xref: /freebsd/sys/netinet6/scope6.c (revision 7850fa71f55a16f414bb21163d80a03a5ab34522) 
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/systm.h>
40 #include <sys/queue.h>
41 #include <sys/syslog.h>
42 #include <sys/vimage.h>
43 
44 #include <net/if.h>
45 #include <net/vnet.h>
46 
47 #include <netinet/in.h>
48 
49 #include <netinet/ip6.h>
50 #include <netinet6/in6_var.h>
51 #include <netinet6/scope6_var.h>
52 #include <netinet6/vinet6.h>
53 
54 
55 /*
56  * The scope6_lock protects the global sid default stored in
57  * sid_default below.
58  */
59 static struct mtx scope6_lock;
60 #define	SCOPE6_LOCK_INIT()	mtx_init(&scope6_lock, "scope6_lock", NULL, MTX_DEF)
61 #define	SCOPE6_LOCK()		mtx_lock(&scope6_lock)
62 #define	SCOPE6_UNLOCK()		mtx_unlock(&scope6_lock)
63 #define	SCOPE6_LOCK_ASSERT()	mtx_assert(&scope6_lock, MA_OWNED)
64 
65 #ifdef VIMAGE_GLOBALS
66 static struct scope6_id sid_default;
67 int ip6_use_defzone;
68 #endif
69 
70 #define SID(ifp) \
71 	(((struct in6_ifextra *)(ifp)->if_afdata[AF_INET6])->scope6_id)
72 
73 void
74 scope6_init(void)
75 {
76 	INIT_VNET_INET6(curvnet);
77 
78 #ifdef ENABLE_DEFAULT_SCOPE
79 	V_ip6_use_defzone = 1;
80 #else
81 	V_ip6_use_defzone = 0;
82 #endif
83 	bzero(&V_sid_default, sizeof(V_sid_default));
84 
85 	if (!IS_DEFAULT_VNET(curvnet))
86 		return;
87 
88 	SCOPE6_LOCK_INIT();
89 }
90 
91 struct scope6_id *
92 scope6_ifattach(struct ifnet *ifp)
93 {
94 	struct scope6_id *sid;
95 
96 	sid = (struct scope6_id *)malloc(sizeof(*sid), M_IFADDR, M_WAITOK);
97 	bzero(sid, sizeof(*sid));
98 
99 	/*
100 	 * XXX: IPV6_ADDR_SCOPE_xxx macros are not standard.
101 	 * Should we rather hardcode here?
102 	 */
103 	sid->s6id_list[IPV6_ADDR_SCOPE_INTFACELOCAL] = ifp->if_index;
104 	sid->s6id_list[IPV6_ADDR_SCOPE_LINKLOCAL] = ifp->if_index;
105 #ifdef MULTI_SCOPE
106 	/* by default, we don't care about scope boundary for these scopes. */
107 	sid->s6id_list[IPV6_ADDR_SCOPE_SITELOCAL] = 1;
108 	sid->s6id_list[IPV6_ADDR_SCOPE_ORGLOCAL] = 1;
109 #endif
110 
111 	return sid;
112 }
113 
114 void
115 scope6_ifdetach(struct scope6_id *sid)
116 {
117 
118 	free(sid, M_IFADDR);
119 }
120 
121 int
122 scope6_set(struct ifnet *ifp, struct scope6_id *idlist)
123 {
124 	INIT_VNET_NET(ifp->if_vnet);
125 	int i;
126 	int error = 0;
127 	struct scope6_id *sid = NULL;
128 
129 	IF_AFDATA_LOCK(ifp);
130 	sid = SID(ifp);
131 
132 	if (!sid) {	/* paranoid? */
133 		IF_AFDATA_UNLOCK(ifp);
134 		return (EINVAL);
135 	}
136 
137 	/*
138 	 * XXX: We need more consistency checks of the relationship among
139 	 * scopes (e.g. an organization should be larger than a site).
140 	 */
141 
142 	/*
143 	 * TODO(XXX): after setting, we should reflect the changes to
144 	 * interface addresses, routing table entries, PCB entries...
145 	 */
146 
147 	SCOPE6_LOCK();
148 	for (i = 0; i < 16; i++) {
149 		if (idlist->s6id_list[i] &&
150 		    idlist->s6id_list[i] != sid->s6id_list[i]) {
151 			/*
152 			 * An interface zone ID must be the corresponding
153 			 * interface index by definition.
154 			 */
155 			if (i == IPV6_ADDR_SCOPE_INTFACELOCAL &&
156 			    idlist->s6id_list[i] != ifp->if_index) {
157 				IF_AFDATA_UNLOCK(ifp);
158 				SCOPE6_UNLOCK();
159 				return (EINVAL);
160 			}
161 
162 			if (i == IPV6_ADDR_SCOPE_LINKLOCAL &&
163 			    idlist->s6id_list[i] > V_if_index) {
164 				/*
165 				 * XXX: theoretically, there should be no
166 				 * relationship between link IDs and interface
167 				 * IDs, but we check the consistency for
168 				 * safety in later use.
169 				 */
170 				IF_AFDATA_UNLOCK(ifp);
171 				SCOPE6_UNLOCK();
172 				return (EINVAL);
173 			}
174 
175 			/*
176 			 * XXX: we must need lots of work in this case,
177 			 * but we simply set the new value in this initial
178 			 * implementation.
179 			 */
180 			sid->s6id_list[i] = idlist->s6id_list[i];
181 		}
182 	}
183 	SCOPE6_UNLOCK();
184 	IF_AFDATA_UNLOCK(ifp);
185 
186 	return (error);
187 }
188 
189 int
190 scope6_get(struct ifnet *ifp, struct scope6_id *idlist)
191 {
192 	/* We only need to lock the interface's afdata for SID() to work. */
193 	IF_AFDATA_LOCK(ifp);
194 	struct scope6_id *sid = SID(ifp);
195 
196 	if (sid == NULL) {	/* paranoid? */
197 		IF_AFDATA_UNLOCK(ifp);
198 		return (EINVAL);
199 	}
200 
201 	SCOPE6_LOCK();
202 	*idlist = *sid;
203 	SCOPE6_UNLOCK();
204 
205 	IF_AFDATA_UNLOCK(ifp);
206 	return (0);
207 }
208 
209 
210 /*
211  * Get a scope of the address. Node-local, link-local, site-local or global.
212  */
213 int
214 in6_addrscope(struct in6_addr *addr)
215 {
216 	int scope;
217 
218 	if (addr->s6_addr[0] == 0xfe) {
219 		scope = addr->s6_addr[1] & 0xc0;
220 
221 		switch (scope) {
222 		case 0x80:
223 			return IPV6_ADDR_SCOPE_LINKLOCAL;
224 			break;
225 		case 0xc0:
226 			return IPV6_ADDR_SCOPE_SITELOCAL;
227 			break;
228 		default:
229 			return IPV6_ADDR_SCOPE_GLOBAL; /* just in case */
230 			break;
231 		}
232 	}
233 
234 
235 	if (addr->s6_addr[0] == 0xff) {
236 		scope = addr->s6_addr[1] & 0x0f;
237 
238 		/*
239 		 * due to other scope such as reserved,
240 		 * return scope doesn't work.
241 		 */
242 		switch (scope) {
243 		case IPV6_ADDR_SCOPE_INTFACELOCAL:
244 			return IPV6_ADDR_SCOPE_INTFACELOCAL;
245 			break;
246 		case IPV6_ADDR_SCOPE_LINKLOCAL:
247 			return IPV6_ADDR_SCOPE_LINKLOCAL;
248 			break;
249 		case IPV6_ADDR_SCOPE_SITELOCAL:
250 			return IPV6_ADDR_SCOPE_SITELOCAL;
251 			break;
252 		default:
253 			return IPV6_ADDR_SCOPE_GLOBAL;
254 			break;
255 		}
256 	}
257 
258 	/*
259 	 * Regard loopback and unspecified addresses as global, since
260 	 * they have no ambiguity.
261 	 */
262 	if (bcmp(&in6addr_loopback, addr, sizeof(*addr) - 1) == 0) {
263 		if (addr->s6_addr[15] == 1) /* loopback */
264 			return IPV6_ADDR_SCOPE_LINKLOCAL;
265 		if (addr->s6_addr[15] == 0) /* unspecified */
266 			return IPV6_ADDR_SCOPE_GLOBAL; /* XXX: correct? */
267 	}
268 
269 	return IPV6_ADDR_SCOPE_GLOBAL;
270 }
271 
272 /*
273  * ifp - note that this might be NULL
274  */
275 
276 void
277 scope6_setdefault(struct ifnet *ifp)
278 {
279 	INIT_VNET_INET6(ifp->if_vnet);
280 
281 	/*
282 	 * Currently, this function just sets the default "interfaces"
283 	 * and "links" according to the given interface.
284 	 * We might eventually have to separate the notion of "link" from
285 	 * "interface" and provide a user interface to set the default.
286 	 */
287 	SCOPE6_LOCK();
288 	if (ifp) {
289 		V_sid_default.s6id_list[IPV6_ADDR_SCOPE_INTFACELOCAL] =
290 			ifp->if_index;
291 		V_sid_default.s6id_list[IPV6_ADDR_SCOPE_LINKLOCAL] =
292 			ifp->if_index;
293 	} else {
294 		V_sid_default.s6id_list[IPV6_ADDR_SCOPE_INTFACELOCAL] = 0;
295 		V_sid_default.s6id_list[IPV6_ADDR_SCOPE_LINKLOCAL] = 0;
296 	}
297 	SCOPE6_UNLOCK();
298 }
299 
300 int
301 scope6_get_default(struct scope6_id *idlist)
302 {
303 	INIT_VNET_INET6(curvnet);
304 
305 	SCOPE6_LOCK();
306 	*idlist = V_sid_default;
307 	SCOPE6_UNLOCK();
308 
309 	return (0);
310 }
311 
312 u_int32_t
313 scope6_addr2default(struct in6_addr *addr)
314 {
315 	INIT_VNET_INET6(curvnet);
316 	u_int32_t id;
317 
318 	/*
319 	 * special case: The loopback address should be considered as
320 	 * link-local, but there's no ambiguity in the syntax.
321 	 */
322 	if (IN6_IS_ADDR_LOOPBACK(addr))
323 		return (0);
324 
325 	/*
326 	 * XXX: 32-bit read is atomic on all our platforms, is it OK
327 	 * not to lock here?
328 	 */
329 	SCOPE6_LOCK();
330 	id = V_sid_default.s6id_list[in6_addrscope(addr)];
331 	SCOPE6_UNLOCK();
332 	return (id);
333 }
334 
335 /*
336  * Validate the specified scope zone ID in the sin6_scope_id field.  If the ID
337  * is unspecified (=0), needs to be specified, and the default zone ID can be
338  * used, the default value will be used.
339  * This routine then generates the kernel-internal form: if the address scope
340  * of is interface-local or link-local, embed the interface index in the
341  * address.
342  */
343 int
344 sa6_embedscope(struct sockaddr_in6 *sin6, int defaultok)
345 {
346 	INIT_VNET_NET(curvnet);
347 	struct ifnet *ifp;
348 	u_int32_t zoneid;
349 
350 	if ((zoneid = sin6->sin6_scope_id) == 0 && defaultok)
351 		zoneid = scope6_addr2default(&sin6->sin6_addr);
352 
353 	if (zoneid != 0 &&
354 	    (IN6_IS_SCOPE_LINKLOCAL(&sin6->sin6_addr) ||
355 	    IN6_IS_ADDR_MC_INTFACELOCAL(&sin6->sin6_addr))) {
356 		/*
357 		 * At this moment, we only check interface-local and
358 		 * link-local scope IDs, and use interface indices as the
359 		 * zone IDs assuming a one-to-one mapping between interfaces
360 		 * and links.
361 		 */
362 		if (V_if_index < zoneid)
363 			return (ENXIO);
364 		ifp = ifnet_byindex(zoneid);
365 		if (ifp == NULL) /* XXX: this can happen for some OS */
366 			return (ENXIO);
367 
368 		/* XXX assignment to 16bit from 32bit variable */
369 		sin6->sin6_addr.s6_addr16[1] = htons(zoneid & 0xffff);
370 
371 		sin6->sin6_scope_id = 0;
372 	}
373 
374 	return 0;
375 }
376 
377 /*
378  * generate standard sockaddr_in6 from embedded form.
379  */
380 int
381 sa6_recoverscope(struct sockaddr_in6 *sin6)
382 {
383 	INIT_VNET_NET(curvnet);
384 	char ip6buf[INET6_ADDRSTRLEN];
385 	u_int32_t zoneid;
386 
387 	if (sin6->sin6_scope_id != 0) {
388 		log(LOG_NOTICE,
389 		    "sa6_recoverscope: assumption failure (non 0 ID): %s%%%d\n",
390 		    ip6_sprintf(ip6buf, &sin6->sin6_addr), sin6->sin6_scope_id);
391 		/* XXX: proceed anyway... */
392 	}
393 	if (IN6_IS_SCOPE_LINKLOCAL(&sin6->sin6_addr) ||
394 	    IN6_IS_ADDR_MC_INTFACELOCAL(&sin6->sin6_addr)) {
395 		/*
396 		 * KAME assumption: link id == interface id
397 		 */
398 		zoneid = ntohs(sin6->sin6_addr.s6_addr16[1]);
399 		if (zoneid) {
400 			/* sanity check */
401 			if (zoneid < 0 || V_if_index < zoneid)
402 				return (ENXIO);
403 			if (!ifnet_byindex(zoneid))
404 				return (ENXIO);
405 			sin6->sin6_addr.s6_addr16[1] = 0;
406 			sin6->sin6_scope_id = zoneid;
407 		}
408 	}
409 
410 	return 0;
411 }
412 
413 /*
414  * Determine the appropriate scope zone ID for in6 and ifp.  If ret_id is
415  * non NULL, it is set to the zone ID.  If the zone ID needs to be embedded
416  * in the in6_addr structure, in6 will be modified.
417  *
418  * ret_id - unnecessary?
419  */
420 int
421 in6_setscope(struct in6_addr *in6, struct ifnet *ifp, u_int32_t *ret_id)
422 {
423 	int scope;
424 	u_int32_t zoneid = 0;
425 	struct scope6_id *sid;
426 
427 	IF_AFDATA_LOCK(ifp);
428 
429 	sid = SID(ifp);
430 
431 #ifdef DIAGNOSTIC
432 	if (sid == NULL) { /* should not happen */
433 		panic("in6_setscope: scope array is NULL");
434 		/* NOTREACHED */
435 	}
436 #endif
437 
438 	/*
439 	 * special case: the loopback address can only belong to a loopback
440 	 * interface.
441 	 */
442 	if (IN6_IS_ADDR_LOOPBACK(in6)) {
443 		if (!(ifp->if_flags & IFF_LOOPBACK)) {
444 			IF_AFDATA_UNLOCK(ifp);
445 			return (EINVAL);
446 		} else {
447 			if (ret_id != NULL)
448 				*ret_id = 0; /* there's no ambiguity */
449 			IF_AFDATA_UNLOCK(ifp);
450 			return (0);
451 		}
452 	}
453 
454 	scope = in6_addrscope(in6);
455 
456 	SCOPE6_LOCK();
457 	switch (scope) {
458 	case IPV6_ADDR_SCOPE_INTFACELOCAL: /* should be interface index */
459 		zoneid = sid->s6id_list[IPV6_ADDR_SCOPE_INTFACELOCAL];
460 		break;
461 
462 	case IPV6_ADDR_SCOPE_LINKLOCAL:
463 		zoneid = sid->s6id_list[IPV6_ADDR_SCOPE_LINKLOCAL];
464 		break;
465 
466 	case IPV6_ADDR_SCOPE_SITELOCAL:
467 		zoneid = sid->s6id_list[IPV6_ADDR_SCOPE_SITELOCAL];
468 		break;
469 
470 	case IPV6_ADDR_SCOPE_ORGLOCAL:
471 		zoneid = sid->s6id_list[IPV6_ADDR_SCOPE_ORGLOCAL];
472 		break;
473 
474 	default:
475 		zoneid = 0;	/* XXX: treat as global. */
476 		break;
477 	}
478 	SCOPE6_UNLOCK();
479 	IF_AFDATA_UNLOCK(ifp);
480 
481 	if (ret_id != NULL)
482 		*ret_id = zoneid;
483 
484 	if (IN6_IS_SCOPE_LINKLOCAL(in6) || IN6_IS_ADDR_MC_INTFACELOCAL(in6))
485 		in6->s6_addr16[1] = htons(zoneid & 0xffff); /* XXX */
486 
487 	return (0);
488 }
489 
490 /*
491  * Just clear the embedded scope identifier.  Return 0 if the original address
492  * is intact; return non 0 if the address is modified.
493  */
494 int
495 in6_clearscope(struct in6_addr *in6)
496 {
497 	int modified = 0;
498 
499 	if (IN6_IS_SCOPE_LINKLOCAL(in6) || IN6_IS_ADDR_MC_INTFACELOCAL(in6)) {
500 		if (in6->s6_addr16[1] != 0)
501 			modified = 1;
502 		in6->s6_addr16[1] = 0;
503 	}
504 
505 	return (modified);
506 }
507