Fix ~PcapFileWriterDevice() to close the pcap file. (#1577)

Author: rndx21033

Pcap++/header/PcapFileDevice.h

@@ -458,7 +458,9 @@ namespace pcpp
 		 * A destructor for this class
 		 */
 		~PcapFileWriterDevice()
-		{}
+		{
+			PcapFileWriterDevice::close();
+		}
 
 		/**
 		 * Write a RawPacket to the file. Before using this method please verify the file is opened using open(). This

Tests/Pcap++Test/Common/PcapFileNamesDef.h

@@ -30,5 +30,7 @@
 #define SLL2_PCAP_PATH "PcapExamples/sll2.pcap"
 #define SLL2_PCAP_WRITE_PATH "PcapExamples/sll2_copy.pcap"
 #define EXAMPLE_PCAP_MICRO_PATH "PcapExamples/microsecs.pcap"
+#define EXAMPLE_PCAP_DESTRUCTOR1_PATH "PcapExamples/destructor1.pcap"
+#define EXAMPLE_PCAP_DESTRUCTOR2_PATH "PcapExamples/destructor2.pcap"
 #define EXAMPLE_PCAP_NANO_PATH "PcapExamples/nanosecs.pcap"
 #define EXAMPLE_PCAPNG_NANO_PATH "PcapExamples/nanosecs.pcapng"

Tests/Pcap++Test/TestDefinition.h

@@ -30,6 +30,7 @@ PTF_TEST_CASE(TestPcapFileReadLinkTypeIPv6);
 PTF_TEST_CASE(TestPcapFileReadLinkTypeIPv4);
 PTF_TEST_CASE(TestSolarisSnoopFileRead);
 PTF_TEST_CASE(TestPcapNgFilePrecision);
+PTF_TEST_CASE(TestPcapFileWriterDeviceDestructor);
 
 // Implemented in LiveDeviceTests.cpp
 PTF_TEST_CASE(TestPcapLiveDeviceList);

Tests/Pcap++Test/Tests/FileTests.cpp

@@ -974,3 +974,45 @@ PTF_TEST_CASE(TestSolarisSnoopFileRead)
 
 	readerDev.close();
 }  // TestSolarisSnoopFileRead
+
+PTF_TEST_CASE(TestPcapFileWriterDeviceDestructor)
+{
+	std::array<uint8_t, 16> testPayload = { 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
+		                                    0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F };
+	pcpp::RawPacket rawPacket1(testPayload.data(), testPayload.size(), timeval{}, false);
+	pcpp::RawPacket rawPacket2(testPayload.data(), testPayload.size(), timeval{}, false);
+
+	// Create some pcaps in a nested scope to test cleanup on destruction.
+	{
+		// create a file to leave open on destruction. If close is properly done on destruction, the contents & size of
+		// this file should match the next explicitly closed file.
+		pcpp::PcapFileWriterDevice writerDevDestructorNoClose(EXAMPLE_PCAP_DESTRUCTOR1_PATH, pcpp::LINKTYPE_ETHERNET,
+		                                                      false);
+		PTF_ASSERT_TRUE(writerDevDestructorNoClose.open());
+		PTF_ASSERT_TRUE(writerDevDestructorNoClose.writePacket(rawPacket1));
+		PTF_ASSERT_TRUE(writerDevDestructorNoClose.writePacket(rawPacket2));
+
+		// create a file that will be explicitly closed before construction
+		pcpp::PcapFileWriterDevice writerDevDestructorExplicitClose(EXAMPLE_PCAP_DESTRUCTOR2_PATH,
+		                                                            pcpp::LINKTYPE_ETHERNET, false);
+		PTF_ASSERT_TRUE(writerDevDestructorExplicitClose.open());
+		PTF_ASSERT_TRUE(writerDevDestructorExplicitClose.writePacket(rawPacket1));
+		PTF_ASSERT_TRUE(writerDevDestructorExplicitClose.writePacket(rawPacket2));
+		writerDevDestructorExplicitClose.close();
+	}
+
+	// Check that file sizes are equal. This should fail if the pcpp::PcapFileWriterDevice destructor does not close
+	// properly.
+	std::ifstream fileDestructorNoClose(EXAMPLE_PCAP_DESTRUCTOR1_PATH, std::ios::binary | std::ios::in);
+	fileDestructorNoClose.seekg(0, std::ios::end);
+	auto posNoClose = fileDestructorNoClose.tellg();
+
+	std::ifstream fileDestructorExplicitClose(EXAMPLE_PCAP_DESTRUCTOR2_PATH, std::ios::binary | std::ios::in);
+	fileDestructorExplicitClose.seekg(0, std::ios::end);
+	auto posExplicitClose = fileDestructorExplicitClose.tellg();
+
+	// sizes should be non-zero and match if files both got closed properly
+	PTF_ASSERT_NOT_EQUAL(0, posNoClose);
+	PTF_ASSERT_NOT_EQUAL(0, posExplicitClose);
+	PTF_ASSERT_EQUAL(posNoClose, posExplicitClose);
+}  // TestPcapFileWriterDeviceDestructor

Tests/Pcap++Test/main.cpp

@@ -227,6 +227,7 @@ int main(int argc, char* argv[])
 	PTF_RUN_TEST(TestPcapFileReadLinkTypeIPv6, "no_network;pcap");
 	PTF_RUN_TEST(TestPcapFileReadLinkTypeIPv4, "no_network;pcap");
 	PTF_RUN_TEST(TestSolarisSnoopFileRead, "no_network;pcap;snoop");
+	PTF_RUN_TEST(TestPcapFileWriterDeviceDestructor, "no_network;pcap");
 
 	PTF_RUN_TEST(TestPcapLiveDeviceList, "no_network;live_device;skip_mem_leak_check");
 	PTF_RUN_TEST(TestPcapLiveDeviceListSearch, "live_device");