xref: /original-bsd/lib/libc/net/inet_lnaof.c (revision fa921481)
1 /*
2  * Copyright (c) 1983 Regents of the University of California.
3  * All rights reserved.
4  *
5  * %sccs.include.redist.c%
6  */
7 
8 #if defined(LIBC_SCCS) && !defined(lint)
9 static char sccsid[] = "@(#)inet_lnaof.c	5.6 (Berkeley) 06/01/90";
10 #endif /* LIBC_SCCS and not lint */
11 
12 #include <sys/types.h>
13 #include <netinet/in.h>
14 
15 /*
16  * Return the local network address portion of an
17  * internet address; handles class a/b/c network
18  * number formats.
19  */
20 u_long
21 inet_lnaof(in)
22 	struct in_addr in;
23 {
24 	register u_long i = ntohl(in.s_addr);
25 
26 	if (IN_CLASSA(i))
27 		return ((i)&IN_CLASSA_HOST);
28 	else if (IN_CLASSB(i))
29 		return ((i)&IN_CLASSB_HOST);
30 	else
31 		return ((i)&IN_CLASSC_HOST);
32 }
33