refactor(libsinsp): use smart pointer for m_resolver in sinsp_dns_manager

userspace/libsinsp/dns_manager.cpp

@@ -118,7 +118,7 @@ bool sinsp_dns_manager::match(const char *name, int af, void *addr, uint64_t ts)
 #if defined(HAS_CAPTURE) && !defined(CYGWING_AGENT) && !defined(_WIN32) && !defined(__EMSCRIPTEN__)
 	if(!m_resolver)
 	{
-		m_resolver = new std::thread(sinsp_dns_resolver::refresh, m_erase_timeout, m_base_refresh_timeout, m_max_refresh_timeout, m_exit_signal.get_future());
+		m_resolver = std::make_unique<std::thread>(sinsp_dns_resolver::refresh, m_erase_timeout, m_base_refresh_timeout, m_max_refresh_timeout, m_exit_signal.get_future());
 	}
 
 	std::string sname = std::string(name);
@@ -195,7 +195,7 @@ void sinsp_dns_manager::cleanup()
 	{
 		m_exit_signal.set_value();
 		m_resolver->join();
-		m_resolver = NULL;
+		m_resolver.reset();
 		m_exit_signal = std::promise<void>();
 	}
 }

userspace/libsinsp/dns_manager.h

@@ -124,7 +124,7 @@ class sinsp_dns_manager
 	// used to let m_resolver know when to terminate
 	std::promise<void> m_exit_signal;
 
-	std::thread *m_resolver;
+	std::unique_ptr<std::thread> m_resolver;
 
 	uint64_t m_erase_timeout;
 	uint64_t m_base_refresh_timeout;

userspace/libsinsp/test/CMakeLists.txt

@@ -110,6 +110,7 @@ set(LIBSINSP_UNIT_TESTS_SOURCES
 	container_info.ut.cpp
 	sinsp_utils.ut.cpp
 	state.ut.cpp
+	dns_manager.ut.cpp
 	eventformatter.ut.cpp
 	savefile.ut.cpp
 	sinsp_stats.ut.cpp
@@ -178,6 +179,7 @@ endif()
 target_link_libraries(unit-test-libsinsp
 	"${GTEST_LIB}"
 	"${GTEST_MAIN_LIB}"
+	"${TBB_LIB}"
 	sinsp
 )
 

userspace/libsinsp/test/dns_manager.ut.cpp

@@ -0,0 +1,33 @@
+// SPDX-License-Identifier: Apache-2.0
+/*
+Copyright (C) 2023 The Falco Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+
+*/
+
+#if defined(HAS_CAPTURE) && !defined(CYGWING_AGENT) && !defined(_WIN32) && !defined(__EMSCRIPTEN__)
+#include <dns_manager.h>
+#include <gtest/gtest.h>
+
+TEST(sinsp_dns_manager, simple_dns_manager_invocation)
+{
+    // Simple dummy test to assert that sinsp_dns_manager is invocated correctly
+    // and not leaking memory
+    const char* name = "bogus";
+    uint64_t ts = 11111111111111;
+    uint32_t addr = 111111;
+    bool result = sinsp_dns_manager::get().match(name, AF_INET, &addr, ts);
+    ASSERT_FALSE(result);
+}
+#endif