1 /* 2 * Copyright (C) 2004, 2005, 2008 Internet Systems Consortium, Inc. ("ISC") 3 * Copyright (C) 1996, 1999, 2001 Internet Software Consortium. 4 * 5 * Permission to use, copy, modify, and/or distribute this software for any 6 * purpose with or without fee is hereby granted, provided that the above 7 * copyright notice and this permission notice appear in all copies. 8 * 9 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH 10 * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY 11 * AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT, 12 * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM 13 * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE 14 * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR 15 * PERFORMANCE OF THIS SOFTWARE. 16 */ 17 18 #include "port_before.h" 19 20 #include <sys/types.h> 21 22 #include <string.h> 23 24 #include "port_after.h" 25 26 #include <isc/misc.h> 27 28 /*% 29 * int 30 * bitncmp(l, r, n) 31 * compare bit masks l and r, for n bits. 32 * return: 33 * -1, 1, or 0 in the libc tradition. 34 * note: 35 * network byte order assumed. this means 192.5.5.240/28 has 36 * 0x11110000 in its fourth octet. 37 * author: 38 * Paul Vixie (ISC), June 1996 39 */ 40 int 41 bitncmp(const void *l, const void *r, int n) { 42 u_int lb, rb; 43 int x, b; 44 45 b = n / 8; 46 x = memcmp(l, r, b); 47 if (x || (n % 8) == 0) 48 return (x); 49 50 lb = ((const u_char *)l)[b]; 51 rb = ((const u_char *)r)[b]; 52 for (b = n % 8; b > 0; b--) { 53 if ((lb & 0x80) != (rb & 0x80)) { 54 if (lb & 0x80) 55 return (1); 56 return (-1); 57 } 58 lb <<= 1; 59 rb <<= 1; 60 } 61 return (0); 62 } 63 64 /*! \file */ 65