/*
* 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.io.IOException;
import java.io.InputStream;
import java.io.InterruptedIOException;
import java.io.OutputStream;
import java.net.InetAddress;
import java.net.SocketException;
import java.net.UnknownHostException;
import org.apache.commons.net.io.FromNetASCIIOutputStream;
import org.apache.commons.net.io.ToNetASCIIInputStream;
/***
* The TFTPClient class encapsulates all the aspects of the TFTP protocol
* necessary to receive and send files through TFTP. It is derived from
* the {@link org.apache.commons.net.tftp.TFTP} because
* it is more convenient than using aggregation, and as a result exposes
* the same set of methods to allow you to deal with the TFTP protocol
* directly. However, almost every user should only be concerend with the
* the {@link org.apache.commons.net.DatagramSocketClient#open open() },
* {@link org.apache.commons.net.DatagramSocketClient#close close() },
* {@link #sendFile sendFile() }, and
* {@link #receiveFile receiveFile() } methods. Additionally, the
* {@link #setMaxTimeouts setMaxTimeouts() } and
* {@link org.apache.commons.net.DatagramSocketClient#setDefaultTimeout setDefaultTimeout() }
* methods may be of importance for performance
* tuning.
* <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.
* <p>
* <p>
* @author Daniel F. Savarese
* @see TFTP
* @see TFTPPacket
* @see TFTPPacketException
***/
public class TFTPClient extends TFTP
{
/***
* The default number of times a receive attempt is allowed to timeout
* before ending attempts to retry the receive and failing. The default
* is 5 timeouts.
***/
public static final int DEFAULT_MAX_TIMEOUTS = 5;
/*** The maximum number of timeouts allowed before failing. ***/
private int __maxTimeouts;
/***
* Creates a TFTPClient instance with a default timeout of DEFAULT_TIMEOUT,
* maximum timeouts value of DEFAULT_MAX_TIMEOUTS, a null socket,
* and buffered operations disabled.
***/
public TFTPClient()
{
__maxTimeouts = DEFAULT_MAX_TIMEOUTS;
}
/***
* Sets the maximum number of times a receive attempt is allowed to
* timeout during a receiveFile() or sendFile() operation before ending
* attempts to retry the receive and failing.
* The default is DEFAULT_MAX_TIMEOUTS.
* <p>
* @param numTimeouts The maximum number of timeouts to allow. Values
* less than 1 should not be used, but if they are, they are
* treated as 1.
***/
public void setMaxTimeouts(int numTimeouts)
{
if (numTimeouts < 1)
__maxTimeouts = 1;
else
__maxTimeouts = numTimeouts;
}
/***
* Returns the maximum number of times a receive attempt is allowed to
* timeout before ending attempts to retry the receive and failing.
* <p>
* @return The maximum number of timeouts allowed.
***/
public int getMaxTimeouts()
{
return __maxTimeouts;
}
/***
* Requests a named file from a remote host, writes the
* file to an OutputStream, closes the connection, and returns the number
* of bytes read. A local UDP socket must first be created by
* {@link org.apache.commons.net.DatagramSocketClient#open open()} before
* invoking this method. This method will not close the OutputStream
* containing the file; you must close it after the method invocation.
* <p>
* @param filename The name of the file to receive.
* @param mode The TFTP mode of the transfer (one of the MODE constants).
* @param output The OutputStream to which the file should be written.
* @param host The remote host serving the file.
* @param port The port number of the remote TFTP server.
* @exception IOException If an I/O error occurs. The nature of the
* error will be reported in the message.
***/
public int receiveFile(String filename, int mode, OutputStream output,
InetAddress host, int port) throws IOException
{
int bytesRead, timeouts, lastBlock, block, hostPort, dataLength;
TFTPPacket sent, received = null;
TFTPErrorPacket error;
TFTPDataPacket data;
TFTPAckPacket ack = new TFTPAckPacket(host, port, 0);
beginBufferedOps();
dataLength = lastBlock = hostPort = bytesRead = 0;
block = 1;
if (mode == TFTP.ASCII_MODE)
output = new FromNetASCIIOutputStream(output);
sent =
new TFTPReadRequestPacket(host, port, filename, mode);
_sendPacket:
do
{
bufferedSend(sent);
_receivePacket:
while (true)
{
timeouts = 0;
while (timeouts < __maxTimeouts)
{
try
{
received = bufferedReceive();
break;
}
catch (SocketException e)
{
if (++timeouts >= __maxTimeouts)
{
endBufferedOps();
throw new IOException("Connection timed out.");
}
continue;
}
catch (InterruptedIOException e)
{
if (++timeouts >= __maxTimeouts)
{
endBufferedOps();
throw new IOException("Connection timed out.");
}
continue;
}
catch (TFTPPacketException e)
{
endBufferedOps();
throw new IOException("Bad packet: " + e.getMessage());
}
}
// The first time we receive we get the port number and
// answering host address (for hosts with multiple IPs)
if (lastBlock == 0)
{
hostPort = received.getPort();
ack.setPort(hostPort);
if(!host.equals(received.getAddress()))
{
host = received.getAddress();
ack.setAddress(host);
sent.setAddress(host);
}
}
// Comply with RFC 783 indication that an error acknowledgement
// should be sent to originator if unexpected TID or host.
if (host.equals(received.getAddress()) &&
received.getPort() == hostPort)
{
switch (received.getType())
{
case TFTPPacket.ERROR:
error = (TFTPErrorPacket)received;
endBufferedOps();
throw new IOException("Error code " + error.getError() +
" received: " + error.getMessage());
case TFTPPacket.DATA:
data = (TFTPDataPacket)received;
dataLength = data.getDataLength();
lastBlock = data.getBlockNumber();
if (lastBlock == block)
{
try
{
output.write(data.getData(), data.getDataOffset(),
dataLength);
}
catch (IOException e)
{
error = new TFTPErrorPacket(host, hostPort,
TFTPErrorPacket.OUT_OF_SPACE,
"File write failed.");
bufferedSend(error);
endBufferedOps();
throw e;
}
++block;
if (block > 65535)
{
// wrap the block number
block = 0;
}
break _receivePacket;
}
else
{
discardPackets();
if (lastBlock == (block == 0 ? 65535 : (block - 1)))
continue _sendPacket; // Resend last acknowledgement.
continue _receivePacket; // Start fetching packets again.
}
//break;
default:
endBufferedOps();
throw new IOException("Received unexpected packet type.");
}
}
else
{
error = new TFTPErrorPacket(received.getAddress(),
received.getPort(),
TFTPErrorPacket.UNKNOWN_TID,
"Unexpected host or port.");
bufferedSend(error);
continue _sendPacket;
}
// We should never get here, but this is a safety to avoid
// infinite loop. If only Java had the goto statement.
//break;
}
ack.setBlockNumber(lastBlock);
sent = ack;
bytesRead += dataLength;
} // First data packet less than 512 bytes signals end of stream.
while (dataLength == TFTPPacket.SEGMENT_SIZE);
bufferedSend(sent);
endBufferedOps();
return bytesRead;
}
/***
* Requests a named file from a remote host, writes the
* file to an OutputStream, closes the connection, and returns the number
* of bytes read. A local UDP socket must first be created by
* {@link org.apache.commons.net.DatagramSocketClient#open open()} before
* invoking this method. This method will not close the OutputStream
* containing the file; you must close it after the method invocation.
* <p>
* @param filename The name of the file to receive.
* @param mode The TFTP mode of the transfer (one of the MODE constants).
* @param output The OutputStream to which the file should be written.
* @param hostname The name of the remote host serving the file.
* @param port The port number of the remote TFTP server.
* @exception IOException If an I/O error occurs. The nature of the
* error will be reported in the message.
* @exception UnknownHostException If the hostname cannot be resolved.
***/
public int receiveFile(String filename, int mode, OutputStream output,
String hostname, int port)
throws UnknownHostException, IOException
{
return receiveFile(filename, mode, output, InetAddress.getByName(hostname),
port);
}
/***
* Same as calling receiveFile(filename, mode, output, host, TFTP.DEFAULT_PORT).
*
* @param filename The name of the file to receive.
* @param mode The TFTP mode of the transfer (one of the MODE constants).
* @param output The OutputStream to which the file should be written.
* @param host The remote host serving the file.
* @exception IOException If an I/O error occurs. The nature of the
* error will be reported in the message.
***/
public int receiveFile(String filename, int mode, OutputStream output,
InetAddress host)
throws IOException
{
return receiveFile(filename, mode, output, host, DEFAULT_PORT);
}
/***
* Same as calling receiveFile(filename, mode, output, hostname, TFTP.DEFAULT_PORT).
*
* @param filename The name of the file to receive.
* @param mode The TFTP mode of the transfer (one of the MODE constants).
* @param output The OutputStream to which the file should be written.
* @param hostname The name of the remote host serving the file.
* @exception IOException If an I/O error occurs. The nature of the
* error will be reported in the message.
* @exception UnknownHostException If the hostname cannot be resolved.
***/
public int receiveFile(String filename, int mode, OutputStream output,
String hostname)
throws UnknownHostException, IOException
{
return receiveFile(filename, mode, output, InetAddress.getByName(hostname),
DEFAULT_PORT);
}
/***
* Requests to send a file to a remote host, reads the file from an
* InputStream, sends the file to the remote host, and closes the
* connection. A local UDP socket must first be created by
* {@link org.apache.commons.net.DatagramSocketClient#open open()} before
* invoking this method. This method will not close the InputStream
* containing the file; you must close it after the method invocation.
* <p>
* @param filename The name the remote server should use when creating
* the file on its file system.
* @param mode The TFTP mode of the transfer (one of the MODE constants).
* @param host The remote host receiving the file.
* @param port The port number of the remote TFTP server.
* @exception IOException If an I/O error occurs. The nature of the
* error will be reported in the message.
***/
public void sendFile(String filename, int mode, InputStream input,
InetAddress host, int port) throws IOException
{
int bytesRead, timeouts, lastBlock, block, hostPort, dataLength, offset, totalThisPacket;
TFTPPacket sent, received = null;
TFTPErrorPacket error;
TFTPDataPacket data =
new TFTPDataPacket(host, port, 0, _sendBuffer, 4, 0);
TFTPAckPacket ack;
boolean justStarted = true;
beginBufferedOps();
dataLength = lastBlock = hostPort = bytesRead = totalThisPacket = 0;
block = 0;
boolean lastAckWait = false;
if (mode == TFTP.ASCII_MODE)
input = new ToNetASCIIInputStream(input);
sent =
new TFTPWriteRequestPacket(host, port, filename, mode);
_sendPacket:
do
{
// first time: block is 0, lastBlock is 0, send a request packet.
// subsequent: block is integer starting at 1, send data packet.
bufferedSend(sent);
// this is trying to receive an ACK
_receivePacket:
while (true)
{
timeouts = 0;
while (timeouts < __maxTimeouts)
{
try
{
received = bufferedReceive();
break;
}
catch (SocketException e)
{
if (++timeouts >= __maxTimeouts)
{
endBufferedOps();
throw new IOException("Connection timed out.");
}
continue;
}
catch (InterruptedIOException e)
{
if (++timeouts >= __maxTimeouts)
{
endBufferedOps();
throw new IOException("Connection timed out.");
}
continue;
}
catch (TFTPPacketException e)
{
endBufferedOps();
throw new IOException("Bad packet: " + e.getMessage());
}
} // end of while loop over tries to receive
// The first time we receive we get the port number and
// answering host address (for hosts with multiple IPs)
if (justStarted)
{
justStarted = false;
hostPort = received.getPort();
data.setPort(hostPort);
if(!host.equals(received.getAddress()))
{
host = received.getAddress();
data.setAddress(host);
sent.setAddress(host);
}
}
// Comply with RFC 783 indication that an error acknowledgement
// should be sent to originator if unexpected TID or host.
if (host.equals(received.getAddress()) &&
received.getPort() == hostPort)
{
switch (received.getType())
{
case TFTPPacket.ERROR:
error = (TFTPErrorPacket)received;
endBufferedOps();
throw new IOException("Error code " + error.getError() +
" received: " + error.getMessage());
case TFTPPacket.ACKNOWLEDGEMENT:
ack = (TFTPAckPacket)received;
lastBlock = ack.getBlockNumber();
if (lastBlock == block)
{
++block;
if (block > 65535)
{
// wrap the block number
block = 0;
}
if (lastAckWait) {
break _sendPacket;
}
else {
break _receivePacket;
}
}
else
{
discardPackets();
if (lastBlock == (block == 0 ? 65535 : (block - 1)))
continue _sendPacket; // Resend last acknowledgement.
continue _receivePacket; // Start fetching packets again.
}
//break;
default:
endBufferedOps();
throw new IOException("Received unexpected packet type.");
}
}
else
{
error = new TFTPErrorPacket(received.getAddress(),
received.getPort(),
TFTPErrorPacket.UNKNOWN_TID,
"Unexpected host or port.");
bufferedSend(error);
continue _sendPacket;
}
// We should never get here, but this is a safety to avoid
// infinite loop. If only Java had the goto statement.
//break;
}
// OK, we have just gotten ACK about the last data we sent. Make another
// and send it
dataLength = TFTPPacket.SEGMENT_SIZE;
offset = 4;
totalThisPacket = 0;
while (dataLength > 0 &&
(bytesRead = input.read(_sendBuffer, offset, dataLength)) > 0)
{
offset += bytesRead;
dataLength -= bytesRead;
totalThisPacket += bytesRead;
}
if( totalThisPacket < TFTPPacket.SEGMENT_SIZE ) {
/* this will be our last packet -- send, wait for ack, stop */
lastAckWait = true;
}
data.setBlockNumber(block);
data.setData(_sendBuffer, 4, totalThisPacket);
sent = data;
}
while ( totalThisPacket > 0 || lastAckWait );
// Note: this was looping while dataLength == 0 || lastAckWait,
// which was discarding the last packet if it was not full size
// Should send the packet.
endBufferedOps();
}
/***
* Requests to send a file to a remote host, reads the file from an
* InputStream, sends the file to the remote host, and closes the
* connection. A local UDP socket must first be created by
* {@link org.apache.commons.net.DatagramSocketClient#open open()} before
* invoking this method. This method will not close the InputStream
* containing the file; you must close it after the method invocation.
* <p>
* @param filename The name the remote server should use when creating
* the file on its file system.
* @param mode The TFTP mode of the transfer (one of the MODE constants).
* @param hostname The name of the remote host receiving the file.
* @param port The port number of the remote TFTP server.
* @exception IOException If an I/O error occurs. The nature of the
* error will be reported in the message.
* @exception UnknownHostException If the hostname cannot be resolved.
***/
public void sendFile(String filename, int mode, InputStream input,
String hostname, int port)
throws UnknownHostException, IOException
{
sendFile(filename, mode, input, InetAddress.getByName(hostname), port);
}
/***
* Same as calling sendFile(filename, mode, input, host, TFTP.DEFAULT_PORT).
*
* @param filename The name the remote server should use when creating
* the file on its file system.
* @param mode The TFTP mode of the transfer (one of the MODE constants).
* @param host The name of the remote host receiving the file.
* @exception IOException If an I/O error occurs. The nature of the
* error will be reported in the message.
* @exception UnknownHostException If the hostname cannot be resolved.
***/
public void sendFile(String filename, int mode, InputStream input,
InetAddress host)
throws IOException
{
sendFile(filename, mode, input, host, DEFAULT_PORT);
}
/***
* Same as calling sendFile(filename, mode, input, hostname, TFTP.DEFAULT_PORT).
*
* @param filename The name the remote server should use when creating
* the file on its file system.
* @param mode The TFTP mode of the transfer (one of the MODE constants).
* @param hostname The name of the remote host receiving the file.
* @exception IOException If an I/O error occurs. The nature of the
* error will be reported in the message.
* @exception UnknownHostException If the hostname cannot be resolved.
***/
public void sendFile(String filename, int mode, InputStream input,
String hostname)
throws UnknownHostException, IOException
{
sendFile(filename, mode, input, InetAddress.getByName(hostname),
DEFAULT_PORT);
}
}