xref: /freebsd/sys/netinet6/scope6.c (revision 35a04710d7286aa9538917fd7f8e417dbee95b82)
1 /*	$FreeBSD$	*/
2 /*	$KAME: scope6.c,v 1.10 2000/07/24 13:29:31 itojun Exp $	*/
3 
4 /*-
5  * Copyright (C) 2000 WIDE Project.
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. Neither the name of the project nor the names of its contributors
17  *    may be used to endorse or promote products derived from this software
18  *    without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30  * SUCH DAMAGE.
31  */
32 
33 #include <sys/param.h>
34 #include <sys/malloc.h>
35 #include <sys/mbuf.h>
36 #include <sys/socket.h>
37 #include <sys/systm.h>
38 #include <sys/queue.h>
39 #include <sys/syslog.h>
40 
41 #include <net/route.h>
42 #include <net/if.h>
43 
44 #include <netinet/in.h>
45 
46 #include <netinet6/in6_var.h>
47 #include <netinet6/scope6_var.h>
48 
49 #ifdef ENABLE_DEFAULT_SCOPE
50 int ip6_use_defzone = 1;
51 #else
52 int ip6_use_defzone = 0;
53 #endif
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 static struct scope6_id sid_default;
66 #define SID(ifp) \
67 	(((struct in6_ifextra *)(ifp)->if_afdata[AF_INET6])->scope6_id)
68 
69 void
70 scope6_init(void)
71 {
72 
73 	SCOPE6_LOCK_INIT();
74 	bzero(&sid_default, sizeof(sid_default));
75 }
76 
77 struct scope6_id *
78 scope6_ifattach(struct ifnet *ifp)
79 {
80 	struct scope6_id *sid;
81 
82 	sid = (struct scope6_id *)malloc(sizeof(*sid), M_IFADDR, M_WAITOK);
83 	bzero(sid, sizeof(*sid));
84 
85 	/*
86 	 * XXX: IPV6_ADDR_SCOPE_xxx macros are not standard.
87 	 * Should we rather hardcode here?
88 	 */
89 	sid->s6id_list[IPV6_ADDR_SCOPE_INTFACELOCAL] = ifp->if_index;
90 	sid->s6id_list[IPV6_ADDR_SCOPE_LINKLOCAL] = ifp->if_index;
91 #ifdef MULTI_SCOPE
92 	/* by default, we don't care about scope boundary for these scopes. */
93 	sid->s6id_list[IPV6_ADDR_SCOPE_SITELOCAL] = 1;
94 	sid->s6id_list[IPV6_ADDR_SCOPE_ORGLOCAL] = 1;
95 #endif
96 
97 	return sid;
98 }
99 
100 void
101 scope6_ifdetach(struct scope6_id *sid)
102 {
103 
104 	free(sid, M_IFADDR);
105 }
106 
107 int
108 scope6_set(struct ifnet *ifp, struct scope6_id *idlist)
109 {
110 	int i;
111 	int error = 0;
112 	struct scope6_id *sid = NULL;
113 
114 	IF_AFDATA_LOCK(ifp);
115 	sid = SID(ifp);
116 
117 	if (!sid) {	/* paranoid? */
118 		IF_AFDATA_UNLOCK(ifp);
119 		return (EINVAL);
120 	}
121 
122 	/*
123 	 * XXX: We need more consistency checks of the relationship among
124 	 * scopes (e.g. an organization should be larger than a site).
125 	 */
126 
127 	/*
128 	 * TODO(XXX): after setting, we should reflect the changes to
129 	 * interface addresses, routing table entries, PCB entries...
130 	 */
131 
132 	SCOPE6_LOCK();
133 	for (i = 0; i < 16; i++) {
134 		if (idlist->s6id_list[i] &&
135 		    idlist->s6id_list[i] != sid->s6id_list[i]) {
136 			/*
137 			 * An interface zone ID must be the corresponding
138 			 * interface index by definition.
139 			 */
140 			if (i == IPV6_ADDR_SCOPE_INTFACELOCAL &&
141 			    idlist->s6id_list[i] != ifp->if_index) {
142 				IF_AFDATA_UNLOCK(ifp);
143 				SCOPE6_UNLOCK();
144 				return (EINVAL);
145 			}
146 
147 			if (i == IPV6_ADDR_SCOPE_LINKLOCAL &&
148 			    idlist->s6id_list[i] > if_index) {
149 				/*
150 				 * XXX: theoretically, there should be no
151 				 * relationship between link IDs and interface
152 				 * IDs, but we check the consistency for
153 				 * safety in later use.
154 				 */
155 				IF_AFDATA_UNLOCK(ifp);
156 				SCOPE6_UNLOCK();
157 				return (EINVAL);
158 			}
159 
160 			/*
161 			 * XXX: we must need lots of work in this case,
162 			 * but we simply set the new value in this initial
163 			 * implementation.
164 			 */
165 			sid->s6id_list[i] = idlist->s6id_list[i];
166 		}
167 	}
168 	SCOPE6_UNLOCK();
169 	IF_AFDATA_UNLOCK(ifp);
170 
171 	return (error);
172 }
173 
174 int
175 scope6_get(struct ifnet *ifp, struct scope6_id *idlist)
176 {
177 	/* We only need to lock the interface's afdata for SID() to work. */
178 	IF_AFDATA_LOCK(ifp);
179 	struct scope6_id *sid = SID(ifp);
180 
181 	if (sid == NULL) {	/* paranoid? */
182 		IF_AFDATA_UNLOCK(ifp);
183 		return (EINVAL);
184 	}
185 
186 	SCOPE6_LOCK();
187 	*idlist = *sid;
188 	SCOPE6_UNLOCK();
189 
190 	IF_AFDATA_UNLOCK(ifp);
191 	return (0);
192 }
193 
194 
195 /*
196  * Get a scope of the address. Node-local, link-local, site-local or global.
197  */
198 int
199 in6_addrscope(struct in6_addr *addr)
200 {
201 	int scope;
202 
203 	if (addr->s6_addr[0] == 0xfe) {
204 		scope = addr->s6_addr[1] & 0xc0;
205 
206 		switch (scope) {
207 		case 0x80:
208 			return IPV6_ADDR_SCOPE_LINKLOCAL;
209 			break;
210 		case 0xc0:
211 			return IPV6_ADDR_SCOPE_SITELOCAL;
212 			break;
213 		default:
214 			return IPV6_ADDR_SCOPE_GLOBAL; /* just in case */
215 			break;
216 		}
217 	}
218 
219 
220 	if (addr->s6_addr[0] == 0xff) {
221 		scope = addr->s6_addr[1] & 0x0f;
222 
223 		/*
224 		 * due to other scope such as reserved,
225 		 * return scope doesn't work.
226 		 */
227 		switch (scope) {
228 		case IPV6_ADDR_SCOPE_INTFACELOCAL:
229 			return IPV6_ADDR_SCOPE_INTFACELOCAL;
230 			break;
231 		case IPV6_ADDR_SCOPE_LINKLOCAL:
232 			return IPV6_ADDR_SCOPE_LINKLOCAL;
233 			break;
234 		case IPV6_ADDR_SCOPE_SITELOCAL:
235 			return IPV6_ADDR_SCOPE_SITELOCAL;
236 			break;
237 		default:
238 			return IPV6_ADDR_SCOPE_GLOBAL;
239 			break;
240 		}
241 	}
242 
243 	/*
244 	 * Regard loopback and unspecified addresses as global, since
245 	 * they have no ambiguity.
246 	 */
247 	if (bcmp(&in6addr_loopback, addr, sizeof(*addr) - 1) == 0) {
248 		if (addr->s6_addr[15] == 1) /* loopback */
249 			return IPV6_ADDR_SCOPE_LINKLOCAL;
250 		if (addr->s6_addr[15] == 0) /* unspecified */
251 			return IPV6_ADDR_SCOPE_GLOBAL; /* XXX: correct? */
252 	}
253 
254 	return IPV6_ADDR_SCOPE_GLOBAL;
255 }
256 
257 /*
258  * ifp - note that this might be NULL
259  */
260 
261 void
262 scope6_setdefault(struct ifnet *ifp)
263 {
264 	/*
265 	 * Currently, this function just sets the default "interfaces"
266 	 * and "links" according to the given interface.
267 	 * We might eventually have to separate the notion of "link" from
268 	 * "interface" and provide a user interface to set the default.
269 	 */
270 	SCOPE6_LOCK();
271 	if (ifp) {
272 		sid_default.s6id_list[IPV6_ADDR_SCOPE_INTFACELOCAL] =
273 			ifp->if_index;
274 		sid_default.s6id_list[IPV6_ADDR_SCOPE_LINKLOCAL] =
275 			ifp->if_index;
276 	} else {
277 		sid_default.s6id_list[IPV6_ADDR_SCOPE_INTFACELOCAL] = 0;
278 		sid_default.s6id_list[IPV6_ADDR_SCOPE_LINKLOCAL] = 0;
279 	}
280 	SCOPE6_UNLOCK();
281 }
282 
283 int
284 scope6_get_default(struct scope6_id *idlist)
285 {
286 
287 	SCOPE6_LOCK();
288 	*idlist = sid_default;
289 	SCOPE6_UNLOCK();
290 
291 	return (0);
292 }
293 
294 u_int32_t
295 scope6_addr2default(struct in6_addr *addr)
296 {
297 	u_int32_t id;
298 
299 	/*
300 	 * special case: The loopback address should be considered as
301 	 * link-local, but there's no ambiguity in the syntax.
302 	 */
303 	if (IN6_IS_ADDR_LOOPBACK(addr))
304 		return (0);
305 
306 	/*
307 	 * XXX: 32-bit read is atomic on all our platforms, is it OK
308 	 * not to lock here?
309 	 */
310 	SCOPE6_LOCK();
311 	id = sid_default.s6id_list[in6_addrscope(addr)];
312 	SCOPE6_UNLOCK();
313 	return (id);
314 }
315 
316 /*
317  * Validate the specified scope zone ID in the sin6_scope_id field.  If the ID
318  * is unspecified (=0), needs to be specified, and the default zone ID can be
319  * used, the default value will be used.
320  * This routine then generates the kernel-internal form: if the address scope
321  * of is interface-local or link-local, embed the interface index in the
322  * address.
323  */
324 int
325 sa6_embedscope(struct sockaddr_in6 *sin6, int defaultok)
326 {
327 	struct ifnet *ifp;
328 	u_int32_t zoneid;
329 
330 	if ((zoneid = sin6->sin6_scope_id) == 0 && defaultok)
331 		zoneid = scope6_addr2default(&sin6->sin6_addr);
332 
333 	if (zoneid != 0 &&
334 	    (IN6_IS_SCOPE_LINKLOCAL(&sin6->sin6_addr) ||
335 	    IN6_IS_ADDR_MC_INTFACELOCAL(&sin6->sin6_addr))) {
336 		/*
337 		 * At this moment, we only check interface-local and
338 		 * link-local scope IDs, and use interface indices as the
339 		 * zone IDs assuming a one-to-one mapping between interfaces
340 		 * and links.
341 		 */
342 		if (if_index < zoneid)
343 			return (ENXIO);
344 		ifp = ifnet_byindex(zoneid);
345 		if (ifp == NULL) /* XXX: this can happen for some OS */
346 			return (ENXIO);
347 
348 		/* XXX assignment to 16bit from 32bit variable */
349 		sin6->sin6_addr.s6_addr16[1] = htons(zoneid & 0xffff);
350 
351 		sin6->sin6_scope_id = 0;
352 	}
353 
354 	return 0;
355 }
356 
357 /*
358  * generate standard sockaddr_in6 from embedded form.
359  */
360 int
361 sa6_recoverscope(struct sockaddr_in6 *sin6)
362 {
363 	char ip6buf[INET6_ADDRSTRLEN];
364 	u_int32_t zoneid;
365 
366 	if (sin6->sin6_scope_id != 0) {
367 		log(LOG_NOTICE,
368 		    "sa6_recoverscope: assumption failure (non 0 ID): %s%%%d\n",
369 		    ip6_sprintf(ip6buf, &sin6->sin6_addr), sin6->sin6_scope_id);
370 		/* XXX: proceed anyway... */
371 	}
372 	if (IN6_IS_SCOPE_LINKLOCAL(&sin6->sin6_addr) ||
373 	    IN6_IS_ADDR_MC_INTFACELOCAL(&sin6->sin6_addr)) {
374 		/*
375 		 * KAME assumption: link id == interface id
376 		 */
377 		zoneid = ntohs(sin6->sin6_addr.s6_addr16[1]);
378 		if (zoneid) {
379 			/* sanity check */
380 			if (zoneid < 0 || if_index < zoneid)
381 				return (ENXIO);
382 			if (!ifnet_byindex(zoneid))
383 				return (ENXIO);
384 			sin6->sin6_addr.s6_addr16[1] = 0;
385 			sin6->sin6_scope_id = zoneid;
386 		}
387 	}
388 
389 	return 0;
390 }
391 
392 /*
393  * Determine the appropriate scope zone ID for in6 and ifp.  If ret_id is
394  * non NULL, it is set to the zone ID.  If the zone ID needs to be embedded
395  * in the in6_addr structure, in6 will be modified.
396  *
397  * ret_id - unnecessary?
398  */
399 int
400 in6_setscope(struct in6_addr *in6, struct ifnet *ifp, u_int32_t *ret_id)
401 {
402 	int scope;
403 	u_int32_t zoneid = 0;
404 	struct scope6_id *sid;
405 
406 	IF_AFDATA_LOCK(ifp);
407 
408 	sid = SID(ifp);
409 
410 #ifdef DIAGNOSTIC
411 	if (sid == NULL) { /* should not happen */
412 		panic("in6_setscope: scope array is NULL");
413 		/* NOTREACHED */
414 	}
415 #endif
416 
417 	/*
418 	 * special case: the loopback address can only belong to a loopback
419 	 * interface.
420 	 */
421 	if (IN6_IS_ADDR_LOOPBACK(in6)) {
422 		if (!(ifp->if_flags & IFF_LOOPBACK)) {
423 			IF_AFDATA_UNLOCK(ifp);
424 			return (EINVAL);
425 		} else {
426 			if (ret_id != NULL)
427 				*ret_id = 0; /* there's no ambiguity */
428 			IF_AFDATA_UNLOCK(ifp);
429 			return (0);
430 		}
431 	}
432 
433 	scope = in6_addrscope(in6);
434 
435 	SCOPE6_LOCK();
436 	switch (scope) {
437 	case IPV6_ADDR_SCOPE_INTFACELOCAL: /* should be interface index */
438 		zoneid = sid->s6id_list[IPV6_ADDR_SCOPE_INTFACELOCAL];
439 		break;
440 
441 	case IPV6_ADDR_SCOPE_LINKLOCAL:
442 		zoneid = sid->s6id_list[IPV6_ADDR_SCOPE_LINKLOCAL];
443 		break;
444 
445 	case IPV6_ADDR_SCOPE_SITELOCAL:
446 		zoneid = sid->s6id_list[IPV6_ADDR_SCOPE_SITELOCAL];
447 		break;
448 
449 	case IPV6_ADDR_SCOPE_ORGLOCAL:
450 		zoneid = sid->s6id_list[IPV6_ADDR_SCOPE_ORGLOCAL];
451 		break;
452 
453 	default:
454 		zoneid = 0;	/* XXX: treat as global. */
455 		break;
456 	}
457 	SCOPE6_UNLOCK();
458 	IF_AFDATA_UNLOCK(ifp);
459 
460 	if (ret_id != NULL)
461 		*ret_id = zoneid;
462 
463 	if (IN6_IS_SCOPE_LINKLOCAL(in6) || IN6_IS_ADDR_MC_INTFACELOCAL(in6))
464 		in6->s6_addr16[1] = htons(zoneid & 0xffff); /* XXX */
465 
466 	return (0);
467 }
468 
469 /*
470  * Just clear the embedded scope identifier.  Return 0 if the original address
471  * is intact; return non 0 if the address is modified.
472  */
473 int
474 in6_clearscope(struct in6_addr *in6)
475 {
476 	int modified = 0;
477 
478 	if (IN6_IS_SCOPE_LINKLOCAL(in6) || IN6_IS_ADDR_MC_INTFACELOCAL(in6)) {
479 		if (in6->s6_addr16[1] != 0)
480 			modified = 1;
481 		in6->s6_addr16[1] = 0;
482 	}
483 
484 	return (modified);
485 }
486