resolv_integration_test: Retrieve NAT64 prefix through DNS event listener

Currently, the unit test could retrieve NAT64 prefix through registering a
DNS event listener. It doesn't need to query the prefix through the binder
interface method getPrefix64() anymore.

Test: built, flashed, booted
      system/netd/tests/runtests.sh passes

Change-Id: I54386f7d8c03f7009c12fe3fc39da85985d8d3ad

8 files changed, 266 insertions, 132 deletions

diff --git a/tests/BaseTestMetricsListener.h b/tests/BaseTestMetricsListener.h
deleted file mode 100644
index 326647b7..00000000
--- a/tests/BaseTestMetricsListener.h
+++ /dev/null
@@ -1,104 +0,0 @@
-/**
- * Copyright (c) 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.
- */
-
-#ifndef _BASE_TEST_METRICS_LISTENER_H_
-#define _BASE_TEST_METRICS_LISTENER_H_
-
-#include <string>
-#include <vector>
-
-#include <binder/BinderService.h>
-
-#include "android/net/metrics/BnNetdEventListener.h"
-
-enum EventFlag : uint32_t {
-    onDnsEvent = 1 << 0,
-    onPrivateDnsValidationEvent = 1 << 1,
-    onConnectEvent = 1 << 2,
-    onWakeupEvent = 1 << 3,
-    onTcpSocketStatsEvent = 1 << 4,
-    onNat64PrefixEvent = 1 << 5,
-};
-
-namespace android {
-namespace net {
-namespace metrics {
-
-class BaseTestMetricsListener : public BnNetdEventListener {
-  public:
-    BaseTestMetricsListener() = default;
-    ~BaseTestMetricsListener() = default;
-
-    // Returns TRUE if the verification was successful. Otherwise, returns FALSE.
-    virtual bool isVerified() = 0;
-
-    std::condition_variable& getCv() { return mCv; }
-    std::mutex& getCvMutex() { return mCvMutex; }
-
-    android::binder::Status onDnsEvent(int32_t /*netId*/, int32_t /*eventType*/,
-                                       int32_t /*returnCode*/, int32_t /*latencyMs*/,
-                                       const std::string& /*hostname*/,
-                                       const ::std::vector<std::string>& /*ipAddresses*/,
-                                       int32_t /*ipAddressesCount*/, int32_t /*uid*/) override;
-    android::binder::Status onPrivateDnsValidationEvent(int32_t /*netId*/,
-                                                        const ::android::String16& /*ipAddress*/,
-                                                        const ::android::String16& /*hostname*/,
-                                                        bool /*validated*/) override;
-    android::binder::Status onConnectEvent(int32_t /*netId*/, int32_t /*error*/,
-                                           int32_t /*latencyMs*/,
-                                           const ::android::String16& /*ipAddr*/, int32_t /*port*/,
-                                           int32_t /*uid*/) override;
-    android::binder::Status onWakeupEvent(const ::android::String16& /*prefix*/, int32_t /*uid*/,
-                                          int32_t /*ethertype*/, int32_t /*ipNextHeader*/,
-                                          const ::std::vector<uint8_t>& /*dstHw*/,
-                                          const ::android::String16& /*srcIp*/,
-                                          const ::android::String16& /*dstIp*/, int32_t /*srcPort*/,
-                                          int32_t /*dstPort*/, int64_t /*timestampNs*/) override;
-    android::binder::Status onTcpSocketStatsEvent(
-            const ::std::vector<int32_t>& /*networkIds*/,
-            const ::std::vector<int32_t>& /*sentPackets*/,
-            const ::std::vector<int32_t>& /*lostPackets*/, const ::std::vector<int32_t>& /*rttUs*/,
-            const ::std::vector<int32_t>& /*sentAckDiffMs*/) override;
-    android::binder::Status onNat64PrefixEvent(int32_t /*netId*/, bool /*added*/,
-                                               const ::std::string& /*prefixString*/,
-                                               int32_t /*prefixLength*/) override;
-
-  private:
-    // The verified event(s) as a bitwise-OR combination of enum EventFlag flags.
-    uint32_t mVerified{};
-
-    // This lock prevents racing condition between signaling thread(s) and waiting thread(s).
-    std::mutex mCvMutex;
-
-    // Condition variable signaled when notify() is called.
-    std::condition_variable mCv;
-
-  protected:
-    // Notify who is waiting for test results. See also mCvMutex and mCv.
-    void notify();
-
-    // Get current verified event(s).
-    uint32_t getVerified() const { return mVerified; }
-
-    // Set the specific event as verified if its verification was successful.
-    void setVerified(EventFlag event);
-};
-
-}  // namespace metrics
-}  // namespace net
-}  // namespace android
-
-#endif  // _BASE_TEST_METRICS_LISTENER_H_
diff --git a/tests/dns_metrics_listener/Android.bp b/tests/dns_metrics_listener/Android.bp
new file mode 100644
index 00000000..a0b93c91
--- /dev/null
+++ b/tests/dns_metrics_listener/Android.bp
@@ -0,0 +1,17 @@
+cc_test_library {
+    name: "libnetd_test_metrics_listener",
+    defaults: ["netd_defaults"],
+    srcs: [
+        "base_metrics_listener.cpp",
+        "dns_metrics_listener.cpp",
+        "test_metrics.cpp",
+    ],
+    shared_libs: [
+        "libbase",
+        "libbinder",
+        "libutils",
+    ],
+    static_libs: [
+        "netd_event_listener_interface-V1-cpp",
+    ],
+}
\ No newline at end of file
diff --git a/tests/BaseTestMetricsListener.cpp b/tests/dns_metrics_listener/base_metrics_listener.cpp
index 414e3835..e6dbb325 100644
--- a/tests/BaseTestMetricsListener.cpp
+++ b/tests/dns_metrics_listener/base_metrics_listener.cpp
@@ -14,22 +14,13 @@
  * limitations under the License.
  */
 
-#include "BaseTestMetricsListener.h"
+#include "base_metrics_listener.h"
 
 namespace android {
 namespace net {
 namespace metrics {
 
-void BaseTestMetricsListener::notify() {
-    std::lock_guard lock(mCvMutex);
-    mCv.notify_one();
-}
-
-void BaseTestMetricsListener::setVerified(EventFlag event) {
-    mVerified |= event;
-}
-
-android::binder::Status BaseTestMetricsListener::onDnsEvent(
+android::binder::Status BaseMetricsListener::onDnsEvent(
         int32_t /*netId*/, int32_t /*eventType*/, int32_t /*returnCode*/, int32_t /*latencyMs*/,
         const std::string& /*hostname*/, const ::std::vector<std::string>& /*ipAddresses*/,
         int32_t /*ipAddressesCount*/, int32_t /*uid*/) {
@@ -37,21 +28,22 @@ android::binder::Status BaseTestMetricsListener::onDnsEvent(
     return android::binder::Status::ok();
 };
 
-android::binder::Status BaseTestMetricsListener::onPrivateDnsValidationEvent(
+android::binder::Status BaseMetricsListener::onPrivateDnsValidationEvent(
         int32_t /*netId*/, const ::android::String16& /*ipAddress*/,
         const ::android::String16& /*hostname*/, bool /*validated*/) {
     // default no-op
     return android::binder::Status::ok();
 };
 
-android::binder::Status BaseTestMetricsListener::onConnectEvent(
-        int32_t /*netId*/, int32_t /*error*/, int32_t /*latencyMs*/,
-        const ::android::String16& /*ipAddr*/, int32_t /*port*/, int32_t /*uid*/) {
+android::binder::Status BaseMetricsListener::onConnectEvent(int32_t /*netId*/, int32_t /*error*/,
+                                                            int32_t /*latencyMs*/,
+                                                            const ::android::String16& /*ipAddr*/,
+                                                            int32_t /*port*/, int32_t /*uid*/) {
     // default no-op
     return android::binder::Status::ok();
 };
 
-android::binder::Status BaseTestMetricsListener::onWakeupEvent(
+android::binder::Status BaseMetricsListener::onWakeupEvent(
         const ::android::String16& /*prefix*/, int32_t /*uid*/, int32_t /*ethertype*/,
         int32_t /*ipNextHeader*/, const ::std::vector<uint8_t>& /*dstHw*/,
         const ::android::String16& /*srcIp*/, const ::android::String16& /*dstIp*/,
@@ -60,7 +52,7 @@ android::binder::Status BaseTestMetricsListener::onWakeupEvent(
     return android::binder::Status::ok();
 };
 
-android::binder::Status BaseTestMetricsListener::onTcpSocketStatsEvent(
+android::binder::Status BaseMetricsListener::onTcpSocketStatsEvent(
         const ::std::vector<int32_t>& /*networkIds*/, const ::std::vector<int32_t>& /*sentPackets*/,
         const ::std::vector<int32_t>& /*lostPackets*/, const ::std::vector<int32_t>& /*rttUs*/,
         const ::std::vector<int32_t>& /*sentAckDiffMs*/) {
@@ -68,7 +60,7 @@ android::binder::Status BaseTestMetricsListener::onTcpSocketStatsEvent(
     return android::binder::Status::ok();
 };
 
-android::binder::Status BaseTestMetricsListener::onNat64PrefixEvent(
+android::binder::Status BaseMetricsListener::onNat64PrefixEvent(
         int32_t /*netId*/, bool /*added*/, const ::std::string& /*prefixString*/,
         int32_t /*prefixLength*/) {
     // default no-op
diff --git a/tests/dns_metrics_listener/base_metrics_listener.h b/tests/dns_metrics_listener/base_metrics_listener.h
new file mode 100644
index 00000000..9ba84239
--- /dev/null
+++ b/tests/dns_metrics_listener/base_metrics_listener.h
@@ -0,0 +1,63 @@
+/**
+ * Copyright (c) 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.
+ */
+
+#pragma once
+
+#include <string>
+#include <vector>
+
+#include "android/net/metrics/BnNetdEventListener.h"
+
+namespace android {
+namespace net {
+namespace metrics {
+
+class BaseMetricsListener : public BnNetdEventListener {
+  public:
+    BaseMetricsListener() = default;
+    ~BaseMetricsListener() = default;
+
+    virtual android::binder::Status onDnsEvent(int32_t /*netId*/, int32_t /*eventType*/,
+                                               int32_t /*returnCode*/, int32_t /*latencyMs*/,
+                                               const std::string& /*hostname*/,
+                                               const ::std::vector<std::string>& /*ipAddresses*/,
+                                               int32_t /*ipAddressesCount*/,
+                                               int32_t /*uid*/) override;
+    virtual android::binder::Status onPrivateDnsValidationEvent(
+            int32_t /*netId*/, const ::android::String16& /*ipAddress*/,
+            const ::android::String16& /*hostname*/, bool /*validated*/) override;
+    virtual android::binder::Status onConnectEvent(int32_t /*netId*/, int32_t /*error*/,
+                                                   int32_t /*latencyMs*/,
+                                                   const ::android::String16& /*ipAddr*/,
+                                                   int32_t /*port*/, int32_t /*uid*/) override;
+    virtual android::binder::Status onWakeupEvent(
+            const ::android::String16& /*prefix*/, int32_t /*uid*/, int32_t /*ethertype*/,
+            int32_t /*ipNextHeader*/, const ::std::vector<uint8_t>& /*dstHw*/,
+            const ::android::String16& /*srcIp*/, const ::android::String16& /*dstIp*/,
+            int32_t /*srcPort*/, int32_t /*dstPort*/, int64_t /*timestampNs*/) override;
+    virtual android::binder::Status onTcpSocketStatsEvent(
+            const ::std::vector<int32_t>& /*networkIds*/,
+            const ::std::vector<int32_t>& /*sentPackets*/,
+            const ::std::vector<int32_t>& /*lostPackets*/, const ::std::vector<int32_t>& /*rttUs*/,
+            const ::std::vector<int32_t>& /*sentAckDiffMs*/) override;
+    virtual android::binder::Status onNat64PrefixEvent(int32_t /*netId*/, bool /*added*/,
+                                                       const ::std::string& /*prefixString*/,
+                                                       int32_t /*prefixLength*/) override;
+};
+
+}  // namespace metrics
+}  // namespace net
+}  // namespace android
\ No newline at end of file
diff --git a/tests/dns_metrics_listener/dns_metrics_listener.cpp b/tests/dns_metrics_listener/dns_metrics_listener.cpp
new file mode 100644
index 00000000..8f3b6463
--- /dev/null
+++ b/tests/dns_metrics_listener/dns_metrics_listener.cpp
@@ -0,0 +1,55 @@
+/**
+ * Copyright (c) 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.
+ */
+
+#include "dns_metrics_listener.h"
+
+#include <android-base/chrono_utils.h>
+#include <thread>
+
+namespace android {
+namespace net {
+namespace metrics {
+
+using std::chrono::milliseconds;
+
+constexpr milliseconds kRetryIntervalMs{20};
+
+android::binder::Status DnsMetricsListener::onNat64PrefixEvent(int32_t netId, bool added,
+                                                               const std::string& prefixString,
+                                                               int32_t /*prefixLength*/) {
+    std::lock_guard lock(mMutex);
+    if (netId == mNetId) mNat64Prefix = added ? prefixString : "";
+    return android::binder::Status::ok();
+}
+
+bool DnsMetricsListener::waitForNat64Prefix(ExpectNat64PrefixStatus status,
+                                            milliseconds timeout) const {
+    android::base::Timer t;
+    while (t.duration() < timeout) {
+        {
+            std::lock_guard lock(mMutex);
+            if ((status == EXPECT_FOUND && !mNat64Prefix.empty()) ||
+                (status == EXPECT_NOT_FOUND && mNat64Prefix.empty()))
+                return true;
+        }
+        std::this_thread::sleep_for(kRetryIntervalMs);
+    }
+    return false;
+}
+
+}  // namespace metrics
+}  // namespace net
+}  // namespace android
\ No newline at end of file
diff --git a/tests/dns_metrics_listener/dns_metrics_listener.h b/tests/dns_metrics_listener/dns_metrics_listener.h
new file mode 100644
index 00000000..1f8170d3
--- /dev/null
+++ b/tests/dns_metrics_listener/dns_metrics_listener.h
@@ -0,0 +1,61 @@
+/**
+ * Copyright (c) 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.
+ */
+
+#pragma once
+
+#include <android-base/thread_annotations.h>
+
+#include "base_metrics_listener.h"
+
+enum ExpectNat64PrefixStatus : bool {
+    EXPECT_FOUND,
+    EXPECT_NOT_FOUND,
+};
+
+namespace android {
+namespace net {
+namespace metrics {
+
+// TODO: Perhaps use condition variable but continually polling.
+// TODO: Perhaps create a queue to monitor the event changes. That improves the unit test which can
+// verify the event count, the event change order, and so on.
+class DnsMetricsListener : public BaseMetricsListener {
+  public:
+    DnsMetricsListener() = delete;
+    DnsMetricsListener(int32_t netId) : mNetId(netId){};
+
+    // Override DNS metrics event(s).
+    android::binder::Status onNat64PrefixEvent(int32_t netId, bool added,
+                                               const std::string& prefixString,
+                                               int32_t /*prefixLength*/) override;
+
+    // Wait for expected NAT64 prefix status until timeout.
+    bool waitForNat64Prefix(ExpectNat64PrefixStatus status,
+                            std::chrono::milliseconds timeout) const;
+
+  private:
+    // Monitor the event which was fired on specific network id.
+    const int32_t mNetId;
+
+    // The NAT64 prefix of the network |mNetId|. It is updated by the event onNat64PrefixEvent().
+    std::string mNat64Prefix GUARDED_BY(mMutex);
+
+    mutable std::mutex mMutex;
+};
+
+}  // namespace metrics
+}  // namespace net
+}  // namespace android
\ No newline at end of file
diff --git a/tests/TestMetrics.cpp b/tests/dns_metrics_listener/test_metrics.cpp
index 4c3d36a7..094c3a87 100644
--- a/tests/TestMetrics.cpp
+++ b/tests/dns_metrics_listener/test_metrics.cpp
@@ -14,14 +14,25 @@
  * limitations under the License.
  */
 
-#include <netdb.h>
+#include "test_metrics.h"
 
-#include "TestMetrics.h"
+#include <netdb.h>
 
 namespace android {
 namespace net {
 namespace metrics {
 
+// Base class BaseTestMetricsEvent.
+void BaseTestMetricsEvent::notify() {
+    std::lock_guard lock(mCvMutex);
+    mCv.notify_one();
+}
+
+void BaseTestMetricsEvent::setVerified(EventFlag event) {
+    mVerified |= event;
+}
+
+// Derived class TestOnDnsEvent.
 android::binder::Status TestOnDnsEvent::onDnsEvent(int32_t netId, int32_t eventType,
                                                    int32_t returnCode, int32_t /*latencyMs*/,
                                                    const std::string& hostname,
diff --git a/tests/TestMetrics.h b/tests/dns_metrics_listener/test_metrics.h
index d3a4ad47..d098acae 100644
--- a/tests/TestMetrics.h
+++ b/tests/dns_metrics_listener/test_metrics.h
@@ -14,18 +14,59 @@
  * limitations under the License.
  */
 
-#ifndef _TEST_METRICS_H_
-#define _TEST_METRICS_H_
+#pragma once
 
-#include "BaseTestMetricsListener.h"
+#include "base_metrics_listener.h"
+
+enum EventFlag : uint32_t {
+    onDnsEvent = 1 << 0,
+    onPrivateDnsValidationEvent = 1 << 1,
+    onConnectEvent = 1 << 2,
+    onWakeupEvent = 1 << 3,
+    onTcpSocketStatsEvent = 1 << 4,
+    onNat64PrefixEvent = 1 << 5,
+};
 
 namespace android {
 namespace net {
 namespace metrics {
 
-class TestOnDnsEvent : public BaseTestMetricsListener {
+// Base class for metrics event unit test. Used for notifications about DNS event changes. Should
+// be extended by unit tests wanting notifications.
+class BaseTestMetricsEvent : public BaseMetricsListener {
+  public:
+    // Returns TRUE if the verification was successful. Otherwise, returns FALSE.
+    virtual bool isVerified() = 0;
+
+    std::condition_variable& getCv() { return mCv; }
+    std::mutex& getCvMutex() { return mCvMutex; }
+
+  private:
+    // The verified event(s) as a bitwise-OR combination of enum EventFlag flags.
+    uint32_t mVerified{};
+
+    // This lock prevents racing condition between signaling thread(s) and waiting thread(s).
+    std::mutex mCvMutex;
+
+    // Condition variable signaled when notify() is called.
+    std::condition_variable mCv;
+
+  protected:
+    // Notify who is waiting for test results. See also mCvMutex and mCv.
+    void notify();
+
+    // Get current verified event(s).
+    uint32_t getVerified() const { return mVerified; }
+
+    // Set the specific event as verified if its verification was successful.
+    void setVerified(EventFlag event);
+};
+
+// Derived class for testing onDnsEvent().
+class TestOnDnsEvent : public BaseTestMetricsEvent {
   public:
     // Both latencyMs and uid are not verified. No special reason.
+    // TODO: Considering to verify uid.
     struct TestResult {
         int netId;
         int eventType;
@@ -38,7 +79,7 @@ class TestOnDnsEvent : public BaseTestMetricsListener {
     TestOnDnsEvent() = delete;
     TestOnDnsEvent(const std::vector<TestResult>& results) : mResults(results){};
 
-    // BaseTestMetricsListener::isVerified() override.
+    // BaseTestMetricsEvent::isVerified() override.
     bool isVerified() override { return (getVerified() & EventFlag::onDnsEvent) != 0; }
 
     // Override for testing verification.
@@ -53,6 +94,4 @@ class TestOnDnsEvent : public BaseTestMetricsListener {
 
 }  // namespace metrics
 }  // namespace net
-}  // namespace android
-
-#endif  // _TEST_METRICS_H_
+}  // namespace android
\ No newline at end of file