Update Linux interface getting to make fewer syscalls

Each time we call if_nametoindex, if_indextoname or somesuch, the libc
needs to open a socket, make an ioctl, and close the socket. Since we've
got most of the information we need anyway in the data from
getifaddrs(3), let's just use it

Change-Id: I572c212a27c4b9ffe57980b36f75bb04e6d5cf29
Reviewed-by: Jonas Gastal <gastal@intel.com>
Reviewed-by: Richard J. Moore <rich@kde.org>

1 files changed, 29 insertions, 29 deletions

diff --git a/src/network/kernel/qnetworkinterface_unix.cpp b/src/network/kernel/qnetworkinterface_unix.cpp
index b090213861..01c082059f 100644
--- a/src/network/kernel/qnetworkinterface_unix.cpp
+++ b/src/network/kernel/qnetworkinterface_unix.cpp
@@ -312,38 +312,38 @@ QT_END_INCLUDE_NAMESPACE
 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)
     for (ifaddrs *ptr = rawList; ptr; ptr = ptr->ifa_next) {
-        if ( !ptr->ifa_addr )
-            continue;
-
-        // Get the interface index
-        int ifindex = if_nametoindex(ptr->ifa_name);
+        if (ptr->ifa_addr && ptr->ifa_addr->sa_family == AF_PACKET) {
+            sockaddr_ll *sll = (sockaddr_ll *)ptr->ifa_addr;
+            QNetworkInterfacePrivate *iface = new QNetworkInterfacePrivate;
+            interfaces << iface;
+            iface->index = sll->sll_ifindex;
+            iface->name = QString::fromLatin1(ptr->ifa_name);
+            iface->flags = convertFlags(ptr->ifa_flags);
+            iface->hardwareAddress = iface->makeHwAddress(sll->sll_halen, (uchar*)sll->sll_addr);
 
-        // on Linux we use AF_PACKET and sockaddr_ll to obtain hHwAddress
-        QList<QNetworkInterfacePrivate *>::Iterator if_it = interfaces.begin();
-        for ( ; if_it != interfaces.end(); ++if_it)
-            if ((*if_it)->index == ifindex) {
-                // this one has been added already
-                if ( ptr->ifa_addr->sa_family == AF_PACKET
-                        && (*if_it)->hardwareAddress.isEmpty()) {
-                    sockaddr_ll *sll = (sockaddr_ll *)ptr->ifa_addr;
-                    (*if_it)->hardwareAddress = (*if_it)->makeHwAddress(sll->sll_halen, (uchar*)sll->sll_addr);
-                }
-                break;
-            }
-        if ( if_it != interfaces.end() )
-            continue;
+            seenInterfaces.insert(iface->name);
+        }
+    }
 
-        QNetworkInterfacePrivate *iface = new QNetworkInterfacePrivate;
-        interfaces << iface;
-        iface->index = ifindex;
-        iface->name = QString::fromLatin1(ptr->ifa_name);
-        iface->flags = convertFlags(ptr->ifa_flags);
+    // see if we missed anything:
+    // virtual interfaces with no HW address have no AF_PACKET
+    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;
 
-        if ( ptr->ifa_addr->sa_family == AF_PACKET ) {
-            sockaddr_ll *sll = (sockaddr_ll *)ptr->ifa_addr;
-            iface->hardwareAddress = iface->makeHwAddress(sll->sll_halen, (uchar*)sll->sll_addr);
+            QNetworkInterfacePrivate *iface = new QNetworkInterfacePrivate;
+            interfaces << iface;
+            iface->name = name;
+            iface->flags = convertFlags(ptr->ifa_flags);
+            iface->index = if_nametoindex(ptr->ifa_name);
         }
     }
 
@@ -423,11 +423,11 @@ static QList<QNetworkInterfacePrivate *> interfaceListing()
     interfaces = createInterfaces(interfaceListing);
     for (ifaddrs *ptr = interfaceListing; ptr; ptr = ptr->ifa_next) {
         // Get the interface index
-        int ifindex = if_nametoindex(ptr->ifa_name);
+        QString name = QString::fromLatin1(ptr->ifa_name);
         QNetworkInterfacePrivate *iface = 0;
         QList<QNetworkInterfacePrivate *>::Iterator if_it = interfaces.begin();
         for ( ; if_it != interfaces.end(); ++if_it)
-            if ((*if_it)->index == ifindex) {
+            if ((*if_it)->name == name) {
                 // found this interface already
                 iface = *if_it;
                 break;