xref: /illumos-gate/usr/src/lib/libresolv2/common/inet/inet_makeaddr.c (revision 8b80e8cb6855118d46f605e91b5ed4ce83417395)
1 /*
2  * Copyright (c) 1997-2001 by Sun Microsystems, Inc.
3  * All rights reserved.
4  */
5 
6 /*
7  * Copyright (c) 1983, 1993
8  *	The Regents of the University of California.  All rights reserved.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. All advertising materials mentioning features or use of this software
19  *    must display the following acknowledgement:
20  *	This product includes software developed by the University of
21  *	California, Berkeley and its contributors.
22  * 4. Neither the name of the University nor the names of its contributors
23  *    may be used to endorse or promote products derived from this software
24  *    without specific prior written permission.
25  *
26  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
27  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
28  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
29  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
30  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
31  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
32  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
33  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
34  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
35  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36  * SUCH DAMAGE.
37  */
38 
39 #pragma ident	"%Z%%M%	%I%	%E% SMI"
40 
41 #if defined(LIBC_SCCS) && !defined(lint)
42 static const char sccsid[] = "@(#)inet_makeaddr.c	8.1 (Berkeley) 6/4/93";
43 #endif /* LIBC_SCCS and not lint */
44 
45 #include "port_before.h"
46 
47 #include <sys/param.h>
48 #include <netinet/in.h>
49 #include <arpa/inet.h>
50 
51 #include "port_after.h"
52 
53 /*
54  * Formulate an Internet address from network + host.  Used in
55  * building addresses stored in the ifnet structure.
56  */
57 struct in_addr
58 inet_makeaddr(net, host)
59 #ifdef	ORIGINAL_ISC_CODE
60 	u_long net, host;
61 #else
62 	in_addr_t net, host;
63 #endif
64 {
65 #ifdef	ORIGINAL_ISC_CODE
66 	u_long addr;
67 #else
68 	in_addr_t addr;
69 	struct in_addr inaddr;
70 #endif
71 
72 	if (net < 128)
73 		addr = (net << IN_CLASSA_NSHIFT) | (host & IN_CLASSA_HOST);
74 	else if (net < 65536)
75 		addr = (net << IN_CLASSB_NSHIFT) | (host & IN_CLASSB_HOST);
76 	else if (net < 16777216L)
77 		addr = (net << IN_CLASSC_NSHIFT) | (host & IN_CLASSC_HOST);
78 	else
79 		addr = net | host;
80 #ifdef	ORIGINAL_ISC_CODE
81 	addr = htonl(addr);
82 	return (*(struct in_addr *)&addr);
83 #else
84 	inaddr.s_addr = htonl(addr);
85 	return (inaddr);
86 #endif
87 }
88