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