xref: /freebsd/lib/libc/net/gethostbyht.c (revision ce834215a70ff69e7e222827437116eee2f9ac6f)
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 static char rcsid[] = "$Id: gethostbyht.c,v 1.9 1997/02/22 15:00:07 peter Exp $";
57 #endif /* LIBC_SCCS and not lint */
58 
59 #include <sys/param.h>
60 #include <sys/socket.h>
61 #include <netinet/in.h>
62 #include <arpa/inet.h>
63 #include <netdb.h>
64 #include <stdio.h>
65 #include <ctype.h>
66 #include <errno.h>
67 #include <string.h>
68 #include <arpa/nameser.h>	/* XXX */
69 #include <resolv.h>		/* XXX */
70 
71 #define	MAXALIASES	35
72 
73 static struct hostent host;
74 static char *host_aliases[MAXALIASES];
75 static char hostbuf[BUFSIZ+1];
76 static FILE *hostf = NULL;
77 static u_char host_addr[16];	/* IPv4 or IPv6 */
78 static char *h_addr_ptrs[2];
79 static int stayopen = 0;
80 
81 void
82 _sethosthtent(f)
83 	int f;
84 {
85 	if (!hostf)
86 		hostf = fopen(_PATH_HOSTS, "r" );
87 	else
88 		rewind(hostf);
89 	stayopen = f;
90 }
91 
92 void
93 _endhosthtent()
94 {
95 	if (hostf && !stayopen) {
96 		(void) fclose(hostf);
97 		hostf = NULL;
98 	}
99 }
100 
101 struct hostent *
102 gethostent()
103 {
104 	char *p;
105 	register char *cp, **q;
106 	int af, len;
107 
108 	if (!hostf && !(hostf = fopen(_PATH_HOSTS, "r" ))) {
109 		h_errno = NETDB_INTERNAL;
110 		return (NULL);
111 	}
112  again:
113 	if (!(p = fgets(hostbuf, sizeof hostbuf, hostf))) {
114 		h_errno = HOST_NOT_FOUND;
115 		return (NULL);
116 	}
117 	if (*p == '#')
118 		goto again;
119 	if (!(cp = strpbrk(p, "#\n")))
120 		goto again;
121 	*cp = '\0';
122 	if (!(cp = strpbrk(p, " \t")))
123 		goto again;
124 	*cp++ = '\0';
125 	if (inet_pton(AF_INET6, p, host_addr) > 0) {
126 		af = AF_INET6;
127 		len = IN6ADDRSZ;
128 	} else if (inet_pton(AF_INET, p, host_addr) > 0) {
129 		if (_res.options & RES_USE_INET6) {
130 			_map_v4v6_address((char*)host_addr, (char*)host_addr);
131 			af = AF_INET6;
132 			len = IN6ADDRSZ;
133 		} else {
134 			af = AF_INET;
135 			len = INADDRSZ;
136 		}
137 	} else {
138 		goto again;
139 	}
140 	h_addr_ptrs[0] = (char *)host_addr;
141 	h_addr_ptrs[1] = NULL;
142 	host.h_addr_list = h_addr_ptrs;
143 	host.h_length = len;
144 	host.h_addrtype = af;
145 	while (*cp == ' ' || *cp == '\t')
146 		cp++;
147 	host.h_name = cp;
148 	q = host.h_aliases = host_aliases;
149 	if ((cp = strpbrk(cp, " \t")) != NULL)
150 		*cp++ = '\0';
151 	while (cp && *cp) {
152 		if (*cp == ' ' || *cp == '\t') {
153 			cp++;
154 			continue;
155 		}
156 		if (q < &host_aliases[MAXALIASES - 1])
157 			*q++ = cp;
158 		if ((cp = strpbrk(cp, " \t")) != NULL)
159 			*cp++ = '\0';
160 	}
161 	*q = NULL;
162 	h_errno = NETDB_SUCCESS;
163 	return (&host);
164 }
165 
166 struct hostent *
167 _gethostbyhtname(name, af)
168 	const char *name;
169 	int af;
170 {
171 	register struct hostent *p;
172 	register char **cp;
173 
174 	sethostent(0);
175 	while ((p = gethostent()) != NULL) {
176 		if (p->h_addrtype != af)
177 			continue;
178 		if (strcasecmp(p->h_name, name) == 0)
179 			break;
180 		for (cp = p->h_aliases; *cp != 0; cp++)
181 			if (strcasecmp(*cp, name) == 0)
182 				goto found;
183 	}
184 found:
185 	endhostent();
186 	return (p);
187 }
188 
189 struct hostent *
190 _gethostbyhtaddr(addr, len, af)
191 	const char *addr;
192 	int len, af;
193 {
194 	register struct hostent *p;
195 
196 	sethostent(0);
197 	while ((p = gethostent()) != NULL)
198 		if (p->h_addrtype == af && !bcmp(p->h_addr, addr, len))
199 			break;
200 	endhostent();
201 	return (p);
202 }
203