOPE6_LOCK_ASSERT()	mtx_assert(&scope6_lock, MA_OWNED)
76 
77 static VNET_DEFINE(struct scope6_id, sid_default);
78 #define	V_sid_default			VNET(sid_default)
79 
80 #define SID(ifp) \
81 	(((struct in6_ifextra *)(ifp)->if_afdata[AF_INET6])->scope6_id)
82 
83 static int	scope6_get(struct ifnet *, struct scope6_id *);
84 static int	scope6_set(struct ifnet *, struct scope6_id *);
85 
86 void
87 scope6_init(void)
88 {
89 
90 	bzero(&V_sid_default, sizeof(V_sid_default));
91 
92 	if (!IS_DEFAULT_VNET(curvnet))
93 		return;
94 
95 	SCOPE6_LOCK_INIT();
96 }
97 
98 struct scope6_id *
99 scope6_ifattach(struct ifnet *ifp)
100 {
101 	struct scope6_id *sid;
102 
103 	sid = (struct scope6_id *)malloc(sizeof(*sid), M_IFADDR, M_WAITOK);
104 	bzero(sid, sizeof(*sid));
105 
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 #ifdef MULTI_SCOPE
113 	/* by default, we don't care about scope boundary for these scopes. */
114 	sid->s6id_list[IPV6_ADDR_SCOPE_SITELOCAL] = 1;
115 	sid->s6id_list[IPV6_ADDR_SCOPE_ORGLOCAL] = 1;
116 #endif
117 
118 	return sid;
119 }
120 
121 void
122 scope6_ifdetach(struct scope6_id *sid)
123 {
124 
125 	free(sid, M_IFADDR);
126 }
127 
128 int
129 scope6_ioctl(u_long cmd, caddr_t data, struct ifnet *ifp)
130 {
131 	struct in6_ifreq *ifr;
132 
133 	if (ifp->if_afdata[AF_INET6] == NULL)
134 		return (EPFNOSUPPORT);
135 
136 	ifr = (struct in6_ifreq *)data;
137 	switch (cmd) {
138 	case SIOCSSCOPE6:
139 		return (scope6_set(ifp,
140 		    (struct scope6_id *)ifr->ifr_ifru.ifru_scope_id));
141 	case SIOCGSCOPE6:
142 		return (scope6_get(ifp,
143 		    (struct scope6_id *)ifr->ifr_ifru.ifru_scope_id));
144 	case SIOCGSCOPE6DEF:
145 		return (scope6_get_default(
146 		    (struct scope6_id *)ifr->ifr_ifru.ifru_scope_id));
147 	default:
148 		return (EOPNOTSUPP);
149 	}
150 }
151 
152 static int
153 scope6_set(struct ifnet *ifp, struct scope6_id *idlist)
154 {
155 	int i;
156 	int error = 0;
157 	struct scope6_id *sid = NULL;
158 
159 	IF_AFDATA_WLOCK(ifp);
160 	sid = SID(ifp);
161 
162 	if (!sid) {	/* paranoid? */
163 		IF_AFDATA_WUNLOCK(ifp);
164 		return (EINVAL);
165 	}
166 
167 	/*
168 	 * XXX: We need more consistency checks of the relationship among
169 	 * scopes (e.g. an organization should be larger than a site).
170 	 */
171 
172 	/*
173 	 * TODO(XXX): after setting, we should reflect the changes to
174 	 * interface addresses, routing table entries, PCB entries...
175 	 */
176 
177 	for (i = 0; i < 16; i++) {
178 		if (idlist->s6id_list[i] &&
179 		    idlist->s6id_list[i] != sid->s6id_list[i]) {
180 			/*
181 			 * An interface zone ID must be the corresponding
182 			 * interface index by definition.
183 			 */
184 			if (i == IPV6_ADDR_SCOPE_INTFACELOCAL &&
185 			    idlist->s6id_list[i] != ifp->if_index) {
186 				IF_AFDATA_WUNLOCK(ifp);
187 				return (EINVAL);
188 			}
189 
190 			if (i == IPV6_ADDR_SCOPE_LINKLOCAL &&
191 			    idlist->s6id_list[i] > V_if_index) {
192 				/*
193 				 * XXX: theoretically, there should be no
194 				 * relationship between link IDs and interface
195 				 * IDs, but we check the consistency for
196 				 * safety in later use.
197 				 */
198 				IF_AFDATA_WUNLOCK(ifp);
199 				return (EINVAL);
200 			}
201 
202 			/*
203 			 * XXX: we must need lots of work in this case,
204 			 * but we simply set the new value in this initial
205 			 * implementation.
206 			 */
207 			sid->s6id_list[i] = idlist->s6id_list[i];
208 		}
209 	}
210 	IF_AFDATA_WUNLOCK(ifp);
211 
212 	return (error);
213 }
214 
215 static int
216 scope6_get(struct ifnet *ifp, struct scope6_id *idlist)
217 {
218 	struct scope6_id *sid;
219 
220 	/* We only need to lock the interface's afdata for SID() to work. */
221 	IF_AFDATA_RLOCK(ifp);
222 	sid = SID(ifp);
223 	if (sid == NULL) {	/* paranoid? */
224 		IF_AFDATA_RUNLOCK(ifp);
225 		return (EINVAL);
226 	}
227 
228 	*idlist = *sid;
229 
230 	IF_AFDATA_RUNLOCK(ifp);
231 	return (0);
232 }
233 
234 /*
235  * Get a scope of the address. Node-local, link-local, site-local or global.
236  */
237 int
238 in6_addrscope(struct in6_addr *addr)
239 {
240 	int scope;
241 
242 	if (addr->s6_addr[0] == 0xfe) {
243 		scope = addr->s6_addr[1] & 0xc0;
244 
245 		switch (scope) {
246 		case 0x80:
247 			return IPV6_ADDR_SCOPE_LINKLOCAL;
248 			break;
249 		case 0xc0:
250 			return IPV6_ADDR_SCOPE_SITELOCAL;
251 			break;
252 		default:
253 			return IPV6_ADDR_SCOPE_GLOBAL; /* just in case */
254 			break;
255 		}
256 	}
257 
258 
259 	if (addr->s6_addr[0] == 0xff) {
260 		scope = addr->s6_addr[1] & 0x0f;
261 
262 		/*
263 		 * due to other scope such as reserved,
264 		 * return scope doesn't work.
265 		 */
266 		switch (scope) {
267 		case IPV6_ADDR_SCOPE_INTFACELOCAL:
268 			return IPV6_ADDR_SCOPE_INTFACELOCAL;
269 			break;
270 		case IPV6_ADDR_SCOPE_LINKLOCAL:
271 			return IPV6_ADDR_SCOPE_LINKLOCAL;
272 			break;
273 		case IPV6_ADDR_SCOPE_SITELOCAL:
274 			return IPV6_ADDR_SCOPE_SITELOCAL;
275 			break;
276 		default:
277 			return IPV6_ADDR_SCOPE_GLOBAL;
278 			break;
279 		}
280 	}
281 
282 	/*
283 	 * Regard loopback and unspecified addresses as global, since
284 	 * they have no ambiguity.
285 	 */
286 	if (bcmp(&in6addr_loopback, addr, sizeof(*addr) - 1) == 0) {
287 		if (addr->s6_addr[15] == 1) /* loopback */
288 			return IPV6_ADDR_SCOPE_LINKLOCAL;
289 		if (addr->s6_addr[15] == 0) /* unspecified */
290 			return IPV6_ADDR_SCOPE_GLOBAL; /* XXX: correct? */
291 	}
292 
293 	return IPV6_ADDR_SCOPE_GLOBAL;
294 }
295 
296 /*
297  * ifp - note that this might be NULL
298  */
299 
300 void
301 scope6_setdefault(struct ifnet *ifp)
302 {
303 
304 	/*
305 	 * Currently, this function just sets the default "interfaces"
306 	 * and "links" according to the given interface.
307 	 * We might eventually have to separate the notion of "link" from
308 	 * "interface" and provide a user interface to set the default.
309 	 */
310 	SCOPE6_LOCK();
311 	if (ifp) {
312 		V_sid_default.s6id_list[IPV6_ADDR_SCOPE_INTFACELOCAL] =
313 			ifp->if_index;
314 		V_sid_default.s6id_list[IPV6_ADDR_SCOPE_LINKLOCAL] =
315 			ifp->if_index;
316 	} else {
317 		V_sid_default.s6id_list[IPV6_ADDR_SCOPE_INTFACELOCAL] = 0;
318 		V_sid_default.s6id_list[IPV6_ADDR_SCOPE_LINKLOCAL] = 0;
319 	}
320 	SCOPE6_UNLOCK();
321 }
322 
323 int
324 scope6_get_default(struct scope6_id *idlist)
325 {
326 
327 	SCOPE6_LOCK();
328 	*idlist = V_sid_default;
329 	SCOPE6_UNLOCK();
330 
331 	return (0);
332 }
333 
334 u_int32_t
335 scope6_addr2default(struct in6_addr *addr)
336 {
337 	u_int32_t id;
338 
339 	/*
340 	 * special case: The loopback address should be considered as
341 	 * link-local, but there's no ambiguity in the syntax.
342 	 */
343 	if (IN6_IS_ADDR_LOOPBACK(addr))
344 		return (0);
345 
346 	/*
347 	 * XXX: 32-bit read is atomic on all our platforms, is it OK
348 	 * not to lock here?
349 	 */
350 	SCOPE6_LOCK();
351 	id = V_sid_default.s6id_list[in6_addrscope(addr)];
352 	SCOPE6_UNLOCK();
353 	return (id);
354 }
355 
356 /*
357  * Validate the specified scope zone ID in the sin6_scope_id field.  If the ID
358  * is unspecified (=0), needs to be specified, and the default zone ID can be
359  * used, the default value will be used.
360  * This routine then generates the kernel-internal form: if the address scope
361  * of is interface-local or link-local, embed the interface index in the
362  * address.
363  */
364 int
365 sa6_embedscope(struct sockaddr_in6 *sin6, int defaultok)
366 {
367 	u_int32_t zoneid;
368 
369 	if ((zoneid = sin6->sin6_scope_id) == 0 && defaultok)
370 		zoneid = scope6_addr2default(&sin6->sin6_addr);
371 
372 	if (zoneid != 0 &&
373 	    (IN6_IS_SCOPE_LINKLOCAL(&sin6->sin6_addr) ||
374 	    IN6_IS_ADDR_MC_INTFACELOCAL(&sin6->sin6_addr))) {
375 		/*
376 		 * At this moment, we only check interface-local and
377 		 * link-local scope IDs, and use interface indices as the
378 		 * zone IDs assuming a one-to-one mapping between interfaces
379 		 * and links.
380 		 */
381 		if (V_if_index < zoneid || ifnet_byindex(zoneid) == NULL)
382 			return (ENXIO);
383 
384 		/* XXX assignment to 16bit from 32bit variable */
385 		sin6->sin6_addr.s6_addr16[1] = htons(zoneid & 0xffff);
386 		sin6->sin6_scope_id = 0;
387 	}
388 
389 	return 0;
390 }
391 
392 /*
393  * generate standard sockaddr_in6 from embedded form.
394  */
395 int
396 sa6_recoverscope(struct sockaddr_in6 *sin6)
397 {
398 	char ip6buf[INET6_ADDRSTRLEN];
399 	u_int32_t zoneid;
400 
401 	if (IN6_IS_SCOPE_LINKLOCAL(&sin6->sin6_addr) ||
402 	    IN6_IS_ADDR_MC_INTFACELOCAL(&sin6->sin6_addr)) {
403 		/*
404 		 * KAME assumption: link id == interface id
405 		 */
406 		zoneid = ntohs(sin6->sin6_addr.s6_addr16[1]);
407 		if (zoneid) {
408 			/* sanity check */
409 			if (V_if_index < zoneid)
410 				return (ENXIO);
411 #if 0
412 			/* XXX: Disabled due to possible deadlock. */
413 			if (!ifnet_byindex(zoneid))
414 				return (ENXIO);
415 #endif
416 			if (sin6->sin6_scope_id != 0 &&
417 			    zoneid != sin6->sin6_scope_id) {
418 				log(LOG_NOTICE,
419 				    "%s: embedded scope mismatch: %s%%%d. "
420 				    "sin6_scope_id was overridden.", __func__,
421 				    ip6_sprintf(ip6buf, &sin6->sin6_addr),
422 				    sin6->sin6_scope_id);
423 			}
424 			sin6->sin6_addr.s6_addr16[1] = 0;
425 			sin6->sin6_scope_id = zoneid;
426 		}
427 	}
428 
429 	return 0;
430 }
431 
432 /*
433  * Determine the appropriate scope zone ID for in6 and ifp.  If ret_id is
434  * non NULL, it is set to the zone ID.  If the zone ID needs to be embedded
435  * in the in6_addr structure, in6 will be modified.
436  *
437  * ret_id - unnecessary?
438  */
439 int
440 in6_setscope(struct in6_addr *in6, struct ifnet *ifp, u_int32_t *ret_id)
441 {
442 	int scope;
443 	u_int32_t zoneid = 0;
444 	struct scope6_id *sid;
445 
446 	/*
447 	 * special case: the loopback address can only belong to a loopback
448 	 * interface.
449 	 */
450 	if (IN6_IS_ADDR_LOOPBACK(in6)) {
451 		if (!(ifp->if_flags & IFF_LOOPBACK))
452 			return (EINVAL);
453 	} else {
454 		scope = in6_addrscope(in6);
455 		if (scope == IPV6_ADDR_SCOPE_INTFACELOCAL ||
456 		    scope == IPV6_ADDR_SCOPE_LINKLOCAL) {
457 			/*
458 			 * Currently we use interface indeces as the
459 			 * zone IDs for interface-local and link-local
460 			 * scopes.
461 			 */
462 			zoneid = ifp->if_index;
463 			in6->s6_addr16[1] = htons(zoneid & 0xffff); /* XXX */
464 		} else if (scope != IPV6_ADDR_SCOPE_GLOBAL) {
465 			IF_AFDATA_RLOCK(ifp);
466 			sid = SID(ifp);
467 			zoneid = sid->s6id_list[scope];
468 			IF_AFDATA_RUNLOCK(ifp);
469 		}
470 	}
471 
472 	if (ret_id != NULL)
473 		*ret_id = zoneid;
474 
475 	return (0);
476 }
477 
478 /*
479  * Just clear the embedded scope identifier.  Return 0 if the original address
480  * is intact; return non 0 if the address is modified.
481  */
482 int
483 in6_clearscope(struct in6_addr *in6)
484 {
485 	int modified = 0;
486 
487 	if (IN6_IS_SCOPE_LINKLOCAL(in6) || IN6_IS_ADDR_MC_INTFACELOCAL(in6)) {
488 		if (in6->s6_addr16[1] != 0)
489 			modified = 1;
490 		in6->s6_addr16[1] = 0;
491 	}
492 
493 	return (modified);
494 }
495 
496 /*
497  * Return the scope identifier or zero.
498  */
499 uint16_t
500 in6_getscope(struct in6_addr *in6)
501 {
502 
503 	if (IN6_IS_SCOPE_LINKLOCAL(in6) || IN6_IS_ADDR_MC_INTFACELOCAL(in6))
504 		return (in6->s6_addr16[1]);
505 
506 	return (0);
507 }
508