Telnet protocol implementation. More...

#include <senf/Utils/Termlib/Telnet.hh>

Inheritance diagram for senf::term::BaseTelnetProtocol:

[legend]

Classes
struct	TelnetHandler
	Telnet handler base class. More...

Public Types
typedef ClientSocketHandle< senf::MakeSocketPolicy< ConnectedCommunicationPolicy, StreamFramingPolicy, ReadablePolicy, WriteablePolicy >::policy >	Handle
	Type of socket handle required. More...

typedef unsigned char	option_type
	Type of telnet option numbers. More...

Public Member Functions
void	write (std::string const &s)
	Send string to peer. More...

void	write (char c)
	Send single character to peer. More...

Handle	handle ()
	Get socket handle. More...

void	sendNOP ()
	Send NOP to peer. More...

void	sendBRK ()
	Send BReaK to peer. More...

void	sendIP ()
	Send InterruptProcess to peer. More...

void	sendAO ()
	Send AbortOutput to peer. More...

void	sendAYT ()
	Send AreYouThere to peer. More...

void	sendEC ()
	Send EraseCharacter to peer. More...

void	sendEL ()
	Send EraseLine to peer. More...

void	sendGA ()
	Send GoAhead to peer. More...

void	sendOptionParameters (option_type option, std::string const &data)
	Send extended option parameter to peer. More...

void	requestLocalOption (option_type option, bool enabled=true)
	Request option to be enabled here. More...

void	acceptLocalOption (option_type option, bool enabled=true)
	Accept a request for an option to be enabled here. More...

void	requestPeerOption (option_type option, bool enabled=true)
	Request peer to enable an option. More...

void	acceptPeerOption (option_type option, bool enabled=true)
	Accept a request by the peer to enable an option. More...

bool	localOption (option_type option)
	`true`, if option locally enabled More...

bool	peerOption (option_type option)
	`true`, if option enabled in peer More...

Static Public Attributes
static unsigned const	DEFAULT_REQUEST_TIMEOUT_MS = 500u

Protected Member Functions
	BaseTelnetProtocol (Handle handle)
	Construct telnet protocol handler. More...

	BaseTelnetProtocol ()
	Provided for TelnetHandler mixins only. More...

virtual	~BaseTelnetProtocol ()

template<class Handler >
void	registerHandler (Handler *h, bool request=true)
	Register a TelnetHandler. More...

void	incrementRequestCounter ()
	Increment request counter. More...

void	decrementRequestCounter ()
	Decrement request counter. More...

bool	requestsPending ()
	`true`, if there are pending requests More...

virtual void	v_setupComplete ()=0
	Called, when no further requests are pending. More...

virtual void	v_charReceived (char c)=0
	Called whenever a data character is received. More...

virtual void	v_eof ()=0
	Called on input EOF. More...

virtual void	v_handleNOP ()
	Called, when the peer sends a NOP. More...

virtual void	v_handleBRK ()
	Called, when the peer sends a BReaK. More...

virtual void	v_handleIP ()
	Called, when the peer sends an InterruptProcess. More...

virtual void	v_handleAO ()
	Called, when the peer sends an AbortOutput. More...

virtual void	v_handleAYT ()
	Called, when the peer sends an AreYouThere. More...

virtual void	v_handleEC ()
	Called, when the peer sends an EraseCharacter. More...

virtual void	v_handleEL ()
	Called, when the peer sends an EraseLine. More...

virtual void	v_handleGA ()
	Called, when the peer sends a GoAhead. More...

Detailed Description

Telnet protocol implementation.

This class implements the basic telnet protocol. It provides option parsing and negotiation and implements the necessary character quoting.

This class is a base class. Several virtual function hooks are provided which will be called by the protocol implementation.

The telnet protocol implementation is symmetric: At this level, there is no difference between a telnet client and a telnet server.

This telnet protocol base class integrates with the SENF Scheduler, it relies on the scheduler main loop to be active.

Telnet option handlers

    To support complex telnet option which require subnegotiation, TelnetHandler's are
    provided. A telnet handler is a class derived from TelnetHandler and then inherited into the
    target telnet implementation class:

class MyTelnet
    : public senf::term::telnethandler::TerminalType,
      public senf::term::telnethandler::NAWS
{
    MyTelnet(Handle handle) : BaseTelnetProtocol(handle) {}
    // ...
};

    It is very important, the BaseTelnetProtocol is \e always inherited by \c public \c virtual
    inheritance. This allows the BaseTelnetProtocol constructor to be called by the most derived
    class directly as above.

    Each terminal handler may provide an additional API and/or additional virtual function
    callbacks.

    To implement a new terminal handler, derive from TelnetHandler and register the
    handler. BaseTelnetProtocol will automatically request the corresponding option to be
    enabled and will call the handlers \c v_init() member as soon as the peer as asserted the
    option.

    Whenever a subnegotiation for the registered handler is received, the handlers
    \c v_handleOptionParameters() member is called.

class MyTelnetHandler
    : public senf::term::BaseTelnetProtocol::TelnetHandler
{
public:
    // This constant is MANDATORY and gives the option code which this handler services
    static option_type const OPTION_CODE = MY_OPTION_CODE;
    void frobble() { // ... }
protected:
    MyTelnetHandler() { registerHandler(this); }
private:
    virtual void v_init()
    {
        sendOptionParameters(OPTION_CODE, "my special subnegotiation");
        incrementRequestCounter();
    }
    virtual void v_handleOptionParameters(std::string const & data)
    {
        if (data == "another special subnegotiation")
            decrementRequestCounter();
    }
};

Todo:: SYNCH handling

Definition at line 131 of file Telnet.hh.

Member Typedef Documentation

◆ Handle

typedef ClientSocketHandle<senf::MakeSocketPolicy< ConnectedCommunicationPolicy, StreamFramingPolicy, ReadablePolicy, WriteablePolicy>::policy> senf::term::BaseTelnetProtocol::Handle

Type of socket handle required.

Definition at line 140 of file Telnet.hh.

◆ option_type

typedef unsigned char senf::term::BaseTelnetProtocol::option_type

Type of telnet option numbers.

Definition at line 142 of file Telnet.hh.

Constructor & Destructor Documentation

◆ BaseTelnetProtocol() [1/2]

senf::term::BaseTelnetProtocol::BaseTelnetProtocol ( Handle handle )

explicitprotected

Construct telnet protocol handler.

Definition at line 30 of file Telnet.cc.

◆ BaseTelnetProtocol() [2/2]

senf::term::BaseTelnetProtocol::BaseTelnetProtocol ( )

protected

Provided for TelnetHandler mixins only.

Definition at line 44 of file Telnet.cc.

◆ ~BaseTelnetProtocol()

virtual senf::term::BaseTelnetProtocol::~BaseTelnetProtocol ( )

protectedvirtual

Member Function Documentation

◆ acceptLocalOption()

void senf::term::BaseTelnetProtocol::acceptLocalOption	(	option_type	option,
		bool	enabled = `true`
	)

Accept a request for an option to be enabled here.

If the peer sends a DO option request, the request will be granted

◆ acceptPeerOption()

void senf::term::BaseTelnetProtocol::acceptPeerOption	(	option_type	option,
		bool	enabled = `true`
	)

Accept a request by the peer to enable an option.

If the peer sends a WILL option request, the request will be ganted

◆ decrementRequestCounter()

void senf::term::BaseTelnetProtocol::decrementRequestCounter ( )

protected

Decrement request counter.

See also: inrementRequestCounter()

Definition at line 430 of file Telnet.cc.

◆ handle()

Handle senf::term::BaseTelnetProtocol::handle ( )

Get socket handle.

◆ incrementRequestCounter()

void senf::term::BaseTelnetProtocol::incrementRequestCounter ( )

protected

Increment request counter.

This member may be called by a telnet handler to wait for additional negotiations. It must be paired with a corresponding decrementRequestCounter() call when that negotiation is received.

Definition at line 327 of file Telnet.cc.

◆ localOption()

bool senf::term::BaseTelnetProtocol::localOption ( option_type option )

true, if option locally enabled

◆ peerOption()

bool senf::term::BaseTelnetProtocol::peerOption ( option_type option )

true, if option enabled in peer

◆ registerHandler()

template<class Handler >

void senf::term::BaseTelnetProtocol::registerHandler	(	Handler *	h,
		bool	request = `true`
	)

protected

Register a TelnetHandler.

◆ requestLocalOption()

void senf::term::BaseTelnetProtocol::requestLocalOption	(	option_type	option,
		bool	enabled = `true`
	)

Request option to be enabled here.

This will send a WILL option request to the peer

◆ requestPeerOption()

void senf::term::BaseTelnetProtocol::requestPeerOption	(	option_type	option,
		bool	enabled = `true`
	)

Request peer to enable an option.

This will send a DO option request to the peer

◆ requestsPending()

bool senf::term::BaseTelnetProtocol::requestsPending ( )

protected

true, if there are pending requests

◆ sendAO()

void senf::term::BaseTelnetProtocol::sendAO ( )

Send AbortOutput to peer.

◆ sendAYT()

void senf::term::BaseTelnetProtocol::sendAYT ( )

Send AreYouThere to peer.

◆ sendBRK()

void senf::term::BaseTelnetProtocol::sendBRK ( )

Send BReaK to peer.

◆ sendEC()

void senf::term::BaseTelnetProtocol::sendEC ( )

Send EraseCharacter to peer.

◆ sendEL()

void senf::term::BaseTelnetProtocol::sendEL ( )

Send EraseLine to peer.

◆ sendGA()

void senf::term::BaseTelnetProtocol::sendGA ( )

Send GoAhead to peer.

◆ sendIP()

void senf::term::BaseTelnetProtocol::sendIP ( )

Send InterruptProcess to peer.

◆ sendNOP()

void senf::term::BaseTelnetProtocol::sendNOP ( )

Send NOP to peer.

◆ sendOptionParameters()

void senf::term::BaseTelnetProtocol::sendOptionParameters	(	option_type	option,
		std::string const &	data
	)

Send extended option parameter to peer.

This will send data as extended option parameter of option option to peer via a subnegotiation.

Definition at line 86 of file Telnet.cc.

◆ v_charReceived()

virtual void senf::term::BaseTelnetProtocol::v_charReceived ( char c )

protectedpure virtual

Called whenever a data character is received.

◆ v_eof()

virtual void senf::term::BaseTelnetProtocol::v_eof ( )

protectedpure virtual

Called on input EOF.

◆ v_handleAO()

void senf::term::BaseTelnetProtocol::v_handleAO ( )

protectedvirtual

Called, when the peer sends an AbortOutput.

Definition at line 112 of file Telnet.cc.

◆ v_handleAYT()

void senf::term::BaseTelnetProtocol::v_handleAYT ( )

protectedvirtual

Called, when the peer sends an AreYouThere.

Definition at line 115 of file Telnet.cc.

◆ v_handleBRK()

void senf::term::BaseTelnetProtocol::v_handleBRK ( )

protectedvirtual

Called, when the peer sends a BReaK.

Definition at line 106 of file Telnet.cc.

◆ v_handleEC()

void senf::term::BaseTelnetProtocol::v_handleEC ( )

protectedvirtual

Called, when the peer sends an EraseCharacter.

Definition at line 118 of file Telnet.cc.

◆ v_handleEL()

void senf::term::BaseTelnetProtocol::v_handleEL ( )

protectedvirtual

Called, when the peer sends an EraseLine.

Definition at line 121 of file Telnet.cc.

◆ v_handleGA()

void senf::term::BaseTelnetProtocol::v_handleGA ( )

protectedvirtual

Called, when the peer sends a GoAhead.

Definition at line 124 of file Telnet.cc.

◆ v_handleIP()

void senf::term::BaseTelnetProtocol::v_handleIP ( )

protectedvirtual

Called, when the peer sends an InterruptProcess.

Definition at line 109 of file Telnet.cc.

◆ v_handleNOP()

void senf::term::BaseTelnetProtocol::v_handleNOP ( )

protectedvirtual

Called, when the peer sends a NOP.

Definition at line 103 of file Telnet.cc.

◆ v_setupComplete()

virtual void senf::term::BaseTelnetProtocol::v_setupComplete ( )

protectedpure virtual

Called, when no further requests are pending.

This callback will be called, when no further negotiations are to be expected. The default negotiation timeout is 500ms. If no reply is received in this time, the request is abandoned and v_setupComplete() is called.

mixin TelnetHandler's may additionally increment the request counter to wait for specific subnegotiations. v_setupComplete() will be called, when all these negotiations are complete or have timed out.

◆ write() [1/2]

void senf::term::BaseTelnetProtocol::write ( std::string const & s )

Send string to peer.

The string will be correctly quoted and newline chars will be sent as CR/LF pairs.

Definition at line 58 of file Telnet.cc.

◆ write() [2/2]

void senf::term::BaseTelnetProtocol::write ( char c )

Send single character to peer.

The character will be correctly quoted and newline chars will be sent as CR/LF pairs.

Definition at line 64 of file Telnet.cc.

Member Data Documentation

◆ DEFAULT_REQUEST_TIMEOUT_MS

unsigned const senf::term::BaseTelnetProtocol::DEFAULT_REQUEST_TIMEOUT_MS = 500u

static

Definition at line 134 of file Telnet.hh.

The documentation for this class was generated from the following files:

SENF Extensible Network Framework

Classes

Public Types

Public Member Functions

Static Public Attributes

Protected Member Functions

Detailed Description

Telnet option handlers

Member Typedef Documentation

◆ Handle

◆ option_type

Constructor & Destructor Documentation

◆ BaseTelnetProtocol() [1/2]

◆ BaseTelnetProtocol() [2/2]

◆ ~BaseTelnetProtocol()

Member Function Documentation

◆ acceptLocalOption()

◆ acceptPeerOption()

◆ decrementRequestCounter()

◆ handle()

◆ incrementRequestCounter()

◆ localOption()

◆ peerOption()

◆ registerHandler()

◆ requestLocalOption()

◆ requestPeerOption()

◆ requestsPending()

◆ sendAO()

◆ sendAYT()

◆ sendBRK()

◆ sendEC()

◆ sendEL()

◆ sendGA()

◆ sendIP()

◆ sendNOP()

◆ sendOptionParameters()

◆ v_charReceived()

◆ v_eof()

◆ v_handleAO()

◆ v_handleAYT()

◆ v_handleBRK()

◆ v_handleEC()

◆ v_handleEL()

◆ v_handleGA()

◆ v_handleIP()

◆ v_handleNOP()

◆ v_setupComplete()

◆ write() [1/2]

◆ write() [2/2]

Member Data Documentation

◆ DEFAULT_REQUEST_TIMEOUT_MS