xref: /netbsd-src/sys/netinet6/scope6.c (revision 0df165c04d0a9ca1adde9ed2b890344c937954a6)
1 /*	$NetBSD: scope6.c,v 1.5 2007/10/24 06:37:22 dyoung Exp $	*/
2 /*	$KAME$	*/
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 static struct scope6_id sid_default;
56 #define SID(ifp) \
57 	(((struct in6_ifextra *)(ifp)->if_afdata[AF_INET6])->scope6_id)
58 
59 void
60 scope6_init()
61 {
62 
63 	memset(&sid_default, 0, sizeof(sid_default));
64 }
65 
66 struct scope6_id *
67 scope6_ifattach(struct ifnet *ifp)
68 {
69 	struct scope6_id *sid;
70 
71 	sid = (struct scope6_id *)malloc(sizeof(*sid), M_IFADDR, M_WAITOK);
72 	memset(sid, 0, sizeof(*sid));
73 
74 	/*
75 	 * XXX: IPV6_ADDR_SCOPE_xxx macros are not standard.
76 	 * Should we rather hardcode here?
77 	 */
78 	sid->s6id_list[IPV6_ADDR_SCOPE_INTFACELOCAL] = ifp->if_index;
79 	sid->s6id_list[IPV6_ADDR_SCOPE_LINKLOCAL] = ifp->if_index;
80 #ifdef MULTI_SCOPE
81 	/* by default, we don't care about scope boundary for these scopes. */
82 	sid->s6id_list[IPV6_ADDR_SCOPE_SITELOCAL] = 1;
83 	sid->s6id_list[IPV6_ADDR_SCOPE_ORGLOCAL] = 1;
84 #endif
85 
86 	return sid;
87 }
88 
89 void
90 scope6_ifdetach(struct scope6_id *sid)
91 {
92 
93 	free(sid, M_IFADDR);
94 }
95 
96 int
97 scope6_set(struct ifnet *ifp, const struct scope6_id *idlist)
98 {
99 	int i;
100 	int error = 0;
101 	struct scope6_id *sid = NULL;
102 
103 	sid = SID(ifp);
104 
105 	if (!sid)	/* paranoid? */
106 		return (EINVAL);
107 
108 	/*
109 	 * XXX: We need more consistency checks of the relationship among
110 	 * scopes (e.g. an organization should be larger than a site).
111 	 */
112 
113 	/*
114 	 * TODO(XXX): after setting, we should reflect the changes to
115 	 * interface addresses, routing table entries, PCB entries...
116 	 */
117 
118 	for (i = 0; i < 16; i++) {
119 		if (idlist->s6id_list[i] &&
120 		    idlist->s6id_list[i] != sid->s6id_list[i]) {
121 			/*
122 			 * An interface zone ID must be the corresponding
123 			 * interface index by definition.
124 			 */
125 			if (i == IPV6_ADDR_SCOPE_INTFACELOCAL &&
126 			    idlist->s6id_list[i] != ifp->if_index)
127 				return (EINVAL);
128 
129 			if (i == IPV6_ADDR_SCOPE_LINKLOCAL &&
130 			    idlist->s6id_list[i] >= if_indexlim) {
131 				/*
132 				 * XXX: theoretically, there should be no
133 				 * relationship between link IDs and interface
134 				 * IDs, but we check the consistency for
135 				 * safety in later use.
136 				 */
137 				return (EINVAL);
138 			}
139 
140 			/*
141 			 * XXX: we must need lots of work in this case,
142 			 * but we simply set the new value in this initial
143 			 * implementation.
144 			 */
145 			sid->s6id_list[i] = idlist->s6id_list[i];
146 		}
147 	}
148 
149 	return (error);
150 }
151 
152 int
153 scope6_get(const struct ifnet *ifp, struct scope6_id *idlist)
154 {
155 	/* We only need to lock the interface's afdata for SID() to work. */
156 	const struct scope6_id *sid = SID(ifp);
157 
158 	if (sid == NULL)	/* paranoid? */
159 		return EINVAL;
160 
161 	*idlist = *sid;
162 
163 	return 0;
164 }
165 
166 /*
167  * Get a scope of the address. Interface-local, link-local, site-local
168  * or global.
169  */
170 int
171 in6_addrscope(const struct in6_addr *addr)
172 {
173 	int scope;
174 
175 	if (addr->s6_addr[0] == 0xfe) {
176 		scope = addr->s6_addr[1] & 0xc0;
177 
178 		switch (scope) {
179 		case 0x80:
180 			return IPV6_ADDR_SCOPE_LINKLOCAL;
181 			break;
182 		case 0xc0:
183 			return IPV6_ADDR_SCOPE_SITELOCAL;
184 			break;
185 		default:
186 			return IPV6_ADDR_SCOPE_GLOBAL; /* just in case */
187 			break;
188 		}
189 	}
190 
191 
192 	if (addr->s6_addr[0] == 0xff) {
193 		scope = addr->s6_addr[1] & 0x0f;
194 
195 		/*
196 		 * due to other scope such as reserved,
197 		 * return scope doesn't work.
198 		 */
199 		switch (scope) {
200 		case IPV6_ADDR_SCOPE_INTFACELOCAL:
201 			return IPV6_ADDR_SCOPE_INTFACELOCAL;
202 			break;
203 		case IPV6_ADDR_SCOPE_LINKLOCAL:
204 			return IPV6_ADDR_SCOPE_LINKLOCAL;
205 			break;
206 		case IPV6_ADDR_SCOPE_SITELOCAL:
207 			return IPV6_ADDR_SCOPE_SITELOCAL;
208 			break;
209 		default:
210 			return IPV6_ADDR_SCOPE_GLOBAL;
211 			break;
212 		}
213 	}
214 
215 	if (memcmp(&in6addr_loopback, addr, sizeof(*addr) - 1) == 0) {
216 		if (addr->s6_addr[15] == 1) /* loopback */
217 			return IPV6_ADDR_SCOPE_LINKLOCAL;
218 		if (addr->s6_addr[15] == 0) {
219 			/*
220 			 * Regard the unspecified addresses as global,
221 			 * since it has no ambiguity.
222 			 * XXX: not sure if it's correct...
223 			 */
224 			return IPV6_ADDR_SCOPE_GLOBAL;
225 		}
226 	}
227 
228 	return IPV6_ADDR_SCOPE_GLOBAL;
229 }
230 
231 /* note that ifp argument might be NULL */
232 void
233 scope6_setdefault(struct ifnet *ifp)
234 {
235 
236 	/*
237 	 * Currently, this function just sets the default "interfaces"
238 	 * and "links" according to the given interface.
239 	 * We might eventually have to separate the notion of "link" from
240 	 * "interface" and provide a user interface to set the default.
241 	 */
242 	if (ifp) {
243 		sid_default.s6id_list[IPV6_ADDR_SCOPE_INTFACELOCAL] =
244 			ifp->if_index;
245 		sid_default.s6id_list[IPV6_ADDR_SCOPE_LINKLOCAL] =
246 			ifp->if_index;
247 	} else {
248 		sid_default.s6id_list[IPV6_ADDR_SCOPE_INTFACELOCAL] = 0;
249 		sid_default.s6id_list[IPV6_ADDR_SCOPE_LINKLOCAL] = 0;
250 	}
251 }
252 
253 int
254 scope6_get_default(struct scope6_id *idlist)
255 {
256 
257 	*idlist = sid_default;
258 
259 	return (0);
260 }
261 
262 uint32_t
263 scope6_addr2default(const struct in6_addr *addr)
264 {
265 	uint32_t id;
266 
267 	/*
268 	 * special case: The loopback address should be considered as
269 	 * link-local, but there's no ambiguity in the syntax.
270 	 */
271 	if (IN6_IS_ADDR_LOOPBACK(addr))
272 		return (0);
273 
274 	/*
275 	 * XXX: 32-bit read is atomic on all our platforms, is it OK
276 	 * not to lock here?
277 	 */
278 	id = sid_default.s6id_list[in6_addrscope(addr)];
279 
280 	return (id);
281 }
282 
283 /*
284  * Validate the specified scope zone ID in the sin6_scope_id field.  If the ID
285  * is unspecified (=0), needs to be specified, and the default zone ID can be
286  * used, the default value will be used.
287  * This routine then generates the kernel-internal form: if the address scope
288  * of is interface-local or link-local, embed the interface index in the
289  * address.
290  */
291 int
292 sa6_embedscope(struct sockaddr_in6 *sin6, int defaultok)
293 {
294 	struct ifnet *ifp;
295 	uint32_t zoneid;
296 
297 	if ((zoneid = sin6->sin6_scope_id) == 0 && defaultok)
298 		zoneid = scope6_addr2default(&sin6->sin6_addr);
299 
300 	if (zoneid != 0 &&
301 	    (IN6_IS_SCOPE_LINKLOCAL(&sin6->sin6_addr) ||
302 	    IN6_IS_ADDR_MC_INTFACELOCAL(&sin6->sin6_addr))) {
303 		/*
304 		 * At this moment, we only check interface-local and
305 		 * link-local scope IDs, and use interface indices as the
306 		 * zone IDs assuming a one-to-one mapping between interfaces
307 		 * and links.
308 		 */
309 		if (if_indexlim <= zoneid)
310 			return (ENXIO);
311 #ifdef __FreeBSD__
312 		ifp = ifnet_byindex(zoneid);
313 #else
314 		ifp = ifindex2ifnet[zoneid];
315 #endif
316 		if (ifp == NULL) /* XXX: this can happen for some OS */
317 			return (ENXIO);
318 
319 		/* XXX assignment to 16bit from 32bit variable */
320 		sin6->sin6_addr.s6_addr16[1] = htons(zoneid & 0xffff);
321 
322 		sin6->sin6_scope_id = 0;
323 	}
324 
325 	return 0;
326 }
327 
328 /*
329  * generate standard sockaddr_in6 from embedded form.
330  */
331 int
332 sa6_recoverscope(struct sockaddr_in6 *sin6)
333 {
334 	uint32_t zoneid;
335 
336 	if (sin6->sin6_scope_id != 0) {
337 		log(LOG_NOTICE,
338 		    "sa6_recoverscope: assumption failure (non 0 ID): %s%%%d\n",
339 		    ip6_sprintf(&sin6->sin6_addr), sin6->sin6_scope_id);
340 		/* XXX: proceed anyway... */
341 	}
342 	if (IN6_IS_SCOPE_LINKLOCAL(&sin6->sin6_addr) ||
343 	    IN6_IS_ADDR_MC_INTFACELOCAL(&sin6->sin6_addr)) {
344 		/*
345 		 * KAME assumption: link id == interface id
346 		 */
347 		zoneid = ntohs(sin6->sin6_addr.s6_addr16[1]);
348 		if (zoneid) {
349 			/* sanity check */
350 			if (/* zoneid < 0 || */ if_indexlim <= zoneid)
351 				return (ENXIO);
352 #ifdef __FreeBSD__
353 			if (!ifnet_byindex(zoneid))
354 #else
355 			if (!ifindex2ifnet[zoneid])
356 #endif
357 				return (ENXIO);
358 			sin6->sin6_addr.s6_addr16[1] = 0;
359 			sin6->sin6_scope_id = zoneid;
360 		}
361 	}
362 
363 	return 0;
364 }
365 
366 int
367 in6_setzoneid(struct in6_addr *in6, uint32_t zoneid)
368 {
369 	if (IN6_IS_SCOPE_EMBEDDABLE(in6))
370 		in6->s6_addr16[1] = htons(zoneid & 0xffff); /* XXX */
371 
372 	return 0;
373 }
374 
375 /*
376  * Determine the appropriate scope zone ID for in6 and ifp.  If ret_id is
377  * non NULL, it is set to the zone ID.  If the zone ID needs to be embedded
378  * in the in6_addr structure, in6 will be modified.
379  */
380 int
381 in6_setscope(struct in6_addr *in6, const struct ifnet *ifp, uint32_t *ret_id)
382 {
383 	int scope;
384 	uint32_t zoneid = 0;
385 	const struct scope6_id *sid = SID(ifp);
386 
387 #ifdef DIAGNOSTIC
388 	if (sid == NULL) { /* should not happen */
389 		panic("in6_setscope: scope array is NULL");
390 		/* NOTREACHED */
391 	}
392 #endif
393 
394 	/*
395 	 * special case: the loopback address can only belong to a loopback
396 	 * interface.
397 	 */
398 	if (IN6_IS_ADDR_LOOPBACK(in6)) {
399 		if (!(ifp->if_flags & IFF_LOOPBACK))
400 			return (EINVAL);
401 		else {
402 			if (ret_id != NULL)
403 				*ret_id = 0; /* there's no ambiguity */
404 			return (0);
405 		}
406 	}
407 
408 	scope = in6_addrscope(in6);
409 
410 	if (!sid->s6id_list)
411 		return 0;
412 
413 	switch (scope) {
414 	case IPV6_ADDR_SCOPE_INTFACELOCAL: /* should be interface index */
415 		zoneid = sid->s6id_list[IPV6_ADDR_SCOPE_INTFACELOCAL];
416 		break;
417 
418 	case IPV6_ADDR_SCOPE_LINKLOCAL:
419 		zoneid = sid->s6id_list[IPV6_ADDR_SCOPE_LINKLOCAL];
420 		break;
421 
422 	case IPV6_ADDR_SCOPE_SITELOCAL:
423 		zoneid = sid->s6id_list[IPV6_ADDR_SCOPE_SITELOCAL];
424 		break;
425 
426 	case IPV6_ADDR_SCOPE_ORGLOCAL:
427 		zoneid = sid->s6id_list[IPV6_ADDR_SCOPE_ORGLOCAL];
428 		break;
429 
430 	default:
431 		zoneid = 0;	/* XXX: treat as global. */
432 		break;
433 	}
434 
435 	if (ret_id != NULL)
436 		*ret_id = zoneid;
437 
438 	return in6_setzoneid(in6, zoneid);
439 }
440 
441 /*
442  * Just clear the embedded scope identifier.  Return 0 if the original address
443  * is intact; return non 0 if the address is modified.
444  */
445 int
446 in6_clearscope(struct in6_addr *in6)
447 {
448 	int modified = 0;
449 
450 	if (IN6_IS_SCOPE_LINKLOCAL(in6) || IN6_IS_ADDR_MC_INTFACELOCAL(in6)) {
451 		if (in6->s6_addr16[1] != 0)
452 			modified = 1;
453 		in6->s6_addr16[1] = 0;
454 	}
455 
456 	return (modified);
457 }
458