/**
* Copyright (c) 2020 LEAP Encryption Access Project and contributers
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see .
*/
package se.leap.bitmaskclient.tethering;
import android.content.Context;
import android.content.IntentFilter;
import java.net.Inet4Address;
import java.net.InterfaceAddress;
import java.net.NetworkInterface;
import java.util.Enumeration;
import java.util.List;
import se.leap.bitmaskclient.base.utils.Cmd;
import static se.leap.bitmaskclient.base.utils.PreferenceHelper.isBluetoothTetheringAllowed;
import static se.leap.bitmaskclient.base.utils.PreferenceHelper.isUsbTetheringAllowed;
import static se.leap.bitmaskclient.base.utils.PreferenceHelper.isWifiTetheringAllowed;
/**
* This manager tries to figure out the current tethering states for Wifi, USB and Bluetooth
* The default behavior differs for failing attempts to get these states:
* Wifi: keeps old state
* USB: defaults to false
* Bluetooth defaults to false
* For Wifi there's a second method to check the current state (see TetheringBroadcastReceiver).
* Either of both methods can change the state if they succeed, but are ignored if they fail.
* This should avoid any interference between both methods.
*/
public class TetheringStateManager {
private static final String TAG = TetheringStateManager.class.getSimpleName();
private static TetheringStateManager instance;
private WifiManagerWrapper wifiManager;
private TetheringStateManager() { }
public static TetheringStateManager getInstance() {
if (instance == null) {
instance = new TetheringStateManager();
}
return instance;
}
public void init(Context context) {
TetheringBroadcastReceiver broadcastReceiver = new TetheringBroadcastReceiver();
IntentFilter intentFilter = new IntentFilter("android.net.conn.TETHER_STATE_CHANGED");
intentFilter.addAction("android.net.wifi.WIFI_AP_STATE_CHANGED");
context.getApplicationContext().registerReceiver(broadcastReceiver, intentFilter);
instance.wifiManager = new WifiManagerWrapper(context);
TetheringObservable.allowVpnWifiTethering(isWifiTetheringAllowed(context));
TetheringObservable.allowVpnUsbTethering(isUsbTetheringAllowed(context));
TetheringObservable.allowVpnBluetoothTethering(isBluetoothTetheringAllowed(context));
updateWifiTetheringState();
updateUsbTetheringState();
updateBluetoothTetheringState();
}
static void updateWifiTetheringState() {
WifiManagerWrapper manager = getInstance().wifiManager;
try {
TetheringObservable.setWifiTethering(manager.isWifiAPEnabled(), getWifiAddressRange(), getWlanInterfaceName());
} catch (Exception e) {
e.printStackTrace();
}
}
static void updateUsbTetheringState() {
TetheringObservable.setUsbTethering(isUsbTetheringEnabled(), getUsbAddressRange(), getUsbInterfaceName());
}
static void updateBluetoothTetheringState() {
TetheringObservable.setBluetoothTethering(isBluetoothTetheringEnabled(), getBluetoothAddressRange(), getBluetoothInterfaceName());
}
private static String getWifiAddressRange() {
String interfaceAddress = getInterfaceAddress(getWlanInterface());
return getAddressRange(interfaceAddress);
}
private static String getUsbAddressRange() {
String interfaceAddress = getInterfaceAddress(getUsbInterface());
return getAddressRange(interfaceAddress);
}
private static String getBluetoothAddressRange() {
String interfaceAddress = getInterfaceAddress(getBluetoothInterface());
return getAddressRange(interfaceAddress);
}
private static String getWlanInterfaceName() {
return getInterfaceName(getWlanInterface());
}
private static String getUsbInterfaceName() {
return getInterfaceName(getUsbInterface());
}
private static String getBluetoothInterfaceName() {
return getInterfaceName(getBluetoothInterface());
}
private static NetworkInterface getWlanInterface() {
return getNetworkInterface(new String[]{"wlan", "eth"});
}
private static NetworkInterface getUsbInterface() {
return getNetworkInterface(new String[]{"rndis"});
}
private static NetworkInterface getBluetoothInterface() {
return getNetworkInterface(new String[]{"bt-pan"});
}
private static boolean isBluetoothTetheringEnabled() {
StringBuilder log = new StringBuilder();
boolean hasBtPan = false;
try {
hasBtPan = Cmd.runBlockingCmd(new String[] {"ifconfig bt-pan"}, log) == 0;
//Log.d(TAG, "ifconfig result: " + log.toString());
} catch (Exception e) {
e.printStackTrace();
}
return hasBtPan;
}
private static boolean isUsbTetheringEnabled() {
return getUsbInterface() != null;
}
private static String getAddressRange(String interfaceAddress) {
if (interfaceAddress.split("\\.").length == 4) {
String result = interfaceAddress.substring(0, interfaceAddress.lastIndexOf("."));
result = result + ".0/24";
return result;
}
return "";
}
private static String getInterfaceAddress(NetworkInterface networkInterface) {
if (networkInterface != null) {
List ifaceAddresses = networkInterface.getInterfaceAddresses();
for (InterfaceAddress ifaceAddres : ifaceAddresses) {
if (ifaceAddres.getAddress() instanceof Inet4Address) {
return ifaceAddres.getAddress().getHostAddress();
}
}
}
return "";
}
private static String getInterfaceName(NetworkInterface networkInterface) {
if (networkInterface != null) {
return networkInterface.getName();
}
return "";
}
private static NetworkInterface getNetworkInterface(String[] interfaceNames) {
try {
for(Enumeration en = NetworkInterface.getNetworkInterfaces(); en.hasMoreElements();) {
NetworkInterface networkInterface = en.nextElement();
if(!networkInterface.isLoopback()){
for (String interfaceName : interfaceNames) {
if (networkInterface.getName().contains(interfaceName)) {
return networkInterface;
}
}
}
}
} catch(Exception e){
e.printStackTrace();
}
return null;
}
}