/* $NetBSD: bitncmp.c,v 1.1.1.2 2012/09/09 16:08:00 christos Exp $ */ /* * Copyright (C) 2004, 2005, 2008 Internet Systems Consortium, Inc. ("ISC") * Copyright (C) 1996, 1999, 2001 Internet Software Consortium. * * Permission to use, copy, modify, and/or distribute this software for any * purpose with or without fee is hereby granted, provided that the above * copyright notice and this permission notice appear in all copies. * * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY * AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT, * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR * PERFORMANCE OF THIS SOFTWARE. */ #if defined(LIBC_SCCS) && !defined(lint) static const char rcsid[] = "Id: bitncmp.c,v 1.5 2008/11/14 02:36:51 marka Exp "; #endif #include "port_before.h" #include #include #include "port_after.h" #include /*% * int * bitncmp(l, r, n) * compare bit masks l and r, for n bits. * return: * -1, 1, or 0 in the libc tradition. * note: * network byte order assumed. this means 192.5.5.240/28 has * 0x11110000 in its fourth octet. * author: * Paul Vixie (ISC), June 1996 */ int bitncmp(const void *l, const void *r, int n) { u_int lb, rb; int x, b; b = n / 8; x = memcmp(l, r, b); if (x || (n % 8) == 0) return (x); lb = ((const u_char *)l)[b]; rb = ((const u_char *)r)[b]; for (b = n % 8; b > 0; b--) { if ((lb & 0x80) != (rb & 0x80)) { if (lb & 0x80) return (1); return (-1); } lb <<= 1; rb <<= 1; } return (0); } /*! \file */