TFTPClient Component
Properties Methods Events Config Settings Errors
The TFTPClient component is used to exchange files with TFTP servers via the TFTP protocol defined in RFC 783.
Syntax
nsoftware.IPWorks.TFTPClient
Remarks
To use the component, first specify the TFTPServer, then a LocalFile and a RemoteFile, and then call GetFile or PutFile. The Transfer event shows the progress of the transfer.
Potential transmission errors and packet loss are managed by the Timeout property, which controls the maximum time to wait for a response from the server, and the MaxRetransmits property, which specifies how many times to resend a failed packet before giving up.
Property List
The following is the full list of the properties of the component with short descriptions. Click on the links for further details.
Idle | This property specifies the current status of the component. |
LocalFile | This property includes a file on the local host to transfer the data to or from. |
LocalHost | This property includes the name of the local host or user-assigned IP interface through which connections are initiated or accepted. |
MaxRetransmits | This property specifies the number of times to retry sending a failed packet before disconnecting. |
RemoteFile | This property includes the file on the remote host. |
RetransmitTimeout | This property includes the maximum time in seconds to wait for a reply packet from the server before retransmitting the last packet. |
TFTPPort | This property specifies the User Datagram Protocol (UDP) port where the remote TFTP server is listening. |
TFTPServer | This property includes the address of the TFTP server to exchange files with. |
Timeout | This property includes the timeout for the component. |
Method List
The following is the full list of the methods of the component with short descriptions. Click on the links for further details.
Config | Sets or retrieves a configuration setting. |
DoEvents | This method processes events from the internal message queue. |
GetFile | This method downloads a RemoteFile from the TFTP server. |
Interrupt | This method interrupts the current method. |
PutFile | This method uploads a file specified by LocalFile to the TFTP server. |
Reset | This method resets the component. |
SetDownloadStream | This method sets the stream to which the downloaded data from the server will be written. |
SetUploadStream | This method sets the stream to be uploaded to the server. |
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.
EndTransfer | This event is fired when a file finishes downloading or uploading. |
Error | Fired when information is available about errors during data delivery. |
StartTransfer | This event fires when a file starts downloading or uploading. |
Transfer | This event is fired during the file download or upload. |
Config Settings
The following is a list of config settings for the component with short descriptions. Click on the links for further details.
BlockSize | Determines the block size that will be used when transferring a file. |
CloseStreamAfterTransfer | If true, the component will close the upload or download stream after the transfer. |
TransferMode | Determines the transfer mode that will be used when transferring a file. |
CaptureIPPacketInfo | Used to capture the packet information. |
DelayHostResolution | Whether the hostname is resolved when RemoteHost is set. |
DestinationAddress | Used to get the destination address from the packet information. |
DontFragment | Used to set the Don't Fragment flag of outgoing packets. |
LocalHost | The name of the local host through which connections are initiated or accepted. |
LocalPort | The port in the local host where the component binds. |
MaxPacketSize | The maximum length of the packets that can be received. |
QOSDSCPValue | Used to specify an arbitrary QOS/DSCP setting (optional). |
QOSTrafficType | Used to specify QOS/DSCP settings (optional). |
ShareLocalPort | If set to True, allows more than one instance of the component to be active on the same local port. |
UseConnection | Determines whether to use a connected socket. |
UseIPv6 | Whether or not to use IPv6. |
AbsoluteTimeout | Determines whether timeouts are inactivity timeouts or absolute timeouts. |
FirewallData | Used to send extra data to the firewall. |
InBufferSize | The size in bytes of the incoming queue of the socket. |
OutBufferSize | The size in bytes of the outgoing queue of the socket. |
BuildInfo | Information about the product's build. |
GUIAvailable | Whether or not a message loop is available for processing events. |
LicenseInfo | Information about the current license. |
MaskSensitiveData | Whether sensitive data is masked in log messages. |
UseInternalSecurityAPI | Whether or not to use the system security libraries or an internal implementation. |
Idle Property (TFTPClient Component)
This property specifies the current status of the component.
Syntax
Default Value
True
Remarks
Idle will be False if the component is currently busy (communicating or waiting for an answer), and True at all other times.
This property is read-only.
LocalFile Property (TFTPClient Component)
This property includes a file on the local host to transfer the data to or from.
Syntax
Default Value
""
Remarks
If GetFile is called, and LocalFile already exists, it is overwritten. If PutFile is called, LocalFile must point to a valid file or an error will be returned.
LocalHost Property (TFTPClient Component)
This property includes the name of the local host or user-assigned IP interface through which connections are initiated or accepted.
Syntax
Default Value
""
Remarks
The LocalHost 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.
MaxRetransmits Property (TFTPClient Component)
This property specifies the number of times to retry sending a failed packet before disconnecting.
Syntax
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.
RemoteFile Property (TFTPClient Component)
This property includes the file on the remote host.
Syntax
Default Value
""
Remarks
When the GetFile is called, this must be a valid file on the TFTPServer.
RetransmitTimeout Property (TFTPClient Component)
This property includes the maximum time in seconds to wait for a reply packet from the server before retransmitting the last packet.
Syntax
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.
TFTPPort Property (TFTPClient Component)
This property specifies the User Datagram Protocol (UDP) port where the remote TFTP server is listening.
Syntax
Default Value
69
Remarks
The TFTPPort is the UDP port on the TFTPServer to send TFTP requests to.
This property is not available at design time.
TFTPServer Property (TFTPClient Component)
This property includes the address of the TFTP server to exchange files with.
Syntax
Default Value
""
Remarks
To be able to transfer file via TFTP, the remote host must be running TFTP services on port TFTPPort (default 69).
Example. Get a File:
TFTPControl.TFTPServer = "MyServer"
TFTPControl.LocalFile = "C:\filename.txt"
TFTPControl.RemoteFile = "/remotefile.txt"
TFTPControl.GetFile()
Timeout Property (TFTPClient Component)
This property includes the timeout for the component.
Syntax
Default Value
60
Remarks
If the Timeout property is set to 0, all operations will run uninterrupted until successful completion or an error condition is encountered.
If Timeout is set to a positive value, the component will wait for the operation to complete before returning control.
The component will use DoEvents to enter an efficient wait loop during any potential waiting period, making sure that all system events are processed immediately as they arrive. This ensures that the host application does not freeze and remains responsive.
If Timeout expires, and the operation is not yet complete, the component throws an exception.
Note: By default, all timeouts are inactivity timeouts, that is, the timeout period is extended by Timeout seconds when any amount of data is successfully sent or received.
The default value for the Timeout property is 60 seconds.
Config Method (TFTPClient Component)
Sets or retrieves a configuration setting.
Syntax
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 (TFTPClient Component)
This method processes events from the internal message queue.
Syntax
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.
GetFile Method (TFTPClient Component)
This method downloads a RemoteFile from the TFTP server.
Syntax
public void GetFile(); Async Version public async Task GetFile(); public async Task GetFile(CancellationToken cancellationToken);
Public Sub GetFile() Async Version Public Sub GetFile() As Task Public Sub GetFile(cancellationToken As CancellationToken) As Task
Remarks
The remote file specified by RemoteFile is downloaded to the local file specified by LocalFile, or it is retrieved through the Transfer event, if the LocalFile property is "" (empty string).
Example. Get a File:
TFTPControl.TFTPServer = "MyServer"
TFTPControl.LocalFile = "C:\filename.txt"
TFTPControl.RemoteFile = "/remotefile.txt"
TFTPControl.GetFile()
Interrupt Method (TFTPClient Component)
This method interrupts the current method.
Syntax
public void Interrupt(); Async Version public async Task Interrupt(); public async Task Interrupt(CancellationToken cancellationToken);
Public Sub Interrupt() Async Version Public Sub Interrupt() As Task Public Sub Interrupt(cancellationToken As CancellationToken) As Task
Remarks
If there is no method in progress, Interrupt simply returns, doing nothing.
PutFile Method (TFTPClient Component)
This method uploads a file specified by LocalFile to the TFTP server.
Syntax
public void PutFile(); Async Version public async Task PutFile(); public async Task PutFile(CancellationToken cancellationToken);
Public Sub PutFile() Async Version Public Sub PutFile() As Task Public Sub PutFile(cancellationToken As CancellationToken) As Task
Remarks
The local file specified by LocalFile is uploaded to the remote file specified by RemoteFile.
Example. Put a File:
TFTPControl.TFTPServer = "MyServer"
TFTPControl.LocalFile = "C:\filename.txt"
TFTPControl.RemoteFile = "/remotefile.txt"
TFTPControl.PutFile()
Reset Method (TFTPClient Component)
This method resets the component.
Syntax
public void Reset(); Async Version public async Task Reset(); public async Task Reset(CancellationToken cancellationToken);
Public Sub Reset() Async Version Public Sub Reset() As Task Public Sub Reset(cancellationToken As CancellationToken) As Task
Remarks
This method will reset the component's properties to their default values.
SetDownloadStream Method (TFTPClient Component)
This method sets the stream to which the downloaded data from the server will be written.
Syntax
public void SetDownloadStream(System.IO.Stream downloadStream); Async Version public async Task SetDownloadStream(System.IO.Stream downloadStream); public async Task SetDownloadStream(System.IO.Stream downloadStream, CancellationToken cancellationToken);
Public Sub SetDownloadStream(ByVal DownloadStream As System.IO.Stream) Async Version Public Sub SetDownloadStream(ByVal DownloadStream As System.IO.Stream) As Task Public Sub SetDownloadStream(ByVal DownloadStream As System.IO.Stream, cancellationToken As CancellationToken) As Task
Remarks
If a download stream is set before the GetFile method is called, the downloaded data will be written to the stream. The stream should be open and normally set to position 0. The component will automatically close this stream if CloseStreamAfterTransfer is set to True (default). If the stream is closed, you will need to call SetDownloadStream again before calling GetFile again. The downloaded content will be written starting at the current position in the stream.
Note: SetDownloadStream and LocalFile will reset the other.
SetUploadStream Method (TFTPClient Component)
This method sets the stream to be uploaded to the server.
Syntax
public void SetUploadStream(System.IO.Stream uploadStream); Async Version public async Task SetUploadStream(System.IO.Stream uploadStream); public async Task SetUploadStream(System.IO.Stream uploadStream, CancellationToken cancellationToken);
Public Sub SetUploadStream(ByVal UploadStream As System.IO.Stream) Async Version Public Sub SetUploadStream(ByVal UploadStream As System.IO.Stream) As Task Public Sub SetUploadStream(ByVal UploadStream As System.IO.Stream, cancellationToken As CancellationToken) As Task
Remarks
If an upload stream is set before the PutFile method is called, the content of the stream will be read by the component and uploaded to the server; The stream should be open and normally set to position 0. The component will automatically close this stream if CloseStreamAfterTransfer is set to True (default). If the stream is closed, you will need to call SetUploadStream again before calling PutFile again. The content of the stream will be read from the current position all the way to the end.
Note: SetUploadStream and LocalFile will reset the other.
EndTransfer Event (TFTPClient Component)
This event is fired when a file finishes downloading or uploading.
Syntax
public event OnEndTransferHandler OnEndTransfer; public delegate void OnEndTransferHandler(object sender, TFTPClientEndTransferEventArgs e); public class TFTPClientEndTransferEventArgs : EventArgs { public int Direction { get; } }
Public Event OnEndTransfer As OnEndTransferHandler Public Delegate Sub OnEndTransferHandler(sender As Object, e As TFTPClientEndTransferEventArgs) Public Class TFTPClientEndTransferEventArgs Inherits EventArgs Public ReadOnly Property Direction As Integer End Class
Remarks
The EndTransfer event fires when a Data Interface connection is closed. This occurs when the file finishes transferring or a directory listing is finished.
The Direction parameter shows whether the client (0) or the server (1) is sending the data.
Error Event (TFTPClient Component)
Fired when information is available about errors during data delivery.
Syntax
public event OnErrorHandler OnError; public delegate void OnErrorHandler(object sender, TFTPClientErrorEventArgs e); public class TFTPClientErrorEventArgs : EventArgs { public int ErrorCode { get; } public string Description { get; } }
Public Event OnError As OnErrorHandler Public Delegate Sub OnErrorHandler(sender As Object, e As TFTPClientErrorEventArgs) Public Class TFTPClientErrorEventArgs 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.
StartTransfer Event (TFTPClient Component)
This event fires when a file starts downloading or uploading.
Syntax
public event OnStartTransferHandler OnStartTransfer; public delegate void OnStartTransferHandler(object sender, TFTPClientStartTransferEventArgs e); public class TFTPClientStartTransferEventArgs : EventArgs { public int Direction { get; } }
Public Event OnStartTransfer As OnStartTransferHandler Public Delegate Sub OnStartTransferHandler(sender As Object, e As TFTPClientStartTransferEventArgs) Public Class TFTPClientStartTransferEventArgs Inherits EventArgs Public ReadOnly Property Direction As Integer End Class
Remarks
The StartTransfer event fires when a Data Interface connection is created. This is when the file starts transferring or a directory listing is started.
The Direction parameter shows whether the client (0) or the server (1) is sending the data.
Transfer Event (TFTPClient Component)
This event is fired during the file download or upload.
Syntax
public event OnTransferHandler OnTransfer; public delegate void OnTransferHandler(object sender, TFTPClientTransferEventArgs e); public class TFTPClientTransferEventArgs : EventArgs { 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 TFTPClientTransferEventArgs) Public Class TFTPClientTransferEventArgs Inherits EventArgs 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
One or more Transfer events are fired during file transfer. The BytesTransferred parameter shows the number of bytes transferred since the beginning of the transfer.
Text contains the portion of the file data being delivered.
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.
Config Settings (TFTPClient Component)
The component 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 component, access to these internal properties is provided through the Config method.TFTPClient Config Settings
Value | Description |
0 (default) | Binary (Octet) |
1 | Ascii (Netascii) |
UDP Config Settings
The default value for this setting is False.
Note: This configuration setting is available only in Windows.
The default value is false for the default library and true for the async library.
Note: This configuration setting is available only in Windows.
In multihomed hosts (machines with more than one IP interface), setting LocalHost to the value of an interface will make the component initiate connections (or accept in the case of server components) only through that interface.
If the component is connected, the LocalHost setting 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).
Setting this to 0 (default) enables the system to choose a port at random. The chosen port will be shown by LocalPort after the connection is established.
LocalPort cannot be changed once a connection is made. Any attempt to set this when a connection is active will generate an error.
This configuration setting is useful when trying to connect to services that require a trusted port on the client side. An example is the remote shell (rsh) service in UNIX systems.
Note: This configuration setting uses the qWAVE API and is available only on Windows 7, Windows Server 2008 R2, and later.
Note: This configuration setting uses the qWAVE API and is available only on Windows Vista and Windows Server 2008 or above.
Note: QOSTrafficType must be set before setting Active to True.
The default value for this setting is False.
The default value for this setting is False.
Socket Config Settings
Note: This option is not valid for User Datagram Protocol (UDP) ports.
Some TCP/IP implementations do not support variable buffer sizes. If that is the case, when the component is activated the InBufferSize reverts to its defined size. The same happens if you attempt to make it too large or too small.
Some TCP/IP implementations do not support variable buffer sizes. If that is the case, when the component is activated the OutBufferSize reverts to its defined size. The same happens if you attempt to make it too large or too small.
Base Config Settings
In some non-GUI applications, an invalid message loop may be discovered that will result in errant behavior. In these cases, setting GUIAvailable to false will ensure that the component does not attempt to process external events.
- Product: The product the license is for.
- Product Key: The key the license was generated from.
- License Source: Where the license was found (e.g., RuntimeLicense, License File).
- License Type: The type of license installed (e.g., Royalty Free, Single Server).
- Last Valid Build: The last valid build number for which the license will work.
This setting only works on these components: AS3Receiver, AS3Sender, Atom, Client(3DS), FTP, FTPServer, IMAP, OFTPClient, SSHClient, SCP, Server(3DS), Sexec, SFTP, SFTPServer, SSHServer, TCPClient, TCPServer.
Setting this configuration setting to true tells the component to use the internal implementation instead of using the system security libraries.
On Windows, this setting is set to false by default. On Linux/macOS, this setting is set to true by default.
If using the .NET Standard Library, this setting will be true on all platforms. The .NET Standard library does not support using the system security libraries.
Note: This setting is static. The value set is applicable to all components used in the application.
When this value is set, the product's system dynamic link library (DLL) is no longer required as a reference, as all unmanaged code is stored in that file.
Trappable Errors (TFTPClient Component)
TFTPClient Errors
122 | Packet too large. |
123 | Wrong response type from server. |
124 | Server error. Description contains detailed information. |
125 | Invalid server response. |
126 | A valid LocalFile must be provided for PUT operations. |
127 | Cannot open local file. |
128 | Cannot write to local file. |
129 | Cannot read local file. |
130 | Busy performing the current transfer. |
301 | Timeout while waiting for server. |
305 | Server error. |
306 | Wrong or invalid response type received from server. |
307 | Invalid response from server. |
The component may also return one of the following error codes, which are inherited from other components.
UDP Errors
104 | UDP is already Active. |
106 | You cannot change the LocalPort while the component is Active. |
107 | You cannot change the LocalHost at this time. A connection is in progress. |
109 | The component must be Active for this operation. |
112 | You cannot change MaxPacketSize while the component is Active. |
113 | You cannot change ShareLocalPort option while the component is Active. |
114 | You cannot change RemoteHost when UseConnection is set and the component Active. |
115 | You cannot change RemotePort when UseConnection is set and the component is Active. |
116 | RemotePort cannot be zero when UseConnection is set. Please specify a valid service port number. |
117 | You cannot change UseConnection while the component is Active. |
118 | Message cannot be longer than MaxPacketSize. |
119 | Message too short. |
434 | Unable to convert string to selected CodePage. |
SSL Errors
270 | Cannot load specified security library. |
271 | Cannot open certificate store. |
272 | Cannot find specified certificate. |
273 | Cannot acquire security credentials. |
274 | Cannot find certificate chain. |
275 | Cannot verify certificate chain. |
276 | Error during handshake. |
280 | Error verifying certificate. |
281 | Could not find client certificate. |
282 | Could not find server certificate. |
283 | Error encrypting data. |
284 | Error decrypting data. |
TCP/IP Errors
10004 | [10004] Interrupted system call. |
10009 | [10009] Bad file number. |
10013 | [10013] Access denied. |
10014 | [10014] Bad address. |
10022 | [10022] Invalid argument. |
10024 | [10024] Too many open files. |
10035 | [10035] Operation would block. |
10036 | [10036] Operation now in progress. |
10037 | [10037] Operation already in progress. |
10038 | [10038] Socket operation on nonsocket. |
10039 | [10039] Destination address required. |
10040 | [10040] Message is too long. |
10041 | [10041] Protocol wrong type for socket. |
10042 | [10042] Bad protocol option. |
10043 | [10043] Protocol is not supported. |
10044 | [10044] Socket type is not supported. |
10045 | [10045] Operation is not supported on socket. |
10046 | [10046] Protocol family is not supported. |
10047 | [10047] Address family is not supported by protocol family. |
10048 | [10048] Address already in use. |
10049 | [10049] Cannot assign requested address. |
10050 | [10050] Network is down. |
10051 | [10051] Network is unreachable. |
10052 | [10052] Net dropped connection or reset. |
10053 | [10053] Software caused connection abort. |
10054 | [10054] Connection reset by peer. |
10055 | [10055] No buffer space available. |
10056 | [10056] Socket is already connected. |
10057 | [10057] Socket is not connected. |
10058 | [10058] Cannot send after socket shutdown. |
10059 | [10059] Too many references, cannot splice. |
10060 | [10060] Connection timed out. |
10061 | [10061] Connection refused. |
10062 | [10062] Too many levels of symbolic links. |
10063 | [10063] File name is too long. |
10064 | [10064] Host is down. |
10065 | [10065] No route to host. |
10066 | [10066] Directory is not empty |
10067 | [10067] Too many processes. |
10068 | [10068] Too many users. |
10069 | [10069] Disc Quota Exceeded. |
10070 | [10070] Stale NFS file handle. |
10071 | [10071] Too many levels of remote in path. |
10091 | [10091] Network subsystem is unavailable. |
10092 | [10092] WINSOCK DLL Version out of range. |
10093 | [10093] Winsock is not loaded yet. |
11001 | [11001] Host not found. |
11002 | [11002] Nonauthoritative 'Host not found' (try again or check DNS setup). |
11003 | [11003] Nonrecoverable errors: FORMERR, REFUSED, NOTIMP. |
11004 | [11004] Valid name, no data record (check DNS setup). |