private void ParseHeaderSecondaryUnbalanced(byte[] msg, int msgSize)
{
int userDataLength = 0;
int userDataStart = 0;
byte c;
int csStart;
int csIndex;
int address = 0;
if (msg [0] == 0x68)
{
if (msg [1] != msg [2])
{
DebugLog("ERROR: L fields differ!");
return;
}
userDataLength = (int)msg [1] - linkLayerParameters.AddressLength - 1;
userDataStart = 5 + linkLayerParameters.AddressLength;
csStart = 4;
csIndex = userDataStart + userDataLength;
// check if message size is reasonable
if (msgSize != (userDataStart + userDataLength + 2 /* CS + END */))
{
DebugLog("ERROR: Invalid message length");
return;
}
c = msg [4];
}
else if (msg [0] == 0x10)
{
c = msg [1];
csStart = 1;
csIndex = 2 + linkLayerParameters.AddressLength;
}
else if (msg [0] == 0xE5)
{
/* Confirmation message from other slave --> ignore */
return;
}
else
{
DebugLog("ERROR: Received unexpected message type in unbalanced slave mode!");
return;
}
bool isBroadcast = false;
//check address
if (linkLayerParameters.AddressLength > 0)
{
address = msg [csStart + 1];
if (linkLayerParameters.AddressLength > 1)
{
address += (msg [csStart + 2] * 0x100);
if (address == 65535)
{
isBroadcast = true;
}
}
else
{
if (address == 255)
{
isBroadcast = true;
}
}
}
int fc = c & 0x0f;
FunctionCodePrimary fcp = (FunctionCodePrimary)fc;
if (isBroadcast)
{
if (fcp != FunctionCodePrimary.USER_DATA_NO_REPLY)
{
DebugLog("ERROR: Invalid function code for broadcast message!");
return;
}
}
else
{
if (address != secondaryLinkLayer.Address)
{
DebugLog("INFO: unknown link layer address -> ignore message");
return;
}
}
//check checksum
byte checksum = 0;
for (int i = csStart; i < csIndex; i++)
{
checksum += msg [i];
}
if (checksum != msg [csIndex])
{
DebugLog("ERROR: checksum invalid!");
return;
}
// parse C field bits
bool prm = ((c & 0x40) == 0x40);
if (prm == false)
{
DebugLog("ERROR: Received secondary message in unbalanced slave mode!");
return;
}
bool fcb = ((c & 0x20) == 0x20);
bool fcv = ((c & 0x10) == 0x10);
DebugLog("PRM=" + (prm == true ? "1":"0") + " FCB=" + (fcb == true ? "1":"0") + " FCV=" + (fcv == true ? "1":"0")
+ " FC=" + fc + "(" + fcp.ToString() + ")");
if (secondaryLinkLayer != null)
{
secondaryLinkLayer.HandleMessage(fcp, isBroadcast, address, fcb, fcv, msg, userDataStart, userDataLength);
}
else
{
DebugLog("No secondary link layer available!");
}
}
public void HandleMessageBalancedAndPrimaryUnbalanced(byte[] msg, int msgSize)
{
int userDataLength = 0;
int userDataStart = 0;
byte c = 0;
int csStart = 0;
int csIndex = 0;
int address = 0; /* address can be ignored in balanced mode? */
bool prm = true;
int fc = 0;
bool isAck = false;
if (msg [0] == 0x68)
{
if (msg [1] != msg [2])
{
DebugLog("ERROR: L fields differ!");
return;
}
userDataLength = (int)msg [1] - linkLayerParameters.AddressLength - 1;
userDataStart = 5 + linkLayerParameters.AddressLength;
csStart = 4;
csIndex = userDataStart + userDataLength;
// check if message size is reasonable
if (msgSize != (userDataStart + userDataLength + 2 /* CS + END */))
{
DebugLog("ERROR: Invalid message length");
return;
}
c = msg [4];
if (linkLayerParameters.AddressLength > 0)
{
address += msg [5];
}
if (linkLayerParameters.AddressLength > 1)
{
address += msg [6] * 0x100;
}
}
else if (msg [0] == 0x10)
{
c = msg [1];
csStart = 1;
csIndex = 2 + linkLayerParameters.AddressLength;
if (linkLayerParameters.AddressLength > 0)
{
address += msg [2];
}
if (linkLayerParameters.AddressLength > 1)
{
address += msg [3] * 0x100;
}
}
else if (msg [0] == 0xe5)
{
isAck = true;
fc = (int)FunctionCodeSecondary.ACK;
prm = false; /* single char ACK is only sent by secondary station */
DebugLog("Received single char ACK");
}
else
{
DebugLog("ERROR: Received unexpected message type!");
return;
}
if (isAck == false)
{
//check checksum
byte checksum = 0;
for (int i = csStart; i < csIndex; i++)
{
checksum += msg [i];
}
if (checksum != msg [csIndex])
{
DebugLog("ERROR: checksum invalid!");
return;
}
// parse C field bits
fc = c & 0x0f;
prm = ((c & 0x40) == 0x40);
if (prm) /* we are secondary link layer */
{
bool fcb = ((c & 0x20) == 0x20);
bool fcv = ((c & 0x10) == 0x10);
DebugLog("PRM=" + (prm == true ? "1" : "0") + " FCB=" + (fcb == true ? "1" : "0") + " FCV=" + (fcv == true ? "1" : "0")
+ " FC=" + fc + "(" + ((FunctionCodePrimary)c).ToString() + ")");
FunctionCodePrimary fcp = (FunctionCodePrimary)fc;
if (secondaryLinkLayer != null)
{
secondaryLinkLayer.HandleMessage(fcp, false, address, fcb, fcv, msg, userDataStart, userDataLength);
}
else
{
DebugLog("No secondary link layer available!");
}
}
else /* we are primary link layer */
{
bool dir = ((c & 0x80) == 0x80); /* DIR - direction for balanced transmission */
bool dfc = ((c & 0x10) == 0x10); /* DFC - Data flow control */
bool acd = ((c & 0x20) == 0x20); /* ACD - access demand for class 1 data - for unbalanced transmission */
DebugLog("PRM=" + (prm == true ? "1" : "0") + " DIR=" + (dir == true ? "1" : "0") + " DFC=" + (dfc == true ? "1" : "0")
+ " FC=" + fc + "(" + ((FunctionCodeSecondary)c).ToString() + ")");
FunctionCodeSecondary fcs = (FunctionCodeSecondary)fc;
if (primaryLinkLayer != null)
{
if (linkLayerMode == LinkLayerMode.BALANCED)
{
primaryLinkLayer.HandleMessage(fcs, dir, dfc, address, msg, userDataStart, userDataLength);
}
else
{
primaryLinkLayer.HandleMessage(fcs, acd, dfc, address, msg, userDataStart, userDataLength);
}
}
else
{
DebugLog("No primary link layer available!");
}
}
}
else /* Single byte ACK */
{
if (primaryLinkLayer != null)
{
primaryLinkLayer.HandleMessage(FunctionCodeSecondary.ACK, false, false, -1, null, 0, 0);
}
}
}
public void SendVariableLengthFramePrimary(FunctionCodePrimary fc, int address, bool fcb, bool fcv, BufferFrame frame)
{
buffer [0] = 0x68; /* START */
buffer [3] = 0x68; /* START */
byte c = (byte)fc;
if (dir)
{
c += 0x80;
}
c += 0x40; // PRM = 1;
if (fcv)
{
c += 0x10;
}
if (fcb)
{
c += 0x20;
}
buffer [4] = c;
int bufPos = 5;
if (linkLayerParameters.AddressLength > 0)
{
buffer [bufPos++] = (byte)(address % 0x100);
if (linkLayerParameters.AddressLength > 1)
{
buffer [bufPos++] = (byte)((address / 0x100) % 0x100);
}
}
byte[] userData = frame.GetBuffer();
int userDataLength = frame.GetMsgSize();
for (int i = 0; i < userDataLength; i++)
{
buffer [bufPos++] = userData[i];
}
int l = 1 + linkLayerParameters.AddressLength + frame.GetMsgSize();
if (l > 255)
{
return;
}
buffer [1] = (byte)l;
buffer [2] = (byte)l;
byte checksum = 0;
for (int i = 4; i < bufPos; i++)
{
checksum += buffer[i];
}
buffer [bufPos++] = checksum;
buffer [bufPos++] = 0x16; /* END */
if (sentRawMessageHandler != null)
{
sentRawMessageHandler(sentRawMessageHandlerParameter, buffer, bufPos);
}
transceiver.SendMessage(buffer, bufPos);
}
public void SendFixedFramePrimary(FunctionCodePrimary fc, int address, bool fcb, bool fcv)
{
SendFixedFrame((byte)fc, address, true, dir, fcb, fcv);
}
public override void HandleMessage(FunctionCodePrimary fcp, bool isBroadcast, int address, bool fcb, bool fcv, byte[] msg, int userDataStart, int userDataLength)
{
// check frame count bit if fcv == true
if (fcv)
{
if (CheckFCB(fcb) == false)
{
return;
}
}
switch (fcp)
{
case FunctionCodePrimary.REQUEST_LINK_STATUS:
DebugLog("SLL - REQUEST LINK STATUS");
{
bool accessDemand = applicationLayer.IsClass1DataAvailable();
linkLayer.SendFixedFrameSecondary(FunctionCodeSecondary.STATUS_OF_LINK_OR_ACCESS_DEMAND, linkLayerAddress, accessDemand, false);
}
break;
case FunctionCodePrimary.RESET_REMOTE_LINK:
DebugLog("SLL - RESET REMOTE LINK");
{
expectedFcb = true;
if (linkLayer.linkLayerParameters.UseSingleCharACK)
{
linkLayer.SendSingleCharACK();
}
else
{
linkLayer.SendFixedFrameSecondary(FunctionCodeSecondary.ACK, linkLayerAddress, false, false);
}
applicationLayer.ResetCUReceived(false);
}
break;
case FunctionCodePrimary.RESET_FCB:
DebugLog("SLL - RESET FCB");
{
expectedFcb = true;
if (linkLayer.linkLayerParameters.UseSingleCharACK)
{
linkLayer.SendSingleCharACK();
}
else
{
linkLayer.SendFixedFrameSecondary(FunctionCodeSecondary.ACK, linkLayerAddress, false, false);
}
applicationLayer.ResetCUReceived(true);
}
break;
case FunctionCodePrimary.REQUEST_USER_DATA_CLASS_2:
DebugLog("SLL - REQUEST USER DATA CLASS 2");
{
BufferFrame asdu = applicationLayer.GetCLass2Data();
bool accessDemand = applicationLayer.IsClass1DataAvailable();
if (asdu != null)
{
linkLayer.SendVariableLengthFrameSecondary(FunctionCodeSecondary.RESP_USER_DATA, linkLayerAddress, accessDemand, false, asdu);
}
else
{
if (linkLayer.linkLayerParameters.UseSingleCharACK && (accessDemand == false))
{
linkLayer.SendSingleCharACK();
}
else
{
linkLayer.SendFixedFrameSecondary(FunctionCodeSecondary.RESP_NACK_NO_DATA, linkLayerAddress, accessDemand, false);
}
}
}
break;
case FunctionCodePrimary.REQUEST_USER_DATA_CLASS_1:
DebugLog("SLL - REQUEST USER DATA CLASS 1");
{
BufferFrame asdu = applicationLayer.GetClass1Data();
bool accessDemand = applicationLayer.IsClass1DataAvailable();
if (asdu != null)
{
linkLayer.SendVariableLengthFrameSecondary(FunctionCodeSecondary.RESP_USER_DATA, linkLayerAddress, accessDemand, false, asdu);
}
else
{
if (linkLayer.linkLayerParameters.UseSingleCharACK && (accessDemand == false))
{
linkLayer.SendSingleCharACK();
}
else
{
linkLayer.SendFixedFrameSecondary(FunctionCodeSecondary.RESP_NACK_NO_DATA, linkLayerAddress, accessDemand, false);
}
}
}
break;
case FunctionCodePrimary.USER_DATA_CONFIRMED:
DebugLog("SLL - USER DATA CONFIRMED");
if (userDataLength > 0)
{
if (applicationLayer.HandleReceivedData(msg, isBroadcast, userDataStart, userDataLength))
{
bool accessDemand = applicationLayer.IsClass1DataAvailable();
linkLayer.SendFixedFrameSecondary(FunctionCodeSecondary.ACK, linkLayerAddress, accessDemand, false);
}
}
break;
case FunctionCodePrimary.USER_DATA_NO_REPLY:
DebugLog("SLL - USER DATA NO REPLY");
if (userDataLength > 0)
{
applicationLayer.HandleReceivedData(msg, isBroadcast, userDataStart, userDataLength);
}
break;
default:
DebugLog("SLL - UNEXPECTED LINK LAYER MESSAGE");
linkLayer.SendFixedFrameSecondary(FunctionCodeSecondary.LINK_SERVICE_NOT_IMPLEMENTED, linkLayerAddress, false, false);
break;
}
}
public abstract void HandleMessage(FunctionCodePrimary fcp, bool isBroadcast, int address, bool fcb, bool fcv, byte[] msg, int userDataStart, int userDataLength);
public override void HandleMessage(FunctionCodePrimary fcp, bool isBroadcast, bool fcb, bool fcv, byte[] msg, int userDataStart, int userDataLength)
{
if (fcv)
{
if (CheckFCB(fcb) == false)
{
return;
}
}
switch (fcp)
{
case FunctionCodePrimary.RESET_REMOTE_LINK:
expectedFcb = true;
DebugLog("SLL - RECV RESET REMOTE LINK");
if (linkLayer.linkLayerParameters.UseSingleCharACK)
{
linkLayer.SendSingleCharACK();
}
else
{
linkLayer.SendFixedFrameSecondary(FunctionCodeSecondary.ACK, linkLayerAddress, false, false);
}
break;
case FunctionCodePrimary.TEST_FUNCTION_FOR_LINK:
DebugLog("SLL -TEST FUNCTION FOR LINK");
// TODO check if DCF has to be sent
if (linkLayer.linkLayerParameters.UseSingleCharACK)
{
linkLayer.SendSingleCharACK();
}
else
{
linkLayer.SendFixedFrameSecondary(FunctionCodeSecondary.ACK, linkLayerAddress, false, false);
}
break;
case FunctionCodePrimary.USER_DATA_CONFIRMED:
DebugLog("SLL - USER DATA CONFIRMED");
if (userDataLength > 0)
{
if (HandleApplicationLayer(msg, userDataStart, userDataLength))
{
linkLayer.SendFixedFrameSecondary(FunctionCodeSecondary.ACK, linkLayerAddress, false, false);
}
}
break;
case FunctionCodePrimary.USER_DATA_NO_REPLY:
DebugLog("SLL - USER DATA NO REPLY");
if (userDataLength > 0)
{
HandleApplicationLayer(msg, userDataStart, userDataLength);
}
break;
case FunctionCodePrimary.REQUEST_LINK_STATUS:
DebugLog("SLL - RECV REQUEST LINK STATUS");
SendStatusOfLink(linkLayerAddress);
break;
default:
DebugLog("SLL - UNEXPECTED LINK LAYER MESSAGE");
linkLayer.SendFixedFrameSecondary(FunctionCodeSecondary.LINK_SERVICE_NOT_IMPLEMENTED, linkLayerAddress, false, false);
break;
}
}
