67 lines
1.7 KiB
C
67 lines
1.7 KiB
C
/*
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* Copyright (c) 1996 by Internet Software Consortium.
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*
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* Permission to use, copy, modify, and distribute this software for any
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* purpose with or without fee is hereby granted, provided that the above
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* copyright notice and this permission notice appear in all copies.
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*
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* THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS
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* ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
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* OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE
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* CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
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* DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
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* PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
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* ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
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* SOFTWARE.
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*/
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#if defined(LIBC_SCCS) && !defined(lint)
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static const char rcsid[] = "$Id: bitncmp.c,v 1.5 1996/11/18 09:09:48 vixie Exp $";
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#endif
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#include "port_before.h"
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#include <sys/types.h>
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#include <string.h>
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#include "port_after.h"
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#include <isc/misc.h>
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/*
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* int
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* bitncmp(l, r, n)
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* compare bit masks l and r, for n bits.
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* return:
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* -1, 1, or 0 in the libc tradition.
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* note:
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* network byte order assumed. this means 192.5.5.240/28 has
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* 0x11110000 in its fourth octet.
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* author:
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* Paul Vixie (ISC), June 1996
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*/
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int
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bitncmp(const void *l, const void *r, int n) {
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u_int lb, rb;
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int x, b;
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b = n / 8;
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x = memcmp(l, r, b);
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if (x)
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return (x);
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lb = ((u_char *)l)[b];
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rb = ((u_char *)r)[b];
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for (b = n % 8; b > 0; b--) {
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if ((lb & 0x80) != (rb & 0x80)) {
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if (lb & 0x80)
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return (1);
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return (-1);
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}
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lb <<= 1;
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rb <<= 1;
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}
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return (0);
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}
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