1 /* $KAME: name6.c,v 1.25 2000/06/26 16:44:40 itojun Exp $ */
2
3 /*
4 * Copyright (C) 1995, 1996, 1997, 1998, and 1999 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 * ++Copyright++ 1985, 1988, 1993
33 * -
34 * Copyright (c) 1985, 1988, 1993
35 * The Regents of the University of California. All rights reserved.
36 *
37 * Redistribution and use in source and binary forms, with or without
38 * modification, are permitted provided that the following conditions
39 * are met:
40 * 1. Redistributions of source code must retain the above copyright
41 * notice, this list of conditions and the following disclaimer.
42 * 2. Redistributions in binary form must reproduce the above copyright
43 * notice, this list of conditions and the following disclaimer in the
44 * documentation and/or other materials provided with the distribution.
45 * 3. Neither the name of the University nor the names of its contributors
46 * may be used to endorse or promote products derived from this software
47 * without specific prior written permission.
48 *
49 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
50 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
51 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
52 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
53 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
54 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
55 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
56 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
57 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
58 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
59 * SUCH DAMAGE.
60 * -
61 * Portions Copyright (c) 1993 by Digital Equipment Corporation.
62 *
63 * Permission to use, copy, modify, and distribute this software for any
64 * purpose with or without fee is hereby granted, provided that the above
65 * copyright notice and this permission notice appear in all copies, and that
66 * the name of Digital Equipment Corporation not be used in advertising or
67 * publicity pertaining to distribution of the document or software without
68 * specific, written prior permission.
69 *
70 * THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL
71 * WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES
72 * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL DIGITAL EQUIPMENT
73 * CORPORATION BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
74 * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
75 * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
76 * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
77 * SOFTWARE.
78 * -
79 * --Copyright--
80 */
81
82 /*
83 * Atsushi Onoe <onoe@sm.sony.co.jp>
84 */
85
86 #include <sys/cdefs.h>
87 __FBSDID("$FreeBSD$");
88
89 #include "namespace.h"
90 #include <sys/param.h>
91 #include <sys/socket.h>
92 #include <sys/time.h>
93 #include <sys/queue.h>
94 #include <netinet/in.h>
95 #ifdef INET6
96 #include <net/if.h>
97 #include <net/if_var.h>
98 #include <sys/sysctl.h>
99 #include <sys/ioctl.h>
100 #include <netinet6/in6_var.h> /* XXX */
101 #endif
102
103 #include <arpa/inet.h>
104 #include <arpa/nameser.h>
105
106 #include <errno.h>
107 #include <netdb.h>
108 #include <resolv.h>
109 #include <stdio.h>
110 #include <stdlib.h>
111 #include <string.h>
112 #include <stdarg.h>
113 #include <nsswitch.h>
114 #include <unistd.h>
115 #include "un-namespace.h"
116 #include "netdb_private.h"
117 #include "res_private.h"
118
119 #ifndef MAXALIASES
120 #define MAXALIASES 10
121 #endif
122 #ifndef MAXADDRS
123 #define MAXADDRS 20
124 #endif
125 #ifndef MAXDNAME
126 #define MAXDNAME 1025
127 #endif
128
129 #ifdef INET6
130 #define ADDRLEN(af) ((af) == AF_INET6 ? sizeof(struct in6_addr) : \
131 sizeof(struct in_addr))
132 #else
133 #define ADDRLEN(af) sizeof(struct in_addr)
134 #endif
135
136 #define MAPADDR(ab, ina) \
137 do { \
138 memcpy(&(ab)->map_inaddr, ina, sizeof(struct in_addr)); \
139 memset((ab)->map_zero, 0, sizeof((ab)->map_zero)); \
140 memset((ab)->map_one, 0xff, sizeof((ab)->map_one)); \
141 } while (0)
142 #define MAPADDRENABLED(flags) \
143 (((flags) & AI_V4MAPPED) || \
144 (((flags) & AI_V4MAPPED_CFG)))
145
146 union inx_addr {
147 struct in_addr in_addr;
148 #ifdef INET6
149 struct in6_addr in6_addr;
150 #endif
151 struct {
152 u_char mau_zero[10];
153 u_char mau_one[2];
154 struct in_addr mau_inaddr;
155 } map_addr_un;
156 #define map_zero map_addr_un.mau_zero
157 #define map_one map_addr_un.mau_one
158 #define map_inaddr map_addr_un.mau_inaddr
159 };
160
161 struct policyqueue {
162 TAILQ_ENTRY(policyqueue) pc_entry;
163 #ifdef INET6
164 struct in6_addrpolicy pc_policy;
165 #endif
166 };
167 TAILQ_HEAD(policyhead, policyqueue);
168
169 #define AIO_SRCFLAG_DEPRECATED 0x1
170
171 struct hp_order {
172 union {
173 struct sockaddr_storage aiou_ss;
174 struct sockaddr aiou_sa;
175 } aio_src_un;
176 #define aio_srcsa aio_src_un.aiou_sa
177 u_int32_t aio_srcflag;
178 int aio_srcscope;
179 int aio_dstscope;
180 struct policyqueue *aio_srcpolicy;
181 struct policyqueue *aio_dstpolicy;
182 union {
183 struct sockaddr_storage aiou_ss;
184 struct sockaddr aiou_sa;
185 } aio_un;
186 #define aio_sa aio_un.aiou_sa
187 int aio_matchlen;
188 char *aio_h_addr;
189 };
190
191 static struct hostent *_hpcopy(struct hostent *, int *);
192 static struct hostent *_hpaddr(int, const char *, void *, int *);
193 #ifdef INET6
194 static struct hostent *_hpmerge(struct hostent *, struct hostent *, int *);
195 static struct hostent *_hpmapv6(struct hostent *, int *);
196 #endif
197 static struct hostent *_hpsort(struct hostent *, res_state);
198
199 #ifdef INET6
200 static struct hostent *_hpreorder(struct hostent *);
201 static int get_addrselectpolicy(struct policyhead *);
202 static void free_addrselectpolicy(struct policyhead *);
203 static struct policyqueue *match_addrselectpolicy(struct sockaddr *,
204 struct policyhead *);
205 static void set_source(struct hp_order *, struct policyhead *);
206 static int matchlen(struct sockaddr *, struct sockaddr *);
207 static int comp_dst(const void *, const void *);
208 static int gai_addr2scopetype(struct sockaddr *);
209 #endif
210
211 /*
212 * Functions defined in RFC2553
213 * getipnodebyname, getipnodebyaddr, freehostent
214 */
215
216 struct hostent *
getipnodebyname(const char * name,int af,int flags,int * errp)217 getipnodebyname(const char *name, int af, int flags, int *errp)
218 {
219 struct hostent *hp;
220 union inx_addr addrbuf;
221 res_state statp;
222 u_long options;
223
224 switch (af) {
225 case AF_INET:
226 #ifdef INET6
227 case AF_INET6:
228 #endif
229 break;
230 default:
231 *errp = NO_RECOVERY;
232 return NULL;
233 }
234
235 if (flags & AI_ADDRCONFIG) {
236 int s;
237
238 if ((s = _socket(af, SOCK_DGRAM | SOCK_CLOEXEC, 0)) < 0)
239 return NULL;
240 /*
241 * TODO:
242 * Note that implementation dependent test for address
243 * configuration should be done everytime called
244 * (or apropriate interval),
245 * because addresses will be dynamically assigned or deleted.
246 */
247 _close(s);
248 }
249
250 #ifdef INET6
251 /* special case for literal address */
252 if (inet_pton(AF_INET6, name, &addrbuf) == 1) {
253 if (af != AF_INET6) {
254 *errp = HOST_NOT_FOUND;
255 return NULL;
256 }
257 return _hpaddr(af, name, &addrbuf, errp);
258 }
259 #endif
260 if (inet_aton(name, (struct in_addr *)&addrbuf) == 1) {
261 if (af != AF_INET) {
262 if (MAPADDRENABLED(flags)) {
263 MAPADDR(&addrbuf, &addrbuf.in_addr);
264 } else {
265 *errp = HOST_NOT_FOUND;
266 return NULL;
267 }
268 }
269 return _hpaddr(af, name, &addrbuf, errp);
270 }
271
272
273 statp = __res_state();
274 if ((statp->options & RES_INIT) == 0) {
275 if (res_ninit(statp) < 0) {
276 *errp = NETDB_INTERNAL;
277 return NULL;
278 }
279 }
280
281 options = statp->options;
282 statp->options &= ~RES_USE_INET6;
283
284 hp = gethostbyname2(name, af);
285 hp = _hpcopy(hp, errp);
286 #ifdef INET6
287 if (af == AF_INET6)
288 hp = _hpreorder(hp);
289
290 if (af == AF_INET6 && ((flags & AI_ALL) || hp == NULL) &&
291 MAPADDRENABLED(flags)) {
292 struct hostent *hp2 = gethostbyname2(name, AF_INET);
293 if (hp == NULL)
294 if (hp2 == NULL)
295 *errp = statp->res_h_errno;
296 else
297 hp = _hpmapv6(hp2, errp);
298 else {
299 if (hp2 && strcmp(hp->h_name, hp2->h_name) == 0) {
300 struct hostent *hpb = hp;
301 hp = _hpmerge(hpb, hp2, errp);
302 freehostent(hpb);
303 }
304 }
305 }
306 #endif
307
308 if (hp == NULL)
309 *errp = statp->res_h_errno;
310
311 statp->options = options;
312 return _hpsort(hp, statp);
313 }
314
315 struct hostent *
getipnodebyaddr(const void * src,size_t len,int af,int * errp)316 getipnodebyaddr(const void *src, size_t len, int af, int *errp)
317 {
318 struct hostent *hp;
319 res_state statp;
320 u_long options;
321
322 #ifdef INET6
323 struct in6_addr addrbuf;
324 #else
325 struct in_addr addrbuf;
326 #endif
327
328 switch (af) {
329 case AF_INET:
330 if (len != sizeof(struct in_addr)) {
331 *errp = NO_RECOVERY;
332 return NULL;
333 }
334 if ((long)src & ~(sizeof(struct in_addr) - 1)) {
335 memcpy(&addrbuf, src, len);
336 src = &addrbuf;
337 }
338 if (((struct in_addr *)src)->s_addr == 0)
339 return NULL;
340 break;
341 #ifdef INET6
342 case AF_INET6:
343 if (len != sizeof(struct in6_addr)) {
344 *errp = NO_RECOVERY;
345 return NULL;
346 }
347 if ((long)src & ~(sizeof(struct in6_addr) / 2 - 1)) { /*XXX*/
348 memcpy(&addrbuf, src, len);
349 src = &addrbuf;
350 }
351 if (IN6_IS_ADDR_UNSPECIFIED((struct in6_addr *)src))
352 return NULL;
353 if (IN6_IS_ADDR_V4MAPPED((struct in6_addr *)src)
354 || IN6_IS_ADDR_V4COMPAT((struct in6_addr *)src)) {
355 src = (char *)src +
356 (sizeof(struct in6_addr) - sizeof(struct in_addr));
357 af = AF_INET;
358 len = sizeof(struct in_addr);
359 }
360 break;
361 #endif
362 default:
363 *errp = NO_RECOVERY;
364 return NULL;
365 }
366
367 statp = __res_state();
368 if ((statp->options & RES_INIT) == 0) {
369 if (res_ninit(statp) < 0) {
370 RES_SET_H_ERRNO(statp, NETDB_INTERNAL);
371 return NULL;
372 }
373 }
374
375 options = statp->options;
376 statp->options &= ~RES_USE_INET6;
377
378 hp = gethostbyaddr(src, len, af);
379 if (hp == NULL)
380 *errp = statp->res_h_errno;
381
382 statp->options = options;
383 return (_hpcopy(hp, errp));
384 }
385
386 void
freehostent(struct hostent * ptr)387 freehostent(struct hostent *ptr)
388 {
389 free(ptr);
390 }
391
392 /*
393 * Private utility functions
394 */
395
396 /*
397 * _hpcopy: allocate and copy hostent structure
398 */
399 static struct hostent *
_hpcopy(struct hostent * hp,int * errp)400 _hpcopy(struct hostent *hp, int *errp)
401 {
402 struct hostent *nhp;
403 char *cp, **pp;
404 int size, addrsize;
405 int nalias = 0, naddr = 0;
406 int al_off;
407 int i;
408
409 if (hp == NULL)
410 return hp;
411
412 /* count size to be allocated */
413 size = sizeof(struct hostent);
414 if (hp->h_name != NULL)
415 size += strlen(hp->h_name) + 1;
416 if ((pp = hp->h_aliases) != NULL) {
417 for (i = 0; *pp != NULL; i++, pp++) {
418 if (**pp != '\0') {
419 size += strlen(*pp) + 1;
420 nalias++;
421 }
422 }
423 }
424 /* adjust alignment */
425 size = ALIGN(size);
426 al_off = size;
427 size += sizeof(char *) * (nalias + 1);
428 addrsize = ALIGN(hp->h_length);
429 if ((pp = hp->h_addr_list) != NULL) {
430 while (*pp++ != NULL)
431 naddr++;
432 }
433 size += addrsize * naddr;
434 size += sizeof(char *) * (naddr + 1);
435
436 /* copy */
437 if ((nhp = (struct hostent *)malloc(size)) == NULL) {
438 *errp = TRY_AGAIN;
439 return NULL;
440 }
441 cp = (char *)&nhp[1];
442 if (hp->h_name != NULL) {
443 nhp->h_name = cp;
444 strcpy(cp, hp->h_name);
445 cp += strlen(cp) + 1;
446 } else
447 nhp->h_name = NULL;
448 nhp->h_aliases = (char **)((char *)nhp + al_off);
449 if ((pp = hp->h_aliases) != NULL) {
450 for (i = 0; *pp != NULL; pp++) {
451 if (**pp != '\0') {
452 nhp->h_aliases[i++] = cp;
453 strcpy(cp, *pp);
454 cp += strlen(cp) + 1;
455 }
456 }
457 }
458 nhp->h_aliases[nalias] = NULL;
459 cp = (char *)&nhp->h_aliases[nalias + 1];
460 nhp->h_addrtype = hp->h_addrtype;
461 nhp->h_length = hp->h_length;
462 nhp->h_addr_list = (char **)cp;
463 if ((pp = hp->h_addr_list) != NULL) {
464 cp = (char *)&nhp->h_addr_list[naddr + 1];
465 for (i = 0; *pp != NULL; pp++) {
466 nhp->h_addr_list[i++] = cp;
467 memcpy(cp, *pp, hp->h_length);
468 cp += addrsize;
469 }
470 }
471 nhp->h_addr_list[naddr] = NULL;
472 return nhp;
473 }
474
475 /*
476 * _hpaddr: construct hostent structure with one address
477 */
478 static struct hostent *
_hpaddr(int af,const char * name,void * addr,int * errp)479 _hpaddr(int af, const char *name, void *addr, int *errp)
480 {
481 struct hostent *hp, hpbuf;
482 char *addrs[2];
483
484 hp = &hpbuf;
485 hp->h_name = (char *)name;
486 hp->h_aliases = NULL;
487 hp->h_addrtype = af;
488 hp->h_length = ADDRLEN(af);
489 hp->h_addr_list = addrs;
490 addrs[0] = (char *)addr;
491 addrs[1] = NULL;
492 return (_hpcopy(hp, errp));
493 }
494
495 #ifdef INET6
496 /*
497 * _hpmerge: merge 2 hostent structure, arguments will be freed
498 */
499 static struct hostent *
_hpmerge(struct hostent * hp1,struct hostent * hp2,int * errp)500 _hpmerge(struct hostent *hp1, struct hostent *hp2, int *errp)
501 {
502 int i, j;
503 int naddr, nalias;
504 char **pp;
505 struct hostent *hp, hpbuf;
506 char *aliases[MAXALIASES + 1], *addrs[MAXADDRS + 1];
507 union inx_addr addrbuf[MAXADDRS];
508
509 if (hp1 == NULL)
510 return _hpcopy(hp2, errp);
511 if (hp2 == NULL)
512 return _hpcopy(hp1, errp);
513
514 #define HP(i) (i == 1 ? hp1 : hp2)
515 hp = &hpbuf;
516 hp->h_name = (hp1->h_name != NULL ? hp1->h_name : hp2->h_name);
517 hp->h_aliases = aliases;
518 nalias = 0;
519 for (i = 1; i <= 2; i++) {
520 if ((pp = HP(i)->h_aliases) == NULL)
521 continue;
522 for (; nalias < MAXALIASES && *pp != NULL; pp++) {
523 /* check duplicates */
524 for (j = 0; j < nalias; j++)
525 if (strcasecmp(*pp, aliases[j]) == 0)
526 break;
527 if (j == nalias)
528 aliases[nalias++] = *pp;
529 }
530 }
531 aliases[nalias] = NULL;
532 if (hp1->h_length != hp2->h_length) {
533 hp->h_addrtype = AF_INET6;
534 hp->h_length = sizeof(struct in6_addr);
535 } else {
536 hp->h_addrtype = hp1->h_addrtype;
537 hp->h_length = hp1->h_length;
538 }
539
540 hp->h_addr_list = addrs;
541 naddr = 0;
542 for (i = 1; i <= 2; i++) {
543 if ((pp = HP(i)->h_addr_list) == NULL)
544 continue;
545 if (HP(i)->h_length == hp->h_length) {
546 while (naddr < MAXADDRS && *pp != NULL)
547 addrs[naddr++] = *pp++;
548 } else {
549 /* copy IPv4 addr as mapped IPv6 addr */
550 while (naddr < MAXADDRS && *pp != NULL) {
551 MAPADDR(&addrbuf[naddr], *pp++);
552 addrs[naddr] = (char *)&addrbuf[naddr];
553 naddr++;
554 }
555 }
556 }
557 addrs[naddr] = NULL;
558 return (_hpcopy(hp, errp));
559 }
560 #endif
561
562 /*
563 * _hpmapv6: convert IPv4 hostent into IPv4-mapped IPv6 addresses
564 */
565 #ifdef INET6
566 static struct hostent *
_hpmapv6(struct hostent * hp,int * errp)567 _hpmapv6(struct hostent *hp, int *errp)
568 {
569 struct hostent hp6;
570
571 if (hp == NULL)
572 return NULL;
573 if (hp->h_addrtype == AF_INET6)
574 return _hpcopy(hp, errp);
575
576 memset(&hp6, 0, sizeof(struct hostent));
577 hp6.h_addrtype = AF_INET6;
578 hp6.h_length = sizeof(struct in6_addr);
579 return _hpmerge(&hp6, hp, errp);
580 }
581 #endif
582
583 /*
584 * _hpsort: sort address by sortlist
585 */
586 static struct hostent *
_hpsort(struct hostent * hp,res_state statp)587 _hpsort(struct hostent *hp, res_state statp)
588 {
589 int i, j, n;
590 u_char *ap, *sp, *mp, **pp;
591 char t;
592 char order[MAXADDRS];
593 int nsort = statp->nsort;
594
595 if (hp == NULL || hp->h_addr_list[1] == NULL || nsort == 0)
596 return hp;
597 for (i = 0; (ap = (u_char *)hp->h_addr_list[i]); i++) {
598 for (j = 0; j < nsort; j++) {
599 #ifdef INET6
600 if (statp->_u._ext.ext->sort_list[j].af !=
601 hp->h_addrtype)
602 continue;
603 sp = (u_char *)&statp->_u._ext.ext->sort_list[j].addr;
604 mp = (u_char *)&statp->_u._ext.ext->sort_list[j].mask;
605 #else
606 sp = (u_char *)&statp->sort_list[j].addr;
607 mp = (u_char *)&statp->sort_list[j].mask;
608 #endif
609 for (n = 0; n < hp->h_length; n++) {
610 if ((ap[n] & mp[n]) != sp[n])
611 break;
612 }
613 if (n == hp->h_length)
614 break;
615 }
616 order[i] = j;
617 }
618 n = i;
619 pp = (u_char **)hp->h_addr_list;
620 for (i = 0; i < n - 1; i++) {
621 for (j = i + 1; j < n; j++) {
622 if (order[i] > order[j]) {
623 ap = pp[i];
624 pp[i] = pp[j];
625 pp[j] = ap;
626 t = order[i];
627 order[i] = order[j];
628 order[j] = t;
629 }
630 }
631 }
632 return hp;
633 }
634
635 #ifdef INET6
636 /*
637 * _hpreorder: sort address by default address selection
638 */
639 static struct hostent *
_hpreorder(struct hostent * hp)640 _hpreorder(struct hostent *hp)
641 {
642 struct hp_order *aio;
643 int i, n;
644 char *ap;
645 struct sockaddr *sa;
646 struct policyhead policyhead;
647
648 if (hp == NULL)
649 return hp;
650
651 switch (hp->h_addrtype) {
652 case AF_INET:
653 #ifdef INET6
654 case AF_INET6:
655 #endif
656 break;
657 default:
658 free_addrselectpolicy(&policyhead);
659 return hp;
660 }
661
662 /* count the number of addrinfo elements for sorting. */
663 for (n = 0; hp->h_addr_list[n] != NULL; n++)
664 ;
665
666 /*
667 * If the number is small enough, we can skip the reordering process.
668 */
669 if (n <= 1)
670 return hp;
671
672 /* allocate a temporary array for sort and initialization of it. */
673 if ((aio = malloc(sizeof(*aio) * n)) == NULL)
674 return hp; /* give up reordering */
675 memset(aio, 0, sizeof(*aio) * n);
676
677 /* retrieve address selection policy from the kernel */
678 TAILQ_INIT(&policyhead);
679 if (!get_addrselectpolicy(&policyhead)) {
680 /* no policy is installed into kernel, we don't sort. */
681 free(aio);
682 return hp;
683 }
684
685 for (i = 0; i < n; i++) {
686 ap = hp->h_addr_list[i];
687 aio[i].aio_h_addr = ap;
688 sa = &aio[i].aio_sa;
689 switch (hp->h_addrtype) {
690 case AF_INET:
691 sa->sa_family = AF_INET;
692 sa->sa_len = sizeof(struct sockaddr_in);
693 memcpy(&((struct sockaddr_in *)sa)->sin_addr, ap,
694 sizeof(struct in_addr));
695 break;
696 #ifdef INET6
697 case AF_INET6:
698 if (IN6_IS_ADDR_V4MAPPED((struct in6_addr *)ap)) {
699 sa->sa_family = AF_INET;
700 sa->sa_len = sizeof(struct sockaddr_in);
701 memcpy(&((struct sockaddr_in *)sa)->sin_addr,
702 &ap[12], sizeof(struct in_addr));
703 } else {
704 sa->sa_family = AF_INET6;
705 sa->sa_len = sizeof(struct sockaddr_in6);
706 memcpy(&((struct sockaddr_in6 *)sa)->sin6_addr,
707 ap, sizeof(struct in6_addr));
708 }
709 break;
710 #endif
711 }
712 aio[i].aio_dstscope = gai_addr2scopetype(sa);
713 aio[i].aio_dstpolicy = match_addrselectpolicy(sa, &policyhead);
714 set_source(&aio[i], &policyhead);
715 }
716
717 /* perform sorting. */
718 qsort(aio, n, sizeof(*aio), comp_dst);
719
720 /* reorder the h_addr_list. */
721 for (i = 0; i < n; i++)
722 hp->h_addr_list[i] = aio[i].aio_h_addr;
723
724 /* cleanup and return */
725 free(aio);
726 free_addrselectpolicy(&policyhead);
727 return hp;
728 }
729
730 static int
get_addrselectpolicy(struct policyhead * head)731 get_addrselectpolicy(struct policyhead *head)
732 {
733 #ifdef INET6
734 int mib[] = { CTL_NET, PF_INET6, IPPROTO_IPV6, IPV6CTL_ADDRCTLPOLICY };
735 size_t l;
736 char *buf;
737 struct in6_addrpolicy *pol, *ep;
738
739 if (sysctl(mib, sizeof(mib) / sizeof(mib[0]), NULL, &l, NULL, 0) < 0)
740 return (0);
741 if ((buf = malloc(l)) == NULL)
742 return (0);
743 if (sysctl(mib, sizeof(mib) / sizeof(mib[0]), buf, &l, NULL, 0) < 0) {
744 free(buf);
745 return (0);
746 }
747
748 ep = (struct in6_addrpolicy *)(buf + l);
749 for (pol = (struct in6_addrpolicy *)buf; pol + 1 <= ep; pol++) {
750 struct policyqueue *new;
751
752 if ((new = malloc(sizeof(*new))) == NULL) {
753 free_addrselectpolicy(head); /* make the list empty */
754 break;
755 }
756 new->pc_policy = *pol;
757 TAILQ_INSERT_TAIL(head, new, pc_entry);
758 }
759
760 free(buf);
761 return (1);
762 #else
763 return (0);
764 #endif
765 }
766
767 static void
free_addrselectpolicy(struct policyhead * head)768 free_addrselectpolicy(struct policyhead *head)
769 {
770 struct policyqueue *ent, *nent;
771
772 for (ent = TAILQ_FIRST(head); ent; ent = nent) {
773 nent = TAILQ_NEXT(ent, pc_entry);
774 TAILQ_REMOVE(head, ent, pc_entry);
775 free(ent);
776 }
777 }
778
779 static struct policyqueue *
match_addrselectpolicy(struct sockaddr * addr,struct policyhead * head)780 match_addrselectpolicy(struct sockaddr *addr, struct policyhead *head)
781 {
782 #ifdef INET6
783 struct policyqueue *ent, *bestent = NULL;
784 struct in6_addrpolicy *pol;
785 int matchlen, bestmatchlen = -1;
786 u_char *mp, *ep, *k, *p, m;
787 struct sockaddr_in6 key;
788
789 switch(addr->sa_family) {
790 case AF_INET6:
791 key = *(struct sockaddr_in6 *)addr;
792 break;
793 case AF_INET:
794 /* convert the address into IPv4-mapped IPv6 address. */
795 memset(&key, 0, sizeof(key));
796 key.sin6_family = AF_INET6;
797 key.sin6_len = sizeof(key);
798 key.sin6_addr.s6_addr[10] = 0xff;
799 key.sin6_addr.s6_addr[11] = 0xff;
800 memcpy(&key.sin6_addr.s6_addr[12],
801 &((struct sockaddr_in *)addr)->sin_addr, 4);
802 break;
803 default:
804 return(NULL);
805 }
806
807 for (ent = TAILQ_FIRST(head); ent; ent = TAILQ_NEXT(ent, pc_entry)) {
808 pol = &ent->pc_policy;
809 matchlen = 0;
810
811 mp = (u_char *)&pol->addrmask.sin6_addr;
812 ep = mp + 16; /* XXX: scope field? */
813 k = (u_char *)&key.sin6_addr;
814 p = (u_char *)&pol->addr.sin6_addr;
815 for (; mp < ep && *mp; mp++, k++, p++) {
816 m = *mp;
817 if ((*k & m) != *p)
818 goto next; /* not match */
819 if (m == 0xff) /* short cut for a typical case */
820 matchlen += 8;
821 else {
822 while (m >= 0x80) {
823 matchlen++;
824 m <<= 1;
825 }
826 }
827 }
828
829 /* matched. check if this is better than the current best. */
830 if (matchlen > bestmatchlen) {
831 bestent = ent;
832 bestmatchlen = matchlen;
833 }
834
835 next:
836 continue;
837 }
838
839 return(bestent);
840 #else
841 return(NULL);
842 #endif
843
844 }
845
846 static void
set_source(struct hp_order * aio,struct policyhead * ph)847 set_source(struct hp_order *aio, struct policyhead *ph)
848 {
849 struct sockaddr_storage ss = aio->aio_un.aiou_ss;
850 socklen_t srclen;
851 int s;
852
853 /* set unspec ("no source is available"), just in case */
854 aio->aio_srcsa.sa_family = AF_UNSPEC;
855 aio->aio_srcscope = -1;
856
857 switch(ss.ss_family) {
858 case AF_INET:
859 ((struct sockaddr_in *)&ss)->sin_port = htons(1);
860 break;
861 #ifdef INET6
862 case AF_INET6:
863 ((struct sockaddr_in6 *)&ss)->sin6_port = htons(1);
864 break;
865 #endif
866 default: /* ignore unsupported AFs explicitly */
867 return;
868 }
869
870 /* open a socket to get the source address for the given dst */
871 if ((s = _socket(ss.ss_family, SOCK_DGRAM | SOCK_CLOEXEC,
872 IPPROTO_UDP)) < 0)
873 return; /* give up */
874 if (_connect(s, (struct sockaddr *)&ss, ss.ss_len) < 0)
875 goto cleanup;
876 srclen = ss.ss_len;
877 if (_getsockname(s, &aio->aio_srcsa, &srclen) < 0) {
878 aio->aio_srcsa.sa_family = AF_UNSPEC;
879 goto cleanup;
880 }
881 aio->aio_srcscope = gai_addr2scopetype(&aio->aio_srcsa);
882 aio->aio_srcpolicy = match_addrselectpolicy(&aio->aio_srcsa, ph);
883 aio->aio_matchlen = matchlen(&aio->aio_srcsa, (struct sockaddr *)&ss);
884 #ifdef INET6
885 if (ss.ss_family == AF_INET6) {
886 struct in6_ifreq ifr6;
887 u_int32_t flags6;
888
889 memset(&ifr6, 0, sizeof(ifr6));
890 memcpy(&ifr6.ifr_addr, &ss, ss.ss_len);
891 if (_ioctl(s, SIOCGIFAFLAG_IN6, &ifr6) == 0) {
892 flags6 = ifr6.ifr_ifru.ifru_flags6;
893 if ((flags6 & IN6_IFF_DEPRECATED))
894 aio->aio_srcflag |= AIO_SRCFLAG_DEPRECATED;
895 }
896 }
897 #endif
898
899 cleanup:
900 _close(s);
901 return;
902 }
903
904 static int
matchlen(struct sockaddr * src,struct sockaddr * dst)905 matchlen(struct sockaddr *src, struct sockaddr *dst)
906 {
907 int match = 0;
908 u_char *s, *d;
909 u_char *lim, r;
910 int addrlen;
911
912 switch (src->sa_family) {
913 #ifdef INET6
914 case AF_INET6:
915 s = (u_char *)&((struct sockaddr_in6 *)src)->sin6_addr;
916 d = (u_char *)&((struct sockaddr_in6 *)dst)->sin6_addr;
917 addrlen = sizeof(struct in6_addr);
918 lim = s + addrlen;
919 break;
920 #endif
921 case AF_INET:
922 s = (u_char *)&((struct sockaddr_in *)src)->sin_addr;
923 d = (u_char *)&((struct sockaddr_in *)dst)->sin_addr;
924 addrlen = sizeof(struct in_addr);
925 lim = s + addrlen;
926 break;
927 default:
928 return(0);
929 }
930
931 while (s < lim)
932 if ((r = (*d++ ^ *s++)) != 0) {
933 while (r < addrlen * 8) {
934 match++;
935 r <<= 1;
936 }
937 break;
938 } else
939 match += 8;
940 return(match);
941 }
942
943 static int
comp_dst(const void * arg1,const void * arg2)944 comp_dst(const void *arg1, const void *arg2)
945 {
946 const struct hp_order *dst1 = arg1, *dst2 = arg2;
947
948 /*
949 * Rule 1: Avoid unusable destinations.
950 * XXX: we currently do not consider if an appropriate route exists.
951 */
952 if (dst1->aio_srcsa.sa_family != AF_UNSPEC &&
953 dst2->aio_srcsa.sa_family == AF_UNSPEC) {
954 return(-1);
955 }
956 if (dst1->aio_srcsa.sa_family == AF_UNSPEC &&
957 dst2->aio_srcsa.sa_family != AF_UNSPEC) {
958 return(1);
959 }
960
961 /* Rule 2: Prefer matching scope. */
962 if (dst1->aio_dstscope == dst1->aio_srcscope &&
963 dst2->aio_dstscope != dst2->aio_srcscope) {
964 return(-1);
965 }
966 if (dst1->aio_dstscope != dst1->aio_srcscope &&
967 dst2->aio_dstscope == dst2->aio_srcscope) {
968 return(1);
969 }
970
971 /* Rule 3: Avoid deprecated addresses. */
972 if (dst1->aio_srcsa.sa_family != AF_UNSPEC &&
973 dst2->aio_srcsa.sa_family != AF_UNSPEC) {
974 if (!(dst1->aio_srcflag & AIO_SRCFLAG_DEPRECATED) &&
975 (dst2->aio_srcflag & AIO_SRCFLAG_DEPRECATED)) {
976 return(-1);
977 }
978 if ((dst1->aio_srcflag & AIO_SRCFLAG_DEPRECATED) &&
979 !(dst2->aio_srcflag & AIO_SRCFLAG_DEPRECATED)) {
980 return(1);
981 }
982 }
983
984 /* Rule 4: Prefer home addresses. */
985 /* XXX: not implemented yet */
986
987 /* Rule 5: Prefer matching label. */
988 #ifdef INET6
989 if (dst1->aio_srcpolicy && dst1->aio_dstpolicy &&
990 dst1->aio_srcpolicy->pc_policy.label ==
991 dst1->aio_dstpolicy->pc_policy.label &&
992 (dst2->aio_srcpolicy == NULL || dst2->aio_dstpolicy == NULL ||
993 dst2->aio_srcpolicy->pc_policy.label !=
994 dst2->aio_dstpolicy->pc_policy.label)) {
995 return(-1);
996 }
997 if (dst2->aio_srcpolicy && dst2->aio_dstpolicy &&
998 dst2->aio_srcpolicy->pc_policy.label ==
999 dst2->aio_dstpolicy->pc_policy.label &&
1000 (dst1->aio_srcpolicy == NULL || dst1->aio_dstpolicy == NULL ||
1001 dst1->aio_srcpolicy->pc_policy.label !=
1002 dst1->aio_dstpolicy->pc_policy.label)) {
1003 return(1);
1004 }
1005 #endif
1006
1007 /* Rule 6: Prefer higher precedence. */
1008 #ifdef INET6
1009 if (dst1->aio_dstpolicy &&
1010 (dst2->aio_dstpolicy == NULL ||
1011 dst1->aio_dstpolicy->pc_policy.preced >
1012 dst2->aio_dstpolicy->pc_policy.preced)) {
1013 return(-1);
1014 }
1015 if (dst2->aio_dstpolicy &&
1016 (dst1->aio_dstpolicy == NULL ||
1017 dst2->aio_dstpolicy->pc_policy.preced >
1018 dst1->aio_dstpolicy->pc_policy.preced)) {
1019 return(1);
1020 }
1021 #endif
1022
1023 /* Rule 7: Prefer native transport. */
1024 /* XXX: not implemented yet */
1025
1026 /* Rule 8: Prefer smaller scope. */
1027 if (dst1->aio_dstscope >= 0 &&
1028 dst1->aio_dstscope < dst2->aio_dstscope) {
1029 return(-1);
1030 }
1031 if (dst2->aio_dstscope >= 0 &&
1032 dst2->aio_dstscope < dst1->aio_dstscope) {
1033 return(1);
1034 }
1035
1036 /*
1037 * Rule 9: Use longest matching prefix.
1038 * We compare the match length in a same AF only.
1039 */
1040 if (dst1->aio_sa.sa_family == dst2->aio_sa.sa_family) {
1041 if (dst1->aio_matchlen > dst2->aio_matchlen) {
1042 return(-1);
1043 }
1044 if (dst1->aio_matchlen < dst2->aio_matchlen) {
1045 return(1);
1046 }
1047 }
1048
1049 /* Rule 10: Otherwise, leave the order unchanged. */
1050 return(-1);
1051 }
1052
1053 /*
1054 * Copy from scope.c.
1055 * XXX: we should standardize the functions and link them as standard
1056 * library.
1057 */
1058 static int
gai_addr2scopetype(struct sockaddr * sa)1059 gai_addr2scopetype(struct sockaddr *sa)
1060 {
1061 #ifdef INET6
1062 struct sockaddr_in6 *sa6;
1063 #endif
1064 struct sockaddr_in *sa4;
1065
1066 switch(sa->sa_family) {
1067 #ifdef INET6
1068 case AF_INET6:
1069 sa6 = (struct sockaddr_in6 *)sa;
1070 if (IN6_IS_ADDR_MULTICAST(&sa6->sin6_addr)) {
1071 /* just use the scope field of the multicast address */
1072 return(sa6->sin6_addr.s6_addr[2] & 0x0f);
1073 }
1074 /*
1075 * Unicast addresses: map scope type to corresponding scope
1076 * value defined for multcast addresses.
1077 * XXX: hardcoded scope type values are bad...
1078 */
1079 if (IN6_IS_ADDR_LOOPBACK(&sa6->sin6_addr))
1080 return(1); /* node local scope */
1081 if (IN6_IS_ADDR_LINKLOCAL(&sa6->sin6_addr))
1082 return(2); /* link-local scope */
1083 if (IN6_IS_ADDR_SITELOCAL(&sa6->sin6_addr))
1084 return(5); /* site-local scope */
1085 return(14); /* global scope */
1086 break;
1087 #endif
1088 case AF_INET:
1089 /*
1090 * IPv4 pseudo scoping according to RFC 3484.
1091 */
1092 sa4 = (struct sockaddr_in *)sa;
1093 /* IPv4 autoconfiguration addresses have link-local scope. */
1094 if (((u_char *)&sa4->sin_addr)[0] == 169 &&
1095 ((u_char *)&sa4->sin_addr)[1] == 254)
1096 return(2);
1097 /* Private addresses have site-local scope. */
1098 if (((u_char *)&sa4->sin_addr)[0] == 10 ||
1099 (((u_char *)&sa4->sin_addr)[0] == 172 &&
1100 (((u_char *)&sa4->sin_addr)[1] & 0xf0) == 16) ||
1101 (((u_char *)&sa4->sin_addr)[0] == 192 &&
1102 ((u_char *)&sa4->sin_addr)[1] == 168))
1103 return(14); /* XXX: It should be 5 unless NAT */
1104 /* Loopback addresses have link-local scope. */
1105 if (((u_char *)&sa4->sin_addr)[0] == 127)
1106 return(2);
1107 return(14);
1108 break;
1109 default:
1110 errno = EAFNOSUPPORT; /* is this a good error? */
1111 return(-1);
1112 }
1113 }
1114 #endif
1115