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-rw-r--r--src/lib/libc/net/getaddrinfo.c1755
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diff --git a/src/lib/libc/net/getaddrinfo.c b/src/lib/libc/net/getaddrinfo.c
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1/* $OpenBSD: getaddrinfo.c,v 1.72 2011/04/05 00:46:06 matthew Exp $ */
2/* $KAME: getaddrinfo.c,v 1.31 2000/08/31 17:36:43 itojun Exp $ */
3
4/*
5 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 3. Neither the name of the project nor the names of its contributors
17 * may be used to endorse or promote products derived from this software
18 * without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 * SUCH DAMAGE.
31 */
32
33/*
34 * Issues to be discussed:
35 * - Thread safe-ness must be checked.
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 * - IPv4 classful (shortened) form. RFC2553 is silent about it. XNET 5.2
40 * says to use inet_aton() to convert IPv4 numeric to binary (allows
41 * classful form as a result).
42 * current code - disallow classful form for IPv4 (due to use of inet_pton).
43 * - freeaddrinfo(NULL). RFC2553 is silent about it. XNET 5.2 says it is
44 * invalid.
45 * current code - SEGV on freeaddrinfo(NULL)
46 * Note:
47 * - We use getipnodebyname() just for thread-safeness. There's no intent
48 * to let it do PF_UNSPEC (actually we never pass PF_UNSPEC to
49 * getipnodebyname().
50 * - The code filters out AFs that are not supported by the kernel,
51 * when globbing NULL hostname (to loopback, or wildcard). Is it the right
52 * thing to do? What is the relationship with post-RFC2553 AI_ADDRCONFIG
53 * in ai_flags?
54 * - (post-2553) semantics of AI_ADDRCONFIG itself is too vague.
55 * (1) what should we do against numeric hostname (2) what should we do
56 * against NULL hostname (3) what is AI_ADDRCONFIG itself. AF not ready?
57 * non-loopback address configured? global address configured?
58 * - To avoid search order issue, we have a big amount of code duplicate
59 * from gethnamaddr.c and some other places. The issues that there's no
60 * lower layer function to lookup "IPv4 or IPv6" record. Calling
61 * gethostbyname2 from getaddrinfo will end up in wrong search order, as
62 * follows:
63 * - The code makes use of following calls when asked to resolver with
64 * ai_family = PF_UNSPEC:
65 * getipnodebyname(host, AF_INET6);
66 * getipnodebyname(host, AF_INET);
67 * This will result in the following queries if the node is configure to
68 * prefer /etc/hosts than DNS:
69 * lookup /etc/hosts for IPv6 address
70 * lookup DNS for IPv6 address
71 * lookup /etc/hosts for IPv4 address
72 * lookup DNS for IPv4 address
73 * which may not meet people's requirement.
74 * The right thing to happen is to have underlying layer which does
75 * PF_UNSPEC lookup (lookup both) and return chain of addrinfos.
76 * This would result in a bit of code duplicate with _dns_ghbyname() and
77 * friends.
78 */
79
80#ifndef INET6
81#define INET6
82#endif
83
84#include <sys/types.h>
85#include <sys/param.h>
86#include <sys/socket.h>
87#include <net/if.h>
88#include <netinet/in.h>
89#include <arpa/inet.h>
90#include <arpa/nameser.h>
91#include <netdb.h>
92#include <resolv.h>
93#include <string.h>
94#include <stdint.h>
95#include <stdlib.h>
96#include <stddef.h>
97#include <ctype.h>
98#include <unistd.h>
99#include <stdio.h>
100#include <errno.h>
101
102#include <syslog.h>
103#include <stdarg.h>
104
105#ifdef YP
106#include <rpc/rpc.h>
107#include <rpcsvc/yp.h>
108#include <rpcsvc/ypclnt.h>
109#include "ypinternal.h"
110#endif
111
112#include "thread_private.h"
113
114#define SUCCESS 0
115#define ANY 0
116#define YES 1
117#define NO 0
118
119static const char in_addrany[] = { 0, 0, 0, 0 };
120static const char in6_addrany[] = {
121 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
122};
123static const char in_loopback[] = { 127, 0, 0, 1 };
124static const char in6_loopback[] = {
125 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1
126};
127
128static const struct afd {
129 int a_af;
130 int a_addrlen;
131 int a_socklen;
132 int a_off;
133 const char *a_addrany;
134 const char *a_loopback;
135 int a_scoped;
136} afdl [] = {
137#ifdef INET6
138 {PF_INET6, sizeof(struct in6_addr),
139 sizeof(struct sockaddr_in6),
140 offsetof(struct sockaddr_in6, sin6_addr),
141 in6_addrany, in6_loopback, 1},
142#endif
143 {PF_INET, sizeof(struct in_addr),
144 sizeof(struct sockaddr_in),
145 offsetof(struct sockaddr_in, sin_addr),
146 in_addrany, in_loopback, 0},
147 {0, 0, 0, 0, NULL, NULL, 0},
148};
149
150struct explore {
151 int e_af;
152 int e_socktype;
153 int e_protocol;
154 const char *e_protostr;
155 int e_wild;
156#define WILD_AF(ex) ((ex)->e_wild & 0x01)
157#define WILD_SOCKTYPE(ex) ((ex)->e_wild & 0x02)
158#define WILD_PROTOCOL(ex) ((ex)->e_wild & 0x04)
159};
160
161static const struct explore explore[] = {
162#if 0
163 { PF_LOCAL, 0, ANY, ANY, NULL, 0x01 },
164#endif
165#ifdef INET6
166 { PF_INET6, SOCK_DGRAM, IPPROTO_UDP, "udp", 0x07 },
167 { PF_INET6, SOCK_STREAM, IPPROTO_TCP, "tcp", 0x07 },
168 { PF_INET6, SOCK_RAW, ANY, NULL, 0x05 },
169#endif
170 { PF_INET, SOCK_DGRAM, IPPROTO_UDP, "udp", 0x07 },
171 { PF_INET, SOCK_STREAM, IPPROTO_TCP, "tcp", 0x07 },
172 { PF_INET, SOCK_RAW, ANY, NULL, 0x05 },
173 { PF_UNSPEC, SOCK_DGRAM, IPPROTO_UDP, "udp", 0x07 },
174 { PF_UNSPEC, SOCK_STREAM, IPPROTO_TCP, "tcp", 0x07 },
175 { PF_UNSPEC, SOCK_RAW, ANY, NULL, 0x05 },
176 { -1, 0, 0, NULL, 0 },
177};
178
179#ifdef INET6
180#define PTON_MAX 16
181#else
182#define PTON_MAX 4
183#endif
184
185#define MAXPACKET (64*1024)
186
187typedef union {
188 HEADER hdr;
189 u_char buf[MAXPACKET];
190} querybuf;
191
192struct res_target {
193 struct res_target *next;
194 const char *name; /* domain name */
195 int qclass, qtype; /* class and type of query */
196 u_char *answer; /* buffer to put answer */
197 int anslen; /* size of answer buffer */
198 int n; /* result length */
199};
200
201static int explore_fqdn(const struct addrinfo *, const char *,
202 const char *, struct addrinfo **);
203static int explore_null(const struct addrinfo *,
204 const char *, struct addrinfo **);
205static int explore_numeric(const struct addrinfo *, const char *,
206 const char *, struct addrinfo **, const char *);
207static int explore_numeric_scope(const struct addrinfo *, const char *,
208 const char *, struct addrinfo **);
209static int get_canonname(const struct addrinfo *,
210 struct addrinfo *, const char *);
211static struct addrinfo *get_ai(const struct addrinfo *,
212 const struct afd *, const char *);
213static int get_portmatch(const struct addrinfo *, const char *);
214static int get_port(struct addrinfo *, const char *, int);
215static const struct afd *find_afd(int);
216#ifdef INET6
217static int ip6_str2scopeid(char *, struct sockaddr_in6 *, u_int32_t *);
218#endif
219
220static struct addrinfo * _gethtent(const char *, const struct addrinfo *,
221 FILE *);
222static struct addrinfo *_files_getaddrinfo(const char *,
223 const struct addrinfo *);
224
225#ifdef YP
226static struct addrinfo *_yphostent(char *, const struct addrinfo *);
227static struct addrinfo *_yp_getaddrinfo(const char *,
228 const struct addrinfo *);
229#endif
230
231static struct addrinfo *getanswer(const querybuf *, int, const char *, int,
232 const struct addrinfo *);
233static int res_queryN(const char *, struct res_target *);
234static int res_searchN(const char *, struct res_target *);
235static int res_querydomainN(const char *, const char *, struct res_target *);
236static struct addrinfo *_dns_getaddrinfo(const char *, const struct addrinfo *,
237 const struct __res_state *);
238
239
240/* XXX macros that make external reference is BAD. */
241
242#define GET_AI(ai, afd, addr) \
243do { \
244 /* external reference: pai, error, and label free */ \
245 (ai) = get_ai(pai, (afd), (addr)); \
246 if ((ai) == NULL) { \
247 error = EAI_MEMORY; \
248 goto free; \
249 } \
250} while (/*CONSTCOND*/0)
251
252#define GET_PORT(ai, serv) \
253do { \
254 /* external reference: error and label free */ \
255 error = get_port((ai), (serv), 0); \
256 if (error != 0) \
257 goto free; \
258} while (/*CONSTCOND*/0)
259
260#define GET_CANONNAME(ai, str) \
261do { \
262 /* external reference: pai, error and label free */ \
263 error = get_canonname(pai, (ai), (str)); \
264 if (error != 0) \
265 goto free; \
266} while (/*CONSTCOND*/0)
267
268#define ERR(err) \
269do { \
270 /* external reference: error, and label bad */ \
271 error = (err); \
272 goto bad; \
273 /*NOTREACHED*/ \
274} while (/*CONSTCOND*/0)
275
276#define MATCH_FAMILY(x, y, w) \
277 ((x) == (y) || (/*CONSTCOND*/(w) && ((x) == PF_UNSPEC || (y) == PF_UNSPEC)))
278#define MATCH(x, y, w) \
279 ((x) == (y) || (/*CONSTCOND*/(w) && ((x) == ANY || (y) == ANY)))
280
281int
282getaddrinfo(const char *hostname, const char *servname,
283 const struct addrinfo *hints, struct addrinfo **res)
284{
285 struct addrinfo sentinel;
286 struct addrinfo *cur;
287 int error = 0;
288 struct addrinfo ai;
289 struct addrinfo ai0;
290 struct addrinfo *pai;
291 const struct explore *ex;
292
293 memset(&sentinel, 0, sizeof(sentinel));
294 cur = &sentinel;
295 pai = &ai;
296 pai->ai_flags = 0;
297 pai->ai_family = PF_UNSPEC;
298 pai->ai_socktype = ANY;
299 pai->ai_protocol = ANY;
300 pai->ai_addrlen = 0;
301 pai->ai_canonname = NULL;
302 pai->ai_addr = NULL;
303 pai->ai_next = NULL;
304
305 if (hostname == NULL && servname == NULL)
306 return EAI_NONAME;
307 if (hints) {
308 /* error check for hints */
309 if (hints->ai_addrlen || hints->ai_canonname ||
310 hints->ai_addr || hints->ai_next)
311 ERR(EAI_BADHINTS); /* xxx */
312 if ((hints->ai_flags & ~AI_MASK) != 0 ||
313 (hints->ai_flags & (AI_CANONNAME | AI_FQDN)) ==
314 (AI_CANONNAME | AI_FQDN))
315 ERR(EAI_BADFLAGS);
316 switch (hints->ai_family) {
317 case PF_UNSPEC:
318 case PF_INET:
319#ifdef INET6
320 case PF_INET6:
321#endif
322 break;
323 default:
324 ERR(EAI_FAMILY);
325 }
326 memcpy(pai, hints, sizeof(*pai));
327
328 /*
329 * if both socktype/protocol are specified, check if they
330 * are meaningful combination.
331 */
332 if (pai->ai_socktype != ANY && pai->ai_protocol != ANY) {
333 for (ex = explore; ex->e_af >= 0; ex++) {
334 if (pai->ai_family != ex->e_af)
335 continue;
336 if (ex->e_socktype == ANY)
337 continue;
338 if (ex->e_protocol == ANY)
339 continue;
340 if (pai->ai_socktype == ex->e_socktype
341 && pai->ai_protocol != ex->e_protocol) {
342 ERR(EAI_BADHINTS);
343 }
344 }
345 }
346 }
347
348 /*
349 * check for special cases. (1) numeric servname is disallowed if
350 * socktype/protocol are left unspecified. (2) servname is disallowed
351 * for raw and other inet{,6} sockets.
352 */
353 if (MATCH_FAMILY(pai->ai_family, PF_INET, 1)
354#ifdef PF_INET6
355 || MATCH_FAMILY(pai->ai_family, PF_INET6, 1)
356#endif
357 ) {
358 ai0 = *pai; /* backup *pai */
359
360 if (pai->ai_family == PF_UNSPEC) {
361#ifdef PF_INET6
362 pai->ai_family = PF_INET6;
363#else
364 pai->ai_family = PF_INET;
365#endif
366 }
367 error = get_portmatch(pai, servname);
368 if (error)
369 ERR(error);
370
371 *pai = ai0;
372 }
373
374 ai0 = *pai;
375
376 /* NULL hostname, or numeric hostname */
377 for (ex = explore; ex->e_af >= 0; ex++) {
378 *pai = ai0;
379
380 /* PF_UNSPEC entries are prepared for DNS queries only */
381 if (ex->e_af == PF_UNSPEC)
382 continue;
383
384 if (!MATCH_FAMILY(pai->ai_family, ex->e_af, WILD_AF(ex)))
385 continue;
386 if (!MATCH(pai->ai_socktype, ex->e_socktype, WILD_SOCKTYPE(ex)))
387 continue;
388 if (!MATCH(pai->ai_protocol, ex->e_protocol, WILD_PROTOCOL(ex)))
389 continue;
390
391 if (pai->ai_family == PF_UNSPEC)
392 pai->ai_family = ex->e_af;
393 if (pai->ai_socktype == ANY && ex->e_socktype != ANY)
394 pai->ai_socktype = ex->e_socktype;
395 if (pai->ai_protocol == ANY && ex->e_protocol != ANY)
396 pai->ai_protocol = ex->e_protocol;
397
398 if (hostname == NULL)
399 error = explore_null(pai, servname, &cur->ai_next);
400 else
401 error = explore_numeric_scope(pai, hostname, servname,
402 &cur->ai_next);
403
404 if (error)
405 goto free;
406
407 while (cur && cur->ai_next)
408 cur = cur->ai_next;
409 }
410
411 /*
412 * XXX
413 * If numeric representation of AF1 can be interpreted as FQDN
414 * representation of AF2, we need to think again about the code below.
415 */
416 if (sentinel.ai_next)
417 goto good;
418
419 if (hostname == NULL)
420 ERR(EAI_NODATA);
421 if (pai->ai_flags & AI_NUMERICHOST)
422 ERR(EAI_NONAME);
423
424 /*
425 * hostname as alphabetical name.
426 * we would like to prefer AF_INET6 than AF_INET, so we'll make an
427 * outer loop by AFs.
428 */
429 for (ex = explore; ex->e_af >= 0; ex++) {
430 *pai = ai0;
431
432 /* require exact match for family field */
433 if (pai->ai_family != ex->e_af)
434 continue;
435
436 if (!MATCH(pai->ai_socktype, ex->e_socktype,
437 WILD_SOCKTYPE(ex))) {
438 continue;
439 }
440 if (!MATCH(pai->ai_protocol, ex->e_protocol,
441 WILD_PROTOCOL(ex))) {
442 continue;
443 }
444
445 if (pai->ai_socktype == ANY && ex->e_socktype != ANY)
446 pai->ai_socktype = ex->e_socktype;
447 if (pai->ai_protocol == ANY && ex->e_protocol != ANY)
448 pai->ai_protocol = ex->e_protocol;
449
450 error = explore_fqdn(pai, hostname, servname,
451 &cur->ai_next);
452
453 while (cur && cur->ai_next)
454 cur = cur->ai_next;
455 }
456
457 /* XXX */
458 if (sentinel.ai_next)
459 error = 0;
460
461 if (error == 0) {
462 if (sentinel.ai_next) {
463 good:
464 *res = sentinel.ai_next;
465 return SUCCESS;
466 } else
467 error = EAI_FAIL;
468 }
469 free:
470 bad:
471 if (sentinel.ai_next)
472 freeaddrinfo(sentinel.ai_next);
473 *res = NULL;
474 return error;
475}
476
477/*
478 * FQDN hostname, DNS lookup
479 */
480
481static int
482explore_fqdn(const struct addrinfo *pai, const char *hostname,
483 const char *servname, struct addrinfo **res)
484{
485 struct __res_state *_resp = _THREAD_PRIVATE(_res, _res, &_res);
486 struct addrinfo *result;
487 struct addrinfo *cur;
488 int error = 0;
489 char lookups[MAXDNSLUS];
490 int i;
491 _THREAD_PRIVATE_MUTEX(_explore_mutex);
492
493 result = NULL;
494
495 /*
496 * if the servname does not match socktype/protocol, ignore it.
497 */
498 if (get_portmatch(pai, servname) != 0) {
499 return 0;
500 }
501
502 if (_res_init(0) == -1)
503 strlcpy(lookups, "f", sizeof lookups);
504 else {
505 bcopy(_resp->lookups, lookups, sizeof lookups);
506 if (lookups[0] == '\0')
507 strlcpy(lookups, "bf", sizeof lookups);
508 }
509
510 /*
511 * The yp/dns/files getaddrinfo functions are not thread safe.
512 * Protect them with a mutex.
513 */
514 _THREAD_PRIVATE_MUTEX_LOCK(_explore_mutex);
515 for (i = 0; i < MAXDNSLUS && result == NULL && lookups[i]; i++) {
516 switch (lookups[i]) {
517#ifdef YP
518 case 'y':
519 result = _yp_getaddrinfo(hostname, pai);
520 break;
521#endif
522 case 'b':
523 result = _dns_getaddrinfo(hostname, pai, _resp);
524 break;
525 case 'f':
526 result = _files_getaddrinfo(hostname, pai);
527 break;
528 }
529 }
530 _THREAD_PRIVATE_MUTEX_UNLOCK(_explore_mutex);
531 if (result) {
532 for (cur = result; cur; cur = cur->ai_next) {
533 GET_PORT(cur, servname);
534 /* canonname should be filled already */
535 }
536 *res = result;
537 return 0;
538 } else {
539 /* translate error code */
540 switch (h_errno) {
541 case NETDB_SUCCESS:
542 error = EAI_FAIL; /*XXX strange */
543 break;
544 case HOST_NOT_FOUND:
545 error = EAI_NODATA;
546 break;
547 case TRY_AGAIN:
548 error = EAI_AGAIN;
549 break;
550 case NO_RECOVERY:
551 error = EAI_FAIL;
552 break;
553 case NO_DATA:
554#if NO_ADDRESS != NO_DATA
555 case NO_ADDRESS:
556#endif
557 error = EAI_NODATA;
558 break;
559 default: /* unknown ones */
560 error = EAI_FAIL;
561 break;
562 }
563 }
564
565free:
566 if (result)
567 freeaddrinfo(result);
568 return error;
569}
570
571/*
572 * hostname == NULL.
573 * passive socket -> anyaddr (0.0.0.0 or ::)
574 * non-passive socket -> localhost (127.0.0.1 or ::1)
575 */
576static int
577explore_null(const struct addrinfo *pai, const char *servname,
578 struct addrinfo **res)
579{
580 int s;
581 const struct afd *afd;
582 struct addrinfo *cur;
583 struct addrinfo sentinel;
584 int error;
585
586 *res = NULL;
587 sentinel.ai_next = NULL;
588 cur = &sentinel;
589
590 /*
591 * filter out AFs that are not supported by the kernel
592 * XXX errno?
593 */
594 s = socket(pai->ai_family, SOCK_DGRAM, 0);
595 if (s < 0) {
596 if (errno != EMFILE)
597 return 0;
598 } else
599 close(s);
600
601 /*
602 * if the servname does not match socktype/protocol, ignore it.
603 */
604 if (get_portmatch(pai, servname) != 0)
605 return 0;
606
607 afd = find_afd(pai->ai_family);
608 if (afd == NULL)
609 return 0;
610
611 if (pai->ai_flags & AI_PASSIVE) {
612 GET_AI(cur->ai_next, afd, afd->a_addrany);
613 /* xxx meaningless?
614 * GET_CANONNAME(cur->ai_next, "anyaddr");
615 */
616 } else {
617 GET_AI(cur->ai_next, afd, afd->a_loopback);
618 /* xxx meaningless?
619 * GET_CANONNAME(cur->ai_next, "localhost");
620 */
621 }
622 GET_PORT(cur->ai_next, servname);
623 cur = cur->ai_next;
624
625 *res = sentinel.ai_next;
626 return 0;
627
628free:
629 if (sentinel.ai_next)
630 freeaddrinfo(sentinel.ai_next);
631 return error;
632}
633
634/*
635 * numeric hostname
636 */
637static int
638explore_numeric(const struct addrinfo *pai, const char *hostname,
639 const char *servname, struct addrinfo **res, const char *canonname)
640{
641 const struct afd *afd;
642 struct addrinfo *cur;
643 struct addrinfo sentinel;
644 int error;
645 char pton[PTON_MAX];
646
647 *res = NULL;
648 sentinel.ai_next = NULL;
649 cur = &sentinel;
650
651 /*
652 * if the servname does not match socktype/protocol, ignore it.
653 */
654 if (get_portmatch(pai, servname) != 0)
655 return 0;
656
657 afd = find_afd(pai->ai_family);
658 if (afd == NULL)
659 return 0;
660
661 switch (afd->a_af) {
662#if 0 /*X/Open spec*/
663 case AF_INET:
664 error = inet_aton(hostname, (struct in_addr *)pton);
665 break;
666#endif
667 default:
668 error = inet_pton(afd->a_af, hostname, pton);
669 break;
670 }
671 if (error == 1) {
672 if (pai->ai_family == afd->a_af ||
673 pai->ai_family == PF_UNSPEC /*?*/) {
674 GET_AI(cur->ai_next, afd, pton);
675 GET_PORT(cur->ai_next, servname);
676 /*
677 * Set the numeric address itself as
678 * the canonical name, based on a
679 * clarification in rfc2553bis-03.
680 */
681 GET_CANONNAME(cur->ai_next, canonname);
682
683 while (cur && cur->ai_next)
684 cur = cur->ai_next;
685 } else
686 ERR(EAI_FAMILY); /*xxx*/
687 }
688
689 *res = sentinel.ai_next;
690 return 0;
691
692free:
693bad:
694 if (sentinel.ai_next)
695 freeaddrinfo(sentinel.ai_next);
696 return error;
697}
698
699/*
700 * numeric hostname with scope
701 */
702static int
703explore_numeric_scope(const struct addrinfo *pai, const char *hostname,
704 const char *servname, struct addrinfo **res)
705{
706#if !defined(SCOPE_DELIMITER) || !defined(INET6)
707 return explore_numeric(pai, hostname, servname, res, hostname);
708#else
709 const struct afd *afd;
710 struct addrinfo *cur;
711 int error;
712 char *cp, *hostname2 = NULL, *scope, *addr;
713 struct sockaddr_in6 *sin6;
714
715 /*
716 * if the servname does not match socktype/protocol, ignore it.
717 */
718 if (get_portmatch(pai, servname) != 0)
719 return 0;
720
721 afd = find_afd(pai->ai_family);
722 if (afd == NULL)
723 return 0;
724
725 if (!afd->a_scoped)
726 return explore_numeric(pai, hostname, servname, res, hostname);
727
728 cp = strchr(hostname, SCOPE_DELIMITER);
729 if (cp == NULL)
730 return explore_numeric(pai, hostname, servname, res, hostname);
731
732 /*
733 * Handle special case of <scoped_address><delimiter><scope id>
734 */
735 hostname2 = strdup(hostname);
736 if (hostname2 == NULL)
737 return EAI_MEMORY;
738 /* terminate at the delimiter */
739 hostname2[cp - hostname] = '\0';
740 addr = hostname2;
741 scope = cp + 1;
742
743 error = explore_numeric(pai, addr, servname, res, hostname);
744 if (error == 0) {
745 u_int32_t scopeid;
746
747 for (cur = *res; cur; cur = cur->ai_next) {
748 if (cur->ai_family != AF_INET6)
749 continue;
750 sin6 = (struct sockaddr_in6 *)(void *)cur->ai_addr;
751 if (ip6_str2scopeid(scope, sin6, &scopeid) == -1) {
752 free(hostname2);
753 return(EAI_NODATA); /* XXX: is return OK? */
754 }
755 sin6->sin6_scope_id = scopeid;
756 }
757 }
758
759 free(hostname2);
760
761 return error;
762#endif
763}
764
765static int
766get_canonname(const struct addrinfo *pai, struct addrinfo *ai, const char *str)
767{
768 if ((pai->ai_flags & (AI_CANONNAME | AI_FQDN)) != 0) {
769 ai->ai_canonname = strdup(str);
770 if (ai->ai_canonname == NULL)
771 return EAI_MEMORY;
772 }
773 return 0;
774}
775
776static struct addrinfo *
777get_ai(const struct addrinfo *pai, const struct afd *afd, const char *addr)
778{
779 char *p;
780 struct addrinfo *ai;
781
782 ai = (struct addrinfo *)malloc(sizeof(struct addrinfo)
783 + (afd->a_socklen));
784 if (ai == NULL)
785 return NULL;
786
787 memcpy(ai, pai, sizeof(struct addrinfo));
788 ai->ai_addr = (struct sockaddr *)(void *)(ai + 1);
789 memset(ai->ai_addr, 0, (size_t)afd->a_socklen);
790 ai->ai_addr->sa_len = afd->a_socklen;
791 ai->ai_addrlen = afd->a_socklen;
792 ai->ai_addr->sa_family = ai->ai_family = afd->a_af;
793 p = (char *)(void *)(ai->ai_addr);
794 memcpy(p + afd->a_off, addr, (size_t)afd->a_addrlen);
795 return ai;
796}
797
798static int
799get_portmatch(const struct addrinfo *ai, const char *servname)
800{
801
802 /* get_port does not touch first argument. when matchonly == 1. */
803 /* LINTED const cast */
804 return get_port((struct addrinfo *)ai, servname, 1);
805}
806
807static int
808get_port(struct addrinfo *ai, const char *servname, int matchonly)
809{
810 const char *errstr, *proto;
811 int port;
812 int allownumeric;
813
814 if (servname == NULL)
815 return 0;
816 switch (ai->ai_family) {
817 case AF_INET:
818#ifdef AF_INET6
819 case AF_INET6:
820#endif
821 break;
822 default:
823 return 0;
824 }
825
826 switch (ai->ai_socktype) {
827 case SOCK_RAW:
828 return EAI_SERVICE;
829 case SOCK_DGRAM:
830 case SOCK_STREAM:
831 case ANY:
832 allownumeric = 1;
833 break;
834 default:
835 return EAI_SOCKTYPE;
836 }
837
838 port = (int)strtonum(servname, 0, USHRT_MAX, &errstr);
839 if (!errstr) {
840 if (!allownumeric)
841 return EAI_SERVICE;
842 port = htons(port);
843 } else {
844 struct servent sp;
845 struct servent_data sd;
846
847 if (errno == ERANGE)
848 return EAI_SERVICE;
849 if (ai->ai_flags & AI_NUMERICSERV)
850 return EAI_NONAME;
851
852 switch (ai->ai_socktype) {
853 case SOCK_DGRAM:
854 proto = "udp";
855 break;
856 case SOCK_STREAM:
857 proto = "tcp";
858 break;
859 default:
860 proto = NULL;
861 break;
862 }
863
864 (void)memset(&sd, 0, sizeof(sd));
865 if (getservbyname_r(servname, proto, &sp, &sd) == -1)
866 return EAI_SERVICE;
867 port = sp.s_port;
868 endservent_r(&sd);
869 }
870
871 if (!matchonly) {
872 switch (ai->ai_family) {
873 case AF_INET:
874 ((struct sockaddr_in *)(void *)
875 ai->ai_addr)->sin_port = port;
876 break;
877#ifdef INET6
878 case AF_INET6:
879 ((struct sockaddr_in6 *)(void *)
880 ai->ai_addr)->sin6_port = port;
881 break;
882#endif
883 }
884 }
885
886 return 0;
887}
888
889static const struct afd *
890find_afd(int af)
891{
892 const struct afd *afd;
893
894 if (af == PF_UNSPEC)
895 return NULL;
896 for (afd = afdl; afd->a_af; afd++) {
897 if (afd->a_af == af)
898 return afd;
899 }
900 return NULL;
901}
902
903#ifdef INET6
904/* convert a string to a scope identifier. XXX: IPv6 specific */
905static int
906ip6_str2scopeid(char *scope, struct sockaddr_in6 *sin6, u_int32_t *scopeid)
907{
908 struct in6_addr *a6 = &sin6->sin6_addr;
909 const char *errstr;
910
911 /* empty scopeid portion is invalid */
912 if (*scope == '\0')
913 return -1;
914
915 if (IN6_IS_ADDR_LINKLOCAL(a6) || IN6_IS_ADDR_MC_LINKLOCAL(a6) ||
916 IN6_IS_ADDR_MC_INTFACELOCAL(a6)) {
917 /*
918 * We currently assume a one-to-one mapping between links
919 * and interfaces, so we simply use interface indices for
920 * like-local scopes.
921 */
922 *scopeid = if_nametoindex(scope);
923 if (*scopeid == 0)
924 goto trynumeric;
925 return 0;
926 }
927
928 /* still unclear about literal, allow numeric only - placeholder */
929 if (IN6_IS_ADDR_SITELOCAL(a6) || IN6_IS_ADDR_MC_SITELOCAL(a6))
930 goto trynumeric;
931 if (IN6_IS_ADDR_MC_ORGLOCAL(a6))
932 goto trynumeric;
933 else
934 goto trynumeric; /* global */
935
936 /* try to convert to a numeric id as a last resort */
937 trynumeric:
938 *scopeid = (u_int32_t)strtonum(scope, 0, UINT32_MAX, &errstr);
939 if (errstr)
940 return (-1);
941 return (0);
942}
943#endif
944
945/* code duplicate with gethnamaddr.c */
946
947static const char AskedForGot[] =
948 "gethostby*.getanswer: asked for \"%s\", got \"%s\"";
949
950static struct addrinfo *
951getanswer(const querybuf *answer, int anslen, const char *qname, int qtype,
952 const struct addrinfo *pai)
953{
954 struct addrinfo sentinel, *cur;
955 struct addrinfo ai;
956 const struct afd *afd;
957 char *canonname;
958 const HEADER *hp;
959 const u_char *cp;
960 int n;
961 const u_char *eom;
962 char *bp, *ep;
963 int type, class, ancount, qdcount;
964 int haveanswer, had_error;
965 char tbuf[MAXDNAME];
966 int (*name_ok)(const char *);
967 char hostbuf[8*1024];
968
969 memset(&sentinel, 0, sizeof(sentinel));
970 cur = &sentinel;
971
972 canonname = NULL;
973 eom = answer->buf + anslen;
974 switch (qtype) {
975 case T_A:
976 case T_AAAA:
977 case T_ANY: /*use T_ANY only for T_A/T_AAAA lookup*/
978 name_ok = res_hnok;
979 break;
980 default:
981 return (NULL); /* XXX should be abort() -- but that is illegal */
982 }
983 /*
984 * find first satisfactory answer
985 */
986 hp = &answer->hdr;
987 ancount = ntohs(hp->ancount);
988 qdcount = ntohs(hp->qdcount);
989 bp = hostbuf;
990 ep = hostbuf + sizeof hostbuf;
991 cp = answer->buf + HFIXEDSZ;
992 if (qdcount != 1) {
993 h_errno = NO_RECOVERY;
994 return (NULL);
995 }
996 n = dn_expand(answer->buf, eom, cp, bp, ep - bp);
997 if ((n < 0) || !(*name_ok)(bp)) {
998 h_errno = NO_RECOVERY;
999 return (NULL);
1000 }
1001 cp += n + QFIXEDSZ;
1002 if (qtype == T_A || qtype == T_AAAA || qtype == T_ANY) {
1003 size_t len;
1004
1005 /* res_send() has already verified that the query name is the
1006 * same as the one we sent; this just gets the expanded name
1007 * (i.e., with the succeeding search-domain tacked on).
1008 */
1009 len = strlen(bp) + 1; /* for the \0 */
1010 if (len >= MAXHOSTNAMELEN) {
1011 h_errno = NO_RECOVERY;
1012 return (NULL);
1013 }
1014 canonname = bp;
1015 bp += len;
1016 /* The qname can be abbreviated, but h_name is now absolute. */
1017 qname = canonname;
1018 }
1019 haveanswer = 0;
1020 had_error = 0;
1021 while (ancount-- > 0 && cp < eom && !had_error) {
1022 n = dn_expand(answer->buf, eom, cp, bp, ep - bp);
1023 if ((n < 0) || !(*name_ok)(bp)) {
1024 had_error++;
1025 continue;
1026 }
1027 cp += n; /* name */
1028 type = _getshort(cp);
1029 cp += INT16SZ; /* type */
1030 class = _getshort(cp);
1031 cp += INT16SZ + INT32SZ; /* class, TTL */
1032 n = _getshort(cp);
1033 cp += INT16SZ; /* len */
1034 if (class != C_IN) {
1035 /* XXX - debug? syslog? */
1036 cp += n;
1037 continue; /* XXX - had_error++ ? */
1038 }
1039 if ((qtype == T_A || qtype == T_AAAA || qtype == T_ANY) &&
1040 type == T_CNAME) {
1041 size_t len;
1042
1043 n = dn_expand(answer->buf, eom, cp, tbuf, sizeof tbuf);
1044 if ((n < 0) || !(*name_ok)(tbuf)) {
1045 had_error++;
1046 continue;
1047 }
1048 cp += n;
1049 /* Get canonical name. */
1050 len = strlen(tbuf) + 1; /* for the \0 */
1051 if (len > ep - bp || len >= MAXHOSTNAMELEN) {
1052 had_error++;
1053 continue;
1054 }
1055 strlcpy(bp, tbuf, ep - bp);
1056 canonname = bp;
1057 bp += len;
1058 continue;
1059 }
1060 if (qtype == T_ANY) {
1061 if (!(type == T_A || type == T_AAAA)) {
1062 cp += n;
1063 continue;
1064 }
1065 } else if (type != qtype) {
1066#ifndef NO_LOG_BAD_DNS_RESPONSES
1067 if (type != T_KEY && type != T_SIG) {
1068 struct syslog_data sdata = SYSLOG_DATA_INIT;
1069
1070 syslog_r(LOG_NOTICE|LOG_AUTH, &sdata,
1071 "gethostby*.getanswer: asked for \"%s %s %s\", got type \"%s\"",
1072 qname, p_class(C_IN), p_type(qtype),
1073 p_type(type));
1074 }
1075#endif /* NO_LOG_BAD_DNS_RESPONSES */
1076 cp += n;
1077 continue; /* XXX - had_error++ ? */
1078 }
1079 switch (type) {
1080 case T_A:
1081 case T_AAAA:
1082 if (strcasecmp(canonname, bp) != 0) {
1083 struct syslog_data sdata = SYSLOG_DATA_INIT;
1084
1085 syslog_r(LOG_NOTICE|LOG_AUTH, &sdata,
1086 AskedForGot, canonname, bp);
1087 cp += n;
1088 continue; /* XXX - had_error++ ? */
1089 }
1090 if (type == T_A && n != INADDRSZ) {
1091 cp += n;
1092 continue;
1093 }
1094 if (type == T_AAAA && n != IN6ADDRSZ) {
1095 cp += n;
1096 continue;
1097 }
1098 if (type == T_AAAA) {
1099 struct in6_addr in6;
1100 memcpy(&in6, cp, IN6ADDRSZ);
1101 if (IN6_IS_ADDR_V4MAPPED(&in6)) {
1102 cp += n;
1103 continue;
1104 }
1105 }
1106 if (!haveanswer) {
1107 canonname = bp;
1108 bp += strlen(bp) + 1; /* for the \0 */
1109 }
1110
1111 /* don't overwrite pai */
1112 ai = *pai;
1113 ai.ai_family = (type == T_A) ? AF_INET : AF_INET6;
1114 afd = find_afd(ai.ai_family);
1115 if (afd == NULL) {
1116 cp += n;
1117 continue;
1118 }
1119 cur->ai_next = get_ai(&ai, afd, (const char *)cp);
1120 if (cur->ai_next == NULL)
1121 had_error++;
1122 while (cur && cur->ai_next)
1123 cur = cur->ai_next;
1124 cp += n;
1125 break;
1126 default:
1127 abort(); /* XXX abort illegal in library */
1128 }
1129 if (!had_error)
1130 haveanswer++;
1131 }
1132 if (haveanswer) {
1133 if (!canonname || (pai->ai_flags & AI_FQDN) != 0)
1134 (void)get_canonname(pai, sentinel.ai_next, qname);
1135 else
1136 (void)get_canonname(pai, sentinel.ai_next, canonname);
1137 h_errno = NETDB_SUCCESS;
1138 return sentinel.ai_next;
1139 }
1140
1141 h_errno = NO_RECOVERY;
1142 return NULL;
1143}
1144
1145/*ARGSUSED*/
1146static struct addrinfo *
1147_dns_getaddrinfo(const char *name, const struct addrinfo *pai,
1148 const struct __res_state *_resp)
1149{
1150 struct addrinfo *ai;
1151 querybuf *buf, *buf2;
1152 struct addrinfo sentinel, *cur;
1153 struct res_target q, q2;
1154
1155 memset(&q, 0, sizeof(q));
1156 memset(&q2, 0, sizeof(q2));
1157 memset(&sentinel, 0, sizeof(sentinel));
1158 cur = &sentinel;
1159
1160 buf = malloc(sizeof(*buf));
1161 if (buf == NULL) {
1162 h_errno = NETDB_INTERNAL;
1163 return NULL;
1164 }
1165 buf2 = malloc(sizeof(*buf2));
1166 if (buf2 == NULL) {
1167 free(buf);
1168 h_errno = NETDB_INTERNAL;
1169 return NULL;
1170 }
1171
1172 switch (pai->ai_family) {
1173 case AF_UNSPEC:
1174 /* respect user supplied order */
1175 q.qclass = C_IN;
1176 q.qtype = (_resp->family[0] == AF_INET6) ? T_AAAA : T_A;
1177 q.answer = buf->buf;
1178 q.anslen = sizeof(buf->buf);
1179 q.next = &q2;
1180
1181 if (_resp->family[1] == -1) {
1182 /* stop here if only one family was given */
1183 q.next = NULL;
1184 break;
1185 }
1186
1187 q2.qclass = C_IN;
1188 q2.qtype = (_resp->family[1] == AF_INET6) ? T_AAAA : T_A;
1189 q2.answer = buf2->buf;
1190 q2.anslen = sizeof(buf2->buf);
1191 break;
1192 case AF_INET:
1193 q.qclass = C_IN;
1194 q.qtype = T_A;
1195 q.answer = buf->buf;
1196 q.anslen = sizeof(buf->buf);
1197 break;
1198 case AF_INET6:
1199 q.qclass = C_IN;
1200 q.qtype = T_AAAA;
1201 q.answer = buf->buf;
1202 q.anslen = sizeof(buf->buf);
1203 break;
1204 default:
1205 free(buf);
1206 free(buf2);
1207 return NULL;
1208 }
1209 if (res_searchN(name, &q) < 0) {
1210 free(buf);
1211 free(buf2);
1212 return NULL;
1213 }
1214 ai = getanswer(buf, q.n, q.name, q.qtype, pai);
1215 if (ai) {
1216 cur->ai_next = ai;
1217 while (cur && cur->ai_next)
1218 cur = cur->ai_next;
1219 }
1220 if (q.next) {
1221 ai = getanswer(buf2, q2.n, q2.name, q2.qtype, pai);
1222 if (ai)
1223 cur->ai_next = ai;
1224 }
1225 free(buf);
1226 free(buf2);
1227 return sentinel.ai_next;
1228}
1229
1230static struct addrinfo *
1231_gethtent(const char *name, const struct addrinfo *pai, FILE *hostf)
1232{
1233 char *p;
1234 char *cp, *tname, *cname;
1235 struct addrinfo hints, *res0, *res;
1236 int error;
1237 const char *addr;
1238 char hostbuf[8*1024];
1239
1240 again:
1241 if (!(p = fgets(hostbuf, sizeof hostbuf, hostf)))
1242 return (NULL);
1243 if (*p == '#')
1244 goto again;
1245 if (!(cp = strpbrk(p, "#\n")))
1246 goto again;
1247 *cp = '\0';
1248 if (!(cp = strpbrk(p, " \t")))
1249 goto again;
1250 *cp++ = '\0';
1251 addr = p;
1252 /* if this is not something we're looking for, skip it. */
1253 cname = NULL;
1254 while (cp && *cp) {
1255 if (*cp == ' ' || *cp == '\t') {
1256 cp++;
1257 continue;
1258 }
1259 if (!cname)
1260 cname = cp;
1261 tname = cp;
1262 if ((cp = strpbrk(cp, " \t")) != NULL)
1263 *cp++ = '\0';
1264 if (strcasecmp(name, tname) == 0)
1265 goto found;
1266 }
1267 goto again;
1268
1269found:
1270 hints = *pai;
1271 hints.ai_flags = AI_NUMERICHOST;
1272 error = getaddrinfo(addr, NULL, &hints, &res0);
1273 if (error)
1274 goto again;
1275 for (res = res0; res; res = res->ai_next) {
1276 /* cover it up */
1277 res->ai_flags = pai->ai_flags;
1278
1279 if (get_canonname(pai, res, cname) != 0) {
1280 freeaddrinfo(res0);
1281 goto again;
1282 }
1283 }
1284 return res0;
1285}
1286
1287/*ARGSUSED*/
1288static struct addrinfo *
1289_files_getaddrinfo(const char *name, const struct addrinfo *pai)
1290{
1291 struct addrinfo sentinel, *cur;
1292 struct addrinfo *p;
1293 FILE *hostf;
1294
1295 hostf = fopen(_PATH_HOSTS, "r");
1296 if (hostf == NULL)
1297 return NULL;
1298
1299 memset(&sentinel, 0, sizeof(sentinel));
1300 cur = &sentinel;
1301
1302 while ((p = _gethtent(name, pai, hostf)) != NULL) {
1303 cur->ai_next = p;
1304 while (cur && cur->ai_next)
1305 cur = cur->ai_next;
1306 }
1307 fclose(hostf);
1308
1309 return sentinel.ai_next;
1310}
1311
1312#ifdef YP
1313static char *__ypdomain;
1314
1315/*ARGSUSED*/
1316static struct addrinfo *
1317_yphostent(char *line, const struct addrinfo *pai)
1318{
1319 struct addrinfo sentinel, *cur;
1320 struct addrinfo hints, *res, *res0;
1321 int error;
1322 char *p = line;
1323 const char *addr, *canonname;
1324 char *nextline;
1325 char *cp;
1326
1327 addr = canonname = NULL;
1328
1329 memset(&sentinel, 0, sizeof(sentinel));
1330 cur = &sentinel;
1331
1332nextline:
1333 /* terminate line */
1334 cp = strchr(p, '\n');
1335 if (cp) {
1336 *cp++ = '\0';
1337 nextline = cp;
1338 } else
1339 nextline = NULL;
1340
1341 cp = strpbrk(p, " \t");
1342 if (cp == NULL) {
1343 if (canonname == NULL)
1344 return (NULL);
1345 else
1346 goto done;
1347 }
1348 *cp++ = '\0';
1349
1350 addr = p;
1351
1352 while (cp && *cp) {
1353 if (*cp == ' ' || *cp == '\t') {
1354 cp++;
1355 continue;
1356 }
1357 if (!canonname)
1358 canonname = cp;
1359 if ((cp = strpbrk(cp, " \t")) != NULL)
1360 *cp++ = '\0';
1361 }
1362
1363 hints = *pai;
1364 hints.ai_flags = AI_NUMERICHOST;
1365 error = getaddrinfo(addr, NULL, &hints, &res0);
1366 if (error == 0) {
1367 for (res = res0; res; res = res->ai_next) {
1368 /* cover it up */
1369 res->ai_flags = pai->ai_flags;
1370
1371 (void)get_canonname(pai, res, canonname);
1372 }
1373 } else
1374 res0 = NULL;
1375 if (res0) {
1376 cur->ai_next = res0;
1377 while (cur && cur->ai_next)
1378 cur = cur->ai_next;
1379 }
1380
1381 if (nextline) {
1382 p = nextline;
1383 goto nextline;
1384 }
1385
1386done:
1387 return sentinel.ai_next;
1388}
1389
1390/*ARGSUSED*/
1391static struct addrinfo *
1392_yp_getaddrinfo(const char *name, const struct addrinfo *pai)
1393{
1394 struct addrinfo sentinel, *cur;
1395 struct addrinfo *ai = NULL;
1396 static char *__ypcurrent;
1397 int __ypcurrentlen, r;
1398
1399 memset(&sentinel, 0, sizeof(sentinel));
1400 cur = &sentinel;
1401
1402 if (!__ypdomain) {
1403 if (_yp_check(&__ypdomain) == 0)
1404 return NULL;
1405 }
1406 if (__ypcurrent)
1407 free(__ypcurrent);
1408 __ypcurrent = NULL;
1409
1410 /* hosts.byname is only for IPv4 (Solaris8) */
1411 if (pai->ai_family == PF_UNSPEC || pai->ai_family == PF_INET) {
1412 r = yp_match(__ypdomain, "hosts.byname", name,
1413 (int)strlen(name), &__ypcurrent, &__ypcurrentlen);
1414 if (r == 0) {
1415 struct addrinfo ai4;
1416
1417 ai4 = *pai;
1418 ai4.ai_family = AF_INET;
1419 ai = _yphostent(__ypcurrent, &ai4);
1420 if (ai) {
1421 cur->ai_next = ai;
1422 while (cur && cur->ai_next)
1423 cur = cur->ai_next;
1424 }
1425 }
1426 }
1427
1428 /* ipnodes.byname can hold both IPv4/v6 */
1429 r = yp_match(__ypdomain, "ipnodes.byname", name,
1430 (int)strlen(name), &__ypcurrent, &__ypcurrentlen);
1431 if (r == 0) {
1432 ai = _yphostent(__ypcurrent, pai);
1433 if (ai) {
1434 cur->ai_next = ai;
1435 while (cur && cur->ai_next)
1436 cur = cur->ai_next;
1437 }
1438 }
1439
1440 return sentinel.ai_next;
1441}
1442#endif
1443
1444
1445/* resolver logic */
1446
1447extern const char *__hostalias(const char *);
1448extern int h_errno;
1449extern int res_opt(int, u_char *, int, int);
1450
1451/*
1452 * Formulate a normal query, send, and await answer.
1453 * Returned answer is placed in supplied buffer "answer".
1454 * Perform preliminary check of answer, returning success only
1455 * if no error is indicated and the answer count is nonzero.
1456 * Return the size of the response on success, -1 on error.
1457 * Error number is left in h_errno.
1458 *
1459 * Caller must parse answer and determine whether it answers the question.
1460 */
1461static int
1462res_queryN(const char *name, struct res_target *target)
1463{
1464 struct __res_state *_resp = _THREAD_PRIVATE(_res, _res, &_res);
1465 u_char *buf;
1466 HEADER *hp;
1467 int n;
1468 struct res_target *t;
1469 int rcode;
1470 int ancount;
1471
1472 buf = malloc(MAXPACKET);
1473 if (buf == NULL) {
1474 h_errno = NETDB_INTERNAL;
1475 return (-1);
1476 }
1477
1478 rcode = NOERROR;
1479 ancount = 0;
1480
1481 if (_res_init(0) == -1) {
1482 h_errno = NETDB_INTERNAL;
1483 free(buf);
1484 return (-1);
1485 }
1486
1487 for (t = target; t; t = t->next) {
1488 int class, type;
1489 u_char *answer;
1490 int anslen;
1491
1492 hp = (HEADER *)(void *)t->answer;
1493 hp->rcode = NOERROR; /* default */
1494
1495 /* make it easier... */
1496 class = t->qclass;
1497 type = t->qtype;
1498 answer = t->answer;
1499 anslen = t->anslen;
1500#ifdef DEBUG
1501 if (_resp->options & RES_DEBUG)
1502 printf(";; res_query(%s, %d, %d)\n", name, class, type);
1503#endif
1504
1505 n = res_mkquery(QUERY, name, class, type, NULL, 0, NULL,
1506 buf, MAXPACKET);
1507 if (n > 0 && (_resp->options & RES_USE_EDNS0) != 0)
1508 n = res_opt(n, buf, MAXPACKET, anslen);
1509 if (n <= 0) {
1510#ifdef DEBUG
1511 if (_resp->options & RES_DEBUG)
1512 printf(";; res_query: mkquery failed\n");
1513#endif
1514 h_errno = NO_RECOVERY;
1515 free(buf);
1516 return (n);
1517 }
1518 n = res_send(buf, n, answer, anslen);
1519#if 0
1520 if (n < 0) {
1521#ifdef DEBUG
1522 if (_resp->options & RES_DEBUG)
1523 printf(";; res_query: send error\n");
1524#endif
1525 h_errno = TRY_AGAIN;
1526 free(buf);
1527 return (n);
1528 }
1529#endif
1530
1531 if (n < 0 || hp->rcode != NOERROR || ntohs(hp->ancount) == 0) {
1532 rcode = hp->rcode; /* record most recent error */
1533#ifdef DEBUG
1534 if (_resp->options & RES_DEBUG)
1535 printf(";; rcode = %u, ancount=%u\n", hp->rcode,
1536 ntohs(hp->ancount));
1537#endif
1538 continue;
1539 }
1540
1541 ancount += ntohs(hp->ancount);
1542
1543 t->n = n;
1544 }
1545
1546 if (ancount == 0) {
1547 switch (rcode) {
1548 case NXDOMAIN:
1549 h_errno = HOST_NOT_FOUND;
1550 break;
1551 case SERVFAIL:
1552 h_errno = TRY_AGAIN;
1553 break;
1554 case NOERROR:
1555 h_errno = NO_DATA;
1556 break;
1557 case FORMERR:
1558 case NOTIMP:
1559 case REFUSED:
1560 default:
1561 h_errno = NO_RECOVERY;
1562 break;
1563 }
1564 free(buf);
1565 return (-1);
1566 }
1567 free(buf);
1568 return (ancount);
1569}
1570
1571/*
1572 * Formulate a normal query, send, and retrieve answer in supplied buffer.
1573 * Return the size of the response on success, -1 on error.
1574 * If enabled, implement search rules until answer or unrecoverable failure
1575 * is detected. Error code, if any, is left in h_errno.
1576 */
1577static int
1578res_searchN(const char *name, struct res_target *target)
1579{
1580 struct __res_state *_resp = _THREAD_PRIVATE(_res, _res, &_res);
1581 const char *cp, * const *domain;
1582 HEADER *hp = (HEADER *)(void *)target->answer; /*XXX*/
1583 u_int dots;
1584 int trailing_dot, ret, saved_herrno;
1585 int got_nodata = 0, got_servfail = 0, tried_as_is = 0;
1586
1587 if (_res_init(0) == -1) {
1588 h_errno = NETDB_INTERNAL;
1589 return (-1);
1590 }
1591
1592 errno = 0;
1593 h_errno = HOST_NOT_FOUND; /* default, if we never query */
1594 dots = 0;
1595 for (cp = name; *cp; cp++)
1596 dots += (*cp == '.');
1597 trailing_dot = 0;
1598 if (cp > name && *--cp == '.')
1599 trailing_dot++;
1600
1601 /*
1602 * if there aren't any dots, it could be a user-level alias
1603 */
1604 if (!dots && (cp = __hostalias(name)) != NULL)
1605 return (res_queryN(cp, target));
1606
1607 /*
1608 * If there are dots in the name already, let's just give it a try
1609 * 'as is'. The threshold can be set with the "ndots" option.
1610 */
1611 saved_herrno = -1;
1612 if (dots >= _resp->ndots) {
1613 ret = res_querydomainN(name, NULL, target);
1614 if (ret > 0)
1615 return (ret);
1616 saved_herrno = h_errno;
1617 tried_as_is++;
1618 }
1619
1620 /*
1621 * We do at least one level of search if
1622 * - there is no dot and RES_DEFNAME is set, or
1623 * - there is at least one dot, there is no trailing dot,
1624 * and RES_DNSRCH is set.
1625 */
1626 if ((!dots && (_resp->options & RES_DEFNAMES)) ||
1627 (dots && !trailing_dot && (_resp->options & RES_DNSRCH))) {
1628 int done = 0;
1629
1630 for (domain = (const char * const *)_resp->dnsrch;
1631 *domain && !done;
1632 domain++) {
1633
1634 ret = res_querydomainN(name, *domain, target);
1635 if (ret > 0)
1636 return (ret);
1637
1638 /*
1639 * If no server present, give up.
1640 * If name isn't found in this domain,
1641 * keep trying higher domains in the search list
1642 * (if that's enabled).
1643 * On a NO_DATA error, keep trying, otherwise
1644 * a wildcard entry of another type could keep us
1645 * from finding this entry higher in the domain.
1646 * If we get some other error (negative answer or
1647 * server failure), then stop searching up,
1648 * but try the input name below in case it's
1649 * fully-qualified.
1650 */
1651 if (errno == ECONNREFUSED) {
1652 h_errno = TRY_AGAIN;
1653 return (-1);
1654 }
1655
1656 switch (h_errno) {
1657 case NO_DATA:
1658 got_nodata++;
1659 /* FALLTHROUGH */
1660 case HOST_NOT_FOUND:
1661 /* keep trying */
1662 break;
1663 case TRY_AGAIN:
1664 if (hp->rcode == SERVFAIL) {
1665 /* try next search element, if any */
1666 got_servfail++;
1667 break;
1668 }
1669 /* FALLTHROUGH */
1670 default:
1671 /* anything else implies that we're done */
1672 done++;
1673 }
1674 /*
1675 * if we got here for some reason other than DNSRCH,
1676 * we only wanted one iteration of the loop, so stop.
1677 */
1678 if (!(_resp->options & RES_DNSRCH))
1679 done++;
1680 }
1681 }
1682
1683 /*
1684 * if we have not already tried the name "as is", do that now.
1685 * note that we do this regardless of how many dots were in the
1686 * name or whether it ends with a dot.
1687 */
1688 if (!tried_as_is) {
1689 ret = res_querydomainN(name, NULL, target);
1690 if (ret > 0)
1691 return (ret);
1692 }
1693
1694 /*
1695 * if we got here, we didn't satisfy the search.
1696 * if we did an initial full query, return that query's h_errno
1697 * (note that we wouldn't be here if that query had succeeded).
1698 * else if we ever got a nodata, send that back as the reason.
1699 * else send back meaningless h_errno, that being the one from
1700 * the last DNSRCH we did.
1701 */
1702 if (saved_herrno != -1)
1703 h_errno = saved_herrno;
1704 else if (got_nodata)
1705 h_errno = NO_DATA;
1706 else if (got_servfail)
1707 h_errno = TRY_AGAIN;
1708 return (-1);
1709}
1710
1711/*
1712 * Perform a call on res_query on the concatenation of name and domain,
1713 * removing a trailing dot from name if domain is NULL.
1714 */
1715static int
1716res_querydomainN(const char *name, const char *domain,
1717 struct res_target *target)
1718{
1719 struct __res_state *_resp = _THREAD_PRIVATE(_res, _res, &_res);
1720 char nbuf[MAXDNAME];
1721 const char *longname = nbuf;
1722 size_t len;
1723
1724 if (_res_init(0) == -1) {
1725 h_errno = NETDB_INTERNAL;
1726 return (-1);
1727 }
1728#ifdef DEBUG
1729 if (_resp->options & RES_DEBUG)
1730 printf(";; res_querydomain(%s, %s)\n",
1731 name, domain?domain:"<Nil>");
1732#endif
1733 if (domain == NULL) {
1734 /*
1735 * Check for trailing '.';
1736 * copy without '.' if present.
1737 */
1738 len = strlcpy(nbuf, name, sizeof(nbuf));
1739 if (len >= sizeof(nbuf)) {
1740 h_errno = NO_RECOVERY;
1741 return (-1);
1742 }
1743 if (len > 0 && nbuf[len - 1] == '.')
1744 nbuf[len - 1] = '\0';
1745 } else {
1746 int i;
1747
1748 i = snprintf(nbuf, sizeof(nbuf), "%s.%s", name, domain);
1749 if (i < 0 || i >= sizeof(nbuf)) {
1750 h_errno = NO_RECOVERY;
1751 return (-1);
1752 }
1753 }
1754 return (res_queryN(longname, target));
1755}
generated by cgit v1.2.3-55-g6feb (git 2.39.1) at 2025-10-23 20:20:42 +0000