/*      $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 <sys/types.h>

#include <string.h>

#include "port_after.h"

#include <isc/misc.h>

/*%
* 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 */