TFTPServer Component

Properties   Methods   Events   Config Settings   Errors  

The TFTP Server Component is used to create a TFTP Server.

Syntax

nsoftware.IPWorks.TFTPServer

Remarks

The TFTP Server component provides a simple way to create a TFTP Server. Any TFTP client will be able to connect and transfer files to and from the server.

Getting Started

By default, the server will listen on port 69. You can specify the listening port by setting the LocalPort property.

Optionally, you can set the LocalDir property to a valid local path. If this property is set, the component will serve files from this location. When clients connect, they can request files from this location. If this property is not set, then the component will fire events allowing customized responses for each operation.

To start the server, call the StartListening method.

Handling Events

Event handlers are the primary method of customizing the component's functionality. When a client attempts to connect or open a file, the corresponding TFTP Server event will fire to allow for custom handling of the client's request.

The following events are fired once the requested operation is executed:

• Error
• Log
• Connected
• ConnectionRequest
• Disconnected
• EndTransfer
• StartTransfer
• Transfer

Property List

The following is the full list of the properties of the component with short descriptions. Click on the links for further details.

Method List

The following is the full list of the methods of the component with short descriptions. Click on the links for further details.

Event List

The following is the full list of the events fired by the component with short descriptions. Click on the links for further details.

Config Settings

The following is a list of config settings for the component with short descriptions. Click on the links for further details.

Connections Property (TFTPServer Component)

This property is a collection of currently connected clients.

Syntax

• C#
• VB.NET

public TFTPConnectionMap Connections { get; }

Public ReadOnly Property Connections As TFTPConnectionMap

Remarks

This property is a collection of TFTPConnection elements that contain information about each connected client.

This property is read-only and not available at design time.

Listening Property (TFTPServer Component)

This property indicates whether the component is listening for incoming connections on LocalPort.

Syntax

• C#
• VB.NET

public bool Listening { get; }

Public ReadOnly Property Listening As Boolean

Default Value

False

Remarks

This property indicates whether the component is listening for connections on the port specified by the LocalPort property. Use the StartListening and StopListening methods to control whether the component is listening.

This property is read-only and not available at design time.

LocalDir Property (TFTPServer Component)

This property defines the local file directory for the server.

Syntax

• C#
• VB.NET

public string LocalDir { get; set; }

Public Property LocalDir As String

Default Value

""

Remarks

This property defines the local file directory on the server. Files can be downloaded to or uploaded from this directory.

This property is not available at design time.

LocalHost Property (TFTPServer Component)

The name of the local host or user-assigned IP interface through which connections are initiated or accepted.

Syntax

• C#
• VB.NET

public string LocalHost { get; set; }

Public Property LocalHost As String

Default Value

""

Remarks

This property contains the name of the local host as obtained by the gethostname() system call, or if the user has assigned an IP address, the value of that address.

In multihomed hosts (machines with more than one IP interface) setting LocalHost to the IP address of an interface will make the component initiate connections (or accept in the case of server components) only through that interface. It is recommended to provide an IP address rather than a hostname when setting this property to ensure the desired interface is used.

If the component is connected, the LocalHost property shows the IP address of the interface through which the connection is made in internet dotted format (aaa.bbb.ccc.ddd). In most cases, this is the address of the local host, except for multihomed hosts (machines with more than one IP interface).

Note: LocalHost is not persistent. You must always set it in code, and never in the property window.

LocalPort Property (TFTPServer Component)

This property includes the port that the server will listen on.

Syntax

• C#
• VB.NET

public int LocalPort { get; set; }

Public Property LocalPort As Integer

Default Value

69

Remarks

This property contains the port that the TFTP Server listens on. The default value is 69.

MaxRetransmits Property (TFTPServer Component)

This property specifies the number of times to retry sending a failed packet before disconnecting.

Syntax

• C#
• VB.NET

public int MaxRetransmits { get; set; }

Public Property MaxRetransmits As Integer

Default Value

3

Remarks

This property allows you to specify the number of times that you would like to try resending the last data packet if the original packet fails.

The RetransmitTimeout determines the wait time (in seconds) between successive retransmissions.

The default value for the MaxRetransmits property is 3.

RetransmitTimeout Property (TFTPServer Component)

This property includes the maximum time in seconds to wait for a reply packet from the server before retransmitting the last packet.

Syntax

• C#
• VB.NET

public int RetransmitTimeout { get; set; }

Public Property RetransmitTimeout As Integer

Default Value

5

Remarks

Please refer to the MaxRetransmits property for the number of retransmit efforts before an error is returned.

The default value for the RetransmitTimeout is 5 seconds.

Config Method (TFTPServer Component)

Sets or retrieves a configuration setting.

Syntax

• C#
• VB.NET

public string Config(string configurationString);

Async Version
public async Task<string> Config(string configurationString);
public async Task<string> Config(string configurationString, CancellationToken cancellationToken);

Public Function Config(ByVal ConfigurationString As String) As String

Async Version
Public Function Config(ByVal ConfigurationString As String) As Task(Of String)
Public Function Config(ByVal ConfigurationString As String, cancellationToken As CancellationToken) As Task(Of String)

Remarks

Config is a generic method available in every component. It is used to set and retrieve configuration settings for the component.

These settings are similar in functionality to properties, but they are rarely used. In order to avoid "polluting" the property namespace of the component, access to these internal properties is provided through the Config method.

To set a configuration setting named PROPERTY, you must call Config("PROPERTY=VALUE"), where VALUE is the value of the setting expressed as a string. For boolean values, use the strings "True", "False", "0", "1", "Yes", or "No" (case does not matter).

To read (query) the value of a configuration setting, you must call Config("PROPERTY"). The value will be returned as a string.

DoEvents Method (TFTPServer Component)

This method processes events from the internal message queue.

Syntax

• C#
• VB.NET

public void DoEvents();

Async Version
public async Task DoEvents();
public async Task DoEvents(CancellationToken cancellationToken);

Public Sub DoEvents()

Async Version
Public Sub DoEvents() As Task
Public Sub DoEvents(cancellationToken As CancellationToken) As Task

Remarks

When DoEvents is called, the component processes any available events. If no events are available, it waits for a preset period of time, and then returns.

StartListening Method (TFTPServer Component)

This method starts listening for incoming connections.

Syntax

• C#
• VB.NET

public void StartListening();

Async Version
public async Task StartListening();
public async Task StartListening(CancellationToken cancellationToken);

Public Sub StartListening()

Async Version
Public Sub StartListening() As Task
Public Sub StartListening(cancellationToken As CancellationToken) As Task

Remarks

This method begins listening for incoming connections on the port specified by LocalPort. Once listening, events will fire as new clients connect and data are transferred.

To stop listening for new connections, call StopListening.

StopListening Method (TFTPServer Component)

This method stops listening for new connections.

Syntax

• C#
• VB.NET

public void StopListening();

Async Version
public async Task StopListening();
public async Task StopListening(CancellationToken cancellationToken);

Public Sub StopListening()

Async Version
Public Sub StopListening() As Task
Public Sub StopListening(cancellationToken As CancellationToken) As Task

Remarks

This method stops listening for new connections. After being called, any new connection attempts will be rejected. Calling this method does not disconnect existing connections.

Connected Event (TFTPServer Component)

This event fires immediately after a connection completes (or fails).

Syntax

• C#
• VB.NET

public event OnConnectedHandler OnConnected;

public delegate void OnConnectedHandler(object sender, TFTPServerConnectedEventArgs e);

public class TFTPServerConnectedEventArgs : EventArgs {
  public string ConnectionId { get; }
  public int StatusCode { get; }
  public string Description { get; }
}

Public Event OnConnected As OnConnectedHandler

Public Delegate Sub OnConnectedHandler(sender As Object, e As TFTPServerConnectedEventArgs)

Public Class TFTPServerConnectedEventArgs Inherits EventArgs
  Public ReadOnly Property ConnectionId As String
  Public ReadOnly Property StatusCode As Integer
  Public ReadOnly Property Description As String
End Class

Remarks

The ConnectionId is the Id of the connected client that caused the event to fire.

Upon a successful connection, the SatusCode is 0, and the Description is OK. If the connection is not successful, the StatusCode will contain an error code. The Description will contain a textual description of the error. For a list of valid error codes and their descriptions, please refer to the Error Codes section.

ConnectionRequest Event (TFTPServer Component)

This event fires anytime a connected client attempts a connection to the server.

Syntax

• C#
• VB.NET

public event OnConnectionRequestHandler OnConnectionRequest;

public delegate void OnConnectionRequestHandler(object sender, TFTPServerConnectionRequestEventArgs e);

public class TFTPServerConnectionRequestEventArgs : EventArgs {
  public string RemoteHost { get; }
  public int RemotePort { get; }
  public string FileName { get; }
  public string TransferMode { get; }
  public int Operation { get; }
  public bool Accept { get; set; }
}

Public Event OnConnectionRequest As OnConnectionRequestHandler

Public Delegate Sub OnConnectionRequestHandler(sender As Object, e As TFTPServerConnectionRequestEventArgs)

Public Class TFTPServerConnectionRequestEventArgs Inherits EventArgs
  Public ReadOnly Property RemoteHost As String
  Public ReadOnly Property RemotePort As Integer
  Public ReadOnly Property FileName As String
  Public ReadOnly Property TransferMode As String
  Public ReadOnly Property Operation As Integer
  Public Property Accept As Boolean
End Class

Remarks

The RemoteHost parameter specifies the IP address (IP number in dotted internet format) of the client attempting to connect.

The RemotePort is the port of the client attempting a connection.

The FileName parameter is the path of the file to upload or download.

The TransferMode parameter specifies which transfer mode to use.

The Operation indicates whether the requested operation is read or write.

The Accept parameter indicates whether to accept or deny the connection. All connections are accepted by default. If you want to refuse a connection, set the Accept parameter to false.

Disconnected Event (TFTPServer Component)

This event fires after a transfer is completed.

Syntax

• C#
• VB.NET

public event OnDisconnectedHandler OnDisconnected;

public delegate void OnDisconnectedHandler(object sender, TFTPServerDisconnectedEventArgs e);

public class TFTPServerDisconnectedEventArgs : EventArgs {
  public string ConnectionId { get; }
  public int StatusCode { get; }
  public string Description { get; }
}

Public Event OnDisconnected As OnDisconnectedHandler

Public Delegate Sub OnDisconnectedHandler(sender As Object, e As TFTPServerDisconnectedEventArgs)

Public Class TFTPServerDisconnectedEventArgs Inherits EventArgs
  Public ReadOnly Property ConnectionId As String
  Public ReadOnly Property StatusCode As Integer
  Public ReadOnly Property Description As String
End Class

Remarks

ConnectionID will be the ConnectionID of the client that has disconnected.

Upon successful transfer and disconnection, the StatusCode will be 0 and the Description will be OK. If a transfer is unsuccessful or a client disconnects due to an error, the StatusCode will contain an error code. The Description will be a textual description of the error.

EndTransfer Event (TFTPServer Component)

This event fires once a transfer is completed.

Syntax

• C#
• VB.NET

public event OnEndTransferHandler OnEndTransfer;

public delegate void OnEndTransferHandler(object sender, TFTPServerEndTransferEventArgs e);

public class TFTPServerEndTransferEventArgs : EventArgs {
  public string ConnectionId { get; }
  public int Direction { get; }
}

Public Event OnEndTransfer As OnEndTransferHandler

Public Delegate Sub OnEndTransferHandler(sender As Object, e As TFTPServerEndTransferEventArgs)

Public Class TFTPServerEndTransferEventArgs Inherits EventArgs
  Public ReadOnly Property ConnectionId As String
  Public ReadOnly Property Direction As Integer
End Class

Remarks

The ConnectionId will be the ConnectionId of the connected client.

The Direction parameter shows whether the client (0) or the server (1) is sending the data.

Error Event (TFTPServer Component)

Fired when information is available about errors during data delivery.

Syntax

• C#
• VB.NET

public event OnErrorHandler OnError;

public delegate void OnErrorHandler(object sender, TFTPServerErrorEventArgs e);

public class TFTPServerErrorEventArgs : EventArgs {
  public int ErrorCode { get; }
  public string Description { get; }
}

Public Event OnError As OnErrorHandler

Public Delegate Sub OnErrorHandler(sender As Object, e As TFTPServerErrorEventArgs)

Public Class TFTPServerErrorEventArgs Inherits EventArgs
  Public ReadOnly Property ErrorCode As Integer
  Public ReadOnly Property Description As String
End Class

Remarks

The Error event is fired in case of exceptional conditions during message processing. Normally the component throws an exception.

The ErrorCode parameter contains an error code, and the Description parameter contains a textual description of the error. For a list of valid error codes and their descriptions, please refer to the Error Codes section.

Log Event (TFTPServer Component)

This event fires once for each log message.

Syntax

• C#
• VB.NET

public event OnLogHandler OnLog;

public delegate void OnLogHandler(object sender, TFTPServerLogEventArgs e);

public class TFTPServerLogEventArgs : EventArgs {
  public string ConnectionId { get; }
  public int LogLevel { get; }
  public string Message { get; }
  public string LogType { get; }
}

Public Event OnLog As OnLogHandler

Public Delegate Sub OnLogHandler(sender As Object, e As TFTPServerLogEventArgs)

Public Class TFTPServerLogEventArgs Inherits EventArgs
  Public ReadOnly Property ConnectionId As String
  Public ReadOnly Property LogLevel As Integer
  Public ReadOnly Property Message As String
  Public ReadOnly Property LogType As String
End Class

Remarks

This event fires once for each log message generated by the component. The verbosity is controlled by the LogLevel setting.

LogLevel indicates the level of message. Possible values are as follows:

The value 1 (Info) logs basic information, including users logging in and out, files transferred, and directories listed.

The value 2 (Verbose) includes logs from the PITrail event as well as basic information about data transfer channels.

The value 3 (Debug) logs additional debug information, such as extended socket connection and data transfer information.

Message is the log entry.

LogType identifies the type of log entry. Possible values are as follows:

• "Info"
• "Error"
• "Verbose"
• "Debug"
• "PITrail"

StartTransfer Event (TFTPServer Component)

This event fires immediately after a client initiates a file transfer.

Syntax

• C#
• VB.NET

public event OnStartTransferHandler OnStartTransfer;

public delegate void OnStartTransferHandler(object sender, TFTPServerStartTransferEventArgs e);

public class TFTPServerStartTransferEventArgs : EventArgs {
  public string ConnectionId { get; }
  public int Direction { get; }
}

Public Event OnStartTransfer As OnStartTransferHandler

Public Delegate Sub OnStartTransferHandler(sender As Object, e As TFTPServerStartTransferEventArgs)

Public Class TFTPServerStartTransferEventArgs Inherits EventArgs
  Public ReadOnly Property ConnectionId As String
  Public ReadOnly Property Direction As Integer
End Class

Remarks

ConnectionId is the ConnectionId of the connected client. Direction represents the direction in which the transfer is going.

Transfer Event (TFTPServer Component)

This event fires repeatedly while data are being transferred. A transfer is marked as complete once a packet that is less than 512 bytes is received.

Syntax

• C#
• VB.NET

public event OnTransferHandler OnTransfer;

public delegate void OnTransferHandler(object sender, TFTPServerTransferEventArgs e);

public class TFTPServerTransferEventArgs : EventArgs {
  public string ConnectionId { get; }
  public int Direction { get; }
  public long BytesTransferred { get; }
  public int PercentDone { get; }
  public string Text { get; }
  public byte[] TextB { get; }
}

Public Event OnTransfer As OnTransferHandler

Public Delegate Sub OnTransferHandler(sender As Object, e As TFTPServerTransferEventArgs)

Public Class TFTPServerTransferEventArgs Inherits EventArgs
  Public ReadOnly Property ConnectionId As String
  Public ReadOnly Property Direction As Integer
  Public ReadOnly Property BytesTransferred As Long
  Public ReadOnly Property PercentDone As Integer
  Public ReadOnly Property Text As String
  Public ReadOnly Property TextB As Byte()
End Class

Remarks

The ConnectionId parameter is the ConnectionId of the client who initiated the transfer.

BytesTransferred specifies the number of bytes transferred.

The Text parameter contains the data being transferred.

The Direction parameter shows whether the client (0) or the server (1) is sending the data.

The PercentDone parameter shows the progress of the transfer in the corresponding direction. If PercentDone can not be calculated the value will be -1.

Note: Events are not re-entrant. Performing time-consuming operations within this event will prevent it from firing again in a timely manner and may affect overall performance.

TFTPConnection Type

This type specifies a client currently connected to the server.

Remarks

This type represents a client connection to the server.

See the Connections property for more information.

Fields

Constructors

• C#
• VB.NET

public TFTPConnection();

Public TFTPConnection()

• C#
• VB.NET

public TFTPConnection(string connID, string remoteHost, int remotePort, string localFile, System.IO.Stream downloadStream, System.IO.Stream uploadStream, string remoteFile, string mode, bool isRead, int blockSize, int rolloverNum);

Public TFTPConnection(ByVal ConnID As String, ByVal RemoteHost As String, ByVal RemotePort As Integer, ByVal LocalFile As String, ByVal DownloadStream As System.IO.Stream, ByVal UploadStream As System.IO.Stream, ByVal RemoteFile As String, ByVal Mode As String, ByVal isRead As Boolean, ByVal blockSize As Integer, ByVal rolloverNum As Integer)

Config Settings (TFTPServer Component)

TFTPServer Config Settings

UDP Config Settings

Socket Config Settings

Base Config Settings

Trappable Errors (TFTPServer Component)

TFTPServer Errors

The component may also return one of the following error codes, which are inherited from other components.

UDP Errors

SSL Errors

TCP/IP Errors