1 /*- 2 * Copyright (c) 2000-2004 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 */ 27 28 #include <sys/cdefs.h> 29 __FBSDID("$FreeBSD$"); 30 31 #include <sys/param.h> 32 #include <sys/systm.h> 33 #include <sys/bus.h> 34 #include <sys/conf.h> 35 #include <sys/fcntl.h> 36 #include <sys/filio.h> 37 #include <sys/kernel.h> 38 #include <sys/kthread.h> 39 #include <sys/lock.h> 40 #include <sys/malloc.h> 41 #include <sys/module.h> 42 #include <sys/mutex.h> 43 #include <sys/poll.h> 44 #include <sys/priv.h> 45 #include <sys/proc.h> 46 #include <sys/selinfo.h> 47 #include <sys/uio.h> 48 #include <sys/unistd.h> 49 50 #include <machine/bus.h> 51 #include <machine/cpu.h> 52 53 #include <dev/random/randomdev.h> 54 55 #define RANDOM_MINOR 0 56 57 static d_close_t random_close; 58 static d_read_t random_read; 59 static d_write_t random_write; 60 static d_ioctl_t random_ioctl; 61 static d_poll_t random_poll; 62 63 static struct cdevsw random_cdevsw = { 64 .d_version = D_VERSION, 65 .d_close = random_close, 66 .d_read = random_read, 67 .d_write = random_write, 68 .d_ioctl = random_ioctl, 69 .d_poll = random_poll, 70 .d_name = "random", 71 }; 72 73 struct random_systat random_systat; 74 75 /* For use with make_dev(9)/destroy_dev(9). */ 76 static struct cdev *random_dev; 77 78 /* Used to fake out unused random calls in random_systat */ 79 void 80 random_null_func(void) 81 { 82 } 83 84 /* ARGSUSED */ 85 static int 86 random_close(struct cdev *dev __unused, int flags, int fmt __unused, 87 struct thread *td) 88 { 89 if ((flags & FWRITE) && (priv_check(td, PRIV_RANDOM_RESEED) == 0) 90 && (securelevel_gt(td->td_ucred, 0) == 0)) { 91 (*random_systat.reseed)(); 92 random_systat.seeded = 1; 93 } 94 95 return (0); 96 } 97 98 /* ARGSUSED */ 99 static int 100 random_read(struct cdev *dev __unused, struct uio *uio, int flag) 101 { 102 int c, error = 0; 103 void *random_buf; 104 105 /* Blocking logic */ 106 if (!random_systat.seeded) 107 error = (*random_systat.block)(flag); 108 109 /* The actual read */ 110 if (!error) { 111 112 random_buf = (void *)malloc(PAGE_SIZE, M_TEMP, M_WAITOK); 113 114 while (uio->uio_resid > 0 && !error) { 115 c = MIN(uio->uio_resid, PAGE_SIZE); 116 c = (*random_systat.read)(random_buf, c); 117 error = uiomove(random_buf, c, uio); 118 } 119 120 free(random_buf, M_TEMP); 121 122 } 123 124 return (error); 125 } 126 127 /* ARGSUSED */ 128 static int 129 random_write(struct cdev *dev __unused, struct uio *uio, int flag __unused) 130 { 131 int c, error = 0; 132 void *random_buf; 133 134 random_buf = (void *)malloc(PAGE_SIZE, M_TEMP, M_WAITOK); 135 136 while (uio->uio_resid > 0) { 137 c = MIN((int)uio->uio_resid, PAGE_SIZE); 138 error = uiomove(random_buf, c, uio); 139 if (error) 140 break; 141 (*random_systat.write)(random_buf, c); 142 } 143 144 free(random_buf, M_TEMP); 145 146 return (error); 147 } 148 149 /* ARGSUSED */ 150 static int 151 random_ioctl(struct cdev *dev __unused, u_long cmd, caddr_t addr __unused, 152 int flags __unused, struct thread *td __unused) 153 { 154 int error = 0; 155 156 switch (cmd) { 157 /* Really handled in upper layer */ 158 case FIOASYNC: 159 case FIONBIO: 160 break; 161 default: 162 error = ENOTTY; 163 } 164 return (error); 165 } 166 167 /* ARGSUSED */ 168 static int 169 random_poll(struct cdev *dev __unused, int events, struct thread *td) 170 { 171 int revents = 0; 172 173 if (events & (POLLIN | POLLRDNORM)) { 174 if (random_systat.seeded) 175 revents = events & (POLLIN | POLLRDNORM); 176 else 177 revents = (*random_systat.poll) (events,td); 178 } 179 return (revents); 180 } 181 182 /* ARGSUSED */ 183 static int 184 random_modevent(module_t mod __unused, int type, void *data __unused) 185 { 186 int error = 0; 187 188 switch (type) { 189 case MOD_LOAD: 190 random_ident_hardware(&random_systat); 191 (*random_systat.init)(); 192 193 if (bootverbose) 194 printf("random: <entropy source, %s>\n", 195 random_systat.ident); 196 197 random_dev = make_dev(&random_cdevsw, RANDOM_MINOR, 198 UID_ROOT, GID_WHEEL, 0666, "random"); 199 make_dev_alias(random_dev, "urandom"); /* XXX Deprecated */ 200 201 break; 202 203 case MOD_UNLOAD: 204 (*random_systat.deinit)(); 205 206 destroy_dev(random_dev); 207 208 break; 209 210 case MOD_SHUTDOWN: 211 break; 212 213 default: 214 error = EOPNOTSUPP; 215 break; 216 217 } 218 return (error); 219 } 220 221 DEV_MODULE(random, random_modevent, NULL); 222 MODULE_VERSION(random, 1); 223