xref: /csrg-svn/lib/libc/net/inet_lnaof.c (revision 33676)
121368Sdist /*
221368Sdist  * Copyright (c) 1983 Regents of the University of California.
3*33676Sbostic  * All rights reserved.
4*33676Sbostic  *
5*33676Sbostic  * Redistribution and use in source and binary forms are permitted
6*33676Sbostic  * provided that this notice is preserved and that due credit is given
7*33676Sbostic  * to the University of California at Berkeley. The name of the University
8*33676Sbostic  * may not be used to endorse or promote products derived from this
9*33676Sbostic  * software without specific prior written permission. This software
10*33676Sbostic  * is provided ``as is'' without express or implied warranty.
1121368Sdist  */
128358Ssam 
1326613Sdonn #if defined(LIBC_SCCS) && !defined(lint)
14*33676Sbostic static char sccsid[] = "@(#)inet_lnaof.c	5.4 (Berkeley) 03/07/88";
15*33676Sbostic #endif /* LIBC_SCCS and not lint */
1621368Sdist 
178358Ssam #include <sys/types.h>
189192Ssam #include <netinet/in.h>
198358Ssam 
208358Ssam /*
218358Ssam  * Return the local network address portion of an
228358Ssam  * internet address; handles class a/b/c network
238358Ssam  * number formats.
248358Ssam  */
2532317Sbostic u_long
268370Ssam inet_lnaof(in)
278358Ssam 	struct in_addr in;
288358Ssam {
299192Ssam 	register u_long i = ntohl(in.s_addr);
309192Ssam 
319192Ssam 	if (IN_CLASSA(i))
329192Ssam 		return ((i)&IN_CLASSA_HOST);
339192Ssam 	else if (IN_CLASSB(i))
349192Ssam 		return ((i)&IN_CLASSB_HOST);
359192Ssam 	else
369192Ssam 		return ((i)&IN_CLASSC_HOST);
378358Ssam }
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