Evaluation context, an interface to the expression evaluation. More...

#include <parser_context.h>

Public Types
enum	ParserContext { NO_KEYWORD , CONFIG , DHCP4 , INTERFACES_CONFIG , SANITY_CHECKS , DHCP_SOCKET_TYPE , OUTBOUND_INTERFACE , LEASE_DATABASE , HOSTS_DATABASE , DATABASE_TYPE , DATABASE_ON_FAIL , HOST_RESERVATION_IDENTIFIERS , HOOKS_LIBRARIES , SUBNET4 , SHARED_NETWORK , RESERVATION_MODE , OPTION_DEF , OPTION_DATA , CLIENT_CLASSES , EXPIRED_LEASES_PROCESSING , SERVER_ID , CONTROL_SOCKET , DHCP_QUEUE_CONTROL , DHCP_MULTI_THREADING , POOLS , RESERVATIONS , RELAY , LOGGERS , OUTPUT_OPTIONS , DHCP_DDNS , NCR_PROTOCOL , NCR_FORMAT , REPLACE_CLIENT_NAME , CONFIG_CONTROL , CONFIG_DATABASE , COMPATIBILITY , DDNS_CONFLICT_RESOLUTION_MODE }
	Defines syntactic contexts for lexical tie-ins. More...

enum	ParserType { PARSER_JSON , PARSER_DHCP4 , SUBPARSER_DHCP4 , PARSER_INTERFACES , PARSER_SUBNET4 , PARSER_POOL4 , PARSER_HOST_RESERVATION , PARSER_OPTION_DEFS , PARSER_OPTION_DEF , PARSER_OPTION_DATA , PARSER_HOOKS_LIBRARY , PARSER_DHCP_DDNS , PARSER_CONFIG_CONTROL }
	Defines currently supported scopes. More...

Public Member Functions
	Parser4Context ()
	Default constructor.

virtual	~Parser4Context ()
	destructor

const std::string	contextName ()
	Get the syntactic context name.

void	enter (const ParserContext &ctx)
	Enter a new syntactic context.

void	error (const isc::dhcp::location &loc, const std::string &what, size_t pos=0)
	Error handler.

void	error (const std::string &what)
	Error handler.

void	includeFile (const std::string &filename)
	Divert input to an include file.

void	leave ()
	Leave a syntactic context.

isc::data::Element::Position	loc2pos (isc::dhcp::location &loc)
	Converts bison's position to one understandable by isc::data::Element.

isc::data::ElementPtr	parseFile (const std::string &filename, ParserType parser_type)
	Run the parser on the file specified.

isc::data::ElementPtr	parseString (const std::string &str, ParserType parser_type)
	Run the parser on the string specified.

void	require (const std::string &name, isc::data::Element::Position open_loc, isc::data::Element::Position close_loc)
	Check if a required parameter is present.

void	scanEnd ()
	Method called after the last tokens are scanned.

void	scanFileBegin (FILE *f, const std::string &filename, ParserType type)
	Method called before scanning starts on a file.

void	scanStringBegin (const std::string &str, ParserType type)
	Method called before scanning starts on a string.

void	unique (const std::string &name, isc::data::Element::Position loc)
	Check if a parameter is already present.

void	warnAboutExtraCommas (const isc::dhcp::location &loc)
	Warning for extra commas.

void	warning (const isc::dhcp::location &loc, const std::string &what)
	Warning handler.

Static Public Member Functions
static void	fatal (const std::string &what)
	Fatal error handler.

Public Attributes
ParserContext	ctx_
	Current syntactic context.

std::string	file_
	File name.

std::vector< std::string >	files_
	File name stack.

isc::dhcp::location	loc_
	Location of the current token.

std::vector< isc::dhcp::location >	locs_
	Location stack.

FILE *	sfile_
	sFile (aka FILE)

std::vector< FILE * >	sfiles_
	sFile (aka FILE) stack

std::vector< isc::data::ElementPtr >	stack_
	JSON elements being parsed.

std::vector< struct yy_buffer_state * >	states_
	Lexer state stack.

Detailed Description

Evaluation context, an interface to the expression evaluation.

Definition at line 35 of file dhcp4/parser_context.h.

Member Enumeration Documentation

◆ ParserContext

enum isc::dhcp::Parser4Context::ParserContext

Defines syntactic contexts for lexical tie-ins.

Enumerator
NO_KEYWORD	This one is used in pure JSON mode. Used while parsing top level (that contains Dhcp4)
CONFIG	Used while parsing content of Dhcp4.
DHCP4
INTERFACES_CONFIG	Used while parsing Dhcp4/interfaces structures.
SANITY_CHECKS	Sanity checks.
DHCP_SOCKET_TYPE	Used while parsing Dhcp4/interfaces/dhcp-socket-type structures.
OUTBOUND_INTERFACE	Used while parsing Dhcp4/interfaces/outbound-interface structures.
LEASE_DATABASE	Used while parsing Dhcp4/lease-database structures.
HOSTS_DATABASE	Used while parsing Dhcp4/hosts-database[s] structures.
DATABASE_TYPE	Used while parsing Dhcp4/*-database/type.
DATABASE_ON_FAIL	Used while parsing Dhcp4/*-database/on-fail.
HOST_RESERVATION_IDENTIFIERS	Used while parsing Dhcp4/host-reservation-identifiers.
HOOKS_LIBRARIES	Used while parsing Dhcp4/hooks-libraries.
SUBNET4	Used while parsing Dhcp4/Subnet4 structures.
SHARED_NETWORK	Used while parsing shared-networks structures.
RESERVATION_MODE	Used while parsing Dhcp4/reservation-mode.
OPTION_DEF	Used while parsing Dhcp4/option-def structures.
OPTION_DATA	Used while parsing Dhcp4/option-data, Dhcp4/subnet4/option-data or anywhere option-data is present (client classes, host reservations and possibly others).
CLIENT_CLASSES	Used while parsing Dhcp4/client-classes structures.
EXPIRED_LEASES_PROCESSING	Used while parsing Dhcp4/expired-leases-processing.
SERVER_ID	Used while parsing Dhcp4/server-id structures.
CONTROL_SOCKET	Used while parsing Dhcp4/control-socket structures.
DHCP_QUEUE_CONTROL	Used while parsing Dhcp4/dhcp-queue-control structures.
DHCP_MULTI_THREADING	Used while parsing Dhcp4/multi-threading structures.
POOLS	Used while parsing Dhcp4/subnet4/pools structures.
RESERVATIONS	Used while parsing Dhcp4/reservations structures.
RELAY	Used while parsing Dhcp4/subnet4relay structures.
LOGGERS	Used while parsing Dhcp4/loggers structures.
OUTPUT_OPTIONS	Used while parsing Dhcp4/loggers/output-options structures.
DHCP_DDNS	Used while parsing Dhcp4/dhcp-ddns.
NCR_PROTOCOL	Used while parsing Dhcp4/dhcp-ddns/ncr-protocol.
NCR_FORMAT	Used while parsing Dhcp4/dhcp-ddns/ncr-format.
REPLACE_CLIENT_NAME	Used while parsing Dhcp4/dhcp-ddns/replace-client-name.
CONFIG_CONTROL	Used while parsing Dhcp4/config-control.
CONFIG_DATABASE	Used while parsing config-control/config-databases.
COMPATIBILITY	Used while parsing compatibility parameters.
DDNS_CONFLICT_RESOLUTION_MODE	Used while parsing Dhcp4/ib-ddns-conflict-resolution-mode.

Definition at line 230 of file dhcp4/parser_context.h.

◆ ParserType

enum isc::dhcp::Parser4Context::ParserType

Defines currently supported scopes.

Dhcp4Parser is able to parse several types of scope. Usually, when it parses a config file, it expects the data to have a map with Dhcp4 in it and all the parameters within that Dhcp4 map. However, sometimes the parser is expected to parse only a subset of that information. For example, it may be asked to parse a structure that is host-reservation only, without the global 'Dhcp4' or 'reservations' around it. In such case the parser is being told to start parsing as PARSER_HOST_RESERVATION4.

Enumerator
PARSER_JSON	This parser will parse the content as generic JSON.
PARSER_DHCP4	This parser will parse the content as Dhcp4 config wrapped in a map (that's the regular config file)
SUBPARSER_DHCP4	This parser will parse the content of Dhcp4 (without outer { } and without "Dhcp4"). It is mostly used in unit-tests as most of the unit-tests do not define the outer map and Dhcp4 entity, just the contents of it.
PARSER_INTERFACES	This will parse the input as interfaces content.
PARSER_SUBNET4	This will parse the input as Subnet4 content.
PARSER_POOL4	This will parse the input as pool4 content.
PARSER_HOST_RESERVATION	This will parse the input as host-reservation.
PARSER_OPTION_DEFS	This will parse the input option definitions (for tests).
PARSER_OPTION_DEF	This will parse the input as option definition.
PARSER_OPTION_DATA	This will parse the input as option data.
PARSER_HOOKS_LIBRARY	This will parse the input as hooks-library.
PARSER_DHCP_DDNS	This will parse the input as dhcp-ddns.
PARSER_CONFIG_CONTROL	This will parse the input as config-control.

Definition at line 49 of file dhcp4/parser_context.h.

Constructor & Destructor Documentation

◆ Parser4Context()

isc::dhcp::Parser4Context::Parser4Context ( )

Default constructor.

Definition at line 22 of file dhcp4/parser_context.cc.

◆ ~Parser4Context()

isc::dhcp::Parser4Context::~Parser4Context ( )

virtual

destructor

Definition at line 27 of file dhcp4/parser_context.cc.

Member Function Documentation

◆ contextName()

const std::string isc::dhcp::Parser4Context::contextName ( )

Get the syntactic context name.

Returns: printable name of the context.

Definition at line 150 of file dhcp4/parser_context.cc.

References CLIENT_CLASSES, COMPATIBILITY, CONFIG, CONFIG_CONTROL, CONFIG_DATABASE, CONTROL_SOCKET, ctx_, DATABASE_ON_FAIL, DATABASE_TYPE, DDNS_CONFLICT_RESOLUTION_MODE, DHCP4, DHCP_DDNS, DHCP_MULTI_THREADING, DHCP_QUEUE_CONTROL, DHCP_SOCKET_TYPE, EXPIRED_LEASES_PROCESSING, HOOKS_LIBRARIES, HOST_RESERVATION_IDENTIFIERS, HOSTS_DATABASE, INTERFACES_CONFIG, LEASE_DATABASE, LOGGERS, NCR_FORMAT, NCR_PROTOCOL, NO_KEYWORD, OPTION_DATA, OPTION_DEF, OUTBOUND_INTERFACE, OUTPUT_OPTIONS, POOLS, RELAY, REPLACE_CLIENT_NAME, RESERVATION_MODE, RESERVATIONS, SANITY_CHECKS, SERVER_ID, SHARED_NETWORK, and SUBNET4.

Referenced by isc::dhcp::Dhcp4Parser::parse(), require(), and unique().

◆ enter()

void isc::dhcp::Parser4Context::enter ( const ParserContext & ctx )

Enter a new syntactic context.

Entering a new syntactic context is useful in several ways. First, it allows the parser to avoid conflicts. Second, it allows the lexer to return different tokens depending on context (e.g. if "renew-timer" string is detected, the lexer will return STRING token if in JSON mode or RENEW_TIMER if in DHCP4 mode. Finally, the syntactic context allows the error message to be more descriptive if the input string does not parse properly.

Parameters

ctx	the syntactic context to enter into

Definition at line 133 of file dhcp4/parser_context.cc.

References ctx_.

Referenced by isc::dhcp::Dhcp4Parser::parse().

◆ error() [1/2]

void isc::dhcp::Parser4Context::error	(	const isc::dhcp::location &	loc,
		const std::string &	what,
		size_t	pos = `0`
	)

Error handler.

Note: The optional position for an error in a string begins by 1 so the caller should add 1 to the position of the C++ string.

Parameters

loc	location within the parsed file where the problem was experienced.
what	string explaining the nature of the error.
pos	optional position for in string errors.

Exceptions

Dhcp4ParseError

Definition at line 72 of file dhcp4/parser_context.cc.

References isc_throw.

◆ error() [2/2]

void isc::dhcp::Parser4Context::error ( const std::string & what )

Error handler.

This is a simplified error reporting tool for possible future cases when the Dhcp4Parser is not able to handle the packet.

Parameters

what	string explaining the nature of the error.

Exceptions

Dhcp4ParseError

Definition at line 83 of file dhcp4/parser_context.cc.

References isc_throw.

◆ fatal()

void isc::dhcp::Parser4Context::fatal ( const std::string & what )

static

Fatal error handler.

This is for should not happen but fatal errors. Used by YY_FATAL_ERROR macro so required to be static.

Parameters

what	string explaining the nature of the error.

Exceptions

Dhcp4ParseError

Definition at line 88 of file dhcp4/parser_context.cc.

References isc_throw.

◆ includeFile()

void Parser4Context::includeFile ( const std::string & filename )

Divert input to an include file.

Parameters

filename file to be included

Definition at line 6939 of file dhcp4_lexer.cc.

References BEGIN, isc::db::fatal, file_, files_, INITIAL, loc_, locs_, sfile_, sfiles_, states_, and YY_CURRENT_BUFFER.

◆ leave()

void isc::dhcp::Parser4Context::leave ( )

Leave a syntactic context.

Exceptions

isc::Unexpected if unbalanced

Definition at line 139 of file dhcp4/parser_context.cc.

References ctx_, and isc::db::fatal.

Referenced by isc::dhcp::Dhcp4Parser::parse().

◆ loc2pos()

isc::data::Element::Position isc::dhcp::Parser4Context::loc2pos ( isc::dhcp::location & loc )

Converts bison's position to one understandable by isc::data::Element.

Convert a bison location into an element position (take the begin, the end is lost)

Parameters

loc	location in bison format

Returns: Position in format accepted by Element

Definition at line 93 of file dhcp4/parser_context.cc.

Referenced by isc::dhcp::Dhcp4Parser::parse().

◆ parseFile()

isc::data::ElementPtr isc::dhcp::Parser4Context::parseFile	(	const std::string &	filename,
		ParserType	parser_type
	)

Run the parser on the file specified.

This method parses specified file. Depending on the value of parser_type, parser may either check only that the input is valid JSON, or may do more specific syntax checking. See ParserType for supported syntax checkers.

Parameters

filename	file to be parsed
parser_type	specifies expected content (usually DHCP4 or generic JSON)

Returns: Element structure representing parsed text.

Definition at line 37 of file dhcp4/parser_context.cc.

References isc_throw, and scanFileBegin().

Referenced by isc::dhcp::ControlledDhcpv4Srv::loadConfigFile(), and main().

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◆ parseString()

isc::data::ElementPtr isc::dhcp::Parser4Context::parseString	(	const std::string &	str,
		ParserType	parser_type
	)

Run the parser on the string specified.

This method parses specified string. Depending on the value of parser_type, parser may either check only that the input is valid JSON, or may do more specific syntax checking. See ParserType for supported syntax checkers.

Parameters