xref: /netbsd-src/lib/libc/net/gethnamaddr.c (revision 4b896b232495b7a9b8b94a1cf1e21873296d53b8)
1 /*	$NetBSD: gethnamaddr.c,v 1.61 2004/06/04 20:05:25 ginsbach Exp $	*/
2 
3 /*
4  * ++Copyright++ 1985, 1988, 1993
5  * -
6  * Copyright (c) 1985, 1988, 1993
7  *    The Regents of the University of California.  All rights reserved.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  * 3. Neither the name of the University nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  * -
33  * Portions Copyright (c) 1993 by Digital Equipment Corporation.
34  *
35  * Permission to use, copy, modify, and distribute this software for any
36  * purpose with or without fee is hereby granted, provided that the above
37  * copyright notice and this permission notice appear in all copies, and that
38  * the name of Digital Equipment Corporation not be used in advertising or
39  * publicity pertaining to distribution of the document or software without
40  * specific, written prior permission.
41  *
42  * THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL
43  * WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES
44  * OF MERCHANTABILITY AND FITNESS.   IN NO EVENT SHALL DIGITAL EQUIPMENT
45  * CORPORATION BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
46  * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
47  * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
48  * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
49  * SOFTWARE.
50  * -
51  * --Copyright--
52  */
53 
54 #include <sys/cdefs.h>
55 #if defined(LIBC_SCCS) && !defined(lint)
56 #if 0
57 static char sccsid[] = "@(#)gethostnamadr.c	8.1 (Berkeley) 6/4/93";
58 static char rcsid[] = "Id: gethnamaddr.c,v 8.21 1997/06/01 20:34:37 vixie Exp ";
59 #else
60 __RCSID("$NetBSD: gethnamaddr.c,v 1.61 2004/06/04 20:05:25 ginsbach Exp $");
61 #endif
62 #endif /* LIBC_SCCS and not lint */
63 
64 #if defined(_LIBC)
65 #include "namespace.h"
66 #endif
67 #include <sys/param.h>
68 #include <sys/socket.h>
69 #include <netinet/in.h>
70 #include <arpa/inet.h>
71 #include <arpa/nameser.h>
72 
73 #include <assert.h>
74 #include <ctype.h>
75 #include <errno.h>
76 #include <netdb.h>
77 #include <resolv.h>
78 #include <stdarg.h>
79 #include <stdio.h>
80 #include <syslog.h>
81 
82 #ifndef LOG_AUTH
83 # define LOG_AUTH 0
84 #endif
85 
86 #define MULTI_PTRS_ARE_ALIASES 1	/* XXX - experimental */
87 
88 #include <nsswitch.h>
89 #include <stdlib.h>
90 #include <string.h>
91 
92 #ifdef YP
93 #include <rpc/rpc.h>
94 #include <rpcsvc/yp_prot.h>
95 #include <rpcsvc/ypclnt.h>
96 #endif
97 
98 #if defined(_LIBC) && defined(__weak_alias)
99 __weak_alias(gethostbyaddr,_gethostbyaddr)
100 __weak_alias(gethostbyname,_gethostbyname)
101 #endif
102 
103 #define	MAXALIASES	35
104 #define	MAXADDRS	35
105 
106 static const char AskedForGot[] =
107 			  "gethostby*.getanswer: asked for \"%s\", got \"%s\"";
108 
109 static char *h_addr_ptrs[MAXADDRS + 1];
110 
111 #ifdef YP
112 static char *__ypdomain;
113 #endif
114 
115 static struct hostent host;
116 static char *host_aliases[MAXALIASES];
117 static char hostbuf[8*1024];
118 static u_int32_t host_addr[16 / sizeof(u_int32_t)];	/* IPv4 or IPv6 */
119 static FILE *hostf = NULL;
120 static int stayopen = 0;
121 
122 #define	MAXPACKET	(64*1024)
123 
124 typedef union {
125     HEADER hdr;
126     u_char buf[MAXPACKET];
127 } querybuf;
128 
129 typedef union {
130     int32_t al;
131     char ac;
132 } align;
133 
134 #ifdef DEBUG
135 static void dprintf(char *, res_state *, ...)
136 	__attribute__((__format__(__printf__, 1, 3)));
137 #endif
138 static struct hostent *getanswer(const querybuf *, int, const char *, int,
139     res_state);
140 static void map_v4v6_address(const char *, char *);
141 static void map_v4v6_hostent(struct hostent *, char **, char *);
142 #ifdef RESOLVSORT
143 static void addrsort(char **, int, res_state *);
144 #endif
145 
146 void _sethtent(int);
147 void _endhtent(void);
148 struct hostent *_gethtent(void);
149 void ht_sethostent(int);
150 void ht_endhostent(void);
151 struct hostent *ht_gethostbyname(char *);
152 struct hostent *ht_gethostbyaddr(const char *, int, int);
153 void dns_service(void);
154 #undef dn_skipname
155 int dn_skipname(const u_char *, const u_char *);
156 int _gethtbyaddr(void *, void *, va_list);
157 int _gethtbyname(void *, void *, va_list);
158 struct hostent *_gethtbyname2(const char *, int);
159 int _dns_gethtbyaddr(void *, void *, va_list);
160 int _dns_gethtbyname(void *, void *, va_list);
161 #ifdef YP
162 struct hostent *_yphostent(char *, int);
163 int _yp_gethtbyaddr(void *, void *, va_list);
164 int _yp_gethtbyname(void *, void *, va_list);
165 #endif
166 
167 static struct hostent *gethostbyname_internal(const char *, int, res_state);
168 
169 static const ns_src default_dns_files[] = {
170 	{ NSSRC_FILES, 	NS_SUCCESS },
171 	{ NSSRC_DNS, 	NS_SUCCESS },
172 	{ 0 }
173 };
174 
175 
176 #ifdef DEBUG
177 static void
178 dprintf(char *msg, res_state res, ...)
179 {
180 	_DIAGASSERT(msg != NULL);
181 
182 	if (res->options & RES_DEBUG) {
183 		int save = errno;
184 		va_list ap;
185 
186 		va_start (ap, msg);
187 		vprintf(msg, ap);
188 		va_end (ap);
189 
190 		errno = save;
191 	}
192 }
193 #else
194 # define dprintf(msg, res, num) /*nada*/
195 #endif
196 
197 #define BOUNDED_INCR(x) \
198 	do { \
199 		cp += (x); \
200 		if (cp > eom) { \
201 			h_errno = NO_RECOVERY; \
202 			return NULL; \
203 		} \
204 	} while (/*CONSTCOND*/0)
205 
206 #define BOUNDS_CHECK(ptr, count) \
207 	do { \
208 		if ((ptr) + (count) > eom) { \
209 			h_errno = NO_RECOVERY; \
210 			return NULL; \
211 		} \
212 	} while (/*CONSTCOND*/0)
213 
214 static struct hostent *
215 getanswer(const querybuf *answer, int anslen, const char *qname, int qtype,
216     res_state res)
217 {
218 	const HEADER *hp;
219 	const u_char *cp;
220 	int n;
221 	const u_char *eom, *erdata;
222 	char *bp, **ap, **hap, *ep;
223 	int type, class, ancount, qdcount;
224 	int haveanswer, had_error;
225 	int toobig = 0;
226 	char tbuf[MAXDNAME];
227 	const char *tname;
228 	int (*name_ok)(const char *);
229 
230 	_DIAGASSERT(answer != NULL);
231 	_DIAGASSERT(qname != NULL);
232 
233 	tname = qname;
234 	host.h_name = NULL;
235 	eom = answer->buf + anslen;
236 	switch (qtype) {
237 	case T_A:
238 	case T_AAAA:
239 		name_ok = res_hnok;
240 		break;
241 	case T_PTR:
242 		name_ok = res_dnok;
243 		break;
244 	default:
245 		return NULL;	/* XXX should be abort(); */
246 	}
247 	/*
248 	 * find first satisfactory answer
249 	 */
250 	hp = &answer->hdr;
251 	ancount = ntohs(hp->ancount);
252 	qdcount = ntohs(hp->qdcount);
253 	bp = hostbuf;
254 	ep = hostbuf + sizeof hostbuf;
255 	cp = answer->buf;
256 	BOUNDED_INCR(HFIXEDSZ);
257 	if (qdcount != 1) {
258 		h_errno = NO_RECOVERY;
259 		return NULL;
260 	}
261 	n = dn_expand(answer->buf, eom, cp, bp, ep - bp);
262 	if ((n < 0) || !(*name_ok)(bp)) {
263 		h_errno = NO_RECOVERY;
264 		return NULL;
265 	}
266 	BOUNDED_INCR(n + QFIXEDSZ);
267 	if (qtype == T_A || qtype == T_AAAA) {
268 		/* res_send() has already verified that the query name is the
269 		 * same as the one we sent; this just gets the expanded name
270 		 * (i.e., with the succeeding search-domain tacked on).
271 		 */
272 		n = strlen(bp) + 1;		/* for the \0 */
273 		if (n >= MAXHOSTNAMELEN) {
274 			h_errno = NO_RECOVERY;
275 			return NULL;
276 		}
277 		host.h_name = bp;
278 		bp += n;
279 		/* The qname can be abbreviated, but h_name is now absolute. */
280 		qname = host.h_name;
281 	}
282 	ap = host_aliases;
283 	*ap = NULL;
284 	host.h_aliases = host_aliases;
285 	hap = h_addr_ptrs;
286 	*hap = NULL;
287 	host.h_addr_list = h_addr_ptrs;
288 	haveanswer = 0;
289 	had_error = 0;
290 	while (ancount-- > 0 && cp < eom && !had_error) {
291 		n = dn_expand(answer->buf, eom, cp, bp, ep - bp);
292 		if ((n < 0) || !(*name_ok)(bp)) {
293 			had_error++;
294 			continue;
295 		}
296 		cp += n;			/* name */
297 		BOUNDS_CHECK(cp, 3 * INT16SZ + INT32SZ);
298 		type = _getshort(cp);
299  		cp += INT16SZ;			/* type */
300 		class = _getshort(cp);
301  		cp += INT16SZ + INT32SZ;	/* class, TTL */
302 		n = _getshort(cp);
303 		cp += INT16SZ;			/* len */
304 		BOUNDS_CHECK(cp, n);
305 		erdata = cp + n;
306 		if (class != C_IN) {
307 			/* XXX - debug? syslog? */
308 			cp += n;
309 			continue;		/* XXX - had_error++ ? */
310 		}
311 		if ((qtype == T_A || qtype == T_AAAA) && type == T_CNAME) {
312 			if (ap >= &host_aliases[MAXALIASES-1])
313 				continue;
314 			n = dn_expand(answer->buf, eom, cp, tbuf, sizeof tbuf);
315 			if ((n < 0) || !(*name_ok)(tbuf)) {
316 				had_error++;
317 				continue;
318 			}
319 			cp += n;
320 			if (cp != erdata) {
321 				h_errno = NO_RECOVERY;
322 				return NULL;
323 			}
324 			/* Store alias. */
325 			*ap++ = bp;
326 			n = strlen(bp) + 1;	/* for the \0 */
327 			if (n >= MAXHOSTNAMELEN) {
328 				had_error++;
329 				continue;
330 			}
331 			bp += n;
332 			/* Get canonical name. */
333 			n = strlen(tbuf) + 1;	/* for the \0 */
334 			if (n > ep - bp || n >= MAXHOSTNAMELEN) {
335 				had_error++;
336 				continue;
337 			}
338 			strlcpy(bp, tbuf, (size_t)(ep - bp));
339 			host.h_name = bp;
340 			bp += n;
341 			continue;
342 		}
343 		if (qtype == T_PTR && type == T_CNAME) {
344 			n = dn_expand(answer->buf, eom, cp, tbuf, sizeof tbuf);
345 			if (n < 0 || !res_dnok(tbuf)) {
346 				had_error++;
347 				continue;
348 			}
349 			cp += n;
350 			if (cp != erdata) {
351 				h_errno = NO_RECOVERY;
352 				return NULL;
353 			}
354 			/* Get canonical name. */
355 			n = strlen(tbuf) + 1;	/* for the \0 */
356 			if (n > ep - bp || n >= MAXHOSTNAMELEN) {
357 				had_error++;
358 				continue;
359 			}
360 			strlcpy(bp, tbuf, (size_t)(ep - bp));
361 			tname = bp;
362 			bp += n;
363 			continue;
364 		}
365 		if (type != qtype) {
366 			if (type != T_KEY && type != T_SIG)
367 				syslog(LOG_NOTICE|LOG_AUTH,
368 	       "gethostby*.getanswer: asked for \"%s %s %s\", got type \"%s\"",
369 				       qname, p_class(C_IN), p_type(qtype),
370 				       p_type(type));
371 			cp += n;
372 			continue;		/* XXX - had_error++ ? */
373 		}
374 		switch (type) {
375 		case T_PTR:
376 			if (strcasecmp(tname, bp) != 0) {
377 				syslog(LOG_NOTICE|LOG_AUTH,
378 				       AskedForGot, qname, bp);
379 				cp += n;
380 				continue;	/* XXX - had_error++ ? */
381 			}
382 			n = dn_expand(answer->buf, eom, cp, bp, ep - bp);
383 			if ((n < 0) || !res_hnok(bp)) {
384 				had_error++;
385 				break;
386 			}
387 #if MULTI_PTRS_ARE_ALIASES
388 			cp += n;
389 			if (cp != erdata) {
390 				h_errno = NO_RECOVERY;
391 				return NULL;
392 			}
393 			if (!haveanswer)
394 				host.h_name = bp;
395 			else if (ap < &host_aliases[MAXALIASES-1])
396 				*ap++ = bp;
397 			else
398 				n = -1;
399 			if (n != -1) {
400 				n = strlen(bp) + 1;	/* for the \0 */
401 				if (n >= MAXHOSTNAMELEN) {
402 					had_error++;
403 					break;
404 				}
405 				bp += n;
406 			}
407 			break;
408 #else
409 			host.h_name = bp;
410 			if (res->options & RES_USE_INET6) {
411 				n = strlen(bp) + 1;	/* for the \0 */
412 				if (n >= MAXHOSTNAMELEN) {
413 					had_error++;
414 					break;
415 				}
416 				bp += n;
417 				map_v4v6_hostent(&host, &bp, ep);
418 			}
419 			h_errno = NETDB_SUCCESS;
420 			return &host;
421 #endif
422 		case T_A:
423 		case T_AAAA:
424 			if (strcasecmp(host.h_name, bp) != 0) {
425 				syslog(LOG_NOTICE|LOG_AUTH,
426 				       AskedForGot, host.h_name, bp);
427 				cp += n;
428 				continue;	/* XXX - had_error++ ? */
429 			}
430 			if (n != host.h_length) {
431 				cp += n;
432 				continue;
433 			}
434 			if (type == T_AAAA) {
435 				struct in6_addr in6;
436 				memcpy(&in6, cp, IN6ADDRSZ);
437 				if (IN6_IS_ADDR_V4MAPPED(&in6)) {
438 					cp += n;
439 					continue;
440 				}
441 			}
442 			if (!haveanswer) {
443 				int nn;
444 
445 				host.h_name = bp;
446 				nn = strlen(bp) + 1;	/* for the \0 */
447 				bp += nn;
448 			}
449 
450 			bp += sizeof(align) -
451 			    (size_t)((u_long)bp % sizeof(align));
452 
453 			if (bp + n >= &hostbuf[sizeof hostbuf]) {
454 				dprintf("size (%d) too big\n", res, n);
455 				had_error++;
456 				continue;
457 			}
458 			if (hap >= &h_addr_ptrs[MAXADDRS-1]) {
459 				if (!toobig++)
460 					dprintf("Too many addresses (%d)\n",
461 						res, MAXADDRS);
462 				cp += n;
463 				continue;
464 			}
465 			(void)memcpy(*hap++ = bp, cp, (size_t)n);
466 			bp += n;
467 			cp += n;
468 			if (cp != erdata) {
469 				h_errno = NO_RECOVERY;
470 				return NULL;
471 			}
472 			break;
473 		default:
474 			abort();
475 		}
476 		if (!had_error)
477 			haveanswer++;
478 	}
479 	if (haveanswer) {
480 		*ap = NULL;
481 		*hap = NULL;
482 # if defined(RESOLVSORT)
483 		/*
484 		 * Note: we sort even if host can take only one address
485 		 * in its return structures - should give it the "best"
486 		 * address in that case, not some random one
487 		 */
488 		if (res->nsort && haveanswer > 1 && qtype == T_A)
489 			addrsort(h_addr_ptrs, haveanswer, res);
490 # endif /*RESOLVSORT*/
491 		if (!host.h_name) {
492 			n = strlen(qname) + 1;	/* for the \0 */
493 			if (n > ep - bp || n >= MAXHOSTNAMELEN)
494 				goto no_recovery;
495 			strlcpy(bp, qname, (size_t)(ep - bp));
496 			host.h_name = bp;
497 			bp += n;
498 		}
499 		if (res->options & RES_USE_INET6)
500 			map_v4v6_hostent(&host, &bp, ep);
501 		h_errno = NETDB_SUCCESS;
502 		return &host;
503 	}
504  no_recovery:
505 	h_errno = NO_RECOVERY;
506 	return NULL;
507 }
508 
509 struct hostent *
510 gethostbyname(const char *name)
511 {
512 	struct hostent *hp;
513 	res_state res = __res_get_state();
514 
515 	if (res == NULL)
516 		return NULL;
517 
518 	_DIAGASSERT(name != NULL);
519 
520 	if (res->options & RES_USE_INET6) {
521 		hp = gethostbyname_internal(name, AF_INET6, res);
522 		if (hp) {
523 			__res_put_state(res);
524 			return hp;
525 		}
526 	}
527 	hp = gethostbyname_internal(name, AF_INET, res);
528 	__res_put_state(res);
529 	return hp;
530 }
531 
532 struct hostent *
533 gethostbyname2(const char *name, int af)
534 {
535 	struct hostent *hp;
536 	res_state res = __res_get_state();
537 
538 	if (res == NULL)
539 		return NULL;
540 	hp = gethostbyname_internal(name, af, res);
541 	__res_put_state(res);
542 	return hp;
543 }
544 
545 static struct hostent *
546 gethostbyname_internal(const char *name, int af, res_state res)
547 {
548 	const char *cp;
549 	char *bp, *ep;
550 	int size;
551 	struct hostent *hp;
552 	static const ns_dtab dtab[] = {
553 		NS_FILES_CB(_gethtbyname, NULL)
554 		{ NSSRC_DNS, _dns_gethtbyname, NULL },	/* force -DHESIOD */
555 		NS_NIS_CB(_yp_gethtbyname, NULL)
556 		{ 0 }
557 	};
558 
559 	_DIAGASSERT(name != NULL);
560 
561 	switch (af) {
562 	case AF_INET:
563 		size = INADDRSZ;
564 		break;
565 	case AF_INET6:
566 		size = IN6ADDRSZ;
567 		break;
568 	default:
569 		h_errno = NETDB_INTERNAL;
570 		errno = EAFNOSUPPORT;
571 		return NULL;
572 	}
573 
574 	host.h_addrtype = af;
575 	host.h_length = size;
576 
577 	/*
578 	 * if there aren't any dots, it could be a user-level alias.
579 	 * this is also done in res_nquery() since we are not the only
580 	 * function that looks up host names.
581 	 */
582 	if (!strchr(name, '.') && (cp = __hostalias(name)))
583 		name = cp;
584 
585 	/*
586 	 * disallow names consisting only of digits/dots, unless
587 	 * they end in a dot.
588 	 */
589 	if (isdigit((u_char) name[0]))
590 		for (cp = name;; ++cp) {
591 			if (!*cp) {
592 				if (*--cp == '.')
593 					break;
594 				/*
595 				 * All-numeric, no dot at the end.
596 				 * Fake up a hostent as if we'd actually
597 				 * done a lookup.
598 				 */
599 				if (inet_pton(af, name,
600 				    (char *)(void *)host_addr) <= 0) {
601 					h_errno = HOST_NOT_FOUND;
602 					return NULL;
603 				}
604 				strncpy(hostbuf, name, MAXDNAME);
605 				hostbuf[MAXDNAME] = '\0';
606 				bp = hostbuf + MAXDNAME;
607 				ep = hostbuf + sizeof hostbuf;
608 				host.h_name = hostbuf;
609 				host.h_aliases = host_aliases;
610 				host_aliases[0] = NULL;
611 				h_addr_ptrs[0] = (char *)(void *)host_addr;
612 				h_addr_ptrs[1] = NULL;
613 				host.h_addr_list = h_addr_ptrs;
614 				if (res->options & RES_USE_INET6)
615 					map_v4v6_hostent(&host, &bp, ep);
616 				h_errno = NETDB_SUCCESS;
617 				return &host;
618 			}
619 			if (!isdigit((u_char) *cp) && *cp != '.')
620 				break;
621 		}
622 	if ((isxdigit((u_char) name[0]) && strchr(name, ':') != NULL) ||
623 	    name[0] == ':')
624 		for (cp = name;; ++cp) {
625 			if (!*cp) {
626 				if (*--cp == '.')
627 					break;
628 				/*
629 				 * All-IPv6-legal, no dot at the end.
630 				 * Fake up a hostent as if we'd actually
631 				 * done a lookup.
632 				 */
633 				if (inet_pton(af, name,
634 				    (char *)(void *)host_addr) <= 0) {
635 					h_errno = HOST_NOT_FOUND;
636 					return NULL;
637 				}
638 				strncpy(hostbuf, name, MAXDNAME);
639 				hostbuf[MAXDNAME] = '\0';
640 				bp = hostbuf + MAXDNAME;
641 				ep = hostbuf + sizeof hostbuf;
642 				host.h_name = hostbuf;
643 				host.h_aliases = host_aliases;
644 				host_aliases[0] = NULL;
645 				h_addr_ptrs[0] = (char *)(void *)host_addr;
646 				h_addr_ptrs[1] = NULL;
647 				host.h_addr_list = h_addr_ptrs;
648 				h_errno = NETDB_SUCCESS;
649 				return &host;
650 			}
651 			if (!isxdigit((u_char) *cp) && *cp != ':' && *cp != '.')
652 				break;
653 		}
654 
655 	hp = NULL;
656 	h_errno = NETDB_INTERNAL;
657 	if (nsdispatch(&hp, dtab, NSDB_HOSTS, "gethostbyname",
658 	    default_dns_files, name, strlen(name), af) != NS_SUCCESS)
659 		return NULL;
660 	h_errno = NETDB_SUCCESS;
661 	return hp;
662 }
663 
664 struct hostent *
665 gethostbyaddr(const char *addr,	/* XXX should have been def'd as u_char! */
666     socklen_t len, int af)
667 {
668 	const u_char *uaddr = (const u_char *)addr;
669 	socklen_t size;
670 	struct hostent *hp;
671 	static const ns_dtab dtab[] = {
672 		NS_FILES_CB(_gethtbyaddr, NULL)
673 		{ NSSRC_DNS, _dns_gethtbyaddr, NULL },	/* force -DHESIOD */
674 		NS_NIS_CB(_yp_gethtbyaddr, NULL)
675 		{ 0 }
676 	};
677 
678 	_DIAGASSERT(addr != NULL);
679 
680 	if (af == AF_INET6 && len == IN6ADDRSZ &&
681 	    (IN6_IS_ADDR_LINKLOCAL((const struct in6_addr *)(const void *)uaddr) ||
682 	     IN6_IS_ADDR_SITELOCAL((const struct in6_addr *)(const void *)uaddr))) {
683 		h_errno = HOST_NOT_FOUND;
684 		return NULL;
685 	}
686 	if (af == AF_INET6 && len == IN6ADDRSZ &&
687 	    (IN6_IS_ADDR_V4MAPPED((const struct in6_addr *)(const void *)uaddr) ||
688 	     IN6_IS_ADDR_V4COMPAT((const struct in6_addr *)(const void *)uaddr))) {
689 		/* Unmap. */
690 		addr += IN6ADDRSZ - INADDRSZ;
691 		uaddr += IN6ADDRSZ - INADDRSZ;
692 		af = AF_INET;
693 		len = INADDRSZ;
694 	}
695 	switch (af) {
696 	case AF_INET:
697 		size = INADDRSZ;
698 		break;
699 	case AF_INET6:
700 		size = IN6ADDRSZ;
701 		break;
702 	default:
703 		errno = EAFNOSUPPORT;
704 		h_errno = NETDB_INTERNAL;
705 		return NULL;
706 	}
707 	if (size != len) {
708 		errno = EINVAL;
709 		h_errno = NETDB_INTERNAL;
710 		return NULL;
711 	}
712 	hp = NULL;
713 	h_errno = NETDB_INTERNAL;
714 	if (nsdispatch(&hp, dtab, NSDB_HOSTS, "gethostbyaddr",
715 	    default_dns_files, uaddr, len, af) != NS_SUCCESS)
716 		return NULL;
717 	h_errno = NETDB_SUCCESS;
718 	return hp;
719 }
720 
721 void
722 _sethtent(int f)
723 {
724 	if (!hostf)
725 		hostf = fopen(_PATH_HOSTS, "r" );
726 	else
727 		rewind(hostf);
728 	stayopen = f;
729 }
730 
731 void
732 _endhtent(void)
733 {
734 	if (hostf && !stayopen) {
735 		(void) fclose(hostf);
736 		hostf = NULL;
737 	}
738 }
739 
740 struct hostent *
741 _gethtent(void)
742 {
743 	char *p;
744 	char *cp, **q;
745 	int af, len;
746 
747 	if (!hostf && !(hostf = fopen(_PATH_HOSTS, "r" ))) {
748 		h_errno = NETDB_INTERNAL;
749 		return NULL;
750 	}
751  again:
752 	if (!(p = fgets(hostbuf, sizeof hostbuf, hostf))) {
753 		h_errno = HOST_NOT_FOUND;
754 		return NULL;
755 	}
756 	if (*p == '#')
757 		goto again;
758 	if (!(cp = strpbrk(p, "#\n")))
759 		goto again;
760 	*cp = '\0';
761 	if (!(cp = strpbrk(p, " \t")))
762 		goto again;
763 	*cp++ = '\0';
764 	if (inet_pton(AF_INET6, p, (char *)(void *)host_addr) > 0) {
765 		af = AF_INET6;
766 		len = IN6ADDRSZ;
767 	} else if (inet_pton(AF_INET, p, (char *)(void *)host_addr) > 0) {
768 		res_state res = __res_get_state();
769 		if (res == NULL)
770 			return NULL;
771 		if (res->options & RES_USE_INET6) {
772 			map_v4v6_address((char *)(void *)host_addr,
773 			    (char *)(void *)host_addr);
774 			af = AF_INET6;
775 			len = IN6ADDRSZ;
776 		} else {
777 			af = AF_INET;
778 			len = INADDRSZ;
779 		}
780 		__res_put_state(res);
781 	} else {
782 		goto again;
783 	}
784 	/* if this is not something we're looking for, skip it. */
785 	if (host.h_addrtype != af)
786 		goto again;
787 	if (host.h_length != len)
788 		goto again;
789 	h_addr_ptrs[0] = (char *)(void *)host_addr;
790 	h_addr_ptrs[1] = NULL;
791 	host.h_addr_list = h_addr_ptrs;
792 	host.h_length = len;
793 	host.h_addrtype = af;
794 	while (*cp == ' ' || *cp == '\t')
795 		cp++;
796 	host.h_name = cp;
797 	q = host.h_aliases = host_aliases;
798 	if ((cp = strpbrk(cp, " \t")) != NULL)
799 		*cp++ = '\0';
800 	while (cp && *cp) {
801 		if (*cp == ' ' || *cp == '\t') {
802 			cp++;
803 			continue;
804 		}
805 		if (q < &host_aliases[MAXALIASES - 1])
806 			*q++ = cp;
807 		if ((cp = strpbrk(cp, " \t")) != NULL)
808 			*cp++ = '\0';
809 	}
810 	*q = NULL;
811 	h_errno = NETDB_SUCCESS;
812 	return &host;
813 }
814 
815 /*ARGSUSED*/
816 int
817 _gethtbyname(void *rv, void *cb_data, va_list ap)
818 {
819 	struct hostent *hp;
820 	const char *name;
821 	int af;
822 
823 	_DIAGASSERT(rv != NULL);
824 
825 	name = va_arg(ap, char *);
826 	/* NOSTRICT skip len */(void)va_arg(ap, int);
827 	af = va_arg(ap, int);
828 
829 	hp = NULL;
830 #if 0
831 	{
832 		res_state res = __res_get_state();
833 		if (res == NULL)
834 			return NS_NOTFOUND;
835 		if (res->options & RES_USE_INET6)
836 			hp = _gethtbyname2(name, AF_INET6);
837 		if (hp==NULL)
838 			hp = _gethtbyname2(name, AF_INET);
839 		__res_put_state(res);
840 	}
841 #else
842 	hp = _gethtbyname2(name, af);
843 #endif
844 	*((struct hostent **)rv) = hp;
845 	if (hp == NULL) {
846 		h_errno = HOST_NOT_FOUND;
847 		return NS_NOTFOUND;
848 	}
849 	return NS_SUCCESS;
850 }
851 
852 struct hostent *
853 _gethtbyname2(const char *name, int af)
854 {
855 	struct hostent *p;
856 	char *tmpbuf, *ptr, **cp;
857 	int num;
858 	size_t len;
859 
860 	_DIAGASSERT(name != NULL);
861 
862 	_sethtent(0);
863 	ptr = tmpbuf = NULL;
864 	num = 0;
865 	while ((p = _gethtent()) != NULL && num < MAXADDRS) {
866 		if (p->h_addrtype != af)
867 			continue;
868 		if (strcasecmp(p->h_name, name) != 0) {
869 			for (cp = p->h_aliases; *cp != NULL; cp++)
870 				if (strcasecmp(*cp, name) == 0)
871 					break;
872 			if (*cp == NULL) continue;
873 		}
874 
875 		if (num == 0) {
876 			size_t bufsize;
877 			char *src;
878 
879 			bufsize = strlen(p->h_name) + 2 +
880 				  MAXADDRS * p->h_length +
881 				  ALIGNBYTES;
882 			for (cp = p->h_aliases; *cp != NULL; cp++)
883 				bufsize += strlen(*cp) + 1;
884 
885 			if ((tmpbuf = malloc(bufsize)) == NULL) {
886 				h_errno = NETDB_INTERNAL;
887 				return NULL;
888 			}
889 
890 			ptr = tmpbuf;
891 			src = p->h_name;
892 			while ((*ptr++ = *src++) != '\0');
893 			for (cp = p->h_aliases; *cp != NULL; cp++) {
894 				src = *cp;
895 				while ((*ptr++ = *src++) != '\0');
896 			}
897 			*ptr++ = '\0';
898 
899 			ptr = (char *)(void *)ALIGN(ptr);
900 		}
901 
902 		(void)memcpy(ptr, p->h_addr_list[0], (size_t)p->h_length);
903 		ptr += p->h_length;
904 		num++;
905 	}
906 	_endhtent();
907 	if (num == 0) return NULL;
908 
909 	len = ptr - tmpbuf;
910 	if (len > (sizeof(hostbuf) - ALIGNBYTES)) {
911 		free(tmpbuf);
912 		errno = ENOSPC;
913 		h_errno = NETDB_INTERNAL;
914 		return NULL;
915 	}
916 	ptr = memcpy((void *)ALIGN(hostbuf), tmpbuf, len);
917 	free(tmpbuf);
918 
919 	host.h_name = ptr;
920 	while (*ptr++);
921 
922 	cp = host_aliases;
923 	while (*ptr) {
924 		*cp++ = ptr;
925 		while (*ptr++);
926 	}
927 	ptr++;
928 	*cp = NULL;
929 
930 	ptr = (char *)(void *)ALIGN(ptr);
931 	cp = h_addr_ptrs;
932 	while (num--) {
933 		*cp++ = ptr;
934 		ptr += host.h_length;
935 	}
936 	*cp = NULL;
937 
938 	return &host;
939 }
940 
941 /*ARGSUSED*/
942 int
943 _gethtbyaddr(void *rv, void *cb_data, va_list ap)
944 {
945 	struct hostent *p;
946 	const unsigned char *addr;
947 	int len, af;
948 
949 	_DIAGASSERT(rv != NULL);
950 
951 	addr = va_arg(ap, unsigned char *);
952 	len = va_arg(ap, int);
953 	af = va_arg(ap, int);
954 
955 	host.h_length = len;
956 	host.h_addrtype = af;
957 
958 	_sethtent(0);
959 	while ((p = _gethtent()) != NULL)
960 		if (p->h_addrtype == af && !memcmp(p->h_addr, addr,
961 		    (size_t)len))
962 			break;
963 	_endhtent();
964 	*((struct hostent **)rv) = p;
965 	if (p==NULL) {
966 		h_errno = HOST_NOT_FOUND;
967 		return NS_NOTFOUND;
968 	}
969 	return NS_SUCCESS;
970 }
971 
972 static void
973 map_v4v6_address(const char *src, char *dst)
974 {
975 	u_char *p = (u_char *)dst;
976 	char tmp[INADDRSZ];
977 	int i;
978 
979 	_DIAGASSERT(src != NULL);
980 	_DIAGASSERT(dst != NULL);
981 
982 	/* Stash a temporary copy so our caller can update in place. */
983 	(void)memcpy(tmp, src, INADDRSZ);
984 	/* Mark this ipv6 addr as a mapped ipv4. */
985 	for (i = 0; i < 10; i++)
986 		*p++ = 0x00;
987 	*p++ = 0xff;
988 	*p++ = 0xff;
989 	/* Retrieve the saved copy and we're done. */
990 	(void)memcpy((void *)p, tmp, INADDRSZ);
991 }
992 
993 static void
994 map_v4v6_hostent(struct hostent *hp, char **bpp, char *ep)
995 {
996 	char **ap;
997 
998 	_DIAGASSERT(hp != NULL);
999 	_DIAGASSERT(bpp != NULL);
1000 	_DIAGASSERT(ep != NULL);
1001 
1002 	if (hp->h_addrtype != AF_INET || hp->h_length != INADDRSZ)
1003 		return;
1004 	hp->h_addrtype = AF_INET6;
1005 	hp->h_length = IN6ADDRSZ;
1006 	for (ap = hp->h_addr_list; *ap; ap++) {
1007 		int i = sizeof(align) - (size_t)((u_long)*bpp % sizeof(align));
1008 
1009 		if (ep - *bpp < (i + IN6ADDRSZ)) {
1010 			/* Out of memory.  Truncate address list here.  XXX */
1011 			*ap = NULL;
1012 			return;
1013 		}
1014 		*bpp += i;
1015 		map_v4v6_address(*ap, *bpp);
1016 		*ap = *bpp;
1017 		*bpp += IN6ADDRSZ;
1018 	}
1019 }
1020 
1021 #ifdef RESOLVSORT
1022 static void
1023 addrsort(char **ap, int num, res_state res)
1024 {
1025 	int i, j;
1026 	char **p;
1027 	short aval[MAXADDRS];
1028 	int needsort = 0;
1029 
1030 	_DIAGASSERT(ap != NULL);
1031 
1032 	p = ap;
1033 	for (i = 0; i < num; i++, p++) {
1034 	    for (j = 0 ; (unsigned)j < res->nsort; j++)
1035 		if (res->sort_list[j].addr.s_addr ==
1036 		    (((struct in_addr *)(void *)(*p))->s_addr &
1037 		    res->sort_list[j].mask))
1038 			break;
1039 	    aval[i] = j;
1040 	    if (needsort == 0 && i > 0 && j < aval[i-1])
1041 		needsort = i;
1042 	}
1043 	if (!needsort)
1044 	    return;
1045 
1046 	while (needsort < num) {
1047 	    for (j = needsort - 1; j >= 0; j--) {
1048 		if (aval[j] > aval[j+1]) {
1049 		    char *hp;
1050 
1051 		    i = aval[j];
1052 		    aval[j] = aval[j+1];
1053 		    aval[j+1] = i;
1054 
1055 		    hp = ap[j];
1056 		    ap[j] = ap[j+1];
1057 		    ap[j+1] = hp;
1058 		} else
1059 		    break;
1060 	    }
1061 	    needsort++;
1062 	}
1063 }
1064 #endif
1065 
1066 #if defined(BSD43_BSD43_NFS) || defined(sun)
1067 /* XXX: should we remove this cruft? - lukem */
1068 /* some libc's out there are bound internally to these names (UMIPS) */
1069 void
1070 ht_sethostent(int stayopen)
1071 {
1072 	_sethtent(stayopen);
1073 }
1074 
1075 void
1076 ht_endhostent(void)
1077 {
1078 	_endhtent();
1079 }
1080 
1081 struct hostent *
1082 ht_gethostbyname(char *name)
1083 {
1084 	return _gethtbyname(name);
1085 }
1086 
1087 struct hostent *
1088 ht_gethostbyaddr(const char *addr, int len, int af)
1089 {
1090 	return _gethtbyaddr(addr, len, af);
1091 }
1092 
1093 struct hostent *
1094 gethostent(void)
1095 {
1096 	return _gethtent();
1097 }
1098 
1099 void
1100 dns_service(void)
1101 {
1102 	return;
1103 }
1104 
1105 int
1106 dn_skipname(const u_char *comp_dn, const u_char *eom)
1107 {
1108 	return __dn_skipname(comp_dn, eom);
1109 }
1110 #endif /*old-style libc with yp junk in it*/
1111 
1112 /*ARGSUSED*/
1113 int
1114 _dns_gethtbyname(void *rv, void *cb_data, va_list ap)
1115 {
1116 	querybuf *buf;
1117 	int n, type;
1118 	struct hostent *hp;
1119 	const char *name;
1120 	int af;
1121 	res_state res;
1122 
1123 	_DIAGASSERT(rv != NULL);
1124 
1125 	name = va_arg(ap, char *);
1126 	/* NOSTRICT skip len */(void)va_arg(ap, int);
1127 	af = va_arg(ap, int);
1128 
1129 	switch (af) {
1130 	case AF_INET:
1131 		type = T_A;
1132 		break;
1133 	case AF_INET6:
1134 		type = T_AAAA;
1135 		break;
1136 	default:
1137 		return NS_UNAVAIL;
1138 	}
1139 	buf = malloc(sizeof(*buf));
1140 	if (buf == NULL) {
1141 		h_errno = NETDB_INTERNAL;
1142 		return NS_NOTFOUND;
1143 	}
1144 	res = __res_get_state();
1145 	if (res == NULL)
1146 		return NS_NOTFOUND;
1147 	n = res_nsearch(res, name, C_IN, type, buf->buf, sizeof(buf->buf));
1148 	if (n < 0) {
1149 		free(buf);
1150 		dprintf("res_nsearch failed (%d)\n", res, n);
1151 		__res_put_state(res);
1152 		return NS_NOTFOUND;
1153 	}
1154 	hp = getanswer(buf, n, name, type, res);
1155 	free(buf);
1156 	__res_put_state(res);
1157 	if (hp == NULL)
1158 		switch (h_errno) {
1159 		case HOST_NOT_FOUND:
1160 			return NS_NOTFOUND;
1161 		case TRY_AGAIN:
1162 			return NS_TRYAGAIN;
1163 		default:
1164 			return NS_UNAVAIL;
1165 		}
1166 	*((struct hostent **)rv) = hp;
1167 	return NS_SUCCESS;
1168 }
1169 
1170 /*ARGSUSED*/
1171 int
1172 _dns_gethtbyaddr(void *rv, void	*cb_data, va_list ap)
1173 {
1174 	char qbuf[MAXDNAME + 1], *qp, *ep;
1175 	int n;
1176 	querybuf *buf;
1177 	struct hostent *hp;
1178 	const unsigned char *uaddr;
1179 	int len, af, advance;
1180 	res_state res;
1181 
1182 	_DIAGASSERT(rv != NULL);
1183 
1184 	uaddr = va_arg(ap, unsigned char *);
1185 	len = va_arg(ap, int);
1186 	af = va_arg(ap, int);
1187 
1188 	switch (af) {
1189 	case AF_INET:
1190 		(void)snprintf(qbuf, sizeof(qbuf), "%u.%u.%u.%u.in-addr.arpa",
1191 		    (uaddr[3] & 0xff), (uaddr[2] & 0xff),
1192 		    (uaddr[1] & 0xff), (uaddr[0] & 0xff));
1193 		break;
1194 
1195 	case AF_INET6:
1196 		qp = qbuf;
1197 		ep = qbuf + sizeof(qbuf) - 1;
1198 		for (n = IN6ADDRSZ - 1; n >= 0; n--) {
1199 			advance = snprintf(qp, (size_t)(ep - qp), "%x.%x.",
1200 			    uaddr[n] & 0xf,
1201 			    ((unsigned int)uaddr[n] >> 4) & 0xf);
1202 			if (advance > 0 && qp + advance < ep)
1203 				qp += advance;
1204 			else {
1205 				h_errno = NETDB_INTERNAL;
1206 				return NS_NOTFOUND;
1207 			}
1208 		}
1209 		if (strlcat(qbuf, "ip6.arpa", sizeof(qbuf)) >= sizeof(qbuf)) {
1210 			h_errno = NETDB_INTERNAL;
1211 			return NS_NOTFOUND;
1212 		}
1213 		break;
1214 	default:
1215 		abort();
1216 	}
1217 
1218 	buf = malloc(sizeof(*buf));
1219 	if (buf == NULL) {
1220 		h_errno = NETDB_INTERNAL;
1221 		return NS_NOTFOUND;
1222 	}
1223 	res = __res_get_state();
1224 	if (res == NULL)
1225 		return NS_NOTFOUND;
1226 	n = res_nquery(res, qbuf, C_IN, T_PTR, buf->buf, sizeof(buf->buf));
1227 	if (n < 0 && af == AF_INET6) {
1228 		*qp = '\0';
1229 		if (strlcat(qbuf, "ip6.int", sizeof(qbuf)) >= sizeof(qbuf)) {
1230 			free(buf);
1231 			h_errno = NETDB_INTERNAL;
1232 			__res_put_state(res);
1233 			return NS_NOTFOUND;
1234 		}
1235 		n = res_nquery(res, qbuf, C_IN, T_PTR, buf->buf, sizeof(buf->buf));
1236 	}
1237 	if (n < 0) {
1238 		free(buf);
1239 		dprintf("res_nquery failed (%d)\n", res, n);
1240 		__res_put_state(res);
1241 		return NS_NOTFOUND;
1242 	}
1243 	hp = getanswer(buf, n, qbuf, T_PTR, res);
1244 	free(buf);
1245 	if (hp == NULL) {
1246 		__res_put_state(res);
1247 		switch (h_errno) {
1248 		case HOST_NOT_FOUND:
1249 			return NS_NOTFOUND;
1250 		case TRY_AGAIN:
1251 			return NS_TRYAGAIN;
1252 		default:
1253 			return NS_UNAVAIL;
1254 		}
1255 	}
1256 	hp->h_addrtype = af;
1257 	hp->h_length = len;
1258 	(void)memcpy(host_addr, uaddr, (size_t)len);
1259 	h_addr_ptrs[0] = (char *)(void *)host_addr;
1260 	h_addr_ptrs[1] = NULL;
1261 	if (af == AF_INET && (res->options & RES_USE_INET6)) {
1262 		map_v4v6_address((char *)(void *)host_addr,
1263 		    (char *)(void *)host_addr);
1264 		hp->h_addrtype = AF_INET6;
1265 		hp->h_length = IN6ADDRSZ;
1266 	}
1267 
1268 	__res_put_state(res);
1269 	*((struct hostent **)rv) = hp;
1270 	h_errno = NETDB_SUCCESS;
1271 	return NS_SUCCESS;
1272 }
1273 
1274 #ifdef YP
1275 /*ARGSUSED*/
1276 struct hostent *
1277 _yphostent(char *line, int af)
1278 {
1279 	static struct in_addr host_addrs[MAXADDRS];
1280 	static struct in6_addr host6_addrs[MAXADDRS];
1281 	char *p = line;
1282 	char *cp, **q;
1283 	char **hap;
1284 	int addrok;
1285 	int more;
1286 	size_t naddrs;
1287 
1288 	_DIAGASSERT(line != NULL);
1289 
1290 	host.h_name = NULL;
1291 	host.h_addr_list = h_addr_ptrs;
1292 	host.h_addrtype = af;
1293 	switch (af) {
1294 	case AF_INET:
1295 		host.h_length = INADDRSZ;
1296 		break;
1297 	case AF_INET6:
1298 		host.h_length = IN6ADDRSZ;
1299 		break;
1300 	default:
1301 		return NULL;
1302 	}
1303 	hap = h_addr_ptrs;
1304 	q = host.h_aliases = host_aliases;
1305 	naddrs = 0;
1306 
1307 nextline:
1308 	/* check for host_addrs overflow */
1309 	if (naddrs >= sizeof(host_addrs) / sizeof(host_addrs[0]))
1310 		goto done;
1311 	if (naddrs >= sizeof(host6_addrs) / sizeof(host6_addrs[0]))
1312 		goto done;
1313 
1314 	more = 0;
1315 	cp = strpbrk(p, " \t");
1316 	if (cp == NULL)
1317 		goto done;
1318 	*cp++ = '\0';
1319 
1320 	/* p has should have an address */
1321 	switch (af) {
1322 	case AF_INET:
1323 		addrok = inet_aton(p, &host_addrs[naddrs]);
1324 		break;
1325 	case AF_INET6:
1326 		addrok = inet_pton(af, p, &host6_addrs[naddrs]);
1327 		break;
1328 	}
1329 	if (addrok != 1) {
1330 		/* skip to the next line */
1331 		while (cp && *cp) {
1332 			if (*cp == '\n') {
1333 				cp++;
1334 				goto nextline;
1335 			}
1336 			cp++;
1337 		}
1338 
1339 		goto done;
1340 	}
1341 
1342 	switch (af) {
1343 	case AF_INET:
1344 		*hap++ = (char *)(void *)&host_addrs[naddrs++];
1345 		break;
1346 	case AF_INET6:
1347 		*hap++ = (char *)(void *)&host6_addrs[naddrs++];
1348 		break;
1349 	}
1350 
1351 	while (*cp == ' ' || *cp == '\t')
1352 		cp++;
1353 	p = cp;
1354 	cp = strpbrk(p, " \t\n");
1355 	if (cp != NULL) {
1356 		if (*cp == '\n')
1357 			more = 1;
1358 		*cp++ = '\0';
1359 	}
1360 	if (!host.h_name)
1361 		host.h_name = p;
1362 	else if (strcmp(host.h_name, p)==0)
1363 		;
1364 	else if (q < &host_aliases[MAXALIASES - 1])
1365 		*q++ = p;
1366 	p = cp;
1367 	if (more)
1368 		goto nextline;
1369 
1370 	while (cp && *cp) {
1371 		if (*cp == ' ' || *cp == '\t') {
1372 			cp++;
1373 			continue;
1374 		}
1375 		if (*cp == '\n') {
1376 			cp++;
1377 			goto nextline;
1378 		}
1379 		if (q < &host_aliases[MAXALIASES - 1])
1380 			*q++ = cp;
1381 		cp = strpbrk(cp, " \t");
1382 		if (cp != NULL)
1383 			*cp++ = '\0';
1384 	}
1385 
1386 done:
1387 	if (host.h_name == NULL)
1388 		return NULL;
1389 	*q = NULL;
1390 	*hap = NULL;
1391 	return &host;
1392 }
1393 
1394 /*ARGSUSED*/
1395 int
1396 _yp_gethtbyaddr(void *rv, void *cb_data, va_list ap)
1397 {
1398 	struct hostent *hp = NULL;
1399 	static char *__ypcurrent;
1400 	int __ypcurrentlen, r;
1401 	char name[INET6_ADDRSTRLEN];	/* XXX enough? */
1402 	const unsigned char *uaddr;
1403 	int af;
1404 	const char *map;
1405 
1406 	_DIAGASSERT(rv != NULL);
1407 
1408 	uaddr = va_arg(ap, unsigned char *);
1409 	/* NOSTRICT skip len */(void)va_arg(ap, int);
1410 	af = va_arg(ap, int);
1411 
1412 	if (!__ypdomain) {
1413 		if (_yp_check(&__ypdomain) == 0)
1414 			return NS_UNAVAIL;
1415 	}
1416 	/*
1417 	 * XXX unfortunately, we cannot support IPv6 extended scoped address
1418 	 * notation here.  gethostbyaddr() is not scope-aware.  too bad.
1419 	 */
1420 	if (inet_ntop(af, uaddr, name, sizeof(name)) == NULL)
1421 		return NS_UNAVAIL;
1422 	if (__ypcurrent)
1423 		free(__ypcurrent);
1424 	__ypcurrent = NULL;
1425 	switch (af) {
1426 	case AF_INET:
1427 		map = "hosts.byaddr";
1428 		break;
1429 	default:
1430 		map = "ipnodes.byaddr";
1431 		break;
1432 	}
1433 	r = yp_match(__ypdomain, map, name,
1434 		(int)strlen(name), &__ypcurrent, &__ypcurrentlen);
1435 	if (r == 0)
1436 		hp = _yphostent(__ypcurrent, af);
1437 	if (hp == NULL) {
1438 		h_errno = HOST_NOT_FOUND;
1439 		return NS_NOTFOUND;
1440 	}
1441 	*((struct hostent **)rv) = hp;
1442 	return NS_SUCCESS;
1443 }
1444 
1445 /*ARGSUSED*/
1446 int
1447 _yp_gethtbyname(void *rv, void *cb_data, va_list ap)
1448 {
1449 	struct hostent *hp = NULL;
1450 	static char *__ypcurrent;
1451 	int __ypcurrentlen, r;
1452 	const char *name;
1453 	int af;
1454 	const char *map;
1455 
1456 	_DIAGASSERT(rv != NULL);
1457 
1458 	name = va_arg(ap, char *);
1459 	/* NOSTRICT skip len */(void)va_arg(ap, int);
1460 	af = va_arg(ap, int);
1461 
1462 	if (!__ypdomain) {
1463 		if (_yp_check(&__ypdomain) == 0)
1464 			return NS_UNAVAIL;
1465 	}
1466 	if (__ypcurrent)
1467 		free(__ypcurrent);
1468 	__ypcurrent = NULL;
1469 	switch (af) {
1470 	case AF_INET:
1471 		map = "hosts.byname";
1472 		break;
1473 	default:
1474 		map = "ipnodes.byname";
1475 		break;
1476 	}
1477 	r = yp_match(__ypdomain, map, name,
1478 		(int)strlen(name), &__ypcurrent, &__ypcurrentlen);
1479 	if (r == 0)
1480 		hp = _yphostent(__ypcurrent, af);
1481 	if (hp == NULL) {
1482 		h_errno = HOST_NOT_FOUND;
1483 		return NS_NOTFOUND;
1484 	}
1485 	*((struct hostent **)rv) = hp;
1486 	return NS_SUCCESS;
1487 }
1488 #endif
1489