xref: /openbsd-src/lib/libc/net/inet_makeaddr.c (revision aea60bee5e9bad0aab62f480f19c2fb34c068de4)
1*aea60beeSderaadt /*	$OpenBSD: inet_makeaddr.c,v 1.7 2015/01/16 16:48:51 deraadt Exp $ */
2df930be7Sderaadt /*
3df930be7Sderaadt  * Copyright (c) 1983, 1993
4df930be7Sderaadt  *	The Regents of the University of California.  All rights reserved.
5df930be7Sderaadt  *
6df930be7Sderaadt  * Redistribution and use in source and binary forms, with or without
7df930be7Sderaadt  * modification, are permitted provided that the following conditions
8df930be7Sderaadt  * are met:
9df930be7Sderaadt  * 1. Redistributions of source code must retain the above copyright
10df930be7Sderaadt  *    notice, this list of conditions and the following disclaimer.
11df930be7Sderaadt  * 2. Redistributions in binary form must reproduce the above copyright
12df930be7Sderaadt  *    notice, this list of conditions and the following disclaimer in the
13df930be7Sderaadt  *    documentation and/or other materials provided with the distribution.
146580fee3Smillert  * 3. Neither the name of the University nor the names of its contributors
15df930be7Sderaadt  *    may be used to endorse or promote products derived from this software
16df930be7Sderaadt  *    without specific prior written permission.
17df930be7Sderaadt  *
18df930be7Sderaadt  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
19df930be7Sderaadt  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20df930be7Sderaadt  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21df930be7Sderaadt  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
22df930be7Sderaadt  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23df930be7Sderaadt  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24df930be7Sderaadt  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25df930be7Sderaadt  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26df930be7Sderaadt  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27df930be7Sderaadt  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28df930be7Sderaadt  * SUCH DAMAGE.
29df930be7Sderaadt  */
30df930be7Sderaadt 
31df930be7Sderaadt #include <netinet/in.h>
32df930be7Sderaadt #include <arpa/inet.h>
33df930be7Sderaadt 
34df930be7Sderaadt /*
35df930be7Sderaadt  * Formulate an Internet address from network + host.  Used in
36df930be7Sderaadt  * building addresses stored in the ifnet structure.
37df930be7Sderaadt  */
38df930be7Sderaadt struct in_addr
inet_makeaddr(in_addr_t net,in_addr_t host)39db5b349cSotto inet_makeaddr(in_addr_t net, in_addr_t host)
40df930be7Sderaadt {
4132210aa3Smillert 	in_addr_t addr;
42df930be7Sderaadt 
43df930be7Sderaadt 	if (net < 128)
44df930be7Sderaadt 		addr = (net << IN_CLASSA_NSHIFT) | (host & IN_CLASSA_HOST);
45df930be7Sderaadt 	else if (net < 65536)
46df930be7Sderaadt 		addr = (net << IN_CLASSB_NSHIFT) | (host & IN_CLASSB_HOST);
47df930be7Sderaadt 	else if (net < 16777216L)
48df930be7Sderaadt 		addr = (net << IN_CLASSC_NSHIFT) | (host & IN_CLASSC_HOST);
49df930be7Sderaadt 	else
50df930be7Sderaadt 		addr = net | host;
51df930be7Sderaadt 	addr = htonl(addr);
52df930be7Sderaadt 	return (*(struct in_addr *)&addr);
53df930be7Sderaadt }
54