added PLOC sequence count. Not tested yet

This commit is contained in:
Jakob Meier 2021-04-27 12:18:04 +02:00
commit 73d56559c3
3 changed files with 62 additions and 20 deletions

View File

@ -92,11 +92,16 @@ ReturnValue_t PlocHandler::scanForReply(const uint8_t *start,
default: {
sif::debug << "PlocHandler::scanForReply: Reply has invalid apid" << std::endl;
*foundLen = remainingSize;
result = INVALID_APID;
break;
return INVALID_APID;
}
}
/**
* This should normally never fail. However, this function is also responsible for incrementing
* the packet sequence count why it is called here.
*/
result = checkPacketSequenceCount(start);
return result;
}
@ -151,7 +156,7 @@ ReturnValue_t PlocHandler::prepareTcMemWriteCommand(const uint8_t * commandData,
| *(commandData + 2) << 8 | *(commandData + 3);
const uint32_t memoryData = *(commandData + 4) << 24 | *(commandData + 5) << 16
| *(commandData + 6) << 8 | *(commandData + 7);
PLOC::TcMemWrite tcMemWrite(memoryAddress, memoryData);
PLOC::TcMemWrite tcMemWrite(memoryAddress, memoryData, packetSequenceCount);
if (tcMemWrite.getFullSize() > PLOC::MAX_COMMAND_SIZE) {
sif::debug << "PlocHandler::prepareTcMemWriteCommand: Command too big" << std::endl;
return RETURN_FAILED;
@ -167,7 +172,7 @@ ReturnValue_t PlocHandler::prepareTcMemReadCommand(const uint8_t * commandData,
size_t commandDataLen) {
const uint32_t memoryAddress = *(commandData) << 24 | *(commandData + 1) << 16
| *(commandData + 2) << 8 | *(commandData + 3);
PLOC::TcMemRead tcMemRead(memoryAddress);
PLOC::TcMemRead tcMemRead(memoryAddress, packetSequenceCount);
if (tcMemRead.getFullSize() > PLOC::MAX_COMMAND_SIZE) {
sif::debug << "PlocHandler::prepareTcMemReadCommand: Command too big" << std::endl;
return RETURN_FAILED;
@ -176,6 +181,7 @@ ReturnValue_t PlocHandler::prepareTcMemReadCommand(const uint8_t * commandData,
rawPacket = commandBuffer;
rawPacketLen = tcMemRead.getFullSize();
nextReplyId = PLOC::ACK_REPORT;
return RETURN_OK;
}
@ -183,7 +189,7 @@ ReturnValue_t PlocHandler::verifyPacket(const uint8_t* start, size_t foundLen) {
uint16_t receivedCrc = *(start + foundLen - 2) << 8 | *(start + foundLen - 1);
uint16_t recalculatedCrc = CRC::crc16ccitt(start, foundLen - 2, 0);
uint16_t recalculatedCrc = CRC::crc16ccitt(start, foundLen - 2);
if (receivedCrc != recalculatedCrc) {
return CRC_FAILURE;
@ -474,3 +480,16 @@ void PlocHandler::disableExeReportReply() {
/* Expected replies is set to one here. The value will set to 0 in replyToReply() */
info->command->second.expectedReplies = 0;
}
ReturnValue_t PlocHandler::checkPacketSequenceCount(const uint8_t* data) {
uint16_t receivedSequenceCount = *(data + 2) << 8 | *(data + 3) & PACKET_SEQUENCE_COUNT_MASK;
if (receivedSequenceCount != ((packetSequenceCount + 1) & PACKET_SEQUENCE_COUNT_MASK)) {
sif::debug << "PlocHandler::checkPacketSequenceCount: Packet sequence count mismatch"
<< std::endl;
/** The packet sequence count is corrected here to match the sequence count of the PLOC */
packetSequenceCount = (receivedSequenceCount + 1) & PACKET_SEQUENCE_COUNT_MASK;
return SUBSEQUENCE_COUNT_FAILURE;
}
packetSequenceCount = (packetSequenceCount + 1) & PACKET_SEQUENCE_COUNT_MASK;
return RETURN_OK;
}

View File

@ -53,6 +53,7 @@ private:
static const ReturnValue_t RECEIVED_ACK_FAILURE = MAKE_RETURN_CODE(0xA1); //!> Received ACK failure reply from PLOC
static const ReturnValue_t RECEIVED_EXE_FAILURE = MAKE_RETURN_CODE(0xA2); //!> Received execution failure reply from PLOC
static const ReturnValue_t INVALID_APID = MAKE_RETURN_CODE(0xA3); //!> Received space packet with invalid APID from PLOC
static const ReturnValue_t SUBSEQUENCE_COUNT_FAILURE = MAKE_RETURN_CODE(0xA4); //!> The packet sequence count does not match the expected packet sequence count. There may be one packet lost.
static const uint8_t SUBSYSTEM_ID = SUBSYSTEM_ID::PLOC_HANDLER;
@ -62,9 +63,22 @@ private:
static const Event CRC_FAILURE_EVENT = MAKE_EVENT(4, severity::LOW); //!> PLOC reply has invalid crc
static const uint16_t APID_MASK = 0x7FF;
static const unit16_t PACKET_SEQUENCE_COUNT_MASK = 0x3FFF;
uint8_t commandBuffer[PLOC::MAX_COMMAND_SIZE];
/**
* @brief This object is incremented each time a packet is sent or received. By checking the
* packet sequence count of a received packet, no packets can be lost without noticing
* it. Only the least significant 14 bits represent the packet sequence count in a
* space packet. Thus the maximum value amounts to 16383 (0x3FFF).
* @note Normally this should never happen because the PLOC replies are always sent in a
* fixed order. However, the PLOC software checks this value and will return an ACK
* failure report in case the sequence count is not incremented with each transferred
* space packet.
*/
uint16_t packetSequenceCount = 0x3FFF;
/**
* This variable is used to store the id of the next reply to receive. This is necessary
* because the PLOC sends as reply to each command at least one acknowledgment and execution
@ -168,6 +182,16 @@ private:
* the variable expectedReplies of an active command will be set to 0.
*/
void disableExeReportReply();
/**
* @brief This function checks the subsequence count of a received space packet to detect
* lost packets.
*
* @param data Pointer to a space packet.
*
* @return RETURN_OK if successful, else SUBSEQUENCE_COUNT_FAILURE
*/
ReturnValue_t checkSubsequenceCount(const uint8_t* data);
};
#endif /* MISSION_DEVICES_PLOCHANDLER_H_ */

View File

@ -63,8 +63,8 @@ namespace PLOC {
*
* @param memAddr The memory address to read from.
*/
TcMemRead(const uint32_t memAddr) :
SpacePacket(LENGTH_TC_MEM_READ - 1, true, APID_TC_MEM_READ) {
TcMemRead(const uint32_t memAddr, uint16_t sequenceCount) :
SpacePacket(LENGTH_TC_MEM_READ - 1, true, APID_TC_MEM_READ, sequenceCount) {
fillPacketDataField(&memAddr);
}
@ -80,22 +80,21 @@ namespace PLOC {
size_t serializedSize = 0;
uint8_t* memoryAddressPos = this->localData.fields.buffer;
SerializeAdapter::serialize<uint32_t>(memAddrPtr, &memoryAddressPos, &serializedSize,
sizeof(*memAddrPtr), SerializeIF::Endianness::BIG);
sizeof(*memAddrPtr), SerializeIF::Endianness::LITTLE);
/* Add memLen to packet data field */
this->localData.fields.buffer[OFFSET_MEM_LEN_FIELD] = 0;
this->localData.fields.buffer[OFFSET_MEM_LEN_FIELD + 1] = 1;
this->localData.fields.buffer[OFFSET_MEM_LEN_FIELD] = 1;
this->localData.fields.buffer[OFFSET_MEM_LEN_FIELD + 1] = 0;
/* Calculate crc */
uint16_t crc = CRC::crc16ccitt(this->localData.byteStream,
sizeof(CCSDSPrimaryHeader) + LENGTH_TC_MEM_READ - CRC_SIZE, 0);
sizeof(CCSDSPrimaryHeader) + LENGTH_TC_MEM_READ - CRC_SIZE);
/* Add crc to packet data field of space packet */
serializedSize = 0;
uint8_t* crcPos = this->localData.fields.buffer + CRC_OFFSET;
SerializeAdapter::serialize<uint16_t>(&crc, &crcPos, &serializedSize,
sizeof(crc), SerializeIF::Endianness::BIG);
memcpy(this->localData.fields.buffer + CRC_OFFSET, &crc, sizeof(crc));
}
static const uint8_t OFFSET_MEM_LEN_FIELD = 4;
@ -117,9 +116,10 @@ namespace PLOC {
*
* @param memAddr The PLOC memory address where to write to.
* @param memoryData The data to write to the specified memory address.
* @param sequenceCount The subsequence count. Must be incremented with each new packet.
*/
TcMemWrite(const uint32_t memAddr, const uint32_t memoryData) :
SpacePacket(LENGTH_TC_MEM_WRITE - 1, true, APID_TC_MEM_WRITE) {
TcMemWrite(const uint32_t memAddr, const uint32_t memoryData, uint16_t sequenceCount) :
SpacePacket(LENGTH_TC_MEM_WRITE - 1, true, APID_TC_MEM_WRITE, sequenceCount) {
fillPacketDataField(&memAddr, &memoryData);
}
@ -140,8 +140,8 @@ namespace PLOC {
sizeof(*memAddrPtr), SerializeIF::Endianness::BIG);
/* Add memLen to packet data field */
this->localData.fields.buffer[OFFSET_MEM_LEN_FIELD] = 0;
this->localData.fields.buffer[OFFSET_MEM_LEN_FIELD + 1] = 1;
this->localData.fields.buffer[OFFSET_MEM_LEN_FIELD] = 1;
this->localData.fields.buffer[OFFSET_MEM_LEN_FIELD + 1] = 0;
/* Add memData to packet data field */
serializedSize = 0;
@ -151,14 +151,13 @@ namespace PLOC {
/* Calculate crc */
uint16_t crc = CRC::crc16ccitt(this->localData.byteStream,
sizeof(CCSDSPrimaryHeader) + LENGTH_TC_MEM_WRITE - CRC_SIZE, 0);
sizeof(CCSDSPrimaryHeader) + LENGTH_TC_MEM_WRITE - CRC_SIZE);
serializedSize = 0;
uint8_t* crcPos = this->localData.fields.buffer + CRC_OFFSET;
/* Add crc to packet data field of space packet */
SerializeAdapter::serialize<uint16_t>(&crc, &crcPos, &serializedSize,
sizeof(crc), SerializeIF::Endianness::BIG);
memcpy(this->localData.fields.buffer + CRC_OFFSET, &crc, sizeof(crc));
}
/** Offsets from base address of packet data field */