Token that represents a value of an option. More...

#include <token.h>

Inheritance diagram for isc::dhcp::TokenOption:

Public Types
enum	RepresentationType { TEXTUAL , HEXADECIMAL , EXISTS }
	Token representation type. More...

Public Member Functions
	TokenOption (const std::vector< uint16_t > &option_codes, const RepresentationType &rep_type)
	Constructor that takes an option code as a parameter.
virtual unsigned	evaluate (Pkt &pkt, ValueStack &values)
	Evaluates the values of the option.
std::vector< uint16_t >	getOptions () const
	Returns option-code.
RepresentationType	getRepresentation () const
	Returns representation-type.
Public Member Functions inherited from isc::dhcp::Token
virtual	~Token ()
	Virtual destructor.
virtual unsigned	getLabel () const
	Return the label of this token.

Protected Member Functions
virtual OptionPtr	getOption (Pkt &pkt)
	Attempts to retrieve an option.
virtual std::string	pushFailure (ValueStack &values)
	Auxiliary method that puts string representing a failure.

Protected Attributes
std::vector< uint16_t >	option_path_
	The options hierarchy.
RepresentationType	representation_type_
	The representation type.

Additional Inherited Members
Static Public Member Functions inherited from isc::dhcp::Token
static bool	toBool (std::string value)
	Coverts a (string) value to a boolean.

Detailed Description

Token that represents a value of an option.

This represents a reference to a given option, e.g. in the expression option[vendor-class].text == "MSFT", it represents option[vendor-class].text

During the evaluation it tries to extract the value of the specified option. If the option is not found, an empty string ("") is returned (or "false" when the representation is EXISTS).

It can represent the following expressions: option[149].exists - check if option 149 exists option[149].hex - return content of option 149

Definition at line 407 of file token.h.

Member Enumeration Documentation

◆ RepresentationType

enum isc::dhcp::TokenOption::RepresentationType

Token representation type.

There are many possible ways in which option can be presented. Currently the textual, hexadecimal and exists representations are supported. The type of representation is specified in the constructor and it affects the value generated by the TokenOption::evaluate function.

Enumerator
TEXTUAL
HEXADECIMAL
EXISTS

Definition at line 417 of file token.h.

Constructor & Destructor Documentation

◆ TokenOption()

isc::dhcp::TokenOption::TokenOption	(	const std::vector< uint16_t > &	option_codes,
		const RepresentationType &	rep_type )

inline

Constructor that takes an option code as a parameter.

Note: There is no constructor that takes option_name, as it would introduce complex dependency of the libkea-eval on libdhcpsrv.

Parameters

option_codes	option hierarchy of the option to be represented.
rep_type	Token representation type.

Definition at line 430 of file token.h.

References option_path_, and representation_type_.

Referenced by isc::dhcp::TokenFilterIA_NA::TokenFilterIA_NA(), isc::dhcp::TokenFilterIA_PD::TokenFilterIA_PD(), isc::dhcp::TokenLeaseIA_NA::TokenLeaseIA_NA(), isc::dhcp::TokenLeaseIA_PD::TokenLeaseIA_PD(), isc::dhcp::TokenRelay4Option::TokenRelay4Option(), isc::dhcp::TokenRelay6Option::TokenRelay6Option(), isc::dhcp::TokenVendor::TokenVendor(), and isc::dhcp::TokenVendor::TokenVendor().

Member Function Documentation

◆ evaluate()

unsigned TokenOption::evaluate	(	Pkt &	pkt,
		ValueStack &	values )

virtual

Evaluates the values of the option.

This token represents a value of the option, so this method attempts to extract the option from the packet and put its value on the stack. If the option is not there, an empty string ("") is put on the stack.

Parameters

pkt	specified option will be extracted from this packet (if present)
values	value of the option will be pushed here (or "")

Returns: 0 which means evaluate next token if any.

Implements isc::dhcp::Token.

Reimplemented in isc::dhcp::TokenFilterIA_NASuboption, isc::dhcp::TokenFilterIA_PDSuboption, isc::dhcp::TokenLeaseIA_NASuboption, isc::dhcp::TokenLeaseIA_PDSuboption, isc::dhcp::TokenVendor, and isc::dhcp::TokenVendorClass.

Definition at line 418 of file token.cc.

References isc::dhcp::EVAL_DBG_STACK, isc::dhcp::EVAL_DEBUG_OPTION, isc::dhcp::eval_logger, EXISTS, isc::dhcp::Pkt::getLabel(), getOption(), HEXADECIMAL, LOG_DEBUG, option_path_, representation_type_, TEXTUAL, and toHex().

Referenced by isc::dhcp::TokenFilterIA_NASuboption::evaluate(), isc::dhcp::TokenFilterIA_PDSuboption::evaluate(), isc::dhcp::TokenLeaseIA_NASuboption::evaluate(), isc::dhcp::TokenLeaseIA_PDSuboption::evaluate(), and isc::dhcp::TokenVendor::evaluate().

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◆ getOption()

OptionPtr TokenOption::getOption ( Pkt & pkt )

protectedvirtual

Attempts to retrieve an option.

For this class it simply attempts to retrieve the option from the packet, but there may be derived classes that would attempt to extract it from other places (e.g. relay option, or as a suboption of other specific option).

Parameters

pkt	the option will be retrieved from here

Returns: option instance (or NULL if not found)

Reimplemented in isc::dhcp::TokenFilterIA_NA, isc::dhcp::TokenFilterIA_NASuboption, isc::dhcp::TokenFilterIA_PD, isc::dhcp::TokenFilterIA_PDSuboption, isc::dhcp::TokenLeaseIA_NA, isc::dhcp::TokenLeaseIA_NASuboption, isc::dhcp::TokenLeaseIA_PD, isc::dhcp::TokenLeaseIA_PDSuboption, isc::dhcp::TokenRelay4Option, isc::dhcp::TokenRelay6Option, and isc::dhcp::TokenVendor.

Definition at line 399 of file token.cc.

References isc::dhcp::Pkt::getOption(), and option_path_.

Referenced by evaluate().

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◆ getOptions()

std::vector< uint16_t > isc::dhcp::TokenOption::getOptions ( ) const

inline

Returns option-code.

This method is used in testing to determine if the parser had instantiated TokenOption with correct parameters.

Returns: option hierarchy of the option this token expects to extract.

Definition at line 450 of file token.h.

References option_path_.

◆ getRepresentation()

RepresentationType isc::dhcp::TokenOption::getRepresentation ( ) const

inline

Returns representation-type.

This method is used in testing to determine if the parser had instantiated TokenOption with correct parameters.

Returns: representation-type of the option this token expects to use.

Definition at line 460 of file token.h.

References representation_type_.

◆ pushFailure()

std::string TokenOption::pushFailure ( ValueStack & values )

protectedvirtual

Auxiliary method that puts string representing a failure.

Depending on the representation type, this is either "" or "false".

Parameters

values a string representing failure will be pushed here.

Returns: value pushed

Definition at line 472 of file token.cc.

References EXISTS, and representation_type_.

Referenced by isc::dhcp::TokenVendor::evaluate(), and isc::dhcp::TokenVendorClass::evaluate().

Member Data Documentation

◆ option_path_

std::vector<uint16_t> isc::dhcp::TokenOption::option_path_

protected

The options hierarchy.

Definition at line 484 of file token.h.

Referenced by TokenOption(), evaluate(), getOption(), isc::dhcp::TokenRelay4Option::getOption(), isc::dhcp::TokenRelay6Option::getOption(), isc::dhcp::TokenVendor::getOption(), and getOptions().

◆ representation_type_

RepresentationType isc::dhcp::TokenOption::representation_type_

protected

The representation type.

Definition at line 487 of file token.h.

Referenced by TokenOption(), evaluate(), getRepresentation(), and pushFailure().

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

Public Types

Public Member Functions

Protected Member Functions

Protected Attributes

Additional Inherited Members

Detailed Description

Member Enumeration Documentation

◆ RepresentationType

Constructor & Destructor Documentation

◆ TokenOption()

Member Function Documentation

◆ evaluate()

◆ getOption()

◆ getOptions()

◆ getRepresentation()

◆ pushFailure()

Member Data Documentation

◆ option_path_

◆ representation_type_