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/*
* Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
* Copyright (c) 1996,1999 by Internet Software Consortium.
*
* Permission to use, copy, modify, and 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.
*
* SPDX-License-Identifier: MIT
*/
#ifndef HAVE_BITNCMP
#include "ares_setup.h"
#include "bitncmp.h"
/*
* int
* bitncmp(l, r, n)
* compare bit masks l and r, for n bits.
* return:
* <0, >0, 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 ares__bitncmp(const void *l, const void *r, int n)
{
unsigned int lb, rb;
int x, b;
b = n / 8;
x = memcmp(l, r, b);
if (x || (n % 8) == 0)
return (x);
lb = ((const unsigned char *)l)[b];
rb = ((const unsigned 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);
}
#endif
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