1 /*
2 * Copyright (c) 2000-2022 Apple Inc. All rights reserved.
3 *
4 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
5 *
6 * This file contains Original Code and/or Modifications of Original Code
7 * as defined in and that are subject to the Apple Public Source License
8 * Version 2.0 (the 'License'). You may not use this file except in
9 * compliance with the License. The rights granted to you under the License
10 * may not be used to create, or enable the creation or redistribution of,
11 * unlawful or unlicensed copies of an Apple operating system, or to
12 * circumvent, violate, or enable the circumvention or violation of, any
13 * terms of an Apple operating system software license agreement.
14 *
15 * Please obtain a copy of the License at
16 * http://www.opensource.apple.com/apsl/ and read it before using this file.
17 *
18 * The Original Code and all software distributed under the License are
19 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
20 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
21 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
22 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
23 * Please see the License for the specific language governing rights and
24 * limitations under the License.
25 *
26 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
27 */
28
29 /*
30 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
31 * All rights reserved.
32 *
33 * Redistribution and use in source and binary forms, with or without
34 * modification, are permitted provided that the following conditions
35 * are met:
36 * 1. Redistributions of source code must retain the above copyright
37 * notice, this list of conditions and the following disclaimer.
38 * 2. Redistributions in binary form must reproduce the above copyright
39 * notice, this list of conditions and the following disclaimer in the
40 * documentation and/or other materials provided with the distribution.
41 * 3. Neither the name of the project nor the names of its contributors
42 * may be used to endorse or promote products derived from this software
43 * without specific prior written permission.
44 *
45 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
46 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
47 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
48 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
49 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
50 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
51 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
52 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
53 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
54 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
55 * SUCH DAMAGE.
56 */
57
58 /*
59 * Copyright (c) 1982, 1986, 1991, 1993
60 * The Regents of the University of California. All rights reserved.
61 *
62 * Redistribution and use in source and binary forms, with or without
63 * modification, are permitted provided that the following conditions
64 * are met:
65 * 1. Redistributions of source code must retain the above copyright
66 * notice, this list of conditions and the following disclaimer.
67 * 2. Redistributions in binary form must reproduce the above copyright
68 * notice, this list of conditions and the following disclaimer in the
69 * documentation and/or other materials provided with the distribution.
70 * 3. All advertising materials mentioning features or use of this software
71 * must display the following acknowledgement:
72 * This product includes software developed by the University of
73 * California, Berkeley and its contributors.
74 * 4. Neither the name of the University nor the names of its contributors
75 * may be used to endorse or promote products derived from this software
76 * without specific prior written permission.
77 *
78 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
79 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
80 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
81 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
82 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
83 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
84 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
85 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
86 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
87 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
88 * SUCH DAMAGE.
89 *
90 * @(#)in_pcb.c 8.2 (Berkeley) 1/4/94
91 */
92
93
94 #include <sys/param.h>
95 #include <sys/systm.h>
96 #include <sys/malloc.h>
97 #include <sys/mbuf.h>
98 #include <sys/protosw.h>
99 #include <sys/socket.h>
100 #include <sys/socketvar.h>
101 #include <sys/errno.h>
102 #include <sys/time.h>
103 #include <sys/proc.h>
104 #include <sys/sysctl.h>
105 #include <sys/kauth.h>
106 #include <sys/priv.h>
107 #include <kern/locks.h>
108 #include <sys/random.h>
109
110 #include <net/if.h>
111 #include <net/if_types.h>
112 #include <net/route.h>
113 #include <net/restricted_in_port.h>
114
115 #include <netinet/in.h>
116 #include <netinet/in_var.h>
117 #include <netinet/in_systm.h>
118 #include <netinet/ip.h>
119 #include <netinet/in_pcb.h>
120
121 #include <netinet6/in6_var.h>
122 #include <netinet/ip6.h>
123 #include <netinet6/in6_pcb.h>
124 #include <netinet6/ip6_var.h>
125 #include <netinet6/scope6_var.h>
126 #include <netinet6/nd6.h>
127
128 #include <net/net_osdep.h>
129
130 #include <net/sockaddr_utils.h>
131
132 #include "loop.h"
133
134 SYSCTL_DECL(_net_inet6_ip6);
135
136 static int ip6_select_srcif_debug = 0;
137 SYSCTL_INT(_net_inet6_ip6, OID_AUTO, select_srcif_debug,
138 CTLFLAG_RW | CTLFLAG_LOCKED, &ip6_select_srcif_debug, 0,
139 "log source interface selection debug info");
140
141 static int ip6_select_srcaddr_debug = 0;
142 SYSCTL_INT(_net_inet6_ip6, OID_AUTO, select_srcaddr_debug,
143 CTLFLAG_RW | CTLFLAG_LOCKED, &ip6_select_srcaddr_debug, 0,
144 "log source address selection debug info");
145
146 static int ip6_select_src_expensive_secondary_if = 0;
147 SYSCTL_INT(_net_inet6_ip6, OID_AUTO, select_src_expensive_secondary_if,
148 CTLFLAG_RW | CTLFLAG_LOCKED, &ip6_select_src_expensive_secondary_if, 0,
149 "allow source interface selection to use expensive secondaries");
150
151 static int ip6_select_src_strong_end = 1;
152 SYSCTL_INT(_net_inet6_ip6, OID_AUTO, select_src_strong_end,
153 CTLFLAG_RW | CTLFLAG_LOCKED, &ip6_select_src_strong_end, 0,
154 "limit source address selection to outgoing interface");
155
156 #define ADDR_LABEL_NOTAPP (-1)
157 struct in6_addrpolicy defaultaddrpolicy;
158
159 int ip6_prefer_tempaddr = 1;
160
161 int ip6_cga_conflict_retries = IPV6_CGA_CONFLICT_RETRIES_DEFAULT;
162
163 extern int udp_use_randomport;
164 extern int tcp_use_randomport;
165
166 static int selectroute(struct sockaddr_in6 *, struct sockaddr_in6 *,
167 struct ip6_pktopts *, struct ip6_moptions *, struct in6_ifaddr **,
168 struct route_in6 *, struct ifnet **, struct rtentry **, int, int,
169 struct ip6_out_args *ip6oa);
170 static int in6_selectif(struct sockaddr_in6 *, struct ip6_pktopts *,
171 struct ip6_moptions *, struct route_in6 *ro,
172 struct ip6_out_args *, struct ifnet **);
173 static void init_policy_queue(void);
174 static int add_addrsel_policyent(const struct in6_addrpolicy *);
175 static int walk_addrsel_policy(int (*)(const struct in6_addrpolicy *, void *),
176 void *);
177 static int dump_addrsel_policyent(const struct in6_addrpolicy *, void *);
178 static struct in6_addrpolicy *match_addrsel_policy(struct sockaddr_in6 *);
179 void addrsel_policy_init(void);
180
181 #define SASEL_DO_DBG(inp) \
182 (ip6_select_srcaddr_debug && (inp) != NULL && \
183 (inp)->inp_socket != NULL && \
184 ((inp)->inp_socket->so_options & SO_DEBUG))
185
186 #define SASEL_LOG(fmt, ...) \
187 do { \
188 if (srcsel_debug) \
189 os_log(OS_LOG_DEFAULT, "%s:%d " fmt,\
190 __FUNCTION__, __LINE__, ##__VA_ARGS__); \
191 } while (0); \
192
193 /*
194 * Return an IPv6 address, which is the most appropriate for a given
195 * destination and user specified options.
196 * If necessary, this function lookups the routing table and returns
197 * an entry to the caller for later use.
198 */
199 #define REPLACE(r) do {\
200 SASEL_LOG("REPLACE r %s ia %s ifp1 %s\n", \
201 (#r), s_src, ifp1->if_xname); \
202 srcrule = (r); \
203 goto replace; \
204 } while (0)
205
206 #define NEXTSRC(r) do {\
207 SASEL_LOG("NEXTSRC r %s ia %s ifp1 %s\n", \
208 (#r), s_src, ifp1->if_xname); \
209 goto next; /* XXX: we can't use 'continue' here */ \
210 } while (0)
211
212 #define BREAK(r) do { \
213 SASEL_LOG("BREAK r %s ia %s ifp1 %s\n", \
214 (#r), s_src, ifp1->if_xname); \
215 srcrule = (r); \
216 goto out; /* XXX: we can't use 'break' here */ \
217 } while (0)
218
219
220 struct ifaddr *
in6_selectsrc_core_ifa(struct sockaddr_in6 * addr,struct ifnet * ifp,int srcsel_debug)221 in6_selectsrc_core_ifa(struct sockaddr_in6 *addr, struct ifnet *ifp, int srcsel_debug)
222 {
223 int err = 0;
224 struct ifnet *src_ifp = NULL;
225 struct in6_addr src_storage = {};
226 struct in6_addr *in6 = NULL;
227 struct ifaddr *ifa = NULL;
228
229 if ((in6 = in6_selectsrc_core(addr,
230 (ip6_prefer_tempaddr ? IPV6_SRCSEL_HINT_PREFER_TMPADDR : 0),
231 ifp, 0, &src_storage, &src_ifp, &err, &ifa, NULL, FALSE)) == NULL) {
232 if (err == 0) {
233 err = EADDRNOTAVAIL;
234 }
235 VERIFY(src_ifp == NULL);
236 if (ifa != NULL) {
237 ifa_remref(ifa);
238 ifa = NULL;
239 }
240 goto done;
241 }
242
243 if (src_ifp != ifp) {
244 if (err == 0) {
245 err = ENETUNREACH;
246 }
247 if (ifa != NULL) {
248 ifa_remref(ifa);
249 ifa = NULL;
250 }
251 goto done;
252 }
253
254 VERIFY(ifa != NULL);
255 ifnet_lock_shared(ifp);
256 if ((ifa->ifa_debug & IFD_DETACHING) != 0) {
257 err = EHOSTUNREACH;
258 ifnet_lock_done(ifp);
259 ifa_remref(ifa);
260 ifa = NULL;
261 goto done;
262 }
263 ifnet_lock_done(ifp);
264
265 done:
266 SASEL_LOG("Returned with error: %d", err);
267 if (src_ifp != NULL) {
268 ifnet_release(src_ifp);
269 }
270 return ifa;
271 }
272
273 struct in6_addr *
in6_selectsrc_core(struct sockaddr_in6 * dstsock,uint32_t hint_mask,struct ifnet * ifp,int srcsel_debug,struct in6_addr * src_storage,struct ifnet ** sifp,int * errorp,struct ifaddr ** ifapp,struct route_in6 * ro,boolean_t is_for_clat46)274 in6_selectsrc_core(struct sockaddr_in6 *dstsock, uint32_t hint_mask,
275 struct ifnet *ifp, int srcsel_debug, struct in6_addr *src_storage,
276 struct ifnet **sifp, int *errorp, struct ifaddr **ifapp, struct route_in6 *ro,
277 boolean_t is_for_clat46)
278 {
279 u_int32_t odstzone;
280 int bestrule = IP6S_SRCRULE_0;
281 struct in6_addrpolicy *dst_policy = NULL, *best_policy = NULL;
282 struct in6_addr dst;
283 struct in6_ifaddr *ia = NULL, *ia_best = NULL;
284 char s_src[MAX_IPv6_STR_LEN] = {0};
285 char s_dst[MAX_IPv6_STR_LEN] = {0};
286 const struct in6_addr *tmp = NULL;
287 int dst_scope = -1, best_scope = -1, best_matchlen = -1;
288 uint64_t secs = net_uptime();
289 struct nd_defrouter *dr = NULL;
290 uint32_t genid = in6_ifaddrlist_genid;
291 VERIFY(dstsock != NULL);
292 VERIFY(src_storage != NULL);
293 VERIFY(ifp != NULL);
294
295 if (sifp != NULL) {
296 *sifp = NULL;
297 }
298
299 if (ifapp != NULL) {
300 *ifapp = NULL;
301 }
302
303 dst = dstsock->sin6_addr; /* make a copy for local operation */
304
305 if (srcsel_debug) {
306 (void) inet_ntop(AF_INET6, &dst, s_dst, sizeof(s_src));
307
308 tmp = &in6addr_any;
309 (void) inet_ntop(AF_INET6, tmp, s_src, sizeof(s_src));
310 os_log(OS_LOG_DEFAULT, "%s out src %s dst %s ifp %s",
311 __func__, s_src, s_dst, ifp->if_xname);
312 }
313
314 *errorp = in6_setscope(&dst, ifp, &odstzone);
315 if (*errorp != 0) {
316 src_storage = NULL;
317 goto done;
318 }
319
320 /*
321 * Determine if the route is an indirect here
322 * and if it is get the default router that would be
323 * used as next hop.
324 * Later in the function it is used to apply rule 5.5 of RFC 6724.
325 */
326 if (ro != NULL && ro->ro_rt != NULL &&
327 (ro->ro_rt->rt_flags & RTF_GATEWAY) &&
328 ro->ro_rt->rt_gateway != NULL) {
329 struct rtentry *rt = ro->ro_rt;
330 lck_mtx_lock(nd6_mutex);
331 dr = defrouter_lookup(NULL,
332 &SIN6(rt->rt_gateway)->sin6_addr, rt->rt_ifp);
333 lck_mtx_unlock(nd6_mutex);
334 }
335
336 lck_rw_lock_shared(&in6_ifaddr_rwlock);
337 addrloop:
338 TAILQ_FOREACH(ia, &in6_ifaddrhead, ia6_link) {
339 int new_scope = -1, new_matchlen = -1;
340 struct in6_addrpolicy *new_policy = NULL;
341 u_int32_t srczone = 0, osrczone, dstzone;
342 struct in6_addr src;
343 struct ifnet *ifp1 = ia->ia_ifp;
344 int srcrule;
345
346 if (srcsel_debug) {
347 (void) inet_ntop(AF_INET6, &ia->ia_addr.sin6_addr,
348 s_src, sizeof(s_src));
349 }
350
351 IFA_LOCK(&ia->ia_ifa);
352
353 /*
354 * Simply skip addresses reserved for CLAT46
355 */
356 if (!is_for_clat46 && (ia->ia6_flags & IN6_IFF_CLAT46)) {
357 SASEL_LOG("NEXT ia %s address on ifp1 %s skipped as it is "
358 "reserved for CLAT46\n", s_src, ifp1->if_xname);
359 goto next;
360 }
361
362 if (is_for_clat46 && !(ia->ia6_flags & IN6_IFF_CLAT46)) {
363 SASEL_LOG("CLAT46: NEXT ia %s address on ifp1 %s skipped as it is "
364 "not reserved for CLAT46\n", s_src, ifp1->if_xname);
365 goto next;
366 }
367
368 /*
369 * XXX By default we are strong end system and will
370 * limit candidate set of source address to the ones
371 * configured on the outgoing interface.
372 */
373 if (ip6_select_src_strong_end &&
374 ifp1 != ifp) {
375 SASEL_LOG("NEXT ia %s ifp1 %s address is not on outgoing "
376 "interface \n", s_src, ifp1->if_xname);
377 goto next;
378 }
379
380 /*
381 * We'll never take an address that breaks the scope zone
382 * of the destination. We also skip an address if its zone
383 * does not contain the outgoing interface.
384 * XXX: we should probably use sin6_scope_id here.
385 */
386 if (in6_setscope(&dst, ifp1, &dstzone) ||
387 odstzone != dstzone) {
388 SASEL_LOG("NEXT ia %s ifp1 %s odstzone %d != dstzone %d\n",
389 s_src, ifp1->if_xname, odstzone, dstzone);
390 goto next;
391 }
392 src = ia->ia_addr.sin6_addr;
393 if (in6_setscope(&src, ifp, &osrczone) ||
394 in6_setscope(&src, ifp1, &srczone) ||
395 osrczone != srczone) {
396 SASEL_LOG("NEXT ia %s ifp1 %s osrczone %d != srczone %d\n",
397 s_src, ifp1->if_xname, osrczone, srczone);
398 goto next;
399 }
400 /* avoid unusable addresses */
401 if ((ia->ia6_flags &
402 (IN6_IFF_NOTREADY | IN6_IFF_ANYCAST | IN6_IFF_DETACHED))) {
403 SASEL_LOG("NEXT ia %s ifp1 %s ia6_flags 0x%x\n",
404 s_src, ifp1->if_xname, ia->ia6_flags);
405 goto next;
406 }
407 if (!ip6_use_deprecated && IFA6_IS_DEPRECATED(ia, secs)) {
408 SASEL_LOG("NEXT ia %s ifp1 %s IFA6_IS_DEPRECATED\n",
409 s_src, ifp1->if_xname);
410 goto next;
411 }
412 if (!nd6_optimistic_dad &&
413 (ia->ia6_flags & IN6_IFF_OPTIMISTIC) != 0) {
414 SASEL_LOG("NEXT ia %s ifp1 %s IN6_IFF_OPTIMISTIC\n",
415 s_src, ifp1->if_xname);
416 goto next;
417 }
418 /* Rule 1: Prefer same address */
419 if (in6_are_addr_equal_scoped(&dst, &ia->ia_addr.sin6_addr, dstzone, srczone)) {
420 BREAK(IP6S_SRCRULE_1); /* there should be no better candidate */
421 }
422 if (ia_best == NULL) {
423 REPLACE(IP6S_SRCRULE_0);
424 }
425
426 /* Rule 2: Prefer appropriate scope */
427 if (dst_scope < 0) {
428 dst_scope = in6_addrscope(&dst);
429 }
430 new_scope = in6_addrscope(&ia->ia_addr.sin6_addr);
431 if (IN6_ARE_SCOPE_CMP(best_scope, new_scope) < 0) {
432 if (IN6_ARE_SCOPE_CMP(best_scope, dst_scope) < 0) {
433 REPLACE(IP6S_SRCRULE_2);
434 }
435 NEXTSRC(IP6S_SRCRULE_2);
436 } else if (IN6_ARE_SCOPE_CMP(new_scope, best_scope) < 0) {
437 if (IN6_ARE_SCOPE_CMP(new_scope, dst_scope) < 0) {
438 NEXTSRC(IP6S_SRCRULE_2);
439 }
440 REPLACE(IP6S_SRCRULE_2);
441 }
442
443 /*
444 * Rule 3: Avoid deprecated addresses. Note that the case of
445 * !ip6_use_deprecated is already rejected above.
446 */
447 if (!IFA6_IS_DEPRECATED(ia_best, secs) &&
448 IFA6_IS_DEPRECATED(ia, secs)) {
449 NEXTSRC(IP6S_SRCRULE_3);
450 }
451 if (IFA6_IS_DEPRECATED(ia_best, secs) &&
452 !IFA6_IS_DEPRECATED(ia, secs)) {
453 REPLACE(IP6S_SRCRULE_3);
454 }
455
456 /*
457 * RFC 4429 says that optimistic addresses are equivalent to
458 * deprecated addresses, so avoid them here.
459 */
460 if ((ia_best->ia6_flags & IN6_IFF_OPTIMISTIC) == 0 &&
461 (ia->ia6_flags & IN6_IFF_OPTIMISTIC) != 0) {
462 NEXTSRC(IP6S_SRCRULE_3);
463 }
464 if ((ia_best->ia6_flags & IN6_IFF_OPTIMISTIC) != 0 &&
465 (ia->ia6_flags & IN6_IFF_OPTIMISTIC) == 0) {
466 REPLACE(IP6S_SRCRULE_3);
467 }
468
469 /* Rule 4: Prefer home addresses */
470 /*
471 * XXX: This is a TODO. We should probably merge the MIP6
472 * case above.
473 */
474
475 /* Rule 5: Prefer outgoing interface */
476 /*
477 * XXX By default we are strong end with source address
478 * selection. That means all address selection candidate
479 * addresses will be the ones hosted on the outgoing interface
480 * making the following check redundant.
481 */
482 if (ip6_select_src_strong_end == 0) {
483 if (ia_best->ia_ifp == ifp && ia->ia_ifp != ifp) {
484 NEXTSRC(IP6S_SRCRULE_5);
485 }
486 if (ia_best->ia_ifp != ifp && ia->ia_ifp == ifp) {
487 REPLACE(IP6S_SRCRULE_5);
488 }
489 }
490
491 /*
492 * Rule 5.5: Prefer addresses in a prefix advertised by the next-hop.
493 * If SA or SA's prefix is assigned by the selected next-hop that will
494 * be used to send to D and SB or SB's prefix is assigned by a different
495 * next-hop, then prefer SA. Similarly, if SB or SB's prefix is
496 * assigned by the next-hop that will be used to send to D and SA or
497 * SA's prefix is assigned by a different next-hop, then prefer SB.
498 */
499 if (dr != NULL && ia_best->ia6_ndpr != ia->ia6_ndpr) {
500 boolean_t ia_best_has_prefix = FALSE;
501 boolean_t ia_has_prefix = FALSE;
502 struct nd_prefix ia_best_prefix = {};
503 struct nd_prefix ia_prefix = {};
504 struct nd_prefix *p_ia_best_prefix = NULL;
505 struct nd_prefix *p_ia_prefix = NULL;
506
507 if (ia_best->ia6_ndpr) {
508 ia_best_prefix = *ia_best->ia6_ndpr;
509 }
510
511 if (ia->ia6_ndpr) {
512 ia_prefix = *ia->ia6_ndpr;
513 }
514
515 IFA_UNLOCK(&ia->ia_ifa);
516 lck_rw_done(&in6_ifaddr_rwlock);
517
518 p_ia_best_prefix = nd6_prefix_lookup(&ia_best_prefix, ND6_PREFIX_EXPIRY_UNSPEC);
519 p_ia_prefix = nd6_prefix_lookup(&ia_prefix, ND6_PREFIX_EXPIRY_UNSPEC);
520
521 lck_mtx_lock(nd6_mutex);
522 if (p_ia_best_prefix != NULL) {
523 NDPR_LOCK(p_ia_best_prefix);
524 ia_best_has_prefix = (pfxrtr_lookup(p_ia_best_prefix, dr) != NULL);
525 NDPR_UNLOCK(p_ia_best_prefix);
526 NDPR_REMREF(p_ia_best_prefix);
527 }
528 if (p_ia_prefix != NULL) {
529 NDPR_LOCK(p_ia_prefix);
530 ia_has_prefix = (pfxrtr_lookup(p_ia_prefix, dr) != NULL);
531 NDPR_UNLOCK(p_ia_prefix);
532 NDPR_REMREF(p_ia_prefix);
533 }
534 lck_mtx_unlock(nd6_mutex);
535
536 lck_rw_lock_shared(&in6_ifaddr_rwlock);
537 if (genid != os_atomic_load(&in6_ifaddrlist_genid, acquire)) {
538 SASEL_LOG("Address list seems to have changed. Restarting source "
539 "address selection.\n");
540 genid = in6_ifaddrlist_genid;
541 /*
542 * We are starting from scratch. Free up the reference
543 * on ia_best and also reset it to NULL.
544 */
545 ifa_remref(&ia_best->ia_ifa);
546 ia_best = NULL;
547 goto addrloop;
548 }
549 IFA_LOCK(&ia->ia_ifa);
550
551 if (ia_best_has_prefix && !ia_has_prefix) {
552 NEXTSRC(IP6S_SRCRULE_5_5);
553 }
554
555 if (!ia_best_has_prefix && ia_has_prefix) {
556 REPLACE(IP6S_SRCRULE_5_5);
557 }
558 }
559
560 /*
561 * Rule 6: Prefer matching label
562 * Note that best_policy should be non-NULL here.
563 */
564 if (dst_policy == NULL) {
565 dst_policy = in6_addrsel_lookup_policy(dstsock);
566 }
567 if (dst_policy->label != ADDR_LABEL_NOTAPP) {
568 new_policy = in6_addrsel_lookup_policy(&ia->ia_addr);
569 if (dst_policy->label == best_policy->label &&
570 dst_policy->label != new_policy->label) {
571 NEXTSRC(IP6S_SRCRULE_6);
572 }
573 if (dst_policy->label != best_policy->label &&
574 dst_policy->label == new_policy->label) {
575 REPLACE(IP6S_SRCRULE_6);
576 }
577 }
578
579 /*
580 * Rule 7: Prefer temporary addresses.
581 * We allow users to reverse the logic by configuring
582 * a sysctl variable, so that transparency conscious users can
583 * always prefer stable addresses.
584 */
585 if (!(ia_best->ia6_flags & IN6_IFF_TEMPORARY) &&
586 (ia->ia6_flags & IN6_IFF_TEMPORARY)) {
587 if (hint_mask & IPV6_SRCSEL_HINT_PREFER_TMPADDR) {
588 REPLACE(IP6S_SRCRULE_7);
589 } else {
590 NEXTSRC(IP6S_SRCRULE_7);
591 }
592 }
593 if ((ia_best->ia6_flags & IN6_IFF_TEMPORARY) &&
594 !(ia->ia6_flags & IN6_IFF_TEMPORARY)) {
595 if (hint_mask & IPV6_SRCSEL_HINT_PREFER_TMPADDR) {
596 NEXTSRC(IP6S_SRCRULE_7);
597 } else {
598 REPLACE(IP6S_SRCRULE_7);
599 }
600 }
601
602 /*
603 * Rule 7x: prefer addresses on alive interfaces.
604 * This is a KAME specific rule.
605 */
606 if ((ia_best->ia_ifp->if_flags & IFF_UP) &&
607 !(ia->ia_ifp->if_flags & IFF_UP)) {
608 NEXTSRC(IP6S_SRCRULE_7x);
609 }
610 if (!(ia_best->ia_ifp->if_flags & IFF_UP) &&
611 (ia->ia_ifp->if_flags & IFF_UP)) {
612 REPLACE(IP6S_SRCRULE_7x);
613 }
614
615 /*
616 * Rule 8: Use longest matching prefix.
617 */
618 new_matchlen = in6_matchlen(&ia->ia_addr.sin6_addr, &dst);
619 if (best_matchlen < new_matchlen) {
620 REPLACE(IP6S_SRCRULE_8);
621 }
622 if (new_matchlen < best_matchlen) {
623 NEXTSRC(IP6S_SRCRULE_8);
624 }
625
626 /*
627 * Last resort: just keep the current candidate.
628 * Or, do we need more rules?
629 */
630 if (ifp1 != ifp && (ifp1->if_eflags & IFEF_EXPENSIVE) &&
631 ip6_select_src_expensive_secondary_if == 0) {
632 SASEL_LOG("NEXT ia %s ifp1 %s IFEF_EXPENSIVE\n",
633 s_src, ifp1->if_xname);
634 ip6stat.ip6s_sources_skip_expensive_secondary_if++;
635 goto next;
636 }
637 SASEL_LOG("NEXT ia %s ifp1 %s last resort\n",
638 s_src, ifp1->if_xname);
639 IFA_UNLOCK(&ia->ia_ifa);
640 continue;
641
642 replace:
643 /*
644 * Ignore addresses on secondary interfaces that are marked
645 * expensive
646 */
647 if (ifp1 != ifp && (ifp1->if_eflags & IFEF_EXPENSIVE) &&
648 ip6_select_src_expensive_secondary_if == 0) {
649 SASEL_LOG("NEXT ia %s ifp1 %s IFEF_EXPENSIVE\n",
650 s_src, ifp1->if_xname);
651 ip6stat.ip6s_sources_skip_expensive_secondary_if++;
652 goto next;
653 }
654 bestrule = srcrule;
655 best_scope = (new_scope >= 0 ? new_scope :
656 in6_addrscope(&ia->ia_addr.sin6_addr));
657 best_policy = (new_policy ? new_policy :
658 in6_addrsel_lookup_policy(&ia->ia_addr));
659 best_matchlen = (new_matchlen >= 0 ? new_matchlen :
660 in6_matchlen(&ia->ia_addr.sin6_addr, &dst));
661 SASEL_LOG("NEXT ia %s ifp1 %s best_scope %d new_scope %d dst_scope %d\n",
662 s_src, ifp1->if_xname, best_scope, new_scope, dst_scope);
663 ifa_addref(&ia->ia_ifa); /* for ia_best */
664 IFA_UNLOCK(&ia->ia_ifa);
665 if (ia_best != NULL) {
666 ifa_remref(&ia_best->ia_ifa);
667 }
668 ia_best = ia;
669 continue;
670
671 next:
672 IFA_UNLOCK(&ia->ia_ifa);
673 continue;
674
675 out:
676 ifa_addref(&ia->ia_ifa); /* for ia_best */
677 IFA_UNLOCK(&ia->ia_ifa);
678 if (ia_best != NULL) {
679 ifa_remref(&ia_best->ia_ifa);
680 }
681 ia_best = ia;
682 break;
683 }
684
685 lck_rw_done(&in6_ifaddr_rwlock);
686
687 if ((ia = ia_best) == NULL) {
688 if (*errorp == 0) {
689 *errorp = EADDRNOTAVAIL;
690 }
691 src_storage = NULL;
692 goto done;
693 }
694
695 if (sifp != NULL) {
696 *sifp = ia->ia_ifa.ifa_ifp;
697 ifnet_reference(*sifp);
698 }
699
700 IFA_LOCK_SPIN(&ia->ia_ifa);
701 if (bestrule < IP6S_SRCRULE_COUNT) {
702 ip6stat.ip6s_sources_rule[bestrule]++;
703 }
704 *src_storage = satosin6(&ia->ia_addr)->sin6_addr;
705 IFA_UNLOCK(&ia->ia_ifa);
706
707 if (ifapp != NULL) {
708 *ifapp = &ia->ia_ifa;
709 } else {
710 ifa_remref(&ia->ia_ifa);
711 }
712
713 done:
714 if (srcsel_debug) {
715 (void) inet_ntop(AF_INET6, &dst, s_dst, sizeof(s_src));
716
717 tmp = (src_storage != NULL) ? src_storage : &in6addr_any;
718 (void) inet_ntop(AF_INET6, tmp, s_src, sizeof(s_src));
719
720 os_log(OS_LOG_DEFAULT, "%s out src %s dst %s dst_scope %d best_scope %d",
721 __func__, s_src, s_dst, dst_scope, best_scope);
722 }
723
724 if (dr != NULL) {
725 NDDR_REMREF(dr);
726 }
727
728 return src_storage;
729 }
730
731 /*
732 * Regardless of error, it will return an ifp with a reference held if the
733 * caller provides a non-NULL ifpp. The caller is responsible for checking
734 * if the returned ifp is valid and release its reference at all times.
735 */
736 struct in6_addr *
in6_selectsrc(struct sockaddr_in6 * dstsock,struct ip6_pktopts * opts,struct inpcb * inp,struct route_in6 * ro,struct ifnet ** ifpp,struct in6_addr * src_storage,unsigned int ifscope,int * errorp)737 in6_selectsrc(struct sockaddr_in6 *dstsock, struct ip6_pktopts *opts,
738 struct inpcb *inp, struct route_in6 *ro,
739 struct ifnet **ifpp, struct in6_addr *src_storage, unsigned int ifscope,
740 int *errorp)
741 {
742 struct ifnet *ifp = NULL;
743 struct in6_pktinfo *pi = NULL;
744 struct ip6_moptions *mopts;
745 struct ip6_out_args ip6oa;
746 boolean_t inp_debug = FALSE;
747 uint32_t hint_mask = 0;
748 int prefer_tempaddr = 0;
749 struct ifnet *sifp = NULL;
750
751 bzero(&ip6oa, sizeof(ip6oa));
752 ip6oa.ip6oa_boundif = ifscope;
753 ip6oa.ip6oa_flags = IP6OAF_SELECT_SRCIF;
754 ip6oa.ip6oa_sotc = SO_TC_UNSPEC;
755 ip6oa.ip6oa_netsvctype = _NET_SERVICE_TYPE_UNSPEC;
756
757 *errorp = 0;
758 if (ifpp != NULL) {
759 *ifpp = NULL;
760 }
761
762 if (inp != NULL) {
763 inp_debug = SASEL_DO_DBG(inp);
764 mopts = inp->in6p_moptions;
765 if (INP_NO_CELLULAR(inp)) {
766 ip6oa.ip6oa_flags |= IP6OAF_NO_CELLULAR;
767 }
768 if (INP_NO_EXPENSIVE(inp)) {
769 ip6oa.ip6oa_flags |= IP6OAF_NO_EXPENSIVE;
770 }
771 if (INP_NO_CONSTRAINED(inp)) {
772 ip6oa.ip6oa_flags |= IP6OAF_NO_CONSTRAINED;
773 }
774 if (INP_AWDL_UNRESTRICTED(inp)) {
775 ip6oa.ip6oa_flags |= IP6OAF_AWDL_UNRESTRICTED;
776 }
777 if (INP_INTCOPROC_ALLOWED(inp)) {
778 ip6oa.ip6oa_flags |= IP6OAF_INTCOPROC_ALLOWED;
779 }
780 if (INP_MANAGEMENT_ALLOWED(inp)) {
781 ip6oa.ip6oa_flags |= IP6OAF_MANAGEMENT_ALLOWED;
782 }
783 } else {
784 mopts = NULL;
785 /* Allow the kernel to retransmit packets. */
786 ip6oa.ip6oa_flags |= IP6OAF_INTCOPROC_ALLOWED |
787 IP6OAF_AWDL_UNRESTRICTED | IP6OAF_MANAGEMENT_ALLOWED;
788 }
789
790 if (ip6oa.ip6oa_boundif != IFSCOPE_NONE) {
791 ip6oa.ip6oa_flags |= IP6OAF_BOUND_IF;
792 }
793
794 /*
795 * If the source address is explicitly specified by the caller,
796 * check if the requested source address is indeed a unicast address
797 * assigned to the node, and can be used as the packet's source
798 * address. If everything is okay, use the address as source.
799 */
800 if (opts && (pi = opts->ip6po_pktinfo) &&
801 !IN6_IS_ADDR_UNSPECIFIED(&pi->ipi6_addr)) {
802 struct sockaddr_in6 srcsock;
803 struct in6_ifaddr *ia6;
804
805 /* get the outgoing interface */
806 if ((*errorp = in6_selectif(dstsock, opts, mopts, ro, &ip6oa,
807 &ifp)) != 0) {
808 src_storage = NULL;
809 goto done;
810 }
811
812 /*
813 * determine the appropriate zone id of the source based on
814 * the zone of the destination and the outgoing interface.
815 * If the specified address is ambiguous wrt the scope zone,
816 * the interface must be specified; otherwise, ifa_ifwithaddr()
817 * will fail matching the address.
818 */
819 SOCKADDR_ZERO(&srcsock, sizeof(srcsock));
820 srcsock.sin6_family = AF_INET6;
821 srcsock.sin6_len = sizeof(srcsock);
822 srcsock.sin6_addr = pi->ipi6_addr;
823 if (ifp != NULL) {
824 *errorp = in6_setscope(&srcsock.sin6_addr, ifp, IN6_NULL_IF_EMBEDDED_SCOPE(&srcsock.sin6_scope_id));
825 if (*errorp != 0) {
826 src_storage = NULL;
827 goto done;
828 }
829 }
830 ia6 = (struct in6_ifaddr *)ifa_ifwithaddr(SA(&srcsock));
831 if (ia6 == NULL) {
832 *errorp = EADDRNOTAVAIL;
833 src_storage = NULL;
834 goto done;
835 }
836 IFA_LOCK_SPIN(&ia6->ia_ifa);
837 if ((ia6->ia6_flags & (IN6_IFF_ANYCAST | IN6_IFF_NOTREADY | IN6_IFF_CLAT46)) ||
838 (inp && inp_restricted_send(inp, ia6->ia_ifa.ifa_ifp))) {
839 IFA_UNLOCK(&ia6->ia_ifa);
840 ifa_remref(&ia6->ia_ifa);
841 *errorp = EHOSTUNREACH;
842 src_storage = NULL;
843 goto done;
844 }
845
846 *src_storage = satosin6(&ia6->ia_addr)->sin6_addr;
847 IFA_UNLOCK(&ia6->ia_ifa);
848 ifa_remref(&ia6->ia_ifa);
849 goto done;
850 }
851
852 /*
853 * Otherwise, if the socket has already bound the source, just use it.
854 */
855 if (inp != NULL && !IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr)) {
856 src_storage = &inp->in6p_laddr;
857 goto done;
858 }
859
860 /*
861 * If the address is not specified, choose the best one based on
862 * the outgoing interface and the destination address.
863 */
864 /* get the outgoing interface */
865 if ((*errorp = in6_selectif(dstsock, opts, mopts, ro, &ip6oa,
866 &ifp)) != 0) {
867 src_storage = NULL;
868 goto done;
869 }
870
871 VERIFY(ifp != NULL);
872
873 if (opts == NULL ||
874 opts->ip6po_prefer_tempaddr == IP6PO_TEMPADDR_SYSTEM) {
875 prefer_tempaddr = ip6_prefer_tempaddr;
876 } else if (opts->ip6po_prefer_tempaddr == IP6PO_TEMPADDR_NOTPREFER) {
877 prefer_tempaddr = 0;
878 } else {
879 prefer_tempaddr = 1;
880 }
881
882 if (prefer_tempaddr) {
883 hint_mask |= IPV6_SRCSEL_HINT_PREFER_TMPADDR;
884 }
885
886 if (in6_selectsrc_core(dstsock, hint_mask, ifp, inp_debug, src_storage,
887 &sifp, errorp, NULL, ro, FALSE) == NULL) {
888 src_storage = NULL;
889 goto done;
890 }
891
892 VERIFY(sifp != NULL);
893
894 if (inp && inp_restricted_send(inp, sifp)) {
895 src_storage = NULL;
896 *errorp = EHOSTUNREACH;
897 ifnet_release(sifp);
898 goto done;
899 } else {
900 ifnet_release(sifp);
901 }
902
903 done:
904 if (ifpp != NULL) {
905 /* if ifp is non-NULL, refcnt held in in6_selectif() */
906 *ifpp = ifp;
907 } else if (ifp != NULL) {
908 ifnet_release(ifp);
909 }
910 return src_storage;
911 }
912
913 /*
914 * Given a source IPv6 address (and route, if available), determine the best
915 * interface to send the packet from. Checking for (and updating) the
916 * ROF_SRCIF_SELECTED flag in the pcb-supplied route placeholder is done
917 * without any locks, based on the assumption that in the event this is
918 * called from ip6_output(), the output operation is single-threaded per-pcb,
919 * i.e. for any given pcb there can only be one thread performing output at
920 * the IPv6 layer.
921 *
922 * This routine is analogous to in_selectsrcif() for IPv4. Regardless of
923 * error, it will return an ifp with a reference held if the caller provides
924 * a non-NULL retifp. The caller is responsible for checking if the
925 * returned ifp is valid and release its reference at all times.
926 *
927 * clone - meaningful only for bsdi and freebsd
928 */
929 static int
selectroute(struct sockaddr_in6 * srcsock,struct sockaddr_in6 * dstsock,struct ip6_pktopts * opts,struct ip6_moptions * mopts,struct in6_ifaddr ** retsrcia,struct route_in6 * ro,struct ifnet ** retifp,struct rtentry ** retrt,int clone,int norouteok,struct ip6_out_args * ip6oa)930 selectroute(struct sockaddr_in6 *srcsock, struct sockaddr_in6 *dstsock,
931 struct ip6_pktopts *opts, struct ip6_moptions *mopts,
932 struct in6_ifaddr **retsrcia, struct route_in6 *ro,
933 struct ifnet **retifp, struct rtentry **retrt, int clone,
934 int norouteok, struct ip6_out_args *ip6oa)
935 {
936 int error = 0;
937 struct ifnet *ifp = NULL, *ifp0 = NULL;
938 struct route_in6 *route = NULL;
939 struct sockaddr_in6 *sin6_next;
940 struct in6_pktinfo *pi = NULL;
941 struct in6_addr *dst = &dstsock->sin6_addr;
942 struct ifaddr *ifa = NULL;
943 char s_src[MAX_IPv6_STR_LEN], s_dst[MAX_IPv6_STR_LEN];
944 boolean_t select_srcif, proxied_ifa = FALSE, local_dst = FALSE;
945 unsigned int ifscope = ((ip6oa != NULL) ?
946 ip6oa->ip6oa_boundif : IFSCOPE_NONE);
947 boolean_t is_direct = FALSE;
948
949 if (retifp != NULL) {
950 *retifp = NULL;
951 }
952
953 if (retrt != NULL) {
954 *retrt = NULL;
955 }
956
957 if (ip6_select_srcif_debug) {
958 struct in6_addr src;
959 src = (srcsock != NULL) ? srcsock->sin6_addr : in6addr_any;
960 (void) inet_ntop(AF_INET6, &src, s_src, sizeof(s_src));
961 (void) inet_ntop(AF_INET6, dst, s_dst, sizeof(s_dst));
962 }
963
964 /*
965 * If the destination address is UNSPECIFIED addr, bail out.
966 */
967 if (IN6_IS_ADDR_UNSPECIFIED(dst)) {
968 error = EHOSTUNREACH;
969 goto done;
970 }
971
972 /*
973 * Perform source interface selection if Scoped Routing
974 * is enabled and a source address that isn't unspecified.
975 */
976 select_srcif = (srcsock != NULL &&
977 !IN6_IS_ADDR_UNSPECIFIED(&srcsock->sin6_addr));
978
979 /*
980 * For scoped routing, if interface scope is 0 or src/dst addr is linklocal
981 * or dst addr is multicast, source interface selection should be performed even
982 * if the destination is directly reachable.
983 */
984 if (ifscope != IFSCOPE_NONE &&
985 !(srcsock != NULL && IN6_IS_ADDR_LINKLOCAL(&srcsock->sin6_addr)) &&
986 !IN6_IS_ADDR_MULTICAST(dst) && !IN6_IS_ADDR_LINKLOCAL(dst)) {
987 struct rtentry *temp_rt = NULL;
988
989 lck_mtx_lock(rnh_lock);
990 temp_rt = rt_lookup(TRUE, SA(dstsock),
991 NULL, rt_tables[AF_INET6], ifscope);
992 lck_mtx_unlock(rnh_lock);
993
994 /*
995 * If the destination is directly reachable, relax
996 * the behavior around select_srcif, i.e. don't force
997 * the packet to go out from the interface that is hosting
998 * the source address.
999 * It happens when we share v6 with NAT66 and want
1000 * the external interface's v6 address to be reachable
1001 * to the clients we are sharing v6 connectivity with
1002 * using NAT.
1003 */
1004 if (temp_rt != NULL) {
1005 if ((temp_rt->rt_flags & RTF_GATEWAY) == 0) {
1006 select_srcif = FALSE;
1007 is_direct = TRUE;
1008 }
1009 rtfree(temp_rt);
1010 }
1011 }
1012
1013 if (ip6_select_srcif_debug) {
1014 os_log(OS_LOG_DEFAULT, "%s src %s dst %s ifscope %d "
1015 "is_direct %d select_srcif %d",
1016 __func__, s_src, s_dst, ifscope, is_direct, select_srcif);
1017 }
1018
1019 /* If the caller specified the outgoing interface explicitly, use it */
1020 if (opts != NULL && (pi = opts->ip6po_pktinfo) != NULL &&
1021 pi->ipi6_ifindex != 0) {
1022 /*
1023 * If IPV6_PKTINFO takes precedence over IPV6_BOUND_IF.
1024 */
1025 ifscope = pi->ipi6_ifindex;
1026 ifnet_head_lock_shared();
1027 /* ifp may be NULL if detached or out of range */
1028 ifp = ifp0 =
1029 ((ifscope <= if_index) ? ifindex2ifnet[ifscope] : NULL);
1030 ifnet_head_done();
1031 if (norouteok || retrt == NULL || IN6_IS_ADDR_MC_LINKLOCAL(dst)) {
1032 /*
1033 * We do not have to check or get the route for
1034 * multicast. If the caller didn't ask/care for
1035 * the route and we have no interface to use,
1036 * it's an error.
1037 */
1038 if (ifp == NULL) {
1039 error = EHOSTUNREACH;
1040 }
1041 goto done;
1042 } else {
1043 goto getsrcif;
1044 }
1045 }
1046
1047 /*
1048 * If the destination address is a multicast address and the outgoing
1049 * interface for the address is specified by the caller, use it.
1050 */
1051 if (IN6_IS_ADDR_MULTICAST(dst) && mopts != NULL) {
1052 IM6O_LOCK(mopts);
1053 ifp = ifp0 = mopts->im6o_multicast_ifp;
1054 if (ifp != NULL && IN6_IS_ADDR_MC_LINKLOCAL(dst)) {
1055 IM6O_UNLOCK(mopts);
1056 goto done; /* we don't need a route for link-local multicast */
1057 }
1058 IM6O_UNLOCK(mopts);
1059 }
1060
1061 getsrcif:
1062 /*
1063 * If the outgoing interface was not set via IPV6_BOUND_IF or
1064 * IPV6_PKTINFO, use the scope ID in the destination address.
1065 */
1066 if (ifscope == IFSCOPE_NONE) {
1067 ifscope = dstsock->sin6_scope_id;
1068 }
1069
1070 /*
1071 * Perform source interface selection; the source IPv6 address
1072 * must belong to one of the addresses of the interface used
1073 * by the route. For performance reasons, do this only if
1074 * there is no route, or if the routing table has changed,
1075 * or if we haven't done source interface selection on this
1076 * route (for this PCB instance) before.
1077 */
1078 if (!select_srcif) {
1079 goto getroute;
1080 } else if (!ROUTE_UNUSABLE(ro) && ro->ro_srcia != NULL &&
1081 (ro->ro_flags & ROF_SRCIF_SELECTED)) {
1082 if (ro->ro_rt->rt_ifp->if_flags & IFF_LOOPBACK) {
1083 local_dst = TRUE;
1084 }
1085 ifa = ro->ro_srcia;
1086 ifa_addref(ifa); /* for caller */
1087 goto getroute;
1088 }
1089
1090 /*
1091 * Given the source IPv6 address, find a suitable source interface
1092 * to use for transmission; if a scope ID has been specified,
1093 * optimize the search by looking at the addresses only for that
1094 * interface. This is still suboptimal, however, as we need to
1095 * traverse the per-interface list.
1096 */
1097 if (ifscope != IFSCOPE_NONE || (ro != NULL && ro->ro_rt != NULL)) {
1098 unsigned int scope = ifscope;
1099 struct ifnet *rt_ifp;
1100
1101 rt_ifp = (ro->ro_rt != NULL) ? ro->ro_rt->rt_ifp : NULL;
1102
1103 /*
1104 * If no scope is specified and the route is stale (pointing
1105 * to a defunct interface) use the current primary interface;
1106 * this happens when switching between interfaces configured
1107 * with the same IPv6 address. Otherwise pick up the scope
1108 * information from the route; the ULP may have looked up a
1109 * correct route and we just need to verify it here and mark
1110 * it with the ROF_SRCIF_SELECTED flag below.
1111 */
1112 if (scope == IFSCOPE_NONE) {
1113 scope = rt_ifp->if_index;
1114 if (scope != get_primary_ifscope(AF_INET6) &&
1115 ROUTE_UNUSABLE(ro)) {
1116 scope = get_primary_ifscope(AF_INET6);
1117 }
1118 }
1119
1120 ifa = (struct ifaddr *)
1121 ifa_foraddr6_scoped(&srcsock->sin6_addr, scope);
1122
1123 /*
1124 * If we are forwarding and proxying prefix(es), see if the
1125 * source address is one of ours and is a proxied address;
1126 * if so, use it.
1127 */
1128 if (ifa == NULL && ip6_forwarding && nd6_prproxy) {
1129 ifa = (struct ifaddr *)
1130 ifa_foraddr6(&srcsock->sin6_addr);
1131 if (ifa != NULL && !(proxied_ifa =
1132 nd6_prproxy_ifaddr((struct in6_ifaddr *)ifa))) {
1133 ifa_remref(ifa);
1134 ifa = NULL;
1135 }
1136 }
1137
1138 if (ip6_select_srcif_debug && ifa != NULL) {
1139 if (ro->ro_rt != NULL) {
1140 os_log(OS_LOG_DEFAULT, "%s %s->%s ifscope %d->%d ifa_if %s "
1141 "ro_if %s",
1142 __func__,
1143 s_src, s_dst, ifscope,
1144 scope, if_name(ifa->ifa_ifp),
1145 if_name(rt_ifp));
1146 } else {
1147 os_log(OS_LOG_DEFAULT, "%s %s->%s ifscope %d->%d ifa_if %s",
1148 __func__,
1149 s_src, s_dst, ifscope, scope,
1150 if_name(ifa->ifa_ifp));
1151 }
1152 }
1153 }
1154
1155 /*
1156 * Slow path; search for an interface having the corresponding source
1157 * IPv6 address if the scope was not specified by the caller, and:
1158 *
1159 * 1) There currently isn't any route, or,
1160 * 2) The interface used by the route does not own that source
1161 * IPv6 address; in this case, the route will get blown away
1162 * and we'll do a more specific scoped search using the newly
1163 * found interface.
1164 */
1165 if (ifa == NULL && ifscope == IFSCOPE_NONE) {
1166 struct ifaddr *ifadst;
1167
1168 /* Check if the destination address is one of ours */
1169 ifadst = (struct ifaddr *)ifa_foraddr6(&dstsock->sin6_addr);
1170 if (ifadst != NULL) {
1171 local_dst = TRUE;
1172 ifa_remref(ifadst);
1173 }
1174
1175 ifa = (struct ifaddr *)ifa_foraddr6(&srcsock->sin6_addr);
1176
1177 if (ip6_select_srcif_debug && ifa != NULL) {
1178 os_log(OS_LOG_DEFAULT, "%s %s->%s ifscope %d ifa_if %s",
1179 __func__,
1180 s_src, s_dst, ifscope, if_name(ifa->ifa_ifp));
1181 } else if (ip6_select_srcif_debug) {
1182 os_log(OS_LOG_DEFAULT, "%s %s->%s ifscope %d ifa_if NULL",
1183 __func__,
1184 s_src, s_dst, ifscope);
1185 }
1186 }
1187
1188 getroute:
1189 if (ifa != NULL && !proxied_ifa && !local_dst) {
1190 ifscope = ifa->ifa_ifp->if_index;
1191 }
1192
1193 /*
1194 * If the next hop address for the packet is specified by the caller,
1195 * use it as the gateway.
1196 */
1197 if (opts != NULL && opts->ip6po_nexthop != NULL) {
1198 struct route_in6 *ron;
1199
1200 sin6_next = satosin6(opts->ip6po_nexthop);
1201
1202 /* at this moment, we only support AF_INET6 next hops */
1203 if (sin6_next->sin6_family != AF_INET6) {
1204 error = EAFNOSUPPORT; /* or should we proceed? */
1205 goto done;
1206 }
1207
1208 /*
1209 * If the next hop is an IPv6 address, then the node identified
1210 * by that address must be a neighbor of the sending host.
1211 */
1212 ron = &opts->ip6po_nextroute;
1213 if (ron->ro_rt != NULL) {
1214 RT_LOCK(ron->ro_rt);
1215 }
1216 if (ROUTE_UNUSABLE(ron) || (ron->ro_rt != NULL &&
1217 (!(ron->ro_rt->rt_flags & RTF_LLINFO) ||
1218 (select_srcif && (ifa == NULL ||
1219 (ifa->ifa_ifp != ron->ro_rt->rt_ifp && !proxied_ifa))))) ||
1220 !in6_are_addr_equal_scoped(&satosin6(&ron->ro_dst)->sin6_addr,
1221 &sin6_next->sin6_addr, ron->ro_rt->rt_ifp->if_index, sin6_next->sin6_scope_id)) {
1222 if (ron->ro_rt != NULL) {
1223 RT_UNLOCK(ron->ro_rt);
1224 }
1225
1226 ROUTE_RELEASE(ron);
1227 *satosin6(&ron->ro_dst) = *sin6_next;
1228 }
1229 if (ron->ro_rt == NULL) {
1230 rtalloc_scoped((struct route *)ron, ifscope);
1231 if (ron->ro_rt != NULL) {
1232 RT_LOCK(ron->ro_rt);
1233 }
1234 if (ROUTE_UNUSABLE(ron) ||
1235 !(ron->ro_rt->rt_flags & RTF_LLINFO) ||
1236 !in6_are_addr_equal_scoped(&satosin6(rt_key(ron->ro_rt))->
1237 sin6_addr, &sin6_next->sin6_addr, ron->ro_rt->rt_ifp->if_index, sin6_next->sin6_scope_id)) {
1238 if (ron->ro_rt != NULL) {
1239 RT_UNLOCK(ron->ro_rt);
1240 }
1241
1242 ROUTE_RELEASE(ron);
1243 error = EHOSTUNREACH;
1244 goto done;
1245 }
1246 }
1247 route = ron;
1248 ifp = ifp0 = ron->ro_rt->rt_ifp;
1249
1250 /*
1251 * When cloning is required, try to allocate a route to the
1252 * destination so that the caller can store path MTU
1253 * information.
1254 */
1255 if (!clone) {
1256 if (select_srcif) {
1257 /* Keep the route locked */
1258 goto validateroute;
1259 }
1260 RT_UNLOCK(ron->ro_rt);
1261 goto done;
1262 }
1263 RT_UNLOCK(ron->ro_rt);
1264 }
1265
1266 /*
1267 * Use a cached route if it exists and is valid, else try to allocate
1268 * a new one. Note that we should check the address family of the
1269 * cached destination, in case of sharing the cache with IPv4.
1270 */
1271 if (ro == NULL) {
1272 goto done;
1273 }
1274 if (ro->ro_rt != NULL) {
1275 RT_LOCK_SPIN(ro->ro_rt);
1276 }
1277 if (ROUTE_UNUSABLE(ro) || (ro->ro_rt != NULL &&
1278 (satosin6(&ro->ro_dst)->sin6_family != AF_INET6 ||
1279 !in6_are_addr_equal_scoped(&satosin6(&ro->ro_dst)->sin6_addr, dst, ro->ro_rt->rt_ifp->if_index, dstsock->sin6_scope_id) ||
1280 (select_srcif && (ifa == NULL ||
1281 (ifa->ifa_ifp != ro->ro_rt->rt_ifp && !proxied_ifa)))))) {
1282 if (ro->ro_rt != NULL) {
1283 RT_UNLOCK(ro->ro_rt);
1284 }
1285
1286 ROUTE_RELEASE(ro);
1287 }
1288 if (ro->ro_rt == NULL) {
1289 struct sockaddr_in6 *sa6;
1290
1291 /* No route yet, so try to acquire one */
1292 SOCKADDR_ZERO(&ro->ro_dst, sizeof(struct sockaddr_in6));
1293 sa6 = SIN6(&ro->ro_dst);
1294 sa6->sin6_family = AF_INET6;
1295 sa6->sin6_len = sizeof(struct sockaddr_in6);
1296 sa6->sin6_addr = *dst;
1297 if (IN6_IS_ADDR_MC_LINKLOCAL(dst)) {
1298 ro->ro_rt = rtalloc1_scoped(
1299 SA(&((struct route *)ro)->ro_dst), 0, 0, ifscope);
1300 } else {
1301 rtalloc_scoped((struct route *)ro, ifscope);
1302 }
1303 if (ro->ro_rt != NULL) {
1304 RT_LOCK_SPIN(ro->ro_rt);
1305 }
1306 }
1307
1308 /*
1309 * Do not care about the result if we have the nexthop
1310 * explicitly specified (in case we're asked to clone.)
1311 */
1312 if (opts != NULL && opts->ip6po_nexthop != NULL) {
1313 if (ro->ro_rt != NULL) {
1314 RT_UNLOCK(ro->ro_rt);
1315 }
1316 goto done;
1317 }
1318
1319 if (ro->ro_rt != NULL) {
1320 RT_LOCK_ASSERT_HELD(ro->ro_rt);
1321 ifp = ifp0 = ro->ro_rt->rt_ifp;
1322 } else {
1323 error = EHOSTUNREACH;
1324 }
1325 route = ro;
1326
1327 validateroute:
1328 if (select_srcif) {
1329 boolean_t has_route = (route != NULL && route->ro_rt != NULL);
1330 boolean_t srcif_selected = FALSE;
1331
1332 if (has_route) {
1333 RT_LOCK_ASSERT_HELD(route->ro_rt);
1334 }
1335 /*
1336 * If there is a non-loopback route with the wrong interface,
1337 * or if there is no interface configured with such an address,
1338 * blow it away. Except for local/loopback, we look for one
1339 * with a matching interface scope/index.
1340 */
1341 if (has_route && (ifa == NULL ||
1342 (ifa->ifa_ifp != ifp && ifp != lo_ifp) ||
1343 !(route->ro_rt->rt_flags & RTF_UP))) {
1344 /*
1345 * If the destination address belongs to a proxied
1346 * prefix, relax the requirement and allow the packet
1347 * to come out of the proxy interface with the source
1348 * address of the real interface.
1349 */
1350 if (ifa != NULL && proxied_ifa &&
1351 (route->ro_rt->rt_flags & (RTF_UP | RTF_PROXY)) ==
1352 (RTF_UP | RTF_PROXY)) {
1353 srcif_selected = TRUE;
1354 } else {
1355 if (ip6_select_srcif_debug) {
1356 if (ifa != NULL) {
1357 os_log(OS_LOG_DEFAULT,
1358 "%s->%s ifscope %d "
1359 "ro_if %s != ifa_if %s "
1360 "(cached route cleared)",
1361 s_src, s_dst,
1362 ifscope, if_name(ifp),
1363 if_name(ifa->ifa_ifp));
1364 } else {
1365 os_log(OS_LOG_DEFAULT,
1366 "%s->%s ifscope %d "
1367 "ro_if %s (no ifa_if "
1368 "found)", s_src, s_dst,
1369 ifscope, if_name(ifp));
1370 }
1371 }
1372 RT_UNLOCK(route->ro_rt);
1373 ROUTE_RELEASE(route);
1374 error = EHOSTUNREACH;
1375 /* Undo the settings done above */
1376 route = NULL;
1377 ifp = NULL; /* ditch ifp; keep ifp0 */
1378 has_route = FALSE;
1379 }
1380 } else if (has_route) {
1381 srcif_selected = TRUE;
1382 }
1383
1384 if (srcif_selected) {
1385 VERIFY(has_route);
1386 if (ifa != route->ro_srcia ||
1387 !(route->ro_flags & ROF_SRCIF_SELECTED)) {
1388 RT_CONVERT_LOCK(route->ro_rt);
1389 if (ifa != NULL) {
1390 ifa_addref(ifa); /* for route_in6 */
1391 }
1392 if (route->ro_srcia != NULL) {
1393 ifa_remref(route->ro_srcia);
1394 }
1395 route->ro_srcia = ifa;
1396 route->ro_flags |= ROF_SRCIF_SELECTED;
1397 RT_GENID_SYNC(route->ro_rt);
1398 }
1399 RT_UNLOCK(route->ro_rt);
1400 }
1401 } else {
1402 if (ro->ro_rt != NULL) {
1403 RT_UNLOCK(ro->ro_rt);
1404 }
1405 if (ifp != NULL && opts != NULL &&
1406 opts->ip6po_pktinfo != NULL &&
1407 opts->ip6po_pktinfo->ipi6_ifindex != 0) {
1408 /*
1409 * Check if the outgoing interface conflicts with the
1410 * interface specified by ipi6_ifindex (if specified).
1411 * Note that loopback interface is always okay.
1412 * (this may happen when we are sending a packet to
1413 * one of our own addresses.)
1414 */
1415 if (!(ifp->if_flags & IFF_LOOPBACK) && ifp->if_index !=
1416 opts->ip6po_pktinfo->ipi6_ifindex) {
1417 error = EHOSTUNREACH;
1418 goto done;
1419 }
1420 }
1421 }
1422
1423 done:
1424 /*
1425 * Check for interface restrictions.
1426 */
1427 #define CHECK_RESTRICTIONS(_ip6oa, _ifp) \
1428 ((((_ip6oa)->ip6oa_flags & IP6OAF_NO_CELLULAR) && \
1429 IFNET_IS_CELLULAR(_ifp)) || \
1430 (((_ip6oa)->ip6oa_flags & IP6OAF_NO_EXPENSIVE) && \
1431 IFNET_IS_EXPENSIVE(_ifp)) || \
1432 (((_ip6oa)->ip6oa_flags & IP6OAF_NO_CONSTRAINED) && \
1433 IFNET_IS_CONSTRAINED(_ifp)) || \
1434 (!((_ip6oa)->ip6oa_flags & IP6OAF_INTCOPROC_ALLOWED) && \
1435 IFNET_IS_INTCOPROC(_ifp)) || \
1436 (!((_ip6oa)->ip6oa_flags & IP6OAF_AWDL_UNRESTRICTED) && \
1437 IFNET_IS_AWDL_RESTRICTED(_ifp)) && \
1438 (!((_ip6oa)->ip6oa_flags & IP6OAF_MANAGEMENT_ALLOWED) && \
1439 IFNET_IS_MANAGEMENT(_ifp)))
1440
1441 if (error == 0 && ip6oa != NULL &&
1442 ((ifp && CHECK_RESTRICTIONS(ip6oa, ifp)) ||
1443 (route && route->ro_rt &&
1444 CHECK_RESTRICTIONS(ip6oa, route->ro_rt->rt_ifp)))) {
1445 if (route != NULL && route->ro_rt != NULL) {
1446 ROUTE_RELEASE(route);
1447 route = NULL;
1448 }
1449 ifp = NULL; /* ditch ifp; keep ifp0 */
1450 error = EHOSTUNREACH;
1451 ip6oa->ip6oa_flags |= IP6OAF_R_IFDENIED;
1452 }
1453 #undef CHECK_RESTRICTIONS
1454
1455 /*
1456 * If the interface is disabled for IPv6, then ENETDOWN error.
1457 */
1458 if (error == 0 &&
1459 ifp != NULL && (ifp->if_eflags & IFEF_IPV6_DISABLED)) {
1460 error = ENETDOWN;
1461 }
1462
1463 if (ifp == NULL && (route == NULL || route->ro_rt == NULL)) {
1464 /*
1465 * This can happen if the caller did not pass a cached route
1466 * nor any other hints. We treat this case an error.
1467 */
1468 error = EHOSTUNREACH;
1469 }
1470 if (error == EHOSTUNREACH || error == ENETDOWN) {
1471 ip6stat.ip6s_noroute++;
1472 }
1473
1474 /*
1475 * We'll return ifp regardless of error, so pick it up from ifp0
1476 * in case it was nullified above. Caller is responsible for
1477 * releasing the ifp if it is non-NULL.
1478 */
1479 ifp = ifp0;
1480 if (retifp != NULL) {
1481 if (ifp != NULL) {
1482 ifnet_reference(ifp); /* for caller */
1483 }
1484 *retifp = ifp;
1485 }
1486
1487 if (retsrcia != NULL) {
1488 if (ifa != NULL) {
1489 ifa_addref(ifa); /* for caller */
1490 }
1491 *retsrcia = (struct in6_ifaddr *)ifa;
1492 }
1493
1494 if (error == 0) {
1495 if (retrt != NULL && route != NULL) {
1496 *retrt = route->ro_rt; /* ro_rt may be NULL */
1497 }
1498 }
1499 if (ip6_select_srcif_debug) {
1500 os_log(OS_LOG_DEFAULT,
1501 "%s %s->%s ifscope %d ifa_if %s ro_if %s (error=%d)",
1502 __func__,
1503 s_src, s_dst, ifscope,
1504 (ifa != NULL) ? if_name(ifa->ifa_ifp) : "NONE",
1505 (ifp != NULL) ? if_name(ifp) : "NONE", error);
1506 }
1507
1508 if (ifa != NULL) {
1509 ifa_remref(ifa);
1510 }
1511
1512 return error;
1513 }
1514
1515 /*
1516 * Regardless of error, it will return an ifp with a reference held if the
1517 * caller provides a non-NULL retifp. The caller is responsible for checking
1518 * if the returned ifp is valid and release its reference at all times.
1519 */
1520 int
in6_selectif(struct sockaddr_in6 * dstsock,struct ip6_pktopts * opts,struct ip6_moptions * mopts,struct route_in6 * ro,struct ip6_out_args * ip6oa,struct ifnet ** retifp)1521 in6_selectif(struct sockaddr_in6 *dstsock, struct ip6_pktopts *opts,
1522 struct ip6_moptions *mopts, struct route_in6 *ro,
1523 struct ip6_out_args *ip6oa, struct ifnet **retifp)
1524 {
1525 int err = 0;
1526 struct route_in6 sro;
1527 struct rtentry *rt = NULL;
1528
1529 if (ro == NULL) {
1530 bzero(&sro, sizeof(sro));
1531 ro = &sro;
1532 }
1533
1534 if ((err = selectroute(NULL, dstsock, opts, mopts, NULL, ro, retifp,
1535 &rt, 0, 1, ip6oa)) != 0) {
1536 goto done;
1537 }
1538
1539 /*
1540 * do not use a rejected or black hole route.
1541 * XXX: this check should be done in the L2 output routine.
1542 * However, if we skipped this check here, we'd see the following
1543 * scenario:
1544 * - install a rejected route for a scoped address prefix
1545 * (like fe80::/10)
1546 * - send a packet to a destination that matches the scoped prefix,
1547 * with ambiguity about the scope zone.
1548 * - pick the outgoing interface from the route, and disambiguate the
1549 * scope zone with the interface.
1550 * - ip6_output() would try to get another route with the "new"
1551 * destination, which may be valid.
1552 * - we'd see no error on output.
1553 * Although this may not be very harmful, it should still be confusing.
1554 * We thus reject the case here.
1555 */
1556 if (rt && (rt->rt_flags & (RTF_REJECT | RTF_BLACKHOLE))) {
1557 err = ((rt->rt_flags & RTF_HOST) ? EHOSTUNREACH : ENETUNREACH);
1558 goto done;
1559 }
1560
1561 /*
1562 * Adjust the "outgoing" interface. If we're going to loop the packet
1563 * back to ourselves, the ifp would be the loopback interface.
1564 * However, we'd rather know the interface associated to the
1565 * destination address (which should probably be one of our own
1566 * addresses.)
1567 */
1568 if (rt != NULL && rt->rt_ifa != NULL && rt->rt_ifa->ifa_ifp != NULL &&
1569 retifp != NULL) {
1570 ifnet_reference(rt->rt_ifa->ifa_ifp);
1571 if (*retifp != NULL) {
1572 ifnet_release(*retifp);
1573 }
1574 *retifp = rt->rt_ifa->ifa_ifp;
1575 }
1576
1577 done:
1578 if (ro == &sro) {
1579 VERIFY(rt == NULL || rt == ro->ro_rt);
1580 ROUTE_RELEASE(ro);
1581 }
1582
1583 /*
1584 * retifp might point to a valid ifp with a reference held;
1585 * caller is responsible for releasing it if non-NULL.
1586 */
1587 return err;
1588 }
1589
1590 /*
1591 * Regardless of error, it will return an ifp with a reference held if the
1592 * caller provides a non-NULL retifp. The caller is responsible for checking
1593 * if the returned ifp is valid and release its reference at all times.
1594 *
1595 * clone - meaningful only for bsdi and freebsd
1596 */
1597 int
in6_selectroute(struct sockaddr_in6 * srcsock,struct sockaddr_in6 * dstsock,struct ip6_pktopts * opts,struct ip6_moptions * mopts,struct in6_ifaddr ** retsrcia,struct route_in6 * ro,struct ifnet ** retifp,struct rtentry ** retrt,int clone,struct ip6_out_args * ip6oa)1598 in6_selectroute(struct sockaddr_in6 *srcsock, struct sockaddr_in6 *dstsock,
1599 struct ip6_pktopts *opts, struct ip6_moptions *mopts,
1600 struct in6_ifaddr **retsrcia, struct route_in6 *ro, struct ifnet **retifp,
1601 struct rtentry **retrt, int clone, struct ip6_out_args *ip6oa)
1602 {
1603 return selectroute(srcsock, dstsock, opts, mopts, retsrcia, ro, retifp,
1604 retrt, clone, 0, ip6oa);
1605 }
1606
1607 /*
1608 * Default hop limit selection. The precedence is as follows:
1609 * 1. Hoplimit value specified via socket option.
1610 * 2. (If the outgoing interface is detected) the current
1611 * hop limit of the interface specified by router advertisement.
1612 * 3. The system default hoplimit.
1613 */
1614 uint8_t
in6_selecthlim(struct in6pcb * in6p,struct ifnet * ifp)1615 in6_selecthlim(struct in6pcb *in6p, struct ifnet *ifp)
1616 {
1617 if (in6p && in6p->in6p_hops >= 0) {
1618 return (uint8_t)in6p->in6p_hops;
1619 } else if (NULL != ifp) {
1620 uint8_t chlim;
1621 struct nd_ifinfo *ndi = ND_IFINFO(ifp);
1622 if (ndi && ndi->initialized) {
1623 /* access chlim without lock, for performance */
1624 chlim = ndi->chlim;
1625 } else {
1626 chlim = (uint8_t)ip6_defhlim;
1627 }
1628 return chlim;
1629 }
1630
1631 return (uint8_t)ip6_defhlim;
1632 }
1633
1634 /*
1635 * XXX: this is borrowed from in6_pcbbind(). If possible, we should
1636 * share this function by all *bsd*...
1637 */
1638 int
in6_pcbsetport(struct in6_addr * laddr,struct inpcb * inp,struct proc * p,int locked)1639 in6_pcbsetport(struct in6_addr *laddr, struct inpcb *inp, struct proc *p,
1640 int locked)
1641 {
1642 struct socket *so = inp->inp_socket;
1643 uint16_t lport = 0, first, last, *lastport, rand_port;
1644 int count, error = 0, wild = 0;
1645 boolean_t counting_down;
1646 bool found, randomport;
1647 struct inpcbinfo *pcbinfo = inp->inp_pcbinfo;
1648 kauth_cred_t cred;
1649 #if SKYWALK
1650 bool laddr_unspecified = IN6_IS_ADDR_UNSPECIFIED(laddr);
1651 #else
1652 #pragma unused(laddr)
1653 #endif
1654 if (!locked) { /* Make sure we don't run into a deadlock: 4052373 */
1655 if (!lck_rw_try_lock_exclusive(&pcbinfo->ipi_lock)) {
1656 socket_unlock(inp->inp_socket, 0);
1657 lck_rw_lock_exclusive(&pcbinfo->ipi_lock);
1658 socket_lock(inp->inp_socket, 0);
1659 }
1660
1661 /*
1662 * Check if a local port was assigned to the inp while
1663 * this thread was waiting for the pcbinfo lock
1664 */
1665 if (inp->inp_lport != 0) {
1666 VERIFY(inp->inp_flags2 & INP2_INHASHLIST);
1667 lck_rw_done(&pcbinfo->ipi_lock);
1668
1669 /*
1670 * It is not an error if another thread allocated
1671 * a port
1672 */
1673 return 0;
1674 }
1675 }
1676
1677 /* XXX: this is redundant when called from in6_pcbbind */
1678 if ((so->so_options & (SO_REUSEADDR | SO_REUSEPORT)) == 0) {
1679 wild = INPLOOKUP_WILDCARD;
1680 }
1681
1682 randomport = (so->so_flags & SOF_BINDRANDOMPORT) > 0 ||
1683 (so->so_type == SOCK_STREAM ? tcp_use_randomport :
1684 udp_use_randomport) > 0;
1685
1686 if (inp->inp_flags & INP_HIGHPORT) {
1687 first = (uint16_t)ipport_hifirstauto; /* sysctl */
1688 last = (uint16_t)ipport_hilastauto;
1689 lastport = &pcbinfo->ipi_lasthi;
1690 } else if (inp->inp_flags & INP_LOWPORT) {
1691 cred = kauth_cred_proc_ref(p);
1692 error = priv_check_cred(cred, PRIV_NETINET_RESERVEDPORT, 0);
1693 kauth_cred_unref(&cred);
1694 if (error != 0) {
1695 if (!locked) {
1696 lck_rw_done(&pcbinfo->ipi_lock);
1697 }
1698 return error;
1699 }
1700 first = (uint16_t)ipport_lowfirstauto; /* 1023 */
1701 last = (uint16_t)ipport_lowlastauto; /* 600 */
1702 lastport = &pcbinfo->ipi_lastlow;
1703 } else {
1704 first = (uint16_t)ipport_firstauto; /* sysctl */
1705 last = (uint16_t)ipport_lastauto;
1706 lastport = &pcbinfo->ipi_lastport;
1707 }
1708
1709 if (first == last) {
1710 randomport = false;
1711 }
1712 /*
1713 * Simple check to ensure all ports are not used up causing
1714 * a deadlock here.
1715 */
1716 found = false;
1717 if (first > last) {
1718 /* counting down */
1719 if (randomport) {
1720 read_frandom(&rand_port, sizeof(rand_port));
1721 *lastport = first - (rand_port % (first - last));
1722 }
1723 count = first - last;
1724 counting_down = TRUE;
1725 } else {
1726 /* counting up */
1727 if (randomport) {
1728 read_frandom(&rand_port, sizeof(rand_port));
1729 *lastport = first + (rand_port % (first - last));
1730 }
1731 count = last - first;
1732 counting_down = FALSE;
1733 }
1734 do {
1735 if (count-- < 0) { /* completely used? */
1736 /*
1737 * Undo any address bind that may have
1738 * occurred above.
1739 */
1740 inp->in6p_laddr = in6addr_any;
1741 inp->in6p_last_outifp = NULL;
1742 inp->inp_lifscope = IFSCOPE_NONE;
1743 #if SKYWALK
1744 if (NETNS_TOKEN_VALID(&inp->inp_netns_token)) {
1745 netns_set_ifnet(&inp->inp_netns_token,
1746 NULL);
1747 }
1748 #endif /* SKYWALK */
1749 if (!locked) {
1750 lck_rw_done(&pcbinfo->ipi_lock);
1751 }
1752 return EAGAIN;
1753 }
1754 if (counting_down) {
1755 --*lastport;
1756 if (*lastport > first || *lastport < last) {
1757 *lastport = first;
1758 }
1759 } else {
1760 ++*lastport;
1761 if (*lastport < first || *lastport > last) {
1762 *lastport = first;
1763 }
1764 }
1765 lport = htons(*lastport);
1766
1767 /*
1768 * Skip if this is a restricted port as we do not want to
1769 * restricted ports as ephemeral
1770 */
1771 if (IS_RESTRICTED_IN_PORT(lport)) {
1772 continue;
1773 }
1774
1775 found = (in6_pcblookup_local(pcbinfo, &inp->in6p_laddr,
1776 lport, inp->inp_lifscope, wild) == NULL);
1777 #if SKYWALK
1778 if (found &&
1779 (SOCK_PROTO(so) == IPPROTO_TCP ||
1780 SOCK_PROTO(so) == IPPROTO_UDP) &&
1781 !(inp->inp_flags2 & INP2_EXTERNAL_PORT)) {
1782 if (laddr_unspecified &&
1783 (inp->inp_flags & IN6P_IPV6_V6ONLY) == 0) {
1784 struct in_addr ip_zero = { .s_addr = 0 };
1785
1786 netns_release(&inp->inp_wildcard_netns_token);
1787 if (netns_reserve_in(
1788 &inp->inp_wildcard_netns_token,
1789 ip_zero,
1790 (uint8_t)SOCK_PROTO(so), lport,
1791 NETNS_BSD, NULL) != 0) {
1792 /* port in use in IPv4 namespace */
1793 found = false;
1794 }
1795 }
1796 if (found &&
1797 netns_reserve_in6(&inp->inp_netns_token,
1798 inp->in6p_laddr, (uint8_t)SOCK_PROTO(so), lport,
1799 NETNS_BSD, NULL) != 0) {
1800 netns_release(&inp->inp_wildcard_netns_token);
1801 found = false;
1802 }
1803 }
1804 #endif /* SKYWALK */
1805 } while (!found);
1806
1807 inp->inp_lport = lport;
1808 inp->inp_flags |= INP_ANONPORT;
1809
1810 if (in_pcbinshash(inp, 1) != 0) {
1811 inp->in6p_laddr = in6addr_any;
1812 inp->in6p_last_outifp = NULL;
1813 inp->inp_lifscope = IFSCOPE_NONE;
1814 #if SKYWALK
1815 netns_release(&inp->inp_netns_token);
1816 #endif /* SKYWALK */
1817 inp->inp_lport = 0;
1818 inp->inp_flags &= ~INP_ANONPORT;
1819 if (!locked) {
1820 lck_rw_done(&pcbinfo->ipi_lock);
1821 }
1822 return EAGAIN;
1823 }
1824
1825 if (!locked) {
1826 lck_rw_done(&pcbinfo->ipi_lock);
1827 }
1828 return 0;
1829 }
1830
1831 /*
1832 * The followings are implementation of the policy table using a
1833 * simple tail queue.
1834 * XXX such details should be hidden.
1835 * XXX implementation using binary tree should be more efficient.
1836 */
1837 struct addrsel_policyent {
1838 TAILQ_ENTRY(addrsel_policyent) ape_entry;
1839 struct in6_addrpolicy ape_policy;
1840 };
1841
1842 TAILQ_HEAD(addrsel_policyhead, addrsel_policyent);
1843
1844 struct addrsel_policyhead addrsel_policytab;
1845
1846 static void
init_policy_queue(void)1847 init_policy_queue(void)
1848 {
1849 TAILQ_INIT(&addrsel_policytab);
1850 }
1851
1852 void
addrsel_policy_init(void)1853 addrsel_policy_init(void)
1854 {
1855 /*
1856 * Default address selection policy based on RFC 6724.
1857 */
1858 static const struct in6_addrpolicy defaddrsel[] = {
1859 /* Loopback -- prefix=::1/128, precedence=50, label=0 */
1860 {
1861 .addr = {
1862 .sin6_family = AF_INET6,
1863 .sin6_addr = IN6ADDR_LOOPBACK_INIT,
1864 .sin6_len = sizeof(struct sockaddr_in6)
1865 },
1866 .addrmask = {
1867 .sin6_family = AF_INET6,
1868 .sin6_addr = IN6MASK128,
1869 .sin6_len = sizeof(struct sockaddr_in6)
1870 },
1871 .preced = 50,
1872 .label = 0
1873 },
1874
1875 /* Unspecified -- prefix=::/0, precedence=40, label=1 */
1876 {
1877 .addr = {
1878 .sin6_family = AF_INET6,
1879 .sin6_addr = IN6ADDR_ANY_INIT,
1880 .sin6_len = sizeof(struct sockaddr_in6)
1881 },
1882 .addrmask = {
1883 .sin6_family = AF_INET6,
1884 .sin6_addr = IN6MASK0,
1885 .sin6_len = sizeof(struct sockaddr_in6)
1886 },
1887 .preced = 40,
1888 .label = 1
1889 },
1890
1891 /* IPv4 Mapped -- prefix=::ffff:0:0/96, precedence=35, label=4 */
1892 {
1893 .addr = {
1894 .sin6_family = AF_INET6,
1895 .sin6_addr = IN6ADDR_V4MAPPED_INIT,
1896 .sin6_len = sizeof(struct sockaddr_in6)
1897 },
1898 .addrmask = {
1899 .sin6_family = AF_INET6,
1900 .sin6_addr = IN6MASK96,
1901 .sin6_len = sizeof(struct sockaddr_in6)
1902 },
1903 .preced = 35,
1904 .label = 4
1905 },
1906
1907 /* 6to4 -- prefix=2002::/16, precedence=30, label=2 */
1908 {
1909 .addr = {
1910 .sin6_family = AF_INET6,
1911 .sin6_addr = {{{ 0x20, 0x02 }}},
1912 .sin6_len = sizeof(struct sockaddr_in6)
1913 },
1914 .addrmask = {
1915 .sin6_family = AF_INET6,
1916 .sin6_addr = IN6MASK16,
1917 .sin6_len = sizeof(struct sockaddr_in6)
1918 },
1919 .preced = 30,
1920 .label = 2
1921 },
1922
1923 /* Teredo -- prefix=2001::/32, precedence=5, label=5 */
1924 {
1925 .addr = {
1926 .sin6_family = AF_INET6,
1927 .sin6_addr = {{{ 0x20, 0x01 }}},
1928 .sin6_len = sizeof(struct sockaddr_in6)
1929 },
1930 .addrmask = {
1931 .sin6_family = AF_INET6,
1932 .sin6_addr = IN6MASK32,
1933 .sin6_len = sizeof(struct sockaddr_in6)
1934 },
1935 .preced = 5,
1936 .label = 5
1937 },
1938
1939 /* Unique Local (ULA) -- prefix=fc00::/7, precedence=3, label=13 */
1940 {
1941 .addr = {
1942 .sin6_family = AF_INET6,
1943 .sin6_addr = {{{ 0xfc }}},
1944 .sin6_len = sizeof(struct sockaddr_in6)
1945 },
1946 .addrmask = {
1947 .sin6_family = AF_INET6,
1948 .sin6_addr = IN6MASK7,
1949 .sin6_len = sizeof(struct sockaddr_in6)
1950 },
1951 .preced = 3,
1952 .label = 13
1953 },
1954
1955 /* IPv4 Compatible -- prefix=::/96, precedence=1, label=3 */
1956 {
1957 .addr = {
1958 .sin6_family = AF_INET6,
1959 .sin6_addr = IN6ADDR_ANY_INIT,
1960 .sin6_len = sizeof(struct sockaddr_in6)
1961 },
1962 .addrmask = {
1963 .sin6_family = AF_INET6,
1964 .sin6_addr = IN6MASK96,
1965 .sin6_len = sizeof(struct sockaddr_in6)
1966 },
1967 .preced = 1,
1968 .label = 3
1969 },
1970
1971 /* Site-local (deprecated) -- prefix=fec0::/10, precedence=1, label=11 */
1972 {
1973 .addr = {
1974 .sin6_family = AF_INET6,
1975 .sin6_addr = {{{ 0xfe, 0xc0 }}},
1976 .sin6_len = sizeof(struct sockaddr_in6)
1977 },
1978 .addrmask = {
1979 .sin6_family = AF_INET6,
1980 .sin6_addr = IN6MASK16,
1981 .sin6_len = sizeof(struct sockaddr_in6)
1982 },
1983 .preced = 1,
1984 .label = 11
1985 },
1986
1987 /* 6bone (deprecated) -- prefix=3ffe::/16, precedence=1, label=12 */
1988 {
1989 .addr = {
1990 .sin6_family = AF_INET6,
1991 .sin6_addr = {{{ 0x3f, 0xfe }}},
1992 .sin6_len = sizeof(struct sockaddr_in6)
1993 },
1994 .addrmask = {
1995 .sin6_family = AF_INET6,
1996 .sin6_addr = IN6MASK16,
1997 .sin6_len = sizeof(struct sockaddr_in6)
1998 },
1999 .preced = 1,
2000 .label = 12
2001 },
2002 };
2003 int i;
2004
2005 init_policy_queue();
2006
2007 /* initialize the "last resort" policy */
2008 bzero(&defaultaddrpolicy, sizeof(defaultaddrpolicy));
2009 defaultaddrpolicy.label = ADDR_LABEL_NOTAPP;
2010
2011 for (i = 0; i < sizeof(defaddrsel) / sizeof(defaddrsel[0]); i++) {
2012 add_addrsel_policyent(&defaddrsel[i]);
2013 }
2014 }
2015
2016 struct in6_addrpolicy *
in6_addrsel_lookup_policy(struct sockaddr_in6 * key)2017 in6_addrsel_lookup_policy(struct sockaddr_in6 *key)
2018 {
2019 struct in6_addrpolicy *match = NULL;
2020
2021 match = match_addrsel_policy(key);
2022
2023 if (match == NULL) {
2024 match = &defaultaddrpolicy;
2025 } else {
2026 match->use++;
2027 }
2028
2029 return match;
2030 }
2031
2032 static struct in6_addrpolicy *
match_addrsel_policy(struct sockaddr_in6 * key)2033 match_addrsel_policy(struct sockaddr_in6 *key)
2034 {
2035 struct addrsel_policyent *pent;
2036 struct in6_addrpolicy *bestpol = NULL, *pol;
2037 int matchlen, bestmatchlen = -1;
2038 u_char *mp, *ep, *k, *p, m;
2039
2040 TAILQ_FOREACH(pent, &addrsel_policytab, ape_entry) {
2041 matchlen = 0;
2042
2043 pol = &pent->ape_policy;
2044 mp = (u_char *)&pol->addrmask.sin6_addr;
2045 ep = mp + 16; /* XXX: scope field? */
2046 k = (u_char *)&key->sin6_addr;
2047 p = (u_char *)&pol->addr.sin6_addr;
2048 for (; mp < ep && *mp; mp++, k++, p++) {
2049 m = *mp;
2050 if ((*k & m) != *p) {
2051 goto next; /* not match */
2052 }
2053 if (m == 0xff) { /* short cut for a typical case */
2054 matchlen += 8;
2055 } else {
2056 while (m >= 0x80) {
2057 matchlen++;
2058 m = (u_char)(m << 1);
2059 }
2060 }
2061 }
2062
2063 /* matched. check if this is better than the current best. */
2064 if (bestpol == NULL ||
2065 matchlen > bestmatchlen) {
2066 bestpol = pol;
2067 bestmatchlen = matchlen;
2068 }
2069
2070 next:
2071 continue;
2072 }
2073
2074 return bestpol;
2075 }
2076
2077 static int
add_addrsel_policyent(const struct in6_addrpolicy * newpolicy)2078 add_addrsel_policyent(const struct in6_addrpolicy *newpolicy)
2079 {
2080 struct addrsel_policyent *new, *pol;
2081
2082 new = kalloc_type(struct addrsel_policyent, Z_WAITOK | Z_ZERO);
2083
2084 /* duplication check */
2085 TAILQ_FOREACH(pol, &addrsel_policytab, ape_entry) {
2086 if (IN6_ARE_ADDR_EQUAL(&newpolicy->addr.sin6_addr,
2087 &pol->ape_policy.addr.sin6_addr) &&
2088 IN6_ARE_ADDR_EQUAL(&newpolicy->addrmask.sin6_addr,
2089 &pol->ape_policy.addrmask.sin6_addr)) {
2090 kfree_type(struct addrsel_policyent, new);
2091 return EEXIST; /* or override it? */
2092 }
2093 }
2094
2095 /* XXX: should validate entry */
2096 new->ape_policy = *newpolicy;
2097
2098 TAILQ_INSERT_TAIL(&addrsel_policytab, new, ape_entry);
2099
2100 return 0;
2101 }
2102
2103 int
walk_addrsel_policy(int (* callback)(const struct in6_addrpolicy *,void *),void * w)2104 walk_addrsel_policy(int (*callback)(const struct in6_addrpolicy *, void *),
2105 void *w)
2106 {
2107 struct addrsel_policyent *pol;
2108 int error = 0;
2109
2110 TAILQ_FOREACH(pol, &addrsel_policytab, ape_entry) {
2111 if ((error = (*callback)(&pol->ape_policy, w)) != 0) {
2112 return error;
2113 }
2114 }
2115 return error;
2116 }
2117 /*
2118 * Subroutines to manage the address selection policy table via sysctl.
2119 */
2120 struct walkarg {
2121 struct sysctl_req *w_req;
2122 };
2123
2124
2125 static int
dump_addrsel_policyent(const struct in6_addrpolicy * pol,void * arg)2126 dump_addrsel_policyent(const struct in6_addrpolicy *pol, void *arg)
2127 {
2128 int error = 0;
2129 struct walkarg *w = arg;
2130
2131 error = SYSCTL_OUT(w->w_req, pol, sizeof(*pol));
2132
2133 return error;
2134 }
2135
2136 static int
2137 in6_src_sysctl SYSCTL_HANDLER_ARGS
2138 {
2139 #pragma unused(oidp, arg1, arg2)
2140 struct walkarg w;
2141
2142 if (req->newptr) {
2143 return EPERM;
2144 }
2145 bzero(&w, sizeof(w));
2146 w.w_req = req;
2147
2148 return walk_addrsel_policy(dump_addrsel_policyent, &w);
2149 }
2150
2151
2152 SYSCTL_NODE(_net_inet6_ip6, IPV6CTL_ADDRCTLPOLICY, addrctlpolicy,
2153 CTLFLAG_RD | CTLFLAG_LOCKED, in6_src_sysctl, "");
2154 int
in6_src_ioctl(u_long cmd,caddr_t data)2155 in6_src_ioctl(u_long cmd, caddr_t data)
2156 {
2157 int i;
2158 struct in6_addrpolicy ent0;
2159
2160 if (cmd != SIOCAADDRCTL_POLICY && cmd != SIOCDADDRCTL_POLICY) {
2161 return EOPNOTSUPP; /* check for safety */
2162 }
2163 bcopy(data, &ent0, sizeof(ent0));
2164
2165 if (ent0.label == ADDR_LABEL_NOTAPP) {
2166 return EINVAL;
2167 }
2168 /* check if the prefix mask is consecutive. */
2169 if (in6_mask2len(&ent0.addrmask.sin6_addr, NULL) < 0) {
2170 return EINVAL;
2171 }
2172 /* clear trailing garbages (if any) of the prefix address. */
2173 for (i = 0; i < 4; i++) {
2174 ent0.addr.sin6_addr.s6_addr32[i] &=
2175 ent0.addrmask.sin6_addr.s6_addr32[i];
2176 }
2177 ent0.use = 0;
2178
2179 switch (cmd) {
2180 case SIOCAADDRCTL_POLICY:
2181 return ENOTSUP;
2182 case SIOCDADDRCTL_POLICY:
2183 return ENOTSUP;
2184 }
2185
2186 return 0; /* XXX: compromise compilers */
2187 }
2188
2189 /*
2190 * generate kernel-internal form (scopeid embedded into s6_addr16[1]).
2191 * If the address scope of is link-local, embed the interface index in the
2192 * address. The routine determines our precedence
2193 * between advanced API scope/interface specification and basic API
2194 * specification.
2195 *
2196 * this function should be nuked in the future, when we get rid of
2197 * embedded scopeid thing.
2198 *
2199 * XXX actually, it is over-specification to return ifp against sin6_scope_id.
2200 * there can be multiple interfaces that belong to a particular scope zone
2201 * (in specification, we have 1:N mapping between a scope zone and interfaces).
2202 * we may want to change the function to return something other than ifp.
2203 */
2204 int
in6_embedscope(struct in6_addr * in6,const struct sockaddr_in6 * sin6,struct in6pcb * in6p,struct ifnet ** ifpp,struct ip6_pktopts * opt,uint32_t * ret_ifscope)2205 in6_embedscope(struct in6_addr *in6, const struct sockaddr_in6 *sin6,
2206 struct in6pcb *in6p, struct ifnet **ifpp, struct ip6_pktopts *opt, uint32_t *ret_ifscope)
2207 {
2208 struct ifnet *ifp = NULL;
2209 u_int32_t scopeid;
2210 struct ip6_pktopts *optp = NULL;
2211
2212 *in6 = sin6->sin6_addr;
2213 scopeid = sin6->sin6_scope_id;
2214 if (ifpp != NULL) {
2215 *ifpp = NULL;
2216 }
2217
2218 /*
2219 * don't try to read sin6->sin6_addr beyond here, since the caller may
2220 * ask us to overwrite existing sockaddr_in6
2221 */
2222
2223 #ifdef ENABLE_DEFAULT_SCOPE
2224 if (scopeid == 0) {
2225 scopeid = scope6_addr2default(in6);
2226 }
2227 #endif
2228
2229 if (IN6_IS_SCOPE_LINKLOCAL(in6) || IN6_IS_ADDR_MC_INTFACELOCAL(in6)) {
2230 struct in6_pktinfo *pi;
2231 struct ifnet *im6o_multicast_ifp = NULL;
2232
2233 if (in6p != NULL && IN6_IS_ADDR_MULTICAST(in6) &&
2234 in6p->in6p_moptions != NULL) {
2235 IM6O_LOCK(in6p->in6p_moptions);
2236 im6o_multicast_ifp =
2237 in6p->in6p_moptions->im6o_multicast_ifp;
2238 IM6O_UNLOCK(in6p->in6p_moptions);
2239 }
2240
2241 if (opt != NULL) {
2242 optp = opt;
2243 } else if (in6p != NULL) {
2244 optp = in6p->in6p_outputopts;
2245 }
2246 /*
2247 * KAME assumption: link id == interface id
2248 */
2249 if (in6p != NULL && optp != NULL &&
2250 (pi = optp->ip6po_pktinfo) != NULL &&
2251 pi->ipi6_ifindex != 0) {
2252 /* ifp is needed here if only we're returning it */
2253 if (ifpp != NULL) {
2254 ifnet_head_lock_shared();
2255 ifp = ifindex2ifnet[pi->ipi6_ifindex];
2256 ifnet_head_done();
2257 }
2258
2259 if (in6_embedded_scope) {
2260 in6->s6_addr16[1] = htons((uint16_t)pi->ipi6_ifindex);
2261 }
2262 if (ret_ifscope != NULL) {
2263 *ret_ifscope = pi->ipi6_ifindex;
2264 }
2265 } else if (in6p != NULL && IN6_IS_ADDR_MULTICAST(in6) &&
2266 in6p->in6p_moptions != NULL && im6o_multicast_ifp != NULL) {
2267 ifp = im6o_multicast_ifp;
2268 if (in6_embedded_scope) {
2269 in6->s6_addr16[1] = htons(ifp->if_index);
2270 }
2271 if (ret_ifscope != NULL) {
2272 *ret_ifscope = ifp->if_index;
2273 }
2274 } else if (scopeid != 0) {
2275 /*
2276 * Since scopeid is unsigned, we only have to check it
2277 * against if_index (ifnet_head_lock not needed since
2278 * if_index is an ever-increasing integer.)
2279 */
2280 if (!IF_INDEX_IN_RANGE(scopeid)) {
2281 return ENXIO; /* XXX EINVAL? */
2282 }
2283 /* ifp is needed here only if we're returning it */
2284 if (ifpp != NULL) {
2285 ifnet_head_lock_shared();
2286 ifp = ifindex2ifnet[scopeid];
2287 ifnet_head_done();
2288 }
2289 if (in6_embedded_scope) {
2290 /* XXX assignment to 16bit from 32bit variable */
2291 in6->s6_addr16[1] = htons(scopeid & 0xffff);
2292 }
2293 if (ret_ifscope != NULL) {
2294 *ret_ifscope = scopeid;
2295 }
2296 }
2297
2298 if (ifpp != NULL) {
2299 if (ifp != NULL) {
2300 ifnet_reference(ifp); /* for caller */
2301 }
2302 *ifpp = ifp;
2303 }
2304 }
2305
2306 return 0;
2307 }
2308
2309 /*
2310 * generate standard sockaddr_in6 from embedded form.
2311 * touches sin6_addr and sin6_scope_id only.
2312 *
2313 * this function should be nuked in the future, when we get rid of
2314 * embedded scopeid thing.
2315 */
2316 int
in6_recoverscope(struct sockaddr_in6 * sin6,const struct in6_addr * in6,struct ifnet * ifp)2317 in6_recoverscope(
2318 struct sockaddr_in6 *sin6,
2319 const struct in6_addr *in6,
2320 struct ifnet *ifp)
2321 {
2322 u_int32_t scopeid;
2323
2324 sin6->sin6_addr = *in6;
2325
2326 if (!in6_embedded_scope) {
2327 if (ifp != NULL && IN6_IS_SCOPE_EMBED(in6)) {
2328 sin6->sin6_scope_id = ifp->if_index;
2329 }
2330 return 0;
2331 }
2332 /*
2333 * don't try to read *in6 beyond here, since the caller may
2334 * ask us to overwrite existing sockaddr_in6
2335 */
2336
2337 sin6->sin6_scope_id = 0;
2338 if (IN6_IS_SCOPE_LINKLOCAL(in6) || IN6_IS_ADDR_MC_INTFACELOCAL(in6)) {
2339 /*
2340 * KAME assumption: link id == interface id
2341 */
2342 scopeid = ntohs(sin6->sin6_addr.s6_addr16[1]);
2343 if (scopeid) {
2344 /*
2345 * sanity check
2346 *
2347 * Since scopeid is unsigned, we only have to check it
2348 * against if_index
2349 */
2350 if (!IF_INDEX_IN_RANGE(scopeid)) {
2351 return ENXIO;
2352 }
2353 if (ifp && ifp->if_index != scopeid) {
2354 return ENXIO;
2355 }
2356 sin6->sin6_addr.s6_addr16[1] = 0;
2357 sin6->sin6_scope_id = scopeid;
2358 }
2359 }
2360
2361 return 0;
2362 }
2363