libicsneo/communication/packet/iso9141packet.cpp

135 lines
4.3 KiB
C++

#include "icsneo/communication/packet/iso9141packet.h"
#include "icsneo/communication/packetizer.h"
#include <algorithm>
using namespace icsneo;
bool HardwareISO9141Packet::EncodeFromMessage(const ISO9141Message& message, std::vector<uint8_t>& bytestream,
const device_eventhandler_t& report, const Packetizer& packetizer)
{
size_t bytesToSend = message.data.size();
if (message.isInit || message.isBreak)
bytesToSend = 0;
if(bytesToSend > 4200) {
report(APIEvent::Type::MessageMaxLengthExceeded, APIEvent::Severity::Error);
return false; // Too much data for the protocol
}
bytestream.clear();
std::vector<uint8_t> packet;
packet.reserve(16);
size_t currentStart = 0;
do {
const bool firstPacket = currentStart == 0;
const uint8_t maxSize = (firstPacket ? 9 : 12);
uint8_t currentSize = maxSize;
if(bytesToSend - currentStart < maxSize)
currentSize = (uint8_t)(bytesToSend - currentStart);
packet.insert(packet.begin(), {
(uint8_t)Network::NetID::RED, // 0x0C for long message
(uint8_t)0, // Size, little endian 16-bit, filled later
(uint8_t)0,
(uint8_t)message.network.getNetID(), // NetID, little endian 16-bit
(uint8_t)(uint16_t(message.network.getNetID()) >> 8)
});
packet.push_back(uint8_t(message.network.getNetID()) + uint8_t((currentSize + (firstPacket ? 6 : 3)) << 4));
packet.push_back(uint8_t(currentSize + (firstPacket ? 5 : 2)));
if(bytesToSend - currentStart > maxSize) // More packets are coming
packet.back() |= 0x40;
if(firstPacket) {
if(message.isInit)
packet.back() |= 0x80;
if(message.isBreak)
packet.back() |= 0x20;
}
// Two bytes for Description ID, big endian
packet.insert(packet.end(), { uint8_t(message.description >> 8), uint8_t(message.description) });
// If we're the first packet and not init/break only, we should put the header in
if(firstPacket && !message.isInit && !message.isBreak)
packet.insert(packet.end(), message.header.begin(), message.header.end());
// Now the data
auto dataIt = message.data.begin() + currentStart;
if(currentSize)
packet.insert(packet.end(), dataIt, dataIt + currentSize);
// Advance for the next packet
currentStart += currentSize;
const uint16_t size = uint16_t(packet.size()) + 2;
packet[1] = uint8_t(size & 0xFF);
packet[2] = uint8_t((size >> 8) & 0xFF);
packetizer.packetWrap(packet, false);
bytestream.insert(bytestream.end(), packet.begin(), packet.end());
packet.clear();
} while(currentStart < bytesToSend);
return true;
}
std::shared_ptr<ISO9141Message> HardwareISO9141Packet::Decoder::decodeToMessage(const std::vector<uint8_t>& bytestream) {
const HardwareISO9141Packet& packet = *reinterpret_cast<const HardwareISO9141Packet*>(bytestream.data());
if(!mMsg) {
mMsg = std::make_shared<ISO9141Message>();
mGotPackets = 0;
}
mGotPackets++;
const bool morePacketsComing = packet.c3.frm == 0;
const uint8_t bytesInCurrentMessage = packet.c3.len;
if(mMsg->data.size() + bytesInCurrentMessage > 500) {
mMsg.reset();
return std::shared_ptr<ISO9141Message>();
}
// This timestamp is raw off the device (in timestampResolution increments)
// Decoder will fix as it has information about the timestampResolution increments
mMsg->timestamp = packet.timestamp.TS;
auto* dataStart = packet.data;
if(mGotPackets == 1) {
// Header
if(bytesInCurrentMessage < 3) {
mMsg.reset(); // We don't have the header for some reason
return std::shared_ptr<ISO9141Message>();
}
std::copy(packet.data, packet.data + 3, mMsg->header.begin());
dataStart += 3;
}
// Data
mMsg->data.insert(mMsg->data.end(), dataStart, packet.data + (bytesInCurrentMessage > 8 ? 8 : bytesInCurrentMessage));
if(bytesInCurrentMessage > 8)
mMsg->data.push_back(packet.c1.d8);
if(bytesInCurrentMessage > 9)
mMsg->data.push_back(packet.c2.d9);
if(bytesInCurrentMessage > 10)
mMsg->data.push_back(packet.c2.d10);
if(bytesInCurrentMessage > 11)
mMsg->data.push_back(packet.c3.d11);
if(morePacketsComing)
return std::shared_ptr<ISO9141Message>();
mMsg->transmitted = packet.c1.tx;
mMsg->isInit = packet.c3.init;
mMsg->framingError = packet.c1.options & 0x1;
mMsg->overflowError = packet.c1.options & 0x2;
mMsg->parityError = packet.c1.options & 0x4;
mMsg->rxTimeoutError = packet.c1.options & 0x8;
mMsg->description = packet.stats;
auto ret = mMsg;
mMsg.reset();
return ret;
}