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 "loop.h"
131
132 SYSCTL_DECL(_net_inet6_ip6);
133
134 static int ip6_select_srcif_debug = 0;
135 SYSCTL_INT(_net_inet6_ip6, OID_AUTO, select_srcif_debug,
136 CTLFLAG_RW | CTLFLAG_LOCKED, &ip6_select_srcif_debug, 0,
137 "log source interface selection debug info");
138
139 static int ip6_select_srcaddr_debug = 0;
140 SYSCTL_INT(_net_inet6_ip6, OID_AUTO, select_srcaddr_debug,
141 CTLFLAG_RW | CTLFLAG_LOCKED, &ip6_select_srcaddr_debug, 0,
142 "log source address selection debug info");
143
144 static int ip6_select_src_expensive_secondary_if = 0;
145 SYSCTL_INT(_net_inet6_ip6, OID_AUTO, select_src_expensive_secondary_if,
146 CTLFLAG_RW | CTLFLAG_LOCKED, &ip6_select_src_expensive_secondary_if, 0,
147 "allow source interface selection to use expensive secondaries");
148
149 static int ip6_select_src_strong_end = 1;
150 SYSCTL_INT(_net_inet6_ip6, OID_AUTO, select_src_strong_end,
151 CTLFLAG_RW | CTLFLAG_LOCKED, &ip6_select_src_strong_end, 0,
152 "limit source address selection to outgoing interface");
153
154 #define ADDR_LABEL_NOTAPP (-1)
155 struct in6_addrpolicy defaultaddrpolicy;
156
157 int ip6_prefer_tempaddr = 1;
158
159 int ip6_cga_conflict_retries = IPV6_CGA_CONFLICT_RETRIES_DEFAULT;
160
161 #ifdef ENABLE_ADDRSEL
162 static LCK_MTX_DECLARE_ATTR(addrsel_mutex, &ip6_mutex_grp, &ip6_mutex_attr);
163 #define ADDRSEL_LOCK() lck_mtx_lock(&addrsel_mutex)
164 #define ADDRSEL_UNLOCK() lck_mtx_unlock(&addrsel_mutex)
165 #else
166 #define ADDRSEL_LOCK()
167 #define ADDRSEL_UNLOCK()
168 #endif
169 extern int udp_use_randomport;
170 extern int tcp_use_randomport;
171
172 static int selectroute(struct sockaddr_in6 *, struct sockaddr_in6 *,
173 struct ip6_pktopts *, struct ip6_moptions *, struct in6_ifaddr **,
174 struct route_in6 *, struct ifnet **, struct rtentry **, int, int,
175 struct ip6_out_args *ip6oa);
176 static int in6_selectif(struct sockaddr_in6 *, struct ip6_pktopts *,
177 struct ip6_moptions *, struct route_in6 *ro,
178 struct ip6_out_args *, struct ifnet **);
179 static void init_policy_queue(void);
180 static int add_addrsel_policyent(const struct in6_addrpolicy *);
181 #ifdef ENABLE_ADDRSEL
182 static int delete_addrsel_policyent(const struct in6_addrpolicy *);
183 #endif
184 static int walk_addrsel_policy(int (*)(const struct in6_addrpolicy *, void *),
185 void *);
186 static int dump_addrsel_policyent(const struct in6_addrpolicy *, void *);
187 static struct in6_addrpolicy *match_addrsel_policy(struct sockaddr_in6 *);
188 void addrsel_policy_init(void);
189
190 #define SASEL_DO_DBG(inp) \
191 (ip6_select_srcaddr_debug && (inp) != NULL && \
192 (inp)->inp_socket != NULL && \
193 ((inp)->inp_socket->so_options & SO_DEBUG))
194
195 #define SASEL_LOG(fmt, ...) \
196 do { \
197 if (srcsel_debug) \
198 os_log(OS_LOG_DEFAULT, "%s:%d " fmt,\
199 __FUNCTION__, __LINE__, ##__VA_ARGS__); \
200 } while (0); \
201
202 /*
203 * Return an IPv6 address, which is the most appropriate for a given
204 * destination and user specified options.
205 * If necessary, this function lookups the routing table and returns
206 * an entry to the caller for later use.
207 */
208 #define REPLACE(r) do {\
209 SASEL_LOG("REPLACE r %s ia %s ifp1 %s\n", \
210 (#r), s_src, ifp1->if_xname); \
211 srcrule = (r); \
212 goto replace; \
213 } while (0)
214
215 #define NEXTSRC(r) do {\
216 SASEL_LOG("NEXTSRC r %s ia %s ifp1 %s\n", \
217 (#r), s_src, ifp1->if_xname); \
218 goto next; /* XXX: we can't use 'continue' here */ \
219 } while (0)
220
221 #define BREAK(r) do { \
222 SASEL_LOG("BREAK r %s ia %s ifp1 %s\n", \
223 (#r), s_src, ifp1->if_xname); \
224 srcrule = (r); \
225 goto out; /* XXX: we can't use 'break' here */ \
226 } while (0)
227
228
229 struct ifaddr *
in6_selectsrc_core_ifa(struct sockaddr_in6 * addr,struct ifnet * ifp,int srcsel_debug)230 in6_selectsrc_core_ifa(struct sockaddr_in6 *addr, struct ifnet *ifp, int srcsel_debug)
231 {
232 int err = 0;
233 struct ifnet *src_ifp = NULL;
234 struct in6_addr src_storage = {};
235 struct in6_addr *in6 = NULL;
236 struct ifaddr *ifa = NULL;
237
238 if ((in6 = in6_selectsrc_core(addr,
239 (ip6_prefer_tempaddr ? IPV6_SRCSEL_HINT_PREFER_TMPADDR : 0),
240 ifp, 0, &src_storage, &src_ifp, &err, &ifa, NULL)) == NULL) {
241 if (err == 0) {
242 err = EADDRNOTAVAIL;
243 }
244 VERIFY(src_ifp == NULL);
245 if (ifa != NULL) {
246 IFA_REMREF(ifa);
247 ifa = NULL;
248 }
249 goto done;
250 }
251
252 if (src_ifp != ifp) {
253 if (err == 0) {
254 err = ENETUNREACH;
255 }
256 if (ifa != NULL) {
257 IFA_REMREF(ifa);
258 ifa = NULL;
259 }
260 goto done;
261 }
262
263 VERIFY(ifa != NULL);
264 ifnet_lock_shared(ifp);
265 if ((ifa->ifa_debug & IFD_DETACHING) != 0) {
266 err = EHOSTUNREACH;
267 ifnet_lock_done(ifp);
268 IFA_REMREF(ifa);
269 ifa = NULL;
270 goto done;
271 }
272 ifnet_lock_done(ifp);
273
274 done:
275 SASEL_LOG("Returned with error: %d", err);
276 if (src_ifp != NULL) {
277 ifnet_release(src_ifp);
278 }
279 return ifa;
280 }
281
282 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)283 in6_selectsrc_core(struct sockaddr_in6 *dstsock, uint32_t hint_mask,
284 struct ifnet *ifp, int srcsel_debug, struct in6_addr *src_storage,
285 struct ifnet **sifp, int *errorp, struct ifaddr **ifapp, struct route_in6 *ro)
286 {
287 u_int32_t odstzone;
288 int bestrule = IP6S_SRCRULE_0;
289 struct in6_addrpolicy *dst_policy = NULL, *best_policy = NULL;
290 struct in6_addr dst;
291 struct in6_ifaddr *ia = NULL, *ia_best = NULL;
292 char s_src[MAX_IPv6_STR_LEN] = {0};
293 char s_dst[MAX_IPv6_STR_LEN] = {0};
294 const struct in6_addr *tmp = NULL;
295 int dst_scope = -1, best_scope = -1, best_matchlen = -1;
296 uint64_t secs = net_uptime();
297 struct nd_defrouter *dr = NULL;
298 uint32_t genid = in6_ifaddrlist_genid;
299 VERIFY(dstsock != NULL);
300 VERIFY(src_storage != NULL);
301 VERIFY(ifp != NULL);
302
303 if (sifp != NULL) {
304 *sifp = NULL;
305 }
306
307 if (ifapp != NULL) {
308 *ifapp = NULL;
309 }
310
311 dst = dstsock->sin6_addr; /* make a copy for local operation */
312
313 if (srcsel_debug) {
314 (void) inet_ntop(AF_INET6, &dst, s_dst, sizeof(s_src));
315
316 tmp = &in6addr_any;
317 (void) inet_ntop(AF_INET6, tmp, s_src, sizeof(s_src));
318 os_log(OS_LOG_DEFAULT, "%s out src %s dst %s ifp %s",
319 __func__, s_src, s_dst, ifp->if_xname);
320 }
321
322 *errorp = in6_setscope(&dst, ifp, &odstzone);
323 if (*errorp != 0) {
324 src_storage = NULL;
325 goto done;
326 }
327
328 /*
329 * Determine if the route is an indirect here
330 * and if it is get the default router that would be
331 * used as next hop.
332 * Later in the function it is used to apply rule 5.5 of RFC 6724.
333 */
334 if (ro != NULL && ro->ro_rt != NULL &&
335 (ro->ro_rt->rt_flags & RTF_GATEWAY) &&
336 ro->ro_rt->rt_gateway != NULL) {
337 struct rtentry *rt = ro->ro_rt;
338 lck_mtx_lock(nd6_mutex);
339 dr = defrouter_lookup(NULL,
340 &SIN6(rt->rt_gateway)->sin6_addr, rt->rt_ifp);
341 lck_mtx_unlock(nd6_mutex);
342 }
343
344 lck_rw_lock_shared(&in6_ifaddr_rwlock);
345 addrloop:
346 TAILQ_FOREACH(ia, &in6_ifaddrhead, ia6_link) {
347 int new_scope = -1, new_matchlen = -1;
348 struct in6_addrpolicy *new_policy = NULL;
349 u_int32_t srczone = 0, osrczone, dstzone;
350 struct in6_addr src;
351 struct ifnet *ifp1 = ia->ia_ifp;
352 int srcrule;
353
354 if (srcsel_debug) {
355 (void) inet_ntop(AF_INET6, &ia->ia_addr.sin6_addr,
356 s_src, sizeof(s_src));
357 }
358
359 IFA_LOCK(&ia->ia_ifa);
360
361 /*
362 * Simply skip addresses reserved for CLAT46
363 */
364 if (ia->ia6_flags & IN6_IFF_CLAT46) {
365 SASEL_LOG("NEXT ia %s address on ifp1 %s skipped as it is "
366 "reserved for CLAT46\n", s_src, ifp1->if_xname);
367 goto next;
368 }
369
370 /*
371 * XXX By default we are strong end system and will
372 * limit candidate set of source address to the ones
373 * configured on the outgoing interface.
374 */
375 if (ip6_select_src_strong_end &&
376 ifp1 != ifp) {
377 SASEL_LOG("NEXT ia %s ifp1 %s address is not on outgoing "
378 "interface \n", s_src, ifp1->if_xname);
379 goto next;
380 }
381
382 /*
383 * We'll never take an address that breaks the scope zone
384 * of the destination. We also skip an address if its zone
385 * does not contain the outgoing interface.
386 * XXX: we should probably use sin6_scope_id here.
387 */
388 if (in6_setscope(&dst, ifp1, &dstzone) ||
389 odstzone != dstzone) {
390 SASEL_LOG("NEXT ia %s ifp1 %s odstzone %d != dstzone %d\n",
391 s_src, ifp1->if_xname, odstzone, dstzone);
392 goto next;
393 }
394 src = ia->ia_addr.sin6_addr;
395 if (in6_setscope(&src, ifp, &osrczone) ||
396 in6_setscope(&src, ifp1, &srczone) ||
397 osrczone != srczone) {
398 SASEL_LOG("NEXT ia %s ifp1 %s osrczone %d != srczone %d\n",
399 s_src, ifp1->if_xname, osrczone, srczone);
400 goto next;
401 }
402 /* avoid unusable addresses */
403 if ((ia->ia6_flags &
404 (IN6_IFF_NOTREADY | IN6_IFF_ANYCAST | IN6_IFF_DETACHED))) {
405 SASEL_LOG("NEXT ia %s ifp1 %s ia6_flags 0x%x\n",
406 s_src, ifp1->if_xname, ia->ia6_flags);
407 goto next;
408 }
409 if (!ip6_use_deprecated && IFA6_IS_DEPRECATED(ia, secs)) {
410 SASEL_LOG("NEXT ia %s ifp1 %s IFA6_IS_DEPRECATED\n",
411 s_src, ifp1->if_xname);
412 goto next;
413 }
414 if (!nd6_optimistic_dad &&
415 (ia->ia6_flags & IN6_IFF_OPTIMISTIC) != 0) {
416 SASEL_LOG("NEXT ia %s ifp1 %s IN6_IFF_OPTIMISTIC\n",
417 s_src, ifp1->if_xname);
418 goto next;
419 }
420 /* Rule 1: Prefer same address */
421 if (in6_are_addr_equal_scoped(&dst, &ia->ia_addr.sin6_addr, dstzone, srczone)) {
422 BREAK(IP6S_SRCRULE_1); /* there should be no better candidate */
423 }
424 if (ia_best == NULL) {
425 REPLACE(IP6S_SRCRULE_0);
426 }
427
428 /* Rule 2: Prefer appropriate scope */
429 if (dst_scope < 0) {
430 dst_scope = in6_addrscope(&dst);
431 }
432 new_scope = in6_addrscope(&ia->ia_addr.sin6_addr);
433 if (IN6_ARE_SCOPE_CMP(best_scope, new_scope) < 0) {
434 if (IN6_ARE_SCOPE_CMP(best_scope, dst_scope) < 0) {
435 REPLACE(IP6S_SRCRULE_2);
436 }
437 NEXTSRC(IP6S_SRCRULE_2);
438 } else if (IN6_ARE_SCOPE_CMP(new_scope, best_scope) < 0) {
439 if (IN6_ARE_SCOPE_CMP(new_scope, dst_scope) < 0) {
440 NEXTSRC(IP6S_SRCRULE_2);
441 }
442 REPLACE(IP6S_SRCRULE_2);
443 }
444
445 /*
446 * Rule 3: Avoid deprecated addresses. Note that the case of
447 * !ip6_use_deprecated is already rejected above.
448 */
449 if (!IFA6_IS_DEPRECATED(ia_best, secs) &&
450 IFA6_IS_DEPRECATED(ia, secs)) {
451 NEXTSRC(IP6S_SRCRULE_3);
452 }
453 if (IFA6_IS_DEPRECATED(ia_best, secs) &&
454 !IFA6_IS_DEPRECATED(ia, secs)) {
455 REPLACE(IP6S_SRCRULE_3);
456 }
457
458 /*
459 * RFC 4429 says that optimistic addresses are equivalent to
460 * deprecated addresses, so avoid them here.
461 */
462 if ((ia_best->ia6_flags & IN6_IFF_OPTIMISTIC) == 0 &&
463 (ia->ia6_flags & IN6_IFF_OPTIMISTIC) != 0) {
464 NEXTSRC(IP6S_SRCRULE_3);
465 }
466 if ((ia_best->ia6_flags & IN6_IFF_OPTIMISTIC) != 0 &&
467 (ia->ia6_flags & IN6_IFF_OPTIMISTIC) == 0) {
468 REPLACE(IP6S_SRCRULE_3);
469 }
470
471 /* Rule 4: Prefer home addresses */
472 /*
473 * XXX: This is a TODO. We should probably merge the MIP6
474 * case above.
475 */
476
477 /* Rule 5: Prefer outgoing interface */
478 /*
479 * XXX By default we are strong end with source address
480 * selection. That means all address selection candidate
481 * addresses will be the ones hosted on the outgoing interface
482 * making the following check redundant.
483 */
484 if (ip6_select_src_strong_end == 0) {
485 if (ia_best->ia_ifp == ifp && ia->ia_ifp != ifp) {
486 NEXTSRC(IP6S_SRCRULE_5);
487 }
488 if (ia_best->ia_ifp != ifp && ia->ia_ifp == ifp) {
489 REPLACE(IP6S_SRCRULE_5);
490 }
491 }
492
493 /*
494 * Rule 5.5: Prefer addresses in a prefix advertised by the next-hop.
495 * If SA or SA's prefix is assigned by the selected next-hop that will
496 * be used to send to D and SB or SB's prefix is assigned by a different
497 * next-hop, then prefer SA. Similarly, if SB or SB's prefix is
498 * assigned by the next-hop that will be used to send to D and SA or
499 * SA's prefix is assigned by a different next-hop, then prefer SB.
500 */
501 if (dr != NULL && ia_best->ia6_ndpr != ia->ia6_ndpr) {
502 boolean_t ia_best_has_prefix = FALSE;
503 boolean_t ia_has_prefix = FALSE;
504 struct nd_prefix ia_best_prefix = {};
505 struct nd_prefix ia_prefix = {};
506 struct nd_prefix *p_ia_best_prefix = NULL;
507 struct nd_prefix *p_ia_prefix = NULL;
508
509 if (ia_best->ia6_ndpr) {
510 ia_best_prefix = *ia_best->ia6_ndpr;
511 }
512
513 if (ia->ia6_ndpr) {
514 ia_prefix = *ia->ia6_ndpr;
515 }
516
517 IFA_UNLOCK(&ia->ia_ifa);
518 lck_rw_done(&in6_ifaddr_rwlock);
519
520 p_ia_best_prefix = nd6_prefix_lookup(&ia_best_prefix, ND6_PREFIX_EXPIRY_UNSPEC);
521 p_ia_prefix = nd6_prefix_lookup(&ia_prefix, ND6_PREFIX_EXPIRY_UNSPEC);
522
523 lck_mtx_lock(nd6_mutex);
524 if (p_ia_best_prefix != NULL) {
525 NDPR_LOCK(p_ia_best_prefix);
526 ia_best_has_prefix = (pfxrtr_lookup(p_ia_best_prefix, dr) != NULL);
527 NDPR_UNLOCK(p_ia_best_prefix);
528 NDPR_REMREF(p_ia_best_prefix);
529 }
530 if (p_ia_prefix != NULL) {
531 NDPR_LOCK(p_ia_prefix);
532 ia_has_prefix = (pfxrtr_lookup(p_ia_prefix, dr) != NULL);
533 NDPR_UNLOCK(p_ia_prefix);
534 NDPR_REMREF(p_ia_prefix);
535 }
536 lck_mtx_unlock(nd6_mutex);
537
538 lck_rw_lock_shared(&in6_ifaddr_rwlock);
539 if (genid != os_atomic_load(&in6_ifaddrlist_genid, acquire)) {
540 SASEL_LOG("Address list seems to have changed. Restarting source "
541 "address selection.\n");
542 genid = in6_ifaddrlist_genid;
543 /*
544 * We are starting from scratch. Free up the reference
545 * on ia_best and also reset it to NULL.
546 */
547 IFA_REMREF(&ia_best->ia_ifa);
548 ia_best = NULL;
549 goto addrloop;
550 }
551 IFA_LOCK(&ia->ia_ifa);
552
553 if (ia_best_has_prefix && !ia_has_prefix) {
554 NEXTSRC(IP6S_SRCRULE_5_5);
555 }
556
557 if (!ia_best_has_prefix && ia_has_prefix) {
558 REPLACE(IP6S_SRCRULE_5_5);
559 }
560 }
561
562 /*
563 * Rule 6: Prefer matching label
564 * Note that best_policy should be non-NULL here.
565 */
566 if (dst_policy == NULL) {
567 dst_policy = in6_addrsel_lookup_policy(dstsock);
568 }
569 if (dst_policy->label != ADDR_LABEL_NOTAPP) {
570 new_policy = in6_addrsel_lookup_policy(&ia->ia_addr);
571 if (dst_policy->label == best_policy->label &&
572 dst_policy->label != new_policy->label) {
573 NEXTSRC(IP6S_SRCRULE_6);
574 }
575 if (dst_policy->label != best_policy->label &&
576 dst_policy->label == new_policy->label) {
577 REPLACE(IP6S_SRCRULE_6);
578 }
579 }
580
581 /*
582 * Rule 7: Prefer temporary addresses.
583 * We allow users to reverse the logic by configuring
584 * a sysctl variable, so that transparency conscious users can
585 * always prefer stable addresses.
586 */
587 if (!(ia_best->ia6_flags & IN6_IFF_TEMPORARY) &&
588 (ia->ia6_flags & IN6_IFF_TEMPORARY)) {
589 if (hint_mask & IPV6_SRCSEL_HINT_PREFER_TMPADDR) {
590 REPLACE(IP6S_SRCRULE_7);
591 } else {
592 NEXTSRC(IP6S_SRCRULE_7);
593 }
594 }
595 if ((ia_best->ia6_flags & IN6_IFF_TEMPORARY) &&
596 !(ia->ia6_flags & IN6_IFF_TEMPORARY)) {
597 if (hint_mask & IPV6_SRCSEL_HINT_PREFER_TMPADDR) {
598 NEXTSRC(IP6S_SRCRULE_7);
599 } else {
600 REPLACE(IP6S_SRCRULE_7);
601 }
602 }
603
604 /*
605 * Rule 7x: prefer addresses on alive interfaces.
606 * This is a KAME specific rule.
607 */
608 if ((ia_best->ia_ifp->if_flags & IFF_UP) &&
609 !(ia->ia_ifp->if_flags & IFF_UP)) {
610 NEXTSRC(IP6S_SRCRULE_7x);
611 }
612 if (!(ia_best->ia_ifp->if_flags & IFF_UP) &&
613 (ia->ia_ifp->if_flags & IFF_UP)) {
614 REPLACE(IP6S_SRCRULE_7x);
615 }
616
617 /*
618 * Rule 8: Use longest matching prefix.
619 */
620 new_matchlen = in6_matchlen(&ia->ia_addr.sin6_addr, &dst);
621 if (best_matchlen < new_matchlen) {
622 REPLACE(IP6S_SRCRULE_8);
623 }
624 if (new_matchlen < best_matchlen) {
625 NEXTSRC(IP6S_SRCRULE_8);
626 }
627
628 /*
629 * Last resort: just keep the current candidate.
630 * Or, do we need more rules?
631 */
632 if (ifp1 != ifp && (ifp1->if_eflags & IFEF_EXPENSIVE) &&
633 ip6_select_src_expensive_secondary_if == 0) {
634 SASEL_LOG("NEXT ia %s ifp1 %s IFEF_EXPENSIVE\n",
635 s_src, ifp1->if_xname);
636 ip6stat.ip6s_sources_skip_expensive_secondary_if++;
637 goto next;
638 }
639 SASEL_LOG("NEXT ia %s ifp1 %s last resort\n",
640 s_src, ifp1->if_xname);
641 IFA_UNLOCK(&ia->ia_ifa);
642 continue;
643
644 replace:
645 /*
646 * Ignore addresses on secondary interfaces that are marked
647 * expensive
648 */
649 if (ifp1 != ifp && (ifp1->if_eflags & IFEF_EXPENSIVE) &&
650 ip6_select_src_expensive_secondary_if == 0) {
651 SASEL_LOG("NEXT ia %s ifp1 %s IFEF_EXPENSIVE\n",
652 s_src, ifp1->if_xname);
653 ip6stat.ip6s_sources_skip_expensive_secondary_if++;
654 goto next;
655 }
656 bestrule = srcrule;
657 best_scope = (new_scope >= 0 ? new_scope :
658 in6_addrscope(&ia->ia_addr.sin6_addr));
659 best_policy = (new_policy ? new_policy :
660 in6_addrsel_lookup_policy(&ia->ia_addr));
661 best_matchlen = (new_matchlen >= 0 ? new_matchlen :
662 in6_matchlen(&ia->ia_addr.sin6_addr, &dst));
663 SASEL_LOG("NEXT ia %s ifp1 %s best_scope %d new_scope %d dst_scope %d\n",
664 s_src, ifp1->if_xname, best_scope, new_scope, dst_scope);
665 IFA_ADDREF_LOCKED(&ia->ia_ifa); /* for ia_best */
666 IFA_UNLOCK(&ia->ia_ifa);
667 if (ia_best != NULL) {
668 IFA_REMREF(&ia_best->ia_ifa);
669 }
670 ia_best = ia;
671 continue;
672
673 next:
674 IFA_UNLOCK(&ia->ia_ifa);
675 continue;
676
677 out:
678 IFA_ADDREF_LOCKED(&ia->ia_ifa); /* for ia_best */
679 IFA_UNLOCK(&ia->ia_ifa);
680 if (ia_best != NULL) {
681 IFA_REMREF(&ia_best->ia_ifa);
682 }
683 ia_best = ia;
684 break;
685 }
686
687 lck_rw_done(&in6_ifaddr_rwlock);
688
689 if ((ia = ia_best) == NULL) {
690 if (*errorp == 0) {
691 *errorp = EADDRNOTAVAIL;
692 }
693 src_storage = NULL;
694 goto done;
695 }
696
697 if (sifp != NULL) {
698 *sifp = ia->ia_ifa.ifa_ifp;
699 ifnet_reference(*sifp);
700 }
701
702 IFA_LOCK_SPIN(&ia->ia_ifa);
703 if (bestrule < IP6S_SRCRULE_COUNT) {
704 ip6stat.ip6s_sources_rule[bestrule]++;
705 }
706 *src_storage = satosin6(&ia->ia_addr)->sin6_addr;
707 IFA_UNLOCK(&ia->ia_ifa);
708
709 if (ifapp != NULL) {
710 *ifapp = &ia->ia_ifa;
711 } else {
712 IFA_REMREF(&ia->ia_ifa);
713 }
714
715 done:
716 if (srcsel_debug) {
717 (void) inet_ntop(AF_INET6, &dst, s_dst, sizeof(s_src));
718
719 tmp = (src_storage != NULL) ? src_storage : &in6addr_any;
720 (void) inet_ntop(AF_INET6, tmp, s_src, sizeof(s_src));
721
722 os_log(OS_LOG_DEFAULT, "%s out src %s dst %s dst_scope %d best_scope %d",
723 __func__, s_src, s_dst, dst_scope, best_scope);
724 }
725
726 if (dr != NULL) {
727 NDDR_REMREF(dr);
728 }
729
730 return src_storage;
731 }
732
733 /*
734 * Regardless of error, it will return an ifp with a reference held if the
735 * caller provides a non-NULL ifpp. The caller is responsible for checking
736 * if the returned ifp is valid and release its reference at all times.
737 */
738 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)739 in6_selectsrc(struct sockaddr_in6 *dstsock, struct ip6_pktopts *opts,
740 struct inpcb *inp, struct route_in6 *ro,
741 struct ifnet **ifpp, struct in6_addr *src_storage, unsigned int ifscope,
742 int *errorp)
743 {
744 struct ifnet *ifp = NULL;
745 struct in6_pktinfo *pi = NULL;
746 struct ip6_moptions *mopts;
747 struct ip6_out_args ip6oa;
748 boolean_t inp_debug = FALSE;
749 uint32_t hint_mask = 0;
750 int prefer_tempaddr = 0;
751 struct ifnet *sifp = NULL;
752
753 bzero(&ip6oa, sizeof(ip6oa));
754 ip6oa.ip6oa_boundif = ifscope;
755 ip6oa.ip6oa_flags = IP6OAF_SELECT_SRCIF;
756 ip6oa.ip6oa_sotc = SO_TC_UNSPEC;
757 ip6oa.ip6oa_netsvctype = _NET_SERVICE_TYPE_UNSPEC;
758
759 *errorp = 0;
760 if (ifpp != NULL) {
761 *ifpp = NULL;
762 }
763
764 if (inp != NULL) {
765 inp_debug = SASEL_DO_DBG(inp);
766 mopts = inp->in6p_moptions;
767 if (INP_NO_CELLULAR(inp)) {
768 ip6oa.ip6oa_flags |= IP6OAF_NO_CELLULAR;
769 }
770 if (INP_NO_EXPENSIVE(inp)) {
771 ip6oa.ip6oa_flags |= IP6OAF_NO_EXPENSIVE;
772 }
773 if (INP_NO_CONSTRAINED(inp)) {
774 ip6oa.ip6oa_flags |= IP6OAF_NO_CONSTRAINED;
775 }
776 if (INP_AWDL_UNRESTRICTED(inp)) {
777 ip6oa.ip6oa_flags |= IP6OAF_AWDL_UNRESTRICTED;
778 }
779 if (INP_INTCOPROC_ALLOWED(inp)) {
780 ip6oa.ip6oa_flags |= IP6OAF_INTCOPROC_ALLOWED;
781 }
782 if (INP_MANAGEMENT_ALLOWED(inp)) {
783 ip6oa.ip6oa_flags |= IP6OAF_MANAGEMENT_ALLOWED;
784 }
785 } else {
786 mopts = NULL;
787 /* Allow the kernel to retransmit packets. */
788 ip6oa.ip6oa_flags |= IP6OAF_INTCOPROC_ALLOWED |
789 IP6OAF_AWDL_UNRESTRICTED | IP6OAF_MANAGEMENT_ALLOWED;
790 }
791
792 if (ip6oa.ip6oa_boundif != IFSCOPE_NONE) {
793 ip6oa.ip6oa_flags |= IP6OAF_BOUND_IF;
794 }
795
796 /*
797 * If the source address is explicitly specified by the caller,
798 * check if the requested source address is indeed a unicast address
799 * assigned to the node, and can be used as the packet's source
800 * address. If everything is okay, use the address as source.
801 */
802 if (opts && (pi = opts->ip6po_pktinfo) &&
803 !IN6_IS_ADDR_UNSPECIFIED(&pi->ipi6_addr)) {
804 struct sockaddr_in6 srcsock;
805 struct in6_ifaddr *ia6;
806
807 /* get the outgoing interface */
808 if ((*errorp = in6_selectif(dstsock, opts, mopts, ro, &ip6oa,
809 &ifp)) != 0) {
810 src_storage = NULL;
811 goto done;
812 }
813
814 /*
815 * determine the appropriate zone id of the source based on
816 * the zone of the destination and the outgoing interface.
817 * If the specified address is ambiguous wrt the scope zone,
818 * the interface must be specified; otherwise, ifa_ifwithaddr()
819 * will fail matching the address.
820 */
821 bzero(&srcsock, sizeof(srcsock));
822 srcsock.sin6_family = AF_INET6;
823 srcsock.sin6_len = sizeof(srcsock);
824 srcsock.sin6_addr = pi->ipi6_addr;
825 if (ifp != NULL) {
826 *errorp = in6_setscope(&srcsock.sin6_addr, ifp, IN6_NULL_IF_EMBEDDED_SCOPE(&srcsock.sin6_scope_id));
827 if (*errorp != 0) {
828 src_storage = NULL;
829 goto done;
830 }
831 }
832 ia6 = (struct in6_ifaddr *)ifa_ifwithaddr((struct sockaddr *)
833 (&srcsock));
834 if (ia6 == NULL) {
835 *errorp = EADDRNOTAVAIL;
836 src_storage = NULL;
837 goto done;
838 }
839 IFA_LOCK_SPIN(&ia6->ia_ifa);
840 if ((ia6->ia6_flags & (IN6_IFF_ANYCAST | IN6_IFF_NOTREADY | IN6_IFF_CLAT46)) ||
841 (inp && inp_restricted_send(inp, ia6->ia_ifa.ifa_ifp))) {
842 IFA_UNLOCK(&ia6->ia_ifa);
843 IFA_REMREF(&ia6->ia_ifa);
844 *errorp = EHOSTUNREACH;
845 src_storage = NULL;
846 goto done;
847 }
848
849 *src_storage = satosin6(&ia6->ia_addr)->sin6_addr;
850 IFA_UNLOCK(&ia6->ia_ifa);
851 IFA_REMREF(&ia6->ia_ifa);
852 goto done;
853 }
854
855 /*
856 * Otherwise, if the socket has already bound the source, just use it.
857 */
858 if (inp != NULL && !IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr)) {
859 src_storage = &inp->in6p_laddr;
860 goto done;
861 }
862
863 /*
864 * If the address is not specified, choose the best one based on
865 * the outgoing interface and the destination address.
866 */
867 /* get the outgoing interface */
868 if ((*errorp = in6_selectif(dstsock, opts, mopts, ro, &ip6oa,
869 &ifp)) != 0) {
870 src_storage = NULL;
871 goto done;
872 }
873
874 VERIFY(ifp != NULL);
875
876 if (opts == NULL ||
877 opts->ip6po_prefer_tempaddr == IP6PO_TEMPADDR_SYSTEM) {
878 prefer_tempaddr = ip6_prefer_tempaddr;
879 } else if (opts->ip6po_prefer_tempaddr == IP6PO_TEMPADDR_NOTPREFER) {
880 prefer_tempaddr = 0;
881 } else {
882 prefer_tempaddr = 1;
883 }
884
885 if (prefer_tempaddr) {
886 hint_mask |= IPV6_SRCSEL_HINT_PREFER_TMPADDR;
887 }
888
889 if (in6_selectsrc_core(dstsock, hint_mask, ifp, inp_debug, src_storage,
890 &sifp, errorp, NULL, ro) == NULL) {
891 src_storage = NULL;
892 goto done;
893 }
894
895 VERIFY(sifp != NULL);
896
897 if (inp && inp_restricted_send(inp, sifp)) {
898 src_storage = NULL;
899 *errorp = EHOSTUNREACH;
900 ifnet_release(sifp);
901 goto done;
902 } else {
903 ifnet_release(sifp);
904 }
905
906 done:
907 if (ifpp != NULL) {
908 /* if ifp is non-NULL, refcnt held in in6_selectif() */
909 *ifpp = ifp;
910 } else if (ifp != NULL) {
911 ifnet_release(ifp);
912 }
913 return src_storage;
914 }
915
916 /*
917 * Given a source IPv6 address (and route, if available), determine the best
918 * interface to send the packet from. Checking for (and updating) the
919 * ROF_SRCIF_SELECTED flag in the pcb-supplied route placeholder is done
920 * without any locks, based on the assumption that in the event this is
921 * called from ip6_output(), the output operation is single-threaded per-pcb,
922 * i.e. for any given pcb there can only be one thread performing output at
923 * the IPv6 layer.
924 *
925 * This routine is analogous to in_selectsrcif() for IPv4. Regardless of
926 * error, it will return an ifp with a reference held if the caller provides
927 * a non-NULL retifp. The caller is responsible for checking if the
928 * returned ifp is valid and release its reference at all times.
929 *
930 * clone - meaningful only for bsdi and freebsd
931 */
932 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)933 selectroute(struct sockaddr_in6 *srcsock, struct sockaddr_in6 *dstsock,
934 struct ip6_pktopts *opts, struct ip6_moptions *mopts,
935 struct in6_ifaddr **retsrcia, struct route_in6 *ro,
936 struct ifnet **retifp, struct rtentry **retrt, int clone,
937 int norouteok, struct ip6_out_args *ip6oa)
938 {
939 int error = 0;
940 struct ifnet *ifp = NULL, *ifp0 = NULL;
941 struct route_in6 *route = NULL;
942 struct sockaddr_in6 *sin6_next;
943 struct in6_pktinfo *pi = NULL;
944 struct in6_addr *dst = &dstsock->sin6_addr;
945 struct ifaddr *ifa = NULL;
946 char s_src[MAX_IPv6_STR_LEN], s_dst[MAX_IPv6_STR_LEN];
947 boolean_t select_srcif, proxied_ifa = FALSE, local_dst = FALSE;
948 unsigned int ifscope = ((ip6oa != NULL) ?
949 ip6oa->ip6oa_boundif : IFSCOPE_NONE);
950 boolean_t is_direct = FALSE;
951
952 if (retifp != NULL) {
953 *retifp = NULL;
954 }
955
956 if (retrt != NULL) {
957 *retrt = NULL;
958 }
959
960 if (ip6_select_srcif_debug) {
961 struct in6_addr src;
962 src = (srcsock != NULL) ? srcsock->sin6_addr : in6addr_any;
963 (void) inet_ntop(AF_INET6, &src, s_src, sizeof(s_src));
964 (void) inet_ntop(AF_INET6, dst, s_dst, sizeof(s_dst));
965 }
966
967 /*
968 * If the destination address is UNSPECIFIED addr, bail out.
969 */
970 if (IN6_IS_ADDR_UNSPECIFIED(dst)) {
971 error = EHOSTUNREACH;
972 goto done;
973 }
974
975 /*
976 * Perform source interface selection if Scoped Routing
977 * is enabled and a source address that isn't unspecified.
978 */
979 select_srcif = (srcsock != NULL &&
980 !IN6_IS_ADDR_UNSPECIFIED(&srcsock->sin6_addr));
981
982 /*
983 * For scoped routing, if interface scope is 0 or src/dst addr is linklocal
984 * or dst addr is multicast, source interface selection should be performed even
985 * if the destination is directly reachable.
986 */
987 if (ifscope != IFSCOPE_NONE &&
988 !(srcsock != NULL && IN6_IS_ADDR_LINKLOCAL(&srcsock->sin6_addr)) &&
989 !IN6_IS_ADDR_MULTICAST(dst) && !IN6_IS_ADDR_LINKLOCAL(dst)) {
990 struct rtentry *temp_rt = NULL;
991
992 lck_mtx_lock(rnh_lock);
993 temp_rt = rt_lookup(TRUE, (struct sockaddr *)dstsock,
994 NULL, rt_tables[AF_INET6], ifscope);
995 lck_mtx_unlock(rnh_lock);
996
997 /*
998 * If the destination is directly reachable, relax
999 * the behavior around select_srcif, i.e. don't force
1000 * the packet to go out from the interface that is hosting
1001 * the source address.
1002 * It happens when we share v6 with NAT66 and want
1003 * the external interface's v6 address to be reachable
1004 * to the clients we are sharing v6 connectivity with
1005 * using NAT.
1006 */
1007 if (temp_rt != NULL) {
1008 if ((temp_rt->rt_flags & RTF_GATEWAY) == 0) {
1009 select_srcif = FALSE;
1010 is_direct = TRUE;
1011 }
1012 rtfree(temp_rt);
1013 }
1014 }
1015
1016 if (ip6_select_srcif_debug) {
1017 os_log(OS_LOG_DEFAULT, "%s src %s dst %s ifscope %d "
1018 "is_direct %d select_srcif %d",
1019 __func__, s_src, s_dst, ifscope, is_direct, select_srcif);
1020 }
1021
1022 /* If the caller specified the outgoing interface explicitly, use it */
1023 if (opts != NULL && (pi = opts->ip6po_pktinfo) != NULL &&
1024 pi->ipi6_ifindex != 0) {
1025 /*
1026 * If IPV6_PKTINFO takes precedence over IPV6_BOUND_IF.
1027 */
1028 ifscope = pi->ipi6_ifindex;
1029 ifnet_head_lock_shared();
1030 /* ifp may be NULL if detached or out of range */
1031 ifp = ifp0 =
1032 ((ifscope <= if_index) ? ifindex2ifnet[ifscope] : NULL);
1033 ifnet_head_done();
1034 if (norouteok || retrt == NULL || IN6_IS_ADDR_MC_LINKLOCAL(dst)) {
1035 /*
1036 * We do not have to check or get the route for
1037 * multicast. If the caller didn't ask/care for
1038 * the route and we have no interface to use,
1039 * it's an error.
1040 */
1041 if (ifp == NULL) {
1042 error = EHOSTUNREACH;
1043 }
1044 goto done;
1045 } else {
1046 goto getsrcif;
1047 }
1048 }
1049
1050 /*
1051 * If the destination address is a multicast address and the outgoing
1052 * interface for the address is specified by the caller, use it.
1053 */
1054 if (IN6_IS_ADDR_MULTICAST(dst) && mopts != NULL) {
1055 IM6O_LOCK(mopts);
1056 ifp = ifp0 = mopts->im6o_multicast_ifp;
1057 if (ifp != NULL && IN6_IS_ADDR_MC_LINKLOCAL(dst)) {
1058 IM6O_UNLOCK(mopts);
1059 goto done; /* we don't need a route for link-local multicast */
1060 }
1061 IM6O_UNLOCK(mopts);
1062 }
1063
1064 getsrcif:
1065 /*
1066 * If the outgoing interface was not set via IPV6_BOUND_IF or
1067 * IPV6_PKTINFO, use the scope ID in the destination address.
1068 */
1069 if (ifscope == IFSCOPE_NONE) {
1070 ifscope = dstsock->sin6_scope_id;
1071 }
1072
1073 /*
1074 * Perform source interface selection; the source IPv6 address
1075 * must belong to one of the addresses of the interface used
1076 * by the route. For performance reasons, do this only if
1077 * there is no route, or if the routing table has changed,
1078 * or if we haven't done source interface selection on this
1079 * route (for this PCB instance) before.
1080 */
1081 if (!select_srcif) {
1082 goto getroute;
1083 } else if (!ROUTE_UNUSABLE(ro) && ro->ro_srcia != NULL &&
1084 (ro->ro_flags & ROF_SRCIF_SELECTED)) {
1085 if (ro->ro_rt->rt_ifp->if_flags & IFF_LOOPBACK) {
1086 local_dst = TRUE;
1087 }
1088 ifa = ro->ro_srcia;
1089 IFA_ADDREF(ifa); /* for caller */
1090 goto getroute;
1091 }
1092
1093 /*
1094 * Given the source IPv6 address, find a suitable source interface
1095 * to use for transmission; if a scope ID has been specified,
1096 * optimize the search by looking at the addresses only for that
1097 * interface. This is still suboptimal, however, as we need to
1098 * traverse the per-interface list.
1099 */
1100 if (ifscope != IFSCOPE_NONE || (ro != NULL && ro->ro_rt != NULL)) {
1101 unsigned int scope = ifscope;
1102 struct ifnet *rt_ifp;
1103
1104 rt_ifp = (ro->ro_rt != NULL) ? ro->ro_rt->rt_ifp : NULL;
1105
1106 /*
1107 * If no scope is specified and the route is stale (pointing
1108 * to a defunct interface) use the current primary interface;
1109 * this happens when switching between interfaces configured
1110 * with the same IPv6 address. Otherwise pick up the scope
1111 * information from the route; the ULP may have looked up a
1112 * correct route and we just need to verify it here and mark
1113 * it with the ROF_SRCIF_SELECTED flag below.
1114 */
1115 if (scope == IFSCOPE_NONE) {
1116 scope = rt_ifp->if_index;
1117 if (scope != get_primary_ifscope(AF_INET6) &&
1118 ROUTE_UNUSABLE(ro)) {
1119 scope = get_primary_ifscope(AF_INET6);
1120 }
1121 }
1122
1123 ifa = (struct ifaddr *)
1124 ifa_foraddr6_scoped(&srcsock->sin6_addr, scope);
1125
1126 /*
1127 * If we are forwarding and proxying prefix(es), see if the
1128 * source address is one of ours and is a proxied address;
1129 * if so, use it.
1130 */
1131 if (ifa == NULL && ip6_forwarding && nd6_prproxy) {
1132 ifa = (struct ifaddr *)
1133 ifa_foraddr6(&srcsock->sin6_addr);
1134 if (ifa != NULL && !(proxied_ifa =
1135 nd6_prproxy_ifaddr((struct in6_ifaddr *)ifa))) {
1136 IFA_REMREF(ifa);
1137 ifa = NULL;
1138 }
1139 }
1140
1141 if (ip6_select_srcif_debug && ifa != NULL) {
1142 if (ro->ro_rt != NULL) {
1143 os_log(OS_LOG_DEFAULT, "%s %s->%s ifscope %d->%d ifa_if %s "
1144 "ro_if %s",
1145 __func__,
1146 s_src, s_dst, ifscope,
1147 scope, if_name(ifa->ifa_ifp),
1148 if_name(rt_ifp));
1149 } else {
1150 os_log(OS_LOG_DEFAULT, "%s %s->%s ifscope %d->%d ifa_if %s",
1151 __func__,
1152 s_src, s_dst, ifscope, scope,
1153 if_name(ifa->ifa_ifp));
1154 }
1155 }
1156 }
1157
1158 /*
1159 * Slow path; search for an interface having the corresponding source
1160 * IPv6 address if the scope was not specified by the caller, and:
1161 *
1162 * 1) There currently isn't any route, or,
1163 * 2) The interface used by the route does not own that source
1164 * IPv6 address; in this case, the route will get blown away
1165 * and we'll do a more specific scoped search using the newly
1166 * found interface.
1167 */
1168 if (ifa == NULL && ifscope == IFSCOPE_NONE) {
1169 struct ifaddr *ifadst;
1170
1171 /* Check if the destination address is one of ours */
1172 ifadst = (struct ifaddr *)ifa_foraddr6(&dstsock->sin6_addr);
1173 if (ifadst != NULL) {
1174 local_dst = TRUE;
1175 IFA_REMREF(ifadst);
1176 }
1177
1178 ifa = (struct ifaddr *)ifa_foraddr6(&srcsock->sin6_addr);
1179
1180 if (ip6_select_srcif_debug && ifa != NULL) {
1181 os_log(OS_LOG_DEFAULT, "%s %s->%s ifscope %d ifa_if %s",
1182 __func__,
1183 s_src, s_dst, ifscope, if_name(ifa->ifa_ifp));
1184 } else if (ip6_select_srcif_debug) {
1185 os_log(OS_LOG_DEFAULT, "%s %s->%s ifscope %d ifa_if NULL",
1186 __func__,
1187 s_src, s_dst, ifscope);
1188 }
1189 }
1190
1191 getroute:
1192 if (ifa != NULL && !proxied_ifa && !local_dst) {
1193 ifscope = ifa->ifa_ifp->if_index;
1194 }
1195
1196 /*
1197 * If the next hop address for the packet is specified by the caller,
1198 * use it as the gateway.
1199 */
1200 if (opts != NULL && opts->ip6po_nexthop != NULL) {
1201 struct route_in6 *ron;
1202
1203 sin6_next = satosin6(opts->ip6po_nexthop);
1204
1205 /* at this moment, we only support AF_INET6 next hops */
1206 if (sin6_next->sin6_family != AF_INET6) {
1207 error = EAFNOSUPPORT; /* or should we proceed? */
1208 goto done;
1209 }
1210
1211 /*
1212 * If the next hop is an IPv6 address, then the node identified
1213 * by that address must be a neighbor of the sending host.
1214 */
1215 ron = &opts->ip6po_nextroute;
1216 if (ron->ro_rt != NULL) {
1217 RT_LOCK(ron->ro_rt);
1218 }
1219 if (ROUTE_UNUSABLE(ron) || (ron->ro_rt != NULL &&
1220 (!(ron->ro_rt->rt_flags & RTF_LLINFO) ||
1221 (select_srcif && (ifa == NULL ||
1222 (ifa->ifa_ifp != ron->ro_rt->rt_ifp && !proxied_ifa))))) ||
1223 !in6_are_addr_equal_scoped(&satosin6(&ron->ro_dst)->sin6_addr,
1224 &sin6_next->sin6_addr, ron->ro_rt->rt_ifp->if_index, sin6_next->sin6_scope_id)) {
1225 if (ron->ro_rt != NULL) {
1226 RT_UNLOCK(ron->ro_rt);
1227 }
1228
1229 ROUTE_RELEASE(ron);
1230 *satosin6(&ron->ro_dst) = *sin6_next;
1231 }
1232 if (ron->ro_rt == NULL) {
1233 rtalloc_scoped((struct route *)ron, ifscope);
1234 if (ron->ro_rt != NULL) {
1235 RT_LOCK(ron->ro_rt);
1236 }
1237 if (ROUTE_UNUSABLE(ron) ||
1238 !(ron->ro_rt->rt_flags & RTF_LLINFO) ||
1239 !in6_are_addr_equal_scoped(&satosin6(rt_key(ron->ro_rt))->
1240 sin6_addr, &sin6_next->sin6_addr, ron->ro_rt->rt_ifp->if_index, sin6_next->sin6_scope_id)) {
1241 if (ron->ro_rt != NULL) {
1242 RT_UNLOCK(ron->ro_rt);
1243 }
1244
1245 ROUTE_RELEASE(ron);
1246 error = EHOSTUNREACH;
1247 goto done;
1248 }
1249 }
1250 route = ron;
1251 ifp = ifp0 = ron->ro_rt->rt_ifp;
1252
1253 /*
1254 * When cloning is required, try to allocate a route to the
1255 * destination so that the caller can store path MTU
1256 * information.
1257 */
1258 if (!clone) {
1259 if (select_srcif) {
1260 /* Keep the route locked */
1261 goto validateroute;
1262 }
1263 RT_UNLOCK(ron->ro_rt);
1264 goto done;
1265 }
1266 RT_UNLOCK(ron->ro_rt);
1267 }
1268
1269 /*
1270 * Use a cached route if it exists and is valid, else try to allocate
1271 * a new one. Note that we should check the address family of the
1272 * cached destination, in case of sharing the cache with IPv4.
1273 */
1274 if (ro == NULL) {
1275 goto done;
1276 }
1277 if (ro->ro_rt != NULL) {
1278 RT_LOCK_SPIN(ro->ro_rt);
1279 }
1280 if (ROUTE_UNUSABLE(ro) || (ro->ro_rt != NULL &&
1281 (satosin6(&ro->ro_dst)->sin6_family != AF_INET6 ||
1282 !in6_are_addr_equal_scoped(&satosin6(&ro->ro_dst)->sin6_addr, dst, ro->ro_rt->rt_ifp->if_index, dstsock->sin6_scope_id) ||
1283 (select_srcif && (ifa == NULL ||
1284 (ifa->ifa_ifp != ro->ro_rt->rt_ifp && !proxied_ifa)))))) {
1285 if (ro->ro_rt != NULL) {
1286 RT_UNLOCK(ro->ro_rt);
1287 }
1288
1289 ROUTE_RELEASE(ro);
1290 }
1291 if (ro->ro_rt == NULL) {
1292 struct sockaddr_in6 *sa6;
1293
1294 /* No route yet, so try to acquire one */
1295 bzero(&ro->ro_dst, sizeof(struct sockaddr_in6));
1296 sa6 = (struct sockaddr_in6 *)&ro->ro_dst;
1297 sa6->sin6_family = AF_INET6;
1298 sa6->sin6_len = sizeof(struct sockaddr_in6);
1299 sa6->sin6_addr = *dst;
1300 if (IN6_IS_ADDR_MC_LINKLOCAL(dst)) {
1301 ro->ro_rt = rtalloc1_scoped(
1302 SA(&((struct route *)ro)->ro_dst), 0, 0, ifscope);
1303 } else {
1304 rtalloc_scoped((struct route *)ro, ifscope);
1305 }
1306 if (ro->ro_rt != NULL) {
1307 RT_LOCK_SPIN(ro->ro_rt);
1308 }
1309 }
1310
1311 /*
1312 * Do not care about the result if we have the nexthop
1313 * explicitly specified (in case we're asked to clone.)
1314 */
1315 if (opts != NULL && opts->ip6po_nexthop != NULL) {
1316 if (ro->ro_rt != NULL) {
1317 RT_UNLOCK(ro->ro_rt);
1318 }
1319 goto done;
1320 }
1321
1322 if (ro->ro_rt != NULL) {
1323 RT_LOCK_ASSERT_HELD(ro->ro_rt);
1324 ifp = ifp0 = ro->ro_rt->rt_ifp;
1325 } else {
1326 error = EHOSTUNREACH;
1327 }
1328 route = ro;
1329
1330 validateroute:
1331 if (select_srcif) {
1332 boolean_t has_route = (route != NULL && route->ro_rt != NULL);
1333 boolean_t srcif_selected = FALSE;
1334
1335 if (has_route) {
1336 RT_LOCK_ASSERT_HELD(route->ro_rt);
1337 }
1338 /*
1339 * If there is a non-loopback route with the wrong interface,
1340 * or if there is no interface configured with such an address,
1341 * blow it away. Except for local/loopback, we look for one
1342 * with a matching interface scope/index.
1343 */
1344 if (has_route && (ifa == NULL ||
1345 (ifa->ifa_ifp != ifp && ifp != lo_ifp) ||
1346 !(route->ro_rt->rt_flags & RTF_UP))) {
1347 /*
1348 * If the destination address belongs to a proxied
1349 * prefix, relax the requirement and allow the packet
1350 * to come out of the proxy interface with the source
1351 * address of the real interface.
1352 */
1353 if (ifa != NULL && proxied_ifa &&
1354 (route->ro_rt->rt_flags & (RTF_UP | RTF_PROXY)) ==
1355 (RTF_UP | RTF_PROXY)) {
1356 srcif_selected = TRUE;
1357 } else {
1358 if (ip6_select_srcif_debug) {
1359 if (ifa != NULL) {
1360 os_log(OS_LOG_DEFAULT,
1361 "%s->%s ifscope %d "
1362 "ro_if %s != ifa_if %s "
1363 "(cached route cleared)",
1364 s_src, s_dst,
1365 ifscope, if_name(ifp),
1366 if_name(ifa->ifa_ifp));
1367 } else {
1368 os_log(OS_LOG_DEFAULT,
1369 "%s->%s ifscope %d "
1370 "ro_if %s (no ifa_if "
1371 "found)", s_src, s_dst,
1372 ifscope, if_name(ifp));
1373 }
1374 }
1375 RT_UNLOCK(route->ro_rt);
1376 ROUTE_RELEASE(route);
1377 error = EHOSTUNREACH;
1378 /* Undo the settings done above */
1379 route = NULL;
1380 ifp = NULL; /* ditch ifp; keep ifp0 */
1381 has_route = FALSE;
1382 }
1383 } else if (has_route) {
1384 srcif_selected = TRUE;
1385 }
1386
1387 if (srcif_selected) {
1388 VERIFY(has_route);
1389 if (ifa != route->ro_srcia ||
1390 !(route->ro_flags & ROF_SRCIF_SELECTED)) {
1391 RT_CONVERT_LOCK(route->ro_rt);
1392 if (ifa != NULL) {
1393 IFA_ADDREF(ifa); /* for route_in6 */
1394 }
1395 if (route->ro_srcia != NULL) {
1396 IFA_REMREF(route->ro_srcia);
1397 }
1398 route->ro_srcia = ifa;
1399 route->ro_flags |= ROF_SRCIF_SELECTED;
1400 RT_GENID_SYNC(route->ro_rt);
1401 }
1402 RT_UNLOCK(route->ro_rt);
1403 }
1404 } else {
1405 if (ro->ro_rt != NULL) {
1406 RT_UNLOCK(ro->ro_rt);
1407 }
1408 if (ifp != NULL && opts != NULL &&
1409 opts->ip6po_pktinfo != NULL &&
1410 opts->ip6po_pktinfo->ipi6_ifindex != 0) {
1411 /*
1412 * Check if the outgoing interface conflicts with the
1413 * interface specified by ipi6_ifindex (if specified).
1414 * Note that loopback interface is always okay.
1415 * (this may happen when we are sending a packet to
1416 * one of our own addresses.)
1417 */
1418 if (!(ifp->if_flags & IFF_LOOPBACK) && ifp->if_index !=
1419 opts->ip6po_pktinfo->ipi6_ifindex) {
1420 error = EHOSTUNREACH;
1421 goto done;
1422 }
1423 }
1424 }
1425
1426 done:
1427 /*
1428 * Check for interface restrictions.
1429 */
1430 #define CHECK_RESTRICTIONS(_ip6oa, _ifp) \
1431 ((((_ip6oa)->ip6oa_flags & IP6OAF_NO_CELLULAR) && \
1432 IFNET_IS_CELLULAR(_ifp)) || \
1433 (((_ip6oa)->ip6oa_flags & IP6OAF_NO_EXPENSIVE) && \
1434 IFNET_IS_EXPENSIVE(_ifp)) || \
1435 (((_ip6oa)->ip6oa_flags & IP6OAF_NO_CONSTRAINED) && \
1436 IFNET_IS_CONSTRAINED(_ifp)) || \
1437 (!((_ip6oa)->ip6oa_flags & IP6OAF_INTCOPROC_ALLOWED) && \
1438 IFNET_IS_INTCOPROC(_ifp)) || \
1439 (!((_ip6oa)->ip6oa_flags & IP6OAF_AWDL_UNRESTRICTED) && \
1440 IFNET_IS_AWDL_RESTRICTED(_ifp)) && \
1441 (!((_ip6oa)->ip6oa_flags & IP6OAF_MANAGEMENT_ALLOWED) && \
1442 IFNET_IS_MANAGEMENT(_ifp)))
1443
1444 if (error == 0 && ip6oa != NULL &&
1445 ((ifp && CHECK_RESTRICTIONS(ip6oa, ifp)) ||
1446 (route && route->ro_rt &&
1447 CHECK_RESTRICTIONS(ip6oa, route->ro_rt->rt_ifp)))) {
1448 if (route != NULL && route->ro_rt != NULL) {
1449 ROUTE_RELEASE(route);
1450 route = NULL;
1451 }
1452 ifp = NULL; /* ditch ifp; keep ifp0 */
1453 error = EHOSTUNREACH;
1454 ip6oa->ip6oa_flags |= IP6OAF_R_IFDENIED;
1455 }
1456 #undef CHECK_RESTRICTIONS
1457
1458 /*
1459 * If the interface is disabled for IPv6, then ENETDOWN error.
1460 */
1461 if (error == 0 &&
1462 ifp != NULL && (ifp->if_eflags & IFEF_IPV6_DISABLED)) {
1463 error = ENETDOWN;
1464 }
1465
1466 if (ifp == NULL && (route == NULL || route->ro_rt == NULL)) {
1467 /*
1468 * This can happen if the caller did not pass a cached route
1469 * nor any other hints. We treat this case an error.
1470 */
1471 error = EHOSTUNREACH;
1472 }
1473 if (error == EHOSTUNREACH || error == ENETDOWN) {
1474 ip6stat.ip6s_noroute++;
1475 }
1476
1477 /*
1478 * We'll return ifp regardless of error, so pick it up from ifp0
1479 * in case it was nullified above. Caller is responsible for
1480 * releasing the ifp if it is non-NULL.
1481 */
1482 ifp = ifp0;
1483 if (retifp != NULL) {
1484 if (ifp != NULL) {
1485 ifnet_reference(ifp); /* for caller */
1486 }
1487 *retifp = ifp;
1488 }
1489
1490 if (retsrcia != NULL) {
1491 if (ifa != NULL) {
1492 IFA_ADDREF(ifa); /* for caller */
1493 }
1494 *retsrcia = (struct in6_ifaddr *)ifa;
1495 }
1496
1497 if (error == 0) {
1498 if (retrt != NULL && route != NULL) {
1499 *retrt = route->ro_rt; /* ro_rt may be NULL */
1500 }
1501 }
1502 if (ip6_select_srcif_debug) {
1503 os_log(OS_LOG_DEFAULT,
1504 "%s %s->%s ifscope %d ifa_if %s ro_if %s (error=%d)",
1505 __func__,
1506 s_src, s_dst, ifscope,
1507 (ifa != NULL) ? if_name(ifa->ifa_ifp) : "NONE",
1508 (ifp != NULL) ? if_name(ifp) : "NONE", error);
1509 }
1510
1511 if (ifa != NULL) {
1512 IFA_REMREF(ifa);
1513 }
1514
1515 return error;
1516 }
1517
1518 /*
1519 * Regardless of error, it will return an ifp with a reference held if the
1520 * caller provides a non-NULL retifp. The caller is responsible for checking
1521 * if the returned ifp is valid and release its reference at all times.
1522 */
1523 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)1524 in6_selectif(struct sockaddr_in6 *dstsock, struct ip6_pktopts *opts,
1525 struct ip6_moptions *mopts, struct route_in6 *ro,
1526 struct ip6_out_args *ip6oa, struct ifnet **retifp)
1527 {
1528 int err = 0;
1529 struct route_in6 sro;
1530 struct rtentry *rt = NULL;
1531
1532 if (ro == NULL) {
1533 bzero(&sro, sizeof(sro));
1534 ro = &sro;
1535 }
1536
1537 if ((err = selectroute(NULL, dstsock, opts, mopts, NULL, ro, retifp,
1538 &rt, 0, 1, ip6oa)) != 0) {
1539 goto done;
1540 }
1541
1542 /*
1543 * do not use a rejected or black hole route.
1544 * XXX: this check should be done in the L2 output routine.
1545 * However, if we skipped this check here, we'd see the following
1546 * scenario:
1547 * - install a rejected route for a scoped address prefix
1548 * (like fe80::/10)
1549 * - send a packet to a destination that matches the scoped prefix,
1550 * with ambiguity about the scope zone.
1551 * - pick the outgoing interface from the route, and disambiguate the
1552 * scope zone with the interface.
1553 * - ip6_output() would try to get another route with the "new"
1554 * destination, which may be valid.
1555 * - we'd see no error on output.
1556 * Although this may not be very harmful, it should still be confusing.
1557 * We thus reject the case here.
1558 */
1559 if (rt && (rt->rt_flags & (RTF_REJECT | RTF_BLACKHOLE))) {
1560 err = ((rt->rt_flags & RTF_HOST) ? EHOSTUNREACH : ENETUNREACH);
1561 goto done;
1562 }
1563
1564 /*
1565 * Adjust the "outgoing" interface. If we're going to loop the packet
1566 * back to ourselves, the ifp would be the loopback interface.
1567 * However, we'd rather know the interface associated to the
1568 * destination address (which should probably be one of our own
1569 * addresses.)
1570 */
1571 if (rt != NULL && rt->rt_ifa != NULL && rt->rt_ifa->ifa_ifp != NULL &&
1572 retifp != NULL) {
1573 ifnet_reference(rt->rt_ifa->ifa_ifp);
1574 if (*retifp != NULL) {
1575 ifnet_release(*retifp);
1576 }
1577 *retifp = rt->rt_ifa->ifa_ifp;
1578 }
1579
1580 done:
1581 if (ro == &sro) {
1582 VERIFY(rt == NULL || rt == ro->ro_rt);
1583 ROUTE_RELEASE(ro);
1584 }
1585
1586 /*
1587 * retifp might point to a valid ifp with a reference held;
1588 * caller is responsible for releasing it if non-NULL.
1589 */
1590 return err;
1591 }
1592
1593 /*
1594 * Regardless of error, it will return an ifp with a reference held if the
1595 * caller provides a non-NULL retifp. The caller is responsible for checking
1596 * if the returned ifp is valid and release its reference at all times.
1597 *
1598 * clone - meaningful only for bsdi and freebsd
1599 */
1600 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)1601 in6_selectroute(struct sockaddr_in6 *srcsock, struct sockaddr_in6 *dstsock,
1602 struct ip6_pktopts *opts, struct ip6_moptions *mopts,
1603 struct in6_ifaddr **retsrcia, struct route_in6 *ro, struct ifnet **retifp,
1604 struct rtentry **retrt, int clone, struct ip6_out_args *ip6oa)
1605 {
1606 return selectroute(srcsock, dstsock, opts, mopts, retsrcia, ro, retifp,
1607 retrt, clone, 0, ip6oa);
1608 }
1609
1610 /*
1611 * Default hop limit selection. The precedence is as follows:
1612 * 1. Hoplimit value specified via socket option.
1613 * 2. (If the outgoing interface is detected) the current
1614 * hop limit of the interface specified by router advertisement.
1615 * 3. The system default hoplimit.
1616 */
1617 uint8_t
in6_selecthlim(struct in6pcb * in6p,struct ifnet * ifp)1618 in6_selecthlim(struct in6pcb *in6p, struct ifnet *ifp)
1619 {
1620 if (in6p && in6p->in6p_hops >= 0) {
1621 return (uint8_t)in6p->in6p_hops;
1622 } else if (NULL != ifp) {
1623 uint8_t chlim;
1624 struct nd_ifinfo *ndi = ND_IFINFO(ifp);
1625 if (ndi && ndi->initialized) {
1626 /* access chlim without lock, for performance */
1627 chlim = ndi->chlim;
1628 } else {
1629 chlim = (uint8_t)ip6_defhlim;
1630 }
1631 return chlim;
1632 }
1633
1634 return (uint8_t)ip6_defhlim;
1635 }
1636
1637 /*
1638 * XXX: this is borrowed from in6_pcbbind(). If possible, we should
1639 * share this function by all *bsd*...
1640 */
1641 int
in6_pcbsetport(struct in6_addr * laddr,struct inpcb * inp,struct proc * p,int locked)1642 in6_pcbsetport(struct in6_addr *laddr, struct inpcb *inp, struct proc *p,
1643 int locked)
1644 {
1645 struct socket *so = inp->inp_socket;
1646 uint16_t lport = 0, first, last, *lastport, rand_port;
1647 int count, error = 0, wild = 0;
1648 boolean_t counting_down;
1649 bool found, randomport;
1650 struct inpcbinfo *pcbinfo = inp->inp_pcbinfo;
1651 kauth_cred_t cred;
1652 #if SKYWALK
1653 bool laddr_unspecified = IN6_IS_ADDR_UNSPECIFIED(laddr);
1654 #else
1655 #pragma unused(laddr)
1656 #endif
1657 if (!locked) { /* Make sure we don't run into a deadlock: 4052373 */
1658 if (!lck_rw_try_lock_exclusive(&pcbinfo->ipi_lock)) {
1659 socket_unlock(inp->inp_socket, 0);
1660 lck_rw_lock_exclusive(&pcbinfo->ipi_lock);
1661 socket_lock(inp->inp_socket, 0);
1662 }
1663
1664 /*
1665 * Check if a local port was assigned to the inp while
1666 * this thread was waiting for the pcbinfo lock
1667 */
1668 if (inp->inp_lport != 0) {
1669 VERIFY(inp->inp_flags2 & INP2_INHASHLIST);
1670 lck_rw_done(&pcbinfo->ipi_lock);
1671
1672 /*
1673 * It is not an error if another thread allocated
1674 * a port
1675 */
1676 return 0;
1677 }
1678 }
1679
1680 /* XXX: this is redundant when called from in6_pcbbind */
1681 if ((so->so_options & (SO_REUSEADDR | SO_REUSEPORT)) == 0) {
1682 wild = INPLOOKUP_WILDCARD;
1683 }
1684
1685 randomport = (so->so_flags & SOF_BINDRANDOMPORT) > 0 ||
1686 (so->so_type == SOCK_STREAM ? tcp_use_randomport :
1687 udp_use_randomport) > 0;
1688
1689 if (inp->inp_flags & INP_HIGHPORT) {
1690 first = (uint16_t)ipport_hifirstauto; /* sysctl */
1691 last = (uint16_t)ipport_hilastauto;
1692 lastport = &pcbinfo->ipi_lasthi;
1693 } else if (inp->inp_flags & INP_LOWPORT) {
1694 cred = kauth_cred_proc_ref(p);
1695 error = priv_check_cred(cred, PRIV_NETINET_RESERVEDPORT, 0);
1696 kauth_cred_unref(&cred);
1697 if (error != 0) {
1698 if (!locked) {
1699 lck_rw_done(&pcbinfo->ipi_lock);
1700 }
1701 return error;
1702 }
1703 first = (uint16_t)ipport_lowfirstauto; /* 1023 */
1704 last = (uint16_t)ipport_lowlastauto; /* 600 */
1705 lastport = &pcbinfo->ipi_lastlow;
1706 } else {
1707 first = (uint16_t)ipport_firstauto; /* sysctl */
1708 last = (uint16_t)ipport_lastauto;
1709 lastport = &pcbinfo->ipi_lastport;
1710 }
1711
1712 if (first == last) {
1713 randomport = false;
1714 }
1715 /*
1716 * Simple check to ensure all ports are not used up causing
1717 * a deadlock here.
1718 */
1719 found = false;
1720 if (first > last) {
1721 /* counting down */
1722 if (randomport) {
1723 read_frandom(&rand_port, sizeof(rand_port));
1724 *lastport = first - (rand_port % (first - last));
1725 }
1726 count = first - last;
1727 counting_down = TRUE;
1728 } else {
1729 /* counting up */
1730 if (randomport) {
1731 read_frandom(&rand_port, sizeof(rand_port));
1732 *lastport = first + (rand_port % (first - last));
1733 }
1734 count = last - first;
1735 counting_down = FALSE;
1736 }
1737 do {
1738 if (count-- < 0) { /* completely used? */
1739 /*
1740 * Undo any address bind that may have
1741 * occurred above.
1742 */
1743 inp->in6p_laddr = in6addr_any;
1744 inp->in6p_last_outifp = NULL;
1745 inp->inp_lifscope = IFSCOPE_NONE;
1746 #if SKYWALK
1747 if (NETNS_TOKEN_VALID(&inp->inp_netns_token)) {
1748 netns_set_ifnet(&inp->inp_netns_token,
1749 NULL);
1750 }
1751 #endif /* SKYWALK */
1752 if (!locked) {
1753 lck_rw_done(&pcbinfo->ipi_lock);
1754 }
1755 return EAGAIN;
1756 }
1757 if (counting_down) {
1758 --*lastport;
1759 if (*lastport > first || *lastport < last) {
1760 *lastport = first;
1761 }
1762 } else {
1763 ++*lastport;
1764 if (*lastport < first || *lastport > last) {
1765 *lastport = first;
1766 }
1767 }
1768 lport = htons(*lastport);
1769
1770 /*
1771 * Skip if this is a restricted port as we do not want to
1772 * restricted ports as ephemeral
1773 */
1774 if (IS_RESTRICTED_IN_PORT(lport)) {
1775 continue;
1776 }
1777
1778 found = (in6_pcblookup_local(pcbinfo, &inp->in6p_laddr,
1779 lport, inp->inp_lifscope, wild) == NULL);
1780 #if SKYWALK
1781 if (found &&
1782 (SOCK_PROTO(so) == IPPROTO_TCP ||
1783 SOCK_PROTO(so) == IPPROTO_UDP) &&
1784 !(inp->inp_flags2 & INP2_EXTERNAL_PORT)) {
1785 if (laddr_unspecified &&
1786 (inp->inp_flags & IN6P_IPV6_V6ONLY) == 0) {
1787 struct in_addr ip_zero = { .s_addr = 0 };
1788
1789 netns_release(&inp->inp_wildcard_netns_token);
1790 if (netns_reserve_in(
1791 &inp->inp_wildcard_netns_token,
1792 ip_zero,
1793 (uint8_t)SOCK_PROTO(so), lport,
1794 NETNS_BSD, NULL) != 0) {
1795 /* port in use in IPv4 namespace */
1796 found = false;
1797 }
1798 }
1799 if (found &&
1800 netns_reserve_in6(&inp->inp_netns_token,
1801 inp->in6p_laddr, (uint8_t)SOCK_PROTO(so), lport,
1802 NETNS_BSD, NULL) != 0) {
1803 netns_release(&inp->inp_wildcard_netns_token);
1804 found = false;
1805 }
1806 }
1807 #endif /* SKYWALK */
1808 } while (!found);
1809
1810 inp->inp_lport = lport;
1811 inp->inp_flags |= INP_ANONPORT;
1812
1813 if (in_pcbinshash(inp, 1) != 0) {
1814 inp->in6p_laddr = in6addr_any;
1815 inp->in6p_last_outifp = NULL;
1816 inp->inp_lifscope = IFSCOPE_NONE;
1817 #if SKYWALK
1818 netns_release(&inp->inp_netns_token);
1819 #endif /* SKYWALK */
1820 inp->inp_lport = 0;
1821 inp->inp_flags &= ~INP_ANONPORT;
1822 if (!locked) {
1823 lck_rw_done(&pcbinfo->ipi_lock);
1824 }
1825 return EAGAIN;
1826 }
1827
1828 if (!locked) {
1829 lck_rw_done(&pcbinfo->ipi_lock);
1830 }
1831 return 0;
1832 }
1833
1834 /*
1835 * The followings are implementation of the policy table using a
1836 * simple tail queue.
1837 * XXX such details should be hidden.
1838 * XXX implementation using binary tree should be more efficient.
1839 */
1840 struct addrsel_policyent {
1841 TAILQ_ENTRY(addrsel_policyent) ape_entry;
1842 struct in6_addrpolicy ape_policy;
1843 };
1844
1845 TAILQ_HEAD(addrsel_policyhead, addrsel_policyent);
1846
1847 struct addrsel_policyhead addrsel_policytab;
1848
1849 static void
init_policy_queue(void)1850 init_policy_queue(void)
1851 {
1852 TAILQ_INIT(&addrsel_policytab);
1853 }
1854
1855 void
addrsel_policy_init(void)1856 addrsel_policy_init(void)
1857 {
1858 /*
1859 * Default address selection policy based on RFC 6724.
1860 */
1861 static const struct in6_addrpolicy defaddrsel[] = {
1862 /* Loopback -- prefix=::1/128, precedence=50, label=0 */
1863 {
1864 .addr = {
1865 .sin6_family = AF_INET6,
1866 .sin6_addr = IN6ADDR_LOOPBACK_INIT,
1867 .sin6_len = sizeof(struct sockaddr_in6)
1868 },
1869 .addrmask = {
1870 .sin6_family = AF_INET6,
1871 .sin6_addr = IN6MASK128,
1872 .sin6_len = sizeof(struct sockaddr_in6)
1873 },
1874 .preced = 50,
1875 .label = 0
1876 },
1877
1878 /* Unspecified -- prefix=::/0, precedence=40, label=1 */
1879 {
1880 .addr = {
1881 .sin6_family = AF_INET6,
1882 .sin6_addr = IN6ADDR_ANY_INIT,
1883 .sin6_len = sizeof(struct sockaddr_in6)
1884 },
1885 .addrmask = {
1886 .sin6_family = AF_INET6,
1887 .sin6_addr = IN6MASK0,
1888 .sin6_len = sizeof(struct sockaddr_in6)
1889 },
1890 .preced = 40,
1891 .label = 1
1892 },
1893
1894 /* IPv4 Mapped -- prefix=::ffff:0:0/96, precedence=35, label=4 */
1895 {
1896 .addr = {
1897 .sin6_family = AF_INET6,
1898 .sin6_addr = IN6ADDR_V4MAPPED_INIT,
1899 .sin6_len = sizeof(struct sockaddr_in6)
1900 },
1901 .addrmask = {
1902 .sin6_family = AF_INET6,
1903 .sin6_addr = IN6MASK96,
1904 .sin6_len = sizeof(struct sockaddr_in6)
1905 },
1906 .preced = 35,
1907 .label = 4
1908 },
1909
1910 /* 6to4 -- prefix=2002::/16, precedence=30, label=2 */
1911 {
1912 .addr = {
1913 .sin6_family = AF_INET6,
1914 .sin6_addr = {{{ 0x20, 0x02 }}},
1915 .sin6_len = sizeof(struct sockaddr_in6)
1916 },
1917 .addrmask = {
1918 .sin6_family = AF_INET6,
1919 .sin6_addr = IN6MASK16,
1920 .sin6_len = sizeof(struct sockaddr_in6)
1921 },
1922 .preced = 30,
1923 .label = 2
1924 },
1925
1926 /* Teredo -- prefix=2001::/32, precedence=5, label=5 */
1927 {
1928 .addr = {
1929 .sin6_family = AF_INET6,
1930 .sin6_addr = {{{ 0x20, 0x01 }}},
1931 .sin6_len = sizeof(struct sockaddr_in6)
1932 },
1933 .addrmask = {
1934 .sin6_family = AF_INET6,
1935 .sin6_addr = IN6MASK32,
1936 .sin6_len = sizeof(struct sockaddr_in6)
1937 },
1938 .preced = 5,
1939 .label = 5
1940 },
1941
1942 /* Unique Local (ULA) -- prefix=fc00::/7, precedence=3, label=13 */
1943 {
1944 .addr = {
1945 .sin6_family = AF_INET6,
1946 .sin6_addr = {{{ 0xfc }}},
1947 .sin6_len = sizeof(struct sockaddr_in6)
1948 },
1949 .addrmask = {
1950 .sin6_family = AF_INET6,
1951 .sin6_addr = IN6MASK7,
1952 .sin6_len = sizeof(struct sockaddr_in6)
1953 },
1954 .preced = 3,
1955 .label = 13
1956 },
1957
1958 /* IPv4 Compatible -- prefix=::/96, precedence=1, label=3 */
1959 {
1960 .addr = {
1961 .sin6_family = AF_INET6,
1962 .sin6_addr = IN6ADDR_ANY_INIT,
1963 .sin6_len = sizeof(struct sockaddr_in6)
1964 },
1965 .addrmask = {
1966 .sin6_family = AF_INET6,
1967 .sin6_addr = IN6MASK96,
1968 .sin6_len = sizeof(struct sockaddr_in6)
1969 },
1970 .preced = 1,
1971 .label = 3
1972 },
1973
1974 /* Site-local (deprecated) -- prefix=fec0::/10, precedence=1, label=11 */
1975 {
1976 .addr = {
1977 .sin6_family = AF_INET6,
1978 .sin6_addr = {{{ 0xfe, 0xc0 }}},
1979 .sin6_len = sizeof(struct sockaddr_in6)
1980 },
1981 .addrmask = {
1982 .sin6_family = AF_INET6,
1983 .sin6_addr = IN6MASK16,
1984 .sin6_len = sizeof(struct sockaddr_in6)
1985 },
1986 .preced = 1,
1987 .label = 11
1988 },
1989
1990 /* 6bone (deprecated) -- prefix=3ffe::/16, precedence=1, label=12 */
1991 {
1992 .addr = {
1993 .sin6_family = AF_INET6,
1994 .sin6_addr = {{{ 0x3f, 0xfe }}},
1995 .sin6_len = sizeof(struct sockaddr_in6)
1996 },
1997 .addrmask = {
1998 .sin6_family = AF_INET6,
1999 .sin6_addr = IN6MASK16,
2000 .sin6_len = sizeof(struct sockaddr_in6)
2001 },
2002 .preced = 1,
2003 .label = 12
2004 },
2005 };
2006 int i;
2007
2008 init_policy_queue();
2009
2010 /* initialize the "last resort" policy */
2011 bzero(&defaultaddrpolicy, sizeof(defaultaddrpolicy));
2012 defaultaddrpolicy.label = ADDR_LABEL_NOTAPP;
2013
2014 for (i = 0; i < sizeof(defaddrsel) / sizeof(defaddrsel[0]); i++) {
2015 add_addrsel_policyent(&defaddrsel[i]);
2016 }
2017 }
2018
2019 struct in6_addrpolicy *
in6_addrsel_lookup_policy(struct sockaddr_in6 * key)2020 in6_addrsel_lookup_policy(struct sockaddr_in6 *key)
2021 {
2022 struct in6_addrpolicy *match = NULL;
2023
2024 ADDRSEL_LOCK();
2025 match = match_addrsel_policy(key);
2026
2027 if (match == NULL) {
2028 match = &defaultaddrpolicy;
2029 } else {
2030 match->use++;
2031 }
2032 ADDRSEL_UNLOCK();
2033
2034 return match;
2035 }
2036
2037 static struct in6_addrpolicy *
match_addrsel_policy(struct sockaddr_in6 * key)2038 match_addrsel_policy(struct sockaddr_in6 *key)
2039 {
2040 struct addrsel_policyent *pent;
2041 struct in6_addrpolicy *bestpol = NULL, *pol;
2042 int matchlen, bestmatchlen = -1;
2043 u_char *mp, *ep, *k, *p, m;
2044
2045 TAILQ_FOREACH(pent, &addrsel_policytab, ape_entry) {
2046 matchlen = 0;
2047
2048 pol = &pent->ape_policy;
2049 mp = (u_char *)&pol->addrmask.sin6_addr;
2050 ep = mp + 16; /* XXX: scope field? */
2051 k = (u_char *)&key->sin6_addr;
2052 p = (u_char *)&pol->addr.sin6_addr;
2053 for (; mp < ep && *mp; mp++, k++, p++) {
2054 m = *mp;
2055 if ((*k & m) != *p) {
2056 goto next; /* not match */
2057 }
2058 if (m == 0xff) { /* short cut for a typical case */
2059 matchlen += 8;
2060 } else {
2061 while (m >= 0x80) {
2062 matchlen++;
2063 m <<= 1;
2064 }
2065 }
2066 }
2067
2068 /* matched. check if this is better than the current best. */
2069 if (bestpol == NULL ||
2070 matchlen > bestmatchlen) {
2071 bestpol = pol;
2072 bestmatchlen = matchlen;
2073 }
2074
2075 next:
2076 continue;
2077 }
2078
2079 return bestpol;
2080 }
2081
2082 static int
add_addrsel_policyent(const struct in6_addrpolicy * newpolicy)2083 add_addrsel_policyent(const struct in6_addrpolicy *newpolicy)
2084 {
2085 struct addrsel_policyent *new, *pol;
2086
2087 new = kalloc_type(struct addrsel_policyent, Z_WAITOK | Z_ZERO);
2088
2089 ADDRSEL_LOCK();
2090
2091 /* duplication check */
2092 TAILQ_FOREACH(pol, &addrsel_policytab, ape_entry) {
2093 if (IN6_ARE_ADDR_EQUAL(&newpolicy->addr.sin6_addr,
2094 &pol->ape_policy.addr.sin6_addr) &&
2095 IN6_ARE_ADDR_EQUAL(&newpolicy->addrmask.sin6_addr,
2096 &pol->ape_policy.addrmask.sin6_addr)) {
2097 ADDRSEL_UNLOCK();
2098 kfree_type(struct addrsel_policyent, new);
2099 return EEXIST; /* or override it? */
2100 }
2101 }
2102
2103 /* XXX: should validate entry */
2104 new->ape_policy = *newpolicy;
2105
2106 TAILQ_INSERT_TAIL(&addrsel_policytab, new, ape_entry);
2107 ADDRSEL_UNLOCK();
2108
2109 return 0;
2110 }
2111 #ifdef ENABLE_ADDRSEL
2112 static int
delete_addrsel_policyent(const struct in6_addrpolicy * key)2113 delete_addrsel_policyent(const struct in6_addrpolicy *key)
2114 {
2115 struct addrsel_policyent *pol;
2116
2117
2118 ADDRSEL_LOCK();
2119
2120 /* search for the entry in the table */
2121 TAILQ_FOREACH(pol, &addrsel_policytab, ape_entry) {
2122 if (in6_are_addr_equal_scoped(&key->addr.sin6_addr,
2123 &pol->ape_policy.addr.sin6_addr, key->addr.sin6_scope_id, pol->ape_policy.addr.sin6_scope_id) &&
2124 IN6_ARE_ADDR_EQUAL(&key->addrmask.sin6_addr,
2125 &pol->ape_policy.addrmask.sin6_addr)) {
2126 break;
2127 }
2128 }
2129 if (pol == NULL) {
2130 ADDRSEL_UNLOCK();
2131 return ESRCH;
2132 }
2133
2134 TAILQ_REMOVE(&addrsel_policytab, pol, ape_entry);
2135 kfree_type(struct addrsel_policyent, pol);
2136 pol = NULL;
2137 ADDRSEL_UNLOCK();
2138
2139 return 0;
2140 }
2141 #endif /* ENABLE_ADDRSEL */
2142
2143 int
walk_addrsel_policy(int (* callback)(const struct in6_addrpolicy *,void *),void * w)2144 walk_addrsel_policy(int (*callback)(const struct in6_addrpolicy *, void *),
2145 void *w)
2146 {
2147 struct addrsel_policyent *pol;
2148 int error = 0;
2149
2150 ADDRSEL_LOCK();
2151 TAILQ_FOREACH(pol, &addrsel_policytab, ape_entry) {
2152 if ((error = (*callback)(&pol->ape_policy, w)) != 0) {
2153 ADDRSEL_UNLOCK();
2154 return error;
2155 }
2156 }
2157 ADDRSEL_UNLOCK();
2158 return error;
2159 }
2160 /*
2161 * Subroutines to manage the address selection policy table via sysctl.
2162 */
2163 struct walkarg {
2164 struct sysctl_req *w_req;
2165 };
2166
2167
2168 static int
dump_addrsel_policyent(const struct in6_addrpolicy * pol,void * arg)2169 dump_addrsel_policyent(const struct in6_addrpolicy *pol, void *arg)
2170 {
2171 int error = 0;
2172 struct walkarg *w = arg;
2173
2174 error = SYSCTL_OUT(w->w_req, pol, sizeof(*pol));
2175
2176 return error;
2177 }
2178
2179 static int
2180 in6_src_sysctl SYSCTL_HANDLER_ARGS
2181 {
2182 #pragma unused(oidp, arg1, arg2)
2183 struct walkarg w;
2184
2185 if (req->newptr) {
2186 return EPERM;
2187 }
2188 bzero(&w, sizeof(w));
2189 w.w_req = req;
2190
2191 return walk_addrsel_policy(dump_addrsel_policyent, &w);
2192 }
2193
2194
2195 SYSCTL_NODE(_net_inet6_ip6, IPV6CTL_ADDRCTLPOLICY, addrctlpolicy,
2196 CTLFLAG_RD | CTLFLAG_LOCKED, in6_src_sysctl, "");
2197 int
in6_src_ioctl(u_long cmd,caddr_t data)2198 in6_src_ioctl(u_long cmd, caddr_t data)
2199 {
2200 int i;
2201 struct in6_addrpolicy ent0;
2202
2203 if (cmd != SIOCAADDRCTL_POLICY && cmd != SIOCDADDRCTL_POLICY) {
2204 return EOPNOTSUPP; /* check for safety */
2205 }
2206 bcopy(data, &ent0, sizeof(ent0));
2207
2208 if (ent0.label == ADDR_LABEL_NOTAPP) {
2209 return EINVAL;
2210 }
2211 /* check if the prefix mask is consecutive. */
2212 if (in6_mask2len(&ent0.addrmask.sin6_addr, NULL) < 0) {
2213 return EINVAL;
2214 }
2215 /* clear trailing garbages (if any) of the prefix address. */
2216 for (i = 0; i < 4; i++) {
2217 ent0.addr.sin6_addr.s6_addr32[i] &=
2218 ent0.addrmask.sin6_addr.s6_addr32[i];
2219 }
2220 ent0.use = 0;
2221
2222 switch (cmd) {
2223 case SIOCAADDRCTL_POLICY:
2224 #ifdef ENABLE_ADDRSEL
2225 return add_addrsel_policyent(&ent0);
2226 #else
2227 return ENOTSUP;
2228 #endif
2229 case SIOCDADDRCTL_POLICY:
2230 #ifdef ENABLE_ADDRSEL
2231 return delete_addrsel_policyent(&ent0);
2232 #else
2233 return ENOTSUP;
2234 #endif
2235 }
2236
2237 return 0; /* XXX: compromise compilers */
2238 }
2239
2240 /*
2241 * generate kernel-internal form (scopeid embedded into s6_addr16[1]).
2242 * If the address scope of is link-local, embed the interface index in the
2243 * address. The routine determines our precedence
2244 * between advanced API scope/interface specification and basic API
2245 * specification.
2246 *
2247 * this function should be nuked in the future, when we get rid of
2248 * embedded scopeid thing.
2249 *
2250 * XXX actually, it is over-specification to return ifp against sin6_scope_id.
2251 * there can be multiple interfaces that belong to a particular scope zone
2252 * (in specification, we have 1:N mapping between a scope zone and interfaces).
2253 * we may want to change the function to return something other than ifp.
2254 */
2255 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)2256 in6_embedscope(struct in6_addr *in6, const struct sockaddr_in6 *sin6,
2257 struct in6pcb *in6p, struct ifnet **ifpp, struct ip6_pktopts *opt, uint32_t *ret_ifscope)
2258 {
2259 struct ifnet *ifp = NULL;
2260 u_int32_t scopeid;
2261 struct ip6_pktopts *optp = NULL;
2262
2263 *in6 = sin6->sin6_addr;
2264 scopeid = sin6->sin6_scope_id;
2265 if (ifpp != NULL) {
2266 *ifpp = NULL;
2267 }
2268
2269 /*
2270 * don't try to read sin6->sin6_addr beyond here, since the caller may
2271 * ask us to overwrite existing sockaddr_in6
2272 */
2273
2274 #ifdef ENABLE_DEFAULT_SCOPE
2275 if (scopeid == 0) {
2276 scopeid = scope6_addr2default(in6);
2277 }
2278 #endif
2279
2280 if (IN6_IS_SCOPE_LINKLOCAL(in6) || IN6_IS_ADDR_MC_INTFACELOCAL(in6)) {
2281 struct in6_pktinfo *pi;
2282 struct ifnet *im6o_multicast_ifp = NULL;
2283
2284 if (in6p != NULL && IN6_IS_ADDR_MULTICAST(in6) &&
2285 in6p->in6p_moptions != NULL) {
2286 IM6O_LOCK(in6p->in6p_moptions);
2287 im6o_multicast_ifp =
2288 in6p->in6p_moptions->im6o_multicast_ifp;
2289 IM6O_UNLOCK(in6p->in6p_moptions);
2290 }
2291
2292 if (opt != NULL) {
2293 optp = opt;
2294 } else if (in6p != NULL) {
2295 optp = in6p->in6p_outputopts;
2296 }
2297 /*
2298 * KAME assumption: link id == interface id
2299 */
2300 if (in6p != NULL && optp != NULL &&
2301 (pi = optp->ip6po_pktinfo) != NULL &&
2302 pi->ipi6_ifindex != 0) {
2303 /* ifp is needed here if only we're returning it */
2304 if (ifpp != NULL) {
2305 ifnet_head_lock_shared();
2306 ifp = ifindex2ifnet[pi->ipi6_ifindex];
2307 ifnet_head_done();
2308 }
2309
2310 if (in6_embedded_scope) {
2311 in6->s6_addr16[1] = htons((uint16_t)pi->ipi6_ifindex);
2312 }
2313 if (ret_ifscope != NULL) {
2314 *ret_ifscope = pi->ipi6_ifindex;
2315 }
2316 } else if (in6p != NULL && IN6_IS_ADDR_MULTICAST(in6) &&
2317 in6p->in6p_moptions != NULL && im6o_multicast_ifp != NULL) {
2318 ifp = im6o_multicast_ifp;
2319 if (in6_embedded_scope) {
2320 in6->s6_addr16[1] = htons(ifp->if_index);
2321 }
2322 if (ret_ifscope != NULL) {
2323 *ret_ifscope = ifp->if_index;
2324 }
2325 } else if (scopeid != 0) {
2326 /*
2327 * Since scopeid is unsigned, we only have to check it
2328 * against if_index (ifnet_head_lock not needed since
2329 * if_index is an ever-increasing integer.)
2330 */
2331 if (if_index < scopeid) {
2332 return ENXIO; /* XXX EINVAL? */
2333 }
2334 /* ifp is needed here only if we're returning it */
2335 if (ifpp != NULL) {
2336 ifnet_head_lock_shared();
2337 ifp = ifindex2ifnet[scopeid];
2338 ifnet_head_done();
2339 }
2340 if (in6_embedded_scope) {
2341 /* XXX assignment to 16bit from 32bit variable */
2342 in6->s6_addr16[1] = htons(scopeid & 0xffff);
2343 }
2344 if (ret_ifscope != NULL) {
2345 *ret_ifscope = scopeid;
2346 }
2347 }
2348
2349 if (ifpp != NULL) {
2350 if (ifp != NULL) {
2351 ifnet_reference(ifp); /* for caller */
2352 }
2353 *ifpp = ifp;
2354 }
2355 }
2356
2357 return 0;
2358 }
2359
2360 /*
2361 * generate standard sockaddr_in6 from embedded form.
2362 * touches sin6_addr and sin6_scope_id only.
2363 *
2364 * this function should be nuked in the future, when we get rid of
2365 * embedded scopeid thing.
2366 */
2367 int
in6_recoverscope(struct sockaddr_in6 * sin6,const struct in6_addr * in6,struct ifnet * ifp)2368 in6_recoverscope(
2369 struct sockaddr_in6 *sin6,
2370 const struct in6_addr *in6,
2371 struct ifnet *ifp)
2372 {
2373 u_int32_t scopeid;
2374
2375 sin6->sin6_addr = *in6;
2376
2377 if (!in6_embedded_scope) {
2378 if (ifp != NULL && IN6_IS_SCOPE_EMBED(in6)) {
2379 sin6->sin6_scope_id = ifp->if_index;
2380 }
2381 return 0;
2382 }
2383 /*
2384 * don't try to read *in6 beyond here, since the caller may
2385 * ask us to overwrite existing sockaddr_in6
2386 */
2387
2388 sin6->sin6_scope_id = 0;
2389 if (IN6_IS_SCOPE_LINKLOCAL(in6) || IN6_IS_ADDR_MC_INTFACELOCAL(in6)) {
2390 /*
2391 * KAME assumption: link id == interface id
2392 */
2393 scopeid = ntohs(sin6->sin6_addr.s6_addr16[1]);
2394 if (scopeid) {
2395 /*
2396 * sanity check
2397 *
2398 * Since scopeid is unsigned, we only have to check it
2399 * against if_index
2400 */
2401 if (if_index < scopeid) {
2402 return ENXIO;
2403 }
2404 if (ifp && ifp->if_index != scopeid) {
2405 return ENXIO;
2406 }
2407 sin6->sin6_addr.s6_addr16[1] = 0;
2408 sin6->sin6_scope_id = scopeid;
2409 }
2410 }
2411
2412 return 0;
2413 }
2414