Manages Click name databases. More...

Public Types
enum	DBType { T_NONE = 0 , T_SCHEDULEINFO = 0x00000001 , T_ANNOTATION = 0x00000002 , T_SCRIPT_INSN = 0x00000003 , T_SIGNO = 0x00000004 , T_SPINLOCK = 0x00000005 , T_ETHERNET_ADDR = 0x01000001 , T_IP_ADDR = 0x04000001 , T_IP_PREFIX = 0x04000002 , T_IP_PROTO = 0x04000003 , T_IPFILTER_TYPE = 0x04000004 , T_TCP_OPT = 0x04000005 , T_IPREWRITER_PATTERN = 0x04000006 , T_ICMP_TYPE = 0x04010000 , T_ICMP_CODE = 0x04010100 , T_IP_PORT = 0x04020000 , T_TCP_PORT = 0x04020006 , T_UDP_PORT = 0x04020011 , T_IP_FIELDNAME = 0x04030000 , T_ICMP_FIELDNAME = 0x04030001 , T_TCP_FIELDNAME = 0x04030006 , T_UDP_FIELDNAME = 0x04030011 , T_IP6_ADDR = 0x06000001 , T_IP6_PREFIX = 0x06000002 }
	Known name database types. More...

Public Member Functions
	NameInfo ()
	Construct a NameInfo element.

	~NameInfo ()
	Destroy a NameInfo object.

Static Public Member Functions
static void	static_initialize ()
	Static initialization for NameInfo.

static void	static_cleanup ()
	Static cleanup for NameInfo.

static NameDB *	getdb (uint32_t type, const Element *context, size_t value_size, bool create)
	Find or create a name database.

static void	installdb (NameDB db, const Element context)
	Install a name database.

static void	uninstalldb (NameDB *db)
	Uninstall a name database.

static bool	query (uint32_t type, const Element context, const String &name, void value_store, size_t value_size)
	Query installed databases for name.

static bool	query_int (uint32_t type, const Element context, const String &name, int32_t value_store)
	Query installed databases for name, returning a 32-bit integer value.

static bool	query_int (uint32_t type, const Element context, const String &name, uint32_t value_store)

static String	revquery (uint32_t type, const Element context, const void value, size_t value_size)
	Query installed databases for value.

static String	revquery_int (uint32_t type, const Element *context, int32_t value)
	Query installed databases for a 32-bit integer value.

static bool	define (uint32_t type, const Element context, const String &name, const void value, size_t value_size)
	Define name to equal value in the installed databases.

static bool	define_int (uint32_t type, const Element *context, const String &name, int32_t value)
	Define name to equal 32-bit integer value in the installed databases.

Detailed Description

Manages Click name databases.

NameInfo is the user interface to Click's name databases, a general mechanism for mapping names to values. NameInfo and NameDB implement generally useful properties like names local to a compound element context.

Every name database maps names, which are nonempty strings, to values, which are sequences of bytes. A database is identified by its type, which indicates the kind of name stored in the database, and, optionally, its compound element context, which is a pair of router and element name prefix. The database is used for queries that take place in the given context. A query bubbles up through the databases, starting with the most specific context and getting more general, until it succeeds. A database stores values with a fixed size; it is an error to query a database with the wrong size.

Many common types are defined in the NameDB::DBType enumeration, but NameInfo allows arbitrary other types to be added at run time.

Here's an example of how to query NameInfo:

EtherAddress ethaddr;
if (NameInfo::query(NameInfo::T_ETHERNET_ADDR, this, name, &ethaddr, 6))
    click_chatter("Found address!");
else
    click_chatter("Didn't find address.");

Many elements also add their own databases to NameInfo; see, for example, the IPNameInfo or IPFilter elements for examples.

Member Enumeration Documentation

◆ DBType

enum NameInfo::DBType

Known name database types.

Enumerator
T_NONE	Nonexistent names database.
T_SCHEDULEINFO	ScheduleInfo database.
T_ANNOTATION	Packet annotation database.
T_SCRIPT_INSN	Script instruction names database.
T_SIGNO	User-level signal names database.
T_SPINLOCK	Spinlock names database.
T_ETHERNET_ADDR	Ethernet address names database.
T_IP_ADDR	IP address names database.
T_IP_PREFIX	IP prefix names database.
T_IP_PROTO	IP protocol names database.
T_IPFILTER_TYPE	IPFilter instruction names database.
T_TCP_OPT	TCP option names database.
T_IPREWRITER_PATTERN	IPRewriterPattern database.
T_ICMP_TYPE	ICMP type names database.
T_ICMP_CODE	ICMP code names database.
T_IP_PORT	Starting point for IP per-protocol port names databases.
T_TCP_PORT	TCP port names database.
T_UDP_PORT	UDP port names database.
T_IP_FIELDNAME	Starting point for IP per-protocol field names databases.
T_ICMP_FIELDNAME	ICMP field names database.
T_TCP_FIELDNAME	TCP field names database.
T_UDP_FIELDNAME	UDP field names database.
T_IP6_ADDR	IPv6 address names database.
T_IP6_PREFIX	IPv6 prefix names database.

Constructor & Destructor Documentation

◆ NameInfo()

NameInfo::NameInfo ( )

Construct a NameInfo element.

Users never need to call this.

◆ ~NameInfo()

NameInfo::~NameInfo ( )

Destroy a NameInfo object.

Also destroys all NameDB objects installed on this NameInfo.

Users never need to call this.

Member Function Documentation

◆ static_initialize()

void NameInfo::static_initialize ( )

static

Static initialization for NameInfo.

Creates the global NameInfo used for databases unconnected to any router. Users never need to call this.

◆ static_cleanup()

void NameInfo::static_cleanup ( )

static

Static cleanup for NameInfo.

Destroys the global NameInfo used for databases unconnected to any router. Users never need to call this.

◆ getdb()

NameDB * NameInfo::getdb	(	uint32_t	type,
		const Element *	context,
		size_t	value_size,
		bool	create
	)

static

Find or create a name database.

Parameters

type	database type
context	compound element context
value_size	size of values stored in database
create	whether to create a DynamicNameDB if no database exists

Returns an installed name database matching type and context. (If context is non-null, then the database matches the implied router and compound element context. Otherwise, the database is the unique global database for the given type.) If create is true, and no database exists exactly matching type and context, then a DynamicNameDB is created and installed with that type, context, and value_size. Otherwise, the search bubbles up through the prefixes of context until an installed database is found.

Returns null if no installed database is found. value_size must match the value size in the returned database.

Most users will use query() and define() directly, not call getdb().

◆ installdb()

void NameInfo::installdb	(	NameDB *	db,
		const Element *	context
	)

static

Install a name database.

Parameters

db	name database
context	compound element context

Installs the given name database for the compound element context implied by context. (If context is non-null, then the database is installed for the implied router and compound element context. If it is null, the database is installed globally.) The query() and define() operations apply only to installed databases.

It is an error to install a database that has already been installed. It is also an error to install a database for a compound element context that already has a different database installed. An installed NameDB is automatically destroyed when its containing NameInfo is destroyed (for example, when context's router is destroyed).

◆ uninstalldb()

void NameInfo::uninstalldb ( NameDB * db )

static

Uninstall a name database.

Parameters

db	name database

Undoes the effects of installdb(). The given database will no longer be used for query() and define() operations.

◆ query()

bool NameInfo::query	(	uint32_t	type,
		const Element *	context,
		const String &	name,
		void *	value_store,
		size_t	value_size
	)

static

Query installed databases for name.

Parameters

type	database type
context	compound element context
name	name to look up
value_store	value storage
value_size	size of value storage

Returns: true iff the query succeeded

Queries all installed type databases that apply to the compound element context, returning the most specific value matching name. The value is stored in value_store. The installed databases must have the given value_size.

◆ query_int() [1/2]

bool NameInfo::query_int	(	uint32_t	type,
		const Element *	context,
		const String &	name,
		int32_t *	value_store
	)

static

Query installed databases for name, returning a 32-bit integer value.

Parameters

type	database type
context	compound element context
name	name to look up
value_store	value storage

Returns: true iff the query succeeded

Queries all installed type databases that apply to the compound element context, returning the most specific value matching name. The value is stored in value_store. The installed databases must have a value size of 4.

If no matching name is found, query_int checks whether name unparses into a 32-bit integer value (for example, "30"). If so, *value_store is set to the corresponding integer and true is returned. Otherwise, false is returned.

◆ query_int() [2/2]

bool NameInfo::query_int	(	uint32_t	type,
		const Element *	context,
		const String &	name,
		uint32_t *	value_store
	)

static

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

◆ revquery()

String NameInfo::revquery	(	uint32_t	type,
		const Element *	context,
		const void *	value,
		size_t	value_size
	)

static

Query installed databases for value.

Parameters

type	database type
context	compound element context
value	points to value to look up
value_size	size of value

Returns: the name, or the empty string if the query failed

Queries all installed type databases that apply to the compound element context, returning the name in the most specific database whose value matches value, or the empty string if the relevant databases don't support reverse queries or no such value exists. The installed databases must have the given value_size.

◆ revquery_int()

String NameInfo::revquery_int	(	uint32_t	type,
		const Element *	context,
		int32_t	value
	)

inlinestatic

Query installed databases for a 32-bit integer value.

Parameters

type	database type
context	compound element context
value	value to look up

Returns: the name, or the empty string if the query failed

Queries all installed type databases that apply to the compound element context, returning the name in the most specific database whose value matches value, or the empty string if the relevant databases don't support reverse queries or no such value exists. The installed databases must have value size 4.

◆ define()

bool NameInfo::define	(	uint32_t	type,
		const Element *	context,
		const String &	name,
		const void *	value,
		size_t	value_size
	)

inlinestatic

Define name to equal value in the installed databases.

Parameters

type	database type
context	compound element context
name	name to define
value	points to defined value
value_size	size of value

Returns: true iff the name was defined

Defines the given name to value in the installed type database with compound element context. If no database exists exactly matching that type and context, a new DynamicNameDB is created and installed with those values (and the given value_size). A name might not be defined if the existing database for that type and context doesn't support definitions, or if no new database can be created. If any database exists, it must match the given value_size.

◆ define_int()

bool NameInfo::define_int	(	uint32_t	type,
		const Element *	context,
		const String &	name,
		int32_t	value
	)

inlinestatic

Define name to equal 32-bit integer value in the installed databases.

Parameters

type	database type
context	compound element context
name	name to define
value	defined value

Returns: true iff the value was defined

Defines the given name to value in the installed type database with compound element context. If no database exists exactly matching that type and context, a new DynamicNameDB is created and installed with those values (and value size 4). A name might not be defined if the existing database for that type and context doesn't support definitions, or if no new database can be created. If any database exists, it must have value size 4.

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

include/click/nameinfo.hh
lib/nameinfo.cc

Public Types

Public Member Functions

Static Public Member Functions

Detailed Description

Member Enumeration Documentation

◆ DBType

Constructor & Destructor Documentation

◆ NameInfo()

◆ ~NameInfo()

Member Function Documentation

◆ static_initialize()

◆ static_cleanup()

◆ getdb()

◆ installdb()

◆ uninstalldb()

◆ query()

◆ query_int() [1/2]

◆ query_int() [2/2]

◆ revquery()

◆ revquery_int()

◆ define()

◆ define_int()