1 /**
2  * \file threading.h
3  *
4  * \brief Threading abstraction layer
5  */
6 /*
7  *  Copyright The Mbed TLS Contributors
8  *  SPDX-License-Identifier: Apache-2.0
9  *
10  *  Licensed under the Apache License, Version 2.0 (the "License"); you may
11  *  not use this file except in compliance with the License.
12  *  You may obtain a copy of the License at
13  *
14  *  http://www.apache.org/licenses/LICENSE-2.0
15  *
16  *  Unless required by applicable law or agreed to in writing, software
17  *  distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
18  *  WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
19  *  See the License for the specific language governing permissions and
20  *  limitations under the License.
21  */
22 #ifndef MBEDTLS_THREADING_H
23 #define MBEDTLS_THREADING_H
24 
25 #if !defined(MBEDTLS_CONFIG_FILE)
26 #include "mbedtls/config.h"
27 #else
28 #include MBEDTLS_CONFIG_FILE
29 #endif
30 
31 #include <stdlib.h>
32 
33 #ifdef __cplusplus
34 extern "C" {
35 #endif
36 
37 /* MBEDTLS_ERR_THREADING_FEATURE_UNAVAILABLE is deprecated and should not be
38  * used. */
39 /** The selected feature is not available. */
40 #define MBEDTLS_ERR_THREADING_FEATURE_UNAVAILABLE         -0x001A
41 
42 /** Bad input parameters to function. */
43 #define MBEDTLS_ERR_THREADING_BAD_INPUT_DATA              -0x001C
44 /** Locking / unlocking / free failed with error code. */
45 #define MBEDTLS_ERR_THREADING_MUTEX_ERROR                 -0x001E
46 
47 #if defined(MBEDTLS_THREADING_PTHREAD)
48 #include <pthread.h>
49 typedef struct mbedtls_threading_mutex_t
50 {
51     pthread_mutex_t mutex;
52     /* is_valid is 0 after a failed init or a free, and nonzero after a
53      * successful init. This field is not considered part of the public
54      * API of Mbed TLS and may change without notice. */
55     char is_valid;
56 } mbedtls_threading_mutex_t;
57 #endif
58 
59 #if defined(MBEDTLS_THREADING_ALT)
60 /* You should define the mbedtls_threading_mutex_t type in your header */
61 #include "threading_alt.h"
62 
63 /**
64  * \brief           Set your alternate threading implementation function
65  *                  pointers and initialize global mutexes. If used, this
66  *                  function must be called once in the main thread before any
67  *                  other mbed TLS function is called, and
68  *                  mbedtls_threading_free_alt() must be called once in the main
69  *                  thread after all other mbed TLS functions.
70  *
71  * \note            mutex_init() and mutex_free() don't return a status code.
72  *                  If mutex_init() fails, it should leave its argument (the
73  *                  mutex) in a state such that mutex_lock() will fail when
74  *                  called with this argument.
75  *
76  * \param mutex_init    the init function implementation
77  * \param mutex_free    the free function implementation
78  * \param mutex_lock    the lock function implementation
79  * \param mutex_unlock  the unlock function implementation
80  */
81 void mbedtls_threading_set_alt( void (*mutex_init)( mbedtls_threading_mutex_t * ),
82                        void (*mutex_free)( mbedtls_threading_mutex_t * ),
83                        int (*mutex_lock)( mbedtls_threading_mutex_t * ),
84                        int (*mutex_unlock)( mbedtls_threading_mutex_t * ) );
85 
86 /**
87  * \brief               Free global mutexes.
88  */
89 void mbedtls_threading_free_alt( void );
90 #endif /* MBEDTLS_THREADING_ALT */
91 
92 #if defined(MBEDTLS_THREADING_C)
93 /*
94  * The function pointers for mutex_init, mutex_free, mutex_ and mutex_unlock
95  *
96  * All these functions are expected to work or the result will be undefined.
97  */
98 extern void (*mbedtls_mutex_init)( mbedtls_threading_mutex_t *mutex );
99 extern void (*mbedtls_mutex_free)( mbedtls_threading_mutex_t *mutex );
100 extern int (*mbedtls_mutex_lock)( mbedtls_threading_mutex_t *mutex );
101 extern int (*mbedtls_mutex_unlock)( mbedtls_threading_mutex_t *mutex );
102 
103 /*
104  * Global mutexes
105  */
106 #if defined(MBEDTLS_FS_IO)
107 extern mbedtls_threading_mutex_t mbedtls_threading_readdir_mutex;
108 #endif
109 
110 #if defined(MBEDTLS_HAVE_TIME_DATE) && !defined(MBEDTLS_PLATFORM_GMTIME_R_ALT)
111 /* This mutex may or may not be used in the default definition of
112  * mbedtls_platform_gmtime_r(), but in order to determine that,
113  * we need to check POSIX features, hence modify _POSIX_C_SOURCE.
114  * With the current approach, this declaration is orphaned, lacking
115  * an accompanying definition, in case mbedtls_platform_gmtime_r()
116  * doesn't need it, but that's not a problem. */
117 extern mbedtls_threading_mutex_t mbedtls_threading_gmtime_mutex;
118 #endif /* MBEDTLS_HAVE_TIME_DATE && !MBEDTLS_PLATFORM_GMTIME_R_ALT */
119 
120 #endif /* MBEDTLS_THREADING_C */
121 
122 #ifdef __cplusplus
123 }
124 #endif
125 
126 #endif /* threading.h */
127