1 /*
2  * Copyright (c) 1983 Regents of the University of California.
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms are permitted
6  * provided that the above copyright notice and this paragraph are
7  * duplicated in all such forms and that any documentation,
8  * advertising materials, and other materials related to such
9  * distribution and use acknowledge that the software was developed
10  * by the University of California, Berkeley.  The name of the
11  * University may not be used to endorse or promote products derived
12  * from this software without specific prior written permission.
13  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
14  * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
15  * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
16  */
17 
18 #if defined(LIBC_SCCS) && !defined(lint)
19 static char sccsid[] = "@(#)gethostent.c	5.6 (Berkeley) 03/09/89";
20 #endif /* LIBC_SCCS and not lint */
21 
22 #include <stdio.h>
23 #include <sys/types.h>
24 #include <sys/socket.h>
25 #include <netdb.h>
26 #include <ctype.h>
27 #include <ndbm.h>
28 
29 /*
30  * Internet version.
31  */
32 #define	MAXALIASES	35
33 #define	MAXADDRSIZE	14
34 
35 static FILE *hostf = NULL;
36 static char line[BUFSIZ+1];
37 static char hostaddr[MAXADDRSIZE];
38 static struct hostent host;
39 static char *host_aliases[MAXALIASES];
40 static char *host_addrs[] = {
41 	hostaddr,
42 	NULL
43 };
44 
45 /*
46  * The following is shared with gethostnamadr.c
47  */
48 char	*_host_file = "/etc/hosts";
49 int	_host_stayopen;
50 DBM	*_host_db;	/* set by gethostbyname(), gethostbyaddr() */
51 
52 char *strpbrk();
53 
54 sethostent(f)
55 	int f;
56 {
57 	if (hostf != NULL)
58 		rewind(hostf);
59 	_host_stayopen |= f;
60 }
61 
62 endhostent()
63 {
64 	if (hostf) {
65 		fclose(hostf);
66 		hostf = NULL;
67 	}
68 	if (_host_db) {
69 		dbm_close(_host_db);
70 		_host_db = (DBM *)NULL;
71 	}
72 	_host_stayopen = 0;
73 }
74 
75 struct hostent *
76 gethostent()
77 {
78 	char *p;
79 	register char *cp, **q;
80 
81 	if (hostf == NULL && (hostf = fopen(_host_file, "r" )) == NULL)
82 		return (NULL);
83 again:
84 	if ((p = fgets(line, BUFSIZ, hostf)) == NULL)
85 		return (NULL);
86 	if (*p == '#')
87 		goto again;
88 	cp = strpbrk(p, "#\n");
89 	if (cp == NULL)
90 		goto again;
91 	*cp = '\0';
92 	cp = strpbrk(p, " \t");
93 	if (cp == NULL)
94 		goto again;
95 	*cp++ = '\0';
96 	/* THIS STUFF IS INTERNET SPECIFIC */
97 	host.h_addr_list = host_addrs;
98 	*((u_long *)host.h_addr) = inet_addr(p);
99 	host.h_length = sizeof (u_long);
100 	host.h_addrtype = AF_INET;
101 	while (*cp == ' ' || *cp == '\t')
102 		cp++;
103 	host.h_name = cp;
104 	q = host.h_aliases = host_aliases;
105 	cp = strpbrk(cp, " \t");
106 	if (cp != NULL)
107 		*cp++ = '\0';
108 	while (cp && *cp) {
109 		if (*cp == ' ' || *cp == '\t') {
110 			cp++;
111 			continue;
112 		}
113 		if (q < &host_aliases[MAXALIASES - 1])
114 			*q++ = cp;
115 		cp = strpbrk(cp, " \t");
116 		if (cp != NULL)
117 			*cp++ = '\0';
118 	}
119 	*q = NULL;
120 	return (&host);
121 }
122 
123 sethostfile(file)
124 	char *file;
125 {
126 	_host_file = file;
127 }
128