363 lines
		
	
	
		
			8.0 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			363 lines
		
	
	
		
			8.0 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
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|  *  Buffer-based memory allocator
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|  *
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|  *  Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
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|  *  SPDX-License-Identifier: Apache-2.0
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|  *
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|  *  Licensed under the Apache License, Version 2.0 (the "License"); you may
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|  *  not use this file except in compliance with the License.
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|  *  You may obtain a copy of the License at
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|  *
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|  *  http://www.apache.org/licenses/LICENSE-2.0
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|  *
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|  *  Unless required by applicable law or agreed to in writing, software
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|  *  distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
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|  *  WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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|  *  See the License for the specific language governing permissions and
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|  *  limitations under the License.
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|  *
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|  *  This file is part of mbed TLS (https://tls.mbed.org)
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|  */
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| 
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| #include "7zAlloc.h"
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| 
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| #include <string.h>
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| 
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| #define MAGIC1       0xFF00AA55
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| #define MAGIC2       0xEE119966
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| #define MAX_BT 20
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| 
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| typedef struct _memory_header memory_header;
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| struct _memory_header
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| {
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|     size_t          magic1;
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|     size_t          size;
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|     size_t          alloc;
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|     memory_header   *prev;
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|     memory_header   *next;
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|     memory_header   *prev_free;
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|     memory_header   *next_free;
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|     size_t          magic2;
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| };
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| 
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| typedef struct
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| {
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|     unsigned char   *buf;
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|     size_t          len;
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|     memory_header   *first;
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|     memory_header   *first_free;
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|     int             verify;
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| }
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| buffer_alloc_ctx;
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| 
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| static buffer_alloc_ctx heap;
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| 
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| static int verify_header( memory_header *hdr )
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| {
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|     if( hdr->magic1 != MAGIC1 )
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|     {
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|         return( 1 );
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|     }
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| 
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|     if( hdr->magic2 != MAGIC2 )
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|     {
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|         return( 1 );
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|     }
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| 
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|     if( hdr->alloc > 1 )
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|     {
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|         return( 1 );
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|     }
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| 
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|     if( hdr->prev != NULL && hdr->prev == hdr->next )
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|     {
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|         return( 1 );
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|     }
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| 
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|     if( hdr->prev_free != NULL && hdr->prev_free == hdr->next_free )
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|     {
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|         return( 1 );
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|     }
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| 
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|     return( 0 );
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| }
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| 
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| static int verify_chain()
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| {
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|     memory_header *prv = heap.first, *cur = heap.first->next;
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| 
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|     if( verify_header( heap.first ) != 0 )
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|     {
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|         return( 1 );
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|     }
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| 
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|     if( heap.first->prev != NULL )
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|     {
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|         return( 1 );
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|     }
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| 
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|     while( cur != NULL )
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|     {
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|         if( verify_header( cur ) != 0 )
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|         {
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|             return( 1 );
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|         }
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| 
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|         if( cur->prev != prv )
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|         {
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|             return( 1 );
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|         }
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| 
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|         prv = cur;
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|         cur = cur->next;
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|     }
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| 
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|     return( 0 );
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| }
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| 
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| void *buffer_alloc_calloc( size_t n, size_t size )
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| {
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|     memory_header *new, *cur = heap.first_free;
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|     unsigned char *p;
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|     void *ret;
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|     size_t original_len, len;
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| 
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|     if( heap.buf == NULL || heap.first == NULL )
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|         return( NULL );
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| 
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|     original_len = len = n * size;
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| 
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|     if( n != 0 && len / n != size )
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|         return( NULL );
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| 
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|     if( len % MBEDTLS_MEMORY_ALIGN_MULTIPLE )
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|     {
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|         len -= len % MBEDTLS_MEMORY_ALIGN_MULTIPLE;
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|         len += MBEDTLS_MEMORY_ALIGN_MULTIPLE;
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|     }
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| 
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|     // Find block that fits
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|     //
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|     while( cur != NULL )
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|     {
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|         if( cur->size >= len )
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|             break;
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| 
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|         cur = cur->next_free;
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|     }
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| 
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|     if( cur == NULL )
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|         return NULL;
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| 
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|     if( cur->alloc != 0 )
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|     {
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|         return NULL;
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|     }
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| 
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|     // Found location, split block if > memory_header + 4 room left
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|     //
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|     if( cur->size - len < sizeof(memory_header) +
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|                           MBEDTLS_MEMORY_ALIGN_MULTIPLE )
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|     {
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|         cur->alloc = 1;
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| 
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|         // Remove from free_list
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|         //
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|         if( cur->prev_free != NULL )
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|             cur->prev_free->next_free = cur->next_free;
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|         else
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|             heap.first_free = cur->next_free;
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| 
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|         if( cur->next_free != NULL )
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|             cur->next_free->prev_free = cur->prev_free;
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| 
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|         cur->prev_free = NULL;
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|         cur->next_free = NULL;
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| 
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|         if( ( heap.verify & MBEDTLS_MEMORY_VERIFY_ALLOC ) && verify_chain() != 0 )
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|             return NULL;
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| 
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|         ret = (unsigned char *) cur + sizeof( memory_header );
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|         memset( ret, 0, original_len );
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| 
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|         return( ret );
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|     }
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| 
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|     p = ( (unsigned char *) cur ) + sizeof(memory_header) + len;
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|     new = (memory_header *) p;
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| 
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|     new->size = cur->size - len - sizeof(memory_header);
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|     new->alloc = 0;
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|     new->prev = cur;
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|     new->next = cur->next;
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|     new->magic1 = MAGIC1;
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|     new->magic2 = MAGIC2;
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| 
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|     if( new->next != NULL )
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|         new->next->prev = new;
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| 
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|     // Replace cur with new in free_list
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|     //
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|     new->prev_free = cur->prev_free;
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|     new->next_free = cur->next_free;
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|     if( new->prev_free != NULL )
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|         new->prev_free->next_free = new;
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|     else
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|         heap.first_free = new;
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| 
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|     if( new->next_free != NULL )
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|         new->next_free->prev_free = new;
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| 
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|     cur->alloc = 1;
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|     cur->size = len;
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|     cur->next = new;
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|     cur->prev_free = NULL;
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|     cur->next_free = NULL;
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| 
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|     if( ( heap.verify & MBEDTLS_MEMORY_VERIFY_ALLOC ) && verify_chain() != 0 )
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|         return NULL;
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| 
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|     ret = (unsigned char *) cur + sizeof( memory_header );
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|     memset( ret, 0, original_len );
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| 
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|     return( ret );
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| }
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| 
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| void *buffer_alloc_malloc(size_t size)
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| {
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|     return buffer_alloc_calloc(1, size);
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| }
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| 
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| void buffer_alloc_free( void *ptr )
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| {
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|     memory_header *hdr, *old = NULL;
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|     unsigned char *p = (unsigned char *) ptr;
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| 
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|     if( ptr == NULL || heap.buf == NULL || heap.first == NULL )
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|         return;
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| 
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|     if( p < heap.buf || p > heap.buf + heap.len )
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|     {
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|         return;
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|     }
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| 
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|     p -= sizeof(memory_header);
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|     hdr = (memory_header *) p;
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| 
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|     if( verify_header( hdr ) != 0 )
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|         return;
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| 
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|     if( hdr->alloc != 1 )
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|     {
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|         return;
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|     }
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| 
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|     hdr->alloc = 0;
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| 
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|     // Regroup with block before
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|     //
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|     if( hdr->prev != NULL && hdr->prev->alloc == 0 )
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|     {
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|         hdr->prev->size += sizeof(memory_header) + hdr->size;
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|         hdr->prev->next = hdr->next;
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|         old = hdr;
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|         hdr = hdr->prev;
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| 
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|         if( hdr->next != NULL )
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|             hdr->next->prev = hdr;
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| 
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|         memset( old, 0, sizeof(memory_header) );
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|     }
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| 
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|     // Regroup with block after
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|     //
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|     if( hdr->next != NULL && hdr->next->alloc == 0 )
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|     {
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|         hdr->size += sizeof(memory_header) + hdr->next->size;
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|         old = hdr->next;
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|         hdr->next = hdr->next->next;
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| 
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|         if( hdr->prev_free != NULL || hdr->next_free != NULL )
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|         {
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|             if( hdr->prev_free != NULL )
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|                 hdr->prev_free->next_free = hdr->next_free;
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|             else
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|                 heap.first_free = hdr->next_free;
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| 
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|             if( hdr->next_free != NULL )
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|                 hdr->next_free->prev_free = hdr->prev_free;
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|         }
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| 
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|         hdr->prev_free = old->prev_free;
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|         hdr->next_free = old->next_free;
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| 
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|         if( hdr->prev_free != NULL )
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|             hdr->prev_free->next_free = hdr;
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|         else
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|             heap.first_free = hdr;
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| 
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|         if( hdr->next_free != NULL )
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|             hdr->next_free->prev_free = hdr;
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| 
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|         if( hdr->next != NULL )
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|             hdr->next->prev = hdr;
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| 
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|         memset( old, 0, sizeof(memory_header) );
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|     }
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| 
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|     // Prepend to free_list if we have not merged
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|     // (Does not have to stay in same order as prev / next list)
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|     //
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|     if( old == NULL )
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|     {
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|         hdr->next_free = heap.first_free;
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|         if( heap.first_free != NULL )
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|             heap.first_free->prev_free = hdr;
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|         heap.first_free = hdr;
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|     }
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| 
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|     if( ( heap.verify & MBEDTLS_MEMORY_VERIFY_FREE ) && verify_chain() != 0 )
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|         return;
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| }
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| 
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| void mbedtls_memory_buffer_set_verify( int verify )
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| {
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|     heap.verify = verify;
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| }
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| 
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| int mbedtls_memory_buffer_alloc_verify()
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| {
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|     return verify_chain();
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| }
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| 
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| 
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| void memory_buffer_alloc_init( unsigned char *buf, size_t len )
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| {
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|     memset( &heap, 0, sizeof(buffer_alloc_ctx) );
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|     memset( buf, 0, len );
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| 
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| 
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|     if( (size_t) buf % MBEDTLS_MEMORY_ALIGN_MULTIPLE )
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|     {
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|         /* Adjust len first since buf is used in the computation */
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|         len -= MBEDTLS_MEMORY_ALIGN_MULTIPLE
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|              - (size_t) buf % MBEDTLS_MEMORY_ALIGN_MULTIPLE;
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|         buf += MBEDTLS_MEMORY_ALIGN_MULTIPLE
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|              - (size_t) buf % MBEDTLS_MEMORY_ALIGN_MULTIPLE;
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|     }
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| 
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|     heap.buf = buf;
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|     heap.len = len;
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| 
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|     heap.first = (memory_header *) buf;
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|     heap.first->size = len - sizeof(memory_header);
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|     heap.first->magic1 = MAGIC1;
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|     heap.first->magic2 = MAGIC2;
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|     heap.first_free = heap.first;
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| }
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| 
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| void memory_buffer_alloc_free()
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| {
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|     memset( &heap, 0x0, sizeof(buffer_alloc_ctx) );
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| }
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