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1 package org.apache.commons.net.tftp; 2 3 /* ==================================================================== 4 * The Apache Software License, Version 1.1 5 * 6 * Copyright (c) 2001 The Apache Software Foundation. All rights 7 * reserved. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in 18 * the documentation and/or other materials provided with the 19 * distribution. 20 * 21 * 3. The end-user documentation included with the redistribution, 22 * if any, must include the following acknowledgment: 23 * "This product includes software developed by the 24 * Apache Software Foundation (http://www.apache.org/)." 25 * Alternately, this acknowledgment may appear in the software itself, 26 * if and wherever such third-party acknowledgments normally appear. 27 * 28 * 4. The names "Apache" and "Apache Software Foundation" and 29 * "Apache Commons" must not be used to endorse or promote products 30 * derived from this software without prior written permission. For 31 * written permission, please contact apache@apache.org. 32 * 33 * 5. Products derived from this software may not be called "Apache", 34 * nor may "Apache" appear in their name, without 35 * prior written permission of the Apache Software Foundation. 36 * 37 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED 38 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 39 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 40 * DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR 41 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 42 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 43 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF 44 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND 45 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 46 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT 47 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 48 * SUCH DAMAGE. 49 * ==================================================================== 50 * 51 * This software consists of voluntary contributions made by many 52 * individuals on behalf of the Apache Software Foundation. For more 53 * information on the Apache Software Foundation, please see 54 * <http://www.apache.org/>;. 55 */ 56 57 import java.net.DatagramPacket; 58 import java.net.InetAddress; 59 60 /**** 61 * An abstract class derived from TFTPPacket definiing a TFTP Request 62 * packet type. It is subclassed by the 63 * <a href="org.apache.commons.net.tftp.TFTPReadRequestPacket.html#_top_"> 64 * TFTPReadRequestPacket</a> and 65 * <a href="org.apache.commons.net.tftp.TFTPWriteRequestPacket.html#_top_"> 66 * TFTPWriteRequestPacket</a> classes. 67 * <p> 68 * Details regarding the TFTP protocol and the format of TFTP packets can 69 * be found in RFC 783. But the point of these classes is to keep you 70 * from having to worry about the internals. Additionally, only very 71 * few people should have to care about any of the TFTPPacket classes 72 * or derived classes. Almost all users should only be concerned with the 73 * <a href="org.apache.commons.net.tftp.TFTPClient.html#_top_">TFTPClient</a> class 74 * <a href="org.apache.commons.net.tftp.TFTPClient.html#receiveFile">receiveFile()</a> 75 * and 76 * <a href="org.apache.commons.net.tftp.TFTPClient.html#sendFile">sendFile()</a> 77 * methods. 78 * <p> 79 * <p> 80 * @author Daniel F. Savarese 81 * @see TFTPPacket 82 * @see TFTPReadRequestPacket 83 * @see TFTPWriteRequestPacket 84 * @see TFTPPacketException 85 * @see TFTP 86 ***/ 87 88 public abstract class TFTPRequestPacket extends TFTPPacket 89 { 90 /**** 91 * An array containing the string names of the transfer modes and indexed 92 * by the transfer mode constants. 93 ***/ 94 static final String[] _modeStrings = { "netascii", "octet" }; 95 96 /**** 97 * A null terminated byte array representation of the ascii names of the 98 * transfer mode constants. This is convenient for creating the TFTP 99 * request packets. 100 ***/ 101 static final byte[] _modeBytes[] = { 102 { (byte)'n', (byte)'e', (byte)'t', (byte)'a', (byte)'s', (byte)'c', 103 (byte)'i', (byte)'i', 0 }, 104 { (byte)'o', (byte)'c', (byte)'t', (byte)'e', (byte)'t', 0 } 105 }; 106 107 /**** The transfer mode of the request. ***/ 108 int _mode; 109 110 /**** The filename of the request. ***/ 111 String _filename; 112 113 /**** 114 * Creates a request packet of a given type to be sent to a host at a 115 * given port with a filename and transfer mode request. 116 * <p> 117 * @param destination The host to which the packet is going to be sent. 118 * @param port The port to which the packet is going to be sent. 119 * @param type The type of the request (either TFTPPacket.READ_REQUEST or 120 * TFTPPacket.WRITE_REQUEST). 121 * @param filename The requested filename. 122 * @param mode The requested transfer mode. This should be on of the TFTP 123 * class MODE constants (e.g., TFTP.NETASCII_MODE). 124 ***/ 125 TFTPRequestPacket(InetAddress destination, int port, 126 int type, String filename, int mode) 127 { 128 super(type, destination, port); 129 130 _filename = filename; 131 _mode = mode; 132 } 133 134 /**** 135 * Creates a request packet of a given type based on a received 136 * datagram. Assumes the datagram is at least length 4, else an 137 * ArrayIndexOutOfBoundsException may be thrown. 138 * <p> 139 * @param type The type of the request (either TFTPPacket.READ_REQUEST or 140 * TFTPPacket.WRITE_REQUEST). 141 * @param datagram The datagram containing the received request. 142 * @throws TFTPPacketException If the datagram isn't a valid TFTP 143 * request packet of the appropriate type. 144 ***/ 145 TFTPRequestPacket(int type, DatagramPacket datagram) 146 throws TFTPPacketException 147 { 148 super(type, datagram.getAddress(), datagram.getPort()); 149 150 byte[] data; 151 int index, length; 152 String mode; 153 StringBuffer buffer; 154 155 data = datagram.getData(); 156 157 if (getType() != data[1]) 158 throw new TFTPPacketException("TFTP operator code does not match type."); 159 160 buffer = new StringBuffer(); 161 162 index = 2; 163 length = datagram.getLength(); 164 165 while (index < length && data[index] != 0) 166 { 167 buffer.append((char)data[index]); 168 ++index; 169 } 170 171 _filename = buffer.toString(); 172 173 if (index >= length) 174 throw new TFTPPacketException("Bad filename and mode format."); 175 176 buffer.setLength(0); 177 ++index; // need to advance beyond the end of string marker 178 while (index < length && data[index] != 0) 179 { 180 buffer.append((char)data[index]); 181 ++index; 182 } 183 184 mode = buffer.toString().toLowerCase(); 185 length = _modeStrings.length; 186 187 for (index = 0; index < length; index++) 188 { 189 if (mode.equals(_modeStrings[index])) 190 { 191 _mode = index; 192 break; 193 } 194 } 195 196 if (index >= length) 197 { 198 throw new TFTPPacketException("Unrecognized TFTP transfer mode: " + mode); 199 // May just want to default to binary mode instead of throwing 200 // exception. 201 //_mode = TFTP.OCTET_MODE; 202 } 203 } 204 205 206 /**** 207 * This is a method only available within the package for 208 * implementing efficient datagram transport by elminating buffering. 209 * It takes a datagram as an argument, and a byte buffer in which 210 * to store the raw datagram data. Inside the method, the data 211 * is set as the datagram's data and the datagram returned. 212 * <p> 213 * @param datagram The datagram to create. 214 * @param data The buffer to store the packet and to use in the datagram. 215 * @return The datagram argument. 216 ***/ 217 final DatagramPacket _newDatagram(DatagramPacket datagram, byte[] data) 218 { 219 int fileLength, modeLength; 220 221 fileLength = _filename.length(); 222 modeLength = _modeBytes[_mode].length; 223 224 data[0] = 0; 225 data[1] = (byte)_type; 226 System.arraycopy(_filename.getBytes(), 0, data, 2, fileLength); 227 data[fileLength + 2] = 0; 228 System.arraycopy(_modeBytes[_mode], 0, data, fileLength + 3, 229 modeLength); 230 231 datagram.setAddress(_address); 232 datagram.setPort(_port); 233 datagram.setData(data); 234 datagram.setLength(fileLength + modeLength + 4); 235 236 return datagram; 237 } 238 239 /**** 240 * Creates a UDP datagram containing all the TFTP 241 * request packet data in the proper format. 242 * This is a method exposed to the programmer in case he 243 * wants to implement his own TFTP client instead of using 244 * the <a href="org.apache.commons.net.tftp.TFTPClient.html#_top_">TFTPClient</a> 245 * class. Under normal circumstances, you should not have a need to call 246 * this method. 247 * <p> 248 * @return A UDP datagram containing the TFTP request packet. 249 ***/ 250 public final DatagramPacket newDatagram() 251 { 252 int fileLength, modeLength; 253 byte[] data; 254 255 fileLength = _filename.length(); 256 modeLength = _modeBytes[_mode].length; 257 258 data = new byte[fileLength + modeLength + 4]; 259 data[0] = 0; 260 data[1] = (byte)_type; 261 System.arraycopy(_filename.getBytes(), 0, data, 2, fileLength); 262 data[fileLength + 2] = 0; 263 System.arraycopy(_modeBytes[_mode], 0, data, fileLength + 3, 264 modeLength); 265 266 return new DatagramPacket(data, data.length, _address, _port); 267 } 268 269 /**** 270 * Returns the transfer mode of the request. 271 * <p> 272 * @return The transfer mode of the request. 273 ***/ 274 public final int getMode() 275 { 276 return _mode; 277 } 278 279 /**** 280 * Returns the requested filename. 281 * <p> 282 * @return The requested filename. 283 ***/ 284 public final String getFilename() 285 { 286 return _filename; 287 } 288 }

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