public bool HandleFileAsdu(ASDU asdu)
{
bool handled = true;
switch (asdu.TypeId)
{
case TypeID.F_AF_NA_1: /* 124 - ACK file, ACK section */
logger("Received file/section ACK F_AF_NA_1");
if (asdu.Cot == CauseOfTransmission.FILE_TRANSFER)
{
if (transferState != FileServerState.UNSELECTED_IDLE)
{
IFileProvider file = selectedFile.provider;
FileACK ack = (FileACK)asdu.GetElement(0);
if (ack.AckQualifier == AcknowledgeQualifier.POS_ACK_FILE)
{
logger("Received positive file ACK");
if (transferState == FileServerState.WAITING_FOR_FILE_ACK)
{
selectedFile.provider.TransferComplete(true);
availableFiles.RemoveFile(selectedFile.provider);
selectedFile = null;
transferState = FileServerState.UNSELECTED_IDLE;
}
else
{
logger("Unexpected file transfer state --> abort file transfer");
transferState = FileServerState.SEND_ABORT;
}
}
else if (ack.AckQualifier == AcknowledgeQualifier.NEG_ACK_FILE)
{
logger("Received negative file ACK - stop transfer");
if (transferState == FileServerState.WAITING_FOR_FILE_ACK)
{
selectedFile.provider.TransferComplete(false);
selectedFile.selectedBy = null;
selectedFile = null;
transferState = FileServerState.UNSELECTED_IDLE;
}
else
{
logger("Unexpected file transfer state --> abort file transfer");
transferState = FileServerState.SEND_ABORT;
}
}
else if (ack.AckQualifier == AcknowledgeQualifier.NEG_ACK_SECTION)
{
logger("Received negative file section ACK - repeat section");
if (transferState == FileServerState.WAITING_FOR_SECTION_ACK)
{
currentSectionOffset = 0;
sectionChecksum = 0;
ASDU sectionReady = new ASDU(alParameters, CauseOfTransmission.FILE_TRANSFER, false, false, 0, file.GetCA(), false);
sectionReady.AddInformationObject(
new SectionReady(selectedFile.provider.GetIOA(), selectedFile.provider.GetNameOfFile(), currentSectionNumber, currentSectionSize, false));
connection.SendASDU(sectionReady);
transferState = FileServerState.TRANSMIT_SECTION;
}
else
{
logger("Unexpected file transfer state --> abort file transfer");
transferState = FileServerState.SEND_ABORT;
}
}
else if (ack.AckQualifier == AcknowledgeQualifier.POS_ACK_SECTION)
{
if (transferState == FileServerState.WAITING_FOR_SECTION_ACK)
{
currentSectionNumber++;
int nextSectionSize =
selectedFile.provider.GetSectionSize(currentSectionNumber);
ASDU responseAsdu = new ASDU(alParameters, CauseOfTransmission.FILE_TRANSFER, false, false, 0, file.GetCA(), false);
if (nextSectionSize == -1)
{
logger("Reveived positive file section ACK - send last section indication");
responseAsdu.AddInformationObject(
new FileLastSegmentOrSection(file.GetIOA(), file.GetNameOfFile(),
(byte)currentSectionNumber,
LastSectionOrSegmentQualifier.FILE_TRANSFER_WITHOUT_DEACT,
fileChecksum));
transferState = FileServerState.WAITING_FOR_FILE_ACK;
}
else
{
logger("Reveived positive file section ACK - send next section ready indication");
currentSectionSize = nextSectionSize;
responseAsdu.AddInformationObject(
new SectionReady(selectedFile.provider.GetIOA(), selectedFile.provider.GetNameOfFile(), currentSectionNumber, currentSectionSize, false));
transferState = FileServerState.WAITING_FOR_SECTION_CALL;
}
connection.SendASDU(responseAsdu);
sectionChecksum = 0;
}
else
{
logger("Unexpected file transfer state --> abort file transfer");
transferState = FileServerState.SEND_ABORT;
}
}
}
else
{
// No file transmission in progress --> what to do?
logger("Unexpected File ACK message -> ignore");
}
}
else
{
asdu.Cot = CauseOfTransmission.UNKNOWN_CAUSE_OF_TRANSMISSION;
connection.SendASDU(asdu);
}
break;
case TypeID.F_SC_NA_1: /* 122 - Call/Select directoy/file/section */
logger("Received call/select F_SC_NA_1");
if (asdu.Cot == CauseOfTransmission.FILE_TRANSFER)
{
FileCallOrSelect sc = (FileCallOrSelect)asdu.GetElement(0);
if (sc.SCQ == SelectAndCallQualifier.SELECT_FILE)
{
if (transferState == FileServerState.UNSELECTED_IDLE)
{
logger("Received SELECT FILE");
CS101n104File file = availableFiles.GetFile(asdu.Ca, sc.ObjectAddress, sc.NOF);
if (file == null)
{
asdu.Cot = CauseOfTransmission.UNKNOWN_INFORMATION_OBJECT_ADDRESS;
connection.SendASDU(asdu);
}
else
{
ASDU fileReady = new ASDU(alParameters, CauseOfTransmission.FILE_TRANSFER, false, false, 0, asdu.Ca, false);
// check if already selected
if (file.selectedBy == null)
{
file.selectedBy = this;
fileReady.AddInformationObject(new FileReady(sc.ObjectAddress, sc.NOF, file.provider.GetFileSize(), true));
}
else
{
fileReady.AddInformationObject(new FileReady(sc.ObjectAddress, sc.NOF, 0, false));
}
connection.SendASDU(fileReady);
selectedFile = file;
transferState = FileServerState.WAITING_FOR_FILE_CALL;
}
}
else
{
logger("Unexpected SELECT FILE message");
}
}
else if (sc.SCQ == SelectAndCallQualifier.DEACTIVATE_FILE)
{
logger("Received DEACTIVATE FILE");
if (transferState != FileServerState.UNSELECTED_IDLE)
{
if (selectedFile != null)
{
selectedFile.selectedBy = null;
selectedFile = null;
}
transferState = FileServerState.UNSELECTED_IDLE;
}
else
{
logger("Unexpected DEACTIVATE FILE message");
}
}
else if (sc.SCQ == SelectAndCallQualifier.REQUEST_FILE)
{
logger("Received CALL FILE");
if (transferState == FileServerState.WAITING_FOR_FILE_CALL)
{
if (selectedFile.provider.GetIOA() != sc.ObjectAddress)
{
logger("Unkown IOA");
asdu.Cot = CauseOfTransmission.UNKNOWN_INFORMATION_OBJECT_ADDRESS;
connection.SendASDU(asdu);
}
else
{
ASDU sectionReady = new ASDU(alParameters, CauseOfTransmission.FILE_TRANSFER, false, false, 0, asdu.Ca, false);
sectionReady.AddInformationObject(new SectionReady(sc.ObjectAddress, selectedFile.provider.GetNameOfFile(), 0, 0, false));
connection.SendASDU(sectionReady);
logger("Send SECTION READY");
currentSectionNumber = 0;
currentSectionOffset = 0;
currentSectionSize = selectedFile.provider.GetSectionSize(0);
transferState = FileServerState.WAITING_FOR_SECTION_CALL;
}
}
else
{
logger("Unexpected FILE CALL message");
}
}
else if (sc.SCQ == SelectAndCallQualifier.REQUEST_SECTION)
{
logger("Received CALL SECTION");
if (transferState == FileServerState.WAITING_FOR_SECTION_CALL)
{
if (selectedFile.provider.GetIOA() != sc.ObjectAddress)
{
logger("Unkown IOA");
asdu.Cot = CauseOfTransmission.UNKNOWN_INFORMATION_OBJECT_ADDRESS;
connection.SendASDU(asdu);
}
else
{
transferState = FileServerState.TRANSMIT_SECTION;
}
}
else
{
logger("Unexpected SECTION CALL message");
}
}
}
else if (asdu.Cot == CauseOfTransmission.REQUEST)
{
logger("Call directory received");
availableFiles.SendDirectoy(connection, false);
}
else
{
asdu.Cot = CauseOfTransmission.UNKNOWN_CAUSE_OF_TRANSMISSION;
connection.SendASDU(asdu);
}
break;
default:
handled = false;
break;
}
return(handled);
}
public void HandleFileTransmission()
{
if (transferState != FileServerState.UNSELECTED_IDLE)
{
if (transferState == FileServerState.TRANSMIT_SECTION)
{
if (selectedFile != null)
{
IFileProvider file = selectedFile.provider;
ASDU fileAsdu = new ASDU(alParameters, CauseOfTransmission.FILE_TRANSFER, false, false, 0, file.GetCA(), false);
if (currentSectionOffset == currentSectionSize)
{
// send last segment
fileAsdu.AddInformationObject(
new FileLastSegmentOrSection(file.GetIOA(), file.GetNameOfFile(),
currentSectionNumber,
LastSectionOrSegmentQualifier.SECTION_TRANSFER_WITHOUT_DEACT,
sectionChecksum));
fileChecksum += sectionChecksum;
sectionChecksum = 0;
logger("Send LAST SEGMENT");
connection.SendASDU(fileAsdu);
transferState = FileServerState.WAITING_FOR_SECTION_ACK;
}
else
{
int currentSegmentSize = currentSectionSize - currentSectionOffset;
if (currentSegmentSize > maxSegmentSize)
{
currentSegmentSize = maxSegmentSize;
}
byte[] segmentData = new byte[currentSegmentSize];
file.GetSegmentData(currentSectionNumber,
currentSectionOffset,
currentSegmentSize,
segmentData);
fileAsdu.AddInformationObject(
new FileSegment(file.GetIOA(), file.GetNameOfFile(), currentSectionNumber,
segmentData));
byte checksum = 0;
foreach (byte octet in segmentData)
{
checksum += octet;
}
connection.SendASDU(fileAsdu);
sectionChecksum += checksum;
logger("Send SEGMENT (CHS=" + sectionChecksum + ")");
currentSectionOffset += currentSegmentSize;
}
}
}
}
}
