001/*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements.  See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License.  You may obtain a copy of the License at
008 *
009 *      http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017
018package org.apache.commons.net.tftp;
019
020import java.io.IOException;
021import java.io.InputStream;
022import java.io.InterruptedIOException;
023import java.io.OutputStream;
024import java.net.InetAddress;
025import java.net.SocketException;
026import java.net.UnknownHostException;
027import org.apache.commons.net.io.FromNetASCIIOutputStream;
028import org.apache.commons.net.io.ToNetASCIIInputStream;
029
030/***
031 * The TFTPClient class encapsulates all the aspects of the TFTP protocol
032 * necessary to receive and send files through TFTP.  It is derived from
033 * the {@link org.apache.commons.net.tftp.TFTP} because
034 * it is more convenient than using aggregation, and as a result exposes
035 * the same set of methods to allow you to deal with the TFTP protocol
036 * directly.  However, almost every user should only be concerend with the
037 * the {@link org.apache.commons.net.DatagramSocketClient#open  open() },
038 * {@link org.apache.commons.net.DatagramSocketClient#close  close() },
039 * {@link #sendFile  sendFile() }, and
040 * {@link #receiveFile  receiveFile() } methods.  Additionally, the
041 * {@link #setMaxTimeouts  setMaxTimeouts() } and
042 * {@link org.apache.commons.net.DatagramSocketClient#setDefaultTimeout setDefaultTimeout() }
043 *  methods may be of importance for performance
044 * tuning.
045 * <p>
046 * Details regarding the TFTP protocol and the format of TFTP packets can
047 * be found in RFC 783.  But the point of these classes is to keep you
048 * from having to worry about the internals.
049 * <p>
050 * <p>
051 * @author Daniel F. Savarese
052 * @see TFTP
053 * @see TFTPPacket
054 * @see TFTPPacketException
055 ***/
056
057public class TFTPClient extends TFTP
058{
059    /***
060     * The default number of times a receive attempt is allowed to timeout
061     * before ending attempts to retry the receive and failing.  The default
062     * is 5 timeouts.
063     ***/
064    public static final int DEFAULT_MAX_TIMEOUTS = 5;
065
066    /*** The maximum number of timeouts allowed before failing. ***/
067    private int __maxTimeouts;
068
069    /***
070     * Creates a TFTPClient instance with a default timeout of DEFAULT_TIMEOUT,
071     * maximum timeouts value of DEFAULT_MAX_TIMEOUTS, a null socket,
072     * and buffered operations disabled.
073     ***/
074    public TFTPClient()
075    {
076        __maxTimeouts = DEFAULT_MAX_TIMEOUTS;
077    }
078
079    /***
080     * Sets the maximum number of times a receive attempt is allowed to
081     * timeout during a receiveFile() or sendFile() operation before ending
082     * attempts to retry the receive and failing.
083     * The default is DEFAULT_MAX_TIMEOUTS.
084     * <p>
085     * @param numTimeouts  The maximum number of timeouts to allow.  Values
086     *        less than 1 should not be used, but if they are, they are
087     *        treated as 1.
088     ***/
089    public void setMaxTimeouts(int numTimeouts)
090    {
091        if (numTimeouts < 1)
092            __maxTimeouts = 1;
093        else
094            __maxTimeouts = numTimeouts;
095    }
096
097    /***
098     * Returns the maximum number of times a receive attempt is allowed to
099     * timeout before ending attempts to retry the receive and failing.
100     * <p>
101     * @return The maximum number of timeouts allowed.
102     ***/
103    public int getMaxTimeouts()
104    {
105        return __maxTimeouts;
106    }
107
108
109    /***
110     * Requests a named file from a remote host, writes the
111     * file to an OutputStream, closes the connection, and returns the number
112     * of bytes read.  A local UDP socket must first be created by
113     * {@link org.apache.commons.net.DatagramSocketClient#open open()} before
114     * invoking this method.  This method will not close the OutputStream
115     * containing the file; you must close it after the method invocation.
116     * <p>
117     * @param filename  The name of the file to receive.
118     * @param mode   The TFTP mode of the transfer (one of the MODE constants).
119     * @param output The OutputStream to which the file should be written.
120     * @param host   The remote host serving the file.
121     * @param port   The port number of the remote TFTP server.
122     * @exception IOException If an I/O error occurs.  The nature of the
123     *            error will be reported in the message.
124     ***/
125    public int receiveFile(String filename, int mode, OutputStream output,
126                           InetAddress host, int port) throws IOException
127    {
128        int bytesRead, timeouts, lastBlock, block, hostPort, dataLength;
129        TFTPPacket sent, received = null;
130        TFTPErrorPacket error;
131        TFTPDataPacket data;
132        TFTPAckPacket ack = new TFTPAckPacket(host, port, 0);
133
134        beginBufferedOps();
135
136        dataLength = lastBlock = hostPort = bytesRead = 0;
137        block = 1;
138
139        if (mode == TFTP.ASCII_MODE)
140            output = new FromNetASCIIOutputStream(output);
141
142        sent =
143            new TFTPReadRequestPacket(host, port, filename, mode);
144
145_sendPacket:
146        do
147        {
148            bufferedSend(sent);
149
150_receivePacket:
151            while (true)
152            {
153                timeouts = 0;
154                while (timeouts < __maxTimeouts)
155                {
156                    try
157                    {
158                        received = bufferedReceive();
159                        break;
160                    }
161                    catch (SocketException e)
162                    {
163                        if (++timeouts >= __maxTimeouts)
164                        {
165                            endBufferedOps();
166                            throw new IOException("Connection timed out.");
167                        }
168                        continue;
169                    }
170                    catch (InterruptedIOException e)
171                    {
172                        if (++timeouts >= __maxTimeouts)
173                        {
174                            endBufferedOps();
175                            throw new IOException("Connection timed out.");
176                        }
177                        continue;
178                    }
179                    catch (TFTPPacketException e)
180                    {
181                        endBufferedOps();
182                        throw new IOException("Bad packet: " + e.getMessage());
183                    }
184                }
185
186                // The first time we receive we get the port number and
187        // answering host address (for hosts with multiple IPs)
188                if (lastBlock == 0)
189                {
190                    hostPort = received.getPort();
191                    ack.setPort(hostPort);
192                    if(!host.equals(received.getAddress()))
193                    {
194                        host = received.getAddress();
195                        ack.setAddress(host);
196                        sent.setAddress(host);
197                    }
198                }
199
200                // Comply with RFC 783 indication that an error acknowledgement
201                // should be sent to originator if unexpected TID or host.
202                if (host.equals(received.getAddress()) &&
203                        received.getPort() == hostPort)
204                {
205
206                    switch (received.getType())
207                    {
208                    case TFTPPacket.ERROR:
209                        error = (TFTPErrorPacket)received;
210                        endBufferedOps();
211                        throw new IOException("Error code " + error.getError() +
212                                              " received: " + error.getMessage());
213                    case TFTPPacket.DATA:
214                        data = (TFTPDataPacket)received;
215                        dataLength = data.getDataLength();
216
217                        lastBlock = data.getBlockNumber();
218
219                        if (lastBlock == block)
220                        {
221                            try
222                            {
223                                output.write(data.getData(), data.getDataOffset(),
224                                             dataLength);
225                            }
226                            catch (IOException e)
227                            {
228                                error = new TFTPErrorPacket(host, hostPort,
229                                                            TFTPErrorPacket.OUT_OF_SPACE,
230                                                            "File write failed.");
231                                bufferedSend(error);
232                                endBufferedOps();
233                                throw e;
234                            }
235                            ++block;
236                            if (block > 65535)
237                            {
238                                // wrap the block number
239                                block = 0;
240                            }
241                            
242                            break _receivePacket;
243                        }
244                        else
245                        {
246                            discardPackets();
247
248                            if (lastBlock == (block == 0 ? 65535 : (block - 1)))
249                                continue _sendPacket;  // Resend last acknowledgement.
250
251                            continue _receivePacket; // Start fetching packets again.
252                        }
253                        //break;
254
255                    default:
256                        endBufferedOps();
257                        throw new IOException("Received unexpected packet type.");
258                    }
259                }
260                else
261                {
262                    error = new TFTPErrorPacket(received.getAddress(),
263                                                received.getPort(),
264                                                TFTPErrorPacket.UNKNOWN_TID,
265                                                "Unexpected host or port.");
266                    bufferedSend(error);
267                    continue _sendPacket;
268                }
269
270                // We should never get here, but this is a safety to avoid
271                // infinite loop.  If only Java had the goto statement.
272                //break;
273            }
274
275            ack.setBlockNumber(lastBlock);
276            sent = ack;
277            bytesRead += dataLength;
278        } // First data packet less than 512 bytes signals end of stream.
279
280        while (dataLength == TFTPPacket.SEGMENT_SIZE);
281
282        bufferedSend(sent);
283        endBufferedOps();
284
285        return bytesRead;
286    }
287
288
289    /***
290     * Requests a named file from a remote host, writes the
291     * file to an OutputStream, closes the connection, and returns the number
292     * of bytes read.  A local UDP socket must first be created by
293     * {@link org.apache.commons.net.DatagramSocketClient#open open()} before
294     * invoking this method.  This method will not close the OutputStream
295     * containing the file; you must close it after the method invocation.
296     * <p>
297     * @param filename The name of the file to receive.
298     * @param mode     The TFTP mode of the transfer (one of the MODE constants).
299     * @param output   The OutputStream to which the file should be written.
300     * @param hostname The name of the remote host serving the file.
301     * @param port     The port number of the remote TFTP server.
302     * @exception IOException If an I/O error occurs.  The nature of the
303     *            error will be reported in the message.
304     * @exception UnknownHostException  If the hostname cannot be resolved.
305     ***/
306    public int receiveFile(String filename, int mode, OutputStream output,
307                           String hostname, int port)
308    throws UnknownHostException, IOException
309    {
310        return receiveFile(filename, mode, output, InetAddress.getByName(hostname),
311                           port);
312    }
313
314
315    /***
316     * Same as calling receiveFile(filename, mode, output, host, TFTP.DEFAULT_PORT).
317     *
318     * @param filename The name of the file to receive.
319     * @param mode     The TFTP mode of the transfer (one of the MODE constants).
320     * @param output   The OutputStream to which the file should be written.
321     * @param host     The remote host serving the file.
322     * @exception IOException If an I/O error occurs.  The nature of the
323     *            error will be reported in the message.
324     ***/
325    public int receiveFile(String filename, int mode, OutputStream output,
326                           InetAddress host)
327    throws IOException
328    {
329        return receiveFile(filename, mode, output, host, DEFAULT_PORT);
330    }
331
332    /***
333     * Same as calling receiveFile(filename, mode, output, hostname, TFTP.DEFAULT_PORT).
334     *
335     * @param filename The name of the file to receive.
336     * @param mode     The TFTP mode of the transfer (one of the MODE constants).
337     * @param output   The OutputStream to which the file should be written.
338     * @param hostname The name of the remote host serving the file.
339     * @exception IOException If an I/O error occurs.  The nature of the
340     *            error will be reported in the message.
341     * @exception UnknownHostException  If the hostname cannot be resolved.
342     ***/
343    public int receiveFile(String filename, int mode, OutputStream output,
344                           String hostname)
345    throws UnknownHostException, IOException
346    {
347        return receiveFile(filename, mode, output, InetAddress.getByName(hostname),
348                           DEFAULT_PORT);
349    }
350
351
352    /***
353     * Requests to send a file to a remote host, reads the file from an
354     * InputStream, sends the file to the remote host, and closes the
355     * connection.  A local UDP socket must first be created by
356     * {@link org.apache.commons.net.DatagramSocketClient#open open()} before
357     * invoking this method.  This method will not close the InputStream
358     * containing the file; you must close it after the method invocation.
359     * <p>
360     * @param filename The name the remote server should use when creating
361     *        the file on its file system.
362     * @param mode     The TFTP mode of the transfer (one of the MODE constants).
363     * @param host     The remote host receiving the file.
364     * @param port     The port number of the remote TFTP server.
365     * @exception IOException If an I/O error occurs.  The nature of the
366     *            error will be reported in the message.
367     ***/
368    public void sendFile(String filename, int mode, InputStream input,
369                         InetAddress host, int port) throws IOException
370    {
371        int bytesRead, timeouts, lastBlock, block, hostPort, dataLength, offset, totalThisPacket;
372        TFTPPacket sent, received = null;
373        TFTPErrorPacket error;
374        TFTPDataPacket data =
375            new TFTPDataPacket(host, port, 0, _sendBuffer, 4, 0);
376        TFTPAckPacket ack;
377
378        boolean justStarted = true;
379        
380        beginBufferedOps();
381
382        dataLength = lastBlock = hostPort = bytesRead = totalThisPacket = 0;
383        block = 0;
384        boolean lastAckWait = false;
385
386        if (mode == TFTP.ASCII_MODE)
387            input = new ToNetASCIIInputStream(input);
388
389        sent =
390            new TFTPWriteRequestPacket(host, port, filename, mode);
391
392_sendPacket:
393        do
394        {
395            // first time: block is 0, lastBlock is 0, send a request packet.
396            // subsequent: block is integer starting at 1, send data packet.
397            bufferedSend(sent);
398            
399            // this is trying to receive an ACK
400_receivePacket:
401            while (true)
402            {
403                
404
405                timeouts = 0;
406                while (timeouts < __maxTimeouts)
407                {
408                    try
409                    {
410                        received = bufferedReceive();
411                        break;
412                    }
413                    catch (SocketException e)
414                    {
415                        if (++timeouts >= __maxTimeouts)
416                        {
417                            endBufferedOps();
418                            throw new IOException("Connection timed out.");
419                        }
420                        continue;
421                    }
422                    catch (InterruptedIOException e)
423                    {
424                        if (++timeouts >= __maxTimeouts)
425                        {
426                            endBufferedOps();
427                            throw new IOException("Connection timed out.");
428                        }
429                        continue;
430                    }
431                    catch (TFTPPacketException e)
432                    {
433                        endBufferedOps();
434                        throw new IOException("Bad packet: " + e.getMessage());
435                    }
436                } // end of while loop over tries to receive
437
438                // The first time we receive we get the port number and
439        // answering host address (for hosts with multiple IPs)
440                if (justStarted)
441                {
442                    justStarted = false;
443                    hostPort = received.getPort();
444                    data.setPort(hostPort);
445                    if(!host.equals(received.getAddress()))
446                    {
447                        host = received.getAddress();
448                        data.setAddress(host);
449                        sent.setAddress(host);
450                    }
451                }
452
453                // Comply with RFC 783 indication that an error acknowledgement
454                // should be sent to originator if unexpected TID or host.
455                if (host.equals(received.getAddress()) &&
456                        received.getPort() == hostPort)
457                {
458
459                    switch (received.getType())
460                    {
461                    case TFTPPacket.ERROR:
462                        error = (TFTPErrorPacket)received;
463                        endBufferedOps();
464                        throw new IOException("Error code " + error.getError() +
465                                              " received: " + error.getMessage());
466                    case TFTPPacket.ACKNOWLEDGEMENT:
467                        ack = (TFTPAckPacket)received;
468
469                        lastBlock = ack.getBlockNumber();
470
471                        if (lastBlock == block)
472                        {
473                            ++block;
474                            if (block > 65535)
475                            {
476                                // wrap the block number
477                                block = 0;
478                            }
479                            if (lastAckWait) {
480                                
481                              break _sendPacket;
482                            }
483                            else {
484                              break _receivePacket;
485                            }
486                        }
487                        else
488                        {
489                            discardPackets();
490
491                            if (lastBlock == (block == 0 ? 65535 : (block - 1)))
492                                continue _sendPacket;  // Resend last acknowledgement.
493
494                            continue _receivePacket; // Start fetching packets again.
495                        }
496                        //break;
497
498                    default:
499                        endBufferedOps();
500                        throw new IOException("Received unexpected packet type.");
501                    }
502                }
503                else
504                {
505                    error = new TFTPErrorPacket(received.getAddress(),
506                                                received.getPort(),
507                                                TFTPErrorPacket.UNKNOWN_TID,
508                                                "Unexpected host or port.");
509                    bufferedSend(error);
510                    continue _sendPacket;
511                }
512
513                // We should never get here, but this is a safety to avoid
514                // infinite loop.  If only Java had the goto statement.
515                //break;
516            }
517
518            // OK, we have just gotten ACK about the last data we sent. Make another
519            // and send it            
520
521            dataLength = TFTPPacket.SEGMENT_SIZE;
522            offset = 4;
523            totalThisPacket = 0;
524            while (dataLength > 0 &&
525                    (bytesRead = input.read(_sendBuffer, offset, dataLength)) > 0)
526            {
527                offset += bytesRead;
528                dataLength -= bytesRead;
529                totalThisPacket += bytesRead;
530            }
531
532            if( totalThisPacket < TFTPPacket.SEGMENT_SIZE ) {
533                /* this will be our last packet -- send, wait for ack, stop */
534                lastAckWait = true;
535            }
536            data.setBlockNumber(block);
537            data.setData(_sendBuffer, 4, totalThisPacket);
538            sent = data;
539        }
540        while ( totalThisPacket > 0 || lastAckWait );
541        // Note: this was looping while dataLength == 0 || lastAckWait,
542        // which was discarding the last packet if it was not full size
543        // Should send the packet. 
544        
545        endBufferedOps();
546    }
547
548
549    /***
550     * Requests to send a file to a remote host, reads the file from an
551     * InputStream, sends the file to the remote host, and closes the
552     * connection.  A local UDP socket must first be created by
553     * {@link org.apache.commons.net.DatagramSocketClient#open open()} before
554     * invoking this method.  This method will not close the InputStream
555     * containing the file; you must close it after the method invocation.
556     * <p>
557     * @param filename The name the remote server should use when creating
558     *        the file on its file system.
559     * @param mode     The TFTP mode of the transfer (one of the MODE constants).
560     * @param hostname The name of the remote host receiving the file.
561     * @param port     The port number of the remote TFTP server.
562     * @exception IOException If an I/O error occurs.  The nature of the
563     *            error will be reported in the message.
564     * @exception UnknownHostException  If the hostname cannot be resolved.
565     ***/
566    public void sendFile(String filename, int mode, InputStream input,
567                         String hostname, int port)
568    throws UnknownHostException, IOException
569    {
570        sendFile(filename, mode, input, InetAddress.getByName(hostname), port);
571    }
572
573
574    /***
575     * Same as calling sendFile(filename, mode, input, host, TFTP.DEFAULT_PORT).
576     *
577     * @param filename The name the remote server should use when creating
578     *        the file on its file system.
579     * @param mode     The TFTP mode of the transfer (one of the MODE constants).
580     * @param host     The name of the remote host receiving the file.
581     * @exception IOException If an I/O error occurs.  The nature of the
582     *            error will be reported in the message.
583     * @exception UnknownHostException  If the hostname cannot be resolved.
584     ***/
585    public void sendFile(String filename, int mode, InputStream input,
586                         InetAddress host)
587    throws IOException
588    {
589        sendFile(filename, mode, input, host, DEFAULT_PORT);
590    }
591
592    /***
593     * Same as calling sendFile(filename, mode, input, hostname, TFTP.DEFAULT_PORT).
594     *
595     * @param filename The name the remote server should use when creating
596     *        the file on its file system.
597     * @param mode     The TFTP mode of the transfer (one of the MODE constants).
598     * @param hostname The name of the remote host receiving the file.
599     * @exception IOException If an I/O error occurs.  The nature of the
600     *            error will be reported in the message.
601     * @exception UnknownHostException  If the hostname cannot be resolved.
602     ***/
603    public void sendFile(String filename, int mode, InputStream input,
604                         String hostname)
605    throws UnknownHostException, IOException
606    {
607        sendFile(filename, mode, input, InetAddress.getByName(hostname),
608                 DEFAULT_PORT);
609    }
610}