1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
|
#include <machine/rtems-bsd-kernel-space.h>
/*-
* Copyright (c) 2000-2004 Mark R V Murray
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer
* in this position and unchanged.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <rtems/bsd/sys/param.h>
#include <sys/kthread.h>
#include <rtems/bsd/sys/lock.h>
#include <sys/malloc.h>
#include <sys/mutex.h>
#include <sys/poll.h>
#include <sys/queue.h>
#include <sys/random.h>
#include <sys/selinfo.h>
#include <sys/systm.h>
#include <sys/sysctl.h>
#include <machine/cpu.h>
#include <dev/random/randomdev_soft.h>
static int read_random_phony(void *, int);
/* Structure holding the desired entropy sources */
struct harvest_select harvest = { 1, 1, 1, 0 };
/* hold the address of the routine which is actually called if
* the randomdev is loaded
*/
static void (*reap_func)(u_int64_t, const void *, u_int, u_int, u_int,
enum esource) = NULL;
static int (*read_func)(void *, int) = read_random_phony;
/* Initialise the harvester at load time */
void
random_yarrow_init_harvester(void (*reaper)(u_int64_t, const void *, u_int,
u_int, u_int, enum esource), int (*reader)(void *, int))
{
reap_func = reaper;
read_func = reader;
}
/* Deinitialise the harvester at unload time */
void
random_yarrow_deinit_harvester(void)
{
reap_func = NULL;
read_func = read_random_phony;
}
/* Entropy harvesting routine. This is supposed to be fast; do
* not do anything slow in here!
* Implemented as in indirect call to allow non-inclusion of
* the entropy device.
*
* XXXRW: get_cyclecount() is cheap on most modern hardware, where cycle
* counters are built in, but on older hardware it will do a real time clock
* read which can be quite expensive.
*/
void
random_harvest(void *entropy, u_int count, u_int bits, u_int frac,
enum esource origin)
{
if (reap_func)
(*reap_func)(get_cyclecount(), entropy, count, bits, frac,
origin);
}
/* Userland-visible version of read_random */
int
read_random(void *buf, int count)
{
return ((*read_func)(buf, count));
}
/* If the entropy device is not loaded, make a token effort to
* provide _some_ kind of randomness. This should only be used
* inside other RNG's, like arc4random(9).
*/
static int
read_random_phony(void *buf, int count)
{
u_long randval;
int size, i;
/* srandom() is called in kern/init_main.c:proc0_post() */
/* Fill buf[] with random(9) output */
for (i = 0; i < count; i+= (int)sizeof(u_long)) {
randval = random();
size = MIN(count - i, sizeof(u_long));
memcpy(&((char *)buf)[i], &randval, (size_t)size);
}
return (count);
}
/* Helper routine to enable kproc_exit() to work while the module is
* being (or has been) unloaded.
* This routine is in this file because it is always linked into the kernel,
* and will thus never be unloaded. This is critical for unloadable modules
* that have threads.
*/
void
random_set_wakeup_exit(void *control)
{
wakeup(control);
kproc_exit(0);
/* NOTREACHED */
}
|
