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934 HK_LFR_SC_RW1_F1_FLAG not updated when RW1_F1 is set
934 HK_LFR_SC_RW1_F1_FLAG not updated when RW1_F1 is set

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tc_acceptance.c
437 lines | 11.8 KiB | text/x-c | CLexer
/** Functions related to TeleCommand acceptance.
*
* @file
* @author P. LEROY
*
* A group of functions to handle TeleCommands parsing.\n
*
*/
#include "tc_acceptance.h"
unsigned int lookUpTableForCRC[256];
//**********************
// GENERAL USE FUNCTIONS
unsigned int Crc_opt( unsigned char D, unsigned int Chk)
{
/** This function generate the CRC for one byte and returns the value of the new syndrome.
*
* @param D is the current byte of data.
* @param Chk is the current syndrom value.
*
* @return the value of the new syndrome on two bytes.
*
*/
return(((Chk << 8) & 0xff00)^lookUpTableForCRC [(((Chk >> 8)^D) & 0x00ff)]);
}
void initLookUpTableForCRC( void )
{
/** This function is used to initiates the look-up table for fast CRC computation.
*
* The global table lookUpTableForCRC[256] is initiated.
*
*/
unsigned int i;
unsigned int tmp;
for (i=0; i<256; i++)
{
tmp = 0;
if((i & 1) != 0) {
tmp = tmp ^ 0x1021;
}
if((i & 2) != 0) {
tmp = tmp ^ 0x2042;
}
if((i & 4) != 0) {
tmp = tmp ^ 0x4084;
}
if((i & 8) != 0) {
tmp = tmp ^ 0x8108;
}
if((i & 16) != 0) {
tmp = tmp ^ 0x1231;
}
if((i & 32) != 0) {
tmp = tmp ^ 0x2462;
}
if((i & 64) != 0) {
tmp = tmp ^ 0x48c4;
}
if((i & 128) != 0) {
tmp = tmp ^ 0x9188;
}
lookUpTableForCRC[i] = tmp;
}
}
void GetCRCAsTwoBytes(unsigned char* data, unsigned char* crcAsTwoBytes, unsigned int sizeOfData)
{
/** This function calculates a two bytes Cyclic Redundancy Code.
*
* @param data points to a buffer containing the data on which to compute the CRC.
* @param crcAsTwoBytes points points to a two bytes buffer in which the CRC is stored.
* @param sizeOfData is the number of bytes of *data* used to compute the CRC.
*
* The specification of the Cyclic Redundancy Code is described in the following document: ECSS-E-70-41-A.
*
*/
unsigned int Chk;
int j;
Chk = 0xffff; // reset the syndrom to all ones
for (j=0; j<sizeOfData; j++) {
Chk = Crc_opt(data[j], Chk);
}
crcAsTwoBytes[0] = (unsigned char) (Chk >> 8);
crcAsTwoBytes[1] = (unsigned char) (Chk & 0x00ff);
}
//*********************
// ACCEPTANCE FUNCTIONS
int tc_parser(ccsdsTelecommandPacket_t * TCPacket, unsigned int estimatedPacketLength, unsigned char *computed_CRC)
{
/** This function parses TeleCommands.
*
* @param TC points to the TeleCommand that will be parsed.
* @param estimatedPacketLength is the PACKET_LENGTH field calculated from the effective length of the received packet.
*
* @return Status code of the parsing.
*
* The parsing checks:
* - process id
* - category
* - length: a global check is performed and a per subtype check also
* - type
* - subtype
* - crc
*
*/
int status;
int status_crc;
unsigned char pid;
unsigned char category;
unsigned int packetLength;
unsigned char packetType;
unsigned char packetSubtype;
unsigned char sid;
status = CCSDS_TM_VALID;
// APID check *** APID on 2 bytes
pid = ((TCPacket->packetID[0] & 0x07)<<4) + ( (TCPacket->packetID[1]>>4) & 0x0f ); // PID = 11 *** 7 bits xxxxx210 7654xxxx
category = (TCPacket->packetID[1] & 0x0f); // PACKET_CATEGORY = 12 *** 4 bits xxxxxxxx xxxx3210
packetLength = (TCPacket->packetLength[0] * 256) + TCPacket->packetLength[1];
packetType = TCPacket->serviceType;
packetSubtype = TCPacket->serviceSubType;
sid = TCPacket->sourceID;
if ( pid != CCSDS_PROCESS_ID ) // CHECK THE PROCESS ID
{
status = ILLEGAL_APID;
}
if (status == CCSDS_TM_VALID) // CHECK THE CATEGORY
{
if ( category != CCSDS_PACKET_CATEGORY )
{
status = ILLEGAL_APID;
}
}
if (status == CCSDS_TM_VALID) // CHECK THE PACKET_LENGTH FIELD AND THE ESTIMATED PACKET_LENGTH COMPLIANCE
{
if (packetLength != estimatedPacketLength ) {
status = WRONG_LEN_PKT;
}
}
if (status == CCSDS_TM_VALID) // CHECK THAT THE PACKET DOES NOT EXCEED THE MAX SIZE
{
if ( packetLength >= CCSDS_TC_PKT_MAX_SIZE ) {
status = WRONG_LEN_PKT;
}
}
if (status == CCSDS_TM_VALID) // CHECK THE TYPE
{
status = tc_check_type( packetType );
}
if (status == CCSDS_TM_VALID) // CHECK THE SUBTYPE
{
status = tc_check_type_subtype( packetType, packetSubtype );
}
if (status == CCSDS_TM_VALID) // CHECK THE SID
{
status = tc_check_sid( sid );
}
if (status == CCSDS_TM_VALID) // CHECK THE SUBTYPE AND LENGTH COMPLIANCE
{
status = tc_check_length( packetSubtype, packetLength );
}
status_crc = tc_check_crc( TCPacket, estimatedPacketLength, computed_CRC );
if (status == CCSDS_TM_VALID ) // CHECK CRC
{
status = status_crc;
}
return status;
}
int tc_check_type( unsigned char packetType )
{
/** This function checks that the type of a TeleCommand is valid.
*
* @param packetType is the type to check.
*
* @return Status code CCSDS_TM_VALID or ILL_TYPE.
*
*/
int status;
if ( (packetType == TC_TYPE_GEN) || (packetType == TC_TYPE_TIME))
{
status = CCSDS_TM_VALID;
}
else
{
status = ILL_TYPE;
}
return status;
}
int tc_check_type_subtype( unsigned char packetType, unsigned char packetSubType )
{
/** This function checks that the subtype of a TeleCommand is valid and coherent with the type.
*
* @param packetType is the type of the TC.
* @param packetSubType is the subtype to check.
*
* @return Status code CCSDS_TM_VALID or ILL_SUBTYPE.
*
*/
int status;
switch(packetType)
{
case TC_TYPE_GEN:
if ( (packetSubType == TC_SUBTYPE_RESET)
|| (packetSubType == TC_SUBTYPE_LOAD_COMM)
|| (packetSubType == TC_SUBTYPE_LOAD_NORM) || (packetSubType == TC_SUBTYPE_LOAD_BURST)
|| (packetSubType == TC_SUBTYPE_LOAD_SBM1) || (packetSubType == TC_SUBTYPE_LOAD_SBM2)
|| (packetSubType == TC_SUBTYPE_DUMP)
|| (packetSubType == TC_SUBTYPE_ENTER)
|| (packetSubType == TC_SUBTYPE_UPDT_INFO)
|| (packetSubType == TC_SUBTYPE_EN_CAL) || (packetSubType == TC_SUBTYPE_DIS_CAL) )
{
status = CCSDS_TM_VALID;
}
else
{
status = ILL_SUBTYPE;
}
break;
case TC_TYPE_TIME:
if (packetSubType == TC_SUBTYPE_UPDT_TIME)
{
status = CCSDS_TM_VALID;
}
else
{
status = ILL_SUBTYPE;
}
break;
default:
status = ILL_SUBTYPE;
break;
}
return status;
}
int tc_check_sid( unsigned char sid )
{
/** This function checks that the sid of a TeleCommand is valid.
*
* @param sid is the sid to check.
*
* @return Status code CCSDS_TM_VALID or CORRUPTED.
*
*/
int status;
if ( (sid == SID_TC_MISSION_TIMELINE) || (sid == SID_TC_TC_SEQUENCES) || (sid == SID_TC_RECOVERY_ACTION_CMD)
|| (sid == SID_TC_BACKUP_MISSION_TIMELINE)
|| (sid == SID_TC_DIRECT_CMD) || (sid == SID_TC_SPARE_GRD_SRC1) || (sid == SID_TC_SPARE_GRD_SRC2)
|| (sid == SID_TC_OBCP) || (sid == SID_TC_SYSTEM_CONTROL) || (sid == SID_TC_AOCS)
|| (sid == SID_TC_RPW_INTERNAL))
{
status = CCSDS_TM_VALID;
}
else
{
status = WRONG_SRC_ID;
}
return status;
}
int tc_check_length( unsigned char packetSubType, unsigned int length )
{
/** This function checks that the subtype and the length are compliant.
*
* @param packetSubType is the subtype to check.
* @param length is the length to check.
*
* @return Status code CCSDS_TM_VALID or ILL_TYPE.
*
*/
int status;
status = LFR_SUCCESSFUL;
switch(packetSubType)
{
case TC_SUBTYPE_RESET:
if (length!=(TC_LEN_RESET-CCSDS_TC_TM_PACKET_OFFSET)) {
status = WRONG_LEN_PKT;
}
else {
status = CCSDS_TM_VALID;
}
break;
case TC_SUBTYPE_LOAD_COMM:
if (length!=(TC_LEN_LOAD_COMM-CCSDS_TC_TM_PACKET_OFFSET)) {
status = WRONG_LEN_PKT;
}
else {
status = CCSDS_TM_VALID;
}
break;
case TC_SUBTYPE_LOAD_NORM:
if (length!=(TC_LEN_LOAD_NORM-CCSDS_TC_TM_PACKET_OFFSET)) {
status = WRONG_LEN_PKT;
}
else {
status = CCSDS_TM_VALID;
}
break;
case TC_SUBTYPE_LOAD_BURST:
if (length!=(TC_LEN_LOAD_BURST-CCSDS_TC_TM_PACKET_OFFSET)) {
status = WRONG_LEN_PKT;
}
else {
status = CCSDS_TM_VALID;
}
break;
case TC_SUBTYPE_LOAD_SBM1:
if (length!=(TC_LEN_LOAD_SBM1-CCSDS_TC_TM_PACKET_OFFSET)) {
status = WRONG_LEN_PKT;
}
else {
status = CCSDS_TM_VALID;
}
break;
case TC_SUBTYPE_LOAD_SBM2:
if (length!=(TC_LEN_LOAD_SBM2-CCSDS_TC_TM_PACKET_OFFSET)) {
status = WRONG_LEN_PKT;
}
else {
status = CCSDS_TM_VALID;
}
break;
case TC_SUBTYPE_DUMP:
if (length!=(TC_LEN_DUMP-CCSDS_TC_TM_PACKET_OFFSET)) {
status = WRONG_LEN_PKT;
}
else {
status = CCSDS_TM_VALID;
}
break;
case TC_SUBTYPE_ENTER:
if (length!=(TC_LEN_ENTER-CCSDS_TC_TM_PACKET_OFFSET)) {
status = WRONG_LEN_PKT;
}
else {
status = CCSDS_TM_VALID;
}
break;
case TC_SUBTYPE_UPDT_INFO:
if (length!=(TC_LEN_UPDT_INFO-CCSDS_TC_TM_PACKET_OFFSET)) {
status = WRONG_LEN_PKT;
}
else {
status = CCSDS_TM_VALID;
}
break;
case TC_SUBTYPE_EN_CAL:
if (length!=(TC_LEN_EN_CAL-CCSDS_TC_TM_PACKET_OFFSET)) {
status = WRONG_LEN_PKT;
}
else {
status = CCSDS_TM_VALID;
}
break;
case TC_SUBTYPE_DIS_CAL:
if (length!=(TC_LEN_DIS_CAL-CCSDS_TC_TM_PACKET_OFFSET)) {
status = WRONG_LEN_PKT;
}
else {
status = CCSDS_TM_VALID;
}
break;
case TC_SUBTYPE_UPDT_TIME:
if (length!=(TC_LEN_UPDT_TIME-CCSDS_TC_TM_PACKET_OFFSET)) {
status = WRONG_LEN_PKT;
}
else {
status = CCSDS_TM_VALID;
}
break;
default: // if the subtype is not a legal value, return ILL_SUBTYPE
status = ILL_SUBTYPE;
break ;
}
return status;
}
int tc_check_crc( ccsdsTelecommandPacket_t * TCPacket, unsigned int length, unsigned char *computed_CRC )
{
/** This function checks the CRC validity of the corresponding TeleCommand packet.
*
* @param TCPacket points to the TeleCommand packet to check.
* @param length is the length of the TC packet.
*
* @return Status code CCSDS_TM_VALID or INCOR_CHECKSUM.
*
*/
int status;
unsigned char * CCSDSContent;
CCSDSContent = (unsigned char*) TCPacket->packetID;
GetCRCAsTwoBytes(CCSDSContent, computed_CRC, length + CCSDS_TC_TM_PACKET_OFFSET - 2); // 2 CRC bytes removed from the calculation of the CRC
if (computed_CRC[0] != CCSDSContent[length + CCSDS_TC_TM_PACKET_OFFSET -2]) {
status = INCOR_CHECKSUM;
}
else if (computed_CRC[1] != CCSDSContent[length + CCSDS_TC_TM_PACKET_OFFSET -1]) {
status = INCOR_CHECKSUM;
}
else {
status = CCSDS_TM_VALID;
}
return status;
}