A Telnet client application that allows communication with an external Telnet server. More...

Methods
	Close
	Closes the Telnet session with the server and stops the Telnet client. More...

	ConnectionState.Get
	Returns the current TCP connection state. More...

	Description.Get
	Returns a textual description of the object.

	Local.Port.Get
	Returns the (local) TCP port used by this client. More...

	Local.Port.Set port
	Configures the (local) TCP port used by this client. More...

	Open
	Starts the Telnet client and opens the session with the Telnet server. More...

	Parent.Get
	Returns the parent object.

	Receive
	Reads data received over the Telnet session from the network and returns it. More...

	Remote.Address.Get
	Returns the IP address of the Telnet server to which this client connects. More...

	Remote.Address.Set address
	Sets the IP address of the Telnet server to which this client connects. More...

	Remote.Port.Get
	Returns the (remote) TCP port on the Telnet server to which this client connects.. More...

	Remote.Port.Set port
	Configures (remote) TCP port on the Telnet server to which this client connects. More...

	Send data
	Sends the provided to the Telnet server over the network.. More...

Class overview

A Telnet client application that allows communication with an external Telnet server.

The Telnet protocol allows for bidirectional interactive communication between a Telnet client (i.e. this application) on a ByteBlower port and an external Telnet server.

The Telnet protocol can be used to log in on other machines using a virtual terminal. By sending Telnet commands using Send, waiting for a small amount of time and reading the respons using Receive, a complete interactive session may be constructed.

The protocol can also be used to debug other network protocols. For example, contacting an HTTP server (on port 80) using a Telnet client and sending a valid HTTP request towards it, should correctly return the HTTP response data.

Since: API 2.2.0

Definition at line 17485 of file api.tcl.

Method documentation

Layer5.Telnet.Client::Close

Closes the Telnet session with the server and stops the Telnet client.

The TCP session will be closed and reset, so a new session can be opened.

If no Telnet session is open, nothing is done.

Example

This command closes the Telnet session if one is active.

1 $telnetClient Close

Definition at line 17499 of file api.tcl.

Layer5.Telnet.Client::ConnectionState.Get

Returns the current TCP connection state.

Returns

TCP ConnectionState Possible values are:

LISTEN
SYN_SENT
SYN_RECEIVED
ESTABLISHED
FIN_WAIT_1
FIN_WAIT_2
CLOSE_WAIT
CLOSING
LAST_ACK
TIME_WAIT
CLOSED

Example

1 set tcpSessionInfo [ $httpClientSessionInfo Tcp.Session.Info.Get ]

2 $tcpSessionInfo ConnectionState.Get

Returns:

TIME_WAIT

Definition at line 17512 of file api.tcl.

Layer5.Telnet.Client::Local.Port.Get

Returns the (local) TCP port used by this client.

The client will communicate with the server through a TCP network socket on this port and listen on it for incoming traffic.

If the TCP port isn't explicitly set (yet), this will return a valid and unique TCP port number for within the scope of the ByteBlower port (e.g. 32687).

Default value: Valid unique client TCP port

Returns: The currently configured TCP port on this client. This is an integer value.

Example

This example returns the port number on which this client connects to the Telnet server.

1 $telnetClient Local.Port.Get

Returns:

Definition at line 17536 of file api.tcl.

Layer5.Telnet.Client::Local.Port.Set			port

Configures the (local) TCP port used by this client.

The client will communicate with the server through a TCP network socket on this port and listen on it for incoming traffic.

If the TCP port isn't explicitly set (yet), the server will use a valid and unique TCP port number for within the scope of the ByteBlower port (e.g. 32687).

Default value: Valid and unique client TCP port

Parameters

port	The TCP port to be used by this client. This should be an integer value. Values larger the maximum port value of 65536 overflow into a valid port number.

Exceptions

InvalidValue.Integer	If the parameter value isn't an integer, this exception is thrown.
ByteBlower.Protocol.ConfigLocked	If a Telnet session is currently opened, this exception is thrown. Use Close to close the session before changing the Telnet server port.

Example

This snippet sets the port number on which this client will connect to the Telnet server.

1 $telnetClient Local.Port.Set 40404

Definition at line 17559 of file api.tcl.

Layer5.Telnet.Client::Open

Starts the Telnet client and opens the session with the Telnet server.

It will create a new TCP connection. The TCP statistics will be reset. If a Telnet session is already open, nothing is done.

After calling this method, data may be sent to the server Send will be queued for transmission after this handshake.

Bug:: When contacting a non-existing or unreachable Telnet server, this application has unexpected behavior. The Layer5.Telnet.Client::Open method returns immediately and TCP moves to the 'active' status. After the timeout expires, TCP moves to the 'finished' status instead of the 'timeOut' status. All the while, data may be sent using Layer5.Telnet.Client::Send. This data is queued during the handshake, but it will not be sent.

Exceptions

ByteBlower.Protocol.Unavailable If the Telnet server address has not been configured, this exception is thrown. Use Remote.Address.Set to configure the Telnet server address.

Example

This command opens the Telnet session, which initiates the handshake of the underlying TCP session. It returns immediately.

1 $telnetClient Open

Definition at line 17577 of file api.tcl.

Layer5.Telnet.Client::Receive

Reads data received over the Telnet session from the network and returns it.

If this method is executed, all received data since the last time it was called is returned. If more data is still flowing in from the network, the rest of the data will be returned the next time the receive method is executed.

Bug:: When contacting a non-existing or unreachable Telnet server, this method will not provide an error. When the TCP handshake fails (probably due to timeout), TCP will move (incorrectly) to finished after a while. None of the traffic sent at layer 5 will be received by the Telnet server.

Returns: The data received from the Telnet server.

Exceptions

ByteBlower.Protocol.InvalidAction When no session is active, this exception is thrown. Use Open to open the session.

Example

This example shows the response received from the Telnet server after sending the 'uname -a' command.

1 $telnetClient Receive

Returns:

Linux mylaptop 3.5.0-43-generic #66~precise1-Ubuntu SMP Thu Oct 24 14:52:23 UTC 2013 x86_64 x86_64 x86_64 GNU/Linux

Definition at line 17600 of file api.tcl.

Layer5.Telnet.Client::Remote.Address.Get

Returns the IP address of the Telnet server to which this client connects.

Before this address is set, no connection can be opened or traffic can be sent.

Both IPv4 and IPv6 addresses are supported, but the provided (remote) address must match use the same IP protocol as the ByteBlower port of this client.

Note: Currently, DNS is not supported, so providing a URL is not possible.

Returns: The IP address of the Telnet server to which this client connects. This should be either an valid IPv4 address or a valid IPv6 address.

Exceptions

ByteBlower.Protocol.InvalidValue If the remote IP address is not configured yet, this exception is thrown.

Example

This example returns the IP address of the Telnet server.

1 $telnetClient Remote.Address.Get

Returns:

10.8.65.65

Definition at line 17620 of file api.tcl.

Layer5.Telnet.Client::Remote.Address.Set			address

Sets the IP address of the Telnet server to which this client connects.

Before this address is set, no connection can be opened or traffic can be sent.

Both IPv4 and IPv6 addresses are supported, but the provided (remote) address must match be of the same type as the ByteBlower port of this client.

Note: Currently, DNS is not supported, so providing a URL is not possible.

Parameters

address The IP address of the Telnet server to which this client connects. This should be either an valid IPv4 address or a valid IPv6 address.

Exceptions

ByteBlower.Exception.API.ConfigError	If an invalid IP address is entered, this error is thrown.
ByteBlower.Protocol.InvalidValue	If an IPv4 address is provided, while this client is on an IPv6 ByteBlower port or vice versa, this exception is thrown.
ByteBlower.Protocol.ConfigLocked	If a Telnet session is currently opened, this exception is thrown. Use Close to close the session before changing the Telnet server address.

Example

This snippet sets the IP address of the Telnet server to be contacted.

1 $telnetClient Remote.Address.Set 1.2.3.4

Definition at line 17644 of file api.tcl.

Layer5.Telnet.Client::Remote.Port.Get

Returns the (remote) TCP port on the Telnet server to which this client connects..

The client will communicate with the Telnet server on the configured port.

If the TCP port isn't explicitly set (yet), this will return the default Telnet server port (23).

Default value: 23

Returns: The currently configured TCP port on the Telnet server to which this client connects. This is an integer value.

Example

This example returns the port number of the Telnet server.

1 $telnetClient Remote.Port.Get

Returns:

Definition at line 17663 of file api.tcl.

Layer5.Telnet.Client::Remote.Port.Set			port

Configures (remote) TCP port on the Telnet server to which this client connects.

The client will communicate with the Telnet server on the configured port.

If the TCP port isn't explicitly set (yet), the server will take the default Telnet server port (23).

Default value: 23

Parameters

port	The TCP port on the Telnet server to which this client connects. This should be an integer value. Values larger the maximum port value of 65536 overflow into a valid port number.

Exceptions

InvalidValue.Integer	If the parameter value isn't an integer, this exception is thrown.
ByteBlower.Protocol.ConfigLocked	If a Telnet session is currently opened, this exception is thrown. Use Close to close the session before changing the Telnet server port.

Example

This snippet sets the port number of the Telnet server to be contacted.

1 $telnetClient Remote.Port.Set 2323

Definition at line 17686 of file api.tcl.

Layer5.Telnet.Client::Send			data

Sends the provided to the Telnet server over the network..

Data may be sent as soon as a connection is opened. Data sent during the TCP handshake will be queued to be sent immediately after it.

Bug:: When contacting a non-existing or unreachable Telnet server, this method will not provide an error. When the TCP handshake fails (probably due to timeout), TCP will move (incorrectly) to finished after a while. None of the traffic sent at layer 5 will be received by the Telnet server.

Parameters

data	This string will be sent to the server for processing.

Exceptions

ByteBlower.Protocol.InvalidAction When no session is active, this exception is thrown. Use Open to open the session.

Example

This command sends the provided data over the network towards the Telnet server.

1 $telnetClient Send "uname -a"

Definition at line 17704 of file api.tcl.

Methods

Class overview

Method documentation