Revert "Revert "don't allow a HifiSockAddr lookup to block application""

This reverts commit fabc3aea57.

libraries/networking/src/HifiSockAddr.cpp

@@ -9,9 +9,9 @@
 //  See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html
 //
 
-#include <QtCore/QDataStream>
-#include <QtNetwork/QHostInfo>
-#include <QtNetwork/QNetworkInterface>
+#include <qdatastream.h>
+#include <qhostinfo.h>
+#include <qnetworkinterface.h>
 
 #include "HifiSockAddr.h"
 
@@ -36,14 +36,15 @@ HifiSockAddr::HifiSockAddr(const HifiSockAddr& otherSockAddr) {
     _port = otherSockAddr._port;
 }
 
-HifiSockAddr::HifiSockAddr(const QString& hostname, quint16 hostOrderPort) {
-    // lookup the IP by the hostname
-    QHostInfo hostInfo = QHostInfo::fromName(hostname);
-    foreach(const QHostAddress& address, hostInfo.addresses()) {
-        if (address.protocol() == QAbstractSocket::IPv4Protocol) {
-            _address = address;
-            _port = hostOrderPort;
-        }
+HifiSockAddr::HifiSockAddr(const QString& hostname, quint16 hostOrderPort) :
+    _address(hostname),
+    _port(hostOrderPort)
+{
+    // if we parsed an IPv4 address out of the hostname, don't look it up
+    if (_address.protocol() != QAbstractSocket::IPv4Protocol) {
+        // sync lookup the IP by the hostname
+        int lookupID = QHostInfo::lookupHost(hostname, this, SLOT(handleLookupResult(QHostInfo)));
+        qDebug() << "Looking up IP address for hostname" << hostname << "- lookup ID is" << lookupID;
     }
 }
 
@@ -75,6 +76,22 @@ bool HifiSockAddr::operator==(const HifiSockAddr& rhsSockAddr) const {
     return _address == rhsSockAddr._address && _port == rhsSockAddr._port;
 }
 
+void HifiSockAddr::handleLookupResult(const QHostInfo& hostInfo) {
+    if (hostInfo.error() != QHostInfo::NoError) {
+        qDebug() << "Lookup failed for" << hostInfo.lookupId() << ":" << hostInfo.errorString();
+    }
+    
+    foreach(const QHostAddress& address, hostInfo.addresses()) {
+        // just take the first IPv4 address
+        if (address.protocol() == QAbstractSocket::IPv4Protocol) {
+            _address = address;
+            qDebug() << "QHostInfo lookup result for"
+                << hostInfo.hostName() << "with lookup ID" << hostInfo.lookupId() << "is" << address.toString();
+            break;
+        }
+    }
+}
+
 QDebug operator<<(QDebug debug, const HifiSockAddr& sockAddr) {
     debug.nospace() << sockAddr._address.toString().toLocal8Bit().constData() << ":" << sockAddr._port;
     return debug.space();

libraries/networking/src/HifiSockAddr.h

@@ -19,9 +19,10 @@
 #include <netinet/in.h>
 #endif
 
-#include <QtNetwork/QHostAddress>
+#include <QtNetwork/QHostInfo>
 
-class HifiSockAddr {
+class HifiSockAddr : public QObject {
+    Q_OBJECT
 public:
     HifiSockAddr();
     HifiSockAddr(const QHostAddress& address, quint16 port);
@@ -51,6 +52,8 @@ public:
     friend QDebug operator<<(QDebug debug, const HifiSockAddr& sockAddr);
     friend QDataStream& operator<<(QDataStream& dataStream, const HifiSockAddr& sockAddr);
     friend QDataStream& operator>>(QDataStream& dataStream, HifiSockAddr& sockAddr);
+private slots:
+    void handleLookupResult(const QHostInfo& hostInfo);
 private:
     QHostAddress _address;
     quint16 _port;

libraries/networking/src/LimitedNodeList.cpp

@@ -73,6 +73,7 @@ LimitedNodeList::LimitedNodeList(unsigned short socketListenPort, unsigned short
     _dtlsSocket(NULL),
     _localSockAddr(),
     _publicSockAddr(),
+    _stunSockAddr(STUN_SERVER_HOSTNAME, STUN_SERVER_PORT),
     _numCollectedPackets(0),
     _numCollectedBytes(0),
     _packetStatTimer()
@@ -583,11 +584,8 @@ void LimitedNodeList::sendSTUNRequest() {
     QUuid randomUUID = QUuid::createUuid();
     memcpy(stunRequestPacket + packetIndex, randomUUID.toRfc4122().data(), NUM_TRANSACTION_ID_BYTES);
     
-    // lookup the IP for the STUN server
-    HifiSockAddr stunSockAddr(STUN_SERVER_HOSTNAME, STUN_SERVER_PORT);
-    
     _nodeSocket.writeDatagram((char*) stunRequestPacket, sizeof(stunRequestPacket),
-                              stunSockAddr.getAddress(), stunSockAddr.getPort());
+                              _stunSockAddr.getAddress(), _stunSockAddr.getPort());
 }
 
 void LimitedNodeList::rebindNodeSocket() {

libraries/networking/src/LimitedNodeList.h

@@ -163,6 +163,7 @@ protected:
     QUdpSocket* _dtlsSocket;
     HifiSockAddr _localSockAddr;
     HifiSockAddr _publicSockAddr;
+    HifiSockAddr _stunSockAddr;
     int _numCollectedPackets;
     int _numCollectedBytes;
     QElapsedTimer _packetStatTimer;