1/* $NetBSD: scope6.c,v 1.15 2016/08/12 11:44:24 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 1.15 2016/08/12 11:44:24 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/if.h>
45
46#include <netinet/in.h>
47
48#include <netinet6/in6_var.h>
49#include <netinet6/scope6_var.h>
50
51#ifdef ENABLE_DEFAULT_SCOPE
52int ip6_use_defzone = 1;
53#else
54int ip6_use_defzone = 0;
55#endif
56
57static struct scope6_id sid_default;
58#define SID(ifp) \
59 ((ifp)->if_afdata[AF_INET6] == NULL ? NULL : \
60 ((struct in6_ifextra *)(ifp)->if_afdata[AF_INET6])->scope6_id)
61
62void
63scope6_init(void)
64{
65
66 memset(&sid_default, 0, sizeof(sid_default));
67}
68
69struct scope6_id *
70scope6_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
92void
93scope6_ifdetach(struct scope6_id *sid)
94{
95
96 free(sid, M_IFADDR);
97}
98
99int
100scope6_set(struct ifnet *ifp, const struct scope6_id *idlist)
101{
102 int i;
103 int error = 0;
104 struct scope6_id *sid = SID(ifp);
105
106 if (!sid) /* paranoid? */
107 return (EINVAL);
108
109 /*
110 * XXX: We need more consistency checks of the relationship among
111 * scopes (e.g. an organization should be larger than a site).
112 */
113
114 /*
115 * TODO(XXX): after setting, we should reflect the changes to
116 * interface addresses, routing table entries, PCB entries...
117 */
118
119 for (i = 0; i < 16; i++) {
120 if (idlist->s6id_list[i] &&
121 idlist->s6id_list[i] != sid->s6id_list[i]) {
122 int s;
123 /*
124 * An interface zone ID must be the corresponding
125 * interface index by definition.
126 */
127 if (i == IPV6_ADDR_SCOPE_INTFACELOCAL &&
128 idlist->s6id_list[i] != ifp->if_index)
129 return (EINVAL);
130
131 s = pserialize_read_enter();
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 pserialize_read_exit(s);
141 return (EINVAL);
142 }
143 pserialize_read_exit(s);
144
145 /*
146 * XXX: we must need lots of work in this case,
147 * but we simply set the new value in this initial
148 * implementation.
149 */
150 sid->s6id_list[i] = idlist->s6id_list[i];
151 }
152 }
153
154 return (error);
155}
156
157int
158scope6_get(const struct ifnet *ifp, struct scope6_id *idlist)
159{
160 /* We only need to lock the interface's afdata for SID() to work. */
161 const struct scope6_id *sid = SID(ifp);
162
163 if (sid == NULL) /* paranoid? */
164 return EINVAL;
165
166 *idlist = *sid;
167
168 return 0;
169}
170
171/*
172 * Get a scope of the address. Interface-local, link-local, site-local
173 * or global.
174 */
175int
176in6_addrscope(const struct in6_addr *addr)
177{
178 int scope;
179
180 if (addr->s6_addr[0] == 0xfe) {
181 scope = addr->s6_addr[1] & 0xc0;
182
183 switch (scope) {
184 case 0x80:
185 return IPV6_ADDR_SCOPE_LINKLOCAL;
186 case 0xc0:
187 return IPV6_ADDR_SCOPE_SITELOCAL;
188 default:
189 return IPV6_ADDR_SCOPE_GLOBAL; /* just in case */
190 }
191 }
192
193
194 if (addr->s6_addr[0] == 0xff) {
195 scope = addr->s6_addr[1] & 0x0f;
196
197 /*
198 * due to other scope such as reserved,
199 * return scope doesn't work.
200 */
201 switch (scope) {
202 case IPV6_ADDR_SCOPE_INTFACELOCAL:
203 return IPV6_ADDR_SCOPE_INTFACELOCAL;
204 case IPV6_ADDR_SCOPE_LINKLOCAL:
205 return IPV6_ADDR_SCOPE_LINKLOCAL;
206 case IPV6_ADDR_SCOPE_SITELOCAL:
207 return IPV6_ADDR_SCOPE_SITELOCAL;
208 default:
209 return IPV6_ADDR_SCOPE_GLOBAL;
210 }
211 }
212
213 if (memcmp(&in6addr_loopback, addr, sizeof(*addr) - 1) == 0) {
214 if (addr->s6_addr[15] == 1) /* loopback */
215 return IPV6_ADDR_SCOPE_LINKLOCAL;
216 if (addr->s6_addr[15] == 0) {
217 /*
218 * Regard the unspecified addresses as global,
219 * since it has no ambiguity.
220 * XXX: not sure if it's correct...
221 */
222 return IPV6_ADDR_SCOPE_GLOBAL;
223 }
224 }
225
226 return IPV6_ADDR_SCOPE_GLOBAL;
227}
228
229/* note that ifp argument might be NULL */
230void
231scope6_setdefault(struct ifnet *ifp)
232{
233
234 /*
235 * Currently, this function just sets the default "interfaces"
236 * and "links" according to the given interface.
237 * We might eventually have to separate the notion of "link" from
238 * "interface" and provide a user interface to set the default.
239 */
240 if (ifp) {
241 sid_default.s6id_list[IPV6_ADDR_SCOPE_INTFACELOCAL] =
242 ifp->if_index;
243 sid_default.s6id_list[IPV6_ADDR_SCOPE_LINKLOCAL] =
244 ifp->if_index;
245 } else {
246 sid_default.s6id_list[IPV6_ADDR_SCOPE_INTFACELOCAL] = 0;
247 sid_default.s6id_list[IPV6_ADDR_SCOPE_LINKLOCAL] = 0;
248 }
249}
250
251int
252scope6_get_default(struct scope6_id *idlist)
253{
254
255 *idlist = sid_default;
256
257 return (0);
258}
259
260uint32_t
261scope6_addr2default(const struct in6_addr *addr)
262{
263 uint32_t id;
264
265 /*
266 * special case: The loopback address should be considered as
267 * link-local, but there's no ambiguity in the syntax.
268 */
269 if (IN6_IS_ADDR_LOOPBACK(addr))
270 return (0);
271
272 /*
273 * XXX: 32-bit read is atomic on all our platforms, is it OK
274 * not to lock here?
275 */
276 id = sid_default.s6id_list[in6_addrscope(addr)];
277
278 return (id);
279}
280
281/*
282 * Validate the specified scope zone ID in the sin6_scope_id field. If the ID
283 * is unspecified (=0), needs to be specified, and the default zone ID can be
284 * used, the default value will be used.
285 * This routine then generates the kernel-internal form: if the address scope
286 * of is interface-local or link-local, embed the interface index in the
287 * address.
288 */
289int
290sa6_embedscope(struct sockaddr_in6 *sin6, int defaultok)
291{
292 struct ifnet *ifp;
293 uint32_t zoneid;
294
295 if ((zoneid = sin6->sin6_scope_id) == 0 && defaultok)
296 zoneid = scope6_addr2default(&sin6->sin6_addr);
297
298 if (zoneid != 0 &&
299 (IN6_IS_SCOPE_LINKLOCAL(&sin6->sin6_addr) ||
300 IN6_IS_ADDR_MC_INTFACELOCAL(&sin6->sin6_addr))) {
301 int s;
302 /*
303 * At this moment, we only check interface-local and
304 * link-local scope IDs, and use interface indices as the
305 * zone IDs assuming a one-to-one mapping between interfaces
306 * and links.
307 */
308 s = pserialize_read_enter();
309 ifp = if_byindex(zoneid);
310 if (ifp == NULL) {
311 pserialize_read_exit(s);
312 return (ENXIO);
313 }
314 pserialize_read_exit(s);
315
316 /* XXX assignment to 16bit from 32bit variable */
317 sin6->sin6_addr.s6_addr16[1] = htons(zoneid & 0xffff);
318
319 sin6->sin6_scope_id = 0;
320 }
321
322 return 0;
323}
324
325struct sockaddr *
326sockaddr_in6_externalize(struct sockaddr *dst, socklen_t socklen,
327 const struct sockaddr *src)
328{
329 struct sockaddr_in6 *sin6;
330
331 sin6 = satosin6(sockaddr_copy(dst, socklen, src));
332
333 if (sin6 == NULL || sa6_recoverscope(sin6) != 0)
334 return NULL;
335
336 return dst;
337}
338
339/*
340 * generate standard sockaddr_in6 from embedded form.
341 */
342int
343sa6_recoverscope(struct sockaddr_in6 *sin6)
344{
345 uint32_t zoneid;
346
347 if (sin6->sin6_scope_id != 0) {
348 log(LOG_NOTICE,
349 "sa6_recoverscope: assumption failure (non 0 ID): %s%%%d\n",
350 ip6_sprintf(&sin6->sin6_addr), sin6->sin6_scope_id);
351 /* XXX: proceed anyway... */
352 }
353 if (IN6_IS_SCOPE_LINKLOCAL(&sin6->sin6_addr) ||
354 IN6_IS_ADDR_MC_INTFACELOCAL(&sin6->sin6_addr)) {
355 /*
356 * KAME assumption: link id == interface id
357 */
358 zoneid = ntohs(sin6->sin6_addr.s6_addr16[1]);
359 if (zoneid) {
360 int s = pserialize_read_enter();
361 if (!if_byindex(zoneid)) {
362 pserialize_read_exit(s);
363 return (ENXIO);
364 }
365 pserialize_read_exit(s);
366 sin6->sin6_addr.s6_addr16[1] = 0;
367 sin6->sin6_scope_id = zoneid;
368 }
369 }
370
371 return 0;
372}
373
374int
375in6_setzoneid(struct in6_addr *in6, uint32_t zoneid)
376{
377 if (IN6_IS_SCOPE_EMBEDDABLE(in6))
378 in6->s6_addr16[1] = htons(zoneid & 0xffff); /* XXX */
379
380 return 0;
381}
382
383/*
384 * Determine the appropriate scope zone ID for in6 and ifp. If ret_id is
385 * non NULL, it is set to the zone ID. If the zone ID needs to be embedded
386 * in the in6_addr structure, in6 will be modified.
387 */
388int
389in6_setscope(struct in6_addr *in6, const struct ifnet *ifp, uint32_t *ret_id)
390{
391 int scope;
392 uint32_t zoneid = 0;
393 const struct scope6_id *sid = SID(ifp);
394
395 if (sid == NULL)
396 return EINVAL;
397
398 /*
399 * special case: the loopback address can only belong to a loopback
400 * interface.
401 */
402 if (IN6_IS_ADDR_LOOPBACK(in6)) {
403 if (!(ifp->if_flags & IFF_LOOPBACK))
404 return (EINVAL);
405 else {
406 if (ret_id != NULL)
407 *ret_id = 0; /* there's no ambiguity */
408 return (0);
409 }
410 }
411
412 scope = in6_addrscope(in6);
413
414 switch (scope) {
415 case IPV6_ADDR_SCOPE_INTFACELOCAL: /* should be interface index */
416 zoneid = sid->s6id_list[IPV6_ADDR_SCOPE_INTFACELOCAL];
417 break;
418
419 case IPV6_ADDR_SCOPE_LINKLOCAL:
420 zoneid = sid->s6id_list[IPV6_ADDR_SCOPE_LINKLOCAL];
421 break;
422
423 case IPV6_ADDR_SCOPE_SITELOCAL:
424 zoneid = sid->s6id_list[IPV6_ADDR_SCOPE_SITELOCAL];
425 break;
426
427 case IPV6_ADDR_SCOPE_ORGLOCAL:
428 zoneid = sid->s6id_list[IPV6_ADDR_SCOPE_ORGLOCAL];
429 break;
430
431 default:
432 zoneid = 0; /* XXX: treat as global. */
433 break;
434 }
435
436 if (ret_id != NULL)
437 *ret_id = zoneid;
438
439 return in6_setzoneid(in6, zoneid);
440}
441
442const char *
443in6_getscopename(const struct in6_addr *addr)
444{
445 switch (in6_addrscope(addr)) {
446 case IPV6_ADDR_SCOPE_INTFACELOCAL: return "interface";
447#if IPV6_ADDR_SCOPE_INTFACELOCAL != IPV6_ADDR_SCOPE_NODELOCAL
448 case IPV6_ADDR_SCOPE_NODELOCAL: return "node";
449#endif
450 case IPV6_ADDR_SCOPE_LINKLOCAL: return "link";
451 case IPV6_ADDR_SCOPE_SITELOCAL: return "site";
452 case IPV6_ADDR_SCOPE_ORGLOCAL: return "organization";
453 case IPV6_ADDR_SCOPE_GLOBAL: return "global";
454 default: return "unknown";
455 }
456}
457
458/*
459 * Just clear the embedded scope identifier. Return 0 if the original address
460 * is intact; return non 0 if the address is modified.
461 */
462int
463in6_clearscope(struct in6_addr *in6)
464{
465 int modified = 0;
466
467 if (IN6_IS_SCOPE_LINKLOCAL(in6) || IN6_IS_ADDR_MC_INTFACELOCAL(in6)) {
468 if (in6->s6_addr16[1] != 0)
469 modified = 1;
470 in6->s6_addr16[1] = 0;
471 }
472
473 return (modified);
474}
475