xref: /netbsd-src/sys/netinet6/scope6.c (revision d48f14661dda8638fee055ba15d35bdfb29b9fa8)
1 /*	$NetBSD: scope6.c,v 1.2 2006/03/05 01:28:51 rpaulo 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, 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(struct ifnet *ifp, struct scope6_id *idlist)
154 {
155 
156 	/* We only need to lock the interface's afdata for SID() to work. */
157 	struct scope6_id *sid = SID(ifp);
158 
159 	if (sid == NULL)	/* paranoid? */
160 		return (EINVAL);
161 
162 	*idlist = *sid;
163 
164 	return (0);
165 }
166 
167 /*
168  * Get a scope of the address. Interface-local, link-local, site-local
169  * or global.
170  */
171 int
172 in6_addrscope(struct in6_addr *addr)
173 {
174 	int scope;
175 
176 	if (addr->s6_addr[0] == 0xfe) {
177 		scope = addr->s6_addr[1] & 0xc0;
178 
179 		switch (scope) {
180 		case 0x80:
181 			return IPV6_ADDR_SCOPE_LINKLOCAL;
182 			break;
183 		case 0xc0:
184 			return IPV6_ADDR_SCOPE_SITELOCAL;
185 			break;
186 		default:
187 			return IPV6_ADDR_SCOPE_GLOBAL; /* just in case */
188 			break;
189 		}
190 	}
191 
192 
193 	if (addr->s6_addr[0] == 0xff) {
194 		scope = addr->s6_addr[1] & 0x0f;
195 
196 		/*
197 		 * due to other scope such as reserved,
198 		 * return scope doesn't work.
199 		 */
200 		switch (scope) {
201 		case IPV6_ADDR_SCOPE_INTFACELOCAL:
202 			return IPV6_ADDR_SCOPE_INTFACELOCAL;
203 			break;
204 		case IPV6_ADDR_SCOPE_LINKLOCAL:
205 			return IPV6_ADDR_SCOPE_LINKLOCAL;
206 			break;
207 		case IPV6_ADDR_SCOPE_SITELOCAL:
208 			return IPV6_ADDR_SCOPE_SITELOCAL;
209 			break;
210 		default:
211 			return IPV6_ADDR_SCOPE_GLOBAL;
212 			break;
213 		}
214 	}
215 
216 	if (bcmp(&in6addr_loopback, addr, sizeof(*addr) - 1) == 0) {
217 		if (addr->s6_addr[15] == 1) /* loopback */
218 			return IPV6_ADDR_SCOPE_LINKLOCAL;
219 		if (addr->s6_addr[15] == 0) {
220 			/*
221 			 * Regard the unspecified addresses as global,
222 			 * since it has no ambiguity.
223 			 * XXX: not sure if it's correct...
224 			 */
225 			return IPV6_ADDR_SCOPE_GLOBAL;
226 		}
227 	}
228 
229 	return IPV6_ADDR_SCOPE_GLOBAL;
230 }
231 
232 /* note that ifp argument might be NULL */
233 void
234 scope6_setdefault(struct ifnet *ifp)
235 {
236 
237 	/*
238 	 * Currently, this function just sets the default "interfaces"
239 	 * and "links" according to the given interface.
240 	 * We might eventually have to separate the notion of "link" from
241 	 * "interface" and provide a user interface to set the default.
242 	 */
243 	if (ifp) {
244 		sid_default.s6id_list[IPV6_ADDR_SCOPE_INTFACELOCAL] =
245 			ifp->if_index;
246 		sid_default.s6id_list[IPV6_ADDR_SCOPE_LINKLOCAL] =
247 			ifp->if_index;
248 	} else {
249 		sid_default.s6id_list[IPV6_ADDR_SCOPE_INTFACELOCAL] = 0;
250 		sid_default.s6id_list[IPV6_ADDR_SCOPE_LINKLOCAL] = 0;
251 	}
252 }
253 
254 int
255 scope6_get_default(struct scope6_id *idlist)
256 {
257 
258 	*idlist = sid_default;
259 
260 	return (0);
261 }
262 
263 uint32_t
264 scope6_addr2default(struct in6_addr *addr)
265 {
266 	uint32_t id;
267 
268 	/*
269 	 * special case: The loopback address should be considered as
270 	 * link-local, but there's no ambiguity in the syntax.
271 	 */
272 	if (IN6_IS_ADDR_LOOPBACK(addr))
273 		return (0);
274 
275 	/*
276 	 * XXX: 32-bit read is atomic on all our platforms, is it OK
277 	 * not to lock here?
278 	 */
279 	id = sid_default.s6id_list[in6_addrscope(addr)];
280 
281 	return (id);
282 }
283 
284 /*
285  * Validate the specified scope zone ID in the sin6_scope_id field.  If the ID
286  * is unspecified (=0), needs to be specified, and the default zone ID can be
287  * used, the default value will be used.
288  * This routine then generates the kernel-internal form: if the address scope
289  * of is interface-local or link-local, embed the interface index in the
290  * address.
291  */
292 int
293 sa6_embedscope(struct sockaddr_in6 *sin6, int defaultok)
294 {
295 	struct ifnet *ifp;
296 	uint32_t zoneid;
297 
298 	if ((zoneid = sin6->sin6_scope_id) == 0 && defaultok)
299 		zoneid = scope6_addr2default(&sin6->sin6_addr);
300 
301 	if (zoneid != 0 &&
302 	    (IN6_IS_SCOPE_LINKLOCAL(&sin6->sin6_addr) ||
303 	    IN6_IS_ADDR_MC_INTFACELOCAL(&sin6->sin6_addr))) {
304 		/*
305 		 * At this moment, we only check interface-local and
306 		 * link-local scope IDs, and use interface indices as the
307 		 * zone IDs assuming a one-to-one mapping between interfaces
308 		 * and links.
309 		 */
310 		if (if_indexlim <= zoneid)
311 			return (ENXIO);
312 #ifdef __FreeBSD__
313 		ifp = ifnet_byindex(zoneid);
314 #else
315 		ifp = ifindex2ifnet[zoneid];
316 #endif
317 		if (ifp == NULL) /* XXX: this can happen for some OS */
318 			return (ENXIO);
319 
320 		/* XXX assignment to 16bit from 32bit variable */
321 		sin6->sin6_addr.s6_addr16[1] = htons(zoneid & 0xffff);
322 
323 		sin6->sin6_scope_id = 0;
324 	}
325 
326 	return 0;
327 }
328 
329 /*
330  * generate standard sockaddr_in6 from embedded form.
331  */
332 int
333 sa6_recoverscope(struct sockaddr_in6 *sin6)
334 {
335 	uint32_t zoneid;
336 
337 	if (sin6->sin6_scope_id != 0) {
338 		log(LOG_NOTICE,
339 		    "sa6_recoverscope: assumption failure (non 0 ID): %s%%%d\n",
340 		    ip6_sprintf(&sin6->sin6_addr), sin6->sin6_scope_id);
341 		/* XXX: proceed anyway... */
342 	}
343 	if (IN6_IS_SCOPE_LINKLOCAL(&sin6->sin6_addr) ||
344 	    IN6_IS_ADDR_MC_INTFACELOCAL(&sin6->sin6_addr)) {
345 		/*
346 		 * KAME assumption: link id == interface id
347 		 */
348 		zoneid = ntohs(sin6->sin6_addr.s6_addr16[1]);
349 		if (zoneid) {
350 			/* sanity check */
351 			if (zoneid < 0 || if_indexlim <= zoneid)
352 				return (ENXIO);
353 #ifdef __FreeBSD__
354 			if (!ifnet_byindex(zoneid))
355 #else
356 			if (!ifindex2ifnet[zoneid])
357 #endif
358 				return (ENXIO);
359 			sin6->sin6_addr.s6_addr16[1] = 0;
360 			sin6->sin6_scope_id = zoneid;
361 		}
362 	}
363 
364 	return 0;
365 }
366 
367 /*
368  * Determine the appropriate scope zone ID for in6 and ifp.  If ret_id is
369  * non NULL, it is set to the zone ID.  If the zone ID needs to be embedded
370  * in the in6_addr structure, in6 will be modified.
371  */
372 int
373 in6_setscope(struct in6_addr *in6, struct ifnet *ifp, uint32_t *ret_id)
374 {
375 	int scope;
376 	uint32_t zoneid = 0;
377 	struct scope6_id *sid = SID(ifp);
378 
379 #ifdef DIAGNOSTIC
380 	if (sid == NULL) { /* should not happen */
381 		panic("in6_setscope: scope array is NULL");
382 		/* NOTREACHED */
383 	}
384 #endif
385 
386 	/*
387 	 * special case: the loopback address can only belong to a loopback
388 	 * interface.
389 	 */
390 	if (IN6_IS_ADDR_LOOPBACK(in6)) {
391 		if (!(ifp->if_flags & IFF_LOOPBACK))
392 			return (EINVAL);
393 		else {
394 			if (ret_id != NULL)
395 				*ret_id = 0; /* there's no ambiguity */
396 			return (0);
397 		}
398 	}
399 
400 	scope = in6_addrscope(in6);
401 
402 	if (!sid->s6id_list)
403 		return 0;
404 
405 	switch (scope) {
406 	case IPV6_ADDR_SCOPE_INTFACELOCAL: /* should be interface index */
407 		zoneid = sid->s6id_list[IPV6_ADDR_SCOPE_INTFACELOCAL];
408 		break;
409 
410 	case IPV6_ADDR_SCOPE_LINKLOCAL:
411 		zoneid = sid->s6id_list[IPV6_ADDR_SCOPE_LINKLOCAL];
412 		break;
413 
414 	case IPV6_ADDR_SCOPE_SITELOCAL:
415 		zoneid = sid->s6id_list[IPV6_ADDR_SCOPE_SITELOCAL];
416 		break;
417 
418 	case IPV6_ADDR_SCOPE_ORGLOCAL:
419 		zoneid = sid->s6id_list[IPV6_ADDR_SCOPE_ORGLOCAL];
420 		break;
421 
422 	default:
423 		zoneid = 0;	/* XXX: treat as global. */
424 		break;
425 	}
426 
427 	if (ret_id != NULL)
428 		*ret_id = zoneid;
429 
430 	if (IN6_IS_SCOPE_LINKLOCAL(in6) || IN6_IS_ADDR_MC_INTFACELOCAL(in6))
431 		in6->s6_addr16[1] = htons(zoneid & 0xffff); /* XXX */
432 
433 	return (0);
434 }
435 
436 /*
437  * Just clear the embedded scope identifier.  Return 0 if the original address
438  * is intact; return non 0 if the address is modified.
439  */
440 int
441 in6_clearscope(struct in6_addr *in6)
442 {
443 	int modified = 0;
444 
445 	if (IN6_IS_SCOPE_LINKLOCAL(in6) || IN6_IS_ADDR_MC_INTFACELOCAL(in6)) {
446 		if (in6->s6_addr16[1] != 0)
447 			modified = 1;
448 		in6->s6_addr16[1] = 0;
449 	}
450 
451 	return (modified);
452 }
453