dnsresolver_binder_test.cpp - platform/packages/modules/DnsResolver - Git at Google

 /*
  * Copyright 2019 The Android Open Source Project
  *
  * 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.
  */

 #ifdef NDEBUG
 #undef NDEBUG
 #endif

 #include <netdb.h>

 #include <iostream>
 #include <vector>

 #include <android-base/strings.h>
 #include <android/net/IDnsResolver.h>
 #include <binder/IPCThreadState.h>
 #include <binder/IServiceManager.h>
 #include <gmock/gmock-matchers.h>
 #include <gtest/gtest.h>
 #include <netdutils/Stopwatch.h>

 #include "tests/dns_metrics_listener/base_metrics_listener.h"
 #include "tests/dns_metrics_listener/test_metrics.h"

 #include "ResolverStats.h"
 #include "dns_responder.h"
 #include "dns_responder_client.h"

 namespace binder = android::binder;

 using android::IBinder;
 using android::IServiceManager;
 using android::ProcessState;
 using android::sp;
 using android::String16;
 using android::String8;
 using android::net::IDnsResolver;
 using android::net::ResolverParamsParcel;
 using android::net::ResolverStats;
 using android::net::metrics::INetdEventListener;
 using android::net::metrics::TestOnDnsEvent;
 using android::netdutils::Stopwatch;

 // TODO: make this dynamic and stop depending on implementation details.
 // Sync from TEST_NETID in dns_responder_client.cpp as resolv_integration_test.cpp does.
 constexpr int TEST_NETID = 30;

 class DnsResolverBinderTest : public ::testing::Test {
   public:
     DnsResolverBinderTest() {
         sp<IServiceManager> sm = android::defaultServiceManager();
         sp<IBinder> binder = sm->getService(String16("dnsresolver"));
         if (binder != nullptr) {
             mDnsResolver = android::interface_cast<IDnsResolver>(binder);
         }
         // This could happen when the test isn't running as root, or if netd isn't running.
         assert(nullptr != mDnsResolver.get());
         // Create cache for test
         mDnsResolver->createNetworkCache(TEST_NETID);
     }

     ~DnsResolverBinderTest() {
         // Destroy cache for test
         mDnsResolver->destroyNetworkCache(TEST_NETID);
     }

   protected:
     sp<IDnsResolver> mDnsResolver;
 };

 class TimedOperation : public Stopwatch {
   public:
     explicit TimedOperation(const std::string& name) : mName(name) {}
     virtual ~TimedOperation() {
         std::cerr << "    " << mName << ": " << timeTakenUs() << "us" << std::endl;
     }

   private:
     std::string mName;
 };

 namespace {

 // TODO: Convert tests to ResolverParamsParcel and delete this stub.
 ResolverParamsParcel makeResolverParamsParcel(int netId, const std::vector<int>& params,
                                               const std::vector<std::string>& servers,
                                               const std::vector<std::string>& domains,
                                               const std::string& tlsHostname,
                                               const std::vector<std::string>& tlsServers) {
     using android::net::IDnsResolver;
     ResolverParamsParcel paramsParcel;

     paramsParcel.netId = netId;
     paramsParcel.sampleValiditySeconds = params[IDnsResolver::RESOLVER_PARAMS_SAMPLE_VALIDITY];
     paramsParcel.successThreshold = params[IDnsResolver::RESOLVER_PARAMS_SUCCESS_THRESHOLD];
     paramsParcel.minSamples = params[IDnsResolver::RESOLVER_PARAMS_MIN_SAMPLES];
     paramsParcel.maxSamples = params[IDnsResolver::RESOLVER_PARAMS_MAX_SAMPLES];
     if (params.size() > IDnsResolver::RESOLVER_PARAMS_BASE_TIMEOUT_MSEC) {
         paramsParcel.baseTimeoutMsec = params[IDnsResolver::RESOLVER_PARAMS_BASE_TIMEOUT_MSEC];
     } else {
         paramsParcel.baseTimeoutMsec = 0;
     }
     if (params.size() > IDnsResolver::RESOLVER_PARAMS_RETRY_COUNT) {
         paramsParcel.retryCount = params[IDnsResolver::RESOLVER_PARAMS_RETRY_COUNT];
     } else {
         paramsParcel.retryCount = 0;
     }
     paramsParcel.servers = servers;
     paramsParcel.domains = domains;
     paramsParcel.tlsName = tlsHostname;
     paramsParcel.tlsServers = tlsServers;
     paramsParcel.tlsFingerprints = {};

     return paramsParcel;
 }

 }  // namespace

 TEST_F(DnsResolverBinderTest, IsAlive) {
     TimedOperation t("isAlive RPC");
     bool isAlive = false;
     mDnsResolver->isAlive(&isAlive);
     ASSERT_TRUE(isAlive);
 }

 TEST_F(DnsResolverBinderTest, RegisterEventListener_NullListener) {
     android::binder::Status status = mDnsResolver->registerEventListener(
             android::interface_cast<INetdEventListener>(nullptr));
     ASSERT_FALSE(status.isOk());
     ASSERT_EQ(EINVAL, status.serviceSpecificErrorCode());
 }

 TEST_F(DnsResolverBinderTest, RegisterEventListener_DuplicateSubscription) {
     class DummyListener : public android::net::metrics::BaseMetricsListener {};

     // Expect to subscribe successfully.
     android::sp<DummyListener> dummyListener = new DummyListener();
     android::binder::Status status = mDnsResolver->registerEventListener(
             android::interface_cast<INetdEventListener>(dummyListener));
     ASSERT_TRUE(status.isOk()) << status.exceptionMessage();

     // Expect to subscribe failed with registered listener instance.
     status = mDnsResolver->registerEventListener(
             android::interface_cast<INetdEventListener>(dummyListener));
     ASSERT_FALSE(status.isOk());
     ASSERT_EQ(EEXIST, status.serviceSpecificErrorCode());
 }

 // TODO: Move this test to resolv_integration_test.cpp
 TEST_F(DnsResolverBinderTest, RegisterEventListener_onDnsEvent) {
     // The test configs are used to trigger expected events. The expected results are defined in
     // expectedResults.
     static const struct TestConfig {
         std::string hostname;
         int returnCode;
     } testConfigs[] = {
             {"hi", 0 /*success*/},
             {"nonexistent", EAI_NODATA},
     };

     // The expected results define expected event content for test verification.
     static const std::vector<TestOnDnsEvent::TestResult> expectedResults = {
             {TEST_NETID, INetdEventListener::EVENT_GETADDRINFO, 0 /*success*/, 1, "hi", "1.2.3.4"},
             {TEST_NETID, INetdEventListener::EVENT_GETADDRINFO, EAI_NODATA, 0, "nonexistent", ""},
     };

     // Start the Binder thread pool.
     // TODO: Consider doing this once if there has another event listener unit test.
     android::ProcessState::self()->startThreadPool();

     // Setup network.
     // TODO: Setup device configuration and DNS responser server as resolver test does.
     // Currently, leave DNS related configuration in this test because only it needs DNS
     // client-server testing environment.
     DnsResponderClient dnsClient;
     dnsClient.SetUp();

     // Setup DNS responder server.
     constexpr char listen_addr[] = "127.0.0.3";
     constexpr char listen_srv[] = "53";
     test::DNSResponder dns(listen_addr, listen_srv, ns_rcode::ns_r_servfail);
     dns.addMapping("hi.example.com.", ns_type::ns_t_a, "1.2.3.4");
     ASSERT_TRUE(dns.startServer());

     // Setup DNS configuration.
     const std::vector<std::string> test_servers = {listen_addr};
     std::vector<std::string> test_domains = {"example.com"};
     std::vector<int> test_params = {300 /*sample_validity*/, 25 /*success_threshold*/,
                                     8 /*min_samples*/, 8 /*max_samples*/};

     ASSERT_TRUE(dnsClient.SetResolversForNetwork(test_servers, test_domains, test_params));
     dns.clearQueries();

     // Register event listener.
     android::sp<TestOnDnsEvent> testOnDnsEvent = new TestOnDnsEvent(expectedResults);
     android::binder::Status status = mDnsResolver->registerEventListener(
             android::interface_cast<INetdEventListener>(testOnDnsEvent));
     ASSERT_TRUE(status.isOk()) << status.exceptionMessage();

     // DNS queries.
     // Once all expected events of expectedResults are received by the listener, the unit test will
     // be notified. Otherwise, notified with a timeout expired failure.
     auto& cv = testOnDnsEvent->getCv();
     auto& cvMutex = testOnDnsEvent->getCvMutex();
     {
         std::unique_lock lock(cvMutex);

         for (const auto& config : testConfigs) {
             SCOPED_TRACE(config.hostname);

             addrinfo* result = nullptr;
             addrinfo hints = {.ai_family = AF_INET, .ai_socktype = SOCK_DGRAM};
             int status = getaddrinfo(config.hostname.c_str(), nullptr, &hints, &result);
             EXPECT_EQ(config.returnCode, status);

             if (result) freeaddrinfo(result);
         }

         // Wait for receiving expected events.
         EXPECT_EQ(std::cv_status::no_timeout, cv.wait_for(lock, std::chrono::seconds(2)));
     }

     // Verify that all testcases are passed.
     EXPECT_TRUE(testOnDnsEvent->isVerified());

     dnsClient.TearDown();
 }

 // TODO: Need to test more than one server cases.
 TEST_F(DnsResolverBinderTest, SetResolverConfiguration_Tls) {
     const std::vector<std::string> LOCALLY_ASSIGNED_DNS{"8.8.8.8", "2001:4860:4860::8888"};
     static const std::vector<std::string> valid_v4_addr = {"192.0.2.1"};
     static const std::vector<std::string> valid_v6_addr = {"2001:db8::2"};
     static const std::vector<std::string> invalid_v4_addr = {"192.0.*.5"};
     static const std::vector<std::string> invalid_v6_addr = {"2001:dg8::6"};
     constexpr char valid_tls_name[] = "example.com";
     std::vector<int> test_params = {300, 25, 8, 8};
     // We enumerate valid and invalid v4/v6 address, and several different TLS names
     // to be the input data and verify the binder status.
     static const struct TestData {
         const std::vector<std::string> servers;
         const std::string tlsName;
         const int expectedReturnCode;
     } kTlsTestData[] = {
             {valid_v4_addr, valid_tls_name, 0},
             {valid_v4_addr, "host.com", 0},
             {valid_v4_addr, "@@@@", 0},
             {valid_v4_addr, "", 0},
             {valid_v6_addr, valid_tls_name, 0},
             {valid_v6_addr, "host.com", 0},
             {valid_v6_addr, "@@@@", 0},
             {valid_v6_addr, "", 0},
             {invalid_v4_addr, valid_tls_name, EINVAL},
             {invalid_v4_addr, "host.com", EINVAL},
             {invalid_v4_addr, "@@@@", EINVAL},
             {invalid_v4_addr, "", EINVAL},
             {invalid_v6_addr, valid_tls_name, EINVAL},
             {invalid_v6_addr, "host.com", EINVAL},
             {invalid_v6_addr, "@@@@", EINVAL},
             {invalid_v6_addr, "", EINVAL},
             {{}, "", 0},
             {{""}, "", EINVAL},
     };

     for (size_t i = 0; i < std::size(kTlsTestData); i++) {
         const auto& td = kTlsTestData[i];

         const auto resolverParams = makeResolverParamsParcel(
                 TEST_NETID, test_params, LOCALLY_ASSIGNED_DNS, {}, td.tlsName, td.servers);
         binder::Status status = mDnsResolver->setResolverConfiguration(resolverParams);

         if (td.expectedReturnCode == 0) {
             SCOPED_TRACE(String8::format("test case %zu should have passed", i));
             SCOPED_TRACE(status.toString8());
             EXPECT_EQ(0, status.exceptionCode());
         } else {
             SCOPED_TRACE(String8::format("test case %zu should have failed", i));
             EXPECT_EQ(binder::Status::EX_SERVICE_SPECIFIC, status.exceptionCode());
             EXPECT_EQ(td.expectedReturnCode, status.serviceSpecificErrorCode());
         }
     }
 }

 TEST_F(DnsResolverBinderTest, GetResolverInfo) {
     std::vector<std::string> servers = {"127.0.0.1", "127.0.0.2"};
     std::vector<std::string> domains = {"example.com"};
     std::vector<int> testParams = {
             300,     // sample validity in seconds
             25,      // success threshod in percent
             8,   8,  // {MIN,MAX}_SAMPLES
             100,     // BASE_TIMEOUT_MSEC
             3,       // retry count
     };
     const auto resolverParams =
             makeResolverParamsParcel(TEST_NETID, testParams, servers, domains, "", {});
     binder::Status status = mDnsResolver->setResolverConfiguration(resolverParams);
     EXPECT_TRUE(status.isOk()) << status.exceptionMessage();

     std::vector<std::string> res_servers;
     std::vector<std::string> res_domains;
     std::vector<std::string> res_tls_servers;
     std::vector<int32_t> params32;
     std::vector<int32_t> stats32;
     std::vector<int32_t> wait_for_pending_req_timeout_count32{0};
     status = mDnsResolver->getResolverInfo(TEST_NETID, &res_servers, &res_domains, &res_tls_servers,
                                            &params32, &stats32,
                                            &wait_for_pending_req_timeout_count32);

     EXPECT_TRUE(status.isOk()) << status.exceptionMessage();
     EXPECT_EQ(servers.size(), res_servers.size());
     EXPECT_EQ(domains.size(), res_domains.size());
     EXPECT_EQ(0U, res_tls_servers.size());
     ASSERT_EQ(static_cast<size_t>(IDnsResolver::RESOLVER_PARAMS_COUNT), testParams.size());
     EXPECT_EQ(testParams[IDnsResolver::RESOLVER_PARAMS_SAMPLE_VALIDITY],
               params32[IDnsResolver::RESOLVER_PARAMS_SAMPLE_VALIDITY]);
     EXPECT_EQ(testParams[IDnsResolver::RESOLVER_PARAMS_SUCCESS_THRESHOLD],
               params32[IDnsResolver::RESOLVER_PARAMS_SUCCESS_THRESHOLD]);
     EXPECT_EQ(testParams[IDnsResolver::RESOLVER_PARAMS_MIN_SAMPLES],
               params32[IDnsResolver::RESOLVER_PARAMS_MIN_SAMPLES]);
     EXPECT_EQ(testParams[IDnsResolver::RESOLVER_PARAMS_MAX_SAMPLES],
               params32[IDnsResolver::RESOLVER_PARAMS_MAX_SAMPLES]);
     EXPECT_EQ(testParams[IDnsResolver::RESOLVER_PARAMS_BASE_TIMEOUT_MSEC],
               params32[IDnsResolver::RESOLVER_PARAMS_BASE_TIMEOUT_MSEC]);
     EXPECT_EQ(testParams[IDnsResolver::RESOLVER_PARAMS_RETRY_COUNT],
               params32[IDnsResolver::RESOLVER_PARAMS_RETRY_COUNT]);

     std::vector<ResolverStats> stats;
     ResolverStats::decodeAll(stats32, &stats);

     EXPECT_EQ(servers.size(), stats.size());

     EXPECT_THAT(res_servers, testing::UnorderedElementsAreArray(servers));
     EXPECT_THAT(res_domains, testing::UnorderedElementsAreArray(domains));
 }

 TEST_F(DnsResolverBinderTest, CreateDestroyNetworkCache) {
     // Must not be the same as TEST_NETID
     const int ANOTHER_TEST_NETID = TEST_NETID + 1;

     // Create a new network cache.
     EXPECT_TRUE(mDnsResolver->createNetworkCache(ANOTHER_TEST_NETID).isOk());

     // create it again, expect a EEXIST.
     EXPECT_EQ(EEXIST,
               mDnsResolver->createNetworkCache(ANOTHER_TEST_NETID).serviceSpecificErrorCode());

     // destroy it.
     EXPECT_TRUE(mDnsResolver->destroyNetworkCache(ANOTHER_TEST_NETID).isOk());

     // re-create it
     EXPECT_TRUE(mDnsResolver->createNetworkCache(ANOTHER_TEST_NETID).isOk());

     // destroy it.
     EXPECT_TRUE(mDnsResolver->destroyNetworkCache(ANOTHER_TEST_NETID).isOk());

     // re-destroy it
     EXPECT_TRUE(mDnsResolver->destroyNetworkCache(ANOTHER_TEST_NETID).isOk());
 }

 TEST_F(DnsResolverBinderTest, setLogSeverity) {
     // Expect fail
     EXPECT_EQ(EINVAL, mDnsResolver->setLogSeverity(-1).serviceSpecificErrorCode());

     // Test set different log level
     EXPECT_TRUE(mDnsResolver->setLogSeverity(IDnsResolver::DNS_RESOLVER_LOG_VERBOSE).isOk());

     EXPECT_TRUE(mDnsResolver->setLogSeverity(IDnsResolver::DNS_RESOLVER_LOG_DEBUG).isOk());

     EXPECT_TRUE(mDnsResolver->setLogSeverity(IDnsResolver::DNS_RESOLVER_LOG_INFO).isOk());

     EXPECT_TRUE(mDnsResolver->setLogSeverity(IDnsResolver::DNS_RESOLVER_LOG_WARNING).isOk());

     EXPECT_TRUE(mDnsResolver->setLogSeverity(IDnsResolver::DNS_RESOLVER_LOG_ERROR).isOk());

     // Set back to default
     EXPECT_TRUE(mDnsResolver->setLogSeverity(IDnsResolver::DNS_RESOLVER_LOG_WARNING).isOk());
 }
	/*
	* Copyright 2019 The Android Open Source Project
	*
	* 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.
	*/

	#ifdef NDEBUG
	#undef NDEBUG
	#endif

	#include <netdb.h>

	#include <iostream>
	#include <vector>

	#include <android-base/strings.h>
	#include <android/net/IDnsResolver.h>
	#include <binder/IPCThreadState.h>
	#include <binder/IServiceManager.h>
	#include <gmock/gmock-matchers.h>
	#include <gtest/gtest.h>
	#include <netdutils/Stopwatch.h>

	#include "tests/dns_metrics_listener/base_metrics_listener.h"
	#include "tests/dns_metrics_listener/test_metrics.h"

	#include "ResolverStats.h"
	#include "dns_responder.h"
	#include "dns_responder_client.h"

	namespace binder = android::binder;

	using android::IBinder;
	using android::IServiceManager;
	using android::ProcessState;
	using android::sp;
	using android::String16;
	using android::String8;
	using android::net::IDnsResolver;
	using android::net::ResolverParamsParcel;
	using android::net::ResolverStats;
	using android::net::metrics::INetdEventListener;
	using android::net::metrics::TestOnDnsEvent;
	using android::netdutils::Stopwatch;

	// TODO: make this dynamic and stop depending on implementation details.
	// Sync from TEST_NETID in dns_responder_client.cpp as resolv_integration_test.cpp does.
	constexpr int TEST_NETID = 30;

	class DnsResolverBinderTest : public ::testing::Test {
	public:
	DnsResolverBinderTest() {
	sp<IServiceManager> sm = android::defaultServiceManager();
	sp<IBinder> binder = sm->getService(String16("dnsresolver"));
	if (binder != nullptr) {
	mDnsResolver = android::interface_cast<IDnsResolver>(binder);
	}
	// This could happen when the test isn't running as root, or if netd isn't running.
	assert(nullptr != mDnsResolver.get());
	// Create cache for test
	mDnsResolver->createNetworkCache(TEST_NETID);
	}

	~DnsResolverBinderTest() {
	// Destroy cache for test
	mDnsResolver->destroyNetworkCache(TEST_NETID);
	}

	protected:
	sp<IDnsResolver> mDnsResolver;
	};

	class TimedOperation : public Stopwatch {
	public:
	explicit TimedOperation(const std::string& name) : mName(name) {}
	virtual ~TimedOperation() {
	std::cerr << " " << mName << ": " << timeTakenUs() << "us" << std::endl;
	}

	private:
	std::string mName;
	};

	namespace {

	// TODO: Convert tests to ResolverParamsParcel and delete this stub.
	ResolverParamsParcel makeResolverParamsParcel(int netId, const std::vector<int>& params,
	const std::vector<std::string>& servers,
	const std::vector<std::string>& domains,
	const std::string& tlsHostname,
	const std::vector<std::string>& tlsServers) {
	using android::net::IDnsResolver;
	ResolverParamsParcel paramsParcel;

	paramsParcel.netId = netId;
	paramsParcel.sampleValiditySeconds = params[IDnsResolver::RESOLVER_PARAMS_SAMPLE_VALIDITY];
	paramsParcel.successThreshold = params[IDnsResolver::RESOLVER_PARAMS_SUCCESS_THRESHOLD];
	paramsParcel.minSamples = params[IDnsResolver::RESOLVER_PARAMS_MIN_SAMPLES];
	paramsParcel.maxSamples = params[IDnsResolver::RESOLVER_PARAMS_MAX_SAMPLES];
	if (params.size() > IDnsResolver::RESOLVER_PARAMS_BASE_TIMEOUT_MSEC) {
	paramsParcel.baseTimeoutMsec = params[IDnsResolver::RESOLVER_PARAMS_BASE_TIMEOUT_MSEC];
	} else {
	paramsParcel.baseTimeoutMsec = 0;
	}
	if (params.size() > IDnsResolver::RESOLVER_PARAMS_RETRY_COUNT) {
	paramsParcel.retryCount = params[IDnsResolver::RESOLVER_PARAMS_RETRY_COUNT];
	} else {
	paramsParcel.retryCount = 0;
	}
	paramsParcel.servers = servers;
	paramsParcel.domains = domains;
	paramsParcel.tlsName = tlsHostname;
	paramsParcel.tlsServers = tlsServers;
	paramsParcel.tlsFingerprints = {};

	return paramsParcel;
	}

	} // namespace

	TEST_F(DnsResolverBinderTest, IsAlive) {
	TimedOperation t("isAlive RPC");
	bool isAlive = false;
	mDnsResolver->isAlive(&isAlive);
	ASSERT_TRUE(isAlive);
	}

	TEST_F(DnsResolverBinderTest, RegisterEventListener_NullListener) {
	android::binder::Status status = mDnsResolver->registerEventListener(
	android::interface_cast<INetdEventListener>(nullptr));
	ASSERT_FALSE(status.isOk());
	ASSERT_EQ(EINVAL, status.serviceSpecificErrorCode());
	}

	TEST_F(DnsResolverBinderTest, RegisterEventListener_DuplicateSubscription) {
	class DummyListener : public android::net::metrics::BaseMetricsListener {};

	// Expect to subscribe successfully.
	android::sp<DummyListener> dummyListener = new DummyListener();
	android::binder::Status status = mDnsResolver->registerEventListener(
	android::interface_cast<INetdEventListener>(dummyListener));
	ASSERT_TRUE(status.isOk()) << status.exceptionMessage();

	// Expect to subscribe failed with registered listener instance.
	status = mDnsResolver->registerEventListener(
	android::interface_cast<INetdEventListener>(dummyListener));
	ASSERT_FALSE(status.isOk());
	ASSERT_EQ(EEXIST, status.serviceSpecificErrorCode());
	}

	// TODO: Move this test to resolv_integration_test.cpp
	TEST_F(DnsResolverBinderTest, RegisterEventListener_onDnsEvent) {
	// The test configs are used to trigger expected events. The expected results are defined in
	// expectedResults.
	static const struct TestConfig {
	std::string hostname;
	int returnCode;
	} testConfigs[] = {
	{"hi", 0 /success/},
	{"nonexistent", EAI_NODATA},
	};

	// The expected results define expected event content for test verification.
	static const std::vector<TestOnDnsEvent::TestResult> expectedResults = {
	{TEST_NETID, INetdEventListener::EVENT_GETADDRINFO, 0 /success/, 1, "hi", "1.2.3.4"},
	{TEST_NETID, INetdEventListener::EVENT_GETADDRINFO, EAI_NODATA, 0, "nonexistent", ""},
	};

	// Start the Binder thread pool.
	// TODO: Consider doing this once if there has another event listener unit test.
	android::ProcessState::self()->startThreadPool();

	// Setup network.
	// TODO: Setup device configuration and DNS responser server as resolver test does.
	// Currently, leave DNS related configuration in this test because only it needs DNS
	// client-server testing environment.
	DnsResponderClient dnsClient;
	dnsClient.SetUp();

	// Setup DNS responder server.
	constexpr char listen_addr[] = "127.0.0.3";
	constexpr char listen_srv[] = "53";
	test::DNSResponder dns(listen_addr, listen_srv, ns_rcode::ns_r_servfail);
	dns.addMapping("hi.example.com.", ns_type::ns_t_a, "1.2.3.4");
	ASSERT_TRUE(dns.startServer());

	// Setup DNS configuration.
	const std::vector<std::string> test_servers = {listen_addr};
	std::vector<std::string> test_domains = {"example.com"};
	std::vector<int> test_params = {300 /sample_validity/, 25 /success_threshold/,
	8 /min_samples/, 8 /max_samples/};

	ASSERT_TRUE(dnsClient.SetResolversForNetwork(test_servers, test_domains, test_params));
	dns.clearQueries();

	// Register event listener.
	android::sp<TestOnDnsEvent> testOnDnsEvent = new TestOnDnsEvent(expectedResults);
	android::binder::Status status = mDnsResolver->registerEventListener(
	android::interface_cast<INetdEventListener>(testOnDnsEvent));
	ASSERT_TRUE(status.isOk()) << status.exceptionMessage();

	// DNS queries.
	// Once all expected events of expectedResults are received by the listener, the unit test will
	// be notified. Otherwise, notified with a timeout expired failure.
	auto& cv = testOnDnsEvent->getCv();
	auto& cvMutex = testOnDnsEvent->getCvMutex();
	{
	std::unique_lock lock(cvMutex);

	for (const auto& config : testConfigs) {
	SCOPED_TRACE(config.hostname);

	addrinfo* result = nullptr;
	addrinfo hints = {.ai_family = AF_INET, .ai_socktype = SOCK_DGRAM};
	int status = getaddrinfo(config.hostname.c_str(), nullptr, &hints, &result);
	EXPECT_EQ(config.returnCode, status);

	if (result) freeaddrinfo(result);
	}

	// Wait for receiving expected events.
	EXPECT_EQ(std::cv_status::no_timeout, cv.wait_for(lock, std::chrono::seconds(2)));
	}

	// Verify that all testcases are passed.
	EXPECT_TRUE(testOnDnsEvent->isVerified());

	dnsClient.TearDown();
	}

	// TODO: Need to test more than one server cases.
	TEST_F(DnsResolverBinderTest, SetResolverConfiguration_Tls) {
	const std::vector<std::string> LOCALLY_ASSIGNED_DNS{"8.8.8.8", "2001:4860:4860::8888"};
	static const std::vector<std::string> valid_v4_addr = {"192.0.2.1"};
	static const std::vector<std::string> valid_v6_addr = {"2001:db8::2"};
	static const std::vector<std::string> invalid_v4_addr = {"192.0.*.5"};
	static const std::vector<std::string> invalid_v6_addr = {"2001:dg8::6"};
	constexpr char valid_tls_name[] = "example.com";
	std::vector<int> test_params = {300, 25, 8, 8};
	// We enumerate valid and invalid v4/v6 address, and several different TLS names
	// to be the input data and verify the binder status.
	static const struct TestData {
	const std::vector<std::string> servers;
	const std::string tlsName;
	const int expectedReturnCode;
	} kTlsTestData[] = {
	{valid_v4_addr, valid_tls_name, 0},
	{valid_v4_addr, "host.com", 0},
	{valid_v4_addr, "@@@@", 0},
	{valid_v4_addr, "", 0},
	{valid_v6_addr, valid_tls_name, 0},
	{valid_v6_addr, "host.com", 0},
	{valid_v6_addr, "@@@@", 0},
	{valid_v6_addr, "", 0},
	{invalid_v4_addr, valid_tls_name, EINVAL},
	{invalid_v4_addr, "host.com", EINVAL},
	{invalid_v4_addr, "@@@@", EINVAL},
	{invalid_v4_addr, "", EINVAL},
	{invalid_v6_addr, valid_tls_name, EINVAL},
	{invalid_v6_addr, "host.com", EINVAL},
	{invalid_v6_addr, "@@@@", EINVAL},
	{invalid_v6_addr, "", EINVAL},
	{{}, "", 0},
	{{""}, "", EINVAL},
	};

	for (size_t i = 0; i < std::size(kTlsTestData); i++) {
	const auto& td = kTlsTestData[i];

	const auto resolverParams = makeResolverParamsParcel(
	TEST_NETID, test_params, LOCALLY_ASSIGNED_DNS, {}, td.tlsName, td.servers);
	binder::Status status = mDnsResolver->setResolverConfiguration(resolverParams);

	if (td.expectedReturnCode == 0) {
	SCOPED_TRACE(String8::format("test case %zu should have passed", i));
	SCOPED_TRACE(status.toString8());
	EXPECT_EQ(0, status.exceptionCode());
	} else {
	SCOPED_TRACE(String8::format("test case %zu should have failed", i));
	EXPECT_EQ(binder::Status::EX_SERVICE_SPECIFIC, status.exceptionCode());
	EXPECT_EQ(td.expectedReturnCode, status.serviceSpecificErrorCode());
	}
	}
	}

	TEST_F(DnsResolverBinderTest, GetResolverInfo) {
	std::vector<std::string> servers = {"127.0.0.1", "127.0.0.2"};
	std::vector<std::string> domains = {"example.com"};
	std::vector<int> testParams = {
	300, // sample validity in seconds
	25, // success threshod in percent
	8, 8, // {MIN,MAX}_SAMPLES
	100, // BASE_TIMEOUT_MSEC
	3, // retry count
	};
	const auto resolverParams =
	makeResolverParamsParcel(TEST_NETID, testParams, servers, domains, "", {});
	binder::Status status = mDnsResolver->setResolverConfiguration(resolverParams);
	EXPECT_TRUE(status.isOk()) << status.exceptionMessage();

	std::vector<std::string> res_servers;
	std::vector<std::string> res_domains;
	std::vector<std::string> res_tls_servers;
	std::vector<int32_t> params32;
	std::vector<int32_t> stats32;
	std::vector<int32_t> wait_for_pending_req_timeout_count32{0};
	status = mDnsResolver->getResolverInfo(TEST_NETID, &res_servers, &res_domains, &res_tls_servers,
	&params32, &stats32,
	&wait_for_pending_req_timeout_count32);

	EXPECT_TRUE(status.isOk()) << status.exceptionMessage();
	EXPECT_EQ(servers.size(), res_servers.size());
	EXPECT_EQ(domains.size(), res_domains.size());
	EXPECT_EQ(0U, res_tls_servers.size());
	ASSERT_EQ(static_cast<size_t>(IDnsResolver::RESOLVER_PARAMS_COUNT), testParams.size());
	EXPECT_EQ(testParams[IDnsResolver::RESOLVER_PARAMS_SAMPLE_VALIDITY],
	params32[IDnsResolver::RESOLVER_PARAMS_SAMPLE_VALIDITY]);
	EXPECT_EQ(testParams[IDnsResolver::RESOLVER_PARAMS_SUCCESS_THRESHOLD],
	params32[IDnsResolver::RESOLVER_PARAMS_SUCCESS_THRESHOLD]);
	EXPECT_EQ(testParams[IDnsResolver::RESOLVER_PARAMS_MIN_SAMPLES],
	params32[IDnsResolver::RESOLVER_PARAMS_MIN_SAMPLES]);
	EXPECT_EQ(testParams[IDnsResolver::RESOLVER_PARAMS_MAX_SAMPLES],
	params32[IDnsResolver::RESOLVER_PARAMS_MAX_SAMPLES]);
	EXPECT_EQ(testParams[IDnsResolver::RESOLVER_PARAMS_BASE_TIMEOUT_MSEC],
	params32[IDnsResolver::RESOLVER_PARAMS_BASE_TIMEOUT_MSEC]);
	EXPECT_EQ(testParams[IDnsResolver::RESOLVER_PARAMS_RETRY_COUNT],
	params32[IDnsResolver::RESOLVER_PARAMS_RETRY_COUNT]);

	std::vector<ResolverStats> stats;
	ResolverStats::decodeAll(stats32, &stats);

	EXPECT_EQ(servers.size(), stats.size());

	EXPECT_THAT(res_servers, testing::UnorderedElementsAreArray(servers));
	EXPECT_THAT(res_domains, testing::UnorderedElementsAreArray(domains));
	}

	TEST_F(DnsResolverBinderTest, CreateDestroyNetworkCache) {
	// Must not be the same as TEST_NETID
	const int ANOTHER_TEST_NETID = TEST_NETID + 1;

	// Create a new network cache.
	EXPECT_TRUE(mDnsResolver->createNetworkCache(ANOTHER_TEST_NETID).isOk());

	// create it again, expect a EEXIST.
	EXPECT_EQ(EEXIST,
	mDnsResolver->createNetworkCache(ANOTHER_TEST_NETID).serviceSpecificErrorCode());

	// destroy it.
	EXPECT_TRUE(mDnsResolver->destroyNetworkCache(ANOTHER_TEST_NETID).isOk());

	// re-create it
	EXPECT_TRUE(mDnsResolver->createNetworkCache(ANOTHER_TEST_NETID).isOk());

	// destroy it.
	EXPECT_TRUE(mDnsResolver->destroyNetworkCache(ANOTHER_TEST_NETID).isOk());

	// re-destroy it
	EXPECT_TRUE(mDnsResolver->destroyNetworkCache(ANOTHER_TEST_NETID).isOk());
	}

	TEST_F(DnsResolverBinderTest, setLogSeverity) {
	// Expect fail
	EXPECT_EQ(EINVAL, mDnsResolver->setLogSeverity(-1).serviceSpecificErrorCode());

	// Test set different log level
	EXPECT_TRUE(mDnsResolver->setLogSeverity(IDnsResolver::DNS_RESOLVER_LOG_VERBOSE).isOk());

	EXPECT_TRUE(mDnsResolver->setLogSeverity(IDnsResolver::DNS_RESOLVER_LOG_DEBUG).isOk());

	EXPECT_TRUE(mDnsResolver->setLogSeverity(IDnsResolver::DNS_RESOLVER_LOG_INFO).isOk());

	EXPECT_TRUE(mDnsResolver->setLogSeverity(IDnsResolver::DNS_RESOLVER_LOG_WARNING).isOk());

	EXPECT_TRUE(mDnsResolver->setLogSeverity(IDnsResolver::DNS_RESOLVER_LOG_ERROR).isOk());

	// Set back to default
	EXPECT_TRUE(mDnsResolver->setLogSeverity(IDnsResolver::DNS_RESOLVER_LOG_WARNING).isOk());
	}