Fixed live device clone method returning wrong device type on win32 m…

…achines. (#1406)

* Added unit test to ensure windows systems get WinPcapLiveDevice after clone.

* Marked clone as a virtual method. Added clone override for WinPcapLiveDevice.

* Lint

* Deduplicated shared code between clones of PcapLiveDevice and WinPcapLiveDevice.

* Changed clone internal signature on derived class.

Pcap++/header/PcapLiveDevice.h

@@ -570,12 +570,14 @@ namespace pcpp
 		 * Clones the current device class
 		 * @return Pointer to the copied class
 		 */
-		PcapLiveDevice* clone();
+		PcapLiveDevice* clone() const;
 
 		void getStatistics(IPcapDevice::PcapStats& stats) const override;
 
 	protected:
 		pcap_t* doOpen(const DeviceConfiguration& config);
+
+		virtual PcapLiveDevice* cloneInternal(pcap_if_t& devInterface) const;
 	};
 
 } // namespace pcpp

Pcap++/header/WinPcapLiveDevice.h

@@ -55,6 +55,9 @@ namespace pcpp
 		 * setMinAmountOfDataToCopyFromKernelToApplication())
 		 */
 		int getMinAmountOfDataToCopyFromKernelToApplication() const { return m_MinAmountOfDataToCopyFromKernelToApplication; }
+
+	protected:
+		WinPcapLiveDevice* cloneInternal(pcap_if_t& devInterface) const override;
 	};
 
 } // namespace pcpp

Pcap++/src/PcapLiveDevice.cpp

@@ -402,11 +402,11 @@ void PcapLiveDevice::close()
 	PCPP_LOG_DEBUG("Device '" << m_Name << "' closed");
 }
 
-PcapLiveDevice* PcapLiveDevice::clone()
+PcapLiveDevice* PcapLiveDevice::clone() const
 {
-	PcapLiveDevice *retval = nullptr;
+	PcapLiveDevice* retval = nullptr;
 
-	pcap_if_t *interfaceList;
+	pcap_if_t* interfaceList;
 	char errbuf[PCAP_ERRBUF_SIZE];
 	int err = pcap_findalldevs(&interfaceList, errbuf);
 	if (err < 0)
@@ -424,14 +424,19 @@ PcapLiveDevice* PcapLiveDevice::clone()
 	}
 
 	if(currInterface)
-		retval = new PcapLiveDevice(currInterface, true, true, true);
+		retval = cloneInternal(*currInterface);
 	else
 		PCPP_LOG_ERROR("Can't find interface " << getName().c_str());
 
 	pcap_freealldevs(interfaceList);
 	return retval;
 }
 
+PcapLiveDevice* PcapLiveDevice::cloneInternal(pcap_if_t& devInterface) const
+{
+	return new PcapLiveDevice(&devInterface, true, true, true);
+}
+
 bool PcapLiveDevice::startCapture(OnPacketArrivesCallback onPacketArrives, void* onPacketArrivesUserCookie)
 {
 	return startCapture(std::move(onPacketArrives), onPacketArrivesUserCookie, 0, nullptr, nullptr);

Pcap++/src/WinPcapLiveDevice.cpp

@@ -126,6 +126,11 @@ bool WinPcapLiveDevice::setMinAmountOfDataToCopyFromKernelToApplication(int size
 	return true;
 }
 
+WinPcapLiveDevice* WinPcapLiveDevice::cloneInternal(pcap_if_t& devInterface) const
+{
+	return new WinPcapLiveDevice(&devInterface, true, true, true);
+}
+
 } // namespace pcpp
 
 #endif // _WIN32

Tests/Pcap++Test/Tests/LiveDeviceTests.cpp

@@ -328,8 +328,26 @@ PTF_TEST_CASE(TestPcapLiveDeviceClone)
 	// Test of clone device should be same with original
 	pcpp::PcapLiveDevice* liveDev = nullptr;
 	pcpp::IPv4Address ipToSearch(PcapTestGlobalArgs.ipToSendReceivePackets.c_str());
-	liveDev = pcpp::PcapLiveDeviceList::getInstance().getPcapLiveDeviceByIp(ipToSearch)->clone();
+
+	{
+		pcpp::PcapLiveDevice* originalDev = pcpp::PcapLiveDeviceList::getInstance().getPcapLiveDeviceByIp(ipToSearch);
+		PTF_ASSERT_NOT_NULL(originalDev);
+
+#ifdef _WIN32
+		// Tests if device pointer points to a Windows Live Device on a Windows machine.
+		PTF_ASSERT_NOT_NULL(dynamic_cast<pcpp::WinPcapLiveDevice*>(originalDev));
+#endif // _WIN32
+
+		liveDev = originalDev->clone();
+	}
+
 	PTF_ASSERT_NOT_NULL(liveDev);
+
+#ifdef _WIN32
+	// Tests if the clone is correctly returns a Windows Live Device on Windows systems.
+	PTF_ASSERT_NOT_NULL(dynamic_cast<pcpp::WinPcapLiveDevice*>(liveDev));
+#endif // _WIN32
+
 	PTF_ASSERT_GREATER_THAN(liveDev->getMtu(), 0);
 	PTF_ASSERT_TRUE(liveDev->open());
 	DeviceTeardown devTeardown(liveDev, true);