xref: /freebsd/lib/libc/net/gethostbynis.c (revision 4c9a0adad18263ec8725d9bfc5f560c6ad1da8bd)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
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/param.h>
29 #include <sys/socket.h>
30 #include <netinet/in.h>
31 #include <arpa/inet.h>
32 #include <arpa/nameser.h>
33 #include <netdb.h>
34 #include <stdio.h>
35 #include <stdlib.h>
36 #include <ctype.h>
37 #include <errno.h>
38 #include <string.h>
39 #include <stdarg.h>
40 #include <nsswitch.h>
41 #include <resolv.h>		/* XXX */
42 #ifdef YP
43 #include <rpc/rpc.h>
44 #include <rpcsvc/yp_prot.h>
45 #include <rpcsvc/ypclnt.h>
46 #endif
47 #include "netdb_private.h"
48 
49 #ifdef YP
50 static int
51 _gethostbynis(const char *name, char *map, int af, struct hostent *he,
52     struct hostent_data *hed)
53 {
54 	char *p, *bp, *ep;
55 	char *cp, **q;
56 	char *result;
57 	int resultlen, size, addrok = 0;
58 	char *ypbuf;
59 	res_state statp;
60 
61 	statp = __res_state();
62 	switch(af) {
63 	case AF_INET:
64 		size = NS_INADDRSZ;
65 		break;
66 	case AF_INET6:
67 		size = NS_IN6ADDRSZ;
68 		break;
69 	default:
70 		errno = EAFNOSUPPORT;
71 		RES_SET_H_ERRNO(statp, NETDB_INTERNAL);
72 		return (-1);
73 	}
74 
75 	if (hed->yp_domain == (char *)NULL)
76 		if (yp_get_default_domain (&hed->yp_domain)) {
77 			RES_SET_H_ERRNO(statp, NETDB_INTERNAL);
78 			return (-1);
79 		}
80 
81 	if (yp_match(hed->yp_domain, map, name, strlen(name), &result,
82 	    &resultlen)) {
83 		RES_SET_H_ERRNO(statp, HOST_NOT_FOUND);
84 		return (-1);
85 	}
86 
87 	/* avoid potential memory leak */
88 	ypbuf = alloca(resultlen + 2);
89 	bcopy(result, ypbuf, resultlen);
90 	ypbuf[resultlen] = '\0';
91 	free(result);
92 	result = ypbuf;
93 
94 	if ((cp = strchr(result, '\n')))
95 		*cp = '\0';
96 
97 	cp = strpbrk(result, " \t");
98 	*cp++ = '\0';
99 	he->h_addr_list = hed->h_addr_ptrs;
100 	he->h_addr = (char *)hed->host_addr;
101 	switch (af) {
102 	case AF_INET:
103 		addrok = inet_aton(result, (struct in_addr *)hed->host_addr);
104 		if (addrok != 1)
105 			break;
106 		if (statp->options & RES_USE_INET6) {
107 			_map_v4v6_address((char *)hed->host_addr,
108 			    (char *)hed->host_addr);
109 			af = AF_INET6;
110 			size = NS_IN6ADDRSZ;
111 		}
112 		break;
113 	case AF_INET6:
114 		addrok = inet_pton(af, result, hed->host_addr);
115 		break;
116 	}
117 	if (addrok != 1) {
118 		RES_SET_H_ERRNO(statp, HOST_NOT_FOUND);
119 		return (-1);
120 	}
121 	he->h_addr_list[1] = NULL;
122 	he->h_length = size;
123 	he->h_addrtype = af;
124 	while (*cp == ' ' || *cp == '\t')
125 		cp++;
126 	bp = hed->hostbuf;
127 	ep = hed->hostbuf + sizeof hed->hostbuf;
128 	he->h_name = bp;
129 	q = he->h_aliases = hed->host_aliases;
130 	p = strpbrk(cp, " \t");
131 	if (p != NULL)
132 		*p++ = '\0';
133 	size = strlen(cp) + 1;
134 	if (ep - bp < size) {
135 		RES_SET_H_ERRNO(statp, NO_RECOVERY);
136 		return (-1);
137 	}
138 	strlcpy(bp, cp, ep - bp);
139 	bp += size;
140 	cp = p;
141 	while (cp && *cp) {
142 		if (*cp == ' ' || *cp == '\t') {
143 			cp++;
144 			continue;
145 		}
146 		if (q >= &hed->host_aliases[_MAXALIASES - 1])
147 			break;
148 		p = strpbrk(cp, " \t");
149 		if (p != NULL)
150 			*p++ = '\0';
151 		size = strlen(cp) + 1;
152 		if (ep - bp < size)
153 			break;
154 		strlcpy(bp, cp, ep - bp);
155 		*q++ = bp;
156 		bp += size;
157 		cp = p;
158 	}
159 	*q = NULL;
160 	return (0);
161 }
162 
163 static int
164 _gethostbynisname_r(const char *name, int af, struct hostent *he,
165     struct hostent_data *hed)
166 {
167 	char *map;
168 
169 	switch (af) {
170 	case AF_INET:
171 		map = "hosts.byname";
172 		break;
173 	default:
174 		map = "ipnodes.byname";
175 		break;
176 	}
177 	return (_gethostbynis(name, map, af, he, hed));
178 }
179 
180 static int
181 _gethostbynisaddr_r(const void *addr, socklen_t len, int af,
182     struct hostent *he, struct hostent_data *hed)
183 {
184 	char *map;
185 	char numaddr[46];
186 
187 	switch (af) {
188 	case AF_INET:
189 		map = "hosts.byaddr";
190 		break;
191 	default:
192 		map = "ipnodes.byaddr";
193 		break;
194 	}
195 	if (inet_ntop(af, addr, numaddr, sizeof(numaddr)) == NULL)
196 		return (-1);
197 	return (_gethostbynis(numaddr, map, af, he, hed));
198 }
199 #endif /* YP */
200 
201 int
202 _nis_gethostbyname(void *rval, void *cb_data, va_list ap)
203 {
204 #ifdef YP
205 	const char *name;
206 	int af;
207 	char *buffer;
208 	size_t buflen;
209 	int *errnop, *h_errnop;
210 	struct hostent *hptr, he;
211 	struct hostent_data *hed;
212 	res_state statp;
213 
214 	name = va_arg(ap, const char *);
215 	af = va_arg(ap, int);
216 	hptr = va_arg(ap, struct hostent *);
217 	buffer = va_arg(ap, char *);
218 	buflen = va_arg(ap, size_t);
219 	errnop = va_arg(ap, int *);
220 	h_errnop = va_arg(ap, int *);
221 
222 	*((struct hostent **)rval) = NULL;
223 
224 	statp = __res_state();
225 	if ((hed = __hostent_data_init()) == NULL) {
226 		RES_SET_H_ERRNO(statp, NETDB_INTERNAL);
227 		*h_errnop = statp->res_h_errno;
228 		return (NS_NOTFOUND);
229 	}
230 
231 	if (_gethostbynisname_r(name, af, &he, hed) != 0) {
232 		*h_errnop = statp->res_h_errno;
233 		return (NS_NOTFOUND);
234 	}
235 	if (__copy_hostent(&he, hptr, buffer, buflen) != 0) {
236 		*errnop = errno;
237 		RES_SET_H_ERRNO(statp, NETDB_INTERNAL);
238 		*h_errnop = statp->res_h_errno;
239 		return (NS_RETURN);
240 	}
241 	*((struct hostent **)rval) = hptr;
242 	return (NS_SUCCESS);
243 #else
244 	*((struct hostent **)rval) = NULL;
245 	return (NS_UNAVAIL);
246 #endif
247 }
248 
249 int
250 _nis_gethostbyaddr(void *rval, void *cb_data, va_list ap)
251 {
252 #ifdef YP
253 	const void *addr;
254 	socklen_t len;
255 	int af;
256 	char *buffer;
257 	size_t buflen;
258 	int *errnop, *h_errnop;
259 	struct hostent *hptr, he;
260 	struct hostent_data *hed;
261 	res_state statp;
262 
263 	addr = va_arg(ap, const void *);
264 	len = va_arg(ap, socklen_t);
265 	af = va_arg(ap, int);
266 	hptr = va_arg(ap, struct hostent *);
267 	buffer = va_arg(ap, char *);
268 	buflen = va_arg(ap, size_t);
269 	errnop = va_arg(ap, int *);
270 	h_errnop = va_arg(ap, int *);
271 
272 	*((struct hostent **)rval) = NULL;
273 
274 	statp = __res_state();
275 	if ((hed = __hostent_data_init()) == NULL) {
276 		RES_SET_H_ERRNO(statp, NETDB_INTERNAL);
277 		*h_errnop = statp->res_h_errno;
278 		return (NS_NOTFOUND);
279 	}
280 
281 	if (_gethostbynisaddr_r(addr, len, af, &he, hed) != 0) {
282 		*h_errnop = statp->res_h_errno;
283 		return (NS_NOTFOUND);
284 	}
285 	if (__copy_hostent(&he, hptr, buffer, buflen) != 0) {
286 		*errnop = errno;
287 		RES_SET_H_ERRNO(statp, NETDB_INTERNAL);
288 		*h_errnop = statp->res_h_errno;
289 		return (NS_RETURN);
290 	}
291 	*((struct hostent **)rval) = hptr;
292 	return (NS_SUCCESS);
293 #else
294 	*((struct hostent **)rval) = NULL;
295 	return (NS_UNAVAIL);
296 #endif
297 }
298