2 * Copyright (c) 2000-2013 Mark R V Murray
3 * Copyright (c) 2013 Arthur Mesh <arthurmesh@gmail.com>
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer
11 * in this position and unchanged.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
21 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
25 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD$");
32 #include <sys/param.h>
33 #include <sys/systm.h>
36 #include <sys/fcntl.h>
37 #include <sys/filio.h>
38 #include <sys/kernel.h>
39 #include <sys/kthread.h>
41 #include <sys/malloc.h>
42 #include <sys/module.h>
43 #include <sys/mutex.h>
47 #include <sys/random.h>
48 #include <sys/selinfo.h>
50 #include <sys/unistd.h>
52 #include <machine/bus.h>
53 #include <machine/cpu.h>
55 #include <dev/random/randomdev.h>
56 #include <dev/random/randomdev_soft.h>
57 #include <dev/random/random_adaptors.h>
58 #include <dev/random/random_harvestq.h>
59 #include <dev/random/live_entropy_sources.h>
61 #define RANDOM_MINOR 0
63 static d_read_t random_read;
64 static d_write_t random_write;
65 static d_ioctl_t random_ioctl;
66 static d_poll_t random_poll;
68 static struct cdevsw random_cdevsw = {
69 .d_version = D_VERSION,
70 .d_read = random_read,
71 .d_write = random_write,
72 .d_ioctl = random_ioctl,
73 .d_poll = random_poll,
77 /* For use with make_dev(9)/destroy_dev(9). */
78 static struct cdev *random_dev;
82 random_read(struct cdev *dev __unused, struct uio *uio, int flag)
88 if (!random_adaptor->seeded)
89 error = (*random_adaptor->block)(flag);
94 random_buf = (void *)malloc(PAGE_SIZE, M_ENTROPY, M_WAITOK);
96 while (uio->uio_resid > 0 && !error) {
97 c = MIN(uio->uio_resid, PAGE_SIZE);
98 c = (*random_adaptor->read)(random_buf, c);
99 error = uiomove(random_buf, c, uio);
101 /* Finished reading; let the source know so it can do some
102 * optional housekeeping */
103 (*random_adaptor->read)(NULL, 0);
105 free(random_buf, M_ENTROPY);
114 random_write(struct cdev *dev __unused, struct uio *uio, int flag __unused)
117 /* We used to allow this to insert userland entropy.
118 * We don't any more because (1) this so-called entropy
119 * is usually lousy and (b) its vaguely possible to
120 * mess with entropy harvesting by overdoing a write.
121 * Now we just ignore input like /dev/null does.
130 random_ioctl(struct cdev *dev __unused, u_long cmd, caddr_t addr __unused,
131 int flags __unused, struct thread *td __unused)
136 /* Really handled in upper layer */
148 random_poll(struct cdev *dev __unused, int events, struct thread *td)
152 if (events & (POLLIN | POLLRDNORM)) {
153 if (random_adaptor->seeded)
154 revents = events & (POLLIN | POLLRDNORM);
156 revents = (*random_adaptor->poll)(events, td);
162 random_initialize(void *p, struct random_adaptor *s)
164 static int random_inited = 0;
167 printf("random: <%s> already initialized\n",
168 random_adaptor->ident);
176 printf("random: <%s> initialized\n", s->ident);
178 /* Use an appropriately evil mode for those who are concerned
180 random_dev = make_dev_credf(MAKEDEV_ETERNAL_KLD, &random_cdevsw,
181 RANDOM_MINOR, NULL, UID_ROOT, GID_WHEEL, 0666, "random");
182 make_dev_alias(random_dev, "urandom"); /* compatibility */
184 /* mark random(4) as initialized, to avoid being called again */
190 random_modevent(module_t mod __unused, int type, void *data __unused)
192 static eventhandler_tag attach_tag = NULL;
197 random_adaptor_choose(&random_adaptor);
199 if (random_adaptor == NULL) {
200 printf("random: No random adaptor attached, "
201 "postponing initialization\n");
202 attach_tag = EVENTHANDLER_REGISTER(random_adaptor_attach,
203 random_initialize, NULL, EVENTHANDLER_PRI_ANY);
205 random_initialize(NULL, random_adaptor);
210 if (random_adaptor != NULL) {
211 (*random_adaptor->deinit)();
212 destroy_dev(random_dev);
214 /* Unregister the event handler */
215 if (attach_tag != NULL)
216 EVENTHANDLER_DEREGISTER(random_adaptor_attach,
232 DEV_MODULE(random, random_modevent, NULL);
233 MODULE_VERSION(random, 1);