1 /* 2 * Copyright (c) 1983 Regents of the University of California. 3 * All rights reserved. 4 * 5 * %sccs.include.redist.c% 6 */ 7 8 #if defined(LIBC_SCCS) && !defined(lint) 9 static char sccsid[] = "@(#)inet_lnaof.c 5.6 (Berkeley) 06/01/90"; 10 #endif /* LIBC_SCCS and not lint */ 11 12 #include <sys/types.h> 13 #include <netinet/in.h> 14 15 /* 16 * Return the local network address portion of an 17 * internet address; handles class a/b/c network 18 * number formats. 19 */ 20 u_long 21 inet_lnaof(in) 22 struct in_addr in; 23 { 24 register u_long i = ntohl(in.s_addr); 25 26 if (IN_CLASSA(i)) 27 return ((i)&IN_CLASSA_HOST); 28 else if (IN_CLASSB(i)) 29 return ((i)&IN_CLASSB_HOST); 30 else 31 return ((i)&IN_CLASSC_HOST); 32 } 33