1 /* $KAME: in6_src.c,v 1.159 2005/10/19 01:40:32 t-momose Exp $ */
2
3 /*
4 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of the project nor the names of its contributors
16 * may be used to endorse or promote products derived from this software
17 * without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 */
31
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 * 3. All advertising materials mentioning features or use of this software
45 * must display the following acknowledgement:
46 * This product includes software developed by the University of
47 * California, Berkeley and its contributors.
48 * 4. Neither the name of the University nor the names of its contributors
49 * may be used to endorse or promote products derived from this software
50 * without specific prior written permission.
51 *
52 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
53 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
54 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
55 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
56 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
57 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
58 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
59 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
60 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
61 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
62 * SUCH DAMAGE.
63 *
64 * @(#)in_pcb.c 8.2 (Berkeley) 1/4/94
65 */
66
67 #include <sys/cdefs.h>
68 __KERNEL_RCSID(0, "$NetBSD: in6_src.c,v 1.43 2008/04/15 03:57:04 thorpej Exp $");
69
70 #include "opt_inet.h"
71
72 #include <sys/param.h>
73 #include <sys/systm.h>
74 #include <sys/malloc.h>
75 #include <sys/mbuf.h>
76 #include <sys/protosw.h>
77 #include <sys/socket.h>
78 #include <sys/socketvar.h>
79 #ifndef __FreeBSD__
80 #include <sys/ioctl.h>
81 #else
82 #include <sys/sockio.h>
83 #endif
84 #ifdef __FreeBSD__
85 #include <sys/sysctl.h>
86 #endif
87 #include <sys/errno.h>
88 #include <sys/time.h>
89 #include <sys/kernel.h>
90 #include <sys/proc.h>
91 #include <sys/kauth.h>
92
93 #include <net/if.h>
94 #include <net/if_types.h>
95 #include <net/route.h>
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 <netinet6/in6_var.h>
103 #include <netinet/ip6.h>
104 #ifndef __OpenBSD__
105 #include <netinet6/in6_pcb.h>
106 #endif
107 #include <netinet6/ip6_var.h>
108 #include <netinet6/ip6_private.h>
109 #include <netinet6/nd6.h>
110 #include <netinet6/scope6_var.h>
111
112 #include <net/net_osdep.h>
113
114 #ifdef MIP6
115 #include <netinet6/mip6.h>
116 #include <netinet6/mip6_var.h>
117 #include "mip.h"
118 #if NMIP > 0
119 #include <net/if_mip.h>
120 #endif /* NMIP > 0 */
121 #endif /* MIP6 */
122
123 #ifndef __OpenBSD__
124 #include "loop.h"
125 #endif
126 #ifdef __NetBSD__
127 extern struct ifnet loif[NLOOP];
128 #endif
129
130 #define ADDR_LABEL_NOTAPP (-1)
131 struct in6_addrpolicy defaultaddrpolicy;
132
133 #ifdef notyet /* until introducing ND extensions and address selection */
134 int ip6_prefer_tempaddr = 0;
135 #endif
136
137 static int selectroute(struct sockaddr_in6 *, struct ip6_pktopts *,
138 struct ip6_moptions *, struct route *, struct ifnet **,
139 struct rtentry **, int, int);
140 static int in6_selectif(struct sockaddr_in6 *, struct ip6_pktopts *,
141 struct ip6_moptions *, struct route *, struct ifnet **);
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 #if 0 /* diabled ad-hoc */
160 #define REPLACE(r) do {\
161 if ((r) < sizeof(ip6stat.ip6s_sources_rule) / \
162 sizeof(ip6stat.ip6s_sources_rule[0])) /* check for safety */ \
163 ip6stat.ip6s_sources_rule[(r)]++; \
164 /* printf("in6_selectsrc: replace %s with %s by %d\n", ia_best ? ip6_sprintf(&ia_best->ia_addr.sin6_addr) : "none", ip6_sprintf(&ia->ia_addr.sin6_addr), (r)); */ \
165 goto replace; \
166 } while(0)
167 #define NEXT(r) do {\
168 if ((r) < sizeof(ip6stat.ip6s_sources_rule) / \
169 sizeof(ip6stat.ip6s_sources_rule[0])) /* check for safety */ \
170 ip6stat.ip6s_sources_rule[(r)]++; \
171 /* printf("in6_selectsrc: keep %s against %s by %d\n", ia_best ? ip6_sprintf(&ia_best->ia_addr.sin6_addr) : "none", ip6_sprintf(&ia->ia_addr.sin6_addr), (r)); */ \
172 goto next; /* XXX: we can't use 'continue' here */ \
173 } while(0)
174 #define BREAK(r) do { \
175 if ((r) < sizeof(ip6stat.ip6s_sources_rule) / \
176 sizeof(ip6stat.ip6s_sources_rule[0])) /* check for safety */ \
177 ip6stat.ip6s_sources_rule[(r)]++; \
178 goto out; /* XXX: we can't use 'break' here */ \
179 } while(0)
180 #else
181 #define REPLACE(r) goto replace
182 #define NEXT(r) goto next
183 #define BREAK(r) goto out
184 #endif
185
186 struct in6_addr *
187 in6_selectsrc(struct sockaddr_in6 *dstsock, struct ip6_pktopts *opts,
188 struct ip6_moptions *mopts, struct route *ro, struct in6_addr *laddr,
189 struct ifnet **ifpp, int *errorp)
190 {
191 struct in6_addr dst;
192 struct ifnet *ifp = NULL;
193 struct in6_ifaddr *ia = NULL, *ia_best = NULL;
194 struct in6_pktinfo *pi = NULL;
195 int dst_scope = -1, best_scope = -1, best_matchlen = -1;
196 struct in6_addrpolicy *dst_policy = NULL, *best_policy = NULL;
197 u_int32_t odstzone;
198 int error;
199 #ifdef notyet /* until introducing ND extensions and address selection */
200 int prefer_tempaddr;
201 #endif
202 #if defined(MIP6) && NMIP > 0
203 u_int8_t ip6po_usecoa = 0;
204 #endif /* MIP6 && NMIP > 0 */
205
206 dst = dstsock->sin6_addr; /* make a copy for local operation */
207 *errorp = 0;
208 if (ifpp)
209 *ifpp = NULL;
210
211 /*
212 * Try to determine the outgoing interface for the given destination.
213 * We do this regardless of whether the socket is bound, since the
214 * caller may need this information as a side effect of the call
215 * to this function (e.g., for identifying the appropriate scope zone
216 * ID).
217 */
218 error = in6_selectif(dstsock, opts, mopts, ro, &ifp);
219 if (ifpp)
220 *ifpp = ifp;
221
222 /*
223 * If the source address is explicitly specified by the caller,
224 * check if the requested source address is indeed a unicast address
225 * assigned to the node, and can be used as the packet's source
226 * address. If everything is okay, use the address as source.
227 */
228 if (opts && (pi = opts->ip6po_pktinfo) &&
229 !IN6_IS_ADDR_UNSPECIFIED(&pi->ipi6_addr)) {
230 struct sockaddr_in6 srcsock;
231 struct in6_ifaddr *ia6;
232
233 /*
234 * Determine the appropriate zone id of the source based on
235 * the zone of the destination and the outgoing interface.
236 * If the specified address is ambiguous wrt the scope zone,
237 * the interface must be specified; otherwise, ifa_ifwithaddr()
238 * will fail matching the address.
239 */
240 bzero(&srcsock, sizeof(srcsock));
241 srcsock.sin6_family = AF_INET6;
242 srcsock.sin6_len = sizeof(srcsock);
243 srcsock.sin6_addr = pi->ipi6_addr;
244 if (ifp) {
245 *errorp = in6_setscope(&srcsock.sin6_addr, ifp, NULL);
246 if (*errorp != 0)
247 return (NULL);
248 }
249
250 ia6 = (struct in6_ifaddr *)ifa_ifwithaddr((struct sockaddr *)(&srcsock));
251 if (ia6 == NULL ||
252 (ia6->ia6_flags & (IN6_IFF_ANYCAST | IN6_IFF_NOTREADY))) {
253 *errorp = EADDRNOTAVAIL;
254 return (NULL);
255 }
256 pi->ipi6_addr = srcsock.sin6_addr; /* XXX: this overrides pi */
257 if (ifpp)
258 *ifpp = ifp;
259 return (&ia6->ia_addr.sin6_addr);
260 }
261
262 /*
263 * If the socket has already bound the source, just use it. We don't
264 * care at the moment whether in6_selectif() succeeded above, even
265 * though it would eventually cause an error.
266 */
267 if (laddr && !IN6_IS_ADDR_UNSPECIFIED(laddr))
268 return (laddr);
269
270 /*
271 * The outgoing interface is crucial in the general selection procedure
272 * below. If it is not known at this point, we fail.
273 */
274 if (ifp == NULL) {
275 *errorp = error;
276 return (NULL);
277 }
278
279 /*
280 * If the address is not yet determined, choose the best one based on
281 * the outgoing interface and the destination address.
282 */
283
284 #if defined(MIP6) && NMIP > 0
285 /*
286 * a caller can specify IP6PO_USECOA to not to use a home
287 * address. for example, the case that the neighbour
288 * unreachability detection to the global address.
289 */
290 if (opts != NULL &&
291 (opts->ip6po_flags & IP6PO_USECOA) != 0) {
292 ip6po_usecoa = 1;
293 }
294 #endif /* MIP6 && NMIP > 0 */
295
296 #ifdef DIAGNOSTIC
297 if (ifp == NULL) /* this should not happen */
298 panic("in6_selectsrc: NULL ifp");
299 #endif
300 *errorp = in6_setscope(&dst, ifp, &odstzone);
301 if (*errorp != 0)
302 return (NULL);
303
304 for (ia = in6_ifaddr; ia; ia = ia->ia_next) {
305 int new_scope = -1, new_matchlen = -1;
306 struct in6_addrpolicy *new_policy = NULL;
307 u_int32_t srczone, osrczone, dstzone;
308 struct in6_addr src;
309 struct ifnet *ifp1 = ia->ia_ifp;
310
311 /*
312 * We'll never take an address that breaks the scope zone
313 * of the destination. We also skip an address if its zone
314 * does not contain the outgoing interface.
315 * XXX: we should probably use sin6_scope_id here.
316 */
317 if (in6_setscope(&dst, ifp1, &dstzone) ||
318 odstzone != dstzone) {
319 continue;
320 }
321 src = ia->ia_addr.sin6_addr;
322 if (in6_setscope(&src, ifp, &osrczone) ||
323 in6_setscope(&src, ifp1, &srczone) ||
324 osrczone != srczone) {
325 continue;
326 }
327
328 /* avoid unusable addresses */
329 if ((ia->ia6_flags &
330 (IN6_IFF_NOTREADY | IN6_IFF_ANYCAST | IN6_IFF_DETACHED))) {
331 continue;
332 }
333 if (!ip6_use_deprecated && IFA6_IS_DEPRECATED(ia))
334 continue;
335
336 #if defined(MIP6) && NMIP > 0
337 /* avoid unusable home addresses. */
338 if ((ia->ia6_flags & IN6_IFF_HOME) &&
339 !mip6_ifa6_is_addr_valid_hoa(ia))
340 continue;
341 #endif /* MIP6 && NMIP > 0 */
342
343 /* Rule 1: Prefer same address */
344 if (IN6_ARE_ADDR_EQUAL(&dst, &ia->ia_addr.sin6_addr)) {
345 ia_best = ia;
346 BREAK(1); /* there should be no better candidate */
347 }
348
349 if (ia_best == NULL)
350 REPLACE(0);
351
352 /* Rule 2: Prefer appropriate scope */
353 if (dst_scope < 0)
354 dst_scope = in6_addrscope(&dst);
355 new_scope = in6_addrscope(&ia->ia_addr.sin6_addr);
356 if (IN6_ARE_SCOPE_CMP(best_scope, new_scope) < 0) {
357 if (IN6_ARE_SCOPE_CMP(best_scope, dst_scope) < 0)
358 REPLACE(2);
359 NEXT(2);
360 } else if (IN6_ARE_SCOPE_CMP(new_scope, best_scope) < 0) {
361 if (IN6_ARE_SCOPE_CMP(new_scope, dst_scope) < 0)
362 NEXT(2);
363 REPLACE(2);
364 }
365
366 /*
367 * Rule 3: Avoid deprecated addresses. Note that the case of
368 * !ip6_use_deprecated is already rejected above.
369 */
370 if (!IFA6_IS_DEPRECATED(ia_best) && IFA6_IS_DEPRECATED(ia))
371 NEXT(3);
372 if (IFA6_IS_DEPRECATED(ia_best) && !IFA6_IS_DEPRECATED(ia))
373 REPLACE(3);
374
375 /* Rule 4: Prefer home addresses */
376 #if defined(MIP6) && NMIP > 0
377 if (!MIP6_IS_MN)
378 goto skip_rule4;
379
380 if ((ia_best->ia6_flags & IN6_IFF_HOME) == 0 &&
381 (ia->ia6_flags & IN6_IFF_HOME) == 0) {
382 /* both address are not home addresses. */
383 goto skip_rule4;
384 }
385
386 /*
387 * If SA is simultaneously a home address and care-of
388 * address and SB is not, then prefer SA. Similarly,
389 * if SB is simultaneously a home address and care-of
390 * address and SA is not, then prefer SB.
391 */
392 if (((ia_best->ia6_flags & IN6_IFF_HOME) != 0 &&
393 ia_best->ia_ifp->if_type != IFT_MIP)
394 &&
395 ((ia->ia6_flags & IN6_IFF_HOME) != 0 &&
396 ia->ia_ifp->if_type == IFT_MIP))
397 NEXT(4);
398 if (((ia_best->ia6_flags & IN6_IFF_HOME) != 0 &&
399 ia_best->ia_ifp->if_type == IFT_MIP)
400 &&
401 ((ia->ia6_flags & IN6_IFF_HOME) != 0 &&
402 ia->ia_ifp->if_type != IFT_MIP))
403 REPLACE(4);
404 if (ip6po_usecoa == 0) {
405 /*
406 * If SA is just a home address and SB is just
407 * a care-of address, then prefer
408 * SA. Similarly, if SB is just a home address
409 * and SA is just a care-of address, then
410 * prefer SB.
411 */
412 if ((ia_best->ia6_flags & IN6_IFF_HOME) != 0 &&
413 (ia->ia6_flags & IN6_IFF_HOME) == 0) {
414 NEXT(4);
415 }
416 if ((ia_best->ia6_flags & IN6_IFF_HOME) == 0 &&
417 (ia->ia6_flags & IN6_IFF_HOME) != 0) {
418 REPLACE(4);
419 }
420 } else {
421 /*
422 * a sender don't want to use a home address
423 * because:
424 *
425 * 1) we cannot use. (ex. NS or NA to global
426 * addresses.)
427 *
428 * 2) a user specified not to use.
429 * (ex. mip6control -u)
430 */
431 if ((ia_best->ia6_flags & IN6_IFF_HOME) == 0 &&
432 (ia->ia6_flags & IN6_IFF_HOME) != 0) {
433 /* XXX breaks stat */
434 NEXT(0);
435 }
436 if ((ia_best->ia6_flags & IN6_IFF_HOME) != 0 &&
437 (ia->ia6_flags & IN6_IFF_HOME) == 0) {
438 /* XXX breaks stat */
439 REPLACE(0);
440 }
441 }
442 skip_rule4:
443 #endif /* MIP6 && NMIP > 0 */
444
445 /* Rule 5: Prefer outgoing interface */
446 if (ia_best->ia_ifp == ifp && ia->ia_ifp != ifp)
447 NEXT(5);
448 if (ia_best->ia_ifp != ifp && ia->ia_ifp == ifp)
449 REPLACE(5);
450
451 /*
452 * Rule 6: Prefer matching label
453 * Note that best_policy should be non-NULL here.
454 */
455 if (dst_policy == NULL)
456 dst_policy = lookup_addrsel_policy(dstsock);
457 if (dst_policy->label != ADDR_LABEL_NOTAPP) {
458 new_policy = lookup_addrsel_policy(&ia->ia_addr);
459 if (dst_policy->label == best_policy->label &&
460 dst_policy->label != new_policy->label)
461 NEXT(6);
462 if (dst_policy->label != best_policy->label &&
463 dst_policy->label == new_policy->label)
464 REPLACE(6);
465 }
466
467 /*
468 * Rule 7: Prefer public addresses.
469 * We allow users to reverse the logic by configuring
470 * a sysctl variable, so that privacy conscious users can
471 * always prefer temporary addresses.
472 */
473 #ifdef notyet /* until introducing ND extensions and address selection */
474 if (opts == NULL ||
475 opts->ip6po_prefer_tempaddr == IP6PO_TEMPADDR_SYSTEM) {
476 prefer_tempaddr = ip6_prefer_tempaddr;
477 } else if (opts->ip6po_prefer_tempaddr ==
478 IP6PO_TEMPADDR_NOTPREFER) {
479 prefer_tempaddr = 0;
480 } else
481 prefer_tempaddr = 1;
482 if (!(ia_best->ia6_flags & IN6_IFF_TEMPORARY) &&
483 (ia->ia6_flags & IN6_IFF_TEMPORARY)) {
484 if (prefer_tempaddr)
485 REPLACE(7);
486 else
487 NEXT(7);
488 }
489 if ((ia_best->ia6_flags & IN6_IFF_TEMPORARY) &&
490 !(ia->ia6_flags & IN6_IFF_TEMPORARY)) {
491 if (prefer_tempaddr)
492 NEXT(7);
493 else
494 REPLACE(7);
495 }
496 #endif
497
498 /*
499 * Rule 8: prefer addresses on alive interfaces.
500 * This is a KAME specific rule.
501 */
502 if ((ia_best->ia_ifp->if_flags & IFF_UP) &&
503 !(ia->ia_ifp->if_flags & IFF_UP))
504 NEXT(8);
505 if (!(ia_best->ia_ifp->if_flags & IFF_UP) &&
506 (ia->ia_ifp->if_flags & IFF_UP))
507 REPLACE(8);
508
509 /*
510 * Rule 9: prefer addresses on "preferred" interfaces.
511 * This is a KAME specific rule.
512 */
513 #ifdef notyet /* until introducing address selection */
514 #define NDI_BEST ND_IFINFO(ia_best->ia_ifp)
515 #define NDI_NEW ND_IFINFO(ia->ia_ifp)
516 if ((NDI_BEST->flags & ND6_IFF_PREFER_SOURCE) &&
517 !(NDI_NEW->flags & ND6_IFF_PREFER_SOURCE))
518 NEXT(9);
519 if (!(NDI_BEST->flags & ND6_IFF_PREFER_SOURCE) &&
520 (NDI_NEW->flags & ND6_IFF_PREFER_SOURCE))
521 REPLACE(9);
522 #undef NDI_BEST
523 #undef NDI_NEW
524 #endif
525
526 /*
527 * Rule 14: Use longest matching prefix.
528 * Note: in the address selection draft, this rule is
529 * documented as "Rule 8". However, since it is also
530 * documented that this rule can be overridden, we assign
531 * a large number so that it is easy to assign smaller numbers
532 * to more preferred rules.
533 */
534 new_matchlen = in6_matchlen(&ia->ia_addr.sin6_addr, &dst);
535 if (best_matchlen < new_matchlen)
536 REPLACE(14);
537 if (new_matchlen < best_matchlen)
538 NEXT(14);
539
540 /* Rule 15 is reserved. */
541
542 /*
543 * Last resort: just keep the current candidate.
544 * Or, do we need more rules?
545 */
546 continue;
547
548 replace:
549 ia_best = ia;
550 best_scope = (new_scope >= 0 ? new_scope :
551 in6_addrscope(&ia_best->ia_addr.sin6_addr));
552 best_policy = (new_policy ? new_policy :
553 lookup_addrsel_policy(&ia_best->ia_addr));
554 best_matchlen = (new_matchlen >= 0 ? new_matchlen :
555 in6_matchlen(&ia_best->ia_addr.sin6_addr,
556 &dst));
557
558 next:
559 continue;
560
561 out:
562 break;
563 }
564
565 if ((ia = ia_best) == NULL) {
566 *errorp = EADDRNOTAVAIL;
567 return (NULL);
568 }
569
570 return (&ia->ia_addr.sin6_addr);
571 }
572 #undef REPLACE
573 #undef BREAK
574 #undef NEXT
575
576 static int
577 selectroute(struct sockaddr_in6 *dstsock, struct ip6_pktopts *opts,
578 struct ip6_moptions *mopts, struct route *ro, struct ifnet **retifp,
579 struct rtentry **retrt, int clone, int norouteok)
580 {
581 int error = 0;
582 struct ifnet *ifp = NULL;
583 struct rtentry *rt = NULL;
584 struct sockaddr_in6 *sin6_next;
585 struct in6_pktinfo *pi = NULL;
586 struct in6_addr *dst;
587
588 dst = &dstsock->sin6_addr;
589
590 #if 0
591 if (dstsock->sin6_addr.s6_addr32[0] == 0 &&
592 dstsock->sin6_addr.s6_addr32[1] == 0 &&
593 !IN6_IS_ADDR_LOOPBACK(&dstsock->sin6_addr)) {
594 printf("in6_selectroute: strange destination %s\n",
595 ip6_sprintf(&dstsock->sin6_addr));
596 } else {
597 printf("in6_selectroute: destination = %s%%%d\n",
598 ip6_sprintf(&dstsock->sin6_addr),
599 dstsock->sin6_scope_id); /* for debug */
600 }
601 #endif
602
603 /* If the caller specify the outgoing interface explicitly, use it. */
604 if (opts && (pi = opts->ip6po_pktinfo) != NULL && pi->ipi6_ifindex) {
605 /* XXX boundary check is assumed to be already done. */
606 #ifdef __FreeBSD__
607 ifp = ifnet_byindex(pi->ipi6_ifindex);
608 #else
609 ifp = ifindex2ifnet[pi->ipi6_ifindex];
610 #endif
611 if (ifp != NULL &&
612 (norouteok || retrt == NULL ||
613 IN6_IS_ADDR_MULTICAST(dst))) {
614 /*
615 * we do not have to check or get the route for
616 * multicast.
617 */
618 goto done;
619 } else
620 goto getroute;
621 }
622
623 /*
624 * If the destination address is a multicast address and the outgoing
625 * interface for the address is specified by the caller, use it.
626 */
627 if (IN6_IS_ADDR_MULTICAST(dst) &&
628 mopts != NULL && (ifp = mopts->im6o_multicast_ifp) != NULL) {
629 goto done; /* we do not need a route for multicast. */
630 }
631
632 getroute:
633 /*
634 * If the next hop address for the packet is specified by the caller,
635 * use it as the gateway.
636 */
637 if (opts && opts->ip6po_nexthop) {
638 struct route *ron;
639
640 sin6_next = satosin6(opts->ip6po_nexthop);
641
642 /* at this moment, we only support AF_INET6 next hops */
643 if (sin6_next->sin6_family != AF_INET6) {
644 error = EAFNOSUPPORT; /* or should we proceed? */
645 goto done;
646 }
647
648 /*
649 * If the next hop is an IPv6 address, then the node identified
650 * by that address must be a neighbor of the sending host.
651 */
652 ron = &opts->ip6po_nextroute;
653 if ((rt = rtcache_lookup(ron, sin6tosa(sin6_next))) == NULL ||
654 (rt->rt_flags & RTF_GATEWAY) != 0 ||
655 !nd6_is_addr_neighbor(sin6_next, rt->rt_ifp)) {
656 rtcache_free(ron);
657 error = EHOSTUNREACH;
658 goto done;
659 }
660 ifp = rt->rt_ifp;
661
662 /*
663 * When cloning is required, try to allocate a route to the
664 * destination so that the caller can store path MTU
665 * information.
666 */
667 if (!clone)
668 goto done;
669 }
670
671 /*
672 * Use a cached route if it exists and is valid, else try to allocate
673 * a new one. Note that we should check the address family of the
674 * cached destination, in case of sharing the cache with IPv4.
675 */
676 if (ro != NULL) {
677 union {
678 struct sockaddr dst;
679 struct sockaddr_in6 dst6;
680 } u;
681
682 /* No route yet, so try to acquire one */
683 u.dst6 = *dstsock;
684 u.dst6.sin6_scope_id = 0;
685 rt = rtcache_lookup1(ro, &u.dst, clone);
686
687 /*
688 * do not care about the result if we have the nexthop
689 * explicitly specified.
690 */
691 if (opts && opts->ip6po_nexthop)
692 goto done;
693
694 if (rt == NULL)
695 error = EHOSTUNREACH;
696 else
697 ifp = rt->rt_ifp;
698
699 /*
700 * Check if the outgoing interface conflicts with
701 * the interface specified by ipi6_ifindex (if specified).
702 * Note that loopback interface is always okay.
703 * (this may happen when we are sending a packet to one of
704 * our own addresses.)
705 */
706 if (opts && opts->ip6po_pktinfo &&
707 opts->ip6po_pktinfo->ipi6_ifindex) {
708 if (!(ifp->if_flags & IFF_LOOPBACK) &&
709 ifp->if_index !=
710 opts->ip6po_pktinfo->ipi6_ifindex) {
711 error = EHOSTUNREACH;
712 goto done;
713 }
714 }
715 }
716
717 done:
718 if (ifp == NULL && rt == NULL) {
719 /*
720 * This can happen if the caller did not pass a cached route
721 * nor any other hints. We treat this case an error.
722 */
723 error = EHOSTUNREACH;
724 }
725 if (error == EHOSTUNREACH)
726 IP6_STATINC(IP6_STAT_NOROUTE);
727
728 if (retifp != NULL)
729 *retifp = ifp;
730 if (retrt != NULL)
731 *retrt = rt; /* rt may be NULL */
732
733 return (error);
734 }
735
736 static int
737 in6_selectif(struct sockaddr_in6 *dstsock, struct ip6_pktopts *opts,
738 struct ip6_moptions *mopts, struct route *ro, struct ifnet **retifp)
739 {
740 int error, clone;
741 struct rtentry *rt = NULL;
742
743 clone = IN6_IS_ADDR_MULTICAST(&dstsock->sin6_addr) ? 0 : 1;
744 if ((error = selectroute(dstsock, opts, mopts, ro, retifp,
745 &rt, clone, 1)) != 0) {
746 return (error);
747 }
748
749 /*
750 * do not use a rejected or black hole route.
751 * XXX: this check should be done in the L2 output routine.
752 * However, if we skipped this check here, we'd see the following
753 * scenario:
754 * - install a rejected route for a scoped address prefix
755 * (like fe80::/10)
756 * - send a packet to a destination that matches the scoped prefix,
757 * with ambiguity about the scope zone.
758 * - pick the outgoing interface from the route, and disambiguate the
759 * scope zone with the interface.
760 * - ip6_output() would try to get another route with the "new"
761 * destination, which may be valid.
762 * - we'd see no error on output.
763 * Although this may not be very harmful, it should still be confusing.
764 * We thus reject the case here.
765 */
766 if (rt && (rt->rt_flags & (RTF_REJECT | RTF_BLACKHOLE)))
767 return (rt->rt_flags & RTF_HOST ? EHOSTUNREACH : ENETUNREACH);
768
769 /*
770 * Adjust the "outgoing" interface. If we're going to loop the packet
771 * back to ourselves, the ifp would be the loopback interface.
772 * However, we'd rather know the interface associated to the
773 * destination address (which should probably be one of our own
774 * addresses.)
775 */
776 if (rt && rt->rt_ifa && rt->rt_ifa->ifa_ifp)
777 *retifp = rt->rt_ifa->ifa_ifp;
778
779 return (0);
780 }
781
782 /*
783 * close - meaningful only for bsdi and freebsd.
784 */
785
786 int
787 in6_selectroute(struct sockaddr_in6 *dstsock, struct ip6_pktopts *opts,
788 struct ip6_moptions *mopts, struct route *ro, struct ifnet **retifp,
789 struct rtentry **retrt, int clone)
790 {
791 return selectroute(dstsock, opts, mopts, ro, retifp,
792 retrt, clone, 0);
793 }
794
795 /*
796 * Default hop limit selection. The precedence is as follows:
797 * 1. Hoplimit value specified via ioctl.
798 * 2. (If the outgoing interface is detected) the current
799 * hop limit of the interface specified by router advertisement.
800 * 3. The system default hoplimit.
801 */
802 int
803 in6_selecthlim(struct in6pcb *in6p, struct ifnet *ifp)
804 {
805 if (in6p && in6p->in6p_hops >= 0)
806 return (in6p->in6p_hops);
807 else if (ifp)
808 return (ND_IFINFO(ifp)->chlim);
809 else
810 return (ip6_defhlim);
811 }
812
813 /*
814 * Find an empty port and set it to the specified PCB.
815 */
816 int
817 in6_pcbsetport(struct in6_addr *laddr, struct in6pcb *in6p, struct lwp *l)
818 {
819 struct socket *so = in6p->in6p_socket;
820 struct inpcbtable *table = in6p->in6p_table;
821 int cnt;
822 u_int16_t minport, maxport;
823 u_int16_t lport, *lastport;
824 int wild = 0;
825 void *t;
826
827 /* XXX: this is redundant when called from in6_pcbbind */
828 if ((so->so_options & (SO_REUSEADDR|SO_REUSEPORT)) == 0 &&
829 ((so->so_proto->pr_flags & PR_CONNREQUIRED) == 0 ||
830 (so->so_options & SO_ACCEPTCONN) == 0))
831 wild = 1;
832
833 if (in6p->in6p_flags & IN6P_LOWPORT) {
834 #ifndef IPNOPRIVPORTS
835 if (l == 0 || (kauth_authorize_generic(l->l_cred,
836 KAUTH_GENERIC_ISSUSER, NULL) != 0))
837 return (EACCES);
838 #endif
839 minport = ip6_lowportmin;
840 maxport = ip6_lowportmax;
841 lastport = &table->inpt_lastlow;
842 } else {
843 minport = ip6_anonportmin;
844 maxport = ip6_anonportmax;
845 lastport = &table->inpt_lastport;
846 }
847
848 if (minport > maxport) { /* sanity check */
849 u_int16_t swp;
850
851 swp = minport;
852 minport = maxport;
853 maxport = swp;
854 }
855
856 lport = *lastport - 1;
857 for (cnt = maxport - minport + 1; cnt; cnt--, lport--) {
858 if (lport < minport || lport > maxport)
859 lport = maxport;
860 #ifdef INET
861 if (IN6_IS_ADDR_V4MAPPED(laddr)) {
862 t = in_pcblookup_port(table,
863 *(struct in_addr *)&laddr->s6_addr32[3],
864 htons(lport), wild);
865 } else
866 #endif
867 {
868 t = in6_pcblookup_port(table, laddr, htons(lport),
869 wild);
870 }
871 if (t == 0)
872 goto found;
873 }
874
875 return (EAGAIN);
876
877 found:
878 in6p->in6p_flags |= IN6P_ANONPORT;
879 *lastport = lport;
880 in6p->in6p_lport = htons(lport);
881 in6_pcbstate(in6p, IN6P_BOUND);
882 return (0); /* success */
883 }
884
885 void
886 addrsel_policy_init(void)
887 {
888 init_policy_queue();
889
890 /* initialize the "last resort" policy */
891 bzero(&defaultaddrpolicy, sizeof(defaultaddrpolicy));
892 defaultaddrpolicy.label = ADDR_LABEL_NOTAPP;
893 }
894
895 static struct in6_addrpolicy *
896 lookup_addrsel_policy(struct sockaddr_in6 *key)
897 {
898 struct in6_addrpolicy *match = NULL;
899
900 match = match_addrsel_policy(key);
901
902 if (match == NULL)
903 match = &defaultaddrpolicy;
904 else
905 match->use++;
906
907 return (match);
908 }
909
910 /*
911 * Subroutines to manage the address selection policy table via sysctl.
912 */
913 struct walkarg {
914 size_t w_total;
915 size_t w_given;
916 void * w_where;
917 void *w_limit;
918 };
919
920 int
921 in6_src_sysctl(void *oldp, size_t *oldlenp, void *newp, size_t newlen)
922 {
923 int error = 0;
924 int s;
925
926 s = splsoftnet();
927
928 if (newp) {
929 error = EPERM;
930 goto end;
931 }
932 if (oldp && oldlenp == NULL) {
933 error = EINVAL;
934 goto end;
935 }
936 if (oldp || oldlenp) {
937 struct walkarg w;
938 size_t oldlen = *oldlenp;
939
940 memset(&w, 0, sizeof(w));
941 w.w_given = oldlen;
942 w.w_where = oldp;
943 if (oldp)
944 w.w_limit = (char *)oldp + oldlen;
945
946 error = walk_addrsel_policy(dump_addrsel_policyent, &w);
947
948 *oldlenp = w.w_total;
949 if (oldp && w.w_total > oldlen && error == 0)
950 error = ENOMEM;
951 }
952
953 end:
954 splx(s);
955
956 return (error);
957 }
958
959 int
960 in6_src_ioctl(u_long cmd, void *data)
961 {
962 int i;
963 struct in6_addrpolicy ent0;
964
965 if (cmd != SIOCAADDRCTL_POLICY && cmd != SIOCDADDRCTL_POLICY)
966 return (EOPNOTSUPP); /* check for safety */
967
968 ent0 = *(struct in6_addrpolicy *)data;
969
970 if (ent0.label == ADDR_LABEL_NOTAPP)
971 return (EINVAL);
972 /* check if the prefix mask is consecutive. */
973 if (in6_mask2len(&ent0.addrmask.sin6_addr, NULL) < 0)
974 return (EINVAL);
975 /* clear trailing garbages (if any) of the prefix address. */
976 for (i = 0; i < 4; i++) {
977 ent0.addr.sin6_addr.s6_addr32[i] &=
978 ent0.addrmask.sin6_addr.s6_addr32[i];
979 }
980 ent0.use = 0;
981
982 switch (cmd) {
983 case SIOCAADDRCTL_POLICY:
984 return (add_addrsel_policyent(&ent0));
985 case SIOCDADDRCTL_POLICY:
986 return (delete_addrsel_policyent(&ent0));
987 }
988
989 return (0); /* XXX: compromise compilers */
990 }
991
992 /*
993 * The followings are implementation of the policy table using a
994 * simple tail queue.
995 * XXX such details should be hidden.
996 * XXX implementation using binary tree should be more efficient.
997 */
998 struct addrsel_policyent {
999 TAILQ_ENTRY(addrsel_policyent) ape_entry;
1000 struct in6_addrpolicy ape_policy;
1001 };
1002
1003 TAILQ_HEAD(addrsel_policyhead, addrsel_policyent);
1004
1005 struct addrsel_policyhead addrsel_policytab;
1006
1007 static void
1008 init_policy_queue(void)
1009 {
1010 TAILQ_INIT(&addrsel_policytab);
1011 }
1012
1013 static int
1014 add_addrsel_policyent(struct in6_addrpolicy *newpolicy)
1015 {
1016 struct addrsel_policyent *new, *pol;
1017
1018 /* duplication check */
1019 for (pol = TAILQ_FIRST(&addrsel_policytab); pol;
1020 pol = TAILQ_NEXT(pol, ape_entry)) {
1021 if (IN6_ARE_ADDR_EQUAL(&newpolicy->addr.sin6_addr,
1022 &pol->ape_policy.addr.sin6_addr) &&
1023 IN6_ARE_ADDR_EQUAL(&newpolicy->addrmask.sin6_addr,
1024 &pol->ape_policy.addrmask.sin6_addr)) {
1025 return (EEXIST); /* or override it? */
1026 }
1027 }
1028
1029 MALLOC(new, struct addrsel_policyent *, sizeof(*new), M_IFADDR,
1030 M_WAITOK);
1031 bzero(new, sizeof(*new));
1032
1033 /* XXX: should validate entry */
1034 new->ape_policy = *newpolicy;
1035
1036 TAILQ_INSERT_TAIL(&addrsel_policytab, new, ape_entry);
1037
1038 return (0);
1039 }
1040
1041 static int
1042 delete_addrsel_policyent(struct in6_addrpolicy *key)
1043 {
1044 struct addrsel_policyent *pol;
1045
1046 /* search for the entry in the table */
1047 for (pol = TAILQ_FIRST(&addrsel_policytab); pol;
1048 pol = TAILQ_NEXT(pol, ape_entry)) {
1049 if (IN6_ARE_ADDR_EQUAL(&key->addr.sin6_addr,
1050 &pol->ape_policy.addr.sin6_addr) &&
1051 IN6_ARE_ADDR_EQUAL(&key->addrmask.sin6_addr,
1052 &pol->ape_policy.addrmask.sin6_addr)) {
1053 break;
1054 }
1055 }
1056 if (pol == NULL) {
1057 return (ESRCH);
1058 }
1059
1060 TAILQ_REMOVE(&addrsel_policytab, pol, ape_entry);
1061
1062 return (0);
1063 }
1064
1065 static int
1066 walk_addrsel_policy(int (*callback)(struct in6_addrpolicy *, void *), void *w)
1067 {
1068 struct addrsel_policyent *pol;
1069 int error = 0;
1070
1071 TAILQ_FOREACH(pol, &addrsel_policytab, ape_entry) {
1072 if ((error = (*callback)(&pol->ape_policy, w)) != 0)
1073 return error;
1074 }
1075
1076 return error;
1077 }
1078
1079 static int
1080 dump_addrsel_policyent(struct in6_addrpolicy *pol, void *arg)
1081 {
1082 int error = 0;
1083 struct walkarg *w = arg;
1084
1085 if (w->w_where && (char *)w->w_where + sizeof(*pol) <= (char *)w->w_limit) {
1086 if ((error = copyout(pol, w->w_where, sizeof(*pol))) != 0)
1087 return error;
1088 w->w_where = (char *)w->w_where + sizeof(*pol);
1089 }
1090 w->w_total += sizeof(*pol);
1091
1092 return error;
1093 }
1094
1095 static struct in6_addrpolicy *
1096 match_addrsel_policy(struct sockaddr_in6 *key)
1097 {
1098 struct addrsel_policyent *pent;
1099 struct in6_addrpolicy *bestpol = NULL, *pol;
1100 int matchlen, bestmatchlen = -1;
1101 u_char *mp, *ep, *k, *p, m;
1102
1103 for (pent = TAILQ_FIRST(&addrsel_policytab); pent;
1104 pent = TAILQ_NEXT(pent, ape_entry)) {
1105 matchlen = 0;
1106
1107 pol = &pent->ape_policy;
1108 mp = (u_char *)&pol->addrmask.sin6_addr;
1109 ep = mp + 16; /* XXX: scope field? */
1110 k = (u_char *)&key->sin6_addr;
1111 p = (u_char *)&pol->addr.sin6_addr;
1112 for (; mp < ep && *mp; mp++, k++, p++) {
1113 m = *mp;
1114 if ((*k & m) != *p)
1115 goto next; /* not match */
1116 if (m == 0xff) /* short cut for a typical case */
1117 matchlen += 8;
1118 else {
1119 while (m >= 0x80) {
1120 matchlen++;
1121 m <<= 1;
1122 }
1123 }
1124 }
1125
1126 /* matched. check if this is better than the current best. */
1127 if (bestpol == NULL ||
1128 matchlen > bestmatchlen) {
1129 bestpol = pol;
1130 bestmatchlen = matchlen;
1131 }
1132
1133 next:
1134 continue;
1135 }
1136
1137 return (bestpol);
1138 }
Cache object: 3fc2d57bc037b48f11e50e8fedd769e0
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