1 | /* |
2 | * Copyright 2001-2017 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 | #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 | |