bring up to rev 6

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

/*
 * Copyright (c) 1983 Regents of the University of California.
 * All rights reserved.  The Berkeley software License Agreement
 * specifies the terms and conditions for redistribution.
 */

#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "@(#)inet_netof.c	5.3 (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);
}