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/*
* Copyright (C) 2014 Andrew Comminos
*
* 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 <http://www.gnu.org/licenses/>.
*/
package com.morlunk.jumble.net;
import android.util.Log;
import com.morlunk.jumble.Constants;
import java.io.IOException;
import java.net.ConnectException;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;
import javax.crypto.BadPaddingException;
import javax.crypto.IllegalBlockSizeException;
import javax.crypto.ShortBufferException;
/**
* Class to maintain and receive packets from the UDP connection to a Mumble server.
*/
public class JumbleUDP extends JumbleNetworkThread {
private static final int BUFFER_SIZE = 2048;
private final CryptState mCryptState;
private DatagramSocket mUDPSocket;
private UDPConnectionListener mListener;
private String mHost;
private int mPort;
private InetAddress mResolvedHost;
private boolean mConnected;
/**
* Sets up a new UDP connection context.
* @param cryptState Cryptographic state provider.
*/
public JumbleUDP(CryptState cryptState) {
mCryptState = cryptState;
}
public void setUDPConnectionListener(UDPConnectionListener listener) {
mListener = listener;
}
public void connect(String host, int port) throws ConnectException {
if(mConnected) throw new ConnectException("UDP connection already established!");
mHost = host;
mPort = port;
startThreads();
}
public boolean isRunning() {
return mConnected;
}
@Override
public void run() {
try {
mResolvedHost = InetAddress.getByName(mHost);
mUDPSocket = new DatagramSocket();
} catch (final IOException e) {
if(mListener != null) {
executeOnMainThread(new Runnable() {
@Override
public void run() {
mListener.onUDPConnectionError(e);
}
});
}
return;
}
mUDPSocket.connect(mResolvedHost, mPort);
final DatagramPacket packet = new DatagramPacket(new byte[BUFFER_SIZE], BUFFER_SIZE);
Log.d(Constants.TAG, "[UDP] Created socket");
mConnected = true;
while(mConnected) {
try {
mUDPSocket.receive(packet);
final byte[] data = packet.getData();
final int length = packet.getLength();
if (!mCryptState.isValid()) {
Log.d(Constants.TAG, "[UDP] CryptState invalid, discarding packet");
continue;
}
if (length < 5) {
Log.d(Constants.TAG, "[UDP] Packet too short, discarding");
continue;
}
try {
final byte[] buffer = mCryptState.decrypt(data, length);
if (mListener != null) {
if (buffer != null) {
executeOnReceiveThread(new Runnable() {
@Override
public void run() {
mListener.onUDPDataReceived(buffer);
}
});
} else if(mCryptState.getLastGoodElapsed() > 5000000 &&
mCryptState.getLastRequestElapsed() > 5000000) {
mCryptState.resetLastRequestTime();
executeOnMainThread(new Runnable() {
@Override
public void run() {
mListener.resyncCryptState();
}
});
Log.d(Constants.TAG, "[UDP] Packet failed to decrypt, discarding and " +
"requesting crypt state resync");
} else {
Log.d(Constants.TAG, "[UDP] Packet failed to decrypt, discarding");
}
}
} catch (BadPaddingException|IllegalBlockSizeException|ShortBufferException e) {
Log.d(Constants.TAG, "[UDP] Discarding packet", e);
}
} catch (final IOException e) {
// If a UDP exception is thrown while connected, notify the listener to fall back to TCP.
if(mConnected && mListener != null) {
executeOnMainThread(new Runnable() {
@Override
public void run() {
mListener.onUDPConnectionError(e);
}
});
}
break;
}
}
disconnect(); // Make sure we close the socket if disconnect wasn't controlled
}
public void sendMessage(final byte[] data, final int length) {
if(!mCryptState.isValid() || !mConnected) return;
executeOnSendThread(new Runnable() {
@Override
public void run() {
try {
if(!mCryptState.isValid() || !mConnected) return;
byte[] encryptedData = mCryptState.encrypt(data, length);
final DatagramPacket packet = new DatagramPacket(encryptedData, encryptedData.length);
packet.setAddress(mResolvedHost);
packet.setPort(mPort);
mUDPSocket.send(packet);
} catch (IOException e) {
e.printStackTrace();
} catch (IllegalBlockSizeException e) {
e.printStackTrace();
} catch (ShortBufferException e) {
e.printStackTrace();
} catch (BadPaddingException e) {
e.printStackTrace();
}
}
});
}
public void disconnect() {
if(!mConnected) return;
mConnected = false;
executeOnSendThread(new Runnable() {
@Override
public void run() {
mUDPSocket.disconnect();
mUDPSocket.close();
}
});
stopThreads();
}
/**
* Note that all connection state related calls are made on the main thread.
* onUDPDataReceived is always called on the UDP receive thread.
*/
public interface UDPConnectionListener {
public void onUDPDataReceived(byte[] data);
public void onUDPConnectionError(Exception e);
public void resyncCryptState();
}
}
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