/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.commons.net.tftp;
import java.net.DatagramPacket;
import java.net.InetAddress;
An abstract class derived from TFTPPacket definiing a TFTP Request packet type. It is subclassed by the TFTPReadRequestPacket and TFTPWriteRequestPacket classes. Details regarding the TFTP protocol and the format of TFTP packets can be found in RFC 783. But the point of these classes is to keep you from having to worry about the internals. Additionally, only very few people should have to care about any of the TFTPPacket classes or derived classes. Almost all users should only be concerned with the TFTPClient class receiveFile() and sendFile() methods.
See Also:
/***
* An abstract class derived from TFTPPacket definiing a TFTP Request
* packet type. It is subclassed by the
* {@link org.apache.commons.net.tftp.TFTPReadRequestPacket}
* and
* {@link org.apache.commons.net.tftp.TFTPWriteRequestPacket}
* classes.
* <p>
* Details regarding the TFTP protocol and the format of TFTP packets can
* be found in RFC 783. But the point of these classes is to keep you
* from having to worry about the internals. Additionally, only very
* few people should have to care about any of the TFTPPacket classes
* or derived classes. Almost all users should only be concerned with the
* {@link org.apache.commons.net.tftp.TFTPClient} class
* {@link org.apache.commons.net.tftp.TFTPClient#receiveFile receiveFile()}
* and
* {@link org.apache.commons.net.tftp.TFTPClient#sendFile sendFile()}
* methods.
*
*
* @see TFTPPacket
* @see TFTPReadRequestPacket
* @see TFTPWriteRequestPacket
* @see TFTPPacketException
* @see TFTP
***/
public abstract class TFTPRequestPacket extends TFTPPacket
{
An array containing the string names of the transfer modes and indexed
by the transfer mode constants.
/***
* An array containing the string names of the transfer modes and indexed
* by the transfer mode constants.
***/
static final String[] _modeStrings = { "netascii", "octet" };
A null terminated byte array representation of the ascii names of the
transfer mode constants. This is convenient for creating the TFTP
request packets.
/***
* A null terminated byte array representation of the ascii names of the
* transfer mode constants. This is convenient for creating the TFTP
* request packets.
***/
private static final byte[] _modeBytes[] = {
{ (byte)'n', (byte)'e', (byte)'t', (byte)'a', (byte)'s', (byte)'c',
(byte)'i', (byte)'i', 0 },
{ (byte)'o', (byte)'c', (byte)'t', (byte)'e', (byte)'t', 0 }
};
The transfer mode of the request. /*** The transfer mode of the request. ***/
private final int _mode;
The filename of the request. /*** The filename of the request. ***/
private final String _filename;
Creates a request packet of a given type to be sent to a host at a
given port with a filename and transfer mode request.
Params: - destination – The host to which the packet is going to be sent.
- port – The port to which the packet is going to be sent.
- type – The type of the request (either TFTPPacket.READ_REQUEST or
TFTPPacket.WRITE_REQUEST).
- filename – The requested filename.
- mode – The requested transfer mode. This should be on of the TFTP
class MODE constants (e.g., TFTP.NETASCII_MODE).
/***
* Creates a request packet of a given type to be sent to a host at a
* given port with a filename and transfer mode request.
*
* @param destination The host to which the packet is going to be sent.
* @param port The port to which the packet is going to be sent.
* @param type The type of the request (either TFTPPacket.READ_REQUEST or
* TFTPPacket.WRITE_REQUEST).
* @param filename The requested filename.
* @param mode The requested transfer mode. This should be on of the TFTP
* class MODE constants (e.g., TFTP.NETASCII_MODE).
***/
TFTPRequestPacket(InetAddress destination, int port,
int type, String filename, int mode)
{
super(type, destination, port);
_filename = filename;
_mode = mode;
}
Creates a request packet of a given type based on a received
datagram. Assumes the datagram is at least length 4, else an
ArrayIndexOutOfBoundsException may be thrown.
Params: - type – The type of the request (either TFTPPacket.READ_REQUEST or
TFTPPacket.WRITE_REQUEST).
- datagram – The datagram containing the received request.
Throws: - TFTPPacketException – If the datagram isn't a valid TFTP
request packet of the appropriate type.
/***
* Creates a request packet of a given type based on a received
* datagram. Assumes the datagram is at least length 4, else an
* ArrayIndexOutOfBoundsException may be thrown.
*
* @param type The type of the request (either TFTPPacket.READ_REQUEST or
* TFTPPacket.WRITE_REQUEST).
* @param datagram The datagram containing the received request.
* @throws TFTPPacketException If the datagram isn't a valid TFTP
* request packet of the appropriate type.
***/
TFTPRequestPacket(int type, DatagramPacket datagram)
throws TFTPPacketException
{
super(type, datagram.getAddress(), datagram.getPort());
byte[] data = datagram.getData();
if (getType() != data[1]) {
throw new TFTPPacketException("TFTP operator code does not match type.");
}
StringBuilder buffer = new StringBuilder();
int index = 2;
int length = datagram.getLength();
while (index < length && data[index] != 0)
{
buffer.append((char)data[index]);
++index;
}
_filename = buffer.toString();
if (index >= length) {
throw new TFTPPacketException("Bad filename and mode format.");
}
buffer.setLength(0);
++index; // need to advance beyond the end of string marker
while (index < length && data[index] != 0)
{
buffer.append((char)data[index]);
++index;
}
String modeString = buffer.toString().toLowerCase(java.util.Locale.ENGLISH);
length = _modeStrings.length;
int mode = 0;
for (index = 0; index < length; index++)
{
if (modeString.equals(_modeStrings[index]))
{
mode = index;
break;
}
}
_mode = mode;
if (index >= length)
{
throw new TFTPPacketException("Unrecognized TFTP transfer mode: " + modeString);
// May just want to default to binary mode instead of throwing
// exception.
//_mode = TFTP.OCTET_MODE;
}
}
This is a method only available within the package for
implementing efficient datagram transport by elminating buffering.
It takes a datagram as an argument, and a byte buffer in which
to store the raw datagram data. Inside the method, the data
is set as the datagram's data and the datagram returned.
Params: - datagram – The datagram to create.
- data – The buffer to store the packet and to use in the datagram.
Returns: The datagram argument.
/***
* This is a method only available within the package for
* implementing efficient datagram transport by elminating buffering.
* It takes a datagram as an argument, and a byte buffer in which
* to store the raw datagram data. Inside the method, the data
* is set as the datagram's data and the datagram returned.
*
* @param datagram The datagram to create.
* @param data The buffer to store the packet and to use in the datagram.
* @return The datagram argument.
***/
@Override
final DatagramPacket _newDatagram(DatagramPacket datagram, byte[] data)
{
int fileLength, modeLength;
fileLength = _filename.length();
modeLength = _modeBytes[_mode].length;
data[0] = 0;
data[1] = (byte)_type;
System.arraycopy(_filename.getBytes(), 0, data, 2, fileLength);
data[fileLength + 2] = 0;
System.arraycopy(_modeBytes[_mode], 0, data, fileLength + 3,
modeLength);
datagram.setAddress(_address);
datagram.setPort(_port);
datagram.setData(data);
datagram.setLength(fileLength + modeLength + 3);
return datagram;
}
Creates a UDP datagram containing all the TFTP request packet data in the proper format. This is a method exposed to the programmer in case he wants to implement his own TFTP client instead of using the TFTPClient class. Under normal circumstances, you should not have a need to call this method. Returns: A UDP datagram containing the TFTP request packet.
/***
* Creates a UDP datagram containing all the TFTP
* request packet data in the proper format.
* This is a method exposed to the programmer in case he
* wants to implement his own TFTP client instead of using
* the {@link org.apache.commons.net.tftp.TFTPClient}
* class. Under normal circumstances, you should not have a need to call
* this method.
*
* @return A UDP datagram containing the TFTP request packet.
***/
@Override
public final DatagramPacket newDatagram()
{
int fileLength, modeLength;
byte[] data;
fileLength = _filename.length();
modeLength = _modeBytes[_mode].length;
data = new byte[fileLength + modeLength + 4];
data[0] = 0;
data[1] = (byte)_type;
System.arraycopy(_filename.getBytes(), 0, data, 2, fileLength);
data[fileLength + 2] = 0;
System.arraycopy(_modeBytes[_mode], 0, data, fileLength + 3,
modeLength);
return new DatagramPacket(data, data.length, _address, _port);
}
Returns the transfer mode of the request.
Returns: The transfer mode of the request.
/***
* Returns the transfer mode of the request.
*
* @return The transfer mode of the request.
***/
public final int getMode()
{
return _mode;
}
Returns the requested filename.
Returns: The requested filename.
/***
* Returns the requested filename.
*
* @return The requested filename.
***/
public final String getFilename()
{
return _filename;
}
}