Q3Dns Class Reference

#include <q3dns.h>

Inheritance diagram for Q3Dns:

[legend]Collaboration diagram for Q3Dns:

[legend]List of all members.

---

Detailed Description

The Q3Dns class provides asynchronous DNS lookups.

Both Windows and Unix provide synchronous DNS lookups; Windows provides some asynchronous support too. At the time of writing neither operating system provides asynchronous support for anything other than hostname-to-address mapping.

Q3Dns rectifies this shortcoming, by providing asynchronous caching lookups for the record types that we expect modern GUI applications to need in the near future.

The class is not straightforward to use (although it is much simpler than the native APIs); Q3Socket provides much easier to use TCP connection facilities. The aim of Q3Dns is to provide a correct and small API to the DNS and nothing more. (We use "correctness" to mean that the DNS information is correctly cached, and correctly timed out.)

The API comprises a constructor, functions to set the DNS node (the domain in DNS terminology) and record type (setLabel() and setRecordType()), the corresponding get functions, an isWorking() function to determine whether Q3Dns is working or reading, a resultsReady() signal and query functions for the result.

There is one query function for each RecordType, namely addresses(), mailServers(), servers(), hostNames() and texts(). There are also two generic query functions: canonicalName() returns the name you'll presumably end up using (the exact meaning of this depends on the record type) and qualifiedNames() returns a list of the fully qualified names label() maps to.

See also:

Q3Socket

Definition at line 43 of file q3dns.h.

Public Types
enum	RecordType
Signals
void	resultsReady ()
Public Member Functions
	Q3Dns ()
	Q3Dns (const QString &label, RecordType rr=A)
	Q3Dns (const QHostAddress &address, RecordType rr=Ptr)
virtual	~Q3Dns ()
virtual void	setLabel (const QString &label)
virtual void	setLabel (const QHostAddress &address)
QString	label () const
virtual void	setRecordType (RecordType rr=A)
RecordType	recordType () const
bool	isWorking () const
Q3ValueList< QHostAddress >	addresses () const
Q3ValueList< MailServer >	mailServers () const
Q3ValueList< Server >	servers () const
QStringList	hostNames () const
QStringList	texts () const
QString	canonicalName () const
QStringList	qualifiedNames () const
Private Slots
void	startQuery ()
Private Member Functions
void	setStartQueryTimer ()
Static Private Member Functions
static void	doResInit ()
static QString	toInAddrArpaDomain (const QHostAddress &address)
Private Attributes
QString	l
QStringList	n
RecordType	t
Q3DnsPrivate *	d
Friends
class	Q3DnsAnswer
class	Q3DnsManager
Classes
class	MailServer
	The Q3Dns::MailServer class is described in Q3Dns::mailServers(). More...
class	Server
	The Q3Dns::Server class is described in Q3Dns::servers(). More...

---

Member Enumeration Documentation

enum Q3Dns::RecordType

This enum type defines the record types Q3Dns can handle. The DNS provides many more; these are the ones we've judged to be in current use, useful for GUI programs and important enough to support right away:

None No information. This exists only so that Q3Dns can have a default.

A IPv4 addresses. By far the most common type.

Aaaa IPv6 addresses. So far mostly unused.

Mx Mail eXchanger names. Used for mail delivery.

Srv SeRVer names. Generic record type for finding servers. So far mostly unused.

Cname Canonical names. Maps from nicknames to the true name (the canonical name) for a host.

Ptr name PoinTeRs. Maps from IPv4 or IPv6 addresses to hostnames.

Txt arbitrary TeXT for domains.

We expect that some support for the {http://www.rfc-editor.org/rfc/rfc2535.txt}{RFC 2535} extensions will be added in future versions.

Definition at line 46 of file q3dns.h.

                    {
  None,
  A, Aaaa,
  Mx, Srv,
  Cname,
  Ptr,
  Txt
    };

---

Constructor & Destructor Documentation

Q3Dns::Q3Dns

(

)

Constructs a DNS query object with invalid settings for both the label and the search type.

Definition at line 1606 of file q3dns.cpp.

References d, None, and t.

{
    d = new Q3DnsPrivate;
    t = None;
}

Q3Dns::Q3Dns	(	const QString &	label,
		RecordType	rr = A
	)

Constructs a DNS query object that will return record type rr information about label.

The DNS lookup is started the next time the application enters the event loop. When the result is found the signal resultsReady() is emitted.

rr defaults to A, IPv4 addresses.

Definition at line 1626 of file q3dns.cpp.

References d, label(), setLabel(), setStartQueryTimer(), and t.

{
    d = new Q3DnsPrivate;
    t = rr;
    setLabel( label );
    setStartQueryTimer(); // start query the next time we enter event loop
}

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Q3Dns::Q3Dns	(	const QHostAddress &	address,
		RecordType	rr = Ptr
	)

Constructs a DNS query object that will return record type rr information about host address address. The label is set to the IN-ADDR.ARPA domain name. This is useful in combination with the Ptr record type (e.g. if you want to look up a hostname for a given address).

The DNS lookup is started the next time the application enters the event loop. When the result is found the signal resultsReady() is emitted.

rr defaults to Ptr, that maps addresses to hostnames.

Definition at line 1650 of file q3dns.cpp.

References d, setLabel(), setStartQueryTimer(), and t.

{
    d = new Q3DnsPrivate;
    t = rr;
    setLabel( address );
    setStartQueryTimer(); // start query the next time we enter event loop
}

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Q3Dns::~Q3Dns

(

)

[virtual]

Destroys the DNS query object and frees its allocated resources.

Definition at line 1665 of file q3dns.cpp.

References d, globalManager, and m.

{
    if ( globalManager ) {
  uint q = 0;
  Q3DnsManager * m = globalManager;
  while( q < m->queries.size() ) {
      Q3DnsQuery * query=m->queries[q];
      if ( query && query->dns )
        (void)query->dns->take( (void*) this );
    q++;
  }

    }

    delete d;
    d = 0;
}

---

Member Function Documentation

void Q3Dns::setLabel

(

const QString &

label

)

[virtual]

Sets this DNS query object to query for information about label.

This does not change the recordType(), but its isWorking() status will probably change as a result.

The DNS lookup is started the next time the application enters the event loop. When the result is found the signal resultsReady() is emitted.

Definition at line 1698 of file q3dns.cpp.

References QList< T >::append(), QList< T >::clear(), QList< T >::count(), d, domains, i, int, l, label(), QString::left(), QString::length(), QUnicodeTables::lower(), Q3DnsManager::manager(), n, Q3DnsPrivate::noNames, Q3StrListIterator, qDebug(), and setStartQueryTimer().

Referenced by Q3Dns(), and setLabel().

{
    l = label;
    d->noNames = false;

    // construct a list of qualified names
    n.clear();
    if ( l.length() > 1 && l[(int)l.length()-1] == '.' ) {
  n.append( l.left( l.length()-1 ).lower() );
    } else {
  int i = l.length();
  int dots = 0;
  const int maxDots = 2;
  while( i && dots < maxDots ) {
      if ( l[--i] == '.' )
    dots++;
  }
  if ( dots < maxDots ) {
      (void)Q3DnsManager::manager(); // create a Q3DnsManager, if it is not already there
      Q3StrListIterator it( *domains );
      const char * dom;
      while( (dom=it.current()) != 0 ) {
    ++it;
    n.append( l.lower() + "." + dom );
      }
  }
  n.append( l.lower() );
    }

#if defined(Q_DNS_SYNCHRONOUS)
    if ( d->noEventLoop ) {
  doSynchronousLookup();
    } else {
  setStartQueryTimer(); // start query the next time we enter event loop
    }
#else
    setStartQueryTimer(); // start query the next time we enter event loop
#endif
#if defined(Q3DNS_DEBUG)
    qDebug( "Q3Dns::setLabel: %d address(es) for %s", n.count(), l.ascii() );
    int i = 0;
    for( i = 0; i < (int)n.count(); i++ )
  qDebug( "Q3Dns::setLabel: %d: %s", i, n[i].ascii() );
#endif
}

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void Q3Dns::setLabel

(

const QHostAddress &

address

)

[virtual]

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts. Sets this DNS query object to query for information about the host address address. The label is set to the IN-ADDR.ARPA domain name. This is useful in combination with the Ptr record type (e.g. if you want to look up a hostname for a given address).

Definition at line 1754 of file q3dns.cpp.

References setLabel(), and toInAddrArpaDomain().

{
    setLabel( toInAddrArpaDomain( address ) );
}

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QString Q3Dns::label

(

)

const [inline]

Returns the domain name for which this object returns information.

See also:

setLabel()

Definition at line 63 of file q3dns.h.

References l.

Referenced by Q3DnsDomain::cached(), Q3DnsAnswer::notify(), Q3Dns(), setLabel(), and Q3DnsUgleHack::ugle().

{ return l; }

void Q3Dns::setRecordType

(

RecordType

rr = A

)

[virtual]

Sets this object to query for record type rr records.

The DNS lookup is started the next time the application enters the event loop. When the result is found the signal resultsReady() is emitted.

See also:

RecordType

Definition at line 1829 of file q3dns.cpp.

References d, Q3DnsPrivate::noNames, setStartQueryTimer(), and t.

{
    t = rr;
    d->noNames = false;
    setStartQueryTimer(); // start query the next time we enter event loop
}

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Q3Dns::RecordType Q3Dns::recordType

(

)

const [inline]

Returns the record type of this DNS query object.

See also:

setRecordType() RecordType

Definition at line 66 of file q3dns.h.

References t.

Referenced by Q3DnsDomain::cached(), and Q3DnsUgleHack::ugle().

{ return t; }

bool Q3Dns::isWorking

(

)

const

Returns true if Q3Dns is doing a lookup for this object (i.e. if it does not already have the necessary information); otherwise returns false.

Q3Dns emits the resultsReady() signal when the status changes to false.

Definition at line 1924 of file q3dns.cpp.

References Q3DnsDomain::cached(), QList< T >::count(), Q3PtrList< type >::current(), d, l, n, Q3PtrList< type >::next(), Q3DnsPrivate::noNames, None, Q3DnsRR::nxdomain, qDebug(), and t.

Referenced by startQuery(), Q3Socket::tryConnecting(), and Q3DnsUgleHack::ugle().

{
#if defined(Q3DNS_DEBUG)
    qDebug( "Q3Dns::isWorking (%s, %d)", l.ascii(), t );
#endif
    if ( t == None )
  return false;

#if defined(Q_DNS_SYNCHRONOUS)
    if ( d->noEventLoop )
  return true;
#endif

    Q3PtrList<Q3DnsRR> * ll = Q3DnsDomain::cached( this );
    Q_LONG queries = n.count();
    while( ll->current() != 0 ) {
  if ( ll->current()->nxdomain ) {
      queries--;
  } else {
      delete ll;
      return false;
  }
  ll->next();
    }
    delete ll;

    if ( queries <= 0 )
  return false;
    if ( d->noNames )
  return false;
    return true;
}

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Q3ValueList< QHostAddress > Q3Dns::addresses

(

)

const

Returns a list of the addresses for this name if this Q3Dns object has a recordType() of Q3Dns::A or Q3Dns::Aaaa and the answer is available; otherwise returns an empty list.

As a special case, if label() is a valid numeric IP address, this function returns that address.

Note that if you want to iterate over the list, you should iterate over a copy, e.g.

    Q3ValueList<QHostAddress> list = myDns.addresses();
    Q3ValueList<QHostAddress>::Iterator it = list.begin();
    while( it != list.end() ) {
        myProcessing( *it );
        ++it;
    }

Definition at line 1979 of file q3dns.cpp.

References A, Aaaa, Q3DnsRR::address, Q3DnsDomain::cached(), cached(), Q3DnsRR::current, l, Q3DnsRR::nxdomain, qDebug(), and t.

Referenced by Q3Socket::tryConnecting().

{
#if defined(Q3DNS_DEBUG)
    qDebug( "Q3Dns::addresses (%s)", l.ascii() );
#endif
    Q3ValueList<QHostAddress> result;
    if ( t != A && t != Aaaa )
  return result;

    Q3PtrList<Q3DnsRR> * cached = Q3DnsDomain::cached( this );

    Q3DnsRR * rr;
    while( (rr=cached->current()) != 0 ) {
  if ( rr->current && !rr->nxdomain )
      result.append( rr->address );
  cached->next();
    }
    delete cached;
    return result;
}

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Q3ValueList< Q3Dns::MailServer > Q3Dns::mailServers

(

)

const

Returns a list of mail servers if the record type is Mx. The class Q3Dns::MailServer contains the following public variables: QString Q3Dns::MailServer::name Q_UINT16 Q3Dns::MailServer::priority

Note that if you want to iterate over the list, you should iterate over a copy, e.g.

    Q3ValueList<Q3Dns::MailServer> list = myDns.mailServers();
    Q3ValueList<Q3Dns::MailServer>::Iterator it = list.begin();
    while( it != list.end() ) {
        myProcessing( *it );
        ++it;
    }

Definition at line 2028 of file q3dns.cpp.

References Q3DnsDomain::cached(), cached(), Q3DnsRR::current, l, Mx, Q3DnsRR::nxdomain, Q3DnsRR::priority, qDebug(), t, and Q3DnsRR::target.

{
#if defined(Q3DNS_DEBUG)
    qDebug( "Q3Dns::mailServers (%s)", l.ascii() );
#endif
    Q3ValueList<Q3Dns::MailServer> result;
    if ( t != Mx )
  return result;

    Q3PtrList<Q3DnsRR> * cached = Q3DnsDomain::cached( this );

    Q3DnsRR * rr;
    while( (rr=cached->current()) != 0 ) {
  if ( rr->current && !rr->nxdomain ) {
      MailServer ms( rr->target, rr->priority );
      result.append( ms );
  }
  cached->next();
    }
    delete cached;
    return result;
}

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Q3ValueList< Q3Dns::Server > Q3Dns::servers

(

)

const

Returns a list of servers if the record type is Srv. The class Q3Dns::Server contains the following public variables: QString Q3Dns::Server::name Q_UINT16 Q3Dns::Server::priority Q_UINT16 Q3Dns::Server::weight Q_UINT16 Q3Dns::Server::port

Note that if you want to iterate over the list, you should iterate over a copy, e.g.

    Q3ValueList<Q3Dns::Server> list = myDns.servers();
    Q3ValueList<Q3Dns::Server>::Iterator it = list.begin();
    while( it != list.end() ) {
        myProcessing( *it );
        ++it;
    }

Definition at line 2080 of file q3dns.cpp.

References Q3DnsDomain::cached(), cached(), Q3DnsRR::current, l, Q3DnsRR::nxdomain, Q3DnsRR::port, Q3DnsRR::priority, qDebug(), s, Srv, t, Q3DnsRR::target, and Q3DnsRR::weight.

{
#if defined(Q3DNS_DEBUG)
    qDebug( "Q3Dns::servers (%s)", l.ascii() );
#endif
    Q3ValueList<Q3Dns::Server> result;
    if ( t != Srv )
  return result;

    Q3PtrList<Q3DnsRR> * cached = Q3DnsDomain::cached( this );

    Q3DnsRR * rr;
    while( (rr=cached->current()) != 0 ) {
  if ( rr->current && !rr->nxdomain ) {
      Server s( rr->target, rr->priority, rr->weight, rr->port );
      result.append( s );
  }
  cached->next();
    }
    delete cached;
    return result;
}

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QStringList Q3Dns::hostNames

(

)

const

Returns a list of host names if the record type is Ptr.

Note that if you want to iterate over the list, you should iterate over a copy, e.g.

    QStringList list = myDns.hostNames();
    QStringList::Iterator it = list.begin();
    while( it != list.end() ) {
        myProcessing( *it );
        ++it;
    }

Definition at line 2119 of file q3dns.cpp.

References Q3DnsDomain::cached(), cached(), Q3DnsRR::current, l, Q3DnsRR::nxdomain, Ptr, qDebug(), t, and Q3DnsRR::target.

{
#if defined(Q3DNS_DEBUG)
    qDebug( "Q3Dns::hostNames (%s)", l.ascii() );
#endif
    QStringList result;
    if ( t != Ptr )
  return result;

    Q3PtrList<Q3DnsRR> * cached = Q3DnsDomain::cached( this );

    Q3DnsRR * rr;
    while( (rr=cached->current()) != 0 ) {
  if ( rr->current && !rr->nxdomain ) {
      QString str( rr->target );
      result.append( str );
  }
  cached->next();
    }
    delete cached;
    return result;
}

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QStringList Q3Dns::texts

(

)

const

Returns a list of texts if the record type is Txt.

Note that if you want to iterate over the list, you should iterate over a copy, e.g.

    QStringList list = myDns.texts();
    QStringList::Iterator it = list.begin();
    while( it != list.end() ) {
        myProcessing( *it );
        ++it;
    }

Definition at line 2157 of file q3dns.cpp.

References Q3DnsDomain::cached(), cached(), Q3DnsRR::current, l, Q3DnsRR::nxdomain, qDebug(), t, Q3DnsRR::text, and Txt.

{
#if defined(Q3DNS_DEBUG)
    qDebug( "Q3Dns::texts (%s)", l.ascii() );
#endif
    QStringList result;
    if ( t != Txt )
  return result;

    Q3PtrList<Q3DnsRR> * cached = Q3DnsDomain::cached( this );

    Q3DnsRR * rr;
    while( (rr=cached->current()) != 0 ) {
  if ( rr->current && !rr->nxdomain ) {
      QString str( rr->text );
      result.append( str );
  }
  cached->next();
    }
    delete cached;
    return result;
}

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QString Q3Dns::canonicalName

(

)

const

Returns the canonical name for this DNS node. (This works regardless of what recordType() is set to.)

If the canonical name isn't known, this function returns a null string.

The canonical name of a DNS node is its full name, or the full name of the target of its CNAME. For example, if l.trolltech.com is a CNAME to lillian.troll.no, and the search path for Q3Dns is "trolltech.com", then the canonical name for all of "lillian", "l", "lillian.troll.no." and "l.trolltech.com" is "lillian.troll.no.".

Definition at line 2196 of file q3dns.cpp.

References Q3DnsDomain::cached(), cached(), Cname, Q3DnsRR::current, Q3DnsRR::domain, Q3DnsRR::nxdomain, t, and Q3DnsRR::target.

{
    // the cname should work regardless of the recordType(), so set the record
    // type temporarily to cname when you look at the cache
    Q3Dns *that = (Q3Dns*) this; // mutable function
    RecordType oldType = t;
    that->t = Cname;
    Q3PtrList<Q3DnsRR> * cached = Q3DnsDomain::cached( that );
    that->t = oldType;

    Q3DnsRR * rr;
    while( (rr=cached->current()) != 0 ) {
  if ( rr->current && !rr->nxdomain && rr->domain ) {
      delete cached;
      return rr->target;
  }
  cached->next();
    }
    delete cached;
    return QString();
}

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QStringList Q3Dns::qualifiedNames

(

)

const [inline]

Returns a list of the fully qualified names label() maps to.

Note that if you want to iterate over the list, you should iterate over a copy, e.g.

    QStringList list = myDns.qualifiedNames();
    QStringList::Iterator it = list.begin();
    while( it != list.end() ) {
        myProcessing( *it );
        ++it;
    }

Definition at line 102 of file q3dns.h.

References n.

Referenced by Q3DnsDomain::cached().

{ return n; }

void Q3Dns::resultsReady

(

)

[signal]

This signal is emitted when results are available for one of the qualifiedNames().

Referenced by startQuery(), and Q3DnsUgleHack::ugle().

void Q3Dns::startQuery

(

)

[private, slot]

Definition at line 1841 of file q3dns.cpp.

References emit, isWorking(), and resultsReady().

Referenced by setStartQueryTimer().

{
    // isWorking() starts the query (if necessary)
    if ( !isWorking() )
  emit resultsReady();
}

void Q3Dns::doResInit

(

)

[static, private]

Definition at line 2495 of file q3dns.cpp.

References a, A, Aaaa, Q3DnsRR::address, Q3PtrList< type >::append(), QList< T >::begin(), Q3DnsRR::current, Q3DnsRR::deleteTime, domains, QList< T >::end(), Q3DnsRR::expireTime, QString::fromLatin1(), i, int, ipv6support, QUnicodeTables::isSpace(), QString::left(), QString::length(), QUnicodeTables::lower(), QString::mid(), n, ns, QFile::open(), Ptr, ptr, QIODevice::ReadOnly, res_init(), QHostAddress::setAddress(), Q3PtrCollection::setAutoDelete(), QList< T >::size(), QString::startsWith(), QTest::stream, Q3DnsRR::t, toInAddrArpaDomain(), QString::truncate(), and type.

Referenced by Q3DnsManager::Q3DnsManager(), and Q3DnsManager::transmitQuery().

{
    if ( ns )
  return;
    ns = new Q3PtrList<QHostAddress>;
    ns->setAutoDelete( true );
    domains = new Q3StrList( true );
    domains->setAutoDelete( true );

    // read resolv.conf manually.
    QFile resolvConf("/etc/resolv.conf");
    if (resolvConf.open(QIODevice::ReadOnly)) {
        QTextStream stream( &resolvConf );
  QString line;

  while ( !stream.atEnd() ) {
            line = stream.readLine();
      QStringList list = QStringList::split( " ", line );
      if( line.startsWith( "#" ) || list.size() < 2 )
         continue;
      const QString type = list[0].lower();

      if ( type == "nameserver" ) {
    QHostAddress *address = new QHostAddress();
    if ( address->setAddress( QString(list[1]) ) ) {
        // only add ipv6 addresses from resolv.conf if
        // this host supports ipv6.
        if ( address->isIPv4Address() || ipv6support )
      ns->append( address );
                    else
                        delete address;
    } else {
        delete address;
    }
      } else if ( type == "search" ) {
    QStringList srch = QStringList::split( " ", list[1] );
    for ( QStringList::Iterator i = srch.begin(); i != srch.end(); ++i )
        domains->append( (*i).lower().local8Bit() );

      } else if ( type == "domain" ) {
    domains->append( list[1].lower().local8Bit() );
      }
  }
    }

    if (ns->isEmpty()) {
#if defined(Q_MODERN_RES_API)
  struct __res_state res;
  res_ninit( &res );
  int i;
  // find the name servers to use
  for( i=0; i < MAXNS && i < res.nscount; i++ )
      ns->append( new QHostAddress( ntohl( res.nsaddr_list[i].sin_addr.s_addr ) ) );
#  if defined(MAXDFLSRCH)
  for( i=0; i < MAXDFLSRCH; i++ ) {
      if ( res.dnsrch[i] && *(res.dnsrch[i]) )
    domains->append( QString::fromLatin1( res.dnsrch[i] ).lower().local8Bit() );
      else
    break;
  }
#  endif
  if ( *res.defdname )
      domains->append( QString::fromLatin1( res.defdname ).lower().local8Bit() );
#else
  res_init();
  int i;
  // find the name servers to use
  for( i=0; i < MAXNS && i < _res.nscount; i++ )
      ns->append( new QHostAddress( ntohl( _res.nsaddr_list[i].sin_addr.s_addr ) ) );
#  if defined(MAXDFLSRCH)
  for( i=0; i < MAXDFLSRCH; i++ ) {
      if ( _res.dnsrch[i] && *(_res.dnsrch[i]) )
    domains->append( QString::fromLatin1( _res.dnsrch[i] ).lower().local8Bit() );
      else
    break;
  }
#  endif
  if ( *_res.defdname )
      domains->append( QString::fromLatin1( _res.defdname ).lower().local8Bit() );
#endif

  // the code above adds "0.0.0.0" as a name server at the slightest
  // hint of trouble. so remove those again.
  ns->first();
  while( ns->current() ) {
      if ( ns->current()->isNull() )
    delete ns->take();
      else
    ns->next();
  }
    }

    QFile hosts( QString::fromLatin1( "/etc/hosts" ) );
    if ( hosts.open( QIODevice::ReadOnly ) ) {
  // read the /etc/hosts file, creating long-life A and PTR RRs
  // for the things we find.
  QTextStream i( &hosts );
  QString line;
  while( !i.atEnd() ) {
      line = i.readLine().simplifyWhiteSpace().lower();
      uint n = 0;
      while( (int) n < line.length() && line[(int)n] != '#' )
    n++;
      line.truncate( n );
      n = 0;
      while( (int) n < line.length() && !line[(int)n].isSpace() )
    n++;
      QString ip = line.left( n );
      QHostAddress a;
      a.setAddress( ip );
      if ( ( a.isIPv4Address() || a.isIPv6Address() ) && !a.isNull() ) {
    bool first = true;
    line = line.mid( n+1 );
    n = 0;
    while( (int) n < line.length() && !line[(int)n].isSpace() )
        n++;
    QString hostname = line.left( n );
    // ### in case of bad syntax, hostname is invalid. do we care?
    if ( n ) {
        Q3DnsRR * rr = new Q3DnsRR( hostname );
        if ( a.isIPv4Address() )
      rr->t = Q3Dns::A;
        else
      rr->t = Q3Dns::Aaaa;
        rr->address = a;
        rr->deleteTime = UINT_MAX;
        rr->expireTime = UINT_MAX;
        rr->current = true;
        if ( first ) {
      first = false;
      Q3DnsRR * ptr = new Q3DnsRR( Q3Dns::toInAddrArpaDomain( a ) );
      ptr->t = Q3Dns::Ptr;
      ptr->target = hostname;
      ptr->deleteTime = UINT_MAX;
      ptr->expireTime = UINT_MAX;
      ptr->current = true;
        }
    }
      }
  }
    }
}

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void Q3Dns::setStartQueryTimer

(

)

[private]

The three functions Q3Dns::Q3Dns(QString, RecordType), Q3Dns::setLabel() and Q3Dns::setRecordType() may start a DNS lookup. This function handles setting up the single shot timer.

Definition at line 1853 of file q3dns.cpp.

References QObject::connect(), d, Q3DnsPrivate::queryTimer, SIGNAL, SLOT, QTimer::start(), and startQuery().

Referenced by Q3Dns(), setLabel(), and setRecordType().

{
#if defined(Q_DNS_SYNCHRONOUS)
    if ( !d->queryTimer && !d->noEventLoop )
#else
    if ( !d->queryTimer )
#endif
    {
  // start the query the next time we enter event loop
  d->queryTimer = new QTimer( this );
  connect( d->queryTimer, SIGNAL(timeout()),
     this, SLOT(startQuery()) );
  d->queryTimer->start( 0, true );
    }
}

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QString Q3Dns::toInAddrArpaDomain

(

const QHostAddress &

address

)

[static, private]

Definition at line 1875 of file q3dns.cpp.

References b, i, QHostAddress::isNull(), QString::number(), s, and QHostAddress::toIPv6Address().

Referenced by doResInit(), and setLabel().

{
    QString s;
    if ( address.isNull() ) {
  // if the address isn't valid, neither of the other two make
  // cases make sense. better to just return.
    } else if ( address.isIp4Addr() ) {
  Q_UINT32 i = address.ip4Addr();
  s.sprintf( "%d.%d.%d.%d.IN-ADDR.ARPA",
       i & 0xff, (i >> 8) & 0xff, (i>>16) & 0xff, (i>>24) & 0xff );
    } else {
  // RFC 3152. (1886 is deprecated, and clients no longer need to
  // support it, in practice).
  Q_IPV6ADDR i = address.toIPv6Address();
  s = "ip6.arpa";
  uint b = 0;
  while( b < 16 ) {
      s = QString::number( i.c[b]%16, 16 ) + "." +
    QString::number( i.c[b]/16, 16 ) + "." + s;
      b++;
  }
    }
    return s;
}

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Friends And Related Function Documentation

friend class Q3DnsAnswer [friend]

Definition at line 128 of file q3dns.h.

friend class Q3DnsManager [friend]

Definition at line 129 of file q3dns.h.

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Member Data Documentation

QString Q3Dns::l [private]

Definition at line 123 of file q3dns.h.

Referenced by addresses(), hostNames(), isWorking(), mailServers(), servers(), setLabel(), and texts().

QStringList Q3Dns::n [private]

Definition at line 124 of file q3dns.h.

Referenced by doResInit(), isWorking(), and setLabel().

RecordType Q3Dns::t [private]

Definition at line 125 of file q3dns.h.

Referenced by addresses(), canonicalName(), hostNames(), isWorking(), mailServers(), Q3Dns(), servers(), setRecordType(), and texts().

Q3DnsPrivate* Q3Dns::d [private]

Definition at line 126 of file q3dns.h.

Referenced by isWorking(), Q3Dns(), setLabel(), setRecordType(), setStartQueryTimer(), and ~Q3Dns().

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

• src/qt3support/network/q3dns.h
• src/qt3support/network/q3dns.cpp

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