xref: /freebsd/sys/netinet6/scope6.c (revision 8655c70597b0e0918c82114b1186df5669b83eb6)
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 "opt_route.h"
36 
37 #include <sys/param.h>
38 #include <sys/malloc.h>
39 #include <sys/mbuf.h>
40 #include <sys/socket.h>
41 #include <sys/systm.h>
42 #include <sys/queue.h>
43 #include <sys/syslog.h>
44 #include <sys/vimage.h>
45 
46 #include <net/route.h>
47 #include <net/if.h>
48 #include <net/vnet.h>
49 
50 #include <netinet/in.h>
51 
52 #include <netinet/ip6.h>
53 #include <netinet6/in6_var.h>
54 #include <netinet6/scope6_var.h>
55 #include <netinet6/vinet6.h>
56 
57 
58 /*
59  * The scope6_lock protects the global sid default stored in
60  * sid_default below.
61  */
62 static struct mtx scope6_lock;
63 #define	SCOPE6_LOCK_INIT()	mtx_init(&scope6_lock, "scope6_lock", NULL, MTX_DEF)
64 #define	SCOPE6_LOCK()		mtx_lock(&scope6_lock)
65 #define	SCOPE6_UNLOCK()		mtx_unlock(&scope6_lock)
66 #define	SCOPE6_LOCK_ASSERT()	mtx_assert(&scope6_lock, MA_OWNED)
67 
68 #ifdef VIMAGE_GLOBALS
69 static struct scope6_id sid_default;
70 int ip6_use_defzone;
71 #endif
72 
73 #define SID(ifp) \
74 	(((struct in6_ifextra *)(ifp)->if_afdata[AF_INET6])->scope6_id)
75 
76 void
77 scope6_init(void)
78 {
79 	INIT_VNET_INET6(curvnet);
80 
81 #ifdef ENABLE_DEFAULT_SCOPE
82 	V_ip6_use_defzone = 1;
83 #else
84 	V_ip6_use_defzone = 0;
85 #endif
86 	SCOPE6_LOCK_INIT();
87 	bzero(&V_sid_default, sizeof(V_sid_default));
88 }
89 
90 struct scope6_id *
91 scope6_ifattach(struct ifnet *ifp)
92 {
93 	struct scope6_id *sid;
94 
95 	sid = (struct scope6_id *)malloc(sizeof(*sid), M_IFADDR, M_WAITOK);
96 	bzero(sid, sizeof(*sid));
97 
98 	/*
99 	 * XXX: IPV6_ADDR_SCOPE_xxx macros are not standard.
100 	 * Should we rather hardcode here?
101 	 */
102 	sid->s6id_list[IPV6_ADDR_SCOPE_INTFACELOCAL] = ifp->if_index;
103 	sid->s6id_list[IPV6_ADDR_SCOPE_LINKLOCAL] = ifp->if_index;
104 #ifdef MULTI_SCOPE
105 	/* by default, we don't care about scope boundary for these scopes. */
106 	sid->s6id_list[IPV6_ADDR_SCOPE_SITELOCAL] = 1;
107 	sid->s6id_list[IPV6_ADDR_SCOPE_ORGLOCAL] = 1;
108 #endif
109 
110 	return sid;
111 }
112 
113 void
114 scope6_ifdetach(struct scope6_id *sid)
115 {
116 
117 	free(sid, M_IFADDR);
118 }
119 
120 int
121 scope6_set(struct ifnet *ifp, struct scope6_id *idlist)
122 {
123 	INIT_VNET_NET(ifp->if_vnet);
124 	int i;
125 	int error = 0;
126 	struct scope6_id *sid = NULL;
127 
128 	IF_AFDATA_LOCK(ifp);
129 	sid = SID(ifp);
130 
131 	if (!sid) {	/* paranoid? */
132 		IF_AFDATA_UNLOCK(ifp);
133 		return (EINVAL);
134 	}
135 
136 	/*
137 	 * XXX: We need more consistency checks of the relationship among
138 	 * scopes (e.g. an organization should be larger than a site).
139 	 */
140 
141 	/*
142 	 * TODO(XXX): after setting, we should reflect the changes to
143 	 * interface addresses, routing table entries, PCB entries...
144 	 */
145 
146 	SCOPE6_LOCK();
147 	for (i = 0; i < 16; i++) {
148 		if (idlist->s6id_list[i] &&
149 		    idlist->s6id_list[i] != sid->s6id_list[i]) {
150 			/*
151 			 * An interface zone ID must be the corresponding
152 			 * interface index by definition.
153 			 */
154 			if (i == IPV6_ADDR_SCOPE_INTFACELOCAL &&
155 			    idlist->s6id_list[i] != ifp->if_index) {
156 				IF_AFDATA_UNLOCK(ifp);
157 				SCOPE6_UNLOCK();
158 				return (EINVAL);
159 			}
160 
161 			if (i == IPV6_ADDR_SCOPE_LINKLOCAL &&
162 			    idlist->s6id_list[i] > V_if_index) {
163 				/*
164 				 * XXX: theoretically, there should be no
165 				 * relationship between link IDs and interface
166 				 * IDs, but we check the consistency for
167 				 * safety in later use.
168 				 */
169 				IF_AFDATA_UNLOCK(ifp);
170 				SCOPE6_UNLOCK();
171 				return (EINVAL);
172 			}
173 
174 			/*
175 			 * XXX: we must need lots of work in this case,
176 			 * but we simply set the new value in this initial
177 			 * implementation.
178 			 */
179 			sid->s6id_list[i] = idlist->s6id_list[i];
180 		}
181 	}
182 	SCOPE6_UNLOCK();
183 	IF_AFDATA_UNLOCK(ifp);
184 
185 	return (error);
186 }
187 
188 int
189 scope6_get(struct ifnet *ifp, struct scope6_id *idlist)
190 {
191 	/* We only need to lock the interface's afdata for SID() to work. */
192 	IF_AFDATA_LOCK(ifp);
193 	struct scope6_id *sid = SID(ifp);
194 
195 	if (sid == NULL) {	/* paranoid? */
196 		IF_AFDATA_UNLOCK(ifp);
197 		return (EINVAL);
198 	}
199 
200 	SCOPE6_LOCK();
201 	*idlist = *sid;
202 	SCOPE6_UNLOCK();
203 
204 	IF_AFDATA_UNLOCK(ifp);
205 	return (0);
206 }
207 
208 
209 /*
210  * Get a scope of the address. Node-local, link-local, site-local or global.
211  */
212 int
213 in6_addrscope(struct in6_addr *addr)
214 {
215 	int scope;
216 
217 	if (addr->s6_addr[0] == 0xfe) {
218 		scope = addr->s6_addr[1] & 0xc0;
219 
220 		switch (scope) {
221 		case 0x80:
222 			return IPV6_ADDR_SCOPE_LINKLOCAL;
223 			break;
224 		case 0xc0:
225 			return IPV6_ADDR_SCOPE_SITELOCAL;
226 			break;
227 		default:
228 			return IPV6_ADDR_SCOPE_GLOBAL; /* just in case */
229 			break;
230 		}
231 	}
232 
233 
234 	if (addr->s6_addr[0] == 0xff) {
235 		scope = addr->s6_addr[1] & 0x0f;
236 
237 		/*
238 		 * due to other scope such as reserved,
239 		 * return scope doesn't work.
240 		 */
241 		switch (scope) {
242 		case IPV6_ADDR_SCOPE_INTFACELOCAL:
243 			return IPV6_ADDR_SCOPE_INTFACELOCAL;
244 			break;
245 		case IPV6_ADDR_SCOPE_LINKLOCAL:
246 			return IPV6_ADDR_SCOPE_LINKLOCAL;
247 			break;
248 		case IPV6_ADDR_SCOPE_SITELOCAL:
249 			return IPV6_ADDR_SCOPE_SITELOCAL;
250 			break;
251 		default:
252 			return IPV6_ADDR_SCOPE_GLOBAL;
253 			break;
254 		}
255 	}
256 
257 	/*
258 	 * Regard loopback and unspecified addresses as global, since
259 	 * they have no ambiguity.
260 	 */
261 	if (bcmp(&in6addr_loopback, addr, sizeof(*addr) - 1) == 0) {
262 		if (addr->s6_addr[15] == 1) /* loopback */
263 			return IPV6_ADDR_SCOPE_LINKLOCAL;
264 		if (addr->s6_addr[15] == 0) /* unspecified */
265 			return IPV6_ADDR_SCOPE_GLOBAL; /* XXX: correct? */
266 	}
267 
268 	return IPV6_ADDR_SCOPE_GLOBAL;
269 }
270 
271 /*
272  * ifp - note that this might be NULL
273  */
274 
275 void
276 scope6_setdefault(struct ifnet *ifp)
277 {
278 	INIT_VNET_INET6(ifp->if_vnet);
279 
280 	/*
281 	 * Currently, this function just sets the default "interfaces"
282 	 * and "links" according to the given interface.
283 	 * We might eventually have to separate the notion of "link" from
284 	 * "interface" and provide a user interface to set the default.
285 	 */
286 	SCOPE6_LOCK();
287 	if (ifp) {
288 		V_sid_default.s6id_list[IPV6_ADDR_SCOPE_INTFACELOCAL] =
289 			ifp->if_index;
290 		V_sid_default.s6id_list[IPV6_ADDR_SCOPE_LINKLOCAL] =
291 			ifp->if_index;
292 	} else {
293 		V_sid_default.s6id_list[IPV6_ADDR_SCOPE_INTFACELOCAL] = 0;
294 		V_sid_default.s6id_list[IPV6_ADDR_SCOPE_LINKLOCAL] = 0;
295 	}
296 	SCOPE6_UNLOCK();
297 }
298 
299 int
300 scope6_get_default(struct scope6_id *idlist)
301 {
302 	INIT_VNET_INET6(curvnet);
303 
304 	SCOPE6_LOCK();
305 	*idlist = V_sid_default;
306 	SCOPE6_UNLOCK();
307 
308 	return (0);
309 }
310 
311 u_int32_t
312 scope6_addr2default(struct in6_addr *addr)
313 {
314 	INIT_VNET_INET6(curvnet);
315 	u_int32_t id;
316 
317 	/*
318 	 * special case: The loopback address should be considered as
319 	 * link-local, but there's no ambiguity in the syntax.
320 	 */
321 	if (IN6_IS_ADDR_LOOPBACK(addr))
322 		return (0);
323 
324 	/*
325 	 * XXX: 32-bit read is atomic on all our platforms, is it OK
326 	 * not to lock here?
327 	 */
328 	SCOPE6_LOCK();
329 	id = V_sid_default.s6id_list[in6_addrscope(addr)];
330 	SCOPE6_UNLOCK();
331 	return (id);
332 }
333 
334 /*
335  * Validate the specified scope zone ID in the sin6_scope_id field.  If the ID
336  * is unspecified (=0), needs to be specified, and the default zone ID can be
337  * used, the default value will be used.
338  * This routine then generates the kernel-internal form: if the address scope
339  * of is interface-local or link-local, embed the interface index in the
340  * address.
341  */
342 int
343 sa6_embedscope(struct sockaddr_in6 *sin6, int defaultok)
344 {
345 	INIT_VNET_NET(curvnet);
346 	struct ifnet *ifp;
347 	u_int32_t zoneid;
348 
349 	if ((zoneid = sin6->sin6_scope_id) == 0 && defaultok)
350 		zoneid = scope6_addr2default(&sin6->sin6_addr);
351 
352 	if (zoneid != 0 &&
353 	    (IN6_IS_SCOPE_LINKLOCAL(&sin6->sin6_addr) ||
354 	    IN6_IS_ADDR_MC_INTFACELOCAL(&sin6->sin6_addr))) {
355 		/*
356 		 * At this moment, we only check interface-local and
357 		 * link-local scope IDs, and use interface indices as the
358 		 * zone IDs assuming a one-to-one mapping between interfaces
359 		 * and links.
360 		 */
361 		if (V_if_index < zoneid)
362 			return (ENXIO);
363 		ifp = ifnet_byindex(zoneid);
364 		if (ifp == NULL) /* XXX: this can happen for some OS */
365 			return (ENXIO);
366 
367 		/* XXX assignment to 16bit from 32bit variable */
368 		sin6->sin6_addr.s6_addr16[1] = htons(zoneid & 0xffff);
369 
370 		sin6->sin6_scope_id = 0;
371 	}
372 
373 	return 0;
374 }
375 
376 /*
377  * generate standard sockaddr_in6 from embedded form.
378  */
379 int
380 sa6_recoverscope(struct sockaddr_in6 *sin6)
381 {
382 	INIT_VNET_NET(curvnet);
383 	char ip6buf[INET6_ADDRSTRLEN];
384 	u_int32_t zoneid;
385 
386 	if (sin6->sin6_scope_id != 0) {
387 		log(LOG_NOTICE,
388 		    "sa6_recoverscope: assumption failure (non 0 ID): %s%%%d\n",
389 		    ip6_sprintf(ip6buf, &sin6->sin6_addr), sin6->sin6_scope_id);
390 		/* XXX: proceed anyway... */
391 	}
392 	if (IN6_IS_SCOPE_LINKLOCAL(&sin6->sin6_addr) ||
393 	    IN6_IS_ADDR_MC_INTFACELOCAL(&sin6->sin6_addr)) {
394 		/*
395 		 * KAME assumption: link id == interface id
396 		 */
397 		zoneid = ntohs(sin6->sin6_addr.s6_addr16[1]);
398 		if (zoneid) {
399 			/* sanity check */
400 			if (zoneid < 0 || V_if_index < zoneid)
401 				return (ENXIO);
402 			if (!ifnet_byindex(zoneid))
403 				return (ENXIO);
404 			sin6->sin6_addr.s6_addr16[1] = 0;
405 			sin6->sin6_scope_id = zoneid;
406 		}
407 	}
408 
409 	return 0;
410 }
411 
412 /*
413  * Determine the appropriate scope zone ID for in6 and ifp.  If ret_id is
414  * non NULL, it is set to the zone ID.  If the zone ID needs to be embedded
415  * in the in6_addr structure, in6 will be modified.
416  *
417  * ret_id - unnecessary?
418  */
419 int
420 in6_setscope(struct in6_addr *in6, struct ifnet *ifp, u_int32_t *ret_id)
421 {
422 	int scope;
423 	u_int32_t zoneid = 0;
424 	struct scope6_id *sid;
425 
426 	IF_AFDATA_LOCK(ifp);
427 
428 	sid = SID(ifp);
429 
430 #ifdef DIAGNOSTIC
431 	if (sid == NULL) { /* should not happen */
432 		panic("in6_setscope: scope array is NULL");
433 		/* NOTREACHED */
434 	}
435 #endif
436 
437 	/*
438 	 * special case: the loopback address can only belong to a loopback
439 	 * interface.
440 	 */
441 	if (IN6_IS_ADDR_LOOPBACK(in6)) {
442 		if (!(ifp->if_flags & IFF_LOOPBACK)) {
443 			IF_AFDATA_UNLOCK(ifp);
444 			return (EINVAL);
445 		} else {
446 			if (ret_id != NULL)
447 				*ret_id = 0; /* there's no ambiguity */
448 			IF_AFDATA_UNLOCK(ifp);
449 			return (0);
450 		}
451 	}
452 
453 	scope = in6_addrscope(in6);
454 
455 	SCOPE6_LOCK();
456 	switch (scope) {
457 	case IPV6_ADDR_SCOPE_INTFACELOCAL: /* should be interface index */
458 		zoneid = sid->s6id_list[IPV6_ADDR_SCOPE_INTFACELOCAL];
459 		break;
460 
461 	case IPV6_ADDR_SCOPE_LINKLOCAL:
462 		zoneid = sid->s6id_list[IPV6_ADDR_SCOPE_LINKLOCAL];
463 		break;
464 
465 	case IPV6_ADDR_SCOPE_SITELOCAL:
466 		zoneid = sid->s6id_list[IPV6_ADDR_SCOPE_SITELOCAL];
467 		break;
468 
469 	case IPV6_ADDR_SCOPE_ORGLOCAL:
470 		zoneid = sid->s6id_list[IPV6_ADDR_SCOPE_ORGLOCAL];
471 		break;
472 
473 	default:
474 		zoneid = 0;	/* XXX: treat as global. */
475 		break;
476 	}
477 	SCOPE6_UNLOCK();
478 	IF_AFDATA_UNLOCK(ifp);
479 
480 	if (ret_id != NULL)
481 		*ret_id = zoneid;
482 
483 	if (IN6_IS_SCOPE_LINKLOCAL(in6) || IN6_IS_ADDR_MC_INTFACELOCAL(in6))
484 		in6->s6_addr16[1] = htons(zoneid & 0xffff); /* XXX */
485 
486 	return (0);
487 }
488 
489 /*
490  * Just clear the embedded scope identifier.  Return 0 if the original address
491  * is intact; return non 0 if the address is modified.
492  */
493 int
494 in6_clearscope(struct in6_addr *in6)
495 {
496 	int modified = 0;
497 
498 	if (IN6_IS_SCOPE_LINKLOCAL(in6) || IN6_IS_ADDR_MC_INTFACELOCAL(in6)) {
499 		if (in6->s6_addr16[1] != 0)
500 			modified = 1;
501 		in6->s6_addr16[1] = 0;
502 	}
503 
504 	return (modified);
505 }
506