1 /*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (C) 2000 WIDE Project.
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of the project nor the names of its contributors
16 * may be used to endorse or promote products derived from this software
17 * without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 *
31 * $KAME: scope6.c,v 1.10 2000/07/24 13:29:31 itojun Exp $
32 */
33
34 #include <sys/cdefs.h>
35 #include <sys/param.h>
36 #include <sys/malloc.h>
37 #include <sys/mbuf.h>
38 #include <sys/socket.h>
39 #include <sys/sockio.h>
40 #include <sys/systm.h>
41 #include <sys/queue.h>
42 #include <sys/sysctl.h>
43 #include <sys/syslog.h>
44
45 #include <net/if.h>
46 #include <net/if_var.h>
47 #include <net/vnet.h>
48
49 #include <netinet/in.h>
50
51 #include <netinet/ip6.h>
52 #include <netinet6/in6_var.h>
53 #include <netinet6/ip6_var.h>
54 #include <netinet6/scope6_var.h>
55
56 #ifdef ENABLE_DEFAULT_SCOPE
57 VNET_DEFINE(int, ip6_use_defzone) = 1;
58 #else
59 VNET_DEFINE(int, ip6_use_defzone) = 0;
60 #endif
61 SYSCTL_DECL(_net_inet6_ip6);
62
63 /*
64 * The scope6_lock protects the global sid default stored in
65 * sid_default below.
66 */
67 static struct mtx scope6_lock;
68 #define SCOPE6_LOCK_INIT() mtx_init(&scope6_lock, "scope6_lock", NULL, MTX_DEF)
69 #define SCOPE6_LOCK() mtx_lock(&scope6_lock)
70 #define SCOPE6_UNLOCK() mtx_unlock(&scope6_lock)
71 #define SCOPE6_LOCK_ASSERT() mtx_assert(&scope6_lock, MA_OWNED)
72
73 VNET_DEFINE_STATIC(struct scope6_id, sid_default);
74 #define V_sid_default VNET(sid_default)
75
76 #define SID(ifp) \
77 (((struct in6_ifextra *)(ifp)->if_afdata[AF_INET6])->scope6_id)
78
79 static int scope6_get(struct ifnet *, struct scope6_id *);
80 static int scope6_set(struct ifnet *, struct scope6_id *);
81
82 void
scope6_init(void)83 scope6_init(void)
84 {
85
86 bzero(&V_sid_default, sizeof(V_sid_default));
87
88 if (!IS_DEFAULT_VNET(curvnet))
89 return;
90
91 SCOPE6_LOCK_INIT();
92 }
93
94 struct scope6_id *
scope6_ifattach(struct ifnet * ifp)95 scope6_ifattach(struct ifnet *ifp)
96 {
97 struct scope6_id *sid;
98
99 sid = malloc(sizeof(*sid), M_IFADDR, M_WAITOK | M_ZERO);
100 /*
101 * XXX: IPV6_ADDR_SCOPE_xxx macros are not standard.
102 * Should we rather hardcode here?
103 */
104 sid->s6id_list[IPV6_ADDR_SCOPE_INTFACELOCAL] = ifp->if_index;
105 sid->s6id_list[IPV6_ADDR_SCOPE_LINKLOCAL] = ifp->if_index;
106 return (sid);
107 }
108
109 void
scope6_ifdetach(struct scope6_id * sid)110 scope6_ifdetach(struct scope6_id *sid)
111 {
112
113 free(sid, M_IFADDR);
114 }
115
116 int
scope6_ioctl(u_long cmd,caddr_t data,struct ifnet * ifp)117 scope6_ioctl(u_long cmd, caddr_t data, struct ifnet *ifp)
118 {
119 struct in6_ifreq *ifr;
120
121 if (ifp->if_afdata[AF_INET6] == NULL)
122 return (EPFNOSUPPORT);
123
124 ifr = (struct in6_ifreq *)data;
125 switch (cmd) {
126 case SIOCSSCOPE6:
127 return (scope6_set(ifp,
128 (struct scope6_id *)ifr->ifr_ifru.ifru_scope_id));
129 case SIOCGSCOPE6:
130 return (scope6_get(ifp,
131 (struct scope6_id *)ifr->ifr_ifru.ifru_scope_id));
132 case SIOCGSCOPE6DEF:
133 return (scope6_get_default(
134 (struct scope6_id *)ifr->ifr_ifru.ifru_scope_id));
135 default:
136 return (EOPNOTSUPP);
137 }
138 }
139
140 static int
scope6_set(struct ifnet * ifp,struct scope6_id * idlist)141 scope6_set(struct ifnet *ifp, struct scope6_id *idlist)
142 {
143 int i;
144 int error = 0;
145 struct scope6_id *sid = NULL;
146
147 IF_AFDATA_WLOCK(ifp);
148 sid = SID(ifp);
149
150 if (!sid) { /* paranoid? */
151 IF_AFDATA_WUNLOCK(ifp);
152 return (EINVAL);
153 }
154
155 /*
156 * XXX: We need more consistency checks of the relationship among
157 * scopes (e.g. an organization should be larger than a site).
158 */
159
160 /*
161 * TODO(XXX): after setting, we should reflect the changes to
162 * interface addresses, routing table entries, PCB entries...
163 */
164
165 for (i = 0; i < 16; i++) {
166 if (idlist->s6id_list[i] &&
167 idlist->s6id_list[i] != sid->s6id_list[i]) {
168 /*
169 * An interface zone ID must be the corresponding
170 * interface index by definition.
171 */
172 if (i == IPV6_ADDR_SCOPE_INTFACELOCAL &&
173 idlist->s6id_list[i] != ifp->if_index) {
174 IF_AFDATA_WUNLOCK(ifp);
175 return (EINVAL);
176 }
177
178 if (i == IPV6_ADDR_SCOPE_LINKLOCAL &&
179 idlist->s6id_list[i] > V_if_index) {
180 /*
181 * XXX: theoretically, there should be no
182 * relationship between link IDs and interface
183 * IDs, but we check the consistency for
184 * safety in later use.
185 */
186 IF_AFDATA_WUNLOCK(ifp);
187 return (EINVAL);
188 }
189
190 /*
191 * XXX: we must need lots of work in this case,
192 * but we simply set the new value in this initial
193 * implementation.
194 */
195 sid->s6id_list[i] = idlist->s6id_list[i];
196 }
197 }
198 IF_AFDATA_WUNLOCK(ifp);
199
200 return (error);
201 }
202
203 static int
scope6_get(struct ifnet * ifp,struct scope6_id * idlist)204 scope6_get(struct ifnet *ifp, struct scope6_id *idlist)
205 {
206 struct epoch_tracker et;
207 struct scope6_id *sid;
208
209 /* We only need to lock the interface's afdata for SID() to work. */
210 NET_EPOCH_ENTER(et);
211 sid = SID(ifp);
212 if (sid == NULL) { /* paranoid? */
213 NET_EPOCH_EXIT(et);
214 return (EINVAL);
215 }
216
217 *idlist = *sid;
218
219 NET_EPOCH_EXIT(et);
220 return (0);
221 }
222
223 /*
224 * Get a scope of the address. Node-local, link-local, site-local or global.
225 */
226 int
in6_addrscope(const struct in6_addr * addr)227 in6_addrscope(const struct in6_addr *addr)
228 {
229
230 if (IN6_IS_ADDR_MULTICAST(addr)) {
231 /*
232 * Addresses with reserved value F must be treated as
233 * global multicast addresses.
234 */
235 if (IPV6_ADDR_MC_SCOPE(addr) == 0x0f)
236 return (IPV6_ADDR_SCOPE_GLOBAL);
237 return (IPV6_ADDR_MC_SCOPE(addr));
238 }
239 if (IN6_IS_ADDR_LINKLOCAL(addr) ||
240 IN6_IS_ADDR_LOOPBACK(addr))
241 return (IPV6_ADDR_SCOPE_LINKLOCAL);
242 if (IN6_IS_ADDR_SITELOCAL(addr))
243 return (IPV6_ADDR_SCOPE_SITELOCAL);
244 return (IPV6_ADDR_SCOPE_GLOBAL);
245 }
246
247 /*
248 * ifp - note that this might be NULL
249 */
250
251 void
scope6_setdefault(struct ifnet * ifp)252 scope6_setdefault(struct ifnet *ifp)
253 {
254
255 /*
256 * Currently, this function just sets the default "interfaces"
257 * and "links" according to the given interface.
258 * We might eventually have to separate the notion of "link" from
259 * "interface" and provide a user interface to set the default.
260 */
261 SCOPE6_LOCK();
262 if (ifp) {
263 V_sid_default.s6id_list[IPV6_ADDR_SCOPE_INTFACELOCAL] =
264 ifp->if_index;
265 V_sid_default.s6id_list[IPV6_ADDR_SCOPE_LINKLOCAL] =
266 ifp->if_index;
267 } else {
268 V_sid_default.s6id_list[IPV6_ADDR_SCOPE_INTFACELOCAL] = 0;
269 V_sid_default.s6id_list[IPV6_ADDR_SCOPE_LINKLOCAL] = 0;
270 }
271 SCOPE6_UNLOCK();
272 }
273
274 int
scope6_get_default(struct scope6_id * idlist)275 scope6_get_default(struct scope6_id *idlist)
276 {
277
278 SCOPE6_LOCK();
279 *idlist = V_sid_default;
280 SCOPE6_UNLOCK();
281
282 return (0);
283 }
284
285 u_int32_t
scope6_addr2default(struct in6_addr * addr)286 scope6_addr2default(struct in6_addr *addr)
287 {
288 u_int32_t id;
289
290 /*
291 * special case: The loopback address should be considered as
292 * link-local, but there's no ambiguity in the syntax.
293 */
294 if (IN6_IS_ADDR_LOOPBACK(addr))
295 return (0);
296
297 /*
298 * XXX: 32-bit read is atomic on all our platforms, is it OK
299 * not to lock here?
300 */
301 SCOPE6_LOCK();
302 id = V_sid_default.s6id_list[in6_addrscope(addr)];
303 SCOPE6_UNLOCK();
304 return (id);
305 }
306
307 /*
308 * Validate the specified scope zone ID in the sin6_scope_id field. If the ID
309 * is unspecified (=0), needs to be specified, and the default zone ID can be
310 * used, the default value will be used.
311 * This routine then generates the kernel-internal form: if the address scope
312 * of is interface-local or link-local, embed the interface index in the
313 * address.
314 */
315 int
sa6_embedscope(struct sockaddr_in6 * sin6,int defaultok)316 sa6_embedscope(struct sockaddr_in6 *sin6, int defaultok)
317 {
318 u_int32_t zoneid;
319
320 if ((zoneid = sin6->sin6_scope_id) == 0 && defaultok)
321 zoneid = scope6_addr2default(&sin6->sin6_addr);
322
323 if (zoneid != 0 &&
324 (IN6_IS_SCOPE_LINKLOCAL(&sin6->sin6_addr) ||
325 IN6_IS_ADDR_MC_INTFACELOCAL(&sin6->sin6_addr))) {
326 /*
327 * At this moment, we only check interface-local and
328 * link-local scope IDs, and use interface indices as the
329 * zone IDs assuming a one-to-one mapping between interfaces
330 * and links.
331 */
332 if (V_if_index < zoneid || ifnet_byindex(zoneid) == NULL)
333 return (ENXIO);
334
335 /* XXX assignment to 16bit from 32bit variable */
336 sin6->sin6_addr.s6_addr16[1] = htons(zoneid & 0xffff);
337 sin6->sin6_scope_id = 0;
338 }
339
340 return 0;
341 }
342
343 /*
344 * generate standard sockaddr_in6 from embedded form.
345 */
346 int
sa6_recoverscope(struct sockaddr_in6 * sin6)347 sa6_recoverscope(struct sockaddr_in6 *sin6)
348 {
349 char ip6buf[INET6_ADDRSTRLEN];
350 u_int32_t zoneid;
351
352 if (IN6_IS_SCOPE_LINKLOCAL(&sin6->sin6_addr) ||
353 IN6_IS_ADDR_MC_INTFACELOCAL(&sin6->sin6_addr)) {
354 /*
355 * KAME assumption: link id == interface id
356 */
357 zoneid = ntohs(sin6->sin6_addr.s6_addr16[1]);
358 if (zoneid) {
359 /* sanity check */
360 if (V_if_index < zoneid)
361 return (ENXIO);
362 #if 0
363 /* XXX: Disabled due to possible deadlock. */
364 if (!ifnet_byindex(zoneid))
365 return (ENXIO);
366 #endif
367 if (sin6->sin6_scope_id != 0 &&
368 zoneid != sin6->sin6_scope_id) {
369 log(LOG_NOTICE,
370 "%s: embedded scope mismatch: %s%%%d. "
371 "sin6_scope_id was overridden\n", __func__,
372 ip6_sprintf(ip6buf, &sin6->sin6_addr),
373 sin6->sin6_scope_id);
374 }
375 sin6->sin6_addr.s6_addr16[1] = 0;
376 sin6->sin6_scope_id = zoneid;
377 }
378 }
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 *
388 * ret_id - unnecessary?
389 */
390 int
in6_setscope(struct in6_addr * in6,struct ifnet * ifp,u_int32_t * ret_id)391 in6_setscope(struct in6_addr *in6, struct ifnet *ifp, u_int32_t *ret_id)
392 {
393 int scope;
394 u_int32_t zoneid = 0;
395 struct scope6_id *sid;
396
397 /*
398 * special case: the loopback address can only belong to a loopback
399 * interface.
400 */
401 if (IN6_IS_ADDR_LOOPBACK(in6)) {
402 if (!(ifp->if_flags & IFF_LOOPBACK))
403 return (EINVAL);
404 } else {
405 scope = in6_addrscope(in6);
406 if (scope == IPV6_ADDR_SCOPE_INTFACELOCAL ||
407 scope == IPV6_ADDR_SCOPE_LINKLOCAL) {
408 /*
409 * Currently we use interface indices as the
410 * zone IDs for interface-local and link-local
411 * scopes.
412 */
413 zoneid = ifp->if_index;
414 in6->s6_addr16[1] = htons(zoneid & 0xffff); /* XXX */
415 } else if (scope != IPV6_ADDR_SCOPE_GLOBAL) {
416 struct epoch_tracker et;
417
418 NET_EPOCH_ENTER(et);
419 if (ifp->if_afdata[AF_INET6] == NULL) {
420 NET_EPOCH_EXIT(et);
421 return (ENETDOWN);
422 }
423 sid = SID(ifp);
424 zoneid = sid->s6id_list[scope];
425 NET_EPOCH_EXIT(et);
426 }
427 }
428
429 if (ret_id != NULL)
430 *ret_id = zoneid;
431
432 return (0);
433 }
434
435 /*
436 * Just clear the embedded scope identifier. Return 0 if the original address
437 * is intact; return non 0 if the address is modified.
438 */
439 int
in6_clearscope(struct in6_addr * in6)440 in6_clearscope(struct in6_addr *in6)
441 {
442 int modified = 0;
443
444 if (IN6_IS_SCOPE_LINKLOCAL(in6) || IN6_IS_ADDR_MC_INTFACELOCAL(in6)) {
445 if (in6->s6_addr16[1] != 0)
446 modified = 1;
447 in6->s6_addr16[1] = 0;
448 }
449
450 return (modified);
451 }
452
453 /*
454 * Return the scope identifier or zero.
455 */
456 uint16_t
in6_getscope(const struct in6_addr * in6)457 in6_getscope(const struct in6_addr *in6)
458 {
459
460 if (IN6_IS_SCOPE_LINKLOCAL(in6) || IN6_IS_ADDR_MC_INTFACELOCAL(in6))
461 return (in6->s6_addr16[1]);
462
463 return (0);
464 }
465
466 /*
467 * Returns scope zone id for the unicast address @in6.
468 *
469 * Returns 0 for global unicast and loopback addresses.
470 * Returns interface index for the link-local addresses.
471 */
472 uint32_t
in6_get_unicast_scopeid(const struct in6_addr * in6,const struct ifnet * ifp)473 in6_get_unicast_scopeid(const struct in6_addr *in6, const struct ifnet *ifp)
474 {
475
476 if (IN6_IS_SCOPE_LINKLOCAL(in6))
477 return (ifp->if_index);
478 return (0);
479 }
480
481 void
in6_set_unicast_scopeid(struct in6_addr * in6,uint32_t scopeid)482 in6_set_unicast_scopeid(struct in6_addr *in6, uint32_t scopeid)
483 {
484
485 in6->s6_addr16[1] = htons(scopeid & 0xffff);
486 }
487
488 /*
489 * Return pointer to ifnet structure, corresponding to the zone id of
490 * link-local scope.
491 */
492 struct ifnet*
in6_getlinkifnet(uint32_t zoneid)493 in6_getlinkifnet(uint32_t zoneid)
494 {
495
496 return (ifnet_byindex((u_short)zoneid));
497 }
498
499 /*
500 * Return zone id for the specified scope.
501 */
502 uint32_t
in6_getscopezone(const struct ifnet * ifp,int scope)503 in6_getscopezone(const struct ifnet *ifp, int scope)
504 {
505
506 if (scope == IPV6_ADDR_SCOPE_INTFACELOCAL ||
507 scope == IPV6_ADDR_SCOPE_LINKLOCAL)
508 return (ifp->if_index);
509 if (scope >= 0 && scope < IPV6_ADDR_SCOPES_COUNT)
510 return (SID(ifp)->s6id_list[scope]);
511 return (0);
512 }
513
514 /*
515 * Extracts scope from address @dst, stores cleared address
516 * inside @dst and zone inside @scopeid
517 */
518 void
in6_splitscope(const struct in6_addr * src,struct in6_addr * dst,uint32_t * scopeid)519 in6_splitscope(const struct in6_addr *src, struct in6_addr *dst,
520 uint32_t *scopeid)
521 {
522 uint32_t zoneid;
523
524 *dst = *src;
525 zoneid = ntohs(in6_getscope(dst));
526 in6_clearscope(dst);
527 *scopeid = zoneid;
528 }
529
530 /*
531 * This function is for checking sockaddr_in6 structure passed
532 * from the application level (usually).
533 *
534 * sin6_scope_id should be set for link-local unicast, link-local and
535 * interface-local multicast addresses.
536 *
537 * If it is zero, then look into default zone ids. If default zone id is
538 * not set or disabled, then return error.
539 */
540 int
sa6_checkzone(struct sockaddr_in6 * sa6)541 sa6_checkzone(struct sockaddr_in6 *sa6)
542 {
543 int scope;
544
545 scope = in6_addrscope(&sa6->sin6_addr);
546 if (scope == IPV6_ADDR_SCOPE_GLOBAL)
547 return (sa6->sin6_scope_id ? EINVAL: 0);
548 if (IN6_IS_ADDR_MULTICAST(&sa6->sin6_addr) &&
549 scope != IPV6_ADDR_SCOPE_LINKLOCAL &&
550 scope != IPV6_ADDR_SCOPE_INTFACELOCAL) {
551 if (sa6->sin6_scope_id == 0 && V_ip6_use_defzone != 0)
552 sa6->sin6_scope_id = V_sid_default.s6id_list[scope];
553 return (0);
554 }
555 /*
556 * Since ::1 address always configured on the lo0, we can
557 * automatically set its zone id, when it is not specified.
558 * Return error, when specified zone id doesn't match with
559 * actual value.
560 */
561 if (IN6_IS_ADDR_LOOPBACK(&sa6->sin6_addr)) {
562 if (sa6->sin6_scope_id == 0)
563 sa6->sin6_scope_id = in6_getscopezone(V_loif, scope);
564 else if (sa6->sin6_scope_id != in6_getscopezone(V_loif, scope))
565 return (EADDRNOTAVAIL);
566 }
567 /* XXX: we can validate sin6_scope_id here */
568 if (sa6->sin6_scope_id != 0)
569 return (0);
570 if (V_ip6_use_defzone != 0)
571 sa6->sin6_scope_id = V_sid_default.s6id_list[scope];
572 /* Return error if we can't determine zone id */
573 return (sa6->sin6_scope_id ? 0: EADDRNOTAVAIL);
574 }
575
576 /*
577 * This function is similar to sa6_checkzone, but it uses given ifp
578 * to initialize sin6_scope_id.
579 */
580 int
sa6_checkzone_ifp(struct ifnet * ifp,struct sockaddr_in6 * sa6)581 sa6_checkzone_ifp(struct ifnet *ifp, struct sockaddr_in6 *sa6)
582 {
583 int scope;
584
585 scope = in6_addrscope(&sa6->sin6_addr);
586 if (scope == IPV6_ADDR_SCOPE_LINKLOCAL ||
587 scope == IPV6_ADDR_SCOPE_INTFACELOCAL) {
588 if (sa6->sin6_scope_id == 0) {
589 sa6->sin6_scope_id = in6_getscopezone(ifp, scope);
590 return (0);
591 } else if (sa6->sin6_scope_id != in6_getscopezone(ifp, scope))
592 return (EADDRNOTAVAIL);
593 }
594 return (sa6_checkzone(sa6));
595 }
596