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 __FBSDID("$FreeBSD$"); 34 35 #include <sys/param.h> 36 #include <sys/systm.h> 37 #include <sys/conf.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 #if defined(RANDOM_LOADABLE) 53 #include <sys/lock.h> 54 #include <sys/sx.h> 55 #endif 56 57 #include <machine/atomic.h> 58 #include <machine/cpu.h> 59 60 #include <crypto/rijndael/rijndael-api-fst.h> 61 #include <crypto/sha2/sha256.h> 62 63 #include <dev/random/hash.h> 64 #include <dev/random/randomdev.h> 65 #include <dev/random/random_harvestq.h> 66 67 #if defined(RANDOM_ENABLE_ETHER) 68 #define _RANDOM_HARVEST_ETHER_OFF 0 69 #else 70 #define _RANDOM_HARVEST_ETHER_OFF (1u << RANDOM_NET_ETHER) 71 #endif 72 #if defined(RANDOM_ENABLE_UMA) 73 #define _RANDOM_HARVEST_UMA_OFF 0 74 #else 75 #define _RANDOM_HARVEST_UMA_OFF (1u << RANDOM_UMA) 76 #endif 77 78 static void random_kthread(void); 79 static void random_sources_feed(void); 80 81 static u_int read_rate; 82 83 /* List for the dynamic sysctls */ 84 static struct sysctl_ctx_list random_clist; 85 86 /* 87 * How many events to queue up. We create this many items in 88 * an 'empty' queue, then transfer them to the 'harvest' queue with 89 * supplied junk. When used, they are transferred back to the 90 * 'empty' queue. 91 */ 92 #define RANDOM_RING_MAX 1024 93 #define RANDOM_ACCUM_MAX 8 94 95 /* 1 to let the kernel thread run, 0 to terminate, -1 to mark completion */ 96 volatile int random_kthread_control; 97 98 99 /* Allow the sysadmin to select the broad category of 100 * entropy types to harvest. 101 */ 102 __read_frequently u_int hc_source_mask; 103 104 /* 105 * Put all the harvest queue context stuff in one place. 106 * this make is a bit easier to lock and protect. 107 */ 108 static struct harvest_context { 109 /* The harvest mutex protects all of harvest_context and 110 * the related data. 111 */ 112 struct mtx hc_mtx; 113 /* Round-robin destination cache. */ 114 u_int hc_destination[ENTROPYSOURCE]; 115 /* The context of the kernel thread processing harvested entropy */ 116 struct proc *hc_kthread_proc; 117 /* 118 * Lockless ring buffer holding entropy events 119 * If ring.in == ring.out, 120 * the buffer is empty. 121 * If ring.in != ring.out, 122 * the buffer contains harvested entropy. 123 * If (ring.in + 1) == ring.out (mod RANDOM_RING_MAX), 124 * the buffer is full. 125 * 126 * NOTE: ring.in points to the last added element, 127 * and ring.out points to the last consumed element. 128 * 129 * The ring.in variable needs locking as there are multiple 130 * sources to the ring. Only the sources may change ring.in, 131 * but the consumer may examine it. 132 * 133 * The ring.out variable does not need locking as there is 134 * only one consumer. Only the consumer may change ring.out, 135 * but the sources may examine it. 136 */ 137 struct entropy_ring { 138 struct harvest_event ring[RANDOM_RING_MAX]; 139 volatile u_int in; 140 volatile u_int out; 141 } hc_entropy_ring; 142 struct fast_entropy_accumulator { 143 volatile u_int pos; 144 uint32_t buf[RANDOM_ACCUM_MAX]; 145 } hc_entropy_fast_accumulator; 146 } harvest_context; 147 148 static struct kproc_desc random_proc_kp = { 149 "rand_harvestq", 150 random_kthread, 151 &harvest_context.hc_kthread_proc, 152 }; 153 154 /* Pass the given event straight through to Fortuna/Whatever. */ 155 static __inline void 156 random_harvestq_fast_process_event(struct harvest_event *event) 157 { 158 #if defined(RANDOM_LOADABLE) 159 RANDOM_CONFIG_S_LOCK(); 160 if (p_random_alg_context) 161 #endif 162 p_random_alg_context->ra_event_processor(event); 163 #if defined(RANDOM_LOADABLE) 164 RANDOM_CONFIG_S_UNLOCK(); 165 #endif 166 explicit_bzero(event, sizeof(*event)); 167 } 168 169 static void 170 random_kthread(void) 171 { 172 u_int maxloop, ring_out, i; 173 174 /* 175 * Locking is not needed as this is the only place we modify ring.out, and 176 * we only examine ring.in without changing it. Both of these are volatile, 177 * and this is a unique thread. 178 */ 179 for (random_kthread_control = 1; random_kthread_control;) { 180 /* Deal with events, if any. Restrict the number we do in one go. */ 181 maxloop = RANDOM_RING_MAX; 182 while (harvest_context.hc_entropy_ring.out != harvest_context.hc_entropy_ring.in) { 183 ring_out = (harvest_context.hc_entropy_ring.out + 1)%RANDOM_RING_MAX; 184 random_harvestq_fast_process_event(harvest_context.hc_entropy_ring.ring + ring_out); 185 harvest_context.hc_entropy_ring.out = ring_out; 186 if (!--maxloop) 187 break; 188 } 189 random_sources_feed(); 190 /* XXX: FIX!! Increase the high-performance data rate? Need some measurements first. */ 191 for (i = 0; i < RANDOM_ACCUM_MAX; i++) { 192 if (harvest_context.hc_entropy_fast_accumulator.buf[i]) { 193 random_harvest_direct(harvest_context.hc_entropy_fast_accumulator.buf + i, sizeof(harvest_context.hc_entropy_fast_accumulator.buf[0]), RANDOM_UMA); 194 harvest_context.hc_entropy_fast_accumulator.buf[i] = 0; 195 } 196 } 197 /* XXX: FIX!! This is a *great* place to pass hardware/live entropy to random(9) */ 198 tsleep_sbt(&harvest_context.hc_kthread_proc, 0, "-", SBT_1S/10, 0, C_PREL(1)); 199 } 200 random_kthread_control = -1; 201 wakeup(&harvest_context.hc_kthread_proc); 202 kproc_exit(0); 203 /* NOTREACHED */ 204 } 205 /* This happens well after SI_SUB_RANDOM */ 206 SYSINIT(random_device_h_proc, SI_SUB_KICK_SCHEDULER, SI_ORDER_ANY, kproc_start, 207 &random_proc_kp); 208 209 /* 210 * Run through all fast sources reading entropy for the given 211 * number of rounds, which should be a multiple of the number 212 * of entropy accumulation pools in use; it is 32 for Fortuna. 213 */ 214 static void 215 random_sources_feed(void) 216 { 217 uint32_t entropy[HARVESTSIZE]; 218 struct random_sources *rrs; 219 u_int i, n, local_read_rate; 220 221 /* 222 * Step over all of live entropy sources, and feed their output 223 * to the system-wide RNG. 224 */ 225 #if defined(RANDOM_LOADABLE) 226 RANDOM_CONFIG_S_LOCK(); 227 if (p_random_alg_context) { 228 /* It's an indenting error. Yeah, Yeah. */ 229 #endif 230 local_read_rate = atomic_readandclear_32(&read_rate); 231 /* Perform at least one read per round */ 232 local_read_rate = MAX(local_read_rate, 1); 233 /* But not exceeding RANDOM_KEYSIZE_WORDS */ 234 local_read_rate = MIN(local_read_rate, RANDOM_KEYSIZE_WORDS); 235 LIST_FOREACH(rrs, &source_list, rrs_entries) { 236 for (i = 0; i < p_random_alg_context->ra_poolcount*local_read_rate; i++) { 237 n = rrs->rrs_source->rs_read(entropy, sizeof(entropy)); 238 KASSERT((n <= sizeof(entropy)), ("%s: rs_read returned too much data (%u > %zu)", __func__, n, sizeof(entropy))); 239 /* 240 * Sometimes the HW entropy source doesn't have anything 241 * ready for us. This isn't necessarily untrustworthy. 242 * We don't perform any other verification of an entropy 243 * source (i.e., length is allowed to be anywhere from 1 244 * to sizeof(entropy), quality is unchecked, etc), so 245 * don't balk verbosely at slow random sources either. 246 * There are reports that RDSEED on x86 metal falls 247 * behind the rate at which we query it, for example. 248 * But it's still a better entropy source than RDRAND. 249 */ 250 if (n == 0) 251 continue; 252 random_harvest_direct(entropy, n, rrs->rrs_source->rs_source); 253 } 254 } 255 explicit_bzero(entropy, sizeof(entropy)); 256 #if defined(RANDOM_LOADABLE) 257 } 258 RANDOM_CONFIG_S_UNLOCK(); 259 #endif 260 } 261 262 void 263 read_rate_increment(u_int chunk) 264 { 265 266 atomic_add_32(&read_rate, chunk); 267 } 268 269 /* ARGSUSED */ 270 static int 271 random_check_uint_harvestmask(SYSCTL_HANDLER_ARGS) 272 { 273 static const u_int user_immutable_mask = 274 (((1 << ENTROPYSOURCE) - 1) & (-1UL << RANDOM_PURE_START)) | 275 _RANDOM_HARVEST_ETHER_OFF | _RANDOM_HARVEST_UMA_OFF; 276 277 int error; 278 u_int value, orig_value; 279 280 orig_value = value = hc_source_mask; 281 error = sysctl_handle_int(oidp, &value, 0, req); 282 if (error != 0 || req->newptr == NULL) 283 return (error); 284 285 if (flsl(value) > ENTROPYSOURCE) 286 return (EINVAL); 287 288 /* 289 * Disallow userspace modification of pure entropy sources. 290 */ 291 hc_source_mask = (value & ~user_immutable_mask) | 292 (orig_value & user_immutable_mask); 293 return (0); 294 } 295 296 /* ARGSUSED */ 297 static int 298 random_print_harvestmask(SYSCTL_HANDLER_ARGS) 299 { 300 struct sbuf sbuf; 301 int error, i; 302 303 error = sysctl_wire_old_buffer(req, 0); 304 if (error == 0) { 305 sbuf_new_for_sysctl(&sbuf, NULL, 128, req); 306 for (i = ENTROPYSOURCE - 1; i >= 0; i--) 307 sbuf_cat(&sbuf, (hc_source_mask & (1 << i)) ? "1" : "0"); 308 error = sbuf_finish(&sbuf); 309 sbuf_delete(&sbuf); 310 } 311 return (error); 312 } 313 314 static const char *random_source_descr[ENTROPYSOURCE] = { 315 [RANDOM_CACHED] = "CACHED", 316 [RANDOM_ATTACH] = "ATTACH", 317 [RANDOM_KEYBOARD] = "KEYBOARD", 318 [RANDOM_MOUSE] = "MOUSE", 319 [RANDOM_NET_TUN] = "NET_TUN", 320 [RANDOM_NET_ETHER] = "NET_ETHER", 321 [RANDOM_NET_NG] = "NET_NG", 322 [RANDOM_INTERRUPT] = "INTERRUPT", 323 [RANDOM_SWI] = "SWI", 324 [RANDOM_FS_ATIME] = "FS_ATIME", 325 [RANDOM_UMA] = "UMA", /* ENVIRONMENTAL_END */ 326 [RANDOM_PURE_OCTEON] = "PURE_OCTEON", /* PURE_START */ 327 [RANDOM_PURE_SAFE] = "PURE_SAFE", 328 [RANDOM_PURE_GLXSB] = "PURE_GLXSB", 329 [RANDOM_PURE_UBSEC] = "PURE_UBSEC", 330 [RANDOM_PURE_HIFN] = "PURE_HIFN", 331 [RANDOM_PURE_RDRAND] = "PURE_RDRAND", 332 [RANDOM_PURE_NEHEMIAH] = "PURE_NEHEMIAH", 333 [RANDOM_PURE_RNDTEST] = "PURE_RNDTEST", 334 [RANDOM_PURE_VIRTIO] = "PURE_VIRTIO", 335 [RANDOM_PURE_BROADCOM] = "PURE_BROADCOM", 336 [RANDOM_PURE_CCP] = "PURE_CCP", 337 [RANDOM_PURE_DARN] = "PURE_DARN", 338 [RANDOM_PURE_TPM] = "PURE_TPM", 339 /* "ENTROPYSOURCE" */ 340 }; 341 342 /* ARGSUSED */ 343 static int 344 random_print_harvestmask_symbolic(SYSCTL_HANDLER_ARGS) 345 { 346 struct sbuf sbuf; 347 int error, i; 348 bool first; 349 350 first = true; 351 error = sysctl_wire_old_buffer(req, 0); 352 if (error == 0) { 353 sbuf_new_for_sysctl(&sbuf, NULL, 128, req); 354 for (i = ENTROPYSOURCE - 1; i >= 0; i--) { 355 if (i >= RANDOM_PURE_START && 356 (hc_source_mask & (1 << i)) == 0) 357 continue; 358 if (!first) 359 sbuf_cat(&sbuf, ","); 360 sbuf_cat(&sbuf, !(hc_source_mask & (1 << i)) ? "[" : ""); 361 sbuf_cat(&sbuf, random_source_descr[i]); 362 sbuf_cat(&sbuf, !(hc_source_mask & (1 << i)) ? "]" : ""); 363 first = false; 364 } 365 error = sbuf_finish(&sbuf); 366 sbuf_delete(&sbuf); 367 } 368 return (error); 369 } 370 371 /* ARGSUSED */ 372 static void 373 random_harvestq_init(void *unused __unused) 374 { 375 static const u_int almost_everything_mask = 376 (((1 << (RANDOM_ENVIRONMENTAL_END + 1)) - 1) & 377 ~_RANDOM_HARVEST_ETHER_OFF & ~_RANDOM_HARVEST_UMA_OFF); 378 379 struct sysctl_oid *random_sys_o; 380 381 random_sys_o = SYSCTL_ADD_NODE(&random_clist, 382 SYSCTL_STATIC_CHILDREN(_kern_random), 383 OID_AUTO, "harvest", CTLFLAG_RW, 0, 384 "Entropy Device Parameters"); 385 hc_source_mask = almost_everything_mask; 386 SYSCTL_ADD_PROC(&random_clist, 387 SYSCTL_CHILDREN(random_sys_o), 388 OID_AUTO, "mask", CTLTYPE_UINT | CTLFLAG_RW, 389 NULL, 0, random_check_uint_harvestmask, "IU", 390 "Entropy harvesting mask"); 391 SYSCTL_ADD_PROC(&random_clist, 392 SYSCTL_CHILDREN(random_sys_o), 393 OID_AUTO, "mask_bin", CTLTYPE_STRING | CTLFLAG_RD, 394 NULL, 0, random_print_harvestmask, "A", "Entropy harvesting mask (printable)"); 395 SYSCTL_ADD_PROC(&random_clist, 396 SYSCTL_CHILDREN(random_sys_o), 397 OID_AUTO, "mask_symbolic", CTLTYPE_STRING | CTLFLAG_RD, 398 NULL, 0, random_print_harvestmask_symbolic, "A", "Entropy harvesting mask (symbolic)"); 399 RANDOM_HARVEST_INIT_LOCK(); 400 harvest_context.hc_entropy_ring.in = harvest_context.hc_entropy_ring.out = 0; 401 } 402 SYSINIT(random_device_h_init, SI_SUB_RANDOM, SI_ORDER_SECOND, random_harvestq_init, NULL); 403 404 /* 405 * This is used to prime the RNG by grabbing any early random stuff 406 * known to the kernel, and inserting it directly into the hashing 407 * module, currently Fortuna. 408 */ 409 /* ARGSUSED */ 410 static void 411 random_harvestq_prime(void *unused __unused) 412 { 413 struct harvest_event event; 414 size_t count, size, i; 415 uint8_t *keyfile, *data; 416 417 /* 418 * Get entropy that may have been preloaded by loader(8) 419 * and use it to pre-charge the entropy harvest queue. 420 */ 421 keyfile = preload_search_by_type(RANDOM_CACHED_BOOT_ENTROPY_MODULE); 422 #ifndef NO_BACKWARD_COMPATIBILITY 423 if (keyfile == NULL) 424 keyfile = preload_search_by_type(RANDOM_LEGACY_BOOT_ENTROPY_MODULE); 425 #endif 426 if (keyfile != NULL) { 427 data = preload_fetch_addr(keyfile); 428 size = preload_fetch_size(keyfile); 429 /* Trim the size. If the admin has a file with a funny size, we lose some. Tough. */ 430 size -= (size % sizeof(event.he_entropy)); 431 if (data != NULL && size != 0) { 432 for (i = 0; i < size; i += sizeof(event.he_entropy)) { 433 count = sizeof(event.he_entropy); 434 event.he_somecounter = (uint32_t)get_cyclecount(); 435 event.he_size = count; 436 event.he_source = RANDOM_CACHED; 437 event.he_destination = 438 harvest_context.hc_destination[RANDOM_CACHED]++; 439 memcpy(event.he_entropy, data + i, sizeof(event.he_entropy)); 440 random_harvestq_fast_process_event(&event); 441 } 442 explicit_bzero(data, size); 443 if (bootverbose) 444 printf("random: read %zu bytes from preloaded cache\n", size); 445 } else 446 if (bootverbose) 447 printf("random: no preloaded entropy cache\n"); 448 } 449 } 450 SYSINIT(random_device_prime, SI_SUB_RANDOM, SI_ORDER_MIDDLE, random_harvestq_prime, NULL); 451 452 /* ARGSUSED */ 453 static void 454 random_harvestq_deinit(void *unused __unused) 455 { 456 457 /* Command the hash/reseed thread to end and wait for it to finish */ 458 random_kthread_control = 0; 459 while (random_kthread_control >= 0) 460 tsleep(&harvest_context.hc_kthread_proc, 0, "harvqterm", hz/5); 461 sysctl_ctx_free(&random_clist); 462 } 463 SYSUNINIT(random_device_h_init, SI_SUB_RANDOM, SI_ORDER_SECOND, random_harvestq_deinit, NULL); 464 465 /*- 466 * Entropy harvesting queue routine. 467 * 468 * This is supposed to be fast; do not do anything slow in here! 469 * It is also illegal (and morally reprehensible) to insert any 470 * high-rate data here. "High-rate" is defined as a data source 471 * that will usually cause lots of failures of the "Lockless read" 472 * check a few lines below. This includes the "always-on" sources 473 * like the Intel "rdrand" or the VIA Nehamiah "xstore" sources. 474 */ 475 /* XXXRW: get_cyclecount() is cheap on most modern hardware, where cycle 476 * counters are built in, but on older hardware it will do a real time clock 477 * read which can be quite expensive. 478 */ 479 void 480 random_harvest_queue_(const void *entropy, u_int size, enum random_entropy_source origin) 481 { 482 struct harvest_event *event; 483 u_int ring_in; 484 485 KASSERT(origin >= RANDOM_START && origin < ENTROPYSOURCE, ("%s: origin %d invalid\n", __func__, origin)); 486 RANDOM_HARVEST_LOCK(); 487 ring_in = (harvest_context.hc_entropy_ring.in + 1)%RANDOM_RING_MAX; 488 if (ring_in != harvest_context.hc_entropy_ring.out) { 489 /* The ring is not full */ 490 event = harvest_context.hc_entropy_ring.ring + ring_in; 491 event->he_somecounter = (uint32_t)get_cyclecount(); 492 event->he_source = origin; 493 event->he_destination = harvest_context.hc_destination[origin]++; 494 if (size <= sizeof(event->he_entropy)) { 495 event->he_size = size; 496 memcpy(event->he_entropy, entropy, size); 497 } 498 else { 499 /* Big event, so squash it */ 500 event->he_size = sizeof(event->he_entropy[0]); 501 event->he_entropy[0] = jenkins_hash(entropy, size, (uint32_t)(uintptr_t)event); 502 } 503 harvest_context.hc_entropy_ring.in = ring_in; 504 } 505 RANDOM_HARVEST_UNLOCK(); 506 } 507 508 /*- 509 * Entropy harvesting fast routine. 510 * 511 * This is supposed to be very fast; do not do anything slow in here! 512 * This is the right place for high-rate harvested data. 513 */ 514 void 515 random_harvest_fast_(const void *entropy, u_int size) 516 { 517 u_int pos; 518 519 pos = harvest_context.hc_entropy_fast_accumulator.pos; 520 harvest_context.hc_entropy_fast_accumulator.buf[pos] ^= jenkins_hash(entropy, size, (uint32_t)get_cyclecount()); 521 harvest_context.hc_entropy_fast_accumulator.pos = (pos + 1)%RANDOM_ACCUM_MAX; 522 } 523 524 /*- 525 * Entropy harvesting direct routine. 526 * 527 * This is not supposed to be fast, but will only be used during 528 * (e.g.) booting when initial entropy is being gathered. 529 */ 530 void 531 random_harvest_direct_(const void *entropy, u_int size, enum random_entropy_source origin) 532 { 533 struct harvest_event event; 534 535 KASSERT(origin >= RANDOM_START && origin < ENTROPYSOURCE, ("%s: origin %d invalid\n", __func__, origin)); 536 size = MIN(size, sizeof(event.he_entropy)); 537 event.he_somecounter = (uint32_t)get_cyclecount(); 538 event.he_size = size; 539 event.he_source = origin; 540 event.he_destination = harvest_context.hc_destination[origin]++; 541 memcpy(event.he_entropy, entropy, size); 542 random_harvestq_fast_process_event(&event); 543 } 544 545 void 546 random_harvest_register_source(enum random_entropy_source source) 547 { 548 549 hc_source_mask |= (1 << source); 550 } 551 552 void 553 random_harvest_deregister_source(enum random_entropy_source source) 554 { 555 556 hc_source_mask &= ~(1 << source); 557 } 558 559 void 560 random_source_register(struct random_source *rsource) 561 { 562 struct random_sources *rrs; 563 564 KASSERT(rsource != NULL, ("invalid input to %s", __func__)); 565 566 rrs = malloc(sizeof(*rrs), M_ENTROPY, M_WAITOK); 567 rrs->rrs_source = rsource; 568 569 random_harvest_register_source(rsource->rs_source); 570 571 printf("random: registering fast source %s\n", rsource->rs_ident); 572 LIST_INSERT_HEAD(&source_list, rrs, rrs_entries); 573 } 574 575 void 576 random_source_deregister(struct random_source *rsource) 577 { 578 struct random_sources *rrs = NULL; 579 580 KASSERT(rsource != NULL, ("invalid input to %s", __func__)); 581 582 random_harvest_deregister_source(rsource->rs_source); 583 584 LIST_FOREACH(rrs, &source_list, rrs_entries) 585 if (rrs->rrs_source == rsource) { 586 LIST_REMOVE(rrs, rrs_entries); 587 break; 588 } 589 if (rrs != NULL) 590 free(rrs, M_ENTROPY); 591 } 592 593 static int 594 random_source_handler(SYSCTL_HANDLER_ARGS) 595 { 596 struct random_sources *rrs; 597 struct sbuf sbuf; 598 int error, count; 599 600 sbuf_new_for_sysctl(&sbuf, NULL, 64, req); 601 count = 0; 602 LIST_FOREACH(rrs, &source_list, rrs_entries) { 603 sbuf_cat(&sbuf, (count++ ? ",'" : "'")); 604 sbuf_cat(&sbuf, rrs->rrs_source->rs_ident); 605 sbuf_cat(&sbuf, "'"); 606 } 607 error = sbuf_finish(&sbuf); 608 sbuf_delete(&sbuf); 609 return (error); 610 } 611 SYSCTL_PROC(_kern_random, OID_AUTO, random_sources, CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_MPSAFE, 612 NULL, 0, random_source_handler, "A", 613 "List of active fast entropy sources."); 614 615 MODULE_VERSION(random_harvestq, 1); 616