KNetwork::KResolver Class Reference

Name and service resolution class. More...

#include <kresolver.h>

Inheritance diagram for KNetwork::KResolver:


Public Types
enum	ErrorCodes { NoError = 0, AddrFamily = -1, TryAgain = -2, NonRecoverable = -3, BadFlags = -4, Memory = -5, NoName = -6, UnsupportedFamily = -7, UnsupportedService = -8, UnsupportedSocketType = -9, UnknownError = -10, SystemError = -11, Canceled = -100 }
enum	Flags { Passive = 0x01, CanonName = 0x02, NoResolve = 0x04, NoSrv = 0x08, Multiport = 0x10, UseSrv = 0x20 }
enum	SocketFamilies { UnknownFamily = 0x0001, UnixFamily = 0x0002, LocalFamily = UnixFamily, IPv4Family = 0x0004, IPv6Family = 0x0008, InternetFamily = IPv4Family \| IPv6Family, InetFamily = InternetFamily, KnownFamily = ~UnknownFamily, AnyFamily = KnownFamily \| UnknownFamily }
enum	StatusCodes { Idle = 0, Queued = 1, InProgress = 5, PostProcessing = 6, Success = 10, Failed = -101 }
Signals
void	finished (KResolverResults results)
Public Member Functions
void	cancel (bool emitSignal=true)
int	error () const
QString	errorString () const
virtual bool	event (QEvent *)
int	flags () const
bool	isRunning () const
	KResolver (const QString &nodename, const QString &servicename=QString::null, QObject =0L, const char =0L)
	KResolver (QObject =0L, const char =0L)
QString	nodeName () const
KResolverResults	results () const
QString	serviceName () const
void	setAddress (const QString &node, const QString &service)
void	setFamily (int families)
int	setFlags (int flags)
void	setNodeName (const QString &nodename)
void	setProtocol (int protonum, const char *name=0L)
void	setServiceName (const QString &service)
void	setSocketType (int type)
bool	start ()
int	status () const
int	systemError () const
bool	wait (int msec=0)
virtual	~KResolver ()
Static Public Member Functions
static QCString	domainToAscii (const QString &unicodeDomain)
static QString	domainToUnicode (const QString &asciiDomain)
static QString	domainToUnicode (const QCString &asciiDomain)
static QString	errorString (int errorcode, int syserror=0)
static QString	localHostName ()
static QString	normalizeDomain (const QString &domain)
static QStrList	protocolName (const char *protoname)
static QStrList	protocolName (int protonum)
static int	protocolNumber (const char *protoname)
static KResolverResults	resolve (const QString &host, const QString &service, int flags=0, int families=KResolver::InternetFamily)
static bool	resolveAsync (QObject userObj, const char userSlot, const QString &host, const QString &service, int flags=0, int families=KResolver::InternetFamily)
static QStrList	serviceName (int port, const char *protoname)
static QStrList	serviceName (const char servname, const char protoname)
static int	servicePort (const char servname, const char protoname)
Protected Member Functions
void	setError (int errorcode, int systemerror=0)
virtual void	virtual_hook (int id, void *data)

Detailed Description

Name and service resolution class.

This class provides support for doing name-to-binary resolution for nodenames and service ports. You should use this class if you need specific resolution techniques when creating a socket or if you want to inspect the results before calling the socket functions.

You can either create an object and set the options you want in it or you can simply call the static member functions, which will create standard Resolver objects and dispatch the resolution for you. Normally, the static functions will be used, except in cases where specific options must be set.

A Resolver object defaults to the following:

address family: any address family
socket type: streaming socket
protocol: implementation-defined. Generally, TCP
host and service: unset

Author:: Thiago Macieira <thiago.macieira@kdemail.net>

Definition at line 295 of file kresolver.h.

Member Enumeration Documentation

enum KNetwork::KResolver::ErrorCodes

Error codes.

These are the possible error values that objects of this class may return. See errorString() for getting a string representation for these errors.

AddrFamily: Address family for the given nodename is not supported.
TryAgain: Temporary failure in name resolution. You should try again.
NonRecoverable: Non-recoverable failure in name resolution.
BadFlags: Invalid flags were given.
Memory: Memory allocation failure.
NoName: The specified name or service doesn't exist.
UnsupportedFamily: The requested socket family is not supported.
UnsupportedService: The requested service is not supported for this socket type (i.e., a datagram service in a streaming socket).
UnsupportedSocketType: The requested socket type is not supported.
UnknownError: An unknown, unexpected error occurred.
SystemError: A system error occurred. See systemError.
Canceled: This request was cancelled by the user.

Enumerator:

NoError
AddrFamily
TryAgain
NonRecoverable
BadFlags
Memory
NoName
UnsupportedFamily
UnsupportedService
UnsupportedSocketType
UnknownError
SystemError
Canceled

Definition at line 382 of file kresolver.h.

enum KNetwork::KResolver::Flags

Flags for the resolution.

These flags are used for setting the resolution behaviour for this object:

Passive: resolve to a passive socket (i.e., one that can be used for binding to a local interface)
CanonName: request that the canonical name for the given nodename be found and recorded
NoResolve: request that no external resolution be performed. The given nodename and servicename will be resolved locally only.
NoSrv: don't try to use SRV-based name-resolution. (deprecated)
UseSrv: use SRV-based name resolution.
Multiport: the port/service argument is a list of port numbers and ranges. (future extension)

Note:: SRV-based lookup and Multiport are not implemented yet.

Enumerator:

Passive
CanonName
NoResolve
NoSrv
Multiport
UseSrv

Definition at line 351 of file kresolver.h.

enum KNetwork::KResolver::SocketFamilies

Address family selection types.

These values can be OR-ed together to form a composite family selection.

UnknownFamily: a family that is unknown to the current implementation
KnownFamily: a family that is known to the implementation (the exact opposite of UnknownFamily)
AnyFamilies: any address family is acceptable
InternetFamily: an address for connecting to the Internet
InetFamily: alias for InternetFamily
IPv6Family: an IPv6 address only
IPv4Family: an IPv4 address only
UnixFamily: an address for the local Unix namespace (i.e., Unix sockets)
LocalFamily: alias for UnixFamily

Enumerator:

UnknownFamily
UnixFamily
LocalFamily
IPv4Family
IPv6Family
InternetFamily
InetFamily
KnownFamily
AnyFamily

Definition at line 317 of file kresolver.h.

enum KNetwork::KResolver::StatusCodes

Status codes.

These are the possible status for a Resolver object. A value greater than zero indicates normal behaviour, while negative values either indicate failure or error.

Idle: resolution has not yet been started.
Queued: resolution is queued but not yet in progress.
InProgress: resolution is in progress.
PostProcessing: resolution is in progress.
Success: resolution is done; you can retrieve the results.
Canceled: request cancelled by the user.
Failed: resolution is done, but failed.

Note: the status Canceled and the error code Canceled are the same.

Note 2: the status Queued and InProgress might not be distinguishable. Some implementations might not differentiate one from the other.

Enumerator:

Idle
Queued
InProgress
PostProcessing
Success
Failed

Definition at line 420 of file kresolver.h.

Constructor & Destructor Documentation

KResolver::KResolver	(	QObject *	parent = `0L`,
		const char *	name = `0L`
	)

Default constructor.

Creates an empty Resolver object. You should set the wanted names and flags using the member functions before starting the name resolution.

Definition at line 292 of file kresolver.cpp.

KResolver::KResolver	(	const QString &	nodename,
		const QString &	servicename = `QString::null`,
		QObject *	parent = `0L`,
		const char *	name = `0L`
	)

Constructor with host and service names.

Creates a Resolver object with the given host and service names. Flags are initialised to 0 and any address family will be accepted.

Parameters:

	nodename	The host name we want resolved.
	servicename	The service name associated, like "http".

Definition at line 298 of file kresolver.cpp.

KResolver::~KResolver ( ) [virtual]

Destructor.

When this object is deleted, it'll destroy all associated resources. If the resolution is still in progress, it will be cancelled and the signal will not be emitted.

Definition at line 305 of file kresolver.cpp.

Member Function Documentation

void KResolver::cancel ( bool emitSignal = true )

Cancels a running request.

This function will cancel a running request. If the request is not currently running or queued, this function does nothing.

Note: if you tell the signal to be emitted, be aware that it might or might not be emitted before this function returns.

Parameters:

emitSignal

whether to emit the finished signal or not

Definition at line 508 of file kresolver.cpp.

QCString KResolver::domainToAscii ( const QString & unicodeDomain ) [static]

Returns the domain name in an ASCII Compatible Encoding form, suitable for DNS lookups.

This is the base for International Domain Name support over the Internet.

Note this function may fail, in which case it'll return a null QCString. Reasons for failure include use of unknown code points (Unicode characters).

Note that the encoding is illegible and, thus, should not be presented to the user, except if requested.

Parameters:

unicodeDomain

the domain name to be encoded

Returns:: the ACE-encoded suitable for DNS queries if successful, a null QCString if failure.

Definition at line 950 of file kresolver.cpp.

QString KResolver::domainToUnicode ( const QString & asciiDomain ) [static]

The same as above, but taking a QString argument.

Parameters:

asciiDomain

the ACE-encoded domain name to be decoded

Returns:: the Unicode representation of the given domain name if successful, QString::null if not.

Definition at line 994 of file kresolver.cpp.

QString KResolver::domainToUnicode ( const QCString & asciiDomain ) [static]

Does the inverse of domainToAscii and return an Unicode domain name from the given ACE-encoded domain.

This function may fail if the given domain cannot be successfully converted back to Unicode. Reasons for failure include a malformed domain name or good ones whose reencoding back to ACE don't match the form given here (e.g., ACE-encoding of an already ASCII-compatible domain).

It is, however, guaranteed that domains returned by domainToAscii will work.

Parameters:

asciiDomain

the ACE-encoded domain name to be decoded

Returns:: the Unicode representation of the given domain name if successful, the original string if not

Note:: ACE = ASCII-Compatible Encoding, i.e., 7-bit

Definition at line 988 of file kresolver.cpp.

int KResolver::error ( ) const

Retrieve the error code in this object.

This function will return NoError if we are not in an error condition. See status and StatusCodes to find out what the current status is.

See also:: errorString for getting a textual representation of this error

Definition at line 318 of file kresolver.cpp.

QString KResolver::errorString	(	int	errorcode,
		int	syserror = `0`
	)			`[static]`

Returns the string representation of this error code.

Parameters:

	errorcode	the error code. See ErrorCodes.
	syserror	the system error code associated.

Returns:: the string representation. This is already i18n'ed.

Definition at line 552 of file kresolver.cpp.

QString KNetwork::KResolver::errorString ( ) const [inline]

Returns the textual representation of the error in this object.

Definition at line 493 of file kresolver.h.

bool KResolver::event ( QEvent * e ) [virtual]

Handles events.

Reimplemented from QObject.

This function handles the events generated by the manager indicating that this object has finished processing.

Do not post events to this object.

Reimplemented from QObject.

Definition at line 528 of file kresolver.cpp.

void KNetwork::KResolver::finished ( KResolverResults results ) [signal]

This signal is emitted whenever the resolution is finished, one way or another (success or failure).

The results parameter will contain the resolved data.

Note: if you are doing multiple resolutions, you can use the QObject::sender() function to distinguish one Resolver object from another.

Parameters:

results

the resolved data; might be empty if the resolution failed

See also:: results for information on what the results are

Note:: This signal is always delivered in the GUI event thread, even for resolutions that were started in secondary threads.

int KResolver::flags ( ) const

Retrieves the flags set for the resolution.

See also:: Flags for an explanation on what flags are possible

Definition at line 379 of file kresolver.cpp.

bool KResolver::isRunning ( ) const

Returns true if this object is currently running.

Definition at line 330 of file kresolver.cpp.

QString KResolver::localHostName ( ) [static]

Returns this machine's local hostname.

Returns:: this machine's local hostname

Since:: 3.5

Definition at line 884 of file kresolver.cpp.

QString KResolver::nodeName ( ) const

The nodename to which the resolution was/is to be performed.

Definition at line 336 of file kresolver.cpp.

QString KResolver::normalizeDomain ( const QString & domain ) [static]

Normalise a domain name.

In order to prevent simple mistakes in International Domain Names (IDN), it has been decided that certain code points (characters in Unicode) would be instead converted to others. This includes turning them all to lower case, as well certain other specific operations, as specified in the documents.

For instance, the German 'ß' will be changed into 'ss', while the micro symbol 'µ' will be changed to the Greek mu 'μ'.

Two equivalent domains have the same normalised form. And the normalised form of a normalised domain is itself (i.e., if d is normalised, the following is true: d == normalizeDomain(d) )

This operation is equivalent to encoding and the decoding a Unicode hostname.

Parameters:

domain

a domain to be normalised

Returns:: the normalised domain, or QString::null if the domain is invalid.

Definition at line 1034 of file kresolver.cpp.

QStrList KResolver::protocolName ( const char * protoname ) [static]

Finds all aliases for a given protocol name.

Parameters:

protoname

the protocol name to be looked for

Returns:: all the protocol names in a list. The first is the "proper" name.

Definition at line 657 of file kresolver.cpp.

QStrList KResolver::protocolName ( int protonum ) [static]

Resolves a protocol number to its names.

Note: the returned QStrList operates on deep-copies.

Parameters:

protonum

the protocol number to be looked for

Returns:: all the protocol names in a list. The first is the "proper" name.

Definition at line 610 of file kresolver.cpp.

int KResolver::protocolNumber ( const char * protoname ) [static]

Resolves a protocol name to its number.

Parameters:

protoname

the protocol name to be looked for

Returns:: the protocol number or -1 if we couldn't locate it

Definition at line 704 of file kresolver.cpp.

KResolverResults KResolver::resolve	(	const QString &	host,
		const QString &	service,
		int	flags = `0`,
		int	families = `KResolver::InternetFamily`
	)			`[static]`

Resolve the nodename and service name synchronously.

This static function is provided as convenience for simplifying name resolution. It resolves the given host and service names synchronously and returns the results it found. It is equivalent to the following code:

   KResolver qres(host, service);
   qres.setFlags(flags);
   qres.setFamily(families)
   qres.start();
   qres.wait();
   return qres.results();

Parameters:

	host	the nodename to resolve
	service	the service to resolve
	flags	flags to be used
	families	the families to be searched

Returns:: a KResolverResults object containing the results

See also:: KResolverResults for information on how to obtain the error code

Definition at line 587 of file kresolver.cpp.

bool KResolver::resolveAsync	(	QObject *	userObj,
		const char *	userSlot,
		const QString &	host,
		const QString &	service,
		int	flags = `0`,
		int	families = `KResolver::InternetFamily`
	)			`[static]`

Start an asynchronous name resolution.

This function is provided as a convenience to simplify the resolution process. It creates an internal KResolver object, connects the finished signal to the given slot and starts the resolution asynchronously. It is more or less equivalent to the following code:

Note: this function may trigger the signal before it returns, so your code must be prepared for this situation.

   KResolver* qres = new KResolver(host, service);
   QObject::connect(qres, SIGNAL(finished(KResolverResults)),
              userObj, userSlot);
   qres->setFlags(flags);
   qres->setFamily(families);
   return qres->start();

You should use it like this in your code:

   KResolver::resolveAsync(myObj, SLOT(mySlot(KResolverResults)), host, service);

Parameters:

	userObj	the object whose slot `userSlot` we will connect
	userSlot	the slot to which we'll connect
	host	the nodename to resolve
	service	the service to resolve
	flags	flags to be used
	families	families to be searcheed

Returns:: true if the queueing was successful, false if not

See also:: KResolverResults for information on how to obtain the error code

Definition at line 598 of file kresolver.cpp.

KResolverResults KResolver::results ( ) const

Retrieves the results of this resolution.

Use this function to retrieve the results of the resolution. If no data was resolved (yet) or if we failed, this function will return an empty object.

Returns:: the resolved data

See also:: status for information on finding out if the resolution was successful

Definition at line 516 of file kresolver.cpp.

QStrList KResolver::serviceName	(	int	port,
		const char *	protoname
	)			`[static]`

Resolves a port number to its names.

Note: the returned QStrList operates on deep copies.

Parameters:

	port	the port number, in host byte-order
	protoname	the protocol it is associated with

Returns:: all the service names in a list. The first is the "proper" name.

Definition at line 837 of file kresolver.cpp.

QStrList KResolver::serviceName	(	const char *	servname,
		const char *	protoname
	)			`[static]`

Finds all the aliases for a given service name.

Note: the returned QStrList operates on deep-copies.

Parameters:

	servname	the service alias to be looked for
	protoname	the protocol it is associated with

Returns:: all the service names in a list. The first is the "proper" name.

Definition at line 790 of file kresolver.cpp.

QString KResolver::serviceName ( ) const

The service name to which the resolution was/is to be performed.

Definition at line 342 of file kresolver.cpp.

int KResolver::servicePort	(	const char *	servname,
		const char *	protoname
	)			`[static]`

Resolves a service name to its port number.

Parameters:

	servname	the service name to be looked for
	protoname	the protocol it is associated with

Returns:: the port number in host byte-order or -1 in case of error

Definition at line 747 of file kresolver.cpp.

void KResolver::setAddress	(	const QString &	node,
		const QString &	service
	)

Sets both the host and the service names.

Setting either value to QString::null will unset them.

Parameters:

	node	The nodename
	service	The service name

Definition at line 372 of file kresolver.cpp.

void KNetwork::KResolver::setError	(	int	errorcode,
		int	systemerror = `0`
	)			`[protected]`

Sets the error codes.

void KResolver::setFamily ( int families )

Sets the allowed socket families.

Parameters:

families

the families that we want/accept

See also:: SocketFamilies for possible values

Definition at line 397 of file kresolver.cpp.

int KResolver::setFlags ( int flags )

Sets the flags.

Parameters:

flags

the new flags

Returns:: the old flags

See also:: Flags for an explanation on the flags

Definition at line 385 of file kresolver.cpp.

void KResolver::setNodeName ( const QString & nodename )

Sets the nodename for the resolution.

Set the nodename to QString::null to unset it.

Parameters:

nodename

The nodename to be resolved.

Definition at line 348 of file kresolver.cpp.

void KResolver::setProtocol	(	int	protonum,
		const char *	name = `0L`
	)

Sets the protocol we want.

Protocols are dependant on the selected address family, so you should know what you are doing if you use this function. Besides, protocols generally are either stream-based or datagram-based, so the value of the socket type is also important. The resolution will fail if these values don't match.

When using an Internet socket, the values for the protocol are the IPPROTO_* constants, defined in <netinet/in.h>.

You may choose to set the protocol either by its number or by its name, or by both. If you set:

the number and the name: both values will be stored internally; you may set the name to an empty value, if wanted
the number only (name = NULL): the name will be searched in the protocols database
the name only (number = 0): the number will be searched in the database
neither name nor number: reset to default behaviour

Parameters:

	protonum	the protocol number we want
	name	the protocol name

Definition at line 417 of file kresolver.cpp.

void KResolver::setServiceName ( const QString & service )

Sets the service name to be resolved.

Set it to QString::null to unset it.

Parameters:

service

The service to be resolved.

Definition at line 360 of file kresolver.cpp.

void KResolver::setSocketType ( int type )

Sets the socket type we want.

The values for the type parameter are the SOCK_* constants, defined in <sys/socket.h>. The most common values are:

SOCK_STREAM streaming socket (= reliable, sequenced, connection-based)
SOCK_DGRAM datagram socket (= unreliable, connectionless)
SOCK_RAW raw socket, with direct access to the container protocol (such as IP)

These three are the only values to which it is guaranteed that resolution will work. Some systems may define other constants (such as SOCK_RDM for reliable datagrams), but support is implementation-defined.

Parameters:

type

the wanted socket type (SOCK_* constants). Set 0 to use the default.

Definition at line 407 of file kresolver.cpp.

bool KResolver::start ( )

Starts the name resolution asynchronously.

This function will queue this object for resolution and will return immediately. The status upon exit will either be Queued or InProgress or Failed.

This function does nothing if the object is already queued. But if it had already succeeded or failed, this function will re-start it.

Note: if both the nodename and the servicename are unset, this function will not queue, but will set a success state and emit the signal. Also note that in this case and maybe others, the signal finished might be emitted before this function returns.

Returns:: true if this request was successfully queued for asynchronous resolution

Definition at line 438 of file kresolver.cpp.

int KResolver::status ( ) const

Retrieve the current status of this object.

See also:: StatusCodes for the possible status codes.

Definition at line 312 of file kresolver.cpp.

int KResolver::systemError ( ) const

Retrieve the associated system error code in this object.

Many resolution operations may generate an extra error code as given by the C errno variable. That value is stored in the object and can be retrieved by this function.

Definition at line 324 of file kresolver.cpp.

void KResolver::virtual_hook	(	int	id,
		void *	data
	)			`[protected, virtual]`

Definition at line 1039 of file kresolver.cpp.

bool KResolver::wait ( int msec = 0 )

Waits for a request to finish resolving.

This function will wait on a running request for its termination. The status upon exit will either be Success or Failed or Canceled.

This function may be called from any thread, even one that is not the GUI thread or the one that started the resolution process. But note this function is not thread-safe nor reentrant: i.e., only one thread can be waiting on one given object.

Also note that this function ensures that the finished signal is emitted before it returns. That means that, as a side-effect, whenever wait() is called, the signal is emitted on the thread calling wait().

Parameters:

msec

the time to wait, in milliseconds or 0 to wait forever

Returns:: true if the resolution has finished processing, even when it failed or was canceled. False means the wait timed out and the resolution is still running.

Definition at line 457 of file kresolver.cpp.

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

KDECore

KNetwork::KResolver Class Reference

Public Types

Signals

Public Member Functions

Static Public Member Functions

Protected Member Functions

Detailed Description

Member Enumeration Documentation

Constructor & Destructor Documentation

Member Function Documentation

KDECore

API Reference