/* Copyright (C) 2012-2016 Tal Aloni . All rights reserved. * * You can redistribute this program and/or modify it under the terms of * the GNU Lesser Public License as published by the Free Software Foundation, * either version 3 of the License, or (at your option) any later version. */ using System; using System.Collections.Generic; using System.Net; using System.Net.Sockets; using System.Text; using Utilities; namespace ISCSI.Server { public partial class ISCSIServer { private bool ValidateCommandNumbering(ISCSIPDU pdu, ConnectionState state) { if (state.Session == null) { return true; } uint? cmdSN = PDUHelper.GetCmdSN(pdu); Log(Severity.Verbose, "[{0}] Received PDU from initiator, Operation: {1}, Size: {2}, CmdSN: {3}", state.ConnectionIdentifier, (ISCSIOpCodeName)pdu.OpCode, pdu.Length, cmdSN); // RFC 3720: On any connection, the iSCSI initiator MUST send the commands in increasing order of CmdSN, // except for commands that are retransmitted due to digest error recovery and connection recovery. if (cmdSN.HasValue) { if (state.Session.CommandNumberingStarted) { if (cmdSN != state.Session.ExpCmdSN) { return false; } } else { state.Session.ExpCmdSN = cmdSN.Value; state.Session.CommandNumberingStarted = true; } if (pdu is LogoutRequestPDU || pdu is TextRequestPDU || pdu is SCSICommandPDU || pdu is RejectPDU) { if (!pdu.ImmediateDelivery) { state.Session.ExpCmdSN++; } } } return true; } private void ProcessPDU(ISCSIPDU pdu, ConnectionState state) { Log(Severity.Trace, "Entering ProcessPDU"); if (state.Session == null || !state.Session.IsFullFeaturePhase) { if (pdu is LoginRequestPDU) { LoginRequestPDU request = (LoginRequestPDU)pdu; string loginIdentifier = String.Format("ISID={0},TSIH={1},CID={2}", request.ISID.ToString("x"), request.TSIH.ToString("x"), request.CID.ToString("x")); Log(Severity.Verbose, "[{0}] Login Request, current stage: {1}, next stage: {2}, parameters: {3}", loginIdentifier, request.CurrentStage, request.NextStage, FormatNullDelimitedText(request.LoginParametersText)); LoginResponsePDU response = GetLoginResponsePDU(request, state.ConnectionParameters); if (state.Session != null && state.Session.IsFullFeaturePhase) { m_connectionManager.AddConnection(state); } Log(Severity.Verbose, "[{0}] Login Response parameters: {1}", state.ConnectionIdentifier, FormatNullDelimitedText(response.LoginParametersText)); state.SendQueue.Enqueue(response); } else { // Before the Full Feature Phase is established, only Login Request and Login Response PDUs are allowed. Log(Severity.Warning, "[{0}] Initiator error: Improper command during login phase, OpCode: 0x{1}", state.ConnectionIdentifier, pdu.OpCode.ToString("x")); if (state.Session == null) { // A target receiving any PDU except a Login request before the Login phase is started MUST // immediately terminate the connection on which the PDU was received. state.ClientSocket.Close(); } else { // Once the Login phase has started, if the target receives any PDU except a Login request, // it MUST send a Login reject (with Status "invalid during login") and then disconnect. LoginResponsePDU loginResponse = new LoginResponsePDU(); loginResponse.TSIH = state.Session.TSIH; loginResponse.Status = LoginResponseStatusName.InvalidDuringLogon; state.SendQueue.Enqueue(loginResponse); } } } else // Logged in { if (pdu is TextRequestPDU) { TextRequestPDU request = (TextRequestPDU)pdu; TextResponsePDU response = GetTextResponsePDU(request, state.ConnectionParameters); state.SendQueue.Enqueue(response); } else if (pdu is LogoutRequestPDU) { LogoutRequestPDU request = (LogoutRequestPDU)pdu; ISCSIPDU response = GetLogoutResponsePDU(request, state.ConnectionParameters); state.SendQueue.Enqueue(response); } else if (state.Session.IsDiscovery) { // The target MUST ONLY accept text requests with the SendTargets key and a logout // request with the reason "close the session". All other requests MUST be rejected. Log(Severity.Warning, "[{0}] Initiator error: Improper command during discovery session, OpCode: 0x{1}", state.ConnectionIdentifier, pdu.OpCode.ToString("x")); RejectPDU reject = new RejectPDU(); reject.Reason = RejectReason.ProtocolError; reject.Data = ByteReader.ReadBytes(pdu.GetBytes(), 0, 48); state.SendQueue.Enqueue(reject); } else if (pdu is NOPOutPDU) { NOPOutPDU request = (NOPOutPDU)pdu; if (request.InitiatorTaskTag != 0xFFFFFFFF) { NOPInPDU response = ServerResponseHelper.GetNOPResponsePDU(request); state.SendQueue.Enqueue(response); } } else if (pdu is SCSIDataOutPDU || pdu is SCSICommandPDU) { // RFC 3720: the iSCSI target layer MUST deliver the commands for execution (to the SCSI execution engine) in the order specified by CmdSN. // e.g. read requests should not be executed while previous write request data is being received (via R2T) List commandsToExecute = null; List readyToTransferPDUs = new List(); if (pdu is SCSIDataOutPDU) { SCSIDataOutPDU request = (SCSIDataOutPDU)pdu; Log(Severity.Debug, "[{0}] SCSIDataOutPDU: Target transfer tag: {1}, LUN: {2}, Buffer offset: {3}, Data segment length: {4}, DataSN: {5}, Final: {6}", state.ConnectionIdentifier, request.TargetTransferTag, (ushort)request.LUN, request.BufferOffset, request.DataSegmentLength, request.DataSN, request.Final); try { readyToTransferPDUs = TargetResponseHelper.GetReadyToTransferPDUs(request, state.ConnectionParameters, out commandsToExecute); } catch (InvalidTargetTransferTagException ex) { Log(Severity.Warning, "[{0}] Initiator error: Invalid TargetTransferTag: {1}", state.ConnectionIdentifier, ex.TargetTransferTag); RejectPDU reject = new RejectPDU(); reject.InitiatorTaskTag = request.InitiatorTaskTag; reject.Reason = RejectReason.InvalidPDUField; reject.Data = ByteReader.ReadBytes(request.GetBytes(), 0, 48); state.SendQueue.Enqueue(reject); } } else { SCSICommandPDU command = (SCSICommandPDU)pdu; Log(Severity.Debug, "[{0}] SCSICommandPDU: CmdSN: {1}, LUN: {2}, Data segment length: {3}, Expected Data Transfer Length: {4}, Final: {5}", state.ConnectionIdentifier, command.CmdSN, (ushort)command.LUN, command.DataSegmentLength, command.ExpectedDataTransferLength, command.Final); readyToTransferPDUs = TargetResponseHelper.GetReadyToTransferPDUs(command, state.ConnectionParameters, out commandsToExecute); } foreach (ReadyToTransferPDU readyToTransferPDU in readyToTransferPDUs) { state.SendQueue.Enqueue(readyToTransferPDU); } if (commandsToExecute != null) { state.RunningSCSICommands.Add(commandsToExecute.Count); } foreach (SCSICommandPDU commandPDU in commandsToExecute) { Log(Severity.Debug, "[{0}] Queuing command: CmdSN: {1}", state.ConnectionIdentifier, commandPDU.CmdSN); state.Target.QueueCommand(commandPDU.CommandDescriptorBlock, commandPDU.LUN, commandPDU.Data, commandPDU, state.OnCommandCompleted); } } else if (pdu is LoginRequestPDU) { Log(Severity.Warning, "[{0}] Initiator Error: Login request during full feature phase", state.ConnectionIdentifier); // RFC 3720: Login requests and responses MUST be used exclusively during Login. // On any connection, the login phase MUST immediately follow TCP connection establishment and // a subsequent Login Phase MUST NOT occur before tearing down a connection RejectPDU reject = new RejectPDU(); reject.Reason = RejectReason.ProtocolError; reject.Data = ByteReader.ReadBytes(pdu.GetBytes(), 0, 48); state.SendQueue.Enqueue(reject); } else { Log(Severity.Error, "[{0}] Unsupported command, OpCode: 0x{1}", state.ConnectionIdentifier, pdu.OpCode.ToString("x")); RejectPDU reject = new RejectPDU(); reject.Reason = RejectReason.CommandNotSupported; reject.Data = ByteReader.ReadBytes(pdu.GetBytes(), 0, 48); state.SendQueue.Enqueue(reject); } } Log(Severity.Trace, "Leaving ProcessPDU"); } private static string FormatNullDelimitedText(string text) { string result = String.Join(", ", text.Split('\0')); if (result.EndsWith(", ")) { result = result.Remove(result.Length - 2); } return result; } } }