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/*-
* Copyright (c) 2013 Arthur Mesh <arthurmesh@gmail.com>
* Copyright (c) 2013 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 "opt_random.h"
#include <sys/param.h>
#include <sys/conf.h>
#include <sys/fcntl.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/random.h>
#include <sys/syslog.h>
#include <sys/systm.h>
#include <dev/random/randomdev.h>
#include <dev/random/random_adaptors.h>
static int
dummy_random_zero(void)
{
return (0);
}
static void
dummy_random(void)
{
}
/* ARGSUSED */
static void
dummy_random_init(void)
{
#ifdef RANDOM_DEBUG
printf("random: %s\n", __func__);
#endif
randomdev_init_reader(dummy_random_read_phony);
}
/* This is used only by the internal read_random(9) call, and then only
* if no entropy processor is loaded.
*
* Make a token effort to provide _some_ kind of output. No warranty of
* the quality of this output is made, mainly because its lousy.
*
* This is only used by the internal read_random(9) call when no other
* adaptor is active.
*
* It has external scope due to the way things work in
* randomdev_[de]init_reader() that the rest of the world doesn't need to
* know about.
*
* Caveat Emptor.
*/
void
dummy_random_read_phony(uint8_t *buf, u_int count)
{
/* If no entropy device is loaded, don't spam the console with warnings */
u_long randval;
size_t size, i;
/* srandom() is called in kern/init_main.c:proc0_post() */
/* Fill buf[] with random(9) output */
for (i = 0; i < count; i += sizeof(randval)) {
randval = random();
size = MIN(count - i, sizeof(randval));
memcpy(buf + i, &randval, (size_t)size);
}
}
struct random_adaptor randomdev_dummy = {
.ra_ident = "Dummy",
.ra_priority = 1, /* Bottom priority, so goes to last position */
.ra_reseed = dummy_random,
.ra_seeded = (random_adaptor_seeded_func_t *)dummy_random_zero,
.ra_read = (random_adaptor_read_func_t *)dummy_random_zero,
.ra_write = (random_adaptor_write_func_t *)dummy_random_zero,
.ra_init = dummy_random_init,
.ra_deinit = dummy_random,
};
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