install approved copyright notice

[unix-history] / usr / src / lib / libc / net / inet_netof.c

/*
 * Copyright (c) 1983 Regents of the University of California.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms are permitted
 * provided that the above copyright notice and this paragraph are
 * duplicated in all such forms and that any documentation,
 * advertising materials, and other materials related to such
 * distribution and use acknowledge that the software was developed
 * by the University of California, Berkeley.  The name of the
 * University may not be used to endorse or promote products derived
 * from this software without specific prior written permission.
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
 * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 */

#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "@(#)inet_netof.c	5.5 (Berkeley) %G%";
#endif /* LIBC_SCCS and not lint */

#include <sys/types.h>
#include <netinet/in.h>

/*
 * Return the network number from an internet
 * address; handles class a/b/c network #'s.
 */
u_long
inet_netof(in)
	struct in_addr in;
{
	register u_long i = ntohl(in.s_addr);

	if (IN_CLASSA(i))
		return (((i)&IN_CLASSA_NET) >> IN_CLASSA_NSHIFT);
	else if (IN_CLASSB(i))
		return (((i)&IN_CLASSB_NET) >> IN_CLASSB_NSHIFT);
	else
		return (((i)&IN_CLASSC_NET) >> IN_CLASSC_NSHIFT);
}