1 /* $NetBSD: inet_netof.c,v 1.1.1.1 2009/04/12 15:33:35 christos Exp $ */
2
3 /*
4 * Copyright (c) 1983, 1993
5 * The Regents of the University of California. All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. All advertising materials mentioning features or use of this software
16 * must display the following acknowledgement:
17 * This product includes software developed by the University of
18 * California, Berkeley and its contributors.
19 * 4. Neither the name of the University nor the names of its contributors
20 * may be used to endorse or promote products derived from this software
21 * without specific prior written permission.
22 *
23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 * SUCH DAMAGE.
34 */
35
36 #if defined(LIBC_SCCS) && !defined(lint)
37 static const char sccsid[] = "@(#)inet_netof.c 8.1 (Berkeley) 6/4/93";
38 #endif /* LIBC_SCCS and not lint */
39
40 #include "port_before.h"
41
42 #include <sys/param.h>
43 #include <netinet/in.h>
44 #include <arpa/inet.h>
45
46 #include "port_after.h"
47
48 /*%
49 * Return the network number from an internet
50 * address; handles class a/b/c network #'s.
51 */
52 u_long
inet_netof(in)53 inet_netof(in)
54 struct in_addr in;
55 {
56 register u_long i = ntohl(in.s_addr);
57
58 if (IN_CLASSA(i))
59 return (((i)&IN_CLASSA_NET) >> IN_CLASSA_NSHIFT);
60 else if (IN_CLASSB(i))
61 return (((i)&IN_CLASSB_NET) >> IN_CLASSB_NSHIFT);
62 else
63 return (((i)&IN_CLASSC_NET) >> IN_CLASSC_NSHIFT);
64 }
65
66 /*! \file */
67