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sethostent.c revision 1.16.18.1 
      1 /*	$NetBSD: sethostent.c,v 1.16.18.1 2013/12/18 20:23:36 bouyer Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 1985, 1993
      5  *	The Regents of the University of California.  All rights reserved.
      6  *
      7  * Redistribution and use in source and binary forms, with or without
      8  * modification, are permitted provided that the following conditions
      9  * are met:
     10  * 1. Redistributions of source code must retain the above copyright
     11  *    notice, this list of conditions and the following disclaimer.
     12  * 2. Redistributions in binary form must reproduce the above copyright
     13  *    notice, this list of conditions and the following disclaimer in the
     14  *    documentation and/or other materials provided with the distribution.
     15  * 3. Neither the name of the University nor the names of its contributors
     16  *    may be used to endorse or promote products derived from this software
     17  *    without specific prior written permission.
     18  *
     19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     29  * SUCH DAMAGE.
     30  */
     31 
     32 #include <sys/cdefs.h>
     33 #if defined(LIBC_SCCS) && !defined(lint)
     34 #if 0
     35 static char sccsid[] = "@(#)sethostent.c	8.1 (Berkeley) 6/4/93";
     36 static char rcsid[] = "Id: sethostent.c,v 8.5 1996/09/28 06:51:07 vixie Exp ";
     37 #else
     38 __RCSID("$NetBSD: sethostent.c,v 1.16.18.1 2013/12/18 20:23:36 bouyer Exp $");
     39 #endif
     40 #endif /* LIBC_SCCS and not lint */
     41 
     42 #include "namespace.h"
     43 #include <sys/param.h>
     44 #include <netinet/in.h>
     45 #include <arpa/nameser.h>
     46 #include <arpa/inet.h>
     47 #include <assert.h>
     48 #include <string.h>
     49 #include <nsswitch.h>
     50 #include <netdb.h>
     51 #include <resolv.h>
     52 #include <errno.h>
     53 #include <stdlib.h>
     54 
     55 #include "hostent.h"
     56 
     57 #ifdef __weak_alias
     58 __weak_alias(sethostent,_sethostent)
     59 __weak_alias(endhostent,_endhostent)
     60 #endif
     61 
     62 #ifndef _REENTRANT
     63 void	res_close(void);
     64 #endif
     65 
     66 static struct hostent *_hf_gethtbyname2(const char *, int, struct getnamaddr *);
     67 
     68 void
     69 /*ARGSUSED*/
     70 sethostent(int stayopen)
     71 {
     72 #ifndef _REENTRANT
     73 	if ((_res.options & RES_INIT) == 0 && res_init() == -1)
     74 		return;
     75 	if (stayopen)
     76 		_res.options |= RES_STAYOPEN | RES_USEVC;
     77 #endif
     78 	sethostent_r(&_h_file);
     79 }
     80 
     81 void
     82 endhostent(void)
     83 {
     84 #ifndef _REENTRANT
     85 	_res.options &= ~(RES_STAYOPEN | RES_USEVC);
     86 	res_close();
     87 #endif
     88 	endhostent_r(&_h_file);
     89 }
     90 static const char *_h_hosts = _PATH_HOSTS;
     91 
     92 void
     93 _hf_sethostsfile(const char *f) {
     94 	_h_hosts = f;
     95 }
     96 
     97 void
     98 sethostent_r(FILE **hf)
     99 {
    100 	if (!*hf)
    101 		*hf = fopen(_h_hosts, "re");
    102 	else
    103 		rewind(*hf);
    104 }
    105 
    106 void
    107 endhostent_r(FILE **hf)
    108 {
    109 	if (*hf) {
    110 		(void)fclose(*hf);
    111 		*hf = NULL;
    112 	}
    113 }
    114 
    115 /*ARGSUSED*/
    116 int
    117 _hf_gethtbyname(void *rv, void *cb_data, va_list ap)
    118 {
    119 	struct hostent *hp;
    120 	const char *name;
    121 	int af;
    122 	struct getnamaddr *info = rv;
    123 
    124 	_DIAGASSERT(rv != NULL);
    125 
    126 	name = va_arg(ap, char *);
    127 	/* NOSTRICT skip string len */(void)va_arg(ap, int);
    128 	af = va_arg(ap, int);
    129 
    130 #if 0
    131 	{
    132 		res_state res = __res_get_state();
    133 		if (res == NULL)
    134 			return NS_NOTFOUND;
    135 		if (res->options & RES_USE_INET6)
    136 			hp = _hf_gethtbyname2(name, AF_INET6, info);
    137 		else
    138 			hp = NULL;
    139 		if (hp == NULL)
    140 			hp = _hf_gethtbyname2(name, AF_INET, info);
    141 		__res_put_state(res);
    142 	}
    143 #else
    144 	hp = _hf_gethtbyname2(name, af, info);
    145 #endif
    146 	if (hp == NULL) {
    147 		*info->he = HOST_NOT_FOUND;
    148 		return NS_NOTFOUND;
    149 	}
    150 	return NS_SUCCESS;
    151 }
    152 
    153 struct hostent *
    154 _hf_gethtbyname2(const char *name, int af, struct getnamaddr *info)
    155 {
    156 	struct hostent *hp, hent;
    157 	char *buf, *ptr;
    158 	size_t len, anum, num, i;
    159 	FILE *hf;
    160 	char *aliases[MAXALIASES];
    161 	char *addr_ptrs[MAXADDRS];
    162 
    163 	_DIAGASSERT(name != NULL);
    164 
    165 	hf = NULL;
    166 	sethostent_r(&hf);
    167 	if (hf == NULL) {
    168 		errno = EINVAL;
    169 		*info->he = NETDB_INTERNAL;
    170 		return NULL;
    171 	}
    172 
    173 	if ((ptr = buf = malloc(len = info->buflen)) == NULL) {
    174 		*info->he = NETDB_INTERNAL;
    175 		return NULL;
    176 	}
    177 
    178 	anum = 0;		/* XXX: gcc */
    179 	hent.h_name = NULL;	/* XXX: gcc */
    180 	hent.h_addrtype = 0;	/* XXX: gcc */
    181 	hent.h_length = 0;	/* XXX: gcc */
    182 
    183 	for (num = 0; num < MAXADDRS;) {
    184 		info->hp->h_addrtype = af;
    185 		info->hp->h_length = 0;
    186 
    187 		hp = gethostent_r(hf, info->hp, info->buf, info->buflen,
    188 		    info->he);
    189 		if (hp == NULL)
    190 			break;
    191 
    192 		if (strcasecmp(hp->h_name, name) != 0) {
    193 			char **cp;
    194 			for (cp = hp->h_aliases; *cp != NULL; cp++)
    195 				if (strcasecmp(*cp, name) == 0)
    196 					break;
    197 			if (*cp == NULL) continue;
    198 		}
    199 
    200 		if (num == 0) {
    201 			hent.h_addrtype = af = hp->h_addrtype;
    202 			hent.h_length = hp->h_length;
    203 
    204 			HENT_SCOPY(hent.h_name, hp->h_name, ptr, len);
    205 			for (anum = 0; hp->h_aliases[anum]; anum++) {
    206 				if (anum >= __arraycount(aliases))
    207 					goto nospc;
    208 				HENT_SCOPY(aliases[anum], hp->h_aliases[anum],
    209 				    ptr, len);
    210 			}
    211 			ptr = (void *)ALIGN(ptr);
    212 			if ((size_t)(ptr - buf) >= info->buflen)
    213 				goto nospc;
    214 		}
    215 
    216 		if (num >= __arraycount(addr_ptrs))
    217 			goto nospc;
    218 		HENT_COPY(addr_ptrs[num], hp->h_addr_list[0], hp->h_length, ptr,
    219 		    len);
    220 		num++;
    221 	}
    222 	endhostent_r(&hf);
    223 
    224 	if (num == 0) {
    225 		*info->he = HOST_NOT_FOUND;
    226 		return NULL;
    227 	}
    228 
    229 	hp = info->hp;
    230 	ptr = info->buf;
    231 	len = info->buflen;
    232 
    233 	hp->h_addrtype = hent.h_addrtype;
    234 	hp->h_length = hent.h_length;
    235 
    236 	HENT_ARRAY(hp->h_aliases, anum, ptr, len);
    237 	HENT_ARRAY(hp->h_addr_list, num, ptr, len);
    238 
    239 	for (i = 0; i < num; i++)
    240 		HENT_COPY(hp->h_addr_list[i], addr_ptrs[i], hp->h_length, ptr,
    241 		    len);
    242 	hp->h_addr_list[num] = NULL;
    243 
    244 	HENT_SCOPY(hp->h_name, hent.h_name, ptr, len);
    245 
    246 	for (i = 0; i < anum; i++)
    247 		HENT_SCOPY(hp->h_aliases[i], aliases[i], ptr, len);
    248 	hp->h_aliases[anum] = NULL;
    249 
    250 	return hp;
    251 nospc:
    252 	*info->he = NETDB_INTERNAL;
    253 	errno = ENOSPC;
    254 	return NULL;
    255 }
    256 
    257 /*ARGSUSED*/
    258 int
    259 _hf_gethtbyaddr(void *rv, void *cb_data, va_list ap)
    260 {
    261 	struct hostent *hp;
    262 	const unsigned char *addr;
    263 	struct getnamaddr *info = rv;
    264 	FILE *hf;
    265 
    266 	_DIAGASSERT(rv != NULL);
    267 
    268 	addr = va_arg(ap, unsigned char *);
    269 	info->hp->h_length = va_arg(ap, int);
    270 	info->hp->h_addrtype = va_arg(ap, int);
    271 
    272 	hf = NULL;
    273 	sethostent_r(&hf);
    274 	if (hf == NULL) {
    275 		*info->he = NETDB_INTERNAL;
    276 		return NS_UNAVAIL;
    277 	}
    278 	while ((hp = gethostent_r(hf, info->hp, info->buf, info->buflen,
    279 	    info->he)) != NULL)
    280 		if (!memcmp(hp->h_addr_list[0], addr, (size_t)hp->h_length))
    281 			break;
    282 	endhostent_r(&hf);
    283 
    284 	if (hp == NULL) {
    285 		*info->he = HOST_NOT_FOUND;
    286 		return NS_NOTFOUND;
    287 	}
    288 	return NS_SUCCESS;
    289 }
    290