testdisk/src/fat_cluster.c
2020-06-19 19:02:41 +02:00

215 lines
7.3 KiB
C

/*
File: fat_cluster.c
Copyright (C) 1998-2009 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_STRING_H
#include <string.h>
#endif
#ifdef HAVE_STDLIB_H
#include <stdlib.h>
#endif
#include "types.h"
#include "common.h"
#include "intrf.h"
#include "intrfn.h"
#include "log.h"
#include "fat_cluster.h"
#include "fat.h"
#include "fat_common.h"
/* Using a couple of inodes of "." directory entries, get the cluster size and where the first cluster begins.
* */
int find_sectors_per_cluster(disk_t *disk_car, const partition_t *partition, const int verbose, const int dump_ind, unsigned int *sectors_per_cluster, uint64_t *offset_org, const upart_type_t upart_type)
{
unsigned int nbr_subdir=0;
sector_cluster_t sector_cluster[10];
uint64_t offset;
uint64_t skip_offset;
int ind_stop=0;
unsigned char *buffer=(unsigned char *)MALLOC(disk_car->sector_size);
#ifdef HAVE_NCURSES
wmove(stdscr,22,0);
wattrset(stdscr, A_REVERSE);
waddstr(stdscr," Stop ");
wattroff(stdscr, A_REVERSE);
#endif
/* 2 fats, maximum cluster size=128 */
skip_offset=(uint64_t)((partition->part_size-32*disk_car->sector_size)/disk_car->sector_size/128*3/2/disk_car->sector_size*2)*disk_car->sector_size;
if(verbose>0)
{
log_verbose("find_sectors_per_cluster skip_sectors=%lu (skip_offset=%lu)\n",
(unsigned long)(skip_offset/disk_car->sector_size),
(unsigned long)skip_offset);
}
for(offset=skip_offset;
offset<partition->part_size && !ind_stop && nbr_subdir<10;
offset+=disk_car->sector_size)
{
#ifdef HAVE_NCURSES
if((offset&(1024*disk_car->sector_size-1))==0)
{
wmove(stdscr,9,0);
wclrtoeol(stdscr);
wprintw(stdscr,"Search subdirectory %10lu/%lu %u",(unsigned long)(offset/disk_car->sector_size),(unsigned long)(partition->part_size/disk_car->sector_size),nbr_subdir);
wrefresh(stdscr);
ind_stop|=check_enter_key_or_s(stdscr);
}
#endif
if((unsigned)disk_car->pread(disk_car, buffer, disk_car->sector_size, partition->part_offset + offset) == disk_car->sector_size)
{
if(buffer[0]=='.' && is_fat_directory(buffer))
{
const unsigned long int cluster=fat_get_cluster_from_entry((const struct msdos_dir_entry *)buffer);
log_info("sector %lu, cluster %lu\n",
(unsigned long)(offset/disk_car->sector_size), cluster);
sector_cluster[nbr_subdir].cluster=cluster;
sector_cluster[nbr_subdir].sector=offset/disk_car->sector_size;
nbr_subdir++;
#ifdef HAVE_NCURSES
if(dump_ind>0)
dump_ncurses(buffer,disk_car->sector_size);
#endif
}
}
}
free(buffer);
return find_sectors_per_cluster_aux(sector_cluster,nbr_subdir,sectors_per_cluster,offset_org,verbose,partition->part_size/disk_car->sector_size, upart_type);
}
int find_sectors_per_cluster_aux(const sector_cluster_t *sector_cluster, const unsigned int nbr_sector_cluster,unsigned int *sectors_per_cluster, uint64_t *offset, const int verbose, const unsigned long int part_size_in_sectors, const upart_type_t upart_type)
{
cluster_offset_t *cluster_offset;
unsigned int i,j;
unsigned int nbr_sol=0;
if(nbr_sector_cluster<2)
return 0;
cluster_offset=(cluster_offset_t *)MALLOC(nbr_sector_cluster*nbr_sector_cluster*sizeof(cluster_offset_t));
log_info("find_sectors_per_cluster_aux\n");
for(i=0;i<nbr_sector_cluster-1;i++)
{
for(j=i+1;j<nbr_sector_cluster;j++)
{
if(sector_cluster[j].cluster > sector_cluster[i].cluster)
{
unsigned int sectors_per_cluster_tmp=(sector_cluster[j].sector-sector_cluster[i].sector)/(sector_cluster[j].cluster-sector_cluster[i].cluster);
switch(sectors_per_cluster_tmp)
{
case 1:
case 2:
case 4:
case 8:
case 16:
case 32:
case 64:
case 128:
if(sector_cluster[i].sector > (uint64_t)(sector_cluster[i].cluster-2) * sectors_per_cluster_tmp)
{
unsigned int sol_cur;
unsigned int found=0;
uint64_t offset_tmp=sector_cluster[i].sector-(uint64_t)(sector_cluster[i].cluster-2)*sectors_per_cluster_tmp;
for(sol_cur=0;sol_cur<nbr_sol && !found;sol_cur++)
{
if(cluster_offset[sol_cur].sectors_per_cluster==sectors_per_cluster_tmp &&
cluster_offset[sol_cur].offset==offset_tmp)
{
if(cluster_offset[sol_cur].first_sol==i)
{
cluster_offset[sol_cur].nbr++;
}
/* log_debug("sectors_per_cluster=%u offset=%lu nbr=%u\n",cluster_offset[sol_cur].sectors_per_cluster,cluster_offset[sol_cur].offset,cluster_offset[sol_cur].nbr); */
found=1;
}
}
if(!found)
{
cluster_offset[nbr_sol].sectors_per_cluster=sectors_per_cluster_tmp;
cluster_offset[nbr_sol].offset=offset_tmp;
cluster_offset[nbr_sol].nbr=1;
cluster_offset[nbr_sol].first_sol=i;
nbr_sol++;
}
}
break;
}
}
}
}
/* Show results */
{
unsigned int nbr_max=0;
for(i=0;i<nbr_sol;i++)
{
const upart_type_t upart_type_new=no_of_cluster2part_type((part_size_in_sectors-cluster_offset[i].offset)/cluster_offset[i].sectors_per_cluster);
if(verbose>0)
{
log_verbose("sectors_per_cluster=%u offset=%lu nbr=%u ",
cluster_offset[i].sectors_per_cluster,
cluster_offset[i].offset,
cluster_offset[i].nbr);
switch(upart_type_new)
{
case UP_FAT12:
log_info("FAT : 12\n");
break;
case UP_FAT16:
log_info("FAT : 16\n");
break;
case UP_FAT32:
log_info("FAT : 32\n");
break;
default: /* No compiler warning */
break;
}
}
if((upart_type==UP_UNK || upart_type==upart_type_new) &&
cluster_offset[i].nbr>nbr_max)
{
nbr_max=cluster_offset[i].nbr;
*sectors_per_cluster=cluster_offset[i].sectors_per_cluster;
*offset=cluster_offset[i].offset;
}
}
free(cluster_offset);
if(nbr_max==0)
return 0;
log_info("Selected: sectors_per_cluster=%u, cluster 2 at sector %lu, nbr=%u\n",
*sectors_per_cluster, (long unsigned int)(*offset), nbr_max);
return 1;
}
}
upart_type_t no_of_cluster2part_type(const unsigned long int no_of_cluster)
{
if(no_of_cluster<65525)
{
if(no_of_cluster<4085)
return UP_FAT12;
else
return UP_FAT16;
}
return UP_FAT32;
}