private void SendResult(BulkOnlyTransportCommandBlockWrapper commandBlockWrapper, CommandStatus status = CommandStatus.Success, uint dataResidue = 0)
{
var response = new CommandStatusWrapper(commandBlockWrapper.Tag, dataResidue, status);
this.Log(LogLevel.Debug, "Sending result: {0}", response);
deviceToHostEndpoint.HandlePacket(Packet.Encode(response));
}
private void HandleCommand(byte[] packet)
{
if (!BulkOnlyTransportCommandBlockWrapper.TryParse(packet, out var commandBlockWrapper))
{
this.Log(LogLevel.Warning, "Broken SCSI command block wrapper detected. Ignoring it.");
return;
}
this.Log(LogLevel.Noisy, "Parsed command block wrapper: {0}", commandBlockWrapper);
var command = SCSICommandDescriptorBlock.DecodeCommand(packet, BulkOnlyTransportCommandBlockWrapper.CommandOffset);
this.Log(LogLevel.Noisy, "Decoded command: {0}", command);
switch (command)
{
case SCSICommand.TestUnitReady:
SendResult(commandBlockWrapper);
break;
case SCSICommand.Inquiry:
// this is just an empty stub
SendData(new byte[36]);
SendResult(commandBlockWrapper);
break;
case SCSICommand.ReadCapacity:
var result = new ReadCapcity10Result
{
BlockLengthInBytes = BlockSize,
ReturnedLogicalBlockAddress = (uint)(dataBackend.Length / BlockSize - 1)
};
SendData(Packet.Encode(result));
SendResult(commandBlockWrapper);
break;
case SCSICommand.Read10:
var cmd = Packet.DecodeDynamic <IReadWrite10Command>(packet, BulkOnlyTransportCommandBlockWrapper.CommandOffset);
this.Log(LogLevel.Noisy, "Command args: LogicalBlockAddress: 0x{0:x}, TransferLength: {1}", (uint)cmd.LogicalBlockAddress, (ushort)cmd.TransferLength);
var bytesCount = (int)(cmd.TransferLength * BlockSize);
var readPosition = (long)cmd.LogicalBlockAddress * BlockSize;
dataBackend.Position = readPosition;
var data = dataBackend.ReadBytes(bytesCount);
this.Log(LogLevel.Noisy, "Reading {0} bytes from address 0x{1:x}", bytesCount, readPosition);
SendData(data);
SendResult(commandBlockWrapper, CommandStatus.Success, (uint)(commandBlockWrapper.DataTransferLength - data.Length));
break;
case SCSICommand.Write10:
// the actual write will be triggered after receiving the next packet with data
// we should not send result now
writeCommandWrapper = commandBlockWrapper;
writeCommandDescriptor = Packet.DecodeDynamic <IReadWrite10Command>(packet, BulkOnlyTransportCommandBlockWrapper.CommandOffset);
var position = (long)((dynamic)writeCommandDescriptor).LogicalBlockAddress * BlockSize;
dataBackend.Position = position;
bytesToWrite = (uint)((dynamic)writeCommandDescriptor).TransferLength * BlockSize;
this.Log(LogLevel.Noisy, "Preparing to write {1} bytes of data at address: 0x{0:x}", dataBackend.Position, bytesToWrite);
mode = Mode.Data;
break;
case SCSICommand.ModeSense6:
// this is just an empty stub
SendData(new byte[192]);
SendResult(commandBlockWrapper);
break;
case SCSICommand.RequestSense:
// this is just an empty stub
SendData(new byte[commandBlockWrapper.DataTransferLength]);
SendResult(commandBlockWrapper);
break;
default:
this.Log(LogLevel.Warning, "Unsupported SCSI command: {0}", command);
SendResult(commandBlockWrapper, CommandStatus.Failure, commandBlockWrapper.DataTransferLength);
break;
}
}
