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testdisk/src/fatp.c
Christophe Grenier 4e44db2b46 Improve Frama-C annotations
2022-07-14 10:09:09 +02:00

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/*
File: fatp.c
Copyright (C) 2006-2007 Christophe GRENIER <grenier@cgsecurity.org>
This software 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 the Free Software Foundation, Inc., 51
Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#include <stdio.h>
#ifdef HAVE_STDLIB_H
#include <stdlib.h>
#endif
#include "types.h"
#include "common.h"
#include "list.h"
#include "filegen.h"
#include "photorec.h"
#include "fatp.h"
#include "fat.h"
#include "fat_common.h"
#include "log.h"
/*@
@ requires \valid(disk);
@ requires valid_disk(disk);
@ requires \valid_read(partition);
@ requires valid_partition(partition);
@ requires \valid(list_search_space);
@ requires \separated(disk, partition, list_search_space);
@ decreases 0;
@*/
static void fat12_remove_used_space(disk_t *disk,const partition_t *partition, alloc_data_t *list_search_space, const unsigned int fat_offset, const unsigned int no_of_cluster, const unsigned int start_data, const unsigned int cluster_size, const unsigned int sector_size)
{
unsigned char *buffer;
unsigned int cluster;
const uint64_t hd_offset=partition->part_offset+(uint64_t)fat_offset*sector_size;
uint64_t start_free=0;
uint64_t end_free=0;
unsigned long int offset_s_prev=0;
log_trace("fat12_remove_used_space\n");
buffer=(unsigned char *)MALLOC(2*sector_size);
del_search_space(list_search_space, partition->part_offset,
partition->part_offset + (uint64_t)start_data * sector_size - 1);
for(cluster=2; cluster<=no_of_cluster+1; cluster++)
{
unsigned long int offset_s,offset_o;
unsigned int next_cluster;
offset_s=(cluster+cluster/2)/disk->sector_size;
offset_o=(cluster+cluster/2)%disk->sector_size;
if(offset_s!=offset_s_prev || cluster==2)
{
offset_s_prev=offset_s;
if((unsigned)disk->pread(disk, buffer, 2*sector_size, hd_offset + offset_s * disk->sector_size) != 2*sector_size)
{
/* Consider these FAT sectors points to free clusters */
}
}
if((cluster&1)!=0)
next_cluster=le16((*((uint16_t*)&buffer[offset_o])))>>4;
else
next_cluster=le16(*((uint16_t*)&buffer[offset_o]))&0x0FFF;
if(next_cluster!=0)
{
/* Not free */
if(end_free+1==partition->part_offset+(start_data+(uint64_t)(cluster-2)*cluster_size)*sector_size)
end_free+=cluster_size*sector_size;
else
{
if(start_free != end_free)
del_search_space(list_search_space, start_free, end_free);
start_free=partition->part_offset+(start_data+(uint64_t)(cluster-2)*cluster_size)*sector_size;
end_free=start_free+(uint64_t)cluster_size*sector_size-1;
}
}
}
free(buffer);
if(start_free != end_free)
del_search_space(list_search_space, start_free, end_free);
}
/*@
@ requires \valid(disk_car);
@ requires valid_disk(disk_car);
@ requires \valid_read(partition);
@ requires valid_partition(partition);
@ requires \valid(list_search_space);
@ requires \separated(disk_car, partition, list_search_space);
@ decreases 0;
@*/
static void fat16_remove_used_space(disk_t *disk_car,const partition_t *partition, alloc_data_t *list_search_space, const unsigned int fat_offset, const unsigned int no_of_cluster, const unsigned int start_data, const unsigned int cluster_size, const unsigned int sector_size)
{
unsigned char *buffer;
const uint16_t *p16;
unsigned int prev_cluster;
uint64_t hd_offset=partition->part_offset+(uint64_t)fat_offset*sector_size;
uint64_t start_free=0;
uint64_t end_free=0;
log_trace("fat16_remove_used_space\n");
buffer=(unsigned char *)MALLOC(sector_size);
p16=(const uint16_t*)buffer;
del_search_space(list_search_space, partition->part_offset,
partition->part_offset + (uint64_t)start_data * sector_size - 1);
for(prev_cluster=2;prev_cluster<=no_of_cluster+1;prev_cluster++)
{
unsigned int offset_o;
offset_o=prev_cluster%(sector_size/2);
if((offset_o==0)||(prev_cluster==2))
{
if((unsigned)disk_car->pread(disk_car, buffer, sector_size, hd_offset) != sector_size)
{
/* Consider these FAT sectors points to free clusters */
}
hd_offset+=sector_size;
}
if(le16(p16[offset_o])!=0)
{
/* Not free */
if(end_free+1==partition->part_offset+(start_data+(uint64_t)(prev_cluster-2)*cluster_size)*sector_size)
end_free+=cluster_size*sector_size;
else
{
if(start_free != end_free)
del_search_space(list_search_space, start_free, end_free);
start_free=partition->part_offset+(start_data+(uint64_t)(prev_cluster-2)*cluster_size)*sector_size;
end_free=start_free+(uint64_t)cluster_size*sector_size-1;
}
}
}
free(buffer);
if(start_free != end_free)
del_search_space(list_search_space, start_free, end_free);
}
/*@
@ requires \valid(disk_car);
@ requires valid_disk(disk_car);
@ requires \valid_read(partition);
@ requires valid_partition(partition);
@ requires \valid(list_search_space);
@ requires \separated(disk_car, partition, list_search_space);
@ decreases 0;
@*/
static void fat32_remove_used_space(disk_t *disk_car,const partition_t *partition, alloc_data_t *list_search_space, const unsigned int fat_offset, const unsigned int no_of_cluster, const unsigned int start_data, const unsigned int cluster_size, const unsigned int sector_size)
{
unsigned char *buffer;
uint32_t *p32;
unsigned int prev_cluster;
uint64_t hd_offset=partition->part_offset+(uint64_t)fat_offset*sector_size;
uint64_t start_free=0;
uint64_t end_free=0;
log_trace("fat32_remove_used_space\n");
buffer=(unsigned char *)MALLOC(sector_size);
p32=(uint32_t*)buffer;
del_search_space(list_search_space, partition->part_offset,
partition->part_offset + (uint64_t)start_data * sector_size - 1);
for(prev_cluster=2;prev_cluster<=no_of_cluster+1;prev_cluster++)
{
unsigned long int cluster;
unsigned int offset_o;
offset_o=prev_cluster%(sector_size/4);
if((offset_o==0)||(prev_cluster==2))
{
if((unsigned)disk_car->pread(disk_car, buffer, sector_size, hd_offset) != sector_size)
{
/* Consider these FAT sectors points to free clusters */
}
hd_offset+=sector_size;
}
cluster=le32(p32[offset_o]) & 0xFFFFFFF;
if(cluster!=0)
{
/* Not free */
if(end_free+1==partition->part_offset+(uint64_t)(start_data+(prev_cluster-2)*cluster_size)*sector_size)
end_free+=cluster_size*sector_size;
else
{
if(start_free != end_free)
del_search_space(list_search_space, start_free, end_free);
start_free=partition->part_offset+(start_data+(uint64_t)(prev_cluster-2)*cluster_size)*sector_size;
end_free=start_free+(uint64_t)cluster_size*sector_size-1;
}
}
}
free(buffer);
if(start_free != end_free)
del_search_space(list_search_space, start_free, end_free);
}
unsigned int fat_remove_used_space(disk_t *disk_car, const partition_t *partition, alloc_data_t *list_search_space)
{
unsigned long int fat_length;
unsigned long int start_fat1;
unsigned long int part_size;
unsigned int no_of_cluster;
unsigned int start_data;
unsigned char *buffer;
unsigned int res;
unsigned int sector_size;
const struct fat_boot_sector *fat_header;
buffer=(unsigned char *)MALLOC(3*disk_car->sector_size);
fat_header=(const struct fat_boot_sector *)buffer;
if((unsigned)disk_car->pread(disk_car, buffer, 3 * disk_car->sector_size, partition->part_offset) != 3 * disk_car->sector_size)
{
free(buffer);
return 0;
}
sector_size=fat_sector_size(fat_header);
if(sector_size==0)
{
free(buffer);
return 0;
}
fat_length=le16(fat_header->fat_length)>0?le16(fat_header->fat_length):le32(fat_header->fat32_length);
part_size=(fat_sectors(fat_header)>0?fat_sectors(fat_header):le32(fat_header->total_sect));
start_fat1=le16(fat_header->reserved);
start_data=start_fat1+fat_header->fats*fat_length+(get_dir_entries(fat_header)*32+sector_size-1)/sector_size;
no_of_cluster=(part_size-start_data)/fat_header->sectors_per_cluster;
if(partition->upart_type==UP_FAT12)
fat12_remove_used_space(disk_car,partition, list_search_space, start_fat1, no_of_cluster, start_data, fat_header->sectors_per_cluster,sector_size);
else if(partition->upart_type==UP_FAT16)
fat16_remove_used_space(disk_car,partition, list_search_space, start_fat1, no_of_cluster, start_data, fat_header->sectors_per_cluster,sector_size);
else if(partition->upart_type==UP_FAT32)
fat32_remove_used_space(disk_car,partition, list_search_space, start_fat1, no_of_cluster, start_data, fat_header->sectors_per_cluster,sector_size);
res=fat_header->sectors_per_cluster * sector_size;
free(buffer);
return res;
}
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