LIN: Network support

2026-08-05 01:18:36 +02:00 · 2023-02-03 18:27:08 +00:00
parent 4229d8b66a
commit 539cfa511b
13 changed files with 723 additions and 4 deletions
@@ -0,0 +1,153 @@
+#include "icsneo/communication/packet/linpacket.h"
+#include "icsneo/communication/message/linmessage.h"
+#include "icsneo/communication/packetizer.h"
+
+namespace icsneo {
+
+std::shared_ptr<Message> HardwareLINPacket::DecodeToMessage(const std::vector<uint8_t>& bytestream) {
+	auto msg = std::make_shared<LINMessage>();
+	const HardwareLINPacket* packet = reinterpret_cast<const HardwareLINPacket*>(bytestream.data());
+	size_t numDataBytes = packet->CoreMiniBitsLIN.len;
+	size_t numHeaderBytes = sizeof(HardwareLINPacket::CoreMiniBitsLIN);
+
+	if( (sizeof(HardwareLINPacket) != bytestream.size()) ||
+		((numDataBytes + numHeaderBytes) > bytestream.size()) )
+		return nullptr;
+
+	if(numDataBytes)
+		--numDataBytes; //If data is present, there will be a checksum included
+
+	msg->network = Network::GetNetIDFromCoreMiniNetwork(static_cast<Network::CoreMini>(packet->networkID));
+	msg->protectedID = packet->CoreMiniBitsLIN.ID;
+	msg->ID = (packet->CoreMiniBitsLIN.ID & 0x3Fu);
+	msg->isEnhancedChecksum = static_cast<bool>(packet->CoreMiniBitsLIN.TxChkSumEnhanced);
+
+	/* Minimum one responder byte and one checksum byte. */
+	if(2u > packet->CoreMiniBitsLIN.len)
+		msg->type = LINMessage::Type::LIN_ERROR;
+
+	auto dataStart = bytestream.begin() + numHeaderBytes;
+	std::copy(dataStart, (dataStart+numDataBytes), std::back_inserter(msg->data));
+
+	/* If OK, validate the checksum*/
+	auto isChecksumInvalid = [&]() -> bool {
+		/* messages with no data have no checksum (e.g. header only) */
+		if(!msg->data.size())
+			return true;
+
+		uint8_t checkSum = (8 > numDataBytes) ? *(dataStart + numDataBytes) : packet->CoreMiniBitsLIN.LINByte9;
+		LINMessage::calcChecksum(*msg);
+		if(checkSum != msg->checksum) {
+			msg->isEnhancedChecksum = true;
+			LINMessage::calcChecksum(*msg);
+			if(checkSum != msg->checksum) {
+				msg->isEnhancedChecksum = false;
+				msg->checksum = checkSum;
+				return true;
+			}
+		}
+		return false;
+	};
+
+	/* if any of the status bits are set, then this is 
+	either a failed reception or a bus status update. */
+	msg->errFlags =
+	{
+		static_cast<bool>(packet->CoreMiniBitsLIN.ErrRxOnlyBreak),
+		static_cast<bool>(packet->CoreMiniBitsLIN.ErrRxOnlyBreakSync),
+		static_cast<bool>(packet->CoreMiniBitsLIN.ErrTxRxMismatch),
+		static_cast<bool>(packet->CoreMiniBitsLIN.ErrRxBreakNotZero),
+		static_cast<bool>(packet->CoreMiniBitsLIN.ErrRxBreakTooShort),
+		static_cast<bool>(packet->CoreMiniBitsLIN.ErrRxSyncNot55),
+		static_cast<bool>(packet->CoreMiniBitsLIN.ErrRxDataGreater8),
+		static_cast<bool>(packet->CoreMiniBitsLIN.SyncFerr),
+		static_cast<bool>(packet->CoreMiniBitsLIN.MidFerr),
+		static_cast<bool>(packet->CoreMiniBitsLIN.ResponderByteFerr),
+		isChecksumInvalid(), /* ErrChecksumMatch */
+	};
+
+	msg->statusFlags =
+	{
+		static_cast<bool>(packet->CoreMiniBitsLIN.TxChkSumEnhanced),
+		static_cast<bool>(packet->CoreMiniBitsLIN.TXCommander),
+		static_cast<bool>(packet->CoreMiniBitsLIN.TXResponder),
+		static_cast<bool>(packet->CoreMiniBitsLIN.TxAborted),
+		static_cast<bool>(packet->CoreMiniBitsLIN.UpdateResponderOnce),
+		static_cast<bool>(packet->CoreMiniBitsLIN.HasUpdatedResponderOnce),
+		static_cast<bool>(packet->CoreMiniBitsLIN.BusRecovered),
+		static_cast<bool>(packet->CoreMiniBitsLIN.BreakOnly)
+	};
+	if(msg->statusFlags.TxCommander || msg->statusFlags.TxResponder)
+		msg->type = LINMessage::Type::LIN_COMMANDER_MSG;
+	else if(msg->statusFlags.BreakOnly)
+		msg->type = LINMessage::Type::LIN_BREAK_ONLY;
+	if( msg->errFlags.ErrRxBreakOnly     || msg->errFlags.ErrRxBreakSyncOnly ||
+		msg->errFlags.ErrTxRxMismatch    || msg->errFlags.ErrRxBreakNotZero  ||
+		msg->errFlags.ErrRxBreakTooShort || msg->errFlags.ErrRxSyncNot55     ||
+		msg->errFlags.ErrRxDataLenOver8  || msg->errFlags.ErrFrameSync       ||
+		msg->errFlags.ErrFrameMessageID  || msg->errFlags.ErrChecksumMatch   ||
+		msg->errFlags.ErrFrameResponderData )
+		{ msg->type = LINMessage::Type::LIN_ERROR; }
+
+	msg->timestamp = packet->timestamp;
+	return msg;
+}
+
+bool HardwareLINPacket::EncodeFromMessage(LINMessage& message, std::vector<uint8_t>& bytestream, const device_eventhandler_t& report)
+{
+	uint8_t size = ((std::min<size_t>(8ul, message.data.size()) + 3ul) & 0xFu);
+	if(size > 3) { ++size; } // add a checksum byte if there's data
+	switch(message.type) {
+		case LINMessage::Type::LIN_HEADER_ONLY:
+		case LINMessage::Type::LIN_COMMANDER_MSG:
+		{
+			size |= 0x80u;
+			break;
+		}
+		case LINMessage::Type::LIN_BREAK_ONLY:
+		{
+			size |= 0x20u;
+			break;
+		}
+		case LINMessage::Type::NOT_SET:
+		{
+			report(APIEvent::Type::RequiredParameterNull, APIEvent::Severity::Error);
+			return false;
+		}
+		default:
+			break;
+	}
+
+	message.protectedID = message.ID;
+	auto bit = [&](uint8_t pos)->uint8_t { return ((message.protectedID >> pos) & 0x1u); };
+	message.protectedID |= (~(bit(1) ^ bit(3) ^ bit(4) ^ bit(5)) << 7);
+	message.protectedID |= ((bit(0) ^ bit(1) ^ bit(2) ^ bit(4)) << 6);
+
+	bytestream.insert(bytestream.end(),
+	{
+		static_cast<uint8_t>(0x00u),
+		static_cast<uint8_t>(size),
+		static_cast<uint8_t>((message.description >> 8) & 0xFF),
+		static_cast<uint8_t>(message.description & 0xFF),
+		static_cast<uint8_t>(message.protectedID)
+	});
+
+	switch(message.type) {
+		case(LINMessage::Type::LIN_COMMANDER_MSG):
+		case(LINMessage::Type::LIN_UPDATE_RESPONDER):
+		{
+			std::copy(message.data.begin(), message.data.end(), std::back_inserter(bytestream));
+			LINMessage::calcChecksum(message);
+			bytestream.push_back(message.checksum);
+			break;
+		}
+		default:
+			break;
+	}
+	if(bytestream.size() % 2)
+		bytestream.push_back(0x41); //padding
+
+	return true;
+}
+
+} //namespace icsneo