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/cdefs.h> 33 #include <sys/param.h> 34 #include <sys/systm.h> 35 #include <sys/ck.h> 36 #include <sys/conf.h> 37 #include <sys/epoch.h> 38 #include <sys/eventhandler.h> 39 #include <sys/hash.h> 40 #include <sys/kernel.h> 41 #include <sys/kthread.h> 42 #include <sys/linker.h> 43 #include <sys/lock.h> 44 #include <sys/malloc.h> 45 #include <sys/module.h> 46 #include <sys/mutex.h> 47 #include <sys/random.h> 48 #include <sys/sbuf.h> 49 #include <sys/sysctl.h> 50 #include <sys/unistd.h> 51 52 #include <machine/atomic.h> 53 #include <machine/cpu.h> 54 55 #include <crypto/rijndael/rijndael-api-fst.h> 56 #include <crypto/sha2/sha256.h> 57 58 #include <dev/random/fortuna.h> 59 #include <dev/random/hash.h> 60 #include <dev/random/randomdev.h> 61 #include <dev/random/random_harvestq.h> 62 63 #if defined(RANDOM_ENABLE_ETHER) 64 #define _RANDOM_HARVEST_ETHER_OFF 0 65 #else 66 #define _RANDOM_HARVEST_ETHER_OFF (1u << RANDOM_NET_ETHER) 67 #endif 68 #if defined(RANDOM_ENABLE_UMA) 69 #define _RANDOM_HARVEST_UMA_OFF 0 70 #else 71 #define _RANDOM_HARVEST_UMA_OFF (1u << RANDOM_UMA) 72 #endif 73 74 /* 75 * Note that random_sources_feed() will also use this to try and split up 76 * entropy into a subset of pools per iteration with the goal of feeding 77 * HARVESTSIZE into every pool at least once per second. 78 */ 79 #define RANDOM_KTHREAD_HZ 10 80 81 static void random_kthread(void); 82 static void random_sources_feed(void); 83 84 /* 85 * Random must initialize much earlier than epoch, but we can initialize the 86 * epoch code before SMP starts. Prior to SMP, we can safely bypass 87 * concurrency primitives. 88 */ 89 static __read_mostly bool epoch_inited; 90 static __read_mostly epoch_t rs_epoch; 91 92 /* 93 * How many events to queue up. We create this many items in 94 * an 'empty' queue, then transfer them to the 'harvest' queue with 95 * supplied junk. When used, they are transferred back to the 96 * 'empty' queue. 97 */ 98 #define RANDOM_RING_MAX 1024 99 #define RANDOM_ACCUM_MAX 8 100 101 /* 1 to let the kernel thread run, 0 to terminate, -1 to mark completion */ 102 volatile int random_kthread_control; 103 104 105 /* Allow the sysadmin to select the broad category of 106 * entropy types to harvest. 107 */ 108 __read_frequently u_int hc_source_mask; 109 110 struct random_sources { 111 CK_LIST_ENTRY(random_sources) rrs_entries; 112 struct random_source *rrs_source; 113 }; 114 115 static CK_LIST_HEAD(sources_head, random_sources) source_list = 116 CK_LIST_HEAD_INITIALIZER(source_list); 117 118 SYSCTL_NODE(_kern_random, OID_AUTO, harvest, CTLFLAG_RW | CTLFLAG_MPSAFE, 0, 119 "Entropy Device Parameters"); 120 121 /* 122 * Put all the harvest queue context stuff in one place. 123 * this make is a bit easier to lock and protect. 124 */ 125 static struct harvest_context { 126 /* The harvest mutex protects all of harvest_context and 127 * the related data. 128 */ 129 struct mtx hc_mtx; 130 /* Round-robin destination cache. */ 131 u_int hc_destination[ENTROPYSOURCE]; 132 /* The context of the kernel thread processing harvested entropy */ 133 struct proc *hc_kthread_proc; 134 /* 135 * Lockless ring buffer holding entropy events 136 * If ring.in == ring.out, 137 * the buffer is empty. 138 * If ring.in != ring.out, 139 * the buffer contains harvested entropy. 140 * If (ring.in + 1) == ring.out (mod RANDOM_RING_MAX), 141 * the buffer is full. 142 * 143 * NOTE: ring.in points to the last added element, 144 * and ring.out points to the last consumed element. 145 * 146 * The ring.in variable needs locking as there are multiple 147 * sources to the ring. Only the sources may change ring.in, 148 * but the consumer may examine it. 149 * 150 * The ring.out variable does not need locking as there is 151 * only one consumer. Only the consumer may change ring.out, 152 * but the sources may examine it. 153 */ 154 struct entropy_ring { 155 struct harvest_event ring[RANDOM_RING_MAX]; 156 volatile u_int in; 157 volatile u_int out; 158 } hc_entropy_ring; 159 struct fast_entropy_accumulator { 160 volatile u_int pos; 161 uint32_t buf[RANDOM_ACCUM_MAX]; 162 } hc_entropy_fast_accumulator; 163 } harvest_context; 164 165 static struct kproc_desc random_proc_kp = { 166 "rand_harvestq", 167 random_kthread, 168 &harvest_context.hc_kthread_proc, 169 }; 170 171 /* Pass the given event straight through to Fortuna/Whatever. */ 172 static __inline void 173 random_harvestq_fast_process_event(struct harvest_event *event) 174 { 175 p_random_alg_context->ra_event_processor(event); 176 explicit_bzero(event, sizeof(*event)); 177 } 178 179 static void 180 random_kthread(void) 181 { 182 u_int maxloop, ring_out, i; 183 184 /* 185 * Locking is not needed as this is the only place we modify ring.out, and 186 * we only examine ring.in without changing it. Both of these are volatile, 187 * and this is a unique thread. 188 */ 189 for (random_kthread_control = 1; random_kthread_control;) { 190 /* Deal with events, if any. Restrict the number we do in one go. */ 191 maxloop = RANDOM_RING_MAX; 192 while (harvest_context.hc_entropy_ring.out != harvest_context.hc_entropy_ring.in) { 193 ring_out = (harvest_context.hc_entropy_ring.out + 1)%RANDOM_RING_MAX; 194 random_harvestq_fast_process_event(harvest_context.hc_entropy_ring.ring + ring_out); 195 harvest_context.hc_entropy_ring.out = ring_out; 196 if (!--maxloop) 197 break; 198 } 199 random_sources_feed(); 200 /* XXX: FIX!! Increase the high-performance data rate? Need some measurements first. */ 201 for (i = 0; i < RANDOM_ACCUM_MAX; i++) { 202 if (harvest_context.hc_entropy_fast_accumulator.buf[i]) { 203 random_harvest_direct(harvest_context.hc_entropy_fast_accumulator.buf + i, sizeof(harvest_context.hc_entropy_fast_accumulator.buf[0]), RANDOM_UMA); 204 harvest_context.hc_entropy_fast_accumulator.buf[i] = 0; 205 } 206 } 207 /* XXX: FIX!! This is a *great* place to pass hardware/live entropy to random(9) */ 208 tsleep_sbt(&harvest_context.hc_kthread_proc, 0, "-", 209 SBT_1S/RANDOM_KTHREAD_HZ, 0, C_PREL(1)); 210 } 211 random_kthread_control = -1; 212 wakeup(&harvest_context.hc_kthread_proc); 213 kproc_exit(0); 214 /* NOTREACHED */ 215 } 216 /* This happens well after SI_SUB_RANDOM */ 217 SYSINIT(random_device_h_proc, SI_SUB_KICK_SCHEDULER, SI_ORDER_ANY, kproc_start, 218 &random_proc_kp); 219 220 static void 221 rs_epoch_init(void *dummy __unused) 222 { 223 rs_epoch = epoch_alloc("Random Sources", EPOCH_PREEMPT); 224 epoch_inited = true; 225 } 226 SYSINIT(rs_epoch_init, SI_SUB_EPOCH, SI_ORDER_ANY, rs_epoch_init, NULL); 227 228 /* 229 * Run through all fast sources reading entropy for the given 230 * number of rounds, which should be a multiple of the number 231 * of entropy accumulation pools in use; it is 32 for Fortuna. 232 */ 233 static void 234 random_sources_feed(void) 235 { 236 uint32_t entropy[HARVESTSIZE]; 237 struct epoch_tracker et; 238 struct random_sources *rrs; 239 u_int i, n, npools; 240 bool rse_warm; 241 242 rse_warm = epoch_inited; 243 244 /* 245 * Evenly-ish distribute pool population across the second based on how 246 * frequently random_kthread iterates. 247 * 248 * For Fortuna, the math currently works out as such: 249 * 250 * 64 bits * 4 pools = 256 bits per iteration 251 * 256 bits * 10 Hz = 2560 bits per second, 320 B/s 252 * 253 */ 254 npools = howmany(p_random_alg_context->ra_poolcount, RANDOM_KTHREAD_HZ); 255 256 /*- 257 * If we're not seeded yet, attempt to perform a "full seed", filling 258 * all of the PRNG's pools with entropy; if there is enough entropy 259 * available from "fast" entropy sources this will allow us to finish 260 * seeding and unblock the boot process immediately rather than being 261 * stuck for a few seconds with random_kthread gradually collecting a 262 * small chunk of entropy every 1 / RANDOM_KTHREAD_HZ seconds. 263 * 264 * We collect RANDOM_FORTUNA_DEFPOOLSIZE bytes per pool, i.e. enough 265 * to fill Fortuna's pools in the default configuration. With another 266 * PRNG or smaller pools for Fortuna, we might collect more entropy 267 * than needed to fill the pools, but this is harmless; alternatively, 268 * a different PRNG, larger pools, or fast entropy sources which are 269 * not able to provide as much entropy as we request may result in the 270 * not being fully seeded (and thus remaining blocked) but in that 271 * case we will return here after 1 / RANDOM_KTHREAD_HZ seconds and 272 * try again for a large amount of entropy. 273 */ 274 if (!p_random_alg_context->ra_seeded()) 275 npools = howmany(p_random_alg_context->ra_poolcount * 276 RANDOM_FORTUNA_DEFPOOLSIZE, sizeof(entropy)); 277 278 /* 279 * Step over all of live entropy sources, and feed their output 280 * to the system-wide RNG. 281 */ 282 if (rse_warm) 283 epoch_enter_preempt(rs_epoch, &et); 284 CK_LIST_FOREACH(rrs, &source_list, rrs_entries) { 285 for (i = 0; i < npools; i++) { 286 n = rrs->rrs_source->rs_read(entropy, sizeof(entropy)); 287 KASSERT((n <= sizeof(entropy)), ("%s: rs_read returned too much data (%u > %zu)", __func__, n, sizeof(entropy))); 288 /* 289 * Sometimes the HW entropy source doesn't have anything 290 * ready for us. This isn't necessarily untrustworthy. 291 * We don't perform any other verification of an entropy 292 * source (i.e., length is allowed to be anywhere from 1 293 * to sizeof(entropy), quality is unchecked, etc), so 294 * don't balk verbosely at slow random sources either. 295 * There are reports that RDSEED on x86 metal falls 296 * behind the rate at which we query it, for example. 297 * But it's still a better entropy source than RDRAND. 298 */ 299 if (n == 0) 300 continue; 301 random_harvest_direct(entropy, n, rrs->rrs_source->rs_source); 302 } 303 } 304 if (rse_warm) 305 epoch_exit_preempt(rs_epoch, &et); 306 explicit_bzero(entropy, sizeof(entropy)); 307 } 308 309 /* ARGSUSED */ 310 static int 311 random_check_uint_harvestmask(SYSCTL_HANDLER_ARGS) 312 { 313 static const u_int user_immutable_mask = 314 (((1 << ENTROPYSOURCE) - 1) & (-1UL << RANDOM_PURE_START)) | 315 _RANDOM_HARVEST_ETHER_OFF | _RANDOM_HARVEST_UMA_OFF; 316 317 int error; 318 u_int value, orig_value; 319 320 orig_value = value = hc_source_mask; 321 error = sysctl_handle_int(oidp, &value, 0, req); 322 if (error != 0 || req->newptr == NULL) 323 return (error); 324 325 if (flsl(value) > ENTROPYSOURCE) 326 return (EINVAL); 327 328 /* 329 * Disallow userspace modification of pure entropy sources. 330 */ 331 hc_source_mask = (value & ~user_immutable_mask) | 332 (orig_value & user_immutable_mask); 333 return (0); 334 } 335 SYSCTL_PROC(_kern_random_harvest, OID_AUTO, mask, 336 CTLTYPE_UINT | CTLFLAG_RW | CTLFLAG_NEEDGIANT, NULL, 0, 337 random_check_uint_harvestmask, "IU", 338 "Entropy harvesting mask"); 339 340 /* ARGSUSED */ 341 static int 342 random_print_harvestmask(SYSCTL_HANDLER_ARGS) 343 { 344 struct sbuf sbuf; 345 int error, i; 346 347 error = sysctl_wire_old_buffer(req, 0); 348 if (error == 0) { 349 sbuf_new_for_sysctl(&sbuf, NULL, 128, req); 350 for (i = ENTROPYSOURCE - 1; i >= 0; i--) 351 sbuf_cat(&sbuf, (hc_source_mask & (1 << i)) ? "1" : "0"); 352 error = sbuf_finish(&sbuf); 353 sbuf_delete(&sbuf); 354 } 355 return (error); 356 } 357 SYSCTL_PROC(_kern_random_harvest, OID_AUTO, mask_bin, 358 CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_MPSAFE, NULL, 0, 359 random_print_harvestmask, "A", 360 "Entropy harvesting mask (printable)"); 361 362 static const char *random_source_descr[ENTROPYSOURCE] = { 363 [RANDOM_CACHED] = "CACHED", 364 [RANDOM_ATTACH] = "ATTACH", 365 [RANDOM_KEYBOARD] = "KEYBOARD", 366 [RANDOM_MOUSE] = "MOUSE", 367 [RANDOM_NET_TUN] = "NET_TUN", 368 [RANDOM_NET_ETHER] = "NET_ETHER", 369 [RANDOM_NET_NG] = "NET_NG", 370 [RANDOM_INTERRUPT] = "INTERRUPT", 371 [RANDOM_SWI] = "SWI", 372 [RANDOM_FS_ATIME] = "FS_ATIME", 373 [RANDOM_UMA] = "UMA", 374 [RANDOM_CALLOUT] = "CALLOUT", /* ENVIRONMENTAL_END */ 375 [RANDOM_PURE_OCTEON] = "PURE_OCTEON", /* PURE_START */ 376 [RANDOM_PURE_SAFE] = "PURE_SAFE", 377 [RANDOM_PURE_GLXSB] = "PURE_GLXSB", 378 [RANDOM_PURE_HIFN] = "PURE_HIFN", 379 [RANDOM_PURE_RDRAND] = "PURE_RDRAND", 380 [RANDOM_PURE_NEHEMIAH] = "PURE_NEHEMIAH", 381 [RANDOM_PURE_RNDTEST] = "PURE_RNDTEST", 382 [RANDOM_PURE_VIRTIO] = "PURE_VIRTIO", 383 [RANDOM_PURE_BROADCOM] = "PURE_BROADCOM", 384 [RANDOM_PURE_CCP] = "PURE_CCP", 385 [RANDOM_PURE_DARN] = "PURE_DARN", 386 [RANDOM_PURE_TPM] = "PURE_TPM", 387 [RANDOM_PURE_VMGENID] = "PURE_VMGENID", 388 [RANDOM_PURE_QUALCOMM] = "PURE_QUALCOMM", 389 [RANDOM_PURE_ARMV8] = "PURE_ARMV8", 390 /* "ENTROPYSOURCE" */ 391 }; 392 393 /* ARGSUSED */ 394 static int 395 random_print_harvestmask_symbolic(SYSCTL_HANDLER_ARGS) 396 { 397 struct sbuf sbuf; 398 int error, i; 399 bool first; 400 401 first = true; 402 error = sysctl_wire_old_buffer(req, 0); 403 if (error == 0) { 404 sbuf_new_for_sysctl(&sbuf, NULL, 128, req); 405 for (i = ENTROPYSOURCE - 1; i >= 0; i--) { 406 if (i >= RANDOM_PURE_START && 407 (hc_source_mask & (1 << i)) == 0) 408 continue; 409 if (!first) 410 sbuf_cat(&sbuf, ","); 411 sbuf_cat(&sbuf, !(hc_source_mask & (1 << i)) ? "[" : ""); 412 sbuf_cat(&sbuf, random_source_descr[i]); 413 sbuf_cat(&sbuf, !(hc_source_mask & (1 << i)) ? "]" : ""); 414 first = false; 415 } 416 error = sbuf_finish(&sbuf); 417 sbuf_delete(&sbuf); 418 } 419 return (error); 420 } 421 SYSCTL_PROC(_kern_random_harvest, OID_AUTO, mask_symbolic, 422 CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_MPSAFE, NULL, 0, 423 random_print_harvestmask_symbolic, "A", 424 "Entropy harvesting mask (symbolic)"); 425 426 /* ARGSUSED */ 427 static void 428 random_harvestq_init(void *unused __unused) 429 { 430 static const u_int almost_everything_mask = 431 (((1 << (RANDOM_ENVIRONMENTAL_END + 1)) - 1) & 432 ~_RANDOM_HARVEST_ETHER_OFF & ~_RANDOM_HARVEST_UMA_OFF); 433 434 hc_source_mask = almost_everything_mask; 435 RANDOM_HARVEST_INIT_LOCK(); 436 harvest_context.hc_entropy_ring.in = harvest_context.hc_entropy_ring.out = 0; 437 } 438 SYSINIT(random_device_h_init, SI_SUB_RANDOM, SI_ORDER_THIRD, random_harvestq_init, NULL); 439 440 /* 441 * Subroutine to slice up a contiguous chunk of 'entropy' and feed it into the 442 * underlying algorithm. Returns number of bytes actually fed into underlying 443 * algorithm. 444 */ 445 static size_t 446 random_early_prime(char *entropy, size_t len) 447 { 448 struct harvest_event event; 449 size_t i; 450 451 len = rounddown(len, sizeof(event.he_entropy)); 452 if (len == 0) 453 return (0); 454 455 for (i = 0; i < len; i += sizeof(event.he_entropy)) { 456 event.he_somecounter = (uint32_t)get_cyclecount(); 457 event.he_size = sizeof(event.he_entropy); 458 event.he_source = RANDOM_CACHED; 459 event.he_destination = 460 harvest_context.hc_destination[RANDOM_CACHED]++; 461 memcpy(event.he_entropy, entropy + i, sizeof(event.he_entropy)); 462 random_harvestq_fast_process_event(&event); 463 } 464 explicit_bzero(entropy, len); 465 return (len); 466 } 467 468 /* 469 * Subroutine to search for known loader-loaded files in memory and feed them 470 * into the underlying algorithm early in boot. Returns the number of bytes 471 * loaded (zero if none were loaded). 472 */ 473 static size_t 474 random_prime_loader_file(const char *type) 475 { 476 uint8_t *keyfile, *data; 477 size_t size; 478 479 keyfile = preload_search_by_type(type); 480 if (keyfile == NULL) 481 return (0); 482 483 data = preload_fetch_addr(keyfile); 484 size = preload_fetch_size(keyfile); 485 if (data == NULL) 486 return (0); 487 488 return (random_early_prime(data, size)); 489 } 490 491 /* 492 * This is used to prime the RNG by grabbing any early random stuff 493 * known to the kernel, and inserting it directly into the hashing 494 * module, currently Fortuna. 495 */ 496 /* ARGSUSED */ 497 static void 498 random_harvestq_prime(void *unused __unused) 499 { 500 size_t size; 501 502 /* 503 * Get entropy that may have been preloaded by loader(8) 504 * and use it to pre-charge the entropy harvest queue. 505 */ 506 size = random_prime_loader_file(RANDOM_CACHED_BOOT_ENTROPY_MODULE); 507 if (bootverbose) { 508 if (size > 0) 509 printf("random: read %zu bytes from preloaded cache\n", 510 size); 511 else 512 printf("random: no preloaded entropy cache\n"); 513 } 514 size = random_prime_loader_file(RANDOM_PLATFORM_BOOT_ENTROPY_MODULE); 515 if (bootverbose) { 516 if (size > 0) 517 printf("random: read %zu bytes from platform bootloader\n", 518 size); 519 else 520 printf("random: no platform bootloader entropy\n"); 521 } 522 } 523 SYSINIT(random_device_prime, SI_SUB_RANDOM, SI_ORDER_MIDDLE, random_harvestq_prime, NULL); 524 525 /* ARGSUSED */ 526 static void 527 random_harvestq_deinit(void *unused __unused) 528 { 529 530 /* Command the hash/reseed thread to end and wait for it to finish */ 531 random_kthread_control = 0; 532 while (random_kthread_control >= 0) 533 tsleep(&harvest_context.hc_kthread_proc, 0, "harvqterm", hz/5); 534 } 535 SYSUNINIT(random_device_h_init, SI_SUB_RANDOM, SI_ORDER_THIRD, random_harvestq_deinit, NULL); 536 537 /*- 538 * Entropy harvesting queue routine. 539 * 540 * This is supposed to be fast; do not do anything slow in here! 541 * It is also illegal (and morally reprehensible) to insert any 542 * high-rate data here. "High-rate" is defined as a data source 543 * that will usually cause lots of failures of the "Lockless read" 544 * check a few lines below. This includes the "always-on" sources 545 * like the Intel "rdrand" or the VIA Nehamiah "xstore" sources. 546 */ 547 /* XXXRW: get_cyclecount() is cheap on most modern hardware, where cycle 548 * counters are built in, but on older hardware it will do a real time clock 549 * read which can be quite expensive. 550 */ 551 void 552 random_harvest_queue_(const void *entropy, u_int size, enum random_entropy_source origin) 553 { 554 struct harvest_event *event; 555 u_int ring_in; 556 557 KASSERT(origin >= RANDOM_START && origin < ENTROPYSOURCE, ("%s: origin %d invalid\n", __func__, origin)); 558 RANDOM_HARVEST_LOCK(); 559 ring_in = (harvest_context.hc_entropy_ring.in + 1)%RANDOM_RING_MAX; 560 if (ring_in != harvest_context.hc_entropy_ring.out) { 561 /* The ring is not full */ 562 event = harvest_context.hc_entropy_ring.ring + ring_in; 563 event->he_somecounter = (uint32_t)get_cyclecount(); 564 event->he_source = origin; 565 event->he_destination = harvest_context.hc_destination[origin]++; 566 if (size <= sizeof(event->he_entropy)) { 567 event->he_size = size; 568 memcpy(event->he_entropy, entropy, size); 569 } 570 else { 571 /* Big event, so squash it */ 572 event->he_size = sizeof(event->he_entropy[0]); 573 event->he_entropy[0] = jenkins_hash(entropy, size, (uint32_t)(uintptr_t)event); 574 } 575 harvest_context.hc_entropy_ring.in = ring_in; 576 } 577 RANDOM_HARVEST_UNLOCK(); 578 } 579 580 /*- 581 * Entropy harvesting fast routine. 582 * 583 * This is supposed to be very fast; do not do anything slow in here! 584 * This is the right place for high-rate harvested data. 585 */ 586 void 587 random_harvest_fast_(const void *entropy, u_int size) 588 { 589 u_int pos; 590 591 pos = harvest_context.hc_entropy_fast_accumulator.pos; 592 harvest_context.hc_entropy_fast_accumulator.buf[pos] ^= jenkins_hash(entropy, size, (uint32_t)get_cyclecount()); 593 harvest_context.hc_entropy_fast_accumulator.pos = (pos + 1)%RANDOM_ACCUM_MAX; 594 } 595 596 /*- 597 * Entropy harvesting direct routine. 598 * 599 * This is not supposed to be fast, but will only be used during 600 * (e.g.) booting when initial entropy is being gathered. 601 */ 602 void 603 random_harvest_direct_(const void *entropy, u_int size, enum random_entropy_source origin) 604 { 605 struct harvest_event event; 606 607 KASSERT(origin >= RANDOM_START && origin < ENTROPYSOURCE, ("%s: origin %d invalid\n", __func__, origin)); 608 size = MIN(size, sizeof(event.he_entropy)); 609 event.he_somecounter = (uint32_t)get_cyclecount(); 610 event.he_size = size; 611 event.he_source = origin; 612 event.he_destination = harvest_context.hc_destination[origin]++; 613 memcpy(event.he_entropy, entropy, size); 614 random_harvestq_fast_process_event(&event); 615 } 616 617 void 618 random_harvest_register_source(enum random_entropy_source source) 619 { 620 621 hc_source_mask |= (1 << source); 622 } 623 624 void 625 random_harvest_deregister_source(enum random_entropy_source source) 626 { 627 628 hc_source_mask &= ~(1 << source); 629 } 630 631 void 632 random_source_register(struct random_source *rsource) 633 { 634 struct random_sources *rrs; 635 636 KASSERT(rsource != NULL, ("invalid input to %s", __func__)); 637 638 rrs = malloc(sizeof(*rrs), M_ENTROPY, M_WAITOK); 639 rrs->rrs_source = rsource; 640 641 random_harvest_register_source(rsource->rs_source); 642 643 printf("random: registering fast source %s\n", rsource->rs_ident); 644 645 RANDOM_HARVEST_LOCK(); 646 CK_LIST_INSERT_HEAD(&source_list, rrs, rrs_entries); 647 RANDOM_HARVEST_UNLOCK(); 648 } 649 650 void 651 random_source_deregister(struct random_source *rsource) 652 { 653 struct random_sources *rrs = NULL; 654 655 KASSERT(rsource != NULL, ("invalid input to %s", __func__)); 656 657 random_harvest_deregister_source(rsource->rs_source); 658 659 RANDOM_HARVEST_LOCK(); 660 CK_LIST_FOREACH(rrs, &source_list, rrs_entries) 661 if (rrs->rrs_source == rsource) { 662 CK_LIST_REMOVE(rrs, rrs_entries); 663 break; 664 } 665 RANDOM_HARVEST_UNLOCK(); 666 667 if (rrs != NULL && epoch_inited) 668 epoch_wait_preempt(rs_epoch); 669 free(rrs, M_ENTROPY); 670 } 671 672 static int 673 random_source_handler(SYSCTL_HANDLER_ARGS) 674 { 675 struct epoch_tracker et; 676 struct random_sources *rrs; 677 struct sbuf sbuf; 678 int error, count; 679 680 error = sysctl_wire_old_buffer(req, 0); 681 if (error != 0) 682 return (error); 683 684 sbuf_new_for_sysctl(&sbuf, NULL, 64, req); 685 count = 0; 686 epoch_enter_preempt(rs_epoch, &et); 687 CK_LIST_FOREACH(rrs, &source_list, rrs_entries) { 688 sbuf_cat(&sbuf, (count++ ? ",'" : "'")); 689 sbuf_cat(&sbuf, rrs->rrs_source->rs_ident); 690 sbuf_cat(&sbuf, "'"); 691 } 692 epoch_exit_preempt(rs_epoch, &et); 693 error = sbuf_finish(&sbuf); 694 sbuf_delete(&sbuf); 695 return (error); 696 } 697 SYSCTL_PROC(_kern_random, OID_AUTO, random_sources, CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_MPSAFE, 698 NULL, 0, random_source_handler, "A", 699 "List of active fast entropy sources."); 700 701 MODULE_VERSION(random_harvestq, 1); 702