mirror of
https://github.com/openbsd/src.git
synced 2024-12-22 07:27:59 -08:00
f04ff968bd
manual review. Based on common practice, relayd.h now includes the necessary headers for itself. OK benno@
68 lines
1.8 KiB
C
68 lines
1.8 KiB
C
/* $OpenBSD: shuffle.c,v 1.4 2015/01/22 17:42:09 reyk Exp $ */
|
|
|
|
/*
|
|
* Portions Copyright (C) 2008 Theo de Raadt
|
|
*
|
|
* 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 INTERNET SOFTWARE CONSORTIUM
|
|
* DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL
|
|
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL
|
|
* INTERNET SOFTWARE CONSORTIUM 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.
|
|
*/
|
|
|
|
/* based on: bind/lib/isc/shuffle.c,v 1.4 2008/07/09 17:07:32 reyk Exp $ */
|
|
|
|
#include <sys/types.h>
|
|
|
|
#include <stdlib.h>
|
|
#include <assert.h>
|
|
|
|
#include "relayd.h"
|
|
|
|
#define VALID_SHUFFLE(x) (x != NULL)
|
|
|
|
void
|
|
shuffle_init(struct shuffle *shuffle)
|
|
{
|
|
int i, i2;
|
|
|
|
assert(VALID_SHUFFLE(shuffle));
|
|
|
|
shuffle->isindex = 0;
|
|
/* Initialize using a Knuth shuffle */
|
|
for (i = 0; i < 65536; ++i) {
|
|
i2 = arc4random_uniform(i + 1);
|
|
shuffle->id_shuffle[i] = shuffle->id_shuffle[i2];
|
|
shuffle->id_shuffle[i2] = i;
|
|
}
|
|
}
|
|
|
|
u_int16_t
|
|
shuffle_generate16(struct shuffle *shuffle)
|
|
{
|
|
u_int32_t si;
|
|
u_int16_t r;
|
|
int i, i2;
|
|
|
|
assert(VALID_SHUFFLE(shuffle));
|
|
|
|
do {
|
|
si = arc4random();
|
|
i = shuffle->isindex & 0xFFFF;
|
|
i2 = (shuffle->isindex - (si & 0x7FFF)) & 0xFFFF;
|
|
r = shuffle->id_shuffle[i];
|
|
shuffle->id_shuffle[i] = shuffle->id_shuffle[i2];
|
|
shuffle->id_shuffle[i2] = r;
|
|
shuffle->isindex++;
|
|
} while (r == 0);
|
|
|
|
return (r);
|
|
}
|