xref: /freebsd/lib/libc/net/gethostbyht.c (revision 81ad6265)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 1985, 1988, 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  * Portions Copyright (c) 1993 by Digital Equipment Corporation.
32  *
33  * Permission to use, copy, modify, and distribute this software for any
34  * purpose with or without fee is hereby granted, provided that the above
35  * copyright notice and this permission notice appear in all copies, and that
36  * the name of Digital Equipment Corporation not be used in advertising or
37  * publicity pertaining to distribution of the document or software without
38  * specific, written prior permission.
39  *
40  * THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL
41  * WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES
42  * OF MERCHANTABILITY AND FITNESS.   IN NO EVENT SHALL DIGITAL EQUIPMENT
43  * CORPORATION BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
44  * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
45  * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
46  * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
47  * SOFTWARE.
48  * -
49  * --Copyright--
50  */
51 
52 #if defined(LIBC_SCCS) && !defined(lint)
53 static char sccsid[] = "@(#)gethostnamadr.c	8.1 (Berkeley) 6/4/93";
54 #endif /* LIBC_SCCS and not lint */
55 #include <sys/cdefs.h>
56 __FBSDID("$FreeBSD$");
57 
58 #include <sys/param.h>
59 #include <sys/socket.h>
60 #include <netinet/in.h>
61 #include <arpa/inet.h>
62 #include <netdb.h>
63 #include <stdio.h>
64 #include <ctype.h>
65 #include <errno.h>
66 #include <string.h>
67 #include <stdarg.h>
68 #include <nsswitch.h>
69 #include <arpa/nameser.h>	/* XXX */
70 #include <resolv.h>		/* XXX */
71 #include "netdb_private.h"
72 
73 void
74 _sethosthtent(int f, struct hostent_data *hed)
75 {
76 	if (!hed->hostf)
77 		hed->hostf = fopen(_PATH_HOSTS, "re");
78 	else
79 		rewind(hed->hostf);
80 	hed->stayopen = f;
81 }
82 
83 void
84 _endhosthtent(struct hostent_data *hed)
85 {
86 	if (hed->hostf && !hed->stayopen) {
87 		(void) fclose(hed->hostf);
88 		hed->hostf = NULL;
89 	}
90 }
91 
92 static int
93 gethostent_p(struct hostent *he, struct hostent_data *hed, int mapped,
94     res_state statp)
95 {
96 	char *p, *bp, *ep;
97 	char *cp, **q;
98 	int af, len;
99 	char hostbuf[BUFSIZ + 1];
100 
101 	if (!hed->hostf && !(hed->hostf = fopen(_PATH_HOSTS, "re"))) {
102 		RES_SET_H_ERRNO(statp, NETDB_INTERNAL);
103 		return (-1);
104 	}
105  again:
106 	if (!(p = fgets(hostbuf, sizeof hostbuf, hed->hostf))) {
107 		RES_SET_H_ERRNO(statp, HOST_NOT_FOUND);
108 		return (-1);
109 	}
110 	if (*p == '#')
111 		goto again;
112 	cp = strpbrk(p, "#\n");
113 	if (cp != NULL)
114 		*cp = '\0';
115 	if (!(cp = strpbrk(p, " \t")))
116 		goto again;
117 	*cp++ = '\0';
118 	if (inet_pton(AF_INET6, p, hed->host_addr) > 0) {
119 		af = AF_INET6;
120 		len = IN6ADDRSZ;
121 	} else if (inet_pton(AF_INET, p, hed->host_addr) > 0) {
122 		if (mapped) {
123 			_map_v4v6_address((char *)hed->host_addr,
124 			    (char *)hed->host_addr);
125 			af = AF_INET6;
126 			len = IN6ADDRSZ;
127 		} else {
128 			af = AF_INET;
129 			len = INADDRSZ;
130 		}
131 	} else {
132 		goto again;
133 	}
134 	hed->h_addr_ptrs[0] = (char *)hed->host_addr;
135 	hed->h_addr_ptrs[1] = NULL;
136 	he->h_addr_list = hed->h_addr_ptrs;
137 	he->h_length = len;
138 	he->h_addrtype = af;
139 	while (*cp == ' ' || *cp == '\t')
140 		cp++;
141 	bp = hed->hostbuf;
142 	ep = hed->hostbuf + sizeof hed->hostbuf;
143 	he->h_name = bp;
144 	q = he->h_aliases = hed->host_aliases;
145 	if ((p = strpbrk(cp, " \t")) != NULL)
146 		*p++ = '\0';
147 	len = strlen(cp) + 1;
148 	if (ep - bp < len) {
149 		RES_SET_H_ERRNO(statp, NO_RECOVERY);
150 		return (-1);
151 	}
152 	strlcpy(bp, cp, ep - bp);
153 	bp += len;
154 	cp = p;
155 	while (cp && *cp) {
156 		if (*cp == ' ' || *cp == '\t') {
157 			cp++;
158 			continue;
159 		}
160 		if (q >= &hed->host_aliases[_MAXALIASES - 1])
161 			break;
162 		if ((p = strpbrk(cp, " \t")) != NULL)
163 			*p++ = '\0';
164 		len = strlen(cp) + 1;
165 		if (ep - bp < len)
166 			break;
167 		strlcpy(bp, cp, ep - bp);
168 		*q++ = bp;
169 		bp += len;
170 		cp = p;
171 	}
172 	*q = NULL;
173 	RES_SET_H_ERRNO(statp, NETDB_SUCCESS);
174 	return (0);
175 }
176 
177 int
178 gethostent_r(struct hostent *hptr, char *buffer, size_t buflen,
179     struct hostent **result, int *h_errnop)
180 {
181 	struct hostent_data *hed;
182 	struct hostent he;
183 	res_state statp;
184 
185 	statp = __res_state();
186 	if ((statp->options & RES_INIT) == 0 && res_ninit(statp) == -1) {
187 		RES_SET_H_ERRNO(statp, NETDB_INTERNAL);
188 		*h_errnop = statp->res_h_errno;
189 		return (-1);
190 	}
191 	if ((hed = __hostent_data_init()) == NULL) {
192 		RES_SET_H_ERRNO(statp, NETDB_INTERNAL);
193 		*h_errnop = statp->res_h_errno;
194 		return (-1);
195 	}
196 	if (gethostent_p(&he, hed, statp->options & RES_USE_INET6, statp) != 0)
197 		return (-1);
198 	if (__copy_hostent(&he, hptr, buffer, buflen) != 0) {
199 		RES_SET_H_ERRNO(statp, NETDB_INTERNAL);
200 		*h_errnop = statp->res_h_errno;
201 		return ((errno != 0) ? errno : -1);
202 	}
203 	*result = hptr;
204 	return (0);
205 }
206 
207 struct hostent *
208 gethostent(void)
209 {
210 	struct hostdata *hd;
211 	struct hostent *rval;
212 	int ret_h_errno;
213 
214 	if ((hd = __hostdata_init()) == NULL)
215 		return (NULL);
216 	if (gethostent_r(&hd->host, hd->data, sizeof(hd->data), &rval,
217 	    &ret_h_errno) != 0)
218 		return (NULL);
219 	return (rval);
220 }
221 
222 int
223 _ht_gethostbyname(void *rval, void *cb_data, va_list ap)
224 {
225 	const char *name;
226 	int af;
227 	char *buffer;
228 	size_t buflen;
229 	int *errnop, *h_errnop;
230 	struct hostent *hptr, he;
231 	struct hostent_data *hed;
232 	char **cp;
233 	res_state statp;
234 	int error;
235 
236 	name = va_arg(ap, const char *);
237 	af = va_arg(ap, int);
238 	hptr = va_arg(ap, struct hostent *);
239 	buffer = va_arg(ap, char *);
240 	buflen = va_arg(ap, size_t);
241 	errnop = va_arg(ap, int *);
242 	h_errnop = va_arg(ap, int *);
243 
244 	*((struct hostent **)rval) = NULL;
245 
246 	statp = __res_state();
247 	if ((hed = __hostent_data_init()) == NULL) {
248 		RES_SET_H_ERRNO(statp, NETDB_INTERNAL);
249 		*h_errnop = statp->res_h_errno;
250 		return (NS_NOTFOUND);
251 	}
252 
253 	_sethosthtent(0, hed);
254 	while ((error = gethostent_p(&he, hed, 0, statp)) == 0) {
255 		if (he.h_addrtype != af)
256 			continue;
257 		if (he.h_addrtype == AF_INET &&
258 		    statp->options & RES_USE_INET6) {
259 			_map_v4v6_address(he.h_addr, he.h_addr);
260 			he.h_length = IN6ADDRSZ;
261 			he.h_addrtype = AF_INET6;
262 		}
263 		if (strcasecmp(he.h_name, name) == 0)
264 			break;
265 		for (cp = he.h_aliases; *cp != 0; cp++)
266 			if (strcasecmp(*cp, name) == 0)
267 				goto found;
268 	}
269 found:
270 	_endhosthtent(hed);
271 
272 	if (error != 0) {
273 		*h_errnop = statp->res_h_errno;
274 		return (NS_NOTFOUND);
275 	}
276 	if (__copy_hostent(&he, hptr, buffer, buflen) != 0) {
277 		*errnop = errno;
278 		RES_SET_H_ERRNO(statp, NETDB_INTERNAL);
279 		*h_errnop = statp->res_h_errno;
280 		return (NS_RETURN);
281 	}
282 	*((struct hostent **)rval) = hptr;
283 	return (NS_SUCCESS);
284 }
285 
286 int
287 _ht_gethostbyaddr(void *rval, void *cb_data, va_list ap)
288 {
289 	const void *addr;
290 	socklen_t len;
291 	int af;
292 	char *buffer;
293 	size_t buflen;
294 	int *errnop, *h_errnop;
295 	struct hostent *hptr, he;
296 	struct hostent_data *hed;
297 	res_state statp;
298 	int error;
299 
300 	addr = va_arg(ap, const void *);
301 	len = va_arg(ap, socklen_t);
302 	af = va_arg(ap, int);
303 	hptr = va_arg(ap, struct hostent *);
304 	buffer = va_arg(ap, char *);
305 	buflen = va_arg(ap, size_t);
306 	errnop = va_arg(ap, int *);
307 	h_errnop = va_arg(ap, int *);
308 
309 	*((struct hostent **)rval) = NULL;
310 
311 	statp = __res_state();
312 	if ((hed = __hostent_data_init()) == NULL) {
313 		RES_SET_H_ERRNO(statp, NETDB_INTERNAL);
314 		*h_errnop = statp->res_h_errno;
315 		return (NS_NOTFOUND);
316 	}
317 
318 	_sethosthtent(0, hed);
319 	while ((error = gethostent_p(&he, hed, 0, statp)) == 0)
320 		if (he.h_addrtype == af && !bcmp(he.h_addr, addr, len)) {
321 			if (he.h_addrtype == AF_INET &&
322 			    statp->options & RES_USE_INET6) {
323 				_map_v4v6_address(he.h_addr, he.h_addr);
324 				he.h_length = IN6ADDRSZ;
325 				he.h_addrtype = AF_INET6;
326 			}
327 			break;
328 		}
329 	_endhosthtent(hed);
330 
331 	if (error != 0)
332 		return (NS_NOTFOUND);
333 	if (__copy_hostent(&he, hptr, buffer, buflen) != 0) {
334 		*errnop = errno;
335 		RES_SET_H_ERRNO(statp, NETDB_INTERNAL);
336 		*h_errnop = statp->res_h_errno;
337 		return (NS_RETURN);
338 	}
339 	*((struct hostent **)rval) = hptr;
340 	return (NS_SUCCESS);
341 }
342