xref: /netbsd-src/sys/netinet6/scope6.c (revision 946379e7b37692fc43f68eb0d1c10daa0a7f3b6c)
1 /*	$NetBSD: scope6.c,v 1.11 2014/12/10 01:10:37 christos 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/cdefs.h>
34 __KERNEL_RCSID(0, "$NetBSD: scope6.c,v 1.11 2014/12/10 01:10:37 christos Exp $");
35 
36 #include <sys/param.h>
37 #include <sys/malloc.h>
38 #include <sys/mbuf.h>
39 #include <sys/socket.h>
40 #include <sys/systm.h>
41 #include <sys/queue.h>
42 #include <sys/syslog.h>
43 
44 #include <net/route.h>
45 #include <net/if.h>
46 
47 #include <netinet/in.h>
48 
49 #include <netinet6/in6_var.h>
50 #include <netinet6/scope6_var.h>
51 
52 #ifdef ENABLE_DEFAULT_SCOPE
53 int ip6_use_defzone = 1;
54 #else
55 int ip6_use_defzone = 0;
56 #endif
57 
58 static struct scope6_id sid_default;
59 #define SID(ifp) \
60 	(((struct in6_ifextra *)(ifp)->if_afdata[AF_INET6])->scope6_id)
61 
62 void
63 scope6_init(void)
64 {
65 
66 	memset(&sid_default, 0, sizeof(sid_default));
67 }
68 
69 struct scope6_id *
70 scope6_ifattach(struct ifnet *ifp)
71 {
72 	struct scope6_id *sid;
73 
74 	sid = (struct scope6_id *)malloc(sizeof(*sid), M_IFADDR, M_WAITOK);
75 	memset(sid, 0, sizeof(*sid));
76 
77 	/*
78 	 * XXX: IPV6_ADDR_SCOPE_xxx macros are not standard.
79 	 * Should we rather hardcode here?
80 	 */
81 	sid->s6id_list[IPV6_ADDR_SCOPE_INTFACELOCAL] = ifp->if_index;
82 	sid->s6id_list[IPV6_ADDR_SCOPE_LINKLOCAL] = ifp->if_index;
83 #ifdef MULTI_SCOPE
84 	/* by default, we don't care about scope boundary for these scopes. */
85 	sid->s6id_list[IPV6_ADDR_SCOPE_SITELOCAL] = 1;
86 	sid->s6id_list[IPV6_ADDR_SCOPE_ORGLOCAL] = 1;
87 #endif
88 
89 	return sid;
90 }
91 
92 void
93 scope6_ifdetach(struct scope6_id *sid)
94 {
95 
96 	free(sid, M_IFADDR);
97 }
98 
99 int
100 scope6_set(struct ifnet *ifp, const struct scope6_id *idlist)
101 {
102 	int i;
103 	int error = 0;
104 	struct scope6_id *sid = NULL;
105 
106 	sid = SID(ifp);
107 
108 	if (!sid)	/* paranoid? */
109 		return (EINVAL);
110 
111 	/*
112 	 * XXX: We need more consistency checks of the relationship among
113 	 * scopes (e.g. an organization should be larger than a site).
114 	 */
115 
116 	/*
117 	 * TODO(XXX): after setting, we should reflect the changes to
118 	 * interface addresses, routing table entries, PCB entries...
119 	 */
120 
121 	for (i = 0; i < 16; i++) {
122 		if (idlist->s6id_list[i] &&
123 		    idlist->s6id_list[i] != sid->s6id_list[i]) {
124 			/*
125 			 * An interface zone ID must be the corresponding
126 			 * interface index by definition.
127 			 */
128 			if (i == IPV6_ADDR_SCOPE_INTFACELOCAL &&
129 			    idlist->s6id_list[i] != ifp->if_index)
130 				return (EINVAL);
131 
132 			if (i == IPV6_ADDR_SCOPE_LINKLOCAL &&
133 			    !if_byindex(idlist->s6id_list[i])) {
134 				/*
135 				 * XXX: theoretically, there should be no
136 				 * relationship between link IDs and interface
137 				 * IDs, but we check the consistency for
138 				 * safety in later use.
139 				 */
140 				return (EINVAL);
141 			}
142 
143 			/*
144 			 * XXX: we must need lots of work in this case,
145 			 * but we simply set the new value in this initial
146 			 * implementation.
147 			 */
148 			sid->s6id_list[i] = idlist->s6id_list[i];
149 		}
150 	}
151 
152 	return (error);
153 }
154 
155 int
156 scope6_get(const struct ifnet *ifp, struct scope6_id *idlist)
157 {
158 	/* We only need to lock the interface's afdata for SID() to work. */
159 	const struct scope6_id *sid = SID(ifp);
160 
161 	if (sid == NULL)	/* paranoid? */
162 		return EINVAL;
163 
164 	*idlist = *sid;
165 
166 	return 0;
167 }
168 
169 /*
170  * Get a scope of the address. Interface-local, link-local, site-local
171  * or global.
172  */
173 int
174 in6_addrscope(const struct in6_addr *addr)
175 {
176 	int scope;
177 
178 	if (addr->s6_addr[0] == 0xfe) {
179 		scope = addr->s6_addr[1] & 0xc0;
180 
181 		switch (scope) {
182 		case 0x80:
183 			return IPV6_ADDR_SCOPE_LINKLOCAL;
184 		case 0xc0:
185 			return IPV6_ADDR_SCOPE_SITELOCAL;
186 		default:
187 			return IPV6_ADDR_SCOPE_GLOBAL; /* just in case */
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 		case IPV6_ADDR_SCOPE_LINKLOCAL:
203 			return IPV6_ADDR_SCOPE_LINKLOCAL;
204 		case IPV6_ADDR_SCOPE_SITELOCAL:
205 			return IPV6_ADDR_SCOPE_SITELOCAL;
206 		default:
207 			return IPV6_ADDR_SCOPE_GLOBAL;
208 		}
209 	}
210 
211 	if (memcmp(&in6addr_loopback, addr, sizeof(*addr) - 1) == 0) {
212 		if (addr->s6_addr[15] == 1) /* loopback */
213 			return IPV6_ADDR_SCOPE_LINKLOCAL;
214 		if (addr->s6_addr[15] == 0) {
215 			/*
216 			 * Regard the unspecified addresses as global,
217 			 * since it has no ambiguity.
218 			 * XXX: not sure if it's correct...
219 			 */
220 			return IPV6_ADDR_SCOPE_GLOBAL;
221 		}
222 	}
223 
224 	return IPV6_ADDR_SCOPE_GLOBAL;
225 }
226 
227 /* note that ifp argument might be NULL */
228 void
229 scope6_setdefault(struct ifnet *ifp)
230 {
231 
232 	/*
233 	 * Currently, this function just sets the default "interfaces"
234 	 * and "links" according to the given interface.
235 	 * We might eventually have to separate the notion of "link" from
236 	 * "interface" and provide a user interface to set the default.
237 	 */
238 	if (ifp) {
239 		sid_default.s6id_list[IPV6_ADDR_SCOPE_INTFACELOCAL] =
240 			ifp->if_index;
241 		sid_default.s6id_list[IPV6_ADDR_SCOPE_LINKLOCAL] =
242 			ifp->if_index;
243 	} else {
244 		sid_default.s6id_list[IPV6_ADDR_SCOPE_INTFACELOCAL] = 0;
245 		sid_default.s6id_list[IPV6_ADDR_SCOPE_LINKLOCAL] = 0;
246 	}
247 }
248 
249 int
250 scope6_get_default(struct scope6_id *idlist)
251 {
252 
253 	*idlist = sid_default;
254 
255 	return (0);
256 }
257 
258 uint32_t
259 scope6_addr2default(const struct in6_addr *addr)
260 {
261 	uint32_t id;
262 
263 	/*
264 	 * special case: The loopback address should be considered as
265 	 * link-local, but there's no ambiguity in the syntax.
266 	 */
267 	if (IN6_IS_ADDR_LOOPBACK(addr))
268 		return (0);
269 
270 	/*
271 	 * XXX: 32-bit read is atomic on all our platforms, is it OK
272 	 * not to lock here?
273 	 */
274 	id = sid_default.s6id_list[in6_addrscope(addr)];
275 
276 	return (id);
277 }
278 
279 /*
280  * Validate the specified scope zone ID in the sin6_scope_id field.  If the ID
281  * is unspecified (=0), needs to be specified, and the default zone ID can be
282  * used, the default value will be used.
283  * This routine then generates the kernel-internal form: if the address scope
284  * of is interface-local or link-local, embed the interface index in the
285  * address.
286  */
287 int
288 sa6_embedscope(struct sockaddr_in6 *sin6, int defaultok)
289 {
290 	struct ifnet *ifp;
291 	uint32_t zoneid;
292 
293 	if ((zoneid = sin6->sin6_scope_id) == 0 && defaultok)
294 		zoneid = scope6_addr2default(&sin6->sin6_addr);
295 
296 	if (zoneid != 0 &&
297 	    (IN6_IS_SCOPE_LINKLOCAL(&sin6->sin6_addr) ||
298 	    IN6_IS_ADDR_MC_INTFACELOCAL(&sin6->sin6_addr))) {
299 		/*
300 		 * At this moment, we only check interface-local and
301 		 * link-local scope IDs, and use interface indices as the
302 		 * zone IDs assuming a one-to-one mapping between interfaces
303 		 * and links.
304 		 */
305 		ifp = if_byindex(zoneid);
306 		if (ifp == NULL)
307 			return (ENXIO);
308 
309 		/* XXX assignment to 16bit from 32bit variable */
310 		sin6->sin6_addr.s6_addr16[1] = htons(zoneid & 0xffff);
311 
312 		sin6->sin6_scope_id = 0;
313 	}
314 
315 	return 0;
316 }
317 
318 struct sockaddr *
319 sockaddr_in6_externalize(struct sockaddr *dst, socklen_t socklen,
320     const struct sockaddr *src)
321 {
322 	struct sockaddr_in6 *sin6;
323 
324 	sin6 = satosin6(sockaddr_copy(dst, socklen, src));
325 
326 	if (sin6 == NULL || sa6_recoverscope(sin6) != 0)
327 		return NULL;
328 
329 	return dst;
330 }
331 
332 /*
333  * generate standard sockaddr_in6 from embedded form.
334  */
335 int
336 sa6_recoverscope(struct sockaddr_in6 *sin6)
337 {
338 	uint32_t zoneid;
339 
340 	if (sin6->sin6_scope_id != 0) {
341 		log(LOG_NOTICE,
342 		    "sa6_recoverscope: assumption failure (non 0 ID): %s%%%d\n",
343 		    ip6_sprintf(&sin6->sin6_addr), sin6->sin6_scope_id);
344 		/* XXX: proceed anyway... */
345 	}
346 	if (IN6_IS_SCOPE_LINKLOCAL(&sin6->sin6_addr) ||
347 	    IN6_IS_ADDR_MC_INTFACELOCAL(&sin6->sin6_addr)) {
348 		/*
349 		 * KAME assumption: link id == interface id
350 		 */
351 		zoneid = ntohs(sin6->sin6_addr.s6_addr16[1]);
352 		if (zoneid) {
353 			if (!if_byindex(zoneid))
354 				return (ENXIO);
355 			sin6->sin6_addr.s6_addr16[1] = 0;
356 			sin6->sin6_scope_id = zoneid;
357 		}
358 	}
359 
360 	return 0;
361 }
362 
363 int
364 in6_setzoneid(struct in6_addr *in6, uint32_t zoneid)
365 {
366 	if (IN6_IS_SCOPE_EMBEDDABLE(in6))
367 		in6->s6_addr16[1] = htons(zoneid & 0xffff); /* XXX */
368 
369 	return 0;
370 }
371 
372 /*
373  * Determine the appropriate scope zone ID for in6 and ifp.  If ret_id is
374  * non NULL, it is set to the zone ID.  If the zone ID needs to be embedded
375  * in the in6_addr structure, in6 will be modified.
376  */
377 int
378 in6_setscope(struct in6_addr *in6, const struct ifnet *ifp, uint32_t *ret_id)
379 {
380 	int scope;
381 	uint32_t zoneid = 0;
382 	const struct scope6_id *sid = SID(ifp);
383 
384 #ifdef DIAGNOSTIC
385 	if (sid == NULL) { /* should not happen */
386 		panic("in6_setscope: scope array is NULL");
387 		/* NOTREACHED */
388 	}
389 #endif
390 
391 	/*
392 	 * special case: the loopback address can only belong to a loopback
393 	 * interface.
394 	 */
395 	if (IN6_IS_ADDR_LOOPBACK(in6)) {
396 		if (!(ifp->if_flags & IFF_LOOPBACK))
397 			return (EINVAL);
398 		else {
399 			if (ret_id != NULL)
400 				*ret_id = 0; /* there's no ambiguity */
401 			return (0);
402 		}
403 	}
404 
405 	scope = in6_addrscope(in6);
406 
407 	switch (scope) {
408 	case IPV6_ADDR_SCOPE_INTFACELOCAL: /* should be interface index */
409 		zoneid = sid->s6id_list[IPV6_ADDR_SCOPE_INTFACELOCAL];
410 		break;
411 
412 	case IPV6_ADDR_SCOPE_LINKLOCAL:
413 		zoneid = sid->s6id_list[IPV6_ADDR_SCOPE_LINKLOCAL];
414 		break;
415 
416 	case IPV6_ADDR_SCOPE_SITELOCAL:
417 		zoneid = sid->s6id_list[IPV6_ADDR_SCOPE_SITELOCAL];
418 		break;
419 
420 	case IPV6_ADDR_SCOPE_ORGLOCAL:
421 		zoneid = sid->s6id_list[IPV6_ADDR_SCOPE_ORGLOCAL];
422 		break;
423 
424 	default:
425 		zoneid = 0;	/* XXX: treat as global. */
426 		break;
427 	}
428 
429 	if (ret_id != NULL)
430 		*ret_id = zoneid;
431 
432 	return in6_setzoneid(in6, zoneid);
433 }
434 
435 const char *
436 in6_getscopename(const struct in6_addr *addr)
437 {
438 	switch (in6_addrscope(addr)) {
439 	case IPV6_ADDR_SCOPE_INTFACELOCAL:	return "interface";
440 #if IPV6_ADDR_SCOPE_INTFACELOCAL != IPV6_ADDR_SCOPE_NODELOCAL
441 	case IPV6_ADDR_SCOPE_NODELOCAL:		return "node";
442 #endif
443 	case IPV6_ADDR_SCOPE_LINKLOCAL:		return "link";
444 	case IPV6_ADDR_SCOPE_SITELOCAL:		return "site";
445 	case IPV6_ADDR_SCOPE_ORGLOCAL:		return "organization";
446 	case IPV6_ADDR_SCOPE_GLOBAL:		return "global";
447 	default:				return "unknown";
448 	}
449 }
450 
451 /*
452  * Just clear the embedded scope identifier.  Return 0 if the original address
453  * is intact; return non 0 if the address is modified.
454  */
455 int
456 in6_clearscope(struct in6_addr *in6)
457 {
458 	int modified = 0;
459 
460 	if (IN6_IS_SCOPE_LINKLOCAL(in6) || IN6_IS_ADDR_MC_INTFACELOCAL(in6)) {
461 		if (in6->s6_addr16[1] != 0)
462 			modified = 1;
463 		in6->s6_addr16[1] = 0;
464 	}
465 
466 	return (modified);
467 }
468