/********************************************************************** * Copyright (c) Digital Equipment Corporation 1984, 1985, 1986. * * All Rights Reserved. * * Reference "/usr/src/COPYRIGHT" for applicable restrictions. * **********************************************************************/ /* * SCCSID: @(#)inet_netof.c 3.0 4/22/86 * Based on inet_netof.c 4.3 82/11/14 */ #include <netdb.h> #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; { u_long i = ntohl(in.s_addr); if (IN_CLASSA(i)) return ((i >> IN_CLASSA_NSHIFT)&0xffL); else if (IN_CLASSB(i)) return ((i >> IN_CLASSB_NSHIFT)&0xffffL); else return ((i >> IN_CLASSC_NSHIFT)&0xffffffL); }