1/*
2 * Copyright 1995-2016 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 <openssl/crypto.h>
11
12/*
13 * Initialisation of global data should never happen via "RUN_ONCE" inside the
14 * FIPS module. Global data should instead always be associated with a specific
15 * OPENSSL_CTX object. In this way data will get cleaned up correctly when the
16 * module gets unloaded.
17 */
18#if !defined(FIPS_MODE) || defined(ALLOW_RUN_ONCE_IN_FIPS)
19/*
20 * DEFINE_RUN_ONCE: Define an initialiser function that should be run exactly
21 * once. It takes no arguments and returns and int result (1 for success or
22 * 0 for failure). Typical usage might be:
23 *
24 * DEFINE_RUN_ONCE(myinitfunc)
25 * {
26 * do_some_initialisation();
27 * if (init_is_successful())
28 * return 1;
29 *
30 * return 0;
31 * }
32 */
33# define DEFINE_RUN_ONCE(init) \
34 static int init(void); \
35 int init##_ossl_ret_ = 0; \
36 void init##_ossl_(void) \
37 { \
38 init##_ossl_ret_ = init(); \
39 } \
40 static int init(void)
41
42/*
43 * DECLARE_RUN_ONCE: Declare an initialiser function that should be run exactly
44 * once that has been defined in another file via DEFINE_RUN_ONCE().
45 */
46# define DECLARE_RUN_ONCE(init) \
47 extern int init##_ossl_ret_; \
48 void init##_ossl_(void);
49
50/*
51 * DEFINE_RUN_ONCE_STATIC: Define an initialiser function that should be run
52 * exactly once. This function will be declared as static within the file. It
53 * takes no arguments and returns and int result (1 for success or 0 for
54 * failure). Typical usage might be:
55 *
56 * DEFINE_RUN_ONCE_STATIC(myinitfunc)
57 * {
58 * do_some_initialisation();
59 * if (init_is_successful())
60 * return 1;
61 *
62 * return 0;
63 * }
64 */
65# define DEFINE_RUN_ONCE_STATIC(init) \
66 static int init(void); \
67 static int init##_ossl_ret_ = 0; \
68 static void init##_ossl_(void) \
69 { \
70 init##_ossl_ret_ = init(); \
71 } \
72 static int init(void)
73
74/*
75 * DEFINE_RUN_ONCE_STATIC_ALT: Define an alternative initialiser function. This
76 * function will be declared as static within the file. It takes no arguments
77 * and returns and int result (1 for success or 0 for failure). An alternative
78 * initialiser function is expected to be associated with a primary initialiser
79 * function defined via DEFINE_ONCE_STATIC where both functions use the same
80 * CRYPTO_ONCE object to synchronise. Where an alternative initialiser function
81 * is used only one of the primary or the alternative initialiser function will
82 * ever be called - and that function will be called exactly once. Definition
83 * of an alternative initialiser function MUST occur AFTER the definition of the
84 * primary initialiser function.
85 *
86 * Typical usage might be:
87 *
88 * DEFINE_RUN_ONCE_STATIC(myinitfunc)
89 * {
90 * do_some_initialisation();
91 * if (init_is_successful())
92 * return 1;
93 *
94 * return 0;
95 * }
96 *
97 * DEFINE_RUN_ONCE_STATIC_ALT(myaltinitfunc, myinitfunc)
98 * {
99 * do_some_alternative_initialisation();
100 * if (init_is_successful())
101 * return 1;
102 *
103 * return 0;
104 * }
105 */
106# define DEFINE_RUN_ONCE_STATIC_ALT(initalt, init) \
107 static int initalt(void); \
108 static void initalt##_ossl_(void) \
109 { \
110 init##_ossl_ret_ = initalt(); \
111 } \
112 static int initalt(void)
113
114/*
115 * RUN_ONCE - use CRYPTO_THREAD_run_once, and check if the init succeeded
116 * @once: pointer to static object of type CRYPTO_ONCE
117 * @init: function name that was previously given to DEFINE_RUN_ONCE,
118 * DEFINE_RUN_ONCE_STATIC or DECLARE_RUN_ONCE. This function
119 * must return 1 for success or 0 for failure.
120 *
121 * The return value is 1 on success (*) or 0 in case of error.
122 *
123 * (*) by convention, since the init function must return 1 on success.
124 */
125# define RUN_ONCE(once, init) \
126 (CRYPTO_THREAD_run_once(once, init##_ossl_) ? init##_ossl_ret_ : 0)
127
128/*
129 * RUN_ONCE_ALT - use CRYPTO_THREAD_run_once, to run an alternative initialiser
130 * function and check if that initialisation succeeded
131 * @once: pointer to static object of type CRYPTO_ONCE
132 * @initalt: alternative initialiser function name that was previously given to
133 * DEFINE_RUN_ONCE_STATIC_ALT. This function must return 1 for
134 * success or 0 for failure.
135 * @init: primary initialiser function name that was previously given to
136 * DEFINE_RUN_ONCE_STATIC. This function must return 1 for success or
137 * 0 for failure.
138 *
139 * The return value is 1 on success (*) or 0 in case of error.
140 *
141 * (*) by convention, since the init function must return 1 on success.
142 */
143# define RUN_ONCE_ALT(once, initalt, init) \
144 (CRYPTO_THREAD_run_once(once, initalt##_ossl_) ? init##_ossl_ret_ : 0)
145
146#endif /* FIPS_MODE */
147