1 /* $NetBSD: getaddrinfo.c,v 1.91.6.1 2009/01/26 00:27:34 snj Exp $ */
2 /* $KAME: getaddrinfo.c,v 1.29 2000/08/31 17:26:57 itojun Exp $ */
3
4 /*
5 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 3. Neither the name of the project nor the names of its contributors
17 * may be used to endorse or promote products derived from this software
18 * without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 * SUCH DAMAGE.
31 */
32
33 /*
34 * Issues to be discussed:
35 * - Return values. There are nonstandard return values defined and used
36 * in the source code. This is because RFC2553 is silent about which error
37 * code must be returned for which situation.
38 * - IPv4 classful (shortened) form. RFC2553 is silent about it. XNET 5.2
39 * says to use inet_aton() to convert IPv4 numeric to binary (alows
40 * classful form as a result).
41 * current code - disallow classful form for IPv4 (due to use of inet_pton).
42 * - freeaddrinfo(NULL). RFC2553 is silent about it. XNET 5.2 says it is
43 * invalid.
44 * current code - SEGV on freeaddrinfo(NULL)
45 * Note:
46 * - The code filters out AFs that are not supported by the kernel,
47 * when globbing NULL hostname (to loopback, or wildcard). Is it the right
48 * thing to do? What is the relationship with post-RFC2553 AI_ADDRCONFIG
49 * in ai_flags?
50 * - (post-2553) semantics of AI_ADDRCONFIG itself is too vague.
51 * (1) what should we do against numeric hostname (2) what should we do
52 * against NULL hostname (3) what is AI_ADDRCONFIG itself. AF not ready?
53 * non-loopback address configured? global address configured?
54 */
55
56 #include <sys/cdefs.h>
57 #if defined(LIBC_SCCS) && !defined(lint)
58 __RCSID("$NetBSD: getaddrinfo.c,v 1.91.6.1 2009/01/26 00:27:34 snj Exp $");
59 #endif /* LIBC_SCCS and not lint */
60
61 #define INET6 1
62
63 #include "namespace.h"
64 #include <sys/types.h>
65 #include <sys/param.h>
66 #include <sys/socket.h>
67 #include <net/if.h>
68 #include <netinet/in.h>
69 #include <arpa/inet.h>
70 #include <arpa/nameser.h>
71 #include <assert.h>
72 #include <ctype.h>
73 #include <errno.h>
74 #include <netdb.h>
75 #include <resolv.h>
76 #include <stddef.h>
77 #include <stdio.h>
78 #include <stdlib.h>
79 #include <string.h>
80 #include <unistd.h>
81
82 #include <stdarg.h>
83 #include <nsswitch.h>
84 #include <resolv.h>
85
86 //#ifdef YP
87 //#include <rpc/rpc.h>
88 //#include <rpcsvc/yp_prot.h>
89 //#include <rpcsvc/ypclnt.h>
90 //#endif
91
92 #include <net/servent.h>
93
94 #define endservent_r(svd) endservent()
95 #define nsdispatch(pResult,dtab,database,routine,files,hostname,pai) NS_NOTFOUND
96 #define res_nmkquery(state,op,dname,class,type,data,datalen,newrr_in,buf,buflen) res_mkquery( op, dname, class, type, data, datalen, newrr_in, buf, buflen )
97 #define res_nsend(state,buf,buflen,ans,anssiz) res_send ( buf, buflen, ans, anssiz )
98
99 /* Things involving an internal (static) resolver context. */
100 __BEGIN_DECLS
101 #define __res_get_state() (( 0 != _res.nscount ) ? &_res : NULL )
102 #define __res_put_state(state)
103 #define __res_state() _res
104 __END_DECLS
105
106 #ifdef __weak_alias
107 __weak_alias(getaddrinfo,_getaddrinfo)
108 __weak_alias(freeaddrinfo,_freeaddrinfo)
109 __weak_alias(gai_strerror,_gai_strerror)
110 #endif
111
112 #define SUCCESS 0
113 #define ANY 0
114 #define YES 1
115 #define NO 0
116
117 static const char in_addrany[] = { 0, 0, 0, 0 };
118 static const char in_loopback[] = { 127, 0, 0, 1 };
119 #ifdef INET6
120 static const char in6_addrany[] = {
121 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
122 };
123 static const char in6_loopback[] = {
124 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1
125 };
126 #endif
127
128 static const struct afd {
129 int a_af;
130 int a_addrlen;
131 int a_socklen;
132 int a_off;
133 const char *a_addrany;
134 const char *a_loopback;
135 int a_scoped;
136 } afdl [] = {
137 #ifdef INET6
138 {PF_INET6, sizeof(struct in6_addr),
139 sizeof(struct sockaddr_in6),
140 offsetof(struct sockaddr_in6, sin6_addr),
141 in6_addrany, in6_loopback, 1},
142 #endif
143 {PF_INET, sizeof(struct in_addr),
144 sizeof(struct sockaddr_in),
145 offsetof(struct sockaddr_in, sin_addr),
146 in_addrany, in_loopback, 0},
147 {0, 0, 0, 0, NULL, NULL, 0},
148 };
149
150 struct explore {
151 int e_af;
152 int e_socktype;
153 int e_protocol;
154 const char *e_protostr;
155 int e_wild;
156 #define WILD_AF(ex) ((ex)->e_wild & 0x01)
157 #define WILD_SOCKTYPE(ex) ((ex)->e_wild & 0x02)
158 #define WILD_PROTOCOL(ex) ((ex)->e_wild & 0x04)
159 };
160
161 static const struct explore explore[] = {
162 #if 0
163 { PF_LOCAL, 0, ANY, ANY, NULL, 0x01 },
164 #endif
165 #ifdef INET6
166 { PF_INET6, SOCK_DGRAM, IPPROTO_UDP, "udp", 0x07 },
167 { PF_INET6, SOCK_STREAM, IPPROTO_TCP, "tcp", 0x07 },
168 { PF_INET6, SOCK_RAW, ANY, NULL, 0x05 },
169 #endif
170 { PF_INET, SOCK_DGRAM, IPPROTO_UDP, "udp", 0x07 },
171 { PF_INET, SOCK_STREAM, IPPROTO_TCP, "tcp", 0x07 },
172 { PF_INET, SOCK_RAW, ANY, NULL, 0x05 },
173 { PF_UNSPEC, SOCK_DGRAM, IPPROTO_UDP, "udp", 0x07 },
174 { PF_UNSPEC, SOCK_STREAM, IPPROTO_TCP, "tcp", 0x07 },
175 { PF_UNSPEC, SOCK_RAW, ANY, NULL, 0x05 },
176 { -1, 0, 0, NULL, 0 },
177 };
178
179 #ifdef INET6
180 #define PTON_MAX 16
181 #else
182 #define PTON_MAX 4
183 #endif
184
185 static const ns_src default_dns_files[] = {
186 { NSSRC_FILES, NS_SUCCESS },
187 { NSSRC_DNS, NS_SUCCESS },
188 { 0, 0 }
189 };
190
191 #define MAXPACKET (64*1024)
192
193 typedef union {
194 HEADER hdr;
195 u_char buf[MAXPACKET];
196 } querybuf;
197
198 struct res_target {
199 struct res_target *next;
200 const char *name; /* domain name */
201 int qclass, qtype; /* class and type of query */
202 u_char *answer; /* buffer to put answer */
203 int anslen; /* size of answer buffer */
204 int n; /* result length */
205 };
206
207 static int str2number(const char *);
208 static int explore_fqdn(const struct addrinfo *, const char *,
209 const char *, struct addrinfo **, struct servent_data *);
210 static int explore_null(const struct addrinfo *,
211 const char *, struct addrinfo **, struct servent_data *);
212 static int explore_numeric(const struct addrinfo *, const char *,
213 const char *, struct addrinfo **, const char *, struct servent_data *);
214 static int explore_numeric_scope(const struct addrinfo *, const char *,
215 const char *, struct addrinfo **, struct servent_data *);
216 static int get_canonname(const struct addrinfo *,
217 struct addrinfo *, const char *);
218 static struct addrinfo *get_ai(const struct addrinfo *,
219 const struct afd *, const char *);
220 static int get_portmatch(const struct addrinfo *, const char *,
221 struct servent_data *);
222 static int get_port(const struct addrinfo *, const char *, int,
223 struct servent_data *);
224 static const struct afd *find_afd(int);
225 #ifdef INET6
226 static int ip6_str2scopeid(char *, struct sockaddr_in6 *, u_int32_t *);
227 #endif
228
229 static struct addrinfo *getanswer(const querybuf *, int, const char *, int,
230 const struct addrinfo *);
231 static void aisort(struct addrinfo *s, res_state res);
232 static int _dns_getaddrinfo(void *, void *, va_list);
233 static void _sethtent(FILE **);
234 static void _endhtent(FILE **);
235 static struct addrinfo *_gethtent(FILE **, const char *,
236 const struct addrinfo *);
237 static int _files_getaddrinfo(void *, void *, va_list);
238 #ifdef YP
239 static struct addrinfo *_yphostent(char *, const struct addrinfo *);
240 static int _yp_getaddrinfo(void *, void *, va_list);
241 #endif
242
243 static int res_queryN(const char *, struct res_target *, res_state);
244 static int res_searchN(const char *, struct res_target *, res_state);
245 static int res_querydomainN(const char *, const char *,
246 struct res_target *, res_state);
247
248 static const char * const ai_errlist[] = {
249 "Success",
250 "Address family for hostname not supported", /* EAI_ADDRFAMILY */
251 "Temporary failure in name resolution", /* EAI_AGAIN */
252 "Invalid value for ai_flags", /* EAI_BADFLAGS */
253 "Non-recoverable failure in name resolution", /* EAI_FAIL */
254 "ai_family not supported", /* EAI_FAMILY */
255 "Memory allocation failure", /* EAI_MEMORY */
256 "No address associated with hostname", /* EAI_NODATA */
257 "hostname nor servname provided, or not known", /* EAI_NONAME */
258 "servname not supported for ai_socktype", /* EAI_SERVICE */
259 "ai_socktype not supported", /* EAI_SOCKTYPE */
260 "System error returned in errno", /* EAI_SYSTEM */
261 "Invalid value for hints", /* EAI_BADHINTS */
262 "Resolved protocol is unknown", /* EAI_PROTOCOL */
263 "Argument buffer overflow", /* EAI_OVERFLOW */
264 "Unknown error", /* EAI_MAX */
265 };
266
267 /* XXX macros that make external reference is BAD. */
268
269 #define GET_AI(ai, afd, addr) \
270 do { \
271 /* external reference: pai, error, and label free */ \
272 (ai) = get_ai(pai, (afd), (addr)); \
273 if ((ai) == NULL) { \
274 error = EAI_MEMORY; \
275 goto free; \
276 } \
277 } while (/*CONSTCOND*/0)
278
279 #define GET_PORT(ai, serv, svd) \
280 do { \
281 /* external reference: error and label free */ \
282 error = get_port((ai), (serv), 0, (svd)); \
283 if (error != 0) \
284 goto free; \
285 } while (/*CONSTCOND*/0)
286
287 #define GET_CANONNAME(ai, str) \
288 do { \
289 /* external reference: pai, error and label free */ \
290 error = get_canonname(pai, (ai), (str)); \
291 if (error != 0) \
292 goto free; \
293 } while (/*CONSTCOND*/0)
294
295 #define ERR(err) \
296 do { \
297 /* external reference: error, and label bad */ \
298 error = (err); \
299 goto bad; \
300 /*NOTREACHED*/ \
301 } while (/*CONSTCOND*/0)
302
303 #define MATCH_FAMILY(x, y, w) \
304 ((x) == (y) || (/*CONSTCOND*/(w) && ((x) == PF_UNSPEC || \
305 (y) == PF_UNSPEC)))
306 #define MATCH(x, y, w) \
307 ((x) == (y) || (/*CONSTCOND*/(w) && ((x) == ANY || (y) == ANY)))
308
309 const char *
gai_strerror(int ecode)310 gai_strerror(int ecode)
311 {
312 if (ecode < 0 || ecode > EAI_MAX)
313 ecode = EAI_MAX;
314 return ai_errlist[ecode];
315 }
316
317 void
freeaddrinfo(struct addrinfo * ai)318 freeaddrinfo(struct addrinfo *ai)
319 {
320 struct addrinfo *next;
321
322 _DIAGASSERT(ai != NULL);
323
324 do {
325 next = ai->ai_next;
326 if (ai->ai_canonname)
327 free(ai->ai_canonname);
328 /* no need to free(ai->ai_addr) */
329 free(ai);
330 ai = next;
331 } while (ai);
332 }
333
334 static int
str2number(const char * p)335 str2number(const char *p)
336 {
337 char *ep;
338 unsigned long v;
339
340 _DIAGASSERT(p != NULL);
341
342 if (*p == '\0')
343 return -1;
344 ep = NULL;
345 errno = 0;
346 v = strtoul(p, &ep, 10);
347 if (errno == 0 && ep && *ep == '\0' && v <= UINT_MAX)
348 return v;
349 else
350 return -1;
351 }
352
353 int
getaddrinfo(const char * hostname,const char * servname,const struct addrinfo * hints,struct addrinfo ** res)354 getaddrinfo(const char *hostname, const char *servname,
355 const struct addrinfo *hints, struct addrinfo **res)
356 {
357 struct addrinfo sentinel;
358 struct addrinfo *cur;
359 int error = 0;
360 struct addrinfo ai;
361 struct addrinfo ai0;
362 struct addrinfo *pai;
363 const struct explore *ex;
364 struct servent_data svd;
365
366 /* hostname is allowed to be NULL */
367 /* servname is allowed to be NULL */
368 /* hints is allowed to be NULL */
369 _DIAGASSERT(res != NULL);
370
371 (void)memset(&svd, 0, sizeof(svd));
372 memset(&sentinel, 0, sizeof(sentinel));
373 cur = &sentinel;
374 memset(&ai, 0, sizeof(ai));
375 pai = &ai;
376 pai->ai_flags = 0;
377 pai->ai_family = PF_UNSPEC;
378 pai->ai_socktype = ANY;
379 pai->ai_protocol = ANY;
380 pai->ai_addrlen = 0;
381 pai->ai_canonname = NULL;
382 pai->ai_addr = NULL;
383 pai->ai_next = NULL;
384
385 if (hostname == NULL && servname == NULL)
386 return EAI_NONAME;
387 if (hints) {
388 /* error check for hints */
389 if (hints->ai_addrlen || hints->ai_canonname ||
390 hints->ai_addr || hints->ai_next)
391 ERR(EAI_BADHINTS); /* xxx */
392 if (hints->ai_flags & ~AI_MASK)
393 ERR(EAI_BADFLAGS);
394 switch (hints->ai_family) {
395 case PF_UNSPEC:
396 case PF_INET:
397 #ifdef INET6
398 case PF_INET6:
399 #endif
400 break;
401 default:
402 ERR(EAI_FAMILY);
403 }
404 memcpy(pai, hints, sizeof(*pai));
405
406 /*
407 * if both socktype/protocol are specified, check if they
408 * are meaningful combination.
409 */
410 if (pai->ai_socktype != ANY && pai->ai_protocol != ANY) {
411 for (ex = explore; ex->e_af >= 0; ex++) {
412 if (pai->ai_family != ex->e_af)
413 continue;
414 if (ex->e_socktype == ANY)
415 continue;
416 if (ex->e_protocol == ANY)
417 continue;
418 if (pai->ai_socktype == ex->e_socktype
419 && pai->ai_protocol != ex->e_protocol) {
420 ERR(EAI_BADHINTS);
421 }
422 }
423 }
424 }
425
426 /*
427 * check for special cases. (1) numeric servname is disallowed if
428 * socktype/protocol are left unspecified. (2) servname is disallowed
429 * for raw and other inet{,6} sockets.
430 */
431 if (MATCH_FAMILY(pai->ai_family, PF_INET, 1)
432 #ifdef PF_INET6
433 || MATCH_FAMILY(pai->ai_family, PF_INET6, 1)
434 #endif
435 ) {
436 ai0 = *pai; /* backup *pai */
437
438 if (pai->ai_family == PF_UNSPEC) {
439 #ifdef PF_INET6
440 pai->ai_family = PF_INET6;
441 #else
442 pai->ai_family = PF_INET;
443 #endif
444 }
445 error = get_portmatch(pai, servname, &svd);
446 if (error)
447 ERR(error);
448
449 *pai = ai0;
450 }
451
452 ai0 = *pai;
453
454 /* NULL hostname, or numeric hostname */
455 for (ex = explore; ex->e_af >= 0; ex++) {
456 *pai = ai0;
457
458 /* PF_UNSPEC entries are prepared for DNS queries only */
459 if (ex->e_af == PF_UNSPEC)
460 continue;
461
462 if (!MATCH_FAMILY(pai->ai_family, ex->e_af, WILD_AF(ex)))
463 continue;
464 if (!MATCH(pai->ai_socktype, ex->e_socktype, WILD_SOCKTYPE(ex)))
465 continue;
466 if (!MATCH(pai->ai_protocol, ex->e_protocol, WILD_PROTOCOL(ex)))
467 continue;
468
469 if (pai->ai_family == PF_UNSPEC)
470 pai->ai_family = ex->e_af;
471 if (pai->ai_socktype == ANY && ex->e_socktype != ANY)
472 pai->ai_socktype = ex->e_socktype;
473 if (pai->ai_protocol == ANY && ex->e_protocol != ANY)
474 pai->ai_protocol = ex->e_protocol;
475
476 if (hostname == NULL)
477 error = explore_null(pai, servname, &cur->ai_next,
478 &svd);
479 else
480 error = explore_numeric_scope(pai, hostname, servname,
481 &cur->ai_next, &svd);
482
483 if (error)
484 goto free;
485
486 while (cur->ai_next)
487 cur = cur->ai_next;
488 }
489
490 /*
491 * XXX
492 * If numeric representation of AF1 can be interpreted as FQDN
493 * representation of AF2, we need to think again about the code below.
494 */
495 if (sentinel.ai_next)
496 goto good;
497
498 if (hostname == NULL)
499 ERR(EAI_NODATA);
500 if (pai->ai_flags & AI_NUMERICHOST)
501 ERR(EAI_NONAME);
502
503 /*
504 * hostname as alphabetical name.
505 * we would like to prefer AF_INET6 than AF_INET, so we'll make a
506 * outer loop by AFs.
507 */
508 for (ex = explore; ex->e_af >= 0; ex++) {
509 *pai = ai0;
510
511 /* require exact match for family field */
512 if (pai->ai_family != ex->e_af)
513 continue;
514
515 if (!MATCH(pai->ai_socktype, ex->e_socktype,
516 WILD_SOCKTYPE(ex))) {
517 continue;
518 }
519 if (!MATCH(pai->ai_protocol, ex->e_protocol,
520 WILD_PROTOCOL(ex))) {
521 continue;
522 }
523
524 if (pai->ai_socktype == ANY && ex->e_socktype != ANY)
525 pai->ai_socktype = ex->e_socktype;
526 if (pai->ai_protocol == ANY && ex->e_protocol != ANY)
527 pai->ai_protocol = ex->e_protocol;
528
529 error = explore_fqdn(pai, hostname, servname, &cur->ai_next,
530 &svd);
531
532 while (cur && cur->ai_next)
533 cur = cur->ai_next;
534 }
535
536 /* XXX */
537 if (sentinel.ai_next)
538 error = 0;
539
540 if (error)
541 goto free;
542
543 if (sentinel.ai_next) {
544 good:
545 endservent_r(&svd);
546 *res = sentinel.ai_next;
547 return SUCCESS;
548 } else
549 error = EAI_FAIL;
550 free:
551 bad:
552 endservent_r(&svd);
553 if (sentinel.ai_next)
554 freeaddrinfo(sentinel.ai_next);
555 *res = NULL;
556 return error;
557 }
558
559 static const ns_dtab dtab[] = {
560 NS_FILES_CB(((nss_method)_files_getaddrinfo), NULL)
561 { NSSRC_DNS, ((nss_method)_dns_getaddrinfo), NULL }, /* force -DHESIOD */
562 NS_NIS_CB(_yp_getaddrinfo, NULL)
563 NS_NULL_CB
564 };
565
566 /*
567 * FQDN hostname, DNS lookup
568 */
569 static int
explore_fqdn(const struct addrinfo * pai,const char * hostname,const char * servname,struct addrinfo ** res,struct servent_data * svd)570 explore_fqdn(const struct addrinfo *pai, const char *hostname,
571 const char *servname, struct addrinfo **res, struct servent_data *svd)
572 {
573 struct addrinfo *result;
574 struct addrinfo *cur;
575 int error = 0;
576
577 _DIAGASSERT(pai != NULL);
578 /* hostname may be NULL */
579 /* servname may be NULL */
580 _DIAGASSERT(res != NULL);
581
582 result = NULL;
583
584 /*
585 * if the servname does not match socktype/protocol, ignore it.
586 */
587 if (get_portmatch(pai, servname, svd) != 0)
588 return 0;
589
590 switch (nsdispatch(&result, dtab, NSDB_HOSTS, "getaddrinfo",
591 default_dns_files, hostname, pai)) {
592 case NS_TRYAGAIN:
593 error = EAI_AGAIN;
594 goto free;
595 case NS_UNAVAIL:
596 error = EAI_FAIL;
597 goto free;
598 case NS_NOTFOUND:
599 error = EAI_NODATA;
600 goto free;
601 case NS_SUCCESS:
602 error = 0;
603 for (cur = result; cur; cur = cur->ai_next) {
604 GET_PORT(cur, servname, svd);
605 /* canonname should be filled already */
606 }
607 break;
608 }
609
610 *res = result;
611
612 return 0;
613
614 free:
615 if (result)
616 freeaddrinfo(result);
617 return error;
618 }
619
620 /*
621 * hostname == NULL.
622 * passive socket -> anyaddr (0.0.0.0 or ::)
623 * non-passive socket -> localhost (127.0.0.1 or ::1)
624 */
625 static int
explore_null(const struct addrinfo * pai,const char * servname,struct addrinfo ** res,struct servent_data * svd)626 explore_null(const struct addrinfo *pai, const char *servname,
627 struct addrinfo **res, struct servent_data *svd)
628 {
629 int s;
630 const struct afd *afd;
631 struct addrinfo *cur;
632 struct addrinfo sentinel;
633 int error;
634
635 _DIAGASSERT(pai != NULL);
636 /* servname may be NULL */
637 _DIAGASSERT(res != NULL);
638
639 *res = NULL;
640 sentinel.ai_next = NULL;
641 cur = &sentinel;
642
643 /*
644 * filter out AFs that are not supported by the kernel
645 * XXX errno?
646 */
647 s = socket(pai->ai_family, SOCK_DGRAM, 0);
648 if (s < 0) {
649 if (errno != EMFILE)
650 return 0;
651 } else
652 close(s);
653
654 /*
655 * if the servname does not match socktype/protocol, ignore it.
656 */
657 if (get_portmatch(pai, servname, svd) != 0)
658 return 0;
659
660 afd = find_afd(pai->ai_family);
661 if (afd == NULL)
662 return 0;
663
664 if (pai->ai_flags & AI_PASSIVE) {
665 GET_AI(cur->ai_next, afd, afd->a_addrany);
666 /* xxx meaningless?
667 * GET_CANONNAME(cur->ai_next, "anyaddr");
668 */
669 GET_PORT(cur->ai_next, servname, svd);
670 } else {
671 GET_AI(cur->ai_next, afd, afd->a_loopback);
672 /* xxx meaningless?
673 * GET_CANONNAME(cur->ai_next, "localhost");
674 */
675 GET_PORT(cur->ai_next, servname, svd);
676 }
677 cur = cur->ai_next;
678
679 *res = sentinel.ai_next;
680 return 0;
681
682 free:
683 if (sentinel.ai_next)
684 freeaddrinfo(sentinel.ai_next);
685 return error;
686 }
687
688 /*
689 * numeric hostname
690 */
691 static int
explore_numeric(const struct addrinfo * pai,const char * hostname,const char * servname,struct addrinfo ** res,const char * canonname,struct servent_data * svd)692 explore_numeric(const struct addrinfo *pai, const char *hostname,
693 const char *servname, struct addrinfo **res, const char *canonname,
694 struct servent_data *svd)
695 {
696 const struct afd *afd;
697 struct addrinfo *cur;
698 struct addrinfo sentinel;
699 int error;
700 char pton[PTON_MAX];
701
702 _DIAGASSERT(pai != NULL);
703 /* hostname may be NULL */
704 /* servname may be NULL */
705 _DIAGASSERT(res != NULL);
706
707 *res = NULL;
708 sentinel.ai_next = NULL;
709 cur = &sentinel;
710
711 /*
712 * if the servname does not match socktype/protocol, ignore it.
713 */
714 if (get_portmatch(pai, servname, svd) != 0)
715 return 0;
716
717 afd = find_afd(pai->ai_family);
718 if (afd == NULL)
719 return 0;
720
721 switch (afd->a_af) {
722 #if 0 /*X/Open spec*/
723 case AF_INET:
724 if (inet_aton(hostname, (struct in_addr *)pton) == 1) {
725 if (pai->ai_family == afd->a_af ||
726 pai->ai_family == PF_UNSPEC /*?*/) {
727 GET_AI(cur->ai_next, afd, pton);
728 GET_PORT(cur->ai_next, servname, svd);
729 if ((pai->ai_flags & AI_CANONNAME)) {
730 /*
731 * Set the numeric address itself as
732 * the canonical name, based on a
733 * clarification in rfc2553bis-03.
734 */
735 GET_CANONNAME(cur->ai_next, canonname);
736 }
737 while (cur && cur->ai_next)
738 cur = cur->ai_next;
739 } else
740 ERR(EAI_FAMILY); /*xxx*/
741 }
742 break;
743 #endif
744 default:
745 if (inet_pton(afd->a_af, hostname, pton) == 1) {
746 if (pai->ai_family == afd->a_af ||
747 pai->ai_family == PF_UNSPEC /*?*/) {
748 GET_AI(cur->ai_next, afd, pton);
749 GET_PORT(cur->ai_next, servname, svd);
750 if ((pai->ai_flags & AI_CANONNAME)) {
751 /*
752 * Set the numeric address itself as
753 * the canonical name, based on a
754 * clarification in rfc2553bis-03.
755 */
756 GET_CANONNAME(cur->ai_next, canonname);
757 }
758 while (cur->ai_next)
759 cur = cur->ai_next;
760 } else
761 ERR(EAI_FAMILY); /*xxx*/
762 }
763 break;
764 }
765
766 *res = sentinel.ai_next;
767 return 0;
768
769 free:
770 bad:
771 if (sentinel.ai_next)
772 freeaddrinfo(sentinel.ai_next);
773 return error;
774 }
775
776 /*
777 * numeric hostname with scope
778 */
779 static int
explore_numeric_scope(const struct addrinfo * pai,const char * hostname,const char * servname,struct addrinfo ** res,struct servent_data * svd)780 explore_numeric_scope(const struct addrinfo *pai, const char *hostname,
781 const char *servname, struct addrinfo **res, struct servent_data *svd)
782 {
783 #if !defined(SCOPE_DELIMITER) || !defined(INET6)
784 return explore_numeric(pai, hostname, servname, res, hostname, svd);
785 #else
786 const struct afd *afd;
787 struct addrinfo *cur;
788 int error;
789 char *cp, *hostname2 = NULL, *scope, *addr;
790 struct sockaddr_in6 *sin6;
791
792 _DIAGASSERT(pai != NULL);
793 /* hostname may be NULL */
794 /* servname may be NULL */
795 _DIAGASSERT(res != NULL);
796
797 /*
798 * if the servname does not match socktype/protocol, ignore it.
799 */
800 if (get_portmatch(pai, servname, svd) != 0)
801 return 0;
802
803 afd = find_afd(pai->ai_family);
804 if (afd == NULL)
805 return 0;
806
807 if (!afd->a_scoped)
808 return explore_numeric(pai, hostname, servname, res, hostname,
809 svd);
810
811 cp = strchr(hostname, SCOPE_DELIMITER);
812 if (cp == NULL)
813 return explore_numeric(pai, hostname, servname, res, hostname,
814 svd);
815
816 /*
817 * Handle special case of <scoped_address><delimiter><scope id>
818 */
819 hostname2 = strdup(hostname);
820 if (hostname2 == NULL)
821 return EAI_MEMORY;
822 /* terminate at the delimiter */
823 hostname2[cp - hostname] = '\0';
824 addr = hostname2;
825 scope = cp + 1;
826
827 error = explore_numeric(pai, addr, servname, res, hostname, svd);
828 if (error == 0) {
829 u_int32_t scopeid;
830
831 for (cur = *res; cur; cur = cur->ai_next) {
832 if (cur->ai_family != AF_INET6)
833 continue;
834 sin6 = (struct sockaddr_in6 *)(void *)cur->ai_addr;
835 if (ip6_str2scopeid(scope, sin6, &scopeid) == -1) {
836 free(hostname2);
837 return(EAI_NODATA); /* XXX: is return OK? */
838 }
839 sin6->sin6_scope_id = scopeid;
840 }
841 }
842
843 free(hostname2);
844
845 return error;
846 #endif
847 }
848
849 static int
get_canonname(const struct addrinfo * pai,struct addrinfo * ai,const char * str)850 get_canonname(const struct addrinfo *pai, struct addrinfo *ai, const char *str)
851 {
852
853 _DIAGASSERT(pai != NULL);
854 _DIAGASSERT(ai != NULL);
855 _DIAGASSERT(str != NULL);
856
857 if ((pai->ai_flags & AI_CANONNAME) != 0) {
858 ai->ai_canonname = strdup(str);
859 if (ai->ai_canonname == NULL)
860 return EAI_MEMORY;
861 }
862 return 0;
863 }
864
865 static struct addrinfo *
get_ai(const struct addrinfo * pai,const struct afd * afd,const char * addr)866 get_ai(const struct addrinfo *pai, const struct afd *afd, const char *addr)
867 {
868 char *p;
869 struct addrinfo *ai;
870
871 _DIAGASSERT(pai != NULL);
872 _DIAGASSERT(afd != NULL);
873 _DIAGASSERT(addr != NULL);
874
875 ai = (struct addrinfo *)malloc(sizeof(struct addrinfo)
876 + (afd->a_socklen));
877 if (ai == NULL)
878 return NULL;
879
880 memcpy(ai, pai, sizeof(struct addrinfo));
881 ai->ai_addr = (struct sockaddr *)(void *)(ai + 1);
882 memset(ai->ai_addr, 0, (size_t)afd->a_socklen);
883 ai->ai_addr->sa_len = (uint8_t)afd->a_socklen;
884 ai->ai_addrlen = afd->a_socklen;
885 ai->ai_family = afd->a_af;
886 ai->ai_addr->sa_family = (sa_family_t)ai->ai_family;
887 p = (char *)(void *)(ai->ai_addr);
888 memcpy(p + afd->a_off, addr, (size_t)afd->a_addrlen);
889 return ai;
890 }
891
892 static int
get_portmatch(const struct addrinfo * ai,const char * servname,struct servent_data * svd)893 get_portmatch(const struct addrinfo *ai, const char *servname,
894 struct servent_data *svd)
895 {
896
897 _DIAGASSERT(ai != NULL);
898 /* servname may be NULL */
899
900 return get_port(ai, servname, 1, svd);
901 }
902
903 static int
get_port(const struct addrinfo * ai,const char * servname,int matchonly,struct servent_data * svd)904 get_port(const struct addrinfo *ai, const char *servname, int matchonly,
905 struct servent_data *svd)
906 {
907 const char *proto;
908 struct servent *sp;
909 int port;
910 int allownumeric;
911
912 _DIAGASSERT(ai != NULL);
913 /* servname may be NULL */
914
915 if (servname == NULL)
916 return 0;
917 switch (ai->ai_family) {
918 case AF_INET:
919 #ifdef AF_INET6
920 case AF_INET6:
921 #endif
922 break;
923 default:
924 return 0;
925 }
926
927 switch (ai->ai_socktype) {
928 case SOCK_RAW:
929 return EAI_SERVICE;
930 case SOCK_DGRAM:
931 case SOCK_STREAM:
932 allownumeric = 1;
933 break;
934 case ANY:
935 /*
936 * This was 0. It is now 1 so that queries specifying
937 * a NULL hint, or hint without socktype (but, hopefully,
938 * with protocol) and numeric address actually work.
939 */
940 allownumeric = 1;
941 break;
942 default:
943 return EAI_SOCKTYPE;
944 }
945
946 port = str2number(servname);
947 if (port >= 0) {
948 if (!allownumeric)
949 return EAI_SERVICE;
950 if (port < 0 || port > 65535)
951 return EAI_SERVICE;
952 port = htons(port);
953 } else {
954 // struct servent sv;
955 if (ai->ai_flags & AI_NUMERICSERV)
956 return EAI_NONAME;
957
958 switch (ai->ai_socktype) {
959 case SOCK_DGRAM:
960 proto = "udp";
961 break;
962 case SOCK_STREAM:
963 proto = "tcp";
964 break;
965 default:
966 proto = NULL;
967 break;
968 }
969
970 // sp = getservbyname_r(servname, proto, &sv, svd);
971 sp = getservbyname ( servname, proto );
972 if (sp == NULL)
973 return EAI_SERVICE;
974 port = sp->s_port;
975 }
976
977 if (!matchonly) {
978 switch (ai->ai_family) {
979 case AF_INET:
980 ((struct sockaddr_in *)(void *)
981 ai->ai_addr)->sin_port = (in_port_t)port;
982 break;
983 #ifdef INET6
984 case AF_INET6:
985 ((struct sockaddr_in6 *)(void *)
986 ai->ai_addr)->sin6_port = (in_port_t)port;
987 break;
988 #endif
989 }
990 }
991
992 return 0;
993 }
994
995 static const struct afd *
find_afd(int af)996 find_afd(int af)
997 {
998 const struct afd *afd;
999
1000 if (af == PF_UNSPEC)
1001 return NULL;
1002 for (afd = afdl; afd->a_af; afd++) {
1003 if (afd->a_af == af)
1004 return afd;
1005 }
1006 return NULL;
1007 }
1008
1009 #ifdef INET6
1010 /* convert a string to a scope identifier. XXX: IPv6 specific */
1011 static int
ip6_str2scopeid(char * scope,struct sockaddr_in6 * sin6,u_int32_t * scopeid)1012 ip6_str2scopeid(char *scope, struct sockaddr_in6 *sin6, u_int32_t *scopeid)
1013 {
1014 u_long lscopeid;
1015 struct in6_addr *a6;
1016 char *ep;
1017
1018 _DIAGASSERT(scope != NULL);
1019 _DIAGASSERT(sin6 != NULL);
1020 _DIAGASSERT(scopeid != NULL);
1021
1022 a6 = &sin6->sin6_addr;
1023
1024 /* empty scopeid portion is invalid */
1025 if (*scope == '\0')
1026 return -1;
1027
1028 if (IN6_IS_ADDR_LINKLOCAL(a6) || IN6_IS_ADDR_MC_LINKLOCAL(a6)) {
1029 /*
1030 * We currently assume a one-to-one mapping between links
1031 * and interfaces, so we simply use interface indices for
1032 * like-local scopes.
1033 */
1034 /*
1035 *scopeid = if_nametoindex(scope);
1036 if (*scopeid == 0)
1037 goto trynumeric;
1038 return 0;
1039 */
1040 return -1;
1041 }
1042
1043 /* still unclear about literal, allow numeric only - placeholder */
1044 if (IN6_IS_ADDR_SITELOCAL(a6) || IN6_IS_ADDR_MC_SITELOCAL(a6))
1045 goto trynumeric;
1046 if (IN6_IS_ADDR_MC_ORGLOCAL(a6))
1047 goto trynumeric;
1048 else
1049 goto trynumeric; /* global */
1050
1051 /* try to convert to a numeric id as a last resort */
1052 trynumeric:
1053 errno = 0;
1054 lscopeid = strtoul(scope, &ep, 10);
1055 *scopeid = (u_int32_t)(lscopeid & 0xffffffffUL);
1056 if (errno == 0 && ep && *ep == '\0' && *scopeid == lscopeid)
1057 return 0;
1058 else
1059 return -1;
1060 }
1061 #endif
1062
1063 /* code duplicate with gethnamaddr.c */
1064
1065 static const char AskedForGot[] =
1066 "gethostby*.getanswer: asked for \"%s\", got \"%s\"";
1067
1068 static struct addrinfo *
getanswer(const querybuf * answer,int anslen,const char * qname,int qtype,const struct addrinfo * pai)1069 getanswer(const querybuf *answer, int anslen, const char *qname, int qtype,
1070 const struct addrinfo *pai)
1071 {
1072 struct addrinfo sentinel, *cur;
1073 struct addrinfo ai;
1074 const struct afd *afd;
1075 char *canonname;
1076 const HEADER *hp;
1077 const u_char *cp;
1078 int n;
1079 const u_char *eom;
1080 char *bp, *ep;
1081 int type, class, ancount, qdcount;
1082 int haveanswer, had_error;
1083 char tbuf[MAXDNAME];
1084 int (*name_ok) (const char *);
1085 static char hostbuf[8*1024];
1086
1087 _DIAGASSERT(answer != NULL);
1088 _DIAGASSERT(qname != NULL);
1089 _DIAGASSERT(pai != NULL);
1090
1091 memset(&sentinel, 0, sizeof(sentinel));
1092 cur = &sentinel;
1093
1094 canonname = NULL;
1095 eom = answer->buf + anslen;
1096 switch (qtype) {
1097 case T_A:
1098 case T_AAAA:
1099 case T_ANY: /*use T_ANY only for T_A/T_AAAA lookup*/
1100 name_ok = res_hnok;
1101 break;
1102 default:
1103 return NULL; /* XXX should be abort(); */
1104 }
1105 /*
1106 * find first satisfactory answer
1107 */
1108 hp = &answer->hdr;
1109 ancount = ntohs(hp->ancount);
1110 qdcount = ntohs(hp->qdcount);
1111 bp = hostbuf;
1112 ep = hostbuf + sizeof hostbuf;
1113 cp = answer->buf + HFIXEDSZ;
1114 if (qdcount != 1) {
1115 h_errno = NO_RECOVERY;
1116 return (NULL);
1117 }
1118 n = dn_expand(answer->buf, eom, cp, bp, (int)(ep - bp));
1119 if ((n < 0) || !(*name_ok)(bp)) {
1120 h_errno = NO_RECOVERY;
1121 return (NULL);
1122 }
1123 cp += n + QFIXEDSZ;
1124 if (qtype == T_A || qtype == T_AAAA || qtype == T_ANY) {
1125 /* res_send() has already verified that the query name is the
1126 * same as the one we sent; this just gets the expanded name
1127 * (i.e., with the succeeding search-domain tacked on).
1128 */
1129 n = (int)strlen(bp) + 1; /* for the \0 */
1130 if (n >= MAXHOSTNAMELEN) {
1131 h_errno = NO_RECOVERY;
1132 return (NULL);
1133 }
1134 canonname = bp;
1135 bp += n;
1136 /* The qname can be abbreviated, but h_name is now absolute. */
1137 qname = canonname;
1138 }
1139 haveanswer = 0;
1140 had_error = 0;
1141 while (ancount-- > 0 && cp < eom && !had_error) {
1142 n = dn_expand(answer->buf, eom, cp, bp, (int)(ep - bp));
1143 if ((n < 0) || !(*name_ok)(bp)) {
1144 had_error++;
1145 continue;
1146 }
1147 cp += n; /* name */
1148 type = _getshort(cp);
1149 cp += INT16SZ; /* type */
1150 class = _getshort(cp);
1151 cp += INT16SZ + INT32SZ; /* class, TTL */
1152 n = _getshort(cp);
1153 cp += INT16SZ; /* len */
1154 if (class != C_IN) {
1155 /* XXX - debug? syslog? */
1156 cp += n;
1157 continue; /* XXX - had_error++ ? */
1158 }
1159 if ((qtype == T_A || qtype == T_AAAA || qtype == T_ANY) &&
1160 type == T_CNAME) {
1161 n = dn_expand(answer->buf, eom, cp, tbuf, sizeof tbuf);
1162 if ((n < 0) || !(*name_ok)(tbuf)) {
1163 had_error++;
1164 continue;
1165 }
1166 cp += n;
1167 /* Get canonical name. */
1168 n = (int)strlen(tbuf) + 1; /* for the \0 */
1169 if (n > ep - bp || n >= MAXHOSTNAMELEN) {
1170 had_error++;
1171 continue;
1172 }
1173 strlcpy(bp, tbuf, (size_t)(ep - bp));
1174 canonname = bp;
1175 bp += n;
1176 continue;
1177 }
1178 if (qtype == T_ANY) {
1179 if (!(type == T_A || type == T_AAAA)) {
1180 cp += n;
1181 continue;
1182 }
1183 } else if (type != qtype) {
1184 if (type != T_KEY && type != T_SIG) {
1185 #ifdef _ORG_FREEBSD_
1186 struct syslog_data sd = SYSLOG_DATA_INIT;
1187 syslog_r(LOG_NOTICE|LOG_AUTH, &sd,
1188 "gethostby*.getanswer: asked for \"%s %s %s\", got type \"%s\"",
1189 qname, p_class(C_IN), p_type(qtype),
1190 p_type(type));
1191 #endif
1192 }
1193 cp += n;
1194 continue; /* XXX - had_error++ ? */
1195 }
1196 switch (type) {
1197 case T_A:
1198 case T_AAAA:
1199 if (strcasecmp(canonname, bp) != 0) {
1200 #ifdef _ORG_FREEBSD_
1201 struct syslog_data sd = SYSLOG_DATA_INIT;
1202 syslog_r(LOG_NOTICE|LOG_AUTH, &sd,
1203 AskedForGot, canonname, bp);
1204 #endif
1205 cp += n;
1206 continue; /* XXX - had_error++ ? */
1207 }
1208 if (type == T_A && n != INADDRSZ) {
1209 cp += n;
1210 continue;
1211 }
1212 if (type == T_AAAA && n != IN6ADDRSZ) {
1213 cp += n;
1214 continue;
1215 }
1216 if (type == T_AAAA) {
1217 struct in6_addr in6;
1218 memcpy(&in6, cp, IN6ADDRSZ);
1219 if (IN6_IS_ADDR_V4MAPPED(&in6)) {
1220 cp += n;
1221 continue;
1222 }
1223 }
1224 if (!haveanswer) {
1225 int nn;
1226
1227 canonname = bp;
1228 nn = (int)strlen(bp) + 1; /* for the \0 */
1229 bp += nn;
1230 }
1231
1232 /* don't overwrite pai */
1233 ai = *pai;
1234 ai.ai_family = (type == T_A) ? AF_INET : AF_INET6;
1235 afd = find_afd(ai.ai_family);
1236 if (afd == NULL) {
1237 cp += n;
1238 continue;
1239 }
1240 cur->ai_next = get_ai(&ai, afd, (const char *)cp);
1241 if (cur->ai_next == NULL)
1242 had_error++;
1243 while (cur && cur->ai_next)
1244 cur = cur->ai_next;
1245 cp += n;
1246 break;
1247 default:
1248 abort();
1249 }
1250 if (!had_error)
1251 haveanswer++;
1252 }
1253 if (haveanswer) {
1254 if (!canonname)
1255 (void)get_canonname(pai, sentinel.ai_next, qname);
1256 else
1257 (void)get_canonname(pai, sentinel.ai_next, canonname);
1258 h_errno = NETDB_SUCCESS;
1259 return sentinel.ai_next;
1260 }
1261
1262 h_errno = NO_RECOVERY;
1263 return NULL;
1264 }
1265
1266 #define SORTEDADDR(p) (((struct sockaddr_in *)(void *)(p->ai_next->ai_addr))->sin_addr.s_addr)
1267 #define SORTMATCH(p, s) ((SORTEDADDR(p) & (s).mask) == (s).addr.s_addr)
1268
1269 static void
aisort(struct addrinfo * s,res_state res)1270 aisort(struct addrinfo *s, res_state res)
1271 {
1272 struct addrinfo head, *t, *p;
1273 int i;
1274
1275 head.ai_next = NULL;
1276 t = &head;
1277
1278 for (i = 0; i < (int)res->nsort; i++) {
1279 p = s;
1280 while (p->ai_next) {
1281 if ((p->ai_next->ai_family != AF_INET)
1282 || SORTMATCH(p, res->sort_list[i])) {
1283 t->ai_next = p->ai_next;
1284 t = t->ai_next;
1285 p->ai_next = p->ai_next->ai_next;
1286 } else {
1287 p = p->ai_next;
1288 }
1289 }
1290 }
1291
1292 /* add rest of list and reset s to the new list*/
1293 t->ai_next = s->ai_next;
1294 s->ai_next = head.ai_next;
1295 }
1296
1297 /*ARGSUSED*/
1298 static int
_dns_getaddrinfo(void * rv,void * cb_data,va_list ap)1299 _dns_getaddrinfo(void *rv, void *cb_data, va_list ap)
1300 {
1301 struct addrinfo *ai;
1302 querybuf *buf, *buf2;
1303 const char *name;
1304 const struct addrinfo *pai;
1305 struct addrinfo sentinel, *cur;
1306 struct res_target q, q2;
1307 res_state res;
1308
1309 name = va_arg(ap, char *);
1310 pai = va_arg(ap, const struct addrinfo *);
1311
1312 memset(&q, 0, sizeof(q));
1313 memset(&q2, 0, sizeof(q2));
1314 memset(&sentinel, 0, sizeof(sentinel));
1315 cur = &sentinel;
1316
1317 buf = malloc(sizeof(*buf));
1318 if (buf == NULL) {
1319 h_errno = NETDB_INTERNAL;
1320 return NS_NOTFOUND;
1321 }
1322 buf2 = malloc(sizeof(*buf2));
1323 if (buf2 == NULL) {
1324 free(buf);
1325 h_errno = NETDB_INTERNAL;
1326 return NS_NOTFOUND;
1327 }
1328
1329 switch (pai->ai_family) {
1330 case AF_UNSPEC:
1331 /* prefer IPv6 */
1332 q.name = name;
1333 q.qclass = C_IN;
1334 q.qtype = T_AAAA;
1335 q.answer = buf->buf;
1336 q.anslen = sizeof(buf->buf);
1337 q.next = &q2;
1338 q2.name = name;
1339 q2.qclass = C_IN;
1340 q2.qtype = T_A;
1341 q2.answer = buf2->buf;
1342 q2.anslen = sizeof(buf2->buf);
1343 break;
1344 case AF_INET:
1345 q.name = name;
1346 q.qclass = C_IN;
1347 q.qtype = T_A;
1348 q.answer = buf->buf;
1349 q.anslen = sizeof(buf->buf);
1350 break;
1351 case AF_INET6:
1352 q.name = name;
1353 q.qclass = C_IN;
1354 q.qtype = T_AAAA;
1355 q.answer = buf->buf;
1356 q.anslen = sizeof(buf->buf);
1357 break;
1358 default:
1359 free(buf);
1360 free(buf2);
1361 return NS_UNAVAIL;
1362 }
1363
1364 res = __res_get_state();
1365 if (res == NULL) {
1366 free(buf);
1367 free(buf2);
1368 return NS_NOTFOUND;
1369 }
1370
1371 if (res_searchN(name, &q, res) < 0) {
1372 __res_put_state(res);
1373 free(buf);
1374 free(buf2);
1375 return NS_NOTFOUND;
1376 }
1377 ai = getanswer(buf, q.n, q.name, q.qtype, pai);
1378 if (ai) {
1379 cur->ai_next = ai;
1380 while (cur && cur->ai_next)
1381 cur = cur->ai_next;
1382 }
1383 if (q.next) {
1384 ai = getanswer(buf2, q2.n, q2.name, q2.qtype, pai);
1385 if (ai)
1386 cur->ai_next = ai;
1387 }
1388 free(buf);
1389 free(buf2);
1390 if (sentinel.ai_next == NULL) {
1391 __res_put_state(res);
1392 switch (h_errno) {
1393 case HOST_NOT_FOUND:
1394 return NS_NOTFOUND;
1395 case TRY_AGAIN:
1396 return NS_TRYAGAIN;
1397 default:
1398 return NS_UNAVAIL;
1399 }
1400 }
1401
1402 if (res->nsort)
1403 aisort(&sentinel, res);
1404
1405 __res_put_state(res);
1406
1407 *((struct addrinfo **)rv) = sentinel.ai_next;
1408 return NS_SUCCESS;
1409 }
1410
1411 static void
_sethtent(FILE ** hostf)1412 _sethtent(FILE **hostf)
1413 {
1414
1415 if (!*hostf)
1416 *hostf = fopen(_PATH_HOSTS, "r" );
1417 else
1418 rewind(*hostf);
1419 }
1420
1421 static void
_endhtent(FILE ** hostf)1422 _endhtent(FILE **hostf)
1423 {
1424
1425 if (*hostf) {
1426 (void) fclose(*hostf);
1427 *hostf = NULL;
1428 }
1429 }
1430
1431 static struct addrinfo *
_gethtent(FILE ** hostf,const char * name,const struct addrinfo * pai)1432 _gethtent(FILE **hostf, const char *name, const struct addrinfo *pai)
1433 {
1434 char *p;
1435 char *cp, *tname, *cname;
1436 struct addrinfo hints, *res0, *res;
1437 int error;
1438 const char *addr;
1439 static char hostbuf[8*1024];
1440
1441 _DIAGASSERT(name != NULL);
1442 _DIAGASSERT(pai != NULL);
1443
1444 if (!*hostf && ( NULL == (*hostf = fopen(_PATH_HOSTS, "r" ))))
1445 return (NULL);
1446 again:
1447 if ( NULL == (p = fgets(hostbuf, sizeof hostbuf, *hostf)))
1448 return (NULL);
1449 if (*p == '#')
1450 goto again;
1451 if ( NULL == (cp = strpbrk(p, "#\n")))
1452 goto again;
1453 *cp = '\0';
1454 if ( NULL == (cp = strpbrk(p, " \t")))
1455 goto again;
1456 *cp++ = '\0';
1457 addr = p;
1458 /* if this is not something we're looking for, skip it. */
1459 cname = NULL;
1460 while (cp && *cp) {
1461 if (*cp == ' ' || *cp == '\t') {
1462 cp++;
1463 continue;
1464 }
1465 if (!cname)
1466 cname = cp;
1467 tname = cp;
1468 if ((cp = strpbrk(cp, " \t")) != NULL)
1469 *cp++ = '\0';
1470 if (strcasecmp(name, tname) == 0)
1471 goto found;
1472 }
1473 goto again;
1474
1475 found:
1476 hints = *pai;
1477 hints.ai_flags = AI_NUMERICHOST;
1478 error = getaddrinfo(addr, NULL, &hints, &res0);
1479 if (error)
1480 goto again;
1481 for (res = res0; res; res = res->ai_next) {
1482 /* cover it up */
1483 res->ai_flags = pai->ai_flags;
1484
1485 if (pai->ai_flags & AI_CANONNAME) {
1486 if (get_canonname(pai, res, cname) != 0) {
1487 freeaddrinfo(res0);
1488 goto again;
1489 }
1490 }
1491 }
1492 return res0;
1493 }
1494
1495 /*ARGSUSED*/
1496 static int
_files_getaddrinfo(void * rv,void * cb_data,va_list ap)1497 _files_getaddrinfo(void *rv, void *cb_data, va_list ap)
1498 {
1499 const char *name;
1500 const struct addrinfo *pai;
1501 struct addrinfo sentinel, *cur;
1502 struct addrinfo *p;
1503 #ifndef _REENTRANT
1504 static
1505 #endif
1506 FILE *hostf = NULL;
1507
1508 name = va_arg(ap, char *);
1509 pai = va_arg(ap, const struct addrinfo *);
1510
1511 memset(&sentinel, 0, sizeof(sentinel));
1512 cur = &sentinel;
1513
1514 _sethtent(&hostf);
1515 while ((p = _gethtent(&hostf, name, pai)) != NULL) {
1516 cur->ai_next = p;
1517 while (cur && cur->ai_next)
1518 cur = cur->ai_next;
1519 }
1520 _endhtent(&hostf);
1521
1522 *((struct addrinfo **)rv) = sentinel.ai_next;
1523 if (sentinel.ai_next == NULL)
1524 return NS_NOTFOUND;
1525 return NS_SUCCESS;
1526 }
1527
1528 #ifdef YP
1529 /*ARGSUSED*/
1530 static struct addrinfo *
_yphostent(char * line,const struct addrinfo * pai)1531 _yphostent(char *line, const struct addrinfo *pai)
1532 {
1533 struct addrinfo sentinel, *cur;
1534 struct addrinfo hints, *res, *res0;
1535 int error;
1536 char *p;
1537 const char *addr, *canonname;
1538 char *nextline;
1539 char *cp;
1540
1541 _DIAGASSERT(line != NULL);
1542 _DIAGASSERT(pai != NULL);
1543
1544 p = line;
1545 addr = canonname = NULL;
1546
1547 memset(&sentinel, 0, sizeof(sentinel));
1548 cur = &sentinel;
1549
1550 nextline:
1551 /* terminate line */
1552 cp = strchr(p, '\n');
1553 if (cp) {
1554 *cp++ = '\0';
1555 nextline = cp;
1556 } else
1557 nextline = NULL;
1558
1559 cp = strpbrk(p, " \t");
1560 if (cp == NULL) {
1561 if (canonname == NULL)
1562 return (NULL);
1563 else
1564 goto done;
1565 }
1566 *cp++ = '\0';
1567
1568 addr = p;
1569
1570 while (cp && *cp) {
1571 if (*cp == ' ' || *cp == '\t') {
1572 cp++;
1573 continue;
1574 }
1575 if (!canonname)
1576 canonname = cp;
1577 if ((cp = strpbrk(cp, " \t")) != NULL)
1578 *cp++ = '\0';
1579 }
1580
1581 hints = *pai;
1582 hints.ai_flags = AI_NUMERICHOST;
1583 error = getaddrinfo(addr, NULL, &hints, &res0);
1584 if (error == 0) {
1585 for (res = res0; res; res = res->ai_next) {
1586 /* cover it up */
1587 res->ai_flags = pai->ai_flags;
1588
1589 if (pai->ai_flags & AI_CANONNAME)
1590 (void)get_canonname(pai, res, canonname);
1591 }
1592 } else
1593 res0 = NULL;
1594 if (res0) {
1595 cur->ai_next = res0;
1596 while (cur->ai_next)
1597 cur = cur->ai_next;
1598 }
1599
1600 if (nextline) {
1601 p = nextline;
1602 goto nextline;
1603 }
1604
1605 done:
1606 return sentinel.ai_next;
1607 }
1608
1609 /*ARGSUSED*/
1610 static int
_yp_getaddrinfo(void * rv,void * cb_data,va_list ap)1611 _yp_getaddrinfo(void *rv, void *cb_data, va_list ap)
1612 {
1613 struct addrinfo sentinel, *cur;
1614 struct addrinfo *ai = NULL;
1615 char *ypbuf;
1616 int ypbuflen, r;
1617 const char *name;
1618 const struct addrinfo *pai;
1619 char *ypdomain;
1620
1621 if (_yp_check(&ypdomain) == 0)
1622 return NS_UNAVAIL;
1623
1624 name = va_arg(ap, char *);
1625 pai = va_arg(ap, const struct addrinfo *);
1626
1627 memset(&sentinel, 0, sizeof(sentinel));
1628 cur = &sentinel;
1629
1630 /* hosts.byname is only for IPv4 (Solaris8) */
1631 if (pai->ai_family == PF_UNSPEC || pai->ai_family == PF_INET) {
1632 r = yp_match(ypdomain, "hosts.byname", name,
1633 (int)strlen(name), &ypbuf, &ypbuflen);
1634 if (r == 0) {
1635 struct addrinfo ai4;
1636
1637 ai4 = *pai;
1638 ai4.ai_family = AF_INET;
1639 ai = _yphostent(ypbuf, &ai4);
1640 if (ai) {
1641 cur->ai_next = ai;
1642 while (cur && cur->ai_next)
1643 cur = cur->ai_next;
1644 }
1645 }
1646 free(ypbuf);
1647 }
1648
1649 /* ipnodes.byname can hold both IPv4/v6 */
1650 r = yp_match(ypdomain, "ipnodes.byname", name,
1651 (int)strlen(name), &ypbuf, &ypbuflen);
1652 if (r == 0) {
1653 ai = _yphostent(ypbuf, pai);
1654 if (ai)
1655 cur->ai_next = ai;
1656 free(ypbuf);
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
1670 /*
1671 * Formulate a normal query, send, and await answer.
1672 * Returned answer is placed in supplied buffer "answer".
1673 * Perform preliminary check of answer, returning success only
1674 * if no error is indicated and the answer count is nonzero.
1675 * Return the size of the response on success, -1 on error.
1676 * Error number is left in h_errno.
1677 *
1678 * Caller must parse answer and determine whether it answers the question.
1679 */
1680 static int
res_queryN(const char * name,struct res_target * target,res_state res)1681 res_queryN(const char *name, /* domain name */ struct res_target *target,
1682 res_state res)
1683 {
1684 static u_char buf[MAXPACKET];
1685 HEADER *hp;
1686 int n;
1687 struct res_target *t;
1688 int rcode;
1689 int ancount;
1690
1691 _DIAGASSERT(name != NULL);
1692 /* XXX: target may be NULL??? */
1693
1694 rcode = NOERROR;
1695 ancount = 0;
1696
1697 for (t = target; t; t = t->next) {
1698 int class, type;
1699 u_char *answer;
1700 int anslen;
1701
1702 hp = (HEADER *)(void *)t->answer;
1703 hp->rcode = NOERROR; /* default */
1704
1705 /* make it easier... */
1706 class = t->qclass;
1707 type = t->qtype;
1708 answer = t->answer;
1709 anslen = t->anslen;
1710 #ifdef DEBUG
1711 if (res->options & RES_DEBUG)
1712 printf(";; res_nquery(%s, %d, %d)\n", name, class, type);
1713 #endif
1714
1715 n = res_nmkquery(res, QUERY, name, class, type, NULL, 0, NULL,
1716 buf, sizeof(buf));
1717 #ifdef RES_USE_EDNS0
1718 if (n > 0 && (res->options & RES_USE_EDNS0) != 0)
1719 n = res_nopt(res, n, buf, sizeof(buf), anslen);
1720 #endif
1721 if (n <= 0) {
1722 #ifdef DEBUG
1723 if (res->options & RES_DEBUG)
1724 printf(";; res_nquery: mkquery failed\n");
1725 #endif
1726 h_errno = NO_RECOVERY;
1727 return n;
1728 }
1729 n = res_nsend(res, buf, n, answer, anslen);
1730 #if 0
1731 if (n < 0) {
1732 #ifdef DEBUG
1733 if (res->options & RES_DEBUG)
1734 printf(";; res_query: send error\n");
1735 #endif
1736 h_errno = TRY_AGAIN;
1737 return n;
1738 }
1739 #endif
1740
1741 if (n < 0 || hp->rcode != NOERROR || ntohs(hp->ancount) == 0) {
1742 rcode = hp->rcode; /* record most recent error */
1743 #ifdef DEBUG
1744 if (res->options & RES_DEBUG)
1745 printf(";; rcode = %u, ancount=%u\n", hp->rcode,
1746 ntohs(hp->ancount));
1747 #endif
1748 continue;
1749 }
1750
1751 ancount += ntohs(hp->ancount);
1752
1753 t->n = n;
1754 }
1755
1756 if (ancount == 0) {
1757 switch (rcode) {
1758 case NXDOMAIN:
1759 h_errno = HOST_NOT_FOUND;
1760 break;
1761 case SERVFAIL:
1762 h_errno = TRY_AGAIN;
1763 break;
1764 case NOERROR:
1765 h_errno = NO_DATA;
1766 break;
1767 case FORMERR:
1768 case NOTIMP:
1769 case REFUSED:
1770 default:
1771 h_errno = NO_RECOVERY;
1772 break;
1773 }
1774 return -1;
1775 }
1776 return ancount;
1777 }
1778
1779 /*
1780 * Formulate a normal query, send, and retrieve answer in supplied buffer.
1781 * Return the size of the response on success, -1 on error.
1782 * If enabled, implement search rules until answer or unrecoverable failure
1783 * is detected. Error code, if any, is left in h_errno.
1784 */
1785 static int
res_searchN(const char * name,struct res_target * target,res_state res)1786 res_searchN(const char *name, struct res_target *target, res_state res)
1787 {
1788 const char *cp, * const *domain;
1789 HEADER *hp;
1790 u_int dots;
1791 int trailing_dot, ret, saved_herrno;
1792 int got_nodata = 0, got_servfail = 0, tried_as_is = 0;
1793
1794 _DIAGASSERT(name != NULL);
1795 _DIAGASSERT(target != NULL);
1796
1797 hp = (HEADER *)(void *)target->answer; /*XXX*/
1798
1799 errno = 0;
1800 h_errno = HOST_NOT_FOUND; /* default, if we never query */
1801 dots = 0;
1802 for (cp = name; *cp; cp++)
1803 dots += (*cp == '.');
1804 trailing_dot = 0;
1805 if (cp > name && *--cp == '.')
1806 trailing_dot++;
1807
1808 /*
1809 * if there aren't any dots, it could be a user-level alias
1810 */
1811 if (!dots && (cp = __hostalias(name)) != NULL) {
1812 ret = res_queryN(cp, target, res);
1813 return ret;
1814 }
1815
1816 /*
1817 * If there are dots in the name already, let's just give it a try
1818 * 'as is'. The threshold can be set with the "ndots" option.
1819 */
1820 saved_herrno = -1;
1821 if (dots >= res->ndots) {
1822 ret = res_querydomainN(name, NULL, target, res);
1823 if (ret > 0)
1824 return (ret);
1825 saved_herrno = h_errno;
1826 tried_as_is++;
1827 }
1828
1829 /*
1830 * We do at least one level of search if
1831 * - there is no dot and RES_DEFNAME is set, or
1832 * - there is at least one dot, there is no trailing dot,
1833 * and RES_DNSRCH is set.
1834 */
1835 if ((!dots && (res->options & RES_DEFNAMES)) ||
1836 (dots && !trailing_dot && (res->options & RES_DNSRCH))) {
1837 int done = 0;
1838
1839 for (domain = (const char * const *)res->dnsrch;
1840 *domain && !done;
1841 domain++) {
1842
1843 ret = res_querydomainN(name, *domain, target, res);
1844 if (ret > 0)
1845 return ret;
1846
1847 /*
1848 * If no server present, give up.
1849 * If name isn't found in this domain,
1850 * keep trying higher domains in the search list
1851 * (if that's enabled).
1852 * On a NO_DATA error, keep trying, otherwise
1853 * a wildcard entry of another type could keep us
1854 * from finding this entry higher in the domain.
1855 * If we get some other error (negative answer or
1856 * server failure), then stop searching up,
1857 * but try the input name below in case it's
1858 * fully-qualified.
1859 */
1860 if (errno == ECONNREFUSED) {
1861 h_errno = TRY_AGAIN;
1862 return -1;
1863 }
1864
1865 switch (h_errno) {
1866 case NO_DATA:
1867 got_nodata++;
1868 /* FALLTHROUGH */
1869 case HOST_NOT_FOUND:
1870 /* keep trying */
1871 break;
1872 case TRY_AGAIN:
1873 if (hp->rcode == SERVFAIL) {
1874 /* try next search element, if any */
1875 got_servfail++;
1876 break;
1877 }
1878 /* FALLTHROUGH */
1879 default:
1880 /* anything else implies that we're done */
1881 done++;
1882 }
1883 /*
1884 * if we got here for some reason other than DNSRCH,
1885 * we only wanted one iteration of the loop, so stop.
1886 */
1887 if (!(res->options & RES_DNSRCH))
1888 done++;
1889 }
1890 }
1891
1892 /*
1893 * if we have not already tried the name "as is", do that now.
1894 * note that we do this regardless of how many dots were in the
1895 * name or whether it ends with a dot.
1896 */
1897 if (!tried_as_is) {
1898 ret = res_querydomainN(name, NULL, target, res);
1899 if (ret > 0)
1900 return ret;
1901 }
1902
1903 /*
1904 * if we got here, we didn't satisfy the search.
1905 * if we did an initial full query, return that query's h_errno
1906 * (note that we wouldn't be here if that query had succeeded).
1907 * else if we ever got a nodata, send that back as the reason.
1908 * else send back meaningless h_errno, that being the one from
1909 * the last DNSRCH we did.
1910 */
1911 if (saved_herrno != -1)
1912 h_errno = saved_herrno;
1913 else if (got_nodata)
1914 h_errno = NO_DATA;
1915 else if (got_servfail)
1916 h_errno = TRY_AGAIN;
1917 return -1;
1918 }
1919
1920 /*
1921 * Perform a call on res_query on the concatenation of name and domain,
1922 * removing a trailing dot from name if domain is NULL.
1923 */
1924 static int
res_querydomainN(const char * name,const char * domain,struct res_target * target,res_state res)1925 res_querydomainN(const char *name, const char *domain,
1926 struct res_target *target, res_state res)
1927 {
1928 char nbuf[MAXDNAME];
1929 const char *longname = nbuf;
1930 size_t n, d;
1931
1932 _DIAGASSERT(name != NULL);
1933 /* XXX: target may be NULL??? */
1934
1935 #ifdef DEBUG
1936 if (res->options & RES_DEBUG)
1937 printf(";; res_querydomain(%s, %s)\n",
1938 name, domain?domain:"<Nil>");
1939 #endif
1940 if (domain == NULL) {
1941 /*
1942 * Check for trailing '.';
1943 * copy without '.' if present.
1944 */
1945 n = strlen(name);
1946 if (n + 1 > sizeof(nbuf)) {
1947 h_errno = NO_RECOVERY;
1948 return -1;
1949 }
1950 if (n > 0 && name[--n] == '.') {
1951 strncpy(nbuf, name, n);
1952 nbuf[n] = '\0';
1953 } else
1954 longname = name;
1955 } else {
1956 n = strlen(name);
1957 d = strlen(domain);
1958 if (n + 1 + d + 1 > sizeof(nbuf)) {
1959 h_errno = NO_RECOVERY;
1960 return -1;
1961 }
1962 snprintf(nbuf, sizeof(nbuf), "%s.%s", name, domain);
1963 }
1964 return res_queryN(longname, target, res);
1965 }
1966