1 /* 2 * Copyright 2001-2017 The OpenSSL Project Authors. All Rights Reserved. 3 * 4 * Licensed under the OpenSSL license (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 #include "e_os.h" 11 #include "eng_local.h" 12 13 /* 14 * Initialise a engine type for use (or up its functional reference count if 15 * it's already in use). This version is only used internally. 16 */ 17 int engine_unlocked_init(ENGINE *e) 18 { 19 int to_return = 1; 20 21 if ((e->funct_ref == 0) && e->init) 22 /* 23 * This is the first functional reference and the engine requires 24 * initialisation so we do it now. 25 */ 26 to_return = e->init(e); 27 if (to_return) { 28 /* 29 * OK, we return a functional reference which is also a structural 30 * reference. 31 */ 32 e->struct_ref++; 33 e->funct_ref++; 34 engine_ref_debug(e, 0, 1); 35 engine_ref_debug(e, 1, 1); 36 } 37 return to_return; 38 } 39 40 /* 41 * Free a functional reference to a engine type. This version is only used 42 * internally. 43 */ 44 int engine_unlocked_finish(ENGINE *e, int unlock_for_handlers) 45 { 46 int to_return = 1; 47 48 /* 49 * Reduce the functional reference count here so if it's the terminating 50 * case, we can release the lock safely and call the finish() handler 51 * without risk of a race. We get a race if we leave the count until 52 * after and something else is calling "finish" at the same time - 53 * there's a chance that both threads will together take the count from 2 54 * to 0 without either calling finish(). 55 */ 56 e->funct_ref--; 57 engine_ref_debug(e, 1, -1); 58 if ((e->funct_ref == 0) && e->finish) { 59 if (unlock_for_handlers) 60 CRYPTO_THREAD_unlock(global_engine_lock); 61 to_return = e->finish(e); 62 if (unlock_for_handlers) 63 CRYPTO_THREAD_write_lock(global_engine_lock); 64 if (!to_return) 65 return 0; 66 } 67 REF_ASSERT_ISNT(e->funct_ref < 0); 68 /* Release the structural reference too */ 69 if (!engine_free_util(e, 0)) { 70 ENGINEerr(ENGINE_F_ENGINE_UNLOCKED_FINISH, ENGINE_R_FINISH_FAILED); 71 return 0; 72 } 73 return to_return; 74 } 75 76 /* The API (locked) version of "init" */ 77 int ENGINE_init(ENGINE *e) 78 { 79 int ret; 80 if (e == NULL) { 81 ENGINEerr(ENGINE_F_ENGINE_INIT, ERR_R_PASSED_NULL_PARAMETER); 82 return 0; 83 } 84 if (!RUN_ONCE(&engine_lock_init, do_engine_lock_init)) { 85 ENGINEerr(ENGINE_F_ENGINE_INIT, ERR_R_MALLOC_FAILURE); 86 return 0; 87 } 88 CRYPTO_THREAD_write_lock(global_engine_lock); 89 ret = engine_unlocked_init(e); 90 CRYPTO_THREAD_unlock(global_engine_lock); 91 return ret; 92 } 93 94 /* The API (locked) version of "finish" */ 95 int ENGINE_finish(ENGINE *e) 96 { 97 int to_return = 1; 98 99 if (e == NULL) 100 return 1; 101 CRYPTO_THREAD_write_lock(global_engine_lock); 102 to_return = engine_unlocked_finish(e, 1); 103 CRYPTO_THREAD_unlock(global_engine_lock); 104 if (!to_return) { 105 ENGINEerr(ENGINE_F_ENGINE_FINISH, ENGINE_R_FINISH_FAILED); 106 return 0; 107 } 108 return to_return; 109 } 110