我正在尝试以编程方式建立并连接到我们自己的 vpn（不是默认的 vpn 提供程序，即 PPTP、L2TP 等，它存在于 Android 设置 -> 无线和网络中）。
我想知道这在 2017 年是否已经可行。
有参考我用
- http://www.thegeekstuff.com/2014/06/android-vpn-service/
- https://android.googlesource.com/platform/development/+/master/samples/ToyVpn/src/com/example/android/toyvpn
在使用数据报通道时，我得到一个 PortUnreachableException。这就是我的代码的样子：
@Override
public void run() {
try {
Log.i(getTag(), "Starting");
// If anything needs to be obtained using the network, get it now.
// This greatly reduces the complexity of seamless handover, which
// tries to recreate the tunnel without shutting down everything.
// In this demo, all we need to know is the server address.
final SocketAddress serverAddress = new InetSocketAddress(mServerName, mServerPort);
// We try to create the tunnel several times.
// TODO: The better way is to work with ConnectivityManager, trying only when the
// network is available.
// Here we just use a counter to keep things simple.
for (int attempt = 0; attempt < 10; ++attempt) {
// Reset the counter if we were connected.
if (run(serverAddress)) {
attempt = 0;
}
// Sleep for a while. This also checks if we got interrupted.
Thread.sleep(3000);
}
Log.i(getTag(), "Giving up");
} catch (IOException | InterruptedException | IllegalArgumentException e) {
Log.e(getTag(), "Connection failed, exiting", e);
}
}
private boolean run(SocketAddress server)
throws IOException, InterruptedException, IllegalArgumentException {
ParcelFileDescriptor iface = null;
boolean connected = false;
// Create a DatagramChannel as the VPN tunnel.
try (DatagramChannel tunnel = DatagramChannel.open()) {
// Protect the tunnel before connecting to avoid loopback.
if (!mService.protect(tunnel.socket())) {
throw new IllegalStateException("Cannot protect the tunnel");
}
// Connect to the server.
tunnel.connect(server);
// For simplicity, we use the same thread for both reading and
// writing. Here we put the tunnel into non-blocking mode.
tunnel.configureBlocking(false);
// Authenticate and configure the virtual network interface.
iface = handshake(tunnel);
// Now we are connected. Set the flag.
connected = true;
// Packets to be sent are queued in this input stream.
FileInputStream in = new FileInputStream(iface.getFileDescriptor());
// Packets received need to be written to this output stream.
FileOutputStream out = new FileOutputStream(iface.getFileDescriptor());
// Allocate the buffer for a single packet.
ByteBuffer packet = ByteBuffer.allocate(MAX_PACKET_SIZE);
// Timeouts:
// - when data has not been sent in a while, send empty keepalive messages.
// - when data has not been received in a while, assume the connection is broken.
long lastSendTime = System.currentTimeMillis();
long lastReceiveTime = System.currentTimeMillis();
// We keep forwarding packets till something goes wrong.
while (true) {
// Assume that we did not make any progress in this iteration.
boolean idle = true;
// Read the outgoing packet from the input stream.
int length = in.read(packet.array());
if (length > 0) {
// Write the outgoing packet to the tunnel.
packet.limit(length);
tunnel.write(packet);
packet.clear();
// There might be more outgoing packets.
idle = false;
lastReceiveTime = System.currentTimeMillis();
}
// Read the incoming packet from the tunnel.
length = tunnel.read(packet);
if (length > 0) {
// Ignore control messages, which start with zero.
if (packet.get(0) != 0) {
// Write the incoming packet to the output stream.
out.write(packet.array(), 0, length);
}
packet.clear();
// There might be more incoming packets.
idle = false;
lastSendTime = System.currentTimeMillis();
}
// If we are idle or waiting for the network, sleep for a
// fraction of time to avoid busy looping.
if (idle) {
Thread.sleep(IDLE_INTERVAL_MS);
final long timeNow = System.currentTimeMillis();
if (lastSendTime + KEEPALIVE_INTERVAL_MS <= timeNow) {
// We are receiving for a long time but not sending.
// Send empty control messages.
packet.put((byte) 0).limit(1);
for (int i = 0; i < 3; ++i) {
packet.position(0);
tunnel.write(packet);
}
packet.clear();
lastSendTime = timeNow;
} else if (lastReceiveTime + RECEIVE_TIMEOUT_MS <= timeNow) {
// We are sending for a long time but not receiving.
throw new IllegalStateException("Timed out");
}
}
}
} catch (SocketException e) {
Log.e(getTag(), "Cannot use socket", e);
} finally {
if (iface != null) {
try {
iface.close();
} catch (IOException e) {
Log.e(getTag(), "Unable to close interface", e);
}
}
}
return connected;
}
和错误信息：
E/ToyVpnConnection[1]: Cannot use socket java.net.PortUnreachableException at sun.nio.ch.DatagramDispatcher.read0(Native Method)
at sun.nio.ch.DatagramDispatcher.read(DatagramDispatcher.java:42)
at sun.nio.ch.IOUtil.readIntoNativeBuffer(IOUtil.java:223)
at sun.nio.ch.IOUtil.read(IOUtil.java:197)
at sun.nio.ch.DatagramChannelImpl.read(DatagramChannelImpl.java:566)
at org.droidplanner.android.fragments.control.ToyVpnConnection.handshake(ToyVpnConnection.java:219)
at org.droidplanner.android.fragments.control.ToyVpnConnection.run(ToyVpnConnection.java:120)
at org.droidplanner.android.fragments.control.ToyVpnConnection.run(ToyVpnConnection.java:93)
我的VPN服务：
class MyVpnService extends VpnService{
private static final String TAG = MyVpnService.class.getSimpleName();
private Thread mThread;
private ParcelFileDescriptor mInterface;
//a. Configure a builder for the interface.
Builder builder = new Builder();
public static final String ACTION_CONNECT = "com.example.android.toyvpn.START";
public static final String ACTION_DISCONNECT = "com.example.android.toyvpn.STOP";
private Handler mHandler;
private PendingIntent mConfigureIntent;
private final AtomicReference<Thread> mConnectingThread = new AtomicReference<>();
private final AtomicReference<Connection> mConnection = new AtomicReference<>();
private AtomicInteger mNextConnectionId = new AtomicInteger(1);
private static class Connection extends Pair<Thread, ParcelFileDescriptor> {
public Connection(Thread thread, ParcelFileDescriptor pfd) {
super(thread, pfd);
}
}
@Override
public void onCreate() {
Log.e("MyVpnService","onCreate");
// The handler is only used to show messages.
if (mHandler == null) {
mHandler = new Handler();
}
//Create the intent to "configure" the connection (just start ToyVpnClient).
mConfigureIntent = PendingIntent.getActivity(this, 0, new Intent(this, ToyVpnClient.class),
PendingIntent.FLAG_UPDATE_CURRENT);
}
// Services interface
@Override
public int onStartCommand(Intent intent, int flags, int startId) {
// Start a new session by creating a new thread.
mThread = new Thread(new Runnable() {
@Override
public void run() {
try {
//a. Configure the TUN and get the interface.
mInterface = builder.setSession("MyVPNService")
.addAddress("192.168.0.1", 24)
.addDnsServer("8.8.8.8")
.addRoute("0.0.0.0", 0).establish();
//b. Packets to be sent are queued in this input stream.
FileInputStream in = new FileInputStream(
mInterface.getFileDescriptor());
//b. Packets received need to be written to this output stream.
FileOutputStream out = new FileOutputStream(
mInterface.getFileDescriptor());
// Allocate the buffer for a single packet.
ByteBuffer packet = ByteBuffer.allocate(32767);
//c. The UDP channel can be used to pass/get ip package to/from server
DatagramChannel tunnel = DatagramChannel.open();
// Connect to the server, localhost is used for demonstration only.
tunnel.connect(new InetSocketAddress("61.31.92.159", 1723));
//tunnel.connect(new InetSocketAddress("127.0.0.1", 8087));
//d. Protect this socket, so package send by it will not be feedback to the vpn service.
protect(tunnel.socket());
//e. Use a loop to pass packets.
while (true) {
//get packet with in
//put packet to tunnel
//get packet form tunnel
//return packet with out
//sleep is a must
Log.e("MyVpnService","true");
Thread.sleep(100);
}
} catch (Exception e) {
// Catch any exception
Log.e(TAG,"Exception:"+e.toString());
e.printStackTrace();
} finally {
try {
if (mInterface != null) {
mInterface.close();
mInterface = null;
}
} catch (Exception e) {
Log.e(TAG,"Exception2:"+e.toString());
}
}
}
}, "MyVpnRunnable");
//start the service
mThread.start();
if (intent != null && ACTION_DISCONNECT.equals(intent.getAction())) {
disconnect();
return START_NOT_STICKY;
} else {
connect();
return START_STICKY;
}
}
@Override
public void onDestroy() {
// TODO Auto-generated method stub
if (mThread != null) {
mThread.interrupt();
}
super.onDestroy();
}
private void connect() {
// Become a foreground service. Background services can be VPN services too, but they can
// be killed by background check before getting a chance to receive onRevoke().
updateForegroundNotification(R.string.connecting);
mHandler.sendEmptyMessage(R.string.connecting);
// Extract information from the shared preferences.
final SharedPreferences prefs = getSharedPreferences(ToyVpnClient.Prefs.NAME, MODE_PRIVATE);
final String server = "61.31.92.159";//prefs.getString(ToyVpnClient.Prefs.SERVER_ADDRESS, "");
final byte[] secret = "123456789".getBytes();//= prefs.getString(ToyVpnClient.Prefs.SHARED_SECRET, "").getBytes();
final int port;
try {
port = Integer.parseInt("1723");//Integer.parseInt(prefs.getString(ToyVpnClient.Prefs.SERVER_PORT, ""));
} catch (NumberFormatException e) {
Log.e("MyVPN", "Bad port: " + prefs.getString(ToyVpnClient.Prefs.SERVER_PORT, null), e);
return;
}
// Kick off a connection.
startConnection(new ToyVpnConnection(
this, mNextConnectionId.getAndIncrement(), server, port, secret));
}
private void disconnect() {
mHandler.sendEmptyMessage(R.string.disconnected);
setConnectingThread(null);
setConnection(null);
stopForeground(true);
}
private void updateForegroundNotification(final int message) {
startForeground(1, new Notification.Builder(this)
//.setSmallIcon(R.drawable.ic_vpn)
.setContentText(getString(message))
.setContentIntent(mConfigureIntent)
.build());
}
private void startConnection(final ToyVpnConnection connection) {
// Replace any existing connecting thread with the new one.
final Thread thread = new Thread(connection, "ToyVpnThread");
setConnectingThread(thread);
// Handler to mark as connected once onEstablish is called.
connection.setConfigureIntent(mConfigureIntent);
connection.setOnEstablishListener(new ToyVpnConnection.OnEstablishListener() {
public void onEstablish(ParcelFileDescriptor tunInterface) {
mHandler.sendEmptyMessage(R.string.connected);
mConnectingThread.compareAndSet(thread, null);
setConnection(new Connection(thread, tunInterface));
}
});
thread.start();
}
private void setConnectingThread(final Thread thread) {
final Thread oldThread = mConnectingThread.getAndSet(thread);
if (oldThread != null) {
oldThread.interrupt();
}
}
private void setConnection(final Connection connection) {
final Connection oldConnection = mConnection.getAndSet(connection);
if (oldConnection != null) {
try {
oldConnection.first.interrupt();
oldConnection.second.close();
} catch (IOException e) {
Log.e(TAG, "Closing VPN interface", e);
}
}
}
}
更新：
一个。ToyVPN 不使用 PPTP 协议（它使用自己的）
湾。ToyVPN 只是一个概念验证演示，它不支持多个 {username, password} 对。
C。API 是 OpenVPN 的一种：http ://code.google.com/p/ics-openvpn/ 这提供了一种潜在的 VPN 解决方案，您可以完全控制（服务器也是开源的），但它不是 PPTP或 IPSec。如果你了解 PPTP 协议，应该可以以此为模型来实现这样的 VPN 客户端。
ToyVPN 和 OpenVPN 不起作用。