1/* $FreeBSD: head/lib/libc/net/getaddrinfo.c 78012 2001-06-10 20:25:24Z 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 * - some of FreeBSD style (#define tabify and others)
83 * - classful IPv4 numeric (127.1) is allowed.
84 */
85
86#include "namespace.h"
87#include <sys/types.h>
88#include <sys/param.h>
89#include <sys/socket.h>
90#include <net/if.h>
91#include <netinet/in.h>
92#include <arpa/inet.h>
93#include <arpa/nameser.h>
94#include <netdb.h>
95#include <resolv.h>
96#include <string.h>
97#include <stdlib.h>
98#include <stddef.h>
99#include <ctype.h>
100#include <unistd.h>
101#include <stdio.h>
102#include <errno.h>
103#ifdef DEBUG
104#include <syslog.h>
105#endif
106
107#include <syslog.h>
108#include <stdarg.h>
109#include <nsswitch.h>
110#include "un-namespace.h"
111
112#if defined(__KAME__) && defined(INET6)
113# define FAITH
114#endif
115
116#define SUCCESS 0
117#define ANY 0
118#define YES 1
119#define NO 0
120
121static const char in_addrany[] = { 0, 0, 0, 0 };
122static const char in6_addrany[] = {
123 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
124};
125static const char in_loopback[] = { 127, 0, 0, 1 };
126static const char in6_loopback[] = {
127 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1
128};
129
130static const struct afd {
131 int a_af;
132 int a_addrlen;
133 int a_socklen;
134 int a_off;
135 const char *a_addrany;
136 const char *a_loopback;
137 int a_scoped;
138} afdl [] = {
139#ifdef INET6
140#define N_INET6 0
141 {PF_INET6, sizeof(struct in6_addr),
142 sizeof(struct sockaddr_in6),
143 offsetof(struct sockaddr_in6, sin6_addr),
144 in6_addrany, in6_loopback, 1},
145#define N_INET 1
146#else
147#define N_INET 0
148#endif
149 {PF_INET, sizeof(struct in_addr),
150 sizeof(struct sockaddr_in),
151 offsetof(struct sockaddr_in, sin_addr),
152 in_addrany, in_loopback, 0},
153 {0, 0, 0, 0, NULL, NULL, 0},
154};
155
156struct explore {
157 int e_af;
158 int e_socktype;
159 int e_protocol;
160 const char *e_protostr;
161 int e_wild;
162#define WILD_AF(ex) ((ex)->e_wild & 0x01)
163#define WILD_SOCKTYPE(ex) ((ex)->e_wild & 0x02)
164#define WILD_PROTOCOL(ex) ((ex)->e_wild & 0x04)
165};
166
167static const struct explore explore[] = {
168#if 0
169 { PF_LOCAL, 0, ANY, ANY, NULL, 0x01 },
170#endif
171#ifdef INET6
172 { PF_INET6, SOCK_DGRAM, IPPROTO_UDP, "udp", 0x07 },
173 { PF_INET6, SOCK_STREAM, IPPROTO_TCP, "tcp", 0x07 },
174 { PF_INET6, SOCK_RAW, ANY, NULL, 0x05 },
175#endif
176 { PF_INET, SOCK_DGRAM, IPPROTO_UDP, "udp", 0x07 },
177 { PF_INET, SOCK_STREAM, IPPROTO_TCP, "tcp", 0x07 },
178 { PF_INET, SOCK_RAW, ANY, NULL, 0x05 },
179 { PF_UNSPEC, SOCK_DGRAM, IPPROTO_UDP, "udp", 0x07 },
180 { PF_UNSPEC, SOCK_STREAM, IPPROTO_TCP, "tcp", 0x07 },
181 { PF_UNSPEC, SOCK_RAW, ANY, NULL, 0x05 },
182 { -1, 0, 0, NULL, 0 },
183};
184
185#ifdef INET6
186#define PTON_MAX 16
187#else
188#define PTON_MAX 4
189#endif
190
191static const ns_src default_dns_files[] = {
192 { NSSRC_FILES, NS_SUCCESS },
193 { NSSRC_DNS, NS_SUCCESS },
194 { 0 }
195};
196
197#if PACKETSZ > 1024
198#define MAXPACKET PACKETSZ
199#else
200#define MAXPACKET 1024
201#endif
202
203typedef union {
204 HEADER hdr;
205 u_char buf[MAXPACKET];
206} querybuf;
207
208struct res_target {
209 struct res_target *next;
210 const char *name; /* domain name */
211 int qclass, qtype; /* class and type of query */
212 u_char *answer; /* buffer to put answer */
213 int anslen; /* size of answer buffer */
214 int n; /* result length */
215};
216
217static int str_isnumber __P((const char *));
218static int explore_fqdn __P((const struct addrinfo *, const char *,
219 const char *, struct addrinfo **));
220static int explore_null __P((const struct addrinfo *,
221 const char *, struct addrinfo **));
222static int explore_numeric __P((const struct addrinfo *, const char *,
223 const char *, struct addrinfo **));
224static int explore_numeric_scope __P((const struct addrinfo *, const char *,
225 const char *, struct addrinfo **));
226static int get_canonname __P((const struct addrinfo *,
227 struct addrinfo *, const char *));
228static struct addrinfo *get_ai __P((const struct addrinfo *,
229 const struct afd *, const char *));
230static int get_portmatch __P((const struct addrinfo *, const char *));
231static int get_port __P((struct addrinfo *, const char *, int));
232static const struct afd *find_afd __P((int));
233static int addrconfig __P((struct addrinfo *));
234#ifdef INET6
235static int ip6_str2scopeid __P((char *, struct sockaddr_in6 *));
236#endif
237
238static struct addrinfo *getanswer __P((const querybuf *, int, const char *, int,
239 const struct addrinfo *));
240static int _dns_getaddrinfo __P((void *, void *, va_list));
241static void _sethtent __P((void));
242static void _endhtent __P((void));
243static struct addrinfo *_gethtent __P((const char *, const struct addrinfo *));
244static int _files_getaddrinfo __P((void *, void *, va_list));
245#ifdef YP
246static struct addrinfo *_yphostent __P((char *, const struct addrinfo *));
247static int _yp_getaddrinfo __P((void *, void *, va_list));
248#endif
249
250static int res_queryN __P((const char *, struct res_target *));
251static int res_searchN __P((const char *, struct res_target *));
252static int res_querydomainN __P((const char *, const char *,
253 struct res_target *));
254
255static char *ai_errlist[] = {
256 "Success",
257 "Address family for hostname not supported", /* EAI_ADDRFAMILY */
258 "Temporary failure in name resolution", /* EAI_AGAIN */
259 "Invalid value for ai_flags", /* EAI_BADFLAGS */
260 "Non-recoverable failure in name resolution", /* EAI_FAIL */
261 "ai_family not supported", /* EAI_FAMILY */
262 "Memory allocation failure", /* EAI_MEMORY */
263 "No address associated with hostname", /* EAI_NODATA */
264 "hostname nor servname provided, or not known", /* EAI_NONAME */
265 "servname not supported for ai_socktype", /* EAI_SERVICE */
266 "ai_socktype not supported", /* EAI_SOCKTYPE */
267 "System error returned in errno", /* EAI_SYSTEM */
268 "Invalid value for hints", /* EAI_BADHINTS */
269 "Resolved protocol is unknown", /* EAI_PROTOCOL */
270 "Unknown error", /* EAI_MAX */
271};
272
273/* XXX macros that make external reference is BAD. */
274
275#define GET_AI(ai, afd, addr) \
276do { \
277 /* external reference: pai, error, and label free */ \
278 (ai) = get_ai(pai, (afd), (addr)); \
279 if ((ai) == NULL) { \
280 error = EAI_MEMORY; \
281 goto free; \
282 } \
283} while (/*CONSTCOND*/0)
284
285#define GET_PORT(ai, serv) \
286do { \
287 /* external reference: error and label free */ \
288 error = get_port((ai), (serv), 0); \
289 if (error != 0) \
290 goto free; \
291} while (/*CONSTCOND*/0)
292
293#define GET_CANONNAME(ai, str) \
294do { \
295 /* external reference: pai, error and label free */ \
296 error = get_canonname(pai, (ai), (str)); \
297 if (error != 0) \
298 goto free; \
299} while (/*CONSTCOND*/0)
300
301#define ERR(err) \
302do { \
303 /* external reference: error, and label bad */ \
304 error = (err); \
305 goto bad; \
306 /*NOTREACHED*/ \
307} while (/*CONSTCOND*/0)
308
309#define MATCH_FAMILY(x, y, w) \
310 ((x) == (y) || (/*CONSTCOND*/(w) && ((x) == PF_UNSPEC || (y) == PF_UNSPEC)))
311#define MATCH(x, y, w) \
312 ((x) == (y) || (/*CONSTCOND*/(w) && ((x) == ANY || (y) == ANY)))
313
314char *
315gai_strerror(ecode)
316 int ecode;
317{
318 if (ecode < 0 || ecode > EAI_MAX)
319 ecode = EAI_MAX;
320 return ai_errlist[ecode];
321}
322
323void
324freeaddrinfo(ai)
325 struct addrinfo *ai;
326{
327 struct addrinfo *next;
328
329 do {
330 next = ai->ai_next;
331 if (ai->ai_canonname)
332 free(ai->ai_canonname);
333 /* no need to free(ai->ai_addr) */
334 free(ai);
335 ai = next;
336 } while (ai);
337}
338
339static int
340str_isnumber(p)
341 const char *p;
342{
343 char *ep;
344
345 if (*p == '\0')
346 return NO;
347 ep = NULL;
348 (void)strtoul(p, &ep, 10);
349 if (ep && *ep == '\0')
350 return YES;
351 else
352 return NO;
353}
354
355int
356getaddrinfo(hostname, servname, hints, res)
357 const char *hostname, *servname;
358 const struct addrinfo *hints;
359 struct addrinfo **res;
360{
361 struct addrinfo sentinel;
362 struct addrinfo *cur;
363 int error = 0;
364 struct addrinfo ai;
365 struct addrinfo ai0;
366 struct addrinfo *pai;
367 const struct explore *ex;
368
369 memset(&sentinel, 0, sizeof(sentinel));
370 cur = &sentinel;
371 pai = &ai;
372 pai->ai_flags = 0;
373 pai->ai_family = PF_UNSPEC;
374 pai->ai_socktype = ANY;
375 pai->ai_protocol = ANY;
376 pai->ai_addrlen = 0;
377 pai->ai_canonname = NULL;
378 pai->ai_addr = NULL;
379 pai->ai_next = NULL;
380
381 if (hostname == NULL && servname == NULL)
382 return EAI_NONAME;
383 if (hints) {
384 /* error check for hints */
385 if (hints->ai_addrlen || hints->ai_canonname ||
386 hints->ai_addr || hints->ai_next)
387 ERR(EAI_BADHINTS); /* xxx */
388 if (hints->ai_flags & ~AI_MASK)
389 ERR(EAI_BADFLAGS);
390 switch (hints->ai_family) {
391 case PF_UNSPEC:
392 case PF_INET:
393#ifdef INET6
394 case PF_INET6:
395#endif
396 break;
397 default:
398 ERR(EAI_FAMILY);
399 }
400 memcpy(pai, hints, sizeof(*pai));
401
402 /*
403 * if both socktype/protocol are specified, check if they
404 * are meaningful combination.
405 */
406 if (pai->ai_socktype != ANY && pai->ai_protocol != ANY) {
407 for (ex = explore; ex->e_af >= 0; ex++) {
408 if (pai->ai_family != ex->e_af)
409 continue;
410 if (ex->e_socktype == ANY)
411 continue;
412 if (ex->e_protocol == ANY)
413 continue;
414 if (pai->ai_socktype == ex->e_socktype
415 && pai->ai_protocol != ex->e_protocol) {
416 ERR(EAI_BADHINTS);
417 }
418 }
419 }
420 }
421
422 /*
423 * post-2553: AI_ALL and AI_V4MAPPED are effective only against
424 * AF_INET6 query. They needs to be ignored if specified in other
425 * occassions.
426 */
427 switch (pai->ai_flags & (AI_ALL | AI_V4MAPPED)) {
428 case AI_V4MAPPED:
429 case AI_ALL | AI_V4MAPPED:
430 if (pai->ai_family != AF_INET6)
431 pai->ai_flags &= ~(AI_ALL | AI_V4MAPPED);
432 break;
433 case AI_ALL:
434#if 1
435 /* illegal */
436 ERR(EAI_BADFLAGS);
437#else
438 pai->ai_flags &= ~(AI_ALL | AI_V4MAPPED);
439#endif
440 break;
441 }
442
443 /*
444 * check for special cases. (1) numeric servname is disallowed if
445 * socktype/protocol are left unspecified. (2) servname is disallowed
446 * for raw and other inet{,6} sockets.
447 */
448 if (MATCH_FAMILY(pai->ai_family, PF_INET, 1)
449#ifdef PF_INET6
450 || MATCH_FAMILY(pai->ai_family, PF_INET6, 1)
451#endif
452 ) {
453 ai0 = *pai; /* backup *pai */
454
455 if (pai->ai_family == PF_UNSPEC) {
456#ifdef PF_INET6
457 pai->ai_family = PF_INET6;
458#else
459 pai->ai_family = PF_INET;
460#endif
461 }
462 error = get_portmatch(pai, servname);
463 if (error)
464 ERR(error);
465
466 *pai = ai0;
467 }
468
469 ai0 = *pai;
470
471 /* NULL hostname, or numeric hostname */
472 for (ex = explore; ex->e_af >= 0; ex++) {
473 *pai = ai0;
474
475 /* PF_UNSPEC entries are prepared for DNS queries only */
476 if (ex->e_af == PF_UNSPEC)
477 continue;
478
479 if (!MATCH_FAMILY(pai->ai_family, ex->e_af, WILD_AF(ex)))
480 continue;
481 if (!MATCH(pai->ai_socktype, ex->e_socktype, WILD_SOCKTYPE(ex)))
482 continue;
483 if (!MATCH(pai->ai_protocol, ex->e_protocol, WILD_PROTOCOL(ex)))
484 continue;
485
486 if (pai->ai_family == PF_UNSPEC)
487 pai->ai_family = ex->e_af;
488 if (pai->ai_socktype == ANY && ex->e_socktype != ANY)
489 pai->ai_socktype = ex->e_socktype;
490 if (pai->ai_protocol == ANY && ex->e_protocol != ANY)
491 pai->ai_protocol = ex->e_protocol;
492
493 if (hostname == NULL)
494 error = explore_null(pai, servname, &cur->ai_next);
495 else
496 error = explore_numeric_scope(pai, hostname, servname, &cur->ai_next);
497
498 if (error)
499 goto free;
500
501 while (cur && cur->ai_next)
502 cur = cur->ai_next;
503 }
504
505 /*
506 * XXX
507 * If numreic representation of AF1 can be interpreted as FQDN
508 * representation of AF2, we need to think again about the code below.
509 */
510 if (sentinel.ai_next)
511 goto good;
512
513 if (pai->ai_flags & AI_NUMERICHOST)
514 ERR(EAI_NODATA);
515 if (hostname == NULL)
516 ERR(EAI_NODATA);
517
518 if ((pai->ai_flags & AI_ADDRCONFIG) != 0 && !addrconfig(&ai0))
519 ERR(EAI_FAIL);
520
521 /*
522 * hostname as alphabetical name.
523 * we would like to prefer AF_INET6 than AF_INET, so we'll make a
524 * outer loop by AFs.
525 */
526 for (ex = explore; ex->e_af >= 0; ex++) {
527 *pai = ai0;
528
529 /* require exact match for family field */
530 if (pai->ai_family != ex->e_af)
531 continue;
532
533 if (!MATCH(pai->ai_socktype, ex->e_socktype,
534 WILD_SOCKTYPE(ex))) {
535 continue;
536 }
537 if (!MATCH(pai->ai_protocol, ex->e_protocol,
538 WILD_PROTOCOL(ex))) {
539 continue;
540 }
541
542 if (pai->ai_socktype == ANY && ex->e_socktype != ANY)
543 pai->ai_socktype = ex->e_socktype;
544 if (pai->ai_protocol == ANY && ex->e_protocol != ANY)
545 pai->ai_protocol = ex->e_protocol;
546
547 error = explore_fqdn(pai, hostname, servname,
548 &cur->ai_next);
549
550 while (cur && cur->ai_next)
551 cur = cur->ai_next;
552 }
553
554 /* XXX */
555 if (sentinel.ai_next)
556 error = 0;
557
558 if (error)
559 goto free;
560 if (error == 0) {
561 if (sentinel.ai_next) {
562 good:
563 *res = sentinel.ai_next;
564 return SUCCESS;
565 } else
566 error = EAI_FAIL;
567 }
568 free:
569 bad:
570 if (sentinel.ai_next)
571 freeaddrinfo(sentinel.ai_next);
572 *res = NULL;
573 return error;
574}
575
576/*
577 * FQDN hostname, DNS lookup
578 */
579static int
580explore_fqdn(pai, hostname, servname, res)
581 const struct addrinfo *pai;
582 const char *hostname;
583 const char *servname;
584 struct addrinfo **res;
585{
586 struct addrinfo *result;
587 struct addrinfo *cur;
588 int error = 0;
589 static const ns_dtab dtab[] = {
590 NS_FILES_CB(_files_getaddrinfo, NULL)
591 { NSSRC_DNS, _dns_getaddrinfo, NULL }, /* force -DHESIOD */
592 NS_NIS_CB(_yp_getaddrinfo, NULL)
593 { 0 }
594 };
595
596 result = NULL;
597
598 /*
599 * if the servname does not match socktype/protocol, ignore it.
600 */
601 if (get_portmatch(pai, servname) != 0)
602 return 0;
603
604 switch (nsdispatch(&result, dtab, NSDB_HOSTS, "getaddrinfo",
605 default_dns_files, hostname, pai)) {
606 case NS_TRYAGAIN:
607 error = EAI_AGAIN;
608 goto free;
609 case NS_UNAVAIL:
610 error = EAI_FAIL;
611 goto free;
612 case NS_NOTFOUND:
613 error = EAI_NODATA;
614 goto free;
615 case NS_SUCCESS:
616 error = 0;
617 for (cur = result; cur; cur = cur->ai_next) {
618 GET_PORT(cur, servname);
619 /* canonname should be filled already */
620 }
621 break;
622 }
623
624 *res = result;
625
626 return 0;
627
628free:
629 if (result)
630 freeaddrinfo(result);
631 return error;
632}
633
634/*
635 * hostname == NULL.
636 * passive socket -> anyaddr (0.0.0.0 or ::)
637 * non-passive socket -> localhost (127.0.0.1 or ::1)
638 */
639static int
640explore_null(pai, servname, res)
641 const struct addrinfo *pai;
642 const char *servname;
643 struct addrinfo **res;
644{
645 int s;
646 const struct afd *afd;
647 struct addrinfo *cur;
648 struct addrinfo sentinel;
649 int error;
650
651 *res = NULL;
652 sentinel.ai_next = NULL;
653 cur = &sentinel;
654
655 /*
656 * filter out AFs that are not supported by the kernel
657 * XXX errno?
658 */
659 s = _socket(pai->ai_family, SOCK_DGRAM, 0);
660 if (s < 0) {
661 if (errno != EMFILE)
662 return 0;
663 } else
664 _close(s);
665
666 /*
667 * if the servname does not match socktype/protocol, ignore it.
668 */
669 if (get_portmatch(pai, servname) != 0)
670 return 0;
671
672 afd = find_afd(pai->ai_family);
673 if (afd == NULL)
674 return 0;
675
676 if (pai->ai_flags & AI_PASSIVE) {
677 GET_AI(cur->ai_next, afd, afd->a_addrany);
678 /* xxx meaningless?
679 * GET_CANONNAME(cur->ai_next, "anyaddr");
680 */
681 GET_PORT(cur->ai_next, servname);
682 } else {
683 GET_AI(cur->ai_next, afd, afd->a_loopback);
684 /* xxx meaningless?
685 * GET_CANONNAME(cur->ai_next, "localhost");
686 */
687 GET_PORT(cur->ai_next, servname);
688 }
689 cur = cur->ai_next;
690
691 *res = sentinel.ai_next;
692 return 0;
693
694free:
695 if (sentinel.ai_next)
696 freeaddrinfo(sentinel.ai_next);
697 return error;
698}
699
700/*
701 * numeric hostname
702 */
703static int
704explore_numeric(pai, hostname, servname, res)
705 const struct addrinfo *pai;
706 const char *hostname;
707 const char *servname;
708 struct addrinfo **res;
709{
710 const struct afd *afd;
711 struct addrinfo *cur;
712 struct addrinfo sentinel;
713 int error;
714 char pton[PTON_MAX];
715
716 *res = NULL;
717 sentinel.ai_next = NULL;
718 cur = &sentinel;
719
720 /*
721 * if the servname does not match socktype/protocol, ignore it.
722 */
723 if (get_portmatch(pai, servname) != 0)
724 return 0;
725
726 afd = find_afd(pai->ai_family);
727 if (afd == NULL)
728 return 0;
729
730 switch (afd->a_af) {
731#if 1 /*X/Open spec*/
732 case AF_INET:
733 if (inet_aton(hostname, (struct in_addr *)pton) == 1) {
734 if (pai->ai_family == afd->a_af ||
735 pai->ai_family == PF_UNSPEC /*?*/) {
736 GET_AI(cur->ai_next, afd, pton);
737 GET_PORT(cur->ai_next, servname);
738 while (cur && cur->ai_next)
739 cur = cur->ai_next;
740 } else
741 ERR(EAI_FAMILY); /*xxx*/
742 }
743 break;
744#endif
745 default:
746 if (inet_pton(afd->a_af, hostname, pton) == 1) {
747 if (pai->ai_family == afd->a_af ||
748 pai->ai_family == PF_UNSPEC /*?*/) {
749 GET_AI(cur->ai_next, afd, pton);
750 GET_PORT(cur->ai_next, servname);
751 while (cur && cur->ai_next)
752 cur = cur->ai_next;
753 } else
754 ERR(EAI_FAMILY); /*xxx*/
755 }
756 break;
757 }
758
759 *res = sentinel.ai_next;
760 return 0;
761
762free:
763bad:
764 if (sentinel.ai_next)
765 freeaddrinfo(sentinel.ai_next);
766 return error;
767}
768
769/*
770 * numeric hostname with scope
771 */
772static int
773explore_numeric_scope(pai, hostname, servname, res)
774 const struct addrinfo *pai;
775 const char *hostname;
776 const char *servname;
777 struct addrinfo **res;
778{
779#if !defined(SCOPE_DELIMITER) || !defined(INET6)
780 return explore_numeric(pai, hostname, servname, res);
781#else
782 const struct afd *afd;
783 struct addrinfo *cur;
784 int error;
785 char *cp, *hostname2 = NULL, *scope, *addr;
786 struct sockaddr_in6 *sin6;
787
788 /*
789 * if the servname does not match socktype/protocol, ignore it.
790 */
791 if (get_portmatch(pai, servname) != 0)
792 return 0;
793
794 afd = find_afd(pai->ai_family);
795 if (afd == NULL)
796 return 0;
797
798 if (!afd->a_scoped)
799 return explore_numeric(pai, hostname, servname, res);
800
801 cp = strchr(hostname, SCOPE_DELIMITER);
802 if (cp == NULL)
803 return explore_numeric(pai, hostname, servname, res);
804
805 /*
806 * Handle special case of <scoped_address><delimiter><scope id>
807 */
808 hostname2 = strdup(hostname);
809 if (hostname2 == NULL)
810 return EAI_MEMORY;
811 /* terminate at the delimiter */
812 hostname2[cp - hostname] = '\0';
813 addr = hostname2;
814 scope = cp + 1;
815
816 error = explore_numeric(pai, addr, servname, res);
817 if (error == 0) {
818 int scopeid;
819
820 for (cur = *res; cur; cur = cur->ai_next) {
821 if (cur->ai_family != AF_INET6)
822 continue;
823 sin6 = (struct sockaddr_in6 *)(void *)cur->ai_addr;
824 if ((scopeid = ip6_str2scopeid(scope, sin6)) == -1) {
825 free(hostname2);
826 return(EAI_NODATA); /* XXX: is return OK? */
827 }
828 sin6->sin6_scope_id = scopeid;
829 }
830 }
831
832 free(hostname2);
833
834 return error;
835#endif
836}
837
838static int
839get_canonname(pai, ai, str)
840 const struct addrinfo *pai;
841 struct addrinfo *ai;
842 const char *str;
843{
844 if ((pai->ai_flags & AI_CANONNAME) != 0) {
845 ai->ai_canonname = (char *)malloc(strlen(str) + 1);
846 if (ai->ai_canonname == NULL)
847 return EAI_MEMORY;
848 strcpy(ai->ai_canonname, str);
849 }
850 return 0;
851}
852
853static struct addrinfo *
854get_ai(pai, afd, addr)
855 const struct addrinfo *pai;
856 const struct afd *afd;
857 const char *addr;
858{
859 char *p;
860 struct addrinfo *ai;
861#ifdef FAITH
862 struct in6_addr faith_prefix;
863 char *fp_str;
864 int translate = 0;
865#endif
866
867#ifdef FAITH
868 /*
869 * Transfrom an IPv4 addr into a special IPv6 addr format for
870 * IPv6->IPv4 translation gateway. (only TCP is supported now)
871 *
872 * +-----------------------------------+------------+
873 * | faith prefix part (12 bytes) | embedded |
874 * | | IPv4 addr part (4 bytes)
875 * +-----------------------------------+------------+
876 *
877 * faith prefix part is specified as ascii IPv6 addr format
878 * in environmental variable GAI.
879 * For FAITH to work correctly, routing to faith prefix must be
880 * setup toward a machine where a FAITH daemon operates.
881 * Also, the machine must enable some mechanizm
882 * (e.g. faith interface hack) to divert those packet with
883 * faith prefixed destination addr to user-land FAITH daemon.
884 */
885 fp_str = getenv("GAI");
886 if (fp_str && inet_pton(AF_INET6, fp_str, &faith_prefix) == 1 &&
887 afd->a_af == AF_INET && pai->ai_socktype == SOCK_STREAM) {
888 u_int32_t v4a;
889 u_int8_t v4a_top;
890
891 memcpy(&v4a, addr, sizeof v4a);
892 v4a_top = v4a >> IN_CLASSA_NSHIFT;
893 if (!IN_MULTICAST(v4a) && !IN_EXPERIMENTAL(v4a) &&
894 v4a_top != 0 && v4a != IN_LOOPBACKNET) {
895 afd = &afdl[N_INET6];
896 memcpy(&faith_prefix.s6_addr[12], addr,
897 sizeof(struct in_addr));
898 translate = 1;
899 }
900 }
901#endif
902
903 ai = (struct addrinfo *)malloc(sizeof(struct addrinfo)
904 + (afd->a_socklen));
905 if (ai == NULL)
906 return NULL;
907
908 memcpy(ai, pai, sizeof(struct addrinfo));
909 ai->ai_addr = (struct sockaddr *)(void *)(ai + 1);
910 memset(ai->ai_addr, 0, (size_t)afd->a_socklen);
911 ai->ai_addr->sa_len = afd->a_socklen;
912 ai->ai_addrlen = afd->a_socklen;
913 ai->ai_addr->sa_family = ai->ai_family = afd->a_af;
914 p = (char *)(void *)(ai->ai_addr);
915#ifdef FAITH
916 if (translate == 1)
917 memcpy(p + afd->a_off, &faith_prefix, (size_t)afd->a_addrlen);
918 else
919#endif
920 memcpy(p + afd->a_off, addr, (size_t)afd->a_addrlen);
921 return ai;
922}
923
924static int
925get_portmatch(ai, servname)
926 const struct addrinfo *ai;
927 const char *servname;
928{
929
930 /* get_port does not touch first argument. when matchonly == 1. */
931 /* LINTED const cast */
932 return get_port((struct addrinfo *)ai, servname, 1);
933}
934
935static int
936get_port(ai, servname, matchonly)
937 struct addrinfo *ai;
938 const char *servname;
939 int matchonly;
940{
941 const char *proto;
942 struct servent *sp;
943 int port;
944 int allownumeric;
945
946 if (servname == NULL)
947 return 0;
948 switch (ai->ai_family) {
949 case AF_INET:
950#ifdef AF_INET6
951 case AF_INET6:
952#endif
953 break;
954 default:
955 return 0;
956 }
957
958 switch (ai->ai_socktype) {
959 case SOCK_RAW:
960 return EAI_SERVICE;
961 case SOCK_DGRAM:
962 case SOCK_STREAM:
963 allownumeric = 1;
964 break;
965 case ANY:
966 allownumeric = 0;
967 break;
968 default:
969 return EAI_SOCKTYPE;
970 }
971
972 if (str_isnumber(servname)) {
973 if (!allownumeric)
974 return EAI_SERVICE;
975 port = htons(atoi(servname));
976 if (port < 0 || port > 65535)
977 return EAI_SERVICE;
978 } else {
979 switch (ai->ai_socktype) {
980 case SOCK_DGRAM:
981 proto = "udp";
982 break;
983 case SOCK_STREAM:
984 proto = "tcp";
985 break;
986 default:
987 proto = NULL;
988 break;
989 }
990
991 if ((sp = getservbyname(servname, proto)) == NULL)
992 return EAI_SERVICE;
993 port = sp->s_port;
994 }
995
996 if (!matchonly) {
997 switch (ai->ai_family) {
998 case AF_INET:
999 ((struct sockaddr_in *)(void *)
1000 ai->ai_addr)->sin_port = port;
1001 break;
1002#ifdef INET6
1003 case AF_INET6:
1004 ((struct sockaddr_in6 *)(void *)
1005 ai->ai_addr)->sin6_port = port;
1006 break;
1007#endif
1008 }
1009 }
1010
1011 return 0;
1012}
1013
1014static const struct afd *
1015find_afd(af)
1016 int af;
1017{
1018 const struct afd *afd;
1019
1020 if (af == PF_UNSPEC)
1021 return NULL;
1022 for (afd = afdl; afd->a_af; afd++) {
1023 if (afd->a_af == af)
1024 return afd;
1025 }
1026 return NULL;
1027}
1028
1029/*
1030 * post-2553: AI_ADDRCONFIG check. if we use getipnodeby* as backend, backend
1031 * will take care of it.
1032 * the semantics of AI_ADDRCONFIG is not defined well. we are not sure
1033 * if the code is right or not.
1034 *
1035 * XXX PF_UNSPEC -> PF_INET6 + PF_INET mapping needs to be in sync with
1036 * _dns_getaddrinfo.
1037 */
1038static int
1039addrconfig(pai)
1040 struct addrinfo *pai;
1041{
1042 int s, af;
1043
1044 /*
1045 * TODO:
1046 * Note that implementation dependent test for address
1047 * configuration should be done everytime called
1048 * (or apropriate interval),
1049 * because addresses will be dynamically assigned or deleted.
1050 */
1051 af = pai->ai_family;
1052 if (af == AF_UNSPEC) {
1053 if ((s = _socket(AF_INET6, SOCK_DGRAM, 0)) < 0)
1054 af = AF_INET;
1055 else {
1056 _close(s);
1057 if ((s = _socket(AF_INET, SOCK_DGRAM, 0)) < 0)
1058 af = AF_INET6;
1059 else
1060 _close(s);
1061 }
1062 }
1063 if (af != AF_UNSPEC) {
1064 if ((s = _socket(af, SOCK_DGRAM, 0)) < 0)
1065 return 0;
1066 _close(s);
1067 }
1068 pai->ai_family = af;
1069 return 1;
1070}
1071
1072#ifdef INET6
1073/* convert a string to a scope identifier. XXX: IPv6 specific */
1074static int
1075ip6_str2scopeid(scope, sin6)
1076 char *scope;
1077 struct sockaddr_in6 *sin6;
1078{
1079 int scopeid;
1080 struct in6_addr *a6 = &sin6->sin6_addr;
1081 char *ep;
1082
1083 /* empty scopeid portion is invalid */
1084 if (*scope == '\0')
1085 return -1;
1086
1087 if (IN6_IS_ADDR_LINKLOCAL(a6) || IN6_IS_ADDR_MC_LINKLOCAL(a6)) {
1088 /*
1089 * We currently assume a one-to-one mapping between links
1090 * and interfaces, so we simply use interface indices for
1091 * like-local scopes.
1092 */
1093 scopeid = if_nametoindex(scope);
1094 if (scopeid == 0)
1095 goto trynumeric;
1096 return(scopeid);
1097 }
1098
1099 /* still unclear about literal, allow numeric only - placeholder */
1100 if (IN6_IS_ADDR_SITELOCAL(a6) || IN6_IS_ADDR_MC_SITELOCAL(a6))
1101 goto trynumeric;
1102 if (IN6_IS_ADDR_MC_ORGLOCAL(a6))
1103 goto trynumeric;
1104 else
1105 goto trynumeric; /* global */
1106
1107 /* try to convert to a numeric id as a last resort */
1108 trynumeric:
1109 scopeid = (int)strtoul(scope, &ep, 10);
1110 if (*ep == '\0')
1111 return scopeid;
1112 else
1113 return -1;
1114}
1115#endif
1116
1117#ifdef DEBUG
1118static const char AskedForGot[] =
1119 "gethostby*.getanswer: asked for \"%s\", got \"%s\"";
1120#endif
1121static FILE *hostf = NULL;
1122
1123static struct addrinfo *
1124getanswer(answer, anslen, qname, qtype, pai)
1125 const querybuf *answer;
1126 int anslen;
1127 const char *qname;
1128 int qtype;
1129 const struct addrinfo *pai;
1130{
1131 struct addrinfo sentinel, *cur;
1132 struct addrinfo ai;
1133 const struct afd *afd;
1134 char *canonname;
1135 const HEADER *hp;
1136 const u_char *cp;
1137 int n;
1138 const u_char *eom;
1139 char *bp;
1140 int type, class, buflen, ancount, qdcount;
1141 int haveanswer, had_error;
1142 char tbuf[MAXDNAME];
1143 int (*name_ok) __P((const char *));
1144 char hostbuf[8*1024];
1145
1146 memset(&sentinel, 0, sizeof(sentinel));
1147 cur = &sentinel;
1148
1149 canonname = NULL;
1150 eom = answer->buf + anslen;
1151 switch (qtype) {
1152 case T_A:
1153 case T_AAAA:
1154 case T_ANY: /*use T_ANY only for T_A/T_AAAA lookup*/
1155 name_ok = res_hnok;
1156 break;
1157 default:
1158 return (NULL); /* XXX should be abort(); */
1159 }
1160 /*
1161 * find first satisfactory answer
1162 */
1163 hp = &answer->hdr;
1164 ancount = ntohs(hp->ancount);
1165 qdcount = ntohs(hp->qdcount);
1166 bp = hostbuf;
1167 buflen = sizeof hostbuf;
1168 cp = answer->buf + HFIXEDSZ;
1169 if (qdcount != 1) {
1170 h_errno = NO_RECOVERY;
1171 return (NULL);
1172 }
1173 n = dn_expand(answer->buf, eom, cp, bp, buflen);
1174 if ((n < 0) || !(*name_ok)(bp)) {
1175 h_errno = NO_RECOVERY;
1176 return (NULL);
1177 }
1178 cp += n + QFIXEDSZ;
1179 if (qtype == T_A || qtype == T_AAAA || qtype == T_ANY) {
1180 /* res_send() has already verified that the query name is the
1181 * same as the one we sent; this just gets the expanded name
1182 * (i.e., with the succeeding search-domain tacked on).
1183 */
1184 n = strlen(bp) + 1; /* for the \0 */
1185 if (n >= MAXHOSTNAMELEN) {
1186 h_errno = NO_RECOVERY;
1187 return (NULL);
1188 }
1189 canonname = bp;
1190 bp += n;
1191 buflen -= n;
1192 /* The qname can be abbreviated, but h_name is now absolute. */
1193 qname = canonname;
1194 }
1195 haveanswer = 0;
1196 had_error = 0;
1197 while (ancount-- > 0 && cp < eom && !had_error) {
1198 n = dn_expand(answer->buf, eom, cp, bp, buflen);
1199 if ((n < 0) || !(*name_ok)(bp)) {
1200 had_error++;
1201 continue;
1202 }
1203 cp += n; /* name */
1204 type = _getshort(cp);
1205 cp += INT16SZ; /* type */
1206 class = _getshort(cp);
1207 cp += INT16SZ + INT32SZ; /* class, TTL */
1208 n = _getshort(cp);
1209 cp += INT16SZ; /* len */
1210 if (class != C_IN) {
1211 /* XXX - debug? syslog? */
1212 cp += n;
1213 continue; /* XXX - had_error++ ? */
1214 }
1215 if ((qtype == T_A || qtype == T_AAAA || qtype == T_ANY) &&
1216 type == T_CNAME) {
1217 n = dn_expand(answer->buf, eom, cp, tbuf, sizeof tbuf);
1218 if ((n < 0) || !(*name_ok)(tbuf)) {
1219 had_error++;
1220 continue;
1221 }
1222 cp += n;
1223 /* Get canonical name. */
1224 n = strlen(tbuf) + 1; /* for the \0 */
1225 if (n > buflen || n >= MAXHOSTNAMELEN) {
1226 had_error++;
1227 continue;
1228 }
1229 strcpy(bp, tbuf);
1230 canonname = bp;
1231 bp += n;
1232 buflen -= n;
1233 continue;
1234 }
1235 if (qtype == T_ANY) {
1236 if (!(type == T_A || type == T_AAAA)) {
1237 cp += n;
1238 continue;
1239 }
1240 } else if (type != qtype) {
1241#ifdef DEBUG
1242 if (type != T_KEY && type != T_SIG)
1243 syslog(LOG_NOTICE|LOG_AUTH,
1244 "gethostby*.getanswer: asked for \"%s %s %s\", got type \"%s\"",
1245 qname, p_class(C_IN), p_type(qtype),
1246 p_type(type));
1247#endif
1248 cp += n;
1249 continue; /* XXX - had_error++ ? */
1250 }
1251 switch (type) {
1252 case T_A:
1253 case T_AAAA:
1254 if (strcasecmp(canonname, bp) != 0) {
1255#ifdef DEBUG
1256 syslog(LOG_NOTICE|LOG_AUTH,
1257 AskedForGot, canonname, bp);
1258#endif
1259 cp += n;
1260 continue; /* XXX - had_error++ ? */
1261 }
1262 if (type == T_A && n != INADDRSZ) {
1263 cp += n;
1264 continue;
1265 }
1266 if (type == T_AAAA && n != IN6ADDRSZ) {
1267 cp += n;
1268 continue;
1269 }
1270#ifdef FILTER_V4MAPPED
1271 if (type == T_AAAA) {
1272 struct in6_addr in6;
1273 memcpy(&in6, cp, sizeof(in6));
1274 if (IN6_IS_ADDR_V4MAPPED(&in6)) {
1275 cp += n;
1276 continue;
1277 }
1278 }
1279#endif
1280 if (!haveanswer) {
1281 int nn;
1282
1283 canonname = bp;
1284 nn = strlen(bp) + 1; /* for the \0 */
1285 bp += nn;
1286 buflen -= nn;
1287 }
1288
1289 /* don't overwrite pai */
1290 ai = *pai;
1291 ai.ai_family = (type == T_A) ? AF_INET : AF_INET6;
1292 afd = find_afd(ai.ai_family);
1293 if (afd == NULL) {
1294 cp += n;
1295 continue;
1296 }
1297 cur->ai_next = get_ai(&ai, afd, (const char *)cp);
1298 if (cur->ai_next == NULL)
1299 had_error++;
1300 while (cur && cur->ai_next)
1301 cur = cur->ai_next;
1302 cp += n;
1303 break;
1304 default:
1305 abort();
1306 }
1307 if (!had_error)
1308 haveanswer++;
1309 }
1310 if (haveanswer) {
1311 if (!canonname)
1312 (void)get_canonname(pai, sentinel.ai_next, qname);
1313 else
1314 (void)get_canonname(pai, sentinel.ai_next, canonname);
1315 h_errno = NETDB_SUCCESS;
1316 return sentinel.ai_next;
1317 }
1318
1319 h_errno = NO_RECOVERY;
1320 return NULL;
1321}
1322
1323/*ARGSUSED*/
1324static int
1325_dns_getaddrinfo(rv, cb_data, ap)
1326 void *rv;
1327 void *cb_data;
1328 va_list ap;
1329{
1330 struct addrinfo *ai;
1331 querybuf buf, buf2;
1332 const char *name;
1333 const struct addrinfo *pai;
1334 struct addrinfo sentinel, *cur;
1335 struct res_target q, q2;
1336
1337 name = va_arg(ap, char *);
1338 pai = va_arg(ap, const struct addrinfo *);
1339
1340 memset(&q, 0, sizeof(q2));
1341 memset(&q2, 0, sizeof(q2));
1342 memset(&sentinel, 0, sizeof(sentinel));
1343 cur = &sentinel;
1344
1345 switch (pai->ai_family) {
1346 case AF_UNSPEC:
1347 /* prefer IPv6 */
1348 q.qclass = C_IN;
1349 q.qtype = T_AAAA;
1350 q.answer = buf.buf;
1351 q.anslen = sizeof(buf);
1352 q.next = &q2;
1353 q2.qclass = C_IN;
1354 q2.qtype = T_A;
1355 q2.answer = buf2.buf;
1356 q2.anslen = sizeof(buf2);
1357 break;
1358 case AF_INET:
1359 q.qclass = C_IN;
1360 q.qtype = T_A;
1361 q.answer = buf.buf;
1362 q.anslen = sizeof(buf);
1363 break;
1364 case AF_INET6:
1365 q.qclass = C_IN;
1366 q.qtype = T_AAAA;
1367 q.answer = buf.buf;
1368 q.anslen = sizeof(buf);
1369 break;
1370 default:
1371 return NS_UNAVAIL;
1372 }
1373 if (res_searchN(name, &q) < 0)
1374 return NS_NOTFOUND;
1375 ai = getanswer(&buf, q.n, q.name, q.qtype, pai);
1376 if (ai) {
1377 cur->ai_next = ai;
1378 while (cur && cur->ai_next)
1379 cur = cur->ai_next;
1380 }
1381 if (q.next) {
1382 ai = getanswer(&buf2, q2.n, q2.name, q2.qtype, pai);
1383 if (ai)
1384 cur->ai_next = ai;
1385 }
1386 if (sentinel.ai_next == NULL)
1387 switch (h_errno) {
1388 case HOST_NOT_FOUND:
1389 return NS_NOTFOUND;
1390 case TRY_AGAIN:
1391 return NS_TRYAGAIN;
1392 default:
1393 return NS_UNAVAIL;
1394 }
1395 *((struct addrinfo **)rv) = sentinel.ai_next;
1396 return NS_SUCCESS;
1397}
1398
1399static void
1400_sethtent()
1401{
1402 if (!hostf)
1403 hostf = fopen(_PATH_HOSTS, "r" );
1404 else
1405 rewind(hostf);
1406}
1407
1408static void
1409_endhtent()
1410{
1411 if (hostf) {
1412 (void) fclose(hostf);
1413 hostf = NULL;
1414 }
1415}
1416
1417static struct addrinfo *
1418_gethtent(name, pai)
1419 const char *name;
1420 const struct addrinfo *pai;
1421{
1422 char *p;
1423 char *cp, *tname, *cname;
1424 struct addrinfo hints, *res0, *res;
1425 int error;
1426 const char *addr;
1427 char hostbuf[8*1024];
1428
1429 if (!hostf && !(hostf = fopen(_PATH_HOSTS, "r" )))
1430 return (NULL);
1431 again:
1432 if (!(p = fgets(hostbuf, sizeof hostbuf, hostf)))
1433 return (NULL);
1434 if (*p == '#')
1435 goto again;
1436 if (!(cp = strpbrk(p, "#\n")))
1437 goto again;
1438 *cp = '\0';
1439 if (!(cp = strpbrk(p, " \t")))
1440 goto again;
1441 *cp++ = '\0';
1442 addr = p;
1443 cname = NULL;
1444 /* if this is not something we're looking for, skip it. */
1445 while (cp && *cp) {
1446 if (*cp == ' ' || *cp == '\t') {
1447 cp++;
1448 continue;
1449 }
1450 tname = cp;
1451 if (cname == NULL)
1452 cname = cp;
1453 if ((cp = strpbrk(cp, " \t")) != NULL)
1454 *cp++ = '\0';
1455 if (strcasecmp(name, tname) == 0)
1456 goto found;
1457 }
1458 goto again;
1459
1460found:
1461 hints = *pai;
1462 hints.ai_flags = AI_NUMERICHOST;
1463 error = getaddrinfo(addr, NULL, &hints, &res0);
1464 if (error)
1465 goto again;
1466#ifdef FILTER_V4MAPPED
1467 /* XXX should check all items in the chain */
1468 if (res0->ai_family == AF_INET6 &&
1469 IN6_IS_ADDR_V4MAPPED(&((struct sockaddr_in6 *)res0->ai_addr)->sin6_addr)) {
1470 freeaddrinfo(res0);
1471 goto again;
1472 }
1473#endif
1474 for (res = res0; res; res = res->ai_next) {
1475 /* cover it up */
1476 res->ai_flags = pai->ai_flags;
1477
1478 if (pai->ai_flags & AI_CANONNAME) {
1479 if (get_canonname(pai, res, cname) != 0) {
1480 freeaddrinfo(res0);
1481 goto again;
1482 }
1483 }
1484 }
1485 return res0;
1486}
1487
1488/*ARGSUSED*/
1489static int
1490_files_getaddrinfo(rv, cb_data, ap)
1491 void *rv;
1492 void *cb_data;
1493 va_list ap;
1494{
1495 const char *name;
1496 const struct addrinfo *pai;
1497 struct addrinfo sentinel, *cur;
1498 struct addrinfo *p;
1499
1500 name = va_arg(ap, char *);
1501 pai = va_arg(ap, struct addrinfo *);
1502
1503 memset(&sentinel, 0, sizeof(sentinel));
1504 cur = &sentinel;
1505
1506 _sethtent();
1507 while ((p = _gethtent(name, pai)) != NULL) {
1508 cur->ai_next = p;
1509 while (cur && cur->ai_next)
1510 cur = cur->ai_next;
1511 }
1512 _endhtent();
1513
1514 *((struct addrinfo **)rv) = sentinel.ai_next;
1515 if (sentinel.ai_next == NULL)
1516 return NS_NOTFOUND;
1517 return NS_SUCCESS;
1518}
1519
1520#ifdef YP
1521static char *__ypdomain;
1522
1523/*ARGSUSED*/
1524static struct addrinfo *
1525_yphostent(line, pai)
1526 char *line;
1527 const struct addrinfo *pai;
1528{
1529 struct addrinfo sentinel, *cur;
1530 struct addrinfo hints, *res, *res0;
1531 int error;
1532 char *p = line;
1533 const char *addr, *canonname;
1534 char *nextline;
1535 char *cp;
1536
1537 addr = canonname = NULL;
1538
1539 memset(&sentinel, 0, sizeof(sentinel));
1540 cur = &sentinel;
1541
1542nextline:
1543 /* terminate line */
1544 cp = strchr(p, '\n');
1545 if (cp) {
1546 *cp++ = '\0';
1547 nextline = cp;
1548 } else
1549 nextline = NULL;
1550
1551 cp = strpbrk(p, " \t");
1552 if (cp == NULL) {
1553 if (canonname == NULL)
1554 return (NULL);
1555 else
1556 goto done;
1557 }
1558 *cp++ = '\0';
1559
1560 addr = p;
1561
1562 while (cp && *cp) {
1563 if (*cp == ' ' || *cp == '\t') {
1564 cp++;
1565 continue;
1566 }
1567 if (!canonname)
1568 canonname = cp;
1569 if ((cp = strpbrk(cp, " \t")) != NULL)
1570 *cp++ = '\0';
1571 }
1572
1573 hints = *pai;
1574 hints.ai_flags = AI_NUMERICHOST;
1575 error = getaddrinfo(addr, NULL, &hints, &res0);
1576 if (error == 0) {
1577 for (res = res0; res; res = res->ai_next) {
1578 /* cover it up */
1579 res->ai_flags = pai->ai_flags;
1580
1581 if (pai->ai_flags & AI_CANONNAME)
1582 (void)get_canonname(pai, res, canonname);
1583 }
1584 } else
1585 res0 = NULL;
1586 if (res0) {
1587 cur->ai_next = res0;
1588 while (cur && cur->ai_next)
1589 cur = cur->ai_next;
1590 }
1591
1592 if (nextline) {
1593 p = nextline;
1594 goto nextline;
1595 }
1596
1597done:
1598 return sentinel.ai_next;
1599}
1600
1601/*ARGSUSED*/
1602static int
1603_yp_getaddrinfo(rv, cb_data, ap)
1604 void *rv;
1605 void *cb_data;
1606 va_list ap;
1607{
1608 struct addrinfo sentinel, *cur;
1609 struct addrinfo *ai = NULL;
1610 static char *__ypcurrent;
1611 int __ypcurrentlen, r;
1612 const char *name;
1613 const struct addrinfo *pai;
1614
1615 name = va_arg(ap, char *);
1616 pai = va_arg(ap, const struct addrinfo *);
1617
1618 memset(&sentinel, 0, sizeof(sentinel));
1619 cur = &sentinel;
1620
1621 if (!__ypdomain) {
1622 if (_yp_check(&__ypdomain) == 0)
1623 return NS_UNAVAIL;
1624 }
1625 if (__ypcurrent)
1626 free(__ypcurrent);
1627 __ypcurrent = NULL;
1628
1629 /* hosts.byname is only for IPv4 (Solaris8) */
1630 if (pai->ai_family == PF_UNSPEC || pai->ai_family == PF_INET) {
1631 r = yp_match(__ypdomain, "hosts.byname", name,
1632 (int)strlen(name), &__ypcurrent, &__ypcurrentlen);
1633 if (r == 0) {
1634 struct addrinfo ai4;
1635
1636 ai4 = *pai;
1637 ai4.ai_family = AF_INET;
1638 ai = _yphostent(__ypcurrent, &ai4);
1639 if (ai) {
1640 cur->ai_next = ai;
1641 while (cur && cur->ai_next)
1642 cur = cur->ai_next;
1643 }
1644 }
1645 }
1646
1647 /* ipnodes.byname can hold both IPv4/v6 */
1648 r = yp_match(__ypdomain, "ipnodes.byname", name,
1649 (int)strlen(name), &__ypcurrent, &__ypcurrentlen);
1650 if (r == 0) {
1651 ai = _yphostent(__ypcurrent, pai);
1652 if (ai) {
1653 cur->ai_next = ai;
1654 while (cur && cur->ai_next)
1655 cur = cur->ai_next;
1656 }
1657 }
1658
1659 if (sentinel.ai_next == NULL) {
1660 h_errno = HOST_NOT_FOUND;
1661 return NS_NOTFOUND;
1662 }
1663 *((struct addrinfo **)rv) = sentinel.ai_next;
1664 return NS_SUCCESS;
1665}
1666#endif
1667
1668/* resolver logic */
1669
1670extern const char *__hostalias __P((const char *));
1671extern int h_errno;
1672
1673/*
1674 * Formulate a normal query, send, and await answer.
1675 * Returned answer is placed in supplied buffer "answer".
1676 * Perform preliminary check of answer, returning success only
1677 * if no error is indicated and the answer count is nonzero.
1678 * Return the size of the response on success, -1 on error.
1679 * Error number is left in h_errno.
1680 *
1681 * Caller must parse answer and determine whether it answers the question.
1682 */
1683static int
1684res_queryN(name, target)
1685 const char *name; /* domain name */
1686 struct res_target *target;
1687{
1688 u_char buf[MAXPACKET];
1689 HEADER *hp;
1690 int n;
1691 struct res_target *t;
1692 int rcode;
1693 int ancount;
1694
1695 rcode = NOERROR;
1696 ancount = 0;
1697
1698 if ((_res.options & RES_INIT) == 0 && res_init() == -1) {
1699 h_errno = NETDB_INTERNAL;
1700 return (-1);
1701 }
1702
1703 for (t = target; t; t = t->next) {
1704 int class, type;
1705 u_char *answer;
1706 int anslen;
1707
1708 hp = (HEADER *)(void *)t->answer;
1709 hp->rcode = NOERROR; /* default */
1710
1711 /* make it easier... */
1712 class = t->qclass;
1713 type = t->qtype;
1714 answer = t->answer;
1715 anslen = t->anslen;
1716#ifdef DEBUG
1717 if (_res.options & RES_DEBUG)
1718 printf(";; res_query(%s, %d, %d)\n", name, class, type);
1719#endif
1720
1721 n = res_mkquery(QUERY, name, class, type, NULL, 0, NULL,
1722 buf, sizeof(buf));
1723 if (n > 0 && (_res.options & RES_USE_EDNS0) != 0)
1724 n = res_opt(n, buf, sizeof(buf), anslen);
1725 if (n <= 0) {
1726#ifdef DEBUG
1727 if (_res.options & RES_DEBUG)
1728 printf(";; res_query: mkquery failed\n");
1729#endif
1730 h_errno = NO_RECOVERY;
1731 return (n);
1732 }
1733 n = res_send(buf, n, answer, anslen);
1734#if 0
1735 if (n < 0) {
1736#ifdef DEBUG
1737 if (_res.options & RES_DEBUG)
1738 printf(";; res_query: send error\n");
1739#endif
1740 h_errno = TRY_AGAIN;
1741 return (n);
1742 }
1743#endif
1744
1745 if (n < 0 || hp->rcode != NOERROR || ntohs(hp->ancount) == 0) {
1746 rcode = hp->rcode; /* record most recent error */
1747#ifdef DEBUG
1748 if (_res.options & RES_DEBUG)
1749 printf(";; rcode = %d, ancount=%d\n", hp->rcode,
1750 ntohs(hp->ancount));
1751#endif
1752 continue;
1753 }
1754
1755 ancount += ntohs(hp->ancount);
1756
1757 t->n = n;
1758 }
1759
1760 if (ancount == 0) {
1761 switch (rcode) {
1762 case NXDOMAIN:
1763 h_errno = HOST_NOT_FOUND;
1764 break;
1765 case SERVFAIL:
1766 h_errno = TRY_AGAIN;
1767 break;
1768 case NOERROR:
1769 h_errno = NO_DATA;
1770 break;
1771 case FORMERR:
1772 case NOTIMP:
1773 case REFUSED:
1774 default:
1775 h_errno = NO_RECOVERY;
1776 break;
1777 }
1778 return (-1);
1779 }
1780 return (ancount);
1781}
1782
1783/*
1784 * Formulate a normal query, send, and retrieve answer in supplied buffer.
1785 * Return the size of the response on success, -1 on error.
1786 * If enabled, implement search rules until answer or unrecoverable failure
1787 * is detected. Error code, if any, is left in h_errno.
1788 */
1789static int
1790res_searchN(name, target)
1791 const char *name; /* domain name */
1792 struct res_target *target;
1793{
1794 const char *cp, * const *domain;
1795 HEADER *hp = (HEADER *)(void *)target->answer; /*XXX*/
1796 u_int dots;
1797 int trailing_dot, ret, saved_herrno;
1798 int got_nodata = 0, got_servfail = 0, tried_as_is = 0;
1799
1800 if ((_res.options & RES_INIT) == 0 && res_init() == -1) {
1801 h_errno = NETDB_INTERNAL;
1802 return (-1);
1803 }
1804
1805 errno = 0;
1806 h_errno = HOST_NOT_FOUND; /* default, if we never query */
1807 dots = 0;
1808 for (cp = name; *cp; cp++)
1809 dots += (*cp == '.');
1810 trailing_dot = 0;
1811 if (cp > name && *--cp == '.')
1812 trailing_dot++;
1813
1814 /*
1815 * if there aren't any dots, it could be a user-level alias
1816 */
1817 if (!dots && (cp = __hostalias(name)) != NULL)
1818 return (res_queryN(cp, target));
1819
1820 /*
1821 * If there are dots in the name already, let's just give it a try
1822 * 'as is'. The threshold can be set with the "ndots" option.
1823 */
1824 saved_herrno = -1;
1825 if (dots >= _res.ndots) {
1826 ret = res_querydomainN(name, NULL, target);
1827 if (ret > 0)
1828 return (ret);
1829 saved_herrno = h_errno;
1830 tried_as_is++;
1831 }
1832
1833 /*
1834 * We do at least one level of search if
1835 * - there is no dot and RES_DEFNAME is set, or
1836 * - there is at least one dot, there is no trailing dot,
1837 * and RES_DNSRCH is set.
1838 */
1839 if ((!dots && (_res.options & RES_DEFNAMES)) ||
1840 (dots && !trailing_dot && (_res.options & RES_DNSRCH))) {
1841 int done = 0;
1842
1843 for (domain = (const char * const *)_res.dnsrch;
1844 *domain && !done;
1845 domain++) {
1846
1847 ret = res_querydomainN(name, *domain, target);
1848 if (ret > 0)
1849 return (ret);
1850
1851 /*
1852 * If no server present, give up.
1853 * If name isn't found in this domain,
1854 * keep trying higher domains in the search list
1855 * (if that's enabled).
1856 * On a NO_DATA error, keep trying, otherwise
1857 * a wildcard entry of another type could keep us
1858 * from finding this entry higher in the domain.
1859 * If we get some other error (negative answer or
1860 * server failure), then stop searching up,
1861 * but try the input name below in case it's
1862 * fully-qualified.
1863 */
1864 if (errno == ECONNREFUSED) {
1865 h_errno = TRY_AGAIN;
1866 return (-1);
1867 }
1868
1869 switch (h_errno) {
1870 case NO_DATA:
1871 got_nodata++;
1872 /* FALLTHROUGH */
1873 case HOST_NOT_FOUND:
1874 /* keep trying */
1875 break;
1876 case TRY_AGAIN:
1877 if (hp->rcode == SERVFAIL) {
1878 /* try next search element, if any */
1879 got_servfail++;
1880 break;
1881 }
1882 /* FALLTHROUGH */
1883 default:
1884 /* anything else implies that we're done */
1885 done++;
1886 }
1887 /*
1888 * if we got here for some reason other than DNSRCH,
1889 * we only wanted one iteration of the loop, so stop.
1890 */
1891 if (!(_res.options & RES_DNSRCH))
1892 done++;
1893 }
1894 }
1895
1896 /*
1897 * if we have not already tried the name "as is", do that now.
1898 * note that we do this regardless of how many dots were in the
1899 * name or whether it ends with a dot.
1900 */
1901 if (!tried_as_is && (dots || !(_res.options & RES_NOTLDQUERY))) {
1902 ret = res_querydomainN(name, NULL, target);
1903 if (ret > 0)
1904 return (ret);
1905 }
1906
1907 /*
1908 * if we got here, we didn't satisfy the search.
1909 * if we did an initial full query, return that query's h_errno
1910 * (note that we wouldn't be here if that query had succeeded).
1911 * else if we ever got a nodata, send that back as the reason.
1912 * else send back meaningless h_errno, that being the one from
1913 * the last DNSRCH we did.
1914 */
1915 if (saved_herrno != -1)
1916 h_errno = saved_herrno;
1917 else if (got_nodata)
1918 h_errno = NO_DATA;
1919 else if (got_servfail)
1920 h_errno = TRY_AGAIN;
1921 return (-1);
1922}
1923
1924/*
1925 * Perform a call on res_query on the concatenation of name and domain,
1926 * removing a trailing dot from name if domain is NULL.
1927 */
1928static int
1929res_querydomainN(name, domain, target)
1930 const char *name, *domain;
1931 struct res_target *target;
1932{
1933 char nbuf[MAXDNAME];
1934 const char *longname = nbuf;
1935 size_t n, d;
1936
1937 if ((_res.options & RES_INIT) == 0 && res_init() == -1) {
1938 h_errno = NETDB_INTERNAL;
1939 return (-1);
1940 }
1941#ifdef DEBUG
1942 if (_res.options & RES_DEBUG)
1943 printf(";; res_querydomain(%s, %s)\n",
1944 name, domain?domain:"<Nil>");
1945#endif
1946 if (domain == NULL) {
1947 /*
1948 * Check for trailing '.';
1949 * copy without '.' if present.
1950 */
1951 n = strlen(name);
1952 if (n >= MAXDNAME) {
1953 h_errno = NO_RECOVERY;
1954 return (-1);
1955 }
1956 if (n > 0 && name[--n] == '.') {
1957 strncpy(nbuf, name, n);
1958 nbuf[n] = '\0';
1959 } else
1960 longname = name;
1961 } else {
1962 n = strlen(name);
1963 d = strlen(domain);
1964 if (n + d + 1 >= MAXDNAME) {
1965 h_errno = NO_RECOVERY;
1966 return (-1);
1967 }
1968 sprintf(nbuf, "%s.%s", name, domain);
1969 }
1970 return (res_queryN(longname, target));
1971}
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 * - some of FreeBSD style (#define tabify and others)
83 * - classful IPv4 numeric (127.1) is allowed.
84 */
85
86#include "namespace.h"
87#include <sys/types.h>
88#include <sys/param.h>
89#include <sys/socket.h>
90#include <net/if.h>
91#include <netinet/in.h>
92#include <arpa/inet.h>
93#include <arpa/nameser.h>
94#include <netdb.h>
95#include <resolv.h>
96#include <string.h>
97#include <stdlib.h>
98#include <stddef.h>
99#include <ctype.h>
100#include <unistd.h>
101#include <stdio.h>
102#include <errno.h>
103#ifdef DEBUG
104#include <syslog.h>
105#endif
106
107#include <syslog.h>
108#include <stdarg.h>
109#include <nsswitch.h>
110#include "un-namespace.h"
111
112#if defined(__KAME__) && defined(INET6)
113# define FAITH
114#endif
115
116#define SUCCESS 0
117#define ANY 0
118#define YES 1
119#define NO 0
120
121static const char in_addrany[] = { 0, 0, 0, 0 };
122static const char in6_addrany[] = {
123 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
124};
125static const char in_loopback[] = { 127, 0, 0, 1 };
126static const char in6_loopback[] = {
127 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1
128};
129
130static const struct afd {
131 int a_af;
132 int a_addrlen;
133 int a_socklen;
134 int a_off;
135 const char *a_addrany;
136 const char *a_loopback;
137 int a_scoped;
138} afdl [] = {
139#ifdef INET6
140#define N_INET6 0
141 {PF_INET6, sizeof(struct in6_addr),
142 sizeof(struct sockaddr_in6),
143 offsetof(struct sockaddr_in6, sin6_addr),
144 in6_addrany, in6_loopback, 1},
145#define N_INET 1
146#else
147#define N_INET 0
148#endif
149 {PF_INET, sizeof(struct in_addr),
150 sizeof(struct sockaddr_in),
151 offsetof(struct sockaddr_in, sin_addr),
152 in_addrany, in_loopback, 0},
153 {0, 0, 0, 0, NULL, NULL, 0},
154};
155
156struct explore {
157 int e_af;
158 int e_socktype;
159 int e_protocol;
160 const char *e_protostr;
161 int e_wild;
162#define WILD_AF(ex) ((ex)->e_wild & 0x01)
163#define WILD_SOCKTYPE(ex) ((ex)->e_wild & 0x02)
164#define WILD_PROTOCOL(ex) ((ex)->e_wild & 0x04)
165};
166
167static const struct explore explore[] = {
168#if 0
169 { PF_LOCAL, 0, ANY, ANY, NULL, 0x01 },
170#endif
171#ifdef INET6
172 { PF_INET6, SOCK_DGRAM, IPPROTO_UDP, "udp", 0x07 },
173 { PF_INET6, SOCK_STREAM, IPPROTO_TCP, "tcp", 0x07 },
174 { PF_INET6, SOCK_RAW, ANY, NULL, 0x05 },
175#endif
176 { PF_INET, SOCK_DGRAM, IPPROTO_UDP, "udp", 0x07 },
177 { PF_INET, SOCK_STREAM, IPPROTO_TCP, "tcp", 0x07 },
178 { PF_INET, SOCK_RAW, ANY, NULL, 0x05 },
179 { PF_UNSPEC, SOCK_DGRAM, IPPROTO_UDP, "udp", 0x07 },
180 { PF_UNSPEC, SOCK_STREAM, IPPROTO_TCP, "tcp", 0x07 },
181 { PF_UNSPEC, SOCK_RAW, ANY, NULL, 0x05 },
182 { -1, 0, 0, NULL, 0 },
183};
184
185#ifdef INET6
186#define PTON_MAX 16
187#else
188#define PTON_MAX 4
189#endif
190
191static const ns_src default_dns_files[] = {
192 { NSSRC_FILES, NS_SUCCESS },
193 { NSSRC_DNS, NS_SUCCESS },
194 { 0 }
195};
196
197#if PACKETSZ > 1024
198#define MAXPACKET PACKETSZ
199#else
200#define MAXPACKET 1024
201#endif
202
203typedef union {
204 HEADER hdr;
205 u_char buf[MAXPACKET];
206} querybuf;
207
208struct res_target {
209 struct res_target *next;
210 const char *name; /* domain name */
211 int qclass, qtype; /* class and type of query */
212 u_char *answer; /* buffer to put answer */
213 int anslen; /* size of answer buffer */
214 int n; /* result length */
215};
216
217static int str_isnumber __P((const char *));
218static int explore_fqdn __P((const struct addrinfo *, const char *,
219 const char *, struct addrinfo **));
220static int explore_null __P((const struct addrinfo *,
221 const char *, struct addrinfo **));
222static int explore_numeric __P((const struct addrinfo *, const char *,
223 const char *, struct addrinfo **));
224static int explore_numeric_scope __P((const struct addrinfo *, const char *,
225 const char *, struct addrinfo **));
226static int get_canonname __P((const struct addrinfo *,
227 struct addrinfo *, const char *));
228static struct addrinfo *get_ai __P((const struct addrinfo *,
229 const struct afd *, const char *));
230static int get_portmatch __P((const struct addrinfo *, const char *));
231static int get_port __P((struct addrinfo *, const char *, int));
232static const struct afd *find_afd __P((int));
233static int addrconfig __P((struct addrinfo *));
234#ifdef INET6
235static int ip6_str2scopeid __P((char *, struct sockaddr_in6 *));
236#endif
237
238static struct addrinfo *getanswer __P((const querybuf *, int, const char *, int,
239 const struct addrinfo *));
240static int _dns_getaddrinfo __P((void *, void *, va_list));
241static void _sethtent __P((void));
242static void _endhtent __P((void));
243static struct addrinfo *_gethtent __P((const char *, const struct addrinfo *));
244static int _files_getaddrinfo __P((void *, void *, va_list));
245#ifdef YP
246static struct addrinfo *_yphostent __P((char *, const struct addrinfo *));
247static int _yp_getaddrinfo __P((void *, void *, va_list));
248#endif
249
250static int res_queryN __P((const char *, struct res_target *));
251static int res_searchN __P((const char *, struct res_target *));
252static int res_querydomainN __P((const char *, const char *,
253 struct res_target *));
254
255static char *ai_errlist[] = {
256 "Success",
257 "Address family for hostname not supported", /* EAI_ADDRFAMILY */
258 "Temporary failure in name resolution", /* EAI_AGAIN */
259 "Invalid value for ai_flags", /* EAI_BADFLAGS */
260 "Non-recoverable failure in name resolution", /* EAI_FAIL */
261 "ai_family not supported", /* EAI_FAMILY */
262 "Memory allocation failure", /* EAI_MEMORY */
263 "No address associated with hostname", /* EAI_NODATA */
264 "hostname nor servname provided, or not known", /* EAI_NONAME */
265 "servname not supported for ai_socktype", /* EAI_SERVICE */
266 "ai_socktype not supported", /* EAI_SOCKTYPE */
267 "System error returned in errno", /* EAI_SYSTEM */
268 "Invalid value for hints", /* EAI_BADHINTS */
269 "Resolved protocol is unknown", /* EAI_PROTOCOL */
270 "Unknown error", /* EAI_MAX */
271};
272
273/* XXX macros that make external reference is BAD. */
274
275#define GET_AI(ai, afd, addr) \
276do { \
277 /* external reference: pai, error, and label free */ \
278 (ai) = get_ai(pai, (afd), (addr)); \
279 if ((ai) == NULL) { \
280 error = EAI_MEMORY; \
281 goto free; \
282 } \
283} while (/*CONSTCOND*/0)
284
285#define GET_PORT(ai, serv) \
286do { \
287 /* external reference: error and label free */ \
288 error = get_port((ai), (serv), 0); \
289 if (error != 0) \
290 goto free; \
291} while (/*CONSTCOND*/0)
292
293#define GET_CANONNAME(ai, str) \
294do { \
295 /* external reference: pai, error and label free */ \
296 error = get_canonname(pai, (ai), (str)); \
297 if (error != 0) \
298 goto free; \
299} while (/*CONSTCOND*/0)
300
301#define ERR(err) \
302do { \
303 /* external reference: error, and label bad */ \
304 error = (err); \
305 goto bad; \
306 /*NOTREACHED*/ \
307} while (/*CONSTCOND*/0)
308
309#define MATCH_FAMILY(x, y, w) \
310 ((x) == (y) || (/*CONSTCOND*/(w) && ((x) == PF_UNSPEC || (y) == PF_UNSPEC)))
311#define MATCH(x, y, w) \
312 ((x) == (y) || (/*CONSTCOND*/(w) && ((x) == ANY || (y) == ANY)))
313
314char *
315gai_strerror(ecode)
316 int ecode;
317{
318 if (ecode < 0 || ecode > EAI_MAX)
319 ecode = EAI_MAX;
320 return ai_errlist[ecode];
321}
322
323void
324freeaddrinfo(ai)
325 struct addrinfo *ai;
326{
327 struct addrinfo *next;
328
329 do {
330 next = ai->ai_next;
331 if (ai->ai_canonname)
332 free(ai->ai_canonname);
333 /* no need to free(ai->ai_addr) */
334 free(ai);
335 ai = next;
336 } while (ai);
337}
338
339static int
340str_isnumber(p)
341 const char *p;
342{
343 char *ep;
344
345 if (*p == '\0')
346 return NO;
347 ep = NULL;
348 (void)strtoul(p, &ep, 10);
349 if (ep && *ep == '\0')
350 return YES;
351 else
352 return NO;
353}
354
355int
356getaddrinfo(hostname, servname, hints, res)
357 const char *hostname, *servname;
358 const struct addrinfo *hints;
359 struct addrinfo **res;
360{
361 struct addrinfo sentinel;
362 struct addrinfo *cur;
363 int error = 0;
364 struct addrinfo ai;
365 struct addrinfo ai0;
366 struct addrinfo *pai;
367 const struct explore *ex;
368
369 memset(&sentinel, 0, sizeof(sentinel));
370 cur = &sentinel;
371 pai = &ai;
372 pai->ai_flags = 0;
373 pai->ai_family = PF_UNSPEC;
374 pai->ai_socktype = ANY;
375 pai->ai_protocol = ANY;
376 pai->ai_addrlen = 0;
377 pai->ai_canonname = NULL;
378 pai->ai_addr = NULL;
379 pai->ai_next = NULL;
380
381 if (hostname == NULL && servname == NULL)
382 return EAI_NONAME;
383 if (hints) {
384 /* error check for hints */
385 if (hints->ai_addrlen || hints->ai_canonname ||
386 hints->ai_addr || hints->ai_next)
387 ERR(EAI_BADHINTS); /* xxx */
388 if (hints->ai_flags & ~AI_MASK)
389 ERR(EAI_BADFLAGS);
390 switch (hints->ai_family) {
391 case PF_UNSPEC:
392 case PF_INET:
393#ifdef INET6
394 case PF_INET6:
395#endif
396 break;
397 default:
398 ERR(EAI_FAMILY);
399 }
400 memcpy(pai, hints, sizeof(*pai));
401
402 /*
403 * if both socktype/protocol are specified, check if they
404 * are meaningful combination.
405 */
406 if (pai->ai_socktype != ANY && pai->ai_protocol != ANY) {
407 for (ex = explore; ex->e_af >= 0; ex++) {
408 if (pai->ai_family != ex->e_af)
409 continue;
410 if (ex->e_socktype == ANY)
411 continue;
412 if (ex->e_protocol == ANY)
413 continue;
414 if (pai->ai_socktype == ex->e_socktype
415 && pai->ai_protocol != ex->e_protocol) {
416 ERR(EAI_BADHINTS);
417 }
418 }
419 }
420 }
421
422 /*
423 * post-2553: AI_ALL and AI_V4MAPPED are effective only against
424 * AF_INET6 query. They needs to be ignored if specified in other
425 * occassions.
426 */
427 switch (pai->ai_flags & (AI_ALL | AI_V4MAPPED)) {
428 case AI_V4MAPPED:
429 case AI_ALL | AI_V4MAPPED:
430 if (pai->ai_family != AF_INET6)
431 pai->ai_flags &= ~(AI_ALL | AI_V4MAPPED);
432 break;
433 case AI_ALL:
434#if 1
435 /* illegal */
436 ERR(EAI_BADFLAGS);
437#else
438 pai->ai_flags &= ~(AI_ALL | AI_V4MAPPED);
439#endif
440 break;
441 }
442
443 /*
444 * check for special cases. (1) numeric servname is disallowed if
445 * socktype/protocol are left unspecified. (2) servname is disallowed
446 * for raw and other inet{,6} sockets.
447 */
448 if (MATCH_FAMILY(pai->ai_family, PF_INET, 1)
449#ifdef PF_INET6
450 || MATCH_FAMILY(pai->ai_family, PF_INET6, 1)
451#endif
452 ) {
453 ai0 = *pai; /* backup *pai */
454
455 if (pai->ai_family == PF_UNSPEC) {
456#ifdef PF_INET6
457 pai->ai_family = PF_INET6;
458#else
459 pai->ai_family = PF_INET;
460#endif
461 }
462 error = get_portmatch(pai, servname);
463 if (error)
464 ERR(error);
465
466 *pai = ai0;
467 }
468
469 ai0 = *pai;
470
471 /* NULL hostname, or numeric hostname */
472 for (ex = explore; ex->e_af >= 0; ex++) {
473 *pai = ai0;
474
475 /* PF_UNSPEC entries are prepared for DNS queries only */
476 if (ex->e_af == PF_UNSPEC)
477 continue;
478
479 if (!MATCH_FAMILY(pai->ai_family, ex->e_af, WILD_AF(ex)))
480 continue;
481 if (!MATCH(pai->ai_socktype, ex->e_socktype, WILD_SOCKTYPE(ex)))
482 continue;
483 if (!MATCH(pai->ai_protocol, ex->e_protocol, WILD_PROTOCOL(ex)))
484 continue;
485
486 if (pai->ai_family == PF_UNSPEC)
487 pai->ai_family = ex->e_af;
488 if (pai->ai_socktype == ANY && ex->e_socktype != ANY)
489 pai->ai_socktype = ex->e_socktype;
490 if (pai->ai_protocol == ANY && ex->e_protocol != ANY)
491 pai->ai_protocol = ex->e_protocol;
492
493 if (hostname == NULL)
494 error = explore_null(pai, servname, &cur->ai_next);
495 else
496 error = explore_numeric_scope(pai, hostname, servname, &cur->ai_next);
497
498 if (error)
499 goto free;
500
501 while (cur && cur->ai_next)
502 cur = cur->ai_next;
503 }
504
505 /*
506 * XXX
507 * If numreic representation of AF1 can be interpreted as FQDN
508 * representation of AF2, we need to think again about the code below.
509 */
510 if (sentinel.ai_next)
511 goto good;
512
513 if (pai->ai_flags & AI_NUMERICHOST)
514 ERR(EAI_NODATA);
515 if (hostname == NULL)
516 ERR(EAI_NODATA);
517
518 if ((pai->ai_flags & AI_ADDRCONFIG) != 0 && !addrconfig(&ai0))
519 ERR(EAI_FAIL);
520
521 /*
522 * hostname as alphabetical name.
523 * we would like to prefer AF_INET6 than AF_INET, so we'll make a
524 * outer loop by AFs.
525 */
526 for (ex = explore; ex->e_af >= 0; ex++) {
527 *pai = ai0;
528
529 /* require exact match for family field */
530 if (pai->ai_family != ex->e_af)
531 continue;
532
533 if (!MATCH(pai->ai_socktype, ex->e_socktype,
534 WILD_SOCKTYPE(ex))) {
535 continue;
536 }
537 if (!MATCH(pai->ai_protocol, ex->e_protocol,
538 WILD_PROTOCOL(ex))) {
539 continue;
540 }
541
542 if (pai->ai_socktype == ANY && ex->e_socktype != ANY)
543 pai->ai_socktype = ex->e_socktype;
544 if (pai->ai_protocol == ANY && ex->e_protocol != ANY)
545 pai->ai_protocol = ex->e_protocol;
546
547 error = explore_fqdn(pai, hostname, servname,
548 &cur->ai_next);
549
550 while (cur && cur->ai_next)
551 cur = cur->ai_next;
552 }
553
554 /* XXX */
555 if (sentinel.ai_next)
556 error = 0;
557
558 if (error)
559 goto free;
560 if (error == 0) {
561 if (sentinel.ai_next) {
562 good:
563 *res = sentinel.ai_next;
564 return SUCCESS;
565 } else
566 error = EAI_FAIL;
567 }
568 free:
569 bad:
570 if (sentinel.ai_next)
571 freeaddrinfo(sentinel.ai_next);
572 *res = NULL;
573 return error;
574}
575
576/*
577 * FQDN hostname, DNS lookup
578 */
579static int
580explore_fqdn(pai, hostname, servname, res)
581 const struct addrinfo *pai;
582 const char *hostname;
583 const char *servname;
584 struct addrinfo **res;
585{
586 struct addrinfo *result;
587 struct addrinfo *cur;
588 int error = 0;
589 static const ns_dtab dtab[] = {
590 NS_FILES_CB(_files_getaddrinfo, NULL)
591 { NSSRC_DNS, _dns_getaddrinfo, NULL }, /* force -DHESIOD */
592 NS_NIS_CB(_yp_getaddrinfo, NULL)
593 { 0 }
594 };
595
596 result = NULL;
597
598 /*
599 * if the servname does not match socktype/protocol, ignore it.
600 */
601 if (get_portmatch(pai, servname) != 0)
602 return 0;
603
604 switch (nsdispatch(&result, dtab, NSDB_HOSTS, "getaddrinfo",
605 default_dns_files, hostname, pai)) {
606 case NS_TRYAGAIN:
607 error = EAI_AGAIN;
608 goto free;
609 case NS_UNAVAIL:
610 error = EAI_FAIL;
611 goto free;
612 case NS_NOTFOUND:
613 error = EAI_NODATA;
614 goto free;
615 case NS_SUCCESS:
616 error = 0;
617 for (cur = result; cur; cur = cur->ai_next) {
618 GET_PORT(cur, servname);
619 /* canonname should be filled already */
620 }
621 break;
622 }
623
624 *res = result;
625
626 return 0;
627
628free:
629 if (result)
630 freeaddrinfo(result);
631 return error;
632}
633
634/*
635 * hostname == NULL.
636 * passive socket -> anyaddr (0.0.0.0 or ::)
637 * non-passive socket -> localhost (127.0.0.1 or ::1)
638 */
639static int
640explore_null(pai, servname, res)
641 const struct addrinfo *pai;
642 const char *servname;
643 struct addrinfo **res;
644{
645 int s;
646 const struct afd *afd;
647 struct addrinfo *cur;
648 struct addrinfo sentinel;
649 int error;
650
651 *res = NULL;
652 sentinel.ai_next = NULL;
653 cur = &sentinel;
654
655 /*
656 * filter out AFs that are not supported by the kernel
657 * XXX errno?
658 */
659 s = _socket(pai->ai_family, SOCK_DGRAM, 0);
660 if (s < 0) {
661 if (errno != EMFILE)
662 return 0;
663 } else
664 _close(s);
665
666 /*
667 * if the servname does not match socktype/protocol, ignore it.
668 */
669 if (get_portmatch(pai, servname) != 0)
670 return 0;
671
672 afd = find_afd(pai->ai_family);
673 if (afd == NULL)
674 return 0;
675
676 if (pai->ai_flags & AI_PASSIVE) {
677 GET_AI(cur->ai_next, afd, afd->a_addrany);
678 /* xxx meaningless?
679 * GET_CANONNAME(cur->ai_next, "anyaddr");
680 */
681 GET_PORT(cur->ai_next, servname);
682 } else {
683 GET_AI(cur->ai_next, afd, afd->a_loopback);
684 /* xxx meaningless?
685 * GET_CANONNAME(cur->ai_next, "localhost");
686 */
687 GET_PORT(cur->ai_next, servname);
688 }
689 cur = cur->ai_next;
690
691 *res = sentinel.ai_next;
692 return 0;
693
694free:
695 if (sentinel.ai_next)
696 freeaddrinfo(sentinel.ai_next);
697 return error;
698}
699
700/*
701 * numeric hostname
702 */
703static int
704explore_numeric(pai, hostname, servname, res)
705 const struct addrinfo *pai;
706 const char *hostname;
707 const char *servname;
708 struct addrinfo **res;
709{
710 const struct afd *afd;
711 struct addrinfo *cur;
712 struct addrinfo sentinel;
713 int error;
714 char pton[PTON_MAX];
715
716 *res = NULL;
717 sentinel.ai_next = NULL;
718 cur = &sentinel;
719
720 /*
721 * if the servname does not match socktype/protocol, ignore it.
722 */
723 if (get_portmatch(pai, servname) != 0)
724 return 0;
725
726 afd = find_afd(pai->ai_family);
727 if (afd == NULL)
728 return 0;
729
730 switch (afd->a_af) {
731#if 1 /*X/Open spec*/
732 case AF_INET:
733 if (inet_aton(hostname, (struct in_addr *)pton) == 1) {
734 if (pai->ai_family == afd->a_af ||
735 pai->ai_family == PF_UNSPEC /*?*/) {
736 GET_AI(cur->ai_next, afd, pton);
737 GET_PORT(cur->ai_next, servname);
738 while (cur && cur->ai_next)
739 cur = cur->ai_next;
740 } else
741 ERR(EAI_FAMILY); /*xxx*/
742 }
743 break;
744#endif
745 default:
746 if (inet_pton(afd->a_af, hostname, pton) == 1) {
747 if (pai->ai_family == afd->a_af ||
748 pai->ai_family == PF_UNSPEC /*?*/) {
749 GET_AI(cur->ai_next, afd, pton);
750 GET_PORT(cur->ai_next, servname);
751 while (cur && cur->ai_next)
752 cur = cur->ai_next;
753 } else
754 ERR(EAI_FAMILY); /*xxx*/
755 }
756 break;
757 }
758
759 *res = sentinel.ai_next;
760 return 0;
761
762free:
763bad:
764 if (sentinel.ai_next)
765 freeaddrinfo(sentinel.ai_next);
766 return error;
767}
768
769/*
770 * numeric hostname with scope
771 */
772static int
773explore_numeric_scope(pai, hostname, servname, res)
774 const struct addrinfo *pai;
775 const char *hostname;
776 const char *servname;
777 struct addrinfo **res;
778{
779#if !defined(SCOPE_DELIMITER) || !defined(INET6)
780 return explore_numeric(pai, hostname, servname, res);
781#else
782 const struct afd *afd;
783 struct addrinfo *cur;
784 int error;
785 char *cp, *hostname2 = NULL, *scope, *addr;
786 struct sockaddr_in6 *sin6;
787
788 /*
789 * if the servname does not match socktype/protocol, ignore it.
790 */
791 if (get_portmatch(pai, servname) != 0)
792 return 0;
793
794 afd = find_afd(pai->ai_family);
795 if (afd == NULL)
796 return 0;
797
798 if (!afd->a_scoped)
799 return explore_numeric(pai, hostname, servname, res);
800
801 cp = strchr(hostname, SCOPE_DELIMITER);
802 if (cp == NULL)
803 return explore_numeric(pai, hostname, servname, res);
804
805 /*
806 * Handle special case of <scoped_address><delimiter><scope id>
807 */
808 hostname2 = strdup(hostname);
809 if (hostname2 == NULL)
810 return EAI_MEMORY;
811 /* terminate at the delimiter */
812 hostname2[cp - hostname] = '\0';
813 addr = hostname2;
814 scope = cp + 1;
815
816 error = explore_numeric(pai, addr, servname, res);
817 if (error == 0) {
818 int scopeid;
819
820 for (cur = *res; cur; cur = cur->ai_next) {
821 if (cur->ai_family != AF_INET6)
822 continue;
823 sin6 = (struct sockaddr_in6 *)(void *)cur->ai_addr;
824 if ((scopeid = ip6_str2scopeid(scope, sin6)) == -1) {
825 free(hostname2);
826 return(EAI_NODATA); /* XXX: is return OK? */
827 }
828 sin6->sin6_scope_id = scopeid;
829 }
830 }
831
832 free(hostname2);
833
834 return error;
835#endif
836}
837
838static int
839get_canonname(pai, ai, str)
840 const struct addrinfo *pai;
841 struct addrinfo *ai;
842 const char *str;
843{
844 if ((pai->ai_flags & AI_CANONNAME) != 0) {
845 ai->ai_canonname = (char *)malloc(strlen(str) + 1);
846 if (ai->ai_canonname == NULL)
847 return EAI_MEMORY;
848 strcpy(ai->ai_canonname, str);
849 }
850 return 0;
851}
852
853static struct addrinfo *
854get_ai(pai, afd, addr)
855 const struct addrinfo *pai;
856 const struct afd *afd;
857 const char *addr;
858{
859 char *p;
860 struct addrinfo *ai;
861#ifdef FAITH
862 struct in6_addr faith_prefix;
863 char *fp_str;
864 int translate = 0;
865#endif
866
867#ifdef FAITH
868 /*
869 * Transfrom an IPv4 addr into a special IPv6 addr format for
870 * IPv6->IPv4 translation gateway. (only TCP is supported now)
871 *
872 * +-----------------------------------+------------+
873 * | faith prefix part (12 bytes) | embedded |
874 * | | IPv4 addr part (4 bytes)
875 * +-----------------------------------+------------+
876 *
877 * faith prefix part is specified as ascii IPv6 addr format
878 * in environmental variable GAI.
879 * For FAITH to work correctly, routing to faith prefix must be
880 * setup toward a machine where a FAITH daemon operates.
881 * Also, the machine must enable some mechanizm
882 * (e.g. faith interface hack) to divert those packet with
883 * faith prefixed destination addr to user-land FAITH daemon.
884 */
885 fp_str = getenv("GAI");
886 if (fp_str && inet_pton(AF_INET6, fp_str, &faith_prefix) == 1 &&
887 afd->a_af == AF_INET && pai->ai_socktype == SOCK_STREAM) {
888 u_int32_t v4a;
889 u_int8_t v4a_top;
890
891 memcpy(&v4a, addr, sizeof v4a);
892 v4a_top = v4a >> IN_CLASSA_NSHIFT;
893 if (!IN_MULTICAST(v4a) && !IN_EXPERIMENTAL(v4a) &&
894 v4a_top != 0 && v4a != IN_LOOPBACKNET) {
895 afd = &afdl[N_INET6];
896 memcpy(&faith_prefix.s6_addr[12], addr,
897 sizeof(struct in_addr));
898 translate = 1;
899 }
900 }
901#endif
902
903 ai = (struct addrinfo *)malloc(sizeof(struct addrinfo)
904 + (afd->a_socklen));
905 if (ai == NULL)
906 return NULL;
907
908 memcpy(ai, pai, sizeof(struct addrinfo));
909 ai->ai_addr = (struct sockaddr *)(void *)(ai + 1);
910 memset(ai->ai_addr, 0, (size_t)afd->a_socklen);
911 ai->ai_addr->sa_len = afd->a_socklen;
912 ai->ai_addrlen = afd->a_socklen;
913 ai->ai_addr->sa_family = ai->ai_family = afd->a_af;
914 p = (char *)(void *)(ai->ai_addr);
915#ifdef FAITH
916 if (translate == 1)
917 memcpy(p + afd->a_off, &faith_prefix, (size_t)afd->a_addrlen);
918 else
919#endif
920 memcpy(p + afd->a_off, addr, (size_t)afd->a_addrlen);
921 return ai;
922}
923
924static int
925get_portmatch(ai, servname)
926 const struct addrinfo *ai;
927 const char *servname;
928{
929
930 /* get_port does not touch first argument. when matchonly == 1. */
931 /* LINTED const cast */
932 return get_port((struct addrinfo *)ai, servname, 1);
933}
934
935static int
936get_port(ai, servname, matchonly)
937 struct addrinfo *ai;
938 const char *servname;
939 int matchonly;
940{
941 const char *proto;
942 struct servent *sp;
943 int port;
944 int allownumeric;
945
946 if (servname == NULL)
947 return 0;
948 switch (ai->ai_family) {
949 case AF_INET:
950#ifdef AF_INET6
951 case AF_INET6:
952#endif
953 break;
954 default:
955 return 0;
956 }
957
958 switch (ai->ai_socktype) {
959 case SOCK_RAW:
960 return EAI_SERVICE;
961 case SOCK_DGRAM:
962 case SOCK_STREAM:
963 allownumeric = 1;
964 break;
965 case ANY:
966 allownumeric = 0;
967 break;
968 default:
969 return EAI_SOCKTYPE;
970 }
971
972 if (str_isnumber(servname)) {
973 if (!allownumeric)
974 return EAI_SERVICE;
975 port = htons(atoi(servname));
976 if (port < 0 || port > 65535)
977 return EAI_SERVICE;
978 } else {
979 switch (ai->ai_socktype) {
980 case SOCK_DGRAM:
981 proto = "udp";
982 break;
983 case SOCK_STREAM:
984 proto = "tcp";
985 break;
986 default:
987 proto = NULL;
988 break;
989 }
990
991 if ((sp = getservbyname(servname, proto)) == NULL)
992 return EAI_SERVICE;
993 port = sp->s_port;
994 }
995
996 if (!matchonly) {
997 switch (ai->ai_family) {
998 case AF_INET:
999 ((struct sockaddr_in *)(void *)
1000 ai->ai_addr)->sin_port = port;
1001 break;
1002#ifdef INET6
1003 case AF_INET6:
1004 ((struct sockaddr_in6 *)(void *)
1005 ai->ai_addr)->sin6_port = port;
1006 break;
1007#endif
1008 }
1009 }
1010
1011 return 0;
1012}
1013
1014static const struct afd *
1015find_afd(af)
1016 int af;
1017{
1018 const struct afd *afd;
1019
1020 if (af == PF_UNSPEC)
1021 return NULL;
1022 for (afd = afdl; afd->a_af; afd++) {
1023 if (afd->a_af == af)
1024 return afd;
1025 }
1026 return NULL;
1027}
1028
1029/*
1030 * post-2553: AI_ADDRCONFIG check. if we use getipnodeby* as backend, backend
1031 * will take care of it.
1032 * the semantics of AI_ADDRCONFIG is not defined well. we are not sure
1033 * if the code is right or not.
1034 *
1035 * XXX PF_UNSPEC -> PF_INET6 + PF_INET mapping needs to be in sync with
1036 * _dns_getaddrinfo.
1037 */
1038static int
1039addrconfig(pai)
1040 struct addrinfo *pai;
1041{
1042 int s, af;
1043
1044 /*
1045 * TODO:
1046 * Note that implementation dependent test for address
1047 * configuration should be done everytime called
1048 * (or apropriate interval),
1049 * because addresses will be dynamically assigned or deleted.
1050 */
1051 af = pai->ai_family;
1052 if (af == AF_UNSPEC) {
1053 if ((s = _socket(AF_INET6, SOCK_DGRAM, 0)) < 0)
1054 af = AF_INET;
1055 else {
1056 _close(s);
1057 if ((s = _socket(AF_INET, SOCK_DGRAM, 0)) < 0)
1058 af = AF_INET6;
1059 else
1060 _close(s);
1061 }
1062 }
1063 if (af != AF_UNSPEC) {
1064 if ((s = _socket(af, SOCK_DGRAM, 0)) < 0)
1065 return 0;
1066 _close(s);
1067 }
1068 pai->ai_family = af;
1069 return 1;
1070}
1071
1072#ifdef INET6
1073/* convert a string to a scope identifier. XXX: IPv6 specific */
1074static int
1075ip6_str2scopeid(scope, sin6)
1076 char *scope;
1077 struct sockaddr_in6 *sin6;
1078{
1079 int scopeid;
1080 struct in6_addr *a6 = &sin6->sin6_addr;
1081 char *ep;
1082
1083 /* empty scopeid portion is invalid */
1084 if (*scope == '\0')
1085 return -1;
1086
1087 if (IN6_IS_ADDR_LINKLOCAL(a6) || IN6_IS_ADDR_MC_LINKLOCAL(a6)) {
1088 /*
1089 * We currently assume a one-to-one mapping between links
1090 * and interfaces, so we simply use interface indices for
1091 * like-local scopes.
1092 */
1093 scopeid = if_nametoindex(scope);
1094 if (scopeid == 0)
1095 goto trynumeric;
1096 return(scopeid);
1097 }
1098
1099 /* still unclear about literal, allow numeric only - placeholder */
1100 if (IN6_IS_ADDR_SITELOCAL(a6) || IN6_IS_ADDR_MC_SITELOCAL(a6))
1101 goto trynumeric;
1102 if (IN6_IS_ADDR_MC_ORGLOCAL(a6))
1103 goto trynumeric;
1104 else
1105 goto trynumeric; /* global */
1106
1107 /* try to convert to a numeric id as a last resort */
1108 trynumeric:
1109 scopeid = (int)strtoul(scope, &ep, 10);
1110 if (*ep == '\0')
1111 return scopeid;
1112 else
1113 return -1;
1114}
1115#endif
1116
1117#ifdef DEBUG
1118static const char AskedForGot[] =
1119 "gethostby*.getanswer: asked for \"%s\", got \"%s\"";
1120#endif
1121static FILE *hostf = NULL;
1122
1123static struct addrinfo *
1124getanswer(answer, anslen, qname, qtype, pai)
1125 const querybuf *answer;
1126 int anslen;
1127 const char *qname;
1128 int qtype;
1129 const struct addrinfo *pai;
1130{
1131 struct addrinfo sentinel, *cur;
1132 struct addrinfo ai;
1133 const struct afd *afd;
1134 char *canonname;
1135 const HEADER *hp;
1136 const u_char *cp;
1137 int n;
1138 const u_char *eom;
1139 char *bp;
1140 int type, class, buflen, ancount, qdcount;
1141 int haveanswer, had_error;
1142 char tbuf[MAXDNAME];
1143 int (*name_ok) __P((const char *));
1144 char hostbuf[8*1024];
1145
1146 memset(&sentinel, 0, sizeof(sentinel));
1147 cur = &sentinel;
1148
1149 canonname = NULL;
1150 eom = answer->buf + anslen;
1151 switch (qtype) {
1152 case T_A:
1153 case T_AAAA:
1154 case T_ANY: /*use T_ANY only for T_A/T_AAAA lookup*/
1155 name_ok = res_hnok;
1156 break;
1157 default:
1158 return (NULL); /* XXX should be abort(); */
1159 }
1160 /*
1161 * find first satisfactory answer
1162 */
1163 hp = &answer->hdr;
1164 ancount = ntohs(hp->ancount);
1165 qdcount = ntohs(hp->qdcount);
1166 bp = hostbuf;
1167 buflen = sizeof hostbuf;
1168 cp = answer->buf + HFIXEDSZ;
1169 if (qdcount != 1) {
1170 h_errno = NO_RECOVERY;
1171 return (NULL);
1172 }
1173 n = dn_expand(answer->buf, eom, cp, bp, buflen);
1174 if ((n < 0) || !(*name_ok)(bp)) {
1175 h_errno = NO_RECOVERY;
1176 return (NULL);
1177 }
1178 cp += n + QFIXEDSZ;
1179 if (qtype == T_A || qtype == T_AAAA || qtype == T_ANY) {
1180 /* res_send() has already verified that the query name is the
1181 * same as the one we sent; this just gets the expanded name
1182 * (i.e., with the succeeding search-domain tacked on).
1183 */
1184 n = strlen(bp) + 1; /* for the \0 */
1185 if (n >= MAXHOSTNAMELEN) {
1186 h_errno = NO_RECOVERY;
1187 return (NULL);
1188 }
1189 canonname = bp;
1190 bp += n;
1191 buflen -= n;
1192 /* The qname can be abbreviated, but h_name is now absolute. */
1193 qname = canonname;
1194 }
1195 haveanswer = 0;
1196 had_error = 0;
1197 while (ancount-- > 0 && cp < eom && !had_error) {
1198 n = dn_expand(answer->buf, eom, cp, bp, buflen);
1199 if ((n < 0) || !(*name_ok)(bp)) {
1200 had_error++;
1201 continue;
1202 }
1203 cp += n; /* name */
1204 type = _getshort(cp);
1205 cp += INT16SZ; /* type */
1206 class = _getshort(cp);
1207 cp += INT16SZ + INT32SZ; /* class, TTL */
1208 n = _getshort(cp);
1209 cp += INT16SZ; /* len */
1210 if (class != C_IN) {
1211 /* XXX - debug? syslog? */
1212 cp += n;
1213 continue; /* XXX - had_error++ ? */
1214 }
1215 if ((qtype == T_A || qtype == T_AAAA || qtype == T_ANY) &&
1216 type == T_CNAME) {
1217 n = dn_expand(answer->buf, eom, cp, tbuf, sizeof tbuf);
1218 if ((n < 0) || !(*name_ok)(tbuf)) {
1219 had_error++;
1220 continue;
1221 }
1222 cp += n;
1223 /* Get canonical name. */
1224 n = strlen(tbuf) + 1; /* for the \0 */
1225 if (n > buflen || n >= MAXHOSTNAMELEN) {
1226 had_error++;
1227 continue;
1228 }
1229 strcpy(bp, tbuf);
1230 canonname = bp;
1231 bp += n;
1232 buflen -= n;
1233 continue;
1234 }
1235 if (qtype == T_ANY) {
1236 if (!(type == T_A || type == T_AAAA)) {
1237 cp += n;
1238 continue;
1239 }
1240 } else if (type != qtype) {
1241#ifdef DEBUG
1242 if (type != T_KEY && type != T_SIG)
1243 syslog(LOG_NOTICE|LOG_AUTH,
1244 "gethostby*.getanswer: asked for \"%s %s %s\", got type \"%s\"",
1245 qname, p_class(C_IN), p_type(qtype),
1246 p_type(type));
1247#endif
1248 cp += n;
1249 continue; /* XXX - had_error++ ? */
1250 }
1251 switch (type) {
1252 case T_A:
1253 case T_AAAA:
1254 if (strcasecmp(canonname, bp) != 0) {
1255#ifdef DEBUG
1256 syslog(LOG_NOTICE|LOG_AUTH,
1257 AskedForGot, canonname, bp);
1258#endif
1259 cp += n;
1260 continue; /* XXX - had_error++ ? */
1261 }
1262 if (type == T_A && n != INADDRSZ) {
1263 cp += n;
1264 continue;
1265 }
1266 if (type == T_AAAA && n != IN6ADDRSZ) {
1267 cp += n;
1268 continue;
1269 }
1270#ifdef FILTER_V4MAPPED
1271 if (type == T_AAAA) {
1272 struct in6_addr in6;
1273 memcpy(&in6, cp, sizeof(in6));
1274 if (IN6_IS_ADDR_V4MAPPED(&in6)) {
1275 cp += n;
1276 continue;
1277 }
1278 }
1279#endif
1280 if (!haveanswer) {
1281 int nn;
1282
1283 canonname = bp;
1284 nn = strlen(bp) + 1; /* for the \0 */
1285 bp += nn;
1286 buflen -= nn;
1287 }
1288
1289 /* don't overwrite pai */
1290 ai = *pai;
1291 ai.ai_family = (type == T_A) ? AF_INET : AF_INET6;
1292 afd = find_afd(ai.ai_family);
1293 if (afd == NULL) {
1294 cp += n;
1295 continue;
1296 }
1297 cur->ai_next = get_ai(&ai, afd, (const char *)cp);
1298 if (cur->ai_next == NULL)
1299 had_error++;
1300 while (cur && cur->ai_next)
1301 cur = cur->ai_next;
1302 cp += n;
1303 break;
1304 default:
1305 abort();
1306 }
1307 if (!had_error)
1308 haveanswer++;
1309 }
1310 if (haveanswer) {
1311 if (!canonname)
1312 (void)get_canonname(pai, sentinel.ai_next, qname);
1313 else
1314 (void)get_canonname(pai, sentinel.ai_next, canonname);
1315 h_errno = NETDB_SUCCESS;
1316 return sentinel.ai_next;
1317 }
1318
1319 h_errno = NO_RECOVERY;
1320 return NULL;
1321}
1322
1323/*ARGSUSED*/
1324static int
1325_dns_getaddrinfo(rv, cb_data, ap)
1326 void *rv;
1327 void *cb_data;
1328 va_list ap;
1329{
1330 struct addrinfo *ai;
1331 querybuf buf, buf2;
1332 const char *name;
1333 const struct addrinfo *pai;
1334 struct addrinfo sentinel, *cur;
1335 struct res_target q, q2;
1336
1337 name = va_arg(ap, char *);
1338 pai = va_arg(ap, const struct addrinfo *);
1339
1340 memset(&q, 0, sizeof(q2));
1341 memset(&q2, 0, sizeof(q2));
1342 memset(&sentinel, 0, sizeof(sentinel));
1343 cur = &sentinel;
1344
1345 switch (pai->ai_family) {
1346 case AF_UNSPEC:
1347 /* prefer IPv6 */
1348 q.qclass = C_IN;
1349 q.qtype = T_AAAA;
1350 q.answer = buf.buf;
1351 q.anslen = sizeof(buf);
1352 q.next = &q2;
1353 q2.qclass = C_IN;
1354 q2.qtype = T_A;
1355 q2.answer = buf2.buf;
1356 q2.anslen = sizeof(buf2);
1357 break;
1358 case AF_INET:
1359 q.qclass = C_IN;
1360 q.qtype = T_A;
1361 q.answer = buf.buf;
1362 q.anslen = sizeof(buf);
1363 break;
1364 case AF_INET6:
1365 q.qclass = C_IN;
1366 q.qtype = T_AAAA;
1367 q.answer = buf.buf;
1368 q.anslen = sizeof(buf);
1369 break;
1370 default:
1371 return NS_UNAVAIL;
1372 }
1373 if (res_searchN(name, &q) < 0)
1374 return NS_NOTFOUND;
1375 ai = getanswer(&buf, q.n, q.name, q.qtype, pai);
1376 if (ai) {
1377 cur->ai_next = ai;
1378 while (cur && cur->ai_next)
1379 cur = cur->ai_next;
1380 }
1381 if (q.next) {
1382 ai = getanswer(&buf2, q2.n, q2.name, q2.qtype, pai);
1383 if (ai)
1384 cur->ai_next = ai;
1385 }
1386 if (sentinel.ai_next == NULL)
1387 switch (h_errno) {
1388 case HOST_NOT_FOUND:
1389 return NS_NOTFOUND;
1390 case TRY_AGAIN:
1391 return NS_TRYAGAIN;
1392 default:
1393 return NS_UNAVAIL;
1394 }
1395 *((struct addrinfo **)rv) = sentinel.ai_next;
1396 return NS_SUCCESS;
1397}
1398
1399static void
1400_sethtent()
1401{
1402 if (!hostf)
1403 hostf = fopen(_PATH_HOSTS, "r" );
1404 else
1405 rewind(hostf);
1406}
1407
1408static void
1409_endhtent()
1410{
1411 if (hostf) {
1412 (void) fclose(hostf);
1413 hostf = NULL;
1414 }
1415}
1416
1417static struct addrinfo *
1418_gethtent(name, pai)
1419 const char *name;
1420 const struct addrinfo *pai;
1421{
1422 char *p;
1423 char *cp, *tname, *cname;
1424 struct addrinfo hints, *res0, *res;
1425 int error;
1426 const char *addr;
1427 char hostbuf[8*1024];
1428
1429 if (!hostf && !(hostf = fopen(_PATH_HOSTS, "r" )))
1430 return (NULL);
1431 again:
1432 if (!(p = fgets(hostbuf, sizeof hostbuf, hostf)))
1433 return (NULL);
1434 if (*p == '#')
1435 goto again;
1436 if (!(cp = strpbrk(p, "#\n")))
1437 goto again;
1438 *cp = '\0';
1439 if (!(cp = strpbrk(p, " \t")))
1440 goto again;
1441 *cp++ = '\0';
1442 addr = p;
1443 cname = NULL;
1444 /* if this is not something we're looking for, skip it. */
1445 while (cp && *cp) {
1446 if (*cp == ' ' || *cp == '\t') {
1447 cp++;
1448 continue;
1449 }
1450 tname = cp;
1451 if (cname == NULL)
1452 cname = cp;
1453 if ((cp = strpbrk(cp, " \t")) != NULL)
1454 *cp++ = '\0';
1455 if (strcasecmp(name, tname) == 0)
1456 goto found;
1457 }
1458 goto again;
1459
1460found:
1461 hints = *pai;
1462 hints.ai_flags = AI_NUMERICHOST;
1463 error = getaddrinfo(addr, NULL, &hints, &res0);
1464 if (error)
1465 goto again;
1466#ifdef FILTER_V4MAPPED
1467 /* XXX should check all items in the chain */
1468 if (res0->ai_family == AF_INET6 &&
1469 IN6_IS_ADDR_V4MAPPED(&((struct sockaddr_in6 *)res0->ai_addr)->sin6_addr)) {
1470 freeaddrinfo(res0);
1471 goto again;
1472 }
1473#endif
1474 for (res = res0; res; res = res->ai_next) {
1475 /* cover it up */
1476 res->ai_flags = pai->ai_flags;
1477
1478 if (pai->ai_flags & AI_CANONNAME) {
1479 if (get_canonname(pai, res, cname) != 0) {
1480 freeaddrinfo(res0);
1481 goto again;
1482 }
1483 }
1484 }
1485 return res0;
1486}
1487
1488/*ARGSUSED*/
1489static int
1490_files_getaddrinfo(rv, cb_data, ap)
1491 void *rv;
1492 void *cb_data;
1493 va_list ap;
1494{
1495 const char *name;
1496 const struct addrinfo *pai;
1497 struct addrinfo sentinel, *cur;
1498 struct addrinfo *p;
1499
1500 name = va_arg(ap, char *);
1501 pai = va_arg(ap, struct addrinfo *);
1502
1503 memset(&sentinel, 0, sizeof(sentinel));
1504 cur = &sentinel;
1505
1506 _sethtent();
1507 while ((p = _gethtent(name, pai)) != NULL) {
1508 cur->ai_next = p;
1509 while (cur && cur->ai_next)
1510 cur = cur->ai_next;
1511 }
1512 _endhtent();
1513
1514 *((struct addrinfo **)rv) = sentinel.ai_next;
1515 if (sentinel.ai_next == NULL)
1516 return NS_NOTFOUND;
1517 return NS_SUCCESS;
1518}
1519
1520#ifdef YP
1521static char *__ypdomain;
1522
1523/*ARGSUSED*/
1524static struct addrinfo *
1525_yphostent(line, pai)
1526 char *line;
1527 const struct addrinfo *pai;
1528{
1529 struct addrinfo sentinel, *cur;
1530 struct addrinfo hints, *res, *res0;
1531 int error;
1532 char *p = line;
1533 const char *addr, *canonname;
1534 char *nextline;
1535 char *cp;
1536
1537 addr = canonname = NULL;
1538
1539 memset(&sentinel, 0, sizeof(sentinel));
1540 cur = &sentinel;
1541
1542nextline:
1543 /* terminate line */
1544 cp = strchr(p, '\n');
1545 if (cp) {
1546 *cp++ = '\0';
1547 nextline = cp;
1548 } else
1549 nextline = NULL;
1550
1551 cp = strpbrk(p, " \t");
1552 if (cp == NULL) {
1553 if (canonname == NULL)
1554 return (NULL);
1555 else
1556 goto done;
1557 }
1558 *cp++ = '\0';
1559
1560 addr = p;
1561
1562 while (cp && *cp) {
1563 if (*cp == ' ' || *cp == '\t') {
1564 cp++;
1565 continue;
1566 }
1567 if (!canonname)
1568 canonname = cp;
1569 if ((cp = strpbrk(cp, " \t")) != NULL)
1570 *cp++ = '\0';
1571 }
1572
1573 hints = *pai;
1574 hints.ai_flags = AI_NUMERICHOST;
1575 error = getaddrinfo(addr, NULL, &hints, &res0);
1576 if (error == 0) {
1577 for (res = res0; res; res = res->ai_next) {
1578 /* cover it up */
1579 res->ai_flags = pai->ai_flags;
1580
1581 if (pai->ai_flags & AI_CANONNAME)
1582 (void)get_canonname(pai, res, canonname);
1583 }
1584 } else
1585 res0 = NULL;
1586 if (res0) {
1587 cur->ai_next = res0;
1588 while (cur && cur->ai_next)
1589 cur = cur->ai_next;
1590 }
1591
1592 if (nextline) {
1593 p = nextline;
1594 goto nextline;
1595 }
1596
1597done:
1598 return sentinel.ai_next;
1599}
1600
1601/*ARGSUSED*/
1602static int
1603_yp_getaddrinfo(rv, cb_data, ap)
1604 void *rv;
1605 void *cb_data;
1606 va_list ap;
1607{
1608 struct addrinfo sentinel, *cur;
1609 struct addrinfo *ai = NULL;
1610 static char *__ypcurrent;
1611 int __ypcurrentlen, r;
1612 const char *name;
1613 const struct addrinfo *pai;
1614
1615 name = va_arg(ap, char *);
1616 pai = va_arg(ap, const struct addrinfo *);
1617
1618 memset(&sentinel, 0, sizeof(sentinel));
1619 cur = &sentinel;
1620
1621 if (!__ypdomain) {
1622 if (_yp_check(&__ypdomain) == 0)
1623 return NS_UNAVAIL;
1624 }
1625 if (__ypcurrent)
1626 free(__ypcurrent);
1627 __ypcurrent = NULL;
1628
1629 /* hosts.byname is only for IPv4 (Solaris8) */
1630 if (pai->ai_family == PF_UNSPEC || pai->ai_family == PF_INET) {
1631 r = yp_match(__ypdomain, "hosts.byname", name,
1632 (int)strlen(name), &__ypcurrent, &__ypcurrentlen);
1633 if (r == 0) {
1634 struct addrinfo ai4;
1635
1636 ai4 = *pai;
1637 ai4.ai_family = AF_INET;
1638 ai = _yphostent(__ypcurrent, &ai4);
1639 if (ai) {
1640 cur->ai_next = ai;
1641 while (cur && cur->ai_next)
1642 cur = cur->ai_next;
1643 }
1644 }
1645 }
1646
1647 /* ipnodes.byname can hold both IPv4/v6 */
1648 r = yp_match(__ypdomain, "ipnodes.byname", name,
1649 (int)strlen(name), &__ypcurrent, &__ypcurrentlen);
1650 if (r == 0) {
1651 ai = _yphostent(__ypcurrent, pai);
1652 if (ai) {
1653 cur->ai_next = ai;
1654 while (cur && cur->ai_next)
1655 cur = cur->ai_next;
1656 }
1657 }
1658
1659 if (sentinel.ai_next == NULL) {
1660 h_errno = HOST_NOT_FOUND;
1661 return NS_NOTFOUND;
1662 }
1663 *((struct addrinfo **)rv) = sentinel.ai_next;
1664 return NS_SUCCESS;
1665}
1666#endif
1667
1668/* resolver logic */
1669
1670extern const char *__hostalias __P((const char *));
1671extern int h_errno;
1672
1673/*
1674 * Formulate a normal query, send, and await answer.
1675 * Returned answer is placed in supplied buffer "answer".
1676 * Perform preliminary check of answer, returning success only
1677 * if no error is indicated and the answer count is nonzero.
1678 * Return the size of the response on success, -1 on error.
1679 * Error number is left in h_errno.
1680 *
1681 * Caller must parse answer and determine whether it answers the question.
1682 */
1683static int
1684res_queryN(name, target)
1685 const char *name; /* domain name */
1686 struct res_target *target;
1687{
1688 u_char buf[MAXPACKET];
1689 HEADER *hp;
1690 int n;
1691 struct res_target *t;
1692 int rcode;
1693 int ancount;
1694
1695 rcode = NOERROR;
1696 ancount = 0;
1697
1698 if ((_res.options & RES_INIT) == 0 && res_init() == -1) {
1699 h_errno = NETDB_INTERNAL;
1700 return (-1);
1701 }
1702
1703 for (t = target; t; t = t->next) {
1704 int class, type;
1705 u_char *answer;
1706 int anslen;
1707
1708 hp = (HEADER *)(void *)t->answer;
1709 hp->rcode = NOERROR; /* default */
1710
1711 /* make it easier... */
1712 class = t->qclass;
1713 type = t->qtype;
1714 answer = t->answer;
1715 anslen = t->anslen;
1716#ifdef DEBUG
1717 if (_res.options & RES_DEBUG)
1718 printf(";; res_query(%s, %d, %d)\n", name, class, type);
1719#endif
1720
1721 n = res_mkquery(QUERY, name, class, type, NULL, 0, NULL,
1722 buf, sizeof(buf));
1723 if (n > 0 && (_res.options & RES_USE_EDNS0) != 0)
1724 n = res_opt(n, buf, sizeof(buf), anslen);
1725 if (n <= 0) {
1726#ifdef DEBUG
1727 if (_res.options & RES_DEBUG)
1728 printf(";; res_query: mkquery failed\n");
1729#endif
1730 h_errno = NO_RECOVERY;
1731 return (n);
1732 }
1733 n = res_send(buf, n, answer, anslen);
1734#if 0
1735 if (n < 0) {
1736#ifdef DEBUG
1737 if (_res.options & RES_DEBUG)
1738 printf(";; res_query: send error\n");
1739#endif
1740 h_errno = TRY_AGAIN;
1741 return (n);
1742 }
1743#endif
1744
1745 if (n < 0 || hp->rcode != NOERROR || ntohs(hp->ancount) == 0) {
1746 rcode = hp->rcode; /* record most recent error */
1747#ifdef DEBUG
1748 if (_res.options & RES_DEBUG)
1749 printf(";; rcode = %d, ancount=%d\n", hp->rcode,
1750 ntohs(hp->ancount));
1751#endif
1752 continue;
1753 }
1754
1755 ancount += ntohs(hp->ancount);
1756
1757 t->n = n;
1758 }
1759
1760 if (ancount == 0) {
1761 switch (rcode) {
1762 case NXDOMAIN:
1763 h_errno = HOST_NOT_FOUND;
1764 break;
1765 case SERVFAIL:
1766 h_errno = TRY_AGAIN;
1767 break;
1768 case NOERROR:
1769 h_errno = NO_DATA;
1770 break;
1771 case FORMERR:
1772 case NOTIMP:
1773 case REFUSED:
1774 default:
1775 h_errno = NO_RECOVERY;
1776 break;
1777 }
1778 return (-1);
1779 }
1780 return (ancount);
1781}
1782
1783/*
1784 * Formulate a normal query, send, and retrieve answer in supplied buffer.
1785 * Return the size of the response on success, -1 on error.
1786 * If enabled, implement search rules until answer or unrecoverable failure
1787 * is detected. Error code, if any, is left in h_errno.
1788 */
1789static int
1790res_searchN(name, target)
1791 const char *name; /* domain name */
1792 struct res_target *target;
1793{
1794 const char *cp, * const *domain;
1795 HEADER *hp = (HEADER *)(void *)target->answer; /*XXX*/
1796 u_int dots;
1797 int trailing_dot, ret, saved_herrno;
1798 int got_nodata = 0, got_servfail = 0, tried_as_is = 0;
1799
1800 if ((_res.options & RES_INIT) == 0 && res_init() == -1) {
1801 h_errno = NETDB_INTERNAL;
1802 return (-1);
1803 }
1804
1805 errno = 0;
1806 h_errno = HOST_NOT_FOUND; /* default, if we never query */
1807 dots = 0;
1808 for (cp = name; *cp; cp++)
1809 dots += (*cp == '.');
1810 trailing_dot = 0;
1811 if (cp > name && *--cp == '.')
1812 trailing_dot++;
1813
1814 /*
1815 * if there aren't any dots, it could be a user-level alias
1816 */
1817 if (!dots && (cp = __hostalias(name)) != NULL)
1818 return (res_queryN(cp, target));
1819
1820 /*
1821 * If there are dots in the name already, let's just give it a try
1822 * 'as is'. The threshold can be set with the "ndots" option.
1823 */
1824 saved_herrno = -1;
1825 if (dots >= _res.ndots) {
1826 ret = res_querydomainN(name, NULL, target);
1827 if (ret > 0)
1828 return (ret);
1829 saved_herrno = h_errno;
1830 tried_as_is++;
1831 }
1832
1833 /*
1834 * We do at least one level of search if
1835 * - there is no dot and RES_DEFNAME is set, or
1836 * - there is at least one dot, there is no trailing dot,
1837 * and RES_DNSRCH is set.
1838 */
1839 if ((!dots && (_res.options & RES_DEFNAMES)) ||
1840 (dots && !trailing_dot && (_res.options & RES_DNSRCH))) {
1841 int done = 0;
1842
1843 for (domain = (const char * const *)_res.dnsrch;
1844 *domain && !done;
1845 domain++) {
1846
1847 ret = res_querydomainN(name, *domain, target);
1848 if (ret > 0)
1849 return (ret);
1850
1851 /*
1852 * If no server present, give up.
1853 * If name isn't found in this domain,
1854 * keep trying higher domains in the search list
1855 * (if that's enabled).
1856 * On a NO_DATA error, keep trying, otherwise
1857 * a wildcard entry of another type could keep us
1858 * from finding this entry higher in the domain.
1859 * If we get some other error (negative answer or
1860 * server failure), then stop searching up,
1861 * but try the input name below in case it's
1862 * fully-qualified.
1863 */
1864 if (errno == ECONNREFUSED) {
1865 h_errno = TRY_AGAIN;
1866 return (-1);
1867 }
1868
1869 switch (h_errno) {
1870 case NO_DATA:
1871 got_nodata++;
1872 /* FALLTHROUGH */
1873 case HOST_NOT_FOUND:
1874 /* keep trying */
1875 break;
1876 case TRY_AGAIN:
1877 if (hp->rcode == SERVFAIL) {
1878 /* try next search element, if any */
1879 got_servfail++;
1880 break;
1881 }
1882 /* FALLTHROUGH */
1883 default:
1884 /* anything else implies that we're done */
1885 done++;
1886 }
1887 /*
1888 * if we got here for some reason other than DNSRCH,
1889 * we only wanted one iteration of the loop, so stop.
1890 */
1891 if (!(_res.options & RES_DNSRCH))
1892 done++;
1893 }
1894 }
1895
1896 /*
1897 * if we have not already tried the name "as is", do that now.
1898 * note that we do this regardless of how many dots were in the
1899 * name or whether it ends with a dot.
1900 */
1901 if (!tried_as_is && (dots || !(_res.options & RES_NOTLDQUERY))) {
1902 ret = res_querydomainN(name, NULL, target);
1903 if (ret > 0)
1904 return (ret);
1905 }
1906
1907 /*
1908 * if we got here, we didn't satisfy the search.
1909 * if we did an initial full query, return that query's h_errno
1910 * (note that we wouldn't be here if that query had succeeded).
1911 * else if we ever got a nodata, send that back as the reason.
1912 * else send back meaningless h_errno, that being the one from
1913 * the last DNSRCH we did.
1914 */
1915 if (saved_herrno != -1)
1916 h_errno = saved_herrno;
1917 else if (got_nodata)
1918 h_errno = NO_DATA;
1919 else if (got_servfail)
1920 h_errno = TRY_AGAIN;
1921 return (-1);
1922}
1923
1924/*
1925 * Perform a call on res_query on the concatenation of name and domain,
1926 * removing a trailing dot from name if domain is NULL.
1927 */
1928static int
1929res_querydomainN(name, domain, target)
1930 const char *name, *domain;
1931 struct res_target *target;
1932{
1933 char nbuf[MAXDNAME];
1934 const char *longname = nbuf;
1935 size_t n, d;
1936
1937 if ((_res.options & RES_INIT) == 0 && res_init() == -1) {
1938 h_errno = NETDB_INTERNAL;
1939 return (-1);
1940 }
1941#ifdef DEBUG
1942 if (_res.options & RES_DEBUG)
1943 printf(";; res_querydomain(%s, %s)\n",
1944 name, domain?domain:"<Nil>");
1945#endif
1946 if (domain == NULL) {
1947 /*
1948 * Check for trailing '.';
1949 * copy without '.' if present.
1950 */
1951 n = strlen(name);
1952 if (n >= MAXDNAME) {
1953 h_errno = NO_RECOVERY;
1954 return (-1);
1955 }
1956 if (n > 0 && name[--n] == '.') {
1957 strncpy(nbuf, name, n);
1958 nbuf[n] = '\0';
1959 } else
1960 longname = name;
1961 } else {
1962 n = strlen(name);
1963 d = strlen(domain);
1964 if (n + d + 1 >= MAXDNAME) {
1965 h_errno = NO_RECOVERY;
1966 return (-1);
1967 }
1968 sprintf(nbuf, "%s.%s", name, domain);
1969 }
1970 return (res_queryN(longname, target));
1971}