xref: /freebsd/lib/libc/net/gethostbyht.c (revision 7773002178c8dbc52b44e4d705f07706409af8e4)
1 /*-
2  * Copyright (c) 1985, 1988, 1993
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. All advertising materials mentioning features or use of this software
14  *    must display the following acknowledgement:
15  *	This product includes software developed by the University of
16  *	California, Berkeley and its contributors.
17  * 4. Neither the name of the University nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  * -
33  * Portions Copyright (c) 1993 by Digital Equipment Corporation.
34  *
35  * Permission to use, copy, modify, and distribute this software for any
36  * purpose with or without fee is hereby granted, provided that the above
37  * copyright notice and this permission notice appear in all copies, and that
38  * the name of Digital Equipment Corporation not be used in advertising or
39  * publicity pertaining to distribution of the document or software without
40  * specific, written prior permission.
41  *
42  * THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL
43  * WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES
44  * OF MERCHANTABILITY AND FITNESS.   IN NO EVENT SHALL DIGITAL EQUIPMENT
45  * CORPORATION BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
46  * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
47  * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
48  * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
49  * SOFTWARE.
50  * -
51  * --Copyright--
52  */
53 
54 #if defined(LIBC_SCCS) && !defined(lint)
55 static char sccsid[] = "@(#)gethostnamadr.c	8.1 (Berkeley) 6/4/93";
56 #endif /* LIBC_SCCS and not lint */
57 #include <sys/cdefs.h>
58 __FBSDID("$FreeBSD$");
59 
60 #include <sys/param.h>
61 #include <sys/socket.h>
62 #include <netinet/in.h>
63 #include <arpa/inet.h>
64 #include <netdb.h>
65 #include <stdio.h>
66 #include <ctype.h>
67 #include <string.h>
68 #include <stdarg.h>
69 #include <nsswitch.h>
70 #include <arpa/nameser.h>	/* XXX */
71 #include <resolv.h>		/* XXX */
72 
73 #define	MAXALIASES	35
74 
75 static struct hostent host;
76 static char *host_aliases[MAXALIASES];
77 static char hostbuf[BUFSIZ+1];
78 static FILE *hostf = NULL;
79 static u_int32_t host_addr[4];	/* IPv4 or IPv6 */
80 static char *h_addr_ptrs[2];
81 static int stayopen = 0;
82 
83 void
84 _sethosthtent(f)
85 	int f;
86 {
87 	if (!hostf)
88 		hostf = fopen(_PATH_HOSTS, "r" );
89 	else
90 		rewind(hostf);
91 	stayopen = f;
92 }
93 
94 void
95 _endhosthtent()
96 {
97 	if (hostf && !stayopen) {
98 		(void) fclose(hostf);
99 		hostf = NULL;
100 	}
101 }
102 
103 struct hostent *
104 gethostent()
105 {
106 	char *p;
107 	char *cp, **q;
108 	int af, len;
109 
110 	if (!hostf && !(hostf = fopen(_PATH_HOSTS, "r" ))) {
111 		h_errno = NETDB_INTERNAL;
112 		return (NULL);
113 	}
114  again:
115 	if (!(p = fgets(hostbuf, sizeof hostbuf, hostf))) {
116 		h_errno = HOST_NOT_FOUND;
117 		return (NULL);
118 	}
119 	if (*p == '#')
120 		goto again;
121 	if (!(cp = strpbrk(p, "#\n")))
122 		goto again;
123 	*cp = '\0';
124 	if (!(cp = strpbrk(p, " \t")))
125 		goto again;
126 	*cp++ = '\0';
127 	if (inet_pton(AF_INET6, p, host_addr) > 0) {
128 		af = AF_INET6;
129 		len = IN6ADDRSZ;
130 	} else if (inet_pton(AF_INET, p, host_addr) > 0) {
131 		if (_res.options & RES_USE_INET6) {
132 			_map_v4v6_address((char*)host_addr, (char*)host_addr);
133 			af = AF_INET6;
134 			len = IN6ADDRSZ;
135 		} else {
136 			af = AF_INET;
137 			len = INADDRSZ;
138 		}
139 	} else {
140 		goto again;
141 	}
142 	h_addr_ptrs[0] = (char *)host_addr;
143 	h_addr_ptrs[1] = NULL;
144 	host.h_addr_list = h_addr_ptrs;
145 	host.h_length = len;
146 	host.h_addrtype = af;
147 	while (*cp == ' ' || *cp == '\t')
148 		cp++;
149 	host.h_name = cp;
150 	q = host.h_aliases = host_aliases;
151 	if ((cp = strpbrk(cp, " \t")) != NULL)
152 		*cp++ = '\0';
153 	while (cp && *cp) {
154 		if (*cp == ' ' || *cp == '\t') {
155 			cp++;
156 			continue;
157 		}
158 		if (q < &host_aliases[MAXALIASES - 1])
159 			*q++ = cp;
160 		if ((cp = strpbrk(cp, " \t")) != NULL)
161 			*cp++ = '\0';
162 	}
163 	*q = NULL;
164 	h_errno = NETDB_SUCCESS;
165 	return (&host);
166 }
167 
168 int
169 _ht_gethostbyname(void *rval, void *cb_data, va_list ap)
170 {
171 	const char *name;
172 	int af;
173 	struct hostent *p;
174 	char **cp;
175 
176 	name = va_arg(ap, const char *);
177 	af = va_arg(ap, int);
178 
179 	sethostent(0);
180 	while ((p = gethostent()) != NULL) {
181 		if (p->h_addrtype != af)
182 			continue;
183 		if (strcasecmp(p->h_name, name) == 0)
184 			break;
185 		for (cp = p->h_aliases; *cp != 0; cp++)
186 			if (strcasecmp(*cp, name) == 0)
187 				goto found;
188 	}
189 found:
190 	endhostent();
191 	*(struct hostent **)rval = p;
192 
193 	return (p != NULL) ? NS_SUCCESS : NS_NOTFOUND;
194 }
195 
196 int
197 _ht_gethostbyaddr(void *rval, void *cb_data, va_list ap)
198 {
199 	const char *addr;
200 	int len, af;
201 	struct hostent *p;
202 
203 	addr = va_arg(ap, const char *);
204 	len = va_arg(ap, int);
205 	af = va_arg(ap, int);
206 
207 	sethostent(0);
208 	while ((p = gethostent()) != NULL)
209 		if (p->h_addrtype == af && !bcmp(p->h_addr, addr, len))
210 			break;
211 	endhostent();
212 
213 	*(struct hostent **)rval = p;
214 	return (p != NULL) ? NS_SUCCESS : NS_NOTFOUND;
215 }
216