Memory-allocation abstraction layer and buffer-based allocator added

include/polarssl/config.h

@@ -401,6 +401,32 @@
 #define POLARSSL_NO_PLATFORM_ENTROPY
  */
 
+/**
+ * \def POLARSSL_MEMORY_DEBUG
+ *
+ * Enable debugging of buffer allocator memory issues. Automatically prints
+ * (to stderr) all (fatal) messages on memory allocation issues. Enables
+ * function for 'debug output' of allocated memory.
+ *
+ * Requires: POLARSSL_MEMORY_BUFFER_ALLOC_C
+ *           fprintf()
+ *
+ * Uncomment this macro to let the buffer allocator print out error messages.
+#define POLARSSL_MEMORY_DEBUG
+*/
+
+/**
+ * \def POLARSSL_MEMORY_BACKTRACE
+ *
+ * Include backtrace information with each allocated block.
+ *
+ * Requires: POLARSSL_MEMORY_BUFFER_ALLOC_C
+ *           GLIBC-compatible backtrace() an backtrace_symbols() support
+ *
+ * Uncomment this macro to include backtrace information
+#define POLARSSL_MEMORY_BACKTRACE
+ */
+
 /**
  * \def POLARSSL_PKCS1_V21
  *
@@ -899,6 +925,32 @@
  */
 #define POLARSSL_MD5_C
 
+/**
+ * \def POLARSSL_MEMORY_C
+ *
+ * Enable the memory allocation layer.
+ * By default PolarSSL uses the system-provided malloc() and free().
+ * (As long as POLARSSL_MEMORY_STDMALLOC and POLARSSL_MEMORY_STDFREE
+ * are defined and unmodified)
+ *
+ * This allows different allocators (self-implemented or provided)
+ *
+ * Enable this layer to allow use of alternative memory allocators.
+#define POLARSSL_MEMORY_C
+ */
+
+/**
+ * The buffer allocator implementation that makes use of a (stack) based
+ * buffer to 'allocate' dynamic memory. (replaces malloc() and free() calls)
+ *
+ * Module:  library/memory_buffer_alloc.c
+ *
+ * Requires: POLARSSL_MEMORY_C
+ *
+ * Enable this module to enable the buffer memory allocator.
+#define POLARSSL_MEMORY_BUFFER_ALLOC_C
+ */
+
 /**
  * \def POLARSSL_NET_C
  *
@@ -1231,6 +1283,11 @@
 #define ENTROPY_MAX_SOURCES                20 /**< Maximum number of sources supported */
 #define ENTROPY_MAX_GATHER                128 /**< Maximum amount requested from entropy sources */
 
+// Memory options
+#define MEMORY_ALIGN_MULTIPLE               4 /**< Align on multiples of this value */
+#define POLARSSL_MEMORY_STDMALLOC      malloc /**< Default allocator to use, can be undefined */
+#define POLARSSL_MEMORY_STDFREE          free /**< Default free to use, can be undefined */
+
 // SSL Cache options
 //
 #define SSL_CACHE_DEFAULT_TIMEOUT       86400 /**< 1 day  */
@@ -1301,6 +1358,10 @@
 #error "POLARSSL_KEY_EXCHANGE_RSA_ENABLED defined, but not all prerequisites"
 #endif
 
+#if defined(POLARSSL_MEMORY_BUFFER_ALLOC_C) && !defined(POLARSSL_MEMORY_C)
+#error "POLARSSL_MEMORY_BUFFER_ALLOC_C defined, but not all prerequisites"
+#endif
+
 #if defined(POLARSSL_PBKDF2_C) && !defined(POLARSSL_MD_C)
 #error "POLARSSL_PBKDF2_C defined, but not all prerequisites"
 #endif

include/polarssl/memory.h

@@ -0,0 +1,124 @@
+/**
+ * \file memory.h
+ *
+ * \brief Memory allocation layer
+ *
+ *  Copyright (C) 2006-2013, Brainspark B.V.
+ *
+ *  This file is part of PolarSSL (http://www.polarssl.org)
+ *  Lead Maintainer: Paul Bakker <polarssl_maintainer at polarssl.org>
+ *
+ *  All rights reserved.
+ *
+ *  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.
+ */
+#ifndef POLARSSL_MEMORY_H
+#define POLARSSL_MEMORY_H
+
+#include "config.h"
+
+#include <stdlib.h>
+
+#if !defined(POLARSSL_CONFIG_OPTIONS)
+#define POLARSSL_MEMORY_ALIGN_MULTIPLE       4 /**< Align on multiples of this value */
+
+#define POLARSSL_MEMORY_STDMALLOC       malloc /**< Default allocator to use, can be undefined */
+#define POLARSSL_MEMORY_STDFREE           free /**< Default free to use, can be undefined */
+#endif /* POLARSSL_CONFIG_OPTIONS */
+
+#define MEMORY_VERIFY_NONE         0
+#define MEMORY_VERIFY_ALLOC        (1 << 0)
+#define MEMORY_VERIFY_FREE         (1 << 1)
+#define MEMORY_VERIFY_ALWAYS       (MEMORY_VERIFY_ALLOC | MEMORY_VERIFY_FREE)
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/*
+ * The function pointers for malloc and free
+ */
+extern void * (*polarssl_malloc)( size_t len );
+extern void (*polarssl_free)( void *ptr );
+
+/**
+ * \brief   Set your own memory implementation function pointers
+ *
+ * \param malloc_func   the malloc function implementation
+ * \param free_func     the free function implementation
+ *
+ * \return              0 if successful
+ */
+int memory_set_own( void * (*malloc_func)( size_t ),
+                    void (*free_func)( void * ) );
+
+#if defined(POLARSSL_MEMORY_BUFFER_ALLOC_C)
+/**
+ * \brief   Initialize use of stack-based memory allocator.
+ *          The stack-based allocator does memory management inside the
+ *          presented buffer and does not call malloc() and free().
+ *          It sets the global polarssl_malloc() and polarssl_free() pointers
+ *          to its own functions.
+ *
+ * \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
+ *
+ * \return              0 if successful
+ */
+int memory_buffer_alloc_init( unsigned char *buf, size_t len );
+
+/**
+ * \brief   Determine when the allocator should automatically verify the state
+ *          of the entire chain of headers / meta-data.
+ *          (Default: MEMORY_VERIFY_NONE)
+ *
+ * \param verify    One of MEMORY_VERIFY_NONE, MEMORY_VERIFY_ALLOC,
+ *                  MEMORY_VERIFY_FREE or MEMORY_VERIFY_ALWAYS
+ */
+void memory_buffer_set_verify( int verify );
+
+#if defined(POLARSSL_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 POLARSSL_MEMORY_BACKTRACE is defined.
+ */
+void memory_buffer_alloc_status();
+#endif /* POLARSSL_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 POLARSSL_MEMORY_DEBUG is defined.
+ *          Prints out full header information if POLARSSL_MEMORY_DEBUG_HEADERS
+ *          is defined. (Includes stack trace information for each block if
+ *          POLARSSL_MEMORY_BACKTRACE is defined as well).
+ *
+ * \returns             0 if verified, 1 otherwise
+ */
+int memory_buffer_alloc_verify();
+
+#endif /* POLARSSL_MEMORY_BUFFER_ALLOC_C */
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* memory.h */