1 /*
2 * Copyright 2015-2021 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
async_ctx_new(void)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
async_get_ctx(void)61 async_ctx *async_get_ctx(void)
62 {
63 return (async_ctx *)CRYPTO_THREAD_get_local(&ctxkey);
64 }
65
async_ctx_free(void)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
async_job_new(void)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
async_job_free(ASYNC_JOB * job)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
async_get_pool_job(void)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
async_release_job(ASYNC_JOB * job)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
async_start_func(void)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
ASYNC_start_job(ASYNC_JOB ** job,ASYNC_WAIT_CTX * wctx,int * ret,int (* func)(void *),void * args,size_t size)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
ASYNC_pause_job(void)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
async_empty_pool(async_pool * pool)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
async_init(void)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 1;
344 }
345
async_deinit(void)346 void async_deinit(void)
347 {
348 CRYPTO_THREAD_cleanup_local(&ctxkey);
349 CRYPTO_THREAD_cleanup_local(&poolkey);
350 }
351
ASYNC_init_thread(size_t max_size,size_t init_size)352 int ASYNC_init_thread(size_t max_size, size_t init_size)
353 {
354 async_pool *pool;
355 size_t curr_size = 0;
356
357 if (init_size > max_size) {
358 ERR_raise(ERR_LIB_ASYNC, ASYNC_R_INVALID_POOL_SIZE);
359 return 0;
360 }
361
362 if (!OPENSSL_init_crypto(OPENSSL_INIT_ASYNC, NULL))
363 return 0;
364
365 if (!ossl_init_thread_start(NULL, NULL, async_delete_thread_state))
366 return 0;
367
368 pool = OPENSSL_zalloc(sizeof(*pool));
369 if (pool == NULL) {
370 ERR_raise(ERR_LIB_ASYNC, ERR_R_MALLOC_FAILURE);
371 return 0;
372 }
373
374 pool->jobs = sk_ASYNC_JOB_new_reserve(NULL, init_size);
375 if (pool->jobs == NULL) {
376 ERR_raise(ERR_LIB_ASYNC, ERR_R_MALLOC_FAILURE);
377 OPENSSL_free(pool);
378 return 0;
379 }
380
381 pool->max_size = max_size;
382
383 /* Pre-create jobs as required */
384 while (init_size--) {
385 ASYNC_JOB *job;
386 job = async_job_new();
387 if (job == NULL || !async_fibre_makecontext(&job->fibrectx)) {
388 /*
389 * Not actually fatal because we already created the pool, just
390 * skip creation of any more jobs
391 */
392 async_job_free(job);
393 break;
394 }
395 job->funcargs = NULL;
396 sk_ASYNC_JOB_push(pool->jobs, job); /* Cannot fail due to reserve */
397 curr_size++;
398 }
399 pool->curr_size = curr_size;
400 if (!CRYPTO_THREAD_set_local(&poolkey, pool)) {
401 ERR_raise(ERR_LIB_ASYNC, ASYNC_R_FAILED_TO_SET_POOL);
402 goto err;
403 }
404
405 return 1;
406 err:
407 async_empty_pool(pool);
408 sk_ASYNC_JOB_free(pool->jobs);
409 OPENSSL_free(pool);
410 return 0;
411 }
412
async_delete_thread_state(void * arg)413 static void async_delete_thread_state(void *arg)
414 {
415 async_pool *pool = (async_pool *)CRYPTO_THREAD_get_local(&poolkey);
416
417 if (pool != NULL) {
418 async_empty_pool(pool);
419 sk_ASYNC_JOB_free(pool->jobs);
420 OPENSSL_free(pool);
421 CRYPTO_THREAD_set_local(&poolkey, NULL);
422 }
423 async_local_cleanup();
424 async_ctx_free();
425 }
426
ASYNC_cleanup_thread(void)427 void ASYNC_cleanup_thread(void)
428 {
429 if (!OPENSSL_init_crypto(OPENSSL_INIT_ASYNC, NULL))
430 return;
431
432 async_delete_thread_state(NULL);
433 }
434
ASYNC_get_current_job(void)435 ASYNC_JOB *ASYNC_get_current_job(void)
436 {
437 async_ctx *ctx;
438
439 if (!OPENSSL_init_crypto(OPENSSL_INIT_ASYNC, NULL))
440 return NULL;
441
442 ctx = async_get_ctx();
443 if (ctx == NULL)
444 return NULL;
445
446 return ctx->currjob;
447 }
448
ASYNC_get_wait_ctx(ASYNC_JOB * job)449 ASYNC_WAIT_CTX *ASYNC_get_wait_ctx(ASYNC_JOB *job)
450 {
451 return job->waitctx;
452 }
453
ASYNC_block_pause(void)454 void ASYNC_block_pause(void)
455 {
456 async_ctx *ctx;
457
458 if (!OPENSSL_init_crypto(OPENSSL_INIT_ASYNC, NULL))
459 return;
460
461 ctx = async_get_ctx();
462 if (ctx == NULL || ctx->currjob == NULL) {
463 /*
464 * We're not in a job anyway so ignore this
465 */
466 return;
467 }
468 ctx->blocked++;
469 }
470
ASYNC_unblock_pause(void)471 void ASYNC_unblock_pause(void)
472 {
473 async_ctx *ctx;
474
475 if (!OPENSSL_init_crypto(OPENSSL_INIT_ASYNC, NULL))
476 return;
477
478 ctx = async_get_ctx();
479 if (ctx == NULL || ctx->currjob == NULL) {
480 /*
481 * We're not in a job anyway so ignore this
482 */
483 return;
484 }
485 if (ctx->blocked > 0)
486 ctx->blocked--;
487 }
488