1 /*-
2 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 3. Neither the name of the project nor the names of its contributors
14 * may be used to endorse or promote products derived from this software
15 * without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 *
29 * $KAME: in6_src.c,v 1.132 2003/08/26 04:42:27 keiichi Exp $
30 */
31
32 /*-
33 * Copyright (c) 1982, 1986, 1991, 1993
34 * The Regents of the University of California. All rights reserved.
35 *
36 * Redistribution and use in source and binary forms, with or without
37 * modification, are permitted provided that the following conditions
38 * are met:
39 * 1. Redistributions of source code must retain the above copyright
40 * notice, this list of conditions and the following disclaimer.
41 * 2. Redistributions in binary form must reproduce the above copyright
42 * notice, this list of conditions and the following disclaimer in the
43 * documentation and/or other materials provided with the distribution.
44 * 4. Neither the name of the University nor the names of its contributors
45 * may be used to endorse or promote products derived from this software
46 * without specific prior written permission.
47 *
48 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
49 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
50 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
51 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
52 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
53 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
54 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
55 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
56 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
57 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
58 * SUCH DAMAGE.
59 *
60 * @(#)in_pcb.c 8.2 (Berkeley) 1/4/94
61 */
62
63 #include <sys/cdefs.h>
64 __FBSDID("$FreeBSD$");
65
66 #include "opt_inet.h"
67 #include "opt_inet6.h"
68 #include "opt_mpath.h"
69
70 #include <sys/param.h>
71 #include <sys/systm.h>
72 #include <sys/lock.h>
73 #include <sys/malloc.h>
74 #include <sys/mbuf.h>
75 #include <sys/priv.h>
76 #include <sys/protosw.h>
77 #include <sys/socket.h>
78 #include <sys/socketvar.h>
79 #include <sys/sockio.h>
80 #include <sys/sysctl.h>
81 #include <sys/errno.h>
82 #include <sys/time.h>
83 #include <sys/jail.h>
84 #include <sys/kernel.h>
85 #include <sys/rmlock.h>
86 #include <sys/sx.h>
87
88 #include <net/if.h>
89 #include <net/if_var.h>
90 #include <net/if_dl.h>
91 #include <net/route.h>
92 #include <net/if_llatbl.h>
93 #ifdef RADIX_MPATH
94 #include <net/radix_mpath.h>
95 #endif
96
97 #include <netinet/in.h>
98 #include <netinet/in_var.h>
99 #include <netinet/in_systm.h>
100 #include <netinet/ip.h>
101 #include <netinet/in_pcb.h>
102 #include <netinet/ip_var.h>
103 #include <netinet/udp.h>
104 #include <netinet/udp_var.h>
105
106 #include <netinet6/in6_var.h>
107 #include <netinet/ip6.h>
108 #include <netinet6/in6_fib.h>
109 #include <netinet6/in6_pcb.h>
110 #include <netinet6/ip6_var.h>
111 #include <netinet6/scope6_var.h>
112 #include <netinet6/nd6.h>
113
114 static struct mtx addrsel_lock;
115 #define ADDRSEL_LOCK_INIT() mtx_init(&addrsel_lock, "addrsel_lock", NULL, MTX_DEF)
116 #define ADDRSEL_LOCK() mtx_lock(&addrsel_lock)
117 #define ADDRSEL_UNLOCK() mtx_unlock(&addrsel_lock)
118 #define ADDRSEL_LOCK_ASSERT() mtx_assert(&addrsel_lock, MA_OWNED)
119
120 static struct sx addrsel_sxlock;
121 #define ADDRSEL_SXLOCK_INIT() sx_init(&addrsel_sxlock, "addrsel_sxlock")
122 #define ADDRSEL_SLOCK() sx_slock(&addrsel_sxlock)
123 #define ADDRSEL_SUNLOCK() sx_sunlock(&addrsel_sxlock)
124 #define ADDRSEL_XLOCK() sx_xlock(&addrsel_sxlock)
125 #define ADDRSEL_XUNLOCK() sx_xunlock(&addrsel_sxlock)
126
127 #define ADDR_LABEL_NOTAPP (-1)
128 static VNET_DEFINE(struct in6_addrpolicy, defaultaddrpolicy);
129 #define V_defaultaddrpolicy VNET(defaultaddrpolicy)
130
131 VNET_DEFINE(int, ip6_prefer_tempaddr) = 0;
132
133 static int selectroute(struct sockaddr_in6 *, struct ip6_pktopts *,
134 struct ip6_moptions *, struct route_in6 *, struct ifnet **,
135 struct rtentry **, int, u_int);
136 static int in6_selectif(struct sockaddr_in6 *, struct ip6_pktopts *,
137 struct ip6_moptions *, struct ifnet **,
138 struct ifnet *, u_int);
139 static int in6_selectsrc(uint32_t, struct sockaddr_in6 *,
140 struct ip6_pktopts *, struct inpcb *, struct ucred *,
141 struct ifnet **, struct in6_addr *);
142
143 static struct in6_addrpolicy *lookup_addrsel_policy(struct sockaddr_in6 *);
144
145 static void init_policy_queue(void);
146 static int add_addrsel_policyent(struct in6_addrpolicy *);
147 static int delete_addrsel_policyent(struct in6_addrpolicy *);
148 static int walk_addrsel_policy(int (*)(struct in6_addrpolicy *, void *),
149 void *);
150 static int dump_addrsel_policyent(struct in6_addrpolicy *, void *);
151 static struct in6_addrpolicy *match_addrsel_policy(struct sockaddr_in6 *);
152
153 /*
154 * Return an IPv6 address, which is the most appropriate for a given
155 * destination and user specified options.
156 * If necessary, this function lookups the routing table and returns
157 * an entry to the caller for later use.
158 */
159 #define REPLACE(r) do {\
160 IP6STAT_INC(ip6s_sources_rule[(r)]); \
161 rule = (r); \
162 /* { \
163 char ip6buf[INET6_ADDRSTRLEN], ip6b[INET6_ADDRSTRLEN]; \
164 printf("in6_selectsrc: replace %s with %s by %d\n", ia_best ? ip6_sprintf(ip6buf, &ia_best->ia_addr.sin6_addr) : "none", ip6_sprintf(ip6b, &ia->ia_addr.sin6_addr), (r)); \
165 } */ \
166 goto replace; \
167 } while(0)
168 #define NEXT(r) do {\
169 /* { \
170 char ip6buf[INET6_ADDRSTRLEN], ip6b[INET6_ADDRSTRLEN]; \
171 printf("in6_selectsrc: keep %s against %s by %d\n", ia_best ? ip6_sprintf(ip6buf, &ia_best->ia_addr.sin6_addr) : "none", ip6_sprintf(ip6b, &ia->ia_addr.sin6_addr), (r)); \
172 } */ \
173 goto next; /* XXX: we can't use 'continue' here */ \
174 } while(0)
175 #define BREAK(r) do { \
176 IP6STAT_INC(ip6s_sources_rule[(r)]); \
177 rule = (r); \
178 goto out; /* XXX: we can't use 'break' here */ \
179 } while(0)
180
181 static int
182 in6_selectsrc(uint32_t fibnum, struct sockaddr_in6 *dstsock,
183 struct ip6_pktopts *opts, struct inpcb *inp, struct ucred *cred,
184 struct ifnet **ifpp, struct in6_addr *srcp)
185 {
186 struct rm_priotracker in6_ifa_tracker;
187 struct in6_addr dst, tmp;
188 struct ifnet *ifp = NULL, *oifp = NULL;
189 struct in6_ifaddr *ia = NULL, *ia_best = NULL;
190 struct in6_pktinfo *pi = NULL;
191 int dst_scope = -1, best_scope = -1, best_matchlen = -1;
192 struct in6_addrpolicy *dst_policy = NULL, *best_policy = NULL;
193 u_int32_t odstzone;
194 int prefer_tempaddr;
195 int error, rule;
196 struct ip6_moptions *mopts;
197
198 KASSERT(srcp != NULL, ("%s: srcp is NULL", __func__));
199
200 dst = dstsock->sin6_addr; /* make a copy for local operation */
201 if (ifpp) {
202 /*
203 * Save a possibly passed in ifp for in6_selectsrc. Only
204 * neighbor discovery code should use this feature, where
205 * we may know the interface but not the FIB number holding
206 * the connected subnet in case someone deleted it from the
207 * default FIB and we need to check the interface.
208 */
209 if (*ifpp != NULL)
210 oifp = *ifpp;
211 *ifpp = NULL;
212 }
213
214 if (inp != NULL) {
215 INP_LOCK_ASSERT(inp);
216 mopts = inp->in6p_moptions;
217 } else {
218 mopts = NULL;
219 }
220
221 /*
222 * If the source address is explicitly specified by the caller,
223 * check if the requested source address is indeed a unicast address
224 * assigned to the node, and can be used as the packet's source
225 * address. If everything is okay, use the address as source.
226 */
227 if (opts && (pi = opts->ip6po_pktinfo) &&
228 !IN6_IS_ADDR_UNSPECIFIED(&pi->ipi6_addr)) {
229 /* get the outgoing interface */
230 if ((error = in6_selectif(dstsock, opts, mopts, &ifp, oifp,
231 fibnum))
232 != 0)
233 return (error);
234
235 /*
236 * determine the appropriate zone id of the source based on
237 * the zone of the destination and the outgoing interface.
238 * If the specified address is ambiguous wrt the scope zone,
239 * the interface must be specified; otherwise, ifa_ifwithaddr()
240 * will fail matching the address.
241 */
242 tmp = pi->ipi6_addr;
243 if (ifp) {
244 error = in6_setscope(&tmp, ifp, &odstzone);
245 if (error)
246 return (error);
247 }
248 if (cred != NULL && (error = prison_local_ip6(cred,
249 &tmp, (inp->inp_flags & IN6P_IPV6_V6ONLY) != 0)) != 0)
250 return (error);
251
252 /*
253 * If IPV6_BINDANY socket option is set, we allow to specify
254 * non local addresses as source address in IPV6_PKTINFO
255 * ancillary data.
256 */
257 if ((inp->inp_flags & INP_BINDANY) == 0) {
258 ia = in6ifa_ifwithaddr(&tmp, 0 /* XXX */);
259 if (ia == NULL || (ia->ia6_flags & (IN6_IFF_ANYCAST |
260 IN6_IFF_NOTREADY))) {
261 if (ia != NULL)
262 ifa_free(&ia->ia_ifa);
263 return (EADDRNOTAVAIL);
264 }
265 bcopy(&ia->ia_addr.sin6_addr, srcp, sizeof(*srcp));
266 ifa_free(&ia->ia_ifa);
267 } else
268 bcopy(&tmp, srcp, sizeof(*srcp));
269 pi->ipi6_addr = tmp; /* XXX: this overrides pi */
270 if (ifpp)
271 *ifpp = ifp;
272 return (0);
273 }
274
275 /*
276 * Otherwise, if the socket has already bound the source, just use it.
277 */
278 if (inp != NULL && !IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr)) {
279 if (cred != NULL &&
280 (error = prison_local_ip6(cred, &inp->in6p_laddr,
281 ((inp->inp_flags & IN6P_IPV6_V6ONLY) != 0))) != 0)
282 return (error);
283 bcopy(&inp->in6p_laddr, srcp, sizeof(*srcp));
284 return (0);
285 }
286
287 /*
288 * Bypass source address selection and use the primary jail IP
289 * if requested.
290 */
291 if (cred != NULL && !prison_saddrsel_ip6(cred, srcp))
292 return (0);
293
294 /*
295 * If the address is not specified, choose the best one based on
296 * the outgoing interface and the destination address.
297 */
298 /* get the outgoing interface */
299 if ((error = in6_selectif(dstsock, opts, mopts, &ifp, oifp,
300 (inp != NULL) ? inp->inp_inc.inc_fibnum : fibnum)) != 0)
301 return (error);
302
303 #ifdef DIAGNOSTIC
304 if (ifp == NULL) /* this should not happen */
305 panic("in6_selectsrc: NULL ifp");
306 #endif
307 error = in6_setscope(&dst, ifp, &odstzone);
308 if (error)
309 return (error);
310
311 rule = 0;
312 IN6_IFADDR_RLOCK(&in6_ifa_tracker);
313 TAILQ_FOREACH(ia, &V_in6_ifaddrhead, ia_link) {
314 int new_scope = -1, new_matchlen = -1;
315 struct in6_addrpolicy *new_policy = NULL;
316 u_int32_t srczone, osrczone, dstzone;
317 struct in6_addr src;
318 struct ifnet *ifp1 = ia->ia_ifp;
319
320 /*
321 * We'll never take an address that breaks the scope zone
322 * of the destination. We also skip an address if its zone
323 * does not contain the outgoing interface.
324 * XXX: we should probably use sin6_scope_id here.
325 */
326 if (in6_setscope(&dst, ifp1, &dstzone) ||
327 odstzone != dstzone) {
328 continue;
329 }
330 src = ia->ia_addr.sin6_addr;
331 if (in6_setscope(&src, ifp, &osrczone) ||
332 in6_setscope(&src, ifp1, &srczone) ||
333 osrczone != srczone) {
334 continue;
335 }
336
337 /* avoid unusable addresses */
338 if ((ia->ia6_flags &
339 (IN6_IFF_NOTREADY | IN6_IFF_ANYCAST | IN6_IFF_DETACHED))) {
340 continue;
341 }
342 if (!V_ip6_use_deprecated && IFA6_IS_DEPRECATED(ia))
343 continue;
344
345 /* If jailed only take addresses of the jail into account. */
346 if (cred != NULL &&
347 prison_check_ip6(cred, &ia->ia_addr.sin6_addr) != 0)
348 continue;
349
350 /* Rule 1: Prefer same address */
351 if (IN6_ARE_ADDR_EQUAL(&dst, &ia->ia_addr.sin6_addr)) {
352 ia_best = ia;
353 BREAK(1); /* there should be no better candidate */
354 }
355
356 if (ia_best == NULL)
357 REPLACE(0);
358
359 /* Rule 2: Prefer appropriate scope */
360 if (dst_scope < 0)
361 dst_scope = in6_addrscope(&dst);
362 new_scope = in6_addrscope(&ia->ia_addr.sin6_addr);
363 if (IN6_ARE_SCOPE_CMP(best_scope, new_scope) < 0) {
364 if (IN6_ARE_SCOPE_CMP(best_scope, dst_scope) < 0)
365 REPLACE(2);
366 NEXT(2);
367 } else if (IN6_ARE_SCOPE_CMP(new_scope, best_scope) < 0) {
368 if (IN6_ARE_SCOPE_CMP(new_scope, dst_scope) < 0)
369 NEXT(2);
370 REPLACE(2);
371 }
372
373 /*
374 * Rule 3: Avoid deprecated addresses. Note that the case of
375 * !ip6_use_deprecated is already rejected above.
376 */
377 if (!IFA6_IS_DEPRECATED(ia_best) && IFA6_IS_DEPRECATED(ia))
378 NEXT(3);
379 if (IFA6_IS_DEPRECATED(ia_best) && !IFA6_IS_DEPRECATED(ia))
380 REPLACE(3);
381
382 /* Rule 4: Prefer home addresses */
383 /*
384 * XXX: This is a TODO. We should probably merge the MIP6
385 * case above.
386 */
387
388 /* Rule 5: Prefer outgoing interface */
389 if (!(ND_IFINFO(ifp)->flags & ND6_IFF_NO_PREFER_IFACE)) {
390 if (ia_best->ia_ifp == ifp && ia->ia_ifp != ifp)
391 NEXT(5);
392 if (ia_best->ia_ifp != ifp && ia->ia_ifp == ifp)
393 REPLACE(5);
394 }
395
396 /*
397 * Rule 6: Prefer matching label
398 * Note that best_policy should be non-NULL here.
399 */
400 if (dst_policy == NULL)
401 dst_policy = lookup_addrsel_policy(dstsock);
402 if (dst_policy->label != ADDR_LABEL_NOTAPP) {
403 new_policy = lookup_addrsel_policy(&ia->ia_addr);
404 if (dst_policy->label == best_policy->label &&
405 dst_policy->label != new_policy->label)
406 NEXT(6);
407 if (dst_policy->label != best_policy->label &&
408 dst_policy->label == new_policy->label)
409 REPLACE(6);
410 }
411
412 /*
413 * Rule 7: Prefer public addresses.
414 * We allow users to reverse the logic by configuring
415 * a sysctl variable, so that privacy conscious users can
416 * always prefer temporary addresses.
417 */
418 if (opts == NULL ||
419 opts->ip6po_prefer_tempaddr == IP6PO_TEMPADDR_SYSTEM) {
420 prefer_tempaddr = V_ip6_prefer_tempaddr;
421 } else if (opts->ip6po_prefer_tempaddr ==
422 IP6PO_TEMPADDR_NOTPREFER) {
423 prefer_tempaddr = 0;
424 } else
425 prefer_tempaddr = 1;
426 if (!(ia_best->ia6_flags & IN6_IFF_TEMPORARY) &&
427 (ia->ia6_flags & IN6_IFF_TEMPORARY)) {
428 if (prefer_tempaddr)
429 REPLACE(7);
430 else
431 NEXT(7);
432 }
433 if ((ia_best->ia6_flags & IN6_IFF_TEMPORARY) &&
434 !(ia->ia6_flags & IN6_IFF_TEMPORARY)) {
435 if (prefer_tempaddr)
436 NEXT(7);
437 else
438 REPLACE(7);
439 }
440
441 /*
442 * Rule 8: prefer addresses on alive interfaces.
443 * This is a KAME specific rule.
444 */
445 if ((ia_best->ia_ifp->if_flags & IFF_UP) &&
446 !(ia->ia_ifp->if_flags & IFF_UP))
447 NEXT(8);
448 if (!(ia_best->ia_ifp->if_flags & IFF_UP) &&
449 (ia->ia_ifp->if_flags & IFF_UP))
450 REPLACE(8);
451
452 /*
453 * Rule 9: prefer address with better virtual status.
454 */
455 if (ifa_preferred(&ia_best->ia_ifa, &ia->ia_ifa))
456 REPLACE(9);
457 if (ifa_preferred(&ia->ia_ifa, &ia_best->ia_ifa))
458 NEXT(9);
459
460 /*
461 * Rule 10: prefer address with `prefer_source' flag.
462 */
463 if ((ia_best->ia6_flags & IN6_IFF_PREFER_SOURCE) == 0 &&
464 (ia->ia6_flags & IN6_IFF_PREFER_SOURCE) != 0)
465 REPLACE(10);
466 if ((ia_best->ia6_flags & IN6_IFF_PREFER_SOURCE) != 0 &&
467 (ia->ia6_flags & IN6_IFF_PREFER_SOURCE) == 0)
468 NEXT(10);
469
470 /*
471 * Rule 14: Use longest matching prefix.
472 * Note: in the address selection draft, this rule is
473 * documented as "Rule 8". However, since it is also
474 * documented that this rule can be overridden, we assign
475 * a large number so that it is easy to assign smaller numbers
476 * to more preferred rules.
477 */
478 new_matchlen = in6_matchlen(&ia->ia_addr.sin6_addr, &dst);
479 if (best_matchlen < new_matchlen)
480 REPLACE(14);
481 if (new_matchlen < best_matchlen)
482 NEXT(14);
483
484 /* Rule 15 is reserved. */
485
486 /*
487 * Last resort: just keep the current candidate.
488 * Or, do we need more rules?
489 */
490 continue;
491
492 replace:
493 ia_best = ia;
494 best_scope = (new_scope >= 0 ? new_scope :
495 in6_addrscope(&ia_best->ia_addr.sin6_addr));
496 best_policy = (new_policy ? new_policy :
497 lookup_addrsel_policy(&ia_best->ia_addr));
498 best_matchlen = (new_matchlen >= 0 ? new_matchlen :
499 in6_matchlen(&ia_best->ia_addr.sin6_addr,
500 &dst));
501
502 next:
503 continue;
504
505 out:
506 break;
507 }
508
509 if ((ia = ia_best) == NULL) {
510 IN6_IFADDR_RUNLOCK(&in6_ifa_tracker);
511 IP6STAT_INC(ip6s_sources_none);
512 return (EADDRNOTAVAIL);
513 }
514
515 /*
516 * At this point at least one of the addresses belonged to the jail
517 * but it could still be, that we want to further restrict it, e.g.
518 * theoratically IN6_IS_ADDR_LOOPBACK.
519 * It must not be IN6_IS_ADDR_UNSPECIFIED anymore.
520 * prison_local_ip6() will fix an IN6_IS_ADDR_LOOPBACK but should
521 * let all others previously selected pass.
522 * Use tmp to not change ::1 on lo0 to the primary jail address.
523 */
524 tmp = ia->ia_addr.sin6_addr;
525 if (cred != NULL && prison_local_ip6(cred, &tmp, (inp != NULL &&
526 (inp->inp_flags & IN6P_IPV6_V6ONLY) != 0)) != 0) {
527 IN6_IFADDR_RUNLOCK(&in6_ifa_tracker);
528 IP6STAT_INC(ip6s_sources_none);
529 return (EADDRNOTAVAIL);
530 }
531
532 if (ifpp)
533 *ifpp = ifp;
534
535 bcopy(&tmp, srcp, sizeof(*srcp));
536 if (ia->ia_ifp == ifp)
537 IP6STAT_INC(ip6s_sources_sameif[best_scope]);
538 else
539 IP6STAT_INC(ip6s_sources_otherif[best_scope]);
540 if (dst_scope == best_scope)
541 IP6STAT_INC(ip6s_sources_samescope[best_scope]);
542 else
543 IP6STAT_INC(ip6s_sources_otherscope[best_scope]);
544 if (IFA6_IS_DEPRECATED(ia))
545 IP6STAT_INC(ip6s_sources_deprecated[best_scope]);
546 IN6_IFADDR_RUNLOCK(&in6_ifa_tracker);
547 return (0);
548 }
549
550 /*
551 * Select source address based on @inp, @dstsock and @opts.
552 * Stores selected address to @srcp. If @scope_ambiguous is set,
553 * embed scope from selected outgoing interface. If @hlim pointer
554 * is provided, stores calculated hop limit there.
555 * Returns 0 on success.
556 */
557 int
558 in6_selectsrc_socket(struct sockaddr_in6 *dstsock, struct ip6_pktopts *opts,
559 struct inpcb *inp, struct ucred *cred, int scope_ambiguous,
560 struct in6_addr *srcp, int *hlim)
561 {
562 struct ifnet *retifp;
563 uint32_t fibnum;
564 int error;
565
566 fibnum = inp->inp_inc.inc_fibnum;
567 retifp = NULL;
568
569 error = in6_selectsrc(fibnum, dstsock, opts, inp, cred, &retifp, srcp);
570 if (error != 0)
571 return (error);
572
573 if (hlim != NULL)
574 *hlim = in6_selecthlim(inp, retifp);
575
576 if (retifp == NULL || scope_ambiguous == 0)
577 return (0);
578
579 /*
580 * Application should provide a proper zone ID or the use of
581 * default zone IDs should be enabled. Unfortunately, some
582 * applications do not behave as it should, so we need a
583 * workaround. Even if an appropriate ID is not determined
584 * (when it's required), if we can determine the outgoing
585 * interface. determine the zone ID based on the interface.
586 */
587 error = in6_setscope(&dstsock->sin6_addr, retifp, NULL);
588
589 return (error);
590 }
591
592 /*
593 * Select source address based on @fibnum, @dst and @scopeid.
594 * Stores selected address to @srcp.
595 * Returns 0 on success.
596 *
597 * Used by non-socket based consumers (ND code mostly)
598 */
599 int
600 in6_selectsrc_addr(uint32_t fibnum, const struct in6_addr *dst,
601 uint32_t scopeid, struct ifnet *ifp, struct in6_addr *srcp,
602 int *hlim)
603 {
604 struct ifnet *retifp;
605 struct sockaddr_in6 dst_sa;
606 int error;
607
608 retifp = ifp;
609 bzero(&dst_sa, sizeof(dst_sa));
610 dst_sa.sin6_family = AF_INET6;
611 dst_sa.sin6_len = sizeof(dst_sa);
612 dst_sa.sin6_addr = *dst;
613 dst_sa.sin6_scope_id = scopeid;
614 sa6_embedscope(&dst_sa, 0);
615
616 error = in6_selectsrc(fibnum, &dst_sa, NULL, NULL, NULL, &retifp, srcp);
617 if (hlim != NULL)
618 *hlim = in6_selecthlim(NULL, retifp);
619
620 return (error);
621 }
622
623 /*
624 * clone - meaningful only for bsdi and freebsd
625 */
626 static int
627 selectroute(struct sockaddr_in6 *dstsock, struct ip6_pktopts *opts,
628 struct ip6_moptions *mopts, struct route_in6 *ro,
629 struct ifnet **retifp, struct rtentry **retrt, int norouteok, u_int fibnum)
630 {
631 int error = 0;
632 struct ifnet *ifp = NULL;
633 struct rtentry *rt = NULL;
634 struct sockaddr_in6 *sin6_next;
635 struct in6_pktinfo *pi = NULL;
636 struct in6_addr *dst = &dstsock->sin6_addr;
637 uint32_t zoneid;
638 #if 0
639 char ip6buf[INET6_ADDRSTRLEN];
640
641 if (dstsock->sin6_addr.s6_addr32[0] == 0 &&
642 dstsock->sin6_addr.s6_addr32[1] == 0 &&
643 !IN6_IS_ADDR_LOOPBACK(&dstsock->sin6_addr)) {
644 printf("in6_selectroute: strange destination %s\n",
645 ip6_sprintf(ip6buf, &dstsock->sin6_addr));
646 } else {
647 printf("in6_selectroute: destination = %s%%%d\n",
648 ip6_sprintf(ip6buf, &dstsock->sin6_addr),
649 dstsock->sin6_scope_id); /* for debug */
650 }
651 #endif
652
653 /* If the caller specify the outgoing interface explicitly, use it. */
654 if (opts && (pi = opts->ip6po_pktinfo) != NULL && pi->ipi6_ifindex) {
655 /* XXX boundary check is assumed to be already done. */
656 ifp = ifnet_byindex(pi->ipi6_ifindex);
657 if (ifp != NULL &&
658 (norouteok || retrt == NULL ||
659 IN6_IS_ADDR_MULTICAST(dst))) {
660 /*
661 * we do not have to check or get the route for
662 * multicast.
663 */
664 goto done;
665 } else
666 goto getroute;
667 }
668 /*
669 * If the destination address is a multicast address and the outgoing
670 * interface for the address is specified by the caller, use it.
671 */
672 if (IN6_IS_ADDR_MULTICAST(dst) &&
673 mopts != NULL && (ifp = mopts->im6o_multicast_ifp) != NULL) {
674 goto done; /* we do not need a route for multicast. */
675 }
676 /*
677 * If destination address is LLA or link- or node-local multicast,
678 * use it's embedded scope zone id to determine outgoing interface.
679 */
680 if (IN6_IS_ADDR_MC_LINKLOCAL(dst) ||
681 IN6_IS_ADDR_MC_NODELOCAL(dst)) {
682 zoneid = ntohs(in6_getscope(dst));
683 if (zoneid > 0) {
684 ifp = in6_getlinkifnet(zoneid);
685 goto done;
686 }
687 }
688
689 getroute:
690 /*
691 * If the next hop address for the packet is specified by the caller,
692 * use it as the gateway.
693 */
694 if (opts && opts->ip6po_nexthop) {
695 struct route_in6 *ron;
696
697 sin6_next = satosin6(opts->ip6po_nexthop);
698 if (IN6_IS_ADDR_LINKLOCAL(&sin6_next->sin6_addr)) {
699 /*
700 * Next hop is LLA, thus it should be neighbor.
701 * Determine outgoing interface by zone index.
702 */
703 zoneid = ntohs(in6_getscope(&sin6_next->sin6_addr));
704 if (zoneid > 0) {
705 ifp = in6_getlinkifnet(zoneid);
706 goto done;
707 }
708 }
709 ron = &opts->ip6po_nextroute;
710 /* Use a cached route if it exists and is valid. */
711 if (ron->ro_rt != NULL && (
712 (ron->ro_rt->rt_flags & RTF_UP) == 0 ||
713 ron->ro_dst.sin6_family != AF_INET6 ||
714 !IN6_ARE_ADDR_EQUAL(&ron->ro_dst.sin6_addr,
715 &sin6_next->sin6_addr)))
716 RO_RTFREE(ron);
717 if (ron->ro_rt == NULL) {
718 ron->ro_dst = *sin6_next;
719 in6_rtalloc(ron, fibnum); /* multi path case? */
720 }
721 /*
722 * The node identified by that address must be a
723 * neighbor of the sending host.
724 */
725 if (ron->ro_rt == NULL ||
726 (ron->ro_rt->rt_flags & RTF_GATEWAY) != 0)
727 error = EHOSTUNREACH;
728 else {
729 rt = ron->ro_rt;
730 ifp = rt->rt_ifp;
731 }
732 goto done;
733 }
734
735 /*
736 * Use a cached route if it exists and is valid, else try to allocate
737 * a new one. Note that we should check the address family of the
738 * cached destination, in case of sharing the cache with IPv4.
739 */
740 if (ro) {
741 if (ro->ro_rt &&
742 (!(ro->ro_rt->rt_flags & RTF_UP) ||
743 ((struct sockaddr *)(&ro->ro_dst))->sa_family != AF_INET6 ||
744 !IN6_ARE_ADDR_EQUAL(&satosin6(&ro->ro_dst)->sin6_addr,
745 dst))) {
746 RTFREE(ro->ro_rt);
747 ro->ro_rt = (struct rtentry *)NULL;
748 }
749 if (ro->ro_rt == (struct rtentry *)NULL) {
750 struct sockaddr_in6 *sa6;
751
752 /* No route yet, so try to acquire one */
753 bzero(&ro->ro_dst, sizeof(struct sockaddr_in6));
754 sa6 = (struct sockaddr_in6 *)&ro->ro_dst;
755 *sa6 = *dstsock;
756 sa6->sin6_scope_id = 0;
757
758 #ifdef RADIX_MPATH
759 rtalloc_mpath_fib((struct route *)ro,
760 ntohl(sa6->sin6_addr.s6_addr32[3]), fibnum);
761 #else
762 ro->ro_rt = in6_rtalloc1((struct sockaddr *)
763 &ro->ro_dst, 0, 0UL, fibnum);
764 if (ro->ro_rt)
765 RT_UNLOCK(ro->ro_rt);
766 #endif
767 }
768
769 /*
770 * do not care about the result if we have the nexthop
771 * explicitly specified.
772 */
773 if (opts && opts->ip6po_nexthop)
774 goto done;
775
776 if (ro->ro_rt) {
777 ifp = ro->ro_rt->rt_ifp;
778
779 if (ifp == NULL) { /* can this really happen? */
780 RTFREE(ro->ro_rt);
781 ro->ro_rt = NULL;
782 }
783 }
784 if (ro->ro_rt == NULL)
785 error = EHOSTUNREACH;
786 rt = ro->ro_rt;
787
788 /*
789 * Check if the outgoing interface conflicts with
790 * the interface specified by ipi6_ifindex (if specified).
791 * Note that loopback interface is always okay.
792 * (this may happen when we are sending a packet to one of
793 * our own addresses.)
794 */
795 if (ifp && opts && opts->ip6po_pktinfo &&
796 opts->ip6po_pktinfo->ipi6_ifindex) {
797 if (!(ifp->if_flags & IFF_LOOPBACK) &&
798 ifp->if_index !=
799 opts->ip6po_pktinfo->ipi6_ifindex) {
800 error = EHOSTUNREACH;
801 goto done;
802 }
803 }
804 }
805
806 done:
807 if (ifp == NULL && rt == NULL) {
808 /*
809 * This can happen if the caller did not pass a cached route
810 * nor any other hints. We treat this case an error.
811 */
812 error = EHOSTUNREACH;
813 }
814 if (error == EHOSTUNREACH)
815 IP6STAT_INC(ip6s_noroute);
816
817 if (retifp != NULL) {
818 *retifp = ifp;
819
820 /*
821 * Adjust the "outgoing" interface. If we're going to loop
822 * the packet back to ourselves, the ifp would be the loopback
823 * interface. However, we'd rather know the interface associated
824 * to the destination address (which should probably be one of
825 * our own addresses.)
826 */
827 if (rt) {
828 if ((rt->rt_ifp->if_flags & IFF_LOOPBACK) &&
829 (rt->rt_gateway->sa_family == AF_LINK))
830 *retifp =
831 ifnet_byindex(((struct sockaddr_dl *)
832 rt->rt_gateway)->sdl_index);
833 }
834 }
835
836 if (retrt != NULL)
837 *retrt = rt; /* rt may be NULL */
838
839 return (error);
840 }
841
842 static int
843 in6_selectif(struct sockaddr_in6 *dstsock, struct ip6_pktopts *opts,
844 struct ip6_moptions *mopts, struct ifnet **retifp,
845 struct ifnet *oifp, u_int fibnum)
846 {
847 int error;
848 struct route_in6 sro;
849 struct rtentry *rt = NULL;
850 int rt_flags;
851
852 KASSERT(retifp != NULL, ("%s: retifp is NULL", __func__));
853
854 bzero(&sro, sizeof(sro));
855 rt_flags = 0;
856
857 error = selectroute(dstsock, opts, mopts, &sro, retifp, &rt, 1, fibnum);
858
859 if (rt)
860 rt_flags = rt->rt_flags;
861 if (rt && rt == sro.ro_rt)
862 RTFREE(rt);
863
864 if (error != 0) {
865 /* Help ND. See oifp comment in in6_selectsrc(). */
866 if (oifp != NULL && fibnum == RT_DEFAULT_FIB) {
867 *retifp = oifp;
868 error = 0;
869 }
870 return (error);
871 }
872
873 /*
874 * do not use a rejected or black hole route.
875 * XXX: this check should be done in the L2 output routine.
876 * However, if we skipped this check here, we'd see the following
877 * scenario:
878 * - install a rejected route for a scoped address prefix
879 * (like fe80::/10)
880 * - send a packet to a destination that matches the scoped prefix,
881 * with ambiguity about the scope zone.
882 * - pick the outgoing interface from the route, and disambiguate the
883 * scope zone with the interface.
884 * - ip6_output() would try to get another route with the "new"
885 * destination, which may be valid.
886 * - we'd see no error on output.
887 * Although this may not be very harmful, it should still be confusing.
888 * We thus reject the case here.
889 */
890
891 if (rt_flags & (RTF_REJECT | RTF_BLACKHOLE)) {
892 error = (rt_flags & RTF_HOST ? EHOSTUNREACH : ENETUNREACH);
893 return (error);
894 }
895
896 return (0);
897 }
898
899 /*
900 * Public wrapper function to selectroute().
901 *
902 * XXX-BZ in6_selectroute() should and will grow the FIB argument. The
903 * in6_selectroute_fib() function is only there for backward compat on stable.
904 */
905 int
906 in6_selectroute(struct sockaddr_in6 *dstsock, struct ip6_pktopts *opts,
907 struct ip6_moptions *mopts, struct route_in6 *ro,
908 struct ifnet **retifp, struct rtentry **retrt)
909 {
910
911 return (selectroute(dstsock, opts, mopts, ro, retifp,
912 retrt, 0, RT_DEFAULT_FIB));
913 }
914
915 #ifndef BURN_BRIDGES
916 int
917 in6_selectroute_fib(struct sockaddr_in6 *dstsock, struct ip6_pktopts *opts,
918 struct ip6_moptions *mopts, struct route_in6 *ro,
919 struct ifnet **retifp, struct rtentry **retrt, u_int fibnum)
920 {
921
922 return (selectroute(dstsock, opts, mopts, ro, retifp,
923 retrt, 0, fibnum));
924 }
925 #endif
926
927 /*
928 * Default hop limit selection. The precedence is as follows:
929 * 1. Hoplimit value specified via ioctl.
930 * 2. (If the outgoing interface is detected) the current
931 * hop limit of the interface specified by router advertisement.
932 * 3. The system default hoplimit.
933 */
934 int
935 in6_selecthlim(struct inpcb *in6p, struct ifnet *ifp)
936 {
937
938 if (in6p && in6p->in6p_hops >= 0)
939 return (in6p->in6p_hops);
940 else if (ifp)
941 return (ND_IFINFO(ifp)->chlim);
942 else if (in6p && !IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_faddr)) {
943 struct nhop6_basic nh6;
944 struct in6_addr dst;
945 uint32_t fibnum, scopeid;
946 int hlim;
947
948 fibnum = in6p->inp_inc.inc_fibnum;
949 in6_splitscope(&in6p->in6p_faddr, &dst, &scopeid);
950 if (fib6_lookup_nh_basic(fibnum, &dst, scopeid, 0, 0, &nh6)==0){
951 hlim = ND_IFINFO(nh6.nh_ifp)->chlim;
952 return (hlim);
953 }
954 }
955 return (V_ip6_defhlim);
956 }
957
958 /*
959 * XXX: this is borrowed from in6_pcbbind(). If possible, we should
960 * share this function by all *bsd*...
961 */
962 int
963 in6_pcbsetport(struct in6_addr *laddr, struct inpcb *inp, struct ucred *cred)
964 {
965 struct socket *so = inp->inp_socket;
966 u_int16_t lport = 0;
967 int error, lookupflags = 0;
968 #ifdef INVARIANTS
969 struct inpcbinfo *pcbinfo = inp->inp_pcbinfo;
970 #endif
971
972 INP_WLOCK_ASSERT(inp);
973 INP_HASH_WLOCK_ASSERT(pcbinfo);
974
975 error = prison_local_ip6(cred, laddr,
976 ((inp->inp_flags & IN6P_IPV6_V6ONLY) != 0));
977 if (error)
978 return(error);
979
980 /* XXX: this is redundant when called from in6_pcbbind */
981 if ((so->so_options & (SO_REUSEADDR|SO_REUSEPORT)) == 0)
982 lookupflags = INPLOOKUP_WILDCARD;
983
984 inp->inp_flags |= INP_ANONPORT;
985
986 error = in_pcb_lport(inp, NULL, &lport, cred, lookupflags);
987 if (error != 0)
988 return (error);
989
990 inp->inp_lport = lport;
991 if (in_pcbinshash(inp) != 0) {
992 inp->in6p_laddr = in6addr_any;
993 inp->inp_lport = 0;
994 return (EAGAIN);
995 }
996
997 return (0);
998 }
999
1000 void
1001 addrsel_policy_init(void)
1002 {
1003
1004 init_policy_queue();
1005
1006 /* initialize the "last resort" policy */
1007 bzero(&V_defaultaddrpolicy, sizeof(V_defaultaddrpolicy));
1008 V_defaultaddrpolicy.label = ADDR_LABEL_NOTAPP;
1009
1010 if (!IS_DEFAULT_VNET(curvnet))
1011 return;
1012
1013 ADDRSEL_LOCK_INIT();
1014 ADDRSEL_SXLOCK_INIT();
1015 }
1016
1017 static struct in6_addrpolicy *
1018 lookup_addrsel_policy(struct sockaddr_in6 *key)
1019 {
1020 struct in6_addrpolicy *match = NULL;
1021
1022 ADDRSEL_LOCK();
1023 match = match_addrsel_policy(key);
1024
1025 if (match == NULL)
1026 match = &V_defaultaddrpolicy;
1027 else
1028 match->use++;
1029 ADDRSEL_UNLOCK();
1030
1031 return (match);
1032 }
1033
1034 /*
1035 * Subroutines to manage the address selection policy table via sysctl.
1036 */
1037 struct walkarg {
1038 struct sysctl_req *w_req;
1039 };
1040
1041 static int in6_src_sysctl(SYSCTL_HANDLER_ARGS);
1042 SYSCTL_DECL(_net_inet6_ip6);
1043 static SYSCTL_NODE(_net_inet6_ip6, IPV6CTL_ADDRCTLPOLICY, addrctlpolicy,
1044 CTLFLAG_RD, in6_src_sysctl, "");
1045
1046 static int
1047 in6_src_sysctl(SYSCTL_HANDLER_ARGS)
1048 {
1049 struct walkarg w;
1050
1051 if (req->newptr)
1052 return EPERM;
1053
1054 bzero(&w, sizeof(w));
1055 w.w_req = req;
1056
1057 return (walk_addrsel_policy(dump_addrsel_policyent, &w));
1058 }
1059
1060 int
1061 in6_src_ioctl(u_long cmd, caddr_t data)
1062 {
1063 struct in6_addrpolicy ent0;
1064
1065 if (cmd != SIOCAADDRCTL_POLICY && cmd != SIOCDADDRCTL_POLICY)
1066 return (EOPNOTSUPP); /* check for safety */
1067
1068 ent0 = *(struct in6_addrpolicy *)data;
1069
1070 if (ent0.label == ADDR_LABEL_NOTAPP)
1071 return (EINVAL);
1072 /* check if the prefix mask is consecutive. */
1073 if (in6_mask2len(&ent0.addrmask.sin6_addr, NULL) < 0)
1074 return (EINVAL);
1075 /* clear trailing garbages (if any) of the prefix address. */
1076 IN6_MASK_ADDR(&ent0.addr.sin6_addr, &ent0.addrmask.sin6_addr);
1077 ent0.use = 0;
1078
1079 switch (cmd) {
1080 case SIOCAADDRCTL_POLICY:
1081 return (add_addrsel_policyent(&ent0));
1082 case SIOCDADDRCTL_POLICY:
1083 return (delete_addrsel_policyent(&ent0));
1084 }
1085
1086 return (0); /* XXX: compromise compilers */
1087 }
1088
1089 /*
1090 * The followings are implementation of the policy table using a
1091 * simple tail queue.
1092 * XXX such details should be hidden.
1093 * XXX implementation using binary tree should be more efficient.
1094 */
1095 struct addrsel_policyent {
1096 TAILQ_ENTRY(addrsel_policyent) ape_entry;
1097 struct in6_addrpolicy ape_policy;
1098 };
1099
1100 TAILQ_HEAD(addrsel_policyhead, addrsel_policyent);
1101
1102 static VNET_DEFINE(struct addrsel_policyhead, addrsel_policytab);
1103 #define V_addrsel_policytab VNET(addrsel_policytab)
1104
1105 static void
1106 init_policy_queue(void)
1107 {
1108
1109 TAILQ_INIT(&V_addrsel_policytab);
1110 }
1111
1112 static int
1113 add_addrsel_policyent(struct in6_addrpolicy *newpolicy)
1114 {
1115 struct addrsel_policyent *new, *pol;
1116
1117 new = malloc(sizeof(*new), M_IFADDR,
1118 M_WAITOK);
1119 ADDRSEL_XLOCK();
1120 ADDRSEL_LOCK();
1121
1122 /* duplication check */
1123 TAILQ_FOREACH(pol, &V_addrsel_policytab, ape_entry) {
1124 if (IN6_ARE_ADDR_EQUAL(&newpolicy->addr.sin6_addr,
1125 &pol->ape_policy.addr.sin6_addr) &&
1126 IN6_ARE_ADDR_EQUAL(&newpolicy->addrmask.sin6_addr,
1127 &pol->ape_policy.addrmask.sin6_addr)) {
1128 ADDRSEL_UNLOCK();
1129 ADDRSEL_XUNLOCK();
1130 free(new, M_IFADDR);
1131 return (EEXIST); /* or override it? */
1132 }
1133 }
1134
1135 bzero(new, sizeof(*new));
1136
1137 /* XXX: should validate entry */
1138 new->ape_policy = *newpolicy;
1139
1140 TAILQ_INSERT_TAIL(&V_addrsel_policytab, new, ape_entry);
1141 ADDRSEL_UNLOCK();
1142 ADDRSEL_XUNLOCK();
1143
1144 return (0);
1145 }
1146
1147 static int
1148 delete_addrsel_policyent(struct in6_addrpolicy *key)
1149 {
1150 struct addrsel_policyent *pol;
1151
1152 ADDRSEL_XLOCK();
1153 ADDRSEL_LOCK();
1154
1155 /* search for the entry in the table */
1156 TAILQ_FOREACH(pol, &V_addrsel_policytab, ape_entry) {
1157 if (IN6_ARE_ADDR_EQUAL(&key->addr.sin6_addr,
1158 &pol->ape_policy.addr.sin6_addr) &&
1159 IN6_ARE_ADDR_EQUAL(&key->addrmask.sin6_addr,
1160 &pol->ape_policy.addrmask.sin6_addr)) {
1161 break;
1162 }
1163 }
1164 if (pol == NULL) {
1165 ADDRSEL_UNLOCK();
1166 ADDRSEL_XUNLOCK();
1167 return (ESRCH);
1168 }
1169
1170 TAILQ_REMOVE(&V_addrsel_policytab, pol, ape_entry);
1171 ADDRSEL_UNLOCK();
1172 ADDRSEL_XUNLOCK();
1173 free(pol, M_IFADDR);
1174
1175 return (0);
1176 }
1177
1178 static int
1179 walk_addrsel_policy(int (*callback)(struct in6_addrpolicy *, void *), void *w)
1180 {
1181 struct addrsel_policyent *pol;
1182 int error = 0;
1183
1184 ADDRSEL_SLOCK();
1185 TAILQ_FOREACH(pol, &V_addrsel_policytab, ape_entry) {
1186 if ((error = (*callback)(&pol->ape_policy, w)) != 0) {
1187 ADDRSEL_SUNLOCK();
1188 return (error);
1189 }
1190 }
1191 ADDRSEL_SUNLOCK();
1192 return (error);
1193 }
1194
1195 static int
1196 dump_addrsel_policyent(struct in6_addrpolicy *pol, void *arg)
1197 {
1198 int error = 0;
1199 struct walkarg *w = arg;
1200
1201 error = SYSCTL_OUT(w->w_req, pol, sizeof(*pol));
1202
1203 return (error);
1204 }
1205
1206 static struct in6_addrpolicy *
1207 match_addrsel_policy(struct sockaddr_in6 *key)
1208 {
1209 struct addrsel_policyent *pent;
1210 struct in6_addrpolicy *bestpol = NULL, *pol;
1211 int matchlen, bestmatchlen = -1;
1212 u_char *mp, *ep, *k, *p, m;
1213
1214 TAILQ_FOREACH(pent, &V_addrsel_policytab, ape_entry) {
1215 matchlen = 0;
1216
1217 pol = &pent->ape_policy;
1218 mp = (u_char *)&pol->addrmask.sin6_addr;
1219 ep = mp + 16; /* XXX: scope field? */
1220 k = (u_char *)&key->sin6_addr;
1221 p = (u_char *)&pol->addr.sin6_addr;
1222 for (; mp < ep && *mp; mp++, k++, p++) {
1223 m = *mp;
1224 if ((*k & m) != *p)
1225 goto next; /* not match */
1226 if (m == 0xff) /* short cut for a typical case */
1227 matchlen += 8;
1228 else {
1229 while (m >= 0x80) {
1230 matchlen++;
1231 m <<= 1;
1232 }
1233 }
1234 }
1235
1236 /* matched. check if this is better than the current best. */
1237 if (bestpol == NULL ||
1238 matchlen > bestmatchlen) {
1239 bestpol = pol;
1240 bestmatchlen = matchlen;
1241 }
1242
1243 next:
1244 continue;
1245 }
1246
1247 return (bestpol);
1248 }
Cache object: c6e3dcfc7a76051461e90a65ace3af3c
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