1 /*
2  *  Threading abstraction layer
3  *
4  *  Copyright The Mbed TLS Contributors
5  *  SPDX-License-Identifier: Apache-2.0
6  *
7  *  Licensed under the Apache License, Version 2.0 (the "License"); you may
8  *  not use this file except in compliance with the License.
9  *  You may obtain a copy of the License at
10  *
11  *  http://www.apache.org/licenses/LICENSE-2.0
12  *
13  *  Unless required by applicable law or agreed to in writing, software
14  *  distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
15  *  WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
16  *  See the License for the specific language governing permissions and
17  *  limitations under the License.
18  */
19 
20 /*
21  * Ensure gmtime_r is available even with -std=c99; must be defined before
22  * config.h, which pulls in glibc's features.h. Harmless on other platforms.
23  */
24 #if !defined(_POSIX_C_SOURCE)
25 #define _POSIX_C_SOURCE 200112L
26 #endif
27 
28 #include "common.h"
29 
30 #if defined(MBEDTLS_THREADING_C)
31 
32 #include "mbedtls/threading.h"
33 
34 #if defined(MBEDTLS_HAVE_TIME_DATE) && !defined(MBEDTLS_PLATFORM_GMTIME_R_ALT)
35 
36 #if !defined(_WIN32) && (defined(unix) || \
37     defined(__unix) || defined(__unix__) || (defined(__APPLE__) && \
38     defined(__MACH__)))
39 #include <unistd.h>
40 #endif /* !_WIN32 && (unix || __unix || __unix__ ||
41         * (__APPLE__ && __MACH__)) */
42 
43 #if !( ( defined(_POSIX_VERSION) && _POSIX_VERSION >= 200809L ) ||     \
44        ( defined(_POSIX_THREAD_SAFE_FUNCTIONS ) &&                     \
45          _POSIX_THREAD_SAFE_FUNCTIONS >= 200112L ) )
46 /*
47  * This is a convenience shorthand macro to avoid checking the long
48  * preprocessor conditions above. Ideally, we could expose this macro in
49  * platform_util.h and simply use it in platform_util.c, threading.c and
50  * threading.h. However, this macro is not part of the Mbed TLS public API, so
51  * we keep it private by only defining it in this file
52  */
53 
54 #if ! ( defined(_WIN32) && !defined(EFIX64) && !defined(EFI32) )
55 #define THREADING_USE_GMTIME
56 #endif /* ! ( defined(_WIN32) && !defined(EFIX64) && !defined(EFI32) ) */
57 
58 #endif /* !( ( defined(_POSIX_VERSION) && _POSIX_VERSION >= 200809L ) ||     \
59              ( defined(_POSIX_THREAD_SAFE_FUNCTIONS ) &&                     \
60                 _POSIX_THREAD_SAFE_FUNCTIONS >= 200112L ) ) */
61 
62 #endif /* MBEDTLS_HAVE_TIME_DATE && !MBEDTLS_PLATFORM_GMTIME_R_ALT */
63 
64 #if defined(MBEDTLS_THREADING_PTHREAD)
threading_mutex_init_pthread(mbedtls_threading_mutex_t * mutex)65 static void threading_mutex_init_pthread( mbedtls_threading_mutex_t *mutex )
66 {
67     if( mutex == NULL )
68         return;
69 
70     mutex->is_valid = pthread_mutex_init( &mutex->mutex, NULL ) == 0;
71 }
72 
threading_mutex_free_pthread(mbedtls_threading_mutex_t * mutex)73 static void threading_mutex_free_pthread( mbedtls_threading_mutex_t *mutex )
74 {
75     if( mutex == NULL || !mutex->is_valid )
76         return;
77 
78     (void) pthread_mutex_destroy( &mutex->mutex );
79     mutex->is_valid = 0;
80 }
81 
threading_mutex_lock_pthread(mbedtls_threading_mutex_t * mutex)82 static int threading_mutex_lock_pthread( mbedtls_threading_mutex_t *mutex )
83 {
84     if( mutex == NULL || ! mutex->is_valid )
85         return( MBEDTLS_ERR_THREADING_BAD_INPUT_DATA );
86 
87     if( pthread_mutex_lock( &mutex->mutex ) != 0 )
88         return( MBEDTLS_ERR_THREADING_MUTEX_ERROR );
89 
90     return( 0 );
91 }
92 
threading_mutex_unlock_pthread(mbedtls_threading_mutex_t * mutex)93 static int threading_mutex_unlock_pthread( mbedtls_threading_mutex_t *mutex )
94 {
95     if( mutex == NULL || ! mutex->is_valid )
96         return( MBEDTLS_ERR_THREADING_BAD_INPUT_DATA );
97 
98     if( pthread_mutex_unlock( &mutex->mutex ) != 0 )
99         return( MBEDTLS_ERR_THREADING_MUTEX_ERROR );
100 
101     return( 0 );
102 }
103 
104 void (*mbedtls_mutex_init)( mbedtls_threading_mutex_t * ) = threading_mutex_init_pthread;
105 void (*mbedtls_mutex_free)( mbedtls_threading_mutex_t * ) = threading_mutex_free_pthread;
106 int (*mbedtls_mutex_lock)( mbedtls_threading_mutex_t * ) = threading_mutex_lock_pthread;
107 int (*mbedtls_mutex_unlock)( mbedtls_threading_mutex_t * ) = threading_mutex_unlock_pthread;
108 
109 /*
110  * With phtreads we can statically initialize mutexes
111  */
112 #define MUTEX_INIT  = { PTHREAD_MUTEX_INITIALIZER, 1 }
113 
114 #endif /* MBEDTLS_THREADING_PTHREAD */
115 
116 #if defined(MBEDTLS_THREADING_ALT)
threading_mutex_fail(mbedtls_threading_mutex_t * mutex)117 static int threading_mutex_fail( mbedtls_threading_mutex_t *mutex )
118 {
119     ((void) mutex );
120     return( MBEDTLS_ERR_THREADING_BAD_INPUT_DATA );
121 }
threading_mutex_dummy(mbedtls_threading_mutex_t * mutex)122 static void threading_mutex_dummy( mbedtls_threading_mutex_t *mutex )
123 {
124     ((void) mutex );
125     return;
126 }
127 
128 void (*mbedtls_mutex_init)( mbedtls_threading_mutex_t * ) = threading_mutex_dummy;
129 void (*mbedtls_mutex_free)( mbedtls_threading_mutex_t * ) = threading_mutex_dummy;
130 int (*mbedtls_mutex_lock)( mbedtls_threading_mutex_t * ) = threading_mutex_fail;
131 int (*mbedtls_mutex_unlock)( mbedtls_threading_mutex_t * ) = threading_mutex_fail;
132 
133 /*
134  * Set functions pointers and initialize global mutexes
135  */
mbedtls_threading_set_alt(void (* mutex_init)(mbedtls_threading_mutex_t *),void (* mutex_free)(mbedtls_threading_mutex_t *),int (* mutex_lock)(mbedtls_threading_mutex_t *),int (* mutex_unlock)(mbedtls_threading_mutex_t *))136 void mbedtls_threading_set_alt( void (*mutex_init)( mbedtls_threading_mutex_t * ),
137                        void (*mutex_free)( mbedtls_threading_mutex_t * ),
138                        int (*mutex_lock)( mbedtls_threading_mutex_t * ),
139                        int (*mutex_unlock)( mbedtls_threading_mutex_t * ) )
140 {
141     mbedtls_mutex_init = mutex_init;
142     mbedtls_mutex_free = mutex_free;
143     mbedtls_mutex_lock = mutex_lock;
144     mbedtls_mutex_unlock = mutex_unlock;
145 
146 #if defined(MBEDTLS_FS_IO)
147     mbedtls_mutex_init( &mbedtls_threading_readdir_mutex );
148 #endif
149 #if defined(THREADING_USE_GMTIME)
150     mbedtls_mutex_init( &mbedtls_threading_gmtime_mutex );
151 #endif
152 }
153 
154 /*
155  * Free global mutexes
156  */
mbedtls_threading_free_alt(void)157 void mbedtls_threading_free_alt( void )
158 {
159 #if defined(MBEDTLS_FS_IO)
160     mbedtls_mutex_free( &mbedtls_threading_readdir_mutex );
161 #endif
162 #if defined(THREADING_USE_GMTIME)
163     mbedtls_mutex_free( &mbedtls_threading_gmtime_mutex );
164 #endif
165 }
166 #endif /* MBEDTLS_THREADING_ALT */
167 
168 /*
169  * Define global mutexes
170  */
171 #ifndef MUTEX_INIT
172 #define MUTEX_INIT
173 #endif
174 #if defined(MBEDTLS_FS_IO)
175 mbedtls_threading_mutex_t mbedtls_threading_readdir_mutex MUTEX_INIT;
176 #endif
177 #if defined(THREADING_USE_GMTIME)
178 mbedtls_threading_mutex_t mbedtls_threading_gmtime_mutex MUTEX_INIT;
179 #endif
180 
181 #endif /* MBEDTLS_THREADING_C */
182