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