Java tutorial
/* * TFTPServer.java * Copyright (C) 2011,2012 Wannes De Smet * * 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 org.xenmaster.connectivity.tftp; import java.io.FileNotFoundException; import java.io.IOException; import java.io.InputStream; import java.net.InetAddress; import java.net.SocketException; import java.net.UnknownHostException; import java.util.HashMap; import java.util.LinkedList; import java.util.Map; import java.util.TimerTask; import java.util.concurrent.TimeUnit; import net.wgr.utility.GlobalExecutorService; import org.apache.commons.net.tftp.ExtendedTFTP; import org.apache.commons.net.tftp.TFTPAckPacket; import org.apache.commons.net.tftp.TFTPErrorPacket; import org.apache.commons.net.tftp.TFTPOptionAckPacket; import org.apache.commons.net.tftp.TFTPOptionReadRequestPacket; import org.apache.commons.net.tftp.TFTPPXEDataPacket; import org.apache.commons.net.tftp.TFTPPacket; import org.apache.commons.net.tftp.TFTPPacketException; import org.apache.log4j.Logger; /** * * @created Oct 27, 2011 * @author double-u */ public class TFTPServer implements Runnable { protected final Thread thread; protected boolean run; protected ExtendedTFTP tftp; protected InetAddress clientAddress; protected InputStream dataInputStream; protected int blockNumber, blockSize = 512; protected LinkedList<ActivityListener> listeners; protected int count; protected ResendTask resendTask; public TFTPServer() { tftp = new ExtendedTFTP(); tftp.beginBufferedOps(); tftp.setDefaultTimeout(0); listeners = new LinkedList<>(); resendTask = new ResendTask(); thread = new Thread(this, "TFTP server"); GlobalExecutorService.get().scheduleAtFixedRate(resendTask, 500, 500, TimeUnit.MILLISECONDS); } public void addListener(ActivityListener al) { listeners.push(al); } public void boot() { run = true; thread.start(); } @Override public void run() { while (run) { if (!tftp.isOpen()) { try { tftp.open(69, InetAddress.getByName("0.0.0.0")); tftp.beginBufferedOps(); } catch (SocketException | UnknownHostException ex) { Logger.getLogger(getClass()).error("TFTP listening failed", ex); run = false; return; } } try { TFTPPacket packet = tftp.bufferedReceive(); count++; handlePacket(packet); } catch (TFTPPacketException | IOException ex) { Logger.getLogger(getClass()).error("TFTP receive failed", ex); } } tftp.endBufferedOps(); tftp.close(); // Send a goodbye to all threads waiting for the tftp server to finish synchronized (this.thread) { this.thread.notifyAll(); } } protected void handlePacket(final TFTPPacket packet) throws IOException { switch (packet.getType()) { case TFTPPacket.READ_REQUEST: if (clientAddress == null) { TFTPOptionReadRequestPacket request = (TFTPOptionReadRequestPacket) packet; dataInputStream = null; try { Logger.getLogger(getClass()).debug("Request for : " + request.getFilename() + " received from " + packet.getAddress().getCanonicalHostName() + ":" + packet.getPort()); for (ActivityListener al : listeners) { InputStream is = al.pathRequest(request); if (is != null) { dataInputStream = is; } break; } if (dataInputStream == null) { Logger.getLogger(getClass()) .debug("No ActivityListener provided valid InputStream for TFTP request"); tftp.bufferedSend(new TFTPErrorPacket(packet.getAddress(), packet.getPort(), TFTPErrorPacket.FILE_NOT_FOUND, request.getFilename())); return; } if (request.getOptions().size() > 0) { HashMap<String, Integer> acks = new HashMap<>(); for (Map.Entry<String, Integer> entry : request.getOptions().entrySet()) { switch (entry.getKey()) { case "blksize": blockSize = entry.getValue(); acks.put(entry.getKey(), blockSize); tftp.restartBufferedOps(blockSize + 4); break; case "tsize": // Client wants to know transfer size acks.put(entry.getKey(), dataInputStream.available()); break; } } blockNumber = 0; clientAddress = packet.getAddress(); tftp.bufferedSend(new TFTPOptionAckPacket(packet.getAddress(), packet.getPort(), acks)); return; } blockNumber = 1; byte[] data = new byte[blockSize]; final int bytesRead = dataInputStream.read(data); tftp.bufferedSend(new TFTPPXEDataPacket(packet.getAddress(), packet.getPort(), blockNumber, data, 0, bytesRead)); // if more blocks to send if (bytesRead == blockSize) { clientAddress = packet.getAddress(); } else { dataInputStream.close(); clientAddress = null; } } catch (FileNotFoundException ex) { tftp.bufferedSend(new TFTPErrorPacket(packet.getAddress(), packet.getPort(), TFTPErrorPacket.FILE_NOT_FOUND, ex.getMessage())); clientAddress = null; } } break; case TFTPPacket.ACKNOWLEDGEMENT: if (packet.getAddress().equals(clientAddress)) { TFTPAckPacket ackPacket = (TFTPAckPacket) packet; Logger.getLogger(getClass()) .debug("ACK : " + ackPacket.getBlockNumber() + " ~ " + blockNumber * blockSize + "/" + dataInputStream.available() + " " + ackPacket.getAddress().getCanonicalHostName()); // Check if client ACKd correctly if (ackPacket.getBlockNumber() == blockNumber) { // send next block final byte[] data = new byte[blockSize]; final int bytesRead = dataInputStream.read(data); blockNumber++; TFTPPXEDataPacket dataPacket = new TFTPPXEDataPacket(packet.getAddress(), packet.getPort(), blockNumber, data, 0, bytesRead); Logger.getLogger(getClass()).debug("Sending " + blockNumber + " to " + packet.getAddress().getCanonicalHostName() + " with " + bytesRead + " bytes"); tftp.bufferedSend(dataPacket); resendTask.set(dataPacket, ackPacket.getBlockNumber()); // It is done if (bytesRead < blockSize) { clientAddress = null; dataInputStream.close(); resendTask.chill(); } } } break; case TFTPPacket.ERROR: TFTPErrorPacket tep = (TFTPErrorPacket) packet; Logger.getLogger(getClass()).warn("TFTP error : " + tep.getMessage()); clientAddress = null; blockNumber = 0; break; } } public void waitTillQuit() throws InterruptedException { synchronized (this.thread) { this.thread.wait(); } } protected class ResendTask extends TimerTask { protected TFTPPXEDataPacket packet; protected int blockCount; public void set(TFTPPXEDataPacket packet, int blockCount) { this.packet = packet; this.blockCount = blockCount; } public void chill() { this.packet = null; } @Override public void run() { if (packet == null) { return; } if (blockNumber > blockCount) { try { Logger.getLogger(getClass()).debug("Resending " + blockNumber); tftp.bufferedSend(packet); } catch (IOException ex) { chill(); Logger.getLogger(getClass()).warn("TFTP resend failed", ex); } } } } public static interface ActivityListener { public InputStream pathRequest(TFTPOptionReadRequestPacket packet); } }