private void ProcessPDU(ISCSIPDU pdu, ConnectionState state)
{
LogTrace("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 <SCSICommandPDU> commandsToExecute = null;
List <ReadyToTransferPDU> readyToTransferPDUs = new List <ReadyToTransferPDU>();
if (pdu is SCSIDataOutPDU)
{
SCSIDataOutPDU request = (SCSIDataOutPDU)pdu;
Log(Severity.Debug, "[{0}] SCSIDataOutPDU: InitiatorTaskTag: {1}, TargetTransferTag: {2}, LUN: {3}, BufferOffset: {4}, DataSegmentLength: {5}, DataSN: {6}, Final: {7}", state.ConnectionIdentifier, request.InitiatorTaskTag.ToString("x"), request.TargetTransferTag.ToString("x"), (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.ToString("x"));
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}, InitiatorTaskTag: {3}, DataSegmentLength: {4}, ExpectedDataTransferLength: {5}, Final: {6}", state.ConnectionIdentifier, command.CmdSN, (ushort)command.LUN, command.InitiatorTaskTag.ToString("x"), command.DataSegmentLength, command.ExpectedDataTransferLength, command.Final);
readyToTransferPDUs = TargetResponseHelper.GetReadyToTransferPDUs(command, state.ConnectionParameters, out commandsToExecute);
}
foreach (ReadyToTransferPDU readyToTransferPDU in readyToTransferPDUs)
{
state.SendQueue.Enqueue(readyToTransferPDU);
Log(Severity.Debug, "[{0}] Enqueued R2T, InitiatorTaskTag: {1}, TargetTransferTag: {2}, BufferOffset: {3}, DesiredDataTransferLength: {4}, R2TSN: {5}", state.ConnectionIdentifier, readyToTransferPDU.InitiatorTaskTag.ToString("x"), readyToTransferPDU.TargetTransferTag.ToString("x"), readyToTransferPDU.BufferOffset, readyToTransferPDU.DesiredDataTransferLength, readyToTransferPDU.R2TSN);
}
if (commandsToExecute != null)
{
state.RunningSCSICommands.Add(commandsToExecute.Count);
}
foreach (SCSICommandPDU commandPDU in commandsToExecute)
{
Log(Severity.Debug, "[{0}] Queuing command: CmdSN: {1}, InitiatorTaskTag: {2}", state.ConnectionIdentifier, commandPDU.CmdSN, commandPDU.InitiatorTaskTag.ToString("x"));
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);
}
}
LogTrace("Leaving ProcessPDU");
}
private LoginResponseStatusName SetUpSession(LoginRequestPDU request, KeyValuePairList <string, string> requestParameters, ConnectionParameters connection)
{
string initiatorName = requestParameters.ValueOf("InitiatorName");
if (String.IsNullOrEmpty(initiatorName))
{
// RFC 3720: InitiatorName: The initiator of the TCP connection MUST provide this key [..]
// at the first Login of the Login Phase for every connection.
string loginIdentifier = String.Format("ISID={0},TSIH={1},CID={2}", request.ISID.ToString("x"), request.TSIH.ToString("x"), request.CID.ToString("x"));
Log(Severity.Warning, "[{0}] Initiator error: InitiatorName was not included in the login request", loginIdentifier);
return(LoginResponseStatusName.InitiatorError);
}
if (request.TSIH == 0)
{
// Note: An initiator could login with the same ISID to a different target (another session),
// We should only perform session reinstatement when an initiator is logging in to the same target.
// For a new session, the request TSIH is zero,
// As part of the response, the target generates a TSIH.
connection.Session = m_sessionManager.StartSession(initiatorName, request.ISID);
connection.CID = request.CID;
Log(Severity.Verbose, "[{0}] Session has been started", connection.Session.SessionIdentifier);
connection.Session.CommandNumberingStarted = true;
connection.Session.ExpCmdSN = request.CmdSN;
string sessionType = requestParameters.ValueOf("SessionType");
if (sessionType == "Discovery")
{
connection.Session.IsDiscovery = true;
}
else //sessionType == "Normal" or unspecified (default is Normal)
{
if (requestParameters.ContainsKey("TargetName"))
{
string targetName = requestParameters.ValueOf("TargetName");
return(SetUpNormalSession(request, targetName, connection));
}
else
{
// RFC 3720: For any connection within a session whose type is not "Discovery", the first Login Request MUST also include the TargetName key=value pair.
Log(Severity.Warning, "[{0}] Initiator error: TargetName was not included in a non-discovery session", connection.ConnectionIdentifier);
return(LoginResponseStatusName.InitiatorError);
}
}
}
else
{
ISCSISession existingSession = m_sessionManager.FindSession(initiatorName, request.ISID, request.TSIH);
if (existingSession == null)
{
return(LoginResponseStatusName.SessionDoesNotExist);
}
else
{
connection.Session = existingSession;
ConnectionState existingConnection = m_connectionManager.FindConnection(existingSession, request.CID);
if (existingConnection != null)
{
// do connection reinstatement
Log(Severity.Verbose, "[{0}] Initiating implicit logout", existingConnection.ConnectionIdentifier);
m_connectionManager.ReleaseConnection(existingConnection);
}
else
{
// add a new connection to the session
if (m_connectionManager.GetSessionConnections(existingSession).Count > existingSession.MaxConnections)
{
return(LoginResponseStatusName.TooManyConnections);
}
}
connection.CID = request.CID;
}
}
return(LoginResponseStatusName.Success);
}
private ISCSIPDU GetLogoutResponsePDU(LogoutRequestPDU request, ConnectionParameters connection)
{
Log(Severity.Verbose, "[{0}] Logour Request", connection.ConnectionIdentifier);
if (connection.Session.IsDiscovery && request.ReasonCode != LogoutReasonCode.CloseTheSession)
{
// RFC 3720: Discovery-session: The target MUST ONLY accept [..] logout request with the reason "close the session"
RejectPDU reject = new RejectPDU();
reject.Reason = RejectReason.ProtocolError;
reject.Data = ByteReader.ReadBytes(request.GetBytes(), 0, 48);
return(reject);
}
else
{
List <ConnectionState> connectionsToClose = new List <ConnectionState>();
if (request.ReasonCode == LogoutReasonCode.CloseTheSession)
{
connectionsToClose = m_connectionManager.GetSessionConnections(connection.Session);
}
else if (request.ReasonCode == LogoutReasonCode.CloseTheConnection)
{
// RFC 3720: A Logout for a CID may be performed on a different transport connection when the TCP connection for the CID has already been terminated.
ConnectionState existingConnection = m_connectionManager.FindConnection(connection.Session, request.CID);
if (existingConnection != null)
{
connectionsToClose.Add(existingConnection);
}
else
{
return(ServerResponseHelper.GetLogoutResponsePDU(request, LogoutResponse.CIDNotFound));
}
}
else if (request.ReasonCode == LogoutReasonCode.RemoveTheConnectionForRecovery)
{
return(ServerResponseHelper.GetLogoutResponsePDU(request, LogoutResponse.ConnectionRecoveryNotSupported));
}
else
{
// Unknown LogoutRequest ReasonCode
RejectPDU reject = new RejectPDU();
reject.Reason = RejectReason.ProtocolError;
reject.Data = ByteReader.ReadBytes(request.GetBytes(), 0, 48);
return(reject);
}
foreach (ConnectionState connectionToClose in connectionsToClose)
{
// Wait for pending I/O to complete.
connectionToClose.RunningSCSICommands.WaitUntilZero();
if (connectionToClose.ConnectionParameters != connection)
{
SocketUtils.ReleaseSocket(connectionToClose.ClientSocket);
}
m_connectionManager.RemoveConnection(connectionToClose);
}
if (request.ReasonCode == LogoutReasonCode.CloseTheSession)
{
Log(Severity.Verbose, "[{0}] Session has been closed", connection.Session.SessionIdentifier);
m_sessionManager.RemoveSession(connection.Session, SessionTerminationReason.Logout);
}
return(ServerResponseHelper.GetLogoutResponsePDU(request, LogoutResponse.ClosedSuccessfully));
// connection will be closed after a LogoutResponsePDU has been sent.
}
}
