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/param.h>
35 #include <sys/malloc.h>
36 #include <sys/mbuf.h>
37 #include <sys/socket.h>
38 #include <sys/sockio.h>
39 #include <sys/systm.h>
40 #include <sys/queue.h>
41 #include <sys/sysctl.h>
42 #include <sys/syslog.h>
43
44 #include <net/if.h>
45 #include <net/if_var.h>
46 #include <net/if_private.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 struct epoch_tracker et;
180
181 NET_EPOCH_ENTER(et);
182 if (!ifnet_byindex(idlist->s6id_list[i])) {
183 /*
184 * XXX: theoretically, there should be
185 * no relationship between link IDs and
186 * interface IDs, but we check the
187 * consistency for safety in later use.
188 */
189 NET_EPOCH_EXIT(et);
190 IF_AFDATA_WUNLOCK(ifp);
191 return (EINVAL);
192 }
193 NET_EPOCH_EXIT(et);
194 }
195
196 /*
197 * XXX: we must need lots of work in this case,
198 * but we simply set the new value in this initial
199 * implementation.
200 */
201 sid->s6id_list[i] = idlist->s6id_list[i];
202 }
203 }
204 IF_AFDATA_WUNLOCK(ifp);
205
206 return (error);
207 }
208
209 static int
scope6_get(struct ifnet * ifp,struct scope6_id * idlist)210 scope6_get(struct ifnet *ifp, struct scope6_id *idlist)
211 {
212 struct epoch_tracker et;
213 struct scope6_id *sid;
214
215 /* We only need to lock the interface's afdata for SID() to work. */
216 NET_EPOCH_ENTER(et);
217 sid = SID(ifp);
218 if (sid == NULL) { /* paranoid? */
219 NET_EPOCH_EXIT(et);
220 return (EINVAL);
221 }
222
223 *idlist = *sid;
224
225 NET_EPOCH_EXIT(et);
226 return (0);
227 }
228
229 /*
230 * Get a scope of the address. Node-local, link-local, site-local or global.
231 */
232 int
in6_addrscope(const struct in6_addr * addr)233 in6_addrscope(const struct in6_addr *addr)
234 {
235
236 if (IN6_IS_ADDR_MULTICAST(addr)) {
237 /*
238 * Addresses with reserved value F must be treated as
239 * global multicast addresses.
240 */
241 if (IPV6_ADDR_MC_SCOPE(addr) == 0x0f)
242 return (IPV6_ADDR_SCOPE_GLOBAL);
243 return (IPV6_ADDR_MC_SCOPE(addr));
244 }
245 if (IN6_IS_ADDR_LINKLOCAL(addr) ||
246 IN6_IS_ADDR_LOOPBACK(addr))
247 return (IPV6_ADDR_SCOPE_LINKLOCAL);
248 if (IN6_IS_ADDR_SITELOCAL(addr))
249 return (IPV6_ADDR_SCOPE_SITELOCAL);
250 return (IPV6_ADDR_SCOPE_GLOBAL);
251 }
252
253 /*
254 * ifp - note that this might be NULL
255 */
256
257 void
scope6_setdefault(struct ifnet * ifp)258 scope6_setdefault(struct ifnet *ifp)
259 {
260
261 /*
262 * Currently, this function just sets the default "interfaces"
263 * and "links" according to the given interface.
264 * We might eventually have to separate the notion of "link" from
265 * "interface" and provide a user interface to set the default.
266 */
267 SCOPE6_LOCK();
268 if (ifp) {
269 V_sid_default.s6id_list[IPV6_ADDR_SCOPE_INTFACELOCAL] =
270 ifp->if_index;
271 V_sid_default.s6id_list[IPV6_ADDR_SCOPE_LINKLOCAL] =
272 ifp->if_index;
273 } else {
274 V_sid_default.s6id_list[IPV6_ADDR_SCOPE_INTFACELOCAL] = 0;
275 V_sid_default.s6id_list[IPV6_ADDR_SCOPE_LINKLOCAL] = 0;
276 }
277 SCOPE6_UNLOCK();
278 }
279
280 int
scope6_get_default(struct scope6_id * idlist)281 scope6_get_default(struct scope6_id *idlist)
282 {
283
284 SCOPE6_LOCK();
285 *idlist = V_sid_default;
286 SCOPE6_UNLOCK();
287
288 return (0);
289 }
290
291 u_int32_t
scope6_addr2default(struct in6_addr * addr)292 scope6_addr2default(struct in6_addr *addr)
293 {
294 u_int32_t id;
295
296 /*
297 * special case: The loopback address should be considered as
298 * link-local, but there's no ambiguity in the syntax.
299 */
300 if (IN6_IS_ADDR_LOOPBACK(addr))
301 return (0);
302
303 /*
304 * XXX: 32-bit read is atomic on all our platforms, is it OK
305 * not to lock here?
306 */
307 SCOPE6_LOCK();
308 id = V_sid_default.s6id_list[in6_addrscope(addr)];
309 SCOPE6_UNLOCK();
310 return (id);
311 }
312
313 /*
314 * Validate the specified scope zone ID in the sin6_scope_id field. If the ID
315 * is unspecified (=0), needs to be specified, and the default zone ID can be
316 * used, the default value will be used.
317 * This routine then generates the kernel-internal form: if the address scope
318 * of is interface-local or link-local, embed the interface index in the
319 * address.
320 */
321 int
sa6_embedscope(struct sockaddr_in6 * sin6,int defaultok)322 sa6_embedscope(struct sockaddr_in6 *sin6, int defaultok)
323 {
324 u_int32_t zoneid;
325
326 if ((zoneid = sin6->sin6_scope_id) == 0 && defaultok)
327 zoneid = scope6_addr2default(&sin6->sin6_addr);
328
329 if (zoneid != 0 &&
330 (IN6_IS_SCOPE_LINKLOCAL(&sin6->sin6_addr) ||
331 IN6_IS_ADDR_MC_INTFACELOCAL(&sin6->sin6_addr))) {
332 struct epoch_tracker et;
333
334 /*
335 * At this moment, we only check interface-local and
336 * link-local scope IDs, and use interface indices as the
337 * zone IDs assuming a one-to-one mapping between interfaces
338 * and links.
339 */
340 NET_EPOCH_ENTER(et);
341 if (ifnet_byindex(zoneid) == NULL) {
342 NET_EPOCH_EXIT(et);
343 return (ENXIO);
344 }
345 NET_EPOCH_EXIT(et);
346
347 /* XXX assignment to 16bit from 32bit variable */
348 sin6->sin6_addr.s6_addr16[1] = htons(zoneid & 0xffff);
349 sin6->sin6_scope_id = 0;
350 }
351
352 return 0;
353 }
354
355 /*
356 * generate standard sockaddr_in6 from embedded form.
357 */
358 int
sa6_recoverscope(struct sockaddr_in6 * sin6)359 sa6_recoverscope(struct sockaddr_in6 *sin6)
360 {
361 char ip6buf[INET6_ADDRSTRLEN];
362 u_int32_t zoneid;
363
364 if (IN6_IS_SCOPE_LINKLOCAL(&sin6->sin6_addr) ||
365 IN6_IS_ADDR_MC_INTFACELOCAL(&sin6->sin6_addr)) {
366 /*
367 * KAME assumption: link id == interface id
368 */
369 zoneid = ntohs(sin6->sin6_addr.s6_addr16[1]);
370 if (zoneid) {
371 struct epoch_tracker et;
372
373 NET_EPOCH_ENTER(et);
374 /* sanity check */
375 if (!ifnet_byindex(zoneid)) {
376 NET_EPOCH_EXIT(et);
377 return (ENXIO);
378 }
379 NET_EPOCH_EXIT(et);
380 if (sin6->sin6_scope_id != 0 &&
381 zoneid != sin6->sin6_scope_id) {
382 log(LOG_NOTICE,
383 "%s: embedded scope mismatch: %s%%%d. "
384 "sin6_scope_id was overridden\n", __func__,
385 ip6_sprintf(ip6buf, &sin6->sin6_addr),
386 sin6->sin6_scope_id);
387 }
388 sin6->sin6_addr.s6_addr16[1] = 0;
389 sin6->sin6_scope_id = zoneid;
390 }
391 }
392
393 return 0;
394 }
395
396 /*
397 * Determine the appropriate scope zone ID for in6 and ifp. If ret_id is
398 * non NULL, it is set to the zone ID. If the zone ID needs to be embedded
399 * in the in6_addr structure, in6 will be modified.
400 *
401 * ret_id - unnecessary?
402 */
403 int
in6_setscope(struct in6_addr * in6,struct ifnet * ifp,u_int32_t * ret_id)404 in6_setscope(struct in6_addr *in6, struct ifnet *ifp, u_int32_t *ret_id)
405 {
406 int scope;
407 u_int32_t zoneid = 0;
408 struct scope6_id *sid;
409
410 /*
411 * special case: the loopback address can only belong to a loopback
412 * interface.
413 */
414 if (IN6_IS_ADDR_LOOPBACK(in6)) {
415 if (!(ifp->if_flags & IFF_LOOPBACK))
416 return (EINVAL);
417 } else {
418 scope = in6_addrscope(in6);
419 if (scope == IPV6_ADDR_SCOPE_INTFACELOCAL ||
420 scope == IPV6_ADDR_SCOPE_LINKLOCAL) {
421 /*
422 * Currently we use interface indices as the
423 * zone IDs for interface-local and link-local
424 * scopes.
425 */
426 zoneid = ifp->if_index;
427 in6->s6_addr16[1] = htons(zoneid & 0xffff); /* XXX */
428 } else if (scope != IPV6_ADDR_SCOPE_GLOBAL) {
429 struct epoch_tracker et;
430
431 NET_EPOCH_ENTER(et);
432 if (ifp->if_afdata[AF_INET6] == NULL) {
433 NET_EPOCH_EXIT(et);
434 return (ENETDOWN);
435 }
436 sid = SID(ifp);
437 zoneid = sid->s6id_list[scope];
438 NET_EPOCH_EXIT(et);
439 }
440 }
441
442 if (ret_id != NULL)
443 *ret_id = zoneid;
444
445 return (0);
446 }
447
448 /*
449 * Just clear the embedded scope identifier. Return 0 if the original address
450 * is intact; return non 0 if the address is modified.
451 */
452 int
in6_clearscope(struct in6_addr * in6)453 in6_clearscope(struct in6_addr *in6)
454 {
455 int modified = 0;
456
457 if (IN6_IS_SCOPE_LINKLOCAL(in6) || IN6_IS_ADDR_MC_INTFACELOCAL(in6)) {
458 if (in6->s6_addr16[1] != 0)
459 modified = 1;
460 in6->s6_addr16[1] = 0;
461 }
462
463 return (modified);
464 }
465
466 /*
467 * Return the scope identifier or zero.
468 */
469 uint16_t
in6_getscope(const struct in6_addr * in6)470 in6_getscope(const struct in6_addr *in6)
471 {
472
473 if (IN6_IS_SCOPE_LINKLOCAL(in6) || IN6_IS_ADDR_MC_INTFACELOCAL(in6))
474 return (in6->s6_addr16[1]);
475
476 return (0);
477 }
478
479 /*
480 * Returns scope zone id for the unicast address @in6.
481 *
482 * Returns 0 for global unicast and loopback addresses.
483 * Returns interface index for the link-local addresses.
484 */
485 uint32_t
in6_get_unicast_scopeid(const struct in6_addr * in6,const struct ifnet * ifp)486 in6_get_unicast_scopeid(const struct in6_addr *in6, const struct ifnet *ifp)
487 {
488
489 if (IN6_IS_SCOPE_LINKLOCAL(in6))
490 return (ifp->if_index);
491 return (0);
492 }
493
494 void
in6_set_unicast_scopeid(struct in6_addr * in6,uint32_t scopeid)495 in6_set_unicast_scopeid(struct in6_addr *in6, uint32_t scopeid)
496 {
497
498 in6->s6_addr16[1] = htons(scopeid & 0xffff);
499 }
500
501 /*
502 * Return pointer to ifnet structure, corresponding to the zone id of
503 * link-local scope.
504 */
505 struct ifnet*
in6_getlinkifnet(uint32_t zoneid)506 in6_getlinkifnet(uint32_t zoneid)
507 {
508
509 return (ifnet_byindex((u_short)zoneid));
510 }
511
512 /*
513 * Return zone id for the specified scope.
514 */
515 uint32_t
in6_getscopezone(const struct ifnet * ifp,int scope)516 in6_getscopezone(const struct ifnet *ifp, int scope)
517 {
518
519 if (scope == IPV6_ADDR_SCOPE_INTFACELOCAL ||
520 scope == IPV6_ADDR_SCOPE_LINKLOCAL)
521 return (ifp->if_index);
522 if (scope >= 0 && scope < IPV6_ADDR_SCOPES_COUNT)
523 return (SID(ifp)->s6id_list[scope]);
524 return (0);
525 }
526
527 /*
528 * Extracts scope from address @dst, stores cleared address
529 * inside @dst and zone inside @scopeid
530 */
531 void
in6_splitscope(const struct in6_addr * src,struct in6_addr * dst,uint32_t * scopeid)532 in6_splitscope(const struct in6_addr *src, struct in6_addr *dst,
533 uint32_t *scopeid)
534 {
535 uint32_t zoneid;
536
537 *dst = *src;
538 zoneid = ntohs(in6_getscope(dst));
539 in6_clearscope(dst);
540 *scopeid = zoneid;
541 }
542
543 /*
544 * This function is for checking sockaddr_in6 structure passed
545 * from the application level (usually).
546 *
547 * sin6_scope_id should be set for link-local unicast, link-local and
548 * interface-local multicast addresses.
549 *
550 * If it is zero, then look into default zone ids. If default zone id is
551 * not set or disabled, then return error.
552 */
553 int
sa6_checkzone(struct sockaddr_in6 * sa6)554 sa6_checkzone(struct sockaddr_in6 *sa6)
555 {
556 int scope;
557
558 scope = in6_addrscope(&sa6->sin6_addr);
559 if (scope == IPV6_ADDR_SCOPE_GLOBAL)
560 return (sa6->sin6_scope_id ? EINVAL: 0);
561 if (IN6_IS_ADDR_MULTICAST(&sa6->sin6_addr) &&
562 scope != IPV6_ADDR_SCOPE_LINKLOCAL &&
563 scope != IPV6_ADDR_SCOPE_INTFACELOCAL) {
564 if (sa6->sin6_scope_id == 0 && V_ip6_use_defzone != 0)
565 sa6->sin6_scope_id = V_sid_default.s6id_list[scope];
566 return (0);
567 }
568 /*
569 * Since ::1 address always configured on the lo0, we can
570 * automatically set its zone id, when it is not specified.
571 * Return error, when specified zone id doesn't match with
572 * actual value.
573 */
574 if (IN6_IS_ADDR_LOOPBACK(&sa6->sin6_addr)) {
575 if (sa6->sin6_scope_id == 0)
576 sa6->sin6_scope_id = in6_getscopezone(V_loif, scope);
577 else if (sa6->sin6_scope_id != in6_getscopezone(V_loif, scope))
578 return (EADDRNOTAVAIL);
579 }
580 /* XXX: we can validate sin6_scope_id here */
581 if (sa6->sin6_scope_id != 0)
582 return (0);
583 if (V_ip6_use_defzone != 0)
584 sa6->sin6_scope_id = V_sid_default.s6id_list[scope];
585 /* Return error if we can't determine zone id */
586 return (sa6->sin6_scope_id ? 0: EADDRNOTAVAIL);
587 }
588
589 /*
590 * This function is similar to sa6_checkzone, but it uses given ifp
591 * to initialize sin6_scope_id.
592 */
593 int
sa6_checkzone_ifp(struct ifnet * ifp,struct sockaddr_in6 * sa6)594 sa6_checkzone_ifp(struct ifnet *ifp, struct sockaddr_in6 *sa6)
595 {
596 int scope;
597
598 scope = in6_addrscope(&sa6->sin6_addr);
599 if (scope == IPV6_ADDR_SCOPE_LINKLOCAL ||
600 scope == IPV6_ADDR_SCOPE_INTFACELOCAL) {
601 if (sa6->sin6_scope_id == 0) {
602 sa6->sin6_scope_id = in6_getscopezone(ifp, scope);
603 return (0);
604 } else if (sa6->sin6_scope_id != in6_getscopezone(ifp, scope))
605 return (EADDRNOTAVAIL);
606 }
607 return (sa6_checkzone(sa6));
608 }
609