1/*	$NetBSD: getaddrinfo.c,v 1.127 2024/01/21 12:58:10 kre 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 (allows
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 1.127 2024/01/21 12:58:10 kre Exp $");
59#endif /* LIBC_SCCS and not lint */
60
61#ifndef RUMP_ACTION
62#include "namespace.h"
63#endif
64#include <sys/types.h>
65#include <sys/param.h>
66#include <sys/socket.h>
67#include <sys/ioctl.h>
68#include <sys/sysctl.h>
69#include <net/if.h>
70#include <netinet/in.h>
71#include <netinet6/in6_var.h>
72#include <arpa/inet.h>
73#include <arpa/nameser.h>
74#include <assert.h>
75#include <ctype.h>
76#include <errno.h>
77#include <netdb.h>
78#include <resolv.h>
79#include <stddef.h>
80#include <stdio.h>
81#include <stdlib.h>
82#include <string.h>
83#include <unistd.h>
84#include <ifaddrs.h>
85
86#include <syslog.h>
87#include <stdarg.h>
88#include <nsswitch.h>
89
90#ifdef YP
91#include <rpc/rpc.h>
92#include <rpcsvc/yp_prot.h>
93#include <rpcsvc/ypclnt.h>
94#endif
95
96#include "servent.h"
97
98#ifndef RUMP_ACTION
99#ifdef __weak_alias
100__weak_alias(getaddrinfo,_getaddrinfo)
101__weak_alias(allocaddrinfo,_allocaddrinfo)
102__weak_alias(freeaddrinfo,_freeaddrinfo)
103__weak_alias(gai_strerror,_gai_strerror)
104#endif
105#endif
106
107#define SUCCESS 0
108#define ANY 0
109#define YES 1
110#define NO  0
111
112#define sa4addr(sa) ((void *)&((struct sockaddr_in *)(void *)sa)->sin_addr)
113#define sa6addr(sa) ((void *)&((struct sockaddr_in6 *)(void *)sa)->sin6_addr)
114
115static const char in_addrany[] = { 0, 0, 0, 0 };
116static const char in_loopback[] = { 127, 0, 0, 1 };
117#ifdef INET6
118static const char in6_addrany[] = {
119	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
120};
121static const char in6_loopback[] = {
122	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1
123};
124#endif
125
126struct policyqueue {
127	TAILQ_ENTRY(policyqueue) pc_entry;
128#ifdef INET6
129	struct in6_addrpolicy pc_policy;
130#endif
131};
132TAILQ_HEAD(policyhead, policyqueue);
133
134static const struct afd {
135	int a_af;
136	int a_addrlen;
137	int a_socklen;
138	int a_off;
139	const char *a_addrany;
140	const char *a_loopback;
141	int a_scoped;
142} afdl [] = {
143#ifdef INET6
144	{PF_INET6, sizeof(struct in6_addr),
145	 sizeof(struct sockaddr_in6),
146	 offsetof(struct sockaddr_in6, sin6_addr),
147	 in6_addrany, in6_loopback, 1},
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
191#define AIO_SRCFLAG_DEPRECATED	0x1
192
193struct ai_order {
194	union {
195		struct sockaddr_storage aiou_ss;
196		struct sockaddr aiou_sa;
197	} aio_src_un;
198#define aio_srcsa aio_src_un.aiou_sa
199	uint32_t aio_srcflag;
200	int aio_srcscope;
201	int aio_dstscope;
202	struct policyqueue *aio_srcpolicy;
203	struct policyqueue *aio_dstpolicy;
204	struct addrinfo *aio_ai;
205	int aio_matchlen;
206};
207
208static const ns_src default_dns_files[] = {
209	{ NSSRC_FILES,	NS_SUCCESS },
210	{ NSSRC_DNS,	NS_SUCCESS },
211	{ 0, 0 }
212};
213
214#define MAXPACKET	(64*1024)
215
216typedef union {
217	HEADER hdr;
218	u_char buf[MAXPACKET];
219} querybuf;
220
221struct res_target {
222	struct res_target *next;
223	const char *name;	/* domain name */
224	int qclass, qtype;	/* class and type of query */
225	u_char *answer;		/* buffer to put answer */
226	int anslen;		/* size of answer buffer */
227	int n;			/* result length */
228};
229
230struct srvinfo {
231       struct srvinfo *next;
232       char name[MAXDNAME];
233       int port, pri, weight;
234};
235
236static int gai_srvok(const char *);
237static int str2number(const char *);
238static int explore_fqdn(const struct addrinfo *, const char *,
239    const char *, struct addrinfo **, struct servent_data *);
240static int explore_null(const struct addrinfo *,
241    const char *, struct addrinfo **, struct servent_data *);
242static int explore_numeric(const struct addrinfo *, const char *,
243    const char *, struct addrinfo **, const char *, struct servent_data *);
244static int explore_numeric_scope(const struct addrinfo *, const char *,
245    const char *, struct addrinfo **, struct servent_data *);
246static int get_canonname(const struct addrinfo *,
247    struct addrinfo *, const char *);
248static struct addrinfo *get_ai(const struct addrinfo *,
249    const struct afd *, const char *);
250static int get_portmatch(const struct addrinfo *, const char *,
251    struct servent_data *);
252static int get_port(const struct addrinfo *, const char *, int,
253    struct servent_data *);
254static const struct afd *find_afd(int);
255static int addrconfig(uint64_t *);
256static void set_source(struct ai_order *, struct policyhead *,
257    struct servent_data *);
258static int comp_dst(const void *, const void *);
259#ifdef INET6
260static int ip6_str2scopeid(const char *, struct sockaddr_in6 *, uint32_t *);
261#endif
262static int gai_addr2scopetype(struct sockaddr *);
263
264static int reorder(struct addrinfo *, struct servent_data *);
265static int get_addrselectpolicy(struct policyhead *);
266static void free_addrselectpolicy(struct policyhead *);
267static struct policyqueue *match_addrselectpolicy(struct sockaddr *,
268	struct policyhead *);
269static int matchlen(struct sockaddr *, struct sockaddr *);
270
271static struct addrinfo *getanswer(res_state, const querybuf *, int,
272    const char *, int, const struct addrinfo *);
273static void aisort(struct addrinfo *s, res_state res);
274static struct addrinfo * _dns_query(struct res_target *,
275    const struct addrinfo *, res_state, int);
276static struct addrinfo * _dns_srv_lookup(const char *, const char *,
277    const struct addrinfo *);
278static struct addrinfo * _dns_host_lookup(const char *,
279    const struct addrinfo *);
280static int _dns_getaddrinfo(void *, void *, va_list);
281static void _sethtent(FILE **);
282static void _endhtent(FILE **);
283static struct addrinfo *_gethtent(FILE **, const char *,
284    const struct addrinfo *);
285static int _files_getaddrinfo(void *, void *, va_list);
286#ifdef YP
287static struct addrinfo *_yphostent(char *, const struct addrinfo *);
288static int _yp_getaddrinfo(void *, void *, va_list);
289#endif
290
291static int res_queryN(const char *, struct res_target *, res_state);
292static int res_searchN(const char *, struct res_target *, res_state);
293static int res_querydomainN(const char *, const char *,
294    struct res_target *, res_state);
295
296static const char * const ai_errlist[] = {
297	"Success",
298	"Address family for hostname not supported",	/* EAI_ADDRFAMILY */
299	"Temporary failure in name resolution",		/* EAI_AGAIN	  */
300	"Invalid value for ai_flags",			/* EAI_BADFLAGS	  */
301	"Non-recoverable failure in name resolution",	/* EAI_FAIL	  */
302	"ai_family not supported",			/* EAI_FAMILY	  */
303	"Memory allocation failure",			/* EAI_MEMORY	  */
304	"No address associated with hostname",		/* EAI_NODATA	  */
305	"hostname or servname not provided or not known", /* EAI_NONAME	  */
306	"servname not supported for ai_socktype",	/* EAI_SERVICE	  */
307	"ai_socktype not supported",			/* EAI_SOCKTYPE	  */
308	"System error returned in errno",		/* EAI_SYSTEM	  */
309	"Invalid value for hints",			/* EAI_BADHINTS	  */
310	"Resolved protocol is unknown",			/* EAI_PROTOCOL	  */
311	"Argument buffer overflow",			/* EAI_OVERFLOW	  */
312	"Unknown error",				/* EAI_MAX	  */
313};
314
315/* XXX macros that make external reference is BAD. */
316
317#define GET_AI(ai, afd, addr)					\
318do {								\
319	/* external reference: pai, error, and label free */	\
320	(ai) = get_ai(pai, (afd), (addr));			\
321	if ((ai) == NULL) {					\
322		error = EAI_MEMORY;				\
323		goto free;					\
324	}							\
325} while (0)
326
327#define GET_PORT(ai, serv, svd)					\
328do {								\
329	/* external reference: error and label free */		\
330	error = get_port((ai), (serv), 0, (svd));		\
331	if (error != 0)						\
332		goto free;					\
333} while (0)
334
335#define GET_CANONNAME(ai, str)					\
336do {								\
337	/* external reference: pai, error and label free */	\
338	error = get_canonname(pai, (ai), (str));		\
339	if (error != 0)						\
340		goto free;					\
341} while (0)
342
343#define ERR(err)						\
344do {								\
345	/* external reference: error, and label bad */		\
346	error = (err);						\
347	goto bad;						\
348	/*NOTREACHED*/						\
349} while (0)
350
351#define MATCH_FAMILY(x, y, w)						\
352	((x) == (y) || (/*CONSTCOND*/(w) && ((x) == PF_UNSPEC ||	\
353	    (y) == PF_UNSPEC)))
354#define MATCH(x, y, w)							\
355	((x) == (y) || (/*CONSTCOND*/(w) && ((x) == ANY || (y) == ANY)))
356
357const char *
358gai_strerror(int ecode)
359{
360	if (ecode < 0 || ecode > EAI_MAX)
361		ecode = EAI_MAX;
362	return ai_errlist[ecode];
363}
364
365void
366freeaddrinfo(struct addrinfo *ai)
367{
368	struct addrinfo *next;
369
370	_DIAGASSERT(ai != NULL);
371
372	do {
373		next = ai->ai_next;
374		if (ai->ai_canonname)
375			free(ai->ai_canonname);
376		/* no need to free(ai->ai_addr) */
377		free(ai);
378		ai = next;
379	} while (ai);
380}
381
382/*
383 * We don't want localization to affect us
384 */
385#define PERIOD '.'
386#define hyphenchar(c) ((c) == '-')
387#define periodchar(c) ((c) == PERIOD)
388#define underschar(c) ((c) == '_')
389#define alphachar(c) (((c) >= 'a' && (c) <= 'z') || ((c) >= 'A' && (c) <= 'Z'))
390#define digitchar(c) ((c) >= '0' && (c) <= '9')
391
392#define firstchar(c)  (alphachar(c) || digitchar(c) || underschar(c))
393#define lastchar(c)   (alphachar(c) || digitchar(c))
394#define middlechar(c) (lastchar(c) || hyphenchar(c))
395
396static int
397gai_srvok(const char *dn)
398{
399	int nch, pch, ch;
400
401	for (pch = PERIOD, nch = ch = *dn++; ch != '\0'; pch = ch, ch = nch) {
402		if (periodchar(ch))
403			continue;
404		if (periodchar(pch)) {
405			if (!firstchar(ch))
406				return 0;
407		} else if (periodchar(nch) || nch == '\0') {
408			if (!lastchar(ch))
409				return 0;
410		} else if (!middlechar(ch))
411			return 0;
412       }
413       return 1;
414}
415
416static in_port_t *
417getport(struct addrinfo *ai) {
418	static in_port_t p;
419
420	switch (ai->ai_family) {
421	case AF_INET:
422		return &((struct sockaddr_in *)(void *)ai->ai_addr)->sin_port;
423#ifdef INET6
424	case AF_INET6:
425		return &((struct sockaddr_in6 *)(void *)ai->ai_addr)->sin6_port;
426#endif
427	default:
428		p = 0;
429		/* XXX: abort()? */
430		return &p;
431	}
432}
433
434static int
435str2number(const char *p)
436{
437	char *ep;
438	unsigned long v;
439
440	_DIAGASSERT(p != NULL);
441
442	if (*p == '\0')
443		return -1;
444	ep = NULL;
445	errno = 0;
446	v = strtoul(p, &ep, 10);
447	if (errno == 0 && ep && *ep == '\0' && v <= INT_MAX)
448		return (int)v;
449	else
450		return -1;
451}
452
453int
454getaddrinfo(const char *hostname, const char *servname,
455    const struct addrinfo *hints, struct addrinfo **res)
456{
457	struct addrinfo sentinel;
458	struct addrinfo *cur;
459	int error = 0;
460	struct addrinfo ai;
461	struct addrinfo ai0;
462	struct addrinfo *pai;
463	const struct explore *ex;
464	struct servent_data svd;
465	uint64_t mask = (uint64_t)~0ULL;
466	int numeric = 0;
467
468	/* hostname is allowed to be NULL */
469	/* servname is allowed to be NULL */
470	/* hints is allowed to be NULL */
471	_DIAGASSERT(res != NULL);
472
473	(void)memset(&svd, 0, sizeof(svd));
474	memset(&sentinel, 0, sizeof(sentinel));
475	cur = &sentinel;
476	memset(&ai, 0, sizeof(ai));
477	pai = &ai;
478	pai->ai_flags = 0;
479	pai->ai_family = PF_UNSPEC;
480	pai->ai_socktype = ANY;
481	pai->ai_protocol = ANY;
482	pai->ai_addrlen = 0;
483	pai->ai_canonname = NULL;
484	pai->ai_addr = NULL;
485	pai->ai_next = NULL;
486
487	if (hostname == NULL && servname == NULL)
488		return EAI_NONAME;
489	if (hints) {
490		/* error check for hints */
491		if (hints->ai_addrlen || hints->ai_canonname ||
492		    hints->ai_addr || hints->ai_next)
493			ERR(EAI_BADHINTS); /* xxx */
494		if (hints->ai_flags & ~AI_MASK)
495			ERR(EAI_BADFLAGS);
496		switch (hints->ai_family) {
497		case PF_UNSPEC:
498		case PF_INET:
499#ifdef INET6
500		case PF_INET6:
501#endif
502			break;
503		default:
504			ERR(EAI_FAMILY);
505		}
506		memcpy(pai, hints, sizeof(*pai));
507
508		/*
509		 * if both socktype/protocol are specified, check if they
510		 * are meaningful combination.
511		 */
512		if (pai->ai_socktype != ANY && pai->ai_protocol != ANY) {
513			for (ex = explore; ex->e_af >= 0; ex++) {
514				if (pai->ai_family != ex->e_af)
515					continue;
516				if (ex->e_socktype == ANY)
517					continue;
518				if (ex->e_protocol == ANY)
519					continue;
520				if (pai->ai_socktype == ex->e_socktype
521				 && pai->ai_protocol != ex->e_protocol) {
522					ERR(EAI_BADHINTS);
523				}
524			}
525		}
526	}
527
528	if ((pai->ai_flags & AI_ADDRCONFIG) != 0 && addrconfig(&mask) == -1)
529		ERR(EAI_FAIL);
530
531	/*
532	 * check for special cases.  (1) numeric servname is disallowed if
533	 * socktype/protocol are left unspecified. (2) servname is disallowed
534	 * for raw and other inet{,6} sockets.
535	 */
536	if (MATCH_FAMILY(pai->ai_family, PF_INET, 1)
537#ifdef PF_INET6
538	 || MATCH_FAMILY(pai->ai_family, PF_INET6, 1)
539#endif
540	    ) {
541		ai0 = *pai;	/* backup *pai */
542
543		if (pai->ai_family == PF_UNSPEC) {
544#ifdef PF_INET6
545			pai->ai_family = PF_INET6;
546#else
547			pai->ai_family = PF_INET;
548#endif
549		}
550		error = get_portmatch(pai, servname, &svd);
551		if (error)
552			goto bad;
553
554		*pai = ai0;
555	}
556
557	ai0 = *pai;
558
559	/* NULL hostname, or numeric hostname */
560	for (ex = explore; ex->e_af >= 0; ex++) {
561		*pai = ai0;
562
563		/* ADDRCONFIG check */
564		if ((((uint64_t)1 << ex->e_af) & mask) == 0)
565			continue;
566
567		/* PF_UNSPEC entries are prepared for DNS queries only */
568		if (ex->e_af == PF_UNSPEC)
569			continue;
570
571		if (!MATCH_FAMILY(pai->ai_family, ex->e_af, WILD_AF(ex)))
572			continue;
573		if (!MATCH(pai->ai_socktype, ex->e_socktype, WILD_SOCKTYPE(ex)))
574			continue;
575		if (!MATCH(pai->ai_protocol, ex->e_protocol, WILD_PROTOCOL(ex)))
576			continue;
577		if (pai->ai_family == PF_UNSPEC)
578			pai->ai_family = ex->e_af;
579		if (pai->ai_socktype == ANY && ex->e_socktype != ANY)
580			pai->ai_socktype = ex->e_socktype;
581		if (pai->ai_protocol == ANY && ex->e_protocol != ANY)
582			pai->ai_protocol = ex->e_protocol;
583
584		if (hostname == NULL)
585			error = explore_null(pai, servname, &cur->ai_next,
586			    &svd);
587		else
588			error = explore_numeric_scope(pai, hostname, servname,
589			    &cur->ai_next, &svd);
590
591		if (error)
592			goto free;
593
594		while (cur->ai_next)
595			cur = cur->ai_next;
596	}
597
598	/*
599	 * XXX
600	 * If numeric representation of AF1 can be interpreted as FQDN
601	 * representation of AF2, we need to think again about the code below.
602	 */
603	if (sentinel.ai_next) {
604		numeric = 1;
605		goto good;
606	}
607
608	if (hostname == NULL)
609		ERR(EAI_NODATA);
610	if (pai->ai_flags & AI_NUMERICHOST)
611		ERR(EAI_NONAME);
612
613	/*
614	 * hostname as alphabetical name.
615	 * we would like to prefer AF_INET6 than AF_INET, so we'll make a
616	 * outer loop by AFs.
617	 */
618	for (ex = explore; ex->e_af >= 0; ex++) {
619		*pai = ai0;
620
621
622		/* ADDRCONFIG check */
623		/* PF_UNSPEC entries are prepared for DNS queries only */
624		if (ex->e_af != PF_UNSPEC &&
625		    (((uint64_t)1 << ex->e_af) & mask) == 0)
626			continue;
627
628		/* require exact match for family field */
629		if (pai->ai_family != ex->e_af)
630			continue;
631
632		if (!MATCH(pai->ai_socktype, ex->e_socktype,
633				WILD_SOCKTYPE(ex))) {
634			continue;
635		}
636		if (!MATCH(pai->ai_protocol, ex->e_protocol,
637				WILD_PROTOCOL(ex))) {
638			continue;
639		}
640
641		if (pai->ai_socktype == ANY && ex->e_socktype != ANY)
642			pai->ai_socktype = ex->e_socktype;
643		if (pai->ai_protocol == ANY && ex->e_protocol != ANY)
644			pai->ai_protocol = ex->e_protocol;
645
646		error = explore_fqdn(pai, hostname, servname, &cur->ai_next,
647		    &svd);
648
649		while (cur && cur->ai_next)
650			cur = cur->ai_next;
651	}
652
653	/* XXX */
654	if (sentinel.ai_next)
655		error = 0;
656
657	if (error)
658		goto free;
659
660	if (sentinel.ai_next) {
661 good:
662		/*
663		 * If the returned entry is for an active connection,
664		 * and the given name is not numeric, reorder the
665		 * list, so that the application would try the list
666		 * in the most efficient order.  Since the head entry
667		 * of the original list may contain ai_canonname and
668		 * that entry may be moved elsewhere in the new list,
669		 * we keep the pointer and will  restore it in the new
670		 * head entry.  (Note that RFC3493 requires the head
671		 * entry store it when requested by the caller).
672		 */
673		if (hints == NULL || !(hints->ai_flags & AI_PASSIVE)) {
674			if (!numeric) {
675				char *canonname;
676
677				canonname = sentinel.ai_next->ai_canonname;
678				sentinel.ai_next->ai_canonname = NULL;
679				(void)reorder(&sentinel, &svd);
680				if (sentinel.ai_next->ai_canonname == NULL) {
681					sentinel.ai_next->ai_canonname
682					    = canonname;
683				} else if (canonname != NULL)
684					free(canonname);
685			}
686		}
687		endservent_r(&svd);
688		*res = sentinel.ai_next;
689		return SUCCESS;
690	} else
691		error = EAI_FAIL;
692 free:
693 bad:
694	endservent_r(&svd);
695	if (sentinel.ai_next)
696		freeaddrinfo(sentinel.ai_next);
697	*res = NULL;
698	return error;
699}
700
701static int
702reorder(struct addrinfo *sentinel, struct servent_data *svd)
703{
704	struct addrinfo *ai, **aip;
705	struct ai_order *aio;
706	int i, n;
707	struct policyhead policyhead;
708
709	/* count the number of addrinfo elements for sorting. */
710	for (n = 0, ai = sentinel->ai_next; ai != NULL; ai = ai->ai_next, n++)
711		;
712
713	/*
714	 * If the number is small enough, we can skip the reordering process.
715	 */
716	if (n <= 1)
717		return n;
718
719	/* allocate a temporary array for sort and initialization of it. */
720	if ((aio = calloc(n, sizeof(*aio))) == NULL)
721		return n;	/* give up reordering */
722
723	/* retrieve address selection policy from the kernel */
724	TAILQ_INIT(&policyhead);
725	if (!get_addrselectpolicy(&policyhead)) {
726		/* no policy is installed into kernel, we don't sort. */
727		free(aio);
728		return n;
729	}
730
731	for (i = 0, ai = sentinel->ai_next; i < n; ai = ai->ai_next, i++) {
732		aio[i].aio_ai = ai;
733		aio[i].aio_dstscope = gai_addr2scopetype(ai->ai_addr);
734		aio[i].aio_dstpolicy = match_addrselectpolicy(ai->ai_addr,
735							      &policyhead);
736		set_source(&aio[i], &policyhead, svd);
737	}
738
739	/* perform sorting. */
740	qsort(aio, n, sizeof(*aio), comp_dst);
741
742	/* reorder the addrinfo chain. */
743	for (i = 0, aip = &sentinel->ai_next; i < n; i++) {
744		*aip = aio[i].aio_ai;
745		aip = &aio[i].aio_ai->ai_next;
746	}
747	*aip = NULL;
748
749	/* cleanup and return */
750	free(aio);
751	free_addrselectpolicy(&policyhead);
752	return n;
753}
754
755static int
756get_addrselectpolicy(struct policyhead *head)
757{
758#ifdef INET6
759	static const int mib[] = {
760	    CTL_NET, PF_INET6, IPPROTO_IPV6, IPV6CTL_ADDRCTLPOLICY };
761	static const u_int miblen = (u_int)__arraycount(mib);
762	size_t l;
763	char *buf;
764	struct in6_addrpolicy *pol, *ep;
765
766	if (sysctl(mib, miblen, NULL, &l, NULL, 0) < 0)
767		return 0;
768	if (l == 0)
769		return 0;
770	if ((buf = malloc(l)) == NULL)
771		return 0;
772	if (sysctl(mib, miblen, buf, &l, NULL, 0) < 0) {
773		free(buf);
774		return 0;
775	}
776
777	ep = (void *)(buf + l);
778	for (pol = (void *)buf; pol + 1 <= ep; pol++) {
779		struct policyqueue *new;
780
781		if ((new = malloc(sizeof(*new))) == NULL) {
782			free_addrselectpolicy(head); /* make the list empty */
783			break;
784		}
785		new->pc_policy = *pol;
786		TAILQ_INSERT_TAIL(head, new, pc_entry);
787	}
788
789	free(buf);
790	return 1;
791#else
792	return 0;
793#endif
794}
795
796static void
797free_addrselectpolicy(struct policyhead *head)
798{
799	struct policyqueue *ent, *nent;
800
801	for (ent = TAILQ_FIRST(head); ent; ent = nent) {
802		nent = TAILQ_NEXT(ent, pc_entry);
803		TAILQ_REMOVE(head, ent, pc_entry);
804		free(ent);
805	}
806}
807
808static struct policyqueue *
809match_addrselectpolicy(struct sockaddr *addr, struct policyhead *head)
810{
811#ifdef INET6
812	struct policyqueue *ent, *bestent = NULL;
813	struct in6_addrpolicy *pol;
814	int curmatchlen, bestmatchlen = -1;
815	u_char *mp, *ep, *k, *p;
816	u_int m;
817	struct sockaddr_in6 key;
818
819	switch(addr->sa_family) {
820	case AF_INET6:
821		memcpy(&key, addr, sizeof(key));
822		break;
823	case AF_INET:
824		/* convert the address into IPv4-mapped IPv6 address. */
825		memset(&key, 0, sizeof(key));
826		key.sin6_family = AF_INET6;
827		key.sin6_len = sizeof(key);
828		key.sin6_addr.s6_addr[10] = 0xff;
829		key.sin6_addr.s6_addr[11] = 0xff;
830		memcpy(&key.sin6_addr.s6_addr[12], sa4addr(addr), 4);
831		break;
832	default:
833		return NULL;
834	}
835
836	for (ent = TAILQ_FIRST(head); ent; ent = TAILQ_NEXT(ent, pc_entry)) {
837		pol = &ent->pc_policy;
838		curmatchlen = 0;
839
840		mp = (void *)&pol->addrmask.sin6_addr;
841		ep = mp + 16;	/* XXX: scope field? */
842		k = (void *)&key.sin6_addr;
843		p = (void *)&pol->addr.sin6_addr;
844		for (; mp < ep && *mp; mp++, k++, p++) {
845			m = *mp;
846			if ((*k & m) != *p)
847				goto next; /* not match */
848			if (m == 0xff) /* short cut for a typical case */
849				curmatchlen += 8;
850			else {
851				while (m >= 0x80) {
852					curmatchlen++;
853					m <<= 1;
854				}
855			}
856		}
857
858		/* matched.  check if this is better than the current best. */
859		if (curmatchlen > bestmatchlen) {
860			bestent = ent;
861			bestmatchlen = curmatchlen;
862		}
863
864	  next:
865		continue;
866	}
867
868	return bestent;
869#else
870	return NULL;
871#endif
872
873}
874
875static void
876set_source(struct ai_order *aio, struct policyhead *ph,
877    struct servent_data *svd)
878{
879	struct addrinfo ai = *aio->aio_ai;
880	struct sockaddr_storage ss;
881	socklen_t srclen;
882	int s;
883
884	/* set unspec ("no source is available"), just in case */
885	aio->aio_srcsa.sa_family = AF_UNSPEC;
886	aio->aio_srcscope = -1;
887
888	switch(ai.ai_family) {
889	case AF_INET:
890#ifdef INET6
891	case AF_INET6:
892#endif
893		break;
894	default:		/* ignore unsupported AFs explicitly */
895		return;
896	}
897
898	/* XXX: make a dummy addrinfo to call connect() */
899	ai.ai_socktype = SOCK_DGRAM;
900	ai.ai_protocol = IPPROTO_UDP; /* is UDP too specific? */
901	ai.ai_next = NULL;
902	memset(&ss, 0, sizeof(ss));
903	memcpy(&ss, ai.ai_addr, ai.ai_addrlen);
904	ai.ai_addr = (void *)&ss;
905	get_port(&ai, "1", 0, svd);
906
907	/* open a socket to get the source address for the given dst */
908	if ((s = socket(ai.ai_family, ai.ai_socktype | SOCK_CLOEXEC,
909	    ai.ai_protocol)) < 0)
910		return;		/* give up */
911	if (connect(s, ai.ai_addr, ai.ai_addrlen) < 0)
912		goto cleanup;
913	srclen = ai.ai_addrlen;
914	if (getsockname(s, &aio->aio_srcsa, &srclen) < 0) {
915		aio->aio_srcsa.sa_family = AF_UNSPEC;
916		goto cleanup;
917	}
918	aio->aio_srcscope = gai_addr2scopetype(&aio->aio_srcsa);
919	aio->aio_srcpolicy = match_addrselectpolicy(&aio->aio_srcsa, ph);
920	aio->aio_matchlen = matchlen(&aio->aio_srcsa, aio->aio_ai->ai_addr);
921#ifdef INET6
922	if (ai.ai_family == AF_INET6) {
923		struct in6_ifreq ifr6;
924		uint32_t flags6;
925
926		memset(&ifr6, 0, sizeof(ifr6));
927		memcpy(&ifr6.ifr_addr, ai.ai_addr, ai.ai_addrlen);
928		if (ioctl(s, SIOCGIFAFLAG_IN6, &ifr6) == 0) {
929			flags6 = ifr6.ifr_ifru.ifru_flags6;
930			if ((flags6 & IN6_IFF_DEPRECATED))
931				aio->aio_srcflag |= AIO_SRCFLAG_DEPRECATED;
932		}
933	}
934#endif
935
936  cleanup:
937	close(s);
938	return;
939}
940
941static int
942matchlen(struct sockaddr *src, struct sockaddr *dst)
943{
944	int match = 0;
945	u_char *s, *d;
946	u_char *lim;
947	u_int r, addrlen;
948
949	switch (src->sa_family) {
950#ifdef INET6
951	case AF_INET6:
952		s = sa6addr(src);
953		d = sa6addr(dst);
954		addrlen = sizeof(struct in6_addr);
955		lim = s + addrlen;
956		break;
957#endif
958	case AF_INET:
959		s = sa4addr(src);
960		d = sa4addr(dst);
961		addrlen = sizeof(struct in_addr);
962		lim = s + addrlen;
963		break;
964	default:
965		return 0;
966	}
967
968	while (s < lim)
969		if ((r = (*d++ ^ *s++)) != 0) {
970			while (r < addrlen * 8) {
971				match++;
972				r <<= 1;
973			}
974			break;
975		} else
976			match += 8;
977	return match;
978}
979
980static int
981comp_dst(const void *arg1, const void *arg2)
982{
983	const struct ai_order *dst1 = arg1, *dst2 = arg2;
984
985	/*
986	 * Rule 1: Avoid unusable destinations.
987	 * XXX: we currently do not consider if an appropriate route exists.
988	 */
989	if (dst1->aio_srcsa.sa_family != AF_UNSPEC &&
990	    dst2->aio_srcsa.sa_family == AF_UNSPEC) {
991		return -1;
992	}
993	if (dst1->aio_srcsa.sa_family == AF_UNSPEC &&
994	    dst2->aio_srcsa.sa_family != AF_UNSPEC) {
995		return 1;
996	}
997
998	/* Rule 2: Prefer matching scope. */
999	if (dst1->aio_dstscope == dst1->aio_srcscope &&
1000	    dst2->aio_dstscope != dst2->aio_srcscope) {
1001		return -1;
1002	}
1003	if (dst1->aio_dstscope != dst1->aio_srcscope &&
1004	    dst2->aio_dstscope == dst2->aio_srcscope) {
1005		return 1;
1006	}
1007
1008	/* Rule 3: Avoid deprecated addresses. */
1009	if (dst1->aio_srcsa.sa_family != AF_UNSPEC &&
1010	    dst2->aio_srcsa.sa_family != AF_UNSPEC) {
1011		if (!(dst1->aio_srcflag & AIO_SRCFLAG_DEPRECATED) &&
1012		    (dst2->aio_srcflag & AIO_SRCFLAG_DEPRECATED)) {
1013			return -1;
1014		}
1015		if ((dst1->aio_srcflag & AIO_SRCFLAG_DEPRECATED) &&
1016		    !(dst2->aio_srcflag & AIO_SRCFLAG_DEPRECATED)) {
1017			return 1;
1018		}
1019	}
1020
1021	/* Rule 4: Prefer home addresses. */
1022	/* XXX: not implemented yet */
1023
1024	/* Rule 5: Prefer matching label. */
1025#ifdef INET6
1026	if (dst1->aio_srcpolicy && dst1->aio_dstpolicy &&
1027	    dst1->aio_srcpolicy->pc_policy.label ==
1028	    dst1->aio_dstpolicy->pc_policy.label &&
1029	    (dst2->aio_srcpolicy == NULL || dst2->aio_dstpolicy == NULL ||
1030	     dst2->aio_srcpolicy->pc_policy.label !=
1031	     dst2->aio_dstpolicy->pc_policy.label)) {
1032		return -1;
1033	}
1034	if (dst2->aio_srcpolicy && dst2->aio_dstpolicy &&
1035	    dst2->aio_srcpolicy->pc_policy.label ==
1036	    dst2->aio_dstpolicy->pc_policy.label &&
1037	    (dst1->aio_srcpolicy == NULL || dst1->aio_dstpolicy == NULL ||
1038	     dst1->aio_srcpolicy->pc_policy.label !=
1039	     dst1->aio_dstpolicy->pc_policy.label)) {
1040		return 1;
1041	}
1042#endif
1043
1044	/* Rule 6: Prefer higher precedence. */
1045#ifdef INET6
1046	if (dst1->aio_dstpolicy &&
1047	    (dst2->aio_dstpolicy == NULL ||
1048	     dst1->aio_dstpolicy->pc_policy.preced >
1049	     dst2->aio_dstpolicy->pc_policy.preced)) {
1050		return -1;
1051	}
1052	if (dst2->aio_dstpolicy &&
1053	    (dst1->aio_dstpolicy == NULL ||
1054	     dst2->aio_dstpolicy->pc_policy.preced >
1055	     dst1->aio_dstpolicy->pc_policy.preced)) {
1056		return 1;
1057	}
1058#endif
1059
1060	/* Rule 7: Prefer native transport. */
1061	/* XXX: not implemented yet */
1062
1063	/* Rule 8: Prefer smaller scope. */
1064	if (dst1->aio_dstscope >= 0 &&
1065	    dst1->aio_dstscope < dst2->aio_dstscope) {
1066		return -1;
1067	}
1068	if (dst2->aio_dstscope >= 0 &&
1069	    dst2->aio_dstscope < dst1->aio_dstscope) {
1070		return 1;
1071	}
1072
1073	/*
1074	 * Rule 9: Use longest matching prefix.
1075	 * We compare the match length in a same AF only.
1076	 */
1077	if (dst1->aio_ai->ai_addr->sa_family ==
1078	    dst2->aio_ai->ai_addr->sa_family &&
1079	    dst1->aio_ai->ai_addr->sa_family != AF_INET) {
1080		if (dst1->aio_matchlen > dst2->aio_matchlen) {
1081			return -1;
1082		}
1083		if (dst1->aio_matchlen < dst2->aio_matchlen) {
1084			return 1;
1085		}
1086	}
1087
1088	/* Rule 10: Otherwise, leave the order unchanged. */
1089	return -1;
1090}
1091
1092/*
1093 * Copy from scope.c.
1094 * XXX: we should standardize the functions and link them as standard
1095 * library.
1096 */
1097static int
1098gai_addr2scopetype(struct sockaddr *sa)
1099{
1100#ifdef INET6
1101	struct sockaddr_in6 *sa6;
1102#endif
1103	struct sockaddr_in *sa4;
1104	u_char *p;
1105
1106	switch(sa->sa_family) {
1107#ifdef INET6
1108	case AF_INET6:
1109		sa6 = (void *)sa;
1110		if (IN6_IS_ADDR_MULTICAST(&sa6->sin6_addr)) {
1111			/* just use the scope field of the multicast address */
1112			return sa6->sin6_addr.s6_addr[2] & 0x0f;
1113		}
1114		/*
1115		 * Unicast addresses: map scope type to corresponding scope
1116		 * value defined for multcast addresses.
1117		 * XXX: hardcoded scope type values are bad...
1118		 */
1119		if (IN6_IS_ADDR_LOOPBACK(&sa6->sin6_addr))
1120			return 1; /* node local scope */
1121		if (IN6_IS_ADDR_LINKLOCAL(&sa6->sin6_addr))
1122			return 2; /* link-local scope */
1123		if (IN6_IS_ADDR_SITELOCAL(&sa6->sin6_addr))
1124			return 5; /* site-local scope */
1125		return 14;	/* global scope */
1126#endif
1127	case AF_INET:
1128		/*
1129		 * IPv4 pseudo scoping according to RFC 3484.
1130		 */
1131		sa4 = (void *)sa;
1132		p = (u_char *)(void *)&sa4->sin_addr;
1133		/* IPv4 autoconfiguration addresses have link-local scope. */
1134		if (p[0] == 169 && p[1] == 254)
1135			return 2;
1136		/* Private addresses have site-local scope. */
1137		if (p[0] == 10 ||
1138		    (p[0] == 172 && (p[1] & 0xf0) == 16) ||
1139		    (p[0] == 192 && p[1] == 168))
1140			return 14;	/* XXX: It should be 5 unless NAT */
1141		/* Loopback addresses have link-local scope. */
1142		if (p[0] == 127)
1143			return 2;
1144		return 14;
1145	default:
1146		errno = EAFNOSUPPORT; /* is this a good error? */
1147		return -1;
1148	}
1149}
1150
1151/*
1152 * FQDN hostname, DNS lookup
1153 */
1154static int
1155explore_fqdn(const struct addrinfo *pai, const char *hostname,
1156    const char *servname, struct addrinfo **res, struct servent_data *svd)
1157{
1158	struct addrinfo *result;
1159	struct addrinfo *cur;
1160	int error = 0;
1161	static const ns_dtab dtab[] = {
1162		NS_FILES_CB(_files_getaddrinfo, NULL)
1163		{ NSSRC_DNS, _dns_getaddrinfo, NULL },	/* force -DHESIOD */
1164		NS_NIS_CB(_yp_getaddrinfo, NULL)
1165		NS_NULL_CB
1166	};
1167
1168	_DIAGASSERT(pai != NULL);
1169	/* hostname may be NULL */
1170	/* servname may be NULL */
1171	_DIAGASSERT(res != NULL);
1172
1173	result = NULL;
1174
1175	/*
1176	 * if the servname does not match socktype/protocol, ignore it.
1177	 */
1178	if (get_portmatch(pai, servname, svd) != 0)
1179		return 0;
1180
1181	switch (nsdispatch(&result, dtab, NSDB_HOSTS, "getaddrinfo",
1182	    default_dns_files, hostname, pai, servname)) {
1183	case NS_TRYAGAIN:
1184		error = EAI_AGAIN;
1185		goto free;
1186	case NS_UNAVAIL:
1187		error = EAI_FAIL;
1188		goto free;
1189	case NS_NOTFOUND:
1190		error = EAI_NODATA;
1191		goto free;
1192	case NS_SUCCESS:
1193		error = 0;
1194		for (cur = result; cur; cur = cur->ai_next) {
1195			/* Check for already filled port. */
1196			if (*getport(cur))
1197				continue;
1198			GET_PORT(cur, servname, svd);
1199			/* canonname should be filled already */
1200		}
1201		break;
1202	}
1203
1204	*res = result;
1205
1206	return 0;
1207
1208free:
1209	if (result)
1210		freeaddrinfo(result);
1211	return error;
1212}
1213
1214/*
1215 * hostname == NULL.
1216 * passive socket -> anyaddr (0.0.0.0 or ::)
1217 * non-passive socket -> localhost (127.0.0.1 or ::1)
1218 */
1219static int
1220explore_null(const struct addrinfo *pai, const char *servname,
1221    struct addrinfo **res, struct servent_data *svd)
1222{
1223	int s;
1224	const struct afd *afd;
1225	struct addrinfo *cur;
1226	struct addrinfo sentinel;
1227	int error;
1228
1229	_DIAGASSERT(pai != NULL);
1230	/* servname may be NULL */
1231	_DIAGASSERT(res != NULL);
1232
1233	*res = NULL;
1234	sentinel.ai_next = NULL;
1235	cur = &sentinel;
1236
1237	/*
1238	 * filter out AFs that are not supported by the kernel
1239	 * XXX errno?
1240	 */
1241	s = socket(pai->ai_family, SOCK_DGRAM, 0);
1242	if (s < 0) {
1243		if (errno != EMFILE)
1244			return 0;
1245	} else
1246		close(s);
1247
1248	/*
1249	 * if the servname does not match socktype/protocol, ignore it.
1250	 */
1251	if (get_portmatch(pai, servname, svd) != 0)
1252		return 0;
1253
1254	afd = find_afd(pai->ai_family);
1255	if (afd == NULL)
1256		return 0;
1257
1258	if (pai->ai_flags & AI_PASSIVE) {
1259		GET_AI(cur->ai_next, afd, afd->a_addrany);
1260		/* xxx meaningless?
1261		 * GET_CANONNAME(cur->ai_next, "anyaddr");
1262		 */
1263		GET_PORT(cur->ai_next, servname, svd);
1264	} else {
1265		GET_AI(cur->ai_next, afd, afd->a_loopback);
1266		/* xxx meaningless?
1267		 * GET_CANONNAME(cur->ai_next, "localhost");
1268		 */
1269		GET_PORT(cur->ai_next, servname, svd);
1270	}
1271	cur = cur->ai_next;
1272
1273	*res = sentinel.ai_next;
1274	return 0;
1275
1276free:
1277	if (sentinel.ai_next)
1278		freeaddrinfo(sentinel.ai_next);
1279	return error;
1280}
1281
1282/*
1283 * numeric hostname
1284 */
1285static int
1286explore_numeric(const struct addrinfo *pai, const char *hostname,
1287    const char *servname, struct addrinfo **res, const char *canonname,
1288    struct servent_data *svd)
1289{
1290	const struct afd *afd;
1291	struct addrinfo *cur;
1292	struct addrinfo sentinel;
1293	int error;
1294	char pton[PTON_MAX];
1295
1296	_DIAGASSERT(pai != NULL);
1297	/* hostname may be NULL */
1298	/* servname may be NULL */
1299	_DIAGASSERT(res != NULL);
1300
1301	*res = NULL;
1302	sentinel.ai_next = NULL;
1303	cur = &sentinel;
1304
1305	/*
1306	 * if the servname does not match socktype/protocol, ignore it.
1307	 */
1308	if (get_portmatch(pai, servname, svd) != 0)
1309		return 0;
1310
1311	afd = find_afd(pai->ai_family);
1312	if (afd == NULL)
1313		return 0;
1314
1315	switch (afd->a_af) {
1316	case AF_INET:
1317	       /*
1318		* RFC3493 section 6.1, requires getaddrinfo() to accept
1319		* AF_INET formats that are accepted by inet_addr(); here
1320		* we use the equivalent inet_aton() function so we can
1321		* check for errors. inet_pton() only accepts addresses
1322		* in the dotted quad format and only in base 10, so we
1323		* need to treat AF_INET specially.
1324		*
1325		* We also check for trailing characters and fail if there
1326		* are any. This matches the inet_pton6(), but not the
1327		* inet_pton4() behavior. We choose to make the protocol
1328		* behavior consistent.
1329		*/
1330		if (inet_aton(hostname, (void *)pton) == 1 &&
1331		    hostname[strspn(hostname, "0123456789.xabcdefXABCDEF")]
1332		    == '\0') {
1333			if (pai->ai_family == afd->a_af ||
1334			    pai->ai_family == PF_UNSPEC /*?*/) {
1335				GET_AI(cur->ai_next, afd, pton);
1336				GET_PORT(cur->ai_next, servname, svd);
1337				if ((pai->ai_flags & AI_CANONNAME)) {
1338					/*
1339					 * Set the numeric address itself as
1340					 * the canonical name, based on a
1341					 * clarification in rfc2553bis-03.
1342					 */
1343					GET_CANONNAME(cur->ai_next, canonname);
1344				}
1345				while (cur && cur->ai_next)
1346					cur = cur->ai_next;
1347			} else
1348				ERR(EAI_FAMILY);	/*xxx*/
1349		}
1350		break;
1351	default:
1352		if (inet_pton(afd->a_af, hostname, pton) == 1) {
1353			if (pai->ai_family == afd->a_af ||
1354			    pai->ai_family == PF_UNSPEC /*?*/) {
1355				GET_AI(cur->ai_next, afd, pton);
1356				GET_PORT(cur->ai_next, servname, svd);
1357				if ((pai->ai_flags & AI_CANONNAME)) {
1358					/*
1359					 * Set the numeric address itself as
1360					 * the canonical name, based on a
1361					 * clarification in rfc2553bis-03.
1362					 */
1363					GET_CANONNAME(cur->ai_next, canonname);
1364				}
1365				while (cur->ai_next)
1366					cur = cur->ai_next;
1367			} else
1368				ERR(EAI_FAMILY);	/*xxx*/
1369		}
1370		break;
1371	}
1372
1373	*res = sentinel.ai_next;
1374	return 0;
1375
1376free:
1377bad:
1378	if (sentinel.ai_next)
1379		freeaddrinfo(sentinel.ai_next);
1380	return error;
1381}
1382
1383/*
1384 * numeric hostname with scope
1385 */
1386static int
1387explore_numeric_scope(const struct addrinfo *pai, const char *hostname,
1388    const char *servname, struct addrinfo **res, struct servent_data *svd)
1389{
1390#if !defined(SCOPE_DELIMITER) || !defined(INET6)
1391	return explore_numeric(pai, hostname, servname, res, hostname, svd);
1392#else
1393	const struct afd *afd;
1394	struct addrinfo *cur;
1395	int error;
1396	char *hostname2 = NULL, *addr;
1397	const char *cp, *scope;
1398	struct sockaddr_in6 *sin6;
1399
1400	_DIAGASSERT(pai != NULL);
1401	/* hostname may be NULL */
1402	/* servname may be NULL */
1403	_DIAGASSERT(res != NULL);
1404
1405	/*
1406	 * if the servname does not match socktype/protocol, ignore it.
1407	 */
1408	if (get_portmatch(pai, servname, svd) != 0)
1409		return 0;
1410
1411	afd = find_afd(pai->ai_family);
1412	if (afd == NULL)
1413		return 0;
1414
1415	if (!afd->a_scoped)
1416		return explore_numeric(pai, hostname, servname, res, hostname,
1417		    svd);
1418
1419	cp = strchr(hostname, SCOPE_DELIMITER);
1420	if (cp == NULL)
1421		return explore_numeric(pai, hostname, servname, res, hostname,
1422		    svd);
1423
1424	/*
1425	 * Handle special case of <scoped_address><delimiter><scope id>
1426	 */
1427	hostname2 = strdup(hostname);
1428	if (hostname2 == NULL)
1429		return EAI_MEMORY;
1430	/* terminate at the delimiter */
1431	hostname2[cp - hostname] = '\0';
1432	addr = hostname2;
1433	scope = cp + 1;
1434
1435	error = explore_numeric(pai, addr, servname, res, hostname, svd);
1436	if (error == 0) {
1437		uint32_t scopeid;
1438
1439		for (cur = *res; cur; cur = cur->ai_next) {
1440			if (cur->ai_family != AF_INET6)
1441				continue;
1442			sin6 = (struct sockaddr_in6 *)(void *)cur->ai_addr;
1443			if (ip6_str2scopeid(scope, sin6, &scopeid) == -1) {
1444				free(hostname2);
1445				return EAI_NODATA; /* XXX: is return OK? */
1446			}
1447			sin6->sin6_scope_id = scopeid;
1448		}
1449	}
1450
1451	free(hostname2);
1452
1453	return error;
1454#endif
1455}
1456
1457static int
1458get_canonname(const struct addrinfo *pai, struct addrinfo *ai, const char *str)
1459{
1460
1461	_DIAGASSERT(pai != NULL);
1462	_DIAGASSERT(ai != NULL);
1463	_DIAGASSERT(str != NULL);
1464
1465	if ((pai->ai_flags & AI_CANONNAME) != 0) {
1466		ai->ai_canonname = strdup(str);
1467		if (ai->ai_canonname == NULL)
1468			return EAI_MEMORY;
1469	}
1470	return 0;
1471}
1472
1473struct addrinfo *
1474allocaddrinfo(socklen_t addrlen)
1475{
1476	struct addrinfo *ai;
1477
1478	ai = calloc(sizeof(struct addrinfo) + addrlen, 1);
1479	if (ai) {
1480		ai->ai_addr = (void *)(ai+1);
1481		ai->ai_addrlen = ai->ai_addr->sa_len = addrlen;
1482	}
1483
1484	return ai;
1485}
1486
1487static struct addrinfo *
1488get_ai(const struct addrinfo *pai, const struct afd *afd, const char *addr)
1489{
1490	char *p;
1491	struct addrinfo *ai;
1492	struct sockaddr *save;
1493
1494	_DIAGASSERT(pai != NULL);
1495	_DIAGASSERT(afd != NULL);
1496	_DIAGASSERT(addr != NULL);
1497
1498	ai = allocaddrinfo((socklen_t)afd->a_socklen);
1499	if (ai == NULL)
1500		return NULL;
1501
1502	save = ai->ai_addr;
1503	memcpy(ai, pai, sizeof(struct addrinfo));
1504
1505	/* since we just overwrote all of ai, we have
1506	   to restore ai_addr and ai_addrlen */
1507	ai->ai_addr = save;
1508	ai->ai_addrlen = (socklen_t)afd->a_socklen;
1509
1510	ai->ai_addr->sa_family = ai->ai_family = afd->a_af;
1511	p = (char *)(void *)(ai->ai_addr);
1512	memcpy(p + afd->a_off, addr, (size_t)afd->a_addrlen);
1513	return ai;
1514}
1515
1516static int
1517get_portmatch(const struct addrinfo *ai, const char *servname,
1518    struct servent_data *svd)
1519{
1520
1521	_DIAGASSERT(ai != NULL);
1522	/* servname may be NULL */
1523
1524	return get_port(ai, servname, 1, svd);
1525}
1526
1527static int
1528get_port(const struct addrinfo *ai, const char *servname, int matchonly,
1529    struct servent_data *svd)
1530{
1531	const char *proto;
1532	struct servent *sp;
1533	int port;
1534	int allownumeric;
1535
1536	_DIAGASSERT(ai != NULL);
1537	/* servname may be NULL */
1538
1539	if (servname == NULL)
1540		return 0;
1541	switch (ai->ai_family) {
1542	case AF_INET:
1543#ifdef AF_INET6
1544	case AF_INET6:
1545#endif
1546		break;
1547	default:
1548		return 0;
1549	}
1550
1551	switch (ai->ai_socktype) {
1552	case SOCK_RAW:
1553		return EAI_SERVICE;
1554	case SOCK_DGRAM:
1555	case SOCK_STREAM:
1556		allownumeric = 1;
1557		break;
1558	case ANY:
1559		/*
1560		 * This was 0.	It is now 1 so that queries specifying
1561		 * a NULL hint, or hint without socktype (but, hopefully,
1562		 * with protocol) and numeric address actually work.
1563		 */
1564		allownumeric = 1;
1565		break;
1566	default:
1567		return EAI_SOCKTYPE;
1568	}
1569
1570	port = str2number(servname);
1571	if (port >= 0) {
1572		if (!allownumeric)
1573			return EAI_SERVICE;
1574		if (port < 0 || port > 65535)
1575			return EAI_SERVICE;
1576		port = htons(port);
1577	} else {
1578		struct servent sv;
1579		if (ai->ai_flags & AI_NUMERICSERV)
1580			return EAI_NONAME;
1581
1582		switch (ai->ai_socktype) {
1583		case SOCK_DGRAM:
1584			proto = "udp";
1585			break;
1586		case SOCK_STREAM:
1587			proto = "tcp";
1588			break;
1589		default:
1590			proto = NULL;
1591			break;
1592		}
1593
1594		sp = getservbyname_r(servname, proto, &sv, svd);
1595		if (sp == NULL)
1596			return EAI_SERVICE;
1597		port = sp->s_port;
1598	}
1599
1600	if (!matchonly)
1601		*getport(__UNCONST(ai)) = port;
1602	return 0;
1603}
1604
1605static const struct afd *
1606find_afd(int af)
1607{
1608	const struct afd *afd;
1609
1610	if (af == PF_UNSPEC)
1611		return NULL;
1612	for (afd = afdl; afd->a_af; afd++) {
1613		if (afd->a_af == af)
1614			return afd;
1615	}
1616	return NULL;
1617}
1618
1619/*
1620 * AI_ADDRCONFIG check: Build a mask containing a bit set for each address
1621 * family configured in the system.
1622 *
1623 */
1624static int
1625addrconfig(uint64_t *mask)
1626{
1627	struct ifaddrs *ifaddrs, *ifa;
1628
1629	if (getifaddrs(&ifaddrs) == -1)
1630		return -1;
1631
1632	*mask = 0;
1633	for (ifa = ifaddrs; ifa != NULL; ifa = ifa->ifa_next)
1634		if (ifa->ifa_addr && (ifa->ifa_flags & IFF_UP)) {
1635			_DIAGASSERT(ifa->ifa_addr->sa_family < 64);
1636			*mask |= (uint64_t)1 << ifa->ifa_addr->sa_family;
1637		}
1638
1639	freeifaddrs(ifaddrs);
1640	return 0;
1641}
1642
1643#ifdef INET6
1644/* convert a string to a scope identifier. XXX: IPv6 specific */
1645static int
1646ip6_str2scopeid(const char *scope, struct sockaddr_in6 *sin6, uint32_t *scopeid)
1647{
1648	u_long lscopeid;
1649	struct in6_addr *a6;
1650	char *ep;
1651
1652	_DIAGASSERT(scope != NULL);
1653	_DIAGASSERT(sin6 != NULL);
1654	_DIAGASSERT(scopeid != NULL);
1655
1656	a6 = &sin6->sin6_addr;
1657
1658	/* empty scopeid portion is invalid */
1659	if (*scope == '\0')
1660		return -1;
1661
1662	if (IN6_IS_ADDR_LINKLOCAL(a6) || IN6_IS_ADDR_MC_LINKLOCAL(a6)) {
1663		/*
1664		 * We currently assume a one-to-one mapping between links
1665		 * and interfaces, so we simply use interface indices for
1666		 * like-local scopes.
1667		 */
1668		*scopeid = if_nametoindex(scope);
1669		if (*scopeid == 0)
1670			goto trynumeric;
1671		return 0;
1672	}
1673
1674	/* still unclear about literal, allow numeric only - placeholder */
1675	if (IN6_IS_ADDR_SITELOCAL(a6) || IN6_IS_ADDR_MC_SITELOCAL(a6))
1676		goto trynumeric;
1677	if (IN6_IS_ADDR_MC_ORGLOCAL(a6))
1678		goto trynumeric;
1679	else
1680		goto trynumeric;	/* global */
1681
1682	/* try to convert to a numeric id as a last resort */
1683  trynumeric:
1684	errno = 0;
1685	lscopeid = strtoul(scope, &ep, 10);
1686	*scopeid = (uint32_t)(lscopeid & 0xffffffffUL);
1687	if (errno == 0 && ep && *ep == '\0' && *scopeid == lscopeid)
1688		return 0;
1689	else
1690		return -1;
1691}
1692#endif
1693
1694/* code duplicate with gethnamaddr.c */
1695
1696static const char AskedForGot[] =
1697	"gethostby*.getanswer: asked for \"%s\", got \"%s\"";
1698
1699#define maybe_ok(res, nm, ok) (((res)->options & RES_NOCHECKNAME) != 0U || \
1700                               (ok)(nm) != 0)
1701static struct addrinfo *
1702getanswer(res_state res, const querybuf *answer, int anslen, const char *qname,
1703    int qtype, const struct addrinfo *pai)
1704{
1705	struct addrinfo sentinel, *cur;
1706	struct addrinfo ai, *aip;
1707	const struct afd *afd;
1708	char *canonname;
1709	const HEADER *hp;
1710	const u_char *cp;
1711	int n;
1712	const u_char *eom;
1713	char *bp, *ep;
1714	int type, class, ancount, qdcount;
1715	int haveanswer, had_error;
1716	char tbuf[MAXDNAME];
1717	int (*name_ok) (const char *);
1718	char hostbuf[8*1024];
1719	int port, pri, weight;
1720	struct srvinfo *srvlist, *srv, *csrv;
1721
1722	_DIAGASSERT(answer != NULL);
1723	_DIAGASSERT(qname != NULL);
1724	_DIAGASSERT(pai != NULL);
1725	_DIAGASSERT(res != NULL);
1726
1727	memset(&sentinel, 0, sizeof(sentinel));
1728	cur = &sentinel;
1729
1730	canonname = NULL;
1731	eom = answer->buf + anslen;
1732	switch (qtype) {
1733	case T_A:
1734	case T_AAAA:
1735	case T_ANY:	/*use T_ANY only for T_A/T_AAAA lookup*/
1736		name_ok = res_hnok;
1737		break;
1738	case T_SRV:
1739		name_ok = gai_srvok;
1740		break;
1741	default:
1742		return NULL;	/* XXX should be abort(); */
1743	}
1744	/*
1745	 * find first satisfactory answer
1746	 */
1747	hp = &answer->hdr;
1748	ancount = ntohs(hp->ancount);
1749	qdcount = ntohs(hp->qdcount);
1750	bp = hostbuf;
1751	ep = hostbuf + sizeof hostbuf;
1752	cp = answer->buf + HFIXEDSZ;
1753	if (qdcount != 1) {
1754		h_errno = NO_RECOVERY;
1755		return NULL;
1756	}
1757	n = dn_expand(answer->buf, eom, cp, bp, (int)(ep - bp));
1758	if ((n < 0) || !maybe_ok(res, bp, name_ok)) {
1759		h_errno = NO_RECOVERY;
1760		return NULL;
1761	}
1762	cp += n + QFIXEDSZ;
1763	if (qtype == T_A || qtype == T_AAAA || qtype == T_ANY) {
1764		/* res_send() has already verified that the query name is the
1765		 * same as the one we sent; this just gets the expanded name
1766		 * (i.e., with the succeeding search-domain tacked on).
1767		 */
1768		n = (int)strlen(bp) + 1;		/* for the \0 */
1769		if (n >= MAXHOSTNAMELEN) {
1770			h_errno = NO_RECOVERY;
1771			return NULL;
1772		}
1773		canonname = bp;
1774		bp += n;
1775		/* The qname can be abbreviated, but h_name is now absolute. */
1776		qname = canonname;
1777	}
1778	haveanswer = 0;
1779	had_error = 0;
1780	srvlist = NULL;
1781	while (ancount-- > 0 && cp < eom && !had_error) {
1782		n = dn_expand(answer->buf, eom, cp, bp, (int)(ep - bp));
1783		if ((n < 0) || !maybe_ok(res, bp, name_ok)) {
1784			had_error++;
1785			continue;
1786		}
1787		cp += n;			/* name */
1788		type = _getshort(cp);
1789		cp += INT16SZ;			/* type */
1790		class = _getshort(cp);
1791		cp += INT16SZ + INT32SZ;	/* class, TTL */
1792		n = _getshort(cp);
1793		cp += INT16SZ;			/* len */
1794		if (class != C_IN) {
1795			/* XXX - debug? syslog? */
1796			cp += n;
1797			continue;		/* XXX - had_error++ ? */
1798		}
1799		if ((qtype == T_A || qtype == T_AAAA || qtype == T_ANY) &&
1800		    type == T_CNAME) {
1801			n = dn_expand(answer->buf, eom, cp, tbuf, (int)sizeof tbuf);
1802			if ((n < 0) || !maybe_ok(res, tbuf, name_ok)) {
1803				had_error++;
1804				continue;
1805			}
1806			cp += n;
1807			/* Get canonical name. */
1808			n = (int)strlen(tbuf) + 1;	/* for the \0 */
1809			if (n > ep - bp || n >= MAXHOSTNAMELEN) {
1810				had_error++;
1811				continue;
1812			}
1813			strlcpy(bp, tbuf, (size_t)(ep - bp));
1814			canonname = bp;
1815			bp += n;
1816			continue;
1817		}
1818		if (qtype == T_ANY) {
1819			if (!(type == T_A || type == T_AAAA)) {
1820				cp += n;
1821				continue;
1822			}
1823		} else if (type != qtype) {
1824			if (type != T_KEY && type != T_SIG && type != T_DNAME) {
1825				struct syslog_data sd = SYSLOG_DATA_INIT;
1826				syslog_r(LOG_NOTICE|LOG_AUTH, &sd,
1827	       "gethostby*.getanswer: asked for \"%s %s %s\", got type \"%s\"",
1828				       qname, p_class(C_IN), p_type(qtype),
1829				       p_type(type));
1830			}
1831			cp += n;
1832			continue;		/* XXX - had_error++ ? */
1833		}
1834		switch (type) {
1835		case T_A:
1836		case T_AAAA:
1837			if (strcasecmp(canonname, bp) != 0) {
1838				struct syslog_data sd = SYSLOG_DATA_INIT;
1839				syslog_r(LOG_NOTICE|LOG_AUTH, &sd,
1840				       AskedForGot, canonname, bp);
1841				cp += n;
1842				continue;	/* XXX - had_error++ ? */
1843			}
1844			if (type == T_A && n != INADDRSZ) {
1845				cp += n;
1846				continue;
1847			}
1848			if (type == T_AAAA && n != IN6ADDRSZ) {
1849				cp += n;
1850				continue;
1851			}
1852			if (type == T_AAAA) {
1853				struct in6_addr in6;
1854				memcpy(&in6, cp, IN6ADDRSZ);
1855				if (IN6_IS_ADDR_V4MAPPED(&in6)) {
1856					cp += n;
1857					continue;
1858				}
1859			}
1860			if (!haveanswer) {
1861				int nn;
1862
1863				canonname = bp;
1864				nn = (int)strlen(bp) + 1;	/* for the \0 */
1865				bp += nn;
1866			}
1867
1868			/* don't overwrite pai */
1869			ai = *pai;
1870			ai.ai_family = (type == T_A) ? AF_INET : AF_INET6;
1871			afd = find_afd(ai.ai_family);
1872			if (afd == NULL) {
1873				cp += n;
1874				continue;
1875			}
1876			cur->ai_next = get_ai(&ai, afd, (const char *)cp);
1877			if (cur->ai_next == NULL)
1878				had_error++;
1879			while (cur && cur->ai_next)
1880				cur = cur->ai_next;
1881			cp += n;
1882			break;
1883		case T_SRV:
1884			/* Add to SRV list. Insertion sort on priority. */
1885			pri = _getshort(cp);
1886			cp += INT16SZ;
1887			weight = _getshort(cp);
1888			cp += INT16SZ;
1889			port = _getshort(cp);
1890			cp += INT16SZ;
1891			n = dn_expand(answer->buf, eom, cp, tbuf,
1892			    (int)sizeof(tbuf));
1893			if ((n < 0) || !maybe_ok(res, tbuf, res_hnok)) {
1894				had_error++;
1895				continue;
1896			}
1897			cp += n;
1898			if (strlen(tbuf) + 1 >= MAXDNAME) {
1899				had_error++;
1900				continue;
1901			}
1902			srv = malloc(sizeof(*srv));
1903			if (!srv) {
1904				had_error++;
1905				continue;
1906			}
1907			strlcpy(srv->name, tbuf, sizeof(srv->name));
1908			srv->pri = pri;
1909			srv->weight = weight;
1910			srv->port = port;
1911			/* Weight 0 is sorted before other weights. */
1912			if (!srvlist
1913			    || srv->pri < srvlist->pri
1914			    || (srv->pri == srvlist->pri &&
1915			    (!srv->weight || srvlist->weight))) {
1916				srv->next = srvlist;
1917				srvlist = srv;
1918			} else {
1919				for (csrv = srvlist;
1920				    csrv->next && csrv->next->pri <= srv->pri;
1921				    csrv = csrv->next) {
1922					if (csrv->next->pri == srv->pri
1923					    && (!srv->weight ||
1924					    csrv->next->weight))
1925						break;
1926				}
1927				srv->next = csrv->next;
1928				csrv->next = srv;
1929			}
1930			continue; /* Don't add to haveanswer yet. */
1931		default:
1932			abort();
1933		}
1934		if (!had_error)
1935			haveanswer++;
1936	}
1937
1938	if (srvlist) {
1939		/*
1940		 * Check for explicit rejection.
1941		 */
1942		if (!srvlist->next && !srvlist->name[0]) {
1943			free(srvlist);
1944			h_errno = HOST_NOT_FOUND;
1945			return NULL;
1946		}
1947
1948		while (srvlist) {
1949			struct res_target q, q2;
1950
1951			srv = srvlist;
1952			srvlist = srvlist->next;
1953
1954			/*
1955			 * Since res_* doesn't give the additional
1956			 * section, we always look up.
1957			 */
1958			memset(&q, 0, sizeof(q));
1959			memset(&q2, 0, sizeof(q2));
1960
1961			q.name = srv->name;
1962			q.qclass = C_IN;
1963			q.qtype = T_AAAA;
1964			q.next = &q2;
1965			q2.name = srv->name;
1966			q2.qclass = C_IN;
1967			q2.qtype = T_A;
1968
1969			aip = _dns_query(&q, pai, res, 0);
1970
1971			if (aip != NULL) {
1972				cur->ai_next = aip;
1973				while (cur && cur->ai_next) {
1974					cur = cur->ai_next;
1975					*getport(cur) = htons(srv->port);
1976					haveanswer++;
1977				}
1978			}
1979			free(srv);
1980		}
1981	}
1982	if (haveanswer) {
1983		if (!sentinel.ai_next->ai_canonname)
1984		       (void)get_canonname(pai, sentinel.ai_next,
1985			   canonname ? canonname : qname);
1986		h_errno = NETDB_SUCCESS;
1987		return sentinel.ai_next;
1988	}
1989
1990	/* We could have walked a CNAME chain, */
1991	/* but the ultimate target may not have what we looked for */
1992	h_errno = ntohs(hp->ancount) > 0? NO_DATA : NO_RECOVERY;
1993	return NULL;
1994}
1995
1996#define SORTEDADDR(p)	(((struct sockaddr_in *)(void *)(p->ai_next->ai_addr))->sin_addr.s_addr)
1997#define SORTMATCH(p, s) ((SORTEDADDR(p) & (s).mask) == (s).addr.s_addr)
1998
1999static void
2000aisort(struct addrinfo *s, res_state res)
2001{
2002	struct addrinfo head, *t, *p;
2003	int i;
2004
2005	head.ai_next = NULL;
2006	t = &head;
2007
2008	for (i = 0; i < res->nsort; i++) {
2009		p = s;
2010		while (p->ai_next) {
2011			if ((p->ai_next->ai_family != AF_INET)
2012			|| SORTMATCH(p, res->sort_list[i])) {
2013				t->ai_next = p->ai_next;
2014				t = t->ai_next;
2015				p->ai_next = p->ai_next->ai_next;
2016			} else {
2017				p = p->ai_next;
2018			}
2019		}
2020	}
2021
2022	/* add rest of list and reset s to the new list*/
2023	t->ai_next = s->ai_next;
2024	s->ai_next = head.ai_next;
2025}
2026
2027static struct addrinfo *
2028_dns_query(struct res_target *q, const struct addrinfo *pai,
2029    res_state res, int dosearch)
2030{
2031	struct res_target *q2 = q->next;
2032 	querybuf *buf, *buf2;
2033	struct addrinfo sentinel, *cur, *ai;
2034
2035#ifdef DNS_DEBUG
2036	struct res_target *iter;
2037	for (iter = q; iter; iter = iter->next)
2038		printf("Query type %d for %s\n", iter->qtype, iter->name);
2039#endif
2040
2041 	buf = malloc(sizeof(*buf));
2042 	if (buf == NULL) {
2043 		h_errno = NETDB_INTERNAL;
2044		return NULL;
2045 	}
2046 	buf2 = malloc(sizeof(*buf2));
2047 	if (buf2 == NULL) {
2048 		free(buf);
2049 		h_errno = NETDB_INTERNAL;
2050		return NULL;
2051	}
2052
2053	memset(&sentinel, 0, sizeof(sentinel));
2054	cur = &sentinel;
2055
2056	q->answer = buf->buf;
2057	q->anslen = sizeof(buf->buf);
2058	if (q2) {
2059		q2->answer = buf2->buf;
2060		q2->anslen = sizeof(buf2->buf);
2061	}
2062
2063	if (dosearch) {
2064		if (res_searchN(q->name, q, res) < 0)
2065			goto out;
2066	} else {
2067		if (res_queryN(q->name, q, res) < 0)
2068			goto out;
2069	}
2070
2071	ai = getanswer(res, buf, q->n, q->name, q->qtype, pai);
2072	if (ai) {
2073		cur->ai_next = ai;
2074		while (cur && cur->ai_next)
2075			cur = cur->ai_next;
2076	}
2077	if (q2) {
2078		ai = getanswer(res, buf2, q2->n, q2->name, q2->qtype, pai);
2079		if (ai)
2080			cur->ai_next = ai;
2081 	}
2082	free(buf);
2083	free(buf2);
2084	return sentinel.ai_next;
2085out:
2086	free(buf);
2087	free(buf2);
2088	return NULL;
2089}
2090
2091/*ARGSUSED*/
2092static struct addrinfo *
2093_dns_srv_lookup(const char *name, const char *servname,
2094    const struct addrinfo *pai)
2095{
2096	static const char * const srvprotos[] = { "tcp", "udp" };
2097	static const int srvnottype[] = { SOCK_DGRAM, SOCK_STREAM };
2098	static const int nsrvprotos = 2;
2099	struct addrinfo sentinel, *cur, *ai;
2100	struct servent *serv, sv;
2101	struct servent_data svd;
2102	struct res_target q;
2103	res_state res;
2104	char *tname;
2105	int i;
2106
2107	res = __res_get_state();
2108	if (res == NULL)
2109		return NULL;
2110
2111	memset(&svd, 0, sizeof(svd));
2112	memset(&sentinel, 0, sizeof(sentinel));
2113	cur = &sentinel;
2114
2115	/*
2116	 * Iterate over supported SRV protocols.
2117	 * (currently UDP and TCP only)
2118	 */
2119	for (i = 0; i < nsrvprotos; i++) {
2120		/*
2121		 * Check that the caller didn't specify a hint
2122		 * which precludes this protocol.
2123		 */
2124		if (pai->ai_socktype == srvnottype[i])
2125			continue;
2126		/*
2127		 * If the caller specified a port,
2128		 * then lookup the database for the
2129		 * official service name.
2130		 */
2131		serv = getservbyname_r(servname, srvprotos[i], &sv, &svd);
2132		if (serv == NULL)
2133			continue;
2134
2135		/*
2136		 * Construct service DNS name.
2137		 */
2138		if (asprintf(&tname, "_%s._%s.%s", serv->s_name, serv->s_proto,
2139		    name) < 0)
2140			continue;
2141
2142		memset(&q, 0, sizeof(q));
2143		q.name = tname;
2144		q.qclass = C_IN;
2145		q.qtype = T_SRV;
2146
2147		/*
2148		 * Do SRV query.
2149		 */
2150		ai = _dns_query(&q, pai, res, 1);
2151		if (ai) {
2152			cur->ai_next = ai;
2153			while (cur && cur->ai_next)
2154				cur = cur->ai_next;
2155		}
2156		free(tname);
2157	}
2158
2159	if (res->nsort)
2160		aisort(&sentinel, res);
2161
2162	__res_put_state(res);
2163
2164	return sentinel.ai_next;
2165}
2166
2167/*ARGSUSED*/
2168static struct addrinfo *
2169_dns_host_lookup(const char *name, const struct addrinfo *pai)
2170{
2171	struct res_target q, q2;
2172	struct addrinfo sentinel, *ai;
2173	res_state res;
2174
2175	res = __res_get_state();
2176	if (res == NULL)
2177		return NULL;
2178
2179	memset(&q, 0, sizeof(q2));
2180	memset(&q2, 0, sizeof(q2));
2181
2182	switch (pai->ai_family) {
2183	case AF_UNSPEC:
2184		/* prefer IPv6 */
2185		q.name = name;
2186		q.qclass = C_IN;
2187		q.qtype = T_AAAA;
2188		q.next = &q2;
2189		q2.name = name;
2190		q2.qclass = C_IN;
2191		q2.qtype = T_A;
2192		break;
2193	case AF_INET:
2194		q.name = name;
2195		q.qclass = C_IN;
2196		q.qtype = T_A;
2197		break;
2198	case AF_INET6:
2199		q.name = name;
2200		q.qclass = C_IN;
2201		q.qtype = T_AAAA;
2202		break;
2203	default:
2204		__res_put_state(res);
2205		h_errno = NETDB_INTERNAL;
2206		return NULL;
2207	}
2208
2209	ai = _dns_query(&q, pai, res, 1);
2210
2211	memset(&sentinel, 0, sizeof(sentinel));
2212	sentinel.ai_next = ai;
2213
2214	if (ai != NULL && res->nsort)
2215		aisort(&sentinel, res);
2216
2217	__res_put_state(res);
2218
2219	return sentinel.ai_next;
2220}
2221
2222/*ARGSUSED*/
2223static int
2224_dns_getaddrinfo(void *rv, void *cb_data, va_list ap)
2225{
2226	struct addrinfo *ai = NULL;
2227	const char *name, *servname;
2228	const struct addrinfo *pai;
2229
2230	name = va_arg(ap, char *);
2231	pai = va_arg(ap, const struct addrinfo *);
2232	servname = va_arg(ap, char *);
2233
2234	/*
2235	 * Try doing SRV lookup on service first.
2236	 */
2237	if (servname
2238#ifdef AI_SRV
2239	    && (pai->ai_flags & AI_SRV)
2240#endif
2241	    && !(pai->ai_flags & AI_NUMERICSERV)
2242	    && str2number(servname) == -1) {
2243
2244#ifdef DNS_DEBUG
2245		printf("%s: try SRV lookup\n", __func__);
2246#endif
2247		ai = _dns_srv_lookup(name, servname, pai);
2248	}
2249
2250	/*
2251	 * Do lookup on name.
2252	 */
2253	if (ai == NULL) {
2254
2255#ifdef DNS_DEBUG
2256		printf("%s: try HOST lookup\n", __func__);
2257#endif
2258		ai = _dns_host_lookup(name, pai);
2259
2260		if (ai == NULL) {
2261			switch (h_errno) {
2262			case HOST_NOT_FOUND:
2263			case NO_DATA:	// XXX: Perhaps we could differentiate
2264					// So that we could return EAI_NODATA?
2265				return NS_NOTFOUND;
2266			case TRY_AGAIN:
2267				return NS_TRYAGAIN;
2268			default:
2269				return NS_UNAVAIL;
2270			}
2271		}
2272	}
2273
2274	*((struct addrinfo **)rv) = ai;
2275	return NS_SUCCESS;
2276}
2277
2278static void
2279_sethtent(FILE **hostf)
2280{
2281
2282	if (!*hostf)
2283		*hostf = fopen(_PATH_HOSTS, "re");
2284	else
2285		rewind(*hostf);
2286}
2287
2288static void
2289_endhtent(FILE **hostf)
2290{
2291
2292	if (*hostf) {
2293		(void) fclose(*hostf);
2294		*hostf = NULL;
2295	}
2296}
2297
2298static struct addrinfo *
2299_gethtent(FILE **hostf, const char *name, const struct addrinfo *pai)
2300{
2301	char *p;
2302	char *cp, *tname, *cname;
2303	struct addrinfo hints, *res0, *res;
2304	int error;
2305	const char *addr;
2306	char hostbuf[8*1024];
2307
2308	_DIAGASSERT(name != NULL);
2309	_DIAGASSERT(pai != NULL);
2310
2311	if (!*hostf && !(*hostf = fopen(_PATH_HOSTS, "re")))
2312		return NULL;
2313 again:
2314	if (!(p = fgets(hostbuf, (int)sizeof hostbuf, *hostf)))
2315		return NULL;
2316	if (*p == '#')
2317		goto again;
2318	if (!(cp = strpbrk(p, "#\n")))
2319		goto again;
2320	*cp = '\0';
2321	if (!(cp = strpbrk(p, " \t")))
2322		goto again;
2323	*cp++ = '\0';
2324	addr = p;
2325	/* if this is not something we're looking for, skip it. */
2326	cname = NULL;
2327	while (cp && *cp) {
2328		if (*cp == ' ' || *cp == '\t') {
2329			cp++;
2330			continue;
2331		}
2332		if (!cname)
2333			cname = cp;
2334		tname = cp;
2335		if ((cp = strpbrk(cp, " \t")) != NULL)
2336			*cp++ = '\0';
2337		if (strcasecmp(name, tname) == 0)
2338			goto found;
2339	}
2340	goto again;
2341
2342found:
2343	hints = *pai;
2344	hints.ai_flags = AI_NUMERICHOST;
2345	error = getaddrinfo(addr, NULL, &hints, &res0);
2346	if (error)
2347		goto again;
2348	for (res = res0; res; res = res->ai_next) {
2349		/* cover it up */
2350		res->ai_flags = pai->ai_flags;
2351
2352		if (pai->ai_flags & AI_CANONNAME) {
2353			if (get_canonname(pai, res, cname) != 0) {
2354				freeaddrinfo(res0);
2355				goto again;
2356			}
2357		}
2358	}
2359	return res0;
2360}
2361
2362/*ARGSUSED*/
2363static int
2364_files_getaddrinfo(void *rv, void *cb_data, va_list ap)
2365{
2366	const char *name;
2367	const struct addrinfo *pai;
2368	struct addrinfo sentinel, *cur;
2369	struct addrinfo *p;
2370#ifndef _REENTRANT
2371	static
2372#endif
2373	FILE *hostf = NULL;
2374
2375	name = va_arg(ap, char *);
2376	pai = va_arg(ap, const struct addrinfo *);
2377
2378	memset(&sentinel, 0, sizeof(sentinel));
2379	cur = &sentinel;
2380
2381	_sethtent(&hostf);
2382	while ((p = _gethtent(&hostf, name, pai)) != NULL) {
2383		cur->ai_next = p;
2384		while (cur && cur->ai_next)
2385			cur = cur->ai_next;
2386	}
2387	_endhtent(&hostf);
2388
2389	*((struct addrinfo **)rv) = sentinel.ai_next;
2390	if (sentinel.ai_next == NULL)
2391		return NS_NOTFOUND;
2392	return NS_SUCCESS;
2393}
2394
2395#ifdef YP
2396/*ARGSUSED*/
2397static struct addrinfo *
2398_yphostent(char *line, const struct addrinfo *pai)
2399{
2400	struct addrinfo sentinel, *cur;
2401	struct addrinfo hints, *res, *res0;
2402	int error;
2403	char *p;
2404	const char *addr, *canonname;
2405	char *nextline;
2406	char *cp;
2407
2408	_DIAGASSERT(line != NULL);
2409	_DIAGASSERT(pai != NULL);
2410
2411	p = line;
2412	addr = canonname = NULL;
2413
2414	memset(&sentinel, 0, sizeof(sentinel));
2415	cur = &sentinel;
2416
2417nextline:
2418	/* terminate line */
2419	cp = strchr(p, '\n');
2420	if (cp) {
2421		*cp++ = '\0';
2422		nextline = cp;
2423	} else
2424		nextline = NULL;
2425
2426	cp = strpbrk(p, " \t");
2427	if (cp == NULL) {
2428		if (canonname == NULL)
2429			return NULL;
2430		else
2431			goto done;
2432	}
2433	*cp++ = '\0';
2434
2435	addr = p;
2436
2437	while (cp && *cp) {
2438		if (*cp == ' ' || *cp == '\t') {
2439			cp++;
2440			continue;
2441		}
2442		if (!canonname)
2443			canonname = cp;
2444		if ((cp = strpbrk(cp, " \t")) != NULL)
2445			*cp++ = '\0';
2446	}
2447
2448	hints = *pai;
2449	hints.ai_flags = AI_NUMERICHOST;
2450	error = getaddrinfo(addr, NULL, &hints, &res0);
2451	if (error == 0) {
2452		for (res = res0; res; res = res->ai_next) {
2453			/* cover it up */
2454			res->ai_flags = pai->ai_flags;
2455
2456			if (pai->ai_flags & AI_CANONNAME)
2457				(void)get_canonname(pai, res, canonname);
2458		}
2459	} else
2460		res0 = NULL;
2461	if (res0) {
2462		cur->ai_next = res0;
2463		while (cur->ai_next)
2464			cur = cur->ai_next;
2465	}
2466
2467	if (nextline) {
2468		p = nextline;
2469		goto nextline;
2470	}
2471
2472done:
2473	return sentinel.ai_next;
2474}
2475
2476/*ARGSUSED*/
2477static int
2478_yp_getaddrinfo(void *rv, void *cb_data, va_list ap)
2479{
2480	struct addrinfo sentinel, *cur;
2481	struct addrinfo *ai = NULL;
2482	char *ypbuf;
2483	int ypbuflen, r;
2484	const char *name;
2485	const struct addrinfo *pai;
2486	char *ypdomain;
2487
2488	if (_yp_check(&ypdomain) == 0)
2489		return NS_UNAVAIL;
2490
2491	name = va_arg(ap, char *);
2492	pai = va_arg(ap, const struct addrinfo *);
2493
2494	memset(&sentinel, 0, sizeof(sentinel));
2495	cur = &sentinel;
2496
2497	/* hosts.byname is only for IPv4 (Solaris8) */
2498	if (pai->ai_family == PF_UNSPEC || pai->ai_family == PF_INET) {
2499		r = yp_match(ypdomain, "hosts.byname", name,
2500			(int)strlen(name), &ypbuf, &ypbuflen);
2501		if (r == 0) {
2502			struct addrinfo ai4;
2503
2504			ai4 = *pai;
2505			ai4.ai_family = AF_INET;
2506			ai = _yphostent(ypbuf, &ai4);
2507			if (ai) {
2508				cur->ai_next = ai;
2509				while (cur && cur->ai_next)
2510					cur = cur->ai_next;
2511			}
2512		}
2513		free(ypbuf);
2514	}
2515
2516	/* ipnodes.byname can hold both IPv4/v6 */
2517	r = yp_match(ypdomain, "ipnodes.byname", name,
2518		(int)strlen(name), &ypbuf, &ypbuflen);
2519	if (r == 0) {
2520		ai = _yphostent(ypbuf, pai);
2521		if (ai)
2522			cur->ai_next = ai;
2523		free(ypbuf);
2524	}
2525
2526	if (sentinel.ai_next == NULL) {
2527		h_errno = HOST_NOT_FOUND;
2528		return NS_NOTFOUND;
2529	}
2530	*((struct addrinfo **)rv) = sentinel.ai_next;
2531	return NS_SUCCESS;
2532}
2533#endif
2534
2535/* resolver logic */
2536
2537/*
2538 * Formulate a normal query, send, and await answer.
2539 * Returned answer is placed in supplied buffer "answer".
2540 * Perform preliminary check of answer, returning success only
2541 * if no error is indicated and the answer count is nonzero.
2542 * Return the size of the response on success, -1 on error.
2543 * Error number is left in h_errno.
2544 *
2545 * Caller must parse answer and determine whether it answers the question.
2546 */
2547static int
2548res_queryN(const char *name, /* domain name */ struct res_target *target,
2549    res_state statp)
2550{
2551	u_char buf[MAXPACKET];
2552	HEADER *hp;
2553	int n;
2554	struct res_target *t;
2555	int rcode;
2556	u_char *rdata;
2557	int ancount;
2558
2559	_DIAGASSERT(name != NULL);
2560	/* XXX: target may be NULL??? */
2561
2562	rcode = NOERROR;
2563	ancount = 0;
2564
2565	for (t = target; t; t = t->next) {
2566		int class, type;
2567		u_char *answer;
2568		int anslen;
2569		u_int oflags;
2570
2571		hp = (HEADER *)(void *)t->answer;
2572		oflags = statp->_flags;
2573
2574again:
2575		hp->rcode = NOERROR;	/* default */
2576
2577		/* make it easier... */
2578		class = t->qclass;
2579		type = t->qtype;
2580		answer = t->answer;
2581		anslen = t->anslen;
2582#ifdef DEBUG
2583		if (statp->options & RES_DEBUG)
2584			printf(";; res_nquery(%s, %d, %d)\n", name, class, type);
2585#endif
2586
2587		n = res_nmkquery(statp, QUERY, name, class, type, NULL, 0, NULL,
2588		    buf, (int)sizeof(buf));
2589#ifdef RES_USE_EDNS0
2590		if (n > 0 && (statp->_flags & RES_F_EDNS0ERR) == 0 &&
2591		    (statp->options & (RES_USE_EDNS0|RES_USE_DNSSEC)) != 0) {
2592			n = res_nopt(statp, n, buf, (int)sizeof(buf), anslen);
2593			rdata = &buf[n];
2594			if (n > 0 && (statp->options & RES_NSID) != 0U) {
2595				n = res_nopt_rdata(statp, n, buf,
2596				    (int)sizeof(buf),
2597				    rdata, NS_OPT_NSID, 0, NULL);
2598			}
2599		}
2600#endif
2601		if (n <= 0) {
2602#ifdef DEBUG
2603			if (statp->options & RES_DEBUG)
2604				printf(";; res_nquery: mkquery failed\n");
2605#endif
2606			h_errno = NO_RECOVERY;
2607			return n;
2608		}
2609		n = res_nsend(statp, buf, n, answer, anslen);
2610		if (n < 0) {
2611#ifdef RES_USE_EDNS0
2612			/* if the query choked with EDNS0, retry without EDNS0 */
2613			if ((statp->options & (RES_USE_EDNS0|RES_USE_DNSSEC)) != 0U &&
2614			    ((oflags ^ statp->_flags) & RES_F_EDNS0ERR) != 0) {
2615				statp->_flags |= RES_F_EDNS0ERR;
2616				if (statp->options & RES_DEBUG)
2617					printf(";; res_nquery: retry without EDNS0\n");
2618				goto again;
2619			}
2620#endif
2621#if 0
2622#ifdef DEBUG
2623			if (statp->options & RES_DEBUG)
2624				printf(";; res_query: send error\n");
2625#endif
2626			h_errno = TRY_AGAIN;
2627			return n;
2628#endif
2629		}
2630
2631		if (n < 0 || hp->rcode != NOERROR || ntohs(hp->ancount) == 0) {
2632			rcode = hp->rcode;	/* record most recent error */
2633#ifdef DEBUG
2634			if (statp->options & RES_DEBUG)
2635				printf(";; rcode = (%s), counts = an:%d ns:%d ar:%d\n",
2636				       p_rcode(hp->rcode),
2637				       ntohs(hp->ancount),
2638				       ntohs(hp->nscount),
2639				       ntohs(hp->arcount));
2640#endif
2641			continue;
2642		}
2643
2644		ancount += ntohs(hp->ancount);
2645
2646		t->n = n;
2647	}
2648
2649	if (ancount == 0) {
2650		switch (rcode) {
2651		case NXDOMAIN:
2652			h_errno = HOST_NOT_FOUND;
2653			break;
2654		case SERVFAIL:
2655			h_errno = TRY_AGAIN;
2656			break;
2657		case NOERROR:
2658			h_errno = NO_DATA;
2659			break;
2660		case FORMERR:
2661		case NOTIMP:
2662		case REFUSED:
2663		default:
2664			h_errno = NO_RECOVERY;
2665			break;
2666		}
2667		return -1;
2668	}
2669	return ancount;
2670}
2671
2672/*
2673 * Formulate a normal query, send, and retrieve answer in supplied buffer.
2674 * Return the size of the response on success, -1 on error.
2675 * If enabled, implement search rules until answer or unrecoverable failure
2676 * is detected.	 Error code, if any, is left in h_errno.
2677 */
2678static int
2679res_searchN(const char *name, struct res_target *target, res_state res)
2680{
2681	const char *cp, * const *domain;
2682	HEADER *hp;
2683	u_int dots;
2684	char buf[MAXHOSTNAMELEN];
2685	int trailing_dot, ret, saved_herrno;
2686	int got_nodata = 0, got_servfail = 0, tried_as_is = 0;
2687
2688	_DIAGASSERT(name != NULL);
2689	_DIAGASSERT(target != NULL);
2690
2691	hp = (HEADER *)(void *)target->answer;	/*XXX*/
2692
2693	errno = 0;
2694	h_errno = HOST_NOT_FOUND;	/* default, if we never query */
2695	dots = 0;
2696	for (cp = name; *cp; cp++)
2697		dots += (*cp == '.');
2698	trailing_dot = 0;
2699	if (cp > name && *--cp == '.')
2700		trailing_dot++;
2701
2702	/*
2703	 * if there aren't any dots, it could be a user-level alias
2704	 */
2705	if (!dots && (cp = res_hostalias(res, name, buf, sizeof(buf))) != NULL) {
2706		ret = res_queryN(cp, target, res);
2707		return ret;
2708	}
2709
2710	/*
2711	 * If there are dots in the name already, let's just give it a try
2712	 * 'as is'.  The threshold can be set with the "ndots" option.
2713	 */
2714	saved_herrno = -1;
2715	if (dots >= res->ndots) {
2716		ret = res_querydomainN(name, NULL, target, res);
2717		if (ret > 0)
2718			return ret;
2719		saved_herrno = h_errno;
2720		tried_as_is++;
2721	}
2722
2723	/*
2724	 * We do at least one level of search if
2725	 *	- there is no dot and RES_DEFNAME is set, or
2726	 *	- there is at least one dot, there is no trailing dot,
2727	 *	  and RES_DNSRCH is set.
2728	 */
2729	if ((!dots && (res->options & RES_DEFNAMES)) ||
2730	    (dots && !trailing_dot && (res->options & RES_DNSRCH))) {
2731		int done = 0;
2732
2733		for (domain = (const char * const *)res->dnsrch;
2734		   *domain && !done;
2735		   domain++) {
2736
2737			ret = res_querydomainN(name, *domain, target, res);
2738			if (ret > 0)
2739				return ret;
2740
2741			/*
2742			 * If no server present, give up.
2743			 * If name isn't found in this domain,
2744			 * keep trying higher domains in the search list
2745			 * (if that's enabled).
2746			 * On a NO_DATA error, keep trying, otherwise
2747			 * a wildcard entry of another type could keep us
2748			 * from finding this entry higher in the domain.
2749			 * If we get some other error (negative answer or
2750			 * server failure), then stop searching up,
2751			 * but try the input name below in case it's
2752			 * fully-qualified.
2753			 */
2754			if (errno == ECONNREFUSED) {
2755				h_errno = TRY_AGAIN;
2756				return -1;
2757			}
2758
2759			switch (h_errno) {
2760			case NO_DATA:
2761				got_nodata++;
2762				/* FALLTHROUGH */
2763			case HOST_NOT_FOUND:
2764				/* keep trying */
2765				break;
2766			case TRY_AGAIN:
2767				if (hp->rcode == SERVFAIL) {
2768					/* try next search element, if any */
2769					got_servfail++;
2770					break;
2771				}
2772				/* FALLTHROUGH */
2773			default:
2774				/* anything else implies that we're done */
2775				done++;
2776			}
2777			/*
2778			 * if we got here for some reason other than DNSRCH,
2779			 * we only wanted one iteration of the loop, so stop.
2780			 */
2781			if (!(res->options & RES_DNSRCH))
2782				done++;
2783		}
2784	}
2785
2786	/*
2787	 * if we have not already tried the name "as is", do that now.
2788	 * note that we do this regardless of how many dots were in the
2789	 * name or whether it ends with a dot.
2790	 */
2791	if (!tried_as_is) {
2792		ret = res_querydomainN(name, NULL, target, res);
2793		if (ret > 0)
2794			return ret;
2795	}
2796
2797	/*
2798	 * if we got here, we didn't satisfy the search.
2799	 * if we did an initial full query, return that query's h_errno
2800	 * (note that we wouldn't be here if that query had succeeded).
2801	 * else if we ever got a nodata, send that back as the reason.
2802	 * else send back meaningless h_errno, that being the one from
2803	 * the last DNSRCH we did.
2804	 */
2805	if (saved_herrno != -1)
2806		h_errno = saved_herrno;
2807	else if (got_nodata)
2808		h_errno = NO_DATA;
2809	else if (got_servfail)
2810		h_errno = TRY_AGAIN;
2811	return -1;
2812}
2813
2814/*
2815 * Perform a call on res_query on the concatenation of name and domain,
2816 * removing a trailing dot from name if domain is NULL.
2817 */
2818static int
2819res_querydomainN(const char *name, const char *domain,
2820    struct res_target *target, res_state res)
2821{
2822	char nbuf[MAXDNAME];
2823	const char *longname = nbuf;
2824	size_t n;
2825
2826	_DIAGASSERT(name != NULL);
2827	/* XXX: target may be NULL??? */
2828
2829#ifdef DEBUG
2830	if (res->options & RES_DEBUG)
2831		printf(";; res_querydomain(%s, %s)\n",
2832			name, domain?domain:"<Nil>");
2833#endif
2834	if (domain == NULL) {
2835		/*
2836		 * Check for trailing '.';
2837		 * copy without '.' if present.
2838		 */
2839		n = strlen(name);
2840		if (n + 1 > sizeof(nbuf)) {
2841			h_errno = NO_RECOVERY;
2842			return -1;
2843		}
2844		if (n > 0 && name[--n] == '.') {
2845			snprintf(nbuf, sizeof(nbuf), "%*s", (int)n, name);
2846		} else
2847			longname = name;
2848	} else {
2849		if ((size_t)snprintf(nbuf, sizeof(nbuf), "%s.%s",
2850				name, domain) >= sizeof(nbuf)) {
2851			h_errno = NO_RECOVERY;
2852			return -1;
2853		}
2854	}
2855	return res_queryN(longname, target, res);
2856}
2857
2858#ifdef TEST
2859int
2860main(int argc, char *argv[]) {
2861	struct addrinfo *ai, *sai;
2862	int i, e;
2863	char buf[1024];
2864
2865	for (i = 1; i < argc; i++) {
2866		if ((e = getaddrinfo(argv[i], NULL, NULL, &sai)) != 0)
2867			warnx("%s: %s", argv[i], gai_strerror(e));
2868		for (ai = sai; ai; ai = ai->ai_next) {
2869			sockaddr_snprintf(buf, sizeof(buf), "%a", ai->ai_addr);
2870             		printf("flags=0x%x family=%d socktype=%d protocol=%d "
2871			    "addrlen=%zu addr=%s canonname=%s next=%p\n",
2872			    ai->ai_flags,
2873             		    ai->ai_family,
2874             		    ai->ai_socktype,
2875             		    ai->ai_protocol,
2876             		    (size_t)ai->ai_addrlen,
2877			    buf,
2878			    ai->ai_canonname,
2879			    ai->ai_next);
2880		}
2881		if (sai)
2882			freeaddrinfo(sai);
2883	}
2884	return 0;
2885}
2886#endif
2887