xref: /titanic_41/usr/src/lib/libbc/libc/inet/inet_netof.c (revision bdfc6d18da790deeec2e0eb09c625902defe2498)
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 #pragma ident	"%Z%%M%	%I%	%E% SMI"
23 	  /* from UCB 4.3 82/11/14 */
24 
25 #include <sys/types.h>
26 #include <netinet/in.h>
27 
28 /*
29  * Return the network number from an internet
30  * address; handles class a/b/c network #'s.
31  */
32 inet_netof(in)
33 	struct in_addr in;
34 {
35 	register u_long i = ntohl(in.s_addr);
36 
37 	if (IN_CLASSA(i))
38 		return (((i)&IN_CLASSA_NET) >> IN_CLASSA_NSHIFT);
39 	else if (IN_CLASSB(i))
40 		return (((i)&IN_CLASSB_NET) >> IN_CLASSB_NSHIFT);
41 	else
42 		return (((i)&IN_CLASSC_NET) >> IN_CLASSC_NSHIFT);
43 }
44