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 5.7 (Berkeley) 02/24/91"; 10 #endif /* LIBC_SCCS and not lint */ 11 12 #include <sys/param.h> 13 #include <netinet/in.h> 14 #include <arpa/inet.h> 15 16 /* 17 * Return the local network address portion of an 18 * internet address; handles class a/b/c network 19 * number formats. 20 */ 21 u_long 22 inet_lnaof(in) 23 struct in_addr in; 24 { 25 register u_long i = ntohl(in.s_addr); 26 27 if (IN_CLASSA(i)) 28 return ((i)&IN_CLASSA_HOST); 29 else if (IN_CLASSB(i)) 30 return ((i)&IN_CLASSB_HOST); 31 else 32 return ((i)&IN_CLASSC_HOST); 33 } 34