2 files changed, 50 insertions, 7 deletions

diff --git a/src/network/kernel/qnetworkinterface_unix.cpp b/src/network/kernel/qnetworkinterface_unix.cpp
index cc53087024..5e6d24dd44 100644
--- a/src/network/kernel/qnetworkinterface_unix.cpp
+++ b/src/network/kernel/qnetworkinterface_unix.cpp
@@ -314,10 +314,15 @@ static QList<QNetworkInterfacePrivate *> createInterfaces(ifaddrs *rawList)
 {
     QList<QNetworkInterfacePrivate *> interfaces;
     QSet<QString> seenInterfaces;
-
-    // on Linux, AF_PACKET addresses carry the hardware address and interface index;
-    // scan for them first (they're usually first, but we have no guarantee this
-    // will be the case forever)
+    QVarLengthArray<int, 16> seenIndexes;   // faster than QSet<int>
+
+    // On Linux, glibc, uClibc and MUSL obtain the address listing via two
+    // netlink calls: first an RTM_GETLINK to obtain the interface listing,
+    // then one RTM_GETADDR to get all the addresses (uClibc implementation is
+    // copied from glibc; Bionic currently doesn't support getifaddrs). They
+    // synthesize AF_PACKET addresses from the RTM_GETLINK responses, which
+    // means by construction they currently show up first in the interface
+    // listing.
     for (ifaddrs *ptr = rawList; ptr; ptr = ptr->ifa_next) {
         if (ptr->ifa_addr && ptr->ifa_addr->sa_family == AF_PACKET) {
             sockaddr_ll *sll = (sockaddr_ll *)ptr->ifa_addr;
@@ -328,23 +333,30 @@ static QList<QNetworkInterfacePrivate *> createInterfaces(ifaddrs *rawList)
             iface->flags = convertFlags(ptr->ifa_flags);
             iface->hardwareAddress = iface->makeHwAddress(sll->sll_halen, (uchar*)sll->sll_addr);
 
+            Q_ASSERT(!seenIndexes.contains(iface->index));
+            seenIndexes.append(iface->index);
             seenInterfaces.insert(iface->name);
         }
     }
 
     // see if we missed anything:
-    // virtual interfaces with no HW address have no AF_PACKET
+    // - virtual interfaces with no HW address have no AF_PACKET
+    // - interface labels have no AF_PACKET, but shouldn't be shown as a new interface
     for (ifaddrs *ptr = rawList; ptr; ptr = ptr->ifa_next) {
         if (ptr->ifa_addr && ptr->ifa_addr->sa_family != AF_PACKET) {
             QString name = QString::fromLatin1(ptr->ifa_name);
             if (seenInterfaces.contains(name))
                 continue;
 
+            int ifindex = if_nametoindex(ptr->ifa_name);
+            if (seenIndexes.contains(ifindex))
+                continue;
+
             QNetworkInterfacePrivate *iface = new QNetworkInterfacePrivate;
             interfaces << iface;
             iface->name = name;
             iface->flags = convertFlags(ptr->ifa_flags);
-            iface->index = if_nametoindex(ptr->ifa_name);
+            iface->index = ifindex;
         }
     }
 
@@ -423,7 +435,7 @@ static QList<QNetworkInterfacePrivate *> interfaceListing()
 
     interfaces = createInterfaces(interfaceListing);
     for (ifaddrs *ptr = interfaceListing; ptr; ptr = ptr->ifa_next) {
-        // Get the interface index
+        // Find the interface
         QString name = QString::fromLatin1(ptr->ifa_name);
         QNetworkInterfacePrivate *iface = 0;
         QList<QNetworkInterfacePrivate *>::Iterator if_it = interfaces.begin();
@@ -433,6 +445,18 @@ static QList<QNetworkInterfacePrivate *> interfaceListing()
                 iface = *if_it;
                 break;
             }
+
+        if (!iface) {
+            // it may be an interface label, search by interface index
+            int ifindex = if_nametoindex(ptr->ifa_name);
+            for (if_it = interfaces.begin(); if_it != interfaces.end(); ++if_it)
+                if ((*if_it)->index == ifindex) {
+                    // found this interface already
+                    iface = *if_it;
+                    break;
+                }
+        }
+
         if (!iface) {
             // skip all non-IP interfaces
             continue;
diff --git a/tests/auto/network/kernel/qnetworkinterface/tst_qnetworkinterface.cpp b/tests/auto/network/kernel/qnetworkinterface/tst_qnetworkinterface.cpp
index f7798bbb70..519ee0dc84 100644
--- a/tests/auto/network/kernel/qnetworkinterface/tst_qnetworkinterface.cpp
+++ b/tests/auto/network/kernel/qnetworkinterface/tst_qnetworkinterface.cpp
@@ -55,6 +55,7 @@ private slots:
     void initTestCase();
     void cleanupTestCase();
     void dump();
+    void consistencyCheck();
     void loopbackIPv4();
     void loopbackIPv6();
     void localAddress();
@@ -148,6 +149,24 @@ void tst_QNetworkInterface::dump()
     }
 }
 
+void tst_QNetworkInterface::consistencyCheck()
+{
+    QList<QNetworkInterface> ifaces = QNetworkInterface::allInterfaces();
+    QSet<QString> interfaceNames;
+    QVector<int> interfaceIndexes;
+
+    foreach (const QNetworkInterface &iface, ifaces) {
+        QVERIFY2(!interfaceNames.contains(iface.name()),
+                 "duplicate name = " + iface.name().toLocal8Bit());
+        interfaceNames << iface.name();
+
+        QVERIFY2(!interfaceIndexes.contains(iface.index()),
+                 "duplicate index = " + QByteArray::number(iface.index()));
+        if (iface.index())
+            interfaceIndexes << iface.index();
+    }
+}
+
 void tst_QNetworkInterface::loopbackIPv4()
 {
     QList<QHostAddress> all = QNetworkInterface::allAddresses();