private T ParseResponse <T>(ProtocolDataUnit pdu)
where T : BaseResponse, new()
{
BaseResponse resp;
switch (pdu.OpCode)
{
case OpCode.LoginResponse:
resp = new LoginResponse();
break;
case OpCode.LogoutResponse:
resp = new LogoutResponse();
break;
case OpCode.ReadyToTransfer:
resp = new ReadyToTransferPacket();
break;
case OpCode.Reject:
resp = new RejectPacket();
break;
case OpCode.ScsiDataIn:
resp = new DataInPacket();
break;
case OpCode.ScsiResponse:
resp = new Response();
break;
case OpCode.TextResponse:
resp = new TextResponse();
break;
default:
throw new InvalidProtocolException("Unrecognized response opcode: " + pdu.OpCode);
}
resp.Parse(pdu);
if (resp.StatusPresent)
{
SeenStatusSequenceNumber(resp.StatusSequenceNumber);
}
T result = resp as T;
if (result == null)
{
throw new InvalidProtocolException("Unexpected response, expected " + typeof(T) + ", got " + result.GetType());
}
return(result);
}
/// <summary>
/// Sends an SCSI command (aka task) to a LUN via the connected target.
/// </summary>
/// <param name="cmd">The command to send</param>
/// <param name="outBuffer">The data to send with the command</param>
/// <param name="outBufferOffset">The offset of the first byte to send</param>
/// <param name="outBufferCount">The number of bytes to send, if any</param>
/// <param name="inBuffer">The buffer to fill with returned data</param>
/// <param name="inBufferOffset">The first byte to fill with returned data</param>
/// <param name="inBufferMax">The maximum amount of data to receive</param>
/// <returns>The number of bytes received</returns>
public int Send(ScsiCommand cmd, byte[] outBuffer, int outBufferOffset, int outBufferCount, byte[] inBuffer, int inBufferOffset, int inBufferMax)
{
CommandRequest req = new CommandRequest(this, cmd.TargetLun);
int toSend = Math.Min(Math.Min(outBufferCount, _session.ImmediateData ? _session.FirstBurstLength : 0), MaxTargetReceiveDataSegmentLength);
byte[] packet = req.GetBytes(cmd, outBuffer, outBufferOffset, toSend, true, inBufferMax != 0, outBufferCount != 0, (uint)(outBufferCount != 0 ? outBufferCount : inBufferMax));
_stream.Write(packet, 0, packet.Length);
_stream.Flush();
int numApproved = 0;
int numSent = toSend;
int pktsSent = 0;
while (numSent < outBufferCount)
{
ProtocolDataUnit pdu = ReadPdu();
ReadyToTransferPacket resp = ParseResponse <ReadyToTransferPacket>(pdu);
numApproved = (int)resp.DesiredTransferLength;
uint targetTransferTag = resp.TargetTransferTag;
while (numApproved > 0)
{
toSend = Math.Min(Math.Min(outBufferCount - numSent, numApproved), MaxTargetReceiveDataSegmentLength);
DataOutPacket pkt = new DataOutPacket(this, cmd.TargetLun);
packet = pkt.GetBytes(outBuffer, outBufferOffset + numSent, toSend, toSend == numApproved, pktsSent++, (uint)numSent, targetTransferTag);
_stream.Write(packet, 0, packet.Length);
_stream.Flush();
numApproved -= toSend;
numSent += toSend;
}
}
bool isFinal = false;
int numRead = 0;
while (!isFinal)
{
ProtocolDataUnit pdu = ReadPdu();
if (pdu.OpCode == OpCode.ScsiResponse)
{
Response resp = ParseResponse <Response>(pdu);
if (resp.StatusPresent && resp.Status == ScsiStatus.CheckCondition)
{
ushort senseLength = Utilities.ToUInt16BigEndian(pdu.ContentData, 0);
byte[] senseData = new byte[senseLength];
Array.Copy(pdu.ContentData, 2, senseData, 0, senseLength);
throw new ScsiCommandException(resp.Status, "Target indicated SCSI failure", senseData);
}
else if (resp.StatusPresent && resp.Status != ScsiStatus.Good)
{
throw new ScsiCommandException(resp.Status, "Target indicated SCSI failure");
}
isFinal = resp.Header.FinalPdu;
}
else if (pdu.OpCode == OpCode.ScsiDataIn)
{
DataInPacket resp = ParseResponse <DataInPacket>(pdu);
if (resp.StatusPresent && resp.Status != ScsiStatus.Good)
{
throw new ScsiCommandException(resp.Status, "Target indicated SCSI failure");
}
if (resp.ReadData != null)
{
Array.Copy(resp.ReadData, 0, inBuffer, inBufferOffset + resp.BufferOffset, resp.ReadData.Length);
numRead += resp.ReadData.Length;
}
isFinal = resp.Header.FinalPdu;
}
}
_session.NextTaskTag();
_session.NextCommandSequenceNumber();
return(numRead);
}