inet_netof.c revision 330897 
1/*-
2 * SPDX-License-Identifier: BSD-3-Clause
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 * 4. Neither the name of the University nor the names of its contributors
16 *    may be used to endorse or promote products derived from this software
17 *    without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 */
31
32#if defined(LIBC_SCCS) && !defined(lint)
33static const char sccsid[] = "@(#)inet_netof.c	8.1 (Berkeley) 6/4/93";
34#endif /* LIBC_SCCS and not lint */
35#include <sys/cdefs.h>
36__FBSDID("$FreeBSD: stable/11/lib/libc/inet/inet_netof.c 330897 2018-03-14 03:19:51Z eadler $");
37
38#include "port_before.h"
39
40#include <sys/param.h>
41#include <netinet/in.h>
42#include <arpa/inet.h>
43
44#include "port_after.h"
45
46/*%
47 * Return the network number from an internet
48 * address; handles class a/b/c network #'s.
49 */
50in_addr_t
51inet_netof(struct in_addr in)
52{
53	in_addr_t i = ntohl(in.s_addr);
54
55	if (IN_CLASSA(i))
56		return (((i)&IN_CLASSA_NET) >> IN_CLASSA_NSHIFT);
57	else if (IN_CLASSB(i))
58		return (((i)&IN_CLASSB_NET) >> IN_CLASSB_NSHIFT);
59	else
60		return (((i)&IN_CLASSC_NET) >> IN_CLASSC_NSHIFT);
61}
62
63/*
64 * Weak aliases for applications that use certain private entry points,
65 * and fail to include <arpa/inet.h>.
66 */
67#undef inet_netof
68__weak_reference(__inet_netof, inet_netof);
69
70/*! \file */
71