randomdev.c revision 65686 
1/*-
2 * Copyright (c) 2000 Mark R V Murray
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer
10 *    in this position and unchanged.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 *    notice, this list of conditions and the following disclaimer in the
13 *    documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25 *
26 * $FreeBSD: head/sys/dev/random/randomdev.c 65686 2000-09-10 13:52:19Z markm $
27 */
28
29#include <sys/param.h>
30#include <sys/queue.h>
31#include <sys/systm.h>
32#include <sys/conf.h>
33#include <sys/fcntl.h>
34#include <sys/uio.h>
35#include <sys/kernel.h>
36#include <sys/malloc.h>
37#include <sys/module.h>
38#include <sys/bus.h>
39#include <sys/random.h>
40#include <machine/bus.h>
41#include <machine/resource.h>
42#include <sys/rman.h>
43#include <sys/signalvar.h>
44#include <sys/sysctl.h>
45#include <crypto/blowfish/blowfish.h>
46
47#include <dev/randomdev/hash.h>
48#include <dev/randomdev/yarrow.h>
49
50static d_open_t random_open;
51static d_read_t random_read;
52static d_write_t random_write;
53static d_ioctl_t random_ioctl;
54
55#define CDEV_MAJOR	2
56#define RANDOM_MINOR	3
57#define URANDOM_MINOR	4
58
59static struct cdevsw random_cdevsw = {
60	/* open */	random_open,
61	/* close */	(d_close_t *)nullop,
62	/* read */	random_read,
63	/* write */	random_write,
64	/* ioctl */	random_ioctl,
65	/* poll */	nopoll,
66	/* mmap */	nommap,
67	/* strategy */	nostrategy,
68	/* name */	"random",
69	/* maj */	CDEV_MAJOR,
70	/* dump */	nodump,
71	/* psize */	nopsize,
72	/* flags */	0,
73	/* bmaj */	-1
74};
75
76/* For use with make_dev(9)/destroy_dev(9). */
77static dev_t random_dev;
78static dev_t urandom_dev; /* XXX Temporary */
79
80SYSCTL_NODE(_kern, OID_AUTO, random, CTLFLAG_RW, 0, "Random Number Generator");
81SYSCTL_NODE(_kern_random, OID_AUTO, yarrow, CTLFLAG_RW, 0, "Yarrow Parameters");
82SYSCTL_INT(_kern_random_yarrow, OID_AUTO, gengateinterval, CTLFLAG_RW,
83	&random_state.gengateinterval, 10, "Generator Gate Interval");
84SYSCTL_INT(_kern_random_yarrow, OID_AUTO, bins, CTLFLAG_RW,
85	&random_state.bins, 10, "Execution time tuner");
86SYSCTL_INT(_kern_random_yarrow, OID_AUTO, fastthresh, CTLFLAG_RW,
87	&random_state.pool[0].thresh, 100, "Fast pool reseed threshhold");
88SYSCTL_INT(_kern_random_yarrow, OID_AUTO, slowthresh, CTLFLAG_RW,
89	&random_state.pool[1].thresh, 160, "Slow pool reseed threshhold");
90SYSCTL_INT(_kern_random_yarrow, OID_AUTO, slowoverthresh, CTLFLAG_RW,
91	&random_state.slowoverthresh, 2, "Slow pool over-threshhold reseed");
92
93static int
94random_open(dev_t dev, int flags, int fmt, struct proc *p)
95{
96	if ((flags & FWRITE) && (securelevel > 0 || suser(p)))
97		return EPERM;
98	else
99		return 0;
100}
101
102static int
103random_read(dev_t dev, struct uio *uio, int flag)
104{
105	u_int c, ret;
106	int error = 0;
107	void *random_buf;
108
109	c = min(uio->uio_resid, PAGE_SIZE);
110	random_buf = (void *)malloc(c, M_TEMP, M_WAITOK);
111	while (uio->uio_resid > 0 && error == 0) {
112		ret = read_random(uio->uio_procp, random_buf, c);
113		error = uiomove(random_buf, ret, uio);
114	}
115	free(random_buf, M_TEMP);
116	return error;
117}
118
119static int
120random_write(dev_t dev, struct uio *uio, int flag)
121{
122	u_int c;
123	int error = 0;
124	void *random_buf;
125
126	random_buf = (void *)malloc(PAGE_SIZE, M_TEMP, M_WAITOK);
127	while (uio->uio_resid > 0) {
128		c = min(uio->uio_resid, PAGE_SIZE);
129		error = uiomove(random_buf, c, uio);
130		if (error)
131			break;
132		write_random(random_buf, c);
133	}
134	free(random_buf, M_TEMP);
135	return error;
136}
137
138static int
139random_ioctl(dev_t dev, u_long cmd, caddr_t addr, int flags, struct proc *p)
140{
141	return ENOTTY;
142}
143
144static int
145random_modevent(module_t mod, int type, void *data)
146{
147	int error;
148
149	switch(type) {
150	case MOD_LOAD:
151		error = random_init();
152		if (error != 0)
153			return error;
154		if (bootverbose)
155			printf("random: <entropy source>\n");
156		random_dev = make_dev(&random_cdevsw, RANDOM_MINOR, UID_ROOT,
157			GID_WHEEL, 0666, "random");
158		urandom_dev = make_dev(&random_cdevsw, URANDOM_MINOR, UID_ROOT,
159			GID_WHEEL, 0666, "urandom"); /* XXX Temporary */
160		return 0;
161
162	case MOD_UNLOAD:
163		random_deinit();
164		destroy_dev(random_dev);
165		destroy_dev(urandom_dev); /* XXX Temporary */
166		return 0;
167
168	case MOD_SHUTDOWN:
169		return 0;
170
171	default:
172		return EOPNOTSUPP;
173	}
174}
175
176DEV_MODULE(random, random_modevent, NULL);
177