/* * 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) 06/27/88"; #endif /* LIBC_SCCS and not lint */ #include #include /* * 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); }