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freebsd/sys/dev/random/randomdev.c
Mark Murray 14636c3b51 Provide the infrastructure for sysadmins to select the broad class
of entropy harvesting they wish to perform: "ethernet" (LAN),
point-to-point and interrupt.
2001-02-18 17:40:47 +00:00

261 lines
7.3 KiB
C

/*-
* Copyright (c) 2000 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.
*
* $FreeBSD$
*/
#include <sys/param.h>
#include <sys/queue.h>
#include <sys/systm.h>
#include <sys/conf.h>
#include <sys/fcntl.h>
#include <sys/uio.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/module.h>
#include <sys/bus.h>
#include <sys/poll.h>
#include <sys/selinfo.h>
#include <sys/random.h>
#include <sys/sysctl.h>
#include <sys/vnode.h>
#include <machine/bus.h>
#include <machine/resource.h>
#include <crypto/blowfish/blowfish.h>
#include <dev/random/hash.h>
#include <dev/random/yarrow.h>
static d_open_t random_open;
static d_close_t random_close;
static d_read_t random_read;
static d_write_t random_write;
static d_ioctl_t random_ioctl;
static d_poll_t random_poll;
#define CDEV_MAJOR 2
#define RANDOM_MINOR 3
#define URANDOM_MINOR 4
static struct cdevsw random_cdevsw = {
/* open */ random_open,
/* close */ random_close,
/* read */ random_read,
/* write */ random_write,
/* ioctl */ random_ioctl,
/* poll */ random_poll,
/* mmap */ nommap,
/* strategy */ nostrategy,
/* name */ "random",
/* maj */ CDEV_MAJOR,
/* dump */ nodump,
/* psize */ nopsize,
/* flags */ 0,
/* bmaj */ -1
};
/* For use with make_dev(9)/destroy_dev(9). */
static dev_t random_dev;
static dev_t urandom_dev; /* XXX Temporary */
/* To stash the sysctl's until they are removed */
static struct sysctl_oid *random_sysctl[12]; /* magic # is sysctl count */
static int sysctlcount = 0;
static int
random_open(dev_t dev, int flags, int fmt, struct proc *p)
{
if ((flags & FWRITE) && (securelevel > 0 || suser(p)))
return EPERM;
else
return 0;
}
static int
random_close(dev_t dev, int flags, int fmt, struct proc *p)
{
if ((flags & FWRITE) && !(securelevel > 0 || suser(p)))
random_reseed();
return 0;
}
static int
random_read(dev_t dev, struct uio *uio, int flag)
{
u_int c, ret;
int error = 0;
void *random_buf;
while (!random_state.seeded) {
if (flag & IO_NDELAY)
error = EWOULDBLOCK;
else
error = tsleep(&random_state, PUSER|PCATCH, "rndblk", 0);
if (error != 0)
return error;
}
c = min(uio->uio_resid, PAGE_SIZE);
random_buf = (void *)malloc(c, M_TEMP, M_WAITOK);
while (uio->uio_resid > 0 && error == 0) {
ret = read_random_real(random_buf, c);
error = uiomove(random_buf, ret, uio);
}
free(random_buf, M_TEMP);
return error;
}
static int
random_write(dev_t dev, struct uio *uio, int flag)
{
u_int c;
int error = 0;
void *random_buf;
random_buf = (void *)malloc(PAGE_SIZE, M_TEMP, M_WAITOK);
while (uio->uio_resid > 0) {
c = min(uio->uio_resid, PAGE_SIZE);
error = uiomove(random_buf, c, uio);
if (error)
break;
write_random(random_buf, c);
}
free(random_buf, M_TEMP);
return error;
}
static int
random_ioctl(dev_t dev, u_long cmd, caddr_t addr, int flags, struct proc *p)
{
return ENOTTY;
}
static int
random_poll(dev_t dev, int events, struct proc *p)
{
int revents;
revents = 0;
if (events & (POLLIN | POLLRDNORM)) {
if (random_state.seeded)
revents = events & (POLLIN | POLLRDNORM);
else
selrecord(p, &random_state.rsel);
}
return revents;
}
static int
random_modevent(module_t mod, int type, void *data)
{
struct sysctl_oid *node_base, *node1, *node2;
int error, i;
switch(type) {
case MOD_LOAD:
error = random_init();
if (error != 0)
return error;
random_sysctl[sysctlcount++] = node_base =
SYSCTL_ADD_NODE(NULL, SYSCTL_STATIC_CHILDREN(_kern),
OID_AUTO, "random", CTLFLAG_RW, 0,
"Random Number Generator");
random_sysctl[sysctlcount++] = node1 =
SYSCTL_ADD_NODE(NULL, SYSCTL_CHILDREN(node_base),
OID_AUTO, "sys", CTLFLAG_RW, 0,
"Entropy Device Parameters");
random_sysctl[sysctlcount++] =
SYSCTL_ADD_INT(NULL, SYSCTL_CHILDREN(node1),
OID_AUTO, "seeded", CTLFLAG_RW,
&random_state.seeded, 0, "Seeded State");
random_sysctl[sysctlcount++] =
SYSCTL_ADD_INT(NULL, SYSCTL_CHILDREN(node1),
OID_AUTO, "harvest_ethernet", CTLFLAG_RW,
&harvest.ethernet, 0, "Harvest NIC entropy");
random_sysctl[sysctlcount++] =
SYSCTL_ADD_INT(NULL, SYSCTL_CHILDREN(node1),
OID_AUTO, "harvest_point_to_point", CTLFLAG_RW,
&harvest.point_to_point, 0, "Harvest serial net entropy");
random_sysctl[sysctlcount++] =
SYSCTL_ADD_INT(NULL, SYSCTL_CHILDREN(node1),
OID_AUTO, "harvest_interrupt", CTLFLAG_RW,
&harvest.interrupt, 0, "Harvest IRQ entropy");
random_sysctl[sysctlcount++] = node2 =
SYSCTL_ADD_NODE(NULL, SYSCTL_CHILDREN(node_base),
OID_AUTO, "yarrow", CTLFLAG_RW, 0,
"Yarrow Parameters");
random_sysctl[sysctlcount++] =
SYSCTL_ADD_INT(NULL, SYSCTL_CHILDREN(node2),
OID_AUTO, "gengateinterval", CTLFLAG_RW,
&random_state.gengateinterval, 0,
"Generator Gate Interval");
random_sysctl[sysctlcount++] =
SYSCTL_ADD_INT(NULL, SYSCTL_CHILDREN(node2),
OID_AUTO, "bins", CTLFLAG_RW,
&random_state.bins, 0,
"Execution time tuner");
random_sysctl[sysctlcount++] =
SYSCTL_ADD_INT(NULL, SYSCTL_CHILDREN(node2),
OID_AUTO, "fastthresh", CTLFLAG_RW,
&random_state.pool[0].thresh, 0,
"Fast pool reseed threshhold");
random_sysctl[sysctlcount++] =
SYSCTL_ADD_INT(NULL, SYSCTL_CHILDREN(node2),
OID_AUTO, "slowthresh", CTLFLAG_RW,
&random_state.pool[1].thresh, 0,
"Slow pool reseed threshhold");
random_sysctl[sysctlcount++] =
SYSCTL_ADD_INT(NULL, SYSCTL_CHILDREN(node2),
OID_AUTO, "slowoverthresh", CTLFLAG_RW,
&random_state.slowoverthresh, 0,
"Slow pool over-threshhold reseed");
if (bootverbose)
printf("random: <entropy source>\n");
random_dev = make_dev(&random_cdevsw, RANDOM_MINOR, UID_ROOT,
GID_WHEEL, 0666, "random");
urandom_dev = make_dev(&random_cdevsw, URANDOM_MINOR, UID_ROOT,
GID_WHEEL, 0666, "urandom"); /* XXX Temporary */
return 0;
case MOD_UNLOAD:
random_deinit();
destroy_dev(random_dev);
destroy_dev(urandom_dev); /* XXX Temporary */
for (i = sysctlcount - 1; i >= 0; i--)
if (sysctl_remove_oid(random_sysctl[i], 1, 0) == EINVAL)
panic("random: removing sysctl");
return 0;
case MOD_SHUTDOWN:
return 0;
default:
return EOPNOTSUPP;
}
}
DEV_MODULE(random, random_modevent, NULL);