159 lines
3.7 KiB
C
159 lines
3.7 KiB
C
/*
|
|
* Copyright (c) 2000, 2001, 2002, 2003, 2004, 2005, 2008, 2009
|
|
* The President and Fellows of Harvard College.
|
|
*
|
|
* 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.
|
|
* 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.
|
|
* 3. Neither the name of the University nor the names of its contributors
|
|
* may be used to endorse or promote products derived from this software
|
|
* without specific prior written permission.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE UNIVERSITY AND CONTRIBUTORS ``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 UNIVERSITY OR CONTRIBUTORS 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 <types.h>
|
|
#include <kern/errno.h>
|
|
#include <kern/fcntl.h>
|
|
#include <lib.h>
|
|
#include <uio.h>
|
|
#include <vfs.h>
|
|
#include <generic/random.h>
|
|
#include "autoconf.h"
|
|
|
|
/*
|
|
* Machine-independent generic randomness device.
|
|
*
|
|
* Remembers something that's a random source, and provides random()
|
|
* and randmax() to the rest of the kernel.
|
|
*
|
|
* The kernel config mechanism can be used to explicitly choose which
|
|
* of the available random sources to use, if more than one is
|
|
* available.
|
|
*/
|
|
|
|
static struct random_softc *the_random = NULL;
|
|
|
|
/*
|
|
* VFS device functions.
|
|
* open: allow reading only.
|
|
*/
|
|
static
|
|
int
|
|
randeachopen(struct device *dev, int openflags)
|
|
{
|
|
(void)dev;
|
|
|
|
if (openflags != O_RDONLY) {
|
|
return EIO;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* VFS I/O function. Hand off to implementation.
|
|
*/
|
|
static
|
|
int
|
|
randio(struct device *dev, struct uio *uio)
|
|
{
|
|
struct random_softc *rs = dev->d_data;
|
|
|
|
if (uio->uio_rw != UIO_READ) {
|
|
return EIO;
|
|
}
|
|
|
|
return rs->rs_read(rs->rs_devdata, uio);
|
|
}
|
|
|
|
/*
|
|
* VFS ioctl function.
|
|
*/
|
|
static
|
|
int
|
|
randioctl(struct device *dev, int op, userptr_t data)
|
|
{
|
|
/*
|
|
* We don't support any ioctls.
|
|
*/
|
|
(void)dev;
|
|
(void)op;
|
|
(void)data;
|
|
return EIOCTL;
|
|
}
|
|
|
|
static const struct device_ops random_devops = {
|
|
.devop_eachopen = randeachopen,
|
|
.devop_io = randio,
|
|
.devop_ioctl = randioctl,
|
|
};
|
|
|
|
/*
|
|
* Config function.
|
|
*/
|
|
int
|
|
config_random(struct random_softc *rs, int unit)
|
|
{
|
|
int result;
|
|
|
|
/* We use only the first random device. */
|
|
if (unit!=0) {
|
|
return ENODEV;
|
|
}
|
|
|
|
KASSERT(the_random==NULL);
|
|
the_random = rs;
|
|
|
|
rs->rs_dev.d_ops = &random_devops;
|
|
rs->rs_dev.d_blocks = 0;
|
|
rs->rs_dev.d_blocksize = 1;
|
|
rs->rs_dev.d_data = rs;
|
|
|
|
/* Add the VFS device structure to the VFS device list. */
|
|
result = vfs_adddev("random", &rs->rs_dev, 0);
|
|
if (result) {
|
|
return result;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
|
|
/*
|
|
* Random number functions exported to the rest of the kernel.
|
|
*/
|
|
|
|
uint32_t
|
|
random(void)
|
|
{
|
|
if (the_random==NULL) {
|
|
panic("No random device\n");
|
|
}
|
|
return the_random->rs_random(the_random->rs_devdata);
|
|
}
|
|
|
|
uint32_t
|
|
randmax(void)
|
|
{
|
|
if (the_random==NULL) {
|
|
panic("No random device\n");
|
|
}
|
|
return the_random->rs_randmax(the_random->rs_devdata);
|
|
}
|