Add TYPE_BLUETOOTH network interface for reverse tethering.

Change-Id: I2aa61ce15f57aea9e8fd3a4cb56799c8bc51e998
diff --git a/core/java/android/bluetooth/BluetoothTetheringDataTracker.java b/core/java/android/bluetooth/BluetoothTetheringDataTracker.java
new file mode 100644
index 0000000..7b083f1
--- /dev/null
+++ b/core/java/android/bluetooth/BluetoothTetheringDataTracker.java
@@ -0,0 +1,299 @@
+/*
+ * Copyright (C) 2010 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 android.bluetooth;
+
+import android.content.Context;
+import android.net.ConnectivityManager;
+import android.net.DhcpInfo;
+import android.net.LinkAddress;
+import android.net.LinkCapabilities;
+import android.net.LinkProperties;
+import android.net.NetworkInfo;
+import android.net.NetworkInfo.DetailedState;
+import android.net.NetworkStateTracker;
+import android.net.NetworkUtils;
+import android.os.Handler;
+import android.os.Message;
+import android.util.Log;
+
+import java.net.InetAddress;
+import java.util.concurrent.atomic.AtomicBoolean;
+import java.util.concurrent.atomic.AtomicInteger;
+
+/**
+ * This class tracks the data connection associated with Bluetooth
+ * reverse tethering. This is a singleton class and an instance will be
+ * created by ConnectivityService. BluetoothService will call into this
+ * when a reverse tethered connection needs to be activated.
+ *
+ * @hide
+ */
+public class BluetoothTetheringDataTracker implements NetworkStateTracker {
+    private static final String NETWORKTYPE = "BLUETOOTH_TETHER";
+    private static final String TAG = "BluetoothTethering";
+
+    private AtomicBoolean mTeardownRequested = new AtomicBoolean(false);
+    private AtomicBoolean mPrivateDnsRouteSet = new AtomicBoolean(false);
+    private AtomicInteger mDefaultGatewayAddr = new AtomicInteger(0);
+    private AtomicBoolean mDefaultRouteSet = new AtomicBoolean(false);
+
+    private LinkProperties mLinkProperties;
+    private LinkCapabilities mLinkCapabilities;
+    private NetworkInfo mNetworkInfo;
+
+    private BluetoothPan mBluetoothPan;
+    private BluetoothDevice mDevice;
+    private static String mIface;
+
+    /* For sending events to connectivity service handler */
+    private Handler mCsHandler;
+    private Context mContext;
+    public static BluetoothTetheringDataTracker sInstance;
+
+    private BluetoothTetheringDataTracker() {
+        mNetworkInfo = new NetworkInfo(ConnectivityManager.TYPE_BLUETOOTH, 0, NETWORKTYPE, "");
+        mLinkProperties = new LinkProperties();
+        mLinkCapabilities = new LinkCapabilities();
+
+        mNetworkInfo.setIsAvailable(false);
+        setTeardownRequested(false);
+    }
+
+    public static synchronized BluetoothTetheringDataTracker getInstance() {
+        if (sInstance == null) sInstance = new BluetoothTetheringDataTracker();
+        return sInstance;
+    }
+
+    public Object Clone() throws CloneNotSupportedException {
+        throw new CloneNotSupportedException();
+    }
+
+    public void setTeardownRequested(boolean isRequested) {
+        mTeardownRequested.set(isRequested);
+    }
+
+    public boolean isTeardownRequested() {
+        return mTeardownRequested.get();
+    }
+
+    /**
+     * Begin monitoring connectivity
+     */
+    public void startMonitoring(Context context, Handler target) {
+        mContext = context;
+        mCsHandler = target;
+        mBluetoothPan = new BluetoothPan(mContext);
+    }
+
+    /**
+     * Disable connectivity to a network
+     * TODO: do away with return value after making MobileDataStateTracker async
+     */
+    public boolean teardown() {
+        mTeardownRequested.set(true);
+        for (BluetoothDevice device: mBluetoothPan.getConnectedDevices()) {
+            mBluetoothPan.disconnect(device);
+        }
+        return true;
+    }
+
+    /**
+     * Re-enable connectivity to a network after a {@link #teardown()}.
+     */
+    public boolean reconnect() {
+        mTeardownRequested.set(false);
+        //Ignore
+        return true;
+    }
+
+    /**
+     * Turn the wireless radio off for a network.
+     * @param turnOn {@code true} to turn the radio on, {@code false}
+     */
+    public boolean setRadio(boolean turnOn) {
+        return true;
+    }
+
+    /**
+     * @return true - If are we currently tethered with another device.
+     */
+    public synchronized boolean isAvailable() {
+        return mNetworkInfo.isAvailable();
+    }
+
+    /**
+     * Tells the underlying networking system that the caller wants to
+     * begin using the named feature. The interpretation of {@code feature}
+     * is completely up to each networking implementation.
+     * @param feature the name of the feature to be used
+     * @param callingPid the process ID of the process that is issuing this request
+     * @param callingUid the user ID of the process that is issuing this request
+     * @return an integer value representing the outcome of the request.
+     * The interpretation of this value is specific to each networking
+     * implementation+feature combination, except that the value {@code -1}
+     * always indicates failure.
+     * TODO: needs to go away
+     */
+    public int startUsingNetworkFeature(String feature, int callingPid, int callingUid) {
+        return -1;
+    }
+
+    /**
+     * Tells the underlying networking system that the caller is finished
+     * using the named feature. The interpretation of {@code feature}
+     * is completely up to each networking implementation.
+     * @param feature the name of the feature that is no longer needed.
+     * @param callingPid the process ID of the process that is issuing this request
+     * @param callingUid the user ID of the process that is issuing this request
+     * @return an integer value representing the outcome of the request.
+     * The interpretation of this value is specific to each networking
+     * implementation+feature combination, except that the value {@code -1}
+     * always indicates failure.
+     * TODO: needs to go away
+     */
+    public int stopUsingNetworkFeature(String feature, int callingPid, int callingUid) {
+        return -1;
+    }
+
+    /**
+     * @param enabled
+     */
+    public void setDataEnable(boolean enabled) {
+        android.util.Log.d(TAG, "setDataEnabled: IGNORING enabled=" + enabled);
+    }
+
+    /**
+     * Check if private DNS route is set for the network
+     */
+    public boolean isPrivateDnsRouteSet() {
+        return mPrivateDnsRouteSet.get();
+    }
+
+    /**
+     * Set a flag indicating private DNS route is set
+     */
+    public void privateDnsRouteSet(boolean enabled) {
+        mPrivateDnsRouteSet.set(enabled);
+    }
+
+    /**
+     * Fetch NetworkInfo for the network
+     */
+    public synchronized NetworkInfo getNetworkInfo() {
+        return mNetworkInfo;
+    }
+
+    /**
+     * Fetch LinkProperties for the network
+     */
+    public synchronized LinkProperties getLinkProperties() {
+        return new LinkProperties(mLinkProperties);
+    }
+
+   /**
+     * A capability is an Integer/String pair, the capabilities
+     * are defined in the class LinkSocket#Key.
+     *
+     * @return a copy of this connections capabilities, may be empty but never null.
+     */
+    public LinkCapabilities getLinkCapabilities() {
+        return new LinkCapabilities(mLinkCapabilities);
+    }
+
+    /**
+     * Fetch default gateway address for the network
+     */
+    public int getDefaultGatewayAddr() {
+        return mDefaultGatewayAddr.get();
+    }
+
+    /**
+     * Check if default route is set
+     */
+    public boolean isDefaultRouteSet() {
+        return mDefaultRouteSet.get();
+    }
+
+    /**
+     * Set a flag indicating default route is set for the network
+     */
+    public void defaultRouteSet(boolean enabled) {
+        mDefaultRouteSet.set(enabled);
+    }
+
+    /**
+     * Return the system properties name associated with the tcp buffer sizes
+     * for this network.
+     */
+    public String getTcpBufferSizesPropName() {
+        return "net.tcp.buffersize.wifi";
+    }
+
+
+    public synchronized void startReverseTether(String iface, BluetoothDevice device) {
+        mIface = iface;
+        mDevice = device;
+        Thread dhcpThread = new Thread(new Runnable() {
+            public void run() {
+                //TODO(): Add callbacks for failure and success case.
+                //Currently this thread runs independently.
+                DhcpInfo dhcpInfo = new DhcpInfo();
+                if (!NetworkUtils.runDhcp(mIface, dhcpInfo)) {
+                    Log.e(TAG, "DHCP request error:" + NetworkUtils.getDhcpError());
+                    return;
+                }
+                mLinkProperties.addLinkAddress(new LinkAddress(
+                    NetworkUtils.intToInetAddress(dhcpInfo.ipAddress),
+                    NetworkUtils.intToInetAddress(dhcpInfo.netmask)));
+                mLinkProperties.setGateway(NetworkUtils.intToInetAddress(dhcpInfo.gateway));
+                InetAddress dns1Addr = NetworkUtils.intToInetAddress(dhcpInfo.dns1);
+                if (dns1Addr == null || dns1Addr.equals("0.0.0.0")) {
+                    mLinkProperties.addDns(dns1Addr);
+                }
+                InetAddress dns2Addr = NetworkUtils.intToInetAddress(dhcpInfo.dns2);
+                if (dns2Addr == null || dns2Addr.equals("0.0.0.0")) {
+                    mLinkProperties.addDns(dns2Addr);
+                }
+                mLinkProperties.setInterfaceName(mIface);
+
+                mNetworkInfo.setIsAvailable(true);
+                mNetworkInfo.setDetailedState(DetailedState.CONNECTED, null, null);
+
+                Message msg = mCsHandler.obtainMessage(EVENT_CONFIGURATION_CHANGED, mNetworkInfo);
+                msg.sendToTarget();
+
+                msg = mCsHandler.obtainMessage(EVENT_STATE_CHANGED, mNetworkInfo);
+                msg.sendToTarget();
+            }
+        });
+        dhcpThread.start();
+    }
+
+    public synchronized void stopReverseTether(String iface) {
+        NetworkUtils.stopDhcp(iface);
+
+        mLinkProperties.clear();
+        mNetworkInfo.setIsAvailable(false);
+        mNetworkInfo.setDetailedState(DetailedState.DISCONNECTED, null, null);
+
+        Message msg = mCsHandler.obtainMessage(EVENT_CONFIGURATION_CHANGED, mNetworkInfo);
+        msg.sendToTarget();
+
+        msg = mCsHandler.obtainMessage(EVENT_STATE_CHANGED, mNetworkInfo);
+        msg.sendToTarget();
+    }
+}