FreeRTOS-Kernel/FreeRTOS/Test/CBMC/proofs/ReadNameField/ReadNameField_harness.c
AniruddhaKanhere 4db195c916
Adding FreeRTOS+TCP CBMC proofs to FreeRTOS/FreeRTOS (#56)
ParseDNSReply is to be added in the next PR.
2020-04-21 15:40:08 -07:00

99 lines
3.2 KiB
C

/* Standard includes. */
#include <stdint.h>
/* FreeRTOS includes. */
#include "FreeRTOS.h"
#include "task.h"
#include "queue.h"
#include "list.h"
#include "semphr.h"
/* FreeRTOS+TCP includes. */
#include "FreeRTOS_IP.h"
#include "FreeRTOS_Sockets.h"
#include "FreeRTOS_IP_Private.h"
#include "FreeRTOS_UDP_IP.h"
#include "FreeRTOS_DNS.h"
#include "NetworkBufferManagement.h"
#include "NetworkInterface.h"
#include "IPTraceMacroDefaults.h"
#include "cbmc.h"
uint8_t *prvReadNameField( uint8_t *pucByte, size_t xSourceLen, char *pcName, size_t xDestLen );
void harness() {
// Choose arbitrary buffer of size at most NETWORK_BUFFER_SIZE
uint8_t my_buffer[NETWORK_BUFFER_SIZE];
size_t my_buffer_offset;
uint8_t *buffer = my_buffer + my_buffer_offset;
size_t buffer_size = NETWORK_BUFFER_SIZE - my_buffer_offset;
__CPROVER_assume(my_buffer_offset <= NETWORK_BUFFER_SIZE);
// Choose arbitrary name of size at most NAME_SIZE
char my_name[NAME_SIZE];
size_t my_name_offset;
char *name = my_name + my_name_offset;
size_t name_size = NAME_SIZE - my_name_offset;
__CPROVER_assume(my_name_offset <= NAME_SIZE);
// Choose arbitrary pointers into buffer and name
size_t buffer_offset;
size_t name_offset;
uint8_t *pucByte = buffer + buffer_offset;
char *pcName = name + name_offset;
__CPROVER_assume(buffer_offset <= NETWORK_BUFFER_SIZE);
__CPROVER_assume(name_offset <= NAME_SIZE);
// Choose arbitrary values for space remaining in the buffers
size_t xSourceLen;
size_t xDestLen;
////////////////////////////////////////////////////////////////
// Specification and proof of prvReadNameField
// CBMC pointer model (this is obviously true)
__CPROVER_assume(NETWORK_BUFFER_SIZE < CBMC_MAX_OBJECT_SIZE);
__CPROVER_assume(NAME_SIZE < CBMC_MAX_OBJECT_SIZE);
// Preconditions
// pointers are valid pointers into buffers
__CPROVER_assume(xSourceLen == 0 ||
(buffer <= pucByte && pucByte < buffer + buffer_size));
__CPROVER_assume(name <= pcName && pcName < name + name_size);
// lengths are valid values for space remaining in the buffers
__CPROVER_assume(pucByte + xSourceLen <= buffer + buffer_size);
__CPROVER_assume(pcName + xDestLen <= name + name_size);
// CBMC loop unwinding: bounds depend on xSourceLen and xDestLen
__CPROVER_assume(xSourceLen <= NETWORK_BUFFER_SIZE);
__CPROVER_assume(xDestLen <= NAME_SIZE);
// Buffer overflow via integer overflow in comparison xNameLen < xDestLen - 1
// In actual code, xDestLen == 254
__CPROVER_assume(xDestLen > 0);
// Save values before function call
SAVE_OLDVAL(pucByte, uint8_t *);
SAVE_OLDVAL(pcName, char *);
SAVE_OLDVAL(xSourceLen, size_t);
SAVE_OLDVAL(xDestLen, size_t);
// function return value is either NULL or the updated value of pucByte
uint8_t *rc = prvReadNameField(pucByte, xSourceLen, pcName, xDestLen);
// Postconditions
// pucByte can be advanced one position past the end of the buffer
__CPROVER_assert((rc == 0) ||
(rc - OLDVAL(pucByte) >= 1 &&
rc - OLDVAL(pucByte) <= OLDVAL(xSourceLen) &&
rc - OLDVAL(pucByte) <= OLDVAL(xDestLen)+2 &&
pucByte == OLDVAL(pucByte) &&
pcName == OLDVAL(pcName) &&
buffer <= rc && rc <= buffer + buffer_size),
"updated pucByte");
}