1 /**
2  * \file memory_buffer_alloc.h
3  *
4  * \brief Buffer-based memory allocator
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_MEMORY_BUFFER_ALLOC_H
23 #define MBEDTLS_MEMORY_BUFFER_ALLOC_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 <stddef.h>
32 
33 /**
34  * \name SECTION: Module settings
35  *
36  * The configuration options you can set for this module are in this section.
37  * Either change them in config.h or define them on the compiler command line.
38  * \{
39  */
40 
41 #if !defined(MBEDTLS_MEMORY_ALIGN_MULTIPLE)
42 #define MBEDTLS_MEMORY_ALIGN_MULTIPLE       4 /**< Align on multiples of this value */
43 #endif
44 
45 /* \} name SECTION: Module settings */
46 
47 #define MBEDTLS_MEMORY_VERIFY_NONE         0
48 #define MBEDTLS_MEMORY_VERIFY_ALLOC        (1 << 0)
49 #define MBEDTLS_MEMORY_VERIFY_FREE         (1 << 1)
50 #define MBEDTLS_MEMORY_VERIFY_ALWAYS       (MBEDTLS_MEMORY_VERIFY_ALLOC | MBEDTLS_MEMORY_VERIFY_FREE)
51 
52 #ifdef __cplusplus
53 extern "C" {
54 #endif
55 
56 /**
57  * \brief   Initialize use of stack-based memory allocator.
58  *          The stack-based allocator does memory management inside the
59  *          presented buffer and does not call calloc() and free().
60  *          It sets the global mbedtls_calloc() and mbedtls_free() pointers
61  *          to its own functions.
62  *          (Provided mbedtls_calloc() and mbedtls_free() are thread-safe if
63  *           MBEDTLS_THREADING_C is defined)
64  *
65  * \note    This code is not optimized and provides a straight-forward
66  *          implementation of a stack-based memory allocator.
67  *
68  * \param buf   buffer to use as heap
69  * \param len   size of the buffer
70  */
71 void mbedtls_memory_buffer_alloc_init( unsigned char *buf, size_t len );
72 
73 /**
74  * \brief   Free the mutex for thread-safety and clear remaining memory
75  */
76 void mbedtls_memory_buffer_alloc_free( void );
77 
78 /**
79  * \brief   Determine when the allocator should automatically verify the state
80  *          of the entire chain of headers / meta-data.
81  *          (Default: MBEDTLS_MEMORY_VERIFY_NONE)
82  *
83  * \param verify    One of MBEDTLS_MEMORY_VERIFY_NONE, MBEDTLS_MEMORY_VERIFY_ALLOC,
84  *                  MBEDTLS_MEMORY_VERIFY_FREE or MBEDTLS_MEMORY_VERIFY_ALWAYS
85  */
86 void mbedtls_memory_buffer_set_verify( int verify );
87 
88 #if defined(MBEDTLS_MEMORY_DEBUG)
89 /**
90  * \brief   Print out the status of the allocated memory (primarily for use
91  *          after a program should have de-allocated all memory)
92  *          Prints out a list of 'still allocated' blocks and their stack
93  *          trace if MBEDTLS_MEMORY_BACKTRACE is defined.
94  */
95 void mbedtls_memory_buffer_alloc_status( void );
96 
97 /**
98  * \brief   Get the peak heap usage so far
99  *
100  * \param max_used      Peak number of bytes in use or committed. This
101  *                      includes bytes in allocated blocks too small to split
102  *                      into smaller blocks but larger than the requested size.
103  * \param max_blocks    Peak number of blocks in use, including free and used
104  */
105 void mbedtls_memory_buffer_alloc_max_get( size_t *max_used, size_t *max_blocks );
106 
107 /**
108  * \brief   Reset peak statistics
109  */
110 void mbedtls_memory_buffer_alloc_max_reset( void );
111 
112 /**
113  * \brief   Get the current heap usage
114  *
115  * \param cur_used      Current number of bytes in use or committed. This
116  *                      includes bytes in allocated blocks too small to split
117  *                      into smaller blocks but larger than the requested size.
118  * \param cur_blocks    Current number of blocks in use, including free and used
119  */
120 void mbedtls_memory_buffer_alloc_cur_get( size_t *cur_used, size_t *cur_blocks );
121 #endif /* MBEDTLS_MEMORY_DEBUG */
122 
123 /**
124  * \brief   Verifies that all headers in the memory buffer are correct
125  *          and contain sane values. Helps debug buffer-overflow errors.
126  *
127  *          Prints out first failure if MBEDTLS_MEMORY_DEBUG is defined.
128  *          Prints out full header information if MBEDTLS_MEMORY_DEBUG
129  *          is defined. (Includes stack trace information for each block if
130  *          MBEDTLS_MEMORY_BACKTRACE is defined as well).
131  *
132  * \return             0 if verified, 1 otherwise
133  */
134 int mbedtls_memory_buffer_alloc_verify( void );
135 
136 #if defined(MBEDTLS_SELF_TEST)
137 /**
138  * \brief          Checkup routine
139  *
140  * \return         0 if successful, or 1 if a test failed
141  */
142 int mbedtls_memory_buffer_alloc_self_test( int verbose );
143 #endif
144 
145 #ifdef __cplusplus
146 }
147 #endif
148 
149 #endif /* memory_buffer_alloc.h */
150