xref: /illumos-gate/usr/src/lib/libresolv2/common/irs/getaddrinfo.c (revision 08855964b9970604433f7b19dcd71cf5af5e5f14)
1 /*	$KAME: getaddrinfo.c,v 1.14 2001/01/06 09:41:15 jinmei Exp $	*/
2 
3 /*
4  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. Neither the name of the project nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 
32 /*! \file
33  * Issues to be discussed:
34  *\li  Thread safe-ness must be checked.
35  *\li  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  *\li  IPv4 classful (shortened) form.  RFC2553 is silent about it.  XNET 5.2
39  *   says to use inet_aton() to convert IPv4 numeric to binary (allows
40  *   classful form as a result).
41  *   current code - disallow classful form for IPv4 (due to use of inet_pton).
42  *\li  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  *\li  We use getipnodebyname() just for thread-safeness.  There's no intent
47  *   to let it do PF_UNSPEC (actually we never pass PF_UNSPEC to
48  *   getipnodebyname().
49  *\li  The code filters out AFs that are not supported by the kernel,
50  *   when globbing NULL hostname (to loopback, or wildcard).  Is it the right
51  *   thing to do?  What is the relationship with post-RFC2553 AI_ADDRCONFIG
52  *   in ai_flags?
53  *\li  (post-2553) semantics of AI_ADDRCONFIG itself is too vague.
54  *   (1) what should we do against numeric hostname (2) what should we do
55  *   against NULL hostname (3) what is AI_ADDRCONFIG itself.  AF not ready?
56  *   non-loopback address configured?  global address configured?
57  * \par Additional Issue:
58  *  To avoid search order issue, we have a big amount of code duplicate
59  *   from gethnamaddr.c and some other places.  The issues that there's no
60  *   lower layer function to lookup "IPv4 or IPv6" record.  Calling
61  *   gethostbyname2 from getaddrinfo will end up in wrong search order, as
62  *   follows:
63  *	\li The code makes use of following calls when asked to resolver with
64  *	  ai_family  = PF_UNSPEC:
65  *\code		getipnodebyname(host, AF_INET6);
66  *		getipnodebyname(host, AF_INET);
67  *\endcode
68  *	\li  This will result in the following queries if the node is configure to
69  *	  prefer /etc/hosts than DNS:
70  *\code
71  *		lookup /etc/hosts for IPv6 address
72  *		lookup DNS for IPv6 address
73  *		lookup /etc/hosts for IPv4 address
74  *		lookup DNS for IPv4 address
75  *\endcode
76  *	  which may not meet people's requirement.
77  *	 \li The right thing to happen is to have underlying layer which does
78  *	  PF_UNSPEC lookup (lookup both) and return chain of addrinfos.
79  *	  This would result in a bit of code duplicate with _dns_ghbyname() and
80  *	  friends.
81  */
82 
83 #include "port_before.h"
84 
85 #include <sys/types.h>
86 #include <sys/param.h>
87 #include <sys/socket.h>
88 
89 #include <net/if.h>
90 #include <netinet/in.h>
91 
92 #include <arpa/inet.h>
93 #include <arpa/nameser.h>
94 
95 #include <netdb.h>
96 #include <resolv.h>
97 #include <string.h>
98 #include <stdlib.h>
99 #include <stddef.h>
100 #include <ctype.h>
101 #include <unistd.h>
102 #include <stdio.h>
103 #include <errno.h>
104 
105 #include <stdarg.h>
106 
107 #include <irs.h>
108 #include <isc/assertions.h>
109 
110 #include "port_after.h"
111 
112 #include "irs_data.h"
113 
114 #define SUCCESS 0
115 #define ANY 0
116 #define YES 1
117 #define NO  0
118 
119 static const char in_addrany[] = { 0, 0, 0, 0 };
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 in_loopback[] = { 127, 0, 0, 1 };
124 static const char in6_loopback[] = {
125 	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1
126 };
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 	{PF_INET6, sizeof(struct in6_addr),
138 	 sizeof(struct sockaddr_in6),
139 	 offsetof(struct sockaddr_in6, sin6_addr),
140 	 in6_addrany, in6_loopback, 1},
141 	{PF_INET, sizeof(struct in_addr),
142 	 sizeof(struct sockaddr_in),
143 	 offsetof(struct sockaddr_in, sin_addr),
144 	 in_addrany, in_loopback, 0},
145 	{0, 0, 0, 0, NULL, NULL, 0},
146 };
147 
148 struct explore {
149 	int e_af;
150 	int e_socktype;
151 	int e_protocol;
152 	const char *e_protostr;
153 	int e_wild;
154 #define WILD_AF(ex)		((ex)->e_wild & 0x01)
155 #define WILD_SOCKTYPE(ex)	((ex)->e_wild & 0x02)
156 #define WILD_PROTOCOL(ex)	((ex)->e_wild & 0x04)
157 };
158 
159 static const struct explore explore[] = {
160 #if 0
161 	{ PF_LOCAL, 0, ANY, ANY, NULL, 0x01 },
162 #endif
163 	{ PF_INET6, SOCK_DGRAM, IPPROTO_UDP, "udp", 0x07 },
164 	{ PF_INET6, SOCK_STREAM, IPPROTO_TCP, "tcp", 0x07 },
165 	{ PF_INET6, SOCK_RAW, ANY, NULL, 0x05 },
166 	{ PF_INET, SOCK_DGRAM, IPPROTO_UDP, "udp", 0x07 },
167 	{ PF_INET, SOCK_STREAM, IPPROTO_TCP, "tcp", 0x07 },
168 	{ PF_INET, SOCK_RAW, ANY, NULL, 0x05 },
169 	{ -1, 0, 0, NULL, 0 },
170 };
171 
172 #define PTON_MAX	16
173 
174 static int str_isnumber __P((const char *));
175 static int explore_fqdn __P((const struct addrinfo *, const char *,
176 	const char *, struct addrinfo **));
177 static int explore_copy __P((const struct addrinfo *, const struct addrinfo *,
178 	struct addrinfo **));
179 static int explore_null __P((const struct addrinfo *,
180 	const char *, struct addrinfo **));
181 static int explore_numeric __P((const struct addrinfo *, const char *,
182 	const char *, struct addrinfo **));
183 static int explore_numeric_scope __P((const struct addrinfo *, const char *,
184 	const char *, struct addrinfo **));
185 static int get_canonname __P((const struct addrinfo *,
186 	struct addrinfo *, const char *));
187 static struct addrinfo *get_ai __P((const struct addrinfo *,
188 	const struct afd *, const char *));
189 static struct addrinfo *copy_ai __P((const struct addrinfo *));
190 static int get_portmatch __P((const struct addrinfo *, const char *));
191 static int get_port __P((const struct addrinfo *, const char *, int));
192 static const struct afd *find_afd __P((int));
193 static int addrconfig __P((int));
194 static int ip6_str2scopeid __P((char *, struct sockaddr_in6 *,
195 				u_int32_t *scopeidp));
196 static struct net_data *init __P((void));
197 
198 struct addrinfo *hostent2addrinfo __P((struct hostent *,
199 				       const struct addrinfo *));
200 struct addrinfo *addr2addrinfo __P((const struct addrinfo *,
201 				    const char *));
202 
203 #if 0
204 static const char *ai_errlist[] = {
205 	"Success",
206 	"Address family for hostname not supported",	/*%< EAI_ADDRFAMILY */
207 	"Temporary failure in name resolution",		/*%< EAI_AGAIN */
208 	"Invalid value for ai_flags",		       	/*%< EAI_BADFLAGS */
209 	"Non-recoverable failure in name resolution", 	/*%< EAI_FAIL */
210 	"ai_family not supported",			/*%< EAI_FAMILY */
211 	"Memory allocation failure", 			/*%< EAI_MEMORY */
212 	"No address associated with hostname", 		/*%< EAI_NODATA */
213 	"hostname nor servname provided, or not known",	/*%< EAI_NONAME */
214 	"servname not supported for ai_socktype",	/*%< EAI_SERVICE */
215 	"ai_socktype not supported", 			/*%< EAI_SOCKTYPE */
216 	"System error returned in errno", 		/*%< EAI_SYSTEM */
217 	"Invalid value for hints",			/*%< EAI_BADHINTS */
218 	"Resolved protocol is unknown",			/*%< EAI_PROTOCOL */
219 	"Unknown error", 				/*%< EAI_MAX */
220 };
221 #endif
222 
223 /* XXX macros that make external reference is BAD. */
224 
225 #define GET_AI(ai, afd, addr) \
226 do { \
227 	/* external reference: pai, error, and label free */ \
228 	(ai) = get_ai(pai, (afd), (addr)); \
229 	if ((ai) == NULL) { \
230 		error = EAI_MEMORY; \
231 		goto free; \
232 	} \
233 } while (/*CONSTCOND*/0)
234 
235 #define GET_PORT(ai, serv) \
236 do { \
237 	/* external reference: error and label free */ \
238 	error = get_port((ai), (serv), 0); \
239 	if (error != 0) \
240 		goto free; \
241 } while (/*CONSTCOND*/0)
242 
243 #define GET_CANONNAME(ai, str) \
244 do { \
245 	/* external reference: pai, error and label free */ \
246 	error = get_canonname(pai, (ai), (str)); \
247 	if (error != 0) \
248 		goto free; \
249 } while (/*CONSTCOND*/0)
250 
251 #ifndef SOLARIS2
252 #define SETERROR(err) \
253 do { \
254 	/* external reference: error, and label bad */ \
255 	error = (err); \
256 	goto bad; \
257 	/*NOTREACHED*/ \
258 } while (/*CONSTCOND*/0)
259 #else
260 #define SETERROR(err) \
261 do { \
262 	/* external reference: error, and label bad */ \
263 	error = (err); \
264 	if (error == error) \
265 		goto bad; \
266 } while (/*CONSTCOND*/0)
267 #endif
268 
269 
270 #define MATCH_FAMILY(x, y, w) \
271 	((x) == (y) || (/*CONSTCOND*/(w) && ((x) == PF_UNSPEC || (y) == PF_UNSPEC)))
272 #define MATCH(x, y, w) \
273 	((x) == (y) || (/*CONSTCOND*/(w) && ((x) == ANY || (y) == ANY)))
274 
275 #if 0				/*%< bind8 has its own version */
276 char *
277 gai_strerror(ecode)
278 	int ecode;
279 {
280 	if (ecode < 0 || ecode > EAI_MAX)
281 		ecode = EAI_MAX;
282 	return ai_errlist[ecode];
283 }
284 #endif
285 
286 void
287 freeaddrinfo(ai)
288 	struct addrinfo *ai;
289 {
290 	struct addrinfo *next;
291 
292 	do {
293 		next = ai->ai_next;
294 		if (ai->ai_canonname)
295 			free(ai->ai_canonname);
296 		/* no need to free(ai->ai_addr) */
297 		free(ai);
298 		ai = next;
299 	} while (ai);
300 }
301 
302 static int
303 str_isnumber(p)
304 	const char *p;
305 {
306 	char *ep;
307 
308 	if (*p == '\0')
309 		return NO;
310 	ep = NULL;
311 	errno = 0;
312 	(void)strtoul(p, &ep, 10);
313 	if (errno == 0 && ep && *ep == '\0')
314 		return YES;
315 	else
316 		return NO;
317 }
318 
319 int
320 getaddrinfo(hostname, servname, hints, res)
321 	const char *hostname, *servname;
322 	const struct addrinfo *hints;
323 	struct addrinfo **res;
324 {
325 	struct addrinfo sentinel;
326 	struct addrinfo *cur;
327 	int error = 0;
328 	struct addrinfo ai, ai0, *afai = NULL;
329 	struct addrinfo *pai;
330 	const struct explore *ex;
331 
332 	memset(&sentinel, 0, sizeof(sentinel));
333 	cur = &sentinel;
334 	pai = &ai;
335 	pai->ai_flags = 0;
336 	pai->ai_family = PF_UNSPEC;
337 	pai->ai_socktype = ANY;
338 	pai->ai_protocol = ANY;
339 #if defined(sun) && defined(_SOCKLEN_T) && defined(__sparcv9)
340 	/*
341 	 * clear _ai_pad to preserve binary
342 	 * compatibility with previously compiled 64-bit
343 	 * applications in a pre-SUSv3 environment by
344 	 * guaranteeing the upper 32-bits are empty.
345 	 */
346 	pai->_ai_pad = 0;
347 #endif
348 	pai->ai_addrlen = 0;
349 	pai->ai_canonname = NULL;
350 	pai->ai_addr = NULL;
351 	pai->ai_next = NULL;
352 
353 	if (hostname == NULL && servname == NULL)
354 		return EAI_NONAME;
355 	if (hints) {
356 		/* error check for hints */
357 		if (hints->ai_addrlen || hints->ai_canonname ||
358 		    hints->ai_addr || hints->ai_next)
359 			SETERROR(EAI_BADHINTS); /*%< xxx */
360 		if (hints->ai_flags & ~AI_MASK)
361 			SETERROR(EAI_BADFLAGS);
362 		switch (hints->ai_family) {
363 		case PF_UNSPEC:
364 		case PF_INET:
365 		case PF_INET6:
366 			break;
367 		default:
368 			SETERROR(EAI_FAMILY);
369 		}
370 		memcpy(pai, hints, sizeof(*pai));
371 
372 #if defined(sun) && defined(_SOCKLEN_T) && defined(__sparcv9)
373 		/*
374 		 * We need to clear _ai_pad to preserve binary
375 		 * compatibility.  See prior comment.
376 		 */
377 		pai->_ai_pad = 0;
378 #endif
379 		/*
380 		 * if both socktype/protocol are specified, check if they
381 		 * are meaningful combination.
382 		 */
383 		if (pai->ai_socktype != ANY && pai->ai_protocol != ANY) {
384 			for (ex = explore; ex->e_af >= 0; ex++) {
385 				if (pai->ai_family != ex->e_af)
386 					continue;
387 				if (ex->e_socktype == ANY)
388 					continue;
389 				if (ex->e_protocol == ANY)
390 					continue;
391 				if (pai->ai_socktype == ex->e_socktype &&
392 				    pai->ai_protocol != ex->e_protocol) {
393 					SETERROR(EAI_BADHINTS);
394 				}
395 			}
396 		}
397 	}
398 
399 	/*
400 	 * post-2553: AI_ALL and AI_V4MAPPED are effective only against
401 	 * AF_INET6 query.  They needs to be ignored if specified in other
402 	 * occassions.
403 	 */
404 	switch (pai->ai_flags & (AI_ALL | AI_V4MAPPED)) {
405 	case AI_V4MAPPED:
406 	case AI_ALL | AI_V4MAPPED:
407 		if (pai->ai_family != AF_INET6)
408 			pai->ai_flags &= ~(AI_ALL | AI_V4MAPPED);
409 		break;
410 	case AI_ALL:
411 #if 1
412 		/* illegal */
413 		SETERROR(EAI_BADFLAGS);
414 #else
415 		pai->ai_flags &= ~(AI_ALL | AI_V4MAPPED);
416 		break;
417 #endif
418 	}
419 
420 	/*
421 	 * check for special cases.  (1) numeric servname is disallowed if
422 	 * socktype/protocol are left unspecified. (2) servname is disallowed
423 	 * for raw and other inet{,6} sockets.
424 	 */
425 	if (MATCH_FAMILY(pai->ai_family, PF_INET, 1)
426 #ifdef PF_INET6
427 	 || MATCH_FAMILY(pai->ai_family, PF_INET6, 1)
428 #endif
429 	    ) {
430 		ai0 = *pai;	/* backup *pai */
431 
432 		if (pai->ai_family == PF_UNSPEC) {
433 #ifdef PF_INET6
434 			pai->ai_family = PF_INET6;
435 #else
436 			pai->ai_family = PF_INET;
437 #endif
438 		}
439 		error = get_portmatch(pai, servname);
440 		if (error)
441 			SETERROR(error);
442 
443 		*pai = ai0;
444 	}
445 
446 	ai0 = *pai;
447 
448 	/* NULL hostname, or numeric hostname */
449 	for (ex = explore; ex->e_af >= 0; ex++) {
450 		*pai = ai0;
451 
452 		if (!MATCH_FAMILY(pai->ai_family, ex->e_af, WILD_AF(ex)))
453 			continue;
454 		if (!MATCH(pai->ai_socktype, ex->e_socktype, WILD_SOCKTYPE(ex)))
455 			continue;
456 		if (!MATCH(pai->ai_protocol, ex->e_protocol, WILD_PROTOCOL(ex)))
457 			continue;
458 
459 		if (pai->ai_family == PF_UNSPEC)
460 			pai->ai_family = ex->e_af;
461 		if (pai->ai_socktype == ANY && ex->e_socktype != ANY)
462 			pai->ai_socktype = ex->e_socktype;
463 		if (pai->ai_protocol == ANY && ex->e_protocol != ANY)
464 			pai->ai_protocol = ex->e_protocol;
465 
466 		/*
467 		 * if the servname does not match socktype/protocol, ignore it.
468 		 */
469 		if (get_portmatch(pai, servname) != 0)
470 			continue;
471 
472 		if (hostname == NULL) {
473 			/*
474 			 * filter out AFs that are not supported by the kernel
475 			 * XXX errno?
476 			 */
477 			if (!addrconfig(pai->ai_family))
478 				continue;
479 			error = explore_null(pai, servname, &cur->ai_next);
480 		} else
481 			error = explore_numeric_scope(pai, hostname, servname,
482 			    &cur->ai_next);
483 
484 		if (error)
485 			goto free;
486 
487 		while (cur && cur->ai_next)
488 			cur = cur->ai_next;
489 	}
490 
491 	/*
492 	 * XXX
493 	 * If numreic representation of AF1 can be interpreted as FQDN
494 	 * representation of AF2, we need to think again about the code below.
495 	 */
496 	if (sentinel.ai_next)
497 		goto good;
498 
499 	if (pai->ai_flags & AI_NUMERICHOST)
500 		SETERROR(EAI_NONAME);
501 	if (hostname == NULL)
502 		SETERROR(EAI_NONAME);
503 
504 	/*
505 	 * hostname as alphabetical name.
506 	 * We'll make sure that
507 	 * - if returning addrinfo list is empty, return non-zero error
508 	 *   value (already known one or EAI_NONAME).
509 	 * - otherwise,
510 	 *   + if we haven't had any errors, return 0 (i.e. success).
511 	 *   + if we've had an error, free the list and return the error.
512 	 * without any assumption on the behavior of explore_fqdn().
513 	 */
514 
515 	/* first, try to query DNS for all possible address families. */
516 	*pai = ai0;
517 	error = explore_fqdn(pai, hostname, servname, &afai);
518 	if (error) {
519 		if (afai != NULL)
520 			freeaddrinfo(afai);
521 		goto free;
522 	}
523 	if (afai == NULL) {
524 		error = EAI_NONAME; /*%< we've had no errors. */
525 		goto free;
526 	}
527 
528 	/*
529 	 * we would like to prefer AF_INET6 than AF_INET, so we'll make an
530 	 * outer loop by AFs.
531 	 */
532 	for (ex = explore; ex->e_af >= 0; ex++) {
533 		*pai = ai0;
534 
535 		if (pai->ai_family == PF_UNSPEC)
536 			pai->ai_family = ex->e_af;
537 
538 		if (!MATCH_FAMILY(pai->ai_family, ex->e_af, WILD_AF(ex)))
539 			continue;
540 		if (!MATCH(pai->ai_socktype, ex->e_socktype,
541 			   WILD_SOCKTYPE(ex))) {
542 			continue;
543 		}
544 		if (!MATCH(pai->ai_protocol, ex->e_protocol,
545 			   WILD_PROTOCOL(ex))) {
546 			continue;
547 		}
548 
549 #ifdef AI_ADDRCONFIG
550 		/*
551 		 * If AI_ADDRCONFIG is specified, check if we are
552 		 * expected to return the address family or not.
553 		 */
554 		if ((pai->ai_flags & AI_ADDRCONFIG) != 0 &&
555 		    !addrconfig(pai->ai_family))
556 			continue;
557 #endif
558 
559 		if (pai->ai_family == PF_UNSPEC)
560 			pai->ai_family = ex->e_af;
561 		if (pai->ai_socktype == ANY && ex->e_socktype != ANY)
562 			pai->ai_socktype = ex->e_socktype;
563 		if (pai->ai_protocol == ANY && ex->e_protocol != ANY)
564 			pai->ai_protocol = ex->e_protocol;
565 
566 		/*
567 		 * if the servname does not match socktype/protocol, ignore it.
568 		 */
569 		if (get_portmatch(pai, servname) != 0)
570 			continue;
571 
572 		if ((error = explore_copy(pai, afai, &cur->ai_next)) != 0) {
573 			freeaddrinfo(afai);
574 			goto free;
575 		}
576 
577 		while (cur && cur->ai_next)
578 			cur = cur->ai_next;
579 	}
580 
581 	freeaddrinfo(afai);	/*%< afai must not be NULL at this point. */
582 
583 	if (sentinel.ai_next) {
584 good:
585 		*res = sentinel.ai_next;
586 		return(SUCCESS);
587 	} else {
588 		/*
589 		 * All the process succeeded, but we've had an empty list.
590 		 * This can happen if the given hints do not match our
591 		 * candidates.
592 		 */
593 		error = EAI_NONAME;
594 	}
595 
596 free:
597 bad:
598 	if (sentinel.ai_next)
599 		freeaddrinfo(sentinel.ai_next);
600 	*res = NULL;
601 	return(error);
602 }
603 
604 /*%
605  * FQDN hostname, DNS lookup
606  */
607 static int
608 explore_fqdn(pai, hostname, servname, res)
609 	const struct addrinfo *pai;
610 	const char *hostname;
611 	const char *servname;
612 	struct addrinfo **res;
613 {
614 	struct addrinfo *result;
615 	struct addrinfo *cur;
616 	struct net_data *net_data = init();
617 	struct irs_ho *ho;
618 	int error = 0;
619 	char tmp[NS_MAXDNAME];
620 	const char *cp;
621 
622 	INSIST(res != NULL && *res == NULL);
623 
624 	/*
625 	 * if the servname does not match socktype/protocol, ignore it.
626 	 */
627 	if (get_portmatch(pai, servname) != 0)
628 		return(0);
629 
630 	if (!net_data || !(ho = net_data->ho))
631 		return(0);
632 #if 0				/*%< XXX (notyet) */
633 	if (net_data->ho_stayopen && net_data->ho_last &&
634 	    net_data->ho_last->h_addrtype == af) {
635 		if (ns_samename(name, net_data->ho_last->h_name) == 1)
636 			return (net_data->ho_last);
637 		for (hap = net_data->ho_last->h_aliases; hap && *hap; hap++)
638 			if (ns_samename(name, *hap) == 1)
639 				return (net_data->ho_last);
640 	}
641 #endif
642 	if (!strchr(hostname, '.') &&
643 	    (cp = res_hostalias(net_data->res, hostname,
644 				tmp, sizeof(tmp))))
645 		hostname = cp;
646 	result = (*ho->addrinfo)(ho, hostname, pai);
647 	if (!net_data->ho_stayopen) {
648 		(*ho->minimize)(ho);
649 	}
650 	if (result == NULL) {
651 		int e = h_errno;
652 
653 		switch(e) {
654 		case NETDB_INTERNAL:
655 			error = EAI_SYSTEM;
656 			break;
657 		case TRY_AGAIN:
658 			error = EAI_AGAIN;
659 			break;
660 		case NO_RECOVERY:
661 			error = EAI_FAIL;
662 			break;
663 		case HOST_NOT_FOUND:
664 		case NO_DATA:
665 			error = EAI_NONAME;
666 			break;
667 		default:
668 		case NETDB_SUCCESS: /*%< should be impossible... */
669 			error = EAI_NONAME;
670 			break;
671 		}
672 		goto free;
673 	}
674 
675 	for (cur = result; cur; cur = cur->ai_next) {
676 		GET_PORT(cur, servname); /*%< XXX: redundant lookups... */
677 		/* canonname should already be filled. */
678 	}
679 
680 	*res = result;
681 
682 	return(0);
683 
684 free:
685 	if (result)
686 		freeaddrinfo(result);
687 	return error;
688 }
689 
690 static int
691 explore_copy(pai, src0, res)
692 	const struct addrinfo *pai;	/*%< seed */
693 	const struct addrinfo *src0;	/*%< source */
694 	struct addrinfo **res;
695 {
696 	int error;
697 	struct addrinfo sentinel, *cur;
698 	const struct addrinfo *src;
699 
700 	error = 0;
701 	sentinel.ai_next = NULL;
702 	cur = &sentinel;
703 
704 	for (src = src0; src != NULL; src = src->ai_next) {
705 		if (src->ai_family != pai->ai_family)
706 			continue;
707 
708 		cur->ai_next = copy_ai(src);
709 		if (!cur->ai_next) {
710 			error = EAI_MEMORY;
711 			goto fail;
712 		}
713 
714 		cur->ai_next->ai_socktype = pai->ai_socktype;
715 		cur->ai_next->ai_protocol = pai->ai_protocol;
716 		cur = cur->ai_next;
717 	}
718 
719 	*res = sentinel.ai_next;
720 	return 0;
721 
722 fail:
723 	freeaddrinfo(sentinel.ai_next);
724 	return error;
725 }
726 
727 /*%
728  * hostname == NULL.
729  * passive socket -> anyaddr (0.0.0.0 or ::)
730  * non-passive socket -> localhost (127.0.0.1 or ::1)
731  */
732 static int
733 explore_null(pai, servname, res)
734 	const struct addrinfo *pai;
735 	const char *servname;
736 	struct addrinfo **res;
737 {
738 	const struct afd *afd;
739 	struct addrinfo *cur;
740 	struct addrinfo sentinel;
741 	int error;
742 
743 	*res = NULL;
744 	sentinel.ai_next = NULL;
745 	cur = &sentinel;
746 
747 	afd = find_afd(pai->ai_family);
748 	if (afd == NULL)
749 		return 0;
750 
751 	if (pai->ai_flags & AI_PASSIVE) {
752 		GET_AI(cur->ai_next, afd, afd->a_addrany);
753 		/* xxx meaningless?
754 		 * GET_CANONNAME(cur->ai_next, "anyaddr");
755 		 */
756 		GET_PORT(cur->ai_next, servname);
757 	} else {
758 		GET_AI(cur->ai_next, afd, afd->a_loopback);
759 		/* xxx meaningless?
760 		 * GET_CANONNAME(cur->ai_next, "localhost");
761 		 */
762 		GET_PORT(cur->ai_next, servname);
763 	}
764 	cur = cur->ai_next;
765 
766 	*res = sentinel.ai_next;
767 	return 0;
768 
769 free:
770 	if (sentinel.ai_next)
771 		freeaddrinfo(sentinel.ai_next);
772 	return error;
773 }
774 
775 /*%
776  * numeric hostname
777  */
778 static int
779 explore_numeric(pai, hostname, servname, res)
780 	const struct addrinfo *pai;
781 	const char *hostname;
782 	const char *servname;
783 	struct addrinfo **res;
784 {
785 	const struct afd *afd;
786 	struct addrinfo *cur;
787 	struct addrinfo sentinel;
788 	int error;
789 	char pton[PTON_MAX];
790 
791 	*res = NULL;
792 	sentinel.ai_next = NULL;
793 	cur = &sentinel;
794 
795 	afd = find_afd(pai->ai_family);
796 	if (afd == NULL)
797 		return 0;
798 
799 	switch (afd->a_af) {
800 #if 0 /*X/Open spec*/
801 	case AF_INET:
802 		if (inet_aton(hostname, (struct in_addr *)pton) == 1) {
803 			if (pai->ai_family == afd->a_af ||
804 			    pai->ai_family == PF_UNSPEC /*?*/) {
805 				GET_AI(cur->ai_next, afd, pton);
806 				GET_PORT(cur->ai_next, servname);
807 				while (cur->ai_next)
808 					cur = cur->ai_next;
809 			} else
810 				SETERROR(EAI_FAMILY);	/*xxx*/
811 		}
812 		break;
813 #endif
814 	default:
815 		if (inet_pton(afd->a_af, hostname, pton) == 1) {
816 			if (pai->ai_family == afd->a_af ||
817 			    pai->ai_family == PF_UNSPEC /*?*/) {
818 				GET_AI(cur->ai_next, afd, pton);
819 				GET_PORT(cur->ai_next, servname);
820 				while (cur->ai_next)
821 					cur = cur->ai_next;
822 			} else
823 				SETERROR(EAI_FAMILY);	/*xxx*/
824 		}
825 		break;
826 	}
827 
828 	*res = sentinel.ai_next;
829 	return 0;
830 
831 free:
832 bad:
833 	if (sentinel.ai_next)
834 		freeaddrinfo(sentinel.ai_next);
835 	return error;
836 }
837 
838 /*%
839  * numeric hostname with scope
840  */
841 static int
842 explore_numeric_scope(pai, hostname, servname, res)
843 	const struct addrinfo *pai;
844 	const char *hostname;
845 	const char *servname;
846 	struct addrinfo **res;
847 {
848 #ifndef SCOPE_DELIMITER
849 	return explore_numeric(pai, hostname, servname, res);
850 #else
851 	const struct afd *afd;
852 	struct addrinfo *cur;
853 	int error;
854 	char *cp, *hostname2 = NULL, *scope, *addr;
855 	struct sockaddr_in6 *sin6;
856 
857 	afd = find_afd(pai->ai_family);
858 	if (afd == NULL)
859 		return 0;
860 
861 	if (!afd->a_scoped)
862 		return explore_numeric(pai, hostname, servname, res);
863 
864 	cp = strchr(hostname, SCOPE_DELIMITER);
865 	if (cp == NULL)
866 		return explore_numeric(pai, hostname, servname, res);
867 
868 	/*
869 	 * Handle special case of <scoped_address><delimiter><scope id>
870 	 */
871 	hostname2 = strdup(hostname);
872 	if (hostname2 == NULL)
873 		return EAI_MEMORY;
874 	/* terminate at the delimiter */
875 	hostname2[cp - hostname] = '\0';
876 	addr = hostname2;
877 	scope = cp + 1;
878 
879 	error = explore_numeric(pai, addr, servname, res);
880 	if (error == 0) {
881 		u_int32_t scopeid = 0;
882 
883 		for (cur = *res; cur; cur = cur->ai_next) {
884 			if (cur->ai_family != AF_INET6)
885 				continue;
886 			sin6 = (struct sockaddr_in6 *)(void *)cur->ai_addr;
887 			if (!ip6_str2scopeid(scope, sin6, &scopeid)) {
888 				free(hostname2);
889 				return(EAI_NONAME); /*%< XXX: is return OK? */
890 			}
891 #ifdef HAVE_SIN6_SCOPE_ID
892 			sin6->sin6_scope_id = scopeid;
893 #endif
894 		}
895 	}
896 
897 	free(hostname2);
898 
899 	return error;
900 #endif
901 }
902 
903 static int
904 get_canonname(pai, ai, str)
905 	const struct addrinfo *pai;
906 	struct addrinfo *ai;
907 	const char *str;
908 {
909 	if ((pai->ai_flags & AI_CANONNAME) != 0) {
910 		ai->ai_canonname = (char *)malloc(strlen(str) + 1);
911 		if (ai->ai_canonname == NULL)
912 			return EAI_MEMORY;
913 		strcpy(ai->ai_canonname, str);
914 	}
915 	return 0;
916 }
917 
918 static struct addrinfo *
919 get_ai(pai, afd, addr)
920 	const struct addrinfo *pai;
921 	const struct afd *afd;
922 	const char *addr;
923 {
924 	char *p;
925 	struct addrinfo *ai;
926 
927 	ai = (struct addrinfo *)malloc(sizeof(struct addrinfo)
928 		+ (afd->a_socklen));
929 	if (ai == NULL)
930 		return NULL;
931 
932 	memcpy(ai, pai, sizeof(struct addrinfo));
933 	ai->ai_addr = (struct sockaddr *)(void *)(ai + 1);
934 	memset(ai->ai_addr, 0, (size_t)afd->a_socklen);
935 #ifdef HAVE_SA_LEN
936 	ai->ai_addr->sa_len = afd->a_socklen;
937 #endif
938 	ai->ai_addrlen = afd->a_socklen;
939 	ai->ai_addr->sa_family = ai->ai_family = afd->a_af;
940 	p = (char *)(void *)(ai->ai_addr);
941 	memcpy(p + afd->a_off, addr, (size_t)afd->a_addrlen);
942 	return ai;
943 }
944 
945 /* XXX need to malloc() the same way we do from other functions! */
946 static struct addrinfo *
947 copy_ai(pai)
948 	const struct addrinfo *pai;
949 {
950 	struct addrinfo *ai;
951 	size_t l;
952 
953 	l = sizeof(*ai) + pai->ai_addrlen;
954 	if ((ai = (struct addrinfo *)malloc(l)) == NULL)
955 		return NULL;
956 	memset(ai, 0, l);
957 	memcpy(ai, pai, sizeof(*ai));
958 	ai->ai_addr = (struct sockaddr *)(void *)(ai + 1);
959 	memcpy(ai->ai_addr, pai->ai_addr, pai->ai_addrlen);
960 
961 	if (pai->ai_canonname) {
962 		l = strlen(pai->ai_canonname) + 1;
963 		if ((ai->ai_canonname = malloc(l)) == NULL) {
964 			free(ai);
965 			return NULL;
966 		}
967 		strcpy(ai->ai_canonname, pai->ai_canonname);	/* (checked) */
968 	} else {
969 		/* just to make sure */
970 		ai->ai_canonname = NULL;
971 	}
972 
973 	ai->ai_next = NULL;
974 
975 	return ai;
976 }
977 
978 static int
979 get_portmatch(const struct addrinfo *ai, const char *servname) {
980 
981 	/* get_port does not touch first argument. when matchonly == 1. */
982 	/* LINTED const cast */
983 	return get_port((const struct addrinfo *)ai, servname, 1);
984 }
985 
986 static int
987 get_port(const struct addrinfo *ai, const char *servname, int matchonly) {
988 	const char *proto;
989 	struct servent *sp;
990 	int port;
991 	int allownumeric;
992 
993 	if (servname == NULL)
994 		return 0;
995 	switch (ai->ai_family) {
996 	case AF_INET:
997 #ifdef AF_INET6
998 	case AF_INET6:
999 #endif
1000 		break;
1001 	default:
1002 		return 0;
1003 	}
1004 
1005 	switch (ai->ai_socktype) {
1006 	case SOCK_RAW:
1007 		return EAI_SERVICE;
1008 	case SOCK_DGRAM:
1009 	case SOCK_STREAM:
1010 		allownumeric = 1;
1011 		break;
1012 	case ANY:
1013 		switch (ai->ai_family) {
1014 		case AF_INET:
1015 #ifdef AF_INET6
1016 		case AF_INET6:
1017 #endif
1018 			allownumeric = 1;
1019 			break;
1020 		default:
1021 			allownumeric = 0;
1022 			break;
1023 		}
1024 		break;
1025 	default:
1026 		return EAI_SOCKTYPE;
1027 	}
1028 
1029 	if (str_isnumber(servname)) {
1030 		if (!allownumeric)
1031 			return EAI_SERVICE;
1032 		port = atoi(servname);
1033 		if (port < 0 || port > 65535)
1034 			return EAI_SERVICE;
1035 		port = htons(port);
1036 	} else {
1037 		switch (ai->ai_socktype) {
1038 		case SOCK_DGRAM:
1039 			proto = "udp";
1040 			break;
1041 		case SOCK_STREAM:
1042 			proto = "tcp";
1043 			break;
1044 		default:
1045 			proto = NULL;
1046 			break;
1047 		}
1048 
1049 		if ((sp = getservbyname(servname, proto)) == NULL)
1050 			return EAI_SERVICE;
1051 		port = sp->s_port;
1052 	}
1053 
1054 	if (!matchonly) {
1055 		switch (ai->ai_family) {
1056 		case AF_INET:
1057 			((struct sockaddr_in *)(void *)
1058 			    ai->ai_addr)->sin_port = port;
1059 			break;
1060 		case AF_INET6:
1061 			((struct sockaddr_in6 *)(void *)
1062 			    ai->ai_addr)->sin6_port = port;
1063 			break;
1064 		}
1065 	}
1066 
1067 	return 0;
1068 }
1069 
1070 static const struct afd *
1071 find_afd(af)
1072 	int af;
1073 {
1074 	const struct afd *afd;
1075 
1076 	if (af == PF_UNSPEC)
1077 		return NULL;
1078 	for (afd = afdl; afd->a_af; afd++) {
1079 		if (afd->a_af == af)
1080 			return afd;
1081 	}
1082 	return NULL;
1083 }
1084 
1085 /*%
1086  * post-2553: AI_ADDRCONFIG check.  if we use getipnodeby* as backend, backend
1087  * will take care of it.
1088  * the semantics of AI_ADDRCONFIG is not defined well.  we are not sure
1089  * if the code is right or not.
1090  */
1091 static int
1092 addrconfig(af)
1093 	int af;
1094 {
1095 	int s;
1096 
1097 	/* XXX errno */
1098 	s = socket(af, SOCK_DGRAM, 0);
1099 	if (s < 0) {
1100 		if (errno != EMFILE)
1101 			return 0;
1102 	} else
1103 		close(s);
1104 	return 1;
1105 }
1106 
1107 /* convert a string to a scope identifier. XXX: IPv6 specific */
1108 static int
1109 ip6_str2scopeid(char *scope, struct sockaddr_in6 *sin6,
1110 		u_int32_t *scopeidp)
1111 {
1112 	u_int32_t scopeid;
1113 	u_long lscopeid;
1114 	struct in6_addr *a6 = &sin6->sin6_addr;
1115 	char *ep;
1116 
1117 	/* empty scopeid portion is invalid */
1118 	if (*scope == '\0')
1119 		return (0);
1120 
1121 #ifdef USE_IFNAMELINKID
1122 	if (IN6_IS_ADDR_LINKLOCAL(a6) || IN6_IS_ADDR_MC_LINKLOCAL(a6) ||
1123 	    IN6_IS_ADDR_MC_NODELOCAL(a6)) {
1124 		/*
1125 		 * Using interface names as link indices can be allowed
1126 		 * only when we can assume a one-to-one mappings between
1127 		 * links and interfaces.  See comments in getnameinfo.c.
1128 		 */
1129 		scopeid = if_nametoindex(scope);
1130 		if (scopeid == 0)
1131 			goto trynumeric;
1132 		*scopeidp = scopeid;
1133 		return (1);
1134 	}
1135 #endif
1136 
1137 	/* still unclear about literal, allow numeric only - placeholder */
1138 	if (IN6_IS_ADDR_SITELOCAL(a6) || IN6_IS_ADDR_MC_SITELOCAL(a6))
1139 		goto trynumeric;
1140 	if (IN6_IS_ADDR_MC_ORGLOCAL(a6))
1141 		goto trynumeric;
1142 	else
1143 		goto trynumeric;	/*%< global */
1144 	/* try to convert to a numeric id as a last resort */
1145 trynumeric:
1146 	errno = 0;
1147 	lscopeid = strtoul(scope, &ep, 10);
1148 	scopeid = lscopeid & 0xffffffff;
1149 	if (errno == 0 && ep && *ep == '\0' && scopeid == lscopeid) {
1150 		*scopeidp = scopeid;
1151 		return (1);
1152 	} else
1153 		return (0);
1154 }
1155 
1156 struct addrinfo *
1157 hostent2addrinfo(hp, pai)
1158 	struct hostent *hp;
1159 	const struct addrinfo *pai;
1160 {
1161 	int i, af, error = 0;
1162 	char **aplist = NULL, *ap;
1163 	struct addrinfo sentinel, *cur;
1164 	const struct afd *afd;
1165 
1166 	af = hp->h_addrtype;
1167 	if (pai->ai_family != AF_UNSPEC && af != pai->ai_family)
1168 		return(NULL);
1169 
1170 	afd = find_afd(af);
1171 	if (afd == NULL)
1172 		return(NULL);
1173 
1174 	aplist = hp->h_addr_list;
1175 
1176 	memset(&sentinel, 0, sizeof(sentinel));
1177 	cur = &sentinel;
1178 
1179 	for (i = 0; (ap = aplist[i]) != NULL; i++) {
1180 #if 0				/*%< the trick seems too much */
1181 		af = hp->h_addr_list;
1182 		if (af == AF_INET6 &&
1183 		    IN6_IS_ADDR_V4MAPPED((struct in6_addr *)ap)) {
1184 			af = AF_INET;
1185 			ap = ap + sizeof(struct in6_addr)
1186 				- sizeof(struct in_addr);
1187 		}
1188 		afd = find_afd(af);
1189 		if (afd == NULL)
1190 			continue;
1191 #endif /* 0 */
1192 
1193 		GET_AI(cur->ai_next, afd, ap);
1194 
1195 		/* GET_PORT(cur->ai_next, servname); */
1196 		if ((pai->ai_flags & AI_CANONNAME) != 0) {
1197 			/*
1198 			 * RFC2553 says that ai_canonname will be set only for
1199 			 * the first element.  we do it for all the elements,
1200 			 * just for convenience.
1201 			 */
1202 			GET_CANONNAME(cur->ai_next, hp->h_name);
1203 		}
1204 		while (cur->ai_next) /*%< no need to loop, actually. */
1205 			cur = cur->ai_next;
1206 		continue;
1207 
1208 	free:
1209 		if (cur->ai_next)
1210 			freeaddrinfo(cur->ai_next);
1211 		cur->ai_next = NULL;
1212 		/* continue, without tht pointer CUR advanced. */
1213 	}
1214 
1215 	return(sentinel.ai_next);
1216 }
1217 
1218 struct addrinfo *
1219 addr2addrinfo(pai, cp)
1220 	const struct addrinfo *pai;
1221 	const char *cp;
1222 {
1223 	const struct afd *afd;
1224 
1225 	afd = find_afd(pai->ai_family);
1226 	if (afd == NULL)
1227 		return(NULL);
1228 
1229 	return(get_ai(pai, afd, cp));
1230 }
1231 
1232 static struct net_data *
1233 init()
1234 {
1235 	struct net_data *net_data;
1236 
1237 	if (!(net_data = net_data_init(NULL)))
1238 		goto error;
1239 	if (!net_data->ho) {
1240 		net_data->ho = (*net_data->irs->ho_map)(net_data->irs);
1241 		if (!net_data->ho || !net_data->res) {
1242 error:
1243 			errno = EIO;
1244 			if (net_data && net_data->res)
1245 				RES_SET_H_ERRNO(net_data->res, NETDB_INTERNAL);
1246 			return (NULL);
1247 		}
1248 
1249 		(*net_data->ho->res_set)(net_data->ho, net_data->res, NULL);
1250 	}
1251 
1252 	return (net_data);
1253 }
1254