crypto/async/async.c

   1 /*
   2  * Copyright 2015-2022 The OpenSSL Project Authors. All Rights Reserved.
   3  *
   4  * Licensed under the Apache License 2.0 (the "License").  You may not use
   5  * this file except in compliance with the License.  You can obtain a copy
   6  * in the file LICENSE in the source distribution or at
   7  * https://www.openssl.org/source/license.html
   8  */
   9
  10 /*
  11  * Without this we start getting longjmp crashes because it thinks we're jumping
  12  * up the stack when in fact we are jumping to an entirely different stack. The
  13  * cost of this is not having certain buffer overrun/underrun checks etc for
  14  * this source file :-(
  15  */
  16 #undef _FORTIFY_SOURCE
  17
  18 /* This must be the first #include file */
  19 #include "async_local.h"
  20
  21 #include <openssl/err.h>
  22 #include "crypto/cryptlib.h"
  23 #include <string.h>
  24
  25 #define ASYNC_JOB_RUNNING   0
  26 #define ASYNC_JOB_PAUSING   1
  27 #define ASYNC_JOB_PAUSED    2
  28 #define ASYNC_JOB_STOPPING  3
  29
  30 static CRYPTO_THREAD_LOCAL ctxkey;
  31 static CRYPTO_THREAD_LOCAL poolkey;
  32
  33 static void async_delete_thread_state(void *arg);
  34
  35 static async_ctx *async_ctx_new(void)
  36 {
  37     async_ctx *nctx;
  38
  39     if (!ossl_init_thread_start(NULL, NULL, async_delete_thread_state))
  40         return NULL;
  41
  42     nctx = OPENSSL_malloc(sizeof(*nctx));
  43     if (nctx == NULL) {
  44         ERR_raise(ERR_LIB_ASYNC, ERR_R_MALLOC_FAILURE);
  45         goto err;
  46     }
  47
  48     async_fibre_init_dispatcher(&nctx->dispatcher);
  49     nctx->currjob = NULL;
  50     nctx->blocked = 0;
  51     if (!CRYPTO_THREAD_set_local(&ctxkey, nctx))
  52         goto err;
  53
  54     return nctx;
  55 err:
  56     OPENSSL_free(nctx);
  57
  58     return NULL;
  59 }
  60
  61 async_ctx *async_get_ctx(void)
  62 {
  63     return (async_ctx *)CRYPTO_THREAD_get_local(&ctxkey);
  64 }
  65
  66 static int async_ctx_free(void)
  67 {
  68     async_ctx *ctx;
  69
  70     ctx = async_get_ctx();
  71
  72     if (!CRYPTO_THREAD_set_local(&ctxkey, NULL))
  73         return 0;
  74
  75     OPENSSL_free(ctx);
  76
  77     return 1;
  78 }
  79
  80 static ASYNC_JOB *async_job_new(void)
  81 {
  82     ASYNC_JOB *job = NULL;
  83
  84     job = OPENSSL_zalloc(sizeof(*job));
  85     if (job == NULL) {
  86         ERR_raise(ERR_LIB_ASYNC, ERR_R_MALLOC_FAILURE);
  87         return NULL;
  88     }
  89
  90     job->status = ASYNC_JOB_RUNNING;
  91
  92     return job;
  93 }
  94
  95 static void async_job_free(ASYNC_JOB *job)
  96 {
  97     if (job != NULL) {
  98         OPENSSL_free(job->funcargs);
  99         async_fibre_free(&job->fibrectx);
 100         OPENSSL_free(job);
 101     }
 102 }
 103
 104 static ASYNC_JOB *async_get_pool_job(void) {
 105     ASYNC_JOB *job;
 106     async_pool *pool;
 107
 108     pool = (async_pool *)CRYPTO_THREAD_get_local(&poolkey);
 109     if (pool == NULL) {
 110         /*
 111          * Pool has not been initialised, so init with the defaults, i.e.
 112          * no max size and no pre-created jobs
 113          */
 114         if (ASYNC_init_thread(0, 0) == 0)
 115             return NULL;
 116         pool = (async_pool *)CRYPTO_THREAD_get_local(&poolkey);
 117     }
 118
 119     job = sk_ASYNC_JOB_pop(pool->jobs);
 120     if (job == NULL) {
 121         /* Pool is empty */
 122         if ((pool->max_size != 0) && (pool->curr_size >= pool->max_size))
 123             return NULL;
 124
 125         job = async_job_new();
 126         if (job != NULL) {
 127             if (! async_fibre_makecontext(&job->fibrectx)) {
 128                 async_job_free(job);
 129                 return NULL;
 130             }
 131             pool->curr_size++;
 132         }
 133     }
 134     return job;
 135 }
 136
 137 static void async_release_job(ASYNC_JOB *job) {
 138     async_pool *pool;
 139
 140     pool = (async_pool *)CRYPTO_THREAD_get_local(&poolkey);
 141     if (pool == NULL) {
 142         ERR_raise(ERR_LIB_ASYNC, ERR_R_INTERNAL_ERROR);
 143         return;
 144     }
 145     OPENSSL_free(job->funcargs);
 146     job->funcargs = NULL;
 147     sk_ASYNC_JOB_push(pool->jobs, job);
 148 }
 149
 150 void async_start_func(void)
 151 {
 152     ASYNC_JOB *job;
 153     async_ctx *ctx = async_get_ctx();
 154
 155     if (ctx == NULL) {
 156         ERR_raise(ERR_LIB_ASYNC, ERR_R_INTERNAL_ERROR);
 157         return;
 158     }
 159     while (1) {
 160         /* Run the job */
 161         job = ctx->currjob;
 162         job->ret = job->func(job->funcargs);
 163
 164         /* Stop the job */
 165         job->status = ASYNC_JOB_STOPPING;
 166         if (!async_fibre_swapcontext(&job->fibrectx,
 167                                      &ctx->dispatcher, 1)) {
 168             /*
 169              * Should not happen. Getting here will close the thread...can't do
 170              * much about it
 171              */
 172             ERR_raise(ERR_LIB_ASYNC, ASYNC_R_FAILED_TO_SWAP_CONTEXT);
 173         }
 174     }
 175 }
 176
 177 int ASYNC_start_job(ASYNC_JOB **job, ASYNC_WAIT_CTX *wctx, int *ret,
 178                     int (*func)(void *), void *args, size_t size)
 179 {
 180     async_ctx *ctx;
 181     OSSL_LIB_CTX *libctx;
 182
 183     if (!OPENSSL_init_crypto(OPENSSL_INIT_ASYNC, NULL))
 184         return ASYNC_ERR;
 185
 186     ctx = async_get_ctx();
 187     if (ctx == NULL)
 188         ctx = async_ctx_new();
 189     if (ctx == NULL)
 190         return ASYNC_ERR;
 191
 192     if (*job != NULL)
 193         ctx->currjob = *job;
 194
 195     for (;;) {
 196         if (ctx->currjob != NULL) {
 197             if (ctx->currjob->status == ASYNC_JOB_STOPPING) {
 198                 *ret = ctx->currjob->ret;
 199                 ctx->currjob->waitctx = NULL;
 200                 async_release_job(ctx->currjob);
 201                 ctx->currjob = NULL;
 202                 *job = NULL;
 203                 return ASYNC_FINISH;
 204             }
 205
 206             if (ctx->currjob->status == ASYNC_JOB_PAUSING) {
 207                 *job = ctx->currjob;
 208                 ctx->currjob->status = ASYNC_JOB_PAUSED;
 209                 ctx->currjob = NULL;
 210                 return ASYNC_PAUSE;
 211             }
 212
 213             if (ctx->currjob->status == ASYNC_JOB_PAUSED) {
 214                 if (*job == NULL)
 215                     return ASYNC_ERR;
 216                 ctx->currjob = *job;
 217
 218                 /*
 219                  * Restore the default libctx to what it was the last time the
 220                  * fibre ran
 221                  */
 222                 libctx = OSSL_LIB_CTX_set0_default(ctx->currjob->libctx);
 223                 if (libctx == NULL) {
 224                     /* Failed to set the default context */
 225                     ERR_raise(ERR_LIB_ASYNC, ERR_R_INTERNAL_ERROR);
 226                     goto err;
 227                 }
 228                 /* Resume previous job */
 229                 if (!async_fibre_swapcontext(&ctx->dispatcher,
 230                         &ctx->currjob->fibrectx, 1)) {
 231                     ctx->currjob->libctx = OSSL_LIB_CTX_set0_default(libctx);
 232                     ERR_raise(ERR_LIB_ASYNC, ASYNC_R_FAILED_TO_SWAP_CONTEXT);
 233                     goto err;
 234                 }
 235                 /*
 236                  * In case the fibre changed the default libctx we set it back
 237                  * again to what it was originally, and remember what it had
 238                  * been changed to.
 239                  */
 240                 ctx->currjob->libctx = OSSL_LIB_CTX_set0_default(libctx);
 241                 continue;
 242             }
 243
 244             /* Should not happen */
 245             ERR_raise(ERR_LIB_ASYNC, ERR_R_INTERNAL_ERROR);
 246             async_release_job(ctx->currjob);
 247             ctx->currjob = NULL;
 248             *job = NULL;
 249             return ASYNC_ERR;
 250         }
 251
 252         /* Start a new job */
 253         if ((ctx->currjob = async_get_pool_job()) == NULL)
 254             return ASYNC_NO_JOBS;
 255
 256         if (args != NULL) {
 257             ctx->currjob->funcargs = OPENSSL_malloc(size);
 258             if (ctx->currjob->funcargs == NULL) {
 259                 ERR_raise(ERR_LIB_ASYNC, ERR_R_MALLOC_FAILURE);
 260                 async_release_job(ctx->currjob);
 261                 ctx->currjob = NULL;
 262                 return ASYNC_ERR;
 263             }
 264             memcpy(ctx->currjob->funcargs, args, size);
 265         } else {
 266             ctx->currjob->funcargs = NULL;
 267         }
 268
 269         ctx->currjob->func = func;
 270         ctx->currjob->waitctx = wctx;
 271         libctx = ossl_lib_ctx_get_concrete(NULL);
 272         if (!async_fibre_swapcontext(&ctx->dispatcher,
 273                 &ctx->currjob->fibrectx, 1)) {
 274             ERR_raise(ERR_LIB_ASYNC, ASYNC_R_FAILED_TO_SWAP_CONTEXT);
 275             goto err;
 276         }
 277         /*
 278          * In case the fibre changed the default libctx we set it back again
 279          * to what it was, and remember what it had been changed to.
 280          */
 281         ctx->currjob->libctx = OSSL_LIB_CTX_set0_default(libctx);
 282     }
 283
 284 err:
 285     async_release_job(ctx->currjob);
 286     ctx->currjob = NULL;
 287     *job = NULL;
 288     return ASYNC_ERR;
 289 }
 290
 291 int ASYNC_pause_job(void)
 292 {
 293     ASYNC_JOB *job;
 294     async_ctx *ctx = async_get_ctx();
 295
 296     if (ctx == NULL
 297             || ctx->currjob == NULL
 298             || ctx->blocked) {
 299         /*
 300          * Could be we've deliberately not been started within a job so this is
 301          * counted as success.
 302          */
 303         return 1;
 304     }
 305
 306     job = ctx->currjob;
 307     job->status = ASYNC_JOB_PAUSING;
 308
 309     if (!async_fibre_swapcontext(&job->fibrectx,
 310                                  &ctx->dispatcher, 1)) {
 311         ERR_raise(ERR_LIB_ASYNC, ASYNC_R_FAILED_TO_SWAP_CONTEXT);
 312         return 0;
 313     }
 314     /* Reset counts of added and deleted fds */
 315     async_wait_ctx_reset_counts(job->waitctx);
 316
 317     return 1;
 318 }
 319
 320 static void async_empty_pool(async_pool *pool)
 321 {
 322     ASYNC_JOB *job;
 323
 324     if (pool == NULL || pool->jobs == NULL)
 325         return;
 326
 327     do {
 328         job = sk_ASYNC_JOB_pop(pool->jobs);
 329         async_job_free(job);
 330     } while (job);
 331 }
 332
 333 int async_init(void)
 334 {
 335     if (!CRYPTO_THREAD_init_local(&ctxkey, NULL))
 336         return 0;
 337
 338     if (!CRYPTO_THREAD_init_local(&poolkey, NULL)) {
 339         CRYPTO_THREAD_cleanup_local(&ctxkey);
 340         return 0;
 341     }
 342
 343     return async_local_init();
 344 }
 345
 346 void async_deinit(void)
 347 {
 348     CRYPTO_THREAD_cleanup_local(&ctxkey);
 349     CRYPTO_THREAD_cleanup_local(&poolkey);
 350     async_local_deinit();
 351 }
 352
 353 int ASYNC_init_thread(size_t max_size, size_t init_size)
 354 {
 355     async_pool *pool;
 356     size_t curr_size = 0;
 357
 358     if (init_size > max_size) {
 359         ERR_raise(ERR_LIB_ASYNC, ASYNC_R_INVALID_POOL_SIZE);
 360         return 0;
 361     }
 362
 363     if (!OPENSSL_init_crypto(OPENSSL_INIT_ASYNC, NULL))
 364         return 0;
 365
 366     if (!ossl_init_thread_start(NULL, NULL, async_delete_thread_state))
 367         return 0;
 368
 369     pool = OPENSSL_zalloc(sizeof(*pool));
 370     if (pool == NULL) {
 371         ERR_raise(ERR_LIB_ASYNC, ERR_R_MALLOC_FAILURE);
 372         return 0;
 373     }
 374
 375     pool->jobs = sk_ASYNC_JOB_new_reserve(NULL, init_size);
 376     if (pool->jobs == NULL) {
 377         ERR_raise(ERR_LIB_ASYNC, ERR_R_MALLOC_FAILURE);
 378         OPENSSL_free(pool);
 379         return 0;
 380     }
 381
 382     pool->max_size = max_size;
 383
 384     /* Pre-create jobs as required */
 385     while (init_size--) {
 386         ASYNC_JOB *job;
 387         job = async_job_new();
 388         if (job == NULL || !async_fibre_makecontext(&job->fibrectx)) {
 389             /*
 390              * Not actually fatal because we already created the pool, just
 391              * skip creation of any more jobs
 392              */
 393             async_job_free(job);
 394             break;
 395         }
 396         job->funcargs = NULL;
 397         sk_ASYNC_JOB_push(pool->jobs, job); /* Cannot fail due to reserve */
 398         curr_size++;
 399     }
 400     pool->curr_size = curr_size;
 401     if (!CRYPTO_THREAD_set_local(&poolkey, pool)) {
 402         ERR_raise(ERR_LIB_ASYNC, ASYNC_R_FAILED_TO_SET_POOL);
 403         goto err;
 404     }
 405
 406     return 1;
 407 err:
 408     async_empty_pool(pool);
 409     sk_ASYNC_JOB_free(pool->jobs);
 410     OPENSSL_free(pool);
 411     return 0;
 412 }
 413
 414 static void async_delete_thread_state(void *arg)
 415 {
 416     async_pool *pool = (async_pool *)CRYPTO_THREAD_get_local(&poolkey);
 417
 418     if (pool != NULL) {
 419         async_empty_pool(pool);
 420         sk_ASYNC_JOB_free(pool->jobs);
 421         OPENSSL_free(pool);
 422         CRYPTO_THREAD_set_local(&poolkey, NULL);
 423     }
 424     async_local_cleanup();
 425     async_ctx_free();
 426 }
 427
 428 void ASYNC_cleanup_thread(void)
 429 {
 430     if (!OPENSSL_init_crypto(OPENSSL_INIT_ASYNC, NULL))
 431         return;
 432
 433     async_delete_thread_state(NULL);
 434 }
 435
 436 ASYNC_JOB *ASYNC_get_current_job(void)
 437 {
 438     async_ctx *ctx;
 439
 440     if (!OPENSSL_init_crypto(OPENSSL_INIT_ASYNC, NULL))
 441         return NULL;
 442
 443     ctx = async_get_ctx();
 444     if (ctx == NULL)
 445         return NULL;
 446
 447     return ctx->currjob;
 448 }
 449
 450 ASYNC_WAIT_CTX *ASYNC_get_wait_ctx(ASYNC_JOB *job)
 451 {
 452     return job->waitctx;
 453 }
 454
 455 void ASYNC_block_pause(void)
 456 {
 457     async_ctx *ctx;
 458
 459     if (!OPENSSL_init_crypto(OPENSSL_INIT_ASYNC, NULL))
 460         return;
 461
 462     ctx = async_get_ctx();
 463     if (ctx == NULL || ctx->currjob == NULL) {
 464         /*
 465          * We're not in a job anyway so ignore this
 466          */
 467         return;
 468     }
 469     ctx->blocked++;
 470 }
 471
 472 void ASYNC_unblock_pause(void)
 473 {
 474     async_ctx *ctx;
 475
 476     if (!OPENSSL_init_crypto(OPENSSL_INIT_ASYNC, NULL))
 477         return;
 478
 479     ctx = async_get_ctx();
 480     if (ctx == NULL || ctx->currjob == NULL) {
 481         /*
 482          * We're not in a job anyway so ignore this
 483          */
 484         return;
 485     }
 486     if (ctx->blocked > 0)
 487         ctx->blocked--;
 488 }