1 /*- 2 * Copyright (c) 2017 Oliver Pinter 3 * Copyright (c) 2017 W. Dean Freeman 4 * Copyright (c) 2000-2015 Mark R V Murray 5 * Copyright (c) 2013 Arthur Mesh 6 * Copyright (c) 2004 Robert N. M. Watson 7 * All rights reserved. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer 14 * in this position and unchanged. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 20 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 21 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 22 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 23 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 24 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 28 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 29 * 30 */ 31 32 #include <sys/param.h> 33 #include <sys/systm.h> 34 #include <sys/ck.h> 35 #include <sys/conf.h> 36 #include <sys/epoch.h> 37 #include <sys/eventhandler.h> 38 #include <sys/hash.h> 39 #include <sys/kernel.h> 40 #include <sys/kthread.h> 41 #include <sys/linker.h> 42 #include <sys/lock.h> 43 #include <sys/malloc.h> 44 #include <sys/module.h> 45 #include <sys/mutex.h> 46 #include <sys/random.h> 47 #include <sys/sbuf.h> 48 #include <sys/sysctl.h> 49 #include <sys/unistd.h> 50 51 #include <machine/atomic.h> 52 #include <machine/cpu.h> 53 54 #include <crypto/rijndael/rijndael-api-fst.h> 55 #include <crypto/sha2/sha256.h> 56 57 #include <dev/random/fortuna.h> 58 #include <dev/random/hash.h> 59 #include <dev/random/randomdev.h> 60 #include <dev/random/random_harvestq.h> 61 62 #if defined(RANDOM_ENABLE_ETHER) 63 #define _RANDOM_HARVEST_ETHER_OFF 0 64 #else 65 #define _RANDOM_HARVEST_ETHER_OFF (1u << RANDOM_NET_ETHER) 66 #endif 67 #if defined(RANDOM_ENABLE_UMA) 68 #define _RANDOM_HARVEST_UMA_OFF 0 69 #else 70 #define _RANDOM_HARVEST_UMA_OFF (1u << RANDOM_UMA) 71 #endif 72 73 /* 74 * Note that random_sources_feed() will also use this to try and split up 75 * entropy into a subset of pools per iteration with the goal of feeding 76 * HARVESTSIZE into every pool at least once per second. 77 */ 78 #define RANDOM_KTHREAD_HZ 10 79 80 static void random_kthread(void); 81 static void random_sources_feed(void); 82 83 /* 84 * Random must initialize much earlier than epoch, but we can initialize the 85 * epoch code before SMP starts. Prior to SMP, we can safely bypass 86 * concurrency primitives. 87 */ 88 static __read_mostly bool epoch_inited; 89 static __read_mostly epoch_t rs_epoch; 90 91 /* 92 * How many events to queue up. We create this many items in 93 * an 'empty' queue, then transfer them to the 'harvest' queue with 94 * supplied junk. When used, they are transferred back to the 95 * 'empty' queue. 96 */ 97 #define RANDOM_RING_MAX 1024 98 #define RANDOM_ACCUM_MAX 8 99 100 /* 1 to let the kernel thread run, 0 to terminate, -1 to mark completion */ 101 volatile int random_kthread_control; 102 103 104 /* Allow the sysadmin to select the broad category of 105 * entropy types to harvest. 106 */ 107 __read_frequently u_int hc_source_mask; 108 109 struct random_sources { 110 CK_LIST_ENTRY(random_sources) rrs_entries; 111 struct random_source *rrs_source; 112 }; 113 114 static CK_LIST_HEAD(sources_head, random_sources) source_list = 115 CK_LIST_HEAD_INITIALIZER(source_list); 116 117 SYSCTL_NODE(_kern_random, OID_AUTO, harvest, CTLFLAG_RW | CTLFLAG_MPSAFE, 0, 118 "Entropy Device Parameters"); 119 120 /* 121 * Put all the harvest queue context stuff in one place. 122 * this make is a bit easier to lock and protect. 123 */ 124 static struct harvest_context { 125 /* The harvest mutex protects all of harvest_context and 126 * the related data. 127 */ 128 struct mtx hc_mtx; 129 /* Round-robin destination cache. */ 130 u_int hc_destination[ENTROPYSOURCE]; 131 /* The context of the kernel thread processing harvested entropy */ 132 struct proc *hc_kthread_proc; 133 /* 134 * Lockless ring buffer holding entropy events 135 * If ring.in == ring.out, 136 * the buffer is empty. 137 * If ring.in != ring.out, 138 * the buffer contains harvested entropy. 139 * If (ring.in + 1) == ring.out (mod RANDOM_RING_MAX), 140 * the buffer is full. 141 * 142 * NOTE: ring.in points to the last added element, 143 * and ring.out points to the last consumed element. 144 * 145 * The ring.in variable needs locking as there are multiple 146 * sources to the ring. Only the sources may change ring.in, 147 * but the consumer may examine it. 148 * 149 * The ring.out variable does not need locking as there is 150 * only one consumer. Only the consumer may change ring.out, 151 * but the sources may examine it. 152 */ 153 struct entropy_ring { 154 struct harvest_event ring[RANDOM_RING_MAX]; 155 volatile u_int in; 156 volatile u_int out; 157 } hc_entropy_ring; 158 struct fast_entropy_accumulator { 159 volatile u_int pos; 160 uint32_t buf[RANDOM_ACCUM_MAX]; 161 } hc_entropy_fast_accumulator; 162 } harvest_context; 163 164 static struct kproc_desc random_proc_kp = { 165 "rand_harvestq", 166 random_kthread, 167 &harvest_context.hc_kthread_proc, 168 }; 169 170 /* Pass the given event straight through to Fortuna/Whatever. */ 171 static __inline void 172 random_harvestq_fast_process_event(struct harvest_event *event) 173 { 174 p_random_alg_context->ra_event_processor(event); 175 explicit_bzero(event, sizeof(*event)); 176 } 177 178 static void 179 random_kthread(void) 180 { 181 u_int maxloop, ring_out, i; 182 183 /* 184 * Locking is not needed as this is the only place we modify ring.out, and 185 * we only examine ring.in without changing it. Both of these are volatile, 186 * and this is a unique thread. 187 */ 188 for (random_kthread_control = 1; random_kthread_control;) { 189 /* Deal with events, if any. Restrict the number we do in one go. */ 190 maxloop = RANDOM_RING_MAX; 191 while (harvest_context.hc_entropy_ring.out != harvest_context.hc_entropy_ring.in) { 192 ring_out = (harvest_context.hc_entropy_ring.out + 1)%RANDOM_RING_MAX; 193 random_harvestq_fast_process_event(harvest_context.hc_entropy_ring.ring + ring_out); 194 harvest_context.hc_entropy_ring.out = ring_out; 195 if (!--maxloop) 196 break; 197 } 198 random_sources_feed(); 199 /* XXX: FIX!! Increase the high-performance data rate? Need some measurements first. */ 200 for (i = 0; i < RANDOM_ACCUM_MAX; i++) { 201 if (harvest_context.hc_entropy_fast_accumulator.buf[i]) { 202 random_harvest_direct(harvest_context.hc_entropy_fast_accumulator.buf + i, sizeof(harvest_context.hc_entropy_fast_accumulator.buf[0]), RANDOM_UMA); 203 harvest_context.hc_entropy_fast_accumulator.buf[i] = 0; 204 } 205 } 206 /* XXX: FIX!! This is a *great* place to pass hardware/live entropy to random(9) */ 207 tsleep_sbt(&harvest_context.hc_kthread_proc, 0, "-", 208 SBT_1S/RANDOM_KTHREAD_HZ, 0, C_PREL(1)); 209 } 210 random_kthread_control = -1; 211 wakeup(&harvest_context.hc_kthread_proc); 212 kproc_exit(0); 213 /* NOTREACHED */ 214 } 215 /* This happens well after SI_SUB_RANDOM */ 216 SYSINIT(random_device_h_proc, SI_SUB_KICK_SCHEDULER, SI_ORDER_ANY, kproc_start, 217 &random_proc_kp); 218 219 static void 220 rs_epoch_init(void *dummy __unused) 221 { 222 rs_epoch = epoch_alloc("Random Sources", EPOCH_PREEMPT); 223 epoch_inited = true; 224 } 225 SYSINIT(rs_epoch_init, SI_SUB_EPOCH, SI_ORDER_ANY, rs_epoch_init, NULL); 226 227 /* 228 * Run through all fast sources reading entropy for the given 229 * number of rounds, which should be a multiple of the number 230 * of entropy accumulation pools in use; it is 32 for Fortuna. 231 */ 232 static void 233 random_sources_feed(void) 234 { 235 uint32_t entropy[HARVESTSIZE]; 236 struct epoch_tracker et; 237 struct random_sources *rrs; 238 u_int i, n, npools; 239 bool rse_warm; 240 241 rse_warm = epoch_inited; 242 243 /* 244 * Evenly-ish distribute pool population across the second based on how 245 * frequently random_kthread iterates. 246 * 247 * For Fortuna, the math currently works out as such: 248 * 249 * 64 bits * 4 pools = 256 bits per iteration 250 * 256 bits * 10 Hz = 2560 bits per second, 320 B/s 251 * 252 */ 253 npools = howmany(p_random_alg_context->ra_poolcount, RANDOM_KTHREAD_HZ); 254 255 /*- 256 * If we're not seeded yet, attempt to perform a "full seed", filling 257 * all of the PRNG's pools with entropy; if there is enough entropy 258 * available from "fast" entropy sources this will allow us to finish 259 * seeding and unblock the boot process immediately rather than being 260 * stuck for a few seconds with random_kthread gradually collecting a 261 * small chunk of entropy every 1 / RANDOM_KTHREAD_HZ seconds. 262 * 263 * We collect RANDOM_FORTUNA_DEFPOOLSIZE bytes per pool, i.e. enough 264 * to fill Fortuna's pools in the default configuration. With another 265 * PRNG or smaller pools for Fortuna, we might collect more entropy 266 * than needed to fill the pools, but this is harmless; alternatively, 267 * a different PRNG, larger pools, or fast entropy sources which are 268 * not able to provide as much entropy as we request may result in the 269 * not being fully seeded (and thus remaining blocked) but in that 270 * case we will return here after 1 / RANDOM_KTHREAD_HZ seconds and 271 * try again for a large amount of entropy. 272 */ 273 if (!p_random_alg_context->ra_seeded()) 274 npools = howmany(p_random_alg_context->ra_poolcount * 275 RANDOM_FORTUNA_DEFPOOLSIZE, sizeof(entropy)); 276 277 /* 278 * Step over all of live entropy sources, and feed their output 279 * to the system-wide RNG. 280 */ 281 if (rse_warm) 282 epoch_enter_preempt(rs_epoch, &et); 283 CK_LIST_FOREACH(rrs, &source_list, rrs_entries) { 284 for (i = 0; i < npools; i++) { 285 n = rrs->rrs_source->rs_read(entropy, sizeof(entropy)); 286 KASSERT((n <= sizeof(entropy)), ("%s: rs_read returned too much data (%u > %zu)", __func__, n, sizeof(entropy))); 287 /* 288 * Sometimes the HW entropy source doesn't have anything 289 * ready for us. This isn't necessarily untrustworthy. 290 * We don't perform any other verification of an entropy 291 * source (i.e., length is allowed to be anywhere from 1 292 * to sizeof(entropy), quality is unchecked, etc), so 293 * don't balk verbosely at slow random sources either. 294 * There are reports that RDSEED on x86 metal falls 295 * behind the rate at which we query it, for example. 296 * But it's still a better entropy source than RDRAND. 297 */ 298 if (n == 0) 299 continue; 300 random_harvest_direct(entropy, n, rrs->rrs_source->rs_source); 301 } 302 } 303 if (rse_warm) 304 epoch_exit_preempt(rs_epoch, &et); 305 explicit_bzero(entropy, sizeof(entropy)); 306 } 307 308 /* ARGSUSED */ 309 static int 310 random_check_uint_harvestmask(SYSCTL_HANDLER_ARGS) 311 { 312 static const u_int user_immutable_mask = 313 (((1 << ENTROPYSOURCE) - 1) & (-1UL << RANDOM_PURE_START)) | 314 _RANDOM_HARVEST_ETHER_OFF | _RANDOM_HARVEST_UMA_OFF; 315 316 int error; 317 u_int value, orig_value; 318 319 orig_value = value = hc_source_mask; 320 error = sysctl_handle_int(oidp, &value, 0, req); 321 if (error != 0 || req->newptr == NULL) 322 return (error); 323 324 if (flsl(value) > ENTROPYSOURCE) 325 return (EINVAL); 326 327 /* 328 * Disallow userspace modification of pure entropy sources. 329 */ 330 hc_source_mask = (value & ~user_immutable_mask) | 331 (orig_value & user_immutable_mask); 332 return (0); 333 } 334 SYSCTL_PROC(_kern_random_harvest, OID_AUTO, mask, 335 CTLTYPE_UINT | CTLFLAG_RW | CTLFLAG_NEEDGIANT, NULL, 0, 336 random_check_uint_harvestmask, "IU", 337 "Entropy harvesting mask"); 338 339 /* ARGSUSED */ 340 static int 341 random_print_harvestmask(SYSCTL_HANDLER_ARGS) 342 { 343 struct sbuf sbuf; 344 int error, i; 345 346 error = sysctl_wire_old_buffer(req, 0); 347 if (error == 0) { 348 sbuf_new_for_sysctl(&sbuf, NULL, 128, req); 349 for (i = ENTROPYSOURCE - 1; i >= 0; i--) 350 sbuf_cat(&sbuf, (hc_source_mask & (1 << i)) ? "1" : "0"); 351 error = sbuf_finish(&sbuf); 352 sbuf_delete(&sbuf); 353 } 354 return (error); 355 } 356 SYSCTL_PROC(_kern_random_harvest, OID_AUTO, mask_bin, 357 CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_MPSAFE, NULL, 0, 358 random_print_harvestmask, "A", 359 "Entropy harvesting mask (printable)"); 360 361 static const char *random_source_descr[ENTROPYSOURCE] = { 362 [RANDOM_CACHED] = "CACHED", 363 [RANDOM_ATTACH] = "ATTACH", 364 [RANDOM_KEYBOARD] = "KEYBOARD", 365 [RANDOM_MOUSE] = "MOUSE", 366 [RANDOM_NET_TUN] = "NET_TUN", 367 [RANDOM_NET_ETHER] = "NET_ETHER", 368 [RANDOM_NET_NG] = "NET_NG", 369 [RANDOM_INTERRUPT] = "INTERRUPT", 370 [RANDOM_SWI] = "SWI", 371 [RANDOM_FS_ATIME] = "FS_ATIME", 372 [RANDOM_UMA] = "UMA", 373 [RANDOM_CALLOUT] = "CALLOUT", /* ENVIRONMENTAL_END */ 374 [RANDOM_PURE_OCTEON] = "PURE_OCTEON", /* PURE_START */ 375 [RANDOM_PURE_SAFE] = "PURE_SAFE", 376 [RANDOM_PURE_GLXSB] = "PURE_GLXSB", 377 [RANDOM_PURE_HIFN] = "PURE_HIFN", 378 [RANDOM_PURE_RDRAND] = "PURE_RDRAND", 379 [RANDOM_PURE_NEHEMIAH] = "PURE_NEHEMIAH", 380 [RANDOM_PURE_RNDTEST] = "PURE_RNDTEST", 381 [RANDOM_PURE_VIRTIO] = "PURE_VIRTIO", 382 [RANDOM_PURE_BROADCOM] = "PURE_BROADCOM", 383 [RANDOM_PURE_CCP] = "PURE_CCP", 384 [RANDOM_PURE_DARN] = "PURE_DARN", 385 [RANDOM_PURE_TPM] = "PURE_TPM", 386 [RANDOM_PURE_VMGENID] = "PURE_VMGENID", 387 [RANDOM_PURE_QUALCOMM] = "PURE_QUALCOMM", 388 [RANDOM_PURE_ARMV8] = "PURE_ARMV8", 389 /* "ENTROPYSOURCE" */ 390 }; 391 392 /* ARGSUSED */ 393 static int 394 random_print_harvestmask_symbolic(SYSCTL_HANDLER_ARGS) 395 { 396 struct sbuf sbuf; 397 int error, i; 398 bool first; 399 400 first = true; 401 error = sysctl_wire_old_buffer(req, 0); 402 if (error == 0) { 403 sbuf_new_for_sysctl(&sbuf, NULL, 128, req); 404 for (i = ENTROPYSOURCE - 1; i >= 0; i--) { 405 if (i >= RANDOM_PURE_START && 406 (hc_source_mask & (1 << i)) == 0) 407 continue; 408 if (!first) 409 sbuf_cat(&sbuf, ","); 410 sbuf_cat(&sbuf, !(hc_source_mask & (1 << i)) ? "[" : ""); 411 sbuf_cat(&sbuf, random_source_descr[i]); 412 sbuf_cat(&sbuf, !(hc_source_mask & (1 << i)) ? "]" : ""); 413 first = false; 414 } 415 error = sbuf_finish(&sbuf); 416 sbuf_delete(&sbuf); 417 } 418 return (error); 419 } 420 SYSCTL_PROC(_kern_random_harvest, OID_AUTO, mask_symbolic, 421 CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_MPSAFE, NULL, 0, 422 random_print_harvestmask_symbolic, "A", 423 "Entropy harvesting mask (symbolic)"); 424 425 /* ARGSUSED */ 426 static void 427 random_harvestq_init(void *unused __unused) 428 { 429 static const u_int almost_everything_mask = 430 (((1 << (RANDOM_ENVIRONMENTAL_END + 1)) - 1) & 431 ~_RANDOM_HARVEST_ETHER_OFF & ~_RANDOM_HARVEST_UMA_OFF); 432 433 hc_source_mask = almost_everything_mask; 434 RANDOM_HARVEST_INIT_LOCK(); 435 harvest_context.hc_entropy_ring.in = harvest_context.hc_entropy_ring.out = 0; 436 } 437 SYSINIT(random_device_h_init, SI_SUB_RANDOM, SI_ORDER_THIRD, random_harvestq_init, NULL); 438 439 /* 440 * Subroutine to slice up a contiguous chunk of 'entropy' and feed it into the 441 * underlying algorithm. Returns number of bytes actually fed into underlying 442 * algorithm. 443 */ 444 static size_t 445 random_early_prime(char *entropy, size_t len) 446 { 447 struct harvest_event event; 448 size_t i; 449 450 len = rounddown(len, sizeof(event.he_entropy)); 451 if (len == 0) 452 return (0); 453 454 for (i = 0; i < len; i += sizeof(event.he_entropy)) { 455 event.he_somecounter = (uint32_t)get_cyclecount(); 456 event.he_size = sizeof(event.he_entropy); 457 event.he_source = RANDOM_CACHED; 458 event.he_destination = 459 harvest_context.hc_destination[RANDOM_CACHED]++; 460 memcpy(event.he_entropy, entropy + i, sizeof(event.he_entropy)); 461 random_harvestq_fast_process_event(&event); 462 } 463 explicit_bzero(entropy, len); 464 return (len); 465 } 466 467 /* 468 * Subroutine to search for known loader-loaded files in memory and feed them 469 * into the underlying algorithm early in boot. Returns the number of bytes 470 * loaded (zero if none were loaded). 471 */ 472 static size_t 473 random_prime_loader_file(const char *type) 474 { 475 uint8_t *keyfile, *data; 476 size_t size; 477 478 keyfile = preload_search_by_type(type); 479 if (keyfile == NULL) 480 return (0); 481 482 data = preload_fetch_addr(keyfile); 483 size = preload_fetch_size(keyfile); 484 if (data == NULL) 485 return (0); 486 487 return (random_early_prime(data, size)); 488 } 489 490 /* 491 * This is used to prime the RNG by grabbing any early random stuff 492 * known to the kernel, and inserting it directly into the hashing 493 * module, currently Fortuna. 494 */ 495 /* ARGSUSED */ 496 static void 497 random_harvestq_prime(void *unused __unused) 498 { 499 size_t size; 500 501 /* 502 * Get entropy that may have been preloaded by loader(8) 503 * and use it to pre-charge the entropy harvest queue. 504 */ 505 size = random_prime_loader_file(RANDOM_CACHED_BOOT_ENTROPY_MODULE); 506 if (bootverbose) { 507 if (size > 0) 508 printf("random: read %zu bytes from preloaded cache\n", 509 size); 510 else 511 printf("random: no preloaded entropy cache\n"); 512 } 513 size = random_prime_loader_file(RANDOM_PLATFORM_BOOT_ENTROPY_MODULE); 514 if (bootverbose) { 515 if (size > 0) 516 printf("random: read %zu bytes from platform bootloader\n", 517 size); 518 else 519 printf("random: no platform bootloader entropy\n"); 520 } 521 } 522 SYSINIT(random_device_prime, SI_SUB_RANDOM, SI_ORDER_MIDDLE, random_harvestq_prime, NULL); 523 524 /* ARGSUSED */ 525 static void 526 random_harvestq_deinit(void *unused __unused) 527 { 528 529 /* Command the hash/reseed thread to end and wait for it to finish */ 530 random_kthread_control = 0; 531 while (random_kthread_control >= 0) 532 tsleep(&harvest_context.hc_kthread_proc, 0, "harvqterm", hz/5); 533 } 534 SYSUNINIT(random_device_h_init, SI_SUB_RANDOM, SI_ORDER_THIRD, random_harvestq_deinit, NULL); 535 536 /*- 537 * Entropy harvesting queue routine. 538 * 539 * This is supposed to be fast; do not do anything slow in here! 540 * It is also illegal (and morally reprehensible) to insert any 541 * high-rate data here. "High-rate" is defined as a data source 542 * that will usually cause lots of failures of the "Lockless read" 543 * check a few lines below. This includes the "always-on" sources 544 * like the Intel "rdrand" or the VIA Nehamiah "xstore" sources. 545 */ 546 /* XXXRW: get_cyclecount() is cheap on most modern hardware, where cycle 547 * counters are built in, but on older hardware it will do a real time clock 548 * read which can be quite expensive. 549 */ 550 void 551 random_harvest_queue_(const void *entropy, u_int size, enum random_entropy_source origin) 552 { 553 struct harvest_event *event; 554 u_int ring_in; 555 556 KASSERT(origin >= RANDOM_START && origin < ENTROPYSOURCE, ("%s: origin %d invalid\n", __func__, origin)); 557 RANDOM_HARVEST_LOCK(); 558 ring_in = (harvest_context.hc_entropy_ring.in + 1)%RANDOM_RING_MAX; 559 if (ring_in != harvest_context.hc_entropy_ring.out) { 560 /* The ring is not full */ 561 event = harvest_context.hc_entropy_ring.ring + ring_in; 562 event->he_somecounter = (uint32_t)get_cyclecount(); 563 event->he_source = origin; 564 event->he_destination = harvest_context.hc_destination[origin]++; 565 if (size <= sizeof(event->he_entropy)) { 566 event->he_size = size; 567 memcpy(event->he_entropy, entropy, size); 568 } 569 else { 570 /* Big event, so squash it */ 571 event->he_size = sizeof(event->he_entropy[0]); 572 event->he_entropy[0] = jenkins_hash(entropy, size, (uint32_t)(uintptr_t)event); 573 } 574 harvest_context.hc_entropy_ring.in = ring_in; 575 } 576 RANDOM_HARVEST_UNLOCK(); 577 } 578 579 /*- 580 * Entropy harvesting fast routine. 581 * 582 * This is supposed to be very fast; do not do anything slow in here! 583 * This is the right place for high-rate harvested data. 584 */ 585 void 586 random_harvest_fast_(const void *entropy, u_int size) 587 { 588 u_int pos; 589 590 pos = harvest_context.hc_entropy_fast_accumulator.pos; 591 harvest_context.hc_entropy_fast_accumulator.buf[pos] ^= jenkins_hash(entropy, size, (uint32_t)get_cyclecount()); 592 harvest_context.hc_entropy_fast_accumulator.pos = (pos + 1)%RANDOM_ACCUM_MAX; 593 } 594 595 /*- 596 * Entropy harvesting direct routine. 597 * 598 * This is not supposed to be fast, but will only be used during 599 * (e.g.) booting when initial entropy is being gathered. 600 */ 601 void 602 random_harvest_direct_(const void *entropy, u_int size, enum random_entropy_source origin) 603 { 604 struct harvest_event event; 605 606 KASSERT(origin >= RANDOM_START && origin < ENTROPYSOURCE, ("%s: origin %d invalid\n", __func__, origin)); 607 size = MIN(size, sizeof(event.he_entropy)); 608 event.he_somecounter = (uint32_t)get_cyclecount(); 609 event.he_size = size; 610 event.he_source = origin; 611 event.he_destination = harvest_context.hc_destination[origin]++; 612 memcpy(event.he_entropy, entropy, size); 613 random_harvestq_fast_process_event(&event); 614 } 615 616 void 617 random_harvest_register_source(enum random_entropy_source source) 618 { 619 620 hc_source_mask |= (1 << source); 621 } 622 623 void 624 random_harvest_deregister_source(enum random_entropy_source source) 625 { 626 627 hc_source_mask &= ~(1 << source); 628 } 629 630 void 631 random_source_register(struct random_source *rsource) 632 { 633 struct random_sources *rrs; 634 635 KASSERT(rsource != NULL, ("invalid input to %s", __func__)); 636 637 rrs = malloc(sizeof(*rrs), M_ENTROPY, M_WAITOK); 638 rrs->rrs_source = rsource; 639 640 random_harvest_register_source(rsource->rs_source); 641 642 printf("random: registering fast source %s\n", rsource->rs_ident); 643 644 RANDOM_HARVEST_LOCK(); 645 CK_LIST_INSERT_HEAD(&source_list, rrs, rrs_entries); 646 RANDOM_HARVEST_UNLOCK(); 647 } 648 649 void 650 random_source_deregister(struct random_source *rsource) 651 { 652 struct random_sources *rrs = NULL; 653 654 KASSERT(rsource != NULL, ("invalid input to %s", __func__)); 655 656 random_harvest_deregister_source(rsource->rs_source); 657 658 RANDOM_HARVEST_LOCK(); 659 CK_LIST_FOREACH(rrs, &source_list, rrs_entries) 660 if (rrs->rrs_source == rsource) { 661 CK_LIST_REMOVE(rrs, rrs_entries); 662 break; 663 } 664 RANDOM_HARVEST_UNLOCK(); 665 666 if (rrs != NULL && epoch_inited) 667 epoch_wait_preempt(rs_epoch); 668 free(rrs, M_ENTROPY); 669 } 670 671 static int 672 random_source_handler(SYSCTL_HANDLER_ARGS) 673 { 674 struct epoch_tracker et; 675 struct random_sources *rrs; 676 struct sbuf sbuf; 677 int error, count; 678 679 error = sysctl_wire_old_buffer(req, 0); 680 if (error != 0) 681 return (error); 682 683 sbuf_new_for_sysctl(&sbuf, NULL, 64, req); 684 count = 0; 685 epoch_enter_preempt(rs_epoch, &et); 686 CK_LIST_FOREACH(rrs, &source_list, rrs_entries) { 687 sbuf_cat(&sbuf, (count++ ? ",'" : "'")); 688 sbuf_cat(&sbuf, rrs->rrs_source->rs_ident); 689 sbuf_cat(&sbuf, "'"); 690 } 691 epoch_exit_preempt(rs_epoch, &et); 692 error = sbuf_finish(&sbuf); 693 sbuf_delete(&sbuf); 694 return (error); 695 } 696 SYSCTL_PROC(_kern_random, OID_AUTO, random_sources, CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_MPSAFE, 697 NULL, 0, random_source_handler, "A", 698 "List of active fast entropy sources."); 699 700 MODULE_VERSION(random_harvestq, 1); 701