crypto/async/async.c

   1 /*
   2  * Copyright 2015-2018 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_locl.h"
  20
  21 #include <openssl/err.h>
  22 #include "internal/cryptlib_int.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, async_delete_thread_state))
  40         return NULL;
  41
  42     nctx = OPENSSL_malloc(sizeof(*nctx));
  43     if (nctx == NULL) {
  44         ASYNCerr(ASYNC_F_ASYNC_CTX_NEW, 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         ASYNCerr(ASYNC_F_ASYNC_JOB_NEW, 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     OPENSSL_free(job->funcargs);
 142     job->funcargs = NULL;
 143     sk_ASYNC_JOB_push(pool->jobs, job);
 144 }
 145
 146 void async_start_func(void)
 147 {
 148     ASYNC_JOB *job;
 149     async_ctx *ctx = async_get_ctx();
 150
 151     while (1) {
 152         /* Run the job */
 153         job = ctx->currjob;
 154         job->ret = job->func(job->funcargs);
 155
 156         /* Stop the job */
 157         job->status = ASYNC_JOB_STOPPING;
 158         if (!async_fibre_swapcontext(&job->fibrectx,
 159                                      &ctx->dispatcher, 1)) {
 160             /*
 161              * Should not happen. Getting here will close the thread...can't do
 162              * much about it
 163              */
 164             ASYNCerr(ASYNC_F_ASYNC_START_FUNC, ASYNC_R_FAILED_TO_SWAP_CONTEXT);
 165         }
 166     }
 167 }
 168
 169 int ASYNC_start_job(ASYNC_JOB **job, ASYNC_WAIT_CTX *wctx, int *ret,
 170                     int (*func)(void *), void *args, size_t size)
 171 {
 172     async_ctx *ctx;
 173
 174     if (!OPENSSL_init_crypto(OPENSSL_INIT_ASYNC, NULL))
 175         return ASYNC_ERR;
 176
 177     ctx = async_get_ctx();
 178     if (ctx == NULL)
 179         ctx = async_ctx_new();
 180     if (ctx == NULL)
 181         return ASYNC_ERR;
 182
 183     if (*job)
 184         ctx->currjob = *job;
 185
 186     for (;;) {
 187         if (ctx->currjob != NULL) {
 188             if (ctx->currjob->status == ASYNC_JOB_STOPPING) {
 189                 *ret = ctx->currjob->ret;
 190                 ctx->currjob->waitctx = NULL;
 191                 async_release_job(ctx->currjob);
 192                 ctx->currjob = NULL;
 193                 *job = NULL;
 194                 return ASYNC_FINISH;
 195             }
 196
 197             if (ctx->currjob->status == ASYNC_JOB_PAUSING) {
 198                 *job = ctx->currjob;
 199                 ctx->currjob->status = ASYNC_JOB_PAUSED;
 200                 ctx->currjob = NULL;
 201                 return ASYNC_PAUSE;
 202             }
 203
 204             if (ctx->currjob->status == ASYNC_JOB_PAUSED) {
 205                 ctx->currjob = *job;
 206                 /* Resume previous job */
 207                 if (!async_fibre_swapcontext(&ctx->dispatcher,
 208                         &ctx->currjob->fibrectx, 1)) {
 209                     ASYNCerr(ASYNC_F_ASYNC_START_JOB,
 210                              ASYNC_R_FAILED_TO_SWAP_CONTEXT);
 211                     goto err;
 212                 }
 213                 continue;
 214             }
 215
 216             /* Should not happen */
 217             ASYNCerr(ASYNC_F_ASYNC_START_JOB, ERR_R_INTERNAL_ERROR);
 218             async_release_job(ctx->currjob);
 219             ctx->currjob = NULL;
 220             *job = NULL;
 221             return ASYNC_ERR;
 222         }
 223
 224         /* Start a new job */
 225         if ((ctx->currjob = async_get_pool_job()) == NULL)
 226             return ASYNC_NO_JOBS;
 227
 228         if (args != NULL) {
 229             ctx->currjob->funcargs = OPENSSL_malloc(size);
 230             if (ctx->currjob->funcargs == NULL) {
 231                 ASYNCerr(ASYNC_F_ASYNC_START_JOB, ERR_R_MALLOC_FAILURE);
 232                 async_release_job(ctx->currjob);
 233                 ctx->currjob = NULL;
 234                 return ASYNC_ERR;
 235             }
 236             memcpy(ctx->currjob->funcargs, args, size);
 237         } else {
 238             ctx->currjob->funcargs = NULL;
 239         }
 240
 241         ctx->currjob->func = func;
 242         ctx->currjob->waitctx = wctx;
 243         if (!async_fibre_swapcontext(&ctx->dispatcher,
 244                 &ctx->currjob->fibrectx, 1)) {
 245             ASYNCerr(ASYNC_F_ASYNC_START_JOB, ASYNC_R_FAILED_TO_SWAP_CONTEXT);
 246             goto err;
 247         }
 248     }
 249
 250 err:
 251     async_release_job(ctx->currjob);
 252     ctx->currjob = NULL;
 253     *job = NULL;
 254     return ASYNC_ERR;
 255 }
 256
 257 int ASYNC_pause_job(void)
 258 {
 259     ASYNC_JOB *job;
 260     async_ctx *ctx = async_get_ctx();
 261
 262     if (ctx == NULL
 263             || ctx->currjob == NULL
 264             || ctx->blocked) {
 265         /*
 266          * Could be we've deliberately not been started within a job so this is
 267          * counted as success.
 268          */
 269         return 1;
 270     }
 271
 272     job = ctx->currjob;
 273     job->status = ASYNC_JOB_PAUSING;
 274
 275     if (!async_fibre_swapcontext(&job->fibrectx,
 276                                  &ctx->dispatcher, 1)) {
 277         ASYNCerr(ASYNC_F_ASYNC_PAUSE_JOB, ASYNC_R_FAILED_TO_SWAP_CONTEXT);
 278         return 0;
 279     }
 280     /* Reset counts of added and deleted fds */
 281     async_wait_ctx_reset_counts(job->waitctx);
 282
 283     return 1;
 284 }
 285
 286 static void async_empty_pool(async_pool *pool)
 287 {
 288     ASYNC_JOB *job;
 289
 290     if (!pool || !pool->jobs)
 291         return;
 292
 293     do {
 294         job = sk_ASYNC_JOB_pop(pool->jobs);
 295         async_job_free(job);
 296     } while (job);
 297 }
 298
 299 int async_init(void)
 300 {
 301     if (!CRYPTO_THREAD_init_local(&ctxkey, NULL))
 302         return 0;
 303
 304     if (!CRYPTO_THREAD_init_local(&poolkey, NULL)) {
 305         CRYPTO_THREAD_cleanup_local(&ctxkey);
 306         return 0;
 307     }
 308
 309     return 1;
 310 }
 311
 312 void async_deinit(void)
 313 {
 314     CRYPTO_THREAD_cleanup_local(&ctxkey);
 315     CRYPTO_THREAD_cleanup_local(&poolkey);
 316 }
 317
 318 int ASYNC_init_thread(size_t max_size, size_t init_size)
 319 {
 320     async_pool *pool;
 321     size_t curr_size = 0;
 322
 323     if (init_size > max_size) {
 324         ASYNCerr(ASYNC_F_ASYNC_INIT_THREAD, ASYNC_R_INVALID_POOL_SIZE);
 325         return 0;
 326     }
 327
 328     if (!OPENSSL_init_crypto(OPENSSL_INIT_ASYNC, NULL))
 329         return 0;
 330
 331     if (!ossl_init_thread_start(NULL, async_delete_thread_state))
 332         return 0;
 333
 334     pool = OPENSSL_zalloc(sizeof(*pool));
 335     if (pool == NULL) {
 336         ASYNCerr(ASYNC_F_ASYNC_INIT_THREAD, ERR_R_MALLOC_FAILURE);
 337         return 0;
 338     }
 339
 340     pool->jobs = sk_ASYNC_JOB_new_reserve(NULL, init_size);
 341     if (pool->jobs == NULL) {
 342         ASYNCerr(ASYNC_F_ASYNC_INIT_THREAD, ERR_R_MALLOC_FAILURE);
 343         OPENSSL_free(pool);
 344         return 0;
 345     }
 346
 347     pool->max_size = max_size;
 348
 349     /* Pre-create jobs as required */
 350     while (init_size--) {
 351         ASYNC_JOB *job;
 352         job = async_job_new();
 353         if (job == NULL || !async_fibre_makecontext(&job->fibrectx)) {
 354             /*
 355              * Not actually fatal because we already created the pool, just
 356              * skip creation of any more jobs
 357              */
 358             async_job_free(job);
 359             break;
 360         }
 361         job->funcargs = NULL;
 362         sk_ASYNC_JOB_push(pool->jobs, job); /* Cannot fail due to reserve */
 363         curr_size++;
 364     }
 365     pool->curr_size = curr_size;
 366     if (!CRYPTO_THREAD_set_local(&poolkey, pool)) {
 367         ASYNCerr(ASYNC_F_ASYNC_INIT_THREAD, ASYNC_R_FAILED_TO_SET_POOL);
 368         goto err;
 369     }
 370
 371     return 1;
 372 err:
 373     async_empty_pool(pool);
 374     sk_ASYNC_JOB_free(pool->jobs);
 375     OPENSSL_free(pool);
 376     return 0;
 377 }
 378
 379 /* TODO(3.0): arg ignored for now */
 380 static void async_delete_thread_state(void *arg)
 381 {
 382     async_pool *pool = (async_pool *)CRYPTO_THREAD_get_local(&poolkey);
 383
 384     if (pool != NULL) {
 385         async_empty_pool(pool);
 386         sk_ASYNC_JOB_free(pool->jobs);
 387         OPENSSL_free(pool);
 388         CRYPTO_THREAD_set_local(&poolkey, NULL);
 389     }
 390     async_local_cleanup();
 391     async_ctx_free();
 392 }
 393
 394 void ASYNC_cleanup_thread(void)
 395 {
 396     if (!OPENSSL_init_crypto(OPENSSL_INIT_ASYNC, NULL))
 397         return;
 398
 399     async_delete_thread_state(NULL);
 400 }
 401
 402 ASYNC_JOB *ASYNC_get_current_job(void)
 403 {
 404     async_ctx *ctx;
 405
 406     if (!OPENSSL_init_crypto(OPENSSL_INIT_ASYNC, NULL))
 407         return NULL;
 408
 409     ctx = async_get_ctx();
 410     if (ctx == NULL)
 411         return NULL;
 412
 413     return ctx->currjob;
 414 }
 415
 416 ASYNC_WAIT_CTX *ASYNC_get_wait_ctx(ASYNC_JOB *job)
 417 {
 418     return job->waitctx;
 419 }
 420
 421 void ASYNC_block_pause(void)
 422 {
 423     async_ctx *ctx;
 424
 425     if (!OPENSSL_init_crypto(OPENSSL_INIT_ASYNC, NULL))
 426         return;
 427
 428     ctx = async_get_ctx();
 429     if (ctx == NULL || ctx->currjob == NULL) {
 430         /*
 431          * We're not in a job anyway so ignore this
 432          */
 433         return;
 434     }
 435     ctx->blocked++;
 436 }
 437
 438 void ASYNC_unblock_pause(void)
 439 {
 440     async_ctx *ctx;
 441
 442     if (!OPENSSL_init_crypto(OPENSSL_INIT_ASYNC, NULL))
 443         return;
 444
 445     ctx = async_get_ctx();
 446     if (ctx == NULL || ctx->currjob == NULL) {
 447         /*
 448          * We're not in a job anyway so ignore this
 449          */
 450         return;
 451     }
 452     if (ctx->blocked > 0)
 453         ctx->blocked--;
 454 }