1 /* $NetBSD: sethostent.c,v 1.21 2023/12/07 22:33:49 kre 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 1.21 2023/12/07 22:33:49 kre 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*/
sethostent(int stayopen)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
endhostent(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
_hf_sethostsfile(const char * f)93 _hf_sethostsfile(const char *f) {
94 _h_hosts = f;
95 }
96
97 void
sethostent_r(FILE ** hf)98 sethostent_r(FILE **hf)
99 {
100 if (!*hf)
101 *hf = fopen(_h_hosts, "re");
102 else
103 rewind(*hf);
104 }
105
106 void
endhostent_r(FILE ** hf)107 endhostent_r(FILE **hf)
108 {
109 if (*hf) {
110 (void)fclose(*hf);
111 *hf = NULL;
112 }
113 }
114
115 /*ARGSUSED*/
116 int
_hf_gethtbyname(void * rv,void * cb_data,va_list ap)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 *
_hf_gethtbyname2(const char * name,int af,struct getnamaddr * info)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 endhostent_r(&hf);
175 *info->he = NETDB_INTERNAL;
176 return NULL;
177 }
178
179 anum = 0; /* XXX: gcc */
180 hent.h_name = NULL; /* XXX: gcc */
181 hent.h_addrtype = 0; /* XXX: gcc */
182 hent.h_length = 0; /* XXX: gcc */
183
184 for (num = 0; num < MAXADDRS;) {
185 info->hp->h_addrtype = af;
186 info->hp->h_length = 0;
187
188 hp = gethostent_r(hf, info->hp, info->buf, info->buflen,
189 info->he);
190 if (hp == NULL)
191 break;
192
193 if (strcasecmp(hp->h_name, name) != 0) {
194 char **cp;
195 for (cp = hp->h_aliases; *cp != NULL; cp++)
196 if (strcasecmp(*cp, name) == 0)
197 break;
198 if (*cp == NULL) continue;
199 }
200
201 if (num == 0) {
202 hent.h_addrtype = af = hp->h_addrtype;
203 hent.h_length = hp->h_length;
204
205 HENT_SCOPY(hent.h_name, hp->h_name, ptr, len);
206 for (anum = 0; hp->h_aliases[anum]; anum++) {
207 if (anum >= __arraycount(aliases))
208 goto nospc;
209 HENT_SCOPY(aliases[anum], hp->h_aliases[anum],
210 ptr, len);
211 }
212 ptr = (void *)ALIGN(ptr);
213 if ((size_t)(ptr - buf) >= info->buflen)
214 goto nospc;
215 }
216
217 if (num >= __arraycount(addr_ptrs))
218 goto nospc;
219 HENT_COPY(addr_ptrs[num], hp->h_addr_list[0], hp->h_length, ptr,
220 len);
221 num++;
222 }
223 endhostent_r(&hf);
224
225 if (num == 0) {
226 *info->he = HOST_NOT_FOUND;
227 free(buf);
228 return NULL;
229 }
230
231 hp = info->hp;
232 ptr = info->buf;
233 len = info->buflen;
234
235 hp->h_addrtype = hent.h_addrtype;
236 hp->h_length = hent.h_length;
237
238 HENT_ARRAY(hp->h_aliases, anum, ptr, len);
239 HENT_ARRAY(hp->h_addr_list, num, ptr, len);
240
241 for (i = 0; i < num; i++)
242 HENT_COPY(hp->h_addr_list[i], addr_ptrs[i], hp->h_length, ptr,
243 len);
244 hp->h_addr_list[num] = NULL;
245
246 HENT_SCOPY(hp->h_name, hent.h_name, ptr, len);
247
248 for (i = 0; i < anum; i++)
249 HENT_SCOPY(hp->h_aliases[i], aliases[i], ptr, len);
250 hp->h_aliases[anum] = NULL;
251
252 free(buf);
253 return hp;
254 nospc:
255 endhostent_r(&hf);
256 *info->he = NETDB_INTERNAL;
257 free(buf);
258 errno = ENOSPC;
259 return NULL;
260 }
261
262 /*ARGSUSED*/
263 int
_hf_gethtbyaddr(void * rv,void * cb_data,va_list ap)264 _hf_gethtbyaddr(void *rv, void *cb_data, va_list ap)
265 {
266 struct hostent *hp;
267 const unsigned char *addr;
268 struct getnamaddr *info = rv;
269 FILE *hf;
270
271 _DIAGASSERT(rv != NULL);
272
273 addr = va_arg(ap, unsigned char *);
274 info->hp->h_length = va_arg(ap, int);
275 info->hp->h_addrtype = va_arg(ap, int);
276
277 hf = NULL;
278 sethostent_r(&hf);
279 if (hf == NULL) {
280 *info->he = NETDB_INTERNAL;
281 return NS_UNAVAIL;
282 }
283 while ((hp = gethostent_r(hf, info->hp, info->buf, info->buflen,
284 info->he)) != NULL)
285 if (!memcmp(hp->h_addr_list[0], addr, (size_t)hp->h_length))
286 break;
287 endhostent_r(&hf);
288
289 if (hp == NULL) {
290 *info->he = HOST_NOT_FOUND;
291 return NS_NOTFOUND;
292 }
293 return NS_SUCCESS;
294 }
295