services/core/java/com/android/server/net/LockdownVpnTracker.java - platform/frameworks/base - Git at Google

 /*
  * 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.net;

 import static android.Manifest.permission.CONNECTIVITY_INTERNAL;
 import static android.net.NetworkPolicyManager.FIREWALL_CHAIN_NONE;
 import static android.net.NetworkPolicyManager.FIREWALL_RULE_ALLOW;
 import static android.net.NetworkPolicyManager.FIREWALL_RULE_DEFAULT;
 import static android.provider.Settings.ACTION_VPN_SETTINGS;

 import android.app.Notification;
 import android.app.NotificationManager;
 import android.app.PendingIntent;
 import android.content.BroadcastReceiver;
 import android.content.Context;
 import android.content.Intent;
 import android.content.IntentFilter;
 import android.net.ConnectivityManager;
 import android.net.LinkProperties;
 import android.net.LinkAddress;
 import android.net.NetworkInfo;
 import android.net.NetworkInfo.DetailedState;
 import android.net.NetworkInfo.State;
 import android.net.NetworkPolicyManager;
 import android.os.INetworkManagementService;
 import android.os.RemoteException;
 import android.security.Credentials;
 import android.security.KeyStore;
 import android.system.Os;
 import android.text.TextUtils;
 import android.util.Slog;

 import com.android.internal.R;
 import com.android.internal.messages.nano.SystemMessageProto.SystemMessage;
 import com.android.internal.net.VpnConfig;
 import com.android.internal.net.VpnProfile;
 import com.android.internal.notification.SystemNotificationChannels;
 import com.android.internal.util.Preconditions;
 import com.android.server.ConnectivityService;
 import com.android.server.EventLogTags;
 import com.android.server.connectivity.Vpn;

 import java.util.List;

 /**
  * State tracker for lockdown mode. Watches for normal {@link NetworkInfo} to be
  * connected and kicks off VPN connection, managing any required {@code netd}
  * firewall rules.
  */
 public class LockdownVpnTracker {
     private static final String TAG = "LockdownVpnTracker";

     /** Number of VPN attempts before waiting for user intervention. */
     private static final int MAX_ERROR_COUNT = 4;

     private static final String ACTION_LOCKDOWN_RESET = "com.android.server.action.LOCKDOWN_RESET";

     private static final int ROOT_UID = 0;

     private final Context mContext;
     private final INetworkManagementService mNetService;
     private final ConnectivityService mConnService;
     private final Vpn mVpn;
     private final VpnProfile mProfile;

     private final Object mStateLock = new Object();

     private final PendingIntent mConfigIntent;
     private final PendingIntent mResetIntent;

     private String mAcceptedEgressIface;
     private String mAcceptedIface;
     private List<LinkAddress> mAcceptedSourceAddr;

     private int mErrorCount;

     public static boolean isEnabled() {
         return KeyStore.getInstance().contains(Credentials.LOCKDOWN_VPN);
     }

     public LockdownVpnTracker(Context context, INetworkManagementService netService,
             ConnectivityService connService, Vpn vpn, VpnProfile profile) {
         mContext = Preconditions.checkNotNull(context);
         mNetService = Preconditions.checkNotNull(netService);
         mConnService = Preconditions.checkNotNull(connService);
         mVpn = Preconditions.checkNotNull(vpn);
         mProfile = Preconditions.checkNotNull(profile);

         final Intent configIntent = new Intent(ACTION_VPN_SETTINGS);
         mConfigIntent = PendingIntent.getActivity(mContext, 0, configIntent, 0);

         final Intent resetIntent = new Intent(ACTION_LOCKDOWN_RESET);
         resetIntent.addFlags(Intent.FLAG_RECEIVER_REGISTERED_ONLY);
         mResetIntent = PendingIntent.getBroadcast(mContext, 0, resetIntent, 0);
     }

     private BroadcastReceiver mResetReceiver = new BroadcastReceiver() {
         @Override
         public void onReceive(Context context, Intent intent) {
             reset();
         }
     };

     /**
      * Watch for state changes to both active egress network, kicking off a VPN
      * connection when ready, or setting firewall rules once VPN is connected.
      */
     private void handleStateChangedLocked() {

         final NetworkInfo egressInfo = mConnService.getActiveNetworkInfoUnfiltered();
         final LinkProperties egressProp = mConnService.getActiveLinkProperties();

         final NetworkInfo vpnInfo = mVpn.getNetworkInfo();
         final VpnConfig vpnConfig = mVpn.getLegacyVpnConfig();

         // Restart VPN when egress network disconnected or changed
         final boolean egressDisconnected = egressInfo == null
                 || State.DISCONNECTED.equals(egressInfo.getState());
         final boolean egressChanged = egressProp == null
                 || !TextUtils.equals(mAcceptedEgressIface, egressProp.getInterfaceName());

         final String egressTypeName = (egressInfo == null) ?
                 null : ConnectivityManager.getNetworkTypeName(egressInfo.getType());
         final String egressIface = (egressProp == null) ?
                 null : egressProp.getInterfaceName();
         Slog.d(TAG, "handleStateChanged: egress=" + egressTypeName +
                 " " + mAcceptedEgressIface + "->" + egressIface);

         if (egressDisconnected || egressChanged) {
             mAcceptedEgressIface = null;
             mVpn.stopLegacyVpnPrivileged();
         }
         if (egressDisconnected) {
             hideNotification();
             return;
         }

         final int egressType = egressInfo.getType();
         if (vpnInfo.getDetailedState() == DetailedState.FAILED) {
             EventLogTags.writeLockdownVpnError(egressType);
         }

         if (mErrorCount > MAX_ERROR_COUNT) {
             showNotification(R.string.vpn_lockdown_error, R.drawable.vpn_disconnected);

         } else if (egressInfo.isConnected() && !vpnInfo.isConnectedOrConnecting()) {
             if (mProfile.isValidLockdownProfile()) {
                 Slog.d(TAG, "Active network connected; starting VPN");
                 EventLogTags.writeLockdownVpnConnecting(egressType);
                 showNotification(R.string.vpn_lockdown_connecting, R.drawable.vpn_disconnected);

                 mAcceptedEgressIface = egressProp.getInterfaceName();
                 try {
                     // Use the privileged method because Lockdown VPN is initiated by the system, so
                     // no additional permission checks are necessary.
                     mVpn.startLegacyVpnPrivileged(mProfile, KeyStore.getInstance(), egressProp);
                 } catch (IllegalStateException e) {
                     mAcceptedEgressIface = null;
                     Slog.e(TAG, "Failed to start VPN", e);
                     showNotification(R.string.vpn_lockdown_error, R.drawable.vpn_disconnected);
                 }
             } else {
                 Slog.e(TAG, "Invalid VPN profile; requires IP-based server and DNS");
                 showNotification(R.string.vpn_lockdown_error, R.drawable.vpn_disconnected);
             }

         } else if (vpnInfo.isConnected() && vpnConfig != null) {
             final String iface = vpnConfig.interfaze;
             final List<LinkAddress> sourceAddrs = vpnConfig.addresses;

             if (TextUtils.equals(iface, mAcceptedIface)
                   && sourceAddrs.equals(mAcceptedSourceAddr)) {
                 return;
             }

             Slog.d(TAG, "VPN connected using iface=" + iface +
                     ", sourceAddr=" + sourceAddrs.toString());
             EventLogTags.writeLockdownVpnConnected(egressType);
             showNotification(R.string.vpn_lockdown_connected, R.drawable.vpn_connected);

             final NetworkInfo clone = new NetworkInfo(egressInfo);
             augmentNetworkInfo(clone);
             mConnService.sendConnectedBroadcast(clone);
         }
     }

     public void init() {
         synchronized (mStateLock) {
             initLocked();
         }
     }

     private void initLocked() {
         Slog.d(TAG, "initLocked()");

         mVpn.setEnableTeardown(false);
         mVpn.setLockdown(true);

         final IntentFilter resetFilter = new IntentFilter(ACTION_LOCKDOWN_RESET);
         mContext.registerReceiver(mResetReceiver, resetFilter, CONNECTIVITY_INTERNAL, null);

         handleStateChangedLocked();
     }

     public void shutdown() {
         synchronized (mStateLock) {
             shutdownLocked();
         }
     }

     private void shutdownLocked() {
         Slog.d(TAG, "shutdownLocked()");

         mAcceptedEgressIface = null;
         mErrorCount = 0;

         mVpn.stopLegacyVpnPrivileged();
         mVpn.setLockdown(false);
         hideNotification();

         mContext.unregisterReceiver(mResetReceiver);
         mVpn.setEnableTeardown(true);
     }

     public void reset() {
         Slog.d(TAG, "reset()");
         synchronized (mStateLock) {
             // cycle tracker, reset error count, and trigger retry
             shutdownLocked();
             initLocked();
             handleStateChangedLocked();
         }
     }

     public void onNetworkInfoChanged() {
         synchronized (mStateLock) {
             handleStateChangedLocked();
         }
     }

     public void onVpnStateChanged(NetworkInfo info) {
         if (info.getDetailedState() == DetailedState.FAILED) {
             mErrorCount++;
         }
         synchronized (mStateLock) {
             handleStateChangedLocked();
         }
     }

     public void augmentNetworkInfo(NetworkInfo info) {
         if (info.isConnected()) {
             final NetworkInfo vpnInfo = mVpn.getNetworkInfo();
             info.setDetailedState(vpnInfo.getDetailedState(), vpnInfo.getReason(), null);
         }
     }

     private void showNotification(int titleRes, int iconRes) {
         final Notification.Builder builder =
                 new Notification.Builder(mContext, SystemNotificationChannels.VPN)
                         .setWhen(0)
                         .setSmallIcon(iconRes)
                         .setContentTitle(mContext.getString(titleRes))
                         .setContentText(mContext.getString(R.string.vpn_lockdown_config))
                         .setContentIntent(mConfigIntent)
                         .setOngoing(true)
                         .addAction(R.drawable.ic_menu_refresh, mContext.getString(R.string.reset),
                                 mResetIntent)
                         .setColor(mContext.getColor(
                                 com.android.internal.R.color.system_notification_accent_color));

         NotificationManager.from(mContext).notify(null, SystemMessage.NOTE_VPN_STATUS,
                 builder.build());
     }

     private void hideNotification() {
         NotificationManager.from(mContext).cancel(null, SystemMessage.NOTE_VPN_STATUS);
     }
 }
	/*
	* 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.net;

	import static android.Manifest.permission.CONNECTIVITY_INTERNAL;
	import static android.net.NetworkPolicyManager.FIREWALL_CHAIN_NONE;
	import static android.net.NetworkPolicyManager.FIREWALL_RULE_ALLOW;
	import static android.net.NetworkPolicyManager.FIREWALL_RULE_DEFAULT;
	import static android.provider.Settings.ACTION_VPN_SETTINGS;

	import android.app.Notification;
	import android.app.NotificationManager;
	import android.app.PendingIntent;
	import android.content.BroadcastReceiver;
	import android.content.Context;
	import android.content.Intent;
	import android.content.IntentFilter;
	import android.net.ConnectivityManager;
	import android.net.LinkProperties;
	import android.net.LinkAddress;
	import android.net.NetworkInfo;
	import android.net.NetworkInfo.DetailedState;
	import android.net.NetworkInfo.State;
	import android.net.NetworkPolicyManager;
	import android.os.INetworkManagementService;
	import android.os.RemoteException;
	import android.security.Credentials;
	import android.security.KeyStore;
	import android.system.Os;
	import android.text.TextUtils;
	import android.util.Slog;

	import com.android.internal.R;
	import com.android.internal.messages.nano.SystemMessageProto.SystemMessage;
	import com.android.internal.net.VpnConfig;
	import com.android.internal.net.VpnProfile;
	import com.android.internal.notification.SystemNotificationChannels;
	import com.android.internal.util.Preconditions;
	import com.android.server.ConnectivityService;
	import com.android.server.EventLogTags;
	import com.android.server.connectivity.Vpn;

	import java.util.List;

	/**
	* State tracker for lockdown mode. Watches for normal {@link NetworkInfo} to be
	* connected and kicks off VPN connection, managing any required {@code netd}
	* firewall rules.
	*/
	public class LockdownVpnTracker {
	private static final String TAG = "LockdownVpnTracker";

	/** Number of VPN attempts before waiting for user intervention. */
	private static final int MAX_ERROR_COUNT = 4;

	private static final String ACTION_LOCKDOWN_RESET = "com.android.server.action.LOCKDOWN_RESET";

	private static final int ROOT_UID = 0;

	private final Context mContext;
	private final INetworkManagementService mNetService;
	private final ConnectivityService mConnService;
	private final Vpn mVpn;
	private final VpnProfile mProfile;

	private final Object mStateLock = new Object();

	private final PendingIntent mConfigIntent;
	private final PendingIntent mResetIntent;

	private String mAcceptedEgressIface;
	private String mAcceptedIface;
	private List<LinkAddress> mAcceptedSourceAddr;

	private int mErrorCount;

	public static boolean isEnabled() {
	return KeyStore.getInstance().contains(Credentials.LOCKDOWN_VPN);
	}

	public LockdownVpnTracker(Context context, INetworkManagementService netService,
	ConnectivityService connService, Vpn vpn, VpnProfile profile) {
	mContext = Preconditions.checkNotNull(context);
	mNetService = Preconditions.checkNotNull(netService);
	mConnService = Preconditions.checkNotNull(connService);
	mVpn = Preconditions.checkNotNull(vpn);
	mProfile = Preconditions.checkNotNull(profile);

	final Intent configIntent = new Intent(ACTION_VPN_SETTINGS);
	mConfigIntent = PendingIntent.getActivity(mContext, 0, configIntent, 0);

	final Intent resetIntent = new Intent(ACTION_LOCKDOWN_RESET);
	resetIntent.addFlags(Intent.FLAG_RECEIVER_REGISTERED_ONLY);
	mResetIntent = PendingIntent.getBroadcast(mContext, 0, resetIntent, 0);
	}

	private BroadcastReceiver mResetReceiver = new BroadcastReceiver() {
	@Override
	public void onReceive(Context context, Intent intent) {
	reset();
	}
	};

	/**
	* Watch for state changes to both active egress network, kicking off a VPN
	* connection when ready, or setting firewall rules once VPN is connected.
	*/
	private void handleStateChangedLocked() {

	final NetworkInfo egressInfo = mConnService.getActiveNetworkInfoUnfiltered();
	final LinkProperties egressProp = mConnService.getActiveLinkProperties();

	final NetworkInfo vpnInfo = mVpn.getNetworkInfo();
	final VpnConfig vpnConfig = mVpn.getLegacyVpnConfig();

	// Restart VPN when egress network disconnected or changed
	final boolean egressDisconnected = egressInfo == null
	\|\| State.DISCONNECTED.equals(egressInfo.getState());
	final boolean egressChanged = egressProp == null
	\|\| !TextUtils.equals(mAcceptedEgressIface, egressProp.getInterfaceName());

	final String egressTypeName = (egressInfo == null) ?
	null : ConnectivityManager.getNetworkTypeName(egressInfo.getType());
	final String egressIface = (egressProp == null) ?
	null : egressProp.getInterfaceName();
	Slog.d(TAG, "handleStateChanged: egress=" + egressTypeName +
	" " + mAcceptedEgressIface + "->" + egressIface);

	if (egressDisconnected \|\| egressChanged) {
	mAcceptedEgressIface = null;
	mVpn.stopLegacyVpnPrivileged();
	}
	if (egressDisconnected) {
	hideNotification();
	return;
	}

	final int egressType = egressInfo.getType();
	if (vpnInfo.getDetailedState() == DetailedState.FAILED) {
	EventLogTags.writeLockdownVpnError(egressType);
	}

	if (mErrorCount > MAX_ERROR_COUNT) {
	showNotification(R.string.vpn_lockdown_error, R.drawable.vpn_disconnected);

	} else if (egressInfo.isConnected() && !vpnInfo.isConnectedOrConnecting()) {
	if (mProfile.isValidLockdownProfile()) {
	Slog.d(TAG, "Active network connected; starting VPN");
	EventLogTags.writeLockdownVpnConnecting(egressType);
	showNotification(R.string.vpn_lockdown_connecting, R.drawable.vpn_disconnected);

	mAcceptedEgressIface = egressProp.getInterfaceName();
	try {
	// Use the privileged method because Lockdown VPN is initiated by the system, so
	// no additional permission checks are necessary.
	mVpn.startLegacyVpnPrivileged(mProfile, KeyStore.getInstance(), egressProp);
	} catch (IllegalStateException e) {
	mAcceptedEgressIface = null;
	Slog.e(TAG, "Failed to start VPN", e);
	showNotification(R.string.vpn_lockdown_error, R.drawable.vpn_disconnected);
	}
	} else {
	Slog.e(TAG, "Invalid VPN profile; requires IP-based server and DNS");
	showNotification(R.string.vpn_lockdown_error, R.drawable.vpn_disconnected);
	}

	} else if (vpnInfo.isConnected() && vpnConfig != null) {
	final String iface = vpnConfig.interfaze;
	final List<LinkAddress> sourceAddrs = vpnConfig.addresses;

	if (TextUtils.equals(iface, mAcceptedIface)
	&& sourceAddrs.equals(mAcceptedSourceAddr)) {
	return;
	}

	Slog.d(TAG, "VPN connected using iface=" + iface +
	", sourceAddr=" + sourceAddrs.toString());
	EventLogTags.writeLockdownVpnConnected(egressType);
	showNotification(R.string.vpn_lockdown_connected, R.drawable.vpn_connected);

	final NetworkInfo clone = new NetworkInfo(egressInfo);
	augmentNetworkInfo(clone);
	mConnService.sendConnectedBroadcast(clone);
	}
	}

	public void init() {
	synchronized (mStateLock) {
	initLocked();
	}
	}

	private void initLocked() {
	Slog.d(TAG, "initLocked()");

	mVpn.setEnableTeardown(false);
	mVpn.setLockdown(true);

	final IntentFilter resetFilter = new IntentFilter(ACTION_LOCKDOWN_RESET);
	mContext.registerReceiver(mResetReceiver, resetFilter, CONNECTIVITY_INTERNAL, null);

	handleStateChangedLocked();
	}

	public void shutdown() {
	synchronized (mStateLock) {
	shutdownLocked();
	}
	}

	private void shutdownLocked() {
	Slog.d(TAG, "shutdownLocked()");

	mAcceptedEgressIface = null;
	mErrorCount = 0;

	mVpn.stopLegacyVpnPrivileged();
	mVpn.setLockdown(false);
	hideNotification();

	mContext.unregisterReceiver(mResetReceiver);
	mVpn.setEnableTeardown(true);
	}

	public void reset() {
	Slog.d(TAG, "reset()");
	synchronized (mStateLock) {
	// cycle tracker, reset error count, and trigger retry
	shutdownLocked();
	initLocked();
	handleStateChangedLocked();
	}
	}

	public void onNetworkInfoChanged() {
	synchronized (mStateLock) {
	handleStateChangedLocked();
	}
	}

	public void onVpnStateChanged(NetworkInfo info) {
	if (info.getDetailedState() == DetailedState.FAILED) {
	mErrorCount++;
	}
	synchronized (mStateLock) {
	handleStateChangedLocked();
	}
	}

	public void augmentNetworkInfo(NetworkInfo info) {
	if (info.isConnected()) {
	final NetworkInfo vpnInfo = mVpn.getNetworkInfo();
	info.setDetailedState(vpnInfo.getDetailedState(), vpnInfo.getReason(), null);
	}
	}

	private void showNotification(int titleRes, int iconRes) {
	final Notification.Builder builder =
	new Notification.Builder(mContext, SystemNotificationChannels.VPN)
	.setWhen(0)
	.setSmallIcon(iconRes)
	.setContentTitle(mContext.getString(titleRes))
	.setContentText(mContext.getString(R.string.vpn_lockdown_config))
	.setContentIntent(mConfigIntent)
	.setOngoing(true)
	.addAction(R.drawable.ic_menu_refresh, mContext.getString(R.string.reset),
	mResetIntent)
	.setColor(mContext.getColor(
	com.android.internal.R.color.system_notification_accent_color));

	NotificationManager.from(mContext).notify(null, SystemMessage.NOTE_VPN_STATUS,
	builder.build());
	}

	private void hideNotification() {
	NotificationManager.from(mContext).cancel(null, SystemMessage.NOTE_VPN_STATUS);
	}
	}