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);
}