| 1 | /* $NetBSD: kern_rndq.c,v 1.89 2016/05/21 15:27:15 riastradh Exp $ */ |
| 2 | |
| 3 | /*- |
| 4 | * Copyright (c) 1997-2013 The NetBSD Foundation, Inc. |
| 5 | * All rights reserved. |
| 6 | * |
| 7 | * This code is derived from software contributed to The NetBSD Foundation |
| 8 | * by Michael Graff <explorer@flame.org> and Thor Lancelot Simon. |
| 9 | * This code uses ideas and algorithms from the Linux driver written by |
| 10 | * Ted Ts'o. |
| 11 | * |
| 12 | * Redistribution and use in source and binary forms, with or without |
| 13 | * modification, are permitted provided that the following conditions |
| 14 | * are met: |
| 15 | * 1. Redistributions of source code must retain the above copyright |
| 16 | * notice, this list of conditions and the following disclaimer. |
| 17 | * 2. Redistributions in binary form must reproduce the above copyright |
| 18 | * notice, this list of conditions and the following disclaimer in the |
| 19 | * documentation and/or other materials provided with the distribution. |
| 20 | * |
| 21 | * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS |
| 22 | * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED |
| 23 | * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR |
| 24 | * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS |
| 25 | * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR |
| 26 | * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF |
| 27 | * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS |
| 28 | * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN |
| 29 | * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
| 30 | * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE |
| 31 | * POSSIBILITY OF SUCH DAMAGE. |
| 32 | */ |
| 33 | |
| 34 | #include <sys/cdefs.h> |
| 35 | __KERNEL_RCSID(0, "$NetBSD: kern_rndq.c,v 1.89 2016/05/21 15:27:15 riastradh Exp $" ); |
| 36 | |
| 37 | #include <sys/param.h> |
| 38 | #include <sys/atomic.h> |
| 39 | #include <sys/callout.h> |
| 40 | #include <sys/fcntl.h> |
| 41 | #include <sys/intr.h> |
| 42 | #include <sys/ioctl.h> |
| 43 | #include <sys/kauth.h> |
| 44 | #include <sys/kernel.h> |
| 45 | #include <sys/kmem.h> |
| 46 | #include <sys/mutex.h> |
| 47 | #include <sys/pool.h> |
| 48 | #include <sys/proc.h> |
| 49 | #include <sys/rnd.h> |
| 50 | #include <sys/rndpool.h> |
| 51 | #include <sys/rndsink.h> |
| 52 | #include <sys/rndsource.h> |
| 53 | #include <sys/rngtest.h> |
| 54 | #include <sys/systm.h> |
| 55 | |
| 56 | #include <dev/rnd_private.h> |
| 57 | |
| 58 | #ifdef COMPAT_50 |
| 59 | #include <compat/sys/rnd.h> |
| 60 | #endif |
| 61 | |
| 62 | #if defined(__HAVE_CPU_RNG) && !defined(_RUMPKERNEL) |
| 63 | #include <machine/cpu_rng.h> |
| 64 | #endif |
| 65 | |
| 66 | #if defined(__HAVE_CPU_COUNTER) |
| 67 | #include <machine/cpu_counter.h> |
| 68 | #endif |
| 69 | |
| 70 | #ifdef RND_DEBUG |
| 71 | #define DPRINTF(l,x) if (rnd_debug & (l)) rnd_printf x |
| 72 | int rnd_debug = 0; |
| 73 | #else |
| 74 | #define DPRINTF(l,x) |
| 75 | #endif |
| 76 | |
| 77 | /* |
| 78 | * list devices attached |
| 79 | */ |
| 80 | #if 0 |
| 81 | #define RND_VERBOSE |
| 82 | #endif |
| 83 | |
| 84 | #ifdef RND_VERBOSE |
| 85 | #define rnd_printf_verbose(fmt, ...) rnd_printf(fmt, ##__VA_ARGS__) |
| 86 | #else |
| 87 | #define rnd_printf_verbose(fmt, ...) ((void)0) |
| 88 | #endif |
| 89 | |
| 90 | #ifdef RND_VERBOSE |
| 91 | static unsigned int deltacnt; |
| 92 | #endif |
| 93 | |
| 94 | /* |
| 95 | * This is a little bit of state information attached to each device that we |
| 96 | * collect entropy from. This is simply a collection buffer, and when it |
| 97 | * is full it will be "detached" from the source and added to the entropy |
| 98 | * pool after entropy is distilled as much as possible. |
| 99 | */ |
| 100 | #define RND_SAMPLE_COUNT 64 /* collect N samples, then compress */ |
| 101 | typedef struct _rnd_sample_t { |
| 102 | SIMPLEQ_ENTRY(_rnd_sample_t) next; |
| 103 | krndsource_t *source; |
| 104 | int cursor; |
| 105 | int entropy; |
| 106 | uint32_t ts[RND_SAMPLE_COUNT]; |
| 107 | uint32_t values[RND_SAMPLE_COUNT]; |
| 108 | } rnd_sample_t; |
| 109 | |
| 110 | SIMPLEQ_HEAD(rnd_sampleq, _rnd_sample_t); |
| 111 | |
| 112 | /* |
| 113 | * The sample queue. Samples are put into the queue and processed in a |
| 114 | * softint in order to limit the latency of adding a sample. |
| 115 | */ |
| 116 | static struct { |
| 117 | kmutex_t lock; |
| 118 | struct rnd_sampleq q; |
| 119 | } rnd_samples __cacheline_aligned; |
| 120 | |
| 121 | /* |
| 122 | * Memory pool for sample buffers |
| 123 | */ |
| 124 | static pool_cache_t rnd_mempc __read_mostly; |
| 125 | |
| 126 | /* |
| 127 | * Global entropy pool and sources. |
| 128 | */ |
| 129 | static struct { |
| 130 | kmutex_t lock; |
| 131 | rndpool_t pool; |
| 132 | LIST_HEAD(, krndsource) sources; |
| 133 | kcondvar_t cv; |
| 134 | } rnd_global __cacheline_aligned; |
| 135 | |
| 136 | /* |
| 137 | * This source is used to easily "remove" queue entries when the source |
| 138 | * which actually generated the events is going away. |
| 139 | */ |
| 140 | static krndsource_t rnd_source_no_collect = { |
| 141 | /* LIST_ENTRY list */ |
| 142 | .name = { 'N', 'o', 'C', 'o', 'l', 'l', 'e', 'c', 't', |
| 143 | 0, 0, 0, 0, 0, 0, 0 }, |
| 144 | .total = 0, |
| 145 | .type = RND_TYPE_UNKNOWN, |
| 146 | .flags = (RND_FLAG_NO_COLLECT | |
| 147 | RND_FLAG_NO_ESTIMATE), |
| 148 | .state = NULL, |
| 149 | .test_cnt = 0, |
| 150 | .test = NULL |
| 151 | }; |
| 152 | |
| 153 | krndsource_t rnd_printf_source, rnd_autoconf_source; |
| 154 | |
| 155 | static void *rnd_process __read_mostly; |
| 156 | static void *rnd_wakeup __read_mostly; |
| 157 | |
| 158 | static inline uint32_t rnd_counter(void); |
| 159 | static void rnd_intr(void *); |
| 160 | static void rnd_wake(void *); |
| 161 | static void rnd_process_events(void); |
| 162 | static void rnd_add_data_ts(krndsource_t *, const void *const, |
| 163 | uint32_t, uint32_t, uint32_t, bool); |
| 164 | static inline void rnd_schedule_process(void); |
| 165 | |
| 166 | int rnd_ready = 0; |
| 167 | int rnd_initial_entropy = 0; |
| 168 | |
| 169 | static volatile unsigned rnd_printing = 0; |
| 170 | |
| 171 | #ifdef DIAGNOSTIC |
| 172 | static int rnd_tested = 0; |
| 173 | static rngtest_t rnd_rt; |
| 174 | static uint8_t rnd_testbits[sizeof(rnd_rt.rt_b)]; |
| 175 | #endif |
| 176 | |
| 177 | static rndsave_t *boot_rsp; |
| 178 | |
| 179 | static inline void |
| 180 | rnd_printf(const char *fmt, ...) |
| 181 | { |
| 182 | va_list ap; |
| 183 | |
| 184 | if (atomic_cas_uint(&rnd_printing, 0, 1) != 0) |
| 185 | return; |
| 186 | va_start(ap, fmt); |
| 187 | vprintf(fmt, ap); |
| 188 | va_end(ap); |
| 189 | rnd_printing = 0; |
| 190 | } |
| 191 | |
| 192 | /* |
| 193 | * Generate a 32-bit counter. |
| 194 | */ |
| 195 | static inline uint32_t |
| 196 | rnd_counter(void) |
| 197 | { |
| 198 | struct bintime bt; |
| 199 | uint32_t ret; |
| 200 | |
| 201 | #if defined(__HAVE_CPU_COUNTER) |
| 202 | if (cpu_hascounter()) |
| 203 | return cpu_counter32(); |
| 204 | #endif |
| 205 | if (!rnd_ready) |
| 206 | /* Too early to call nanotime. */ |
| 207 | return 0; |
| 208 | |
| 209 | binuptime(&bt); |
| 210 | ret = bt.sec; |
| 211 | ret ^= bt.sec >> 32; |
| 212 | ret ^= bt.frac; |
| 213 | ret ^= bt.frac >> 32; |
| 214 | |
| 215 | return ret; |
| 216 | } |
| 217 | |
| 218 | /* |
| 219 | * We may be called from low IPL -- protect our softint. |
| 220 | */ |
| 221 | |
| 222 | static inline void |
| 223 | rnd_schedule_softint(void *softint) |
| 224 | { |
| 225 | |
| 226 | kpreempt_disable(); |
| 227 | softint_schedule(softint); |
| 228 | kpreempt_enable(); |
| 229 | } |
| 230 | |
| 231 | static inline void |
| 232 | rnd_schedule_process(void) |
| 233 | { |
| 234 | |
| 235 | if (__predict_true(rnd_process)) { |
| 236 | rnd_schedule_softint(rnd_process); |
| 237 | return; |
| 238 | } |
| 239 | rnd_process_events(); |
| 240 | } |
| 241 | |
| 242 | static inline void |
| 243 | rnd_schedule_wakeup(void) |
| 244 | { |
| 245 | |
| 246 | if (__predict_true(rnd_wakeup)) { |
| 247 | rnd_schedule_softint(rnd_wakeup); |
| 248 | return; |
| 249 | } |
| 250 | rndsinks_distribute(); |
| 251 | } |
| 252 | |
| 253 | /* |
| 254 | * Tell any sources with "feed me" callbacks that we are hungry. |
| 255 | */ |
| 256 | void |
| 257 | rnd_getmore(size_t byteswanted) |
| 258 | { |
| 259 | krndsource_t *rs, *next; |
| 260 | |
| 261 | /* |
| 262 | * Due to buffering in rnd_process_events, even if the entropy |
| 263 | * sources provide the requested number of bytes, users may not |
| 264 | * be woken because the data may be stuck in unfilled buffers. |
| 265 | * So ask for enough data to fill all the buffers. |
| 266 | * |
| 267 | * XXX Just get rid of this buffering and solve the |
| 268 | * /dev/random-as-side-channel-for-keystroke-timings a |
| 269 | * different way. |
| 270 | */ |
| 271 | byteswanted = MAX(byteswanted, |
| 272 | MAX(RND_POOLBITS/NBBY, sizeof(uint32_t)*RND_SAMPLE_COUNT)); |
| 273 | |
| 274 | mutex_spin_enter(&rnd_global.lock); |
| 275 | LIST_FOREACH_SAFE(rs, &rnd_global.sources, list, next) { |
| 276 | /* Skip if the source is disabled. */ |
| 277 | if (!RND_ENABLED(rs)) |
| 278 | continue; |
| 279 | |
| 280 | /* Skip if there's no callback. */ |
| 281 | if (!ISSET(rs->flags, RND_FLAG_HASCB)) |
| 282 | continue; |
| 283 | KASSERT(rs->get != NULL); |
| 284 | |
| 285 | /* Skip if there are too many users right now. */ |
| 286 | if (rs->refcnt == UINT_MAX) |
| 287 | continue; |
| 288 | |
| 289 | /* |
| 290 | * Hold a reference while we release rnd_global.lock to |
| 291 | * call the callback. The callback may in turn call |
| 292 | * rnd_add_data, which acquires rnd_global.lock. |
| 293 | */ |
| 294 | rs->refcnt++; |
| 295 | mutex_spin_exit(&rnd_global.lock); |
| 296 | rs->get(byteswanted, rs->getarg); |
| 297 | mutex_spin_enter(&rnd_global.lock); |
| 298 | if (--rs->refcnt == 0) |
| 299 | cv_broadcast(&rnd_global.cv); |
| 300 | |
| 301 | /* Dribble some goo to the console. */ |
| 302 | rnd_printf_verbose("rnd: entropy estimate %zu bits\n" , |
| 303 | rndpool_get_entropy_count(&rnd_global.pool)); |
| 304 | rnd_printf_verbose("rnd: asking source %s for %zu bytes\n" , |
| 305 | rs->name, byteswanted); |
| 306 | } |
| 307 | mutex_spin_exit(&rnd_global.lock); |
| 308 | |
| 309 | /* |
| 310 | * Check whether we got entropy samples to process. In that |
| 311 | * case, we may need to distribute entropy to waiters. Do |
| 312 | * that, if we can do it asynchronously. |
| 313 | * |
| 314 | * - Conditionally because we don't want a softint loop. |
| 315 | * - Asynchronously because if we did it synchronously, we may |
| 316 | * end up with lock recursion on rndsinks_lock. |
| 317 | */ |
| 318 | if (!SIMPLEQ_EMPTY(&rnd_samples.q) && rnd_process != NULL) |
| 319 | rnd_schedule_process(); |
| 320 | } |
| 321 | |
| 322 | /* |
| 323 | * Use the timing/value of the event to estimate the entropy gathered. |
| 324 | * If all the differentials (first, second, and third) are non-zero, return |
| 325 | * non-zero. If any of these are zero, return zero. |
| 326 | */ |
| 327 | static inline uint32_t |
| 328 | rnd_delta_estimate(rnd_delta_t *d, uint32_t v, int32_t delta) |
| 329 | { |
| 330 | int32_t delta2, delta3; |
| 331 | |
| 332 | d->insamples++; |
| 333 | |
| 334 | /* |
| 335 | * Calculate the second and third order differentials |
| 336 | */ |
| 337 | delta2 = d->dx - delta; |
| 338 | if (delta2 < 0) |
| 339 | delta2 = -delta2; |
| 340 | |
| 341 | delta3 = d->d2x - delta2; |
| 342 | if (delta3 < 0) |
| 343 | delta3 = -delta3; |
| 344 | |
| 345 | d->x = v; |
| 346 | d->dx = delta; |
| 347 | d->d2x = delta2; |
| 348 | |
| 349 | /* |
| 350 | * If any delta is 0, we got no entropy. If all are non-zero, we |
| 351 | * might have something. |
| 352 | */ |
| 353 | if (delta == 0 || delta2 == 0 || delta3 == 0) |
| 354 | return 0; |
| 355 | |
| 356 | d->outbits++; |
| 357 | return 1; |
| 358 | } |
| 359 | |
| 360 | /* |
| 361 | * Delta estimator for 32-bit timeestamps. Must handle wrap. |
| 362 | */ |
| 363 | static inline uint32_t |
| 364 | rnd_dt_estimate(krndsource_t *rs, uint32_t t) |
| 365 | { |
| 366 | int32_t delta; |
| 367 | uint32_t ret; |
| 368 | rnd_delta_t *d = &rs->time_delta; |
| 369 | |
| 370 | if (t < d->x) { |
| 371 | delta = UINT32_MAX - d->x + t; |
| 372 | } else { |
| 373 | delta = d->x - t; |
| 374 | } |
| 375 | |
| 376 | if (delta < 0) { |
| 377 | delta = -delta; |
| 378 | } |
| 379 | |
| 380 | ret = rnd_delta_estimate(d, t, delta); |
| 381 | |
| 382 | KASSERT(d->x == t); |
| 383 | KASSERT(d->dx == delta); |
| 384 | #ifdef RND_VERBOSE |
| 385 | if (deltacnt++ % 1151 == 0) { |
| 386 | rnd_printf_verbose("rnd_dt_estimate: %s x = %lld, dx = %lld, " |
| 387 | "d2x = %lld\n" , rs->name, |
| 388 | (int)d->x, (int)d->dx, (int)d->d2x); |
| 389 | } |
| 390 | #endif |
| 391 | return ret; |
| 392 | } |
| 393 | |
| 394 | /* |
| 395 | * Delta estimator for 32 or bit values. "Wrap" isn't. |
| 396 | */ |
| 397 | static inline uint32_t |
| 398 | rnd_dv_estimate(krndsource_t *rs, uint32_t v) |
| 399 | { |
| 400 | int32_t delta; |
| 401 | uint32_t ret; |
| 402 | rnd_delta_t *d = &rs->value_delta; |
| 403 | |
| 404 | delta = d->x - v; |
| 405 | |
| 406 | if (delta < 0) { |
| 407 | delta = -delta; |
| 408 | } |
| 409 | ret = rnd_delta_estimate(d, v, (uint32_t)delta); |
| 410 | |
| 411 | KASSERT(d->x == v); |
| 412 | KASSERT(d->dx == delta); |
| 413 | #ifdef RND_VERBOSE |
| 414 | if (deltacnt++ % 1151 == 0) { |
| 415 | rnd_printf_verbose("rnd_dv_estimate: %s x = %lld, dx = %lld, " |
| 416 | " d2x = %lld\n" , rs->name, |
| 417 | (long long int)d->x, |
| 418 | (long long int)d->dx, |
| 419 | (long long int)d->d2x); |
| 420 | } |
| 421 | #endif |
| 422 | return ret; |
| 423 | } |
| 424 | |
| 425 | #if defined(__HAVE_CPU_RNG) && !defined(_RUMPKERNEL) |
| 426 | static struct { |
| 427 | kmutex_t lock; /* unfortunately, must protect krndsource */ |
| 428 | krndsource_t source; |
| 429 | } rnd_cpu __cacheline_aligned; |
| 430 | |
| 431 | static void |
| 432 | rnd_cpu_get(size_t bytes, void *priv) |
| 433 | { |
| 434 | krndsource_t *cpusrcp = priv; |
| 435 | cpu_rng_t buf[2 * RND_ENTROPY_THRESHOLD / sizeof(cpu_rng_t)]; |
| 436 | cpu_rng_t *bufp; |
| 437 | size_t cnt = __arraycount(buf); |
| 438 | size_t entropy = 0; |
| 439 | |
| 440 | KASSERT(cpusrcp == &rnd_cpu.source); |
| 441 | |
| 442 | for (bufp = buf; bufp < buf + cnt; bufp++) { |
| 443 | entropy += cpu_rng(bufp); |
| 444 | } |
| 445 | if (__predict_true(entropy)) { |
| 446 | mutex_spin_enter(&rnd_cpu.lock); |
| 447 | rnd_add_data_sync(cpusrcp, buf, sizeof(buf), entropy); |
| 448 | explicit_memset(buf, 0, sizeof(buf)); |
| 449 | mutex_spin_exit(&rnd_cpu.lock); |
| 450 | } |
| 451 | } |
| 452 | |
| 453 | #endif |
| 454 | |
| 455 | #if defined(__HAVE_CPU_COUNTER) |
| 456 | static struct { |
| 457 | kmutex_t lock; |
| 458 | int iter; |
| 459 | struct callout callout; |
| 460 | krndsource_t source; |
| 461 | } rnd_skew __cacheline_aligned; |
| 462 | |
| 463 | static void rnd_skew_intr(void *); |
| 464 | |
| 465 | static void |
| 466 | rnd_skew_enable(krndsource_t *rs, bool enabled) |
| 467 | { |
| 468 | |
| 469 | if (enabled) { |
| 470 | rnd_skew_intr(rs); |
| 471 | } else { |
| 472 | callout_stop(&rnd_skew.callout); |
| 473 | } |
| 474 | } |
| 475 | |
| 476 | static void |
| 477 | rnd_skew_get(size_t bytes, void *priv) |
| 478 | { |
| 479 | krndsource_t *skewsrcp __diagused = priv; |
| 480 | |
| 481 | KASSERT(skewsrcp == &rnd_skew.source); |
| 482 | |
| 483 | /* Measure 100 times */ |
| 484 | rnd_skew.iter = 100; |
| 485 | callout_schedule(&rnd_skew.callout, 1); |
| 486 | } |
| 487 | |
| 488 | static void |
| 489 | rnd_skew_intr(void *arg) |
| 490 | { |
| 491 | /* |
| 492 | * Even on systems with seemingly stable clocks, the |
| 493 | * delta-time entropy estimator seems to think we get 1 bit here |
| 494 | * about every 2 calls. |
| 495 | * |
| 496 | */ |
| 497 | mutex_spin_enter(&rnd_skew.lock); |
| 498 | |
| 499 | if (RND_ENABLED(&rnd_skew.source)) { |
| 500 | int next_ticks = 1; |
| 501 | if (rnd_skew.iter & 1) { |
| 502 | rnd_add_uint32(&rnd_skew.source, rnd_counter()); |
| 503 | next_ticks = hz / 10; |
| 504 | } |
| 505 | if (--rnd_skew.iter > 0) { |
| 506 | callout_schedule(&rnd_skew.callout, next_ticks); |
| 507 | } |
| 508 | } |
| 509 | mutex_spin_exit(&rnd_skew.lock); |
| 510 | } |
| 511 | #endif |
| 512 | |
| 513 | void |
| 514 | rnd_init_softint(void) |
| 515 | { |
| 516 | |
| 517 | rnd_process = softint_establish(SOFTINT_SERIAL|SOFTINT_MPSAFE, |
| 518 | rnd_intr, NULL); |
| 519 | rnd_wakeup = softint_establish(SOFTINT_CLOCK|SOFTINT_MPSAFE, |
| 520 | rnd_wake, NULL); |
| 521 | rnd_schedule_process(); |
| 522 | } |
| 523 | |
| 524 | /* |
| 525 | * Entropy was just added to the pool. If we crossed the threshold for |
| 526 | * the first time, set rnd_initial_entropy = 1. |
| 527 | */ |
| 528 | static void |
| 529 | rnd_entropy_added(void) |
| 530 | { |
| 531 | uint32_t pool_entropy; |
| 532 | |
| 533 | KASSERT(mutex_owned(&rnd_global.lock)); |
| 534 | |
| 535 | if (__predict_true(rnd_initial_entropy)) |
| 536 | return; |
| 537 | pool_entropy = rndpool_get_entropy_count(&rnd_global.pool); |
| 538 | if (pool_entropy > RND_ENTROPY_THRESHOLD * NBBY) { |
| 539 | rnd_printf_verbose("rnd: have initial entropy (%zu)\n" , |
| 540 | pool_entropy); |
| 541 | rnd_initial_entropy = 1; |
| 542 | } |
| 543 | } |
| 544 | |
| 545 | /* |
| 546 | * initialize the global random pool for our use. |
| 547 | * rnd_init() must be called very early on in the boot process, so |
| 548 | * the pool is ready for other devices to attach as sources. |
| 549 | */ |
| 550 | void |
| 551 | rnd_init(void) |
| 552 | { |
| 553 | uint32_t c; |
| 554 | |
| 555 | if (rnd_ready) |
| 556 | return; |
| 557 | |
| 558 | /* |
| 559 | * take a counter early, hoping that there's some variance in |
| 560 | * the following operations |
| 561 | */ |
| 562 | c = rnd_counter(); |
| 563 | |
| 564 | rndsinks_init(); |
| 565 | |
| 566 | /* Initialize the sample queue. */ |
| 567 | mutex_init(&rnd_samples.lock, MUTEX_DEFAULT, IPL_VM); |
| 568 | SIMPLEQ_INIT(&rnd_samples.q); |
| 569 | |
| 570 | /* Initialize the global pool and sources list. */ |
| 571 | mutex_init(&rnd_global.lock, MUTEX_DEFAULT, IPL_VM); |
| 572 | rndpool_init(&rnd_global.pool); |
| 573 | LIST_INIT(&rnd_global.sources); |
| 574 | cv_init(&rnd_global.cv, "rndsrc" ); |
| 575 | |
| 576 | rnd_mempc = pool_cache_init(sizeof(rnd_sample_t), 0, 0, 0, |
| 577 | "rndsample" , NULL, IPL_VM, |
| 578 | NULL, NULL, NULL); |
| 579 | |
| 580 | /* |
| 581 | * Set resource limit. The rnd_process_events() function |
| 582 | * is called every tick and process the sample queue. |
| 583 | * Without limitation, if a lot of rnd_add_*() are called, |
| 584 | * all kernel memory may be eaten up. |
| 585 | */ |
| 586 | pool_cache_sethardlimit(rnd_mempc, RND_POOLBITS, NULL, 0); |
| 587 | |
| 588 | /* |
| 589 | * Mix *something*, *anything* into the pool to help it get started. |
| 590 | * However, it's not safe for rnd_counter() to call microtime() yet, |
| 591 | * so on some platforms we might just end up with zeros anyway. |
| 592 | * XXX more things to add would be nice. |
| 593 | */ |
| 594 | if (c) { |
| 595 | mutex_spin_enter(&rnd_global.lock); |
| 596 | rndpool_add_data(&rnd_global.pool, &c, sizeof(c), 1); |
| 597 | c = rnd_counter(); |
| 598 | rndpool_add_data(&rnd_global.pool, &c, sizeof(c), 1); |
| 599 | mutex_spin_exit(&rnd_global.lock); |
| 600 | } |
| 601 | |
| 602 | /* |
| 603 | * Attach CPU RNG if available. |
| 604 | */ |
| 605 | #if defined(__HAVE_CPU_RNG) && !defined(_RUMPKERNEL) |
| 606 | if (cpu_rng_init()) { |
| 607 | /* IPL_VM because taken while rnd_global.lock is held. */ |
| 608 | mutex_init(&rnd_cpu.lock, MUTEX_DEFAULT, IPL_VM); |
| 609 | rndsource_setcb(&rnd_cpu.source, rnd_cpu_get, &rnd_cpu.source); |
| 610 | rnd_attach_source(&rnd_cpu.source, "cpurng" , |
| 611 | RND_TYPE_RNG, RND_FLAG_COLLECT_VALUE| |
| 612 | RND_FLAG_HASCB|RND_FLAG_HASENABLE); |
| 613 | rnd_cpu_get(RND_ENTROPY_THRESHOLD, &rnd_cpu.source); |
| 614 | } |
| 615 | #endif |
| 616 | |
| 617 | /* |
| 618 | * If we have a cycle counter, take its error with respect |
| 619 | * to the callout mechanism as a source of entropy, ala |
| 620 | * TrueRand. |
| 621 | * |
| 622 | */ |
| 623 | #if defined(__HAVE_CPU_COUNTER) |
| 624 | /* IPL_VM because taken while rnd_global.lock is held. */ |
| 625 | mutex_init(&rnd_skew.lock, MUTEX_DEFAULT, IPL_VM); |
| 626 | callout_init(&rnd_skew.callout, CALLOUT_MPSAFE); |
| 627 | callout_setfunc(&rnd_skew.callout, rnd_skew_intr, NULL); |
| 628 | rndsource_setcb(&rnd_skew.source, rnd_skew_get, &rnd_skew.source); |
| 629 | rndsource_setenable(&rnd_skew.source, rnd_skew_enable); |
| 630 | rnd_attach_source(&rnd_skew.source, "callout" , RND_TYPE_SKEW, |
| 631 | RND_FLAG_COLLECT_VALUE|RND_FLAG_ESTIMATE_VALUE| |
| 632 | RND_FLAG_HASCB|RND_FLAG_HASENABLE); |
| 633 | rnd_skew.iter = 100; |
| 634 | rnd_skew_intr(NULL); |
| 635 | #endif |
| 636 | |
| 637 | rnd_printf_verbose("rnd: initialised (%u)%s" , RND_POOLBITS, |
| 638 | c ? " with counter\n" : "\n" ); |
| 639 | if (boot_rsp != NULL) { |
| 640 | mutex_spin_enter(&rnd_global.lock); |
| 641 | rndpool_add_data(&rnd_global.pool, boot_rsp->data, |
| 642 | sizeof(boot_rsp->data), |
| 643 | MIN(boot_rsp->entropy, RND_POOLBITS / 2)); |
| 644 | rnd_entropy_added(); |
| 645 | mutex_spin_exit(&rnd_global.lock); |
| 646 | rnd_printf("rnd: seeded with %d bits\n" , |
| 647 | MIN(boot_rsp->entropy, RND_POOLBITS / 2)); |
| 648 | explicit_memset(boot_rsp, 0, sizeof(*boot_rsp)); |
| 649 | } |
| 650 | rnd_attach_source(&rnd_printf_source, "printf" , RND_TYPE_UNKNOWN, |
| 651 | RND_FLAG_NO_ESTIMATE); |
| 652 | rnd_attach_source(&rnd_autoconf_source, "autoconf" , |
| 653 | RND_TYPE_UNKNOWN, |
| 654 | RND_FLAG_COLLECT_TIME|RND_FLAG_ESTIMATE_TIME); |
| 655 | rnd_ready = 1; |
| 656 | } |
| 657 | |
| 658 | static rnd_sample_t * |
| 659 | rnd_sample_allocate(krndsource_t *source) |
| 660 | { |
| 661 | rnd_sample_t *c; |
| 662 | |
| 663 | c = pool_cache_get(rnd_mempc, PR_WAITOK); |
| 664 | if (c == NULL) |
| 665 | return NULL; |
| 666 | |
| 667 | c->source = source; |
| 668 | c->cursor = 0; |
| 669 | c->entropy = 0; |
| 670 | |
| 671 | return c; |
| 672 | } |
| 673 | |
| 674 | /* |
| 675 | * Don't wait on allocation. To be used in an interrupt context. |
| 676 | */ |
| 677 | static rnd_sample_t * |
| 678 | rnd_sample_allocate_isr(krndsource_t *source) |
| 679 | { |
| 680 | rnd_sample_t *c; |
| 681 | |
| 682 | c = pool_cache_get(rnd_mempc, PR_NOWAIT); |
| 683 | if (c == NULL) |
| 684 | return NULL; |
| 685 | |
| 686 | c->source = source; |
| 687 | c->cursor = 0; |
| 688 | c->entropy = 0; |
| 689 | |
| 690 | return c; |
| 691 | } |
| 692 | |
| 693 | static void |
| 694 | rnd_sample_free(rnd_sample_t *c) |
| 695 | { |
| 696 | |
| 697 | explicit_memset(c, 0, sizeof(*c)); |
| 698 | pool_cache_put(rnd_mempc, c); |
| 699 | } |
| 700 | |
| 701 | /* |
| 702 | * Add a source to our list of sources. |
| 703 | */ |
| 704 | void |
| 705 | rnd_attach_source(krndsource_t *rs, const char *name, uint32_t type, |
| 706 | uint32_t flags) |
| 707 | { |
| 708 | uint32_t ts; |
| 709 | |
| 710 | ts = rnd_counter(); |
| 711 | |
| 712 | strlcpy(rs->name, name, sizeof(rs->name)); |
| 713 | memset(&rs->time_delta, 0, sizeof(rs->time_delta)); |
| 714 | rs->time_delta.x = ts; |
| 715 | memset(&rs->value_delta, 0, sizeof(rs->value_delta)); |
| 716 | rs->total = 0; |
| 717 | |
| 718 | /* |
| 719 | * Some source setup, by type |
| 720 | */ |
| 721 | rs->test = NULL; |
| 722 | rs->test_cnt = -1; |
| 723 | |
| 724 | if (flags == 0) { |
| 725 | flags = RND_FLAG_DEFAULT; |
| 726 | } |
| 727 | |
| 728 | switch (type) { |
| 729 | case RND_TYPE_NET: /* Don't collect by default */ |
| 730 | flags |= (RND_FLAG_NO_COLLECT | RND_FLAG_NO_ESTIMATE); |
| 731 | break; |
| 732 | case RND_TYPE_RNG: /* Space for statistical testing */ |
| 733 | rs->test = kmem_alloc(sizeof(rngtest_t), KM_NOSLEEP); |
| 734 | rs->test_cnt = 0; |
| 735 | /* FALLTHRU */ |
| 736 | case RND_TYPE_VM: /* Process samples in bulk always */ |
| 737 | flags |= RND_FLAG_FAST; |
| 738 | break; |
| 739 | default: |
| 740 | break; |
| 741 | } |
| 742 | |
| 743 | rs->type = type; |
| 744 | rs->flags = flags; |
| 745 | rs->refcnt = 1; |
| 746 | |
| 747 | rs->state = rnd_sample_allocate(rs); |
| 748 | |
| 749 | mutex_spin_enter(&rnd_global.lock); |
| 750 | LIST_INSERT_HEAD(&rnd_global.sources, rs, list); |
| 751 | |
| 752 | #ifdef RND_VERBOSE |
| 753 | rnd_printf_verbose("rnd: %s attached as an entropy source (" , |
| 754 | rs->name); |
| 755 | if (!(flags & RND_FLAG_NO_COLLECT)) { |
| 756 | rnd_printf_verbose("collecting" ); |
| 757 | if (flags & RND_FLAG_NO_ESTIMATE) |
| 758 | rnd_printf_verbose(" without estimation" ); |
| 759 | } else { |
| 760 | rnd_printf_verbose("off" ); |
| 761 | } |
| 762 | rnd_printf_verbose(")\n" ); |
| 763 | #endif |
| 764 | |
| 765 | /* |
| 766 | * Again, put some more initial junk in the pool. |
| 767 | * FreeBSD claim to have an analysis that show 4 bits of |
| 768 | * entropy per source-attach timestamp. I am skeptical, |
| 769 | * but we count 1 bit per source here. |
| 770 | */ |
| 771 | rndpool_add_data(&rnd_global.pool, &ts, sizeof(ts), 1); |
| 772 | mutex_spin_exit(&rnd_global.lock); |
| 773 | } |
| 774 | |
| 775 | /* |
| 776 | * Remove a source from our list of sources. |
| 777 | */ |
| 778 | void |
| 779 | rnd_detach_source(krndsource_t *source) |
| 780 | { |
| 781 | rnd_sample_t *sample; |
| 782 | |
| 783 | mutex_spin_enter(&rnd_global.lock); |
| 784 | LIST_REMOVE(source, list); |
| 785 | if (0 < --source->refcnt) { |
| 786 | do { |
| 787 | cv_wait(&rnd_global.cv, &rnd_global.lock); |
| 788 | } while (0 < source->refcnt); |
| 789 | } |
| 790 | mutex_spin_exit(&rnd_global.lock); |
| 791 | |
| 792 | /* |
| 793 | * If there are samples queued up "remove" them from the sample queue |
| 794 | * by setting the source to the no-collect pseudosource. |
| 795 | */ |
| 796 | mutex_spin_enter(&rnd_samples.lock); |
| 797 | sample = SIMPLEQ_FIRST(&rnd_samples.q); |
| 798 | while (sample != NULL) { |
| 799 | if (sample->source == source) |
| 800 | sample->source = &rnd_source_no_collect; |
| 801 | |
| 802 | sample = SIMPLEQ_NEXT(sample, next); |
| 803 | } |
| 804 | mutex_spin_exit(&rnd_samples.lock); |
| 805 | |
| 806 | if (source->state) { |
| 807 | rnd_sample_free(source->state); |
| 808 | source->state = NULL; |
| 809 | } |
| 810 | |
| 811 | if (source->test) { |
| 812 | kmem_free(source->test, sizeof(rngtest_t)); |
| 813 | } |
| 814 | |
| 815 | rnd_printf_verbose("rnd: %s detached as an entropy source\n" , |
| 816 | source->name); |
| 817 | } |
| 818 | |
| 819 | static inline uint32_t |
| 820 | rnd_estimate(krndsource_t *rs, uint32_t ts, uint32_t val) |
| 821 | { |
| 822 | uint32_t entropy = 0, dt_est, dv_est; |
| 823 | |
| 824 | dt_est = rnd_dt_estimate(rs, ts); |
| 825 | dv_est = rnd_dv_estimate(rs, val); |
| 826 | |
| 827 | if (!(rs->flags & RND_FLAG_NO_ESTIMATE)) { |
| 828 | if (rs->flags & RND_FLAG_ESTIMATE_TIME) { |
| 829 | entropy += dt_est; |
| 830 | } |
| 831 | |
| 832 | if (rs->flags & RND_FLAG_ESTIMATE_VALUE) { |
| 833 | entropy += dv_est; |
| 834 | } |
| 835 | |
| 836 | } |
| 837 | return entropy; |
| 838 | } |
| 839 | |
| 840 | /* |
| 841 | * Add a 32-bit value to the entropy pool. The rs parameter should point to |
| 842 | * the source-specific source structure. |
| 843 | */ |
| 844 | void |
| 845 | _rnd_add_uint32(krndsource_t *rs, uint32_t val) |
| 846 | { |
| 847 | uint32_t ts; |
| 848 | uint32_t entropy = 0; |
| 849 | |
| 850 | if (rs->flags & RND_FLAG_NO_COLLECT) |
| 851 | return; |
| 852 | |
| 853 | /* |
| 854 | * Sample the counter as soon as possible to avoid |
| 855 | * entropy overestimation. |
| 856 | */ |
| 857 | ts = rnd_counter(); |
| 858 | |
| 859 | /* |
| 860 | * Calculate estimates - we may not use them, but if we do |
| 861 | * not calculate them, the estimators' history becomes invalid. |
| 862 | */ |
| 863 | entropy = rnd_estimate(rs, ts, val); |
| 864 | |
| 865 | rnd_add_data_ts(rs, &val, sizeof(val), entropy, ts, true); |
| 866 | } |
| 867 | |
| 868 | void |
| 869 | _rnd_add_uint64(krndsource_t *rs, uint64_t val) |
| 870 | { |
| 871 | uint32_t ts; |
| 872 | uint32_t entropy = 0; |
| 873 | |
| 874 | if (rs->flags & RND_FLAG_NO_COLLECT) |
| 875 | return; |
| 876 | |
| 877 | /* |
| 878 | * Sample the counter as soon as possible to avoid |
| 879 | * entropy overestimation. |
| 880 | */ |
| 881 | ts = rnd_counter(); |
| 882 | |
| 883 | /* |
| 884 | * Calculate estimates - we may not use them, but if we do |
| 885 | * not calculate them, the estimators' history becomes invalid. |
| 886 | */ |
| 887 | entropy = rnd_estimate(rs, ts, (uint32_t)(val & (uint64_t)0xffffffff)); |
| 888 | |
| 889 | rnd_add_data_ts(rs, &val, sizeof(val), entropy, ts, true); |
| 890 | } |
| 891 | |
| 892 | void |
| 893 | rnd_add_data(krndsource_t *rs, const void *const data, uint32_t len, |
| 894 | uint32_t entropy) |
| 895 | { |
| 896 | |
| 897 | /* |
| 898 | * This interface is meant for feeding data which is, |
| 899 | * itself, random. Don't estimate entropy based on |
| 900 | * timestamp, just directly add the data. |
| 901 | */ |
| 902 | if (__predict_false(rs == NULL)) { |
| 903 | mutex_spin_enter(&rnd_global.lock); |
| 904 | rndpool_add_data(&rnd_global.pool, data, len, entropy); |
| 905 | mutex_spin_exit(&rnd_global.lock); |
| 906 | } else { |
| 907 | rnd_add_data_ts(rs, data, len, entropy, rnd_counter(), true); |
| 908 | } |
| 909 | } |
| 910 | |
| 911 | void |
| 912 | rnd_add_data_sync(krndsource_t *rs, const void *data, uint32_t len, |
| 913 | uint32_t entropy) |
| 914 | { |
| 915 | |
| 916 | KASSERT(rs != NULL); |
| 917 | rnd_add_data_ts(rs, data, len, entropy, rnd_counter(), false); |
| 918 | } |
| 919 | |
| 920 | static void |
| 921 | rnd_add_data_ts(krndsource_t *rs, const void *const data, uint32_t len, |
| 922 | uint32_t entropy, uint32_t ts, bool schedule) |
| 923 | { |
| 924 | rnd_sample_t *state = NULL; |
| 925 | const uint8_t *p = data; |
| 926 | uint32_t dint; |
| 927 | int todo, done, filled = 0; |
| 928 | int sample_count; |
| 929 | struct rnd_sampleq tmp_samples = SIMPLEQ_HEAD_INITIALIZER(tmp_samples); |
| 930 | |
| 931 | if (rs && |
| 932 | (rs->flags & RND_FLAG_NO_COLLECT || |
| 933 | __predict_false(!(rs->flags & |
| 934 | (RND_FLAG_COLLECT_TIME|RND_FLAG_COLLECT_VALUE))))) { |
| 935 | return; |
| 936 | } |
| 937 | todo = len / sizeof(dint); |
| 938 | /* |
| 939 | * Let's try to be efficient: if we are warm, and a source |
| 940 | * is adding entropy at a rate of at least 1 bit every 10 seconds, |
| 941 | * mark it as "fast" and add its samples in bulk. |
| 942 | */ |
| 943 | if (__predict_true(rs->flags & RND_FLAG_FAST) || |
| 944 | (todo >= RND_SAMPLE_COUNT)) { |
| 945 | sample_count = RND_SAMPLE_COUNT; |
| 946 | } else { |
| 947 | if (!(rs->flags & RND_FLAG_HASCB) && |
| 948 | !cold && rnd_initial_entropy) { |
| 949 | struct timeval upt; |
| 950 | |
| 951 | getmicrouptime(&upt); |
| 952 | if ((upt.tv_sec > 0 && rs->total > upt.tv_sec * 10) || |
| 953 | (upt.tv_sec > 10 && rs->total > upt.tv_sec) || |
| 954 | (upt.tv_sec > 100 && |
| 955 | rs->total > upt.tv_sec / 10)) { |
| 956 | rnd_printf_verbose("rnd: source %s is fast" |
| 957 | " (%d samples at once," |
| 958 | " %d bits in %lld seconds), " |
| 959 | "processing samples in bulk.\n" , |
| 960 | rs->name, todo, rs->total, |
| 961 | (long long int)upt.tv_sec); |
| 962 | rs->flags |= RND_FLAG_FAST; |
| 963 | } |
| 964 | } |
| 965 | sample_count = 2; |
| 966 | } |
| 967 | |
| 968 | /* |
| 969 | * Loop over data packaging it into sample buffers. |
| 970 | * If a sample buffer allocation fails, drop all data. |
| 971 | */ |
| 972 | for (done = 0; done < todo ; done++) { |
| 973 | state = rs->state; |
| 974 | if (state == NULL) { |
| 975 | state = rnd_sample_allocate_isr(rs); |
| 976 | if (__predict_false(state == NULL)) { |
| 977 | break; |
| 978 | } |
| 979 | rs->state = state; |
| 980 | } |
| 981 | |
| 982 | state->ts[state->cursor] = ts; |
| 983 | (void)memcpy(&dint, &p[done*4], 4); |
| 984 | state->values[state->cursor] = dint; |
| 985 | state->cursor++; |
| 986 | |
| 987 | if (state->cursor == sample_count) { |
| 988 | SIMPLEQ_INSERT_HEAD(&tmp_samples, state, next); |
| 989 | filled++; |
| 990 | rs->state = NULL; |
| 991 | } |
| 992 | } |
| 993 | |
| 994 | if (__predict_false(state == NULL)) { |
| 995 | while ((state = SIMPLEQ_FIRST(&tmp_samples))) { |
| 996 | SIMPLEQ_REMOVE_HEAD(&tmp_samples, next); |
| 997 | rnd_sample_free(state); |
| 998 | } |
| 999 | return; |
| 1000 | } |
| 1001 | |
| 1002 | /* |
| 1003 | * Claim all the entropy on the last one we send to |
| 1004 | * the pool, so we don't rely on it being evenly distributed |
| 1005 | * in the supplied data. |
| 1006 | * |
| 1007 | * XXX The rndpool code must accept samples with more |
| 1008 | * XXX claimed entropy than bits for this to work right. |
| 1009 | */ |
| 1010 | state->entropy += entropy; |
| 1011 | rs->total += entropy; |
| 1012 | |
| 1013 | /* |
| 1014 | * If we didn't finish any sample buffers, we're done. |
| 1015 | */ |
| 1016 | if (!filled) { |
| 1017 | return; |
| 1018 | } |
| 1019 | |
| 1020 | mutex_spin_enter(&rnd_samples.lock); |
| 1021 | while ((state = SIMPLEQ_FIRST(&tmp_samples))) { |
| 1022 | SIMPLEQ_REMOVE_HEAD(&tmp_samples, next); |
| 1023 | SIMPLEQ_INSERT_HEAD(&rnd_samples.q, state, next); |
| 1024 | } |
| 1025 | mutex_spin_exit(&rnd_samples.lock); |
| 1026 | |
| 1027 | /* Cause processing of queued samples, if caller wants it. */ |
| 1028 | if (schedule) |
| 1029 | rnd_schedule_process(); |
| 1030 | } |
| 1031 | |
| 1032 | static int |
| 1033 | rnd_hwrng_test(rnd_sample_t *sample) |
| 1034 | { |
| 1035 | krndsource_t *source = sample->source; |
| 1036 | size_t cmplen; |
| 1037 | uint8_t *v1, *v2; |
| 1038 | size_t resid, totest; |
| 1039 | |
| 1040 | KASSERT(source->type == RND_TYPE_RNG); |
| 1041 | |
| 1042 | /* |
| 1043 | * Continuous-output test: compare two halves of the |
| 1044 | * sample buffer to each other. The sample buffer (64 ints, |
| 1045 | * so either 256 or 512 bytes on any modern machine) should be |
| 1046 | * much larger than a typical hardware RNG output, so this seems |
| 1047 | * a reasonable way to do it without retaining extra data. |
| 1048 | */ |
| 1049 | cmplen = sizeof(sample->values) / 2; |
| 1050 | v1 = (uint8_t *)sample->values; |
| 1051 | v2 = (uint8_t *)sample->values + cmplen; |
| 1052 | |
| 1053 | if (__predict_false(!memcmp(v1, v2, cmplen))) { |
| 1054 | rnd_printf("rnd: source \"%s\"" |
| 1055 | " failed continuous-output test.\n" , |
| 1056 | source->name); |
| 1057 | return 1; |
| 1058 | } |
| 1059 | |
| 1060 | /* |
| 1061 | * FIPS 140 statistical RNG test. We must accumulate 20,000 bits. |
| 1062 | */ |
| 1063 | if (__predict_true(source->test_cnt == -1)) { |
| 1064 | /* already passed the test */ |
| 1065 | return 0; |
| 1066 | } |
| 1067 | resid = FIPS140_RNG_TEST_BYTES - source->test_cnt; |
| 1068 | totest = MIN(RND_SAMPLE_COUNT * 4, resid); |
| 1069 | memcpy(source->test->rt_b + source->test_cnt, sample->values, totest); |
| 1070 | resid -= totest; |
| 1071 | source->test_cnt += totest; |
| 1072 | if (resid == 0) { |
| 1073 | strlcpy(source->test->rt_name, source->name, |
| 1074 | sizeof(source->test->rt_name)); |
| 1075 | if (rngtest(source->test)) { |
| 1076 | rnd_printf("rnd: source \"%s\"" |
| 1077 | " failed statistical test." , |
| 1078 | source->name); |
| 1079 | return 1; |
| 1080 | } |
| 1081 | source->test_cnt = -1; |
| 1082 | explicit_memset(source->test, 0, sizeof(*source->test)); |
| 1083 | } |
| 1084 | return 0; |
| 1085 | } |
| 1086 | |
| 1087 | /* |
| 1088 | * Process the events in the ring buffer. Called by rnd_timeout or |
| 1089 | * by the add routines directly if the callout has never fired (that |
| 1090 | * is, if we are "cold" -- just booted). |
| 1091 | * |
| 1092 | */ |
| 1093 | static void |
| 1094 | rnd_process_events(void) |
| 1095 | { |
| 1096 | rnd_sample_t *sample = NULL; |
| 1097 | krndsource_t *source; |
| 1098 | static krndsource_t *last_source; |
| 1099 | uint32_t entropy; |
| 1100 | size_t pool_entropy; |
| 1101 | int wake = 0; |
| 1102 | struct rnd_sampleq dq_samples = SIMPLEQ_HEAD_INITIALIZER(dq_samples); |
| 1103 | struct rnd_sampleq df_samples = SIMPLEQ_HEAD_INITIALIZER(df_samples); |
| 1104 | |
| 1105 | /* |
| 1106 | * Drain to the on-stack queue and drop the lock. |
| 1107 | */ |
| 1108 | mutex_spin_enter(&rnd_samples.lock); |
| 1109 | while ((sample = SIMPLEQ_FIRST(&rnd_samples.q))) { |
| 1110 | SIMPLEQ_REMOVE_HEAD(&rnd_samples.q, next); |
| 1111 | /* |
| 1112 | * We repeat this check here, since it is possible |
| 1113 | * the source was disabled before we were called, but |
| 1114 | * after the entry was queued. |
| 1115 | */ |
| 1116 | if (__predict_false(!(sample->source->flags & |
| 1117 | (RND_FLAG_COLLECT_TIME|RND_FLAG_COLLECT_VALUE)))) { |
| 1118 | SIMPLEQ_INSERT_TAIL(&df_samples, sample, next); |
| 1119 | } else { |
| 1120 | SIMPLEQ_INSERT_TAIL(&dq_samples, sample, next); |
| 1121 | } |
| 1122 | } |
| 1123 | mutex_spin_exit(&rnd_samples.lock); |
| 1124 | |
| 1125 | /* Don't thrash the rndpool mtx either. Hold, add all samples. */ |
| 1126 | mutex_spin_enter(&rnd_global.lock); |
| 1127 | |
| 1128 | pool_entropy = rndpool_get_entropy_count(&rnd_global.pool); |
| 1129 | |
| 1130 | while ((sample = SIMPLEQ_FIRST(&dq_samples))) { |
| 1131 | int sample_count; |
| 1132 | |
| 1133 | SIMPLEQ_REMOVE_HEAD(&dq_samples, next); |
| 1134 | source = sample->source; |
| 1135 | entropy = sample->entropy; |
| 1136 | sample_count = sample->cursor; |
| 1137 | |
| 1138 | /* |
| 1139 | * Don't provide a side channel for timing attacks on |
| 1140 | * low-rate sources: require mixing with some other |
| 1141 | * source before we schedule a wakeup. |
| 1142 | */ |
| 1143 | if (!wake && |
| 1144 | (source != last_source || source->flags & RND_FLAG_FAST)) { |
| 1145 | wake++; |
| 1146 | } |
| 1147 | last_source = source; |
| 1148 | |
| 1149 | /* |
| 1150 | * If the source has been disabled, ignore samples from |
| 1151 | * it. |
| 1152 | */ |
| 1153 | if (source->flags & RND_FLAG_NO_COLLECT) |
| 1154 | goto skip; |
| 1155 | |
| 1156 | /* |
| 1157 | * Hardware generators are great but sometimes they |
| 1158 | * have...hardware issues. Don't use any data from |
| 1159 | * them unless it passes some tests. |
| 1160 | */ |
| 1161 | if (source->type == RND_TYPE_RNG) { |
| 1162 | if (__predict_false(rnd_hwrng_test(sample))) { |
| 1163 | source->flags |= RND_FLAG_NO_COLLECT; |
| 1164 | rnd_printf("rnd: disabling source \"%s\".\n" , |
| 1165 | source->name); |
| 1166 | goto skip; |
| 1167 | } |
| 1168 | } |
| 1169 | |
| 1170 | if (source->flags & RND_FLAG_COLLECT_VALUE) { |
| 1171 | rndpool_add_data(&rnd_global.pool, sample->values, |
| 1172 | sample_count * sizeof(sample->values[1]), |
| 1173 | 0); |
| 1174 | } |
| 1175 | if (source->flags & RND_FLAG_COLLECT_TIME) { |
| 1176 | rndpool_add_data(&rnd_global.pool, sample->ts, |
| 1177 | sample_count * sizeof(sample->ts[1]), |
| 1178 | 0); |
| 1179 | } |
| 1180 | |
| 1181 | pool_entropy += entropy; |
| 1182 | source->total += sample->entropy; |
| 1183 | skip: SIMPLEQ_INSERT_TAIL(&df_samples, sample, next); |
| 1184 | } |
| 1185 | rndpool_set_entropy_count(&rnd_global.pool, pool_entropy); |
| 1186 | rnd_entropy_added(); |
| 1187 | mutex_spin_exit(&rnd_global.lock); |
| 1188 | |
| 1189 | /* |
| 1190 | * If we filled the pool past the threshold, wake anyone |
| 1191 | * waiting for entropy. |
| 1192 | */ |
| 1193 | if (pool_entropy > RND_ENTROPY_THRESHOLD * 8) { |
| 1194 | wake++; |
| 1195 | } |
| 1196 | |
| 1197 | /* Now we hold no locks: clean up. */ |
| 1198 | while ((sample = SIMPLEQ_FIRST(&df_samples))) { |
| 1199 | SIMPLEQ_REMOVE_HEAD(&df_samples, next); |
| 1200 | rnd_sample_free(sample); |
| 1201 | } |
| 1202 | |
| 1203 | /* |
| 1204 | * Wake up any potential readers waiting. |
| 1205 | */ |
| 1206 | if (wake) { |
| 1207 | rnd_schedule_wakeup(); |
| 1208 | } |
| 1209 | } |
| 1210 | |
| 1211 | static void |
| 1212 | rnd_intr(void *arg) |
| 1213 | { |
| 1214 | |
| 1215 | rnd_process_events(); |
| 1216 | } |
| 1217 | |
| 1218 | static void |
| 1219 | rnd_wake(void *arg) |
| 1220 | { |
| 1221 | |
| 1222 | rndsinks_distribute(); |
| 1223 | } |
| 1224 | |
| 1225 | static uint32_t |
| 1226 | (void *p, uint32_t len, uint32_t flags) |
| 1227 | { |
| 1228 | static int timed_in; |
| 1229 | uint32_t retval; |
| 1230 | |
| 1231 | mutex_spin_enter(&rnd_global.lock); |
| 1232 | if (__predict_false(!timed_in)) { |
| 1233 | if (boottime.tv_sec) { |
| 1234 | rndpool_add_data(&rnd_global.pool, &boottime, |
| 1235 | sizeof(boottime), 0); |
| 1236 | } |
| 1237 | timed_in++; |
| 1238 | } |
| 1239 | if (__predict_false(!rnd_initial_entropy)) { |
| 1240 | uint32_t c; |
| 1241 | |
| 1242 | rnd_printf_verbose("rnd: WARNING! initial entropy low (%u).\n" , |
| 1243 | rndpool_get_entropy_count(&rnd_global.pool)); |
| 1244 | /* Try once again to put something in the pool */ |
| 1245 | c = rnd_counter(); |
| 1246 | rndpool_add_data(&rnd_global.pool, &c, sizeof(c), 1); |
| 1247 | } |
| 1248 | |
| 1249 | #ifdef DIAGNOSTIC |
| 1250 | while (!rnd_tested) { |
| 1251 | int entropy_count = |
| 1252 | rndpool_get_entropy_count(&rnd_global.pool); |
| 1253 | rnd_printf_verbose("rnd: starting statistical RNG test," |
| 1254 | " entropy = %d.\n" , |
| 1255 | entropy_count); |
| 1256 | if (rndpool_extract_data(&rnd_global.pool, rnd_rt.rt_b, |
| 1257 | sizeof(rnd_rt.rt_b), RND_EXTRACT_ANY) |
| 1258 | != sizeof(rnd_rt.rt_b)) { |
| 1259 | panic("rnd: could not get bits for statistical test" ); |
| 1260 | } |
| 1261 | /* |
| 1262 | * Stash the tested bits so we can put them back in the |
| 1263 | * pool, restoring the entropy count. DO NOT rely on |
| 1264 | * rngtest to maintain the bits pristine -- we could end |
| 1265 | * up adding back non-random data claiming it were pure |
| 1266 | * entropy. |
| 1267 | */ |
| 1268 | memcpy(rnd_testbits, rnd_rt.rt_b, sizeof(rnd_rt.rt_b)); |
| 1269 | strlcpy(rnd_rt.rt_name, "entropy pool" , |
| 1270 | sizeof(rnd_rt.rt_name)); |
| 1271 | if (rngtest(&rnd_rt)) { |
| 1272 | /* |
| 1273 | * The probabiliity of a Type I error is 3/10000, |
| 1274 | * but note this can only happen at boot time. |
| 1275 | * The relevant standard says to reset the module, |
| 1276 | * but developers objected... |
| 1277 | */ |
| 1278 | rnd_printf("rnd: WARNING, ENTROPY POOL FAILED " |
| 1279 | "STATISTICAL TEST!\n" ); |
| 1280 | continue; |
| 1281 | } |
| 1282 | explicit_memset(&rnd_rt, 0, sizeof(rnd_rt)); |
| 1283 | rndpool_add_data(&rnd_global.pool, rnd_testbits, |
| 1284 | sizeof(rnd_testbits), entropy_count); |
| 1285 | explicit_memset(rnd_testbits, 0, sizeof(rnd_testbits)); |
| 1286 | rnd_printf_verbose("rnd: statistical RNG test done," |
| 1287 | " entropy = %d.\n" , |
| 1288 | rndpool_get_entropy_count(&rnd_global.pool)); |
| 1289 | rnd_tested++; |
| 1290 | } |
| 1291 | #endif |
| 1292 | retval = rndpool_extract_data(&rnd_global.pool, p, len, flags); |
| 1293 | mutex_spin_exit(&rnd_global.lock); |
| 1294 | |
| 1295 | return retval; |
| 1296 | } |
| 1297 | |
| 1298 | /* |
| 1299 | * Fill the buffer with as much entropy as we can. Return true if it |
| 1300 | * has full entropy and false if not. |
| 1301 | */ |
| 1302 | bool |
| 1303 | (void *buffer, size_t bytes) |
| 1304 | { |
| 1305 | const size_t = rnd_extract_data(buffer, bytes, |
| 1306 | RND_EXTRACT_GOOD); |
| 1307 | |
| 1308 | if (extracted < bytes) { |
| 1309 | rnd_getmore(bytes - extracted); |
| 1310 | (void)rnd_extract_data((uint8_t *)buffer + extracted, |
| 1311 | bytes - extracted, RND_EXTRACT_ANY); |
| 1312 | return false; |
| 1313 | } |
| 1314 | |
| 1315 | return true; |
| 1316 | } |
| 1317 | |
| 1318 | /* |
| 1319 | * If we have as much entropy as is requested, fill the buffer with it |
| 1320 | * and return true. Otherwise, leave the buffer alone and return |
| 1321 | * false. |
| 1322 | */ |
| 1323 | |
| 1324 | CTASSERT(RND_ENTROPY_THRESHOLD <= 0xffffffffUL); |
| 1325 | CTASSERT(RNDSINK_MAX_BYTES <= (0xffffffffUL - RND_ENTROPY_THRESHOLD)); |
| 1326 | CTASSERT((RNDSINK_MAX_BYTES + RND_ENTROPY_THRESHOLD) <= |
| 1327 | (0xffffffffUL / NBBY)); |
| 1328 | |
| 1329 | bool |
| 1330 | (void *buffer, size_t bytes) |
| 1331 | { |
| 1332 | uint32_t bits_needed, bytes_requested; |
| 1333 | |
| 1334 | KASSERT(bytes <= RNDSINK_MAX_BYTES); |
| 1335 | bits_needed = ((bytes + RND_ENTROPY_THRESHOLD) * NBBY); |
| 1336 | |
| 1337 | mutex_spin_enter(&rnd_global.lock); |
| 1338 | if (bits_needed <= rndpool_get_entropy_count(&rnd_global.pool)) { |
| 1339 | const uint32_t __diagused = |
| 1340 | rndpool_extract_data(&rnd_global.pool, buffer, bytes, |
| 1341 | RND_EXTRACT_GOOD); |
| 1342 | |
| 1343 | KASSERT(extracted == bytes); |
| 1344 | bytes_requested = 0; |
| 1345 | } else { |
| 1346 | /* XXX Figure the threshold into this... */ |
| 1347 | bytes_requested = howmany((bits_needed - |
| 1348 | rndpool_get_entropy_count(&rnd_global.pool)), NBBY); |
| 1349 | KASSERT(0 < bytes_requested); |
| 1350 | } |
| 1351 | mutex_spin_exit(&rnd_global.lock); |
| 1352 | |
| 1353 | if (0 < bytes_requested) |
| 1354 | rnd_getmore(bytes_requested); |
| 1355 | |
| 1356 | return bytes_requested == 0; |
| 1357 | } |
| 1358 | |
| 1359 | void |
| 1360 | rnd_seed(void *base, size_t len) |
| 1361 | { |
| 1362 | SHA1_CTX s; |
| 1363 | uint8_t digest[SHA1_DIGEST_LENGTH]; |
| 1364 | |
| 1365 | if (len != sizeof(*boot_rsp)) { |
| 1366 | rnd_printf("rnd: bad seed length %d\n" , (int)len); |
| 1367 | return; |
| 1368 | } |
| 1369 | |
| 1370 | boot_rsp = (rndsave_t *)base; |
| 1371 | SHA1Init(&s); |
| 1372 | SHA1Update(&s, (uint8_t *)&boot_rsp->entropy, |
| 1373 | sizeof(boot_rsp->entropy)); |
| 1374 | SHA1Update(&s, boot_rsp->data, sizeof(boot_rsp->data)); |
| 1375 | SHA1Final(digest, &s); |
| 1376 | |
| 1377 | if (memcmp(digest, boot_rsp->digest, sizeof(digest))) { |
| 1378 | rnd_printf("rnd: bad seed checksum\n" ); |
| 1379 | return; |
| 1380 | } |
| 1381 | |
| 1382 | /* |
| 1383 | * It's not really well-defined whether bootloader-supplied |
| 1384 | * modules run before or after rnd_init(). Handle both cases. |
| 1385 | */ |
| 1386 | if (rnd_ready) { |
| 1387 | rnd_printf_verbose("rnd: ready," |
| 1388 | " feeding in seed data directly.\n" ); |
| 1389 | mutex_spin_enter(&rnd_global.lock); |
| 1390 | rndpool_add_data(&rnd_global.pool, boot_rsp->data, |
| 1391 | sizeof(boot_rsp->data), |
| 1392 | MIN(boot_rsp->entropy, RND_POOLBITS / 2)); |
| 1393 | explicit_memset(boot_rsp, 0, sizeof(*boot_rsp)); |
| 1394 | mutex_spin_exit(&rnd_global.lock); |
| 1395 | } else { |
| 1396 | rnd_printf_verbose("rnd: not ready, deferring seed feed.\n" ); |
| 1397 | } |
| 1398 | } |
| 1399 | |
| 1400 | static void |
| 1401 | krndsource_to_rndsource(krndsource_t *kr, rndsource_t *r) |
| 1402 | { |
| 1403 | |
| 1404 | memset(r, 0, sizeof(*r)); |
| 1405 | strlcpy(r->name, kr->name, sizeof(r->name)); |
| 1406 | r->total = kr->total; |
| 1407 | r->type = kr->type; |
| 1408 | r->flags = kr->flags; |
| 1409 | } |
| 1410 | |
| 1411 | static void |
| 1412 | krndsource_to_rndsource_est(krndsource_t *kr, rndsource_est_t *re) |
| 1413 | { |
| 1414 | |
| 1415 | memset(re, 0, sizeof(*re)); |
| 1416 | krndsource_to_rndsource(kr, &re->rt); |
| 1417 | re->dt_samples = kr->time_delta.insamples; |
| 1418 | re->dt_total = kr->time_delta.outbits; |
| 1419 | re->dv_samples = kr->value_delta.insamples; |
| 1420 | re->dv_total = kr->value_delta.outbits; |
| 1421 | } |
| 1422 | |
| 1423 | static void |
| 1424 | krs_setflags(krndsource_t *kr, uint32_t flags, uint32_t mask) |
| 1425 | { |
| 1426 | uint32_t oflags = kr->flags; |
| 1427 | |
| 1428 | kr->flags &= ~mask; |
| 1429 | kr->flags |= (flags & mask); |
| 1430 | |
| 1431 | if (oflags & RND_FLAG_HASENABLE && |
| 1432 | ((oflags & RND_FLAG_NO_COLLECT) != |
| 1433 | (flags & RND_FLAG_NO_COLLECT))) { |
| 1434 | kr->enable(kr, !(flags & RND_FLAG_NO_COLLECT)); |
| 1435 | } |
| 1436 | } |
| 1437 | |
| 1438 | int |
| 1439 | rnd_system_ioctl(struct file *fp, u_long cmd, void *addr) |
| 1440 | { |
| 1441 | krndsource_t *kr; |
| 1442 | rndstat_t *rst; |
| 1443 | rndstat_name_t *rstnm; |
| 1444 | rndstat_est_t *rset; |
| 1445 | rndstat_est_name_t *rsetnm; |
| 1446 | rndctl_t *rctl; |
| 1447 | rnddata_t *rnddata; |
| 1448 | uint32_t count, start; |
| 1449 | int ret = 0; |
| 1450 | int estimate_ok = 0, estimate = 0; |
| 1451 | |
| 1452 | switch (cmd) { |
| 1453 | case RNDGETENTCNT: |
| 1454 | break; |
| 1455 | |
| 1456 | case RNDGETPOOLSTAT: |
| 1457 | case RNDGETSRCNUM: |
| 1458 | case RNDGETSRCNAME: |
| 1459 | case RNDGETESTNUM: |
| 1460 | case RNDGETESTNAME: |
| 1461 | ret = kauth_authorize_device(curlwp->l_cred, |
| 1462 | KAUTH_DEVICE_RND_GETPRIV, NULL, NULL, NULL, NULL); |
| 1463 | if (ret) |
| 1464 | return ret; |
| 1465 | break; |
| 1466 | |
| 1467 | case RNDCTL: |
| 1468 | ret = kauth_authorize_device(curlwp->l_cred, |
| 1469 | KAUTH_DEVICE_RND_SETPRIV, NULL, NULL, NULL, NULL); |
| 1470 | if (ret) |
| 1471 | return ret; |
| 1472 | break; |
| 1473 | |
| 1474 | case RNDADDDATA: |
| 1475 | ret = kauth_authorize_device(curlwp->l_cred, |
| 1476 | KAUTH_DEVICE_RND_ADDDATA, NULL, NULL, NULL, NULL); |
| 1477 | if (ret) |
| 1478 | return ret; |
| 1479 | estimate_ok = !kauth_authorize_device(curlwp->l_cred, |
| 1480 | KAUTH_DEVICE_RND_ADDDATA_ESTIMATE, NULL, NULL, NULL, NULL); |
| 1481 | break; |
| 1482 | |
| 1483 | default: |
| 1484 | #ifdef COMPAT_50 |
| 1485 | return compat_50_rnd_ioctl(fp, cmd, addr); |
| 1486 | #else |
| 1487 | return ENOTTY; |
| 1488 | #endif |
| 1489 | } |
| 1490 | |
| 1491 | switch (cmd) { |
| 1492 | case RNDGETENTCNT: |
| 1493 | mutex_spin_enter(&rnd_global.lock); |
| 1494 | *(uint32_t *)addr = |
| 1495 | rndpool_get_entropy_count(&rnd_global.pool); |
| 1496 | mutex_spin_exit(&rnd_global.lock); |
| 1497 | break; |
| 1498 | |
| 1499 | case RNDGETPOOLSTAT: |
| 1500 | mutex_spin_enter(&rnd_global.lock); |
| 1501 | rndpool_get_stats(&rnd_global.pool, addr, |
| 1502 | sizeof(rndpoolstat_t)); |
| 1503 | mutex_spin_exit(&rnd_global.lock); |
| 1504 | break; |
| 1505 | |
| 1506 | case RNDGETSRCNUM: |
| 1507 | rst = (rndstat_t *)addr; |
| 1508 | |
| 1509 | if (rst->count == 0) |
| 1510 | break; |
| 1511 | |
| 1512 | if (rst->count > RND_MAXSTATCOUNT) |
| 1513 | return EINVAL; |
| 1514 | |
| 1515 | mutex_spin_enter(&rnd_global.lock); |
| 1516 | /* |
| 1517 | * Find the starting source by running through the |
| 1518 | * list of sources. |
| 1519 | */ |
| 1520 | kr = LIST_FIRST(&rnd_global.sources); |
| 1521 | start = rst->start; |
| 1522 | while (kr != NULL && start >= 1) { |
| 1523 | kr = LIST_NEXT(kr, list); |
| 1524 | start--; |
| 1525 | } |
| 1526 | |
| 1527 | /* |
| 1528 | * Return up to as many structures as the user asked |
| 1529 | * for. If we run out of sources, a count of zero |
| 1530 | * will be returned, without an error. |
| 1531 | */ |
| 1532 | for (count = 0; count < rst->count && kr != NULL; count++) { |
| 1533 | krndsource_to_rndsource(kr, &rst->source[count]); |
| 1534 | kr = LIST_NEXT(kr, list); |
| 1535 | } |
| 1536 | |
| 1537 | rst->count = count; |
| 1538 | |
| 1539 | mutex_spin_exit(&rnd_global.lock); |
| 1540 | break; |
| 1541 | |
| 1542 | case RNDGETESTNUM: |
| 1543 | rset = (rndstat_est_t *)addr; |
| 1544 | |
| 1545 | if (rset->count == 0) |
| 1546 | break; |
| 1547 | |
| 1548 | if (rset->count > RND_MAXSTATCOUNT) |
| 1549 | return EINVAL; |
| 1550 | |
| 1551 | mutex_spin_enter(&rnd_global.lock); |
| 1552 | /* |
| 1553 | * Find the starting source by running through the |
| 1554 | * list of sources. |
| 1555 | */ |
| 1556 | kr = LIST_FIRST(&rnd_global.sources); |
| 1557 | start = rset->start; |
| 1558 | while (kr != NULL && start > 0) { |
| 1559 | kr = LIST_NEXT(kr, list); |
| 1560 | start--; |
| 1561 | } |
| 1562 | |
| 1563 | /* |
| 1564 | * Return up to as many structures as the user asked |
| 1565 | * for. If we run out of sources, a count of zero |
| 1566 | * will be returned, without an error. |
| 1567 | */ |
| 1568 | for (count = 0; count < rset->count && kr != NULL; count++) { |
| 1569 | krndsource_to_rndsource_est(kr, &rset->source[count]); |
| 1570 | kr = LIST_NEXT(kr, list); |
| 1571 | } |
| 1572 | |
| 1573 | rset->count = count; |
| 1574 | |
| 1575 | mutex_spin_exit(&rnd_global.lock); |
| 1576 | break; |
| 1577 | |
| 1578 | case RNDGETSRCNAME: |
| 1579 | /* |
| 1580 | * Scan through the list, trying to find the name. |
| 1581 | */ |
| 1582 | mutex_spin_enter(&rnd_global.lock); |
| 1583 | rstnm = (rndstat_name_t *)addr; |
| 1584 | kr = LIST_FIRST(&rnd_global.sources); |
| 1585 | while (kr != NULL) { |
| 1586 | if (strncmp(kr->name, rstnm->name, |
| 1587 | MIN(sizeof(kr->name), |
| 1588 | sizeof(rstnm->name))) == 0) { |
| 1589 | krndsource_to_rndsource(kr, &rstnm->source); |
| 1590 | mutex_spin_exit(&rnd_global.lock); |
| 1591 | return 0; |
| 1592 | } |
| 1593 | kr = LIST_NEXT(kr, list); |
| 1594 | } |
| 1595 | mutex_spin_exit(&rnd_global.lock); |
| 1596 | |
| 1597 | ret = ENOENT; /* name not found */ |
| 1598 | |
| 1599 | break; |
| 1600 | |
| 1601 | case RNDGETESTNAME: |
| 1602 | /* |
| 1603 | * Scan through the list, trying to find the name. |
| 1604 | */ |
| 1605 | mutex_spin_enter(&rnd_global.lock); |
| 1606 | rsetnm = (rndstat_est_name_t *)addr; |
| 1607 | kr = LIST_FIRST(&rnd_global.sources); |
| 1608 | while (kr != NULL) { |
| 1609 | if (strncmp(kr->name, rsetnm->name, |
| 1610 | MIN(sizeof(kr->name), sizeof(rsetnm->name))) |
| 1611 | == 0) { |
| 1612 | krndsource_to_rndsource_est(kr, |
| 1613 | &rsetnm->source); |
| 1614 | mutex_spin_exit(&rnd_global.lock); |
| 1615 | return 0; |
| 1616 | } |
| 1617 | kr = LIST_NEXT(kr, list); |
| 1618 | } |
| 1619 | mutex_spin_exit(&rnd_global.lock); |
| 1620 | |
| 1621 | ret = ENOENT; /* name not found */ |
| 1622 | |
| 1623 | break; |
| 1624 | |
| 1625 | case RNDCTL: |
| 1626 | /* |
| 1627 | * Set flags to enable/disable entropy counting and/or |
| 1628 | * collection. |
| 1629 | */ |
| 1630 | mutex_spin_enter(&rnd_global.lock); |
| 1631 | rctl = (rndctl_t *)addr; |
| 1632 | kr = LIST_FIRST(&rnd_global.sources); |
| 1633 | |
| 1634 | /* |
| 1635 | * Flags set apply to all sources of this type. |
| 1636 | */ |
| 1637 | if (rctl->type != 0xff) { |
| 1638 | while (kr != NULL) { |
| 1639 | if (kr->type == rctl->type) { |
| 1640 | krs_setflags(kr, rctl->flags, |
| 1641 | rctl->mask); |
| 1642 | } |
| 1643 | kr = LIST_NEXT(kr, list); |
| 1644 | } |
| 1645 | mutex_spin_exit(&rnd_global.lock); |
| 1646 | return 0; |
| 1647 | } |
| 1648 | |
| 1649 | /* |
| 1650 | * scan through the list, trying to find the name |
| 1651 | */ |
| 1652 | while (kr != NULL) { |
| 1653 | if (strncmp(kr->name, rctl->name, |
| 1654 | MIN(sizeof(kr->name), sizeof(rctl->name))) |
| 1655 | == 0) { |
| 1656 | krs_setflags(kr, rctl->flags, rctl->mask); |
| 1657 | mutex_spin_exit(&rnd_global.lock); |
| 1658 | return 0; |
| 1659 | } |
| 1660 | kr = LIST_NEXT(kr, list); |
| 1661 | } |
| 1662 | |
| 1663 | mutex_spin_exit(&rnd_global.lock); |
| 1664 | ret = ENOENT; /* name not found */ |
| 1665 | |
| 1666 | break; |
| 1667 | |
| 1668 | case RNDADDDATA: |
| 1669 | /* |
| 1670 | * Don't seed twice if our bootloader has |
| 1671 | * seed loading support. |
| 1672 | */ |
| 1673 | if (!boot_rsp) { |
| 1674 | rnddata = (rnddata_t *)addr; |
| 1675 | |
| 1676 | if (rnddata->len > sizeof(rnddata->data)) |
| 1677 | return EINVAL; |
| 1678 | |
| 1679 | if (estimate_ok) { |
| 1680 | /* |
| 1681 | * Do not accept absurd entropy estimates, and |
| 1682 | * do not flood the pool with entropy such that |
| 1683 | * new samples are discarded henceforth. |
| 1684 | */ |
| 1685 | estimate = MIN((rnddata->len * NBBY) / 2, |
| 1686 | MIN(rnddata->entropy, RND_POOLBITS / 2)); |
| 1687 | } else { |
| 1688 | estimate = 0; |
| 1689 | } |
| 1690 | |
| 1691 | mutex_spin_enter(&rnd_global.lock); |
| 1692 | rndpool_add_data(&rnd_global.pool, rnddata->data, |
| 1693 | rnddata->len, estimate); |
| 1694 | rnd_entropy_added(); |
| 1695 | mutex_spin_exit(&rnd_global.lock); |
| 1696 | |
| 1697 | rndsinks_distribute(); |
| 1698 | } else { |
| 1699 | rnd_printf_verbose("rnd" |
| 1700 | ": already seeded by boot loader\n" ); |
| 1701 | } |
| 1702 | break; |
| 1703 | |
| 1704 | default: |
| 1705 | return ENOTTY; |
| 1706 | } |
| 1707 | |
| 1708 | return ret; |
| 1709 | } |
| 1710 | |