better discovery of default IP address via ZeroConf

src/gui/src/ZeroconfService.cpp

@@ -30,16 +30,12 @@
 #ifdef _WIN32
 #define WIN32_LEAN_AND_MEAN
 #include <windows.h>
+#include <wlanapi.h>
+#pragma comment(lib, "wlanapi.lib")
 #else
 #include <stdlib.h>
 #endif
 
-static const QStringList preferedIPAddress(
-                QStringList() <<
-                "192.168." <<
-                "10." <<
-                "172.");
-
 const char* ZeroconfService:: m_ServerServiceName = "_barrierServerZeroconf._tcp";
 const char* ZeroconfService:: m_ClientServiceName = "_barrierClientZeroconf._tcp";
 
@@ -124,25 +120,75 @@ void ZeroconfService::errorHandle(DNSServiceErrorType errorCode)
         tr("Error code: %1.").arg(errorCode));
 }
 
+#ifdef _WIN32
+static QString mac_to_string(DOT11_MAC_ADDRESS mac)
+{
+    char str[18];
+    snprintf(str, 18, "%.2X:%.2X:%.2X:%.2X:%.2X:%.2X",
+        mac[0], mac[1], mac[2], mac[3], mac[4], mac[5]);
+    return str;
+}
+
+static QList<QString> wireless_mac_strings()
+{
+    QList<QString> wlanMAC;
+    DWORD version;
+    HANDLE client;
+    if (WlanOpenHandle(2, NULL, &version, &client) == 0) {
+        WLAN_INTERFACE_INFO_LIST * list;
+        if (WlanEnumInterfaces(client, NULL, &list) == 0) {
+            for (DWORD idx = 0; idx < list->dwNumberOfItems; ++idx) {
+                const GUID * PGuid = &(list->InterfaceInfo[0].InterfaceGuid);
+                const WLAN_INTF_OPCODE OpCode = wlan_intf_opcode_current_connection;
+                WLAN_CONNECTION_ATTRIBUTES * attrs;
+                DWORD attrsSz;
+                if (WlanQueryInterface(client, PGuid, OpCode, NULL, &attrsSz,
+                    (void**)&attrs, NULL) == 0) {
+                    wlanMAC.append(mac_to_string(
+                        attrs->wlanAssociationAttributes.dot11Bssid));
+                    WlanFreeMemory(attrs);
+                }
+            }
+            WlanFreeMemory(list);
+        }
+        WlanCloseHandle(client, NULL);
+    }
+    return wlanMAC;
+}
+#else
+static QList<QString> wireless_mac_strings()
+{
+    // TODO
+    return QList<QString>();
+}
+#endif
+
 QString ZeroconfService::getLocalIPAddresses()
 {
-    QStringList addresses;
-    foreach (const QHostAddress& address, QNetworkInterface::allAddresses()) {
-        if (address.protocol() == QAbstractSocket::IPv4Protocol &&
-            address != QHostAddress(QHostAddress::LocalHost)) {
-            addresses.append(address.toString());
-        }
-    }
-
-    foreach (const QString& preferedIP, preferedIPAddress) {
-        foreach (const QString& address, addresses) {
-            if (address.startsWith(preferedIP)) {
-                return address;
+    const QString NonEthernetMAC = "00:00:00:00:00:00";
+    const auto wlanMAC = wireless_mac_strings();
+    QString wirelessIP = "";
+    foreach(const auto qni, QNetworkInterface::allInterfaces()) {
+        // weed out loopback, inactive, and non-ethernet interfaces
+        if (!qni.flags().testFlag(QNetworkInterface::IsLoopBack) &&
+            qni.flags().testFlag(QNetworkInterface::IsUp) &&
+            qni.hardwareAddress() != NonEthernetMAC) {
+            bool isWireless = wlanMAC.contains(qni.hardwareAddress().toUpper());
+            foreach(const auto address, qni.allAddresses()) {
+                if (address.protocol() == QAbstractSocket::IPv4Protocol) {
+                    // use the first non-wireless address we find
+                    if (!isWireless)
+                        return address.toString();
+                    // save the first wireless address we find
+                    if (wirelessIP.isEmpty())
+                        wirelessIP = address.toString();
+                }
             }
         }
     }
-
-    return "";
+    // if no non-wireless address could be found use a wireless one
+    // if one was found. otherwise return an empty string
+    return wirelessIP;
 }
 
 bool ZeroconfService::registerService(bool server)