Merge "Translate v4 keepalive packet on clat started network to v6"
diff --git a/service/src/com/android/server/connectivity/AutomaticOnOffKeepaliveTracker.java b/service/src/com/android/server/connectivity/AutomaticOnOffKeepaliveTracker.java
index 6ba2033..368860e 100644
--- a/service/src/com/android/server/connectivity/AutomaticOnOffKeepaliveTracker.java
+++ b/service/src/com/android/server/connectivity/AutomaticOnOffKeepaliveTracker.java
@@ -291,6 +291,18 @@
             }
         }
 
+        /**
+         * Construct a new AutomaticOnOffKeepalive from existing AutomaticOnOffKeepalive with a
+         * new KeepaliveInfo.
+         */
+        public AutomaticOnOffKeepalive withKeepaliveInfo(KeepaliveTracker.KeepaliveInfo ki)
+                throws InvalidSocketException {
+            return new AutomaticOnOffKeepalive(
+                    ki,
+                    mAutomaticOnOffState != STATE_ALWAYS_ON /* autoOnOff */,
+                    mUnderpinnedNetwork);
+        }
+
         @Override
         public String toString() {
             return "AutomaticOnOffKeepalive [ "
@@ -470,13 +482,26 @@
      * The message is expected to contain a KeepaliveTracker.KeepaliveInfo.
      */
     public void handleStartKeepalive(Message message) {
-        final AutomaticOnOffKeepalive autoKi = (AutomaticOnOffKeepalive) message.obj;
-        final int error = mKeepaliveTracker.handleStartKeepalive(autoKi.mKi);
+        final AutomaticOnOffKeepalive target = (AutomaticOnOffKeepalive) message.obj;
+        final Pair<Integer, KeepaliveTracker.KeepaliveInfo> res =
+                mKeepaliveTracker.handleStartKeepalive(target.mKi);
+        final int error = res.first;
         if (error != SUCCESS) {
-            mEventLog.log("Failed to start keepalive " + autoKi.mCallback + " on "
-                    + autoKi.getNetwork() + " with error " + error);
+            mEventLog.log("Failed to start keepalive " + target.mCallback + " on "
+                    + target.getNetwork() + " with error " + error);
             return;
         }
+        // Generate a new auto ki with the started keepalive info.
+        final AutomaticOnOffKeepalive autoKi;
+        try {
+            autoKi = target.withKeepaliveInfo(res.second);
+            // Close the duplicated fd.
+            target.close();
+        } catch (InvalidSocketException e) {
+            Log.wtf(TAG, "Fail to create AutomaticOnOffKeepalive", e);
+            return;
+        }
+
         mEventLog.log("Start keepalive " + autoKi.mCallback + " on " + autoKi.getNetwork());
         mKeepaliveStatsTracker.onStartKeepalive(
                 autoKi.getNetwork(),
@@ -506,14 +531,19 @@
      * @return SUCCESS if the keepalive is successfully starting and the error reason otherwise.
      */
     private int handleResumeKeepalive(@NonNull final KeepaliveTracker.KeepaliveInfo ki) {
-        final int error = mKeepaliveTracker.handleStartKeepalive(ki);
+        final Pair<Integer, KeepaliveTracker.KeepaliveInfo> res =
+                mKeepaliveTracker.handleStartKeepalive(ki);
+        final KeepaliveTracker.KeepaliveInfo startedKi = res.second;
+        final int error = res.first;
         if (error != SUCCESS) {
-            mEventLog.log("Failed to resume keepalive " + ki.mCallback + " on " + ki.mNai
-                    + " with error " + error);
+            mEventLog.log("Failed to resume keepalive " + startedKi.mCallback + " on "
+                    + startedKi.mNai + " with error " + error);
             return error;
         }
-        mKeepaliveStatsTracker.onResumeKeepalive(ki.getNai().network(), ki.getSlot());
-        mEventLog.log("Resumed successfully keepalive " + ki.mCallback + " on " + ki.mNai);
+
+        mKeepaliveStatsTracker.onResumeKeepalive(startedKi.getNai().network(), startedKi.getSlot());
+        mEventLog.log("Resumed successfully keepalive " + startedKi.mCallback
+                + " on " + startedKi.mNai);
 
         return SUCCESS;
     }
diff --git a/service/src/com/android/server/connectivity/KeepaliveTracker.java b/service/src/com/android/server/connectivity/KeepaliveTracker.java
index 76e97e2..125c269 100644
--- a/service/src/com/android/server/connectivity/KeepaliveTracker.java
+++ b/service/src/com/android/server/connectivity/KeepaliveTracker.java
@@ -54,6 +54,7 @@
 import android.system.ErrnoException;
 import android.system.Os;
 import android.util.Log;
+import android.util.Pair;
 
 import com.android.connectivity.resources.R;
 import com.android.internal.annotations.VisibleForTesting;
@@ -62,6 +63,8 @@
 import com.android.net.module.util.IpUtils;
 
 import java.io.FileDescriptor;
+import java.net.Inet4Address;
+import java.net.Inet6Address;
 import java.net.InetAddress;
 import java.net.InetSocketAddress;
 import java.net.SocketAddress;
@@ -292,11 +295,15 @@
 
         private int checkSourceAddress() {
             // Check that we have the source address.
-            for (InetAddress address : mNai.linkProperties.getAddresses()) {
+            for (InetAddress address : mNai.linkProperties.getAllAddresses()) {
                 if (address.equals(mPacket.getSrcAddress())) {
                     return SUCCESS;
                 }
             }
+            // Or the address is the clat source address.
+            if (mPacket.getSrcAddress().equals(mNai.getClatv6SrcAddress())) {
+                return SUCCESS;
+            }
             return ERROR_INVALID_IP_ADDRESS;
         }
 
@@ -479,6 +486,15 @@
             return new KeepaliveInfo(mCallback, mNai, mPacket, mPid, mUid, mInterval, mType,
                     fd, mSlot, true /* resumed */);
         }
+
+        /**
+         * Construct a new KeepaliveInfo from existing KeepaliveInfo with a new KeepalivePacketData.
+         */
+        public KeepaliveInfo withPacketData(@NonNull KeepalivePacketData packet)
+                throws InvalidSocketException {
+            return new KeepaliveInfo(mCallback, mNai, packet, mPid, mUid, mInterval, mType,
+                    mFd, mSlot, mResumed);
+        }
     }
 
     void notifyErrorCallback(ISocketKeepaliveCallback cb, int error) {
@@ -512,15 +528,47 @@
      * Handle start keepalives with the message.
      *
      * @param ki the keepalive to start.
-     * @return SUCCESS if the keepalive is successfully starting and the error reason otherwise.
+     * @return Pair of (SUCCESS if the keepalive is successfully starting and the error reason
+     *         otherwise, the started KeepaliveInfo object)
      */
-    public int handleStartKeepalive(KeepaliveInfo ki) {
-        NetworkAgentInfo nai = ki.getNai();
+    public Pair<Integer, KeepaliveInfo> handleStartKeepalive(KeepaliveInfo ki) {
+        final KeepaliveInfo newKi;
+        try {
+            newKi = handleUpdateKeepaliveForClat(ki);
+        } catch (InvalidSocketException | InvalidPacketException e) {
+            Log.e(TAG, "Fail to construct keepalive packet");
+            notifyErrorCallback(ki.mCallback, ERROR_INVALID_IP_ADDRESS);
+            // Fail to create new keepalive packet for clat. Return the original keepalive info.
+            return new Pair<>(ERROR_INVALID_IP_ADDRESS, ki);
+        }
+
+        final NetworkAgentInfo nai = newKi.getNai();
         // If this was a paused keepalive, then reuse the same slot that was kept for it. Otherwise,
         // use the first free slot for this network agent.
-        final int slot = NO_KEEPALIVE != ki.mSlot ? ki.mSlot : findFirstFreeSlot(nai);
-        mKeepalives.get(nai).put(slot, ki);
-        return ki.start(slot);
+        final int slot = NO_KEEPALIVE != newKi.mSlot ? newKi.mSlot : findFirstFreeSlot(nai);
+        mKeepalives.get(nai).put(slot, newKi);
+
+        return new Pair<>(newKi.start(slot), newKi);
+    }
+
+    private KeepaliveInfo handleUpdateKeepaliveForClat(KeepaliveInfo ki)
+            throws InvalidSocketException, InvalidPacketException {
+        // Only try to translate address if the packet source address is the clat's source address.
+        if (!ki.mPacket.getSrcAddress().equals(ki.getNai().getClatv4SrcAddress())) return ki;
+
+        final InetAddress dstAddr = ki.mPacket.getDstAddress();
+        // Do not perform translation for a v6 dst address.
+        if (!(dstAddr instanceof Inet4Address)) return ki;
+
+        final Inet6Address address = ki.getNai().translateV4toClatV6((Inet4Address) dstAddr);
+
+        if (address == null) return ki;
+
+        final int srcPort = ki.mPacket.getSrcPort();
+        final KeepaliveInfo newInfo = ki.withPacketData(NattKeepalivePacketData.nattKeepalivePacket(
+                ki.getNai().getClatv6SrcAddress(), srcPort, address, NATT_PORT));
+        Log.d(TAG, "Src is clat v4 address. Convert from " + ki + " to " + newInfo);
+        return newInfo;
     }
 
     public void handleStopAllKeepalives(NetworkAgentInfo nai, int reason) {
diff --git a/tests/unit/java/com/android/server/ConnectivityServiceTest.java b/tests/unit/java/com/android/server/ConnectivityServiceTest.java
index 9406edd..bbde9b4 100755
--- a/tests/unit/java/com/android/server/ConnectivityServiceTest.java
+++ b/tests/unit/java/com/android/server/ConnectivityServiceTest.java
@@ -6857,17 +6857,19 @@
 
     @Test
     public void testPacketKeepalives() throws Exception {
-        InetAddress myIPv4 = InetAddress.getByName("192.0.2.129");
+        final LinkAddress v4Addr = new LinkAddress("192.0.2.129/24");
+        final InetAddress myIPv4 = v4Addr.getAddress();
         InetAddress notMyIPv4 = InetAddress.getByName("192.0.2.35");
         InetAddress myIPv6 = InetAddress.getByName("2001:db8::1");
         InetAddress dstIPv4 = InetAddress.getByName("8.8.8.8");
         InetAddress dstIPv6 = InetAddress.getByName("2001:4860:4860::8888");
-
+        doReturn(getClatInterfaceConfigParcel(v4Addr)).when(mMockNetd)
+                .interfaceGetCfg(CLAT_MOBILE_IFNAME);
         final int validKaInterval = 15;
         final int invalidKaInterval = 9;
 
         LinkProperties lp = new LinkProperties();
-        lp.setInterfaceName("wlan12");
+        lp.setInterfaceName(MOBILE_IFNAME);
         lp.addLinkAddress(new LinkAddress(myIPv6, 64));
         lp.addLinkAddress(new LinkAddress(myIPv4, 25));
         lp.addRoute(new RouteInfo(InetAddress.getByName("fe80::1234")));
diff --git a/tests/unit/java/com/android/server/connectivity/AutomaticOnOffKeepaliveTrackerTest.java b/tests/unit/java/com/android/server/connectivity/AutomaticOnOffKeepaliveTrackerTest.java
index 9e604e3..eeffbe1 100644
--- a/tests/unit/java/com/android/server/connectivity/AutomaticOnOffKeepaliveTrackerTest.java
+++ b/tests/unit/java/com/android/server/connectivity/AutomaticOnOffKeepaliveTrackerTest.java
@@ -52,6 +52,7 @@
 import android.content.res.Resources;
 import android.net.INetd;
 import android.net.ISocketKeepaliveCallback;
+import android.net.InetAddresses;
 import android.net.KeepalivePacketData;
 import android.net.LinkAddress;
 import android.net.LinkProperties;
@@ -116,7 +117,8 @@
     private static final int MOCK_RESOURCE_ID = 5;
     private static final int TEST_KEEPALIVE_INTERVAL_SEC = 10;
     private static final int TEST_KEEPALIVE_INVALID_INTERVAL_SEC = 9;
-
+    private static final byte[] V4_SRC_ADDR = new byte[] { (byte) 192, 0, 0, (byte) 129 };
+    private static final String TEST_V4_IFACE = "v4-testIface";
     private AutomaticOnOffKeepaliveTracker mAOOKeepaliveTracker;
     private HandlerThread mHandlerThread;
 
@@ -327,6 +329,8 @@
                 NetworkInfo.DetailedState.CONNECTED, "test reason", "test extra info");
         doReturn(new Network(TEST_NETID)).when(mNai).network();
         mNai.linkProperties = new LinkProperties();
+        doReturn(null).when(mNai).translateV4toClatV6(any());
+        doReturn(null).when(mNai).getClatv6SrcAddress();
 
         doReturn(PERMISSION_GRANTED).when(mCtx).checkPermission(any() /* permission */,
                 anyInt() /* pid */, anyInt() /* uid */);
@@ -429,8 +433,7 @@
     }
 
     private TestKeepaliveInfo doStartNattKeepalive(int intervalSeconds) throws Exception {
-        final InetAddress srcAddress = InetAddress.getByAddress(
-                new byte[] { (byte) 192, 0, 0, (byte) 129 });
+        final InetAddress srcAddress = InetAddress.getByAddress(V4_SRC_ADDR);
         final int srcPort = 12345;
         final InetAddress dstAddress = InetAddress.getByAddress(new byte[] {8, 8, 8, 8});
         final int dstPort = 12345;
@@ -610,6 +613,42 @@
     }
 
     @Test
+    public void testStartNattKeepalive_addressTranslationOnClat() throws Exception {
+        final InetAddress v6AddrSrc = InetAddresses.parseNumericAddress("2001:db8::1");
+        final InetAddress v6AddrDst = InetAddresses.parseNumericAddress("2001:db8::2");
+        doReturn(v6AddrDst).when(mNai).translateV4toClatV6(any());
+        doReturn(v6AddrSrc).when(mNai).getClatv6SrcAddress();
+        doReturn(InetAddress.getByAddress(V4_SRC_ADDR)).when(mNai).getClatv4SrcAddress();
+        // Setup nai to add clat address
+        final LinkProperties stacked = new LinkProperties();
+        stacked.setInterfaceName(TEST_V4_IFACE);
+        mNai.linkProperties.addStackedLink(stacked);
+
+        final TestKeepaliveInfo testInfo = doStartNattKeepalive();
+        final ArgumentCaptor<NattKeepalivePacketData> kpdCaptor =
+                ArgumentCaptor.forClass(NattKeepalivePacketData.class);
+        verify(mNai).onStartNattSocketKeepalive(
+                eq(TEST_SLOT), eq(TEST_KEEPALIVE_INTERVAL_SEC), kpdCaptor.capture());
+        final NattKeepalivePacketData kpd = kpdCaptor.getValue();
+        // Verify the addresses are updated to v6 when clat is started.
+        assertEquals(v6AddrSrc, kpd.getSrcAddress());
+        assertEquals(v6AddrDst, kpd.getDstAddress());
+
+        triggerEventKeepalive(TEST_SLOT, SocketKeepalive.SUCCESS);
+        verify(testInfo.socketKeepaliveCallback).onStarted();
+
+        // Remove clat address should stop the keepalive.
+        doReturn(null).when(mNai).getClatv6SrcAddress();
+        visibleOnHandlerThread(
+                mTestHandler, () -> mAOOKeepaliveTracker.handleCheckKeepalivesStillValid(mNai));
+        checkAndProcessKeepaliveStop();
+        assertNull(getAutoKiForBinder(testInfo.binder));
+
+        verify(testInfo.socketKeepaliveCallback).onError(SocketKeepalive.ERROR_INVALID_IP_ADDRESS);
+        verifyNoMoreInteractions(ignoreStubs(testInfo.socketKeepaliveCallback));
+    }
+
+    @Test
     public void testHandleEventSocketKeepalive_startingFailureHardwareError() throws Exception {
         final TestKeepaliveInfo testInfo = doStartNattKeepalive();