GCC Code Coverage Report
Directory: ./ Exec Total Coverage
File: usr.sbin/relayd/shuffle.c Lines: 0 17 0.0 %
Date: 2017-11-13 Branches: 0 8 0.0 %

Line Branch Exec Source
1
/*	$OpenBSD: shuffle.c,v 1.4 2015/01/22 17:42:09 reyk Exp $	*/
2
3
/*
4
 * Portions Copyright (C) 2008 Theo de Raadt
5
 *
6
 * Permission to use, copy, modify, and distribute this software for any
7
 * purpose with or without fee is hereby granted, provided that the above
8
 * copyright notice and this permission notice appear in all copies.
9
 *
10
 * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM
11
 * DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL
12
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL
13
 * INTERNET SOFTWARE CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT,
14
 * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING
15
 * FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
16
 * NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION
17
 * WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
18
 */
19
20
/* based on: bind/lib/isc/shuffle.c,v 1.4 2008/07/09 17:07:32 reyk Exp $ */
21
22
#include <sys/types.h>
23
24
#include <stdlib.h>
25
#include <assert.h>
26
27
#include "relayd.h"
28
29
#define VALID_SHUFFLE(x)	(x != NULL)
30
31
void
32
shuffle_init(struct shuffle *shuffle)
33
{
34
	int i, i2;
35
36
	assert(VALID_SHUFFLE(shuffle));
37
38
	shuffle->isindex = 0;
39
	/* Initialize using a Knuth shuffle */
40
	for (i = 0; i < 65536; ++i) {
41
		i2 = arc4random_uniform(i + 1);
42
		shuffle->id_shuffle[i] = shuffle->id_shuffle[i2];
43
		shuffle->id_shuffle[i2] = i;
44
	}
45
}
46
47
u_int16_t
48
shuffle_generate16(struct shuffle *shuffle)
49
{
50
	u_int32_t si;
51
	u_int16_t r;
52
	int i, i2;
53
54
	assert(VALID_SHUFFLE(shuffle));
55
56
	do {
57
		si = arc4random();
58
		i = shuffle->isindex & 0xFFFF;
59
		i2 = (shuffle->isindex - (si & 0x7FFF)) & 0xFFFF;
60
		r = shuffle->id_shuffle[i];
61
		shuffle->id_shuffle[i] = shuffle->id_shuffle[i2];
62
		shuffle->id_shuffle[i2] = r;
63
		shuffle->isindex++;
64
	} while (r == 0);
65
66
	return (r);
67
}