randomdev.c revision 70834
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 70834 2001-01-09 04:33:49Z wollman $ 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/poll.h> 40#include <sys/selinfo.h> 41#include <sys/random.h> 42#include <sys/vnode.h> 43#include <machine/bus.h> 44#include <machine/resource.h> 45#include <sys/sysctl.h> 46#include <crypto/blowfish/blowfish.h> 47 48#include <dev/random/hash.h> 49#include <dev/random/yarrow.h> 50 51#include "opt_noblockrandom.h" 52 53static d_open_t random_open; 54static d_close_t random_close; 55static d_read_t random_read; 56static d_write_t random_write; 57static d_ioctl_t random_ioctl; 58static d_poll_t random_poll; 59 60#define CDEV_MAJOR 2 61#define RANDOM_MINOR 3 62#define URANDOM_MINOR 4 63 64static struct cdevsw random_cdevsw = { 65 /* open */ random_open, 66 /* close */ random_close, 67 /* read */ random_read, 68 /* write */ random_write, 69 /* ioctl */ random_ioctl, 70 /* poll */ random_poll, 71 /* mmap */ nommap, 72 /* strategy */ nostrategy, 73 /* name */ "random", 74 /* maj */ CDEV_MAJOR, 75 /* dump */ nodump, 76 /* psize */ nopsize, 77 /* flags */ 0, 78 /* bmaj */ -1 79}; 80 81/* For use with make_dev(9)/destroy_dev(9). */ 82static dev_t random_dev; 83static dev_t urandom_dev; /* XXX Temporary */ 84 85SYSCTL_NODE(_kern, OID_AUTO, random, CTLFLAG_RW, 0, "Random Number Generator"); 86SYSCTL_NODE(_kern_random, OID_AUTO, yarrow, CTLFLAG_RW, 0, "Yarrow Parameters"); 87SYSCTL_INT(_kern_random_yarrow, OID_AUTO, gengateinterval, CTLFLAG_RW, 88 &random_state.gengateinterval, 10, "Generator Gate Interval"); 89SYSCTL_INT(_kern_random_yarrow, OID_AUTO, bins, CTLFLAG_RW, 90 &random_state.bins, 10, "Execution time tuner"); 91SYSCTL_INT(_kern_random_yarrow, OID_AUTO, fastthresh, CTLFLAG_RW, 92 &random_state.pool[0].thresh, 100, "Fast pool reseed threshhold"); 93SYSCTL_INT(_kern_random_yarrow, OID_AUTO, slowthresh, CTLFLAG_RW, 94 &random_state.pool[1].thresh, 160, "Slow pool reseed threshhold"); 95SYSCTL_INT(_kern_random_yarrow, OID_AUTO, slowoverthresh, CTLFLAG_RW, 96 &random_state.slowoverthresh, 2, "Slow pool over-threshhold reseed"); 97 98static int 99random_open(dev_t dev, int flags, int fmt, struct proc *p) 100{ 101 if ((flags & FWRITE) && (securelevel > 0 || suser(p))) 102 return EPERM; 103 else 104 return 0; 105} 106 107static int 108random_close(dev_t dev, int flags, int fmt, struct proc *p) 109{ 110 if ((flags & FWRITE) && !(securelevel > 0 || suser(p))) 111 random_reseed(); 112 return 0; 113} 114 115static int 116random_read(dev_t dev, struct uio *uio, int flag) 117{ 118 u_int c, ret; 119 int error = 0; 120 void *random_buf; 121 122/* XXX Temporary ifndef to allow users to have a nonblocking device */ 123#ifndef NOBLOCKRANDOM 124 while (!random_state.seeded) { 125 if (flag & IO_NDELAY) 126 error = EWOULDBLOCK; 127 else 128 error = tsleep(&random_state, PUSER|PCATCH, "rndblk", 0); 129 if (error != 0) 130 return error; 131 } 132#endif 133 c = min(uio->uio_resid, PAGE_SIZE); 134 random_buf = (void *)malloc(c, M_TEMP, M_WAITOK); 135 while (uio->uio_resid > 0 && error == 0) { 136 ret = read_random_real(random_buf, c); 137 error = uiomove(random_buf, ret, uio); 138 } 139 free(random_buf, M_TEMP); 140 return error; 141} 142 143static int 144random_write(dev_t dev, struct uio *uio, int flag) 145{ 146 u_int c; 147 int error = 0; 148 void *random_buf; 149 150 random_buf = (void *)malloc(PAGE_SIZE, M_TEMP, M_WAITOK); 151 while (uio->uio_resid > 0) { 152 c = min(uio->uio_resid, PAGE_SIZE); 153 error = uiomove(random_buf, c, uio); 154 if (error) 155 break; 156 write_random(random_buf, c); 157 } 158 free(random_buf, M_TEMP); 159 return error; 160} 161 162static int 163random_ioctl(dev_t dev, u_long cmd, caddr_t addr, int flags, struct proc *p) 164{ 165 return ENOTTY; 166} 167 168static int 169random_poll(dev_t dev, int events, struct proc *p) 170{ 171 int revents; 172 173 revents = 0; 174 if (events & (POLLIN | POLLRDNORM)) { 175 if (random_state.seeded) 176 revents = events & (POLLIN | POLLRDNORM); 177 else 178 selrecord(p, &random_state.rsel); 179 } 180 return revents; 181} 182 183static int 184random_modevent(module_t mod, int type, void *data) 185{ 186 int error; 187 188 switch(type) { 189 case MOD_LOAD: 190 error = random_init(); 191 if (error != 0) 192 return error; 193 if (bootverbose) 194 printf("random: <entropy source>\n"); 195 random_dev = make_dev(&random_cdevsw, RANDOM_MINOR, UID_ROOT, 196 GID_WHEEL, 0666, "random"); 197 urandom_dev = make_dev(&random_cdevsw, URANDOM_MINOR, UID_ROOT, 198 GID_WHEEL, 0666, "urandom"); /* XXX Temporary */ 199 return 0; 200 201 case MOD_UNLOAD: 202 random_deinit(); 203 destroy_dev(random_dev); 204 destroy_dev(urandom_dev); /* XXX Temporary */ 205 return 0; 206 207 case MOD_SHUTDOWN: 208 return 0; 209 210 default: 211 return EOPNOTSUPP; 212 } 213} 214 215DEV_MODULE(random, random_modevent, NULL); 216