79}; 80 81static void random_kthread(void *); 82static void random_harvest_internal(u_int64_t, void *, u_int, u_int, u_int, enum esource); 83static void random_write_internal(void *, int); 84 85/* Ring buffer holding harvested entropy */ 86static struct harvestring { 87 volatile u_int head; 88 volatile u_int tail; 89 struct harvest data[HARVEST_RING_SIZE]; 90} harvestring; 91 92static struct random_systat { 93 u_int seeded; /* 0 causes blocking 1 allows normal output */ 94 u_int burst; /* number of events to do before sleeping */ 95 struct selinfo rsel; /* For poll(2) */ 96} random_systat; 97 98/* <0 to end the kthread, 0 to let it run */ 99static int random_kthread_control = 0; 100 101static struct proc *random_kthread_proc; 102 103/* For use with make_dev(9)/destroy_dev(9). */ 104static dev_t random_dev; 105static dev_t urandom_dev; 106 107/* ARGSUSED */ 108static int 109random_check_boolean(SYSCTL_HANDLER_ARGS) 110{ 111 if (oidp->oid_arg1 != NULL && *(u_int *)(oidp->oid_arg1) != 0) 112 *(u_int *)(oidp->oid_arg1) = 1; 113 return sysctl_handle_int(oidp, oidp->oid_arg1, oidp->oid_arg2, req); 114} 115 116RANDOM_CHECK_UINT(burst, 0, 20); 117 118SYSCTL_NODE(_kern, OID_AUTO, random, CTLFLAG_RW, 119 0, "Random Number Generator"); 120SYSCTL_NODE(_kern_random, OID_AUTO, sys, CTLFLAG_RW, 121 0, "Entropy Device Parameters"); 122SYSCTL_PROC(_kern_random_sys, OID_AUTO, seeded, 123 CTLTYPE_INT|CTLFLAG_RW, &random_systat.seeded, 1, 124 random_check_boolean, "I", "Seeded State"); 125SYSCTL_PROC(_kern_random_sys, OID_AUTO, burst, 126 CTLTYPE_INT|CTLFLAG_RW, &random_systat.burst, 20, 127 random_check_uint_burst, "I", "Harvest Burst Size"); 128SYSCTL_NODE(_kern_random_sys, OID_AUTO, harvest, CTLFLAG_RW, 129 0, "Entropy Sources"); 130SYSCTL_PROC(_kern_random_sys_harvest, OID_AUTO, ethernet, 131 CTLTYPE_INT|CTLFLAG_RW, &harvest.ethernet, 0, 132 random_check_boolean, "I", "Harvest NIC entropy"); 133SYSCTL_PROC(_kern_random_sys_harvest, OID_AUTO, point_to_point, 134 CTLTYPE_INT|CTLFLAG_RW, &harvest.point_to_point, 0, 135 random_check_boolean, "I", "Harvest serial net entropy"); 136SYSCTL_PROC(_kern_random_sys_harvest, OID_AUTO, interrupt, 137 CTLTYPE_INT|CTLFLAG_RW, &harvest.interrupt, 0, 138 random_check_boolean, "I", "Harvest IRQ entropy"); 139SYSCTL_PROC(_kern_random_sys_harvest, OID_AUTO, swi, 140 CTLTYPE_INT|CTLFLAG_RW, &harvest.swi, 0, 141 random_check_boolean, "I", "Harvest SWI entropy"); 142 143/* ARGSUSED */ 144static int 145random_open(dev_t dev __unused, int flags, int fmt __unused, struct thread *td) 146{ 147 int error; 148 149 if (flags & FWRITE) { 150 error = suser(td); 151 if (error) 152 return (error); 153 error = securelevel_gt(td->td_ucred, 0); 154 if (error) 155 return (error); 156 } 157 return 0; 158} 159 160/* ARGSUSED */ 161static int 162random_close(dev_t dev __unused, int flags, int fmt __unused, struct thread *td) 163{ 164 if (flags & FWRITE) { 165 if (!(suser(td) || 166 securelevel_gt(td->td_ucred, 0))) 167 random_reseed(); 168 } 169 return 0; 170} 171 172/* ARGSUSED */ 173static int 174random_read(dev_t dev __unused, struct uio *uio, int flag) 175{ 176 int c, ret; 177 int error = 0; 178 void *random_buf; 179 180 while (!random_systat.seeded) { 181 if (flag & IO_NDELAY) 182 error = EWOULDBLOCK; 183 else 184 error = tsleep(&random_systat, PUSER|PCATCH, 185 "block", 0); 186 if (error != 0) 187 return error; 188 } 189 c = uio->uio_resid < PAGE_SIZE ? uio->uio_resid : PAGE_SIZE; 190 random_buf = (void *)malloc((u_long)c, M_TEMP, M_WAITOK); 191 while (uio->uio_resid > 0 && error == 0) { 192 ret = read_random_real(random_buf, c); 193 error = uiomove(random_buf, ret, uio); 194 } 195 free(random_buf, M_TEMP); 196 return error; 197} 198 199/* ARGSUSED */ 200static int 201random_write(dev_t dev __unused, struct uio *uio, int flag __unused) 202{ 203 int c; 204 int error; 205 void *random_buf; 206 207 error = 0; 208 random_buf = (void *)malloc(PAGE_SIZE, M_TEMP, M_WAITOK); 209 while (uio->uio_resid > 0) { 210 c = (int)(uio->uio_resid < PAGE_SIZE 211 ? uio->uio_resid 212 : PAGE_SIZE); 213 error = uiomove(random_buf, c, uio); 214 if (error) 215 break; 216 random_write_internal(random_buf, c); 217 } 218 free(random_buf, M_TEMP); 219 return error; 220} 221 222/* ARGSUSED */ 223static int 224random_ioctl(dev_t dev __unused, u_long cmd, caddr_t addr __unused, 225 int flags __unused, struct thread *td __unused) 226{ 227 switch (cmd) { 228 /* Really handled in upper layer */ 229 case FIOASYNC: 230 case FIONBIO: 231 return 0; 232 default: 233 return ENOTTY; 234 } 235} 236 237/* ARGSUSED */ 238static int 239random_poll(dev_t dev __unused, int events, struct thread *td) 240{ 241 int revents; 242 243 revents = 0; 244 if (events & (POLLIN | POLLRDNORM)) { 245 if (random_systat.seeded) 246 revents = events & (POLLIN | POLLRDNORM); 247 else 248 selrecord(td, &random_systat.rsel); 249 } 250 return revents; 251} 252 253/* ARGSUSED */ 254static int 255random_modevent(module_t mod __unused, int type, void *data __unused) 256{ 257 int error; 258 259 switch(type) { 260 case MOD_LOAD: 261 random_init(); 262 263 /* This can be turned off by the very paranoid 264 * a reseed will turn it back on. 265 */ 266 random_systat.seeded = 1; 267 268 /* Number of envents to process off the harvest 269 * queue before giving it a break and sleeping 270 */ 271 random_systat.burst = 20; 272 273 /* Initialise the harvest ringbuffer */ 274 harvestring.head = 0; 275 harvestring.tail = 0; 276 277 if (bootverbose) 278 printf("random: <entropy source>\n"); 279 random_dev = make_dev(&random_cdevsw, RANDOM_MINOR, UID_ROOT, 280 GID_WHEEL, 0666, "random"); 281 urandom_dev = make_dev_alias(random_dev, "urandom"); 282 283 /* Start the hash/reseed thread */ 284 error = kthread_create(random_kthread, NULL, 285 &random_kthread_proc, RFHIGHPID, 0, "random"); 286 if (error != 0) 287 return error; 288 289 /* Register the randomness harvesting routine */ 290 random_init_harvester(random_harvest_internal, 291 read_random_real); 292 293 return 0; 294 295 case MOD_UNLOAD: 296 /* Deregister the randomness harvesting routine */ 297 random_deinit_harvester(); 298 299 /* Command the hash/reseed thread to end and 300 * wait for it to finish 301 */ 302 random_kthread_control = -1; 303 tsleep((void *)&random_kthread_control, PUSER, "term", 0); 304 305 random_deinit(); 306 307 destroy_dev(random_dev); 308 destroy_dev(urandom_dev); 309 return 0; 310 311 case MOD_SHUTDOWN: 312 return 0; 313 314 default: 315 return EOPNOTSUPP; 316 } 317} 318 319DEV_MODULE(random, random_modevent, NULL); 320 321/* ARGSUSED */ 322static void 323random_kthread(void *arg __unused) 324{ 325 struct harvest *event; 326 u_int newtail, burst; 327 328 /* Drain the harvest queue (in 'burst' size chunks, 329 * if 'burst' > 0. If 'burst' == 0, then completely 330 * drain the queue. 331 */ 332 for (burst = 0; ; burst++) { 333 334 if ((harvestring.tail == harvestring.head) || 335 (random_systat.burst && burst == random_systat.burst)) { 336 tsleep(&harvestring, PUSER, "sleep", hz/10); 337 burst = 0; 338 339 } 340 else { 341 342 /* Suck a harvested entropy event out of the queue and 343 * hand it to the event processor 344 */ 345 346 newtail = (harvestring.tail + 1) & HARVEST_RING_MASK; 347 event = &harvestring.data[harvestring.tail]; 348 349 /* Bump the ring counter. This action is assumed 350 * to be atomic. 351 */ 352 harvestring.tail = newtail; 353 354 random_process_event(event); 355 356 } 357 358 /* Is the thread scheduled for a shutdown? */ 359 if (random_kthread_control != 0) { 360#ifdef DEBUG 361 printf("Random kthread setting terminate\n"); 362#endif 363 random_set_wakeup_exit(&random_kthread_control); 364 /* NOTREACHED */ 365 break; 366 } 367 368 } 369 370} 371 372/* Entropy harvesting routine. This is supposed to be fast; do 373 * not do anything slow in here! 374 */ 375static void 376random_harvest_internal(u_int64_t somecounter, void *entropy, u_int count, 377 u_int bits, u_int frac, enum esource origin) 378{ 379 struct harvest *pharvest; 380 u_int newhead; 381 382 newhead = (harvestring.head + 1) & HARVEST_RING_MASK; 383 384 if (newhead != harvestring.tail) { 385 386 /* Add the harvested data to the ring buffer */ 387 388 pharvest = &harvestring.data[harvestring.head]; 389 390 /* Stuff the harvested data into the ring */ 391 pharvest->somecounter = somecounter; 392 count = count > HARVESTSIZE ? HARVESTSIZE : count; 393 memcpy(pharvest->entropy, entropy, count); 394 pharvest->size = count; 395 pharvest->bits = bits; 396 pharvest->frac = frac; 397 pharvest->source = 398 origin < ENTROPYSOURCE ? origin : RANDOM_START; 399 400 /* Bump the ring counter. This action is assumed 401 * to be atomic. 402 */ 403 harvestring.head = newhead; 404 405 } 406 407} 408 409static void 410random_write_internal(void *buf, int count) 411{ 412 int i; 413 414 /* Break the input up into HARVESTSIZE chunks. 415 * The writer has too much control here, so "estimate" the 416 * the entropy as zero. 417 */ 418 for (i = 0; i < count; i += HARVESTSIZE) { 419 random_harvest_internal(get_cyclecount(), (char *)buf + i, 420 HARVESTSIZE, 0, 0, RANDOM_WRITE); 421 } 422 423 /* Maybe the loop iterated at least once */ 424 if (i > count) 425 i -= HARVESTSIZE; 426 427 /* Get the last bytes even if the input length is not 428 * a multiple of HARVESTSIZE. 429 */ 430 count %= HARVESTSIZE; 431 if (count) { 432 random_harvest_internal(get_cyclecount(), (char *)buf + i, 433 (u_int)count, 0, 0, RANDOM_WRITE); 434 } 435} 436 437void 438random_unblock(void) 439{ 440 if (!random_systat.seeded) { 441 random_systat.seeded = 1; 442 selwakeup(&random_systat.rsel); 443 wakeup(&random_systat); 444 } 445}
| 73}; 74 75static void random_kthread(void *); 76static void random_harvest_internal(u_int64_t, void *, u_int, u_int, u_int, enum esource); 77static void random_write_internal(void *, int); 78 79/* Ring buffer holding harvested entropy */ 80static struct harvestring { 81 volatile u_int head; 82 volatile u_int tail; 83 struct harvest data[HARVEST_RING_SIZE]; 84} harvestring; 85 86static struct random_systat { 87 u_int seeded; /* 0 causes blocking 1 allows normal output */ 88 u_int burst; /* number of events to do before sleeping */ 89 struct selinfo rsel; /* For poll(2) */ 90} random_systat; 91 92/* <0 to end the kthread, 0 to let it run */ 93static int random_kthread_control = 0; 94 95static struct proc *random_kthread_proc; 96 97/* For use with make_dev(9)/destroy_dev(9). */ 98static dev_t random_dev; 99static dev_t urandom_dev; 100 101/* ARGSUSED */ 102static int 103random_check_boolean(SYSCTL_HANDLER_ARGS) 104{ 105 if (oidp->oid_arg1 != NULL && *(u_int *)(oidp->oid_arg1) != 0) 106 *(u_int *)(oidp->oid_arg1) = 1; 107 return sysctl_handle_int(oidp, oidp->oid_arg1, oidp->oid_arg2, req); 108} 109 110RANDOM_CHECK_UINT(burst, 0, 20); 111 112SYSCTL_NODE(_kern, OID_AUTO, random, CTLFLAG_RW, 113 0, "Random Number Generator"); 114SYSCTL_NODE(_kern_random, OID_AUTO, sys, CTLFLAG_RW, 115 0, "Entropy Device Parameters"); 116SYSCTL_PROC(_kern_random_sys, OID_AUTO, seeded, 117 CTLTYPE_INT|CTLFLAG_RW, &random_systat.seeded, 1, 118 random_check_boolean, "I", "Seeded State"); 119SYSCTL_PROC(_kern_random_sys, OID_AUTO, burst, 120 CTLTYPE_INT|CTLFLAG_RW, &random_systat.burst, 20, 121 random_check_uint_burst, "I", "Harvest Burst Size"); 122SYSCTL_NODE(_kern_random_sys, OID_AUTO, harvest, CTLFLAG_RW, 123 0, "Entropy Sources"); 124SYSCTL_PROC(_kern_random_sys_harvest, OID_AUTO, ethernet, 125 CTLTYPE_INT|CTLFLAG_RW, &harvest.ethernet, 0, 126 random_check_boolean, "I", "Harvest NIC entropy"); 127SYSCTL_PROC(_kern_random_sys_harvest, OID_AUTO, point_to_point, 128 CTLTYPE_INT|CTLFLAG_RW, &harvest.point_to_point, 0, 129 random_check_boolean, "I", "Harvest serial net entropy"); 130SYSCTL_PROC(_kern_random_sys_harvest, OID_AUTO, interrupt, 131 CTLTYPE_INT|CTLFLAG_RW, &harvest.interrupt, 0, 132 random_check_boolean, "I", "Harvest IRQ entropy"); 133SYSCTL_PROC(_kern_random_sys_harvest, OID_AUTO, swi, 134 CTLTYPE_INT|CTLFLAG_RW, &harvest.swi, 0, 135 random_check_boolean, "I", "Harvest SWI entropy"); 136 137/* ARGSUSED */ 138static int 139random_open(dev_t dev __unused, int flags, int fmt __unused, struct thread *td) 140{ 141 int error; 142 143 if (flags & FWRITE) { 144 error = suser(td); 145 if (error) 146 return (error); 147 error = securelevel_gt(td->td_ucred, 0); 148 if (error) 149 return (error); 150 } 151 return 0; 152} 153 154/* ARGSUSED */ 155static int 156random_close(dev_t dev __unused, int flags, int fmt __unused, struct thread *td) 157{ 158 if (flags & FWRITE) { 159 if (!(suser(td) || 160 securelevel_gt(td->td_ucred, 0))) 161 random_reseed(); 162 } 163 return 0; 164} 165 166/* ARGSUSED */ 167static int 168random_read(dev_t dev __unused, struct uio *uio, int flag) 169{ 170 int c, ret; 171 int error = 0; 172 void *random_buf; 173 174 while (!random_systat.seeded) { 175 if (flag & IO_NDELAY) 176 error = EWOULDBLOCK; 177 else 178 error = tsleep(&random_systat, PUSER|PCATCH, 179 "block", 0); 180 if (error != 0) 181 return error; 182 } 183 c = uio->uio_resid < PAGE_SIZE ? uio->uio_resid : PAGE_SIZE; 184 random_buf = (void *)malloc((u_long)c, M_TEMP, M_WAITOK); 185 while (uio->uio_resid > 0 && error == 0) { 186 ret = read_random_real(random_buf, c); 187 error = uiomove(random_buf, ret, uio); 188 } 189 free(random_buf, M_TEMP); 190 return error; 191} 192 193/* ARGSUSED */ 194static int 195random_write(dev_t dev __unused, struct uio *uio, int flag __unused) 196{ 197 int c; 198 int error; 199 void *random_buf; 200 201 error = 0; 202 random_buf = (void *)malloc(PAGE_SIZE, M_TEMP, M_WAITOK); 203 while (uio->uio_resid > 0) { 204 c = (int)(uio->uio_resid < PAGE_SIZE 205 ? uio->uio_resid 206 : PAGE_SIZE); 207 error = uiomove(random_buf, c, uio); 208 if (error) 209 break; 210 random_write_internal(random_buf, c); 211 } 212 free(random_buf, M_TEMP); 213 return error; 214} 215 216/* ARGSUSED */ 217static int 218random_ioctl(dev_t dev __unused, u_long cmd, caddr_t addr __unused, 219 int flags __unused, struct thread *td __unused) 220{ 221 switch (cmd) { 222 /* Really handled in upper layer */ 223 case FIOASYNC: 224 case FIONBIO: 225 return 0; 226 default: 227 return ENOTTY; 228 } 229} 230 231/* ARGSUSED */ 232static int 233random_poll(dev_t dev __unused, int events, struct thread *td) 234{ 235 int revents; 236 237 revents = 0; 238 if (events & (POLLIN | POLLRDNORM)) { 239 if (random_systat.seeded) 240 revents = events & (POLLIN | POLLRDNORM); 241 else 242 selrecord(td, &random_systat.rsel); 243 } 244 return revents; 245} 246 247/* ARGSUSED */ 248static int 249random_modevent(module_t mod __unused, int type, void *data __unused) 250{ 251 int error; 252 253 switch(type) { 254 case MOD_LOAD: 255 random_init(); 256 257 /* This can be turned off by the very paranoid 258 * a reseed will turn it back on. 259 */ 260 random_systat.seeded = 1; 261 262 /* Number of envents to process off the harvest 263 * queue before giving it a break and sleeping 264 */ 265 random_systat.burst = 20; 266 267 /* Initialise the harvest ringbuffer */ 268 harvestring.head = 0; 269 harvestring.tail = 0; 270 271 if (bootverbose) 272 printf("random: <entropy source>\n"); 273 random_dev = make_dev(&random_cdevsw, RANDOM_MINOR, UID_ROOT, 274 GID_WHEEL, 0666, "random"); 275 urandom_dev = make_dev_alias(random_dev, "urandom"); 276 277 /* Start the hash/reseed thread */ 278 error = kthread_create(random_kthread, NULL, 279 &random_kthread_proc, RFHIGHPID, 0, "random"); 280 if (error != 0) 281 return error; 282 283 /* Register the randomness harvesting routine */ 284 random_init_harvester(random_harvest_internal, 285 read_random_real); 286 287 return 0; 288 289 case MOD_UNLOAD: 290 /* Deregister the randomness harvesting routine */ 291 random_deinit_harvester(); 292 293 /* Command the hash/reseed thread to end and 294 * wait for it to finish 295 */ 296 random_kthread_control = -1; 297 tsleep((void *)&random_kthread_control, PUSER, "term", 0); 298 299 random_deinit(); 300 301 destroy_dev(random_dev); 302 destroy_dev(urandom_dev); 303 return 0; 304 305 case MOD_SHUTDOWN: 306 return 0; 307 308 default: 309 return EOPNOTSUPP; 310 } 311} 312 313DEV_MODULE(random, random_modevent, NULL); 314 315/* ARGSUSED */ 316static void 317random_kthread(void *arg __unused) 318{ 319 struct harvest *event; 320 u_int newtail, burst; 321 322 /* Drain the harvest queue (in 'burst' size chunks, 323 * if 'burst' > 0. If 'burst' == 0, then completely 324 * drain the queue. 325 */ 326 for (burst = 0; ; burst++) { 327 328 if ((harvestring.tail == harvestring.head) || 329 (random_systat.burst && burst == random_systat.burst)) { 330 tsleep(&harvestring, PUSER, "sleep", hz/10); 331 burst = 0; 332 333 } 334 else { 335 336 /* Suck a harvested entropy event out of the queue and 337 * hand it to the event processor 338 */ 339 340 newtail = (harvestring.tail + 1) & HARVEST_RING_MASK; 341 event = &harvestring.data[harvestring.tail]; 342 343 /* Bump the ring counter. This action is assumed 344 * to be atomic. 345 */ 346 harvestring.tail = newtail; 347 348 random_process_event(event); 349 350 } 351 352 /* Is the thread scheduled for a shutdown? */ 353 if (random_kthread_control != 0) { 354#ifdef DEBUG 355 printf("Random kthread setting terminate\n"); 356#endif 357 random_set_wakeup_exit(&random_kthread_control); 358 /* NOTREACHED */ 359 break; 360 } 361 362 } 363 364} 365 366/* Entropy harvesting routine. This is supposed to be fast; do 367 * not do anything slow in here! 368 */ 369static void 370random_harvest_internal(u_int64_t somecounter, void *entropy, u_int count, 371 u_int bits, u_int frac, enum esource origin) 372{ 373 struct harvest *pharvest; 374 u_int newhead; 375 376 newhead = (harvestring.head + 1) & HARVEST_RING_MASK; 377 378 if (newhead != harvestring.tail) { 379 380 /* Add the harvested data to the ring buffer */ 381 382 pharvest = &harvestring.data[harvestring.head]; 383 384 /* Stuff the harvested data into the ring */ 385 pharvest->somecounter = somecounter; 386 count = count > HARVESTSIZE ? HARVESTSIZE : count; 387 memcpy(pharvest->entropy, entropy, count); 388 pharvest->size = count; 389 pharvest->bits = bits; 390 pharvest->frac = frac; 391 pharvest->source = 392 origin < ENTROPYSOURCE ? origin : RANDOM_START; 393 394 /* Bump the ring counter. This action is assumed 395 * to be atomic. 396 */ 397 harvestring.head = newhead; 398 399 } 400 401} 402 403static void 404random_write_internal(void *buf, int count) 405{ 406 int i; 407 408 /* Break the input up into HARVESTSIZE chunks. 409 * The writer has too much control here, so "estimate" the 410 * the entropy as zero. 411 */ 412 for (i = 0; i < count; i += HARVESTSIZE) { 413 random_harvest_internal(get_cyclecount(), (char *)buf + i, 414 HARVESTSIZE, 0, 0, RANDOM_WRITE); 415 } 416 417 /* Maybe the loop iterated at least once */ 418 if (i > count) 419 i -= HARVESTSIZE; 420 421 /* Get the last bytes even if the input length is not 422 * a multiple of HARVESTSIZE. 423 */ 424 count %= HARVESTSIZE; 425 if (count) { 426 random_harvest_internal(get_cyclecount(), (char *)buf + i, 427 (u_int)count, 0, 0, RANDOM_WRITE); 428 } 429} 430 431void 432random_unblock(void) 433{ 434 if (!random_systat.seeded) { 435 random_systat.seeded = 1; 436 selwakeup(&random_systat.rsel); 437 wakeup(&random_systat); 438 } 439}
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