src/main/java/org/apache/commons/net/tftp/TFTPDataPacket.java - commons-net - Git at Google

 /*
  * 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;

 /***
  * A final class derived from TFTPPacket definiing the TFTP Data
  * packet type.
  * <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 TFTPPacketException
  * @see TFTP
  ***/

 public final class TFTPDataPacket extends TFTPPacket
 {
     /*** The maximum number of bytes in a TFTP data packet (512) ***/
     public static final int MAX_DATA_LENGTH = 512;

     /*** The minimum number of bytes in a TFTP data packet (0) ***/
     public static final int MIN_DATA_LENGTH = 0;

     /*** The block number of the packet. ***/
     int _blockNumber;

     /*** The length of the data. ***/
     int _length;

     /*** The offset into the _data array at which the data begins. ***/
     int _offset;

     /*** The data stored in the packet. ***/
     byte[] _data;

     /***
      * Creates a data packet to be sent to a host at a given port
      * with a given block number.  The actual data to be sent is passed as
      * an array, an offset, and a length.  The offset is the offset into
      * the byte array where the data starts.  The length is the length of
      * the data.  If the length is greater than MAX_DATA_LENGTH, it is
      * truncated.
      *
      * @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 blockNumber The block number of the data.
      * @param data The byte array containing the data.
      * @param offset The offset into the array where the data starts.
      * @param length The length of the data.
      ***/
     public TFTPDataPacket(InetAddress destination, int port, int blockNumber,
                           byte[] data, int offset, int length)
     {
         super(TFTPPacket.DATA, destination, port);

         _blockNumber = blockNumber;
         _data = data;
         _offset = offset;

         if (length > MAX_DATA_LENGTH) {
             _length = MAX_DATA_LENGTH;
         } else {
             _length = length;
         }
     }

     public TFTPDataPacket(InetAddress destination, int port, int blockNumber,
                           byte[] data)
     {
         this(destination, port, blockNumber, data, 0, data.length);
     }


     /***
      * Creates a data packet based from a received
      * datagram.  Assumes the datagram is at least length 4, else an
      * ArrayIndexOutOfBoundsException may be thrown.
      *
      * @param datagram  The datagram containing the received data.
      * @throws TFTPPacketException  If the datagram isn't a valid TFTP
      *         data packet.
      ***/
     TFTPDataPacket(DatagramPacket datagram) throws TFTPPacketException
     {
         super(TFTPPacket.DATA, datagram.getAddress(), datagram.getPort());

         _data = datagram.getData();
         _offset = 4;

         if (getType() != _data[1]) {
             throw new TFTPPacketException("TFTP operator code does not match type.");
         }

         _blockNumber = (((_data[2] & 0xff) << 8) | (_data[3] & 0xff));

         _length = datagram.getLength() - 4;

         if (_length > MAX_DATA_LENGTH) {
             _length = MAX_DATA_LENGTH;
         }
     }

     /***
      * 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
     DatagramPacket _newDatagram(DatagramPacket datagram, byte[] data)
     {
         data[0] = 0;
         data[1] = (byte)_type;
         data[2] = (byte)((_blockNumber & 0xffff) >> 8);
         data[3] = (byte)(_blockNumber & 0xff);

         // Doublecheck we're not the same
         if (data != _data) {
             System.arraycopy(_data, _offset, data, 4, _length);
         }

         datagram.setAddress(_address);
         datagram.setPort(_port);
         datagram.setData(data);
         datagram.setLength(_length + 4);

         return datagram;
     }

     /***
      * Creates a UDP datagram containing all the TFTP
      * data 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 data packet.
      ***/
     @Override
     public DatagramPacket newDatagram()
     {
         byte[] data;

         data = new byte[_length + 4];
         data[0] = 0;
         data[1] = (byte)_type;
         data[2] = (byte)((_blockNumber & 0xffff) >> 8);
         data[3] = (byte)(_blockNumber & 0xff);

         System.arraycopy(_data, _offset, data, 4, _length);

         return new DatagramPacket(data, _length + 4, _address, _port);
     }

     /***
      * Returns the block number of the data packet.
      *
      * @return The block number of the data packet.
      ***/
     public int getBlockNumber()
     {
         return _blockNumber;
     }

     /*** Sets the block number of the data packet.
      * @param blockNumber the number to set
      ***/
     public void setBlockNumber(int blockNumber)
     {
         _blockNumber = blockNumber;
     }

     /***
      * Sets the data for the data packet.
      *
      * @param data The byte array containing the data.
      * @param offset The offset into the array where the data starts.
      * @param length The length of the data.
      ***/
     public void setData(byte[] data, int offset, int length)
     {
         _data = data;
         _offset = offset;
         _length = length;

         if (length > MAX_DATA_LENGTH) {
             _length = MAX_DATA_LENGTH;
         } else {
             _length = length;
         }
     }

     /***
      * Returns the length of the data part of the data packet.
      *
      * @return The length of the data part of the data packet.
      ***/
     public int getDataLength()
     {
         return _length;
     }

     /***
      * Returns the offset into the byte array where the packet data actually
      * starts.
      *
      * @return The offset into the byte array where the packet data actually
      *         starts.
      ***/
     public int getDataOffset()
     {
         return _offset;
     }

     /***
      * Returns the byte array containing the packet data.
      *
      * @return The byte array containing the packet data.
      ***/
     public byte[] getData()
     {
         return _data;
     }

     // for debugging
     @Override
     public String toString() {
         return super.toString() + " DATA " + _blockNumber + " " + _length;
     }
 }
	/*
	* 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;

	/***
	* A final class derived from TFTPPacket definiing the TFTP Data
	* packet type.
	* <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 TFTPPacketException
	* @see TFTP
	***/

	public final class TFTPDataPacket extends TFTPPacket
	{
	/* The maximum number of bytes in a TFTP data packet (512) */
	public static final int MAX_DATA_LENGTH = 512;

	/* The minimum number of bytes in a TFTP data packet (0) */
	public static final int MIN_DATA_LENGTH = 0;

	/* The block number of the packet. */
	int _blockNumber;

	/* The length of the data. */
	int _length;

	/* The offset into the _data array at which the data begins. */
	int _offset;

	/* The data stored in the packet. */
	byte[] _data;

	/***
	* Creates a data packet to be sent to a host at a given port
	* with a given block number. The actual data to be sent is passed as
	* an array, an offset, and a length. The offset is the offset into
	* the byte array where the data starts. The length is the length of
	* the data. If the length is greater than MAX_DATA_LENGTH, it is
	* truncated.
	*
	* @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 blockNumber The block number of the data.
	* @param data The byte array containing the data.
	* @param offset The offset into the array where the data starts.
	* @param length The length of the data.
	***/
	public TFTPDataPacket(InetAddress destination, int port, int blockNumber,
	byte[] data, int offset, int length)
	{
	super(TFTPPacket.DATA, destination, port);

	_blockNumber = blockNumber;
	_data = data;
	_offset = offset;

	if (length > MAX_DATA_LENGTH) {
	_length = MAX_DATA_LENGTH;
	} else {
	_length = length;
	}
	}

	public TFTPDataPacket(InetAddress destination, int port, int blockNumber,
	byte[] data)
	{
	this(destination, port, blockNumber, data, 0, data.length);
	}


	/***
	* Creates a data packet based from a received
	* datagram. Assumes the datagram is at least length 4, else an
	* ArrayIndexOutOfBoundsException may be thrown.
	*
	* @param datagram The datagram containing the received data.
	* @throws TFTPPacketException If the datagram isn't a valid TFTP
	* data packet.
	***/
	TFTPDataPacket(DatagramPacket datagram) throws TFTPPacketException
	{
	super(TFTPPacket.DATA, datagram.getAddress(), datagram.getPort());

	_data = datagram.getData();
	_offset = 4;

	if (getType() != _data[1]) {
	throw new TFTPPacketException("TFTP operator code does not match type.");
	}

	_blockNumber = (((_data[2] & 0xff) << 8) \| (_data[3] & 0xff));

	_length = datagram.getLength() - 4;

	if (_length > MAX_DATA_LENGTH) {
	_length = MAX_DATA_LENGTH;
	}
	}

	/***
	* 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
	DatagramPacket _newDatagram(DatagramPacket datagram, byte[] data)
	{
	data[0] = 0;
	data[1] = (byte)_type;
	data[2] = (byte)((_blockNumber & 0xffff) >> 8);
	data[3] = (byte)(_blockNumber & 0xff);

	// Doublecheck we're not the same
	if (data != _data) {
	System.arraycopy(_data, _offset, data, 4, _length);
	}

	datagram.setAddress(_address);
	datagram.setPort(_port);
	datagram.setData(data);
	datagram.setLength(_length + 4);

	return datagram;
	}

	/***
	* Creates a UDP datagram containing all the TFTP
	* data 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 data packet.
	***/
	@Override
	public DatagramPacket newDatagram()
	{
	byte[] data;

	data = new byte[_length + 4];
	data[0] = 0;
	data[1] = (byte)_type;
	data[2] = (byte)((_blockNumber & 0xffff) >> 8);
	data[3] = (byte)(_blockNumber & 0xff);

	System.arraycopy(_data, _offset, data, 4, _length);

	return new DatagramPacket(data, _length + 4, _address, _port);
	}

	/***
	* Returns the block number of the data packet.
	*
	* @return The block number of the data packet.
	***/
	public int getBlockNumber()
	{
	return _blockNumber;
	}

	/*** Sets the block number of the data packet.
	* @param blockNumber the number to set
	***/
	public void setBlockNumber(int blockNumber)
	{
	_blockNumber = blockNumber;
	}

	/***
	* Sets the data for the data packet.
	*
	* @param data The byte array containing the data.
	* @param offset The offset into the array where the data starts.
	* @param length The length of the data.
	***/
	public void setData(byte[] data, int offset, int length)
	{
	_data = data;
	_offset = offset;
	_length = length;

	if (length > MAX_DATA_LENGTH) {
	_length = MAX_DATA_LENGTH;
	} else {
	_length = length;
	}
	}

	/***
	* Returns the length of the data part of the data packet.
	*
	* @return The length of the data part of the data packet.
	***/
	public int getDataLength()
	{
	return _length;
	}

	/***
	* Returns the offset into the byte array where the packet data actually
	* starts.
	*
	* @return The offset into the byte array where the packet data actually
	* starts.
	***/
	public int getDataOffset()
	{
	return _offset;
	}

	/***
	* Returns the byte array containing the packet data.
	*
	* @return The byte array containing the packet data.
	***/
	public byte[] getData()
	{
	return _data;
	}

	// for debugging
	@Override
	public String toString() {
	return super.toString() + " DATA " + _blockNumber + " " + _length;
	}
	}