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/*-
* Copyright (c) 2000-2013 Mark R V Murray
* Copyright (c) 2013 Arthur Mesh <arthurmesh@gmail.com>
* 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 <sys/param.h>
#include <sys/systm.h>
#include <sys/bus.h>
#include <sys/conf.h>
#include <sys/fcntl.h>
#include <sys/filio.h>
#include <sys/kernel.h>
#include <sys/kthread.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/module.h>
#include <sys/mutex.h>
#include <sys/poll.h>
#include <sys/priv.h>
#include <sys/proc.h>
#include <sys/random.h>
#include <sys/selinfo.h>
#include <sys/uio.h>
#include <sys/unistd.h>
#include <machine/bus.h>
#include <machine/cpu.h>
#include <dev/random/randomdev.h>
#include <dev/random/randomdev_soft.h>
#include <dev/random/random_adaptors.h>
#include <dev/random/random_harvestq.h>
#include <dev/random/live_entropy_sources.h>
#define RANDOM_MINOR 0
static d_read_t random_read;
static d_write_t random_write;
static d_ioctl_t random_ioctl;
static d_poll_t random_poll;
static struct cdevsw random_cdevsw = {
.d_version = D_VERSION,
.d_read = random_read,
.d_write = random_write,
.d_ioctl = random_ioctl,
.d_poll = random_poll,
.d_name = "random",
};
/* For use with make_dev(9)/destroy_dev(9). */
static struct cdev *random_dev;
/* ARGSUSED */
static int
random_read(struct cdev *dev __unused, struct uio *uio, int flag)
{
int c, error = 0;
void *random_buf;
/* Blocking logic */
if (!random_adaptor->seeded)
error = (*random_adaptor->block)(flag);
/* The actual read */
if (!error) {
random_buf = (void *)malloc(PAGE_SIZE, M_ENTROPY, M_WAITOK);
while (uio->uio_resid > 0 && !error) {
c = MIN(uio->uio_resid, PAGE_SIZE);
c = (*random_adaptor->read)(random_buf, c);
error = uiomove(random_buf, c, uio);
}
/* Finished reading; let the source know so it can do some
* optional housekeeping */
(*random_adaptor->read)(NULL, 0);
free(random_buf, M_ENTROPY);
}
return (error);
}
/* ARGSUSED */
static int
random_write(struct cdev *dev __unused, struct uio *uio, int flag __unused)
{
/* We used to allow this to insert userland entropy.
* We don't any more because (1) this so-called entropy
* is usually lousy and (b) its vaguely possible to
* mess with entropy harvesting by overdoing a write.
* Now we just ignore input like /dev/null does.
*/
uio->uio_resid = 0;
return (0);
}
/* ARGSUSED */
static int
random_ioctl(struct cdev *dev __unused, u_long cmd, caddr_t addr __unused,
int flags __unused, struct thread *td __unused)
{
int error = 0;
switch (cmd) {
/* Really handled in upper layer */
case FIOASYNC:
case FIONBIO:
break;
default:
error = ENOTTY;
}
return (error);
}
/* ARGSUSED */
static int
random_poll(struct cdev *dev __unused, int events, struct thread *td)
{
int revents = 0;
if (events & (POLLIN | POLLRDNORM)) {
if (random_adaptor->seeded)
revents = events & (POLLIN | POLLRDNORM);
else
revents = (*random_adaptor->poll)(events, td);
}
return (revents);
}
static void
random_initialize(void *p, struct random_adaptor *s)
{
static int random_inited = 0;
if (random_inited) {
printf("random: <%s> already initialized\n",
random_adaptor->ident);
return;
}
random_adaptor = s;
(s->init)();
printf("random: <%s> initialized\n", s->ident);
/* Use an appropriately evil mode for those who are concerned
* with daemons */
random_dev = make_dev_credf(MAKEDEV_ETERNAL_KLD, &random_cdevsw,
RANDOM_MINOR, NULL, UID_ROOT, GID_WHEEL, 0666, "random");
/* mark random(4) as initialized, to avoid being called again */
random_inited = 1;
}
/* ARGSUSED */
static int
random_modevent(module_t mod __unused, int type, void *data __unused)
{
static eventhandler_tag attach_tag = NULL;
int error = 0;
switch (type) {
case MOD_LOAD:
random_adaptor_choose(&random_adaptor);
if (random_adaptor == NULL) {
printf("random: No random adaptor attached, "
"postponing initialization\n");
attach_tag = EVENTHANDLER_REGISTER(random_adaptor_attach,
random_initialize, NULL, EVENTHANDLER_PRI_ANY);
} else
random_initialize(NULL, random_adaptor);
break;
case MOD_UNLOAD:
if (random_adaptor != NULL) {
(*random_adaptor->deinit)();
destroy_dev(random_dev);
}
/* Unregister the event handler */
if (attach_tag != NULL)
EVENTHANDLER_DEREGISTER(random_adaptor_attach,
attach_tag);
break;
case MOD_SHUTDOWN:
break;
default:
error = EOPNOTSUPP;
break;
}
return (error);
}
DEV_MODULE(random, random_modevent, NULL);
MODULE_VERSION(random, 1);
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