File memory_buffer_alloc.h

Buffer-based memory allocator.

SECTION: Module settings

The configuration options you can set for this module are in this section. Either change them in mbedtls_config.h or define them on the compiler command line.

MBEDTLS_MEMORY_ALIGN_MULTIPLE

Align on multiples of this value

Defines

MBEDTLS_MEMORY_VERIFY_NONE
MBEDTLS_MEMORY_VERIFY_ALLOC
MBEDTLS_MEMORY_VERIFY_FREE
MBEDTLS_MEMORY_VERIFY_ALWAYS

Functions

void mbedtls_memory_buffer_alloc_init(unsigned char *buf, size_t len)

Initialize use of stack-based memory allocator. The stack-based allocator does memory management inside the presented buffer and does not call calloc() and free(). It sets the global mbedtls_calloc() and mbedtls_free() pointers to its own functions. (Provided mbedtls_calloc() and mbedtls_free() are thread-safe if MBEDTLS_THREADING_C is defined)

Note

This code is not optimized and provides a straight-forward implementation of a stack-based memory allocator.

Parameters

  • buf – buffer to use as heap

  • len – size of the buffer

void mbedtls_memory_buffer_alloc_free(void)

Free the mutex for thread-safety and clear remaining memory.

void mbedtls_memory_buffer_set_verify(int verify)

Determine when the allocator should automatically verify the state of the entire chain of headers / meta-data. (Default: MBEDTLS_MEMORY_VERIFY_NONE)

Parameters

verify – One of MBEDTLS_MEMORY_VERIFY_NONE, MBEDTLS_MEMORY_VERIFY_ALLOC, MBEDTLS_MEMORY_VERIFY_FREE or MBEDTLS_MEMORY_VERIFY_ALWAYS

void mbedtls_memory_buffer_alloc_status(void)

Print out the status of the allocated memory (primarily for use after a program should have de-allocated all memory) Prints out a list of ‘still allocated’ blocks and their stack trace if MBEDTLS_MEMORY_BACKTRACE is defined.

void mbedtls_memory_buffer_alloc_count_get(size_t *alloc_count, size_t *free_count)

Get the number of alloc/free so far.

Parameters

  • alloc_count – Number of allocations.

  • free_count – Number of frees.

void mbedtls_memory_buffer_alloc_max_get(size_t *max_used, size_t *max_blocks)

Get the peak heap usage so far.

Parameters

  • max_used – Peak number of bytes in use or committed. This includes bytes in allocated blocks too small to split into smaller blocks but larger than the requested size.

  • max_blocks – Peak number of blocks in use, including free and used

void mbedtls_memory_buffer_alloc_max_reset(void)

Reset peak statistics.

void mbedtls_memory_buffer_alloc_cur_get(size_t *cur_used, size_t *cur_blocks)

Get the current heap usage.

Parameters

  • cur_used – Current number of bytes in use or committed. This includes bytes in allocated blocks too small to split into smaller blocks but larger than the requested size.

  • cur_blocks – Current number of blocks in use, including free and used

int mbedtls_memory_buffer_alloc_verify(void)

Verifies that all headers in the memory buffer are correct and contain sane values. Helps debug buffer-overflow errors.

Prints out first failure if MBEDTLS_MEMORY_DEBUG is defined. Prints out full header information if MBEDTLS_MEMORY_DEBUG is defined. (Includes stack trace information for each block if MBEDTLS_MEMORY_BACKTRACE is defined as well).

Returns

0 if verified, 1 otherwise

int mbedtls_memory_buffer_alloc_self_test(int verbose)

Checkup routine.

Returns

0 if successful, or 1 if a test failed