I am currently trying to send a message from my Android-Smartphone to a raspberry pi.
I implemented an Android-Client by the example code given here:
Really simple TCP client
I changed the ip-address an port so it works with my server running on the pi. This server is written in c and before switching to android, I implemented a C-Client which worked so far without any problems.
The server just needs to receive a message and then it prints it and stops, so it is very simple.
EDIT 3
I created new outputs for debugging and analysis, I may got an idea now what is not working. As far as I can see, the SendMessageTask is never executed.
The Server outputs are now:
Success - create socket
Success - Binding
Listening
Success - Accept
now it stalls, "reading..." is never printed! (should happen in the while loop)
In Android I receive the following neccessary outputs:
D/TCP Client: C: Connecting...
D/TcpOptimizer: TcpOptimizer-ON
--> Connection happened
When I push the Send button:
D/myMessage1: button pushed
D/myMessage: testing
But I do not get the messages which should be logged in the SendMessageTask
When I click the disconnect button the server prints:
Client disconnected
And now Android logs:
D/RESPONSE FROM SERVER: S: Received Message: 'null'
D/sendMessageTask: try to send message
D/TcpClient: Cannot send --> mBufferOut is null
Therefore my guess is, the SendMessageTask never runs until it fails due to disconnection, but why?
Edit 3 - End
This is the (edited) server code:
#include <stdio.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <string.h>
#include <unistd.h>
int main(){
int welcomeSocket, newSocket, read_size;
char buffer[10000];
struct sockaddr_in serverAddr;
struct sockaddr_storage serverStorage;
socklen_t addr_size;
/*---- Create the socket. The three arguments are: ----*/
/* 1) Internet domain 2) Stream socket 3) Default protocol (TCP in this case) */
welcomeSocket = socket(AF_INET, SOCK_STREAM, 0);
if (welcomeSocket == -1) {
printf("Could not create socket\n");
}else {
printf("Success - create socket\n");
}
/*---- Configure settings of the server address struct ----*/
serverAddr.sin_family = AF_INET;
serverAddr.sin_port = htons(7891);
serverAddr.sin_addr.s_addr = INADDR_ANY;
/* Set all bits of the padding field to 0 */
memset(serverAddr.sin_zero, '\0', sizeof serverAddr.sin_zero);
/*---- Bind the address struct to the socket ----*/
if(bind(welcomeSocket, (struct sockaddr *) &serverAddr, sizeof(serverAddr)) < 0){
printf("Error - Binding\n");
}else {
printf("Success - Binding\n");
}
/*---- Listen on the socket, with 5 max connection requests queued ----*/
if(listen(welcomeSocket,5)==0)
printf("Listening\n");
else
printf("Error\n");
/*---- Accept call creates a new socket for the incoming connection ----*/
addr_size = sizeof serverStorage;
newSocket = accept(welcomeSocket, (struct sockaddr *) &serverStorage, &addr_size);
if(newSocket < 0){
printf("Error - Accept\n");
}else {
printf("Success - Accept\n");
}
while( (read_size = recv(newSocket, buffer, 10000, 0)) > 0){
write(newSocket, buffer, strlen(buffer));
printf("reading...");
}
if(read_size == 0){
printf("Client disconnected");
fflush(stdout);
}
else if(read_size == -1){
printf("Error - recv failed");
}
return 0;
}
I am not quite sure if the parameters in
welcomeSocket = socket(AF_INET, SOCK_STREAM, 0);
are still correct?
The Client-Code in Android is:
import android.util.Log;
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.net.InetAddress;
import java.net.Socket;
public class TcpClient {
public static final String TAG = TcpClient.class.getSimpleName();
public static final String SERVER_IP = "192.168.4.1"; //server IP address
public static final int SERVER_PORT = 7891;
// message to send to the server
private String mServerMessage;
// sends message received notifications
private OnMessageReceived mMessageListener = null;
// while this is true, the server will continue running
private boolean mRun = false;
// used to send messages
private PrintWriter mBufferOut;
// used to read messages from the server
private BufferedReader mBufferIn;
/**
* Constructor of the class. OnMessagedReceived listens for the messages received from server
*/
public TcpClient(OnMessageReceived listener) {
mMessageListener = listener;
}
/**
* Sends the message entered by client to the server
*
* #param message text entered by client
*/
public void sendMessage(final String message) {
Runnable runnable = new Runnable() {
#Override
public void run() {
if (mBufferOut != null) {
Log.d(TAG, "Sending: " + message);
mBufferOut.println(message);
mBufferOut.flush();
}else{
Log.d(TAG, "Cannot send --> mBufferOut is null");
}
}
};
Thread thread = new Thread(runnable);
thread.start();
}
/**
* Close the connection and release the members
*/
public void stopClient() {
mRun = false;
if (mBufferOut != null) {
mBufferOut.flush();
mBufferOut.close();
}
mMessageListener = null;
mBufferIn = null;
mBufferOut = null;
mServerMessage = null;
}
public void run() {
mRun = true;
try {
//here you must put your computer's IP address.
InetAddress serverAddr = InetAddress.getByName(SERVER_IP);
Log.d("TCP Client", "C: Connecting...");
//create a socket to make the connection with the server
Socket socket = new Socket(serverAddr, SERVER_PORT);
try {
//sends the message to the server
mBufferOut = new PrintWriter(new BufferedWriter(new OutputStreamWriter(socket.getOutputStream())), true);
//receives the message which the server sends back
mBufferIn = new BufferedReader(new InputStreamReader(socket.getInputStream()));
//in this while the client listens for the messages sent by the server
while (mRun) {
/*
mServerMessage = mBufferIn.readLine();
if (mServerMessage != null && mMessageListener != null) {
//call the method messageReceived from MyActivity class
mMessageListener.messageReceived(mServerMessage);
}
*/
}
Log.d("RESPONSE FROM SERVER", "S: Received Message: '" + mServerMessage + "'");
} catch (Exception e) {
Log.e("TCP", "S: Error", e);
} finally {
//the socket must be closed. It is not possible to reconnect to this socket
// after it is closed, which means a new socket instance has to be created.
socket.close();
}
} catch (Exception e) {
Log.e("TCP", "C: Error", e);
}
}
//Declare the interface. The method messageReceived(String message) will must be implemented in the Activity
//class at on AsyncTask doInBackground
public interface OnMessageReceived {
public void messageReceived(String message);
}
}
And my (edited) Mainactivity including the AsyncTask for connection is
import android.os.AsyncTask;
import android.os.Bundle;
import android.support.annotation.NonNull;
import android.support.design.widget.BottomNavigationView;
import android.support.v7.app.AppCompatActivity;
import android.util.Log;
import android.view.MenuItem;
import android.view.View;
import android.widget.TextView;
import android.widget.Button;
public class MyActivity extends AppCompatActivity {
private TextView mTextMessage;
private TextView myAwesomeTextView;
private TcpClient mTcpClient;
private BottomNavigationView.OnNavigationItemSelectedListener mOnNavigationItemSelectedListener
= new BottomNavigationView.OnNavigationItemSelectedListener() {
#Override
public boolean onNavigationItemSelected(#NonNull MenuItem item) {
switch (item.getItemId()) {
case R.id.navigation_home:
mTextMessage.setText(R.string.title_home);
return true;
case R.id.navigation_dashboard:
mTextMessage.setText(R.string.title_dashboard);
return true;
case R.id.navigation_notifications:
mTextMessage.setText(R.string.title_notifications);
return true;
}
return false;
}
};
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_myActivity);
mTextMessage = (TextView) findViewById(R.id.message);
BottomNavigationView navigation = (BottomNavigationView) findViewById(R.id.navigation);
navigation.setOnNavigationItemSelectedListener(mOnNavigationItemSelectedListener);
myAwesomeTextView = (TextView)findViewById(R.id.editText);
//TCP connect
new ConnectTask().execute("");
//Buttons
final Button button_Send = findViewById(R.id.button_Send);
button_Send.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
//Set text (debugging)
myAwesomeTextView.setText("My Awesome Text");
Log.d("myMessage1", "button pushed ");
//sends the message to the server
String message = "testing\0";
//String message = "testing\n\r";
if (mTcpClient != null) {
new SendMessageTask().execute(message);
//not needed just for debugging
Log.d("myMessage", "testing ");
}
}
});
final Button button_Disconnect = findViewById(R.id.button_Disconnect);
button_Disconnect.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
if (mTcpClient != null) {
mTcpClient.stopClient();
}
}
});
}
#Override
protected void onPause() {
super.onPause();
if (mTcpClient != null) {
// disconnect
new DisconnectTask().execute();
}
}
/**
* Sends a message using a background task to avoid doing long/network operations on the UI thread
*/
public class SendMessageTask extends AsyncTask<String, Void, Void> {
#Override
protected Void doInBackground(String... params) {
// send the message
mTcpClient.sendMessage(params[0]);
Log.d("sendMessageTask", "try to send message ");
return null;
}
#Override
protected void onPostExecute(Void nothing) {
super.onPostExecute(nothing);
//nothing to do yet
}
}
/**
* Disconnects using a background task to avoid doing long/network operations on the UI thread
*/
public class DisconnectTask extends AsyncTask<Void, Void, Void> {
#Override
protected Void doInBackground(Void... voids) {
// disconnect
mTcpClient.stopClient();
mTcpClient = null;
return null;
}
#Override
protected void onPostExecute(Void nothing) {
super.onPostExecute(nothing);
//nothing to do yet
}
}
public class ConnectTask extends AsyncTask<String, String, TcpClient> {
#Override
protected TcpClient doInBackground(String... message) {
//we create a TCPClient object and
mTcpClient = new TcpClient(new TcpClient.OnMessageReceived() {
#Override
//here the messageReceived method is implemented
public void messageReceived(String message) {
//this method calls the onProgressUpdate
publishProgress(message);
}
});
mTcpClient.run();
return null;
}
#Override
protected void onProgressUpdate(String... values) {
super.onProgressUpdate(values);
Log.d("test", "response " + values[0]);
//process server response here....
}
}
}
EDIT #2 (failing behaviour still remains)
uncommented while(mRun) Loop in run-method of TcpClient
--> thought maybe the socket is closed by finally before the message has been sent.
moved the initial connection into onCreate(), so the button will just
handle the sending and the connection is established before.
removed closing the socket after sending the message
I managed to got this working.
I changed the line
new SendMessageTask().execute(message);
to
new SendMessageTask().executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR, message);
This got the sending working.
I also changed the server code to this:
#define MAX 2048
#define PORT 7891
#define SA struct sockaddr
// Function designed for chat between client and server.
void communicate(int sockfd)
{
char buff[MAX];
int n;
// infinite loop for chat
for (;;) {
bzero(buff, MAX);
// read the message from client and copy it in buffer
read(sockfd, buff, sizeof(buff));
// print buffer which contains the client contents
printf("From client: %s\t To client : ", buff);
bzero(buff, MAX);
n = 0;
// copy server message in the buffer
while ((buff[n++] = getchar()) != '\n');
// and send that buffer to client
write(sockfd, buff, sizeof(buff));
// if msg contains "Exit" then server exit and chat ended.
if (strncmp("exit", buff, 4) == 0) {
printf("Server Exit...\n");
break;
}
}
}
// Driver function
int main()
{
int sockfd, connfd, len;
struct sockaddr_in servaddr, cli;
// socket create and verification
sockfd = socket(AF_INET, SOCK_STREAM, 0);
if (sockfd == -1) {
printf("socket creation failed...\n");
exit(0);
}
else
printf("Socket successfully created..\n");
bzero(&servaddr, sizeof(servaddr));
// assign IP, PORT
servaddr.sin_family = AF_INET;
servaddr.sin_addr.s_addr = htonl(INADDR_ANY);
servaddr.sin_port = htons(PORT);
// Binding newly created socket to given IP and verification
if ((bind(sockfd, (SA*)&servaddr, sizeof(servaddr))) != 0) {
printf("socket bind failed...\n");
exit(0);
}
else
printf("Socket successfully binded..\n");
// Now server is ready to listen and verification
if ((listen(sockfd, 5)) != 0) {
printf("Listen failed..\n");
exit(0);
}
else
printf("Server listening...\n");
len = sizeof(cli);
// Accept the data packet from client and verification
connfd = accept(sockfd, (SA*)&cli, &len);
if (connfd < 0) {
printf("server acccept failed...\n");
exit(0);
}
else
printf("server acccept the client..\n");
// Function for chatting between client and server
communicate(connfd);
// After chatting close the socket
if(close(sockfd) < 0){
printf("Error - closing socket...\n");
}
else{
printf("Socket successfully closed..\n");
}
}
Related
I want to connect with VPN server but I don't want to use secret key. Currently the code snippet i found to programmatically create vpn connection is as follows:
MyVpnClient:
package com.example.android.toyvpn;
import android.app.Activity;
import android.content.Intent;
import android.content.SharedPreferences;
import android.net.VpnService;
import android.os.Bundle;
import android.widget.TextView;
public class ToyVpnClient extends Activity {
public interface Prefs {
String NAME = "connection";
String SERVER_ADDRESS = "server.address";
String SERVER_PORT = "server.port";
String SHARED_SECRET = "shared.secret";
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.form);
final TextView serverAddress = (TextView) findViewById(R.id.address);
final TextView serverPort = (TextView) findViewById(R.id.port);
final TextView sharedSecret = (TextView) findViewById(R.id.secret);
final SharedPreferences prefs = getSharedPreferences(Prefs.NAME, MODE_PRIVATE);
serverAddress.setText(prefs.getString(Prefs.SERVER_ADDRESS, ""));
serverPort.setText(prefs.getString(Prefs.SERVER_PORT, ""));
sharedSecret.setText(prefs.getString(Prefs.SHARED_SECRET, ""));
findViewById(R.id.connect).setOnClickListener(v -> {
prefs.edit()
.putString(Prefs.SERVER_ADDRESS, serverAddress.getText().toString())
.putString(Prefs.SERVER_PORT, serverPort.getText().toString())
.putString(Prefs.SHARED_SECRET, sharedSecret.getText().toString())
.commit();
Intent intent = VpnService.prepare(ToyVpnClient.this);
if (intent != null) {
startActivityForResult(intent, 0);
} else {
onActivityResult(0, RESULT_OK, null);
}
});
findViewById(R.id.disconnect).setOnClickListener(v -> {
startService(getServiceIntent().setAction(ToyVpnService.ACTION_DISCONNECT));
});
}
#Override
protected void onActivityResult(int request, int result, Intent data) {
if (result == RESULT_OK) {
startService(getServiceIntent().setAction(ToyVpnService.ACTION_CONNECT));
}
}
private Intent getServiceIntent() {
return new Intent(this, ToyVpnService.class);
}
}
MyVpnConnection:
package com.example.android.toyvpn;
import static java.nio.charset.StandardCharsets.US_ASCII;
import android.app.PendingIntent;
import android.net.VpnService;
import android.os.ParcelFileDescriptor;
import android.util.Log;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.net.InetSocketAddress;
import java.net.SocketAddress;
import java.net.SocketException;
import java.nio.ByteBuffer;
import java.nio.channels.DatagramChannel;
import java.util.concurrent.TimeUnit;
public class ToyVpnConnection implements Runnable {
/**
* Callback interface to let the {#link ToyVpnService} know about new connections
* and update the foreground notification with connection status.
*/
public interface OnEstablishListener {
void onEstablish(ParcelFileDescriptor tunInterface);
}
/** Maximum packet size is constrained by the MTU, which is given as a signed short. */
private static final int MAX_PACKET_SIZE = Short.MAX_VALUE;
/** Time to wait in between losing the connection and retrying. */
private static final long RECONNECT_WAIT_MS = TimeUnit.SECONDS.toMillis(3);
/** Time between keepalives if there is no traffic at the moment.
*
* TODO: don't do this; it's much better to let the connection die and then reconnect when
* necessary instead of keeping the network hardware up for hours on end in between.
**/
private static final long KEEPALIVE_INTERVAL_MS = TimeUnit.SECONDS.toMillis(15);
/** Time to wait without receiving any response before assuming the server is gone. */
private static final long RECEIVE_TIMEOUT_MS = TimeUnit.SECONDS.toMillis(20);
/**
* Time between polling the VPN interface for new traffic, since it's non-blocking.
*
* TODO: really don't do this; a blocking read on another thread is much cleaner.
*/
private static final long IDLE_INTERVAL_MS = TimeUnit.MILLISECONDS.toMillis(100);
/**
* Number of periods of length {#IDLE_INTERVAL_MS} to wait before declaring the handshake a
* complete and abject failure.
*
* TODO: use a higher-level protocol; hand-rolling is a fun but pointless exercise.
*/
private static final int MAX_HANDSHAKE_ATTEMPTS = 50;
private final VpnService mService;
private final int mConnectionId;
private final String mServerName;
private final int mServerPort;
private final byte[] mSharedSecret;
private PendingIntent mConfigureIntent;
private OnEstablishListener mOnEstablishListener;
public ToyVpnConnection(final VpnService service, final int connectionId,
final String serverName, final int serverPort, final byte[] sharedSecret) {
mService = service;
mConnectionId = connectionId;
mServerName = serverName;
mServerPort= serverPort;
mSharedSecret = sharedSecret;
}
/**
* Optionally, set an intent to configure the VPN. This is {#code null} by default.
*/
public void setConfigureIntent(PendingIntent intent) {
mConfigureIntent = intent;
}
public void setOnEstablishListener(OnEstablishListener listener) {
mOnEstablishListener = listener;
}
#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;
}
private ParcelFileDescriptor handshake(DatagramChannel tunnel)
throws IOException, InterruptedException {
// To build a secured tunnel, we should perform mutual authentication
// and exchange session keys for encryption. To keep things simple in
// this demo, we just send the shared secret in plaintext and wait
// for the server to send the parameters.
// Allocate the buffer for handshaking. We have a hardcoded maximum
// handshake size of 1024 bytes, which should be enough for demo
// purposes.
ByteBuffer packet = ByteBuffer.allocate(1024);
// Control messages always start with zero.
packet.put((byte) 0).put(mSharedSecret).flip();
// Send the secret several times in case of packet loss.
for (int i = 0; i < 3; ++i) {
packet.position(0);
tunnel.write(packet);
}
packet.clear();
// Wait for the parameters within a limited time.
for (int i = 0; i < MAX_HANDSHAKE_ATTEMPTS; ++i) {
Thread.sleep(IDLE_INTERVAL_MS);
// Normally we should not receive random packets. Check that the first
// byte is 0 as expected.
int length = tunnel.read(packet);
if (length > 0 && packet.get(0) == 0) {
return configure(new String(packet.array(), 1, length - 1, US_ASCII).trim());
}
}
throw new IOException("Timed out");
}
private ParcelFileDescriptor configure(String parameters) throws IllegalArgumentException {
// Configure a builder while parsing the parameters.
VpnService.Builder builder = mService.new Builder();
for (String parameter : parameters.split(" ")) {
String[] fields = parameter.split(",");
try {
switch (fields[0].charAt(0)) {
case 'm':
builder.setMtu(Short.parseShort(fields[1]));
break;
case 'a':
builder.addAddress(fields[1], Integer.parseInt(fields[2]));
break;
case 'r':
builder.addRoute(fields[1], Integer.parseInt(fields[2]));
break;
case 'd':
builder.addDnsServer(fields[1]);
break;
case 's':
builder.addSearchDomain(fields[1]);
break;
}
} catch (NumberFormatException e) {
throw new IllegalArgumentException("Bad parameter: " + parameter);
}
}
// Create a new interface using the builder and save the parameters.
final ParcelFileDescriptor vpnInterface;
synchronized (mService) {
vpnInterface = builder
.setSession(mServerName)
.setConfigureIntent(mConfigureIntent)
.establish();
if (mOnEstablishListener != null) {
mOnEstablishListener.onEstablish(vpnInterface);
}
}
Log.i(getTag(), "New interface: " + vpnInterface + " (" + parameters + ")");
return vpnInterface;
}
private final String getTag() {
return ToyVpnConnection.class.getSimpleName() + "[" + mConnectionId + "]";
}
}
MyVpnService:
package com.example.android.toyvpn;
import android.app.Notification;
import android.app.PendingIntent;
import android.app.Service;
import android.content.Intent;
import android.content.SharedPreferences;
import android.net.VpnService;
import android.os.Handler;
import android.os.Message;
import android.os.ParcelFileDescriptor;
import android.util.Log;
import android.util.Pair;
import android.widget.Toast;
import java.io.IOException;
import java.util.concurrent.atomic.AtomicInteger;
import java.util.concurrent.atomic.AtomicReference;
public class ToyVpnService extends VpnService implements Handler.Callback {
private static final String TAG = ToyVpnService.class.getSimpleName();
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 static class Connection extends Pair<Thread, ParcelFileDescriptor> {
public Connection(Thread thread, ParcelFileDescriptor pfd) {
super(thread, pfd);
}
}
private final AtomicReference<Thread> mConnectingThread = new AtomicReference<>();
private final AtomicReference<Connection> mConnection = new AtomicReference<>();
private AtomicInteger mNextConnectionId = new AtomicInteger(1);
private PendingIntent mConfigureIntent;
#Override
public void onCreate() {
// The handler is only used to show messages.
if (mHandler == null) {
mHandler = new Handler(this);
}
// Create the intent to "configure" the connection (just start ToyVpnClient).
mConfigureIntent = PendingIntent.getActivity(this, 0, new Intent(this, ToyVpnClient.class),
PendingIntent.FLAG_UPDATE_CURRENT);
}
#Override
public int onStartCommand(Intent intent, int flags, int startId) {
if (intent != null && ACTION_DISCONNECT.equals(intent.getAction())) {
disconnect();
return START_NOT_STICKY;
} else {
connect();
return START_STICKY;
}
}
#Override
public void onDestroy() {
disconnect();
}
#Override
public boolean handleMessage(Message message) {
Toast.makeText(this, message.what, Toast.LENGTH_SHORT).show();
if (message.what != R.string.disconnected) {
updateForegroundNotification(message.what);
}
return true;
}
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 = prefs.getString(ToyVpnClient.Prefs.SERVER_ADDRESS, "");
final byte[] secret = prefs.getString(ToyVpnClient.Prefs.SHARED_SECRET, "").getBytes();
final int port;
try {
port = Integer.parseInt(prefs.getString(ToyVpnClient.Prefs.SERVER_PORT, ""));
} catch (NumberFormatException e) {
Log.e(TAG, "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 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);
}
}
}
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());
}
}
The above code is from the following url:
https://android.googlesource.com/platform/development/+/master/samples/ToyVpn
I have tried but I am not getting any workaround without secret key. Please help.
Unfortunately, we don't have any further requirements / spec of your VPN server.
You might want to have a look at the OpenVPN or strongSwan VPN (open source) implementations to see if they can fit your requirements. The latter for example provides the following ways of authentication on Android (https://wiki.strongswan.org/projects/strongswan/wiki/androidvpnclient):
Only IKEv2 is supported
Client authentication is limited to:
EAP authentication based on username/password (EAP-MSCHAPv2, EAP-MD5, EAP-GTC)
RSA/ECDSA authentication with private key/certificate
EAP-TLS with private key/certificate (see 1.4.5 for limitations)
I want to build an app that can connect with a single click of button which will create a vpn profile and connect to the vpn profile by parsig the username and password of the vpn server.
The code that is developed and modified is good to create and connect vpn but my vpn requires username and password to be entered so i want to do that programatically.
Here is my project
VpnClient.java
import android.content.Context;
import android.content.Intent;
import android.content.SharedPreferences;
import android.net.VpnService;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
public class VpnClient extends AppCompatActivity{
public interface Prefs {
String NAME = "connection";
String SERVER_ADDRESS = "server.address";
String SERVER_PORT = "server.port";
String SHARED_SECRET = "shared.secret";
}
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Button disconnect = (Button) findViewById(R.id.disconnect);
Button connect = (Button) findViewById(R.id.connect);
// final TextView serverAddress = (TextView) findViewById(R.id.address);
//final TextView serverPort = (TextView) findViewById(R.id.port);
// final TextView sharedSecret = (TextView) findViewById(R.id.secret);
final SharedPreferences prefs = getSharedPreferences(Prefs.NAME, MODE_PRIVATE);
final String serverAddress = ""; !!I insert my vpnserver address in here which is my.vpnserver.com
final String serverPort = ""; !!As server port i am using 1723 for PPTP connection
connect.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
prefs.edit()
.putString(Prefs.SERVER_ADDRESS,"")
.putString(Prefs.SERVER_PORT, "")
.putString(Prefs.SHARED_SECRET, "")
.commit();
Intent intent = VpnService.prepare(VpnClient.this);
if (intent != null) {
startActivityForResult(intent, 0);
} else {
onActivityResult(0, RESULT_OK, null);
}
}
});
disconnect.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
startService(getServiceIntent().setAction(MyVpnService.ACTION_DISCONNECT));
}
});
}
#Override
protected void onActivityResult(int request, int result, Intent data) {
if (result == RESULT_OK) {
startService(getServiceIntent().setAction(MyVpnService.ACTION_CONNECT));
}
}
private Intent getServiceIntent() {
return new Intent(this, MyVpnService.class);
}
}
MyVpnService.java
import android.app.Notification;
import android.app.PendingIntent;
import android.content.Intent;
import android.content.SharedPreferences;
import android.os.Build;
import android.os.Handler;
import android.os.Message;
import android.os.ParcelFileDescriptor;
import android.support.annotation.RequiresApi;
import android.support.v4.util.Pair;
import android.util.Log;
import android.widget.Toast;
import java.io.IOException;
import java.util.concurrent.atomic.AtomicInteger;
import java.util.concurrent.atomic.AtomicReference;
import java.util.logging.LogRecord;
public class MyVpnService extends andenter code hereroid.net.VpnService implements android.os.Handler.Callback {
private static final String TAG = MyVpnService.class.getSimpleName();
public static final String ACTION_CONNECT = "com.yaksh.vpn.START";
public static final String ACTION_DISCONNECT = "com.yaksh.vpn.STOP";
private Handler mHandler;
private static class Connection extends Pair<Thread, ParcelFileDescriptor> {
public Connection(Thread thread, ParcelFileDescriptor pfd) {
super(thread, pfd);
}
}
private final AtomicReference<Thread> mConnectingThread = new AtomicReference<>();
private final AtomicReference<Connection> mConnection = new AtomicReference<>();
private AtomicInteger mNextConnectionId = new AtomicInteger(1);
private PendingIntent mConfigureIntent;
#Override
public void onCreate() {
// The handler is only used to show messages.
if (mHandler == null) {
mHandler = new Handler(this);
}
// Create the intent to "configure" the connection (just start ToyVpnClient).
mConfigureIntent = PendingIntent.getActivity(this, 0, new Intent(this, VpnClient.class),
PendingIntent.FLAG_UPDATE_CURRENT);
}
#RequiresApi(api = Build.VERSION_CODES.JELLY_BEAN)
#Override
public int onStartCommand(Intent intent, int flags, int startId) {
if (intent != null && ACTION_DISCONNECT.equals(intent.getAction())) {
disconnect();
return START_NOT_STICKY;
} else {
connect();
return START_STICKY;
}
}
#Override
public void onDestroy() {
disconnect();
}
#RequiresApi(api = Build.VERSION_CODES.JELLY_BEAN)
#Override
public boolean handleMessage(Message message) {
Toast.makeText(this, message.what, Toast.LENGTH_SHORT).show();
if (message.what != R.string.disconnected) {
updateForegroundNotification(message.what);
}
return true;
}
#RequiresApi(api = Build.VERSION_CODES.JELLY_BEAN)
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(VpnClient.Prefs.NAME, MODE_PRIVATE);
final String server = prefs.getString(VpnClient.Prefs.SERVER_ADDRESS, "");
final byte[] secret = prefs.getString(VpnClient.Prefs.SHARED_SECRET, "").getBytes();
final int port;
try {
port = Integer.parseInt(prefs.getString(VpnClient.Prefs.SERVER_PORT, ""));
} catch (NumberFormatException e) {
Log.e(TAG, "Bad port: " + prefs.getString(VpnClient.Prefs.SERVER_PORT, null), e);
return;
}
// Kick off a connection.
startConnection(new VpnConnection(
this, mNextConnectionId.getAndIncrement(), server, port, secret));
}
private void startConnection(final VpnConnection 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 VpnConnection.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);
}
}
}
private void disconnect() {
mHandler.sendEmptyMessage(R.string.disconnected);
setConnectingThread(null);
setConnection(null);
stopForeground(true);
}
#RequiresApi(api = Build.VERSION_CODES.JELLY_BEAN)
private void updateForegroundNotification(final int message) {
startForeground(1, new Notification.Builder(this)
.setSmallIcon(R.drawable.ic_vpn)
.setContentText(getString(message))
.setContentIntent(mConfigureIntent)
.build());
}
}
VpnConnection.java
import android.app.PendingIntent;
import android.os.Build;
import android.os.ParcelFileDescriptor;
import android.support.annotation.RequiresApi;
import android.util.Log;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.net.InetSocketAddress;
import java.net.SocketAddress;
import java.net.SocketException;
import java.nio.ByteBuffer;
import java.nio.channels.DatagramChannel;
import java.util.concurrent.TimeUnit;
/**
* Created by Yaksh on 11/3/2017.
*/
public class VpnConnection implements Runnable{
/**
* Callback interface to let the {#link MyVpnService} know about new connections
* and update the foreground notification with connection status.
*/
public interface OnEstablishListener {
void onEstablish(ParcelFileDescriptor tunInterface);
}
/** Maximum packet size is constrained by the MTU, which is given as a signed short. */
private static final int MAX_PACKET_SIZE = Short.MAX_VALUE;
/** Time to wait in between losing the connection and retrying. */
private static final long RECONNECT_WAIT_MS = TimeUnit.SECONDS.toMillis(3);
/** Time between keepalives if there is no traffic at the moment.
*
* TODO: don't do this; it's much better to let the connection die and then reconnect when
* necessary instead of keeping the network hardware up for hours on end in between.
**/
private static final long KEEPALIVE_INTERVAL_MS = TimeUnit.SECONDS.toMillis(15);
/** Time to wait without receiving any response before assuming the server is gone. */
private static final long RECEIVE_TIMEOUT_MS = TimeUnit.SECONDS.toMillis(20);
/**
* Time between polling the VPN interface for new traffic, since it's non-blocking.
*
* TODO: really don't do this; a blocking read on another thread is much cleaner.
*/
private static final long IDLE_INTERVAL_MS = TimeUnit.MILLISECONDS.toMillis(100);
/**
* Number of periods of length {#IDLE_INTERVAL_MS} to wait before declaring the handshake a
* complete and abject failure.
*
* TODO: use a higher-level protocol; hand-rolling is a fun but pointless exercise.
*/
private static final int MAX_HANDSHAKE_ATTEMPTS = 50;
private final MyVpnService mService;
private final int mConnectionId;
private final String mServerName;
private final int mServerPort;
private final byte[] mSharedSecret;
private PendingIntent mConfigureIntent;
private OnEstablishListener mOnEstablishListener;
public VpnConnection(final MyVpnService service, final int connectionId,
final String serverName, final int serverPort, final byte[] sharedSecret) {
mService = service;
mConnectionId = connectionId;
mServerName = serverName;
mServerPort= serverPort;
mSharedSecret = sharedSecret;
}
/**
* Optionally, set an intent to configure the VPN. This is {#code null} by default.
*/
public void setConfigureIntent(PendingIntent intent) {
mConfigureIntent = intent;
}
public void setOnEstablishListener(OnEstablishListener listener) {
mOnEstablishListener = listener;
}
#RequiresApi(api = Build.VERSION_CODES.KITKAT)
#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.
// 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);
}
}
#RequiresApi(api = Build.VERSION_CODES.KITKAT)
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;
}
private ParcelFileDescriptor handshake(DatagramChannel tunnel)
throws IOException, InterruptedException {
// To build a secured tunnel, we should perform mutual authentication
// and exchange session keys for encryption. To keep things simple in
// this demo, we just send the shared secret in plaintext and wait
// for the server to send the parameters.
// Allocate the buffer for handshaking. We have a hardcoded maximum
// handshake size of 1024 bytes, which should be enough for demo
// purposes.
ByteBuffer packet = ByteBuffer.allocate(1024);
// Control messages always start with zero.
packet.put((byte) 0).put(mSharedSecret).flip();
// Send the secret several times in case of packet loss.
for (int i = 0; i < 3; ++i) {
packet.position(0);
tunnel.write(packet);
}
packet.clear();
// Wait for the parameters within a limited time.
for (int i = 0; i < MAX_HANDSHAKE_ATTEMPTS; ++i) {
Thread.sleep(IDLE_INTERVAL_MS);
// Normally we should not receive random packets. Check that the first
// byte is 0 as expected.
int length = tunnel.read(packet);
if (length > 0 && packet.get(0) == 0) {
return configure(new String(packet.array(), 1, length - 1).trim());
}
}
throw new IOException("Timed out");
}
private ParcelFileDescriptor configure(String parameters) throws IllegalArgumentException {
// Configure a builder while parsing the parameters.
MyVpnService.Builder builder = mService.new Builder();
for (String parameter : parameters.split(" ")) {
String[] fields = parameter.split(",");
try {
switch (fields[0].charAt(0)) {
case 'm':
builder.setMtu(Short.parseShort(fields[1]));
break;
case 'a':
builder.addAddress(fields[1], Integer.parseInt(fields[2]));
break;
case 'r':
builder.addRoute(fields[1], Integer.parseInt(fields[2]));
break;
case 'd':
builder.addDnsServer(fields[1]);
break;
case 's':
builder.addSearchDomain(fields[1]);
break;
}
} catch (NumberFormatException e) {
throw new IllegalArgumentException("Bad parameter: " + parameter);
}
}
// Create a new interface using the builder and save the parameters.
final ParcelFileDescriptor vpnInterface;
synchronized (mService) {
vpnInterface = builder
.setSession(mServerName)
.setConfigureIntent(mConfigureIntent)
.establish();
if (mOnEstablishListener != null) {
mOnEstablishListener.onEstablish(vpnInterface);
}
}
Log.i(getTag(), "New interface: " + vpnInterface + " (" + parameters + ")");
return vpnInterface;
}
private final String getTag() {
return VpnConnection.class.getSimpleName() + "[" + mConnectionId + "]";
}
}
Happy new year all :)
I am working on a home automation project using Arduino Uno and Android application what can communicate through my TP-Link router.
I am having a java.io.IOException: unexpected end of stream on Connection
once I send a query to the Arduino and I'm not being able to solve it.
01-01 16:51:47.771 10592-11256/com.projects.mahmoudmahdi.etherdroid E/EtherDroid: java.io.IOException: unexpected end of stream on Connection{192.168.1.215:80, proxy=DIRECT# hostAddress=192.168.1.215 cipherSuite=none protocol=http/1.1} (recycle count=0)
at com.android.okhttp.internal.http.HttpConnection.readResponse(HttpConnection.java:210)
at com.android.okhttp.internal.http.HttpTransport.readResponseHeaders(HttpTransport.java:80)
at com.android.okhttp.internal.http.HttpEngine.readNetworkResponse(HttpEngine.java:904)
at com.android.okhttp.internal.http.HttpEngine.readResponse(HttpEngine.java:788)
at com.android.okhttp.internal.huc.HttpURLConnectionImpl.execute(HttpURLConnectionImpl.java:443)
at com.android.okhttp.internal.huc.HttpURLConnectionImpl.getResponse(HttpURLConnectionImpl.java:388)
at com.android.okhttp.internal.huc.HttpURLConnectionImpl.getResponseCode(HttpURLConnectionImpl.java:501)
at com.projects.mahmoudmahdi.etherdroid.MainActivity$commandArduino.doInBackground(MainActivity.java:50)
at com.projects.mahmoudmahdi.etherdroid.MainActivity$commandArduino.doInBackground(MainActivity.java:31)
at android.os.AsyncTask$2.call(AsyncTask.java:295)
at java.util.concurrent.FutureTask.run(FutureTask.java:237)
at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:234)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1113)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:588)
at java.lang.Thread.run(Thread.java:818)
Caused by: java.io.EOFException: \n not found: size=0 content=...
at com.android.okhttp.okio.RealBufferedSource.readUtf8LineStrict(RealBufferedSource.java:200)
at com.android.okhttp.internal.http.HttpConnection.readHeaders(HttpConnection.java:220)
at com.android.okhttp.internal.http.HttpConnection.readResponse(HttpConnection.java:199)
at com.android.okhttp.internal.http.HttpTransport.readResponseHeaders(HttpTransport.java:80)
at com.android.okhttp.internal.http.HttpEngine.readNetworkResponse(HttpEngine.java:904)
at com.android.okhttp.internal.http.HttpEngine.readResponse(HttpEngine.java:788)
at com.android.okhttp.internal.huc.HttpURLConnectionImpl.execute(HttpURLConnectionImpl.java:443)
at com.android.okhttp.internal.huc.HttpURLConnectionImpl.getResponse(HttpURLConnectionImpl.java:388)
at com.android.okhttp.internal.huc.HttpURLConnectionImpl.getResponseCode(HttpURLConnectionImpl.java:501)
at com.projects.mahmoudmahdi.etherdroid.MainActivity$commandArduino.doInBackground(MainActivity.java:50)
at com.projects.mahmoudmahdi.etherdroid.MainActivity$commandArduino.doInBackground(MainActivity.java:31)
at android.os.AsyncTask$2.call(AsyncTask.java:295)
at java.util.concurrent.FutureTask.run(FutureTask.java:237)
at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:234)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1113)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:588)
at java.lang.Thread.run(Thread.java:818)
My Arduino Sketch:
#include <UIPEthernet.h>
int relay = 2;
byte mac[] = { 0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED }; //physical mac address
byte ip[] = { 192, 168, 1, 215 }; // ip in lan (that's what you need to use in your browser. (F("192.168.1.200"))
byte gateway[] = { 192, 168, 1, 10 }; // internet access via router
byte subnet[] = { 255, 255, 255, 0 }; //subnet mask
EthernetServer server(80); //server port
String readString;
void setup() {
// Open serial communications and wait for port to open:
Serial.begin(9600);
pinMode(relay, OUTPUT);
// start the Ethernet connection and the server:
Ethernet.begin(mac, ip, gateway, subnet);
server.begin();
Serial.print(F("server is at "));
Serial.println(Ethernet.localIP());
}
void loop() {
// Create a client connection
EthernetClient client = server.available();
if (client) {
//clearing string for next read
readString = "";
while (client.connected()) {
if (client.available()) {
char c = client.read();
//read char by char HTTP request
if (readString.length() < 100) {
//store characters to string
readString += c;
Serial.print(c);
}
//if HTTP request has ended
if (c == '\n') {
Serial.println(readString); //print to serial monitor for debuging
client.println("HTTP/1.1 200 OK"); //send new page
client.println("Content-Type: text/html");
//stopping client
client.stop();
//controls the Arduino if you press the buttons
if (readString.indexOf("?relay1on") > 0) {
digitalWrite(relay, LOW);
Serial.println("relay is on");
}
if (readString.indexOf("?relay1off") > 0) {
digitalWrite(relay, HIGH);
Serial.println("relay is off");
}
}
}
}
}
}
My Android Code:
package com.projects.mahmoudmahdi.etherdroid;
import android.content.Context;
import android.net.ConnectivityManager;
import android.net.NetworkInfo;
import android.os.AsyncTask;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.Toast;
import java.net.HttpURLConnection;
import java.net.URL;
public class MainActivity extends AppCompatActivity implements OnClickListener {
private class commandArduino extends AsyncTask<URL, Void, Integer> {
#Override
protected Integer doInBackground(URL... url) {
int response = 0;
if (isNetworkAvailable()) {
// params comes from the execute() call: params[0] is the url.
try {
HttpURLConnection urlConnection = (HttpURLConnection) url[0].openConnection();
urlConnection.setRequestMethod("GET");
urlConnection.connect();
switch (urlConnection.getResponseCode()) {
case HttpURLConnection.HTTP_OK:
Log.d("RESPONSE", "**OK**");
break; // fine, go on
case HttpURLConnection.HTTP_GATEWAY_TIMEOUT:
Log.d("RESPONSE", "**gateway timeout**");
break;// retry
case HttpURLConnection.HTTP_UNAVAILABLE:
Log.d("RESPONSE", "**unavailable**");
break;// retry, server is unstable
default:
Log.d("RESPONSE", "**unknown response code**.");
break; // abort
}
urlConnection.disconnect();
Log.d("RESPONSE", "Aborting download of dataset.");
} catch (Exception e) {
Log.e("EtherDroid", "STACKTRACE");
Log.e("EtherDroid", Log.getStackTraceString(e));
}
}
return response;
}
}
static boolean relay1 = false;
commandArduino cmdAdn;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Button Relay1 = (Button) findViewById(R.id.relay1);
Relay1.setOnClickListener(this);
}
private boolean isNetworkAvailable() {
boolean available = false;
/** Getting the system's connectivity service */
ConnectivityManager connMgr = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);
/** Getting active network interface to get the network's status */
NetworkInfo networkInfo = connMgr.getActiveNetworkInfo();
if (networkInfo != null && networkInfo.isAvailable())
available = true;
/** Returning the status of the network */
return available;
}
public void onClick(View thisView) {
cmdAdn = new commandArduino();
switch (thisView.getId()) {
case R.id.relay1:
if (!relay1) {
relay1 = true;
try {
cmdAdn.execute(new URL("http://192.168.1.215/?relay1on"));
} catch (Exception e) {
e.printStackTrace();
}
Toast.makeText(getApplicationContext(), "relay1 on", Toast.LENGTH_SHORT).show();
} else {
relay1 = false;
try {
cmdAdn.execute(new URL("http://192.168.1.215/?relay1off"));
} catch (Exception e) {
e.printStackTrace();
}
Toast.makeText(getApplicationContext(), "relay1 off", Toast.LENGTH_SHORT).show();
}
break;
}
}
}
In general terms, you're missing:
Send data in the response
Giving time for the socket to send data before closing
Reading Android's response before closing the connection.
More in detail, make sure to send some data after establishing the connection:
client.println("HTTP/1.1 200 OK"); //send new page
client.println("Content-Type: text/html");
client.println("Connection: close"); // the connection will be closed after completion of the response
client.println();
client.println("<!DOCTYPE HTML>");
client.println("<html>");
client.println("</html>");
// Give it time to close
delay(1);
client.close();
Reference: https://www.arduino.cc/en/Tutorial/WebServer , here's the full example:
void loop() {
// listen for incoming clients
EthernetClient client = server.available();
if (client) {
Serial.println("new client");
// an http request ends with a blank line
boolean currentLineIsBlank = true;
while (client.connected()) {
if (client.available()) {
char c = client.read(); // NOTE: You're missing this in your code
Serial.write(c);
// if you've gotten to the end of the line (received a newline
// character) and the line is blank, the http request has ended,
// so you can send a reply
if (c == '\n' && currentLineIsBlank) {
// send a standard http response header
client.println("HTTP/1.1 200 OK");
client.println("Content-Type: text/html");
client.println("Connection: close"); // the connection will be closed after completion of the response
client.println("Refresh: 5"); // refresh the page automatically every 5 sec
client.println();
client.println("<!DOCTYPE HTML>");
client.println("<html>");
// output the value of each analog input pin
for (int analogChannel = 0; analogChannel < 6; analogChannel++) {
int sensorReading = analogRead(analogChannel);
client.print("analog input ");
client.print(analogChannel);
client.print(" is ");
client.print(sensorReading);
client.println("<br />");
}
client.println("</html>");
break;
}
if (c == '\n') {
// you're starting a new line
currentLineIsBlank = true;
} else if (c != '\r') {
// you've gotten a character on the current line
currentLineIsBlank = false;
}
}
}
// give the web browser time to receive the data
delay(1);
// close the connection:
client.stop();
Serial.println("client disconnected");
Ethernet.maintain();
}
}
Also, consider using json instead of html for Arduino's response. To do that, you'll need to change:
client.println("HTTP/1.1 200 OK");
client.println("Content-Type: application/json");
client.println("Connection: close");
client.println();
client.println("{\"status\":\"ok\"}"); // Or whatever you want to change
I want to connect the VPN in my Application.
I download the demo from https://github.com/guardianproject/OrbotVPN
package org.torproject.android.vpn;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.net.DatagramSocket;
import java.net.InetAddress;
import java.net.InetSocketAddress;
import java.net.UnknownHostException;
import java.nio.ByteBuffer;
import java.nio.channels.DatagramChannel;
import android.app.PendingIntent;
import android.content.Intent;
import android.net.VpnService;
import android.os.Handler;
import android.os.Message;
import android.os.ParcelFileDescriptor;
import android.util.Log;
import android.widget.Toast;
import com.runjva.sourceforge.jsocks.protocol.ProxyServer;
import com.runjva.sourceforge.jsocks.server.ServerAuthenticatorNone;
public class OrbotVpnService extends VpnService implements Handler.Callback, Runnable {
private static final String TAG = "OrbotVpnService";
private String mServerAddress = "192.xx.xx.xx";
private int mServerPort = xxxx;
private PendingIntent mConfigureIntent;
private Handler mHandler;
private Thread mThread;
private String mSessionName = "OrbotVPN";
private ParcelFileDescriptor mInterface;
private int mSocksProxyPort = 9999;
private boolean mKeepRunning = true;
#Override
public int onStartCommand(Intent intent, int flags, int startId) {
// The handler is only used to show messages.
if (mHandler == null) {
mHandler = new Handler(this);
}
// Stop the previous session by interrupting the thread.
if (mThread != null) {
mThread.interrupt();
}
// Start a new session by creating a new thread.
mThread = new Thread(this, "OrbotVpnThread");
mThread.start();
startSocksBypass ();
return START_STICKY;
}
private void startSocksBypass ()
{
Thread thread = new Thread ()
{
public void run ()
{
try {
final ProxyServer server = new ProxyServer(new ServerAuthenticatorNone(null, null));
server.setVpnService(OrbotVpnService.this);
server.start(9999, 5, InetAddress.getLocalHost());
} catch (UnknownHostException e) {
e.printStackTrace();
}
}
};
thread.start();
}
#Override
public void onDestroy() {
if (mThread != null) {
mKeepRunning = false;
mThread.interrupt();
}
}
#Override
public boolean handleMessage(Message message) {
if (message != null) {
Toast.makeText(this, message.what, Toast.LENGTH_SHORT).show();
}
return true;
}
#Override
public synchronized void run() {
try {
Log.i(TAG, "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.
InetSocketAddress server = new InetSocketAddress(
mServerAddress, mServerPort);
mHandler.sendEmptyMessage(R.string.connecting);
run(server);
} catch (Exception e) {
Log.e(TAG, "Got " + e.toString());
try {
mInterface.close();
} catch (Exception e2) {
// ignore
}
mHandler.sendEmptyMessage(R.string.disconnected);
} finally {
}
}
/*
#Override
public synchronized void run() {
try {
Log.i(TAG, "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.
InetSocketAddress server = new InetSocketAddress(
mServerAddress, mServerPort);
// We try to create the tunnel for several times. The better way
// is to work with ConnectivityManager, such as trying only when
// the network is avaiable. Here we just use a counter to keep
// things simple.
for (int attempt = 0; attempt < 10; ++attempt) {
mHandler.sendEmptyMessage(R.string.connecting);
// Reset the counter if we were connected.
if (run(server)) {
attempt = 0;
}
// Sleep for a while. This also checks if we got interrupted.
Thread.sleep(3000);
}
Log.i(TAG, "Giving up");
} catch (Exception e) {
Log.e(TAG, "Got " + e.toString());
} finally {
try {
mInterface.close();
} catch (Exception e) {
// ignore
}
mInterface = null;
mHandler.sendEmptyMessage(R.string.disconnected);
Log.i(TAG, "Exiting");
}
}*/
DatagramChannel mTunnel = null;
private boolean run(InetSocketAddress server) throws Exception {
boolean connected = false;
// Create a DatagramChannel as the VPN tunnel.
mTunnel = DatagramChannel.open();
DatagramSocket s = mTunnel.socket();
// Protect the tunnel before connecting to avoid loopback.
if (!protect(s)) {
throw new IllegalStateException("Cannot protect the tunnel");
}
mTunnel.connect(server);
// For simplicity, we use the same thread for both reading and
// writing. Here we put the tunnel into non-blocking mode.
mTunnel.configureBlocking(false);
// Authenticate and configure the virtual network interface.
handshake();
// Now we are connected. Set the flag and show the message.
connected = true;
mHandler.sendEmptyMessage(R.string.connected);
new Thread ()
{
public void run ()
{
// Allocate the buffer for a single packet.
ByteBuffer packet = ByteBuffer.allocate(32767);
// Packets to be sent are queued in this input stream.
FileInputStream in = new FileInputStream(mInterface.getFileDescriptor());
// Packets received need to be written to this output stream.
FileOutputStream out = new FileOutputStream(mInterface.getFileDescriptor());
// We use a timer to determine the status of the tunnel. It
// works on both sides. A positive value means sending, and
// any other means receiving. We start with receiving.
int timer = 0;
Log.d(TAG,"tunnel open:" + mTunnel.isOpen() + " connected:" + mTunnel.isConnected());
// We keep forwarding packets till something goes wrong.
while (true) {
try
{
// 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) {
Log.d(TAG,"got outgoing packet; length=" + length);
// Write the outgoing packet to the tunnel.
packet.limit(length);
mTunnel.write(packet);
packet.clear();
// There might be more outgoing packets.
idle = false;
// If we were receiving, switch to sending.
if (timer < 1) {
timer = 1;
}
}
// Read the incoming packet from the mTunnel.
length = mTunnel.read(packet);
if (length > 0) {
Log.d(TAG,"got inbound packet; length=" + length);
// Write the incoming packet to the output stream.
out.write(packet.array(), 0, length);
packet.clear();
// There might be more incoming packets.
idle = false;
// If we were sending, switch to receiving.
if (timer > 0) {
timer = 0;
}
}
// If we are idle or waiting for the network, sleep for a
// fraction of time to avoid busy looping.
if (idle) {
Thread.sleep(100);
// Increase the timer. This is inaccurate but good enough,
// since everything is operated in non-blocking mode.
timer += (timer > 0) ? 100 : -100;
// We are receiving for a long time but not sending.
if (timer < -15000) {
// Switch to sending.
timer = 1;
}
// We are sending for a long time but not receiving.
if (timer > 20000) {
//throw new IllegalStateException("Timed out");
//Log.d(TAG,"receiving timed out? timer=" + timer);
}
}
}
catch (Exception e)
{
Log.d(TAG,"error in tunnel",e);
}
}
}
}.start();
return connected;
}
private void handshake() throws Exception {
if (mInterface == null)
{
Builder builder = new Builder();
builder.setMtu(1500);
builder.addAddress("10.0.2.0",24);
builder.setSession("OrbotVPN");
builder.addRoute("0.0.0.0",0);
builder.addDnsServer("8.8.8.8");
// builder.addDnsServer("127.0.0.1:5400");
// Close the old interface since the parameters have been changed.
try {
mInterface.close();
} catch (Exception e) {
// ignore
}
// Create a new interface using the builder and save the parameters.
mInterface = builder.setSession(mSessionName)
.setConfigureIntent(mConfigureIntent)
.establish();
}
}
private void debugPacket(ByteBuffer packet)
{
/*
for(int i = 0; i < length; ++i)
{
byte buffer = packet.get();
Log.d(TAG, "byte:"+buffer);
}*/
int buffer = packet.get();
int version;
int headerlength;
version = buffer >> 4;
headerlength = buffer & 0x0F;
headerlength *= 4;
Log.d(TAG, "IP Version:"+version);
Log.d(TAG, "Header Length:"+headerlength);
String status = "";
status += "Header Length:"+headerlength;
buffer = packet.get(); //DSCP + EN
buffer = packet.getChar(); //Total Length
Log.d(TAG, "Total Length:"+buffer);
buffer = packet.getChar(); //Identification
buffer = packet.getChar(); //Flags + Fragment Offset
buffer = packet.get(); //Time to Live
buffer = packet.get(); //Protocol
Log.d(TAG, "Protocol:"+buffer);
status += " Protocol:"+buffer;
buffer = packet.getChar(); //Header checksum
String sourceIP = "";
buffer = packet.get(); //Source IP 1st Octet
sourceIP += buffer;
sourceIP += ".";
buffer = packet.get(); //Source IP 2nd Octet
sourceIP += buffer;
sourceIP += ".";
buffer = packet.get(); //Source IP 3rd Octet
sourceIP += buffer;
sourceIP += ".";
buffer = packet.get(); //Source IP 4th Octet
sourceIP += buffer;
Log.d(TAG, "Source IP:"+sourceIP);
status += " Source IP:"+sourceIP;
String destIP = "";
buffer = packet.get(); //Destination IP 1st Octet
destIP += buffer;
destIP += ".";
buffer = packet.get(); //Destination IP 2nd Octet
destIP += buffer;
destIP += ".";
buffer = packet.get(); //Destination IP 3rd Octet
destIP += buffer;
destIP += ".";
buffer = packet.get(); //Destination IP 4th Octet
destIP += buffer;
Log.d(TAG, "Destination IP:"+destIP);
status += " Destination IP:"+destIP;
/*
msgObj = mHandler.obtainMessage();
msgObj.obj = status;
mHandler.sendMessage(msgObj);
*/
//Log.d(TAG, "version:"+packet.getInt());
//Log.d(TAG, "version:"+packet.getInt());
//Log.d(TAG, "version:"+packet.getInt());
}
}
It also connected with VPN and show the key symbol on top of the bar, but dont found any server entry in my server Interfaces.Same server I register in mobile network it Connected and I found the Server entry in my server Interfaces.
Is there any server Implementation require?
Am I wrong in above VPN service or I make the mistake in it?
Is there other way for connecting the VPN using the Username,password and server Id?
Try this :
void startVPN(String name) {
Intent i=new Intent("doenter.onevpn.ACTION_CONNECT");
i.putExtra("name",name);
i.putExtra("force", true);
i.putExtra("force_same", false);
startActivity(i);
}
void restartVPN(String name) {
Intent i=new Intent("doenter.onevpn.ACTION_CONNECT");
i.putExtra("name",name);
i.putExtra("force", true);
i.putExtra("force_same", true);
startActivity(i);
}
void stopVPN() {
Intent i=new Intent("doenter.onevpn.ACTION_DISCONNECT");
// Stops any VPN regardless of name
startActivity(i);
}
I am creating an Android application that allows client to server messaging at the moment but I am looking for a way to also allow server to client messaging, so both client and server can message back and forth. Any suggestion on how I could do this would be appreciated. I know that I will need to edit my ChatServer class, which is as follows;
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.LinkedList;
import java.util.List;
public class ChatServer {
private static final String USAGE = "Usage: java ChatServer";
/** Default port number on which this server to be run. */
private static final int PORT_NUMBER = 8008;
/**
* List of print writers associated with current clients, one for each.
*/
private List<PrintWriter> clients;
/** Creates a new server. */
public ChatServer() {
clients = new LinkedList<PrintWriter>();
}
/** Starts the server. */
public void start() {
System.out.println("AndroidChatApplication server started on port "
+ PORT_NUMBER + "!");
try {
ServerSocket s = new ServerSocket(PORT_NUMBER);
for (;;) {
Socket incoming = s.accept();
new ClientHandler(incoming).start();
}
} catch (Exception e) {
e.printStackTrace();
}
System.out.println("AndroidChatApplication server stopped.");
}
/** Adds a new client identified by the given print writer. */
private void addClient(PrintWriter out) {
synchronized (clients) {
clients.add(out);
}
}
/** Adds the client with given print writer. */
private void removeClient(PrintWriter out) {
synchronized (clients) {
clients.remove(out);
}
}
/** Broadcasts the given text to all clients. */
private void broadcast(String msg) {
for (PrintWriter out : clients) {
out.println(msg);
out.flush();
}
}
public static void main(String[] args) {
if (args.length > 0) {
System.out.println(USAGE);
System.exit(-1);
}
new ChatServer().start();
}
/**
* A thread to serve a client. This class receive messages from a client and
* broadcasts them to all clients including the message sender.
*/
private class ClientHandler extends Thread {
/** Socket to read client messages. */
private Socket incoming;
/** Creates a hander to serve the client on the given socket. */
public ClientHandler(Socket incoming) {
this.incoming = incoming;
}
/** Starts receiving and broadcasting messages. */
public void run() {
PrintWriter out = null;
try {
out = new PrintWriter(new OutputStreamWriter(
incoming.getOutputStream()));
// inform the server of this new client
ChatServer.this.addClient(out);
out.print("Welcome to AndroidChatApplication! ");
out.println("Enter BYE to exit.");
out.flush();
BufferedReader in = new BufferedReader(new InputStreamReader(
incoming.getInputStream()));
for (;;) {
String msg = in.readLine();
if (msg == null) {
break;
} else {
if (msg.trim().equals("BYE"))
break;
System.out.println("Received: " + msg);
// broadcast the receive message
ChatServer.this.broadcast(msg);
}
}
incoming.close();
ChatServer.this.removeClient(out);
} catch (Exception e) {
if (out != null) {
ChatServer.this.removeClient(out);
}
e.printStackTrace();
}
}
}
}
You can just use the push notification service from Google, check GoogleCloudMessaging and friends for more details. And here's some simple tutorial on how to use it.