xref: /openbsd-src/lib/libc/net/getnetent.c (revision db5b349cf7aa19c2b6169fbb65597f2e741714ab)
1 /*
2  * Copyright (c) 1983, 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. Neither the name of the University nor the names of its contributors
14  *    may be used to endorse or promote products derived from this software
15  *    without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  */
29 
30 #if defined(LIBC_SCCS) && !defined(lint)
31 static char rcsid[] = "$OpenBSD: getnetent.c,v 1.10 2005/03/25 13:24:12 otto Exp $";
32 #endif /* LIBC_SCCS and not lint */
33 
34 #include <sys/types.h>
35 #include <sys/socket.h>
36 #include <netinet/in.h>
37 #include <arpa/inet.h>
38 #include <netdb.h>
39 #include <stdio.h>
40 #include <string.h>
41 
42 #define	MAXALIASES	35
43 
44 static FILE *netf;
45 static char line[BUFSIZ+1];
46 static struct netent net;
47 static char *net_aliases[MAXALIASES];
48 int _net_stayopen;
49 
50 void
51 setnetent(int f)
52 {
53 	if (netf == NULL)
54 		netf = fopen(_PATH_NETWORKS, "r" );
55 	else
56 		rewind(netf);
57 	_net_stayopen |= f;
58 }
59 
60 void
61 endnetent(void)
62 {
63 	if (netf) {
64 		fclose(netf);
65 		netf = NULL;
66 	}
67 	_net_stayopen = 0;
68 }
69 
70 struct netent *
71 getnetent(void)
72 {
73 	char *p, *cp, **q;
74 	size_t len;
75 
76 	if (netf == NULL && (netf = fopen(_PATH_NETWORKS, "r" )) == NULL)
77 		return (NULL);
78 again:
79 	if ((p = fgetln(netf, &len)) == NULL)
80 		return (NULL);
81 	if (p[len-1] == '\n')
82 		len--;
83 	if (len >= sizeof(line) || len == 0)
84 		goto again;
85 	p = memcpy(line, p, len);
86 	line[len] = '\0';
87 	if (*p == '#')
88 		goto again;
89 	if ((cp = strchr(p, '#')) != NULL)
90 		*cp = '\0';
91 	net.n_name = p;
92 	if (strlen(net.n_name) >= MAXHOSTNAMELEN-1)
93 		net.n_name[MAXHOSTNAMELEN-1] = '\0';
94 	cp = strpbrk(p, " \t");
95 	if (cp == NULL)
96 		goto again;
97 	*cp++ = '\0';
98 	while (*cp == ' ' || *cp == '\t')
99 		cp++;
100 	p = strpbrk(cp, " \t");
101 	if (p != NULL)
102 		*p++ = '\0';
103 	net.n_net = inet_network(cp);
104 	net.n_addrtype = AF_INET;
105 	q = net.n_aliases = net_aliases;
106 	if (p != NULL)
107 		cp = p;
108 	while (cp && *cp) {
109 		if (*cp == ' ' || *cp == '\t') {
110 			cp++;
111 			continue;
112 		}
113 		if (q < &net_aliases[MAXALIASES - 1]) {
114 			*q++ = cp;
115 			if (strlen(cp) >= MAXHOSTNAMELEN-1)
116 				cp[MAXHOSTNAMELEN-1] = '\0';
117 		}
118 		cp = strpbrk(cp, " \t");
119 		if (cp != NULL)
120 			*cp++ = '\0';
121 	}
122 	*q = NULL;
123 	return (&net);
124 }
125