/**************************************************************************** ** ** Implementation of QDns class. ** ** Created : 991122 ** ** Copyright (C) 1999-2008 Trolltech ASA. All rights reserved. ** ** This file is part of the network module of the Qt GUI Toolkit. ** ** This file may be used under the terms of the GNU General ** Public License versions 2.0 or 3.0 as published by the Free ** Software Foundation and appearing in the files LICENSE.GPL2 ** and LICENSE.GPL3 included in the packaging of this file. ** Alternatively you may (at your option) use any later version ** of the GNU General Public License if such license has been ** publicly approved by Trolltech ASA (or its successors, if any) ** and the KDE Free Qt Foundation. ** ** Please review the following information to ensure GNU General ** Public Licensing requirements will be met: ** http://trolltech.com/products/qt/licenses/licensing/opensource/. ** If you are unsure which license is appropriate for your use, please ** review the following information: ** http://trolltech.com/products/qt/licenses/licensing/licensingoverview ** or contact the sales department at sales@trolltech.com. ** ** This file may be used under the terms of the Q Public License as ** defined by Trolltech ASA and appearing in the file LICENSE.QPL ** included in the packaging of this file. Licensees holding valid Qt ** Commercial licenses may use this file in accordance with the Qt ** Commercial License Agreement provided with the Software. ** ** This file is provided "AS IS" with NO WARRANTY OF ANY KIND, ** INCLUDING THE WARRANTIES OF DESIGN, MERCHANTABILITY AND FITNESS FOR ** A PARTICULAR PURPOSE. Trolltech reserves all rights not granted ** herein. ** **********************************************************************/ #include "qplatformdefs.h" // POSIX Large File Support redefines open -> open64 #if defined(open) # undef open #endif // POSIX Large File Support redefines truncate -> truncate64 #if defined(truncate) # undef truncate #endif // Solaris redefines connect -> __xnet_connect with _XOPEN_SOURCE_EXTENDED. #if defined(connect) # undef connect #endif // UnixWare 7 redefines socket -> _socket #if defined(socket) # undef socket #endif #include "qdns.h" #ifndef QT_NO_DNS #include "qdatetime.h" #include "qdict.h" #include "qptrlist.h" #include "qstring.h" #include "qtimer.h" #include "qapplication.h" #include "qptrvector.h" #include "qstrlist.h" #include "qptrdict.h" #include "qfile.h" #include "qtextstream.h" #include "qsocketdevice.h" #include "qcleanuphandler.h" #include #ifdef Q_OS_MAC #include "../3rdparty/dlcompat/dlfcn.h" #endif //#define QDNS_DEBUG static Q_UINT16 id; // ### seeded started by now() static QDateTime * originOfTime = 0; static QCleanupHandler qdns_cleanup_time; static Q_UINT32 now() { if ( originOfTime ) return originOfTime->secsTo( QDateTime::currentDateTime() ); originOfTime = new QDateTime( QDateTime::currentDateTime() ); ::id = originOfTime->time().msec() * 60 + originOfTime->time().second(); qdns_cleanup_time.add( &originOfTime ); return 0; } static QPtrList * ns = 0; static QStrList * domains = 0; static bool ipv6support = FALSE; static int qdns_res_init() { #ifdef Q_OS_MAC typedef int (*PtrRes_init)(); static PtrRes_init ptrRes_init = 0; if (!ptrRes_init) ptrRes_init = (PtrRes_init)DL_PREFIX(dlsym)(RTLD_NEXT, "res_init"); if (ptrRes_init) return (*ptrRes_init)(); else return -1; #elif defined(Q_OS_UNIX) return res_init(); #else return 0; // not called at all on Windows. #endif } class QDnsPrivate { public: QDnsPrivate() : queryTimer( 0 ), noNames(FALSE) { #if defined(Q_DNS_SYNCHRONOUS) #if defined(Q_OS_UNIX) noEventLoop = qApp==0 || qApp->loopLevel()==0; #else noEventLoop = FALSE; #endif #endif } ~QDnsPrivate() { delete queryTimer; } private: QTimer * queryTimer; bool noNames; #if defined(Q_DNS_SYNCHRONOUS) bool noEventLoop; #endif friend class QDns; friend class QDnsAnswer; }; class QDnsRR; class QDnsDomain; // QDnsRR is the class used to store a single RR. QDnsRR can store // all of the supported RR types. a QDnsRR is always cached. // QDnsRR is mostly constructed from the outside. a but hacky, but // permissible since the entire class is internal. class QDnsRR { public: QDnsRR( const QString & label ); ~QDnsRR(); public: QDnsDomain * domain; QDns::RecordType t; bool nxdomain; bool current; Q_UINT32 expireTime; Q_UINT32 deleteTime; // somewhat space-wasting per-type data // a / aaaa QHostAddress address; // cname / mx / srv / ptr QString target; // mx / srv Q_UINT16 priority; // srv Q_UINT16 weight; Q_UINT16 port; // txt QString text; // could be overloaded into target... private: }; class QDnsDomain { public: QDnsDomain( const QString & label ); ~QDnsDomain(); static void add( const QString & label, QDnsRR * ); static QPtrList * cached( const QDns * ); void take( QDnsRR * ); void sweep( Q_UINT32 thisSweep ); bool isEmpty() const { return rrs == 0 || rrs->isEmpty(); } QString name() const { return l; } public: QString l; QPtrList * rrs; }; class QDnsQuery: public QTimer { // this inheritance is a very evil hack public: QDnsQuery(): id( 0 ), t( QDns::None ), step(0), started(0), dns( new QPtrDict(17) ) {} ~QDnsQuery() { delete dns; } Q_UINT16 id; QDns::RecordType t; QString l; uint step; Q_UINT32 started; QPtrDict * dns; }; class QDnsAnswer { public: QDnsAnswer( QDnsQuery * ); QDnsAnswer( const QByteArray &, QDnsQuery * ); ~QDnsAnswer(); void parse(); void notify(); bool ok; private: QDnsQuery * query; Q_UINT8 * answer; int size; int pp; QPtrList * rrs; // convenience int next; int ttl; QString label; QDnsRR * rr; QString readString(bool multipleLabels = TRUE); void parseA(); void parseAaaa(); void parseMx(); void parseSrv(); void parseCname(); void parsePtr(); void parseTxt(); void parseNs(); }; QDnsRR::QDnsRR( const QString & label ) : domain( 0 ), t( QDns::None ), nxdomain( FALSE ), current( FALSE ), expireTime( 0 ), deleteTime( 0 ), priority( 0 ), weight( 0 ), port( 0 ) { QDnsDomain::add( label, this ); } // not supposed to be deleted except by QDnsDomain QDnsRR::~QDnsRR() { // nothing is necessary } // this one just sticks in a NXDomain QDnsAnswer::QDnsAnswer( QDnsQuery * query_ ) { ok = TRUE; answer = 0; size = 0; query = query_; pp = 0; rrs = new QPtrList; rrs->setAutoDelete( FALSE ); next = size; ttl = 0; label = QString::null; rr = 0; QDnsRR * newrr = new QDnsRR( 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 ); } QDnsAnswer::QDnsAnswer( const QByteArray& answer_, QDnsQuery * query_ ) { ok = TRUE; answer = (Q_UINT8 *)(answer_.data()); size = (int)answer_.size(); query = query_; pp = 0; rrs = new QPtrList; rrs->setAutoDelete( FALSE ); next = size; ttl = 0; label = QString::null; rr = 0; } QDnsAnswer::~QDnsAnswer() { if ( !ok && rrs ) { QPtrListIterator it( *rrs ); QDnsRR * tmprr; while( (tmprr=it.current()) != 0 ) { ++it; tmprr->t = QDns::None; // will be deleted soonish } } delete rrs; } QString QDnsAnswer::readString(bool multipleLabels) { int p = pp; QString r = QString::null; 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] ); 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::null; } void QDnsAnswer::parseA() { if ( next != pp + 4 ) { #if defined(QDNS_DEBUG) qDebug( "QDns: saw %d bytes long IN A for %s", next - pp, label.ascii() ); #endif return; } rr = new QDnsRR( label ); rr->t = QDns::A; rr->address = QHostAddress( ( answer[pp+0] << 24 ) + ( answer[pp+1] << 16 ) + ( answer[pp+2] << 8 ) + ( answer[pp+3] ) ); #if defined(QDNS_DEBUG) qDebug( "QDns: saw %s IN A %s (ttl %d)", label.ascii(), rr->address.toString().ascii(), ttl ); #endif } void QDnsAnswer::parseAaaa() { if ( next != pp + 16 ) { #if defined(QDNS_DEBUG) qDebug( "QDns: saw %d bytes long IN Aaaa for %s", next - pp, label.ascii() ); #endif return; } rr = new QDnsRR( label ); rr->t = QDns::Aaaa; rr->address = QHostAddress( answer+pp ); #if defined(QDNS_DEBUG) qDebug( "QDns: saw %s IN Aaaa %s (ttl %d)", label.ascii(), rr->address.toString().ascii(), ttl ); #endif } void QDnsAnswer::parseMx() { if ( next < pp + 2 ) { #if defined(QDNS_DEBUG) qDebug( "QDns: saw %d bytes long IN MX for %s", next - pp, label.ascii() ); #endif return; } rr = new QDnsRR( label ); rr->priority = (answer[pp] << 8) + answer[pp+1]; pp += 2; rr->target = readString().lower(); if ( !ok ) { #if defined(QDNS_DEBUG) qDebug( "QDns: saw bad string in MX for %s", label.ascii() ); #endif return; } rr->t = QDns::Mx; #if defined(QDNS_DEBUG) qDebug( "QDns: saw %s IN MX %d %s (ttl %d)", label.ascii(), rr->priority, rr->target.ascii(), ttl ); #endif } void QDnsAnswer::parseSrv() { if ( next < pp + 6 ) { #if defined(QDNS_DEBUG) qDebug( "QDns: saw %d bytes long IN SRV for %s", next - pp, label.ascii() ); #endif return; } rr = new QDnsRR( 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(QDNS_DEBUG) qDebug( "QDns: saw bad string in SRV for %s", label.ascii() ); #endif return; } rr->t = QDns::Srv; #if defined(QDNS_DEBUG) qDebug( "QDns: saw %s IN SRV %d %d %d %s (ttl %d)", label.ascii(), rr->priority, rr->weight, rr->port, rr->target.ascii(), ttl ); #endif } void QDnsAnswer::parseCname() { QString target = readString().lower(); if ( !ok ) { #if defined(QDNS_DEBUG) qDebug( "QDns: saw bad cname for for %s", label.ascii() ); #endif return; } rr = new QDnsRR( label ); rr->t = QDns::Cname; rr->target = target; #if defined(QDNS_DEBUG) qDebug( "QDns: saw %s IN CNAME %s (ttl %d)", label.ascii(), rr->target.ascii(), ttl ); #endif } void QDnsAnswer::parseNs() { QString target = readString().lower(); if ( !ok ) { #if defined(QDNS_DEBUG) qDebug( "QDns: saw bad cname for for %s", label.ascii() ); #endif return; } // parse, but ignore #if defined(QDNS_DEBUG) qDebug( "QDns: saw %s IN NS %s (ttl %d)", label.ascii(), target.ascii(), ttl ); #endif } void QDnsAnswer::parsePtr() { QString target = readString().lower(); if ( !ok ) { #if defined(QDNS_DEBUG) qDebug( "QDns: saw bad PTR for for %s", label.ascii() ); #endif return; } rr = new QDnsRR( label ); rr->t = QDns::Ptr; rr->target = target; #if defined(QDNS_DEBUG) qDebug( "QDns: saw %s IN PTR %s (ttl %d)", label.ascii(), rr->target.ascii(), ttl ); #endif } void QDnsAnswer::parseTxt() { QString text = readString(FALSE); if ( !ok ) { #if defined(QDNS_DEBUG) qDebug( "QDns: saw bad TXT for for %s", label.ascii() ); #endif return; } rr = new QDnsRR( label ); rr->t = QDns::Txt; rr->text = text; #if defined(QDNS_DEBUG) qDebug( "QDns: saw %s IN TXT \"%s\" (ttl %d)", label.ascii(), rr->text.ascii(), ttl ); #endif } void QDnsAnswer::parse() { // okay, do the work... if ( (answer[2] & 0x78) != 0 ) { #if defined(QDNS_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(QDNS_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(QDNS_DEBUG) qDebug( "DNS Manager: saw NXDomain for %s", query->l.ascii() ); #endif // NXDomain. cache that for one minute. rr = new QDnsRR( 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(QDNS_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(QDNS_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(QDNS_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(QDNS_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(QDNS_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(); QDict 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 == QDns::A || rr->t == QDns::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 ) { QPtrList * drrs = rr->domain->rrs; drrs->first(); QDnsRR * 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(QDNS_DEBUG) qDebug( "killing off old %d for %s, expire was %d", older->t, older->domain->name().latin1(), rr->expireTime ); #endif older->t = QDns::None; rr->expireTime = QMAX( older->expireTime, rr->expireTime ); rr->deleteTime = QMAX( older->deleteTime, rr->deleteTime ); older->deleteTime = 0; #if defined(QDNS_DEBUG) qDebug( " adjusted expire is %d", rr->expireTime ); #endif } drrs->next(); } } } #if defined(QDNS_DEBUG) //qDebug( "DNS Manager: ()" ); #endif } class QDnsUgleHack: public QDns { public: void ugle( bool emitAnyway=FALSE ); }; void QDnsAnswer::notify() { if ( !rrs || !ok || !query || !query->dns ) return; QPtrDict notified; notified.setAutoDelete( FALSE ); QPtrDictIterator it( *query->dns ); QDns * dns; it.toFirst(); while( (dns=(QDns*)(it.current())) != 0 ) { ++it; if ( notified.find( (void*)dns ) == 0 ) { notified.insert( (void*)dns, (void*)42 ); if ( rrs->count() == 0 ) { #if defined(QDNS_DEBUG) qDebug( "DNS Manager: found no answers!" ); #endif dns->d->noNames = TRUE; ((QDnsUgleHack*)dns)->ugle( TRUE ); } else { QStringList n = dns->qualifiedNames(); if ( query && n.contains(query->l) ) ((QDnsUgleHack*)dns)->ugle(); #if defined(QDNS_DEBUG) else qDebug( "DNS Manager: DNS thing %s not notified for %s", dns->label().ascii(), query->l.ascii() ); #endif } } } } // // // QDnsManager // // class QDnsManager: public QDnsSocket { private: public: // just to silence the moronic g++. QDnsManager(); ~QDnsManager(); public: static QDnsManager * manager(); QDnsDomain * domain( const QString & ); void transmitQuery( QDnsQuery * ); void transmitQuery( int ); // reimplementation of the slots void cleanCache(); void retransmit(); void answer(); public: QPtrVector queries; QDict cache; QSocketDevice * ipv4Socket; #if !defined (QT_NO_IPV6) QSocketDevice * ipv6Socket; #endif }; static QDnsManager * globalManager = 0; static void cleanupDns() { delete globalManager; globalManager = 0; } QDnsManager * QDnsManager::manager() { if ( !globalManager ) { qAddPostRoutine(cleanupDns); new QDnsManager(); } return globalManager; } void QDnsUgleHack::ugle( bool emitAnyway) { if ( emitAnyway || !isWorking() ) { #if defined(QDNS_DEBUG) qDebug( "DNS Manager: status change for %s (type %d)", label().ascii(), recordType() ); #endif emit resultsReady(); } } QDnsManager::QDnsManager() : QDnsSocket( qApp, "Internal DNS manager" ), queries( QPtrVector( 0 ) ), cache( QDict( 83, FALSE ) ), ipv4Socket( new QSocketDevice( QSocketDevice::Datagram, QSocketDevice::IPv4, 0 ) ) #if !defined (QT_NO_IPV6) , ipv6Socket( new QSocketDevice( QSocketDevice::Datagram, QSocketDevice::IPv6, 0 ) ) #endif { cache.setAutoDelete( TRUE ); globalManager = this; QTimer * sweepTimer = new QTimer( this ); sweepTimer->start( 1000 * 60 * 3 ); connect( sweepTimer, SIGNAL(timeout()), this, SLOT(cleanCache()) ); QSocketNotifier * rn4 = new QSocketNotifier( ipv4Socket->socket(), QSocketNotifier::Read, this, "dns IPv4 socket watcher" ); ipv4Socket->setAddressReusable( FALSE ); ipv4Socket->setBlocking( FALSE ); connect( rn4, SIGNAL(activated(int)), SLOT(answer()) ); #if !defined (QT_NO_IPV6) // Don't connect the IPv6 socket notifier if the host does not // support IPv6. if ( ipv6Socket->socket() != -1 ) { QSocketNotifier * rn6 = new QSocketNotifier( ipv6Socket->socket(), QSocketNotifier::Read, this, "dns IPv6 socket watcher" ); ipv6support = TRUE; ipv6Socket->setAddressReusable( FALSE ); ipv6Socket->setBlocking( FALSE ); connect( rn6, SIGNAL(activated(int)), SLOT(answer()) ); } #endif if ( !ns ) QDns::doResInit(); // O(n*n) stuff here. but for 3 and 6, O(n*n) with a low k should // be perfect. the point is to eliminate any duplicates that // might be hidden in the lists. QPtrList * ns = new QPtrList; ::ns->first(); QHostAddress * h; while( (h=::ns->current()) != 0 ) { ns->first(); while( ns->current() != 0 && !(*ns->current() == *h) ) ns->next(); if ( !ns->current() ) { ns->append( new QHostAddress(*h) ); #if defined(QDNS_DEBUG) qDebug( "using name server %s", h->toString().latin1() ); } else { qDebug( "skipping address %s", h->toString().latin1() ); #endif } ::ns->next(); } delete ::ns; ::ns = ns; ::ns->setAutoDelete( TRUE ); QStrList * domains = new QStrList( TRUE ); ::domains->first(); const char * s; while( (s=::domains->current()) != 0 ) { domains->first(); while( domains->current() != 0 && qstrcmp( domains->current(), s ) ) domains->next(); if ( !domains->current() ) { domains->append( s ); #if defined(QDNS_DEBUG) qDebug( "searching domain %s", s ); } else { qDebug( "skipping domain %s", s ); #endif } ::domains->next(); } delete ::domains; ::domains = domains; ::domains->setAutoDelete( TRUE ); } QDnsManager::~QDnsManager() { if ( globalManager ) globalManager = 0; queries.setAutoDelete( TRUE ); cache.setAutoDelete( TRUE ); delete ipv4Socket; #if !defined (QT_NO_IPV6) delete ipv6Socket; #endif } static Q_UINT32 lastSweep = 0; void QDnsManager::cleanCache() { bool again = FALSE; QDictIterator it( cache ); QDnsDomain * d; Q_UINT32 thisSweep = now(); #if defined(QDNS_DEBUG) qDebug( "QDnsManager::cleanCache(: Called, time is %u, last was %u", thisSweep, lastSweep ); #endif while( (d=it.current()) != 0 ) { ++it; d->sweep( thisSweep ); // after this, d may be empty if ( !again ) again = !d->isEmpty(); } if ( !again ) delete this; lastSweep = thisSweep; } void QDnsManager::retransmit() { const QObject * o = sender(); if ( o == 0 || globalManager == 0 || this != globalManager ) return; uint q = 0; while( q < queries.size() && queries[q] != o ) q++; if ( q < queries.size() ) transmitQuery( q ); } void QDnsManager::answer() { QByteArray a( 16383 ); // large enough for anything, one suspects int r; #if defined (QT_NO_IPV6) r = ipv4Socket->readBlock(a.data(), a.size()); #else if (((QSocketNotifier *)sender())->socket() == ipv4Socket->socket()) r = ipv4Socket->readBlock(a.data(), a.size()); else r = ipv6Socket->readBlock(a.data(), a.size()); #endif #if defined(QDNS_DEBUG) #if !defined (QT_NO_IPV6) qDebug("DNS Manager: answer arrived: %d bytes from %s:%d", r, useIpv4Socket ? ipv4Socket->peerAddress().toString().ascii() : ipv6Socket->peerAddress().toString().ascii(), useIpv4Socket ? ipv4Socket->peerPort() : ipv6Socket->peerPort() ); #else qDebug("DNS Manager: answer arrived: %d bytes from %s:%d", r, ipv4Socket->peerAddress().toString().ascii(), ipv4Socket->peerPort());; #endif #endif if ( r < 12 ) return; // maybe we should check that the answer comes from port 53 on one // of our name servers... a.resize( r ); Q_UINT16 aid = (((Q_UINT8)a[0]) << 8) + ((Q_UINT8)a[1]); uint i = 0; while( i < queries.size() && !( queries[i] && queries[i]->id == aid ) ) i++; if ( i == queries.size() ) { #if defined(QDNS_DEBUG) qDebug( "DNS Manager: bad id (0x%04x) %d", aid, i ); #endif return; } // at this point queries[i] is whatever we asked for. if ( ( (Q_UINT8)(a[2]) & 0x80 ) == 0 ) { #if defined(QDNS_DEBUG) qDebug( "DNS Manager: received a query" ); #endif return; } QDnsQuery * q = queries[i]; QDnsAnswer answer( a, q ); answer.parse(); if ( answer.ok ) { queries.take( i ); answer.notify(); delete q; } } void QDnsManager::transmitQuery( QDnsQuery * query_ ) { if ( !query_ ) return; uint i = 0; while( i < queries.size() && queries[i] != 0 ) i++; if ( i == queries.size() ) queries.resize( i+1 ); queries.insert( i, query_ ); transmitQuery( i ); } void QDnsManager::transmitQuery( int i ) { if ( i < 0 || i >= (int)queries.size() ) return; QDnsQuery * q = queries[i]; if ( q && q->step > 8 ) { // okay, we've run out of retransmissions. we fake an NXDomain // with a very short life time... QDnsAnswer answer( q ); answer.notify(); if (globalManager == 0) return; // and then get rid of the query queries.take( i ); #if defined(QDNS_DEBUG) qDebug( "DNS Manager: giving up on query 0x%04x", q->id ); #endif delete q; QTimer::singleShot( 0, QDnsManager::manager(), SLOT(cleanCache()) ); // and don't process anything more return; } if ( q && !q->dns || q->dns->isEmpty() ) // noone currently wants the answer, so there's no point in // retransmitting the query. we keep it, though. an answer may // arrive for an earlier query transmission, and if it does we // may benefit from caching the result. return; QByteArray p( 12 + q->l.length() + 2 + 4 ); if ( p.size() > 500 ) return; // way over the limit, so don't even try // header // id p[0] = (q->id & 0xff00) >> 8; p[1] = q->id & 0x00ff; p[2] = 1; // recursion desired, rest is 0 p[3] = 0; // all is 0 // one query p[4] = 0; p[5] = 1; // no answers, name servers or additional data p[6] = p[7] = p[8] = p[9] = p[10] = p[11] = 0; // the name is composed of several components. each needs to be // written by itself... so we write... // oh, and we assume that there's no funky characters in there. int pp = 12; uint lp = 0; while( lp < q->l.length() ) { int le = q->l.find( '.', lp ); if ( le < 0 ) le = q->l.length(); QString component = q->l.mid( lp, le-lp ); p[pp++] = component.length(); int cp; for( cp=0; cp < (int)component.length(); cp++ ) p[pp++] = component[cp].latin1(); lp = le + 1; } // final null p[pp++] = 0; // query type p[pp++] = 0; switch( q->t ) { case QDns::A: p[pp++] = 1; break; case QDns::Aaaa: p[pp++] = 28; break; case QDns::Mx: p[pp++] = 15; break; case QDns::Srv: p[pp++] = 33; break; case QDns::Cname: p[pp++] = 5; break; case QDns::Ptr: p[pp++] = 12; break; case QDns::Txt: p[pp++] = 16; break; default: p[pp++] = (char)255; // any break; } // query class (always internet) p[pp++] = 0; p[pp++] = 1; // if we have no name servers, we should regenerate ns in case // name servers have recently been defined (like on windows, // plugging/unplugging the network cable will change the name // server entries) if ( !ns || ns->isEmpty() ) QDns::doResInit(); if ( !ns || ns->isEmpty() ) { // we don't find any name servers. We fake an NXDomain // with a very short life time... QDnsAnswer answer( q ); answer.notify(); // and then get rid of the query queries.take( i ); #if defined(QDNS_DEBUG) qDebug( "DNS Manager: no DNS server found on query 0x%04x", q->id ); #endif delete q; QTimer::singleShot( 1000*10, QDnsManager::manager(), SLOT(cleanCache()) ); // and don't process anything more return; } QHostAddress receiver = *ns->at( q->step % ns->count() ); if (receiver.isIPv4Address()) ipv4Socket->writeBlock( p.data(), pp, receiver, 53 ); #if !defined (QT_NO_IPV6) else ipv6Socket->writeBlock( p.data(), pp, receiver, 53 ); #endif #if defined(QDNS_DEBUG) qDebug( "issuing query 0x%04x (%d) about %s type %d to %s", q->id, q->step, q->l.ascii(), q->t, ns->at( q->step % ns->count() )->toString().ascii() ); #endif if ( ns->count() > 1 && q->step == 0 && queries.count() == 1 ) { // if it's the first time, and we don't have any other // outstanding queries, send nonrecursive queries to the other // name servers too. p[2] = 0; QHostAddress * server; while( (server=ns->next()) != 0 ) { if (server->isIPv4Address()) ipv4Socket->writeBlock( p.data(), pp, *server, 53 ); #if !defined (QT_NO_IPV6) else ipv6Socket->writeBlock( p.data(), pp, *server, 53 ); #endif #if defined(QDNS_DEBUG) qDebug( "copying query to %s", server->toString().ascii() ); #endif } } q->step++; // some testing indicates that normal dns queries take up to 0.6 // seconds. the graph becomes steep around that point, and the // number of errors rises... so it seems good to retry at that // point. q->start( q->step < ns->count() ? 800 : 1500, TRUE ); } QDnsDomain * QDnsManager::domain( const QString & label ) { QDnsDomain * d = cache.find( label ); if ( !d ) { d = new QDnsDomain( label ); cache.insert( label, d ); } return d; } // // // the QDnsDomain class looks after and coordinates queries for QDnsRRs for // each domain, and the cached QDnsRRs. (A domain, in DNS terminology, is // a node in the DNS. "no", "trolltech.com" and "lupinella.troll.no" are // all domains.) // // // this is ONLY to be called by QDnsManager::domain(). noone else. QDnsDomain::QDnsDomain( const QString & label ) { l = label; rrs = 0; } QDnsDomain::~QDnsDomain() { delete rrs; rrs = 0; } void QDnsDomain::add( const QString & label, QDnsRR * rr ) { QDnsDomain * d = QDnsManager::manager()->domain( label ); if ( !d->rrs ) { d->rrs = new QPtrList; d->rrs->setAutoDelete( TRUE ); } d->rrs->append( rr ); rr->domain = d; } QPtrList * QDnsDomain::cached( const QDns * r ) { QPtrList * l = new QPtrList; // test at first if you have to start a query at all if ( r->recordType() == QDns::A ) { if ( r->label().lower() == "localhost" ) { // undocumented hack. ipv4-specific. also, may be a memory // leak? not sure. would be better to do this in doResInit(), // anyway. QDnsRR *rrTmp = new QDnsRR( r->label() ); rrTmp->t = QDns::A; rrTmp->address = QHostAddress( 0x7f000001 ); rrTmp->current = TRUE; l->append( rrTmp ); return l; } QHostAddress tmp; if ( tmp.setAddress( r->label() ) ) { QDnsRR *rrTmp = new QDnsRR( r->label() ); if ( tmp.isIPv4Address() ) { rrTmp->t = QDns::A; rrTmp->address = tmp; rrTmp->current = TRUE; l->append( rrTmp ); } else { rrTmp->nxdomain = TRUE; } return l; } } if ( r->recordType() == QDns::Aaaa ) { QHostAddress tmp; if ( tmp.setAddress(r->label()) ) { QDnsRR *rrTmp = new QDnsRR( r->label() ); if ( tmp.isIPv6Address() ) { rrTmp->t = QDns::Aaaa; rrTmp->address = tmp; rrTmp->current = TRUE; l->append( rrTmp ); } else { rrTmp->nxdomain = TRUE; } return l; } } // if you reach this point, you have to do the query QDnsManager * m = QDnsManager::manager(); QStringList n = r->qualifiedNames(); QValueListIterator it = n.begin(); QValueListIterator end = n.end(); bool nxdomain; int cnamecount = 0; while( it != end ) { QString s = *it++; nxdomain = FALSE; #if defined(QDNS_DEBUG) qDebug( "looking at cache for %s (%s %d)", s.ascii(), r->label().ascii(), r->recordType() ); #endif QDnsDomain * d = m->domain( s ); #if defined(QDNS_DEBUG) qDebug( " - found %d RRs", d && d->rrs ? d->rrs->count() : 0 ); #endif if ( d->rrs ) d->rrs->first(); QDnsRR * rr; bool answer = FALSE; while( d->rrs && (rr=d->rrs->current()) != 0 ) { if ( rr->t == QDns::Cname && r->recordType() != QDns::Cname && !rr->nxdomain && cnamecount < 16 ) { // cname. if the code is ugly, that may just // possibly be because the concept is. #if defined(QDNS_DEBUG) qDebug( "found cname from %s to %s", r->label().ascii(), rr->target.ascii() ); #endif s = rr->target; d = m->domain( s ); if ( d->rrs ) d->rrs->first(); it = end; // we've elegantly moved over to whatever the cname // pointed to. well, not elegantly. let's remember // that we've done something, anyway, so we can't be // fooled into an infinte loop as well. cnamecount++; } else { if ( rr->t == r->recordType() ) { if ( rr->nxdomain ) nxdomain = TRUE; else answer = TRUE; l->append( rr ); if ( rr->deleteTime <= lastSweep ) { // we're returning something that'll be // deleted soon. we assume that if the client // wanted it twice, it'll want it again, so we // ask the name server again right now. QDnsQuery * query = new QDnsQuery; query->started = now(); query->id = ++::id; query->t = rr->t; query->l = rr->domain->name(); // note that here, we don't bother about // notification. but we do bother about // timeouts: we make sure to use high timeouts // and few tramsissions. query->step = ns->count(); QObject::connect( query, SIGNAL(timeout()), QDnsManager::manager(), SLOT(retransmit()) ); QDnsManager::manager()->transmitQuery( query ); } } d->rrs->next(); } } // if we found a positive result, return quickly if ( answer && l->count() ) { #if defined(QDNS_DEBUG) qDebug( "found %d records for %s", l->count(), r->label().ascii() ); l->first(); while( l->current() ) { qDebug( " type %d target %s address %s", l->current()->t, l->current()->target.latin1(), l->current()->address.toString().latin1() ); l->next(); } #endif l->first(); return l; } #if defined(QDNS_DEBUG) if ( nxdomain ) qDebug( "found NXDomain %s", s.ascii() ); #endif if ( !nxdomain ) { // if we didn't, and not a negative result either, perhaps // we need to transmit a query. uint q = 0; while ( q < m->queries.size() && ( m->queries[q] == 0 || m->queries[q]->t != r->recordType() || m->queries[q]->l != s ) ) q++; // we haven't done it before, so maybe we should. but // wait - if it's an unqualified name, only ask when all // the other alternatives are exhausted. if ( q == m->queries.size() && ( s.find( '.' ) >= 0 || l->count() >= n.count()-1 ) ) { QDnsQuery * query = new QDnsQuery; query->started = now(); query->id = ++::id; query->t = r->recordType(); query->l = s; query->dns->replace( (void*)r, (void*)r ); QObject::connect( query, SIGNAL(timeout()), QDnsManager::manager(), SLOT(retransmit()) ); QDnsManager::manager()->transmitQuery( query ); } else if ( q < m->queries.size() ) { // if we've found an earlier query for the same // domain/type, subscribe to its answer m->queries[q]->dns->replace( (void*)r, (void*)r ); } } } l->first(); return l; } void QDnsDomain::sweep( Q_UINT32 thisSweep ) { if ( !rrs ) return; QDnsRR * rr; rrs->first(); while( (rr=rrs->current()) != 0 ) { if ( !rr->deleteTime ) rr->deleteTime = thisSweep; // will hit next time around #if defined(QDNS_DEBUG) qDebug( "QDns::sweep: %s type %d expires %u %u - %s / %s", rr->domain->name().latin1(), rr->t, rr->expireTime, rr->deleteTime, rr->target.latin1(), rr->address.toString().latin1()); #endif if ( rr->current == FALSE || rr->t == QDns::None || rr->deleteTime <= thisSweep || rr->expireTime <= thisSweep ) rrs->remove(); else rrs->next(); } if ( rrs->isEmpty() ) { delete rrs; rrs = 0; } } // the itsy-bitsy little socket class I don't really need except for // so I can subclass and reimplement the slots. QDnsSocket::QDnsSocket( QObject * parent, const char * name ) : QObject( parent, name ) { // nothing } QDnsSocket::~QDnsSocket() { // nothing } void QDnsSocket::cleanCache() { // nothing } void QDnsSocket::retransmit() { // nothing } void QDnsSocket::answer() { // nothing } /*! \class QDns qdns.h \brief The QDns class provides asynchronous DNS lookups. \if defined(commercial) It is part of the Qt Enterprise Edition. \endif \module network \ingroup io 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. QDns 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 \e not straightforward to use (although it is much simpler than the native APIs); QSocket provides much easier to use TCP connection facilities. The aim of QDns 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 QDns 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. \sa QSocket */ /*! Constructs a DNS query object with invalid settings for both the label and the search type. */ QDns::QDns() { d = new QDnsPrivate; t = None; } /*! Constructs a DNS query object that will return record type \a rr information about \a 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. \a rr defaults to \c A, IPv4 addresses. */ QDns::QDns( const QString & label, RecordType rr ) { d = new QDnsPrivate; t = rr; setLabel( label ); setStartQueryTimer(); // start query the next time we enter event loop } /*! Constructs a DNS query object that will return record type \a rr information about host address \a address. The label is set to the IN-ADDR.ARPA domain name. This is useful in combination with the \c 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. \a rr defaults to \c Ptr, that maps addresses to hostnames. */ QDns::QDns( const QHostAddress & address, RecordType rr ) { d = new QDnsPrivate; t = rr; setLabel( address ); setStartQueryTimer(); // start query the next time we enter event loop } /*! Destroys the DNS query object and frees its allocated resources. */ QDns::~QDns() { if ( globalManager ) { uint q = 0; QDnsManager * m = globalManager; while( q < m->queries.size() ) { QDnsQuery * query=m->queries[q]; if ( query && query->dns ) (void)query->dns->take( (void*) this ); q++; } } delete d; d = 0; } /*! Sets this DNS query object to query for information about \a 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. */ void QDns::setLabel( const QString & label ) { 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)QDnsManager::manager(); // create a QDnsManager, if it is not already there QStrListIterator 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(QDNS_DEBUG) qDebug( "QDns::setLabel: %d address(es) for %s", n.count(), l.ascii() ); int i = 0; for( i = 0; i < (int)n.count(); i++ ) qDebug( "QDns::setLabel: %d: %s", i, n[i].ascii() ); #endif } /*! \overload Sets this DNS query object to query for information about the host address \a address. The label is set to the IN-ADDR.ARPA domain name. This is useful in combination with the \c Ptr record type (e.g. if you want to look up a hostname for a given address). */ void QDns::setLabel( const QHostAddress & address ) { setLabel( toInAddrArpaDomain( address ) ); } /*! \fn QStringList QDns::qualifiedNames() const 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. \code QStringList list = myDns.qualifiedNames(); QStringList::Iterator it = list.begin(); while( it != list.end() ) { myProcessing( *it ); ++it; } \endcode */ /*! \fn QString QDns::label() const Returns the domain name for which this object returns information. \sa setLabel() */ /*! \enum QDns::RecordType This enum type defines the record types QDns 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: \value None No information. This exists only so that QDns can have a default. \value A IPv4 addresses. By far the most common type. \value Aaaa IPv6 addresses. So far mostly unused. \value Mx Mail eXchanger names. Used for mail delivery. \value Srv SeRVer names. Generic record type for finding servers. So far mostly unused. \value Cname Canonical names. Maps from nicknames to the true name (the canonical name) for a host. \value Ptr name PoinTeRs. Maps from IPv4 or IPv6 addresses to hostnames. \value Txt arbitrary TeXT for domains. We expect that some support for the \link http://www.dns.net/dnsrd/rfc/rfc2535.html RFC-2535 \endlink extensions will be added in future versions. */ /*! Sets this object to query for record type \a 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. \sa RecordType */ void QDns::setRecordType( RecordType rr ) { t = rr; d->noNames = FALSE; setStartQueryTimer(); // start query the next time we enter event loop } /*! \internal Private slot for starting the query. */ void QDns::startQuery() { // isWorking() starts the query (if necessary) if ( !isWorking() ) emit resultsReady(); } /*! The three functions QDns::QDns(QString, RecordType), QDns::setLabel() and QDns::setRecordType() may start a DNS lookup. This function handles setting up the single shot timer. */ void QDns::setStartQueryTimer() { #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 ); } } /* Transforms the host address \a address to the IN-ADDR.ARPA domain name. Returns something indeterminate if you're sloppy or naughty. This function has an IPv4-specific name, but works for IPv6 too. */ QString QDns::toInAddrArpaDomain( const QHostAddress &address ) { 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; } /*! \fn QDns::RecordType QDns::recordType() const Returns the record type of this DNS query object. \sa setRecordType() RecordType */ /*! \fn void QDns::resultsReady() This signal is emitted when results are available for one of the qualifiedNames(). */ /*! Returns TRUE if QDns is doing a lookup for this object (i.e. if it does not already have the necessary information); otherwise returns FALSE. QDns emits the resultsReady() signal when the status changes to FALSE. */ bool QDns::isWorking() const { #if defined(QDNS_DEBUG) qDebug( "QDns::isWorking (%s, %d)", l.ascii(), t ); #endif if ( t == None ) return FALSE; #if defined(Q_DNS_SYNCHRONOUS) if ( d->noEventLoop ) return TRUE; #endif QPtrList * ll = QDnsDomain::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; } /*! Returns a list of the addresses for this name if this QDns object has a recordType() of \c QDns::A or \c QDns::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. \code QValueList list = myDns.addresses(); QValueList::Iterator it = list.begin(); while( it != list.end() ) { myProcessing( *it ); ++it; } \endcode */ QValueList QDns::addresses() const { #if defined(QDNS_DEBUG) qDebug( "QDns::addresses (%s)", l.ascii() ); #endif QValueList result; if ( t != A && t != Aaaa ) return result; QPtrList * cached = QDnsDomain::cached( this ); QDnsRR * rr; while( (rr=cached->current()) != 0 ) { if ( rr->current && !rr->nxdomain ) result.append( rr->address ); cached->next(); } delete cached; return result; } /*! \class QDns::MailServer \brief The QDns::MailServer class is described in QDns::mailServers(). \if defined(commercial) It is part of the Qt Enterprise Edition. \endif \ingroup io \internal */ /*! Returns a list of mail servers if the record type is \c Mx. The class \c QDns::MailServer contains the following public variables: \list \i QString QDns::MailServer::name \i Q_UINT16 QDns::MailServer::priority \endlist Note that if you want to iterate over the list, you should iterate over a copy, e.g. \code QValueList list = myDns.mailServers(); QValueList::Iterator it = list.begin(); while( it != list.end() ) { myProcessing( *it ); ++it; } \endcode */ QValueList QDns::mailServers() const { #if defined(QDNS_DEBUG) qDebug( "QDns::mailServers (%s)", l.ascii() ); #endif QValueList result; if ( t != Mx ) return result; QPtrList * cached = QDnsDomain::cached( this ); QDnsRR * 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; } /*! \class QDns::Server \brief The QDns::Server class is described in QDns::servers(). \if defined(commercial) It is part of the Qt Enterprise Edition. \endif \ingroup io \internal */ /*! Returns a list of servers if the record type is \c Srv. The class \c QDns::Server contains the following public variables: \list \i QString QDns::Server::name \i Q_UINT16 QDns::Server::priority \i Q_UINT16 QDns::Server::weight \i Q_UINT16 QDns::Server::port \endlist Note that if you want to iterate over the list, you should iterate over a copy, e.g. \code QValueList list = myDns.servers(); QValueList::Iterator it = list.begin(); while( it != list.end() ) { myProcessing( *it ); ++it; } \endcode */ QValueList QDns::servers() const { #if defined(QDNS_DEBUG) qDebug( "QDns::servers (%s)", l.ascii() ); #endif QValueList result; if ( t != Srv ) return result; QPtrList * cached = QDnsDomain::cached( this ); QDnsRR * 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; } /*! Returns a list of host names if the record type is \c Ptr. Note that if you want to iterate over the list, you should iterate over a copy, e.g. \code QStringList list = myDns.hostNames(); QStringList::Iterator it = list.begin(); while( it != list.end() ) { myProcessing( *it ); ++it; } \endcode */ QStringList QDns::hostNames() const { #if defined(QDNS_DEBUG) qDebug( "QDns::hostNames (%s)", l.ascii() ); #endif QStringList result; if ( t != Ptr ) return result; QPtrList * cached = QDnsDomain::cached( this ); QDnsRR * rr; while( (rr=cached->current()) != 0 ) { if ( rr->current && !rr->nxdomain ) { QString str( rr->target ); result.append( str ); } cached->next(); } delete cached; return result; } /*! Returns a list of texts if the record type is \c Txt. Note that if you want to iterate over the list, you should iterate over a copy, e.g. \code QStringList list = myDns.texts(); QStringList::Iterator it = list.begin(); while( it != list.end() ) { myProcessing( *it ); ++it; } \endcode */ QStringList QDns::texts() const { #if defined(QDNS_DEBUG) qDebug( "QDns::texts (%s)", l.ascii() ); #endif QStringList result; if ( t != Txt ) return result; QPtrList * cached = QDnsDomain::cached( this ); QDnsRR * rr; while( (rr=cached->current()) != 0 ) { if ( rr->current && !rr->nxdomain ) { QString str( rr->text ); result.append( str ); } cached->next(); } delete cached; return result; } /*! 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 QDns is "trolltech.com", then the canonical name for all of "lillian", "l", "lillian.troll.no." and "l.trolltech.com" is "lillian.troll.no.". */ QString QDns::canonicalName() const { // the cname should work regardless of the recordType(), so set the record // type temporarily to cname when you look at the cache QDns *that = (QDns*) this; // mutable function RecordType oldType = t; that->t = Cname; QPtrList * cached = QDnsDomain::cached( that ); that->t = oldType; QDnsRR * rr; while( (rr=cached->current()) != 0 ) { if ( rr->current && !rr->nxdomain && rr->domain ) { delete cached; return rr->target; } cached->next(); } delete cached; return QString::null; } #if defined(Q_DNS_SYNCHRONOUS) /*! \reimp */ void QDns::connectNotify( const char *signal ) { if ( d->noEventLoop && qstrcmp(signal,SIGNAL(resultsReady()) )==0 ) { doSynchronousLookup(); } } #endif #if defined(Q_OS_WIN32) || defined(Q_OS_CYGWIN) #if defined(Q_DNS_SYNCHRONOUS) void QDns::doSynchronousLookup() { // ### not implemented yet } #endif // the following typedefs are needed for GetNetworkParams() API call #ifndef IP_TYPES_INCLUDED #define MAX_HOSTNAME_LEN 128 #define MAX_DOMAIN_NAME_LEN 128 #define MAX_SCOPE_ID_LEN 256 typedef struct { char String[4 * 4]; } IP_ADDRESS_STRING, *PIP_ADDRESS_STRING, IP_MASK_STRING, *PIP_MASK_STRING; typedef struct _IP_ADDR_STRING { struct _IP_ADDR_STRING* Next; IP_ADDRESS_STRING IpAddress; IP_MASK_STRING IpMask; DWORD Context; } IP_ADDR_STRING, *PIP_ADDR_STRING; typedef struct { char HostName[MAX_HOSTNAME_LEN + 4] ; char DomainName[MAX_DOMAIN_NAME_LEN + 4]; PIP_ADDR_STRING CurrentDnsServer; IP_ADDR_STRING DnsServerList; UINT NodeType; char ScopeId[MAX_SCOPE_ID_LEN + 4]; UINT EnableRouting; UINT EnableProxy; UINT EnableDns; } FIXED_INFO, *PFIXED_INFO; #endif typedef DWORD (WINAPI *GNP)( PFIXED_INFO, PULONG ); // ### FIXME: this code is duplicated in qfiledialog.cpp static QString getWindowsRegString( HKEY key, const QString &subKey ) { QString s; QT_WA( { char buf[1024]; DWORD bsz = sizeof(buf); int r = RegQueryValueEx( key, (TCHAR*)subKey.ucs2(), 0, 0, (LPBYTE)buf, &bsz ); if ( r == ERROR_SUCCESS ) { s = QString::fromUcs2( (unsigned short *)buf ); } else if ( r == ERROR_MORE_DATA ) { char *ptr = new char[bsz+1]; r = RegQueryValueEx( key, (TCHAR*)subKey.ucs2(), 0, 0, (LPBYTE)ptr, &bsz ); if ( r == ERROR_SUCCESS ) s = ptr; delete [] ptr; } } , { char buf[512]; DWORD bsz = sizeof(buf); int r = RegQueryValueExA( key, subKey.local8Bit(), 0, 0, (LPBYTE)buf, &bsz ); if ( r == ERROR_SUCCESS ) { s = buf; } else if ( r == ERROR_MORE_DATA ) { char *ptr = new char[bsz+1]; r = RegQueryValueExA( key, subKey.local8Bit(), 0, 0, (LPBYTE)ptr, &bsz ); if ( r == ERROR_SUCCESS ) s = ptr; delete [] ptr; } } ); return s; } static bool getDnsParamsFromRegistry( const QString &path, QString *domainName, QString *nameServer, QString *searchList ) { HKEY k; int r; QT_WA( { r = RegOpenKeyEx( HKEY_LOCAL_MACHINE, (TCHAR*)path.ucs2(), 0, KEY_READ, &k ); } , { r = RegOpenKeyExA( HKEY_LOCAL_MACHINE, path, 0, KEY_READ, &k ); } ); if ( r == ERROR_SUCCESS ) { *domainName = getWindowsRegString( k, "DhcpDomain" ); if ( domainName->isEmpty() ) *domainName = getWindowsRegString( k, "Domain" ); *nameServer = getWindowsRegString( k, "DhcpNameServer" ); if ( nameServer->isEmpty() ) *nameServer = getWindowsRegString( k, "NameServer" ); *searchList = getWindowsRegString( k, "SearchList" ); } RegCloseKey( k ); return r == ERROR_SUCCESS; } void QDns::doResInit() { char separator = 0; if ( ns ) delete ns; ns = new QPtrList; ns->setAutoDelete( TRUE ); domains = new QStrList( TRUE ); domains->setAutoDelete( TRUE ); QString domainName, nameServer, searchList; bool gotNetworkParams = FALSE; // try the API call GetNetworkParams() first and use registry lookup only // as a fallback #ifdef Q_OS_TEMP HINSTANCE hinstLib = LoadLibraryW( L"iphlpapi" ); #else HINSTANCE hinstLib = LoadLibraryA( "iphlpapi" ); #endif if ( hinstLib != 0 ) { #ifdef Q_OS_TEMP GNP getNetworkParams = (GNP) GetProcAddressW( hinstLib, L"GetNetworkParams" ); #else GNP getNetworkParams = (GNP) GetProcAddress( hinstLib, "GetNetworkParams" ); #endif if ( getNetworkParams != 0 ) { ULONG l = 0; DWORD res; res = getNetworkParams( 0, &l ); if ( res == ERROR_BUFFER_OVERFLOW ) { FIXED_INFO *finfo = (FIXED_INFO*)new char[l]; res = getNetworkParams( finfo, &l ); if ( res == ERROR_SUCCESS ) { domainName = finfo->DomainName; nameServer = ""; IP_ADDR_STRING *dnsServer = &finfo->DnsServerList; while ( dnsServer != 0 ) { nameServer += dnsServer->IpAddress.String; dnsServer = dnsServer->Next; if ( dnsServer != 0 ) nameServer += " "; } searchList = ""; separator = ' '; gotNetworkParams = TRUE; } delete[] finfo; } } FreeLibrary( hinstLib ); } if ( !gotNetworkParams ) { if ( getDnsParamsFromRegistry( QString( "System\\CurrentControlSet\\Services\\Tcpip\\Parameters" ), &domainName, &nameServer, &searchList )) { // for NT separator = ' '; } else if ( getDnsParamsFromRegistry( QString( "System\\CurrentControlSet\\Services\\VxD\\MSTCP" ), &domainName, &nameServer, &searchList )) { // for 95/98 separator = ','; } else { // Could not access the TCP/IP parameters domainName = ""; nameServer = "127.0.0.1"; searchList = ""; separator = ' '; } } nameServer = nameServer.simplifyWhiteSpace(); int first, last; if ( !nameServer.isEmpty() ) { first = 0; do { last = nameServer.find( separator, first ); if ( last < 0 ) last = nameServer.length(); QDns tmp( nameServer.mid( first, last-first ), QDns::A ); QValueList address = tmp.addresses(); Q_LONG i = address.count(); while( i ) ns->append( new QHostAddress(address[--i]) ); first = last+1; } while( first < (int)nameServer.length() ); } searchList = searchList + " " + domainName; searchList = searchList.simplifyWhiteSpace().lower(); first = 0; do { last = searchList.find( separator, first ); if ( last < 0 ) last = searchList.length(); domains->append( qstrdup( searchList.mid( first, last-first ) ) ); first = last+1; } while( first < (int)searchList.length() ); } #elif defined(Q_OS_UNIX) #if defined(Q_DNS_SYNCHRONOUS) void QDns::doSynchronousLookup() { if ( t!=None && !l.isEmpty() ) { QValueListIterator it = n.begin(); QValueListIterator end = n.end(); int type; switch( t ) { case QDns::A: type = 1; break; case QDns::Aaaa: type = 28; break; case QDns::Mx: type = 15; break; case QDns::Srv: type = 33; break; case QDns::Cname: type = 5; break; case QDns::Ptr: type = 12; break; case QDns::Txt: type = 16; break; default: type = (char)255; // any break; } while( it != end ) { QString s = *it; it++; QByteArray ba( 512 ); int len = res_search( s.latin1(), 1, type, (uchar*)ba.data(), ba.size() ); if ( len > 0 ) { ba.resize( len ); QDnsQuery * query = new QDnsQuery; query->started = now(); query->id = ++::id; query->t = t; query->l = s; QDnsAnswer a( ba, query ); a.parse(); } else if ( len == -1 ) { // res_search error } } emit resultsReady(); } } #endif #if defined(__GLIBC__) && ((__GLIBC__ > 2) || ((__GLIBC__ == 2) && (__GLIBC_MINOR__ >= 3))) #define Q_MODERN_RES_API #else #endif void QDns::doResInit() { if ( ns ) return; ns = new QPtrList; ns->setAutoDelete( TRUE ); domains = new QStrList( TRUE ); domains->setAutoDelete( TRUE ); // read resolv.conf manually. QFile resolvConf("/etc/resolv.conf"); if (resolvConf.open(IO_ReadOnly)) { QTextStream stream( &resolvConf ); QString line; while ( !stream.atEnd() ) { line = stream.readLine(); QStringList list = QStringList::split( " ", line ); if ( line.startsWith( "#" ) || list.count() < 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() ); } else if ( type == "domain" ) { domains->append( list[1].lower() ); } } } 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() ); else break; } # endif if ( *res.defdname ) domains->append( QString::fromLatin1( res.defdname ).lower() ); #else qdns_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() ); else break; } # endif if ( *_res.defdname ) domains->append( QString::fromLatin1( _res.defdname ).lower() ); #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( IO_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( n < line.length() && line[(int)n] != '#' ) n++; line.truncate( n ); n = 0; while( 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( 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 ) { QDnsRR * rr = new QDnsRR( hostname ); if ( a.isIPv4Address() ) rr->t = QDns::A; else rr->t = QDns::Aaaa; rr->address = a; rr->deleteTime = UINT_MAX; rr->expireTime = UINT_MAX; rr->current = TRUE; if ( first ) { first = FALSE; QDnsRR * ptr = new QDnsRR( QDns::toInAddrArpaDomain( a ) ); ptr->t = QDns::Ptr; ptr->target = hostname; ptr->deleteTime = UINT_MAX; ptr->expireTime = UINT_MAX; ptr->current = TRUE; } } } } } } #endif #endif // QT_NO_DNS