xref: /illumos-gate/usr/src/lib/libc/port/inet/inet_lnaof.c (revision 2c5ec7a875dcd76853e6618614e990f1e8cdd56d)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License, Version 1.0 only
6  * (the "License").  You may not use this file except in compliance
7  * with the License.
8  *
9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10  * or http://www.opensolaris.org/os/licensing.
11  * See the License for the specific language governing permissions
12  * and limitations under the License.
13  *
14  * When distributing Covered Code, include this CDDL HEADER in each
15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16  * If applicable, add the following below this CDDL HEADER, with the
17  * fields enclosed by brackets "[]" replaced with your own identifying
18  * information: Portions Copyright [yyyy] [name of copyright owner]
19  *
20  * CDDL HEADER END
21  */
22 /*
23  * Copyright 1997 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 /*	Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T	*/
28 /*	All Rights Reserved	*/
29 
30 /*
31  * University Copyright- Copyright (c) 1982, 1986, 1988
32  * The Regents of the University of California
33  * All Rights Reserved
34  *
35  * University Acknowledgment- Portions of this document are derived from
36  * software developed by the University of California, Berkeley, and its
37  * contributors.
38  */
39 
40 #include "lint.h"
41 
42 #include <sys/types.h>
43 
44 #include <netinet/in.h>
45 
46 /*
47  * Return the local network address portion of an
48  * internet address; handles class a/b/c network
49  * number formats.
50  */
51 in_addr_t
52 inet_lnaof(struct in_addr in)
53 {
54 	uint32_t i = ntohl(in.s_addr);
55 
56 	if (IN_CLASSA(i))
57 		return ((i)&IN_CLASSA_HOST);
58 	else if (IN_CLASSB(i))
59 		return ((i)&IN_CLASSB_HOST);
60 	else
61 		return ((i)&IN_CLASSC_HOST);
62 }
63