1/** @File
2  Return the network number from an internet address.
3
4  Copyright (c) 2011, Intel Corporation. All rights reserved.<BR>
5  This program and the accompanying materials are licensed and made available under
6  the terms and conditions of the BSD License that accompanies this distribution.
7  The full text of the license may be found at
8  http://opensource.org/licenses/bsd-license.
9
10  THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
11  WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
12
13 * Copyright (c) 1983, 1993
14 *  The Regents of the University of California.  All rights reserved.
15 *
16 * Redistribution and use in source and binary forms, with or without
17 * modification, are permitted provided that the following conditions
18 * are met:
19 * 1. Redistributions of source code must retain the above copyright
20 *    notice, this list of conditions and the following disclaimer.
21 * 2. Redistributions in binary form must reproduce the above copyright
22 *    notice, this list of conditions and the following disclaimer in the
23 *    documentation and/or other materials provided with the distribution.
24 * 3. Neither the name of the University nor the names of its contributors
25 *    may be used to endorse or promote products derived from this software
26 *    without specific prior written permission.
27 *
28 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
29 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
30 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
31 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
32 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
33 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
34 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
35 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
36 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
37 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
38 * SUCH DAMAGE.
39
40  NetBSD: inet_netof.c,v 1.1 2004/05/20 23:13:02 christos Exp
41  inet_netof.c  8.1 (Berkeley) 6/4/93
42**/
43#include  <LibConfig.h>
44
45#include "namespace.h"
46#include <sys/param.h>
47#include <netinet/in.h>
48#include <arpa/inet.h>
49
50#ifdef __weak_alias
51__weak_alias(inet_netof,_inet_netof)
52#endif
53
54/*
55 * Return the network number from an internet
56 * address; handles class a/b/c network #'s.
57 */
58in_addr_t
59inet_netof(struct in_addr in)
60{
61  in_addr_t i = ntohl(in.s_addr);
62
63  if (IN_CLASSA(i))
64    return (((i)&IN_CLASSA_NET) >> IN_CLASSA_NSHIFT);
65  else if (IN_CLASSB(i))
66    return (((i)&IN_CLASSB_NET) >> IN_CLASSB_NSHIFT);
67  else
68    return (((i)&IN_CLASSC_NET) >> IN_CLASSC_NSHIFT);
69}
70