Q3DnsAnswer Class Reference

Collaboration diagram for Q3DnsAnswer:

[legend]List of all members.

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Detailed Description

Definition at line 208 of file q3dns.cpp.

Public Member Functions
	Q3DnsAnswer (Q3DnsQuery *)
	Q3DnsAnswer (const QByteArray &, Q3DnsQuery *)
	~Q3DnsAnswer ()
void	parse ()
void	notify ()
Public Attributes
bool	ok
Private Member Functions
QString	readString (bool multipleLabels=true)
void	parseA ()
void	parseAaaa ()
void	parseMx ()
void	parseSrv ()
void	parseCname ()
void	parsePtr ()
void	parseTxt ()
void	parseNs ()
Private Attributes
Q3DnsQuery *	query
Q_UINT8 *	answer
int	size
int	pp
Q3PtrList< Q3DnsRR > *	rrs
int	next
int	ttl
QString	label
Q3DnsRR *	rr

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Constructor & Destructor Documentation

Q3DnsAnswer::Q3DnsAnswer

(

Q3DnsQuery *

)

Definition at line 264 of file q3dns.cpp.

References answer, Q3PtrList< type >::append(), QString::clear(), Q3DnsRR::current, Q3DnsRR::deleteTime, Q3DnsRR::expireTime, Q3DnsQuery::l, label, next, Q3DnsRR::nxdomain, ok, pp, query, rr, rrs, Q3PtrCollection::setAutoDelete(), size, Q3DnsQuery::started, Q3DnsQuery::t, Q3DnsRR::t, and ttl.

{
    ok = true;

    answer = 0;
    size = 0;
    query = query_;
    pp = 0;
    rrs = new Q3PtrList<Q3DnsRR>;
    rrs->setAutoDelete( false );
    next = size;
    ttl = 0;
    label.clear();
    rr = 0;

    Q3DnsRR * newrr = new Q3DnsRR( query->l );
    newrr->t = query->t;
    newrr->deleteTime = query->started + 10;
    newrr->expireTime = query->started + 10;
    newrr->nxdomain = true;
    newrr->current = true;
    rrs->append( newrr );
}

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Q3DnsAnswer::Q3DnsAnswer	(	const QByteArray &	,
		Q3DnsQuery *
	)

Definition at line 289 of file q3dns.cpp.

References answer, QString::clear(), QByteArray::data(), int, label, next, ok, pp, query, rr, rrs, Q3PtrCollection::setAutoDelete(), QByteArray::size(), size, and ttl.

{
    ok = true;

    answer = (Q_UINT8 *)(answer_.data());
    size = (int)answer_.size();
    query = query_;
    pp = 0;
    rrs = new Q3PtrList<Q3DnsRR>;
    rrs->setAutoDelete( false );
    next = size;
    ttl = 0;
    label.clear();
    rr = 0;
}

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Q3DnsAnswer::~Q3DnsAnswer

(

)

Definition at line 307 of file q3dns.cpp.

References Q3PtrListIterator< type >::current(), Q3Dns::None, ok, rrs, and Q3DnsRR::t.

{
    if ( !ok && rrs ) {
  Q3PtrListIterator<Q3DnsRR> it( *rrs );
  Q3DnsRR * tmprr;
  while( (tmprr=it.current()) != 0 ) {
      ++it;
      tmprr->t = Q3Dns::None; // will be deleted soonish
  }
    }
    delete rrs;
}

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Member Function Documentation

void Q3DnsAnswer::parse

(

)

Definition at line 560 of file q3dns.cpp.

References Q3Dns::A, Q3Dns::Aaaa, Q3DnsRR::address, answer, Q3PtrList< type >::append(), Q3PtrList< type >::current(), Q3DnsRR::current, Q3DnsRR::deleteTime, Q3DnsRR::domain, Q3DnsRR::expireTime, Q3PtrList< type >::first(), QString::isNull(), Q3DnsQuery::l, label, QString::length(), Q3DnsDomain::name(), next, Q3PtrList< type >::next(), Q3Dns::None, Q3DnsRR::nxdomain, ok, parseA(), parseAaaa(), parseCname(), parseMx(), parseNs(), parsePtr(), parseSrv(), parseTxt(), Q3DnsRR::port, pp, Q3DnsRR::priority, qDebug(), query, readString(), rr, rrs, Q3DnsDomain::rrs, size, Q3DnsQuery::started, Q3DnsQuery::t, Q3DnsRR::t, Q3DnsRR::target, Q3DnsRR::text, ttl, type, used, and Q3DnsRR::weight.

{
    // okay, do the work...
    if ( (answer[2] & 0x78) != 0 ) {
#if defined(Q3DNS_DEBUG)
  qDebug( "DNS Manager: answer to wrong query type (%d)", answer[1] );
#endif
  ok = false;
  return;
    }

    // AA
    bool aa = (answer[2] & 4) != 0;

    // TC
    if ( (answer[2] & 2) != 0 ) {
#if defined(Q3DNS_DEBUG)
  qDebug( "DNS Manager: truncated answer; pressing on" );
#endif
    }

    // RD
    bool rd = (answer[2] & 1) != 0;

    // we don't test RA
    // we don't test the MBZ fields

    if ( (answer[3] & 0x0f) == 3 ) {
#if defined(Q3DNS_DEBUG)
  qDebug( "DNS Manager: saw NXDomain for %s", query->l.ascii() );
#endif
  // NXDomain.  cache that for one minute.
  rr = new Q3DnsRR( query->l );
  rr->t = query->t;
  rr->deleteTime = query->started + 60;
  rr->expireTime = query->started + 60;
  rr->nxdomain = true;
  rr->current = true;
  rrs->append( rr );
  return;
    }

    if ( (answer[3] & 0x0f) != 0 ) {
#if defined(Q3DNS_DEBUG)
  qDebug( "DNS Manager: error code %d", answer[3] & 0x0f );
#endif
  ok = false;
  return;
    }

    int qdcount = ( answer[4] << 8 ) + answer[5];
    int ancount = ( answer[6] << 8 ) + answer[7];
    int nscount = ( answer[8] << 8 ) + answer[9];
    int adcount = (answer[10] << 8 ) +answer[11];

    pp = 12;

    // read query
    while( qdcount > 0 && pp < size ) {
  // should I compare the string against query->l?
  (void)readString();
  if ( !ok )
      return;
  pp += 4;
  qdcount--;
    }

    // answers and stuff
    int rrno = 0;
    // if we parse the answer completely, but there are no answers,
    // ignore the entire thing.
    int answers = 0;
    while( ( rrno < ancount ||
       ( ok && answers >0 && rrno < ancount + nscount + adcount ) ) &&
     pp < size ) {
  label = readString().lower();
  if ( !ok )
      return;
  int rdlength = 0;
  if ( pp + 10 <= size )
      rdlength = ( answer[pp+8] << 8 ) + answer[pp+9];
  if ( pp + 10 + rdlength > size ) {
#if defined(Q3DNS_DEBUG)
      qDebug( "DNS Manager: ran out of stuff to parse (%d+%d>%d (%d)",
        pp, rdlength, size, rrno < ancount );
#endif
      // if we're still in the AN section, we should go back and
      // at least down the TTLs.  probably best to invalidate
      // the results.
      // the rrs list is good for this
      ok = ( rrno < ancount );
      return;
  }
  uint type, clas;
  type = ( answer[pp+0] << 8 ) + answer[pp+1];
  clas = ( answer[pp+2] << 8 ) + answer[pp+3];
  ttl = ( answer[pp+4] << 24 ) + ( answer[pp+5] << 16 ) +
        ( answer[pp+6] <<  8 ) + answer[pp+7];
  pp = pp + 10;
  if ( clas != 1 ) {
#if defined(Q3DNS_DEBUG)
      qDebug( "DNS Manager: class %d (not internet) for %s",
        clas, label.isNull() ? "." : label.ascii() );
#endif
  } else {
            next = pp + rdlength;
      rr = 0;
      switch( type ) {
      case 1:
    parseA();
    break;
      case 28:
    parseAaaa();
    break;
      case 15:
    parseMx();
    break;
      case 33:
    parseSrv();
    break;
      case 5:
    parseCname();
    break;
      case 12:
    parsePtr();
    break;
      case 16:
    parseTxt();
    break;
      case 2:
    parseNs();
    break;
      default:
    // something we don't know
#if defined(Q3DNS_DEBUG)
    qDebug( "DNS Manager: type %d for %s", type,
      label.isNull() ? "." : label.ascii() );
#endif
    break;
      }
      if ( rr ) {
    rr->deleteTime = 0;
    if ( ttl > 0 )
        rr->expireTime = query->started + ttl;
    else
        rr->expireTime = query->started + 20;
    if ( rrno < ancount ) {
        answers++;
        rr->deleteTime = rr->expireTime;
    }
    rr->current = true;
    rrs->append( rr );
      }
        }
  if ( !ok )
      return;
  pp = next;
  next = size;
  rrno++;
    }
    if ( answers == 0 ) {
#if defined(Q3DNS_DEBUG)
  qDebug( "DNS Manager: answer contained no answers" );
#endif
  ok = ( aa && rd );
    }

    // now go through the list and mark all the As that are referenced
    // by something we care about.  we want to cache such As.
    rrs->first();
    Q3Dict<void> used( 17 );
    used.setAutoDelete( false );
    while( (rr=rrs->current()) != 0 ) {
  rrs->next();
  if ( rr->target.length() && rr->deleteTime > 0 && rr->current )
      used.insert( rr->target, (void*)42 );
  if ( ( rr->t == Q3Dns::A || rr->t == Q3Dns::Aaaa ) &&
       used.find( rr->domain->name() ) != 0 )
      rr->deleteTime = rr->expireTime;
    }

    // next, for each RR, delete any older RRs that are equal to it
    rrs->first();
    while( (rr=rrs->current()) != 0 ) {
  rrs->next();
  if ( rr && rr->domain && rr->domain->rrs ) {
      Q3PtrList<Q3DnsRR> * drrs = rr->domain->rrs;
      drrs->first();
      Q3DnsRR * older;
      while( (older=drrs->current()) != 0 ) {
    if ( older != rr &&
         older->t == rr->t &&
         older->nxdomain == rr->nxdomain &&
         older->address == rr->address &&
         older->target == rr->target &&
         older->priority == rr->priority &&
         older->weight == rr->weight &&
         older->port == rr->port &&
         older->text == rr->text ) {
        // well, it's equal, but it's not the same. so we kill it,
        // but use its expiry time.
#if defined(Q3DNS_DEBUG)
        qDebug( "killing off old %d for %s, expire was %d",
                            older->t, older->domain->name().latin1(),
                            rr->expireTime );
#endif
        older->t = Q3Dns::None;
        rr->expireTime = QMAX( older->expireTime, rr->expireTime );
        rr->deleteTime = QMAX( older->deleteTime, rr->deleteTime );
        older->deleteTime = 0;
#if defined(Q3DNS_DEBUG)
        qDebug( "    adjusted expire is %d", rr->expireTime );
#endif
    }
    drrs->next();
      }
  }
    }

#if defined(Q3DNS_DEBUG)
    //qDebug( "DNS Manager: ()" );
#endif
}

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void Q3DnsAnswer::notify

(

)

Definition at line 791 of file q3dns.cpp.

References Q3PtrList< type >::count(), Q3PtrDictIterator< type >::current(), Q3DnsQuery::dns, Q3PtrDict< type >::find(), Q3PtrDict< type >::insert(), Q3DnsQuery::l, Q3Dns::label(), n, ok, qDebug(), query, rrs, Q3PtrCollection::setAutoDelete(), and Q3PtrDictIterator< type >::toFirst().

{
    if ( !rrs || !ok || !query || !query->dns )
  return;

    Q3PtrDict<void> notified;
    notified.setAutoDelete( false );

    Q3PtrDictIterator<void> it( *query->dns );
    Q3Dns * dns;
    it.toFirst();
    while( (dns=(Q3Dns*)(it.current())) != 0 ) {
  ++it;
  if ( notified.find( (void*)dns ) == 0 ) {
      notified.insert( (void*)dns, (void*)42 );
      if ( rrs->count() == 0 ) {
#if defined(Q3DNS_DEBUG)
    qDebug( "DNS Manager: found no answers!" );
#endif
    dns->d->noNames = true;
    ((Q3DnsUgleHack*)dns)->ugle( true );
      } else {
    QStringList n = dns->qualifiedNames();
    if ( n.contains(query->l) )
        ((Q3DnsUgleHack*)dns)->ugle();
#if defined(Q3DNS_DEBUG)
    else
        qDebug( "DNS Manager: DNS thing %s not notified for %s",
          dns->label().ascii(), query->l.ascii() );
#endif
      }
  }
    }
}

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QString Q3DnsAnswer::readString

(

bool

multipleLabels = true

)

[private]

Definition at line 321 of file q3dns.cpp.

References answer, b, QString::isNull(), ok, p, pp, and size.

Referenced by parse(), parseCname(), parseMx(), parseNs(), parsePtr(), parseSrv(), and parseTxt().

{
    int p = pp;
    QString r;
    Q_UINT8 b;
    for( ;; ) {
  b = 128;
        // Read one character
        if ( p >= 0 && p < size )
      b = answer[p];

  switch( b >> 6 ) {
  case 0:
            // b is less than 64
      p++;

            // Detect end of data
      if ( b == 0 ) {
    if ( p > pp )
        pp = p;
                return r.isNull() ? QString( "." ) : r;
      }

            // Read a label of size 'b' characters
            if ( !r.isNull() )
    r += '.';
      while( b-- > 0 )
                r += QChar( answer[p++] );

            // Return immediately if we were only supposed to read one
            // label.
            if (!multipleLabels)
                return r;

      break;
  default:
            // Ignore unrecognized control character, or p was out of
            // range.
      goto not_ok;
  case 3:
            // Use the next character to determine the relative offset
            // to jump to before continuing the packet parsing.
      int q = ( (answer[p] & 0x3f) << 8 ) + answer[p+1];

      if ( q >= pp || q >= p )
    goto not_ok;
      if ( p >= pp )
    pp = p + 2;
      p = q;
        }
    }
not_ok:
    ok = false;
    return QString();
}

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void Q3DnsAnswer::parseA

(

)

[private]

Definition at line 379 of file q3dns.cpp.

References Q3Dns::A, Q3DnsRR::address, answer, label, next, pp, qDebug(), rr, Q3DnsRR::t, QHostAddress::toString(), and ttl.

Referenced by parse().

{
    if ( next != pp + 4 ) {
#if defined(Q3DNS_DEBUG)
  qDebug( "Q3Dns: saw %d bytes long IN A for %s",
    next - pp, label.ascii() );
#endif
  return;
    }

    rr = new Q3DnsRR( label );
    rr->t = Q3Dns::A;
    rr->address = QHostAddress( ( answer[pp+0] << 24 ) +
        ( answer[pp+1] << 16 ) +
        ( answer[pp+2] <<  8 ) +
        ( answer[pp+3] ) );
#if defined(Q3DNS_DEBUG)
    qDebug( "Q3Dns: saw %s IN A %s (ttl %d)", label.ascii(),
      rr->address.toString().ascii(), ttl );
#endif
}

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void Q3DnsAnswer::parseAaaa

(

)

[private]

Definition at line 402 of file q3dns.cpp.

References Q3Dns::Aaaa, Q3DnsRR::address, answer, label, next, pp, qDebug(), rr, Q3DnsRR::t, QHostAddress::toString(), and ttl.

Referenced by parse().

{
    if ( next != pp + 16 ) {
#if defined(Q3DNS_DEBUG)
  qDebug( "Q3Dns: saw %d bytes long IN Aaaa for %s",
    next - pp, label.ascii() );
#endif
  return;
    }

    rr = new Q3DnsRR( label );
    rr->t = Q3Dns::Aaaa;
    rr->address = QHostAddress( answer+pp );
#if defined(Q3DNS_DEBUG)
    qDebug( "Q3Dns: saw %s IN Aaaa %s (ttl %d)", label.ascii(),
      rr->address.toString().ascii(), ttl );
#endif
}

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void Q3DnsAnswer::parseMx

(

)

[private]

Definition at line 423 of file q3dns.cpp.

References answer, label, Q3Dns::Mx, next, ok, pp, Q3DnsRR::priority, qDebug(), readString(), rr, Q3DnsRR::t, Q3DnsRR::target, and ttl.

Referenced by parse().

{
    if ( next < pp + 2 ) {
#if defined(Q3DNS_DEBUG)
  qDebug( "Q3Dns: saw %d bytes long IN MX for %s",
    next - pp, label.ascii() );
#endif
  return;
    }

    rr = new Q3DnsRR( label );
    rr->priority = (answer[pp] << 8) + answer[pp+1];
    pp += 2;
    rr->target = readString().lower();
    if ( !ok ) {
#if defined(Q3DNS_DEBUG)
  qDebug( "Q3Dns: saw bad string in MX for %s", label.ascii() );
#endif
  return;
    }
    rr->t = Q3Dns::Mx;
#if defined(Q3DNS_DEBUG)
    qDebug( "Q3Dns: saw %s IN MX %d %s (ttl %d)", label.ascii(),
      rr->priority, rr->target.ascii(), ttl );
#endif
}

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void Q3DnsAnswer::parseSrv

(

)

[private]

Definition at line 451 of file q3dns.cpp.

References answer, label, next, ok, Q3DnsRR::port, pp, Q3DnsRR::priority, qDebug(), readString(), rr, Q3Dns::Srv, Q3DnsRR::t, Q3DnsRR::target, ttl, and Q3DnsRR::weight.

Referenced by parse().

{
    if ( next < pp + 6 ) {
#if defined(Q3DNS_DEBUG)
  qDebug( "Q3Dns: saw %d bytes long IN SRV for %s",
    next - pp, label.ascii() );
#endif
  return;
    }

    rr = new Q3DnsRR( label );
    rr->priority = (answer[pp] << 8) + answer[pp+1];
    rr->weight = (answer[pp+2] << 8) + answer[pp+3];
    rr->port = (answer[pp+4] << 8) + answer[pp+5];
    pp += 6;
    rr->target = readString().lower();
    if ( !ok ) {
#if defined(Q3DNS_DEBUG)
  qDebug( "Q3Dns: saw bad string in SRV for %s", label.ascii() );
#endif
  return;
    }
    rr->t = Q3Dns::Srv;
#if defined(Q3DNS_DEBUG)
    qDebug( "Q3Dns: saw %s IN SRV %d %d %d %s (ttl %d)", label.ascii(),
      rr->priority, rr->weight, rr->port, rr->target.ascii(), ttl );
#endif
}

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void Q3DnsAnswer::parseCname

(

)

[private]

Definition at line 481 of file q3dns.cpp.

References Q3Dns::Cname, label, ok, qDebug(), readString(), rr, Q3DnsRR::t, Q3DnsRR::target, and ttl.

Referenced by parse().

{
    QString target = readString().lower();
    if ( !ok ) {
#if defined(Q3DNS_DEBUG)
  qDebug( "Q3Dns: saw bad cname for for %s", label.ascii() );
#endif
  return;
    }

    rr = new Q3DnsRR( label );
    rr->t = Q3Dns::Cname;
    rr->target = target;
#if defined(Q3DNS_DEBUG)
    qDebug( "Q3Dns: saw %s IN CNAME %s (ttl %d)", label.ascii(),
      rr->target.ascii(), ttl );
#endif
}

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void Q3DnsAnswer::parsePtr

(

)

[private]

Definition at line 520 of file q3dns.cpp.

References label, ok, Q3Dns::Ptr, qDebug(), readString(), rr, Q3DnsRR::t, Q3DnsRR::target, and ttl.

Referenced by parse().

{
    QString target = readString().lower();
    if ( !ok ) {
#if defined(Q3DNS_DEBUG)
  qDebug( "Q3Dns: saw bad PTR for for %s", label.ascii() );
#endif
  return;
    }

    rr = new Q3DnsRR( label );
    rr->t = Q3Dns::Ptr;
    rr->target = target;
#if defined(Q3DNS_DEBUG)
    qDebug( "Q3Dns: saw %s IN PTR %s (ttl %d)", label.ascii(),
      rr->target.ascii(), ttl );
#endif
}

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void Q3DnsAnswer::parseTxt

(

)

[private]

Definition at line 540 of file q3dns.cpp.

References label, ok, qDebug(), readString(), rr, Q3DnsRR::t, Q3DnsRR::text, ttl, and Q3Dns::Txt.

Referenced by parse().

{
    QString text = readString(false);
    if ( !ok ) {
#if defined(Q3DNS_DEBUG)
  qDebug( "Q3Dns: saw bad TXT for for %s", label.ascii() );
#endif
  return;
    }

    rr = new Q3DnsRR( label );
    rr->t = Q3Dns::Txt;
    rr->text = text;
#if defined(Q3DNS_DEBUG)
    qDebug( "Q3Dns: saw %s IN TXT \"%s\" (ttl %d)", label.ascii(),
      rr->text.ascii(), ttl );
#endif
}

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void Q3DnsAnswer::parseNs

(

)

[private]

Definition at line 501 of file q3dns.cpp.

References label, ok, qDebug(), readString(), and ttl.

Referenced by parse().

{
    QString target = readString().lower();
    if ( !ok ) {
#if defined(Q3DNS_DEBUG)
  qDebug( "Q3Dns: saw bad cname for for %s", label.ascii() );
#endif
  return;
    }

    // parse, but ignore

#if defined(Q3DNS_DEBUG)
    qDebug( "Q3Dns: saw %s IN NS %s (ttl %d)", label.ascii(),
      target.ascii(), ttl );
#endif
}

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Member Data Documentation

bool Q3DnsAnswer::ok

Definition at line 217 of file q3dns.cpp.

Referenced by notify(), parse(), parseCname(), parseMx(), parseNs(), parsePtr(), parseSrv(), parseTxt(), Q3DnsAnswer(), readString(), and ~Q3DnsAnswer().

Q3DnsQuery* Q3DnsAnswer::query [private]

Definition at line 220 of file q3dns.cpp.

Referenced by notify(), parse(), and Q3DnsAnswer().

Q_UINT8* Q3DnsAnswer::answer [private]

Definition at line 222 of file q3dns.cpp.

Referenced by parse(), parseA(), parseAaaa(), parseMx(), parseSrv(), Q3DnsAnswer(), and readString().

int Q3DnsAnswer::size [private]

Definition at line 223 of file q3dns.cpp.

Referenced by parse(), Q3DnsAnswer(), and readString().

int Q3DnsAnswer::pp [private]

Definition at line 224 of file q3dns.cpp.

Referenced by parse(), parseA(), parseAaaa(), parseMx(), parseSrv(), Q3DnsAnswer(), and readString().

Q3PtrList<Q3DnsRR>* Q3DnsAnswer::rrs [private]

Definition at line 226 of file q3dns.cpp.

Referenced by notify(), parse(), Q3DnsAnswer(), and ~Q3DnsAnswer().

int Q3DnsAnswer::next [private]

Definition at line 229 of file q3dns.cpp.

Referenced by parse(), parseA(), parseAaaa(), parseMx(), parseSrv(), and Q3DnsAnswer().

int Q3DnsAnswer::ttl [private]

Definition at line 230 of file q3dns.cpp.

Referenced by parse(), parseA(), parseAaaa(), parseCname(), parseMx(), parseNs(), parsePtr(), parseSrv(), parseTxt(), and Q3DnsAnswer().

QString Q3DnsAnswer::label [private]

Definition at line 231 of file q3dns.cpp.

Referenced by parse(), parseA(), parseAaaa(), parseCname(), parseMx(), parseNs(), parsePtr(), parseSrv(), parseTxt(), and Q3DnsAnswer().

Q3DnsRR* Q3DnsAnswer::rr [private]

Definition at line 232 of file q3dns.cpp.

Referenced by parse(), parseA(), parseAaaa(), parseCname(), parseMx(), parsePtr(), parseSrv(), parseTxt(), and Q3DnsAnswer().

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

• src/qt3support/network/q3dns.cpp

---