FreeBSD/Linux Kernel Cross Reference
sys/netinet6/scope6.c
1 /*-
2 * Copyright (C) 2000 WIDE Project.
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 3. Neither the name of the project nor the names of its contributors
14 * may be used to endorse or promote products derived from this software
15 * without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 *
29 * $KAME: scope6.c,v 1.10 2000/07/24 13:29:31 itojun Exp $
30 */
31
32 #include <sys/cdefs.h>
33 __FBSDID("$FreeBSD: releng/11.2/sys/netinet6/scope6.c 331722 2018-03-29 02:50:57Z eadler $");
34
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 VNET_DEFINE(int, deembed_scopeid) = 1;
62 SYSCTL_DECL(_net_inet6_ip6);
63 SYSCTL_INT(_net_inet6_ip6, OID_AUTO, deembed_scopeid, CTLFLAG_VNET | CTLFLAG_RW,
64 &VNET_NAME(deembed_scopeid), 0,
65 "Extract embedded zone ID and set it to sin6_scope_id in sockaddr_in6.");
66
67 /*
68 * The scope6_lock protects the global sid default stored in
69 * sid_default below.
70 */
71 static struct mtx scope6_lock;
72 #define SCOPE6_LOCK_INIT() mtx_init(&scope6_lock, "scope6_lock", NULL, MTX_DEF)
73 #define SCOPE6_LOCK() mtx_lock(&scope6_lock)
74 #define SCOPE6_UNLOCK() mtx_unlock(&scope6_lock)
75 #define SCOPE6_LOCK_ASSERT() mtx_assert(&scope6_lock, MA_OWNED)
76
77 static VNET_DEFINE(struct scope6_id, sid_default);
78 #define V_sid_default VNET(sid_default)
79
80 #define SID(ifp) \
81 (((struct in6_ifextra *)(ifp)->if_afdata[AF_INET6])->scope6_id)
82
83 static int scope6_get(struct ifnet *, struct scope6_id *);
84 static int scope6_set(struct ifnet *, struct scope6_id *);
85
86 void
87 scope6_init(void)
88 {
89
90 bzero(&V_sid_default, sizeof(V_sid_default));
91
92 if (!IS_DEFAULT_VNET(curvnet))
93 return;
94
95 SCOPE6_LOCK_INIT();
96 }
97
98 struct scope6_id *
99 scope6_ifattach(struct ifnet *ifp)
100 {
101 struct scope6_id *sid;
102
103 sid = malloc(sizeof(*sid), M_IFADDR, M_WAITOK | M_ZERO);
104 /*
105 * XXX: IPV6_ADDR_SCOPE_xxx macros are not standard.
106 * Should we rather hardcode here?
107 */
108 sid->s6id_list[IPV6_ADDR_SCOPE_INTFACELOCAL] = ifp->if_index;
109 sid->s6id_list[IPV6_ADDR_SCOPE_LINKLOCAL] = ifp->if_index;
110 return (sid);
111 }
112
113 void
114 scope6_ifdetach(struct scope6_id *sid)
115 {
116
117 free(sid, M_IFADDR);
118 }
119
120 int
121 scope6_ioctl(u_long cmd, caddr_t data, struct ifnet *ifp)
122 {
123 struct in6_ifreq *ifr;
124
125 if (ifp->if_afdata[AF_INET6] == NULL)
126 return (EPFNOSUPPORT);
127
128 ifr = (struct in6_ifreq *)data;
129 switch (cmd) {
130 case SIOCSSCOPE6:
131 return (scope6_set(ifp,
132 (struct scope6_id *)ifr->ifr_ifru.ifru_scope_id));
133 case SIOCGSCOPE6:
134 return (scope6_get(ifp,
135 (struct scope6_id *)ifr->ifr_ifru.ifru_scope_id));
136 case SIOCGSCOPE6DEF:
137 return (scope6_get_default(
138 (struct scope6_id *)ifr->ifr_ifru.ifru_scope_id));
139 default:
140 return (EOPNOTSUPP);
141 }
142 }
143
144 static int
145 scope6_set(struct ifnet *ifp, struct scope6_id *idlist)
146 {
147 int i;
148 int error = 0;
149 struct scope6_id *sid = NULL;
150
151 IF_AFDATA_WLOCK(ifp);
152 sid = SID(ifp);
153
154 if (!sid) { /* paranoid? */
155 IF_AFDATA_WUNLOCK(ifp);
156 return (EINVAL);
157 }
158
159 /*
160 * XXX: We need more consistency checks of the relationship among
161 * scopes (e.g. an organization should be larger than a site).
162 */
163
164 /*
165 * TODO(XXX): after setting, we should reflect the changes to
166 * interface addresses, routing table entries, PCB entries...
167 */
168
169 for (i = 0; i < 16; i++) {
170 if (idlist->s6id_list[i] &&
171 idlist->s6id_list[i] != sid->s6id_list[i]) {
172 /*
173 * An interface zone ID must be the corresponding
174 * interface index by definition.
175 */
176 if (i == IPV6_ADDR_SCOPE_INTFACELOCAL &&
177 idlist->s6id_list[i] != ifp->if_index) {
178 IF_AFDATA_WUNLOCK(ifp);
179 return (EINVAL);
180 }
181
182 if (i == IPV6_ADDR_SCOPE_LINKLOCAL &&
183 idlist->s6id_list[i] > V_if_index) {
184 /*
185 * XXX: theoretically, there should be no
186 * relationship between link IDs and interface
187 * IDs, but we check the consistency for
188 * safety in later use.
189 */
190 IF_AFDATA_WUNLOCK(ifp);
191 return (EINVAL);
192 }
193
194 /*
195 * XXX: we must need lots of work in this case,
196 * but we simply set the new value in this initial
197 * implementation.
198 */
199 sid->s6id_list[i] = idlist->s6id_list[i];
200 }
201 }
202 IF_AFDATA_WUNLOCK(ifp);
203
204 return (error);
205 }
206
207 static int
208 scope6_get(struct ifnet *ifp, struct scope6_id *idlist)
209 {
210 struct scope6_id *sid;
211
212 /* We only need to lock the interface's afdata for SID() to work. */
213 IF_AFDATA_RLOCK(ifp);
214 sid = SID(ifp);
215 if (sid == NULL) { /* paranoid? */
216 IF_AFDATA_RUNLOCK(ifp);
217 return (EINVAL);
218 }
219
220 *idlist = *sid;
221
222 IF_AFDATA_RUNLOCK(ifp);
223 return (0);
224 }
225
226 /*
227 * Get a scope of the address. Node-local, link-local, site-local or global.
228 */
229 int
230 in6_addrscope(const struct in6_addr *addr)
231 {
232
233 if (IN6_IS_ADDR_MULTICAST(addr)) {
234 /*
235 * Addresses with reserved value F must be treated as
236 * global multicast addresses.
237 */
238 if (IPV6_ADDR_MC_SCOPE(addr) == 0x0f)
239 return (IPV6_ADDR_SCOPE_GLOBAL);
240 return (IPV6_ADDR_MC_SCOPE(addr));
241 }
242 if (IN6_IS_ADDR_LINKLOCAL(addr) ||
243 IN6_IS_ADDR_LOOPBACK(addr))
244 return (IPV6_ADDR_SCOPE_LINKLOCAL);
245 if (IN6_IS_ADDR_SITELOCAL(addr))
246 return (IPV6_ADDR_SCOPE_SITELOCAL);
247 return (IPV6_ADDR_SCOPE_GLOBAL);
248 }
249
250 /*
251 * ifp - note that this might be NULL
252 */
253
254 void
255 scope6_setdefault(struct ifnet *ifp)
256 {
257
258 /*
259 * Currently, this function just sets the default "interfaces"
260 * and "links" according to the given interface.
261 * We might eventually have to separate the notion of "link" from
262 * "interface" and provide a user interface to set the default.
263 */
264 SCOPE6_LOCK();
265 if (ifp) {
266 V_sid_default.s6id_list[IPV6_ADDR_SCOPE_INTFACELOCAL] =
267 ifp->if_index;
268 V_sid_default.s6id_list[IPV6_ADDR_SCOPE_LINKLOCAL] =
269 ifp->if_index;
270 } else {
271 V_sid_default.s6id_list[IPV6_ADDR_SCOPE_INTFACELOCAL] = 0;
272 V_sid_default.s6id_list[IPV6_ADDR_SCOPE_LINKLOCAL] = 0;
273 }
274 SCOPE6_UNLOCK();
275 }
276
277 int
278 scope6_get_default(struct scope6_id *idlist)
279 {
280
281 SCOPE6_LOCK();
282 *idlist = V_sid_default;
283 SCOPE6_UNLOCK();
284
285 return (0);
286 }
287
288 u_int32_t
289 scope6_addr2default(struct in6_addr *addr)
290 {
291 u_int32_t id;
292
293 /*
294 * special case: The loopback address should be considered as
295 * link-local, but there's no ambiguity in the syntax.
296 */
297 if (IN6_IS_ADDR_LOOPBACK(addr))
298 return (0);
299
300 /*
301 * XXX: 32-bit read is atomic on all our platforms, is it OK
302 * not to lock here?
303 */
304 SCOPE6_LOCK();
305 id = V_sid_default.s6id_list[in6_addrscope(addr)];
306 SCOPE6_UNLOCK();
307 return (id);
308 }
309
310 /*
311 * Validate the specified scope zone ID in the sin6_scope_id field. If the ID
312 * is unspecified (=0), needs to be specified, and the default zone ID can be
313 * used, the default value will be used.
314 * This routine then generates the kernel-internal form: if the address scope
315 * of is interface-local or link-local, embed the interface index in the
316 * address.
317 */
318 int
319 sa6_embedscope(struct sockaddr_in6 *sin6, int defaultok)
320 {
321 u_int32_t zoneid;
322
323 if ((zoneid = sin6->sin6_scope_id) == 0 && defaultok)
324 zoneid = scope6_addr2default(&sin6->sin6_addr);
325
326 if (zoneid != 0 &&
327 (IN6_IS_SCOPE_LINKLOCAL(&sin6->sin6_addr) ||
328 IN6_IS_ADDR_MC_INTFACELOCAL(&sin6->sin6_addr))) {
329 /*
330 * At this moment, we only check interface-local and
331 * link-local scope IDs, and use interface indices as the
332 * zone IDs assuming a one-to-one mapping between interfaces
333 * and links.
334 */
335 if (V_if_index < zoneid || ifnet_byindex(zoneid) == NULL)
336 return (ENXIO);
337
338 /* XXX assignment to 16bit from 32bit variable */
339 sin6->sin6_addr.s6_addr16[1] = htons(zoneid & 0xffff);
340 sin6->sin6_scope_id = 0;
341 }
342
343 return 0;
344 }
345
346 /*
347 * generate standard sockaddr_in6 from embedded form.
348 */
349 int
350 sa6_recoverscope(struct sockaddr_in6 *sin6)
351 {
352 char ip6buf[INET6_ADDRSTRLEN];
353 u_int32_t zoneid;
354
355 if (IN6_IS_SCOPE_LINKLOCAL(&sin6->sin6_addr) ||
356 IN6_IS_ADDR_MC_INTFACELOCAL(&sin6->sin6_addr)) {
357 /*
358 * KAME assumption: link id == interface id
359 */
360 zoneid = ntohs(sin6->sin6_addr.s6_addr16[1]);
361 if (zoneid) {
362 /* sanity check */
363 if (V_if_index < zoneid)
364 return (ENXIO);
365 #if 0
366 /* XXX: Disabled due to possible deadlock. */
367 if (!ifnet_byindex(zoneid))
368 return (ENXIO);
369 #endif
370 if (sin6->sin6_scope_id != 0 &&
371 zoneid != sin6->sin6_scope_id) {
372 log(LOG_NOTICE,
373 "%s: embedded scope mismatch: %s%%%d. "
374 "sin6_scope_id was overridden\n", __func__,
375 ip6_sprintf(ip6buf, &sin6->sin6_addr),
376 sin6->sin6_scope_id);
377 }
378 sin6->sin6_addr.s6_addr16[1] = 0;
379 sin6->sin6_scope_id = zoneid;
380 }
381 }
382
383 return 0;
384 }
385
386 /*
387 * Determine the appropriate scope zone ID for in6 and ifp. If ret_id is
388 * non NULL, it is set to the zone ID. If the zone ID needs to be embedded
389 * in the in6_addr structure, in6 will be modified.
390 *
391 * ret_id - unnecessary?
392 */
393 int
394 in6_setscope(struct in6_addr *in6, struct ifnet *ifp, u_int32_t *ret_id)
395 {
396 int scope;
397 u_int32_t zoneid = 0;
398 struct scope6_id *sid;
399
400 /*
401 * special case: the loopback address can only belong to a loopback
402 * interface.
403 */
404 if (IN6_IS_ADDR_LOOPBACK(in6)) {
405 if (!(ifp->if_flags & IFF_LOOPBACK))
406 return (EINVAL);
407 } else {
408 scope = in6_addrscope(in6);
409 if (scope == IPV6_ADDR_SCOPE_INTFACELOCAL ||
410 scope == IPV6_ADDR_SCOPE_LINKLOCAL) {
411 /*
412 * Currently we use interface indices as the
413 * zone IDs for interface-local and link-local
414 * scopes.
415 */
416 zoneid = ifp->if_index;
417 in6->s6_addr16[1] = htons(zoneid & 0xffff); /* XXX */
418 } else if (scope != IPV6_ADDR_SCOPE_GLOBAL) {
419 IF_AFDATA_RLOCK(ifp);
420 sid = SID(ifp);
421 zoneid = sid->s6id_list[scope];
422 IF_AFDATA_RUNLOCK(ifp);
423 }
424 }
425
426 if (ret_id != NULL)
427 *ret_id = zoneid;
428
429 return (0);
430 }
431
432 /*
433 * Just clear the embedded scope identifier. Return 0 if the original address
434 * is intact; return non 0 if the address is modified.
435 */
436 int
437 in6_clearscope(struct in6_addr *in6)
438 {
439 int modified = 0;
440
441 if (IN6_IS_SCOPE_LINKLOCAL(in6) || IN6_IS_ADDR_MC_INTFACELOCAL(in6)) {
442 if (in6->s6_addr16[1] != 0)
443 modified = 1;
444 in6->s6_addr16[1] = 0;
445 }
446
447 return (modified);
448 }
449
450 /*
451 * Return the scope identifier or zero.
452 */
453 uint16_t
454 in6_getscope(struct in6_addr *in6)
455 {
456
457 if (IN6_IS_SCOPE_LINKLOCAL(in6) || IN6_IS_ADDR_MC_INTFACELOCAL(in6))
458 return (in6->s6_addr16[1]);
459
460 return (0);
461 }
462
463 /*
464 * Return pointer to ifnet structure, corresponding to the zone id of
465 * link-local scope.
466 */
467 struct ifnet*
468 in6_getlinkifnet(uint32_t zoneid)
469 {
470
471 return (ifnet_byindex((u_short)zoneid));
472 }
473
474 /*
475 * Return zone id for the specified scope.
476 */
477 uint32_t
478 in6_getscopezone(const struct ifnet *ifp, int scope)
479 {
480
481 if (scope == IPV6_ADDR_SCOPE_INTFACELOCAL ||
482 scope == IPV6_ADDR_SCOPE_LINKLOCAL)
483 return (ifp->if_index);
484 if (scope >= 0 && scope < IPV6_ADDR_SCOPES_COUNT)
485 return (SID(ifp)->s6id_list[scope]);
486 return (0);
487 }
488
489 /*
490 * Extracts scope from adddress @dst, stores cleared address
491 * inside @dst and zone inside @scopeid
492 */
493 void
494 in6_splitscope(const struct in6_addr *src, struct in6_addr *dst,
495 uint32_t *scopeid)
496 {
497 uint32_t zoneid;
498
499 *dst = *src;
500 zoneid = ntohs(in6_getscope(dst));
501 in6_clearscope(dst);
502 *scopeid = zoneid;
503 }
504
505 /*
506 * This function is for checking sockaddr_in6 structure passed
507 * from the application level (usually).
508 *
509 * sin6_scope_id should be set for link-local unicast, link-local and
510 * interface-local multicast addresses.
511 *
512 * If it is zero, then look into default zone ids. If default zone id is
513 * not set or disabled, then return error.
514 */
515 int
516 sa6_checkzone(struct sockaddr_in6 *sa6)
517 {
518 int scope;
519
520 scope = in6_addrscope(&sa6->sin6_addr);
521 if (scope == IPV6_ADDR_SCOPE_GLOBAL)
522 return (sa6->sin6_scope_id ? EINVAL: 0);
523 if (IN6_IS_ADDR_MULTICAST(&sa6->sin6_addr) &&
524 scope != IPV6_ADDR_SCOPE_LINKLOCAL &&
525 scope != IPV6_ADDR_SCOPE_INTFACELOCAL) {
526 if (sa6->sin6_scope_id == 0 && V_ip6_use_defzone != 0)
527 sa6->sin6_scope_id = V_sid_default.s6id_list[scope];
528 return (0);
529 }
530 /*
531 * Since ::1 address always configured on the lo0, we can
532 * automatically set its zone id, when it is not specified.
533 * Return error, when specified zone id doesn't match with
534 * actual value.
535 */
536 if (IN6_IS_ADDR_LOOPBACK(&sa6->sin6_addr)) {
537 if (sa6->sin6_scope_id == 0)
538 sa6->sin6_scope_id = in6_getscopezone(V_loif, scope);
539 else if (sa6->sin6_scope_id != in6_getscopezone(V_loif, scope))
540 return (EADDRNOTAVAIL);
541 }
542 /* XXX: we can validate sin6_scope_id here */
543 if (sa6->sin6_scope_id != 0)
544 return (0);
545 if (V_ip6_use_defzone != 0)
546 sa6->sin6_scope_id = V_sid_default.s6id_list[scope];
547 /* Return error if we can't determine zone id */
548 return (sa6->sin6_scope_id ? 0: EADDRNOTAVAIL);
549 }
550
551 /*
552 * This function is similar to sa6_checkzone, but it uses given ifp
553 * to initialize sin6_scope_id.
554 */
555 int
556 sa6_checkzone_ifp(struct ifnet *ifp, struct sockaddr_in6 *sa6)
557 {
558 int scope;
559
560 scope = in6_addrscope(&sa6->sin6_addr);
561 if (scope == IPV6_ADDR_SCOPE_LINKLOCAL ||
562 scope == IPV6_ADDR_SCOPE_INTFACELOCAL) {
563 if (sa6->sin6_scope_id == 0) {
564 sa6->sin6_scope_id = in6_getscopezone(ifp, scope);
565 return (0);
566 } else if (sa6->sin6_scope_id != in6_getscopezone(ifp, scope))
567 return (EADDRNOTAVAIL);
568 }
569 return (sa6_checkzone(sa6));
570 }
571
572
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