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
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39 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
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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
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49 * ====================================================================
50 *
51 * This software consists of voluntary contributions made by many
52 * individuals on behalf of the Apache Software Foundation. For more
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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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