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/*
File: file_fcs.c
Copyright (C) 2008 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.
*/
#if !defined(SINGLE_FORMAT) || defined(SINGLE_FORMAT_fcs)
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#ifdef HAVE_STRING_H
#include <string.h>
#endif
#include <stdio.h>
#include "types.h"
#include "filegen.h"
#include "log.h"
/*@
@ requires valid_register_header_check(file_stat);
@*/
static void register_header_check_fcs(file_stat_t *file_stat);
const file_hint_t file_hint_fcs= {
.extension="fcs",
.description="Flow Cytometry Standard 3.0",
.max_filesize=PHOTOREC_MAX_FILE_SIZE,
.recover=1,
.enable_by_default=1,
.register_header_check=®ister_header_check_fcs
};
struct fcs_header
{
unsigned char magic[6];
unsigned char reserved[4];
unsigned char text_start[8]; /* 10 */
unsigned char text_end[8]; /* 18 */
unsigned char data_start[8]; /* 26 */
unsigned char data_end[8]; /* 34 */
unsigned char analysis_start[8]; /* 34 */
unsigned char analysis_end[8]; /* 50 */
} __attribute__ ((gcc_struct, __packed__));
/*@
@ requires \valid_read(string + (0 .. max_length-1));
@ terminates \true;
@ assigns \nothing;
@*/
static uint64_t ascii2int(const unsigned char *string, const unsigned int max_length)
{
uint64_t res=0;
unsigned int i;
/*@
@ loop invariant res <= 0x1999999999999998;
@ loop assigns res,i;
@ loop variant max_length - i;
@*/
for(i=0;i<max_length;i++)
{
if(string[i]>='0' && string[i]<='9')
{
res=res*10+(string[i]-'0');
if(res > 0x1999999999999998)
return 0xffffffffffffffff;
}
else if(!(string[i]==' ' && res==0))
return 0;
}
return res;
}
/*@
@ requires \valid_read(string + (0 .. max_length-1));
@ terminates \true;
@ assigns \nothing;
@*/
static uint64_t ascii2int2(const unsigned char *string, const unsigned int max_length, const unsigned int delimiter)
{
uint64_t res=0;
unsigned int i;
/*@
@ loop invariant res <= 0x1999999999999998;
@ loop assigns res,i;
@ loop variant max_length - i;
@*/
for(i=0;i<max_length;i++)
{
if(string[i]>='0' && string[i]<='9')
{
res=res*10+(string[i]-'0');
if(res > 0x1999999999999998)
return res;
}
else if(string[i]==delimiter)
return res;
else if(string[i]==' ' && res>0)
return res;
else if(string[i]!=' ')
return 0;
}
return res;
}
/*@
@ requires buffer_size >= sizeof(struct fcs_header);
@ requires separation: \separated(&file_hint_fcs, buffer+(..), file_recovery, file_recovery_new);
@ requires valid_header_check_param(buffer, buffer_size, safe_header_only, file_recovery, file_recovery_new);
@ ensures valid_header_check_result(\result, file_recovery_new);
@ ensures (\result == 1) ==> file_recovery_new->file_size == 0;
@ ensures (\result != 0) ==> file_recovery_new->extension != \null;
@ ensures (\result == 1) ==> (file_recovery_new->time == 0);
@ ensures (\result == 1) ==> (file_recovery_new->min_filesize == 58);
@ ensures (\result == 1) ==> (file_recovery_new->calculated_file_size > 0);
@ ensures (\result == 1) ==> (file_recovery_new->extension == file_hint_fcs.extension);
@ ensures (\result == 1) ==> (file_recovery_new->data_check == &data_check_size);
@ ensures (\result == 1) ==> (file_recovery_new->file_check == &file_check_size);
@ ensures (\result == 1) ==> (file_recovery_new->file_rename == \null);
@ assigns *file_recovery_new;
@*/
static int header_check_fcs(const unsigned char *buffer, const unsigned int buffer_size, const unsigned int safe_header_only, const file_recovery_t *file_recovery, file_recovery_t *file_recovery_new)
{
const struct fcs_header *fcs=(const struct fcs_header*)buffer;
uint64_t text_start;
uint64_t text_end;
uint64_t data_start;
uint64_t data_end;
uint64_t analysis_start;
uint64_t analysis_end;
uint64_t stext_end=0;
text_start=ascii2int(fcs->text_start, 8);
text_end=ascii2int(fcs->text_end, 8);
data_start=ascii2int(fcs->data_start, 8);
data_end=ascii2int(fcs->data_end, 8);
analysis_start=ascii2int(fcs->analysis_start, 8);
analysis_end=ascii2int(fcs->analysis_end, 8);
if(!(text_start<=text_end && data_start<=data_end && analysis_start<=analysis_end))
return 0;
if((data_end==0 || analysis_end==0) && text_start < buffer_size)
{ /* Explore TEXT segment */
unsigned int i;
const unsigned char delimiter=buffer[text_start];
const unsigned int smallest=(buffer_size < text_end ? buffer_size : text_end);
/*@
@ loop assigns i, data_end, stext_end, analysis_end;
@ loop variant smallest - i;
@*/
for(i=0; i<smallest; i++)
{
if(buffer[i]==delimiter)
{
if(i+1+8+1 < smallest &&
memcmp(buffer+i+1,"$ENDDATA",8)==0 && buffer[i+1+8]==delimiter)
data_end=ascii2int2(&buffer[i+1+8+1], smallest-(i+1+8+1), delimiter);
else if(i+1+9+1 < smallest &&
memcmp(buffer+i+1,"$ENDSTEXT",9)==0 && buffer[i+1+9]==delimiter)
stext_end=ascii2int2(&buffer[i+1+9+1], smallest-(i+1+9+1), delimiter);
else if(i+1+12+1 < smallest &&
memcmp(buffer+i+1,"$ENDANALYSIS",12)==0 && buffer[i+1+12]==delimiter)
analysis_end=ascii2int2(&buffer[i+1+12+1], smallest-(i+1+12+1), delimiter);
}
}
}
#ifdef DEBUG_FCS
log_info("$ENDDATA %llu\n", (long long unsigned) data_end);
log_info("$ENDSTEXT %llu\n", (long long unsigned) stext_end);
log_info("$ENDANALYSIS %llu\n", (long long unsigned) analysis_end);
#endif
if( data_end >= 0x8000000000000000 - 9 ||
analysis_end >= 0x8000000000000000 - 9 ||
stext_end >= 0x8000000000000000 - 9)
return 0;
reset_file_recovery(file_recovery_new);
file_recovery_new->extension=file_hint_fcs.extension;
file_recovery_new->min_filesize=58;
file_recovery_new->calculated_file_size=data_end+9;
if(file_recovery_new->calculated_file_size < analysis_end+9)
file_recovery_new->calculated_file_size=analysis_end+9;
if(file_recovery_new->calculated_file_size < stext_end+9)
file_recovery_new->calculated_file_size=stext_end+9;
file_recovery_new->data_check=&data_check_size;
file_recovery_new->file_check=&file_check_size;
return 1;
}
static void register_header_check_fcs(file_stat_t *file_stat)
{
static const unsigned char fcs_signature[6]= {'F','C','S','3','.','0'};
register_header_check(0, fcs_signature, sizeof(fcs_signature), &header_check_fcs, file_stat);
}
#endif
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