TFTPServer Class

Properties   Methods   Events   Config Settings   Errors  

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

Syntax

ipworks.TFTPServer

Remarks

The TFTP Server class 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 class will serve files from this location. When clients connect, they can request files from this location. If this property is not set, then the class 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 class'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

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

Method List

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

Event List

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

Config Settings

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

Connections Property (TFTPServer Class)

This property is a collection of currently connected clients.

Syntax

public TFTPConnectionMap getConnections();

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.

Please refer to the TFTPConnection type for a complete list of fields.

Listening Property (TFTPServer Class)

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

Syntax

public boolean isListening();

Default Value

False

Remarks

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

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

LocalDir Property (TFTPServer Class)

This property defines the local file directory for the server.

Syntax

public String getLocalDir();
public void setLocalDir(String localDir);

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 Class)

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

Syntax

public String getLocalHost();
public void setLocalHost(String localHost);

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 class initiate connections (or accept in the case of server classs) 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 class 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 Class)

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

Syntax

public int getLocalPort();
public void setLocalPort(int localPort);

Default Value

69

Remarks

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

MaxRetransmits Property (TFTPServer Class)

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

Syntax

public int getMaxRetransmits();
public void setMaxRetransmits(int maxRetransmits);

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 Class)

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

Syntax

public int getRetransmitTimeout();
public void setRetransmitTimeout(int retransmitTimeout);

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 Class)

Sets or retrieves a configuration setting.

Syntax

public String config(String configurationString);

Remarks

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

These settings are similar in functionality to properties, but they are rarely used. In order to avoid "polluting" the property namespace of the class, 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 Class)

This method processes events from the internal message queue.

Syntax

public void doEvents();

Remarks

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

StartListening Method (TFTPServer Class)

This method starts listening for incoming connections.

Syntax

public void startListening();

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 Class)

This method stops listening for new connections.

Syntax

public void stopListening();

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 Class)

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

Syntax

public class DefaultTFTPServerEventListener implements TFTPServerEventListener {
  ...
  public void connected(TFTPServerConnectedEvent e) {}
  ...
}

public class TFTPServerConnectedEvent {
  public String connectionId;
  public int statusCode;
  public String description;
}

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 Class)

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

Syntax

public class DefaultTFTPServerEventListener implements TFTPServerEventListener {
  ...
  public void connectionRequest(TFTPServerConnectionRequestEvent e) {}
  ...
}

public class TFTPServerConnectionRequestEvent {
  public String remoteHost;
  public int remotePort;
  public String fileName;
  public String transferMode;
  public int operation;
  public boolean accept; //read-write
}

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 Class)

This event fires after a transfer is completed.

Syntax

public class DefaultTFTPServerEventListener implements TFTPServerEventListener {
  ...
  public void disconnected(TFTPServerDisconnectedEvent e) {}
  ...
}

public class TFTPServerDisconnectedEvent {
  public String connectionId;
  public int statusCode;
  public String description;
}

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 Class)

This event fires once a transfer is completed.

Syntax

public class DefaultTFTPServerEventListener implements TFTPServerEventListener {
  ...
  public void endTransfer(TFTPServerEndTransferEvent e) {}
  ...
}

public class TFTPServerEndTransferEvent {
  public String connectionId;
  public int direction;
}

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 Class)

Fired when information is available about errors during data delivery.

Syntax

public class DefaultTFTPServerEventListener implements TFTPServerEventListener {
  ...
  public void error(TFTPServerErrorEvent e) {}
  ...
}

public class TFTPServerErrorEvent {
  public int errorCode;
  public String description;
}

Remarks

The Error event is fired in case of exceptional conditions during message processing. Normally the class 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 Class)

This event fires once for each log message.

Syntax

public class DefaultTFTPServerEventListener implements TFTPServerEventListener {
  ...
  public void log(TFTPServerLogEvent e) {}
  ...
}

public class TFTPServerLogEvent {
  public String connectionId;
  public int logLevel;
  public String message;
  public String logType;
}

Remarks

This event fires once for each log message generated by the class. 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 Class)

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

Syntax

public class DefaultTFTPServerEventListener implements TFTPServerEventListener {
  ...
  public void startTransfer(TFTPServerStartTransferEvent e) {}
  ...
}

public class TFTPServerStartTransferEvent {
  public String connectionId;
  public int direction;
}

Remarks

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

Transfer Event (TFTPServer Class)

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

public class DefaultTFTPServerEventListener implements TFTPServerEventListener {
  ...
  public void transfer(TFTPServerTransferEvent e) {}
  ...
}

public class TFTPServerTransferEvent {
  public String connectionId;
  public int direction;
  public long bytesTransferred;
  public int percentDone;
  public byte[] text;
}

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

public TFTPConnection();

public TFTPConnection( connID,  remoteHost,  remotePort,  localFile,  downloadStream,  uploadStream,  remoteFile,  mode,  isRead,  blockSize,  rolloverNum);

Config Settings (TFTPServer Class)

The class accepts one or more of the following configuration settings. Configuration settings are similar in functionality to properties, but they are rarely used. In order to avoid "polluting" the property namespace of the class, access to these internal properties is provided through the Config method.

TFTPServer Config Settings

UDP Config Settings

Socket Config Settings

Base Config Settings

Trappable Errors (TFTPServer Class)

TFTPServer Errors

UDP Errors

SSL Errors

TCP/IP Errors