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src/file_ogg.c: fix frama-c warnings

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This commit is contained in:
Christophe Grenier 2021-02-25 22:18:18 +01:00
parent fe86da028b
commit ec9b9b363a
1 changed files with 64 additions and 35 deletions
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99
src/file_ogg.c
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@ -32,8 +32,8 @@
#include "filegen.h"
#include "log.h"
/*@ requires \valid(file_stat); */
static void register_header_check_ogg(file_stat_t *file_stat);
static data_check_t data_check_ogg(const unsigned char *buffer, const unsigned int buffer_size, file_recovery_t *file_recovery);
const file_hint_t file_hint_ogg= {
.extension="ogg",
@ -47,6 +47,69 @@ const file_hint_t file_hint_ogg= {
/* header=OggS, version=0 */
static const unsigned char ogg_header[5]= {'O','g','g','S', 0x00};
/* http://www.ietf.org/rfc/rfc3533.txt */
/*@
@ requires buffer_size > 0;
@ requires (buffer_size&1)==0;
@ requires \valid_read(buffer+(0..buffer_size-1));
@ requires \valid(file_recovery);
@ requires file_recovery->data_check==&data_check_ogg;
@ requires file_recovery->calculated_file_size <= PHOTOREC_MAX_FILE_SIZE;
@ requires \separated(buffer, file_recovery);
@ ensures \result == DC_CONTINUE || \result == DC_STOP;
@ assigns file_recovery->calculated_file_size;
@*/
static data_check_t data_check_ogg(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 + 27 +255 < file_recovery->file_size + buffer_size/2)
{
const unsigned int i=file_recovery->calculated_file_size + buffer_size/2 - file_recovery->file_size;
/*@ assert 0 <= i < buffer_size - (27 + 255); */
if(memcmp(&buffer[i],ogg_header,sizeof(ogg_header))==0)
{
const unsigned int number_page_segments=buffer[i+26];
const unsigned int header_size = number_page_segments + 27;
unsigned int page_size;
unsigned int j;
page_size=header_size;
/*@
@ loop invariant page_size <= 255 + 27 + j * 255;
@ loop assigns j, page_size;
@ */
for(j=0; j<number_page_segments; j++)
page_size+=buffer[i+27+j];
if(page_size<27)
{
return DC_STOP;
}
/* By definition, page_size<=27+255+255*255=65307 */
file_recovery->calculated_file_size+=page_size;
/*
log_debug("+0x%x=0x%x\n",page_size,file_recovery->calculated_file_size);
*/
}
else
{
return DC_STOP;
}
}
return DC_CONTINUE;
}
/*@
@ requires buffer_size >= 0x78+7;
@ requires \valid_read(buffer+(0..buffer_size-1));
@ requires valid_file_recovery(file_recovery);
@ requires \valid(file_recovery_new);
@ requires file_recovery_new->blocksize > 0;
@ requires separation: \separated(&file_hint_ogg, buffer+(..), file_recovery, file_recovery_new);
@ ensures \result == 0 || \result == 1;
@ ensures \result!=0 ==> valid_file_recovery(file_recovery_new);
@*/
static int header_check_ogg(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 sign_theora[7]= {0x80, 't', 'h', 'e', 'o', 'r', 'a'};
@ -76,40 +139,6 @@ static int header_check_ogg(const unsigned char *buffer, const unsigned int buff
return 1;
}
/* http://www.ietf.org/rfc/rfc3533.txt */
static data_check_t data_check_ogg(const unsigned char *buffer, const unsigned int buffer_size, file_recovery_t *file_recovery)
{
while(file_recovery->calculated_file_size + buffer_size/2 >= file_recovery->file_size &&
file_recovery->calculated_file_size + 27 +255 < file_recovery->file_size + buffer_size/2)
{
const unsigned int i=file_recovery->calculated_file_size - file_recovery->file_size + buffer_size/2;
if(memcmp(&buffer[i],ogg_header,sizeof(ogg_header))==0)
{
const unsigned int number_page_segments=buffer[i+26];
const unsigned int header_size = number_page_segments + 27;
unsigned int page_size;
unsigned int j;
page_size=header_size;
for(j=0;j<number_page_segments;j++)
page_size+=buffer[i+27+j];
if(page_size<27)
{
return DC_STOP;
}
/* By definition, page_size<=27+255+255*255=65307 */
file_recovery->calculated_file_size+=page_size;
/*
log_debug("+0x%x=0x%x\n",page_size,file_recovery->calculated_file_size);
*/
}
else
{
return DC_STOP;
}
}
return DC_CONTINUE;
}
static void register_header_check_ogg(file_stat_t *file_stat)
{
register_header_check(0, ogg_header,sizeof(ogg_header), &header_check_ogg, file_stat);