1 /* $KAME: getaddrinfo.c,v 1.15 2000/07/09 04:37:24 itojun 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 * "#ifdef FAITH" part is local hack for supporting IPv4-v6 translator.
34 *
35 * Issues to be discussed:
36 * - Return values. There are nonstandard return values defined and used
37 * in the source code. This is because RFC2553 is silent about which error
38 * code must be returned for which situation.
39 * - freeaddrinfo(NULL). RFC2553 is silent about it. XNET 5.2 says it is
40 * invalid. current code - SEGV on freeaddrinfo(NULL)
41 *
42 * Note:
43 * - The code filters out AFs that are not supported by the kernel,
44 * when globbing NULL hostname (to loopback, or wildcard). Is it the right
45 * thing to do? What is the relationship with post-RFC2553 AI_ADDRCONFIG
46 * in ai_flags?
47 * - (post-2553) semantics of AI_ADDRCONFIG itself is too vague.
48 * (1) what should we do against numeric hostname (2) what should we do
49 * against NULL hostname (3) what is AI_ADDRCONFIG itself. AF not ready?
50 * non-loopback address configured? global address configured?
51 *
52 * OS specific notes for freebsd4:
53 * - FreeBSD supported $GAI. The code does not.
54 */
55
56 #include <sys/cdefs.h>
57 __FBSDID("$FreeBSD$");
58
59 #include "namespace.h"
60 #include <sys/types.h>
61 #include <sys/param.h>
62 #include <sys/socket.h>
63 #include <net/if.h>
64 #include <netinet/in.h>
65 #include <net/if_types.h>
66 #include <ifaddrs.h>
67 #include <sys/queue.h>
68 #ifdef INET6
69 #include <net/if_var.h>
70 #include <sys/sysctl.h>
71 #include <sys/ioctl.h>
72 #include <netinet6/in6_var.h>
73 #include <netinet6/nd6.h>
74 #endif
75 #include <arpa/inet.h>
76 #include <arpa/nameser.h>
77 #include <rpc/rpc.h>
78 #include <rpcsvc/yp_prot.h>
79 #include <rpcsvc/ypclnt.h>
80 #include <netdb.h>
81 #include <resolv.h>
82 #include <string.h>
83 #include <stdlib.h>
84 #include <stddef.h>
85 #include <ctype.h>
86 #include <unistd.h>
87 #include <stdio.h>
88 #include <errno.h>
89
90 #include "res_config.h"
91
92 #ifdef DEBUG
93 #include <syslog.h>
94 #endif
95
96 #include <stdarg.h>
97 #include <nsswitch.h>
98 #include "un-namespace.h"
99 #include "libc_private.h"
100 #ifdef NS_CACHING
101 #include "nscache.h"
102 #endif
103
104 #if defined(__KAME__) && defined(INET6)
105 # define FAITH
106 #endif
107
108 #define ANY 0
109 #define YES 1
110 #define NO 0
111
112 static const char in_addrany[] = { 0, 0, 0, 0 };
113 static const char in_loopback[] = { 127, 0, 0, 1 };
114 #ifdef INET6
115 static const char in6_addrany[] = {
116 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
117 };
118 static const char in6_loopback[] = {
119 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1
120 };
121 #endif
122
123 struct policyqueue {
124 TAILQ_ENTRY(policyqueue) pc_entry;
125 #ifdef INET6
126 struct in6_addrpolicy pc_policy;
127 #endif
128 };
129 TAILQ_HEAD(policyhead, policyqueue);
130
131 static const struct afd {
132 int a_af;
133 int a_addrlen;
134 socklen_t a_socklen;
135 int a_off;
136 const char *a_addrany;
137 const char *a_loopback;
138 int a_scoped;
139 } afdl [] = {
140 #ifdef INET6
141 #define N_INET6 0
142 {PF_INET6, sizeof(struct in6_addr),
143 sizeof(struct sockaddr_in6),
144 offsetof(struct sockaddr_in6, sin6_addr),
145 in6_addrany, in6_loopback, 1},
146 #define N_INET 1
147 #else
148 #define N_INET 0
149 #endif
150 {PF_INET, sizeof(struct in_addr),
151 sizeof(struct sockaddr_in),
152 offsetof(struct sockaddr_in, sin_addr),
153 in_addrany, in_loopback, 0},
154 {0, 0, 0, 0, NULL, NULL, 0},
155 };
156
157 struct explore {
158 int e_af;
159 int e_socktype;
160 int e_protocol;
161 int e_wild;
162 #define WILD_AF(ex) ((ex)->e_wild & 0x01)
163 #define WILD_SOCKTYPE(ex) ((ex)->e_wild & 0x02)
164 #define WILD_PROTOCOL(ex) ((ex)->e_wild & 0x04)
165 };
166
167 static const struct explore explore[] = {
168 #if 0
169 { PF_LOCAL, ANY, ANY, 0x01 },
170 #endif
171 #ifdef INET6
172 { PF_INET6, SOCK_DGRAM, IPPROTO_UDP, 0x07 },
173 { PF_INET6, SOCK_STREAM, IPPROTO_TCP, 0x07 },
174 { PF_INET6, SOCK_STREAM, IPPROTO_SCTP, 0x03 },
175 { PF_INET6, SOCK_SEQPACKET, IPPROTO_SCTP, 0x07 },
176 { PF_INET6, SOCK_DGRAM, IPPROTO_UDPLITE, 0x03 },
177 { PF_INET6, SOCK_RAW, ANY, 0x05 },
178 #endif
179 { PF_INET, SOCK_DGRAM, IPPROTO_UDP, 0x07 },
180 { PF_INET, SOCK_STREAM, IPPROTO_TCP, 0x07 },
181 { PF_INET, SOCK_STREAM, IPPROTO_SCTP, 0x03 },
182 { PF_INET, SOCK_SEQPACKET, IPPROTO_SCTP, 0x07 },
183 { PF_INET, SOCK_DGRAM, IPPROTO_UDPLITE, 0x03 },
184 { PF_INET, SOCK_RAW, ANY, 0x05 },
185 { -1, 0, 0, 0 },
186 };
187
188 #ifdef INET6
189 #define PTON_MAX 16
190 #else
191 #define PTON_MAX 4
192 #endif
193
194 #define AIO_SRCFLAG_DEPRECATED 0x1
195
196 struct ai_order {
197 union {
198 struct sockaddr_storage aiou_ss;
199 struct sockaddr aiou_sa;
200 } aio_src_un;
201 #define aio_srcsa aio_src_un.aiou_sa
202 u_int32_t aio_srcflag;
203 int aio_srcscope;
204 int aio_dstscope;
205 struct policyqueue *aio_srcpolicy;
206 struct policyqueue *aio_dstpolicy;
207 struct addrinfo *aio_ai;
208 int aio_matchlen;
209 };
210
211 static const ns_src default_dns_files[] = {
212 { NSSRC_FILES, NS_SUCCESS },
213 { NSSRC_DNS, NS_SUCCESS },
214 { 0 }
215 };
216
217 struct res_target {
218 struct res_target *next;
219 const char *name; /* domain name */
220 int qclass, qtype; /* class and type of query */
221 u_char *answer; /* buffer to put answer */
222 int anslen; /* size of answer buffer */
223 int n; /* result length */
224 };
225
226 #define MAXPACKET (64*1024)
227
228 typedef union {
229 HEADER hdr;
230 u_char buf[MAXPACKET];
231 } querybuf;
232
233 static int str2number(const char *, int *);
234 static int explore_copy(const struct addrinfo *, const struct addrinfo *,
235 struct addrinfo **);
236 static int explore_null(const struct addrinfo *,
237 const char *, struct addrinfo **);
238 static int explore_numeric(const struct addrinfo *, const char *,
239 const char *, struct addrinfo **, const char *);
240 static int explore_numeric_scope(const struct addrinfo *, const char *,
241 const char *, struct addrinfo **);
242 static int get_canonname(const struct addrinfo *,
243 struct addrinfo *, const char *);
244 static struct addrinfo *get_ai(const struct addrinfo *,
245 const struct afd *, const char *);
246 static struct addrinfo *copy_ai(const struct addrinfo *);
247 static int get_portmatch(const struct addrinfo *, const char *);
248 static int get_port(struct addrinfo *, const char *, int);
249 static const struct afd *find_afd(int);
250 static int addrconfig(struct addrinfo *);
251 #ifdef INET6
252 static int is_ifdisabled(char *);
253 #endif
254 static void set_source(struct ai_order *, struct policyhead *);
255 static int comp_dst(const void *, const void *);
256 #ifdef INET6
257 static int ip6_str2scopeid(char *, struct sockaddr_in6 *, u_int32_t *);
258 #endif
259 static int gai_addr2scopetype(struct sockaddr *);
260
261 static int explore_fqdn(const struct addrinfo *, const char *,
262 const char *, struct addrinfo **);
263
264 static int reorder(struct addrinfo *);
265 static int get_addrselectpolicy(struct policyhead *);
266 static void free_addrselectpolicy(struct policyhead *);
267 static struct policyqueue *match_addrselectpolicy(struct sockaddr *,
268 struct policyhead *);
269 static int matchlen(struct sockaddr *, struct sockaddr *);
270
271 static struct addrinfo *getanswer(const querybuf *, int, const char *, int,
272 const struct addrinfo *, res_state);
273 #if defined(RESOLVSORT)
274 static int addr4sort(struct addrinfo *, res_state);
275 #endif
276 static int _dns_getaddrinfo(void *, void *, va_list);
277 static void _sethtent(FILE **);
278 static void _endhtent(FILE **);
279 static struct addrinfo *_gethtent(FILE **, const char *,
280 const struct addrinfo *);
281 static int _files_getaddrinfo(void *, void *, va_list);
282 #ifdef YP
283 static struct addrinfo *_yphostent(char *, const struct addrinfo *);
284 static int _yp_getaddrinfo(void *, void *, va_list);
285 #endif
286 #ifdef NS_CACHING
287 static int addrinfo_id_func(char *, size_t *, va_list, void *);
288 static int addrinfo_marshal_func(char *, size_t *, void *, va_list, void *);
289 static int addrinfo_unmarshal_func(char *, size_t, void *, va_list, void *);
290 #endif
291
292 static int res_queryN(const char *, struct res_target *, res_state);
293 static int res_searchN(const char *, struct res_target *, res_state);
294 static int res_querydomainN(const char *, const char *,
295 struct res_target *, res_state);
296
297 /* XXX macros that make external reference is BAD. */
298
299 #define GET_AI(ai, afd, addr) \
300 do { \
301 /* external reference: pai, error, and label free */ \
302 (ai) = get_ai(pai, (afd), (addr)); \
303 if ((ai) == NULL) { \
304 error = EAI_MEMORY; \
305 goto free; \
306 } \
307 } while (/*CONSTCOND*/0)
308
309 #define GET_PORT(ai, serv) \
310 do { \
311 /* external reference: error and label free */ \
312 error = get_port((ai), (serv), 0); \
313 if (error != 0) \
314 goto free; \
315 } while (/*CONSTCOND*/0)
316
317 #define GET_CANONNAME(ai, str) \
318 do { \
319 /* external reference: pai, error and label free */ \
320 error = get_canonname(pai, (ai), (str)); \
321 if (error != 0) \
322 goto free; \
323 } while (/*CONSTCOND*/0)
324
325 #define ERR(err) \
326 do { \
327 /* external reference: error, and label bad */ \
328 error = (err); \
329 goto bad; \
330 /*NOTREACHED*/ \
331 } while (/*CONSTCOND*/0)
332
333 #define MATCH_FAMILY(x, y, w) \
334 ((x) == (y) || (/*CONSTCOND*/(w) && ((x) == PF_UNSPEC || (y) == PF_UNSPEC)))
335 #define MATCH(x, y, w) \
336 ((x) == (y) || (/*CONSTCOND*/(w) && ((x) == ANY || (y) == ANY)))
337
338 void
freeaddrinfo(struct addrinfo * ai)339 freeaddrinfo(struct addrinfo *ai)
340 {
341 struct addrinfo *next;
342
343 do {
344 next = ai->ai_next;
345 if (ai->ai_canonname)
346 free(ai->ai_canonname);
347 /* no need to free(ai->ai_addr) */
348 free(ai);
349 ai = next;
350 } while (ai);
351 }
352
353 static int
str2number(const char * p,int * portp)354 str2number(const char *p, int *portp)
355 {
356 char *ep;
357 unsigned long v;
358
359 if (*p == '\0')
360 return -1;
361 ep = NULL;
362 errno = 0;
363 v = strtoul(p, &ep, 10);
364 if (errno == 0 && ep && *ep == '\0' && v <= UINT_MAX) {
365 *portp = v;
366 return 0;
367 } else
368 return -1;
369 }
370
371 int
getaddrinfo(const char * hostname,const char * servname,const struct addrinfo * hints,struct addrinfo ** res)372 getaddrinfo(const char *hostname, const char *servname,
373 const struct addrinfo *hints, struct addrinfo **res)
374 {
375 struct addrinfo sentinel;
376 struct addrinfo *cur;
377 int error = 0;
378 struct addrinfo ai, ai0, *afai;
379 struct addrinfo *pai;
380 const struct afd *afd;
381 const struct explore *ex;
382 struct addrinfo *afailist[sizeof(afdl)/sizeof(afdl[0])];
383 struct addrinfo *afai_unspec;
384 int found;
385 int numeric = 0;
386
387 /* ensure we return NULL on errors */
388 *res = NULL;
389
390 memset(&ai, 0, sizeof(ai));
391
392 memset(afailist, 0, sizeof(afailist));
393 afai_unspec = NULL;
394
395 memset(&sentinel, 0, sizeof(sentinel));
396 cur = &sentinel;
397 pai = &ai;
398 pai->ai_flags = 0;
399 pai->ai_family = PF_UNSPEC;
400 pai->ai_socktype = ANY;
401 pai->ai_protocol = ANY;
402 pai->ai_addrlen = 0;
403 pai->ai_canonname = NULL;
404 pai->ai_addr = NULL;
405 pai->ai_next = NULL;
406
407 if (hostname == NULL && servname == NULL)
408 return EAI_NONAME;
409 if (hints) {
410 /* error check for hints */
411 if (hints->ai_addrlen || hints->ai_canonname ||
412 hints->ai_addr || hints->ai_next)
413 ERR(EAI_BADHINTS); /* xxx */
414 if (hints->ai_flags & ~AI_MASK)
415 ERR(EAI_BADFLAGS);
416 switch (hints->ai_family) {
417 case PF_UNSPEC:
418 case PF_INET:
419 #ifdef INET6
420 case PF_INET6:
421 #endif
422 break;
423 default:
424 ERR(EAI_FAMILY);
425 }
426 memcpy(pai, hints, sizeof(*pai));
427
428 /*
429 * if both socktype/protocol are specified, check if they
430 * are meaningful combination.
431 */
432 if (pai->ai_socktype != ANY && pai->ai_protocol != ANY) {
433 for (ex = explore; ex->e_af >= 0; ex++) {
434 if (!MATCH_FAMILY(pai->ai_family, ex->e_af,
435 WILD_AF(ex)))
436 continue;
437 if (!MATCH(pai->ai_socktype, ex->e_socktype,
438 WILD_SOCKTYPE(ex)))
439 continue;
440 if (!MATCH(pai->ai_protocol, ex->e_protocol,
441 WILD_PROTOCOL(ex)))
442 continue;
443
444 /* matched */
445 break;
446 }
447
448 if (ex->e_af < 0)
449 ERR(EAI_BADHINTS);
450 }
451 }
452
453 /*
454 * check for special cases. (1) numeric servname is disallowed if
455 * socktype/protocol are left unspecified. (2) servname is disallowed
456 * for raw and other inet{,6} sockets.
457 */
458 if (MATCH_FAMILY(pai->ai_family, PF_INET, 1)
459 #ifdef PF_INET6
460 || MATCH_FAMILY(pai->ai_family, PF_INET6, 1)
461 #endif
462 ) {
463 ai0 = *pai; /* backup *pai */
464
465 if (pai->ai_family == PF_UNSPEC) {
466 #ifdef PF_INET6
467 pai->ai_family = PF_INET6;
468 #else
469 pai->ai_family = PF_INET;
470 #endif
471 }
472 error = get_portmatch(pai, servname);
473 if (error)
474 goto bad;
475
476 *pai = ai0;
477 }
478
479 ai0 = *pai;
480
481 /*
482 * NULL hostname, or numeric hostname.
483 * If numeric representation of AF1 can be interpreted as FQDN
484 * representation of AF2, we need to think again about the code below.
485 */
486 found = 0;
487 for (afd = afdl; afd->a_af; afd++) {
488 *pai = ai0;
489
490 if (!MATCH_FAMILY(pai->ai_family, afd->a_af, 1))
491 continue;
492
493 if (pai->ai_family == PF_UNSPEC)
494 pai->ai_family = afd->a_af;
495
496 if (hostname == NULL) {
497 error = explore_null(pai, servname,
498 &afailist[afd - afdl]);
499
500 /*
501 * Errors from explore_null should be unexpected and
502 * be caught to avoid returning an incomplete result.
503 */
504 if (error != 0)
505 goto bad;
506 } else {
507 error = explore_numeric_scope(pai, hostname, servname,
508 &afailist[afd - afdl]);
509
510 /*
511 * explore_numeric_scope returns an error for address
512 * families that do not match that of hostname.
513 * Thus we should not catch the error at this moment.
514 */
515 }
516
517 if (!error && afailist[afd - afdl])
518 found++;
519 }
520 if (found) {
521 numeric = 1;
522 goto globcopy;
523 }
524
525 if (hostname == NULL)
526 ERR(EAI_NONAME); /* used to be EAI_NODATA */
527 if (pai->ai_flags & AI_NUMERICHOST)
528 ERR(EAI_NONAME);
529
530 if ((pai->ai_flags & AI_ADDRCONFIG) != 0 && !addrconfig(&ai0))
531 ERR(EAI_FAIL);
532
533 /*
534 * hostname as alphabetical name.
535 */
536 *pai = ai0;
537 error = explore_fqdn(pai, hostname, servname, &afai_unspec);
538
539 globcopy:
540 for (ex = explore; ex->e_af >= 0; ex++) {
541 *pai = ai0;
542
543 if (!MATCH_FAMILY(pai->ai_family, ex->e_af, WILD_AF(ex)))
544 continue;
545 if (!MATCH(pai->ai_socktype, ex->e_socktype,
546 WILD_SOCKTYPE(ex)))
547 continue;
548 if (!MATCH(pai->ai_protocol, ex->e_protocol,
549 WILD_PROTOCOL(ex)))
550 continue;
551
552 if (pai->ai_family == PF_UNSPEC)
553 pai->ai_family = ex->e_af;
554 if (pai->ai_socktype == ANY && ex->e_socktype != ANY)
555 pai->ai_socktype = ex->e_socktype;
556 if (pai->ai_protocol == ANY && ex->e_protocol != ANY)
557 pai->ai_protocol = ex->e_protocol;
558
559 /*
560 * if the servname does not match socktype/protocol, ignore it.
561 */
562 if (get_portmatch(pai, servname) != 0)
563 continue;
564
565 if (afai_unspec)
566 afai = afai_unspec;
567 else {
568 if ((afd = find_afd(pai->ai_family)) == NULL)
569 continue;
570 /* XXX assumes that afd points inside afdl[] */
571 afai = afailist[afd - afdl];
572 }
573 if (!afai)
574 continue;
575
576 error = explore_copy(pai, afai, &cur->ai_next);
577 if (error != 0)
578 goto bad;
579
580 while (cur && cur->ai_next)
581 cur = cur->ai_next;
582 }
583
584 /*
585 * ensure we return either:
586 * - error == 0, non-NULL *res
587 * - error != 0, NULL *res
588 */
589 if (error == 0) {
590 if (sentinel.ai_next) {
591 /*
592 * If the returned entry is for an active connection,
593 * and the given name is not numeric, reorder the
594 * list, so that the application would try the list
595 * in the most efficient order. Since the head entry
596 * of the original list may contain ai_canonname and
597 * that entry may be moved elsewhere in the new list,
598 * we keep the pointer and will restore it in the new
599 * head entry. (Note that RFC3493 requires the head
600 * entry store it when requested by the caller).
601 */
602 if (hints == NULL || !(hints->ai_flags & AI_PASSIVE)) {
603 if (!numeric) {
604 char *canonname;
605
606 canonname =
607 sentinel.ai_next->ai_canonname;
608 sentinel.ai_next->ai_canonname = NULL;
609 (void)reorder(&sentinel);
610 if (sentinel.ai_next->ai_canonname ==
611 NULL) {
612 sentinel.ai_next->ai_canonname
613 = canonname;
614 } else if (canonname != NULL)
615 free(canonname);
616 }
617 }
618 *res = sentinel.ai_next;
619 } else
620 error = EAI_FAIL;
621 }
622
623 bad:
624 if (afai_unspec)
625 freeaddrinfo(afai_unspec);
626 for (afd = afdl; afd->a_af; afd++) {
627 if (afailist[afd - afdl])
628 freeaddrinfo(afailist[afd - afdl]);
629 }
630 if (!*res)
631 if (sentinel.ai_next)
632 freeaddrinfo(sentinel.ai_next);
633
634 return (error);
635 }
636
637 static int
reorder(struct addrinfo * sentinel)638 reorder(struct addrinfo *sentinel)
639 {
640 struct addrinfo *ai, **aip;
641 struct ai_order *aio;
642 int i, n;
643 struct policyhead policyhead;
644
645 /* count the number of addrinfo elements for sorting. */
646 for (n = 0, ai = sentinel->ai_next; ai != NULL; ai = ai->ai_next, n++)
647 ;
648
649 /*
650 * If the number is small enough, we can skip the reordering process.
651 */
652 if (n <= 1)
653 return(n);
654
655 /* allocate a temporary array for sort and initialization of it. */
656 if ((aio = malloc(sizeof(*aio) * n)) == NULL)
657 return(n); /* give up reordering */
658 memset(aio, 0, sizeof(*aio) * n);
659
660 /* retrieve address selection policy from the kernel */
661 TAILQ_INIT(&policyhead);
662 if (!get_addrselectpolicy(&policyhead)) {
663 /* no policy is installed into kernel, we don't sort. */
664 free(aio);
665 return (n);
666 }
667
668 for (i = 0, ai = sentinel->ai_next; i < n; ai = ai->ai_next, i++) {
669 aio[i].aio_ai = ai;
670 aio[i].aio_dstscope = gai_addr2scopetype(ai->ai_addr);
671 aio[i].aio_dstpolicy = match_addrselectpolicy(ai->ai_addr,
672 &policyhead);
673 set_source(&aio[i], &policyhead);
674 }
675
676 /* perform sorting. */
677 qsort(aio, n, sizeof(*aio), comp_dst);
678
679 /* reorder the addrinfo chain. */
680 for (i = 0, aip = &sentinel->ai_next; i < n; i++) {
681 *aip = aio[i].aio_ai;
682 aip = &aio[i].aio_ai->ai_next;
683 }
684 *aip = NULL;
685
686 /* cleanup and return */
687 free(aio);
688 free_addrselectpolicy(&policyhead);
689 return(n);
690 }
691
692 static int
get_addrselectpolicy(struct policyhead * head)693 get_addrselectpolicy(struct policyhead *head)
694 {
695 #ifdef INET6
696 int mib[] = { CTL_NET, PF_INET6, IPPROTO_IPV6, IPV6CTL_ADDRCTLPOLICY };
697 size_t l;
698 char *buf;
699 struct in6_addrpolicy *pol, *ep;
700
701 if (sysctl(mib, sizeof(mib) / sizeof(mib[0]), NULL, &l, NULL, 0) < 0)
702 return (0);
703 if (l == 0)
704 return (0);
705 if ((buf = malloc(l)) == NULL)
706 return (0);
707 if (sysctl(mib, sizeof(mib) / sizeof(mib[0]), buf, &l, NULL, 0) < 0) {
708 free(buf);
709 return (0);
710 }
711
712 ep = (struct in6_addrpolicy *)(buf + l);
713 for (pol = (struct in6_addrpolicy *)buf; pol + 1 <= ep; pol++) {
714 struct policyqueue *new;
715
716 if ((new = malloc(sizeof(*new))) == NULL) {
717 free_addrselectpolicy(head); /* make the list empty */
718 break;
719 }
720 new->pc_policy = *pol;
721 TAILQ_INSERT_TAIL(head, new, pc_entry);
722 }
723
724 free(buf);
725 return (1);
726 #else
727 return (0);
728 #endif
729 }
730
731 static void
free_addrselectpolicy(struct policyhead * head)732 free_addrselectpolicy(struct policyhead *head)
733 {
734 struct policyqueue *ent, *nent;
735
736 for (ent = TAILQ_FIRST(head); ent; ent = nent) {
737 nent = TAILQ_NEXT(ent, pc_entry);
738 TAILQ_REMOVE(head, ent, pc_entry);
739 free(ent);
740 }
741 }
742
743 static struct policyqueue *
match_addrselectpolicy(struct sockaddr * addr,struct policyhead * head)744 match_addrselectpolicy(struct sockaddr *addr, struct policyhead *head)
745 {
746 #ifdef INET6
747 struct policyqueue *ent, *bestent = NULL;
748 struct in6_addrpolicy *pol;
749 int matchlen, bestmatchlen = -1;
750 u_char *mp, *ep, *k, *p, m;
751 struct sockaddr_in6 key;
752
753 switch(addr->sa_family) {
754 case AF_INET6:
755 key = *(struct sockaddr_in6 *)addr;
756 break;
757 case AF_INET:
758 /* convert the address into IPv4-mapped IPv6 address. */
759 memset(&key, 0, sizeof(key));
760 key.sin6_family = AF_INET6;
761 key.sin6_len = sizeof(key);
762 key.sin6_addr.s6_addr[10] = 0xff;
763 key.sin6_addr.s6_addr[11] = 0xff;
764 memcpy(&key.sin6_addr.s6_addr[12],
765 &((struct sockaddr_in *)addr)->sin_addr, 4);
766 break;
767 default:
768 return(NULL);
769 }
770
771 for (ent = TAILQ_FIRST(head); ent; ent = TAILQ_NEXT(ent, pc_entry)) {
772 pol = &ent->pc_policy;
773 matchlen = 0;
774
775 mp = (u_char *)&pol->addrmask.sin6_addr;
776 ep = mp + 16; /* XXX: scope field? */
777 k = (u_char *)&key.sin6_addr;
778 p = (u_char *)&pol->addr.sin6_addr;
779 for (; mp < ep && *mp; mp++, k++, p++) {
780 m = *mp;
781 if ((*k & m) != *p)
782 goto next; /* not match */
783 if (m == 0xff) /* short cut for a typical case */
784 matchlen += 8;
785 else {
786 while (m >= 0x80) {
787 matchlen++;
788 m <<= 1;
789 }
790 }
791 }
792
793 /* matched. check if this is better than the current best. */
794 if (matchlen > bestmatchlen) {
795 bestent = ent;
796 bestmatchlen = matchlen;
797 }
798
799 next:
800 continue;
801 }
802
803 return(bestent);
804 #else
805 return(NULL);
806 #endif
807
808 }
809
810 static void
set_source(struct ai_order * aio,struct policyhead * ph)811 set_source(struct ai_order *aio, struct policyhead *ph)
812 {
813 struct addrinfo ai = *aio->aio_ai;
814 struct sockaddr_storage ss;
815 socklen_t srclen;
816 int s;
817
818 /* set unspec ("no source is available"), just in case */
819 aio->aio_srcsa.sa_family = AF_UNSPEC;
820 aio->aio_srcscope = -1;
821
822 switch(ai.ai_family) {
823 case AF_INET:
824 #ifdef INET6
825 case AF_INET6:
826 #endif
827 break;
828 default: /* ignore unsupported AFs explicitly */
829 return;
830 }
831
832 /* XXX: make a dummy addrinfo to call connect() */
833 ai.ai_socktype = SOCK_DGRAM;
834 ai.ai_protocol = IPPROTO_UDP; /* is UDP too specific? */
835 ai.ai_next = NULL;
836 memset(&ss, 0, sizeof(ss));
837 memcpy(&ss, ai.ai_addr, ai.ai_addrlen);
838 ai.ai_addr = (struct sockaddr *)&ss;
839 get_port(&ai, "1", 0);
840
841 /* open a socket to get the source address for the given dst */
842 if ((s = _socket(ai.ai_family, ai.ai_socktype | SOCK_CLOEXEC,
843 ai.ai_protocol)) < 0)
844 return; /* give up */
845 if (_connect(s, ai.ai_addr, ai.ai_addrlen) < 0)
846 goto cleanup;
847 srclen = ai.ai_addrlen;
848 if (_getsockname(s, &aio->aio_srcsa, &srclen) < 0) {
849 aio->aio_srcsa.sa_family = AF_UNSPEC;
850 goto cleanup;
851 }
852 aio->aio_srcscope = gai_addr2scopetype(&aio->aio_srcsa);
853 aio->aio_srcpolicy = match_addrselectpolicy(&aio->aio_srcsa, ph);
854 aio->aio_matchlen = matchlen(&aio->aio_srcsa, aio->aio_ai->ai_addr);
855 #ifdef INET6
856 if (ai.ai_family == AF_INET6) {
857 struct in6_ifreq ifr6;
858 u_int32_t flags6;
859
860 memset(&ifr6, 0, sizeof(ifr6));
861 memcpy(&ifr6.ifr_addr, ai.ai_addr, ai.ai_addrlen);
862 if (_ioctl(s, SIOCGIFAFLAG_IN6, &ifr6) == 0) {
863 flags6 = ifr6.ifr_ifru.ifru_flags6;
864 if ((flags6 & IN6_IFF_DEPRECATED))
865 aio->aio_srcflag |= AIO_SRCFLAG_DEPRECATED;
866 }
867 }
868 #endif
869
870 cleanup:
871 _close(s);
872 return;
873 }
874
875 static int
matchlen(struct sockaddr * src,struct sockaddr * dst)876 matchlen(struct sockaddr *src, struct sockaddr *dst)
877 {
878 int match = 0;
879 u_char *s, *d;
880 u_char *lim, r;
881 int addrlen;
882
883 switch (src->sa_family) {
884 #ifdef INET6
885 case AF_INET6:
886 s = (u_char *)&((struct sockaddr_in6 *)src)->sin6_addr;
887 d = (u_char *)&((struct sockaddr_in6 *)dst)->sin6_addr;
888 addrlen = sizeof(struct in6_addr);
889 lim = s + addrlen;
890 break;
891 #endif
892 case AF_INET:
893 s = (u_char *)&((struct sockaddr_in *)src)->sin_addr;
894 d = (u_char *)&((struct sockaddr_in *)dst)->sin_addr;
895 addrlen = sizeof(struct in_addr);
896 lim = s + addrlen;
897 break;
898 default:
899 return(0);
900 }
901
902 while (s < lim)
903 if ((r = (*d++ ^ *s++)) != 0) {
904 while (r < addrlen * 8) {
905 match++;
906 r <<= 1;
907 }
908 break;
909 } else
910 match += 8;
911 return(match);
912 }
913
914 static int
comp_dst(const void * arg1,const void * arg2)915 comp_dst(const void *arg1, const void *arg2)
916 {
917 const struct ai_order *dst1 = arg1, *dst2 = arg2;
918
919 /*
920 * Rule 1: Avoid unusable destinations.
921 * XXX: we currently do not consider if an appropriate route exists.
922 */
923 if (dst1->aio_srcsa.sa_family != AF_UNSPEC &&
924 dst2->aio_srcsa.sa_family == AF_UNSPEC) {
925 return(-1);
926 }
927 if (dst1->aio_srcsa.sa_family == AF_UNSPEC &&
928 dst2->aio_srcsa.sa_family != AF_UNSPEC) {
929 return(1);
930 }
931
932 /* Rule 2: Prefer matching scope. */
933 if (dst1->aio_dstscope == dst1->aio_srcscope &&
934 dst2->aio_dstscope != dst2->aio_srcscope) {
935 return(-1);
936 }
937 if (dst1->aio_dstscope != dst1->aio_srcscope &&
938 dst2->aio_dstscope == dst2->aio_srcscope) {
939 return(1);
940 }
941
942 /* Rule 3: Avoid deprecated addresses. */
943 if (dst1->aio_srcsa.sa_family != AF_UNSPEC &&
944 dst2->aio_srcsa.sa_family != AF_UNSPEC) {
945 if (!(dst1->aio_srcflag & AIO_SRCFLAG_DEPRECATED) &&
946 (dst2->aio_srcflag & AIO_SRCFLAG_DEPRECATED)) {
947 return(-1);
948 }
949 if ((dst1->aio_srcflag & AIO_SRCFLAG_DEPRECATED) &&
950 !(dst2->aio_srcflag & AIO_SRCFLAG_DEPRECATED)) {
951 return(1);
952 }
953 }
954
955 /* Rule 4: Prefer home addresses. */
956 /* XXX: not implemented yet */
957
958 /* Rule 5: Prefer matching label. */
959 #ifdef INET6
960 if (dst1->aio_srcpolicy && dst1->aio_dstpolicy &&
961 dst1->aio_srcpolicy->pc_policy.label ==
962 dst1->aio_dstpolicy->pc_policy.label &&
963 (dst2->aio_srcpolicy == NULL || dst2->aio_dstpolicy == NULL ||
964 dst2->aio_srcpolicy->pc_policy.label !=
965 dst2->aio_dstpolicy->pc_policy.label)) {
966 return(-1);
967 }
968 if (dst2->aio_srcpolicy && dst2->aio_dstpolicy &&
969 dst2->aio_srcpolicy->pc_policy.label ==
970 dst2->aio_dstpolicy->pc_policy.label &&
971 (dst1->aio_srcpolicy == NULL || dst1->aio_dstpolicy == NULL ||
972 dst1->aio_srcpolicy->pc_policy.label !=
973 dst1->aio_dstpolicy->pc_policy.label)) {
974 return(1);
975 }
976 #endif
977
978 /* Rule 6: Prefer higher precedence. */
979 #ifdef INET6
980 if (dst1->aio_dstpolicy &&
981 (dst2->aio_dstpolicy == NULL ||
982 dst1->aio_dstpolicy->pc_policy.preced >
983 dst2->aio_dstpolicy->pc_policy.preced)) {
984 return(-1);
985 }
986 if (dst2->aio_dstpolicy &&
987 (dst1->aio_dstpolicy == NULL ||
988 dst2->aio_dstpolicy->pc_policy.preced >
989 dst1->aio_dstpolicy->pc_policy.preced)) {
990 return(1);
991 }
992 #endif
993
994 /* Rule 7: Prefer native transport. */
995 /* XXX: not implemented yet */
996
997 /* Rule 8: Prefer smaller scope. */
998 if (dst1->aio_dstscope >= 0 &&
999 dst1->aio_dstscope < dst2->aio_dstscope) {
1000 return(-1);
1001 }
1002 if (dst2->aio_dstscope >= 0 &&
1003 dst2->aio_dstscope < dst1->aio_dstscope) {
1004 return(1);
1005 }
1006
1007 /*
1008 * Rule 9: Use longest matching prefix.
1009 * We compare the match length in a same AF only.
1010 */
1011 if (dst1->aio_ai->ai_addr->sa_family ==
1012 dst2->aio_ai->ai_addr->sa_family &&
1013 dst1->aio_ai->ai_addr->sa_family != AF_INET) {
1014 if (dst1->aio_matchlen > dst2->aio_matchlen) {
1015 return(-1);
1016 }
1017 if (dst1->aio_matchlen < dst2->aio_matchlen) {
1018 return(1);
1019 }
1020 }
1021
1022 /* Rule 10: Otherwise, leave the order unchanged. */
1023 return(-1);
1024 }
1025
1026 /*
1027 * Copy from scope.c.
1028 * XXX: we should standardize the functions and link them as standard
1029 * library.
1030 */
1031 static int
gai_addr2scopetype(struct sockaddr * sa)1032 gai_addr2scopetype(struct sockaddr *sa)
1033 {
1034 #ifdef INET6
1035 struct sockaddr_in6 *sa6;
1036 #endif
1037 struct sockaddr_in *sa4;
1038
1039 switch(sa->sa_family) {
1040 #ifdef INET6
1041 case AF_INET6:
1042 sa6 = (struct sockaddr_in6 *)sa;
1043 if (IN6_IS_ADDR_MULTICAST(&sa6->sin6_addr)) {
1044 /* just use the scope field of the multicast address */
1045 return(sa6->sin6_addr.s6_addr[2] & 0x0f);
1046 }
1047 /*
1048 * Unicast addresses: map scope type to corresponding scope
1049 * value defined for multcast addresses.
1050 * XXX: hardcoded scope type values are bad...
1051 */
1052 if (IN6_IS_ADDR_LOOPBACK(&sa6->sin6_addr))
1053 return(1); /* node local scope */
1054 if (IN6_IS_ADDR_LINKLOCAL(&sa6->sin6_addr))
1055 return(2); /* link-local scope */
1056 if (IN6_IS_ADDR_SITELOCAL(&sa6->sin6_addr))
1057 return(5); /* site-local scope */
1058 return(14); /* global scope */
1059 break;
1060 #endif
1061 case AF_INET:
1062 /*
1063 * IPv4 pseudo scoping according to RFC 3484.
1064 */
1065 sa4 = (struct sockaddr_in *)sa;
1066 /* IPv4 autoconfiguration addresses have link-local scope. */
1067 if (((u_char *)&sa4->sin_addr)[0] == 169 &&
1068 ((u_char *)&sa4->sin_addr)[1] == 254)
1069 return(2);
1070 /* Private addresses have site-local scope. */
1071 if (((u_char *)&sa4->sin_addr)[0] == 10 ||
1072 (((u_char *)&sa4->sin_addr)[0] == 172 &&
1073 (((u_char *)&sa4->sin_addr)[1] & 0xf0) == 16) ||
1074 (((u_char *)&sa4->sin_addr)[0] == 192 &&
1075 ((u_char *)&sa4->sin_addr)[1] == 168))
1076 return(14); /* XXX: It should be 5 unless NAT */
1077 /* Loopback addresses have link-local scope. */
1078 if (((u_char *)&sa4->sin_addr)[0] == 127)
1079 return(2);
1080 return(14);
1081 break;
1082 default:
1083 errno = EAFNOSUPPORT; /* is this a good error? */
1084 return(-1);
1085 }
1086 }
1087
1088 static int
explore_copy(const struct addrinfo * pai,const struct addrinfo * src0,struct addrinfo ** res)1089 explore_copy(const struct addrinfo *pai, const struct addrinfo *src0,
1090 struct addrinfo **res)
1091 {
1092 int error;
1093 struct addrinfo sentinel, *cur;
1094 const struct addrinfo *src;
1095
1096 error = 0;
1097 sentinel.ai_next = NULL;
1098 cur = &sentinel;
1099
1100 for (src = src0; src != NULL; src = src->ai_next) {
1101 if (src->ai_family != pai->ai_family)
1102 continue;
1103
1104 cur->ai_next = copy_ai(src);
1105 if (!cur->ai_next) {
1106 error = EAI_MEMORY;
1107 goto fail;
1108 }
1109
1110 cur->ai_next->ai_socktype = pai->ai_socktype;
1111 cur->ai_next->ai_protocol = pai->ai_protocol;
1112 cur = cur->ai_next;
1113 }
1114
1115 *res = sentinel.ai_next;
1116 return 0;
1117
1118 fail:
1119 freeaddrinfo(sentinel.ai_next);
1120 return error;
1121 }
1122
1123 /*
1124 * hostname == NULL.
1125 * passive socket -> anyaddr (0.0.0.0 or ::)
1126 * non-passive socket -> localhost (127.0.0.1 or ::1)
1127 */
1128 static int
explore_null(const struct addrinfo * pai,const char * servname,struct addrinfo ** res)1129 explore_null(const struct addrinfo *pai, const char *servname,
1130 struct addrinfo **res)
1131 {
1132 int s;
1133 const struct afd *afd;
1134 struct addrinfo *ai;
1135 int error;
1136
1137 *res = NULL;
1138 ai = NULL;
1139
1140 /*
1141 * filter out AFs that are not supported by the kernel
1142 * XXX errno?
1143 */
1144 s = _socket(pai->ai_family, SOCK_DGRAM | SOCK_CLOEXEC, 0);
1145 if (s < 0) {
1146 if (errno != EMFILE)
1147 return 0;
1148 } else
1149 _close(s);
1150
1151 afd = find_afd(pai->ai_family);
1152 if (afd == NULL)
1153 return 0;
1154
1155 if (pai->ai_flags & AI_PASSIVE) {
1156 GET_AI(ai, afd, afd->a_addrany);
1157 GET_PORT(ai, servname);
1158 } else {
1159 GET_AI(ai, afd, afd->a_loopback);
1160 GET_PORT(ai, servname);
1161 }
1162
1163 *res = ai;
1164 return 0;
1165
1166 free:
1167 if (ai != NULL)
1168 freeaddrinfo(ai);
1169 return error;
1170 }
1171
1172 /*
1173 * numeric hostname
1174 */
1175 static int
explore_numeric(const struct addrinfo * pai,const char * hostname,const char * servname,struct addrinfo ** res,const char * canonname)1176 explore_numeric(const struct addrinfo *pai, const char *hostname,
1177 const char *servname, struct addrinfo **res, const char *canonname)
1178 {
1179 const struct afd *afd;
1180 struct addrinfo *ai;
1181 int error;
1182 char pton[PTON_MAX];
1183
1184 *res = NULL;
1185 ai = NULL;
1186
1187 afd = find_afd(pai->ai_family);
1188 if (afd == NULL)
1189 return 0;
1190
1191 switch (afd->a_af) {
1192 case AF_INET:
1193 /*
1194 * RFC3493 requires getaddrinfo() to accept AF_INET formats
1195 * that are accepted by inet_addr() and its family. The
1196 * accepted forms includes the "classful" one, which inet_pton
1197 * does not accept. So we need to separate the case for
1198 * AF_INET.
1199 */
1200 if (inet_aton(hostname, (struct in_addr *)pton) != 1)
1201 return 0;
1202 break;
1203 default:
1204 if (inet_pton(afd->a_af, hostname, pton) != 1)
1205 return 0;
1206 break;
1207 }
1208
1209 if (pai->ai_family == afd->a_af) {
1210 GET_AI(ai, afd, pton);
1211 GET_PORT(ai, servname);
1212 if ((pai->ai_flags & AI_CANONNAME)) {
1213 /*
1214 * Set the numeric address itself as the canonical
1215 * name, based on a clarification in RFC3493.
1216 */
1217 GET_CANONNAME(ai, canonname);
1218 }
1219 } else {
1220 /*
1221 * XXX: This should not happen since we already matched the AF
1222 * by find_afd.
1223 */
1224 ERR(EAI_FAMILY);
1225 }
1226
1227 *res = ai;
1228 return 0;
1229
1230 free:
1231 bad:
1232 if (ai != NULL)
1233 freeaddrinfo(ai);
1234 return error;
1235 }
1236
1237 /*
1238 * numeric hostname with scope
1239 */
1240 static int
explore_numeric_scope(const struct addrinfo * pai,const char * hostname,const char * servname,struct addrinfo ** res)1241 explore_numeric_scope(const struct addrinfo *pai, const char *hostname,
1242 const char *servname, struct addrinfo **res)
1243 {
1244 #if !defined(SCOPE_DELIMITER) || !defined(INET6)
1245 return explore_numeric(pai, hostname, servname, res, hostname);
1246 #else
1247 const struct afd *afd;
1248 struct addrinfo *cur;
1249 int error;
1250 char *cp, *hostname2 = NULL, *scope, *addr;
1251 struct sockaddr_in6 *sin6;
1252
1253 afd = find_afd(pai->ai_family);
1254 if (afd == NULL)
1255 return 0;
1256
1257 if (!afd->a_scoped)
1258 return explore_numeric(pai, hostname, servname, res, hostname);
1259
1260 cp = strchr(hostname, SCOPE_DELIMITER);
1261 if (cp == NULL)
1262 return explore_numeric(pai, hostname, servname, res, hostname);
1263
1264 /*
1265 * Handle special case of <scoped_address><delimiter><scope id>
1266 */
1267 hostname2 = strdup(hostname);
1268 if (hostname2 == NULL)
1269 return EAI_MEMORY;
1270 /* terminate at the delimiter */
1271 hostname2[cp - hostname] = '\0';
1272 addr = hostname2;
1273 scope = cp + 1;
1274
1275 error = explore_numeric(pai, addr, servname, res, hostname);
1276 if (error == 0) {
1277 u_int32_t scopeid;
1278
1279 for (cur = *res; cur; cur = cur->ai_next) {
1280 if (cur->ai_family != AF_INET6)
1281 continue;
1282 sin6 = (struct sockaddr_in6 *)(void *)cur->ai_addr;
1283 if (ip6_str2scopeid(scope, sin6, &scopeid) == -1) {
1284 free(hostname2);
1285 freeaddrinfo(*res);
1286 *res = NULL;
1287 return(EAI_NONAME); /* XXX: is return OK? */
1288 }
1289 sin6->sin6_scope_id = scopeid;
1290 }
1291 }
1292
1293 free(hostname2);
1294
1295 if (error && *res) {
1296 freeaddrinfo(*res);
1297 *res = NULL;
1298 }
1299 return error;
1300 #endif
1301 }
1302
1303 static int
get_canonname(const struct addrinfo * pai,struct addrinfo * ai,const char * str)1304 get_canonname(const struct addrinfo *pai, struct addrinfo *ai, const char *str)
1305 {
1306 if ((pai->ai_flags & AI_CANONNAME) != 0) {
1307 ai->ai_canonname = strdup(str);
1308 if (ai->ai_canonname == NULL)
1309 return EAI_MEMORY;
1310 }
1311 return 0;
1312 }
1313
1314 static struct addrinfo *
get_ai(const struct addrinfo * pai,const struct afd * afd,const char * addr)1315 get_ai(const struct addrinfo *pai, const struct afd *afd, const char *addr)
1316 {
1317 char *p;
1318 struct addrinfo *ai;
1319 #ifdef FAITH
1320 struct in6_addr faith_prefix;
1321 char *fp_str;
1322 int translate = 0;
1323 #endif
1324
1325 #ifdef FAITH
1326 /*
1327 * Transfrom an IPv4 addr into a special IPv6 addr format for
1328 * IPv6->IPv4 translation gateway. (only TCP is supported now)
1329 *
1330 * +-----------------------------------+------------+
1331 * | faith prefix part (12 bytes) | embedded |
1332 * | | IPv4 addr part (4 bytes)
1333 * +-----------------------------------+------------+
1334 *
1335 * faith prefix part is specified as ascii IPv6 addr format
1336 * in environmental variable GAI.
1337 * For FAITH to work correctly, routing to faith prefix must be
1338 * setup toward a machine where a FAITH daemon operates.
1339 * Also, the machine must enable some mechanizm
1340 * (e.g. faith interface hack) to divert those packet with
1341 * faith prefixed destination addr to user-land FAITH daemon.
1342 */
1343 fp_str = getenv("GAI");
1344 if (fp_str && inet_pton(AF_INET6, fp_str, &faith_prefix) == 1 &&
1345 afd->a_af == AF_INET && pai->ai_socktype == SOCK_STREAM) {
1346 u_int32_t v4a;
1347 u_int8_t v4a_top;
1348
1349 memcpy(&v4a, addr, sizeof v4a);
1350 v4a_top = v4a >> IN_CLASSA_NSHIFT;
1351 if (!IN_MULTICAST(v4a) && !IN_EXPERIMENTAL(v4a) &&
1352 v4a_top != 0 && v4a != IN_LOOPBACKNET) {
1353 afd = &afdl[N_INET6];
1354 memcpy(&faith_prefix.s6_addr[12], addr,
1355 sizeof(struct in_addr));
1356 translate = 1;
1357 }
1358 }
1359 #endif
1360
1361 ai = (struct addrinfo *)malloc(sizeof(struct addrinfo)
1362 + (afd->a_socklen));
1363 if (ai == NULL)
1364 return NULL;
1365
1366 memcpy(ai, pai, sizeof(struct addrinfo));
1367 ai->ai_addr = (struct sockaddr *)(void *)(ai + 1);
1368 memset(ai->ai_addr, 0, (size_t)afd->a_socklen);
1369 ai->ai_addr->sa_len = afd->a_socklen;
1370 ai->ai_addrlen = afd->a_socklen;
1371 ai->ai_addr->sa_family = ai->ai_family = afd->a_af;
1372 p = (char *)(void *)(ai->ai_addr);
1373 #ifdef FAITH
1374 if (translate == 1)
1375 memcpy(p + afd->a_off, &faith_prefix, (size_t)afd->a_addrlen);
1376 else
1377 #endif
1378 memcpy(p + afd->a_off, addr, (size_t)afd->a_addrlen);
1379 return ai;
1380 }
1381
1382 /* XXX need to malloc() the same way we do from other functions! */
1383 static struct addrinfo *
copy_ai(const struct addrinfo * pai)1384 copy_ai(const struct addrinfo *pai)
1385 {
1386 struct addrinfo *ai;
1387 size_t l;
1388
1389 l = sizeof(*ai) + pai->ai_addrlen;
1390 if ((ai = (struct addrinfo *)malloc(l)) == NULL)
1391 return NULL;
1392 memset(ai, 0, l);
1393 memcpy(ai, pai, sizeof(*ai));
1394 ai->ai_addr = (struct sockaddr *)(void *)(ai + 1);
1395 memcpy(ai->ai_addr, pai->ai_addr, pai->ai_addrlen);
1396
1397 if (pai->ai_canonname) {
1398 l = strlen(pai->ai_canonname) + 1;
1399 if ((ai->ai_canonname = malloc(l)) == NULL) {
1400 free(ai);
1401 return NULL;
1402 }
1403 strlcpy(ai->ai_canonname, pai->ai_canonname, l);
1404 } else {
1405 /* just to make sure */
1406 ai->ai_canonname = NULL;
1407 }
1408
1409 ai->ai_next = NULL;
1410
1411 return ai;
1412 }
1413
1414 static int
get_portmatch(const struct addrinfo * ai,const char * servname)1415 get_portmatch(const struct addrinfo *ai, const char *servname)
1416 {
1417
1418 /* get_port does not touch first argument when matchonly == 1. */
1419 /* LINTED const cast */
1420 return get_port((struct addrinfo *)ai, servname, 1);
1421 }
1422
1423 static int
get_port(struct addrinfo * ai,const char * servname,int matchonly)1424 get_port(struct addrinfo *ai, const char *servname, int matchonly)
1425 {
1426 const char *proto;
1427 struct servent *sp;
1428 int port, error;
1429 int allownumeric;
1430
1431 if (servname == NULL)
1432 return 0;
1433 switch (ai->ai_family) {
1434 case AF_INET:
1435 #ifdef AF_INET6
1436 case AF_INET6:
1437 #endif
1438 break;
1439 default:
1440 return 0;
1441 }
1442
1443 switch (ai->ai_socktype) {
1444 case SOCK_RAW:
1445 return EAI_SERVICE;
1446 case SOCK_DGRAM:
1447 case SOCK_STREAM:
1448 case SOCK_SEQPACKET:
1449 allownumeric = 1;
1450 break;
1451 case ANY:
1452 switch (ai->ai_family) {
1453 case AF_INET:
1454 #ifdef AF_INET6
1455 case AF_INET6:
1456 #endif
1457 allownumeric = 1;
1458 break;
1459 default:
1460 allownumeric = 0;
1461 break;
1462 }
1463 break;
1464 default:
1465 return EAI_SOCKTYPE;
1466 }
1467
1468 error = str2number(servname, &port);
1469 if (error == 0) {
1470 if (!allownumeric)
1471 return EAI_SERVICE;
1472 if (port < 0 || port > 65535)
1473 return EAI_SERVICE;
1474 port = htons(port);
1475 } else {
1476 if (ai->ai_flags & AI_NUMERICSERV)
1477 return EAI_NONAME;
1478
1479 switch (ai->ai_protocol) {
1480 case IPPROTO_UDP:
1481 proto = "udp";
1482 break;
1483 case IPPROTO_TCP:
1484 proto = "tcp";
1485 break;
1486 case IPPROTO_SCTP:
1487 proto = "sctp";
1488 break;
1489 case IPPROTO_UDPLITE:
1490 proto = "udplite";
1491 break;
1492 default:
1493 proto = NULL;
1494 break;
1495 }
1496
1497 if ((sp = getservbyname(servname, proto)) == NULL)
1498 return EAI_SERVICE;
1499 port = sp->s_port;
1500 }
1501
1502 if (!matchonly) {
1503 switch (ai->ai_family) {
1504 case AF_INET:
1505 ((struct sockaddr_in *)(void *)
1506 ai->ai_addr)->sin_port = port;
1507 break;
1508 #ifdef INET6
1509 case AF_INET6:
1510 ((struct sockaddr_in6 *)(void *)
1511 ai->ai_addr)->sin6_port = port;
1512 break;
1513 #endif
1514 }
1515 }
1516
1517 return 0;
1518 }
1519
1520 static const struct afd *
find_afd(int af)1521 find_afd(int af)
1522 {
1523 const struct afd *afd;
1524
1525 if (af == PF_UNSPEC)
1526 return NULL;
1527 for (afd = afdl; afd->a_af; afd++) {
1528 if (afd->a_af == af)
1529 return afd;
1530 }
1531 return NULL;
1532 }
1533
1534 /*
1535 * RFC 3493: AI_ADDRCONFIG check. Determines which address families are
1536 * configured on the local system and correlates with pai->ai_family value.
1537 * If an address family is not configured on the system, it will not be
1538 * queried for. For this purpose, loopback addresses are not considered
1539 * configured addresses.
1540 *
1541 * XXX PF_UNSPEC -> PF_INET6 + PF_INET mapping needs to be in sync with
1542 * _dns_getaddrinfo.
1543 */
1544 static int
addrconfig(struct addrinfo * pai)1545 addrconfig(struct addrinfo *pai)
1546 {
1547 struct ifaddrs *ifaddrs, *ifa;
1548 struct sockaddr_in *sin;
1549 #ifdef INET6
1550 struct sockaddr_in6 *sin6;
1551 #endif
1552 int seen_inet = 0, seen_inet6 = 0;
1553
1554 if (getifaddrs(&ifaddrs) != 0)
1555 return (0);
1556
1557 for (ifa = ifaddrs; ifa != NULL; ifa = ifa->ifa_next) {
1558 if (ifa->ifa_addr == NULL || (ifa->ifa_flags & IFF_UP) == 0)
1559 continue;
1560 switch (ifa->ifa_addr->sa_family) {
1561 case AF_INET:
1562 if (seen_inet)
1563 continue;
1564 sin = (struct sockaddr_in *)(ifa->ifa_addr);
1565 if (IN_LOOPBACK(htonl(sin->sin_addr.s_addr)))
1566 continue;
1567 seen_inet = 1;
1568 break;
1569 #ifdef INET6
1570 case AF_INET6:
1571 if (seen_inet6)
1572 continue;
1573 sin6 = (struct sockaddr_in6 *)(ifa->ifa_addr);
1574 if (IN6_IS_ADDR_LOOPBACK(&sin6->sin6_addr))
1575 continue;
1576 if ((ifa->ifa_flags & IFT_LOOP) != 0 &&
1577 IN6_IS_ADDR_LINKLOCAL(&sin6->sin6_addr))
1578 continue;
1579 if (is_ifdisabled(ifa->ifa_name))
1580 continue;
1581 seen_inet6 = 1;
1582 break;
1583 #endif
1584 }
1585 }
1586 freeifaddrs(ifaddrs);
1587
1588 switch(pai->ai_family) {
1589 case AF_INET6:
1590 return (seen_inet6);
1591 case AF_INET:
1592 return (seen_inet);
1593 case AF_UNSPEC:
1594 if (seen_inet == seen_inet6)
1595 return (seen_inet);
1596 pai->ai_family = seen_inet ? AF_INET : AF_INET6;
1597 return (1);
1598 }
1599 return (1);
1600 }
1601
1602 #ifdef INET6
1603 static int
is_ifdisabled(char * name)1604 is_ifdisabled(char *name)
1605 {
1606 struct in6_ndireq nd;
1607 int fd;
1608
1609 if ((fd = _socket(AF_INET6, SOCK_DGRAM | SOCK_CLOEXEC, 0)) < 0)
1610 return (-1);
1611 memset(&nd, 0, sizeof(nd));
1612 strlcpy(nd.ifname, name, sizeof(nd.ifname));
1613 if (_ioctl(fd, SIOCGIFINFO_IN6, &nd) < 0) {
1614 _close(fd);
1615 return (-1);
1616 }
1617 _close(fd);
1618 return ((nd.ndi.flags & ND6_IFF_IFDISABLED) != 0);
1619 }
1620
1621 /* convert a string to a scope identifier. XXX: IPv6 specific */
1622 static int
ip6_str2scopeid(char * scope,struct sockaddr_in6 * sin6,u_int32_t * scopeid)1623 ip6_str2scopeid(char *scope, struct sockaddr_in6 *sin6, u_int32_t *scopeid)
1624 {
1625 u_long lscopeid;
1626 struct in6_addr *a6;
1627 char *ep;
1628
1629 a6 = &sin6->sin6_addr;
1630
1631 /* empty scopeid portion is invalid */
1632 if (*scope == '\0')
1633 return -1;
1634
1635 if (IN6_IS_ADDR_LINKLOCAL(a6) || IN6_IS_ADDR_MC_LINKLOCAL(a6) ||
1636 IN6_IS_ADDR_MC_NODELOCAL(a6)) {
1637 /*
1638 * We currently assume a one-to-one mapping between links
1639 * and interfaces, so we simply use interface indices for
1640 * like-local scopes.
1641 */
1642 *scopeid = if_nametoindex(scope);
1643 if (*scopeid == 0)
1644 goto trynumeric;
1645 return 0;
1646 }
1647
1648 /* still unclear about literal, allow numeric only - placeholder */
1649 if (IN6_IS_ADDR_SITELOCAL(a6) || IN6_IS_ADDR_MC_SITELOCAL(a6))
1650 goto trynumeric;
1651 if (IN6_IS_ADDR_MC_ORGLOCAL(a6))
1652 goto trynumeric;
1653 else
1654 goto trynumeric; /* global */
1655
1656 /* try to convert to a numeric id as a last resort */
1657 trynumeric:
1658 errno = 0;
1659 lscopeid = strtoul(scope, &ep, 10);
1660 *scopeid = (u_int32_t)(lscopeid & 0xffffffffUL);
1661 if (errno == 0 && ep && *ep == '\0' && *scopeid == lscopeid)
1662 return 0;
1663 else
1664 return -1;
1665 }
1666 #endif
1667
1668
1669 #ifdef NS_CACHING
1670 static int
addrinfo_id_func(char * buffer,size_t * buffer_size,va_list ap,void * cache_mdata)1671 addrinfo_id_func(char *buffer, size_t *buffer_size, va_list ap,
1672 void *cache_mdata)
1673 {
1674 res_state statp;
1675 u_long res_options;
1676
1677 const int op_id = 0; /* identifies the getaddrinfo for the cache */
1678 char *hostname;
1679 struct addrinfo *hints;
1680
1681 char *p;
1682 int ai_flags, ai_family, ai_socktype, ai_protocol;
1683 size_t desired_size, size;
1684
1685 statp = __res_state();
1686 res_options = statp->options & (RES_RECURSE | RES_DEFNAMES |
1687 RES_DNSRCH | RES_NOALIASES | RES_USE_INET6);
1688
1689 hostname = va_arg(ap, char *);
1690 hints = va_arg(ap, struct addrinfo *);
1691
1692 desired_size = sizeof(res_options) + sizeof(int) + sizeof(int) * 4;
1693 if (hostname != NULL) {
1694 size = strlen(hostname);
1695 desired_size += size + 1;
1696 } else
1697 size = 0;
1698
1699 if (desired_size > *buffer_size) {
1700 *buffer_size = desired_size;
1701 return (NS_RETURN);
1702 }
1703
1704 if (hints == NULL)
1705 ai_flags = ai_family = ai_socktype = ai_protocol = 0;
1706 else {
1707 ai_flags = hints->ai_flags;
1708 ai_family = hints->ai_family;
1709 ai_socktype = hints->ai_socktype;
1710 ai_protocol = hints->ai_protocol;
1711 }
1712
1713 p = buffer;
1714 memcpy(p, &res_options, sizeof(res_options));
1715 p += sizeof(res_options);
1716
1717 memcpy(p, &op_id, sizeof(int));
1718 p += sizeof(int);
1719
1720 memcpy(p, &ai_flags, sizeof(int));
1721 p += sizeof(int);
1722
1723 memcpy(p, &ai_family, sizeof(int));
1724 p += sizeof(int);
1725
1726 memcpy(p, &ai_socktype, sizeof(int));
1727 p += sizeof(int);
1728
1729 memcpy(p, &ai_protocol, sizeof(int));
1730 p += sizeof(int);
1731
1732 if (hostname != NULL)
1733 memcpy(p, hostname, size);
1734
1735 *buffer_size = desired_size;
1736 return (NS_SUCCESS);
1737 }
1738
1739 static int
addrinfo_marshal_func(char * buffer,size_t * buffer_size,void * retval,va_list ap,void * cache_mdata)1740 addrinfo_marshal_func(char *buffer, size_t *buffer_size, void *retval,
1741 va_list ap, void *cache_mdata)
1742 {
1743 struct addrinfo *ai, *cai;
1744 char *p;
1745 size_t desired_size, size, ai_size;
1746
1747 ai = *((struct addrinfo **)retval);
1748
1749 desired_size = sizeof(size_t);
1750 ai_size = 0;
1751 for (cai = ai; cai != NULL; cai = cai->ai_next) {
1752 desired_size += sizeof(struct addrinfo) + cai->ai_addrlen;
1753 if (cai->ai_canonname != NULL)
1754 desired_size += sizeof(size_t) +
1755 strlen(cai->ai_canonname);
1756 ++ai_size;
1757 }
1758
1759 if (desired_size > *buffer_size) {
1760 /* this assignment is here for future use */
1761 errno = ERANGE;
1762 *buffer_size = desired_size;
1763 return (NS_RETURN);
1764 }
1765
1766 memset(buffer, 0, desired_size);
1767 p = buffer;
1768
1769 memcpy(p, &ai_size, sizeof(size_t));
1770 p += sizeof(size_t);
1771 for (cai = ai; cai != NULL; cai = cai->ai_next) {
1772 memcpy(p, cai, sizeof(struct addrinfo));
1773 p += sizeof(struct addrinfo);
1774
1775 memcpy(p, cai->ai_addr, cai->ai_addrlen);
1776 p += cai->ai_addrlen;
1777
1778 if (cai->ai_canonname != NULL) {
1779 size = strlen(cai->ai_canonname);
1780 memcpy(p, &size, sizeof(size_t));
1781 p += sizeof(size_t);
1782
1783 memcpy(p, cai->ai_canonname, size);
1784 p += size;
1785 }
1786 }
1787
1788 return (NS_SUCCESS);
1789 }
1790
1791 static int
addrinfo_unmarshal_func(char * buffer,size_t buffer_size,void * retval,va_list ap,void * cache_mdata)1792 addrinfo_unmarshal_func(char *buffer, size_t buffer_size, void *retval,
1793 va_list ap, void *cache_mdata)
1794 {
1795 struct addrinfo new_ai, *result, *sentinel, *lasts;
1796
1797 char *p;
1798 size_t ai_size, ai_i, size;
1799
1800 p = buffer;
1801 memcpy(&ai_size, p, sizeof(size_t));
1802 p += sizeof(size_t);
1803
1804 result = NULL;
1805 lasts = NULL;
1806 for (ai_i = 0; ai_i < ai_size; ++ai_i) {
1807 memcpy(&new_ai, p, sizeof(struct addrinfo));
1808 p += sizeof(struct addrinfo);
1809 size = new_ai.ai_addrlen + sizeof(struct addrinfo) +
1810 _ALIGNBYTES;
1811
1812 sentinel = (struct addrinfo *)malloc(size);
1813 memset(sentinel, 0, size);
1814
1815 memcpy(sentinel, &new_ai, sizeof(struct addrinfo));
1816 sentinel->ai_addr = (struct sockaddr *)_ALIGN((char *)sentinel +
1817 sizeof(struct addrinfo));
1818
1819 memcpy(sentinel->ai_addr, p, new_ai.ai_addrlen);
1820 p += new_ai.ai_addrlen;
1821
1822 if (new_ai.ai_canonname != NULL) {
1823 memcpy(&size, p, sizeof(size_t));
1824 p += sizeof(size_t);
1825
1826 sentinel->ai_canonname = (char *)malloc(size + 1);
1827 memset(sentinel->ai_canonname, 0, size + 1);
1828
1829 memcpy(sentinel->ai_canonname, p, size);
1830 p += size;
1831 }
1832
1833 if (result == NULL) {
1834 result = sentinel;
1835 lasts = sentinel;
1836 } else {
1837 lasts->ai_next = sentinel;
1838 lasts = sentinel;
1839 }
1840 }
1841
1842 *((struct addrinfo **)retval) = result;
1843 return (NS_SUCCESS);
1844 }
1845 #endif /* NS_CACHING */
1846
1847 /*
1848 * FQDN hostname, DNS lookup
1849 */
1850 static int
explore_fqdn(const struct addrinfo * pai,const char * hostname,const char * servname,struct addrinfo ** res)1851 explore_fqdn(const struct addrinfo *pai, const char *hostname,
1852 const char *servname, struct addrinfo **res)
1853 {
1854 struct addrinfo *result;
1855 struct addrinfo *cur;
1856 int error = 0;
1857
1858 #ifdef NS_CACHING
1859 static const nss_cache_info cache_info =
1860 NS_COMMON_CACHE_INFO_INITIALIZER(
1861 hosts, NULL, addrinfo_id_func, addrinfo_marshal_func,
1862 addrinfo_unmarshal_func);
1863 #endif
1864 static const ns_dtab dtab[] = {
1865 NS_FILES_CB(_files_getaddrinfo, NULL)
1866 { NSSRC_DNS, _dns_getaddrinfo, NULL }, /* force -DHESIOD */
1867 NS_NIS_CB(_yp_getaddrinfo, NULL)
1868 #ifdef NS_CACHING
1869 NS_CACHE_CB(&cache_info)
1870 #endif
1871 { 0 }
1872 };
1873
1874 result = NULL;
1875
1876 /*
1877 * if the servname does not match socktype/protocol, ignore it.
1878 */
1879 if (get_portmatch(pai, servname) != 0)
1880 return 0;
1881
1882 switch (_nsdispatch(&result, dtab, NSDB_HOSTS, "getaddrinfo",
1883 default_dns_files, hostname, pai)) {
1884 case NS_TRYAGAIN:
1885 error = EAI_AGAIN;
1886 goto free;
1887 case NS_UNAVAIL:
1888 error = EAI_FAIL;
1889 goto free;
1890 case NS_NOTFOUND:
1891 error = EAI_NONAME;
1892 goto free;
1893 case NS_SUCCESS:
1894 error = 0;
1895 for (cur = result; cur; cur = cur->ai_next) {
1896 GET_PORT(cur, servname);
1897 /* canonname should be filled already */
1898 }
1899 break;
1900 }
1901
1902 *res = result;
1903
1904 return 0;
1905
1906 free:
1907 if (result)
1908 freeaddrinfo(result);
1909 return error;
1910 }
1911
1912 #ifdef DEBUG
1913 static const char AskedForGot[] =
1914 "gethostby*.getanswer: asked for \"%s\", got \"%s\"";
1915 #endif
1916
1917 static struct addrinfo *
getanswer(const querybuf * answer,int anslen,const char * qname,int qtype,const struct addrinfo * pai,res_state res)1918 getanswer(const querybuf *answer, int anslen, const char *qname, int qtype,
1919 const struct addrinfo *pai, res_state res)
1920 {
1921 struct addrinfo sentinel, *cur;
1922 struct addrinfo ai;
1923 const struct afd *afd;
1924 char *canonname;
1925 const HEADER *hp;
1926 const u_char *cp;
1927 int n;
1928 const u_char *eom;
1929 char *bp, *ep;
1930 int type, class, ancount, qdcount;
1931 int haveanswer, had_error;
1932 char tbuf[MAXDNAME];
1933 int (*name_ok)(const char *);
1934 char hostbuf[8*1024];
1935
1936 memset(&sentinel, 0, sizeof(sentinel));
1937 cur = &sentinel;
1938
1939 canonname = NULL;
1940 eom = answer->buf + anslen;
1941 switch (qtype) {
1942 case T_A:
1943 case T_AAAA:
1944 case T_ANY: /*use T_ANY only for T_A/T_AAAA lookup*/
1945 name_ok = res_hnok;
1946 break;
1947 default:
1948 return (NULL); /* XXX should be abort(); */
1949 }
1950 /*
1951 * find first satisfactory answer
1952 */
1953 hp = &answer->hdr;
1954 ancount = ntohs(hp->ancount);
1955 qdcount = ntohs(hp->qdcount);
1956 bp = hostbuf;
1957 ep = hostbuf + sizeof hostbuf;
1958 cp = answer->buf + HFIXEDSZ;
1959 if (qdcount != 1) {
1960 RES_SET_H_ERRNO(res, NO_RECOVERY);
1961 return (NULL);
1962 }
1963 n = dn_expand(answer->buf, eom, cp, bp, ep - bp);
1964 if ((n < 0) || !(*name_ok)(bp)) {
1965 RES_SET_H_ERRNO(res, NO_RECOVERY);
1966 return (NULL);
1967 }
1968 cp += n + QFIXEDSZ;
1969 if (qtype == T_A || qtype == T_AAAA || qtype == T_ANY) {
1970 /* res_send() has already verified that the query name is the
1971 * same as the one we sent; this just gets the expanded name
1972 * (i.e., with the succeeding search-domain tacked on).
1973 */
1974 n = strlen(bp) + 1; /* for the \0 */
1975 if (n >= MAXHOSTNAMELEN) {
1976 RES_SET_H_ERRNO(res, NO_RECOVERY);
1977 return (NULL);
1978 }
1979 canonname = bp;
1980 bp += n;
1981 /* The qname can be abbreviated, but h_name is now absolute. */
1982 qname = canonname;
1983 }
1984 haveanswer = 0;
1985 had_error = 0;
1986 while (ancount-- > 0 && cp < eom && !had_error) {
1987 n = dn_expand(answer->buf, eom, cp, bp, ep - bp);
1988 if ((n < 0) || !(*name_ok)(bp)) {
1989 had_error++;
1990 continue;
1991 }
1992 cp += n; /* name */
1993 type = _getshort(cp);
1994 cp += INT16SZ; /* type */
1995 class = _getshort(cp);
1996 cp += INT16SZ + INT32SZ; /* class, TTL */
1997 n = _getshort(cp);
1998 cp += INT16SZ; /* len */
1999 if (class != C_IN) {
2000 /* XXX - debug? syslog? */
2001 cp += n;
2002 continue; /* XXX - had_error++ ? */
2003 }
2004 if ((qtype == T_A || qtype == T_AAAA || qtype == T_ANY) &&
2005 type == T_CNAME) {
2006 n = dn_expand(answer->buf, eom, cp, tbuf, sizeof tbuf);
2007 if ((n < 0) || !(*name_ok)(tbuf)) {
2008 had_error++;
2009 continue;
2010 }
2011 cp += n;
2012 /* Get canonical name. */
2013 n = strlen(tbuf) + 1; /* for the \0 */
2014 if (n > ep - bp || n >= MAXHOSTNAMELEN) {
2015 had_error++;
2016 continue;
2017 }
2018 strlcpy(bp, tbuf, ep - bp);
2019 canonname = bp;
2020 bp += n;
2021 continue;
2022 }
2023 if (qtype == T_ANY) {
2024 if (!(type == T_A || type == T_AAAA)) {
2025 cp += n;
2026 continue;
2027 }
2028 } else if (type != qtype) {
2029 #ifdef DEBUG
2030 if (type != T_KEY && type != T_SIG &&
2031 type != ns_t_dname)
2032 syslog(LOG_NOTICE|LOG_AUTH,
2033 "gethostby*.getanswer: asked for \"%s %s %s\", got type \"%s\"",
2034 qname, p_class(C_IN), p_type(qtype),
2035 p_type(type));
2036 #endif
2037 cp += n;
2038 continue; /* XXX - had_error++ ? */
2039 }
2040 switch (type) {
2041 case T_A:
2042 case T_AAAA:
2043 if (strcasecmp(canonname, bp) != 0) {
2044 #ifdef DEBUG
2045 syslog(LOG_NOTICE|LOG_AUTH,
2046 AskedForGot, canonname, bp);
2047 #endif
2048 cp += n;
2049 continue; /* XXX - had_error++ ? */
2050 }
2051 if (type == T_A && n != INADDRSZ) {
2052 cp += n;
2053 continue;
2054 }
2055 if (type == T_AAAA && n != IN6ADDRSZ) {
2056 cp += n;
2057 continue;
2058 }
2059 #ifdef FILTER_V4MAPPED
2060 if (type == T_AAAA) {
2061 struct in6_addr in6;
2062 memcpy(&in6, cp, sizeof(in6));
2063 if (IN6_IS_ADDR_V4MAPPED(&in6)) {
2064 cp += n;
2065 continue;
2066 }
2067 }
2068 #endif
2069 if (!haveanswer) {
2070 int nn;
2071
2072 canonname = bp;
2073 nn = strlen(bp) + 1; /* for the \0 */
2074 bp += nn;
2075 }
2076
2077 /* don't overwrite pai */
2078 ai = *pai;
2079 ai.ai_family = (type == T_A) ? AF_INET : AF_INET6;
2080 afd = find_afd(ai.ai_family);
2081 if (afd == NULL) {
2082 cp += n;
2083 continue;
2084 }
2085 cur->ai_next = get_ai(&ai, afd, (const char *)cp);
2086 if (cur->ai_next == NULL)
2087 had_error++;
2088 while (cur && cur->ai_next)
2089 cur = cur->ai_next;
2090 cp += n;
2091 break;
2092 default:
2093 abort();
2094 }
2095 if (!had_error)
2096 haveanswer++;
2097 }
2098 if (haveanswer) {
2099 #if defined(RESOLVSORT)
2100 /*
2101 * We support only IPv4 address for backward
2102 * compatibility against gethostbyname(3).
2103 */
2104 if (res->nsort && qtype == T_A) {
2105 if (addr4sort(&sentinel, res) < 0) {
2106 freeaddrinfo(sentinel.ai_next);
2107 RES_SET_H_ERRNO(res, NO_RECOVERY);
2108 return NULL;
2109 }
2110 }
2111 #endif /*RESOLVSORT*/
2112 if (!canonname)
2113 (void)get_canonname(pai, sentinel.ai_next, qname);
2114 else
2115 (void)get_canonname(pai, sentinel.ai_next, canonname);
2116 RES_SET_H_ERRNO(res, NETDB_SUCCESS);
2117 return sentinel.ai_next;
2118 }
2119
2120 RES_SET_H_ERRNO(res, NO_RECOVERY);
2121 return NULL;
2122 }
2123
2124 #ifdef RESOLVSORT
2125 struct addr_ptr {
2126 struct addrinfo *ai;
2127 int aval;
2128 };
2129
2130 static int
addr4sort(struct addrinfo * sentinel,res_state res)2131 addr4sort(struct addrinfo *sentinel, res_state res)
2132 {
2133 struct addrinfo *ai;
2134 struct addr_ptr *addrs, addr;
2135 struct sockaddr_in *sin;
2136 int naddrs, i, j;
2137 int needsort = 0;
2138
2139 if (!sentinel)
2140 return -1;
2141 naddrs = 0;
2142 for (ai = sentinel->ai_next; ai; ai = ai->ai_next)
2143 naddrs++;
2144 if (naddrs < 2)
2145 return 0; /* We don't need sorting. */
2146 if ((addrs = malloc(sizeof(struct addr_ptr) * naddrs)) == NULL)
2147 return -1;
2148 i = 0;
2149 for (ai = sentinel->ai_next; ai; ai = ai->ai_next) {
2150 sin = (struct sockaddr_in *)ai->ai_addr;
2151 for (j = 0; (unsigned)j < res->nsort; j++) {
2152 if (res->sort_list[j].addr.s_addr ==
2153 (sin->sin_addr.s_addr & res->sort_list[j].mask))
2154 break;
2155 }
2156 addrs[i].ai = ai;
2157 addrs[i].aval = j;
2158 if (needsort == 0 && i > 0 && j < addrs[i - 1].aval)
2159 needsort = i;
2160 i++;
2161 }
2162 if (!needsort) {
2163 free(addrs);
2164 return 0;
2165 }
2166
2167 while (needsort < naddrs) {
2168 for (j = needsort - 1; j >= 0; j--) {
2169 if (addrs[j].aval > addrs[j+1].aval) {
2170 addr = addrs[j];
2171 addrs[j] = addrs[j + 1];
2172 addrs[j + 1] = addr;
2173 } else
2174 break;
2175 }
2176 needsort++;
2177 }
2178
2179 ai = sentinel;
2180 for (i = 0; i < naddrs; ++i) {
2181 ai->ai_next = addrs[i].ai;
2182 ai = ai->ai_next;
2183 }
2184 ai->ai_next = NULL;
2185 free(addrs);
2186 return 0;
2187 }
2188 #endif /*RESOLVSORT*/
2189
2190 /*ARGSUSED*/
2191 static int
_dns_getaddrinfo(void * rv,void * cb_data,va_list ap)2192 _dns_getaddrinfo(void *rv, void *cb_data, va_list ap)
2193 {
2194 struct addrinfo *ai;
2195 querybuf *buf, *buf2;
2196 const char *hostname;
2197 const struct addrinfo *pai;
2198 struct addrinfo sentinel, *cur;
2199 struct res_target q, q2;
2200 res_state res;
2201
2202 hostname = va_arg(ap, char *);
2203 pai = va_arg(ap, const struct addrinfo *);
2204
2205 memset(&q, 0, sizeof(q));
2206 memset(&q2, 0, sizeof(q2));
2207 memset(&sentinel, 0, sizeof(sentinel));
2208 cur = &sentinel;
2209
2210 buf = malloc(sizeof(*buf));
2211 if (!buf) {
2212 RES_SET_H_ERRNO(res, NETDB_INTERNAL);
2213 return NS_NOTFOUND;
2214 }
2215 buf2 = malloc(sizeof(*buf2));
2216 if (!buf2) {
2217 free(buf);
2218 RES_SET_H_ERRNO(res, NETDB_INTERNAL);
2219 return NS_NOTFOUND;
2220 }
2221
2222 switch (pai->ai_family) {
2223 case AF_UNSPEC:
2224 q.name = hostname;
2225 q.qclass = C_IN;
2226 q.qtype = T_A;
2227 q.answer = buf->buf;
2228 q.anslen = sizeof(buf->buf);
2229 q.next = &q2;
2230 q2.name = hostname;
2231 q2.qclass = C_IN;
2232 q2.qtype = T_AAAA;
2233 q2.answer = buf2->buf;
2234 q2.anslen = sizeof(buf2->buf);
2235 break;
2236 case AF_INET:
2237 q.name = hostname;
2238 q.qclass = C_IN;
2239 q.qtype = T_A;
2240 q.answer = buf->buf;
2241 q.anslen = sizeof(buf->buf);
2242 break;
2243 case AF_INET6:
2244 q.name = hostname;
2245 q.qclass = C_IN;
2246 q.qtype = T_AAAA;
2247 q.answer = buf->buf;
2248 q.anslen = sizeof(buf->buf);
2249 break;
2250 default:
2251 free(buf);
2252 free(buf2);
2253 return NS_UNAVAIL;
2254 }
2255
2256 res = __res_state();
2257 if ((res->options & RES_INIT) == 0 && res_ninit(res) == -1) {
2258 RES_SET_H_ERRNO(res, NETDB_INTERNAL);
2259 free(buf);
2260 free(buf2);
2261 return NS_NOTFOUND;
2262 }
2263
2264 if (res_searchN(hostname, &q, res) < 0) {
2265 free(buf);
2266 free(buf2);
2267 return NS_NOTFOUND;
2268 }
2269 /* prefer IPv6 */
2270 if (q.next) {
2271 ai = getanswer(buf2, q2.n, q2.name, q2.qtype, pai, res);
2272 if (ai) {
2273 cur->ai_next = ai;
2274 while (cur && cur->ai_next)
2275 cur = cur->ai_next;
2276 }
2277 }
2278 ai = getanswer(buf, q.n, q.name, q.qtype, pai, res);
2279 if (ai)
2280 cur->ai_next = ai;
2281 free(buf);
2282 free(buf2);
2283 if (sentinel.ai_next == NULL)
2284 switch (res->res_h_errno) {
2285 case HOST_NOT_FOUND:
2286 return NS_NOTFOUND;
2287 case TRY_AGAIN:
2288 return NS_TRYAGAIN;
2289 default:
2290 return NS_UNAVAIL;
2291 }
2292 *((struct addrinfo **)rv) = sentinel.ai_next;
2293 return NS_SUCCESS;
2294 }
2295
2296 static void
_sethtent(FILE ** hostf)2297 _sethtent(FILE **hostf)
2298 {
2299 if (!*hostf)
2300 *hostf = fopen(_PATH_HOSTS, "re");
2301 else
2302 rewind(*hostf);
2303 }
2304
2305 static void
_endhtent(FILE ** hostf)2306 _endhtent(FILE **hostf)
2307 {
2308 if (*hostf) {
2309 (void) fclose(*hostf);
2310 *hostf = NULL;
2311 }
2312 }
2313
2314 static struct addrinfo *
_gethtent(FILE ** hostf,const char * name,const struct addrinfo * pai)2315 _gethtent(FILE **hostf, const char *name, const struct addrinfo *pai)
2316 {
2317 char *p;
2318 char *cp, *tname, *cname;
2319 struct addrinfo hints, *res0, *res;
2320 int error;
2321 const char *addr;
2322 char hostbuf[8*1024];
2323
2324 if (!*hostf && !(*hostf = fopen(_PATH_HOSTS, "re")))
2325 return (NULL);
2326 again:
2327 if (!(p = fgets(hostbuf, sizeof hostbuf, *hostf)))
2328 return (NULL);
2329 if (*p == '#')
2330 goto again;
2331 cp = strpbrk(p, "#\n");
2332 if (cp != NULL)
2333 *cp = '\0';
2334 if (!(cp = strpbrk(p, " \t")))
2335 goto again;
2336 *cp++ = '\0';
2337 addr = p;
2338 cname = NULL;
2339 /* if this is not something we're looking for, skip it. */
2340 while (cp && *cp) {
2341 if (*cp == ' ' || *cp == '\t') {
2342 cp++;
2343 continue;
2344 }
2345 tname = cp;
2346 if (cname == NULL)
2347 cname = cp;
2348 if ((cp = strpbrk(cp, " \t")) != NULL)
2349 *cp++ = '\0';
2350 if (strcasecmp(name, tname) == 0)
2351 goto found;
2352 }
2353 goto again;
2354
2355 found:
2356 /* we should not glob socktype/protocol here */
2357 memset(&hints, 0, sizeof(hints));
2358 hints.ai_family = pai->ai_family;
2359 hints.ai_socktype = SOCK_DGRAM;
2360 hints.ai_protocol = 0;
2361 hints.ai_flags = AI_NUMERICHOST;
2362 error = getaddrinfo(addr, "0", &hints, &res0);
2363 if (error)
2364 goto again;
2365 #ifdef FILTER_V4MAPPED
2366 /* XXX should check all items in the chain */
2367 if (res0->ai_family == AF_INET6 &&
2368 IN6_IS_ADDR_V4MAPPED(&((struct sockaddr_in6 *)res0->ai_addr)->sin6_addr)) {
2369 freeaddrinfo(res0);
2370 goto again;
2371 }
2372 #endif
2373 for (res = res0; res; res = res->ai_next) {
2374 /* cover it up */
2375 res->ai_flags = pai->ai_flags;
2376 res->ai_socktype = pai->ai_socktype;
2377 res->ai_protocol = pai->ai_protocol;
2378
2379 if (pai->ai_flags & AI_CANONNAME) {
2380 if (get_canonname(pai, res, cname) != 0) {
2381 freeaddrinfo(res0);
2382 goto again;
2383 }
2384 }
2385 }
2386 return res0;
2387 }
2388
2389 /*ARGSUSED*/
2390 static int
_files_getaddrinfo(void * rv,void * cb_data,va_list ap)2391 _files_getaddrinfo(void *rv, void *cb_data, va_list ap)
2392 {
2393 const char *name;
2394 const struct addrinfo *pai;
2395 struct addrinfo sentinel, *cur;
2396 struct addrinfo *p;
2397 FILE *hostf = NULL;
2398
2399 name = va_arg(ap, char *);
2400 pai = va_arg(ap, struct addrinfo *);
2401
2402 memset(&sentinel, 0, sizeof(sentinel));
2403 cur = &sentinel;
2404
2405 _sethtent(&hostf);
2406 while ((p = _gethtent(&hostf, name, pai)) != NULL) {
2407 cur->ai_next = p;
2408 while (cur && cur->ai_next)
2409 cur = cur->ai_next;
2410 }
2411 _endhtent(&hostf);
2412
2413 *((struct addrinfo **)rv) = sentinel.ai_next;
2414 if (sentinel.ai_next == NULL)
2415 return NS_NOTFOUND;
2416 return NS_SUCCESS;
2417 }
2418
2419 #ifdef YP
2420 /*ARGSUSED*/
2421 static struct addrinfo *
_yphostent(char * line,const struct addrinfo * pai)2422 _yphostent(char *line, const struct addrinfo *pai)
2423 {
2424 struct addrinfo sentinel, *cur;
2425 struct addrinfo hints, *res, *res0;
2426 int error;
2427 char *p = line;
2428 const char *addr, *canonname;
2429 char *nextline;
2430 char *cp;
2431
2432 addr = canonname = NULL;
2433
2434 memset(&sentinel, 0, sizeof(sentinel));
2435 cur = &sentinel;
2436
2437 nextline:
2438 /* terminate line */
2439 cp = strchr(p, '\n');
2440 if (cp) {
2441 *cp++ = '\0';
2442 nextline = cp;
2443 } else
2444 nextline = NULL;
2445
2446 cp = strpbrk(p, " \t");
2447 if (cp == NULL) {
2448 if (canonname == NULL)
2449 return (NULL);
2450 else
2451 goto done;
2452 }
2453 *cp++ = '\0';
2454
2455 addr = p;
2456
2457 while (cp && *cp) {
2458 if (*cp == ' ' || *cp == '\t') {
2459 cp++;
2460 continue;
2461 }
2462 if (!canonname)
2463 canonname = cp;
2464 if ((cp = strpbrk(cp, " \t")) != NULL)
2465 *cp++ = '\0';
2466 }
2467
2468 hints = *pai;
2469 hints.ai_flags = AI_NUMERICHOST;
2470 error = getaddrinfo(addr, NULL, &hints, &res0);
2471 if (error == 0) {
2472 for (res = res0; res; res = res->ai_next) {
2473 /* cover it up */
2474 res->ai_flags = pai->ai_flags;
2475
2476 if (pai->ai_flags & AI_CANONNAME)
2477 (void)get_canonname(pai, res, canonname);
2478 }
2479 } else
2480 res0 = NULL;
2481 if (res0) {
2482 cur->ai_next = res0;
2483 while (cur && cur->ai_next)
2484 cur = cur->ai_next;
2485 }
2486
2487 if (nextline) {
2488 p = nextline;
2489 goto nextline;
2490 }
2491
2492 done:
2493 return sentinel.ai_next;
2494 }
2495
2496 /*ARGSUSED*/
2497 static int
_yp_getaddrinfo(void * rv,void * cb_data,va_list ap)2498 _yp_getaddrinfo(void *rv, void *cb_data, va_list ap)
2499 {
2500 struct addrinfo sentinel, *cur;
2501 struct addrinfo *ai = NULL;
2502 char *ypbuf;
2503 int ypbuflen, r;
2504 const char *name;
2505 const struct addrinfo *pai;
2506 char *ypdomain;
2507
2508 if (_yp_check(&ypdomain) == 0)
2509 return NS_UNAVAIL;
2510
2511 name = va_arg(ap, char *);
2512 pai = va_arg(ap, const struct addrinfo *);
2513
2514 memset(&sentinel, 0, sizeof(sentinel));
2515 cur = &sentinel;
2516
2517 /* hosts.byname is only for IPv4 (Solaris8) */
2518 if (pai->ai_family == PF_UNSPEC || pai->ai_family == PF_INET) {
2519 r = yp_match(ypdomain, "hosts.byname", name,
2520 (int)strlen(name), &ypbuf, &ypbuflen);
2521 if (r == 0) {
2522 struct addrinfo ai4;
2523
2524 ai4 = *pai;
2525 ai4.ai_family = AF_INET;
2526 ai = _yphostent(ypbuf, &ai4);
2527 if (ai) {
2528 cur->ai_next = ai;
2529 while (cur && cur->ai_next)
2530 cur = cur->ai_next;
2531 }
2532 free(ypbuf);
2533 }
2534 }
2535
2536 /* ipnodes.byname can hold both IPv4/v6 */
2537 r = yp_match(ypdomain, "ipnodes.byname", name,
2538 (int)strlen(name), &ypbuf, &ypbuflen);
2539 if (r == 0) {
2540 ai = _yphostent(ypbuf, pai);
2541 if (ai)
2542 cur->ai_next = ai;
2543 free(ypbuf);
2544 }
2545
2546 if (sentinel.ai_next == NULL) {
2547 RES_SET_H_ERRNO(__res_state(), HOST_NOT_FOUND);
2548 return NS_NOTFOUND;
2549 }
2550 *((struct addrinfo **)rv) = sentinel.ai_next;
2551 return NS_SUCCESS;
2552 }
2553 #endif
2554
2555 /* resolver logic */
2556
2557 /*
2558 * Formulate a normal query, send, and await answer.
2559 * Returned answer is placed in supplied buffer "answer".
2560 * Perform preliminary check of answer, returning success only
2561 * if no error is indicated and the answer count is nonzero.
2562 * Return the size of the response on success, -1 on error.
2563 * Error number is left in h_errno.
2564 *
2565 * Caller must parse answer and determine whether it answers the question.
2566 */
2567 static int
res_queryN(const char * name,struct res_target * target,res_state res)2568 res_queryN(const char *name, struct res_target *target, res_state res)
2569 {
2570 u_char *buf;
2571 HEADER *hp;
2572 int n;
2573 u_int oflags;
2574 struct res_target *t;
2575 int rcode;
2576 int ancount;
2577
2578 rcode = NOERROR;
2579 ancount = 0;
2580
2581 buf = malloc(MAXPACKET);
2582 if (!buf) {
2583 RES_SET_H_ERRNO(res, NETDB_INTERNAL);
2584 return -1;
2585 }
2586
2587 for (t = target; t; t = t->next) {
2588 int class, type;
2589 u_char *answer;
2590 int anslen;
2591
2592 hp = (HEADER *)(void *)t->answer;
2593
2594 /* make it easier... */
2595 class = t->qclass;
2596 type = t->qtype;
2597 answer = t->answer;
2598 anslen = t->anslen;
2599
2600 oflags = res->_flags;
2601
2602 again:
2603 hp->rcode = NOERROR; /* default */
2604
2605 #ifdef DEBUG
2606 if (res->options & RES_DEBUG)
2607 printf(";; res_query(%s, %d, %d)\n", name, class, type);
2608 #endif
2609
2610 n = res_nmkquery(res, QUERY, name, class, type, NULL, 0, NULL,
2611 buf, MAXPACKET);
2612 if (n > 0 && (res->_flags & RES_F_EDNS0ERR) == 0 &&
2613 (res->options & (RES_USE_EDNS0|RES_USE_DNSSEC)) != 0U)
2614 n = res_nopt(res, n, buf, MAXPACKET, anslen);
2615 if (n <= 0) {
2616 #ifdef DEBUG
2617 if (res->options & RES_DEBUG)
2618 printf(";; res_query: mkquery failed\n");
2619 #endif
2620 free(buf);
2621 RES_SET_H_ERRNO(res, NO_RECOVERY);
2622 return (n);
2623 }
2624 n = res_nsend(res, buf, n, answer, anslen);
2625 if (n < 0) {
2626 /*
2627 * if the query choked with EDNS0, retry
2628 * without EDNS0
2629 */
2630 if ((res->options & (RES_USE_EDNS0|RES_USE_DNSSEC))
2631 != 0U &&
2632 ((oflags ^ res->_flags) & RES_F_EDNS0ERR) != 0) {
2633 res->_flags |= RES_F_EDNS0ERR;
2634 if (res->options & RES_DEBUG)
2635 printf(";; res_nquery: retry without EDNS0\n");
2636 goto again;
2637 }
2638 rcode = hp->rcode; /* record most recent error */
2639 #ifdef DEBUG
2640 if (res->options & RES_DEBUG)
2641 printf(";; res_query: send error\n");
2642 #endif
2643 continue;
2644 }
2645
2646 if (n > anslen)
2647 hp->rcode = FORMERR; /* XXX not very informative */
2648 if (hp->rcode != NOERROR || ntohs(hp->ancount) == 0) {
2649 rcode = hp->rcode; /* record most recent error */
2650 #ifdef DEBUG
2651 if (res->options & RES_DEBUG)
2652 printf(";; rcode = %u, ancount=%u\n", hp->rcode,
2653 ntohs(hp->ancount));
2654 #endif
2655 continue;
2656 }
2657
2658 ancount += ntohs(hp->ancount);
2659
2660 t->n = n;
2661 }
2662
2663 free(buf);
2664
2665 if (ancount == 0) {
2666 switch (rcode) {
2667 case NXDOMAIN:
2668 RES_SET_H_ERRNO(res, HOST_NOT_FOUND);
2669 break;
2670 case SERVFAIL:
2671 RES_SET_H_ERRNO(res, TRY_AGAIN);
2672 break;
2673 case NOERROR:
2674 RES_SET_H_ERRNO(res, NO_DATA);
2675 break;
2676 case FORMERR:
2677 case NOTIMP:
2678 case REFUSED:
2679 default:
2680 RES_SET_H_ERRNO(res, NO_RECOVERY);
2681 break;
2682 }
2683 return (-1);
2684 }
2685 return (ancount);
2686 }
2687
2688 /*
2689 * Formulate a normal query, send, and retrieve answer in supplied buffer.
2690 * Return the size of the response on success, -1 on error.
2691 * If enabled, implement search rules until answer or unrecoverable failure
2692 * is detected. Error code, if any, is left in h_errno.
2693 */
2694 static int
res_searchN(const char * name,struct res_target * target,res_state res)2695 res_searchN(const char *name, struct res_target *target, res_state res)
2696 {
2697 const char *cp, * const *domain;
2698 HEADER *hp = (HEADER *)(void *)target->answer; /*XXX*/
2699 u_int dots;
2700 int trailing_dot, ret, saved_herrno;
2701 int got_nodata = 0, got_servfail = 0, root_on_list = 0;
2702 int tried_as_is = 0;
2703 int searched = 0;
2704 char abuf[MAXDNAME];
2705
2706 errno = 0;
2707 RES_SET_H_ERRNO(res, HOST_NOT_FOUND); /* default, if we never query */
2708 dots = 0;
2709 for (cp = name; *cp; cp++)
2710 dots += (*cp == '.');
2711 trailing_dot = 0;
2712 if (cp > name && *--cp == '.')
2713 trailing_dot++;
2714
2715 /*
2716 * if there aren't any dots, it could be a user-level alias
2717 */
2718 if (!dots &&
2719 (cp = res_hostalias(res, name, abuf, sizeof(abuf))) != NULL)
2720 return (res_queryN(cp, target, res));
2721
2722 /*
2723 * If there are enough dots in the name, let's just give it a
2724 * try 'as is'. The threshold can be set with the "ndots" option.
2725 * Also, query 'as is', if there is a trailing dot in the name.
2726 */
2727 saved_herrno = -1;
2728 if (dots >= res->ndots || trailing_dot) {
2729 ret = res_querydomainN(name, NULL, target, res);
2730 if (ret > 0 || trailing_dot)
2731 return (ret);
2732 if (errno == ECONNREFUSED) {
2733 RES_SET_H_ERRNO(res, TRY_AGAIN);
2734 return (-1);
2735 }
2736 switch (res->res_h_errno) {
2737 case NO_DATA:
2738 case HOST_NOT_FOUND:
2739 break;
2740 case TRY_AGAIN:
2741 if (hp->rcode == SERVFAIL)
2742 break;
2743 /* FALLTHROUGH */
2744 default:
2745 return (-1);
2746 }
2747 saved_herrno = res->res_h_errno;
2748 tried_as_is++;
2749 }
2750
2751 /*
2752 * We do at least one level of search if
2753 * - there is no dot and RES_DEFNAME is set, or
2754 * - there is at least one dot, there is no trailing dot,
2755 * and RES_DNSRCH is set.
2756 */
2757 if ((!dots && (res->options & RES_DEFNAMES)) ||
2758 (dots && !trailing_dot && (res->options & RES_DNSRCH))) {
2759 int done = 0;
2760
2761 for (domain = (const char * const *)res->dnsrch;
2762 *domain && !done;
2763 domain++) {
2764 searched = 1;
2765
2766 if (domain[0][0] == '\0' ||
2767 (domain[0][0] == '.' && domain[0][1] == '\0'))
2768 root_on_list++;
2769
2770 if (root_on_list && tried_as_is)
2771 continue;
2772
2773 ret = res_querydomainN(name, *domain, target, res);
2774 if (ret > 0)
2775 return (ret);
2776
2777 /*
2778 * If no server present, give up.
2779 * If name isn't found in this domain,
2780 * keep trying higher domains in the search list
2781 * (if that's enabled).
2782 * On a NO_DATA error, keep trying, otherwise
2783 * a wildcard entry of another type could keep us
2784 * from finding this entry higher in the domain.
2785 * If we get some other error (negative answer or
2786 * server failure), then stop searching up,
2787 * but try the input name below in case it's
2788 * fully-qualified.
2789 */
2790 if (errno == ECONNREFUSED) {
2791 RES_SET_H_ERRNO(res, TRY_AGAIN);
2792 return (-1);
2793 }
2794
2795 switch (res->res_h_errno) {
2796 case NO_DATA:
2797 got_nodata++;
2798 /* FALLTHROUGH */
2799 case HOST_NOT_FOUND:
2800 /* keep trying */
2801 break;
2802 case TRY_AGAIN:
2803 got_servfail++;
2804 if (hp->rcode == SERVFAIL) {
2805 /* try next search element, if any */
2806 break;
2807 }
2808 /* FALLTHROUGH */
2809 default:
2810 /* anything else implies that we're done */
2811 done++;
2812 }
2813 /*
2814 * if we got here for some reason other than DNSRCH,
2815 * we only wanted one iteration of the loop, so stop.
2816 */
2817 if (!(res->options & RES_DNSRCH))
2818 done++;
2819 }
2820 }
2821
2822 switch (res->res_h_errno) {
2823 case NO_DATA:
2824 case HOST_NOT_FOUND:
2825 break;
2826 case TRY_AGAIN:
2827 if (hp->rcode == SERVFAIL)
2828 break;
2829 /* FALLTHROUGH */
2830 default:
2831 goto giveup;
2832 }
2833
2834 /*
2835 * If the query has not already been tried as is then try it
2836 * unless RES_NOTLDQUERY is set and there were no dots.
2837 */
2838 if ((dots || !searched || !(res->options & RES_NOTLDQUERY)) &&
2839 !(tried_as_is || root_on_list)) {
2840 ret = res_querydomainN(name, NULL, target, res);
2841 if (ret > 0)
2842 return (ret);
2843 }
2844
2845 /*
2846 * if we got here, we didn't satisfy the search.
2847 * if we did an initial full query, return that query's h_errno
2848 * (note that we wouldn't be here if that query had succeeded).
2849 * else if we ever got a nodata, send that back as the reason.
2850 * else send back meaningless h_errno, that being the one from
2851 * the last DNSRCH we did.
2852 */
2853 giveup:
2854 if (saved_herrno != -1)
2855 RES_SET_H_ERRNO(res, saved_herrno);
2856 else if (got_nodata)
2857 RES_SET_H_ERRNO(res, NO_DATA);
2858 else if (got_servfail)
2859 RES_SET_H_ERRNO(res, TRY_AGAIN);
2860 return (-1);
2861 }
2862
2863 /*
2864 * Perform a call on res_query on the concatenation of name and domain,
2865 * removing a trailing dot from name if domain is NULL.
2866 */
2867 static int
res_querydomainN(const char * name,const char * domain,struct res_target * target,res_state res)2868 res_querydomainN(const char *name, const char *domain,
2869 struct res_target *target, res_state res)
2870 {
2871 char nbuf[MAXDNAME];
2872 const char *longname = nbuf;
2873 size_t n, d;
2874
2875 #ifdef DEBUG
2876 if (res->options & RES_DEBUG)
2877 printf(";; res_querydomain(%s, %s)\n",
2878 name, domain?domain:"<Nil>");
2879 #endif
2880 if (domain == NULL) {
2881 /*
2882 * Check for trailing '.';
2883 * copy without '.' if present.
2884 */
2885 n = strlen(name);
2886 if (n >= MAXDNAME) {
2887 RES_SET_H_ERRNO(res, NO_RECOVERY);
2888 return (-1);
2889 }
2890 if (n > 0 && name[--n] == '.') {
2891 strncpy(nbuf, name, n);
2892 nbuf[n] = '\0';
2893 } else
2894 longname = name;
2895 } else {
2896 n = strlen(name);
2897 d = strlen(domain);
2898 if (n + d + 1 >= MAXDNAME) {
2899 RES_SET_H_ERRNO(res, NO_RECOVERY);
2900 return (-1);
2901 }
2902 snprintf(nbuf, sizeof(nbuf), "%s.%s", name, domain);
2903 }
2904 return (res_queryN(longname, target, res));
2905 }
2906