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 <sys/sysctl.h>
98 #include <sys/ioctl.h>
99 #include <netinet6/in6_var.h> /* XXX */
100 #endif
101
102 #include <arpa/inet.h>
103 #include <arpa/nameser.h>
104
105 #include <errno.h>
106 #include <netdb.h>
107 #include <resolv.h>
108 #include <stdio.h>
109 #include <stdlib.h>
110 #include <string.h>
111 #include <stdarg.h>
112 #include <nsswitch.h>
113 #include <unistd.h>
114 #include "un-namespace.h"
115 #include "netdb_private.h"
116 #include "res_private.h"
117
118 #ifndef MAXALIASES
119 #define MAXALIASES 10
120 #endif
121 #ifndef MAXADDRS
122 #define MAXADDRS 20
123 #endif
124 #ifndef MAXDNAME
125 #define MAXDNAME 1025
126 #endif
127
128 #ifdef INET6
129 #define ADDRLEN(af) ((af) == AF_INET6 ? sizeof(struct in6_addr) : \
130 sizeof(struct in_addr))
131 #else
132 #define ADDRLEN(af) sizeof(struct in_addr)
133 #endif
134
135 #define MAPADDR(ab, ina) \
136 do { \
137 memcpy(&(ab)->map_inaddr, ina, sizeof(struct in_addr)); \
138 memset((ab)->map_zero, 0, sizeof((ab)->map_zero)); \
139 memset((ab)->map_one, 0xff, sizeof((ab)->map_one)); \
140 } while (0)
141 #define MAPADDRENABLED(flags) \
142 (((flags) & AI_V4MAPPED) || \
143 (((flags) & AI_V4MAPPED_CFG)))
144
145 union inx_addr {
146 struct in_addr in_addr;
147 #ifdef INET6
148 struct in6_addr in6_addr;
149 #endif
150 struct {
151 u_char mau_zero[10];
152 u_char mau_one[2];
153 struct in_addr mau_inaddr;
154 } map_addr_un;
155 #define map_zero map_addr_un.mau_zero
156 #define map_one map_addr_un.mau_one
157 #define map_inaddr map_addr_un.mau_inaddr
158 };
159
160 struct policyqueue {
161 TAILQ_ENTRY(policyqueue) pc_entry;
162 #ifdef INET6
163 struct in6_addrpolicy pc_policy;
164 #endif
165 };
166 TAILQ_HEAD(policyhead, policyqueue);
167
168 #define AIO_SRCFLAG_DEPRECATED 0x1
169
170 struct hp_order {
171 union {
172 struct sockaddr_storage aiou_ss;
173 struct sockaddr aiou_sa;
174 } aio_src_un;
175 #define aio_srcsa aio_src_un.aiou_sa
176 u_int32_t aio_srcflag;
177 int aio_srcscope;
178 int aio_dstscope;
179 struct policyqueue *aio_srcpolicy;
180 struct policyqueue *aio_dstpolicy;
181 union {
182 struct sockaddr_storage aiou_ss;
183 struct sockaddr aiou_sa;
184 } aio_un;
185 #define aio_sa aio_un.aiou_sa
186 int aio_matchlen;
187 char *aio_h_addr;
188 };
189
190 static struct hostent *_hpcopy(struct hostent *, int *);
191 static struct hostent *_hpaddr(int, const char *, void *, int *);
192 #ifdef INET6
193 static struct hostent *_hpmerge(struct hostent *, struct hostent *, int *);
194 static struct hostent *_hpmapv6(struct hostent *, int *);
195 #endif
196 static struct hostent *_hpsort(struct hostent *, res_state);
197
198 #ifdef INET6
199 static struct hostent *_hpreorder(struct hostent *);
200 static int get_addrselectpolicy(struct policyhead *);
201 static void free_addrselectpolicy(struct policyhead *);
202 static struct policyqueue *match_addrselectpolicy(struct sockaddr *,
203 struct policyhead *);
204 static void set_source(struct hp_order *, struct policyhead *);
205 static int matchlen(struct sockaddr *, struct sockaddr *);
206 static int comp_dst(const void *, const void *);
207 static int gai_addr2scopetype(struct sockaddr *);
208 #endif
209
210 /*
211 * Functions defined in RFC2553
212 * getipnodebyname, getipnodebyaddr, freehostent
213 */
214
215 struct hostent *
getipnodebyname(const char * name,int af,int flags,int * errp)216 getipnodebyname(const char *name, int af, int flags, int *errp)
217 {
218 struct hostent *hp;
219 union inx_addr addrbuf;
220 res_state statp;
221 u_long options;
222
223 switch (af) {
224 case AF_INET:
225 #ifdef INET6
226 case AF_INET6:
227 #endif
228 break;
229 default:
230 *errp = NO_RECOVERY;
231 return NULL;
232 }
233
234 if (flags & AI_ADDRCONFIG) {
235 int s;
236
237 if ((s = _socket(af, SOCK_DGRAM | SOCK_CLOEXEC, 0)) < 0)
238 return NULL;
239 /*
240 * TODO:
241 * Note that implementation dependent test for address
242 * configuration should be done everytime called
243 * (or apropriate interval),
244 * because addresses will be dynamically assigned or deleted.
245 */
246 _close(s);
247 }
248
249 #ifdef INET6
250 /* special case for literal address */
251 if (inet_pton(AF_INET6, name, &addrbuf) == 1) {
252 if (af != AF_INET6) {
253 *errp = HOST_NOT_FOUND;
254 return NULL;
255 }
256 return _hpaddr(af, name, &addrbuf, errp);
257 }
258 #endif
259 if (inet_aton(name, (struct in_addr *)&addrbuf) == 1) {
260 if (af != AF_INET) {
261 if (MAPADDRENABLED(flags)) {
262 MAPADDR(&addrbuf, &addrbuf.in_addr);
263 } else {
264 *errp = HOST_NOT_FOUND;
265 return NULL;
266 }
267 }
268 return _hpaddr(af, name, &addrbuf, errp);
269 }
270
271
272 statp = __res_state();
273 if ((statp->options & RES_INIT) == 0) {
274 if (res_ninit(statp) < 0) {
275 *errp = NETDB_INTERNAL;
276 return NULL;
277 }
278 }
279
280 options = statp->options;
281 statp->options &= ~RES_USE_INET6;
282
283 hp = gethostbyname2(name, af);
284 hp = _hpcopy(hp, errp);
285 #ifdef INET6
286 if (af == AF_INET6)
287 hp = _hpreorder(hp);
288
289 if (af == AF_INET6 && ((flags & AI_ALL) || hp == NULL) &&
290 MAPADDRENABLED(flags)) {
291 struct hostent *hp2 = gethostbyname2(name, AF_INET);
292 if (hp == NULL)
293 if (hp2 == NULL)
294 *errp = statp->res_h_errno;
295 else
296 hp = _hpmapv6(hp2, errp);
297 else {
298 if (hp2 && strcmp(hp->h_name, hp2->h_name) == 0) {
299 struct hostent *hpb = hp;
300 hp = _hpmerge(hpb, hp2, errp);
301 freehostent(hpb);
302 }
303 }
304 }
305 #endif
306
307 if (hp == NULL)
308 *errp = statp->res_h_errno;
309
310 statp->options = options;
311 return _hpsort(hp, statp);
312 }
313
314 struct hostent *
getipnodebyaddr(const void * src,size_t len,int af,int * errp)315 getipnodebyaddr(const void *src, size_t len, int af, int *errp)
316 {
317 struct hostent *hp;
318 res_state statp;
319 u_long options;
320
321 #ifdef INET6
322 struct in6_addr addrbuf;
323 #else
324 struct in_addr addrbuf;
325 #endif
326
327 switch (af) {
328 case AF_INET:
329 if (len != sizeof(struct in_addr)) {
330 *errp = NO_RECOVERY;
331 return NULL;
332 }
333 if ((long)src & ~(sizeof(struct in_addr) - 1)) {
334 memcpy(&addrbuf, src, len);
335 src = &addrbuf;
336 }
337 if (((struct in_addr *)src)->s_addr == 0)
338 return NULL;
339 break;
340 #ifdef INET6
341 case AF_INET6:
342 if (len != sizeof(struct in6_addr)) {
343 *errp = NO_RECOVERY;
344 return NULL;
345 }
346 if ((long)src & ~(sizeof(struct in6_addr) / 2 - 1)) { /*XXX*/
347 memcpy(&addrbuf, src, len);
348 src = &addrbuf;
349 }
350 if (IN6_IS_ADDR_UNSPECIFIED((struct in6_addr *)src))
351 return NULL;
352 if (IN6_IS_ADDR_V4MAPPED((struct in6_addr *)src)
353 || IN6_IS_ADDR_V4COMPAT((struct in6_addr *)src)) {
354 src = (char *)src +
355 (sizeof(struct in6_addr) - sizeof(struct in_addr));
356 af = AF_INET;
357 len = sizeof(struct in_addr);
358 }
359 break;
360 #endif
361 default:
362 *errp = NO_RECOVERY;
363 return NULL;
364 }
365
366 statp = __res_state();
367 if ((statp->options & RES_INIT) == 0) {
368 if (res_ninit(statp) < 0) {
369 RES_SET_H_ERRNO(statp, NETDB_INTERNAL);
370 return NULL;
371 }
372 }
373
374 options = statp->options;
375 statp->options &= ~RES_USE_INET6;
376
377 hp = gethostbyaddr(src, len, af);
378 if (hp == NULL)
379 *errp = statp->res_h_errno;
380
381 statp->options = options;
382 return (_hpcopy(hp, errp));
383 }
384
385 void
freehostent(struct hostent * ptr)386 freehostent(struct hostent *ptr)
387 {
388 free(ptr);
389 }
390
391 /*
392 * Private utility functions
393 */
394
395 /*
396 * _hpcopy: allocate and copy hostent structure
397 */
398 static struct hostent *
_hpcopy(struct hostent * hp,int * errp)399 _hpcopy(struct hostent *hp, int *errp)
400 {
401 struct hostent *nhp;
402 char *cp, **pp;
403 int size, addrsize;
404 int nalias = 0, naddr = 0;
405 int al_off;
406 int i;
407
408 if (hp == NULL)
409 return hp;
410
411 /* count size to be allocated */
412 size = sizeof(struct hostent);
413 if (hp->h_name != NULL)
414 size += strlen(hp->h_name) + 1;
415 if ((pp = hp->h_aliases) != NULL) {
416 for (i = 0; *pp != NULL; i++, pp++) {
417 if (**pp != '\0') {
418 size += strlen(*pp) + 1;
419 nalias++;
420 }
421 }
422 }
423 /* adjust alignment */
424 size = ALIGN(size);
425 al_off = size;
426 size += sizeof(char *) * (nalias + 1);
427 addrsize = ALIGN(hp->h_length);
428 if ((pp = hp->h_addr_list) != NULL) {
429 while (*pp++ != NULL)
430 naddr++;
431 }
432 size += addrsize * naddr;
433 size += sizeof(char *) * (naddr + 1);
434
435 /* copy */
436 if ((nhp = (struct hostent *)malloc(size)) == NULL) {
437 *errp = TRY_AGAIN;
438 return NULL;
439 }
440 cp = (char *)&nhp[1];
441 if (hp->h_name != NULL) {
442 nhp->h_name = cp;
443 strcpy(cp, hp->h_name);
444 cp += strlen(cp) + 1;
445 } else
446 nhp->h_name = NULL;
447 nhp->h_aliases = (char **)((char *)nhp + al_off);
448 if ((pp = hp->h_aliases) != NULL) {
449 for (i = 0; *pp != NULL; pp++) {
450 if (**pp != '\0') {
451 nhp->h_aliases[i++] = cp;
452 strcpy(cp, *pp);
453 cp += strlen(cp) + 1;
454 }
455 }
456 }
457 nhp->h_aliases[nalias] = NULL;
458 cp = (char *)&nhp->h_aliases[nalias + 1];
459 nhp->h_addrtype = hp->h_addrtype;
460 nhp->h_length = hp->h_length;
461 nhp->h_addr_list = (char **)cp;
462 if ((pp = hp->h_addr_list) != NULL) {
463 cp = (char *)&nhp->h_addr_list[naddr + 1];
464 for (i = 0; *pp != NULL; pp++) {
465 nhp->h_addr_list[i++] = cp;
466 memcpy(cp, *pp, hp->h_length);
467 cp += addrsize;
468 }
469 }
470 nhp->h_addr_list[naddr] = NULL;
471 return nhp;
472 }
473
474 /*
475 * _hpaddr: construct hostent structure with one address
476 */
477 static struct hostent *
_hpaddr(int af,const char * name,void * addr,int * errp)478 _hpaddr(int af, const char *name, void *addr, int *errp)
479 {
480 struct hostent *hp, hpbuf;
481 char *addrs[2];
482
483 hp = &hpbuf;
484 hp->h_name = (char *)name;
485 hp->h_aliases = NULL;
486 hp->h_addrtype = af;
487 hp->h_length = ADDRLEN(af);
488 hp->h_addr_list = addrs;
489 addrs[0] = (char *)addr;
490 addrs[1] = NULL;
491 return (_hpcopy(hp, errp));
492 }
493
494 #ifdef INET6
495 /*
496 * _hpmerge: merge 2 hostent structure, arguments will be freed
497 */
498 static struct hostent *
_hpmerge(struct hostent * hp1,struct hostent * hp2,int * errp)499 _hpmerge(struct hostent *hp1, struct hostent *hp2, int *errp)
500 {
501 int i, j;
502 int naddr, nalias;
503 char **pp;
504 struct hostent *hp, hpbuf;
505 char *aliases[MAXALIASES + 1], *addrs[MAXADDRS + 1];
506 union inx_addr addrbuf[MAXADDRS];
507
508 if (hp1 == NULL)
509 return _hpcopy(hp2, errp);
510 if (hp2 == NULL)
511 return _hpcopy(hp1, errp);
512
513 #define HP(i) (i == 1 ? hp1 : hp2)
514 hp = &hpbuf;
515 hp->h_name = (hp1->h_name != NULL ? hp1->h_name : hp2->h_name);
516 hp->h_aliases = aliases;
517 nalias = 0;
518 for (i = 1; i <= 2; i++) {
519 if ((pp = HP(i)->h_aliases) == NULL)
520 continue;
521 for (; nalias < MAXALIASES && *pp != NULL; pp++) {
522 /* check duplicates */
523 for (j = 0; j < nalias; j++)
524 if (strcasecmp(*pp, aliases[j]) == 0)
525 break;
526 if (j == nalias)
527 aliases[nalias++] = *pp;
528 }
529 }
530 aliases[nalias] = NULL;
531 if (hp1->h_length != hp2->h_length) {
532 hp->h_addrtype = AF_INET6;
533 hp->h_length = sizeof(struct in6_addr);
534 } else {
535 hp->h_addrtype = hp1->h_addrtype;
536 hp->h_length = hp1->h_length;
537 }
538
539 hp->h_addr_list = addrs;
540 naddr = 0;
541 for (i = 1; i <= 2; i++) {
542 if ((pp = HP(i)->h_addr_list) == NULL)
543 continue;
544 if (HP(i)->h_length == hp->h_length) {
545 while (naddr < MAXADDRS && *pp != NULL)
546 addrs[naddr++] = *pp++;
547 } else {
548 /* copy IPv4 addr as mapped IPv6 addr */
549 while (naddr < MAXADDRS && *pp != NULL) {
550 MAPADDR(&addrbuf[naddr], *pp++);
551 addrs[naddr] = (char *)&addrbuf[naddr];
552 naddr++;
553 }
554 }
555 }
556 addrs[naddr] = NULL;
557 return (_hpcopy(hp, errp));
558 }
559 #endif
560
561 /*
562 * _hpmapv6: convert IPv4 hostent into IPv4-mapped IPv6 addresses
563 */
564 #ifdef INET6
565 static struct hostent *
_hpmapv6(struct hostent * hp,int * errp)566 _hpmapv6(struct hostent *hp, int *errp)
567 {
568 struct hostent hp6;
569
570 if (hp == NULL)
571 return NULL;
572 if (hp->h_addrtype == AF_INET6)
573 return _hpcopy(hp, errp);
574
575 memset(&hp6, 0, sizeof(struct hostent));
576 hp6.h_addrtype = AF_INET6;
577 hp6.h_length = sizeof(struct in6_addr);
578 return _hpmerge(&hp6, hp, errp);
579 }
580 #endif
581
582 /*
583 * _hpsort: sort address by sortlist
584 */
585 static struct hostent *
_hpsort(struct hostent * hp,res_state statp)586 _hpsort(struct hostent *hp, res_state statp)
587 {
588 int i, j, n;
589 u_char *ap, *sp, *mp, **pp;
590 char t;
591 char order[MAXADDRS];
592 int nsort = statp->nsort;
593
594 if (hp == NULL || hp->h_addr_list[1] == NULL || nsort == 0)
595 return hp;
596 for (i = 0; (ap = (u_char *)hp->h_addr_list[i]); i++) {
597 for (j = 0; j < nsort; j++) {
598 #ifdef INET6
599 if (statp->_u._ext.ext->sort_list[j].af !=
600 hp->h_addrtype)
601 continue;
602 sp = (u_char *)&statp->_u._ext.ext->sort_list[j].addr;
603 mp = (u_char *)&statp->_u._ext.ext->sort_list[j].mask;
604 #else
605 sp = (u_char *)&statp->sort_list[j].addr;
606 mp = (u_char *)&statp->sort_list[j].mask;
607 #endif
608 for (n = 0; n < hp->h_length; n++) {
609 if ((ap[n] & mp[n]) != sp[n])
610 break;
611 }
612 if (n == hp->h_length)
613 break;
614 }
615 order[i] = j;
616 }
617 n = i;
618 pp = (u_char **)hp->h_addr_list;
619 for (i = 0; i < n - 1; i++) {
620 for (j = i + 1; j < n; j++) {
621 if (order[i] > order[j]) {
622 ap = pp[i];
623 pp[i] = pp[j];
624 pp[j] = ap;
625 t = order[i];
626 order[i] = order[j];
627 order[j] = t;
628 }
629 }
630 }
631 return hp;
632 }
633
634 #ifdef INET6
635 /*
636 * _hpreorder: sort address by default address selection
637 */
638 static struct hostent *
_hpreorder(struct hostent * hp)639 _hpreorder(struct hostent *hp)
640 {
641 struct hp_order *aio;
642 int i, n;
643 char *ap;
644 struct sockaddr *sa;
645 struct policyhead policyhead;
646
647 if (hp == NULL)
648 return hp;
649
650 switch (hp->h_addrtype) {
651 case AF_INET:
652 #ifdef INET6
653 case AF_INET6:
654 #endif
655 break;
656 default:
657 free_addrselectpolicy(&policyhead);
658 return hp;
659 }
660
661 /* count the number of addrinfo elements for sorting. */
662 for (n = 0; hp->h_addr_list[n] != NULL; n++)
663 ;
664
665 /*
666 * If the number is small enough, we can skip the reordering process.
667 */
668 if (n <= 1)
669 return hp;
670
671 /* allocate a temporary array for sort and initialization of it. */
672 if ((aio = malloc(sizeof(*aio) * n)) == NULL)
673 return hp; /* give up reordering */
674 memset(aio, 0, sizeof(*aio) * n);
675
676 /* retrieve address selection policy from the kernel */
677 TAILQ_INIT(&policyhead);
678 if (!get_addrselectpolicy(&policyhead)) {
679 /* no policy is installed into kernel, we don't sort. */
680 free(aio);
681 return hp;
682 }
683
684 for (i = 0; i < n; i++) {
685 ap = hp->h_addr_list[i];
686 aio[i].aio_h_addr = ap;
687 sa = &aio[i].aio_sa;
688 switch (hp->h_addrtype) {
689 case AF_INET:
690 sa->sa_family = AF_INET;
691 sa->sa_len = sizeof(struct sockaddr_in);
692 memcpy(&((struct sockaddr_in *)sa)->sin_addr, ap,
693 sizeof(struct in_addr));
694 break;
695 #ifdef INET6
696 case AF_INET6:
697 if (IN6_IS_ADDR_V4MAPPED((struct in6_addr *)ap)) {
698 sa->sa_family = AF_INET;
699 sa->sa_len = sizeof(struct sockaddr_in);
700 memcpy(&((struct sockaddr_in *)sa)->sin_addr,
701 &ap[12], sizeof(struct in_addr));
702 } else {
703 sa->sa_family = AF_INET6;
704 sa->sa_len = sizeof(struct sockaddr_in6);
705 memcpy(&((struct sockaddr_in6 *)sa)->sin6_addr,
706 ap, sizeof(struct in6_addr));
707 }
708 break;
709 #endif
710 }
711 aio[i].aio_dstscope = gai_addr2scopetype(sa);
712 aio[i].aio_dstpolicy = match_addrselectpolicy(sa, &policyhead);
713 set_source(&aio[i], &policyhead);
714 }
715
716 /* perform sorting. */
717 qsort(aio, n, sizeof(*aio), comp_dst);
718
719 /* reorder the h_addr_list. */
720 for (i = 0; i < n; i++)
721 hp->h_addr_list[i] = aio[i].aio_h_addr;
722
723 /* cleanup and return */
724 free(aio);
725 free_addrselectpolicy(&policyhead);
726 return hp;
727 }
728
729 static int
get_addrselectpolicy(struct policyhead * head)730 get_addrselectpolicy(struct policyhead *head)
731 {
732 #ifdef INET6
733 int mib[] = { CTL_NET, PF_INET6, IPPROTO_IPV6, IPV6CTL_ADDRCTLPOLICY };
734 size_t l;
735 char *buf;
736 struct in6_addrpolicy *pol, *ep;
737
738 if (sysctl(mib, sizeof(mib) / sizeof(mib[0]), NULL, &l, NULL, 0) < 0)
739 return (0);
740 if ((buf = malloc(l)) == NULL)
741 return (0);
742 if (sysctl(mib, sizeof(mib) / sizeof(mib[0]), buf, &l, NULL, 0) < 0) {
743 free(buf);
744 return (0);
745 }
746
747 ep = (struct in6_addrpolicy *)(buf + l);
748 for (pol = (struct in6_addrpolicy *)buf; pol + 1 <= ep; pol++) {
749 struct policyqueue *new;
750
751 if ((new = malloc(sizeof(*new))) == NULL) {
752 free_addrselectpolicy(head); /* make the list empty */
753 break;
754 }
755 new->pc_policy = *pol;
756 TAILQ_INSERT_TAIL(head, new, pc_entry);
757 }
758
759 free(buf);
760 return (1);
761 #else
762 return (0);
763 #endif
764 }
765
766 static void
free_addrselectpolicy(struct policyhead * head)767 free_addrselectpolicy(struct policyhead *head)
768 {
769 struct policyqueue *ent, *nent;
770
771 for (ent = TAILQ_FIRST(head); ent; ent = nent) {
772 nent = TAILQ_NEXT(ent, pc_entry);
773 TAILQ_REMOVE(head, ent, pc_entry);
774 free(ent);
775 }
776 }
777
778 static struct policyqueue *
match_addrselectpolicy(struct sockaddr * addr,struct policyhead * head)779 match_addrselectpolicy(struct sockaddr *addr, struct policyhead *head)
780 {
781 #ifdef INET6
782 struct policyqueue *ent, *bestent = NULL;
783 struct in6_addrpolicy *pol;
784 int matchlen, bestmatchlen = -1;
785 u_char *mp, *ep, *k, *p, m;
786 struct sockaddr_in6 key;
787
788 switch(addr->sa_family) {
789 case AF_INET6:
790 key = *(struct sockaddr_in6 *)addr;
791 break;
792 case AF_INET:
793 /* convert the address into IPv4-mapped IPv6 address. */
794 memset(&key, 0, sizeof(key));
795 key.sin6_family = AF_INET6;
796 key.sin6_len = sizeof(key);
797 _map_v4v6_address(
798 (char *)&((struct sockaddr_in *)addr)->sin_addr,
799 (char *)&key.sin6_addr);
800 break;
801 default:
802 return(NULL);
803 }
804
805 for (ent = TAILQ_FIRST(head); ent; ent = TAILQ_NEXT(ent, pc_entry)) {
806 pol = &ent->pc_policy;
807 matchlen = 0;
808
809 mp = (u_char *)&pol->addrmask.sin6_addr;
810 ep = mp + 16; /* XXX: scope field? */
811 k = (u_char *)&key.sin6_addr;
812 p = (u_char *)&pol->addr.sin6_addr;
813 for (; mp < ep && *mp; mp++, k++, p++) {
814 m = *mp;
815 if ((*k & m) != *p)
816 goto next; /* not match */
817 if (m == 0xff) /* short cut for a typical case */
818 matchlen += 8;
819 else {
820 while (m >= 0x80) {
821 matchlen++;
822 m <<= 1;
823 }
824 }
825 }
826
827 /* matched. check if this is better than the current best. */
828 if (matchlen > bestmatchlen) {
829 bestent = ent;
830 bestmatchlen = matchlen;
831 }
832
833 next:
834 continue;
835 }
836
837 return(bestent);
838 #else
839 return(NULL);
840 #endif
841
842 }
843
844 static void
set_source(struct hp_order * aio,struct policyhead * ph)845 set_source(struct hp_order *aio, struct policyhead *ph)
846 {
847 struct sockaddr_storage ss = aio->aio_un.aiou_ss;
848 socklen_t srclen;
849 int s;
850
851 /* set unspec ("no source is available"), just in case */
852 aio->aio_srcsa.sa_family = AF_UNSPEC;
853 aio->aio_srcscope = -1;
854
855 switch(ss.ss_family) {
856 case AF_INET:
857 ((struct sockaddr_in *)&ss)->sin_port = htons(1);
858 break;
859 #ifdef INET6
860 case AF_INET6:
861 ((struct sockaddr_in6 *)&ss)->sin6_port = htons(1);
862 break;
863 #endif
864 default: /* ignore unsupported AFs explicitly */
865 return;
866 }
867
868 /* open a socket to get the source address for the given dst */
869 if ((s = _socket(ss.ss_family, SOCK_DGRAM | SOCK_CLOEXEC,
870 IPPROTO_UDP)) < 0)
871 return; /* give up */
872 if (_connect(s, (struct sockaddr *)&ss, ss.ss_len) < 0)
873 goto cleanup;
874 srclen = ss.ss_len;
875 if (_getsockname(s, &aio->aio_srcsa, &srclen) < 0) {
876 aio->aio_srcsa.sa_family = AF_UNSPEC;
877 goto cleanup;
878 }
879 aio->aio_srcscope = gai_addr2scopetype(&aio->aio_srcsa);
880 aio->aio_srcpolicy = match_addrselectpolicy(&aio->aio_srcsa, ph);
881 aio->aio_matchlen = matchlen(&aio->aio_srcsa, (struct sockaddr *)&ss);
882 #ifdef INET6
883 if (ss.ss_family == AF_INET6) {
884 struct in6_ifreq ifr6;
885 u_int32_t flags6;
886
887 memset(&ifr6, 0, sizeof(ifr6));
888 memcpy(&ifr6.ifr_addr, &ss, ss.ss_len);
889 if (_ioctl(s, SIOCGIFAFLAG_IN6, &ifr6) == 0) {
890 flags6 = ifr6.ifr_ifru.ifru_flags6;
891 if ((flags6 & IN6_IFF_DEPRECATED))
892 aio->aio_srcflag |= AIO_SRCFLAG_DEPRECATED;
893 }
894 }
895 #endif
896
897 cleanup:
898 _close(s);
899 return;
900 }
901
902 static int
matchlen(struct sockaddr * src,struct sockaddr * dst)903 matchlen(struct sockaddr *src, struct sockaddr *dst)
904 {
905 int match = 0;
906 u_char *s, *d;
907 u_char *lim, r;
908 int addrlen;
909
910 switch (src->sa_family) {
911 #ifdef INET6
912 case AF_INET6:
913 s = (u_char *)&((struct sockaddr_in6 *)src)->sin6_addr;
914 d = (u_char *)&((struct sockaddr_in6 *)dst)->sin6_addr;
915 addrlen = sizeof(struct in6_addr);
916 lim = s + addrlen;
917 break;
918 #endif
919 case AF_INET:
920 s = (u_char *)&((struct sockaddr_in *)src)->sin_addr;
921 d = (u_char *)&((struct sockaddr_in *)dst)->sin_addr;
922 addrlen = sizeof(struct in_addr);
923 lim = s + addrlen;
924 break;
925 default:
926 return(0);
927 }
928
929 while (s < lim)
930 if ((r = (*d++ ^ *s++)) != 0) {
931 while (r < addrlen * 8) {
932 match++;
933 r <<= 1;
934 }
935 break;
936 } else
937 match += 8;
938 return(match);
939 }
940
941 static int
comp_dst(const void * arg1,const void * arg2)942 comp_dst(const void *arg1, const void *arg2)
943 {
944 const struct hp_order *dst1 = arg1, *dst2 = arg2;
945
946 /*
947 * Rule 1: Avoid unusable destinations.
948 * XXX: we currently do not consider if an appropriate route exists.
949 */
950 if (dst1->aio_srcsa.sa_family != AF_UNSPEC &&
951 dst2->aio_srcsa.sa_family == AF_UNSPEC) {
952 return(-1);
953 }
954 if (dst1->aio_srcsa.sa_family == AF_UNSPEC &&
955 dst2->aio_srcsa.sa_family != AF_UNSPEC) {
956 return(1);
957 }
958
959 /* Rule 2: Prefer matching scope. */
960 if (dst1->aio_dstscope == dst1->aio_srcscope &&
961 dst2->aio_dstscope != dst2->aio_srcscope) {
962 return(-1);
963 }
964 if (dst1->aio_dstscope != dst1->aio_srcscope &&
965 dst2->aio_dstscope == dst2->aio_srcscope) {
966 return(1);
967 }
968
969 /* Rule 3: Avoid deprecated addresses. */
970 if (dst1->aio_srcsa.sa_family != AF_UNSPEC &&
971 dst2->aio_srcsa.sa_family != AF_UNSPEC) {
972 if (!(dst1->aio_srcflag & AIO_SRCFLAG_DEPRECATED) &&
973 (dst2->aio_srcflag & AIO_SRCFLAG_DEPRECATED)) {
974 return(-1);
975 }
976 if ((dst1->aio_srcflag & AIO_SRCFLAG_DEPRECATED) &&
977 !(dst2->aio_srcflag & AIO_SRCFLAG_DEPRECATED)) {
978 return(1);
979 }
980 }
981
982 /* Rule 4: Prefer home addresses. */
983 /* XXX: not implemented yet */
984
985 /* Rule 5: Prefer matching label. */
986 #ifdef INET6
987 if (dst1->aio_srcpolicy && dst1->aio_dstpolicy &&
988 dst1->aio_srcpolicy->pc_policy.label ==
989 dst1->aio_dstpolicy->pc_policy.label &&
990 (dst2->aio_srcpolicy == NULL || dst2->aio_dstpolicy == NULL ||
991 dst2->aio_srcpolicy->pc_policy.label !=
992 dst2->aio_dstpolicy->pc_policy.label)) {
993 return(-1);
994 }
995 if (dst2->aio_srcpolicy && dst2->aio_dstpolicy &&
996 dst2->aio_srcpolicy->pc_policy.label ==
997 dst2->aio_dstpolicy->pc_policy.label &&
998 (dst1->aio_srcpolicy == NULL || dst1->aio_dstpolicy == NULL ||
999 dst1->aio_srcpolicy->pc_policy.label !=
1000 dst1->aio_dstpolicy->pc_policy.label)) {
1001 return(1);
1002 }
1003 #endif
1004
1005 /* Rule 6: Prefer higher precedence. */
1006 #ifdef INET6
1007 if (dst1->aio_dstpolicy &&
1008 (dst2->aio_dstpolicy == NULL ||
1009 dst1->aio_dstpolicy->pc_policy.preced >
1010 dst2->aio_dstpolicy->pc_policy.preced)) {
1011 return(-1);
1012 }
1013 if (dst2->aio_dstpolicy &&
1014 (dst1->aio_dstpolicy == NULL ||
1015 dst2->aio_dstpolicy->pc_policy.preced >
1016 dst1->aio_dstpolicy->pc_policy.preced)) {
1017 return(1);
1018 }
1019 #endif
1020
1021 /* Rule 7: Prefer native transport. */
1022 /* XXX: not implemented yet */
1023
1024 /* Rule 8: Prefer smaller scope. */
1025 if (dst1->aio_dstscope >= 0 &&
1026 dst1->aio_dstscope < dst2->aio_dstscope) {
1027 return(-1);
1028 }
1029 if (dst2->aio_dstscope >= 0 &&
1030 dst2->aio_dstscope < dst1->aio_dstscope) {
1031 return(1);
1032 }
1033
1034 /*
1035 * Rule 9: Use longest matching prefix.
1036 * We compare the match length in a same AF only.
1037 */
1038 if (dst1->aio_sa.sa_family == dst2->aio_sa.sa_family) {
1039 if (dst1->aio_matchlen > dst2->aio_matchlen) {
1040 return(-1);
1041 }
1042 if (dst1->aio_matchlen < dst2->aio_matchlen) {
1043 return(1);
1044 }
1045 }
1046
1047 /* Rule 10: Otherwise, leave the order unchanged. */
1048 return(-1);
1049 }
1050
1051 /*
1052 * Copy from scope.c.
1053 * XXX: we should standardize the functions and link them as standard
1054 * library.
1055 */
1056 static int
gai_addr2scopetype(struct sockaddr * sa)1057 gai_addr2scopetype(struct sockaddr *sa)
1058 {
1059 #ifdef INET6
1060 struct sockaddr_in6 *sa6;
1061 #endif
1062 struct sockaddr_in *sa4;
1063
1064 switch(sa->sa_family) {
1065 #ifdef INET6
1066 case AF_INET6:
1067 sa6 = (struct sockaddr_in6 *)sa;
1068 if (IN6_IS_ADDR_MULTICAST(&sa6->sin6_addr)) {
1069 /* just use the scope field of the multicast address */
1070 return(sa6->sin6_addr.s6_addr[2] & 0x0f);
1071 }
1072 /*
1073 * Unicast addresses: map scope type to corresponding scope
1074 * value defined for multcast addresses.
1075 * XXX: hardcoded scope type values are bad...
1076 */
1077 if (IN6_IS_ADDR_LOOPBACK(&sa6->sin6_addr))
1078 return(1); /* node local scope */
1079 if (IN6_IS_ADDR_LINKLOCAL(&sa6->sin6_addr))
1080 return(2); /* link-local scope */
1081 if (IN6_IS_ADDR_SITELOCAL(&sa6->sin6_addr))
1082 return(5); /* site-local scope */
1083 return(14); /* global scope */
1084 break;
1085 #endif
1086 case AF_INET:
1087 /*
1088 * IPv4 pseudo scoping according to RFC 3484.
1089 */
1090 sa4 = (struct sockaddr_in *)sa;
1091 /* IPv4 autoconfiguration addresses have link-local scope. */
1092 if (((u_char *)&sa4->sin_addr)[0] == 169 &&
1093 ((u_char *)&sa4->sin_addr)[1] == 254)
1094 return(2);
1095 /* Private addresses have site-local scope. */
1096 if (((u_char *)&sa4->sin_addr)[0] == 10 ||
1097 (((u_char *)&sa4->sin_addr)[0] == 172 &&
1098 (((u_char *)&sa4->sin_addr)[1] & 0xf0) == 16) ||
1099 (((u_char *)&sa4->sin_addr)[0] == 192 &&
1100 ((u_char *)&sa4->sin_addr)[1] == 168))
1101 return(14); /* XXX: It should be 5 unless NAT */
1102 /* Loopback addresses have link-local scope. */
1103 if (((u_char *)&sa4->sin_addr)[0] == 127)
1104 return(2);
1105 return(14);
1106 break;
1107 default:
1108 errno = EAFNOSUPPORT; /* is this a good error? */
1109 return(-1);
1110 }
1111 }
1112 #endif
1113