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src/file_emf.c: add frama-c annotations

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This commit is contained in:
Christophe Grenier 2020-01-01 11:07:13 +01:00
parent 00539e593c
commit 5e04d6fc53
1 changed files with 159 additions and 28 deletions
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187
src/file_emf.c
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@ -30,10 +30,11 @@
#include "filegen.h"
#include "log.h"
#include "common.h"
#if defined(__FRAMAC__)
#include "__fc_builtin.h"
#endif
static void register_header_check_emf(file_stat_t *file_stat);
static int header_check_emf(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);
static data_check_t data_check_emf(const unsigned char *buffer, const unsigned int buffer_size, file_recovery_t *file_recovery);
const file_hint_t file_hint_emf= {
.extension="emf",
@ -201,37 +202,30 @@ struct EMF_HDR
#define EMR_COLORMATCHTOTARGETW 121
#define EMR_CREATECOLORSPACEW 122
static int header_check_emf(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)
{
static const unsigned char emf_header[4]= { 0x01, 0x00, 0x00, 0x00};
const struct EMF_HDR *hdr=(const struct EMF_HDR *)buffer;
const unsigned int atom_size=le32(hdr->emr.nSize);
if(memcmp(buffer,emf_header,sizeof(emf_header))==0 &&
le32(hdr->nBytes) >= 88 &&
le16(hdr->sReserved)==0 &&
atom_size>=0x34 && atom_size%4==0)
{
reset_file_recovery(file_recovery_new);
file_recovery_new->extension=file_hint_emf.extension;
if(file_recovery_new->blocksize >= 8)
{
file_recovery_new->data_check=&data_check_emf;
file_recovery_new->file_check=&file_check_size;
file_recovery_new->calculated_file_size=atom_size;
}
return 1;
}
return 0;
}
/*@
@ requires buffer_size >= 2;
@ requires (buffer_size&1)==0;
@ requires \valid_read(buffer+(0..buffer_size-1));
@ requires \valid(file_recovery);
@ requires file_recovery->data_check==&data_check_emf;
@ ensures \result == DC_CONTINUE || \result == DC_STOP || \result == DC_ERROR;
@ ensures \result == DC_CONTINUE ==> (file_recovery->calculated_file_size >= file_recovery->file_size + buffer_size/2 - 8);
@ ensures file_recovery->data_check==&data_check_emf;
@ assigns file_recovery->calculated_file_size;
@*/
static data_check_t data_check_emf(const unsigned char *buffer, const unsigned int buffer_size, file_recovery_t *file_recovery)
{
/*@
@ loop assigns file_recovery->calculated_file_size;
@*/
while(file_recovery->calculated_file_size + buffer_size/2 >= file_recovery->file_size &&
file_recovery->calculated_file_size + 8 < file_recovery->file_size + buffer_size/2)
{
const unsigned int i=file_recovery->calculated_file_size - file_recovery->file_size + buffer_size/2;
const unsigned int itype=buffer[i]+(buffer[i+1]<<8)+(buffer[i+2]<<16)+(buffer[i+3]<<24);
const unsigned int atom_size=buffer[i+4]+(buffer[i+5]<<8)+(buffer[i+6]<<16)+(buffer[i+7]<<24);
const unsigned int i=file_recovery->calculated_file_size + buffer_size/2 - file_recovery->file_size;
/*@ assert 0 <= i < buffer_size - 8 ; */
const U_EMR *hdr=(const U_EMR *)&buffer[i];
const unsigned int itype=le32(hdr->iType);
const unsigned int atom_size=le32(hdr->nSize);
#ifdef DEBUG_EMF
log_trace("0x%llx ", (long long unsigned)file_recovery->calculated_file_size);
switch(itype)
@ -362,15 +356,152 @@ static data_check_t data_check_emf(const unsigned char *buffer, const unsigned i
#endif
if(atom_size<8 || atom_size%4!=0 || atom_size>1024*1024)
return DC_ERROR;
/*@ assert 8 <= atom_size <= 1024*1024; */
file_recovery->calculated_file_size+=(uint64_t)atom_size;
if(itype==EMR_EOF)
return DC_STOP;
/*@ assert file_recovery->calculated_file_size < file_recovery->file_size + buffer_size/2 - 8 + 1024*1024; */
}
/*@ assert file_recovery->calculated_file_size < file_recovery->file_size - buffer_size/2 || file_recovery->calculated_file_size >= file_recovery->file_size + buffer_size/2 - 8; */
/*@ assert file_recovery->calculated_file_size >= file_recovery->file_size + buffer_size/2 - 8; */
return DC_CONTINUE;
}
/*@
@ requires buffer_size >= sizeof(struct EMF_HDR);
@ requires \valid_read(buffer+(0..buffer_size-1));
@ requires \valid_read(file_recovery);
@ requires \valid(file_recovery_new);
@ requires file_recovery_new->blocksize > 0;
@ requires separation: \separated(file_recovery, file_recovery_new);
@ ensures \result == 0 || \result == 1;
@ ensures (\result == 1) ==> (file_recovery_new->extension == file_hint_emf.extension);
@ ensures (\result == 1) ==> (file_recovery_new->calculated_file_size >= 0x34);
@ ensures (\result == 1) ==> (file_recovery_new->file_size == 0);
@ ensures (\result == 1) ==> (file_recovery_new->min_filesize == 0);
@ ensures (\result == 1) ==> (file_recovery_new->file_check == &file_check_size);
@ ensures (\result == 1) ==> (file_recovery_new->data_check == &data_check_emf);
@ ensures (\result == 1) ==> (file_recovery_new->file_rename== \null);
@ ensures (\result == 1) ==> (valid_read_string(file_recovery_new->extension));
@ ensures (\result == 1) ==> \separated(file_recovery_new, file_recovery_new->extension);
@*/
static int header_check_emf(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)
{
static const unsigned char emf_header[4]= { 0x01, 0x00, 0x00, 0x00};
const struct EMF_HDR *hdr=(const struct EMF_HDR *)buffer;
const unsigned int atom_size=le32(hdr->emr.nSize);
if(memcmp(buffer,emf_header,sizeof(emf_header))==0 &&
le32(hdr->nBytes) >= 88 &&
le16(hdr->sReserved)==0 &&
atom_size>=0x34 && atom_size%4==0)
{
reset_file_recovery(file_recovery_new);
file_recovery_new->extension=file_hint_emf.extension;
if(file_recovery_new->blocksize >= 8)
{
file_recovery_new->data_check=&data_check_emf;
file_recovery_new->file_check=&file_check_size;
file_recovery_new->calculated_file_size=atom_size;
}
return 1;
}
return 0;
}
/*@
@ requires \valid(file_stat);
@*/
static void register_header_check_emf(file_stat_t *file_stat)
{
static const unsigned char emf_sign[4]= { ' ','E', 'M','F'};
register_header_check(0x28, emf_sign,sizeof(emf_sign), &header_check_emf, file_stat);
}
#if defined(MAIN_emf)
#define BLOCKSIZE 65536u
int main()
{
const char fn[] = "recup_dir.1/f0000000.emf";
unsigned char buffer[BLOCKSIZE];
file_recovery_t file_recovery_new;
file_recovery_t file_recovery;
file_stat_t file_stats;
/*@ assert \valid(buffer + (0 .. (BLOCKSIZE - 1))); */
#if defined(__FRAMAC__)
Frama_C_make_unknown((char *)buffer, BLOCKSIZE);
#endif
reset_file_recovery(&file_recovery);
file_recovery.blocksize=BLOCKSIZE;
file_recovery_new.blocksize=BLOCKSIZE;
file_recovery_new.data_check=NULL;
file_recovery_new.file_stat=NULL;
file_recovery_new.file_check=NULL;
file_recovery_new.file_rename=NULL;
file_recovery_new.calculated_file_size=0;
file_recovery_new.file_size=0;
file_recovery_new.location.start=0;
file_stats.file_hint=&file_hint_emf;
file_stats.not_recovered=0;
file_stats.recovered=0;
register_header_check_emf(&file_stats);
if(header_check_emf(buffer, BLOCKSIZE, 0u, &file_recovery, &file_recovery_new)!=1)
return 0;
/*@ assert file_recovery_new.file_size == 0; */
/*@ assert file_recovery_new.calculated_file_size > 0; */
/*@ assert file_recovery_new.data_check == &data_check_emf; */
/*@ assert file_recovery_new.file_check == &file_check_size; */
/*@ assert file_recovery_new.file_rename == \null; */
/*@ assert file_recovery_new.extension == file_hint_emf.extension; */
/*@ assert valid_read_string(file_recovery_new.extension); */
/*@ assert \separated(&file_recovery_new, file_recovery_new.extension); */
/*@ assert valid_read_string((char *)&fn); */
memcpy(file_recovery_new.filename, fn, sizeof(fn));
/*@ assert valid_read_string((char *)&file_recovery_new.filename); */
/*@ assert valid_read_string((char *)file_recovery_new.filename); */
/*X TODO assert valid_read_string(file_recovery_new.extension); */
file_recovery_new.file_stat=&file_stats;
{
unsigned char big_buffer[2*BLOCKSIZE];
data_check_t res_data_check=DC_CONTINUE;
memset(big_buffer, 0, BLOCKSIZE);
memcpy(big_buffer + BLOCKSIZE, buffer, BLOCKSIZE);
/*@ assert file_recovery_new.data_check == &data_check_emf; */
/*@ assert file_recovery_new.file_size == 0; */;
/*@ assert file_recovery_new.file_size <= file_recovery_new.calculated_file_size; */;
res_data_check=data_check_emf(big_buffer, 2*BLOCKSIZE, &file_recovery_new);
file_recovery_new.file_size+=BLOCKSIZE;
if(res_data_check == DC_CONTINUE)
{
memcpy(big_buffer, big_buffer + BLOCKSIZE, BLOCKSIZE);
#if defined(__FRAMAC__)
Frama_C_make_unknown((char *)big_buffer + BLOCKSIZE, BLOCKSIZE);
#endif
data_check_emf(big_buffer, 2*BLOCKSIZE, &file_recovery_new);
}
}
{
file_recovery_t file_recovery_new2;
/* Test when another file of the same is detected in the next block */
file_recovery_new2.blocksize=BLOCKSIZE;
file_recovery_new2.file_stat=NULL;
file_recovery_new2.file_check=NULL;
file_recovery_new2.location.start=BLOCKSIZE;
file_recovery_new.handle=NULL; /* In theory should be not null */
header_check_emf(buffer, BLOCKSIZE, 0, &file_recovery_new, &file_recovery_new2);
/*@ assert valid_read_string((char *)file_recovery_new.filename); */
}
/*@ assert valid_read_string((char *)file_recovery_new.filename); */
{
file_recovery_new.handle=fopen(fn, "rb");
if(file_recovery_new.handle!=NULL)
{
file_check_size(&file_recovery_new);
fclose(file_recovery_new.handle);
}
}
return 0;
}
#endif