xref: /freebsd/lib/libc/net/gethostbynis.c (revision 8ddb146abcdf061be9f2c0db7e391697dafad85c)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 1994, Garrett Wollman
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE CONTRIBUTORS ``AS IS'' AND
16  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
19  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25  * SUCH DAMAGE.
26  */
27 
28 #include <sys/cdefs.h>
29 __FBSDID("$FreeBSD$");
30 
31 #include <sys/param.h>
32 #include <sys/socket.h>
33 #include <netinet/in.h>
34 #include <arpa/inet.h>
35 #include <arpa/nameser.h>
36 #include <netdb.h>
37 #include <stdio.h>
38 #include <stdlib.h>
39 #include <ctype.h>
40 #include <errno.h>
41 #include <string.h>
42 #include <stdarg.h>
43 #include <nsswitch.h>
44 #include <resolv.h>		/* XXX */
45 #ifdef YP
46 #include <rpc/rpc.h>
47 #include <rpcsvc/yp_prot.h>
48 #include <rpcsvc/ypclnt.h>
49 #endif
50 #include "netdb_private.h"
51 
52 #ifdef YP
53 static int
54 _gethostbynis(const char *name, char *map, int af, struct hostent *he,
55     struct hostent_data *hed)
56 {
57 	char *p, *bp, *ep;
58 	char *cp, **q;
59 	char *result;
60 	int resultlen, size, addrok = 0;
61 	char *ypbuf;
62 	res_state statp;
63 
64 	statp = __res_state();
65 	switch(af) {
66 	case AF_INET:
67 		size = NS_INADDRSZ;
68 		break;
69 	case AF_INET6:
70 		size = NS_IN6ADDRSZ;
71 		break;
72 	default:
73 		errno = EAFNOSUPPORT;
74 		RES_SET_H_ERRNO(statp, NETDB_INTERNAL);
75 		return (-1);
76 	}
77 
78 	if (hed->yp_domain == (char *)NULL)
79 		if (yp_get_default_domain (&hed->yp_domain)) {
80 			RES_SET_H_ERRNO(statp, NETDB_INTERNAL);
81 			return (-1);
82 		}
83 
84 	if (yp_match(hed->yp_domain, map, name, strlen(name), &result,
85 	    &resultlen)) {
86 		RES_SET_H_ERRNO(statp, HOST_NOT_FOUND);
87 		return (-1);
88 	}
89 
90 	/* avoid potential memory leak */
91 	ypbuf = alloca(resultlen + 2);
92 	bcopy(result, ypbuf, resultlen);
93 	ypbuf[resultlen] = '\0';
94 	free(result);
95 	result = ypbuf;
96 
97 	if ((cp = strchr(result, '\n')))
98 		*cp = '\0';
99 
100 	cp = strpbrk(result, " \t");
101 	*cp++ = '\0';
102 	he->h_addr_list = hed->h_addr_ptrs;
103 	he->h_addr = (char *)hed->host_addr;
104 	switch (af) {
105 	case AF_INET:
106 		addrok = inet_aton(result, (struct in_addr *)hed->host_addr);
107 		if (addrok != 1)
108 			break;
109 		if (statp->options & RES_USE_INET6) {
110 			_map_v4v6_address((char *)hed->host_addr,
111 			    (char *)hed->host_addr);
112 			af = AF_INET6;
113 			size = NS_IN6ADDRSZ;
114 		}
115 		break;
116 	case AF_INET6:
117 		addrok = inet_pton(af, result, hed->host_addr);
118 		break;
119 	}
120 	if (addrok != 1) {
121 		RES_SET_H_ERRNO(statp, HOST_NOT_FOUND);
122 		return (-1);
123 	}
124 	he->h_addr_list[1] = NULL;
125 	he->h_length = size;
126 	he->h_addrtype = af;
127 	while (*cp == ' ' || *cp == '\t')
128 		cp++;
129 	bp = hed->hostbuf;
130 	ep = hed->hostbuf + sizeof hed->hostbuf;
131 	he->h_name = bp;
132 	q = he->h_aliases = hed->host_aliases;
133 	p = strpbrk(cp, " \t");
134 	if (p != NULL)
135 		*p++ = '\0';
136 	size = strlen(cp) + 1;
137 	if (ep - bp < size) {
138 		RES_SET_H_ERRNO(statp, NO_RECOVERY);
139 		return (-1);
140 	}
141 	strlcpy(bp, cp, ep - bp);
142 	bp += size;
143 	cp = p;
144 	while (cp && *cp) {
145 		if (*cp == ' ' || *cp == '\t') {
146 			cp++;
147 			continue;
148 		}
149 		if (q >= &hed->host_aliases[_MAXALIASES - 1])
150 			break;
151 		p = strpbrk(cp, " \t");
152 		if (p != NULL)
153 			*p++ = '\0';
154 		size = strlen(cp) + 1;
155 		if (ep - bp < size)
156 			break;
157 		strlcpy(bp, cp, ep - bp);
158 		*q++ = bp;
159 		bp += size;
160 		cp = p;
161 	}
162 	*q = NULL;
163 	return (0);
164 }
165 
166 static int
167 _gethostbynisname_r(const char *name, int af, struct hostent *he,
168     struct hostent_data *hed)
169 {
170 	char *map;
171 
172 	switch (af) {
173 	case AF_INET:
174 		map = "hosts.byname";
175 		break;
176 	default:
177 		map = "ipnodes.byname";
178 		break;
179 	}
180 	return (_gethostbynis(name, map, af, he, hed));
181 }
182 
183 static int
184 _gethostbynisaddr_r(const void *addr, socklen_t len, int af,
185     struct hostent *he, struct hostent_data *hed)
186 {
187 	char *map;
188 	char numaddr[46];
189 
190 	switch (af) {
191 	case AF_INET:
192 		map = "hosts.byaddr";
193 		break;
194 	default:
195 		map = "ipnodes.byaddr";
196 		break;
197 	}
198 	if (inet_ntop(af, addr, numaddr, sizeof(numaddr)) == NULL)
199 		return (-1);
200 	return (_gethostbynis(numaddr, map, af, he, hed));
201 }
202 #endif /* YP */
203 
204 int
205 _nis_gethostbyname(void *rval, void *cb_data, va_list ap)
206 {
207 #ifdef YP
208 	const char *name;
209 	int af;
210 	char *buffer;
211 	size_t buflen;
212 	int *errnop, *h_errnop;
213 	struct hostent *hptr, he;
214 	struct hostent_data *hed;
215 	res_state statp;
216 
217 	name = va_arg(ap, const char *);
218 	af = va_arg(ap, int);
219 	hptr = va_arg(ap, struct hostent *);
220 	buffer = va_arg(ap, char *);
221 	buflen = va_arg(ap, size_t);
222 	errnop = va_arg(ap, int *);
223 	h_errnop = va_arg(ap, int *);
224 
225 	*((struct hostent **)rval) = NULL;
226 
227 	statp = __res_state();
228 	if ((hed = __hostent_data_init()) == NULL) {
229 		RES_SET_H_ERRNO(statp, NETDB_INTERNAL);
230 		*h_errnop = statp->res_h_errno;
231 		return (NS_NOTFOUND);
232 	}
233 
234 	if (_gethostbynisname_r(name, af, &he, hed) != 0) {
235 		*h_errnop = statp->res_h_errno;
236 		return (NS_NOTFOUND);
237 	}
238 	if (__copy_hostent(&he, hptr, buffer, buflen) != 0) {
239 		*errnop = errno;
240 		RES_SET_H_ERRNO(statp, NETDB_INTERNAL);
241 		*h_errnop = statp->res_h_errno;
242 		return (NS_RETURN);
243 	}
244 	*((struct hostent **)rval) = hptr;
245 	return (NS_SUCCESS);
246 #else
247 	*((struct hostent **)rval) = NULL;
248 	return (NS_UNAVAIL);
249 #endif
250 }
251 
252 int
253 _nis_gethostbyaddr(void *rval, void *cb_data, va_list ap)
254 {
255 #ifdef YP
256 	const void *addr;
257 	socklen_t len;
258 	int af;
259 	char *buffer;
260 	size_t buflen;
261 	int *errnop, *h_errnop;
262 	struct hostent *hptr, he;
263 	struct hostent_data *hed;
264 	res_state statp;
265 
266 	addr = va_arg(ap, const void *);
267 	len = va_arg(ap, socklen_t);
268 	af = va_arg(ap, int);
269 	hptr = va_arg(ap, struct hostent *);
270 	buffer = va_arg(ap, char *);
271 	buflen = va_arg(ap, size_t);
272 	errnop = va_arg(ap, int *);
273 	h_errnop = va_arg(ap, int *);
274 
275 	*((struct hostent **)rval) = NULL;
276 
277 	statp = __res_state();
278 	if ((hed = __hostent_data_init()) == NULL) {
279 		RES_SET_H_ERRNO(statp, NETDB_INTERNAL);
280 		*h_errnop = statp->res_h_errno;
281 		return (NS_NOTFOUND);
282 	}
283 
284 	if (_gethostbynisaddr_r(addr, len, af, &he, hed) != 0) {
285 		*h_errnop = statp->res_h_errno;
286 		return (NS_NOTFOUND);
287 	}
288 	if (__copy_hostent(&he, hptr, buffer, buflen) != 0) {
289 		*errnop = errno;
290 		RES_SET_H_ERRNO(statp, NETDB_INTERNAL);
291 		*h_errnop = statp->res_h_errno;
292 		return (NS_RETURN);
293 	}
294 	*((struct hostent **)rval) = hptr;
295 	return (NS_SUCCESS);
296 #else
297 	*((struct hostent **)rval) = NULL;
298 	return (NS_UNAVAIL);
299 #endif
300 }
301