Home | History | Annotate | Download | only in net
      1 /*	$NetBSD: sethostent.c,v 1.20 2014/03/17 13:24:23 christos 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 1.20 2014/03/17 13:24:23 christos 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 #include "resolv_private.h"
     57 
     58 #define ALIGNBYTES (sizeof(uintptr_t) - 1)
     59 #define ALIGN(p) (((uintptr_t)(p) + ALIGNBYTES) &~ ALIGNBYTES)
     60 
     61 #ifndef _REENTRANT
     62 void	res_close(void);
     63 #endif
     64 
     65 static struct hostent *_hf_gethtbyname2(const char *, int, struct getnamaddr *);
     66 
     67 static const char *_h_hosts = _PATH_HOSTS;
     68 
     69 void
     70 sethostent_r(FILE **hf)
     71 {
     72 	if (!*hf)
     73 		*hf = fopen(_h_hosts, "re");
     74 	else
     75 		rewind(*hf);
     76 }
     77 
     78 void
     79 endhostent_r(FILE **hf)
     80 {
     81 	if (*hf) {
     82 		(void)fclose(*hf);
     83 		*hf = NULL;
     84 	}
     85 }
     86 
     87 /*ARGSUSED*/
     88 int
     89 _hf_gethtbyname(void *rv, void *cb_data, va_list ap)
     90 {
     91 	struct hostent *hp;
     92 	const char *name;
     93 	int af;
     94 	struct getnamaddr *info = rv;
     95 
     96 	_DIAGASSERT(rv != NULL);
     97 
     98 	name = va_arg(ap, char *);
     99 	/* NOSTRICT skip string len */(void)va_arg(ap, int);
    100 	af = va_arg(ap, int);
    101 
    102 #if 0
    103 	{
    104 		res_state res = __res_get_state();
    105 		if (res == NULL)
    106 			return NS_NOTFOUND;
    107 		if (res->options & RES_USE_INET6)
    108 			hp = _hf_gethtbyname2(name, AF_INET6, info);
    109 		else
    110 			hp = NULL;
    111 		if (hp == NULL)
    112 			hp = _hf_gethtbyname2(name, AF_INET, info);
    113 		__res_put_state(res);
    114 	}
    115 #else
    116 	hp = _hf_gethtbyname2(name, af, info);
    117 #endif
    118 	if (hp == NULL) {
    119 		if (*info->he == NETDB_INTERNAL && errno == ENOSPC) {
    120 			return NS_UNAVAIL;
    121 		}
    122 		return NS_NOTFOUND;
    123 	}
    124 	return NS_SUCCESS;
    125 }
    126 
    127 static struct hostent *
    128 _hf_gethtbyname2(const char *name, int af, struct getnamaddr *info)
    129 {
    130 	struct hostent *hp, hent;
    131 	char *buf, *ptr;
    132 	size_t len, anum, num, i;
    133 	FILE *hf;
    134 	char *aliases[MAXALIASES];
    135 	char *addr_ptrs[MAXADDRS];
    136 
    137 	_DIAGASSERT(name != NULL);
    138 
    139 	hf = NULL;
    140 	sethostent_r(&hf);
    141 	if (hf == NULL) {
    142 		errno = EINVAL;
    143 		*info->he = NETDB_INTERNAL;
    144 		return NULL;
    145 	}
    146 
    147 	if ((ptr = buf = malloc(len = info->buflen)) == NULL) {
    148 		endhostent_r(&hf);
    149 		*info->he = NETDB_INTERNAL;
    150 		return NULL;
    151 	}
    152 
    153 	anum = 0;		/* XXX: gcc */
    154 	hent.h_name = NULL;	/* XXX: gcc */
    155 	hent.h_addrtype = 0;	/* XXX: gcc */
    156 	hent.h_length = 0;	/* XXX: gcc */
    157 
    158 	for (num = 0; num < MAXADDRS;) {
    159 		info->hp->h_addrtype = af;
    160 		info->hp->h_length = 0;
    161 
    162 		hp = netbsd_gethostent_r(hf, info->hp, info->buf, info->buflen,
    163 		    info->he);
    164 		if (hp == NULL) {
    165 			if (*info->he == NETDB_INTERNAL && errno == ENOSPC) {
    166 				goto nospc;
    167 			}
    168 			break;
    169 		}
    170 
    171 		if (strcasecmp(hp->h_name, name) != 0) {
    172 			char **cp;
    173 			for (cp = hp->h_aliases; *cp != NULL; cp++)
    174 				if (strcasecmp(*cp, name) == 0)
    175 					break;
    176 			if (*cp == NULL) continue;
    177 		}
    178 
    179 		if (num == 0) {
    180 			hent.h_addrtype = af = hp->h_addrtype;
    181 			hent.h_length = hp->h_length;
    182 
    183 			HENT_SCOPY(hent.h_name, hp->h_name, ptr, len);
    184 			for (anum = 0; hp->h_aliases[anum]; anum++) {
    185 				if (anum >= MAXALIASES)
    186 					goto nospc;
    187 				HENT_SCOPY(aliases[anum], hp->h_aliases[anum],
    188 				    ptr, len);
    189 			}
    190 			ptr = (void *)ALIGN(ptr);
    191 			if ((size_t)(ptr - buf) >= info->buflen)
    192 				goto nospc;
    193 		}
    194 
    195 		if (num >= MAXADDRS)
    196 			goto nospc;
    197 		HENT_COPY(addr_ptrs[num], hp->h_addr_list[0], hp->h_length, ptr,
    198 		    len);
    199 		num++;
    200 	}
    201 	endhostent_r(&hf);
    202 
    203 	if (num == 0) {
    204 		*info->he = HOST_NOT_FOUND;
    205 		free(buf);
    206 		return NULL;
    207 	}
    208 
    209 	hp = info->hp;
    210 	ptr = info->buf;
    211 	len = info->buflen;
    212 
    213 	hp->h_addrtype = hent.h_addrtype;
    214 	hp->h_length = hent.h_length;
    215 
    216 	HENT_ARRAY(hp->h_aliases, anum, ptr, len);
    217 	HENT_ARRAY(hp->h_addr_list, num, ptr, len);
    218 
    219 	for (i = 0; i < num; i++)
    220 		HENT_COPY(hp->h_addr_list[i], addr_ptrs[i], hp->h_length, ptr,
    221 		    len);
    222 	hp->h_addr_list[num] = NULL;
    223 
    224 	HENT_SCOPY(hp->h_name, hent.h_name, ptr, len);
    225 
    226 	for (i = 0; i < anum; i++)
    227 		HENT_SCOPY(hp->h_aliases[i], aliases[i], ptr, len);
    228 	hp->h_aliases[anum] = NULL;
    229 
    230 	free(buf);
    231 	return hp;
    232 nospc:
    233 	endhostent_r(&hf);
    234 	*info->he = NETDB_INTERNAL;
    235 	free(buf);
    236 	errno = ENOSPC;
    237 	return NULL;
    238 }
    239 
    240 /*ARGSUSED*/
    241 int
    242 _hf_gethtbyaddr(void *rv, void *cb_data, va_list ap)
    243 {
    244 	struct hostent *hp;
    245 	const unsigned char *addr;
    246 	struct getnamaddr *info = rv;
    247 	FILE *hf;
    248 
    249 	_DIAGASSERT(rv != NULL);
    250 
    251 	addr = va_arg(ap, unsigned char *);
    252 	info->hp->h_length = va_arg(ap, int);
    253 	info->hp->h_addrtype = va_arg(ap, int);
    254 
    255 	hf = NULL;
    256 	sethostent_r(&hf);
    257 	if (hf == NULL) {
    258 		*info->he = NETDB_INTERNAL;
    259 		return NS_UNAVAIL;
    260 	}
    261 	while ((hp = netbsd_gethostent_r(hf, info->hp, info->buf, info->buflen,
    262 	    info->he)) != NULL)
    263 		if (!memcmp(hp->h_addr_list[0], addr, (size_t)hp->h_length))
    264 			break;
    265 	endhostent_r(&hf);
    266 
    267 	if (hp == NULL) {
    268 		if (errno == ENOSPC) {
    269 			return NS_UNAVAIL;
    270 		}
    271 		*info->he = HOST_NOT_FOUND;
    272 		return NS_NOTFOUND;
    273 	}
    274 	return NS_SUCCESS;
    275 }
    276