QNetworkAccessManager: delay IPv4 or IPv6 based on getaddrinfo order

Instead of always delaying IPv4 when we have both Ipv4 and IPv6 we
should use the order we get from getaddrinfo to descide which one
that should be delayed.

Task-number: QTBUG-23066
Change-Id: Ibe8c4d7000abd6e57fe8c6afac8a4a843e17ff27
Reviewed-by: Peter Hartmann <peter.hartmann@nokia.com>
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
Reviewed-by: Shane Kearns <shane.kearns@accenture.com>

1 files changed, 29 insertions, 13 deletions

diff --git a/src/network/access/qhttpnetworkconnection.cpp b/src/network/access/qhttpnetworkconnection.cpp
index b43f2b9bcd..b4004eae14 100644
--- a/src/network/access/qhttpnetworkconnection.cpp
+++ b/src/network/access/qhttpnetworkconnection.cpp
@@ -81,7 +81,7 @@ const int QHttpNetworkConnectionPrivate::defaultRePipelineLength = 2;
 QHttpNetworkConnectionPrivate::QHttpNetworkConnectionPrivate(const QString &hostName, quint16 port, bool encrypt)
 : state(RunningState),
   networkLayerState(Unknown),
-  hostName(hostName), port(port), encrypt(encrypt),
+  hostName(hostName), port(port), encrypt(encrypt), delayIpv4(true),
   channelCount(defaultChannelCount)
 #ifndef QT_NO_NETWORKPROXY
   , networkProxy(QNetworkProxy::NoProxy)
@@ -92,7 +92,7 @@ QHttpNetworkConnectionPrivate::QHttpNetworkConnectionPrivate(const QString &host
 
 QHttpNetworkConnectionPrivate::QHttpNetworkConnectionPrivate(quint16 channelCount, const QString &hostName, quint16 port, bool encrypt)
 : state(RunningState), networkLayerState(Unknown),
-  hostName(hostName), port(port), encrypt(encrypt),
+  hostName(hostName), port(port), encrypt(encrypt), delayIpv4(true),
   channelCount(channelCount)
 #ifndef QT_NO_NETWORKPROXY
   , networkProxy(QNetworkProxy::NoProxy)
@@ -126,8 +126,8 @@ void QHttpNetworkConnectionPrivate::init()
 #endif
         channels[i].init();
     }
-    ipv4ConnectTimer.setSingleShot(true);
-    QObject::connect(&ipv4ConnectTimer, SIGNAL(timeout()), q, SLOT(_q_connectIPv4Channel()));
+    delayedConnectionTimer.setSingleShot(true);
+    QObject::connect(&delayedConnectionTimer, SIGNAL(timeout()), q, SLOT(_q_connectDelayedChannel()));
 }
 
 void QHttpNetworkConnectionPrivate::pauseConnection()
@@ -189,9 +189,9 @@ bool QHttpNetworkConnectionPrivate::shouldEmitChannelError(QAbstractSocket *sock
     int otherSocket = (i == 0 ? 1 : 0);
 
     // If the IPv4 connection still isn't started we need to start it now.
-    if (ipv4ConnectTimer.isActive()) {
-        ipv4ConnectTimer.stop();
-        channels[0].ensureConnection();
+    if (delayedConnectionTimer.isActive()) {
+        delayedConnectionTimer.stop();
+        channels[otherSocket].ensureConnection();
     }
 
     if (channelCount == 1) {
@@ -974,12 +974,22 @@ void QHttpNetworkConnectionPrivate::_q_hostLookupFinished(QHostInfo info)
 {
     bool bIpv4 = false;
     bool bIpv6 = false;
+    bool foundAddress = false;
 
     foreach (QHostAddress address, info.addresses()) {
-        if (address.protocol() == QAbstractSocket::IPv4Protocol)
+        if (address.protocol() == QAbstractSocket::IPv4Protocol) {
+            if (!foundAddress) {
+                foundAddress = true;
+                delayIpv4 = false;
+            }
             bIpv4 = true;
-        else if (address.protocol() == QAbstractSocket::IPv6Protocol)
+        } else if (address.protocol() == QAbstractSocket::IPv6Protocol) {
+            if (!foundAddress) {
+                foundAddress = true;
+                delayIpv4 = true;
+            }
             bIpv6 = true;
+        }
     }
 
     if (bIpv4 && bIpv6)
@@ -1030,8 +1040,11 @@ void QHttpNetworkConnectionPrivate::startNetworkLayerStateLookup()
         else if (networkSession->configuration().bearerType() == QNetworkConfiguration::BearerHSPA)
             timeout = 400;
 #endif
-        ipv4ConnectTimer.start(timeout);
-        channels[1].ensureConnection();
+        delayedConnectionTimer.start(timeout);
+        if (delayIpv4)
+            channels[1].ensureConnection();
+        else
+            channels[0].ensureConnection();
     } else {
         networkLayerState = InProgress;
         channels[0].networkLayerPreference = QAbstractSocket::AnyIPProtocol;
@@ -1039,9 +1052,12 @@ void QHttpNetworkConnectionPrivate::startNetworkLayerStateLookup()
     }
 }
 
-void QHttpNetworkConnectionPrivate::_q_connectIPv4Channel()
+void QHttpNetworkConnectionPrivate::_q_connectDelayedChannel()
 {
-    channels[0].ensureConnection();
+    if (delayIpv4)
+        channels[0].ensureConnection();
+    else
+        channels[1].ensureConnection();
 }
 
 #ifndef QT_NO_BEARERMANAGEMENT