/*
 * 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.
 */

#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 */