randomdev.c revision 67112
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 67112 2000-10-14 10:59:56Z 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/poll.h> 40#include <sys/proc.h> 41#include <sys/select.h> 42#include <sys/random.h> 43#include <sys/vnode.h> 44#include <machine/bus.h> 45#include <machine/resource.h> 46#include <sys/sysctl.h> 47#include <crypto/blowfish/blowfish.h> 48 49#include <dev/random/hash.h> 50#include <dev/random/yarrow.h> 51 52static d_open_t random_open; 53static d_read_t random_read; 54static d_write_t random_write; 55static d_ioctl_t random_ioctl; 56static d_poll_t random_poll; 57 58#define CDEV_MAJOR 2 59#define RANDOM_MINOR 3 60#define URANDOM_MINOR 4 61 62static struct cdevsw random_cdevsw = { 63 /* open */ random_open, 64 /* close */ (d_close_t *)nullop, 65 /* read */ random_read, 66 /* write */ random_write, 67 /* ioctl */ random_ioctl, 68 /* poll */ random_poll, 69 /* mmap */ nommap, 70 /* strategy */ nostrategy, 71 /* name */ "random", 72 /* maj */ CDEV_MAJOR, 73 /* dump */ nodump, 74 /* psize */ nopsize, 75 /* flags */ 0, 76 /* bmaj */ -1 77}; 78 79/* For use with make_dev(9)/destroy_dev(9). */ 80static dev_t random_dev; 81static dev_t urandom_dev; /* XXX Temporary */ 82 83SYSCTL_NODE(_kern, OID_AUTO, random, CTLFLAG_RW, 0, "Random Number Generator"); 84SYSCTL_NODE(_kern_random, OID_AUTO, yarrow, CTLFLAG_RW, 0, "Yarrow Parameters"); 85SYSCTL_INT(_kern_random_yarrow, OID_AUTO, gengateinterval, CTLFLAG_RW, 86 &random_state.gengateinterval, 10, "Generator Gate Interval"); 87SYSCTL_INT(_kern_random_yarrow, OID_AUTO, bins, CTLFLAG_RW, 88 &random_state.bins, 10, "Execution time tuner"); 89SYSCTL_INT(_kern_random_yarrow, OID_AUTO, fastthresh, CTLFLAG_RW, 90 &random_state.pool[0].thresh, 100, "Fast pool reseed threshhold"); 91SYSCTL_INT(_kern_random_yarrow, OID_AUTO, slowthresh, CTLFLAG_RW, 92 &random_state.pool[1].thresh, 160, "Slow pool reseed threshhold"); 93SYSCTL_INT(_kern_random_yarrow, OID_AUTO, slowoverthresh, CTLFLAG_RW, 94 &random_state.slowoverthresh, 2, "Slow pool over-threshhold reseed"); 95 96static int 97random_open(dev_t dev, int flags, int fmt, struct proc *p) 98{ 99 if ((flags & FWRITE) && (securelevel > 0 || suser(p))) 100 return EPERM; 101 else 102 return 0; 103} 104 105static int 106random_read(dev_t dev, struct uio *uio, int flag) 107{ 108 u_int c, ret; 109 int error = 0; 110 void *random_buf; 111 112 if (flag & IO_NDELAY && !random_state.seeded) { 113 error = EWOULDBLOCK; 114 } 115 else { 116 if (random_state.seeded) { 117 c = min(uio->uio_resid, PAGE_SIZE); 118 random_buf = (void *)malloc(c, M_TEMP, M_WAITOK); 119 while (uio->uio_resid > 0 && error == 0) { 120 ret = read_random_real(random_buf, c); 121 error = uiomove(random_buf, ret, uio); 122 } 123 free(random_buf, M_TEMP); 124 } 125 else 126 error = tsleep(&random_state, 0, "rndblk", 0); 127 } 128 return error; 129} 130 131static int 132random_write(dev_t dev, struct uio *uio, int flag) 133{ 134 u_int c; 135 int error = 0; 136 void *random_buf; 137 138 random_buf = (void *)malloc(PAGE_SIZE, M_TEMP, M_WAITOK); 139 while (uio->uio_resid > 0) { 140 c = min(uio->uio_resid, PAGE_SIZE); 141 error = uiomove(random_buf, c, uio); 142 if (error) 143 break; 144 write_random(random_buf, c); 145 } 146 free(random_buf, M_TEMP); 147 return error; 148} 149 150static int 151random_ioctl(dev_t dev, u_long cmd, caddr_t addr, int flags, struct proc *p) 152{ 153 return ENOTTY; 154} 155 156static int 157random_poll(dev_t dev, int events, struct proc *p) 158{ 159 int revents; 160 161 revents = 0; 162 if (events & (POLLIN | POLLRDNORM)) { 163 if (random_state.seeded) 164 revents = events & (POLLIN | POLLRDNORM); 165 else 166 selrecord(p, &random_state.rsel); 167 } 168 return revents; 169} 170 171static int 172random_modevent(module_t mod, int type, void *data) 173{ 174 int error; 175 176 switch(type) { 177 case MOD_LOAD: 178 error = random_init(); 179 if (error != 0) 180 return error; 181 if (bootverbose) 182 printf("random: <entropy source>\n"); 183 random_dev = make_dev(&random_cdevsw, RANDOM_MINOR, UID_ROOT, 184 GID_WHEEL, 0666, "random"); 185 urandom_dev = make_dev(&random_cdevsw, URANDOM_MINOR, UID_ROOT, 186 GID_WHEEL, 0666, "urandom"); /* XXX Temporary */ 187 return 0; 188 189 case MOD_UNLOAD: 190 random_deinit(); 191 destroy_dev(random_dev); 192 destroy_dev(urandom_dev); /* XXX Temporary */ 193 return 0; 194 195 case MOD_SHUTDOWN: 196 return 0; 197 198 default: 199 return EOPNOTSUPP; 200 } 201} 202 203DEV_MODULE(random, random_modevent, NULL); 204