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 * 4. 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)
31static const char sccsid[] = "@(#)inet_netof.c	8.1 (Berkeley) 6/4/93";
32#endif /* LIBC_SCCS and not lint */
33#include <sys/cdefs.h>
34__FBSDID("$FreeBSD$");
35
36#include "port_before.h"
37
38#include <sys/param.h>
39#include <netinet/in.h>
40#include <arpa/inet.h>
41
42#include "port_after.h"
43
44/*%
45 * Return the network number from an internet
46 * address; handles class a/b/c network #'s.
47 */
48in_addr_t
49inet_netof(struct in_addr in)
50{
51	in_addr_t i = ntohl(in.s_addr);
52
53	if (IN_CLASSA(i))
54		return (((i)&IN_CLASSA_NET) >> IN_CLASSA_NSHIFT);
55	else if (IN_CLASSB(i))
56		return (((i)&IN_CLASSB_NET) >> IN_CLASSB_NSHIFT);
57	else
58		return (((i)&IN_CLASSC_NET) >> IN_CLASSC_NSHIFT);
59}
60
61/*
62 * Weak aliases for applications that use certain private entry points,
63 * and fail to include <arpa/inet.h>.
64 */
65#undef inet_netof
66__weak_reference(__inet_netof, inet_netof);
67
68/*! \file */
69