add Berkeley specific headers

[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 this notice is preserved and that due credit is given
* to the University of California at 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'' without express or implied warranty.
*/

#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "@(#)inet_netof.c        5.4 (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);
}