NetworkDeviceDiscovery: Skip duplicated discovery if there are multiple network interfaces connected to the same network

libnymea-core/hardware/network/networkdevicediscoveryimpl.cpp

@@ -29,10 +29,11 @@
 * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
 
 #include "networkdevicediscoveryimpl.h"
-
 #include "nymeasettings.h"
 #include "loggingcategories.h"
 
+#include <math.h>
+
 #include <network/ping.h>
 #include <network/arpsocket.h>
 #include <network/networkutils.h>
@@ -339,6 +340,9 @@ void NetworkDeviceDiscoveryImpl::setEnabled(bool enabled)
 
 void NetworkDeviceDiscoveryImpl::pingAllNetworkDevices()
 {
+    QList<QHostAddress> ownAddresses;
+    QList<TargetNetwork> targetNetworks;
+
     qCDebug(dcNetworkDeviceDiscovery()) << "Starting ping for all network devices...";
     foreach (const QNetworkInterface &networkInterface, QNetworkInterface::allInterfaces()) {
         if (networkInterface.flags().testFlag(QNetworkInterface::IsLoopBack))
@@ -352,31 +356,64 @@ void NetworkDeviceDiscoveryImpl::pingAllNetworkDevices()
 
         qCDebug(dcNetworkDeviceDiscovery()) << "Verifying network interface" << networkInterface.name() << networkInterface.hardwareAddress() << "...";
         foreach (const QNetworkAddressEntry &entry, networkInterface.addressEntries()) {
-            qCDebug(dcNetworkDeviceDiscovery()) << "  Checking entry" << entry.ip().toString();
 
             // Only IPv4
             if (entry.ip().protocol() != QAbstractSocket::IPv4Protocol)
                 continue;
 
+            // Store the own address of this network interface in any case,
+            // since we don't want to ping our self
+            ownAddresses.append(entry.ip());
+
+            TargetNetwork targetNetwork;
+            targetNetwork.networkInterface = networkInterface;
+            targetNetwork.addressEntry = entry;
+            targetNetwork.address = QHostAddress(entry.ip().toIPv4Address() & entry.netmask().toIPv4Address());
+
+            qCDebug(dcNetworkDeviceDiscovery()) << "  Checking entry" << entry.ip().toString();
             qCDebug(dcNetworkDeviceDiscovery()) << "    Host address:" << entry.ip().toString();
+            qCDebug(dcNetworkDeviceDiscovery()) << "    Network address:" << targetNetwork.address.toString();
             qCDebug(dcNetworkDeviceDiscovery()) << "    Broadcast address:" << entry.broadcast().toString();
             qCDebug(dcNetworkDeviceDiscovery()) << "    Netmask:" << entry.netmask().toString();
-            quint32 addressRangeStart = entry.ip().toIPv4Address() & entry.netmask().toIPv4Address();
+            qCDebug(dcNetworkDeviceDiscovery()) << "    Address rang from" << targetNetwork.address.toString() << "-->" << targetNetwork.addressEntry.broadcast().toString();
-            quint32 addressRangeStop = entry.broadcast().toIPv4Address() | addressRangeStart;
-            quint32 range = addressRangeStop - addressRangeStart;
 
             // Let's scan only 255.255.255.0 networks for now
-            if (range > 255)
+            if (entry.prefixLength() < 24) {
+                qCDebug(dcNetworkDeviceDiscovery()) << "Skipping network interface" << networkInterface.name() << "because there are to many hosts to contact. The network detector was designed for /24 networks.";
+                continue;
+            }
+
+            // Filter out duplicated networks (for example connected using wifi and ethernet to the same network) ...
+
+            bool duplicatedNetwork = false;
+            foreach (const TargetNetwork &tn, targetNetworks) {
+                if (tn.address == targetNetwork.address && tn.addressEntry.netmask() == targetNetwork.addressEntry.netmask()) {
+                    qCDebug(dcNetworkDeviceDiscovery()) << "Skipping network interface" << targetNetwork.networkInterface.name() << targetNetwork.address.toString() << "as ping target network because it seems to be the same network as" << tn.networkInterface.name() << tn.address.toString();
+                    duplicatedNetwork = true;
+                    break;
+                }
+            }
+
+            if (duplicatedNetwork)
                 continue;
 
-            qCDebug(dcNetworkDeviceDiscovery()) << "    Address range" << range << " | from" << QHostAddress(addressRangeStart).toString() << "-->" << QHostAddress(addressRangeStop).toString();
+            targetNetworks.append(targetNetwork);
+        }
+    }
+
+    foreach (const TargetNetwork &targetNetwork, targetNetworks) {
+
         // Send ping request to each address within the range
-            for (quint32 i = 1; i < range; i++) {
+        quint32 targetHostsCount = pow(2, 32 - targetNetwork.addressEntry.prefixLength()) - 1;
-                quint32 address = addressRangeStart + i;
+        for (quint32 i = 1; i < targetHostsCount; i++) {
-                QHostAddress targetAddress(address);
+            QHostAddress targetAddress(targetNetwork.address.toIPv4Address() + i);
+
+            // Skip the broadcast
+            if (targetAddress == targetNetwork.addressEntry.broadcast())
+                continue;
 
             // Skip our self
-                if (targetAddress == entry.ip())
+            if (ownAddresses.contains(targetAddress))
                 continue;
 
             // Retry only once to ping a device and lookup the hostname on success
@@ -404,7 +441,6 @@ void NetworkDeviceDiscoveryImpl::pingAllNetworkDevices()
         }
     }
 }
-}
 
 void NetworkDeviceDiscoveryImpl::processMonitorPingResult(PingReply *reply, NetworkDeviceMonitorImpl *monitor)
 {

libnymea-core/hardware/network/networkdevicediscoveryimpl.h

@@ -85,6 +85,12 @@ protected:
     void setEnabled(bool enabled) override;
 
 private:
+    typedef struct TargetNetwork {
+        QNetworkInterface networkInterface;
+        QNetworkAddressEntry addressEntry;
+        QHostAddress address;
+    } TargetNetwork;
+
     MacAddressDatabase *m_macAddressDatabase = nullptr;
     ArpSocket *m_arpSocket = nullptr;
     Ping *m_ping = nullptr;