1 /* 2 * Copyright 1997-2002 Sun Microsystems, Inc. All rights reserved. 3 * Use is subject to license terms. 4 */ 5 6 /* 7 * Copyright (c) 1996,1999 by Internet Software Consortium. 8 * 9 * Permission to use, copy, modify, and distribute this software for any 10 * purpose with or without fee is hereby granted, provided that the above 11 * copyright notice and this permission notice appear in all copies. 12 * 13 * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS 14 * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES 15 * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE 16 * CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL 17 * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR 18 * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS 19 * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS 20 * SOFTWARE. 21 */ 22 23 #pragma ident "%Z%%M% %I% %E% SMI" 24 25 #if defined(LIBC_SCCS) && !defined(lint) 26 static const char rcsid[] = "$Id: bitncmp.c,v 1.7 2001/05/29 05:49:23 marka Exp $"; 27 #endif 28 29 #include "port_before.h" 30 31 #include <sys/types.h> 32 33 #include <string.h> 34 35 #include "port_after.h" 36 37 #include <isc/misc.h> 38 39 /* 40 * int 41 * bitncmp(l, r, n) 42 * compare bit masks l and r, for n bits. 43 * return: 44 * -1, 1, or 0 in the libc tradition. 45 * note: 46 * network byte order assumed. this means 192.5.5.240/28 has 47 * 0x11110000 in its fourth octet. 48 * author: 49 * Paul Vixie (ISC), June 1996 50 */ 51 int 52 bitncmp(const void *l, const void *r, int n) { 53 u_int lb, rb; 54 int x, b; 55 56 b = n / 8; 57 x = memcmp(l, r, b); 58 if (x) 59 return (x); 60 61 lb = ((const u_char *)l)[b]; 62 rb = ((const u_char *)r)[b]; 63 for (b = n % 8; b > 0; b--) { 64 if ((lb & 0x80) != (rb & 0x80)) { 65 if (lb & 0x80) 66 return (1); 67 return (-1); 68 } 69 lb <<= 1; 70 rb <<= 1; 71 } 72 return (0); 73 } 74