1 files changed, 200 insertions, 0 deletions
diff --git a/services/core/java/com/android/server/connectivity/Nat464Xlat.java b/services/core/java/com/android/server/connectivity/Nat464Xlat.java
new file mode 100644
index 0000000..a15d678
--- /dev/null
+++ b/services/core/java/com/android/server/connectivity/Nat464Xlat.java
@@ -0,0 +1,200 @@
+/*
+ * Copyright (C) 2012 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.
+ */
+
+package com.android.server.connectivity;
+
+import static android.net.ConnectivityManager.TYPE_MOBILE;
+
+import java.net.Inet4Address;
+
+import android.content.Context;
+import android.net.IConnectivityManager;
+import android.net.InterfaceConfiguration;
+import android.net.LinkAddress;
+import android.net.LinkProperties;
+import android.net.NetworkStateTracker;
+import android.net.NetworkUtils;
+import android.net.RouteInfo;
+import android.os.Handler;
+import android.os.Message;
+import android.os.INetworkManagementService;
+import android.os.RemoteException;
+import android.util.Slog;
+
+import com.android.server.net.BaseNetworkObserver;
+
+/**
+ * @hide
+ *
+ * Class to manage a 464xlat CLAT daemon.
+ */
+public class Nat464Xlat extends BaseNetworkObserver {
+    private Context mContext;
+    private INetworkManagementService mNMService;
+    private IConnectivityManager mConnService;
+    private NetworkStateTracker mTracker;
+    private Handler mHandler;
+
+    // Whether we started clatd and expect it to be running.
+    private boolean mIsStarted;
+    // Whether the clatd interface exists (i.e., clatd is running).
+    private boolean mIsRunning;
+    // The LinkProperties of the clat interface.
+    private LinkProperties mLP;
+
+    // This must match the interface name in clatd.conf.
+    private static final String CLAT_INTERFACE_NAME = "clat4";
+
+    private static final String TAG = "Nat464Xlat";
+
+    public Nat464Xlat(Context context, INetworkManagementService nmService,
+                      IConnectivityManager connService, Handler handler) {
+        mContext = context;
+        mNMService = nmService;
+        mConnService = connService;
+        mHandler = handler;
+
+        mIsStarted = false;
+        mIsRunning = false;
+        mLP = new LinkProperties();
+    }
+
+    /**
+     * Determines whether an interface requires clat.
+     * @param netType the network type (one of the
+     *   android.net.ConnectivityManager.TYPE_* constants)
+     * @param tracker the NetworkStateTracker corresponding to the network type.
+     * @return true if the interface requires clat, false otherwise.
+     */
+    public boolean requiresClat(int netType, NetworkStateTracker tracker) {
+        LinkProperties lp = tracker.getLinkProperties();
+        // Only support clat on mobile for now.
+        Slog.d(TAG, "requiresClat: netType=" + netType + ", hasIPv4Address=" +
+               lp.hasIPv4Address());
+        return netType == TYPE_MOBILE && !lp.hasIPv4Address();
+    }
+
+    public static boolean isRunningClat(LinkProperties lp) {
+      return lp != null && lp.getAllInterfaceNames().contains(CLAT_INTERFACE_NAME);
+    }
+
+    /**
+     * Starts the clat daemon.
+     * @param lp The link properties of the interface to start clatd on.
+     */
+    public void startClat(NetworkStateTracker tracker) {
+        if (mIsStarted) {
+            Slog.e(TAG, "startClat: already started");
+            return;
+        }
+        mTracker = tracker;
+        LinkProperties lp = mTracker.getLinkProperties();
+        String iface = lp.getInterfaceName();
+        Slog.i(TAG, "Starting clatd on " + iface + ", lp=" + lp);
+        try {
+            mNMService.startClatd(iface);
+        } catch(RemoteException e) {
+            Slog.e(TAG, "Error starting clat daemon: " + e);
+        }
+        mIsStarted = true;
+    }
+
+    /**
+     * Stops the clat daemon.
+     */
+    public void stopClat() {
+        if (mIsStarted) {
+            Slog.i(TAG, "Stopping clatd");
+            try {
+                mNMService.stopClatd();
+            } catch(RemoteException e) {
+                Slog.e(TAG, "Error stopping clat daemon: " + e);
+            }
+            mIsStarted = false;
+            mIsRunning = false;
+            mTracker = null;
+            mLP.clear();
+        } else {
+            Slog.e(TAG, "stopClat: already stopped");
+        }
+    }
+
+    public boolean isStarted() {
+        return mIsStarted;
+    }
+
+    public boolean isRunning() {
+        return mIsRunning;
+    }
+
+    @Override
+    public void interfaceAdded(String iface) {
+        if (iface.equals(CLAT_INTERFACE_NAME)) {
+            Slog.i(TAG, "interface " + CLAT_INTERFACE_NAME +
+                   " added, mIsRunning = " + mIsRunning + " -> true");
+            mIsRunning = true;
+
+            // Create the LinkProperties for the clat interface by fetching the
+            // IPv4 address for the interface and adding an IPv4 default route,
+            // then stack the LinkProperties on top of the link it's running on.
+            // Although the clat interface is a point-to-point tunnel, we don't
+            // point the route directly at the interface because some apps don't
+            // understand routes without gateways (see, e.g., http://b/9597256
+            // http://b/9597516). Instead, set the next hop of the route to the
+            // clat IPv4 address itself (for those apps, it doesn't matter what
+            // the IP of the gateway is, only that there is one).
+            try {
+                InterfaceConfiguration config = mNMService.getInterfaceConfig(iface);
+                LinkAddress clatAddress = config.getLinkAddress();
+                mLP.clear();
+                mLP.setInterfaceName(iface);
+                RouteInfo ipv4Default = new RouteInfo(new LinkAddress(Inet4Address.ANY, 0),
+                                                      clatAddress.getAddress(), iface);
+                mLP.addRoute(ipv4Default);
+                mLP.addLinkAddress(clatAddress);
+                mTracker.addStackedLink(mLP);
+                Slog.i(TAG, "Adding stacked link. tracker LP: " +
+                       mTracker.getLinkProperties());
+            } catch(RemoteException e) {
+                Slog.e(TAG, "Error getting link properties: " + e);
+            }
+
+            // Inform ConnectivityService that things have changed.
+            Message msg = mHandler.obtainMessage(
+                NetworkStateTracker.EVENT_CONFIGURATION_CHANGED,
+                mTracker.getNetworkInfo());
+            Slog.i(TAG, "sending message to ConnectivityService: " + msg);
+            msg.sendToTarget();
+        }
+    }
+
+    @Override
+    public void interfaceRemoved(String iface) {
+        if (iface == CLAT_INTERFACE_NAME) {
+            if (mIsRunning) {
+                NetworkUtils.resetConnections(
+                    CLAT_INTERFACE_NAME,
+                    NetworkUtils.RESET_IPV4_ADDRESSES);
+            }
+            Slog.i(TAG, "interface " + CLAT_INTERFACE_NAME +
+                   " removed, mIsRunning = " + mIsRunning + " -> false");
+            mIsRunning = false;
+            mTracker.removeStackedLink(mLP);
+            mLP.clear();
+            Slog.i(TAG, "mLP = " + mLP);
+        }
+    }
+};