xref: /openbsd/lib/libc/net/getnetent.c (revision 17df1aa7)
1 /*	$OpenBSD: getnetent.c,v 1.12 2006/01/17 15:37:58 millert Exp $ */
2 /*
3  * Copyright (c) 1983, 1993
4  *	The Regents of the University of California.  All rights reserved.
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  * 3. Neither the name of the University nor the names of its contributors
15  *    may be used to endorse or promote products derived from this software
16  *    without specific prior written permission.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
19  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
22  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28  * SUCH DAMAGE.
29  */
30 
31 #include <sys/param.h>
32 #include <sys/socket.h>
33 #include <netinet/in.h>
34 #include <arpa/inet.h>
35 #include <netdb.h>
36 #include <stdio.h>
37 #include <string.h>
38 
39 #define	MAXALIASES	35
40 
41 static FILE *netf;
42 static char line[BUFSIZ+1];
43 static struct netent net;
44 static char *net_aliases[MAXALIASES];
45 int _net_stayopen;
46 
47 void
48 setnetent(int f)
49 {
50 	if (netf == NULL)
51 		netf = fopen(_PATH_NETWORKS, "r" );
52 	else
53 		rewind(netf);
54 	_net_stayopen |= f;
55 }
56 
57 void
58 endnetent(void)
59 {
60 	if (netf) {
61 		fclose(netf);
62 		netf = NULL;
63 	}
64 	_net_stayopen = 0;
65 }
66 
67 struct netent *
68 getnetent(void)
69 {
70 	char *p, *cp, **q;
71 	size_t len;
72 
73 	if (netf == NULL && (netf = fopen(_PATH_NETWORKS, "r" )) == NULL)
74 		return (NULL);
75 again:
76 	if ((p = fgetln(netf, &len)) == NULL)
77 		return (NULL);
78 	if (p[len-1] == '\n')
79 		len--;
80 	if (len >= sizeof(line) || len == 0)
81 		goto again;
82 	p = memcpy(line, p, len);
83 	line[len] = '\0';
84 	if (*p == '#')
85 		goto again;
86 	if ((cp = strchr(p, '#')) != NULL)
87 		*cp = '\0';
88 	net.n_name = p;
89 	if (strlen(net.n_name) >= MAXHOSTNAMELEN-1)
90 		net.n_name[MAXHOSTNAMELEN-1] = '\0';
91 	cp = strpbrk(p, " \t");
92 	if (cp == NULL)
93 		goto again;
94 	*cp++ = '\0';
95 	while (*cp == ' ' || *cp == '\t')
96 		cp++;
97 	p = strpbrk(cp, " \t");
98 	if (p != NULL)
99 		*p++ = '\0';
100 	net.n_net = inet_network(cp);
101 	net.n_addrtype = AF_INET;
102 	q = net.n_aliases = net_aliases;
103 	if (p != NULL)
104 		cp = p;
105 	while (cp && *cp) {
106 		if (*cp == ' ' || *cp == '\t') {
107 			cp++;
108 			continue;
109 		}
110 		if (q < &net_aliases[MAXALIASES - 1]) {
111 			*q++ = cp;
112 			if (strlen(cp) >= MAXHOSTNAMELEN-1)
113 				cp[MAXHOSTNAMELEN-1] = '\0';
114 		}
115 		cp = strpbrk(cp, " \t");
116 		if (cp != NULL)
117 			*cp++ = '\0';
118 	}
119 	*q = NULL;
120 	return (&net);
121 }
122