| /* |
| * 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 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.net.VpnConfig; |
| import com.android.internal.net.VpnProfile; |
| 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 String ACTION_VPN_SETTINGS = "android.net.vpn.SETTINGS"; |
| private static final String EXTRA_PICK_LOCKDOWN = "android.net.vpn.PICK_LOCKDOWN"; |
| |
| 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); |
| configIntent.putExtra(EXTRA_PICK_LOCKDOWN, true); |
| 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) { |
| clearSourceRulesLocked(); |
| 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); |
| |
| try { |
| clearSourceRulesLocked(); |
| |
| mNetService.setFirewallInterfaceRule(iface, true); |
| for (LinkAddress addr : sourceAddrs) { |
| setFirewallEgressSourceRule(addr, true); |
| } |
| |
| mNetService.setFirewallUidRule(FIREWALL_CHAIN_NONE, ROOT_UID, FIREWALL_RULE_ALLOW); |
| mNetService.setFirewallUidRule(FIREWALL_CHAIN_NONE, Os.getuid(), FIREWALL_RULE_ALLOW); |
| |
| mErrorCount = 0; |
| mAcceptedIface = iface; |
| mAcceptedSourceAddr = sourceAddrs; |
| } catch (RemoteException e) { |
| throw new RuntimeException("Problem setting firewall rules", e); |
| } |
| |
| mConnService.sendConnectedBroadcast(augmentNetworkInfo(egressInfo)); |
| } |
| } |
| |
| public void init() { |
| synchronized (mStateLock) { |
| initLocked(); |
| } |
| } |
| |
| private void initLocked() { |
| Slog.d(TAG, "initLocked()"); |
| |
| mVpn.setEnableTeardown(false); |
| |
| final IntentFilter resetFilter = new IntentFilter(ACTION_LOCKDOWN_RESET); |
| mContext.registerReceiver(mResetReceiver, resetFilter, CONNECTIVITY_INTERNAL, null); |
| |
| try { |
| // TODO: support non-standard port numbers |
| mNetService.setFirewallEgressDestRule(mProfile.server, 500, true); |
| mNetService.setFirewallEgressDestRule(mProfile.server, 4500, true); |
| mNetService.setFirewallEgressDestRule(mProfile.server, 1701, true); |
| } catch (RemoteException e) { |
| throw new RuntimeException("Problem setting firewall rules", e); |
| } |
| |
| handleStateChangedLocked(); |
| } |
| |
| public void shutdown() { |
| synchronized (mStateLock) { |
| shutdownLocked(); |
| } |
| } |
| |
| private void shutdownLocked() { |
| Slog.d(TAG, "shutdownLocked()"); |
| |
| mAcceptedEgressIface = null; |
| mErrorCount = 0; |
| |
| mVpn.stopLegacyVpnPrivileged(); |
| try { |
| mNetService.setFirewallEgressDestRule(mProfile.server, 500, false); |
| mNetService.setFirewallEgressDestRule(mProfile.server, 4500, false); |
| mNetService.setFirewallEgressDestRule(mProfile.server, 1701, false); |
| } catch (RemoteException e) { |
| throw new RuntimeException("Problem setting firewall rules", e); |
| } |
| clearSourceRulesLocked(); |
| 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(); |
| } |
| } |
| |
| private void clearSourceRulesLocked() { |
| try { |
| if (mAcceptedIface != null) { |
| mNetService.setFirewallInterfaceRule(mAcceptedIface, false); |
| mAcceptedIface = null; |
| } |
| if (mAcceptedSourceAddr != null) { |
| for (LinkAddress addr : mAcceptedSourceAddr) { |
| setFirewallEgressSourceRule(addr, false); |
| } |
| |
| mNetService.setFirewallUidRule(FIREWALL_CHAIN_NONE, ROOT_UID, FIREWALL_RULE_DEFAULT); |
| mNetService.setFirewallUidRule(FIREWALL_CHAIN_NONE,Os.getuid(), FIREWALL_RULE_DEFAULT); |
| |
| mAcceptedSourceAddr = null; |
| } |
| } catch (RemoteException e) { |
| throw new RuntimeException("Problem setting firewall rules", e); |
| } |
| } |
| |
| private void setFirewallEgressSourceRule( |
| LinkAddress address, boolean allow) throws RemoteException { |
| // Our source address based firewall rules must only cover our own source address, not the |
| // whole subnet |
| final String addrString = address.getAddress().getHostAddress(); |
| mNetService.setFirewallEgressSourceRule(addrString, allow); |
| } |
| |
| public void onNetworkInfoChanged() { |
| synchronized (mStateLock) { |
| handleStateChangedLocked(); |
| } |
| } |
| |
| public void onVpnStateChanged(NetworkInfo info) { |
| if (info.getDetailedState() == DetailedState.FAILED) { |
| mErrorCount++; |
| } |
| synchronized (mStateLock) { |
| handleStateChangedLocked(); |
| } |
| } |
| |
| public NetworkInfo augmentNetworkInfo(NetworkInfo info) { |
| if (info.isConnected()) { |
| final NetworkInfo vpnInfo = mVpn.getNetworkInfo(); |
| info = new NetworkInfo(info); |
| info.setDetailedState(vpnInfo.getDetailedState(), vpnInfo.getReason(), null); |
| } |
| return info; |
| } |
| |
| private void showNotification(int titleRes, int iconRes) { |
| final Notification.Builder builder = new Notification.Builder(mContext) |
| .setWhen(0) |
| .setSmallIcon(iconRes) |
| .setContentTitle(mContext.getString(titleRes)) |
| .setContentText(mContext.getString(R.string.vpn_lockdown_config)) |
| .setContentIntent(mConfigIntent) |
| .setPriority(Notification.PRIORITY_LOW) |
| .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(TAG, 0, builder.build()); |
| } |
| |
| private void hideNotification() { |
| NotificationManager.from(mContext).cancel(TAG, 0); |
| } |
| } |