private void ProcessAndPush(PacketBuffer Buffer, MemoryStream PacketStream)
{
int hdrLen = DtmPacketStruct.GetHeaderSize();
int pktLen = 0;
// get the header
DtmPacketStruct pktHdr = new DtmPacketStruct(PacketStream);
PacketStream.Seek(0, SeekOrigin.Begin);
// track high sequence number
if (pktHdr.Sequence > _seqCounter)
{
_seqCounter = pktHdr.Sequence;
}
// out of sync, possible packet loss
if (_seqCounter - _rcvSequence > _bufferCount / 4)
{
// request a retransmission
Transmit(DtmPacketFlags.Service, (short)DtmServiceFlags.Resend, _rcvSequence + 1);
}
// packet aligned
if (pktHdr.PayloadLength + hdrLen == PacketStream.Length)
{
// resend was already processed
if (pktHdr.Sequence < _rcvSequence)
{
return;
}
// push onto buffer
Buffer.Push(pktHdr.Sequence, PacketStream);
}
// more than one packet
else if (pktHdr.PayloadLength + hdrLen < PacketStream.Length)
{
byte[] buffer;
long pos = 0;
do
{
// get packet position and size
pos = PacketStream.Position;
if (PacketStream.Length - pos < DtmPacketStruct.GetHeaderSize())
{
// next packet corrupted, request a retransmission and exit
Transmit(DtmPacketFlags.Service, (short)DtmServiceFlags.Resend, Buffer.GetHighKey() + 1);
return;
}
pktHdr = new DtmPacketStruct(PacketStream);
pktLen = (int)(hdrLen + pktHdr.PayloadLength);
if (pktLen > MAXRCVBUFFER || pktLen < 0 || PacketStream.Length - pos < pktLen)
{
// packet corrupted, request a retransmission and exit
Transmit(DtmPacketFlags.Service, (short)DtmServiceFlags.Resend, Buffer.GetHighKey() + 1);
return;
}
else
{
// create the buffer
buffer = new byte[pktLen];
PacketStream.Seek(pos, SeekOrigin.Begin);
PacketStream.Read(buffer, 0, (int)pktLen);
// push onto buffer
Buffer.Push(pktHdr.Sequence, new MemoryStream(buffer));
}
} while (PacketStream.Position < PacketStream.Length);
}
// malformed packet, send retransmit request
else if (pktHdr.PayloadLength > MAXRCVBUFFER || pktHdr.PayloadLength < 0 || pktHdr.PayloadLength + hdrLen > PacketStream.Length)
{
// packet corrupted, request a retransmission of last in queue + 1
Transmit(DtmPacketFlags.Service, (short)DtmServiceFlags.Resend, Buffer.GetHighKey() + 1);
}
}
public void SendFile()
{
int bytesRead = 0;
long len = new FileInfo(_filePath).Length;
DtmFileInfoSruct flHdr = new DtmFileInfoSruct(_filePath, len, 0);
int ckSize = _clientSocket.SendBufferSize - (flHdr.GetHeaderSize() + DtmPacketStruct.GetHeaderSize());
byte[] inputBuffer = new byte[ckSize];
try
{
using (FileStream inStream = new FileStream(_filePath, FileMode.Open, FileAccess.Read, FileShare.Read))
{
// loop through file
while ((bytesRead = inStream.Read(inputBuffer, 0, ckSize)) > 0)
{
// wrap in a file info; option flag is used for payload length
flHdr.OptionsFlag = bytesRead;
byte[] hdrArr = flHdr.ToBytes();
// add data
if (bytesRead == ckSize)
{
hdrArr = ArrayUtils.Concat(hdrArr, inputBuffer);
}
else
{
hdrArr = ArrayUtils.Concat(hdrArr, ArrayUtils.GetRange(inputBuffer, 0, bytesRead));
}
// encrypt the header and data
byte[] enc = SymmetricTransform(_fileSymProcessor, hdrArr);
// send to the remote host
Transmit(DtmPacketFlags.Transfer, (short)DtmTransferFlags.DataChunk, _fileId, new MemoryStream(enc));
// increment counter
_bytesSent += bytesRead;
// progress
if (ProgressPercent != null)
{
double progress = 100.0 * (double)_bytesSent / inStream.Length;
ProgressPercent(this, new System.ComponentModel.ProgressChangedEventArgs((int)progress, (object)inStream.Length));
}
}
}
// notify app
if (FileTransferred != null)
{
FileTransferred(this, new DtmPacketArgs((short)DtmTransferFlags.Sent, _fileId));
}
}
catch (Exception ex)
{
throw new CryptoFileTransferException("DtmFileTransfer:SendFile", "The file transfer did not complete!", ex);
}
finally
{
// flush
SendFlush();
}
}
