tftp.rar tftp 协议 源代码 java tftp.java

/** * (c) Melexis Telecom and/or Remote Operating Services B.V. * * Distributable under LGPL license * See terms of license at gnu.org */ package com.skyzoo.Jutil.tftp.server; import java.io.BufferedInputStream; import java.io.IOException; import java.io.InputStream; import java.io.OutputStream; import java.net.InetAddress; import java.net.SocketException; import java.util.Vector; import org.apache.log4j.Logger; import com.skyzoo.Jutil.tftp.common.ACK; import com.skyzoo.Jutil.tftp.common.DATA; import com.skyzoo.Jutil.tftp.common.ERROR; import com.skyzoo.Jutil.tftp.common.OACK; import com.skyzoo.Jutil.tftp.common.TFTPOptions; import com.skyzoo.Jutil.tftp.common.TFTPPacket; import com.skyzoo.Jutil.tftp.common.TFTPSocket; import com.skyzoo.Jutil.tftp.common.TFTPUtils; /** * However this class is called ClientHandler it is meant to be the * class that handles the actual client tftp transfers. * * @author marco */ public class ClientHandler { /** * Boolean flag that is used internally to indicate we might have stuffed * the connection to the client with resent packages. This flag is cleared * when we duplicate the timeout with the next data package sent which * should help to clean up the channel that did get stuffed */ private boolean stuffedLink = false; /** * The private field for storage of the timeout setting for the communication * with the client */ private int timeout = 5; /** * Creates a new instance of TFTPSocket */ public ClientHandler() throws SocketException { tftpSock = new TFTPSocket(timeout); /* would like to replace with dynamic array! */ /* fileContent = new byte[MAX_FILE_SIZE]; */ } /** * * Connects the clienthandler to the client, packages send do not need to contain a * address. If they do they are overwritten by the ones of the connected socket. * * @return */ public void connect(InetAddress inetAddress, int clientPort) { tftpSock.connect(inetAddress, clientPort); } /** * * disconnects from the client, any packet send after a disconnect needs to contain a * destination address and port, because nne is available on the socket. * */ public void disconnect() { tftpSock.disconnect(); } /** * This method returns the IP address and port number of the * client this class is talking to. */ public String getClient() { String client = ""; InetAddress addr = tftpSock.getAddress(); int port = tftpSock.getPort(); if (addr != null) client += addr.getHostAddress(); if (port != 0) { client += ":"; client += port; } return client; } /** * This method is an internal helper function that checks if the * received ack packet matches the expectations. That means * that the opcode and blocknumbers are expected. * * @param expecting The expected acknowledgement * @param received The received acknowledgement * @return true if received matched the expectations */ private boolean correctAnswer(ACK expecting, ACK received) { if (expecting == null) return false; if (received == null) return false; if (expecting.getOpCode() != received.getOpCode()) return false; if (expecting.getBlockNr() != received.getBlockNr()) return false; return true; } // public ACK DataTransfer(ACK send, ACK recv) // { // int retransmits = 0; // int spamcount = 0; // // // send the packet.... // try // { // tftpSock.write(send); // // if stuffed use duplicate timeout // if (stuffedLink) // tftpSock.setSocketTimeOut(timeout * 2); // } // catch (Exception e) // { // tftpLog.debug(getClient() + " UDP send packet failure."); // tftpLog.debug(e.toString()); // } // // TFTPPacket tftpP; // boolean receiving = true; // // wait for succesfull acknowledgement!..... // while (receiving) // { // try // { // tftpP = tftpSock.read(); // // set timout back because we gave enough time to clean up stuffed channel // if (stuffedLink) // { // tftpSock.setSocketTimeOut(timeout); // stuffedLink = false; // } // } // catch (IOException ios) // { // tftpLog.info("IOException: " + ios.getMessage()); // return null; // } // // // case we did not receive any packet // if (tftpP == null) // { // if (retransmits++ > 5) // { // // Too many retries, give up. // sendErrPacket( // ERROR.ERR_NOT_DEFINED, // "Retransmit limit exceeded"); // tftpLog.debug( // getClient() + " Maximum retransmit count exceeded"); // return null; // } // else // { // // resend the packet and wait again! // tftpLog.debug( // getClient() // + " expected packet before time out, sending ACK/DATA again"); // try // { // tftpSock.write(send); // // set the flag to indicate that we might be stuffing the pipe for the // // client, next packet needs to have longer timeout to give client some // // time to clean up the pipe // stuffedLink = true; // } // catch (Exception e) // { // tftpLog.debug(getClient() + " UDP send packet failure."); // tftpLog.debug(e.toString()); // } // continue; // } // } // // // case we received error // if (tftpP instanceof ERROR) // { // tftpLog.debug( // getClient() + " " + ((ERROR) tftpP).getErrorMessage()); // return null; // } // // // case we did receive expected // if ((tftpP instanceof ACK) && correctAnswer(recv, (ACK) tftpP)) // { // return (ACK) tftpP; // } // // // all other is spam and when too many of this crap is give up, and do not signal // if (spamcount++ > 5) // { // return null; // } // } // return null; // } public boolean receiveFileFromClient(OutputStream os, InetAddress clientAddress, int clientPort, boolean useOptions) { /* filename should not be empty, else send ERROR and say goodbye */ tftpSock.connect(clientAddress, clientPort); Vector dataBlocks = new Vector(10); // not expecting more then 10 * 512 bytes // Send the first ackowledgement on received WRQ int blockNumber = 0; byte[] data = new byte[1]; int totalSize = 0; ACK send; DATA receive; DATA expect; // if frq has options then we oack instead of ack to receive data if (useOptions) { TFTPOptions options = new TFTPOptions(); options.setTimeout(getTimeout()); options.setTransferSize(getTransferSize()); send = new OACK(0, options); } else { send = new ACK(blockNumber); } do { try { expect = new DATA(blockNumber + 1, data); receive = (DATA) TFTPUtils.dataTransfer(tftpSock, send, expect); } catch (ClassCastException e) { tftpLog.debug("CODING ERROR? this case should be fetched in DataTransfer!"); ret