1/* $FreeBSD: head/lib/libc/net/getaddrinfo.c 74393 2001-03-17 14:25:23Z ume $ */
2/* $KAME: getaddrinfo.c,v 1.15 2000/07/09 04:37:24 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 * "#ifdef FAITH" part is local hack for supporting IPv4-v6 translator.
35 *
36 * Issues to be discussed:
37 * - Thread safe-ness must be checked.
38 * - Return values. There are nonstandard return values defined and used
39 * in the source code. This is because RFC2553 is silent about which error
40 * code must be returned for which situation.
41 * - freeaddrinfo(NULL). RFC2553 is silent about it. XNET 5.2 says it is
42 * invalid.
43 * current code - SEGV on freeaddrinfo(NULL)
44 * Note:
45 * - We use getipnodebyname() just for thread-safeness. There's no intent
46 * to let it do PF_UNSPEC (actually we never pass PF_UNSPEC to
47 * getipnodebyname().
48 * - The code filters out AFs that are not supported by the kernel,
49 * when globbing NULL hostname (to loopback, or wildcard). Is it the right
50 * thing to do? What is the relationship with post-RFC2553 AI_ADDRCONFIG
51 * in ai_flags?
52 * - (post-2553) semantics of AI_ADDRCONFIG itself is too vague.
53 * (1) what should we do against numeric hostname (2) what should we do
54 * against NULL hostname (3) what is AI_ADDRCONFIG itself. AF not ready?
55 * non-loopback address configured? global address configured?
56 * - To avoid search order issue, we have a big amount of code duplicate
57 * from gethnamaddr.c and some other places. The issues that there's no
58 * lower layer function to lookup "IPv4 or IPv6" record. Calling
59 * gethostbyname2 from getaddrinfo will end up in wrong search order, as
60 * follows:
61 * - The code makes use of following calls when asked to resolver with
62 * ai_family = PF_UNSPEC:
63 * getipnodebyname(host, AF_INET6);
64 * getipnodebyname(host, AF_INET);
65 * This will result in the following queries if the node is configure to
66 * prefer /etc/hosts than DNS:
67 * lookup /etc/hosts for IPv6 address
68 * lookup DNS for IPv6 address
69 * lookup /etc/hosts for IPv4 address
70 * lookup DNS for IPv4 address
71 * which may not meet people's requirement.
72 * The right thing to happen is to have underlying layer which does
73 * PF_UNSPEC lookup (lookup both) and return chain of addrinfos.
74 * This would result in a bit of code duplicate with _dns_ghbyname() and
75 * friends.
76 */
77/*
78 * diffs with other KAME platforms:
79 * - other KAME platforms already nuked FAITH ($GAI), but as FreeBSD
80 * 4.0-RELEASE supplies it, we still have the code here.
81 * - AI_ADDRCONFIG support is supplied
82 * - EDNS0 support is not available due to resolver differences
83 * - some of FreeBSD style (#define tabify and others)
84 * - classful IPv4 numeric (127.1) is allowed.
85 */
86
87#include "namespace.h"
88#include <sys/types.h>
89#include <sys/param.h>
90#include <sys/socket.h>
91#include <net/if.h>
92#include <netinet/in.h>
93#include <arpa/inet.h>
94#include <arpa/nameser.h>
95#include <netdb.h>
96#include <resolv.h>
97#include <string.h>
98#include <stdlib.h>
99#include <stddef.h>
100#include <ctype.h>
101#include <unistd.h>
102#include <stdio.h>
103#include <errno.h>
104
105#include <syslog.h>
106#include <stdarg.h>
107#include <nsswitch.h>
108#include "un-namespace.h"
109
110#if defined(__KAME__) && defined(INET6)
111# define FAITH
112#endif
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#define N_INET6 0
139 {PF_INET6, sizeof(struct in6_addr),
140 sizeof(struct sockaddr_in6),
141 offsetof(struct sockaddr_in6, sin6_addr),
142 in6_addrany, in6_loopback, 1},
143#define N_INET 1
144#else
145#define N_INET 0
146#endif
147 {PF_INET, sizeof(struct in_addr),
148 sizeof(struct sockaddr_in),
149 offsetof(struct sockaddr_in, sin_addr),
150 in_addrany, in_loopback, 0},
151 {0, 0, 0, 0, NULL, NULL, 0},
152};
153
154struct explore {
155 int e_af;
156 int e_socktype;
157 int e_protocol;
158 const char *e_protostr;
159 int e_wild;
160#define WILD_AF(ex) ((ex)->e_wild & 0x01)
161#define WILD_SOCKTYPE(ex) ((ex)->e_wild & 0x02)
162#define WILD_PROTOCOL(ex) ((ex)->e_wild & 0x04)
163};
164
165static const struct explore explore[] = {
166#if 0
167 { PF_LOCAL, 0, ANY, ANY, NULL, 0x01 },
168#endif
169#ifdef INET6
170 { PF_INET6, SOCK_DGRAM, IPPROTO_UDP, "udp", 0x07 },
171 { PF_INET6, SOCK_STREAM, IPPROTO_TCP, "tcp", 0x07 },
172 { PF_INET6, SOCK_RAW, ANY, NULL, 0x05 },
173#endif
174 { PF_INET, SOCK_DGRAM, IPPROTO_UDP, "udp", 0x07 },
175 { PF_INET, SOCK_STREAM, IPPROTO_TCP, "tcp", 0x07 },
176 { PF_INET, SOCK_RAW, ANY, NULL, 0x05 },
177 { PF_UNSPEC, SOCK_DGRAM, IPPROTO_UDP, "udp", 0x07 },
178 { PF_UNSPEC, SOCK_STREAM, IPPROTO_TCP, "tcp", 0x07 },
179 { PF_UNSPEC, SOCK_RAW, ANY, NULL, 0x05 },
180 { -1, 0, 0, NULL, 0 },
181};
182
183#ifdef INET6
184#define PTON_MAX 16
185#else
186#define PTON_MAX 4
187#endif
188
189static const ns_src default_dns_files[] = {
190 { NSSRC_FILES, NS_SUCCESS },
191 { NSSRC_DNS, NS_SUCCESS },
192 { 0 }
193};
194
195#if PACKETSZ > 1024
196#define MAXPACKET PACKETSZ
197#else
198#define MAXPACKET 1024
199#endif
200
201typedef union {
202 HEADER hdr;
203 u_char buf[MAXPACKET];
204} querybuf;
205
206struct res_target {
207 struct res_target *next;
208 const char *name; /* domain name */
209 int qclass, qtype; /* class and type of query */
210 u_char *answer; /* buffer to put answer */
211 int anslen; /* size of answer buffer */
212 int n; /* result length */
213};
214
215static int str_isnumber __P((const char *));
216static int explore_fqdn __P((const struct addrinfo *, const char *,
217 const char *, struct addrinfo **));
218static int explore_null __P((const struct addrinfo *,
219 const char *, struct addrinfo **));
220static int explore_numeric __P((const struct addrinfo *, const char *,
221 const char *, struct addrinfo **));
222static int explore_numeric_scope __P((const struct addrinfo *, const char *,
223 const char *, struct addrinfo **));
224static int get_canonname __P((const struct addrinfo *,
225 struct addrinfo *, const char *));
226static struct addrinfo *get_ai __P((const struct addrinfo *,
227 const struct afd *, const char *));
228static int get_portmatch __P((const struct addrinfo *, const char *));
229static int get_port __P((struct addrinfo *, const char *, int));
230static const struct afd *find_afd __P((int));
231static int addrconfig __P((struct addrinfo *));
232#ifdef INET6
233static int ip6_str2scopeid __P((char *, struct sockaddr_in6 *));
234#endif
235
236static struct addrinfo *getanswer __P((const querybuf *, int, const char *, int,
237 const struct addrinfo *));
238static int _dns_getaddrinfo __P((void *, void *, va_list));
239static void _sethtent __P((void));
240static void _endhtent __P((void));
241static struct addrinfo *_gethtent __P((const char *, const struct addrinfo *));
242static int _files_getaddrinfo __P((void *, void *, va_list));
243#ifdef YP
244static struct addrinfo *_yphostent __P((char *, const struct addrinfo *));
245static int _yp_getaddrinfo __P((void *, void *, va_list));
246#endif
247
248static int res_queryN __P((const char *, struct res_target *));
249static int res_searchN __P((const char *, struct res_target *));
250static int res_querydomainN __P((const char *, const char *,
251 struct res_target *));
252
253static char *ai_errlist[] = {
254 "Success",
255 "Address family for hostname not supported", /* EAI_ADDRFAMILY */
256 "Temporary failure in name resolution", /* EAI_AGAIN */
257 "Invalid value for ai_flags", /* EAI_BADFLAGS */
258 "Non-recoverable failure in name resolution", /* EAI_FAIL */
259 "ai_family not supported", /* EAI_FAMILY */
260 "Memory allocation failure", /* EAI_MEMORY */
261 "No address associated with hostname", /* EAI_NODATA */
262 "hostname nor servname provided, or not known", /* EAI_NONAME */
263 "servname not supported for ai_socktype", /* EAI_SERVICE */
264 "ai_socktype not supported", /* EAI_SOCKTYPE */
265 "System error returned in errno", /* EAI_SYSTEM */
266 "Invalid value for hints", /* EAI_BADHINTS */
267 "Resolved protocol is unknown", /* EAI_PROTOCOL */
268 "Unknown error", /* EAI_MAX */
269};
270
271/* XXX macros that make external reference is BAD. */
272
273#define GET_AI(ai, afd, addr) \
274do { \
275 /* external reference: pai, error, and label free */ \
276 (ai) = get_ai(pai, (afd), (addr)); \
277 if ((ai) == NULL) { \
278 error = EAI_MEMORY; \
279 goto free; \
280 } \
281} while (/*CONSTCOND*/0)
282
283#define GET_PORT(ai, serv) \
284do { \
285 /* external reference: error and label free */ \
286 error = get_port((ai), (serv), 0); \
287 if (error != 0) \
288 goto free; \
289} while (/*CONSTCOND*/0)
290
291#define GET_CANONNAME(ai, str) \
292do { \
293 /* external reference: pai, error and label free */ \
294 error = get_canonname(pai, (ai), (str)); \
295 if (error != 0) \
296 goto free; \
297} while (/*CONSTCOND*/0)
298
299#define ERR(err) \
300do { \
301 /* external reference: error, and label bad */ \
302 error = (err); \
303 goto bad; \
304 /*NOTREACHED*/ \
305} while (/*CONSTCOND*/0)
306
307#define MATCH_FAMILY(x, y, w) \
308 ((x) == (y) || (/*CONSTCOND*/(w) && ((x) == PF_UNSPEC || (y) == PF_UNSPEC)))
309#define MATCH(x, y, w) \
310 ((x) == (y) || (/*CONSTCOND*/(w) && ((x) == ANY || (y) == ANY)))
311
312char *
313gai_strerror(ecode)
314 int ecode;
315{
316 if (ecode < 0 || ecode > EAI_MAX)
317 ecode = EAI_MAX;
318 return ai_errlist[ecode];
319}
320
321void
322freeaddrinfo(ai)
323 struct addrinfo *ai;
324{
325 struct addrinfo *next;
326
327 do {
328 next = ai->ai_next;
329 if (ai->ai_canonname)
330 free(ai->ai_canonname);
331 /* no need to free(ai->ai_addr) */
332 free(ai);
333 ai = next;
334 } while (ai);
335}
336
337static int
338str_isnumber(p)
339 const char *p;
340{
341 char *ep;
342
343 if (*p == '\0')
344 return NO;
345 ep = NULL;
346 (void)strtoul(p, &ep, 10);
347 if (ep && *ep == '\0')
348 return YES;
349 else
350 return NO;
351}
352
353int
354getaddrinfo(hostname, servname, hints, res)
355 const char *hostname, *servname;
356 const struct addrinfo *hints;
357 struct addrinfo **res;
358{
359 struct addrinfo sentinel;
360 struct addrinfo *cur;
361 int error = 0;
362 struct addrinfo ai;
363 struct addrinfo ai0;
364 struct addrinfo *pai;
365 const struct explore *ex;
366
367 memset(&sentinel, 0, sizeof(sentinel));
368 cur = &sentinel;
369 pai = &ai;
370 pai->ai_flags = 0;
371 pai->ai_family = PF_UNSPEC;
372 pai->ai_socktype = ANY;
373 pai->ai_protocol = ANY;
374 pai->ai_addrlen = 0;
375 pai->ai_canonname = NULL;
376 pai->ai_addr = NULL;
377 pai->ai_next = NULL;
378
379 if (hostname == NULL && servname == NULL)
380 return EAI_NONAME;
381 if (hints) {
382 /* error check for hints */
383 if (hints->ai_addrlen || hints->ai_canonname ||
384 hints->ai_addr || hints->ai_next)
385 ERR(EAI_BADHINTS); /* xxx */
386 if (hints->ai_flags & ~AI_MASK)
387 ERR(EAI_BADFLAGS);
388 switch (hints->ai_family) {
389 case PF_UNSPEC:
390 case PF_INET:
391#ifdef INET6
392 case PF_INET6:
393#endif
394 break;
395 default:
396 ERR(EAI_FAMILY);
397 }
398 memcpy(pai, hints, sizeof(*pai));
399
400 /*
401 * if both socktype/protocol are specified, check if they
402 * are meaningful combination.
403 */
404 if (pai->ai_socktype != ANY && pai->ai_protocol != ANY) {
405 for (ex = explore; ex->e_af >= 0; ex++) {
406 if (pai->ai_family != ex->e_af)
407 continue;
408 if (ex->e_socktype == ANY)
409 continue;
410 if (ex->e_protocol == ANY)
411 continue;
412 if (pai->ai_socktype == ex->e_socktype
413 && pai->ai_protocol != ex->e_protocol) {
414 ERR(EAI_BADHINTS);
415 }
416 }
417 }
418 }
419
420 /*
421 * post-2553: AI_ALL and AI_V4MAPPED are effective only against
422 * AF_INET6 query. They needs to be ignored if specified in other
423 * occassions.
424 */
425 switch (pai->ai_flags & (AI_ALL | AI_V4MAPPED)) {
426 case AI_V4MAPPED:
427 case AI_ALL | AI_V4MAPPED:
428 if (pai->ai_family != AF_INET6)
429 pai->ai_flags &= ~(AI_ALL | AI_V4MAPPED);
430 break;
431 case AI_ALL:
432#if 1
433 /* illegal */
434 ERR(EAI_BADFLAGS);
435#else
436 pai->ai_flags &= ~(AI_ALL | AI_V4MAPPED);
437#endif
438 break;
439 }
440
441 /*
442 * check for special cases. (1) numeric servname is disallowed if
443 * socktype/protocol are left unspecified. (2) servname is disallowed
444 * for raw and other inet{,6} sockets.
445 */
446 if (MATCH_FAMILY(pai->ai_family, PF_INET, 1)
447#ifdef PF_INET6
448 || MATCH_FAMILY(pai->ai_family, PF_INET6, 1)
449#endif
450 ) {
451 ai0 = *pai; /* backup *pai */
452
453 if (pai->ai_family == PF_UNSPEC) {
454#ifdef PF_INET6
455 pai->ai_family = PF_INET6;
456#else
457 pai->ai_family = PF_INET;
458#endif
459 }
460 error = get_portmatch(pai, servname);
461 if (error)
462 ERR(error);
463
464 *pai = ai0;
465 }
466
467 ai0 = *pai;
468
469 /* NULL hostname, or numeric hostname */
470 for (ex = explore; ex->e_af >= 0; ex++) {
471 *pai = ai0;
472
473 /* PF_UNSPEC entries are prepared for DNS queries only */
474 if (ex->e_af == PF_UNSPEC)
475 continue;
476
477 if (!MATCH_FAMILY(pai->ai_family, ex->e_af, WILD_AF(ex)))
478 continue;
479 if (!MATCH(pai->ai_socktype, ex->e_socktype, WILD_SOCKTYPE(ex)))
480 continue;
481 if (!MATCH(pai->ai_protocol, ex->e_protocol, WILD_PROTOCOL(ex)))
482 continue;
483
484 if (pai->ai_family == PF_UNSPEC)
485 pai->ai_family = ex->e_af;
486 if (pai->ai_socktype == ANY && ex->e_socktype != ANY)
487 pai->ai_socktype = ex->e_socktype;
488 if (pai->ai_protocol == ANY && ex->e_protocol != ANY)
489 pai->ai_protocol = ex->e_protocol;
490
491 if (hostname == NULL)
492 error = explore_null(pai, servname, &cur->ai_next);
493 else
494 error = explore_numeric_scope(pai, hostname, servname, &cur->ai_next);
495
496 if (error)
497 goto free;
498
499 while (cur && cur->ai_next)
500 cur = cur->ai_next;
501 }
502
503 /*
504 * XXX
505 * If numreic representation of AF1 can be interpreted as FQDN
506 * representation of AF2, we need to think again about the code below.
507 */
508 if (sentinel.ai_next)
509 goto good;
510
511 if (pai->ai_flags & AI_NUMERICHOST)
512 ERR(EAI_NODATA);
513 if (hostname == NULL)
514 ERR(EAI_NODATA);
515
516 if ((pai->ai_flags & AI_ADDRCONFIG) != 0 && !addrconfig(&ai0))
517 ERR(EAI_FAIL);
518
519 /*
520 * hostname as alphabetical name.
521 * we would like to prefer AF_INET6 than AF_INET, so we'll make a
522 * outer loop by AFs.
523 */
524 for (ex = explore; ex->e_af >= 0; ex++) {
525 *pai = ai0;
526
527 /* require exact match for family field */
528 if (pai->ai_family != ex->e_af)
529 continue;
530
531 if (!MATCH(pai->ai_socktype, ex->e_socktype,
532 WILD_SOCKTYPE(ex))) {
533 continue;
534 }
535 if (!MATCH(pai->ai_protocol, ex->e_protocol,
536 WILD_PROTOCOL(ex))) {
537 continue;
538 }
539
540 if (pai->ai_socktype == ANY && ex->e_socktype != ANY)
541 pai->ai_socktype = ex->e_socktype;
542 if (pai->ai_protocol == ANY && ex->e_protocol != ANY)
543 pai->ai_protocol = ex->e_protocol;
544
545 error = explore_fqdn(pai, hostname, servname,
546 &cur->ai_next);
547
548 while (cur && cur->ai_next)
549 cur = cur->ai_next;
550 }
551
552 /* XXX */
553 if (sentinel.ai_next)
554 error = 0;
555
556 if (error)
557 goto free;
558 if (error == 0) {
559 if (sentinel.ai_next) {
560 good:
561 *res = sentinel.ai_next;
562 return SUCCESS;
563 } else
564 error = EAI_FAIL;
565 }
566 free:
567 bad:
568 if (sentinel.ai_next)
569 freeaddrinfo(sentinel.ai_next);
570 *res = NULL;
571 return error;
572}
573
574/*
575 * FQDN hostname, DNS lookup
576 */
577static int
578explore_fqdn(pai, hostname, servname, res)
579 const struct addrinfo *pai;
580 const char *hostname;
581 const char *servname;
582 struct addrinfo **res;
583{
584 struct addrinfo *result;
585 struct addrinfo *cur;
586 int error = 0;
587 static const ns_dtab dtab[] = {
588 NS_FILES_CB(_files_getaddrinfo, NULL)
589 { NSSRC_DNS, _dns_getaddrinfo, NULL }, /* force -DHESIOD */
590 NS_NIS_CB(_yp_getaddrinfo, NULL)
591 { 0 }
592 };
593
594 result = NULL;
595
596 /*
597 * if the servname does not match socktype/protocol, ignore it.
598 */
599 if (get_portmatch(pai, servname) != 0)
600 return 0;
601
602 switch (nsdispatch(&result, dtab, NSDB_HOSTS, "getaddrinfo",
603 default_dns_files, hostname, pai)) {
604 case NS_TRYAGAIN:
605 error = EAI_AGAIN;
606 goto free;
607 case NS_UNAVAIL:
608 error = EAI_FAIL;
609 goto free;
610 case NS_NOTFOUND:
611 error = EAI_NODATA;
612 goto free;
613 case NS_SUCCESS:
614 error = 0;
615 for (cur = result; cur; cur = cur->ai_next) {
616 GET_PORT(cur, servname);
617 /* canonname should be filled already */
618 }
619 break;
620 }
621
622 *res = result;
623
624 return 0;
625
626free:
627 if (result)
628 freeaddrinfo(result);
629 return error;
630}
631
632/*
633 * hostname == NULL.
634 * passive socket -> anyaddr (0.0.0.0 or ::)
635 * non-passive socket -> localhost (127.0.0.1 or ::1)
636 */
637static int
638explore_null(pai, servname, res)
639 const struct addrinfo *pai;
640 const char *servname;
641 struct addrinfo **res;
642{
643 int s;
644 const struct afd *afd;
645 struct addrinfo *cur;
646 struct addrinfo sentinel;
647 int error;
648
649 *res = NULL;
650 sentinel.ai_next = NULL;
651 cur = &sentinel;
652
653 /*
654 * filter out AFs that are not supported by the kernel
655 * XXX errno?
656 */
657 s = _socket(pai->ai_family, SOCK_DGRAM, 0);
658 if (s < 0) {
659 if (errno != EMFILE)
660 return 0;
661 } else
662 _close(s);
663
664 /*
665 * if the servname does not match socktype/protocol, ignore it.
666 */
667 if (get_portmatch(pai, servname) != 0)
668 return 0;
669
670 afd = find_afd(pai->ai_family);
671 if (afd == NULL)
672 return 0;
673
674 if (pai->ai_flags & AI_PASSIVE) {
675 GET_AI(cur->ai_next, afd, afd->a_addrany);
676 /* xxx meaningless?
677 * GET_CANONNAME(cur->ai_next, "anyaddr");
678 */
679 GET_PORT(cur->ai_next, servname);
680 } else {
681 GET_AI(cur->ai_next, afd, afd->a_loopback);
682 /* xxx meaningless?
683 * GET_CANONNAME(cur->ai_next, "localhost");
684 */
685 GET_PORT(cur->ai_next, servname);
686 }
687 cur = cur->ai_next;
688
689 *res = sentinel.ai_next;
690 return 0;
691
692free:
693 if (sentinel.ai_next)
694 freeaddrinfo(sentinel.ai_next);
695 return error;
696}
697
698/*
699 * numeric hostname
700 */
701static int
702explore_numeric(pai, hostname, servname, res)
703 const struct addrinfo *pai;
704 const char *hostname;
705 const char *servname;
706 struct addrinfo **res;
707{
708 const struct afd *afd;
709 struct addrinfo *cur;
710 struct addrinfo sentinel;
711 int error;
712 char pton[PTON_MAX];
713
714 *res = NULL;
715 sentinel.ai_next = NULL;
716 cur = &sentinel;
717
718 /*
719 * if the servname does not match socktype/protocol, ignore it.
720 */
721 if (get_portmatch(pai, servname) != 0)
722 return 0;
723
724 afd = find_afd(pai->ai_family);
725 if (afd == NULL)
726 return 0;
727
728 switch (afd->a_af) {
729#if 1 /*X/Open spec*/
730 case AF_INET:
731 if (inet_aton(hostname, (struct in_addr *)pton) == 1) {
732 if (pai->ai_family == afd->a_af ||
733 pai->ai_family == PF_UNSPEC /*?*/) {
734 GET_AI(cur->ai_next, afd, pton);
735 GET_PORT(cur->ai_next, servname);
736 while (cur && cur->ai_next)
737 cur = cur->ai_next;
738 } else
739 ERR(EAI_FAMILY); /*xxx*/
740 }
741 break;
742#endif
743 default:
744 if (inet_pton(afd->a_af, hostname, pton) == 1) {
745 if (pai->ai_family == afd->a_af ||
746 pai->ai_family == PF_UNSPEC /*?*/) {
747 GET_AI(cur->ai_next, afd, pton);
748 GET_PORT(cur->ai_next, servname);
749 while (cur && cur->ai_next)
750 cur = cur->ai_next;
751 } else
752 ERR(EAI_FAMILY); /*xxx*/
753 }
754 break;
755 }
756
757 *res = sentinel.ai_next;
758 return 0;
759
760free:
761bad:
762 if (sentinel.ai_next)
763 freeaddrinfo(sentinel.ai_next);
764 return error;
765}
766
767/*
768 * numeric hostname with scope
769 */
770static int
771explore_numeric_scope(pai, hostname, servname, res)
772 const struct addrinfo *pai;
773 const char *hostname;
774 const char *servname;
775 struct addrinfo **res;
776{
777#if !defined(SCOPE_DELIMITER) || !defined(INET6)
778 return explore_numeric(pai, hostname, servname, res);
779#else
780 const struct afd *afd;
781 struct addrinfo *cur;
782 int error;
783 char *cp, *hostname2 = NULL, *scope, *addr;
784 struct sockaddr_in6 *sin6;
785
786 /*
787 * if the servname does not match socktype/protocol, ignore it.
788 */
789 if (get_portmatch(pai, servname) != 0)
790 return 0;
791
792 afd = find_afd(pai->ai_family);
793 if (afd == NULL)
794 return 0;
795
796 if (!afd->a_scoped)
797 return explore_numeric(pai, hostname, servname, res);
798
799 cp = strchr(hostname, SCOPE_DELIMITER);
800 if (cp == NULL)
801 return explore_numeric(pai, hostname, servname, res);
802
803 /*
804 * Handle special case of <scoped_address><delimiter><scope id>
805 */
806 hostname2 = strdup(hostname);
807 if (hostname2 == NULL)
808 return EAI_MEMORY;
809 /* terminate at the delimiter */
810 hostname2[cp - hostname] = '\0';
811 addr = hostname2;
812 scope = cp + 1;
813
814 error = explore_numeric(pai, addr, servname, res);
815 if (error == 0) {
816 int scopeid;
817
818 for (cur = *res; cur; cur = cur->ai_next) {
819 if (cur->ai_family != AF_INET6)
820 continue;
821 sin6 = (struct sockaddr_in6 *)(void *)cur->ai_addr;
822 if ((scopeid = ip6_str2scopeid(scope, sin6)) == -1) {
823 free(hostname2);
824 return(EAI_NODATA); /* XXX: is return OK? */
825 }
826 sin6->sin6_scope_id = scopeid;
827 }
828 }
829
830 free(hostname2);
831
832 return error;
833#endif
834}
835
836static int
837get_canonname(pai, ai, str)
838 const struct addrinfo *pai;
839 struct addrinfo *ai;
840 const char *str;
841{
842 if ((pai->ai_flags & AI_CANONNAME) != 0) {
843 ai->ai_canonname = (char *)malloc(strlen(str) + 1);
844 if (ai->ai_canonname == NULL)
845 return EAI_MEMORY;
846 strcpy(ai->ai_canonname, str);
847 }
848 return 0;
849}
850
851static struct addrinfo *
852get_ai(pai, afd, addr)
853 const struct addrinfo *pai;
854 const struct afd *afd;
855 const char *addr;
856{
857 char *p;
858 struct addrinfo *ai;
859#ifdef FAITH
860 struct in6_addr faith_prefix;
861 char *fp_str;
862 int translate = 0;
863#endif
864
865#ifdef FAITH
866 /*
867 * Transfrom an IPv4 addr into a special IPv6 addr format for
868 * IPv6->IPv4 translation gateway. (only TCP is supported now)
869 *
870 * +-----------------------------------+------------+
871 * | faith prefix part (12 bytes) | embedded |
872 * | | IPv4 addr part (4 bytes)
873 * +-----------------------------------+------------+
874 *
875 * faith prefix part is specified as ascii IPv6 addr format
876 * in environmental variable GAI.
877 * For FAITH to work correctly, routing to faith prefix must be
878 * setup toward a machine where a FAITH daemon operates.
879 * Also, the machine must enable some mechanizm
880 * (e.g. faith interface hack) to divert those packet with
881 * faith prefixed destination addr to user-land FAITH daemon.
882 */
883 fp_str = getenv("GAI");
884 if (fp_str && inet_pton(AF_INET6, fp_str, &faith_prefix) == 1 &&
885 afd->a_af == AF_INET && pai->ai_socktype == SOCK_STREAM) {
886 u_int32_t v4a;
887 u_int8_t v4a_top;
888
889 memcpy(&v4a, addr, sizeof v4a);
890 v4a_top = v4a >> IN_CLASSA_NSHIFT;
891 if (!IN_MULTICAST(v4a) && !IN_EXPERIMENTAL(v4a) &&
892 v4a_top != 0 && v4a != IN_LOOPBACKNET) {
893 afd = &afdl[N_INET6];
894 memcpy(&faith_prefix.s6_addr[12], addr,
895 sizeof(struct in_addr));
896 translate = 1;
897 }
898 }
899#endif
900
901 ai = (struct addrinfo *)malloc(sizeof(struct addrinfo)
902 + (afd->a_socklen));
903 if (ai == NULL)
904 return NULL;
905
906 memcpy(ai, pai, sizeof(struct addrinfo));
907 ai->ai_addr = (struct sockaddr *)(void *)(ai + 1);
908 memset(ai->ai_addr, 0, (size_t)afd->a_socklen);
909 ai->ai_addr->sa_len = afd->a_socklen;
910 ai->ai_addrlen = afd->a_socklen;
911 ai->ai_addr->sa_family = ai->ai_family = afd->a_af;
912 p = (char *)(void *)(ai->ai_addr);
913#ifdef FAITH
914 if (translate == 1)
915 memcpy(p + afd->a_off, &faith_prefix, (size_t)afd->a_addrlen);
916 else
917#endif
918 memcpy(p + afd->a_off, addr, (size_t)afd->a_addrlen);
919 return ai;
920}
921
922static int
923get_portmatch(ai, servname)
924 const struct addrinfo *ai;
925 const char *servname;
926{
927
928 /* get_port does not touch first argument. when matchonly == 1. */
929 /* LINTED const cast */
930 return get_port((struct addrinfo *)ai, servname, 1);
931}
932
933static int
934get_port(ai, servname, matchonly)
935 struct addrinfo *ai;
936 const char *servname;
937 int matchonly;
938{
939 const char *proto;
940 struct servent *sp;
941 int port;
942 int allownumeric;
943
944 if (servname == NULL)
945 return 0;
946 switch (ai->ai_family) {
947 case AF_INET:
948#ifdef AF_INET6
949 case AF_INET6:
950#endif
951 break;
952 default:
953 return 0;
954 }
955
956 switch (ai->ai_socktype) {
957 case SOCK_RAW:
958 return EAI_SERVICE;
959 case SOCK_DGRAM:
960 case SOCK_STREAM:
961 allownumeric = 1;
962 break;
963 case ANY:
964 allownumeric = 0;
965 break;
966 default:
967 return EAI_SOCKTYPE;
968 }
969
970 if (str_isnumber(servname)) {
971 if (!allownumeric)
972 return EAI_SERVICE;
973 port = htons(atoi(servname));
974 if (port < 0 || port > 65535)
975 return EAI_SERVICE;
976 } else {
977 switch (ai->ai_socktype) {
978 case SOCK_DGRAM:
979 proto = "udp";
980 break;
981 case SOCK_STREAM:
982 proto = "tcp";
983 break;
984 default:
985 proto = NULL;
986 break;
987 }
988
989 if ((sp = getservbyname(servname, proto)) == NULL)
990 return EAI_SERVICE;
991 port = sp->s_port;
992 }
993
994 if (!matchonly) {
995 switch (ai->ai_family) {
996 case AF_INET:
997 ((struct sockaddr_in *)(void *)
998 ai->ai_addr)->sin_port = port;
999 break;
1000#ifdef INET6
1001 case AF_INET6:
1002 ((struct sockaddr_in6 *)(void *)
1003 ai->ai_addr)->sin6_port = port;
1004 break;
1005#endif
1006 }
1007 }
1008
1009 return 0;
1010}
1011
1012static const struct afd *
1013find_afd(af)
1014 int af;
1015{
1016 const struct afd *afd;
1017
1018 if (af == PF_UNSPEC)
1019 return NULL;
1020 for (afd = afdl; afd->a_af; afd++) {
1021 if (afd->a_af == af)
1022 return afd;
1023 }
1024 return NULL;
1025}
1026
1027/*
1028 * post-2553: AI_ADDRCONFIG check. if we use getipnodeby* as backend, backend
1029 * will take care of it.
1030 * the semantics of AI_ADDRCONFIG is not defined well. we are not sure
1031 * if the code is right or not.
1032 *
1033 * XXX PF_UNSPEC -> PF_INET6 + PF_INET mapping needs to be in sync with
1034 * _dns_getaddrinfo.
1035 */
1036static int
1037addrconfig(pai)
1038 struct addrinfo *pai;
1039{
1040 int s, af;
1041
1042 /*
1043 * TODO:
1044 * Note that implementation dependent test for address
1045 * configuration should be done everytime called
1046 * (or apropriate interval),
1047 * because addresses will be dynamically assigned or deleted.
1048 */
1049 af = pai->ai_family;
1050 if (af == AF_UNSPEC) {
1051 if ((s = _socket(AF_INET6, SOCK_DGRAM, 0)) < 0)
1052 af = AF_INET;
1053 else {
1054 _close(s);
1055 if ((s = _socket(AF_INET, SOCK_DGRAM, 0)) < 0)
1056 af = AF_INET6;
1057 else
1058 _close(s);
1059 }
1060 }
1061 if (af != AF_UNSPEC) {
1062 if ((s = _socket(af, SOCK_DGRAM, 0)) < 0)
1063 return 0;
1064 _close(s);
1065 }
1066 pai->ai_family = af;
1067 return 1;
1068}
1069
1070#ifdef INET6
1071/* convert a string to a scope identifier. XXX: IPv6 specific */
1072static int
1073ip6_str2scopeid(scope, sin6)
1074 char *scope;
1075 struct sockaddr_in6 *sin6;
1076{
1077 int scopeid;
1078 struct in6_addr *a6 = &sin6->sin6_addr;
1079 char *ep;
1080
1081 /* empty scopeid portion is invalid */
1082 if (*scope == '\0')
1083 return -1;
1084
1085 if (IN6_IS_ADDR_LINKLOCAL(a6) || IN6_IS_ADDR_MC_LINKLOCAL(a6)) {
1086 /*
1087 * We currently assume a one-to-one mapping between links
1088 * and interfaces, so we simply use interface indices for
1089 * like-local scopes.
1090 */
1091 scopeid = if_nametoindex(scope);
1092 if (scopeid == 0)
1093 goto trynumeric;
1094 return(scopeid);
1095 }
1096
1097 /* still unclear about literal, allow numeric only - placeholder */
1098 if (IN6_IS_ADDR_SITELOCAL(a6) || IN6_IS_ADDR_MC_SITELOCAL(a6))
1099 goto trynumeric;
1100 if (IN6_IS_ADDR_MC_ORGLOCAL(a6))
1101 goto trynumeric;
1102 else
1103 goto trynumeric; /* global */
1104
1105 /* try to convert to a numeric id as a last resort */
1106 trynumeric:
1107 scopeid = (int)strtoul(scope, &ep, 10);
1108 if (*ep == '\0')
1109 return scopeid;
1110 else
1111 return -1;
1112}
1113#endif
1114
1115#ifdef DEBUG
1116static const char AskedForGot[] =
1117 "gethostby*.getanswer: asked for \"%s\", got \"%s\"";
1118#endif
1119static FILE *hostf = NULL;
1120
1121static struct addrinfo *
1122getanswer(answer, anslen, qname, qtype, pai)
1123 const querybuf *answer;
1124 int anslen;
1125 const char *qname;
1126 int qtype;
1127 const struct addrinfo *pai;
1128{
1129 struct addrinfo sentinel, *cur;
1130 struct addrinfo ai;
1131 const struct afd *afd;
1132 char *canonname;
1133 const HEADER *hp;
1134 const u_char *cp;
1135 int n;
1136 const u_char *eom;
1137 char *bp;
1138 int type, class, buflen, ancount, qdcount;
1139 int haveanswer, had_error;
1140 char tbuf[MAXDNAME];
1141 int (*name_ok) __P((const char *));
1142 char hostbuf[8*1024];
1143
1144 memset(&sentinel, 0, sizeof(sentinel));
1145 cur = &sentinel;
1146
1147 canonname = NULL;
1148 eom = answer->buf + anslen;
1149 switch (qtype) {
1150 case T_A:
1151 case T_AAAA:
1152 case T_ANY: /*use T_ANY only for T_A/T_AAAA lookup*/
1153 name_ok = res_hnok;
1154 break;
1155 default:
1156 return (NULL); /* XXX should be abort(); */
1157 }
1158 /*
1159 * find first satisfactory answer
1160 */
1161 hp = &answer->hdr;
1162 ancount = ntohs(hp->ancount);
1163 qdcount = ntohs(hp->qdcount);
1164 bp = hostbuf;
1165 buflen = sizeof hostbuf;
1166 cp = answer->buf + HFIXEDSZ;
1167 if (qdcount != 1) {
1168 h_errno = NO_RECOVERY;
1169 return (NULL);
1170 }
1171 n = dn_expand(answer->buf, eom, cp, bp, buflen);
1172 if ((n < 0) || !(*name_ok)(bp)) {
1173 h_errno = NO_RECOVERY;
1174 return (NULL);
1175 }
1176 cp += n + QFIXEDSZ;
1177 if (qtype == T_A || qtype == T_AAAA || qtype == T_ANY) {
1178 /* res_send() has already verified that the query name is the
1179 * same as the one we sent; this just gets the expanded name
1180 * (i.e., with the succeeding search-domain tacked on).
1181 */
1182 n = strlen(bp) + 1; /* for the \0 */
1183 if (n >= MAXHOSTNAMELEN) {
1184 h_errno = NO_RECOVERY;
1185 return (NULL);
1186 }
1187 canonname = bp;
1188 bp += n;
1189 buflen -= n;
1190 /* The qname can be abbreviated, but h_name is now absolute. */
1191 qname = canonname;
1192 }
1193 haveanswer = 0;
1194 had_error = 0;
1195 while (ancount-- > 0 && cp < eom && !had_error) {
1196 n = dn_expand(answer->buf, eom, cp, bp, buflen);
1197 if ((n < 0) || !(*name_ok)(bp)) {
1198 had_error++;
1199 continue;
1200 }
1201 cp += n; /* name */
1202 type = _getshort(cp);
1203 cp += INT16SZ; /* type */
1204 class = _getshort(cp);
1205 cp += INT16SZ + INT32SZ; /* class, TTL */
1206 n = _getshort(cp);
1207 cp += INT16SZ; /* len */
1208 if (class != C_IN) {
1209 /* XXX - debug? syslog? */
1210 cp += n;
1211 continue; /* XXX - had_error++ ? */
1212 }
1213 if ((qtype == T_A || qtype == T_AAAA || qtype == T_ANY) &&
1214 type == T_CNAME) {
1215 n = dn_expand(answer->buf, eom, cp, tbuf, sizeof tbuf);
1216 if ((n < 0) || !(*name_ok)(tbuf)) {
1217 had_error++;
1218 continue;
1219 }
1220 cp += n;
1221 /* Get canonical name. */
1222 n = strlen(tbuf) + 1; /* for the \0 */
1223 if (n > buflen || n >= MAXHOSTNAMELEN) {
1224 had_error++;
1225 continue;
1226 }
1227 strcpy(bp, tbuf);
1228 canonname = bp;
1229 bp += n;
1230 buflen -= n;
1231 continue;
1232 }
1233 if (qtype == T_ANY) {
1234 if (!(type == T_A || type == T_AAAA)) {
1235 cp += n;
1236 continue;
1237 }
1238 } else if (type != qtype) {
1239#ifdef DEBUG
1240 if (type != T_KEY && type != T_SIG)
1241 syslog(LOG_NOTICE|LOG_AUTH,
1242 "gethostby*.getanswer: asked for \"%s %s %s\", got type \"%s\"",
1243 qname, p_class(C_IN), p_type(qtype),
1244 p_type(type));
1245#endif
1246 cp += n;
1247 continue; /* XXX - had_error++ ? */
1248 }
1249 switch (type) {
1250 case T_A:
1251 case T_AAAA:
1252 if (strcasecmp(canonname, bp) != 0) {
1253#ifdef DEBUG
1254 syslog(LOG_NOTICE|LOG_AUTH,
1255 AskedForGot, canonname, bp);
1256#endif
1257 cp += n;
1258 continue; /* XXX - had_error++ ? */
1259 }
1260 if (type == T_A && n != INADDRSZ) {
1261 cp += n;
1262 continue;
1263 }
1264 if (type == T_AAAA && n != IN6ADDRSZ) {
1265 cp += n;
1266 continue;
1267 }
1268#ifdef FILTER_V4MAPPED
1269 if (type == T_AAAA) {
1270 struct in6_addr in6;
1271 memcpy(&in6, cp, sizeof(in6));
1272 if (IN6_IS_ADDR_V4MAPPED(&in6)) {
1273 cp += n;
1274 continue;
1275 }
1276 }
1277#endif
1278 if (!haveanswer) {
1279 int nn;
1280
1281 canonname = bp;
1282 nn = strlen(bp) + 1; /* for the \0 */
1283 bp += nn;
1284 buflen -= nn;
1285 }
1286
1287 /* don't overwrite pai */
1288 ai = *pai;
1289 ai.ai_family = (type == T_A) ? AF_INET : AF_INET6;
1290 afd = find_afd(ai.ai_family);
1291 if (afd == NULL) {
1292 cp += n;
1293 continue;
1294 }
1295 cur->ai_next = get_ai(&ai, afd, (const char *)cp);
1296 if (cur->ai_next == NULL)
1297 had_error++;
1298 while (cur && cur->ai_next)
1299 cur = cur->ai_next;
1300 cp += n;
1301 break;
1302 default:
1303 abort();
1304 }
1305 if (!had_error)
1306 haveanswer++;
1307 }
1308 if (haveanswer) {
1309 if (!canonname)
1310 (void)get_canonname(pai, sentinel.ai_next, qname);
1311 else
1312 (void)get_canonname(pai, sentinel.ai_next, canonname);
1313 h_errno = NETDB_SUCCESS;
1314 return sentinel.ai_next;
1315 }
1316
1317 h_errno = NO_RECOVERY;
1318 return NULL;
1319}
1320
1321/*ARGSUSED*/
1322static int
1323_dns_getaddrinfo(rv, cb_data, ap)
1324 void *rv;
1325 void *cb_data;
1326 va_list ap;
1327{
1328 struct addrinfo *ai;
1329 querybuf buf, buf2;
1330 const char *name;
1331 const struct addrinfo *pai;
1332 struct addrinfo sentinel, *cur;
1333 struct res_target q, q2;
1334
1335 name = va_arg(ap, char *);
1336 pai = va_arg(ap, const struct addrinfo *);
1337
1338 memset(&q, 0, sizeof(q2));
1339 memset(&q2, 0, sizeof(q2));
1340 memset(&sentinel, 0, sizeof(sentinel));
1341 cur = &sentinel;
1342
1343 switch (pai->ai_family) {
1344 case AF_UNSPEC:
1345 /* prefer IPv6 */
1346 q.qclass = C_IN;
1347 q.qtype = T_AAAA;
1348 q.answer = buf.buf;
1349 q.anslen = sizeof(buf);
1350 q.next = &q2;
1351 q2.qclass = C_IN;
1352 q2.qtype = T_A;
1353 q2.answer = buf2.buf;
1354 q2.anslen = sizeof(buf2);
1355 break;
1356 case AF_INET:
1357 q.qclass = C_IN;
1358 q.qtype = T_A;
1359 q.answer = buf.buf;
1360 q.anslen = sizeof(buf);
1361 break;
1362 case AF_INET6:
1363 q.qclass = C_IN;
1364 q.qtype = T_AAAA;
1365 q.answer = buf.buf;
1366 q.anslen = sizeof(buf);
1367 break;
1368 default:
1369 return NS_UNAVAIL;
1370 }
1371 if (res_searchN(name, &q) < 0)
1372 return NS_NOTFOUND;
1373 ai = getanswer(&buf, q.n, q.name, q.qtype, pai);
1374 if (ai) {
1375 cur->ai_next = ai;
1376 while (cur && cur->ai_next)
1377 cur = cur->ai_next;
1378 }
1379 if (q.next) {
1380 ai = getanswer(&buf2, q2.n, q2.name, q2.qtype, pai);
1381 if (ai)
1382 cur->ai_next = ai;
1383 }
1384 if (sentinel.ai_next == NULL)
1385 switch (h_errno) {
1386 case HOST_NOT_FOUND:
1387 return NS_NOTFOUND;
1388 case TRY_AGAIN:
1389 return NS_TRYAGAIN;
1390 default:
1391 return NS_UNAVAIL;
1392 }
1393 *((struct addrinfo **)rv) = sentinel.ai_next;
1394 return NS_SUCCESS;
1395}
1396
1397static void
1398_sethtent()
1399{
1400 if (!hostf)
1401 hostf = fopen(_PATH_HOSTS, "r" );
1402 else
1403 rewind(hostf);
1404}
1405
1406static void
1407_endhtent()
1408{
1409 if (hostf) {
1410 (void) fclose(hostf);
1411 hostf = NULL;
1412 }
1413}
1414
1415static struct addrinfo *
1416_gethtent(name, pai)
1417 const char *name;
1418 const struct addrinfo *pai;
1419{
1420 char *p;
1421 char *cp, *tname, *cname;
1422 struct addrinfo hints, *res0, *res;
1423 int error;
1424 const char *addr;
1425 char hostbuf[8*1024];
1426
1427 if (!hostf && !(hostf = fopen(_PATH_HOSTS, "r" )))
1428 return (NULL);
1429 again:
1430 if (!(p = fgets(hostbuf, sizeof hostbuf, hostf)))
1431 return (NULL);
1432 if (*p == '#')
1433 goto again;
1434 if (!(cp = strpbrk(p, "#\n")))
1435 goto again;
1436 *cp = '\0';
1437 if (!(cp = strpbrk(p, " \t")))
1438 goto again;
1439 *cp++ = '\0';
1440 addr = p;
1441 cname = NULL;
1442 /* if this is not something we're looking for, skip it. */
1443 while (cp && *cp) {
1444 if (*cp == ' ' || *cp == '\t') {
1445 cp++;
1446 continue;
1447 }
1448 tname = cp;
1449 if (cname == NULL)
1450 cname = cp;
1451 if ((cp = strpbrk(cp, " \t")) != NULL)
1452 *cp++ = '\0';
1453 if (strcasecmp(name, tname) == 0)
1454 goto found;
1455 }
1456 goto again;
1457
1458found:
1459 hints = *pai;
1460 hints.ai_flags = AI_NUMERICHOST;
1461 error = getaddrinfo(addr, NULL, &hints, &res0);
1462 if (error)
1463 goto again;
1464#ifdef FILTER_V4MAPPED
1465 /* XXX should check all items in the chain */
1466 if (res0->ai_family == AF_INET6 &&
1467 IN6_IS_ADDR_V4MAPPED(&((struct sockaddr_in6 *)res0->ai_addr)->sin6_addr)) {
1468 freeaddrinfo(res0);
1469 goto again;
1470 }
1471#endif
1472 for (res = res0; res; res = res->ai_next) {
1473 /* cover it up */
1474 res->ai_flags = pai->ai_flags;
1475
1476 if (pai->ai_flags & AI_CANONNAME) {
1477 if (get_canonname(pai, res, cname) != 0) {
1478 freeaddrinfo(res0);
1479 goto again;
1480 }
1481 }
1482 }
1483 return res0;
1484}
1485
1486/*ARGSUSED*/
1487static int
1488_files_getaddrinfo(rv, cb_data, ap)
1489 void *rv;
1490 void *cb_data;
1491 va_list ap;
1492{
1493 const char *name;
1494 const struct addrinfo *pai;
1495 struct addrinfo sentinel, *cur;
1496 struct addrinfo *p;
1497
1498 name = va_arg(ap, char *);
1499 pai = va_arg(ap, struct addrinfo *);
1500
1501 memset(&sentinel, 0, sizeof(sentinel));
1502 cur = &sentinel;
1503
1504 _sethtent();
1505 while ((p = _gethtent(name, pai)) != NULL) {
1506 cur->ai_next = p;
1507 while (cur && cur->ai_next)
1508 cur = cur->ai_next;
1509 }
1510 _endhtent();
1511
1512 *((struct addrinfo **)rv) = sentinel.ai_next;
1513 if (sentinel.ai_next == NULL)
1514 return NS_NOTFOUND;
1515 return NS_SUCCESS;
1516}
1517
1518#ifdef YP
1519static char *__ypdomain;
1520
1521/*ARGSUSED*/
1522static struct addrinfo *
1523_yphostent(line, pai)
1524 char *line;
1525 const struct addrinfo *pai;
1526{
1527 struct addrinfo sentinel, *cur;
1528 struct addrinfo hints, *res, *res0;
1529 int error;
1530 char *p = line;
1531 const char *addr, *canonname;
1532 char *nextline;
1533 char *cp;
1534
1535 addr = canonname = NULL;
1536
1537 memset(&sentinel, 0, sizeof(sentinel));
1538 cur = &sentinel;
1539
1540nextline:
1541 /* terminate line */
1542 cp = strchr(p, '\n');
1543 if (cp) {
1544 *cp++ = '\0';
1545 nextline = cp;
1546 } else
1547 nextline = NULL;
1548
1549 cp = strpbrk(p, " \t");
1550 if (cp == NULL) {
1551 if (canonname == NULL)
1552 return (NULL);
1553 else
1554 goto done;
1555 }
1556 *cp++ = '\0';
1557
1558 addr = p;
1559
1560 while (cp && *cp) {
1561 if (*cp == ' ' || *cp == '\t') {
1562 cp++;
1563 continue;
1564 }
1565 if (!canonname)
1566 canonname = cp;
1567 if ((cp = strpbrk(cp, " \t")) != NULL)
1568 *cp++ = '\0';
1569 }
1570
1571 hints = *pai;
1572 hints.ai_flags = AI_NUMERICHOST;
1573 error = getaddrinfo(addr, NULL, &hints, &res0);
1574 if (error == 0) {
1575 for (res = res0; res; res = res->ai_next) {
1576 /* cover it up */
1577 res->ai_flags = pai->ai_flags;
1578
1579 if (pai->ai_flags & AI_CANONNAME)
1580 (void)get_canonname(pai, res, canonname);
1581 }
1582 } else
1583 res0 = NULL;
1584 if (res0) {
1585 cur->ai_next = res0;
1586 while (cur && cur->ai_next)
1587 cur = cur->ai_next;
1588 }
1589
1590 if (nextline) {
1591 p = nextline;
1592 goto nextline;
1593 }
1594
1595done:
1596 return sentinel.ai_next;
1597}
1598
1599/*ARGSUSED*/
1600static int
1601_yp_getaddrinfo(rv, cb_data, ap)
1602 void *rv;
1603 void *cb_data;
1604 va_list ap;
1605{
1606 struct addrinfo sentinel, *cur;
1607 struct addrinfo *ai = NULL;
1608 static char *__ypcurrent;
1609 int __ypcurrentlen, r;
1610 const char *name;
1611 const struct addrinfo *pai;
1612
1613 name = va_arg(ap, char *);
1614 pai = va_arg(ap, const struct addrinfo *);
1615
1616 memset(&sentinel, 0, sizeof(sentinel));
1617 cur = &sentinel;
1618
1619 if (!__ypdomain) {
1620 if (_yp_check(&__ypdomain) == 0)
1621 return NS_UNAVAIL;
1622 }
1623 if (__ypcurrent)
1624 free(__ypcurrent);
1625 __ypcurrent = NULL;
1626
1627 /* hosts.byname is only for IPv4 (Solaris8) */
1628 if (pai->ai_family == PF_UNSPEC || pai->ai_family == PF_INET) {
1629 r = yp_match(__ypdomain, "hosts.byname", name,
1630 (int)strlen(name), &__ypcurrent, &__ypcurrentlen);
1631 if (r == 0) {
1632 struct addrinfo ai4;
1633
1634 ai4 = *pai;
1635 ai4.ai_family = AF_INET;
1636 ai = _yphostent(__ypcurrent, &ai4);
1637 if (ai) {
1638 cur->ai_next = ai;
1639 while (cur && cur->ai_next)
1640 cur = cur->ai_next;
1641 }
1642 }
1643 }
1644
1645 /* ipnodes.byname can hold both IPv4/v6 */
1646 r = yp_match(__ypdomain, "ipnodes.byname", name,
1647 (int)strlen(name), &__ypcurrent, &__ypcurrentlen);
1648 if (r == 0) {
1649 ai = _yphostent(__ypcurrent, pai);
1650 if (ai) {
1651 cur->ai_next = ai;
1652 while (cur && cur->ai_next)
1653 cur = cur->ai_next;
1654 }
1655 }
1656
1657 if (sentinel.ai_next == NULL) {
1658 h_errno = HOST_NOT_FOUND;
1659 return NS_NOTFOUND;
1660 }
1661 *((struct addrinfo **)rv) = sentinel.ai_next;
1662 return NS_SUCCESS;
1663}
1664#endif
1665
1666/* resolver logic */
1667
1668extern const char *__hostalias __P((const char *));
1669extern int h_errno;
1670
1671/*
1672 * Formulate a normal query, send, and await answer.
1673 * Returned answer is placed in supplied buffer "answer".
1674 * Perform preliminary check of answer, returning success only
1675 * if no error is indicated and the answer count is nonzero.
1676 * Return the size of the response on success, -1 on error.
1677 * Error number is left in h_errno.
1678 *
1679 * Caller must parse answer and determine whether it answers the question.
1680 */
1681static int
1682res_queryN(name, target)
1683 const char *name; /* domain name */
1684 struct res_target *target;
1685{
1686 u_char buf[MAXPACKET];
1687 HEADER *hp;
1688 int n;
1689 struct res_target *t;
1690 int rcode;
1691 int ancount;
1692
1693 rcode = NOERROR;
1694 ancount = 0;
1695
1696 if ((_res.options & RES_INIT) == 0 && res_init() == -1) {
1697 h_errno = NETDB_INTERNAL;
1698 return (-1);
1699 }
1700
1701 for (t = target; t; t = t->next) {
1702 int class, type;
1703 u_char *answer;
1704 int anslen;
1705
1706 hp = (HEADER *)(void *)t->answer;
1707 hp->rcode = NOERROR; /* default */
1708
1709 /* make it easier... */
1710 class = t->qclass;
1711 type = t->qtype;
1712 answer = t->answer;
1713 anslen = t->anslen;
1714#ifdef DEBUG
1715 if (_res.options & RES_DEBUG)
1716 printf(";; res_query(%s, %d, %d)\n", name, class, type);
1717#endif
1718
1719 n = res_mkquery(QUERY, name, class, type, NULL, 0, NULL,
1720 buf, sizeof(buf));
1721 if (n <= 0) {
1722#ifdef DEBUG
1723 if (_res.options & RES_DEBUG)
1724 printf(";; res_query: mkquery failed\n");
1725#endif
1726 h_errno = NO_RECOVERY;
1727 return (n);
1728 }
1729 n = res_send(buf, n, answer, anslen);
1730#if 0
1731 if (n < 0) {
1732#ifdef DEBUG
1733 if (_res.options & RES_DEBUG)
1734 printf(";; res_query: send error\n");
1735#endif
1736 h_errno = TRY_AGAIN;
1737 return (n);
1738 }
1739#endif
1740
1741 if (n < 0 || hp->rcode != NOERROR || ntohs(hp->ancount) == 0) {
1742 rcode = hp->rcode; /* record most recent error */
1743#ifdef DEBUG
1744 if (_res.options & RES_DEBUG)
1745 printf(";; rcode = %d, ancount=%d\n", hp->rcode,
1746 ntohs(hp->ancount));
1747#endif
1748 continue;
1749 }
1750
1751 ancount += ntohs(hp->ancount);
1752
1753 t->n = n;
1754 }
1755
1756 if (ancount == 0) {
1757 switch (rcode) {
1758 case NXDOMAIN:
1759 h_errno = HOST_NOT_FOUND;
1760 break;
1761 case SERVFAIL:
1762 h_errno = TRY_AGAIN;
1763 break;
1764 case NOERROR:
1765 h_errno = NO_DATA;
1766 break;
1767 case FORMERR:
1768 case NOTIMP:
1769 case REFUSED:
1770 default:
1771 h_errno = NO_RECOVERY;
1772 break;
1773 }
1774 return (-1);
1775 }
1776 return (ancount);
1777}
1778
1779/*
1780 * Formulate a normal query, send, and retrieve answer in supplied buffer.
1781 * Return the size of the response on success, -1 on error.
1782 * If enabled, implement search rules until answer or unrecoverable failure
1783 * is detected. Error code, if any, is left in h_errno.
1784 */
1785static int
1786res_searchN(name, target)
1787 const char *name; /* domain name */
1788 struct res_target *target;
1789{
1790 const char *cp, * const *domain;
1791 HEADER *hp = (HEADER *)(void *)target->answer; /*XXX*/
1792 u_int dots;
1793 int trailing_dot, ret, saved_herrno;
1794 int got_nodata = 0, got_servfail = 0, tried_as_is = 0;
1795
1796 if ((_res.options & RES_INIT) == 0 && res_init() == -1) {
1797 h_errno = NETDB_INTERNAL;
1798 return (-1);
1799 }
1800
1801 errno = 0;
1802 h_errno = HOST_NOT_FOUND; /* default, if we never query */
1803 dots = 0;
1804 for (cp = name; *cp; cp++)
1805 dots += (*cp == '.');
1806 trailing_dot = 0;
1807 if (cp > name && *--cp == '.')
1808 trailing_dot++;
1809
1810 /*
1811 * if there aren't any dots, it could be a user-level alias
1812 */
1813 if (!dots && (cp = __hostalias(name)) != NULL)
1814 return (res_queryN(cp, target));
1815
1816 /*
1817 * If there are dots in the name already, let's just give it a try
1818 * 'as is'. The threshold can be set with the "ndots" option.
1819 */
1820 saved_herrno = -1;
1821 if (dots >= _res.ndots) {
1822 ret = res_querydomainN(name, NULL, target);
1823 if (ret > 0)
1824 return (ret);
1825 saved_herrno = h_errno;
1826 tried_as_is++;
1827 }
1828
1829 /*
1830 * We do at least one level of search if
1831 * - there is no dot and RES_DEFNAME is set, or
1832 * - there is at least one dot, there is no trailing dot,
1833 * and RES_DNSRCH is set.
1834 */
1835 if ((!dots && (_res.options & RES_DEFNAMES)) ||
1836 (dots && !trailing_dot && (_res.options & RES_DNSRCH))) {
1837 int done = 0;
1838
1839 for (domain = (const char * const *)_res.dnsrch;
1840 *domain && !done;
1841 domain++) {
1842
1843 ret = res_querydomainN(name, *domain, target);
1844 if (ret > 0)
1845 return (ret);
1846
1847 /*
1848 * If no server present, give up.
1849 * If name isn't found in this domain,
1850 * keep trying higher domains in the search list
1851 * (if that's enabled).
1852 * On a NO_DATA error, keep trying, otherwise
1853 * a wildcard entry of another type could keep us
1854 * from finding this entry higher in the domain.
1855 * If we get some other error (negative answer or
1856 * server failure), then stop searching up,
1857 * but try the input name below in case it's
1858 * fully-qualified.
1859 */
1860 if (errno == ECONNREFUSED) {
1861 h_errno = TRY_AGAIN;
1862 return (-1);
1863 }
1864
1865 switch (h_errno) {
1866 case NO_DATA:
1867 got_nodata++;
1868 /* FALLTHROUGH */
1869 case HOST_NOT_FOUND:
1870 /* keep trying */
1871 break;
1872 case TRY_AGAIN:
1873 if (hp->rcode == SERVFAIL) {
1874 /* try next search element, if any */
1875 got_servfail++;
1876 break;
1877 }
1878 /* FALLTHROUGH */
1879 default:
1880 /* anything else implies that we're done */
1881 done++;
1882 }
1883 /*
1884 * if we got here for some reason other than DNSRCH,
1885 * we only wanted one iteration of the loop, so stop.
1886 */
1887 if (!(_res.options & RES_DNSRCH))
1888 done++;
1889 }
1890 }
1891
1892 /*
1893 * if we have not already tried the name "as is", do that now.
1894 * note that we do this regardless of how many dots were in the
1895 * name or whether it ends with a dot.
1896 */
1897 if (!tried_as_is && (dots || !(_res.options & RES_NOTLDQUERY))) {
1898 ret = res_querydomainN(name, NULL, target);
1899 if (ret > 0)
1900 return (ret);
1901 }
1902
1903 /*
1904 * if we got here, we didn't satisfy the search.
1905 * if we did an initial full query, return that query's h_errno
1906 * (note that we wouldn't be here if that query had succeeded).
1907 * else if we ever got a nodata, send that back as the reason.
1908 * else send back meaningless h_errno, that being the one from
1909 * the last DNSRCH we did.
1910 */
1911 if (saved_herrno != -1)
1912 h_errno = saved_herrno;
1913 else if (got_nodata)
1914 h_errno = NO_DATA;
1915 else if (got_servfail)
1916 h_errno = TRY_AGAIN;
1917 return (-1);
1918}
1919
1920/*
1921 * Perform a call on res_query on the concatenation of name and domain,
1922 * removing a trailing dot from name if domain is NULL.
1923 */
1924static int
1925res_querydomainN(name, domain, target)
1926 const char *name, *domain;
1927 struct res_target *target;
1928{
1929 char nbuf[MAXDNAME];
1930 const char *longname = nbuf;
1931 size_t n, d;
1932
1933 if ((_res.options & RES_INIT) == 0 && res_init() == -1) {
1934 h_errno = NETDB_INTERNAL;
1935 return (-1);
1936 }
1937#ifdef DEBUG
1938 if (_res.options & RES_DEBUG)
1939 printf(";; res_querydomain(%s, %s)\n",
1940 name, domain?domain:"<Nil>");
1941#endif
1942 if (domain == NULL) {
1943 /*
1944 * Check for trailing '.';
1945 * copy without '.' if present.
1946 */
1947 n = strlen(name);
1948 if (n >= MAXDNAME) {
1949 h_errno = NO_RECOVERY;
1950 return (-1);
1951 }
1952 if (n > 0 && name[--n] == '.') {
1953 strncpy(nbuf, name, n);
1954 nbuf[n] = '\0';
1955 } else
1956 longname = name;
1957 } else {
1958 n = strlen(name);
1959 d = strlen(domain);
1960 if (n + d + 1 >= MAXDNAME) {
1961 h_errno = NO_RECOVERY;
1962 return (-1);
1963 }
1964 sprintf(nbuf, "%s.%s", name, domain);
1965 }
1966 return (res_queryN(longname, target));
1967}
2/* $KAME: getaddrinfo.c,v 1.15 2000/07/09 04:37:24 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 * "#ifdef FAITH" part is local hack for supporting IPv4-v6 translator.
35 *
36 * Issues to be discussed:
37 * - Thread safe-ness must be checked.
38 * - Return values. There are nonstandard return values defined and used
39 * in the source code. This is because RFC2553 is silent about which error
40 * code must be returned for which situation.
41 * - freeaddrinfo(NULL). RFC2553 is silent about it. XNET 5.2 says it is
42 * invalid.
43 * current code - SEGV on freeaddrinfo(NULL)
44 * Note:
45 * - We use getipnodebyname() just for thread-safeness. There's no intent
46 * to let it do PF_UNSPEC (actually we never pass PF_UNSPEC to
47 * getipnodebyname().
48 * - The code filters out AFs that are not supported by the kernel,
49 * when globbing NULL hostname (to loopback, or wildcard). Is it the right
50 * thing to do? What is the relationship with post-RFC2553 AI_ADDRCONFIG
51 * in ai_flags?
52 * - (post-2553) semantics of AI_ADDRCONFIG itself is too vague.
53 * (1) what should we do against numeric hostname (2) what should we do
54 * against NULL hostname (3) what is AI_ADDRCONFIG itself. AF not ready?
55 * non-loopback address configured? global address configured?
56 * - To avoid search order issue, we have a big amount of code duplicate
57 * from gethnamaddr.c and some other places. The issues that there's no
58 * lower layer function to lookup "IPv4 or IPv6" record. Calling
59 * gethostbyname2 from getaddrinfo will end up in wrong search order, as
60 * follows:
61 * - The code makes use of following calls when asked to resolver with
62 * ai_family = PF_UNSPEC:
63 * getipnodebyname(host, AF_INET6);
64 * getipnodebyname(host, AF_INET);
65 * This will result in the following queries if the node is configure to
66 * prefer /etc/hosts than DNS:
67 * lookup /etc/hosts for IPv6 address
68 * lookup DNS for IPv6 address
69 * lookup /etc/hosts for IPv4 address
70 * lookup DNS for IPv4 address
71 * which may not meet people's requirement.
72 * The right thing to happen is to have underlying layer which does
73 * PF_UNSPEC lookup (lookup both) and return chain of addrinfos.
74 * This would result in a bit of code duplicate with _dns_ghbyname() and
75 * friends.
76 */
77/*
78 * diffs with other KAME platforms:
79 * - other KAME platforms already nuked FAITH ($GAI), but as FreeBSD
80 * 4.0-RELEASE supplies it, we still have the code here.
81 * - AI_ADDRCONFIG support is supplied
82 * - EDNS0 support is not available due to resolver differences
83 * - some of FreeBSD style (#define tabify and others)
84 * - classful IPv4 numeric (127.1) is allowed.
85 */
86
87#include "namespace.h"
88#include <sys/types.h>
89#include <sys/param.h>
90#include <sys/socket.h>
91#include <net/if.h>
92#include <netinet/in.h>
93#include <arpa/inet.h>
94#include <arpa/nameser.h>
95#include <netdb.h>
96#include <resolv.h>
97#include <string.h>
98#include <stdlib.h>
99#include <stddef.h>
100#include <ctype.h>
101#include <unistd.h>
102#include <stdio.h>
103#include <errno.h>
104
105#include <syslog.h>
106#include <stdarg.h>
107#include <nsswitch.h>
108#include "un-namespace.h"
109
110#if defined(__KAME__) && defined(INET6)
111# define FAITH
112#endif
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#define N_INET6 0
139 {PF_INET6, sizeof(struct in6_addr),
140 sizeof(struct sockaddr_in6),
141 offsetof(struct sockaddr_in6, sin6_addr),
142 in6_addrany, in6_loopback, 1},
143#define N_INET 1
144#else
145#define N_INET 0
146#endif
147 {PF_INET, sizeof(struct in_addr),
148 sizeof(struct sockaddr_in),
149 offsetof(struct sockaddr_in, sin_addr),
150 in_addrany, in_loopback, 0},
151 {0, 0, 0, 0, NULL, NULL, 0},
152};
153
154struct explore {
155 int e_af;
156 int e_socktype;
157 int e_protocol;
158 const char *e_protostr;
159 int e_wild;
160#define WILD_AF(ex) ((ex)->e_wild & 0x01)
161#define WILD_SOCKTYPE(ex) ((ex)->e_wild & 0x02)
162#define WILD_PROTOCOL(ex) ((ex)->e_wild & 0x04)
163};
164
165static const struct explore explore[] = {
166#if 0
167 { PF_LOCAL, 0, ANY, ANY, NULL, 0x01 },
168#endif
169#ifdef INET6
170 { PF_INET6, SOCK_DGRAM, IPPROTO_UDP, "udp", 0x07 },
171 { PF_INET6, SOCK_STREAM, IPPROTO_TCP, "tcp", 0x07 },
172 { PF_INET6, SOCK_RAW, ANY, NULL, 0x05 },
173#endif
174 { PF_INET, SOCK_DGRAM, IPPROTO_UDP, "udp", 0x07 },
175 { PF_INET, SOCK_STREAM, IPPROTO_TCP, "tcp", 0x07 },
176 { PF_INET, SOCK_RAW, ANY, NULL, 0x05 },
177 { PF_UNSPEC, SOCK_DGRAM, IPPROTO_UDP, "udp", 0x07 },
178 { PF_UNSPEC, SOCK_STREAM, IPPROTO_TCP, "tcp", 0x07 },
179 { PF_UNSPEC, SOCK_RAW, ANY, NULL, 0x05 },
180 { -1, 0, 0, NULL, 0 },
181};
182
183#ifdef INET6
184#define PTON_MAX 16
185#else
186#define PTON_MAX 4
187#endif
188
189static const ns_src default_dns_files[] = {
190 { NSSRC_FILES, NS_SUCCESS },
191 { NSSRC_DNS, NS_SUCCESS },
192 { 0 }
193};
194
195#if PACKETSZ > 1024
196#define MAXPACKET PACKETSZ
197#else
198#define MAXPACKET 1024
199#endif
200
201typedef union {
202 HEADER hdr;
203 u_char buf[MAXPACKET];
204} querybuf;
205
206struct res_target {
207 struct res_target *next;
208 const char *name; /* domain name */
209 int qclass, qtype; /* class and type of query */
210 u_char *answer; /* buffer to put answer */
211 int anslen; /* size of answer buffer */
212 int n; /* result length */
213};
214
215static int str_isnumber __P((const char *));
216static int explore_fqdn __P((const struct addrinfo *, const char *,
217 const char *, struct addrinfo **));
218static int explore_null __P((const struct addrinfo *,
219 const char *, struct addrinfo **));
220static int explore_numeric __P((const struct addrinfo *, const char *,
221 const char *, struct addrinfo **));
222static int explore_numeric_scope __P((const struct addrinfo *, const char *,
223 const char *, struct addrinfo **));
224static int get_canonname __P((const struct addrinfo *,
225 struct addrinfo *, const char *));
226static struct addrinfo *get_ai __P((const struct addrinfo *,
227 const struct afd *, const char *));
228static int get_portmatch __P((const struct addrinfo *, const char *));
229static int get_port __P((struct addrinfo *, const char *, int));
230static const struct afd *find_afd __P((int));
231static int addrconfig __P((struct addrinfo *));
232#ifdef INET6
233static int ip6_str2scopeid __P((char *, struct sockaddr_in6 *));
234#endif
235
236static struct addrinfo *getanswer __P((const querybuf *, int, const char *, int,
237 const struct addrinfo *));
238static int _dns_getaddrinfo __P((void *, void *, va_list));
239static void _sethtent __P((void));
240static void _endhtent __P((void));
241static struct addrinfo *_gethtent __P((const char *, const struct addrinfo *));
242static int _files_getaddrinfo __P((void *, void *, va_list));
243#ifdef YP
244static struct addrinfo *_yphostent __P((char *, const struct addrinfo *));
245static int _yp_getaddrinfo __P((void *, void *, va_list));
246#endif
247
248static int res_queryN __P((const char *, struct res_target *));
249static int res_searchN __P((const char *, struct res_target *));
250static int res_querydomainN __P((const char *, const char *,
251 struct res_target *));
252
253static char *ai_errlist[] = {
254 "Success",
255 "Address family for hostname not supported", /* EAI_ADDRFAMILY */
256 "Temporary failure in name resolution", /* EAI_AGAIN */
257 "Invalid value for ai_flags", /* EAI_BADFLAGS */
258 "Non-recoverable failure in name resolution", /* EAI_FAIL */
259 "ai_family not supported", /* EAI_FAMILY */
260 "Memory allocation failure", /* EAI_MEMORY */
261 "No address associated with hostname", /* EAI_NODATA */
262 "hostname nor servname provided, or not known", /* EAI_NONAME */
263 "servname not supported for ai_socktype", /* EAI_SERVICE */
264 "ai_socktype not supported", /* EAI_SOCKTYPE */
265 "System error returned in errno", /* EAI_SYSTEM */
266 "Invalid value for hints", /* EAI_BADHINTS */
267 "Resolved protocol is unknown", /* EAI_PROTOCOL */
268 "Unknown error", /* EAI_MAX */
269};
270
271/* XXX macros that make external reference is BAD. */
272
273#define GET_AI(ai, afd, addr) \
274do { \
275 /* external reference: pai, error, and label free */ \
276 (ai) = get_ai(pai, (afd), (addr)); \
277 if ((ai) == NULL) { \
278 error = EAI_MEMORY; \
279 goto free; \
280 } \
281} while (/*CONSTCOND*/0)
282
283#define GET_PORT(ai, serv) \
284do { \
285 /* external reference: error and label free */ \
286 error = get_port((ai), (serv), 0); \
287 if (error != 0) \
288 goto free; \
289} while (/*CONSTCOND*/0)
290
291#define GET_CANONNAME(ai, str) \
292do { \
293 /* external reference: pai, error and label free */ \
294 error = get_canonname(pai, (ai), (str)); \
295 if (error != 0) \
296 goto free; \
297} while (/*CONSTCOND*/0)
298
299#define ERR(err) \
300do { \
301 /* external reference: error, and label bad */ \
302 error = (err); \
303 goto bad; \
304 /*NOTREACHED*/ \
305} while (/*CONSTCOND*/0)
306
307#define MATCH_FAMILY(x, y, w) \
308 ((x) == (y) || (/*CONSTCOND*/(w) && ((x) == PF_UNSPEC || (y) == PF_UNSPEC)))
309#define MATCH(x, y, w) \
310 ((x) == (y) || (/*CONSTCOND*/(w) && ((x) == ANY || (y) == ANY)))
311
312char *
313gai_strerror(ecode)
314 int ecode;
315{
316 if (ecode < 0 || ecode > EAI_MAX)
317 ecode = EAI_MAX;
318 return ai_errlist[ecode];
319}
320
321void
322freeaddrinfo(ai)
323 struct addrinfo *ai;
324{
325 struct addrinfo *next;
326
327 do {
328 next = ai->ai_next;
329 if (ai->ai_canonname)
330 free(ai->ai_canonname);
331 /* no need to free(ai->ai_addr) */
332 free(ai);
333 ai = next;
334 } while (ai);
335}
336
337static int
338str_isnumber(p)
339 const char *p;
340{
341 char *ep;
342
343 if (*p == '\0')
344 return NO;
345 ep = NULL;
346 (void)strtoul(p, &ep, 10);
347 if (ep && *ep == '\0')
348 return YES;
349 else
350 return NO;
351}
352
353int
354getaddrinfo(hostname, servname, hints, res)
355 const char *hostname, *servname;
356 const struct addrinfo *hints;
357 struct addrinfo **res;
358{
359 struct addrinfo sentinel;
360 struct addrinfo *cur;
361 int error = 0;
362 struct addrinfo ai;
363 struct addrinfo ai0;
364 struct addrinfo *pai;
365 const struct explore *ex;
366
367 memset(&sentinel, 0, sizeof(sentinel));
368 cur = &sentinel;
369 pai = &ai;
370 pai->ai_flags = 0;
371 pai->ai_family = PF_UNSPEC;
372 pai->ai_socktype = ANY;
373 pai->ai_protocol = ANY;
374 pai->ai_addrlen = 0;
375 pai->ai_canonname = NULL;
376 pai->ai_addr = NULL;
377 pai->ai_next = NULL;
378
379 if (hostname == NULL && servname == NULL)
380 return EAI_NONAME;
381 if (hints) {
382 /* error check for hints */
383 if (hints->ai_addrlen || hints->ai_canonname ||
384 hints->ai_addr || hints->ai_next)
385 ERR(EAI_BADHINTS); /* xxx */
386 if (hints->ai_flags & ~AI_MASK)
387 ERR(EAI_BADFLAGS);
388 switch (hints->ai_family) {
389 case PF_UNSPEC:
390 case PF_INET:
391#ifdef INET6
392 case PF_INET6:
393#endif
394 break;
395 default:
396 ERR(EAI_FAMILY);
397 }
398 memcpy(pai, hints, sizeof(*pai));
399
400 /*
401 * if both socktype/protocol are specified, check if they
402 * are meaningful combination.
403 */
404 if (pai->ai_socktype != ANY && pai->ai_protocol != ANY) {
405 for (ex = explore; ex->e_af >= 0; ex++) {
406 if (pai->ai_family != ex->e_af)
407 continue;
408 if (ex->e_socktype == ANY)
409 continue;
410 if (ex->e_protocol == ANY)
411 continue;
412 if (pai->ai_socktype == ex->e_socktype
413 && pai->ai_protocol != ex->e_protocol) {
414 ERR(EAI_BADHINTS);
415 }
416 }
417 }
418 }
419
420 /*
421 * post-2553: AI_ALL and AI_V4MAPPED are effective only against
422 * AF_INET6 query. They needs to be ignored if specified in other
423 * occassions.
424 */
425 switch (pai->ai_flags & (AI_ALL | AI_V4MAPPED)) {
426 case AI_V4MAPPED:
427 case AI_ALL | AI_V4MAPPED:
428 if (pai->ai_family != AF_INET6)
429 pai->ai_flags &= ~(AI_ALL | AI_V4MAPPED);
430 break;
431 case AI_ALL:
432#if 1
433 /* illegal */
434 ERR(EAI_BADFLAGS);
435#else
436 pai->ai_flags &= ~(AI_ALL | AI_V4MAPPED);
437#endif
438 break;
439 }
440
441 /*
442 * check for special cases. (1) numeric servname is disallowed if
443 * socktype/protocol are left unspecified. (2) servname is disallowed
444 * for raw and other inet{,6} sockets.
445 */
446 if (MATCH_FAMILY(pai->ai_family, PF_INET, 1)
447#ifdef PF_INET6
448 || MATCH_FAMILY(pai->ai_family, PF_INET6, 1)
449#endif
450 ) {
451 ai0 = *pai; /* backup *pai */
452
453 if (pai->ai_family == PF_UNSPEC) {
454#ifdef PF_INET6
455 pai->ai_family = PF_INET6;
456#else
457 pai->ai_family = PF_INET;
458#endif
459 }
460 error = get_portmatch(pai, servname);
461 if (error)
462 ERR(error);
463
464 *pai = ai0;
465 }
466
467 ai0 = *pai;
468
469 /* NULL hostname, or numeric hostname */
470 for (ex = explore; ex->e_af >= 0; ex++) {
471 *pai = ai0;
472
473 /* PF_UNSPEC entries are prepared for DNS queries only */
474 if (ex->e_af == PF_UNSPEC)
475 continue;
476
477 if (!MATCH_FAMILY(pai->ai_family, ex->e_af, WILD_AF(ex)))
478 continue;
479 if (!MATCH(pai->ai_socktype, ex->e_socktype, WILD_SOCKTYPE(ex)))
480 continue;
481 if (!MATCH(pai->ai_protocol, ex->e_protocol, WILD_PROTOCOL(ex)))
482 continue;
483
484 if (pai->ai_family == PF_UNSPEC)
485 pai->ai_family = ex->e_af;
486 if (pai->ai_socktype == ANY && ex->e_socktype != ANY)
487 pai->ai_socktype = ex->e_socktype;
488 if (pai->ai_protocol == ANY && ex->e_protocol != ANY)
489 pai->ai_protocol = ex->e_protocol;
490
491 if (hostname == NULL)
492 error = explore_null(pai, servname, &cur->ai_next);
493 else
494 error = explore_numeric_scope(pai, hostname, servname, &cur->ai_next);
495
496 if (error)
497 goto free;
498
499 while (cur && cur->ai_next)
500 cur = cur->ai_next;
501 }
502
503 /*
504 * XXX
505 * If numreic representation of AF1 can be interpreted as FQDN
506 * representation of AF2, we need to think again about the code below.
507 */
508 if (sentinel.ai_next)
509 goto good;
510
511 if (pai->ai_flags & AI_NUMERICHOST)
512 ERR(EAI_NODATA);
513 if (hostname == NULL)
514 ERR(EAI_NODATA);
515
516 if ((pai->ai_flags & AI_ADDRCONFIG) != 0 && !addrconfig(&ai0))
517 ERR(EAI_FAIL);
518
519 /*
520 * hostname as alphabetical name.
521 * we would like to prefer AF_INET6 than AF_INET, so we'll make a
522 * outer loop by AFs.
523 */
524 for (ex = explore; ex->e_af >= 0; ex++) {
525 *pai = ai0;
526
527 /* require exact match for family field */
528 if (pai->ai_family != ex->e_af)
529 continue;
530
531 if (!MATCH(pai->ai_socktype, ex->e_socktype,
532 WILD_SOCKTYPE(ex))) {
533 continue;
534 }
535 if (!MATCH(pai->ai_protocol, ex->e_protocol,
536 WILD_PROTOCOL(ex))) {
537 continue;
538 }
539
540 if (pai->ai_socktype == ANY && ex->e_socktype != ANY)
541 pai->ai_socktype = ex->e_socktype;
542 if (pai->ai_protocol == ANY && ex->e_protocol != ANY)
543 pai->ai_protocol = ex->e_protocol;
544
545 error = explore_fqdn(pai, hostname, servname,
546 &cur->ai_next);
547
548 while (cur && cur->ai_next)
549 cur = cur->ai_next;
550 }
551
552 /* XXX */
553 if (sentinel.ai_next)
554 error = 0;
555
556 if (error)
557 goto free;
558 if (error == 0) {
559 if (sentinel.ai_next) {
560 good:
561 *res = sentinel.ai_next;
562 return SUCCESS;
563 } else
564 error = EAI_FAIL;
565 }
566 free:
567 bad:
568 if (sentinel.ai_next)
569 freeaddrinfo(sentinel.ai_next);
570 *res = NULL;
571 return error;
572}
573
574/*
575 * FQDN hostname, DNS lookup
576 */
577static int
578explore_fqdn(pai, hostname, servname, res)
579 const struct addrinfo *pai;
580 const char *hostname;
581 const char *servname;
582 struct addrinfo **res;
583{
584 struct addrinfo *result;
585 struct addrinfo *cur;
586 int error = 0;
587 static const ns_dtab dtab[] = {
588 NS_FILES_CB(_files_getaddrinfo, NULL)
589 { NSSRC_DNS, _dns_getaddrinfo, NULL }, /* force -DHESIOD */
590 NS_NIS_CB(_yp_getaddrinfo, NULL)
591 { 0 }
592 };
593
594 result = NULL;
595
596 /*
597 * if the servname does not match socktype/protocol, ignore it.
598 */
599 if (get_portmatch(pai, servname) != 0)
600 return 0;
601
602 switch (nsdispatch(&result, dtab, NSDB_HOSTS, "getaddrinfo",
603 default_dns_files, hostname, pai)) {
604 case NS_TRYAGAIN:
605 error = EAI_AGAIN;
606 goto free;
607 case NS_UNAVAIL:
608 error = EAI_FAIL;
609 goto free;
610 case NS_NOTFOUND:
611 error = EAI_NODATA;
612 goto free;
613 case NS_SUCCESS:
614 error = 0;
615 for (cur = result; cur; cur = cur->ai_next) {
616 GET_PORT(cur, servname);
617 /* canonname should be filled already */
618 }
619 break;
620 }
621
622 *res = result;
623
624 return 0;
625
626free:
627 if (result)
628 freeaddrinfo(result);
629 return error;
630}
631
632/*
633 * hostname == NULL.
634 * passive socket -> anyaddr (0.0.0.0 or ::)
635 * non-passive socket -> localhost (127.0.0.1 or ::1)
636 */
637static int
638explore_null(pai, servname, res)
639 const struct addrinfo *pai;
640 const char *servname;
641 struct addrinfo **res;
642{
643 int s;
644 const struct afd *afd;
645 struct addrinfo *cur;
646 struct addrinfo sentinel;
647 int error;
648
649 *res = NULL;
650 sentinel.ai_next = NULL;
651 cur = &sentinel;
652
653 /*
654 * filter out AFs that are not supported by the kernel
655 * XXX errno?
656 */
657 s = _socket(pai->ai_family, SOCK_DGRAM, 0);
658 if (s < 0) {
659 if (errno != EMFILE)
660 return 0;
661 } else
662 _close(s);
663
664 /*
665 * if the servname does not match socktype/protocol, ignore it.
666 */
667 if (get_portmatch(pai, servname) != 0)
668 return 0;
669
670 afd = find_afd(pai->ai_family);
671 if (afd == NULL)
672 return 0;
673
674 if (pai->ai_flags & AI_PASSIVE) {
675 GET_AI(cur->ai_next, afd, afd->a_addrany);
676 /* xxx meaningless?
677 * GET_CANONNAME(cur->ai_next, "anyaddr");
678 */
679 GET_PORT(cur->ai_next, servname);
680 } else {
681 GET_AI(cur->ai_next, afd, afd->a_loopback);
682 /* xxx meaningless?
683 * GET_CANONNAME(cur->ai_next, "localhost");
684 */
685 GET_PORT(cur->ai_next, servname);
686 }
687 cur = cur->ai_next;
688
689 *res = sentinel.ai_next;
690 return 0;
691
692free:
693 if (sentinel.ai_next)
694 freeaddrinfo(sentinel.ai_next);
695 return error;
696}
697
698/*
699 * numeric hostname
700 */
701static int
702explore_numeric(pai, hostname, servname, res)
703 const struct addrinfo *pai;
704 const char *hostname;
705 const char *servname;
706 struct addrinfo **res;
707{
708 const struct afd *afd;
709 struct addrinfo *cur;
710 struct addrinfo sentinel;
711 int error;
712 char pton[PTON_MAX];
713
714 *res = NULL;
715 sentinel.ai_next = NULL;
716 cur = &sentinel;
717
718 /*
719 * if the servname does not match socktype/protocol, ignore it.
720 */
721 if (get_portmatch(pai, servname) != 0)
722 return 0;
723
724 afd = find_afd(pai->ai_family);
725 if (afd == NULL)
726 return 0;
727
728 switch (afd->a_af) {
729#if 1 /*X/Open spec*/
730 case AF_INET:
731 if (inet_aton(hostname, (struct in_addr *)pton) == 1) {
732 if (pai->ai_family == afd->a_af ||
733 pai->ai_family == PF_UNSPEC /*?*/) {
734 GET_AI(cur->ai_next, afd, pton);
735 GET_PORT(cur->ai_next, servname);
736 while (cur && cur->ai_next)
737 cur = cur->ai_next;
738 } else
739 ERR(EAI_FAMILY); /*xxx*/
740 }
741 break;
742#endif
743 default:
744 if (inet_pton(afd->a_af, hostname, pton) == 1) {
745 if (pai->ai_family == afd->a_af ||
746 pai->ai_family == PF_UNSPEC /*?*/) {
747 GET_AI(cur->ai_next, afd, pton);
748 GET_PORT(cur->ai_next, servname);
749 while (cur && cur->ai_next)
750 cur = cur->ai_next;
751 } else
752 ERR(EAI_FAMILY); /*xxx*/
753 }
754 break;
755 }
756
757 *res = sentinel.ai_next;
758 return 0;
759
760free:
761bad:
762 if (sentinel.ai_next)
763 freeaddrinfo(sentinel.ai_next);
764 return error;
765}
766
767/*
768 * numeric hostname with scope
769 */
770static int
771explore_numeric_scope(pai, hostname, servname, res)
772 const struct addrinfo *pai;
773 const char *hostname;
774 const char *servname;
775 struct addrinfo **res;
776{
777#if !defined(SCOPE_DELIMITER) || !defined(INET6)
778 return explore_numeric(pai, hostname, servname, res);
779#else
780 const struct afd *afd;
781 struct addrinfo *cur;
782 int error;
783 char *cp, *hostname2 = NULL, *scope, *addr;
784 struct sockaddr_in6 *sin6;
785
786 /*
787 * if the servname does not match socktype/protocol, ignore it.
788 */
789 if (get_portmatch(pai, servname) != 0)
790 return 0;
791
792 afd = find_afd(pai->ai_family);
793 if (afd == NULL)
794 return 0;
795
796 if (!afd->a_scoped)
797 return explore_numeric(pai, hostname, servname, res);
798
799 cp = strchr(hostname, SCOPE_DELIMITER);
800 if (cp == NULL)
801 return explore_numeric(pai, hostname, servname, res);
802
803 /*
804 * Handle special case of <scoped_address><delimiter><scope id>
805 */
806 hostname2 = strdup(hostname);
807 if (hostname2 == NULL)
808 return EAI_MEMORY;
809 /* terminate at the delimiter */
810 hostname2[cp - hostname] = '\0';
811 addr = hostname2;
812 scope = cp + 1;
813
814 error = explore_numeric(pai, addr, servname, res);
815 if (error == 0) {
816 int scopeid;
817
818 for (cur = *res; cur; cur = cur->ai_next) {
819 if (cur->ai_family != AF_INET6)
820 continue;
821 sin6 = (struct sockaddr_in6 *)(void *)cur->ai_addr;
822 if ((scopeid = ip6_str2scopeid(scope, sin6)) == -1) {
823 free(hostname2);
824 return(EAI_NODATA); /* XXX: is return OK? */
825 }
826 sin6->sin6_scope_id = scopeid;
827 }
828 }
829
830 free(hostname2);
831
832 return error;
833#endif
834}
835
836static int
837get_canonname(pai, ai, str)
838 const struct addrinfo *pai;
839 struct addrinfo *ai;
840 const char *str;
841{
842 if ((pai->ai_flags & AI_CANONNAME) != 0) {
843 ai->ai_canonname = (char *)malloc(strlen(str) + 1);
844 if (ai->ai_canonname == NULL)
845 return EAI_MEMORY;
846 strcpy(ai->ai_canonname, str);
847 }
848 return 0;
849}
850
851static struct addrinfo *
852get_ai(pai, afd, addr)
853 const struct addrinfo *pai;
854 const struct afd *afd;
855 const char *addr;
856{
857 char *p;
858 struct addrinfo *ai;
859#ifdef FAITH
860 struct in6_addr faith_prefix;
861 char *fp_str;
862 int translate = 0;
863#endif
864
865#ifdef FAITH
866 /*
867 * Transfrom an IPv4 addr into a special IPv6 addr format for
868 * IPv6->IPv4 translation gateway. (only TCP is supported now)
869 *
870 * +-----------------------------------+------------+
871 * | faith prefix part (12 bytes) | embedded |
872 * | | IPv4 addr part (4 bytes)
873 * +-----------------------------------+------------+
874 *
875 * faith prefix part is specified as ascii IPv6 addr format
876 * in environmental variable GAI.
877 * For FAITH to work correctly, routing to faith prefix must be
878 * setup toward a machine where a FAITH daemon operates.
879 * Also, the machine must enable some mechanizm
880 * (e.g. faith interface hack) to divert those packet with
881 * faith prefixed destination addr to user-land FAITH daemon.
882 */
883 fp_str = getenv("GAI");
884 if (fp_str && inet_pton(AF_INET6, fp_str, &faith_prefix) == 1 &&
885 afd->a_af == AF_INET && pai->ai_socktype == SOCK_STREAM) {
886 u_int32_t v4a;
887 u_int8_t v4a_top;
888
889 memcpy(&v4a, addr, sizeof v4a);
890 v4a_top = v4a >> IN_CLASSA_NSHIFT;
891 if (!IN_MULTICAST(v4a) && !IN_EXPERIMENTAL(v4a) &&
892 v4a_top != 0 && v4a != IN_LOOPBACKNET) {
893 afd = &afdl[N_INET6];
894 memcpy(&faith_prefix.s6_addr[12], addr,
895 sizeof(struct in_addr));
896 translate = 1;
897 }
898 }
899#endif
900
901 ai = (struct addrinfo *)malloc(sizeof(struct addrinfo)
902 + (afd->a_socklen));
903 if (ai == NULL)
904 return NULL;
905
906 memcpy(ai, pai, sizeof(struct addrinfo));
907 ai->ai_addr = (struct sockaddr *)(void *)(ai + 1);
908 memset(ai->ai_addr, 0, (size_t)afd->a_socklen);
909 ai->ai_addr->sa_len = afd->a_socklen;
910 ai->ai_addrlen = afd->a_socklen;
911 ai->ai_addr->sa_family = ai->ai_family = afd->a_af;
912 p = (char *)(void *)(ai->ai_addr);
913#ifdef FAITH
914 if (translate == 1)
915 memcpy(p + afd->a_off, &faith_prefix, (size_t)afd->a_addrlen);
916 else
917#endif
918 memcpy(p + afd->a_off, addr, (size_t)afd->a_addrlen);
919 return ai;
920}
921
922static int
923get_portmatch(ai, servname)
924 const struct addrinfo *ai;
925 const char *servname;
926{
927
928 /* get_port does not touch first argument. when matchonly == 1. */
929 /* LINTED const cast */
930 return get_port((struct addrinfo *)ai, servname, 1);
931}
932
933static int
934get_port(ai, servname, matchonly)
935 struct addrinfo *ai;
936 const char *servname;
937 int matchonly;
938{
939 const char *proto;
940 struct servent *sp;
941 int port;
942 int allownumeric;
943
944 if (servname == NULL)
945 return 0;
946 switch (ai->ai_family) {
947 case AF_INET:
948#ifdef AF_INET6
949 case AF_INET6:
950#endif
951 break;
952 default:
953 return 0;
954 }
955
956 switch (ai->ai_socktype) {
957 case SOCK_RAW:
958 return EAI_SERVICE;
959 case SOCK_DGRAM:
960 case SOCK_STREAM:
961 allownumeric = 1;
962 break;
963 case ANY:
964 allownumeric = 0;
965 break;
966 default:
967 return EAI_SOCKTYPE;
968 }
969
970 if (str_isnumber(servname)) {
971 if (!allownumeric)
972 return EAI_SERVICE;
973 port = htons(atoi(servname));
974 if (port < 0 || port > 65535)
975 return EAI_SERVICE;
976 } else {
977 switch (ai->ai_socktype) {
978 case SOCK_DGRAM:
979 proto = "udp";
980 break;
981 case SOCK_STREAM:
982 proto = "tcp";
983 break;
984 default:
985 proto = NULL;
986 break;
987 }
988
989 if ((sp = getservbyname(servname, proto)) == NULL)
990 return EAI_SERVICE;
991 port = sp->s_port;
992 }
993
994 if (!matchonly) {
995 switch (ai->ai_family) {
996 case AF_INET:
997 ((struct sockaddr_in *)(void *)
998 ai->ai_addr)->sin_port = port;
999 break;
1000#ifdef INET6
1001 case AF_INET6:
1002 ((struct sockaddr_in6 *)(void *)
1003 ai->ai_addr)->sin6_port = port;
1004 break;
1005#endif
1006 }
1007 }
1008
1009 return 0;
1010}
1011
1012static const struct afd *
1013find_afd(af)
1014 int af;
1015{
1016 const struct afd *afd;
1017
1018 if (af == PF_UNSPEC)
1019 return NULL;
1020 for (afd = afdl; afd->a_af; afd++) {
1021 if (afd->a_af == af)
1022 return afd;
1023 }
1024 return NULL;
1025}
1026
1027/*
1028 * post-2553: AI_ADDRCONFIG check. if we use getipnodeby* as backend, backend
1029 * will take care of it.
1030 * the semantics of AI_ADDRCONFIG is not defined well. we are not sure
1031 * if the code is right or not.
1032 *
1033 * XXX PF_UNSPEC -> PF_INET6 + PF_INET mapping needs to be in sync with
1034 * _dns_getaddrinfo.
1035 */
1036static int
1037addrconfig(pai)
1038 struct addrinfo *pai;
1039{
1040 int s, af;
1041
1042 /*
1043 * TODO:
1044 * Note that implementation dependent test for address
1045 * configuration should be done everytime called
1046 * (or apropriate interval),
1047 * because addresses will be dynamically assigned or deleted.
1048 */
1049 af = pai->ai_family;
1050 if (af == AF_UNSPEC) {
1051 if ((s = _socket(AF_INET6, SOCK_DGRAM, 0)) < 0)
1052 af = AF_INET;
1053 else {
1054 _close(s);
1055 if ((s = _socket(AF_INET, SOCK_DGRAM, 0)) < 0)
1056 af = AF_INET6;
1057 else
1058 _close(s);
1059 }
1060 }
1061 if (af != AF_UNSPEC) {
1062 if ((s = _socket(af, SOCK_DGRAM, 0)) < 0)
1063 return 0;
1064 _close(s);
1065 }
1066 pai->ai_family = af;
1067 return 1;
1068}
1069
1070#ifdef INET6
1071/* convert a string to a scope identifier. XXX: IPv6 specific */
1072static int
1073ip6_str2scopeid(scope, sin6)
1074 char *scope;
1075 struct sockaddr_in6 *sin6;
1076{
1077 int scopeid;
1078 struct in6_addr *a6 = &sin6->sin6_addr;
1079 char *ep;
1080
1081 /* empty scopeid portion is invalid */
1082 if (*scope == '\0')
1083 return -1;
1084
1085 if (IN6_IS_ADDR_LINKLOCAL(a6) || IN6_IS_ADDR_MC_LINKLOCAL(a6)) {
1086 /*
1087 * We currently assume a one-to-one mapping between links
1088 * and interfaces, so we simply use interface indices for
1089 * like-local scopes.
1090 */
1091 scopeid = if_nametoindex(scope);
1092 if (scopeid == 0)
1093 goto trynumeric;
1094 return(scopeid);
1095 }
1096
1097 /* still unclear about literal, allow numeric only - placeholder */
1098 if (IN6_IS_ADDR_SITELOCAL(a6) || IN6_IS_ADDR_MC_SITELOCAL(a6))
1099 goto trynumeric;
1100 if (IN6_IS_ADDR_MC_ORGLOCAL(a6))
1101 goto trynumeric;
1102 else
1103 goto trynumeric; /* global */
1104
1105 /* try to convert to a numeric id as a last resort */
1106 trynumeric:
1107 scopeid = (int)strtoul(scope, &ep, 10);
1108 if (*ep == '\0')
1109 return scopeid;
1110 else
1111 return -1;
1112}
1113#endif
1114
1115#ifdef DEBUG
1116static const char AskedForGot[] =
1117 "gethostby*.getanswer: asked for \"%s\", got \"%s\"";
1118#endif
1119static FILE *hostf = NULL;
1120
1121static struct addrinfo *
1122getanswer(answer, anslen, qname, qtype, pai)
1123 const querybuf *answer;
1124 int anslen;
1125 const char *qname;
1126 int qtype;
1127 const struct addrinfo *pai;
1128{
1129 struct addrinfo sentinel, *cur;
1130 struct addrinfo ai;
1131 const struct afd *afd;
1132 char *canonname;
1133 const HEADER *hp;
1134 const u_char *cp;
1135 int n;
1136 const u_char *eom;
1137 char *bp;
1138 int type, class, buflen, ancount, qdcount;
1139 int haveanswer, had_error;
1140 char tbuf[MAXDNAME];
1141 int (*name_ok) __P((const char *));
1142 char hostbuf[8*1024];
1143
1144 memset(&sentinel, 0, sizeof(sentinel));
1145 cur = &sentinel;
1146
1147 canonname = NULL;
1148 eom = answer->buf + anslen;
1149 switch (qtype) {
1150 case T_A:
1151 case T_AAAA:
1152 case T_ANY: /*use T_ANY only for T_A/T_AAAA lookup*/
1153 name_ok = res_hnok;
1154 break;
1155 default:
1156 return (NULL); /* XXX should be abort(); */
1157 }
1158 /*
1159 * find first satisfactory answer
1160 */
1161 hp = &answer->hdr;
1162 ancount = ntohs(hp->ancount);
1163 qdcount = ntohs(hp->qdcount);
1164 bp = hostbuf;
1165 buflen = sizeof hostbuf;
1166 cp = answer->buf + HFIXEDSZ;
1167 if (qdcount != 1) {
1168 h_errno = NO_RECOVERY;
1169 return (NULL);
1170 }
1171 n = dn_expand(answer->buf, eom, cp, bp, buflen);
1172 if ((n < 0) || !(*name_ok)(bp)) {
1173 h_errno = NO_RECOVERY;
1174 return (NULL);
1175 }
1176 cp += n + QFIXEDSZ;
1177 if (qtype == T_A || qtype == T_AAAA || qtype == T_ANY) {
1178 /* res_send() has already verified that the query name is the
1179 * same as the one we sent; this just gets the expanded name
1180 * (i.e., with the succeeding search-domain tacked on).
1181 */
1182 n = strlen(bp) + 1; /* for the \0 */
1183 if (n >= MAXHOSTNAMELEN) {
1184 h_errno = NO_RECOVERY;
1185 return (NULL);
1186 }
1187 canonname = bp;
1188 bp += n;
1189 buflen -= n;
1190 /* The qname can be abbreviated, but h_name is now absolute. */
1191 qname = canonname;
1192 }
1193 haveanswer = 0;
1194 had_error = 0;
1195 while (ancount-- > 0 && cp < eom && !had_error) {
1196 n = dn_expand(answer->buf, eom, cp, bp, buflen);
1197 if ((n < 0) || !(*name_ok)(bp)) {
1198 had_error++;
1199 continue;
1200 }
1201 cp += n; /* name */
1202 type = _getshort(cp);
1203 cp += INT16SZ; /* type */
1204 class = _getshort(cp);
1205 cp += INT16SZ + INT32SZ; /* class, TTL */
1206 n = _getshort(cp);
1207 cp += INT16SZ; /* len */
1208 if (class != C_IN) {
1209 /* XXX - debug? syslog? */
1210 cp += n;
1211 continue; /* XXX - had_error++ ? */
1212 }
1213 if ((qtype == T_A || qtype == T_AAAA || qtype == T_ANY) &&
1214 type == T_CNAME) {
1215 n = dn_expand(answer->buf, eom, cp, tbuf, sizeof tbuf);
1216 if ((n < 0) || !(*name_ok)(tbuf)) {
1217 had_error++;
1218 continue;
1219 }
1220 cp += n;
1221 /* Get canonical name. */
1222 n = strlen(tbuf) + 1; /* for the \0 */
1223 if (n > buflen || n >= MAXHOSTNAMELEN) {
1224 had_error++;
1225 continue;
1226 }
1227 strcpy(bp, tbuf);
1228 canonname = bp;
1229 bp += n;
1230 buflen -= n;
1231 continue;
1232 }
1233 if (qtype == T_ANY) {
1234 if (!(type == T_A || type == T_AAAA)) {
1235 cp += n;
1236 continue;
1237 }
1238 } else if (type != qtype) {
1239#ifdef DEBUG
1240 if (type != T_KEY && type != T_SIG)
1241 syslog(LOG_NOTICE|LOG_AUTH,
1242 "gethostby*.getanswer: asked for \"%s %s %s\", got type \"%s\"",
1243 qname, p_class(C_IN), p_type(qtype),
1244 p_type(type));
1245#endif
1246 cp += n;
1247 continue; /* XXX - had_error++ ? */
1248 }
1249 switch (type) {
1250 case T_A:
1251 case T_AAAA:
1252 if (strcasecmp(canonname, bp) != 0) {
1253#ifdef DEBUG
1254 syslog(LOG_NOTICE|LOG_AUTH,
1255 AskedForGot, canonname, bp);
1256#endif
1257 cp += n;
1258 continue; /* XXX - had_error++ ? */
1259 }
1260 if (type == T_A && n != INADDRSZ) {
1261 cp += n;
1262 continue;
1263 }
1264 if (type == T_AAAA && n != IN6ADDRSZ) {
1265 cp += n;
1266 continue;
1267 }
1268#ifdef FILTER_V4MAPPED
1269 if (type == T_AAAA) {
1270 struct in6_addr in6;
1271 memcpy(&in6, cp, sizeof(in6));
1272 if (IN6_IS_ADDR_V4MAPPED(&in6)) {
1273 cp += n;
1274 continue;
1275 }
1276 }
1277#endif
1278 if (!haveanswer) {
1279 int nn;
1280
1281 canonname = bp;
1282 nn = strlen(bp) + 1; /* for the \0 */
1283 bp += nn;
1284 buflen -= nn;
1285 }
1286
1287 /* don't overwrite pai */
1288 ai = *pai;
1289 ai.ai_family = (type == T_A) ? AF_INET : AF_INET6;
1290 afd = find_afd(ai.ai_family);
1291 if (afd == NULL) {
1292 cp += n;
1293 continue;
1294 }
1295 cur->ai_next = get_ai(&ai, afd, (const char *)cp);
1296 if (cur->ai_next == NULL)
1297 had_error++;
1298 while (cur && cur->ai_next)
1299 cur = cur->ai_next;
1300 cp += n;
1301 break;
1302 default:
1303 abort();
1304 }
1305 if (!had_error)
1306 haveanswer++;
1307 }
1308 if (haveanswer) {
1309 if (!canonname)
1310 (void)get_canonname(pai, sentinel.ai_next, qname);
1311 else
1312 (void)get_canonname(pai, sentinel.ai_next, canonname);
1313 h_errno = NETDB_SUCCESS;
1314 return sentinel.ai_next;
1315 }
1316
1317 h_errno = NO_RECOVERY;
1318 return NULL;
1319}
1320
1321/*ARGSUSED*/
1322static int
1323_dns_getaddrinfo(rv, cb_data, ap)
1324 void *rv;
1325 void *cb_data;
1326 va_list ap;
1327{
1328 struct addrinfo *ai;
1329 querybuf buf, buf2;
1330 const char *name;
1331 const struct addrinfo *pai;
1332 struct addrinfo sentinel, *cur;
1333 struct res_target q, q2;
1334
1335 name = va_arg(ap, char *);
1336 pai = va_arg(ap, const struct addrinfo *);
1337
1338 memset(&q, 0, sizeof(q2));
1339 memset(&q2, 0, sizeof(q2));
1340 memset(&sentinel, 0, sizeof(sentinel));
1341 cur = &sentinel;
1342
1343 switch (pai->ai_family) {
1344 case AF_UNSPEC:
1345 /* prefer IPv6 */
1346 q.qclass = C_IN;
1347 q.qtype = T_AAAA;
1348 q.answer = buf.buf;
1349 q.anslen = sizeof(buf);
1350 q.next = &q2;
1351 q2.qclass = C_IN;
1352 q2.qtype = T_A;
1353 q2.answer = buf2.buf;
1354 q2.anslen = sizeof(buf2);
1355 break;
1356 case AF_INET:
1357 q.qclass = C_IN;
1358 q.qtype = T_A;
1359 q.answer = buf.buf;
1360 q.anslen = sizeof(buf);
1361 break;
1362 case AF_INET6:
1363 q.qclass = C_IN;
1364 q.qtype = T_AAAA;
1365 q.answer = buf.buf;
1366 q.anslen = sizeof(buf);
1367 break;
1368 default:
1369 return NS_UNAVAIL;
1370 }
1371 if (res_searchN(name, &q) < 0)
1372 return NS_NOTFOUND;
1373 ai = getanswer(&buf, q.n, q.name, q.qtype, pai);
1374 if (ai) {
1375 cur->ai_next = ai;
1376 while (cur && cur->ai_next)
1377 cur = cur->ai_next;
1378 }
1379 if (q.next) {
1380 ai = getanswer(&buf2, q2.n, q2.name, q2.qtype, pai);
1381 if (ai)
1382 cur->ai_next = ai;
1383 }
1384 if (sentinel.ai_next == NULL)
1385 switch (h_errno) {
1386 case HOST_NOT_FOUND:
1387 return NS_NOTFOUND;
1388 case TRY_AGAIN:
1389 return NS_TRYAGAIN;
1390 default:
1391 return NS_UNAVAIL;
1392 }
1393 *((struct addrinfo **)rv) = sentinel.ai_next;
1394 return NS_SUCCESS;
1395}
1396
1397static void
1398_sethtent()
1399{
1400 if (!hostf)
1401 hostf = fopen(_PATH_HOSTS, "r" );
1402 else
1403 rewind(hostf);
1404}
1405
1406static void
1407_endhtent()
1408{
1409 if (hostf) {
1410 (void) fclose(hostf);
1411 hostf = NULL;
1412 }
1413}
1414
1415static struct addrinfo *
1416_gethtent(name, pai)
1417 const char *name;
1418 const struct addrinfo *pai;
1419{
1420 char *p;
1421 char *cp, *tname, *cname;
1422 struct addrinfo hints, *res0, *res;
1423 int error;
1424 const char *addr;
1425 char hostbuf[8*1024];
1426
1427 if (!hostf && !(hostf = fopen(_PATH_HOSTS, "r" )))
1428 return (NULL);
1429 again:
1430 if (!(p = fgets(hostbuf, sizeof hostbuf, hostf)))
1431 return (NULL);
1432 if (*p == '#')
1433 goto again;
1434 if (!(cp = strpbrk(p, "#\n")))
1435 goto again;
1436 *cp = '\0';
1437 if (!(cp = strpbrk(p, " \t")))
1438 goto again;
1439 *cp++ = '\0';
1440 addr = p;
1441 cname = NULL;
1442 /* if this is not something we're looking for, skip it. */
1443 while (cp && *cp) {
1444 if (*cp == ' ' || *cp == '\t') {
1445 cp++;
1446 continue;
1447 }
1448 tname = cp;
1449 if (cname == NULL)
1450 cname = cp;
1451 if ((cp = strpbrk(cp, " \t")) != NULL)
1452 *cp++ = '\0';
1453 if (strcasecmp(name, tname) == 0)
1454 goto found;
1455 }
1456 goto again;
1457
1458found:
1459 hints = *pai;
1460 hints.ai_flags = AI_NUMERICHOST;
1461 error = getaddrinfo(addr, NULL, &hints, &res0);
1462 if (error)
1463 goto again;
1464#ifdef FILTER_V4MAPPED
1465 /* XXX should check all items in the chain */
1466 if (res0->ai_family == AF_INET6 &&
1467 IN6_IS_ADDR_V4MAPPED(&((struct sockaddr_in6 *)res0->ai_addr)->sin6_addr)) {
1468 freeaddrinfo(res0);
1469 goto again;
1470 }
1471#endif
1472 for (res = res0; res; res = res->ai_next) {
1473 /* cover it up */
1474 res->ai_flags = pai->ai_flags;
1475
1476 if (pai->ai_flags & AI_CANONNAME) {
1477 if (get_canonname(pai, res, cname) != 0) {
1478 freeaddrinfo(res0);
1479 goto again;
1480 }
1481 }
1482 }
1483 return res0;
1484}
1485
1486/*ARGSUSED*/
1487static int
1488_files_getaddrinfo(rv, cb_data, ap)
1489 void *rv;
1490 void *cb_data;
1491 va_list ap;
1492{
1493 const char *name;
1494 const struct addrinfo *pai;
1495 struct addrinfo sentinel, *cur;
1496 struct addrinfo *p;
1497
1498 name = va_arg(ap, char *);
1499 pai = va_arg(ap, struct addrinfo *);
1500
1501 memset(&sentinel, 0, sizeof(sentinel));
1502 cur = &sentinel;
1503
1504 _sethtent();
1505 while ((p = _gethtent(name, pai)) != NULL) {
1506 cur->ai_next = p;
1507 while (cur && cur->ai_next)
1508 cur = cur->ai_next;
1509 }
1510 _endhtent();
1511
1512 *((struct addrinfo **)rv) = sentinel.ai_next;
1513 if (sentinel.ai_next == NULL)
1514 return NS_NOTFOUND;
1515 return NS_SUCCESS;
1516}
1517
1518#ifdef YP
1519static char *__ypdomain;
1520
1521/*ARGSUSED*/
1522static struct addrinfo *
1523_yphostent(line, pai)
1524 char *line;
1525 const struct addrinfo *pai;
1526{
1527 struct addrinfo sentinel, *cur;
1528 struct addrinfo hints, *res, *res0;
1529 int error;
1530 char *p = line;
1531 const char *addr, *canonname;
1532 char *nextline;
1533 char *cp;
1534
1535 addr = canonname = NULL;
1536
1537 memset(&sentinel, 0, sizeof(sentinel));
1538 cur = &sentinel;
1539
1540nextline:
1541 /* terminate line */
1542 cp = strchr(p, '\n');
1543 if (cp) {
1544 *cp++ = '\0';
1545 nextline = cp;
1546 } else
1547 nextline = NULL;
1548
1549 cp = strpbrk(p, " \t");
1550 if (cp == NULL) {
1551 if (canonname == NULL)
1552 return (NULL);
1553 else
1554 goto done;
1555 }
1556 *cp++ = '\0';
1557
1558 addr = p;
1559
1560 while (cp && *cp) {
1561 if (*cp == ' ' || *cp == '\t') {
1562 cp++;
1563 continue;
1564 }
1565 if (!canonname)
1566 canonname = cp;
1567 if ((cp = strpbrk(cp, " \t")) != NULL)
1568 *cp++ = '\0';
1569 }
1570
1571 hints = *pai;
1572 hints.ai_flags = AI_NUMERICHOST;
1573 error = getaddrinfo(addr, NULL, &hints, &res0);
1574 if (error == 0) {
1575 for (res = res0; res; res = res->ai_next) {
1576 /* cover it up */
1577 res->ai_flags = pai->ai_flags;
1578
1579 if (pai->ai_flags & AI_CANONNAME)
1580 (void)get_canonname(pai, res, canonname);
1581 }
1582 } else
1583 res0 = NULL;
1584 if (res0) {
1585 cur->ai_next = res0;
1586 while (cur && cur->ai_next)
1587 cur = cur->ai_next;
1588 }
1589
1590 if (nextline) {
1591 p = nextline;
1592 goto nextline;
1593 }
1594
1595done:
1596 return sentinel.ai_next;
1597}
1598
1599/*ARGSUSED*/
1600static int
1601_yp_getaddrinfo(rv, cb_data, ap)
1602 void *rv;
1603 void *cb_data;
1604 va_list ap;
1605{
1606 struct addrinfo sentinel, *cur;
1607 struct addrinfo *ai = NULL;
1608 static char *__ypcurrent;
1609 int __ypcurrentlen, r;
1610 const char *name;
1611 const struct addrinfo *pai;
1612
1613 name = va_arg(ap, char *);
1614 pai = va_arg(ap, const struct addrinfo *);
1615
1616 memset(&sentinel, 0, sizeof(sentinel));
1617 cur = &sentinel;
1618
1619 if (!__ypdomain) {
1620 if (_yp_check(&__ypdomain) == 0)
1621 return NS_UNAVAIL;
1622 }
1623 if (__ypcurrent)
1624 free(__ypcurrent);
1625 __ypcurrent = NULL;
1626
1627 /* hosts.byname is only for IPv4 (Solaris8) */
1628 if (pai->ai_family == PF_UNSPEC || pai->ai_family == PF_INET) {
1629 r = yp_match(__ypdomain, "hosts.byname", name,
1630 (int)strlen(name), &__ypcurrent, &__ypcurrentlen);
1631 if (r == 0) {
1632 struct addrinfo ai4;
1633
1634 ai4 = *pai;
1635 ai4.ai_family = AF_INET;
1636 ai = _yphostent(__ypcurrent, &ai4);
1637 if (ai) {
1638 cur->ai_next = ai;
1639 while (cur && cur->ai_next)
1640 cur = cur->ai_next;
1641 }
1642 }
1643 }
1644
1645 /* ipnodes.byname can hold both IPv4/v6 */
1646 r = yp_match(__ypdomain, "ipnodes.byname", name,
1647 (int)strlen(name), &__ypcurrent, &__ypcurrentlen);
1648 if (r == 0) {
1649 ai = _yphostent(__ypcurrent, pai);
1650 if (ai) {
1651 cur->ai_next = ai;
1652 while (cur && cur->ai_next)
1653 cur = cur->ai_next;
1654 }
1655 }
1656
1657 if (sentinel.ai_next == NULL) {
1658 h_errno = HOST_NOT_FOUND;
1659 return NS_NOTFOUND;
1660 }
1661 *((struct addrinfo **)rv) = sentinel.ai_next;
1662 return NS_SUCCESS;
1663}
1664#endif
1665
1666/* resolver logic */
1667
1668extern const char *__hostalias __P((const char *));
1669extern int h_errno;
1670
1671/*
1672 * Formulate a normal query, send, and await answer.
1673 * Returned answer is placed in supplied buffer "answer".
1674 * Perform preliminary check of answer, returning success only
1675 * if no error is indicated and the answer count is nonzero.
1676 * Return the size of the response on success, -1 on error.
1677 * Error number is left in h_errno.
1678 *
1679 * Caller must parse answer and determine whether it answers the question.
1680 */
1681static int
1682res_queryN(name, target)
1683 const char *name; /* domain name */
1684 struct res_target *target;
1685{
1686 u_char buf[MAXPACKET];
1687 HEADER *hp;
1688 int n;
1689 struct res_target *t;
1690 int rcode;
1691 int ancount;
1692
1693 rcode = NOERROR;
1694 ancount = 0;
1695
1696 if ((_res.options & RES_INIT) == 0 && res_init() == -1) {
1697 h_errno = NETDB_INTERNAL;
1698 return (-1);
1699 }
1700
1701 for (t = target; t; t = t->next) {
1702 int class, type;
1703 u_char *answer;
1704 int anslen;
1705
1706 hp = (HEADER *)(void *)t->answer;
1707 hp->rcode = NOERROR; /* default */
1708
1709 /* make it easier... */
1710 class = t->qclass;
1711 type = t->qtype;
1712 answer = t->answer;
1713 anslen = t->anslen;
1714#ifdef DEBUG
1715 if (_res.options & RES_DEBUG)
1716 printf(";; res_query(%s, %d, %d)\n", name, class, type);
1717#endif
1718
1719 n = res_mkquery(QUERY, name, class, type, NULL, 0, NULL,
1720 buf, sizeof(buf));
1721 if (n <= 0) {
1722#ifdef DEBUG
1723 if (_res.options & RES_DEBUG)
1724 printf(";; res_query: mkquery failed\n");
1725#endif
1726 h_errno = NO_RECOVERY;
1727 return (n);
1728 }
1729 n = res_send(buf, n, answer, anslen);
1730#if 0
1731 if (n < 0) {
1732#ifdef DEBUG
1733 if (_res.options & RES_DEBUG)
1734 printf(";; res_query: send error\n");
1735#endif
1736 h_errno = TRY_AGAIN;
1737 return (n);
1738 }
1739#endif
1740
1741 if (n < 0 || hp->rcode != NOERROR || ntohs(hp->ancount) == 0) {
1742 rcode = hp->rcode; /* record most recent error */
1743#ifdef DEBUG
1744 if (_res.options & RES_DEBUG)
1745 printf(";; rcode = %d, ancount=%d\n", hp->rcode,
1746 ntohs(hp->ancount));
1747#endif
1748 continue;
1749 }
1750
1751 ancount += ntohs(hp->ancount);
1752
1753 t->n = n;
1754 }
1755
1756 if (ancount == 0) {
1757 switch (rcode) {
1758 case NXDOMAIN:
1759 h_errno = HOST_NOT_FOUND;
1760 break;
1761 case SERVFAIL:
1762 h_errno = TRY_AGAIN;
1763 break;
1764 case NOERROR:
1765 h_errno = NO_DATA;
1766 break;
1767 case FORMERR:
1768 case NOTIMP:
1769 case REFUSED:
1770 default:
1771 h_errno = NO_RECOVERY;
1772 break;
1773 }
1774 return (-1);
1775 }
1776 return (ancount);
1777}
1778
1779/*
1780 * Formulate a normal query, send, and retrieve answer in supplied buffer.
1781 * Return the size of the response on success, -1 on error.
1782 * If enabled, implement search rules until answer or unrecoverable failure
1783 * is detected. Error code, if any, is left in h_errno.
1784 */
1785static int
1786res_searchN(name, target)
1787 const char *name; /* domain name */
1788 struct res_target *target;
1789{
1790 const char *cp, * const *domain;
1791 HEADER *hp = (HEADER *)(void *)target->answer; /*XXX*/
1792 u_int dots;
1793 int trailing_dot, ret, saved_herrno;
1794 int got_nodata = 0, got_servfail = 0, tried_as_is = 0;
1795
1796 if ((_res.options & RES_INIT) == 0 && res_init() == -1) {
1797 h_errno = NETDB_INTERNAL;
1798 return (-1);
1799 }
1800
1801 errno = 0;
1802 h_errno = HOST_NOT_FOUND; /* default, if we never query */
1803 dots = 0;
1804 for (cp = name; *cp; cp++)
1805 dots += (*cp == '.');
1806 trailing_dot = 0;
1807 if (cp > name && *--cp == '.')
1808 trailing_dot++;
1809
1810 /*
1811 * if there aren't any dots, it could be a user-level alias
1812 */
1813 if (!dots && (cp = __hostalias(name)) != NULL)
1814 return (res_queryN(cp, target));
1815
1816 /*
1817 * If there are dots in the name already, let's just give it a try
1818 * 'as is'. The threshold can be set with the "ndots" option.
1819 */
1820 saved_herrno = -1;
1821 if (dots >= _res.ndots) {
1822 ret = res_querydomainN(name, NULL, target);
1823 if (ret > 0)
1824 return (ret);
1825 saved_herrno = h_errno;
1826 tried_as_is++;
1827 }
1828
1829 /*
1830 * We do at least one level of search if
1831 * - there is no dot and RES_DEFNAME is set, or
1832 * - there is at least one dot, there is no trailing dot,
1833 * and RES_DNSRCH is set.
1834 */
1835 if ((!dots && (_res.options & RES_DEFNAMES)) ||
1836 (dots && !trailing_dot && (_res.options & RES_DNSRCH))) {
1837 int done = 0;
1838
1839 for (domain = (const char * const *)_res.dnsrch;
1840 *domain && !done;
1841 domain++) {
1842
1843 ret = res_querydomainN(name, *domain, target);
1844 if (ret > 0)
1845 return (ret);
1846
1847 /*
1848 * If no server present, give up.
1849 * If name isn't found in this domain,
1850 * keep trying higher domains in the search list
1851 * (if that's enabled).
1852 * On a NO_DATA error, keep trying, otherwise
1853 * a wildcard entry of another type could keep us
1854 * from finding this entry higher in the domain.
1855 * If we get some other error (negative answer or
1856 * server failure), then stop searching up,
1857 * but try the input name below in case it's
1858 * fully-qualified.
1859 */
1860 if (errno == ECONNREFUSED) {
1861 h_errno = TRY_AGAIN;
1862 return (-1);
1863 }
1864
1865 switch (h_errno) {
1866 case NO_DATA:
1867 got_nodata++;
1868 /* FALLTHROUGH */
1869 case HOST_NOT_FOUND:
1870 /* keep trying */
1871 break;
1872 case TRY_AGAIN:
1873 if (hp->rcode == SERVFAIL) {
1874 /* try next search element, if any */
1875 got_servfail++;
1876 break;
1877 }
1878 /* FALLTHROUGH */
1879 default:
1880 /* anything else implies that we're done */
1881 done++;
1882 }
1883 /*
1884 * if we got here for some reason other than DNSRCH,
1885 * we only wanted one iteration of the loop, so stop.
1886 */
1887 if (!(_res.options & RES_DNSRCH))
1888 done++;
1889 }
1890 }
1891
1892 /*
1893 * if we have not already tried the name "as is", do that now.
1894 * note that we do this regardless of how many dots were in the
1895 * name or whether it ends with a dot.
1896 */
1897 if (!tried_as_is && (dots || !(_res.options & RES_NOTLDQUERY))) {
1898 ret = res_querydomainN(name, NULL, target);
1899 if (ret > 0)
1900 return (ret);
1901 }
1902
1903 /*
1904 * if we got here, we didn't satisfy the search.
1905 * if we did an initial full query, return that query's h_errno
1906 * (note that we wouldn't be here if that query had succeeded).
1907 * else if we ever got a nodata, send that back as the reason.
1908 * else send back meaningless h_errno, that being the one from
1909 * the last DNSRCH we did.
1910 */
1911 if (saved_herrno != -1)
1912 h_errno = saved_herrno;
1913 else if (got_nodata)
1914 h_errno = NO_DATA;
1915 else if (got_servfail)
1916 h_errno = TRY_AGAIN;
1917 return (-1);
1918}
1919
1920/*
1921 * Perform a call on res_query on the concatenation of name and domain,
1922 * removing a trailing dot from name if domain is NULL.
1923 */
1924static int
1925res_querydomainN(name, domain, target)
1926 const char *name, *domain;
1927 struct res_target *target;
1928{
1929 char nbuf[MAXDNAME];
1930 const char *longname = nbuf;
1931 size_t n, d;
1932
1933 if ((_res.options & RES_INIT) == 0 && res_init() == -1) {
1934 h_errno = NETDB_INTERNAL;
1935 return (-1);
1936 }
1937#ifdef DEBUG
1938 if (_res.options & RES_DEBUG)
1939 printf(";; res_querydomain(%s, %s)\n",
1940 name, domain?domain:"<Nil>");
1941#endif
1942 if (domain == NULL) {
1943 /*
1944 * Check for trailing '.';
1945 * copy without '.' if present.
1946 */
1947 n = strlen(name);
1948 if (n >= MAXDNAME) {
1949 h_errno = NO_RECOVERY;
1950 return (-1);
1951 }
1952 if (n > 0 && name[--n] == '.') {
1953 strncpy(nbuf, name, n);
1954 nbuf[n] = '\0';
1955 } else
1956 longname = name;
1957 } else {
1958 n = strlen(name);
1959 d = strlen(domain);
1960 if (n + d + 1 >= MAXDNAME) {
1961 h_errno = NO_RECOVERY;
1962 return (-1);
1963 }
1964 sprintf(nbuf, "%s.%s", name, domain);
1965 }
1966 return (res_queryN(longname, target));
1967}