internal static ISCSIPDU GetSCSIDataOutResponsePDU(SCSIDataOutPDU request, ISCSITarget target, SessionParameters session, ConnectionParameters connection) { string connectionIdentifier = StateObject.GetConnectionIdentifier(session, connection); TransferEntry transfer = connection.GetTransferEntry(request.TargetTransferTag); if (transfer == null) { ISCSIServer.Log("[{0}][GetSCSIDataOutResponsePDU] Invalid TargetTransferTag {1}", connectionIdentifier, request.TargetTransferTag); RejectPDU reject = new RejectPDU(); reject.InitiatorTaskTag = request.InitiatorTaskTag; reject.Reason = RejectReason.InvalidPDUField; reject.Data = ByteReader.ReadBytes(request.GetBytes(), 0, 48); return(reject); } ushort LUN = (ushort)request.LUN; Disk disk = target.Disks[LUN]; uint offset = request.BufferOffset; uint totalLength = (uint)transfer.CommandDataBuffer.Length; // Store segment (we only execute the command after receiving all of its data) Array.Copy(request.Data, 0, transfer.CommandDataBuffer, offset, request.DataSegmentLength); ISCSIServer.Log(String.Format("[{0}][GetSCSIDataOutResponsePDU] Buffer offset: {1}, Total length: {2}", connectionIdentifier, offset, totalLength)); if (offset + request.DataSegmentLength == totalLength) { // Last Data-out PDU ISCSIServer.Log("[{0}][GetSCSIDataOutResponsePDU] Last Data-out PDU", connectionIdentifier); byte[] scsiResponse; SCSIStatusCodeName status = target.ExecuteCommand(transfer.CommandBytes, request.LUN, transfer.CommandDataBuffer, out scsiResponse); SCSIResponsePDU response = new SCSIResponsePDU(); response.InitiatorTaskTag = request.InitiatorTaskTag; response.Status = status; response.Data = scsiResponse; connection.RemoveTransfer(request.TargetTransferTag); return(response); } else { // Send R2T ReadyToTransferPDU response = new ReadyToTransferPDU(); response.InitiatorTaskTag = request.InitiatorTaskTag; response.TargetTransferTag = request.TargetTransferTag; response.R2TSN = transfer.NextR2NSN; response.BufferOffset = offset + request.DataSegmentLength; // where we left off response.DesiredDataTransferLength = Math.Min((uint)connection.TargetMaxRecvDataSegmentLength, totalLength - response.BufferOffset); transfer.NextR2NSN++; return(response); } }
public static void EnforceExpectedDataTransferLength(SCSIResponsePDU response, uint expectedDataTransferLength) { if (response.Data.Length > expectedDataTransferLength) { response.ResidualOverflow = true; response.ResidualCount = (uint)(response.Data.Length - expectedDataTransferLength); response.Data = ByteReader.ReadBytes(response.Data, 0, (int)expectedDataTransferLength); } else if (response.Data.Length < expectedDataTransferLength) { response.ResidualUnderflow = true; response.ResidualCount = (uint)(expectedDataTransferLength - response.Data.Length); } }
internal static List <ISCSIPDU> PrepareSCSICommandResponse(SCSICommandPDU command, SCSIStatusCodeName status, byte[] scsiResponse, ConnectionParameters connection) { List <ISCSIPDU> responseList = new List <ISCSIPDU>(); if (!command.Read || status != SCSIStatusCodeName.Good) { // RFC 3720: if the command is completed with an error, then the response and sense data MUST be sent in a SCSI Response PDU SCSIResponsePDU response = new SCSIResponsePDU(); response.InitiatorTaskTag = command.InitiatorTaskTag; response.Status = status; response.Data = scsiResponse; if (command.Read) { EnforceExpectedDataTransferLength(response, command.ExpectedDataTransferLength); } responseList.Add(response); } else if (scsiResponse.Length <= connection.InitiatorMaxRecvDataSegmentLength) { SCSIDataInPDU response = new SCSIDataInPDU(); response.InitiatorTaskTag = command.InitiatorTaskTag; response.Status = status; response.StatusPresent = true; response.Final = true; response.Data = scsiResponse; EnforceExpectedDataTransferLength(response, command.ExpectedDataTransferLength); responseList.Add(response); } else // we have to split the response to multiple Data-In PDUs { int bytesLeftToSend = scsiResponse.Length; uint dataSN = 0; while (bytesLeftToSend > 0) { int dataSegmentLength = Math.Min(connection.InitiatorMaxRecvDataSegmentLength, bytesLeftToSend); int dataOffset = scsiResponse.Length - bytesLeftToSend; SCSIDataInPDU response = new SCSIDataInPDU(); response.InitiatorTaskTag = command.InitiatorTaskTag; if (bytesLeftToSend == dataSegmentLength) { // last Data-In PDU response.Status = status; response.StatusPresent = true; response.Final = true; } response.BufferOffset = (uint)dataOffset; response.DataSN = dataSN; dataSN++; response.Data = new byte[dataSegmentLength]; Array.Copy(scsiResponse, dataOffset, response.Data, 0, dataSegmentLength); responseList.Add(response); bytesLeftToSend -= dataSegmentLength; } } return(responseList); }
internal static List <ISCSIPDU> GetSCSIResponsePDU(SCSICommandPDU command, ISCSITarget target, SessionParameters session, ConnectionParameters connection) { // We return either SCSIResponsePDU or List<SCSIDataInPDU> List <ISCSIPDU> responseList = new List <ISCSIPDU>(); string connectionIdentifier = StateObject.GetConnectionIdentifier(session, connection); if (command.Write && command.DataSegmentLength < command.ExpectedDataTransferLength) { uint transferTag = session.GetNextTransferTag(); // Store segment (we only execute the command after receiving all of its data) byte[] commandDataBuffer = new byte[command.ExpectedDataTransferLength]; Array.Copy(command.Data, 0, commandDataBuffer, 0, command.DataSegmentLength); // Send R2T ReadyToTransferPDU response = new ReadyToTransferPDU(); response.InitiatorTaskTag = command.InitiatorTaskTag; response.R2TSN = 0; // R2Ts are sequenced per command and must start with 0 for each new command; response.TargetTransferTag = transferTag; response.BufferOffset = command.DataSegmentLength; response.DesiredDataTransferLength = Math.Min((uint)connection.TargetMaxRecvDataSegmentLength, command.ExpectedDataTransferLength - response.BufferOffset); connection.AddTransfer(transferTag, command.CommandDescriptorBlock, commandDataBuffer, 1); responseList.Add(response); return(responseList); } byte[] scsiResponse; SCSIStatusCodeName status = target.ExecuteCommand(command.CommandDescriptorBlock, command.LUN, command.Data, out scsiResponse); if (!command.Read || status != SCSIStatusCodeName.Good) { // RFC 3720: if the command is completed with an error, then the response and sense data MUST be sent in a SCSI Response PDU SCSIResponsePDU response = new SCSIResponsePDU(); response.InitiatorTaskTag = command.InitiatorTaskTag; response.Status = status; response.Data = scsiResponse; if (command.Read) { EnforceExpectedDataTransferLength(response, command.ExpectedDataTransferLength); } responseList.Add(response); } else if (scsiResponse.Length <= connection.InitiatorMaxRecvDataSegmentLength) { SCSIDataInPDU response = new SCSIDataInPDU(); response.InitiatorTaskTag = command.InitiatorTaskTag; response.Status = status; response.StatusPresent = true; response.Final = true; response.Data = scsiResponse; EnforceExpectedDataTransferLength(response, command.ExpectedDataTransferLength); responseList.Add(response); } else // we have to split the response to multiple Data-In PDUs { int bytesLeftToSend = scsiResponse.Length; uint dataSN = 0; while (bytesLeftToSend > 0) { int dataSegmentLength = Math.Min(connection.InitiatorMaxRecvDataSegmentLength, bytesLeftToSend); int dataOffset = scsiResponse.Length - bytesLeftToSend; SCSIDataInPDU response = new SCSIDataInPDU(); response.InitiatorTaskTag = command.InitiatorTaskTag; if (bytesLeftToSend == dataSegmentLength) { // last Data-In PDU response.Status = status; response.StatusPresent = true; response.Final = true; } response.BufferOffset = (uint)dataOffset; response.DataSN = dataSN; dataSN++; response.Data = new byte[dataSegmentLength]; Array.Copy(scsiResponse, dataOffset, response.Data, 0, dataSegmentLength); responseList.Add(response); bytesLeftToSend -= dataSegmentLength; } } return(responseList); }