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 * $FreeBSD$ 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 52 #include "opt_noblockrandom.h" 53 54 static d_open_t random_open; 55 static d_read_t random_read; 56 static d_write_t random_write; 57 static d_ioctl_t random_ioctl; 58 static d_poll_t random_poll; 59 60 #define CDEV_MAJOR 2 61 #define RANDOM_MINOR 3 62 #define URANDOM_MINOR 4 63 64 static struct cdevsw random_cdevsw = { 65 /* open */ random_open, 66 /* close */ (d_close_t *)nullop, 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). */ 82 static dev_t random_dev; 83 static dev_t urandom_dev; /* XXX Temporary */ 84 85 SYSCTL_NODE(_kern, OID_AUTO, random, CTLFLAG_RW, 0, "Random Number Generator"); 86 SYSCTL_NODE(_kern_random, OID_AUTO, yarrow, CTLFLAG_RW, 0, "Yarrow Parameters"); 87 SYSCTL_INT(_kern_random_yarrow, OID_AUTO, gengateinterval, CTLFLAG_RW, 88 &random_state.gengateinterval, 10, "Generator Gate Interval"); 89 SYSCTL_INT(_kern_random_yarrow, OID_AUTO, bins, CTLFLAG_RW, 90 &random_state.bins, 10, "Execution time tuner"); 91 SYSCTL_INT(_kern_random_yarrow, OID_AUTO, fastthresh, CTLFLAG_RW, 92 &random_state.pool[0].thresh, 100, "Fast pool reseed threshhold"); 93 SYSCTL_INT(_kern_random_yarrow, OID_AUTO, slowthresh, CTLFLAG_RW, 94 &random_state.pool[1].thresh, 160, "Slow pool reseed threshhold"); 95 SYSCTL_INT(_kern_random_yarrow, OID_AUTO, slowoverthresh, CTLFLAG_RW, 96 &random_state.slowoverthresh, 2, "Slow pool over-threshhold reseed"); 97 98 static int 99 random_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 } 106 107 static int 108 random_read(dev_t dev, struct uio *uio, int flag) 109 { 110 u_int c, ret; 111 int error = 0; 112 void *random_buf; 113 114 /* XXX Temporary ifndef to allow users to have a nonblocking device */ 115 #ifndef NOBLOCKRANDOM 116 while (!random_state.seeded) { 117 if (flag & IO_NDELAY) 118 error = EWOULDBLOCK; 119 else 120 error = tsleep(&random_state, PUSER|PCATCH, "rndblk", 0); 121 if (error != 0) 122 return error; 123 } 124 #endif 125 c = min(uio->uio_resid, PAGE_SIZE); 126 random_buf = (void *)malloc(c, M_TEMP, M_WAITOK); 127 while (uio->uio_resid > 0 && error == 0) { 128 ret = read_random_real(random_buf, c); 129 error = uiomove(random_buf, ret, uio); 130 } 131 free(random_buf, M_TEMP); 132 return error; 133 } 134 135 static int 136 random_write(dev_t dev, struct uio *uio, int flag) 137 { 138 u_int c; 139 int error = 0; 140 void *random_buf; 141 142 random_buf = (void *)malloc(PAGE_SIZE, M_TEMP, M_WAITOK); 143 while (uio->uio_resid > 0) { 144 c = min(uio->uio_resid, PAGE_SIZE); 145 error = uiomove(random_buf, c, uio); 146 if (error) 147 break; 148 write_random(random_buf, c); 149 } 150 free(random_buf, M_TEMP); 151 return error; 152 } 153 154 static int 155 random_ioctl(dev_t dev, u_long cmd, caddr_t addr, int flags, struct proc *p) 156 { 157 return ENOTTY; 158 } 159 160 static int 161 random_poll(dev_t dev, int events, struct proc *p) 162 { 163 int revents; 164 165 revents = 0; 166 if (events & (POLLIN | POLLRDNORM)) { 167 if (random_state.seeded) 168 revents = events & (POLLIN | POLLRDNORM); 169 else 170 selrecord(p, &random_state.rsel); 171 } 172 return revents; 173 } 174 175 static int 176 random_modevent(module_t mod, int type, void *data) 177 { 178 int error; 179 180 switch(type) { 181 case MOD_LOAD: 182 error = random_init(); 183 if (error != 0) 184 return error; 185 if (bootverbose) 186 printf("random: <entropy source>\n"); 187 random_dev = make_dev(&random_cdevsw, RANDOM_MINOR, UID_ROOT, 188 GID_WHEEL, 0666, "random"); 189 urandom_dev = make_dev(&random_cdevsw, URANDOM_MINOR, UID_ROOT, 190 GID_WHEEL, 0666, "urandom"); /* XXX Temporary */ 191 return 0; 192 193 case MOD_UNLOAD: 194 random_deinit(); 195 destroy_dev(random_dev); 196 destroy_dev(urandom_dev); /* XXX Temporary */ 197 return 0; 198 199 case MOD_SHUTDOWN: 200 return 0; 201 202 default: 203 return EOPNOTSUPP; 204 } 205 } 206 207 DEV_MODULE(random, random_modevent, NULL); 208