randomdev.c revision 62840 
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 62840 2000-07-09 11:49:07Z 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/yarrow.h>
48
49static d_read_t random_read;
50static d_write_t random_write;
51
52#define CDEV_MAJOR	2
53#define RANDOM_MINOR	3
54#define URANDOM_MINOR	4
55
56static struct cdevsw random_cdevsw = {
57	/* open */	(d_open_t *)nullop,
58	/* close */	(d_close_t *)nullop,
59	/* read */	random_read,
60	/* write */	random_write,
61	/* ioctl */	noioctl,
62	/* poll */	nopoll,
63	/* mmap */	nommap,
64	/* strategy */	nostrategy,
65	/* name */	"random",
66	/* maj */	CDEV_MAJOR,
67	/* dump */	nodump,
68	/* psize */	nopsize,
69	/* flags */	0,
70	/* bmaj */	-1
71};
72
73/* For use with make_dev(9)/destroy_dev(9). */
74static dev_t random_dev;
75static dev_t urandom_dev;
76
77SYSCTL_NODE(_kern, OID_AUTO, random, CTLFLAG_RW, 0, "Random Number Generator");
78SYSCTL_NODE(_kern_random, OID_AUTO, yarrow, CTLFLAG_RW, 0, "Yarrow Parameters");
79SYSCTL_INT(_kern_random_yarrow, OID_AUTO, gengateinterval, CTLFLAG_RW,
80	&random_state.gengateinterval, 10, "Generator Gate Interval");
81SYSCTL_INT(_kern_random_yarrow, OID_AUTO, bins, CTLFLAG_RW,
82	&random_state.bins, 10, "Execution time tuner");
83SYSCTL_INT(_kern_random_yarrow, OID_AUTO, fastthresh, CTLFLAG_RW,
84	&random_state.pool[0].thresh, 100, "Fast pool reseed threshhold");
85SYSCTL_INT(_kern_random_yarrow, OID_AUTO, slowthresh, CTLFLAG_RW,
86	&random_state.pool[1].thresh, 100, "Slow pool reseed threshhold");
87SYSCTL_INT(_kern_random_yarrow, OID_AUTO, slowoverthresh, CTLFLAG_RW,
88	&random_state.slowoverthresh, 2, "Slow pool over-threshhold reseed");
89
90static int
91random_read(dev_t dev, struct uio *uio, int flag)
92{
93	u_int c, ret;
94	int error = 0;
95	void *random_buf;
96
97	c = min(uio->uio_resid, PAGE_SIZE);
98	random_buf = (void *)malloc(c, M_TEMP, M_WAITOK);
99	while (uio->uio_resid > 0 && error == 0) {
100		ret = read_random(random_buf, c);
101		error = uiomove(random_buf, ret, uio);
102	}
103	free(random_buf, M_TEMP);
104	return error;
105}
106
107static int
108random_write(dev_t dev, struct uio *uio, int flag)
109{
110	u_int c;
111	int error = 0;
112	void *random_buf;
113
114	random_buf = (void *)malloc(PAGE_SIZE, M_TEMP, M_WAITOK);
115	while (uio->uio_resid > 0) {
116		c = min(uio->uio_resid, PAGE_SIZE);
117		error = uiomove(random_buf, c, uio);
118		if (error)
119			break;
120		/* write_random(random_buf, c); */
121	}
122	free(random_buf, M_TEMP);
123	return error;
124}
125
126static int
127random_modevent(module_t mod, int type, void *data)
128{
129	switch(type) {
130	case MOD_LOAD:
131		if (bootverbose)
132			printf("random: <entropy source>\n");
133		random_dev = make_dev(&random_cdevsw, RANDOM_MINOR, UID_ROOT,
134			GID_WHEEL, 0666, "random");
135		urandom_dev = make_dev(&random_cdevsw, URANDOM_MINOR, UID_ROOT,
136			GID_WHEEL, 0666, "urandom");
137		random_init();
138		return 0;
139
140	case MOD_UNLOAD:
141		random_deinit();
142		destroy_dev(random_dev);
143		destroy_dev(urandom_dev);
144		return 0;
145
146	case MOD_SHUTDOWN:
147		return 0;
148
149	default:
150		return EOPNOTSUPP;
151	}
152}
153
154DEV_MODULE(random, random_modevent, NULL);
155