2 * Copyright (c) 2015 Mark R V Murray
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer
10 * in this position and unchanged.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28 #include <sys/cdefs.h>
29 __FBSDID("$FreeBSD$");
31 #include <sys/param.h>
32 #include <sys/systm.h>
33 #include <sys/kernel.h>
34 #include <sys/malloc.h>
35 #include <sys/random.h>
36 #include <sys/sysctl.h>
38 #if defined(RANDOM_LOADABLE)
43 #include <dev/random/randomdev.h>
45 /* Set up the sysctl root node for the entropy device */
46 SYSCTL_NODE(_kern, OID_AUTO, random, CTLFLAG_RW, 0, "Cryptographically Secure Random Number Generator");
48 MALLOC_DEFINE(M_ENTROPY, "entropy", "Entropy harvesting buffers and data structures");
50 struct sources_head source_list = LIST_HEAD_INITIALIZER(source_list);
52 #if defined(RANDOM_LOADABLE)
53 struct random_algorithm *p_random_alg_context = NULL;
54 #else /* !defined(RANDOM_LOADABLE) */
55 struct random_algorithm *p_random_alg_context = &random_alg_context;
56 #endif /* defined(RANDOM_LOADABLE) */
58 #if defined(RANDOM_LOADABLE)
61 null_read_random(void *dummy __unused, u_int dummy2 __unused)
63 panic("%s: no random module is loaded", __func__);
66 struct random_readers {
67 int (*read_random_uio)(struct uio *, bool);
68 void (*read_random)(void *, u_int);
69 } random_reader_context = {
70 (int (*)(struct uio *, bool))nullop,
74 struct sx randomdev_config_lock;
77 random_infra_sysinit(void *dummy __unused)
80 RANDOM_CONFIG_INIT_LOCK();
82 SYSINIT(random_device_h_init, SI_SUB_RANDOM, SI_ORDER_FIRST, random_infra_sysinit, NULL);
85 random_infra_init(int (*p_random_read_uio)(struct uio *, bool), void (*p_random_read)(void *, u_int))
88 RANDOM_CONFIG_X_LOCK();
89 random_reader_context.read_random_uio = p_random_read_uio;
90 random_reader_context.read_random = p_random_read;
91 RANDOM_CONFIG_X_UNLOCK();
95 random_infra_uninit(void)
98 RANDOM_CONFIG_X_LOCK();
99 random_reader_context.read_random_uio = (int (*)(struct uio *, bool))nullop;
100 random_reader_context.read_random = null_read_random;
101 RANDOM_CONFIG_X_UNLOCK();
105 random_infra_sysuninit(void *dummy __unused)
108 RANDOM_CONFIG_DEINIT_LOCK();
110 SYSUNINIT(random_device_h_init, SI_SUB_RANDOM, SI_ORDER_FIRST, random_infra_sysuninit, NULL);
113 read_random_uio(struct uio *uio, bool nonblock)
117 RANDOM_CONFIG_S_LOCK();
118 retval = random_reader_context.read_random_uio(uio, nonblock);
119 RANDOM_CONFIG_S_UNLOCK();
124 read_random(void *buf, u_int len)
127 RANDOM_CONFIG_S_LOCK();
128 random_reader_context.read_random(buf, len);
129 RANDOM_CONFIG_S_UNLOCK();
132 #endif /* defined(RANDOM_LOADABLE) */