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src/file_mpg.c: add frama-c annotations

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This commit is contained in:
Christophe Grenier 2020-10-01 18:48:14 +02:00
parent 2ac4c3a15b
commit be80b162a7
1 changed files with 73 additions and 4 deletions
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77
src/file_mpg.c
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@ -29,6 +29,7 @@
#endif
#include <stdio.h>
#include "types.h"
#include "common.h"
#include "filegen.h"
#include "log.h"
@ -43,6 +44,10 @@ const file_hint_t file_hint_mpg= {
.register_header_check=&register_header_check_mpg
};
/*@
@ requires \valid_read(buffer + (0 .. 13));
@ assigns \nothing;
@*/
static unsigned int calculate_packet_size(const unsigned char *buffer)
{
/* http://dvd.sourceforge.net/dvdinfo/mpeghdrs.html */
@ -134,8 +139,21 @@ static unsigned int calculate_packet_size(const unsigned char *buffer)
}
}
/*@
@ 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_mpg;
@ requires \separated(buffer + (..), file_recovery);
@ ensures \result == DC_CONTINUE || \result == DC_STOP;
@ assigns file_recovery->calculated_file_size;
@*/
static data_check_t data_check_mpg(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 + 14 < file_recovery->file_size + buffer_size/2)
{
@ -162,10 +180,22 @@ static int header_mpg_found(file_recovery_t *file_recovery_new)
return 1;
}
/*@
@ requires buffer_size >= 13;
@ requires \valid_read(buffer+(0..buffer_size-1));
@ requires \valid_read(file_recovery);
@ requires file_recovery->file_stat==\null || valid_read_string((char*)file_recovery->filename);
@ requires \valid(file_recovery_new);
@ requires file_recovery_new->blocksize > 0;
@ requires separation: \separated(&file_hint_mpg, buffer+(..), file_recovery, file_recovery_new);
@*/
static int header_check_mpg_Pack(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)
{
unsigned int i=0;
while(i<buffer_size && i+14<512)
/*@
@ loop assigns i;
@*/
while(i+14 < td_min(buffer_size,512U))
{
const unsigned int ret=calculate_packet_size(&buffer[i]);
if(ret==0)
@ -225,6 +255,15 @@ static int header_check_mpg_Pack(const unsigned char *buffer, const unsigned int
return 0;
}
/*@
@ requires buffer_size >= 12;
@ requires \valid_read(buffer+(0..buffer_size-1));
@ requires \valid_read(file_recovery);
@ requires file_recovery->file_stat==\null || valid_read_string((char*)file_recovery->filename);
@ requires \valid(file_recovery_new);
@ requires file_recovery_new->blocksize > 0;
@ requires separation: \separated(&file_hint_mpg, buffer+(..), file_recovery, file_recovery_new);
@*/
static int header_check_mpg_System(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)
{
/* MPEG-1 http://andrewduncan.ws/MPEG/MPEG-1.ps */
@ -249,7 +288,10 @@ static int header_check_mpg_System(const unsigned char *buffer, const unsigned i
if((buffer[6]&0x80)==0x80 && (buffer[8]&0x01)==0x01 && buffer[11]==0xff)
{
unsigned int i=0;
while(i<buffer_size && i+14<512)
/*@
@ loop assigns i;
@*/
while(i+14 < td_min(buffer_size,512U))
{
const unsigned int ret=calculate_packet_size(&buffer[i]);
if(ret==0)
@ -266,6 +308,15 @@ static int header_check_mpg_System(const unsigned char *buffer, const unsigned i
return 0;
}
/*@
@ requires buffer_size >= 11;
@ requires \valid_read(buffer+(0..buffer_size-1));
@ requires \valid_read(file_recovery);
@ requires file_recovery->file_stat==\null || valid_read_string((char*)file_recovery->filename);
@ requires \valid(file_recovery_new);
@ requires file_recovery_new->blocksize > 0;
@ requires separation: \separated(&file_hint_mpg, buffer+(..), file_recovery, file_recovery_new);
@*/
static int header_check_mpg_Sequence(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)
{
/* MPEG-1 sequence header code 0x1B3 */
@ -283,7 +334,10 @@ static int header_check_mpg_Sequence(const unsigned char *buffer, const unsigned
(buffer[10]&0x20)==0x20)
{
unsigned int i=0;
while(i<buffer_size && i+14<512)
/*@
@ loop assigns i;
@*/
while(i+14 < td_min(buffer_size,512U))
{
const unsigned int ret=calculate_packet_size(&buffer[i]);
if(ret==0)
@ -300,6 +354,15 @@ static int header_check_mpg_Sequence(const unsigned char *buffer, const unsigned
return 0;
}
/*@
@ requires buffer_size >= 6;
@ requires \valid_read(buffer+(0..buffer_size-1));
@ requires \valid_read(file_recovery);
@ requires file_recovery->file_stat==\null || valid_read_string((char*)file_recovery->filename);
@ requires \valid(file_recovery_new);
@ requires file_recovery_new->blocksize > 0;
@ requires separation: \separated(&file_hint_mpg, buffer+(..), file_recovery, file_recovery_new);
@*/
static int header_check_mpg4_ElemVideo(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)
{
/* ISO/IEC 14496-2 (MPEG-4 video) ELEMENTARY VIDEO HEADER - visual object start code */
@ -314,7 +377,10 @@ static int header_check_mpg4_ElemVideo(const unsigned char *buffer, const unsign
)
{
unsigned int i=0;
while(i<buffer_size && i+14<512)
/*@
@ loop assigns i;
@*/
while(i+14 < td_min(buffer_size,512U))
{
const unsigned int ret=calculate_packet_size(&buffer[i]);
if(ret==0)
@ -331,6 +397,9 @@ static int header_check_mpg4_ElemVideo(const unsigned char *buffer, const unsign
return 0;
}
/*@
@ requires \valid(file_stat);
@*/
static void register_header_check_mpg(file_stat_t *file_stat)
{
static const unsigned char mpg_header_B3[4]= {0x00, 0x00, 0x01, 0xB3};