tc_acceptance.c
417 lines
| 11.2 KiB
| text/x-c
|
CLexer
/ src / tc_acceptance.c
paul
|
r45 | /** 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. | ||||
paul
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r51 | * | ||
paul
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r45 | * @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 TC_LEN_RCV, unsigned char *computed_CRC) | ||||
{ | ||||
/** This function parses TeleCommands. | ||||
* | ||||
* @param TC points to the TeleCommand that will be parsed. | ||||
* @param TC_LEN_RCV is the received packet length. | ||||
paul
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r46 | * | ||
paul
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r45 | * @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; | ||||
paul
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r68 | int status_crc; | ||
paul
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r45 | unsigned char pid; | ||
unsigned char category; | ||||
unsigned int length; | ||||
unsigned char packetType; | ||||
unsigned char packetSubtype; | ||||
paul
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r46 | unsigned char sid; | ||
paul
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r45 | |||
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 | ||||
length = (TCPacket->packetLength[0] * 256) + TCPacket->packetLength[1]; | ||||
packetType = TCPacket->serviceType; | ||||
packetSubtype = TCPacket->serviceSubType; | ||||
paul
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r46 | sid = TCPacket->sourceID; | ||
paul
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r45 | |||
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 ACTUAL LENGTH COMPLIANCE | ||||
{ | ||||
if (length != TC_LEN_RCV ) { | ||||
paul
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r51 | status = WRONG_LEN_PKT; | ||
paul
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r45 | } | ||
} | ||||
if (status == CCSDS_TM_VALID) // CHECK THAT THE PACKET DOES NOT EXCEED THE MAX SIZE | ||||
{ | ||||
if ( length >= CCSDS_TC_PKT_MAX_SIZE ) { | ||||
paul
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r51 | status = WRONG_LEN_PKT; | ||
paul
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r45 | } | ||
} | ||||
if (status == CCSDS_TM_VALID) // CHECK THE TYPE | ||||
{ | ||||
status = tc_check_type( packetType ); | ||||
} | ||||
if (status == CCSDS_TM_VALID) // CHECK THE SUBTYPE | ||||
{ | ||||
status = tc_check_subtype( packetSubtype ); | ||||
} | ||||
paul
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r46 | if (status == CCSDS_TM_VALID) // CHECK THE SID | ||
{ | ||||
status = tc_check_sid( sid ); | ||||
} | ||||
paul
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r45 | if (status == CCSDS_TM_VALID) // CHECK THE SUBTYPE AND LENGTH COMPLIANCE | ||
{ | ||||
status = tc_check_length( packetSubtype, length ); | ||||
} | ||||
paul
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r68 | status_crc = tc_check_crc( TCPacket, length, computed_CRC ); | ||
paul
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r45 | if (status == CCSDS_TM_VALID ) // CHECK CRC | ||
{ | ||||
paul
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r68 | status = status_crc; | ||
paul
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r45 | } | ||
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. | ||||
paul
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r46 | * | ||
paul
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r45 | * @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_subtype( unsigned char packetSubType ) | ||||
{ | ||||
/** This function checks that the subtype of a TeleCommand is valid. | ||||
* | ||||
* @param packetSubType is the subtype to check. | ||||
paul
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r46 | * | ||
paul
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r45 | * @return Status code CCSDS_TM_VALID or ILL_SUBTYPE. | ||
* | ||||
*/ | ||||
int status; | ||||
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_UPDT_TIME) | ||||
|| (packetSubType == TC_SUBTYPE_EN_CAL) || (packetSubType == TC_SUBTYPE_DIS_CAL) ) | ||||
{ | ||||
status = CCSDS_TM_VALID; | ||||
} | ||||
else | ||||
{ | ||||
paul
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r51 | status = ILL_SUBTYPE; | ||
paul
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r45 | } | ||
return status; | ||||
} | ||||
paul
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r46 | 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_GROUND) | ||||
|| (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 | ||||
{ | ||||
paul
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r51 | status = WRONG_SRC_ID; | ||
paul
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r46 | } | ||
return status; | ||||
} | ||||
paul
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r45 | 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. | ||||
paul
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r46 | * | ||
paul
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r45 | * @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)) { | ||||
paul
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r51 | status = WRONG_LEN_PKT; | ||
paul
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r45 | } | ||
else { | ||||
status = CCSDS_TM_VALID; | ||||
} | ||||
break; | ||||
case TC_SUBTYPE_LOAD_COMM: | ||||
if (length!=(TC_LEN_LOAD_COMM-CCSDS_TC_TM_PACKET_OFFSET)) { | ||||
paul
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r51 | status = WRONG_LEN_PKT; | ||
paul
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r45 | } | ||
else { | ||||
status = CCSDS_TM_VALID; | ||||
} | ||||
break; | ||||
case TC_SUBTYPE_LOAD_NORM: | ||||
if (length!=(TC_LEN_LOAD_NORM-CCSDS_TC_TM_PACKET_OFFSET)) { | ||||
paul
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r51 | status = WRONG_LEN_PKT; | ||
paul
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r45 | } | ||
else { | ||||
status = CCSDS_TM_VALID; | ||||
} | ||||
break; | ||||
case TC_SUBTYPE_LOAD_BURST: | ||||
if (length!=(TC_LEN_LOAD_BURST-CCSDS_TC_TM_PACKET_OFFSET)) { | ||||
paul
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r51 | status = WRONG_LEN_PKT; | ||
paul
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r45 | } | ||
else { | ||||
status = CCSDS_TM_VALID; | ||||
} | ||||
break; | ||||
case TC_SUBTYPE_LOAD_SBM1: | ||||
if (length!=(TC_LEN_LOAD_SBM1-CCSDS_TC_TM_PACKET_OFFSET)) { | ||||
paul
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r51 | status = WRONG_LEN_PKT; | ||
paul
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r45 | } | ||
else { | ||||
status = CCSDS_TM_VALID; | ||||
} | ||||
break; | ||||
case TC_SUBTYPE_LOAD_SBM2: | ||||
if (length!=(TC_LEN_LOAD_SBM2-CCSDS_TC_TM_PACKET_OFFSET)) { | ||||
paul
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r51 | status = WRONG_LEN_PKT; | ||
paul
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r45 | } | ||
else { | ||||
status = CCSDS_TM_VALID; | ||||
} | ||||
break; | ||||
case TC_SUBTYPE_DUMP: | ||||
if (length!=(TC_LEN_DUMP-CCSDS_TC_TM_PACKET_OFFSET)) { | ||||
paul
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r51 | status = WRONG_LEN_PKT; | ||
paul
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r45 | } | ||
else { | ||||
status = CCSDS_TM_VALID; | ||||
} | ||||
break; | ||||
case TC_SUBTYPE_ENTER: | ||||
if (length!=(TC_LEN_ENTER-CCSDS_TC_TM_PACKET_OFFSET)) { | ||||
paul
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r51 | status = WRONG_LEN_PKT; | ||
paul
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r45 | } | ||
else { | ||||
status = CCSDS_TM_VALID; | ||||
} | ||||
break; | ||||
case TC_SUBTYPE_UPDT_INFO: | ||||
if (length!=(TC_LEN_UPDT_INFO-CCSDS_TC_TM_PACKET_OFFSET)) { | ||||
paul
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r51 | status = WRONG_LEN_PKT; | ||
paul
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r45 | } | ||
else { | ||||
status = CCSDS_TM_VALID; | ||||
} | ||||
break; | ||||
case TC_SUBTYPE_EN_CAL: | ||||
if (length!=(TC_LEN_EN_CAL-CCSDS_TC_TM_PACKET_OFFSET)) { | ||||
paul
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r51 | status = WRONG_LEN_PKT; | ||
paul
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r45 | } | ||
else { | ||||
status = CCSDS_TM_VALID; | ||||
} | ||||
break; | ||||
case TC_SUBTYPE_DIS_CAL: | ||||
if (length!=(TC_LEN_DIS_CAL-CCSDS_TC_TM_PACKET_OFFSET)) { | ||||
paul
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r51 | status = WRONG_LEN_PKT; | ||
paul
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r45 | } | ||
else { | ||||
status = CCSDS_TM_VALID; | ||||
} | ||||
break; | ||||
case TC_SUBTYPE_UPDT_TIME: | ||||
if (length!=(TC_LEN_UPDT_TIME-CCSDS_TC_TM_PACKET_OFFSET)) { | ||||
paul
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r51 | status = WRONG_LEN_PKT; | ||
paul
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r45 | } | ||
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. | ||||
paul
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r46 | * | ||
paul
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r45 | * @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; | ||||
} | ||||