include/mbedtls/memory_buffer_alloc.h

/**
 * \file memory_buffer_alloc.h
 *
 * \brief Buffer-based memory allocator
 */
/*
 *  Copyright The Mbed TLS Contributors
 *  SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later
 *
 *  This file is provided under the Apache License 2.0, or the
 *  GNU General Public License v2.0 or later.
 *
 *  **********
 *  Apache License 2.0:
 *
 *  Licensed under the Apache License, Version 2.0 (the "License"); you may
 *  not use this file except in compliance with the License.
 *  You may obtain a copy of the License at
 *
 *  http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 *  WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 *
 *  **********
 *
 *  **********
 *  GNU General Public License v2.0 or later:
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License along
 *  with this program; if not, write to the Free Software Foundation, Inc.,
 *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
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 */
#ifndef MBEDTLS_MEMORY_BUFFER_ALLOC_H
#define MBEDTLS_MEMORY_BUFFER_ALLOC_H

#if !defined(MBEDTLS_CONFIG_FILE)
#include "config.h"
#else
#include MBEDTLS_CONFIG_FILE
#endif

#include <stddef.h>

/**
 * \name SECTION: Module settings
 *
 * The configuration options you can set for this module are in this section.
 * Either change them in config.h or define them on the compiler command line.
 * \{
 */

#if !defined(MBEDTLS_MEMORY_ALIGN_MULTIPLE)
#define MBEDTLS_MEMORY_ALIGN_MULTIPLE       4 /**< Align on multiples of this value */
#endif

/* \} name SECTION: Module settings */

#define MBEDTLS_MEMORY_VERIFY_NONE         0
#define MBEDTLS_MEMORY_VERIFY_ALLOC        (1 << 0)
#define MBEDTLS_MEMORY_VERIFY_FREE         (1 << 1)
#define MBEDTLS_MEMORY_VERIFY_ALWAYS       (MBEDTLS_MEMORY_VERIFY_ALLOC | MBEDTLS_MEMORY_VERIFY_FREE)

#ifdef __cplusplus
extern "C" {
#endif

/**
 * \brief   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.
 *
 * \param buf   buffer to use as heap
 * \param len   size of the buffer
 */
void mbedtls_memory_buffer_alloc_init( unsigned char *buf, size_t len );

/**
 * \brief   Free the mutex for thread-safety and clear remaining memory
 */
void mbedtls_memory_buffer_alloc_free( void );

/**
 * \brief   Determine when the allocator should automatically verify the state
 *          of the entire chain of headers / meta-data.
 *          (Default: MBEDTLS_MEMORY_VERIFY_NONE)
 *
 * \param verify    One of MBEDTLS_MEMORY_VERIFY_NONE, MBEDTLS_MEMORY_VERIFY_ALLOC,
 *                  MBEDTLS_MEMORY_VERIFY_FREE or MBEDTLS_MEMORY_VERIFY_ALWAYS
 */
void mbedtls_memory_buffer_set_verify( int verify );

#if defined(MBEDTLS_MEMORY_DEBUG)
/**
 * \brief   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_status( void );

/**
 * \brief   Get the peak heap usage so far
 *
 * \param 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.
 * \param max_blocks    Peak number of blocks in use, including free and used
 */
void mbedtls_memory_buffer_alloc_max_get( size_t *max_used, size_t *max_blocks );

/**
 * \brief   Reset peak statistics
 */
void mbedtls_memory_buffer_alloc_max_reset( void );

/**
 * \brief   Get the current heap usage
 *
 * \param 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.
 * \param cur_blocks    Current number of blocks in use, including free and used
 */
void mbedtls_memory_buffer_alloc_cur_get( size_t *cur_used, size_t *cur_blocks );
#endif /* MBEDTLS_MEMORY_DEBUG */

/**
 * \brief   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).
 *
 * \return             0 if verified, 1 otherwise
 */
int mbedtls_memory_buffer_alloc_verify( void );

#if defined(MBEDTLS_SELF_TEST)
/**
 * \brief          Checkup routine
 *
 * \return         0 if successful, or 1 if a test failed
 */
int mbedtls_memory_buffer_alloc_self_test( int verbose );
#endif

#ifdef __cplusplus
}
#endif

#endif /* memory_buffer_alloc.h */