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ea91242c KL |
1 | /** |
2 | * Jexer - Java Text User Interface | |
3 | * | |
4 | * License: LGPLv3 or later | |
5 | * | |
6 | * This module is licensed under the GNU Lesser General Public License | |
7 | * Version 3. Please see the file "COPYING" in this directory for more | |
8 | * information about the GNU Lesser General Public License Version 3. | |
9 | * | |
10 | * Copyright (C) 2015 Kevin Lamonte | |
11 | * | |
12 | * This program is free software; you can redistribute it and/or | |
13 | * modify it under the terms of the GNU Lesser General Public License | |
14 | * as published by the Free Software Foundation; either version 3 of | |
15 | * the License, or (at your option) any later version. | |
16 | * | |
17 | * This program is distributed in the hope that it will be useful, but | |
18 | * WITHOUT ANY WARRANTY; without even the implied warranty of | |
19 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
20 | * General Public License for more details. | |
21 | * | |
22 | * You should have received a copy of the GNU Lesser General Public | |
23 | * License along with this program; if not, see | |
24 | * http://www.gnu.org/licenses/, or write to the Free Software | |
25 | * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA | |
26 | * 02110-1301 USA | |
27 | * | |
28 | * @author Kevin Lamonte [kevin.lamonte@gmail.com] | |
29 | * @version 1 | |
30 | */ | |
31 | package jexer.net; | |
32 | ||
33 | import java.io.InputStream; | |
34 | import java.io.IOException; | |
9b1afdde | 35 | import java.util.ArrayList; |
ea91242c KL |
36 | import java.util.Map; |
37 | import java.util.TreeMap; | |
38 | ||
39 | import jexer.session.SessionInfo; | |
40 | import static jexer.net.TelnetSocket.*; | |
41 | ||
42 | /** | |
43 | * TelnetInputStream works with TelnetSocket to perform the telnet protocol. | |
44 | */ | |
9b1afdde KL |
45 | public final class TelnetInputStream extends InputStream |
46 | implements SessionInfo { | |
ea91242c KL |
47 | |
48 | /** | |
49 | * The root TelnetSocket that has my telnet protocol state. | |
50 | */ | |
51 | private TelnetSocket master; | |
52 | ||
53 | /** | |
54 | * The raw socket's InputStream. | |
55 | */ | |
56 | private InputStream input; | |
57 | ||
005ec497 KL |
58 | /** |
59 | * The telnet-aware OutputStream. | |
60 | */ | |
61 | private TelnetOutputStream output; | |
62 | ||
63 | /** | |
64 | * Persistent read buffer. In practice this will only be used if the | |
65 | * single-byte read() is called sometime. | |
66 | */ | |
67 | private byte [] readBuffer; | |
68 | ||
69 | /** | |
70 | * Current writing position in readBuffer - what is passed into | |
71 | * input.read(). | |
72 | */ | |
73 | private int readBufferEnd; | |
74 | ||
75 | /** | |
76 | * Current read position in readBuffer - what is passed to the client in | |
77 | * response to this.read(). | |
78 | */ | |
79 | private int readBufferStart; | |
80 | ||
ea91242c KL |
81 | /** |
82 | * Package private constructor. | |
83 | * | |
84 | * @param master the master TelnetSocket | |
85 | * @param input the underlying socket's InputStream | |
005ec497 | 86 | * @param output the telnet-aware OutputStream |
ea91242c | 87 | */ |
005ec497 KL |
88 | TelnetInputStream(final TelnetSocket master, final InputStream input, |
89 | final TelnetOutputStream output) { | |
90 | ||
ea91242c KL |
91 | this.master = master; |
92 | this.input = input; | |
005ec497 KL |
93 | this.output = output; |
94 | ||
95 | // Setup new read buffer | |
96 | readBuffer = new byte[1024]; | |
97 | readBufferStart = 0; | |
98 | readBufferEnd = 0; | |
9b1afdde | 99 | subnegBuffer = new ArrayList<Byte>(); |
ea91242c KL |
100 | } |
101 | ||
102 | // SessionInfo interface -------------------------------------------------- | |
103 | ||
104 | /** | |
105 | * User name. | |
106 | */ | |
107 | private String username = ""; | |
108 | ||
109 | /** | |
110 | * Language. | |
111 | */ | |
112 | private String language = "en_US"; | |
113 | ||
114 | /** | |
115 | * Text window width. | |
116 | */ | |
117 | private int windowWidth = 80; | |
118 | ||
119 | /** | |
120 | * Text window height. | |
121 | */ | |
122 | private int windowHeight = 24; | |
123 | ||
124 | /** | |
125 | * Username getter. | |
126 | * | |
127 | * @return the username | |
128 | */ | |
129 | public String getUsername() { | |
130 | return this.username; | |
131 | } | |
132 | ||
133 | /** | |
134 | * Username setter. | |
135 | * | |
136 | * @param username the value | |
137 | */ | |
138 | public void setUsername(final String username) { | |
139 | this.username = username; | |
140 | } | |
141 | ||
142 | /** | |
143 | * Language getter. | |
144 | * | |
145 | * @return the language | |
146 | */ | |
147 | public String getLanguage() { | |
148 | return this.language; | |
149 | } | |
150 | ||
151 | /** | |
152 | * Language setter. | |
153 | * | |
154 | * @param language the value | |
155 | */ | |
156 | public void setLanguage(final String language) { | |
157 | this.language = language; | |
158 | } | |
159 | ||
160 | /** | |
161 | * Text window width getter. | |
162 | * | |
163 | * @return the window width | |
164 | */ | |
165 | public int getWindowWidth() { | |
166 | return windowWidth; | |
167 | } | |
168 | ||
169 | /** | |
170 | * Text window height getter. | |
171 | * | |
172 | * @return the window height | |
173 | */ | |
174 | public int getWindowHeight() { | |
175 | return windowHeight; | |
176 | } | |
177 | ||
178 | /** | |
179 | * Re-query the text window size. | |
180 | */ | |
181 | public void queryWindowSize() { | |
182 | // NOP | |
183 | } | |
184 | ||
185 | // InputStream interface -------------------------------------------------- | |
186 | ||
187 | /** | |
188 | * Returns an estimate of the number of bytes that can be read (or | |
189 | * skipped over) from this input stream without blocking by the next | |
190 | * invocation of a method for this input stream. | |
191 | * | |
9b1afdde KL |
192 | * @return an estimate of the number of bytes that can be read (or |
193 | * skipped over) from this input stream without blocking or 0 when it | |
194 | * reaches the end of the input stream. | |
195 | * @throws IOException if an I/O error occurs | |
ea91242c KL |
196 | */ |
197 | @Override | |
198 | public int available() throws IOException { | |
005ec497 KL |
199 | if (readBuffer == null) { |
200 | throw new IOException("InputStream is closed"); | |
201 | } | |
202 | if (readBufferEnd - readBufferStart > 0) { | |
203 | return (readBufferEnd - readBufferStart); | |
204 | } | |
205 | return input.available(); | |
ea91242c KL |
206 | } |
207 | ||
208 | /** | |
209 | * Closes this input stream and releases any system resources associated | |
210 | * with the stream. | |
9b1afdde KL |
211 | * |
212 | * @throws IOException if an I/O error occurs | |
ea91242c KL |
213 | */ |
214 | @Override | |
215 | public void close() throws IOException { | |
005ec497 KL |
216 | if (readBuffer != null) { |
217 | readBuffer = null; | |
218 | input.close(); | |
219 | } | |
ea91242c KL |
220 | } |
221 | ||
222 | /** | |
223 | * Marks the current position in this input stream. | |
9b1afdde KL |
224 | * |
225 | * @param readLimit the maximum limit of bytes that can be read before | |
226 | * the mark position becomes invalid | |
ea91242c KL |
227 | */ |
228 | @Override | |
9b1afdde | 229 | public void mark(final int readLimit) { |
005ec497 | 230 | // Do nothing |
ea91242c KL |
231 | } |
232 | ||
233 | /** | |
234 | * Tests if this input stream supports the mark and reset methods. | |
9b1afdde KL |
235 | * |
236 | * @return true if this stream instance supports the mark and reset | |
237 | * methods; false otherwise | |
ea91242c KL |
238 | */ |
239 | @Override | |
240 | public boolean markSupported() { | |
241 | return false; | |
242 | } | |
243 | ||
244 | /** | |
245 | * Reads the next byte of data from the input stream. | |
9b1afdde KL |
246 | * |
247 | * @return the next byte of data, or -1 if there is no more data because | |
248 | * the end of the stream has been reached. | |
249 | * @throws IOException if an I/O error occurs | |
ea91242c KL |
250 | */ |
251 | @Override | |
252 | public int read() throws IOException { | |
005ec497 KL |
253 | |
254 | // If the post-processed buffer has bytes, use that. | |
255 | if (readBufferEnd - readBufferStart > 0) { | |
256 | readBufferStart++; | |
257 | return readBuffer[readBufferStart - 1]; | |
258 | } | |
259 | ||
260 | // The buffer is empty, so reset the indexes to 0. | |
261 | readBufferStart = 0; | |
262 | readBufferEnd = 0; | |
263 | ||
264 | // Read some fresh data and run it through the telnet protocol. | |
265 | int rc = readImpl(readBuffer, readBufferEnd, | |
266 | readBuffer.length - readBufferEnd); | |
267 | ||
268 | // If we got something, return it. | |
269 | if (rc > 0) { | |
270 | readBufferStart++; | |
271 | return readBuffer[readBufferStart - 1]; | |
272 | } | |
273 | // If we read 0, I screwed up big time. | |
274 | assert (rc != 0); | |
275 | ||
276 | // We read -1 (EOF). | |
277 | return rc; | |
ea91242c KL |
278 | } |
279 | ||
280 | /** | |
281 | * Reads some number of bytes from the input stream and stores them into | |
282 | * the buffer array b. | |
9b1afdde KL |
283 | * |
284 | * @param b the buffer into which the data is read. | |
285 | * @return the total number of bytes read into the buffer, or -1 if there | |
286 | * is no more data because the end of the stream has been reached. | |
287 | * @throws IOException if an I/O error occurs | |
ea91242c KL |
288 | */ |
289 | @Override | |
9b1afdde | 290 | public int read(final byte[] b) throws IOException { |
005ec497 | 291 | return read(b, 0, b.length); |
ea91242c KL |
292 | } |
293 | ||
294 | /** | |
295 | * Reads up to len bytes of data from the input stream into an array of | |
296 | * bytes. | |
9b1afdde KL |
297 | * |
298 | * @param b the buffer into which the data is read. | |
299 | * @param off the start offset in array b at which the data is written. | |
300 | * @param len the maximum number of bytes to read. | |
301 | * @return the total number of bytes read into the buffer, or -1 if there | |
302 | * is no more data because the end of the stream has been reached. | |
303 | * @throws IOException if an I/O error occurs | |
ea91242c KL |
304 | */ |
305 | @Override | |
9b1afdde KL |
306 | public int read(final byte[] b, final int off, |
307 | final int len) throws IOException { | |
308 | ||
005ec497 KL |
309 | // The only time we can return 0 is if len is 0, as per the |
310 | // InputStream contract. | |
311 | if (len == 0) { | |
312 | return 0; | |
313 | } | |
314 | ||
315 | // If the post-processed buffer has bytes, use that. | |
316 | if (readBufferEnd - readBufferStart > 0) { | |
317 | int n = Math.min(len, readBufferEnd - readBufferStart); | |
318 | System.arraycopy(b, off, readBuffer, readBufferStart, n); | |
319 | readBufferStart += n; | |
320 | return n; | |
321 | } | |
322 | ||
323 | // The buffer is empty, so reset the indexes to 0. | |
324 | readBufferStart = 0; | |
325 | readBufferEnd = 0; | |
326 | ||
327 | // The maximum number of bytes we will ask for will definitely be | |
328 | // within the bounds of what we can return in a single call. | |
329 | int n = Math.min(len, readBuffer.length); | |
330 | ||
331 | // Read some fresh data and run it through the telnet protocol. | |
332 | int rc = readImpl(readBuffer, readBufferEnd, n); | |
333 | ||
334 | // If we got something, return it. | |
335 | if (rc > 0) { | |
9b1afdde | 336 | System.arraycopy(readBuffer, 0, b, off, rc); |
005ec497 KL |
337 | return rc; |
338 | } | |
339 | // If we read 0, I screwed up big time. | |
340 | assert (rc != 0); | |
341 | ||
342 | // We read -1 (EOF). | |
343 | return rc; | |
ea91242c KL |
344 | } |
345 | ||
346 | /** | |
347 | * Repositions this stream to the position at the time the mark method | |
9b1afdde KL |
348 | * was last called on this input stream. This is not supported by |
349 | * TelnetInputStream, so IOException is always thrown. | |
350 | * | |
351 | * @throws IOException if this function is used | |
ea91242c KL |
352 | */ |
353 | @Override | |
354 | public void reset() throws IOException { | |
005ec497 | 355 | throw new IOException("InputStream does not support mark/reset"); |
ea91242c KL |
356 | } |
357 | ||
358 | /** | |
359 | * Skips over and discards n bytes of data from this input stream. | |
9b1afdde KL |
360 | * |
361 | * @param n the number of bytes to be skipped | |
362 | * @return the actual number of bytes skipped | |
363 | * @throws IOException if an I/O error occurs | |
ea91242c KL |
364 | */ |
365 | @Override | |
9b1afdde | 366 | public long skip(final long n) throws IOException { |
005ec497 KL |
367 | if (n < 0) { |
368 | return 0; | |
369 | } | |
370 | for (int i = 0; i < n; i++) { | |
371 | read(); | |
372 | } | |
373 | return n; | |
ea91242c KL |
374 | } |
375 | ||
ea91242c KL |
376 | // Telnet protocol -------------------------------------------------------- |
377 | ||
9b1afdde KL |
378 | |
379 | /** | |
380 | * When true, the last read byte from the remote side was IAC. | |
381 | */ | |
382 | private boolean iac = false; | |
383 | ||
384 | /** | |
385 | * When true, we are in the middle of a DO/DONT/WILL/WONT negotiation. | |
386 | */ | |
387 | private boolean dowill = false; | |
388 | ||
389 | /** | |
390 | * The telnet option being negotiated. | |
391 | */ | |
392 | private int dowillType = 0; | |
393 | ||
394 | /** | |
395 | * When true, we are waiting to see the end of the sub-negotiation | |
396 | * sequence. | |
397 | */ | |
398 | private boolean subnegEnd = false; | |
399 | ||
400 | /** | |
401 | * When true, the last byte read from the remote side was CR. | |
402 | */ | |
403 | private boolean readCR = false; | |
404 | ||
ea91242c KL |
405 | /** |
406 | * The subnegotiation buffer. | |
407 | */ | |
9b1afdde | 408 | private ArrayList<Byte> subnegBuffer; |
ea91242c KL |
409 | |
410 | /** | |
411 | * For debugging, return a descriptive string for this telnet option. | |
412 | * These are pulled from: http://www.iana.org/assignments/telnet-options | |
413 | * | |
9b1afdde | 414 | * @param option the telnet option byte |
ea91242c KL |
415 | * @return a string describing the telnet option code |
416 | */ | |
0d47c546 | 417 | @SuppressWarnings("unused") |
ea91242c KL |
418 | private String optionString(final int option) { |
419 | switch (option) { | |
420 | case 0: return "Binary Transmission"; | |
421 | case 1: return "Echo"; | |
422 | case 2: return "Reconnection"; | |
423 | case 3: return "Suppress Go Ahead"; | |
424 | case 4: return "Approx Message Size Negotiation"; | |
425 | case 5: return "Status"; | |
426 | case 6: return "Timing Mark"; | |
427 | case 7: return "Remote Controlled Trans and Echo"; | |
428 | case 8: return "Output Line Width"; | |
429 | case 9: return "Output Page Size"; | |
430 | case 10: return "Output Carriage-Return Disposition"; | |
431 | case 11: return "Output Horizontal Tab Stops"; | |
432 | case 12: return "Output Horizontal Tab Disposition"; | |
433 | case 13: return "Output Formfeed Disposition"; | |
434 | case 14: return "Output Vertical Tabstops"; | |
435 | case 15: return "Output Vertical Tab Disposition"; | |
436 | case 16: return "Output Linefeed Disposition"; | |
437 | case 17: return "Extended ASCII"; | |
438 | case 18: return "Logout"; | |
439 | case 19: return "Byte Macro"; | |
440 | case 20: return "Data Entry Terminal"; | |
441 | case 21: return "SUPDUP"; | |
442 | case 22: return "SUPDUP Output"; | |
443 | case 23: return "Send Location"; | |
444 | case 24: return "Terminal Type"; | |
445 | case 25: return "End of Record"; | |
446 | case 26: return "TACACS User Identification"; | |
447 | case 27: return "Output Marking"; | |
448 | case 28: return "Terminal Location Number"; | |
449 | case 29: return "Telnet 3270 Regime"; | |
450 | case 30: return "X.3 PAD"; | |
451 | case 31: return "Negotiate About Window Size"; | |
452 | case 32: return "Terminal Speed"; | |
453 | case 33: return "Remote Flow Control"; | |
454 | case 34: return "Linemode"; | |
455 | case 35: return "X Display Location"; | |
456 | case 36: return "Environment Option"; | |
457 | case 37: return "Authentication Option"; | |
458 | case 38: return "Encryption Option"; | |
459 | case 39: return "New Environment Option"; | |
460 | case 40: return "TN3270E"; | |
461 | case 41: return "XAUTH"; | |
462 | case 42: return "CHARSET"; | |
463 | case 43: return "Telnet Remote Serial Port (RSP)"; | |
464 | case 44: return "Com Port Control Option"; | |
465 | case 45: return "Telnet Suppress Local Echo"; | |
466 | case 46: return "Telnet Start TLS"; | |
467 | case 47: return "KERMIT"; | |
468 | case 48: return "SEND-URL"; | |
469 | case 49: return "FORWARD_X"; | |
470 | case 138: return "TELOPT PRAGMA LOGON"; | |
471 | case 139: return "TELOPT SSPI LOGON"; | |
472 | case 140: return "TELOPT PRAGMA HEARTBEAT"; | |
473 | case 255: return "Extended-Options-List"; | |
474 | default: | |
475 | if ((option >= 50) && (option <= 137)) { | |
476 | return "Unassigned"; | |
477 | } | |
478 | return "UNKNOWN - OTHER"; | |
479 | } | |
480 | } | |
481 | ||
482 | /** | |
483 | * Send a DO/DON'T/WILL/WON'T response to the remote side. | |
484 | * | |
485 | * @param response a TELNET_DO/DONT/WILL/WONT byte | |
486 | * @param option telnet option byte (binary mode, term type, etc.) | |
9b1afdde | 487 | * @throws IOException if an I/O error occurs |
ea91242c KL |
488 | */ |
489 | private void respond(final int response, | |
490 | final int option) throws IOException { | |
491 | ||
492 | byte [] buffer = new byte[3]; | |
493 | buffer[0] = (byte)TELNET_IAC; | |
494 | buffer[1] = (byte)response; | |
495 | buffer[2] = (byte)option; | |
496 | ||
005ec497 | 497 | output.rawWrite(buffer); |
ea91242c KL |
498 | } |
499 | ||
500 | /** | |
501 | * Tell the remote side we WILL support an option. | |
502 | * | |
503 | * @param option telnet option byte (binary mode, term type, etc.) | |
9b1afdde | 504 | * @throws IOException if an I/O error occurs |
ea91242c KL |
505 | */ |
506 | private void WILL(final int option) throws IOException { | |
507 | respond(TELNET_WILL, option); | |
508 | } | |
509 | ||
510 | /** | |
511 | * Tell the remote side we WON'T support an option. | |
512 | * | |
513 | * @param option telnet option byte (binary mode, term type, etc.) | |
9b1afdde | 514 | * @throws IOException if an I/O error occurs |
ea91242c KL |
515 | */ |
516 | private void WONT(final int option) throws IOException { | |
517 | respond(TELNET_WONT, option); | |
518 | } | |
519 | ||
520 | /** | |
521 | * Tell the remote side we DO support an option. | |
522 | * | |
523 | * @param option telnet option byte (binary mode, term type, etc.) | |
9b1afdde | 524 | * @throws IOException if an I/O error occurs |
ea91242c KL |
525 | */ |
526 | private void DO(final int option) throws IOException { | |
527 | respond(TELNET_DO, option); | |
528 | } | |
529 | ||
530 | /** | |
531 | * Tell the remote side we DON'T support an option. | |
532 | * | |
533 | * @param option telnet option byte (binary mode, term type, etc.) | |
9b1afdde | 534 | * @throws IOException if an I/O error occurs |
ea91242c KL |
535 | */ |
536 | private void DONT(final int option) throws IOException { | |
537 | respond(TELNET_DONT, option); | |
538 | } | |
539 | ||
540 | /** | |
541 | * Tell the remote side we WON't or DON'T support an option. | |
542 | * | |
543 | * @param remoteQuery a TELNET_DO/DONT/WILL/WONT byte | |
544 | * @param option telnet option byte (binary mode, term type, etc.) | |
9b1afdde | 545 | * @throws IOException if an I/O error occurs |
ea91242c KL |
546 | */ |
547 | private void refuse(final int remoteQuery, | |
548 | final int option) throws IOException { | |
549 | ||
550 | if (remoteQuery == TELNET_DO) { | |
551 | WONT(option); | |
552 | } else { | |
553 | DONT(option); | |
554 | } | |
555 | } | |
556 | ||
557 | /** | |
9b1afdde | 558 | * Build sub-negotiation packet (RFC 855). |
ea91242c KL |
559 | * |
560 | * @param option telnet option | |
561 | * @param response output buffer of response bytes | |
9b1afdde | 562 | * @throws IOException if an I/O error occurs |
ea91242c KL |
563 | */ |
564 | private void telnetSendSubnegResponse(final int option, | |
565 | final byte [] response) throws IOException { | |
566 | ||
567 | byte [] buffer = new byte[response.length + 5]; | |
568 | buffer[0] = (byte)TELNET_IAC; | |
569 | buffer[1] = (byte)TELNET_SB; | |
570 | buffer[2] = (byte)option; | |
571 | System.arraycopy(response, 0, buffer, 3, response.length); | |
572 | buffer[response.length + 3] = (byte)TELNET_IAC; | |
573 | buffer[response.length + 4] = (byte)TELNET_SE; | |
005ec497 | 574 | output.rawWrite(buffer); |
ea91242c KL |
575 | } |
576 | ||
577 | /** | |
578 | * Telnet option: Terminal Speed (RFC 1079). Client side. | |
9b1afdde KL |
579 | * |
580 | * @throws IOException if an I/O error occurs | |
ea91242c KL |
581 | */ |
582 | private void telnetSendTerminalSpeed() throws IOException { | |
583 | byte [] response = {0, '3', '8', '4', '0', '0', ',', | |
584 | '3', '8', '4', '0', '0'}; | |
585 | telnetSendSubnegResponse(32, response); | |
586 | } | |
587 | ||
588 | /** | |
589 | * Telnet option: Terminal Type (RFC 1091). Client side. | |
9b1afdde KL |
590 | * |
591 | * @throws IOException if an I/O error occurs | |
ea91242c KL |
592 | */ |
593 | private void telnetSendTerminalType() throws IOException { | |
594 | byte [] response = {0, 'v', 't', '1', '0', '0' }; | |
595 | telnetSendSubnegResponse(24, response); | |
596 | } | |
597 | ||
598 | /** | |
599 | * Telnet option: Terminal Type (RFC 1091). Server side. | |
9b1afdde KL |
600 | * |
601 | * @throws IOException if an I/O error occurs | |
ea91242c KL |
602 | */ |
603 | private void requestTerminalType() throws IOException { | |
604 | byte [] response = new byte[1]; | |
605 | response[0] = 1; | |
606 | telnetSendSubnegResponse(24, response); | |
607 | } | |
608 | ||
609 | /** | |
610 | * Telnet option: Terminal Speed (RFC 1079). Server side. | |
9b1afdde KL |
611 | * |
612 | * @throws IOException if an I/O error occurs | |
ea91242c KL |
613 | */ |
614 | private void requestTerminalSpeed() throws IOException { | |
615 | byte [] response = new byte[1]; | |
616 | response[0] = 1; | |
617 | telnetSendSubnegResponse(32, response); | |
618 | } | |
619 | ||
620 | /** | |
621 | * Telnet option: New Environment (RFC 1572). Server side. | |
9b1afdde KL |
622 | * |
623 | * @throws IOException if an I/O error occurs | |
ea91242c KL |
624 | */ |
625 | private void requestEnvironment() throws IOException { | |
626 | byte [] response = new byte[1]; | |
627 | response[0] = 1; | |
628 | telnetSendSubnegResponse(39, response); | |
629 | } | |
630 | ||
631 | /** | |
9b1afdde KL |
632 | * Send the options we want to negotiate on. |
633 | * | |
634 | * <p>The options we use are: | |
635 | * | |
636 | * <p> | |
637 | * <pre> | |
ea91242c KL |
638 | * Binary Transmission RFC 856 |
639 | * Suppress Go Ahead RFC 858 | |
640 | * Negotiate About Window Size RFC 1073 | |
641 | * Terminal Type RFC 1091 | |
642 | * Terminal Speed RFC 1079 | |
643 | * New Environment RFC 1572 | |
644 | * | |
645 | * When run as a server: | |
9b1afdde KL |
646 | * Echo RFC 857 |
647 | * </pre> | |
648 | * | |
649 | * @throws IOException if an I/O error occurs | |
ea91242c | 650 | */ |
005ec497 | 651 | void telnetSendOptions() throws IOException { |
9b1afdde | 652 | if (master.binaryMode == false) { |
ea91242c KL |
653 | // Binary Transmission: must ask both do and will |
654 | DO(0); | |
655 | WILL(0); | |
656 | } | |
657 | ||
9b1afdde | 658 | if (master.goAhead == true) { |
ea91242c KL |
659 | // Suppress Go Ahead |
660 | DO(3); | |
661 | WILL(3); | |
662 | } | |
663 | ||
664 | // Server only options | |
9b1afdde | 665 | if (master.isServer == true) { |
ea91242c KL |
666 | // Enable Echo - I echo to them, they do not echo back to me. |
667 | DONT(1); | |
668 | WILL(1); | |
669 | ||
9b1afdde | 670 | if (master.doTermType == true) { |
ea91242c KL |
671 | // Terminal type - request it |
672 | DO(24); | |
673 | } | |
674 | ||
9b1afdde | 675 | if (master.doTermSpeed == true) { |
ea91242c KL |
676 | // Terminal speed - request it |
677 | DO(32); | |
678 | } | |
679 | ||
9b1afdde | 680 | if (master.doNAWS == true) { |
ea91242c KL |
681 | // NAWS - request it |
682 | DO(31); | |
683 | } | |
684 | ||
9b1afdde | 685 | if (master.doEnvironment == true) { |
ea91242c KL |
686 | // Environment - request it |
687 | DO(39); | |
688 | } | |
689 | ||
690 | } else { | |
691 | ||
9b1afdde | 692 | if (master.doTermType == true) { |
ea91242c KL |
693 | // Terminal type - request it |
694 | WILL(24); | |
695 | } | |
696 | ||
9b1afdde | 697 | if (master.doTermSpeed == true) { |
ea91242c KL |
698 | // Terminal speed - request it |
699 | WILL(32); | |
700 | } | |
701 | ||
9b1afdde | 702 | if (master.doNAWS == true) { |
ea91242c KL |
703 | // NAWS - request it |
704 | WILL(31); | |
705 | } | |
706 | ||
9b1afdde | 707 | if (master.doEnvironment == true) { |
ea91242c KL |
708 | // Environment - request it |
709 | WILL(39); | |
710 | } | |
ea91242c | 711 | } |
9b1afdde KL |
712 | |
713 | // Push it all out | |
714 | output.flush(); | |
ea91242c KL |
715 | } |
716 | ||
717 | /** | |
718 | * New Environment parsing state. | |
719 | */ | |
720 | private enum EnvState { | |
721 | INIT, | |
722 | TYPE, | |
723 | NAME, | |
724 | VALUE | |
725 | } | |
726 | ||
727 | /** | |
728 | * Handle the New Environment option. Note that this implementation | |
729 | * fails to handle ESC as defined in RFC 1572. | |
730 | */ | |
731 | private void handleNewEnvironment() { | |
9b1afdde KL |
732 | Map<StringBuilder, StringBuilder> newEnv = |
733 | new TreeMap<StringBuilder, StringBuilder>(); | |
734 | ||
ea91242c KL |
735 | EnvState state = EnvState.INIT; |
736 | StringBuilder name = new StringBuilder(); | |
737 | StringBuilder value = new StringBuilder(); | |
738 | ||
9b1afdde KL |
739 | for (int i = 0; i < subnegBuffer.size(); i++) { |
740 | Byte b = subnegBuffer.get(i); | |
ea91242c KL |
741 | |
742 | switch (state) { | |
743 | ||
744 | case INIT: | |
745 | // Looking for "IS" | |
746 | if (b == 0) { | |
747 | state = EnvState.TYPE; | |
748 | } else { | |
749 | // The other side isn't following the rules, see ya. | |
750 | return; | |
751 | } | |
752 | break; | |
753 | ||
754 | case TYPE: | |
755 | // Looking for "VAR" or "USERVAR" | |
756 | if (b == 0) { | |
757 | // VAR | |
758 | state = EnvState.NAME; | |
759 | name = new StringBuilder(); | |
760 | } else if (b == 3) { | |
761 | // USERVAR | |
762 | state = EnvState.NAME; | |
763 | name = new StringBuilder(); | |
764 | } else { | |
765 | // The other side isn't following the rules, see ya | |
766 | return; | |
767 | } | |
768 | break; | |
769 | ||
770 | case NAME: | |
771 | // Looking for "VALUE" or a name byte | |
772 | if (b == 1) { | |
773 | // VALUE | |
774 | state = EnvState.VALUE; | |
775 | value = new StringBuilder(); | |
776 | } else { | |
777 | // Take it as an environment variable name/key byte | |
9b1afdde | 778 | name.append((char)b.byteValue()); |
ea91242c KL |
779 | } |
780 | ||
781 | break; | |
782 | ||
783 | case VALUE: | |
784 | // Looking for "VAR", "USERVAR", or a name byte, or the end | |
785 | if (b == 0) { | |
786 | // VAR | |
787 | state = EnvState.NAME; | |
788 | if (value.length() > 0) { | |
789 | newEnv.put(name, value); | |
790 | } | |
791 | name = new StringBuilder(); | |
792 | } else if (b == 3) { | |
793 | // USERVAR | |
794 | state = EnvState.NAME; | |
795 | if (value.length() > 0) { | |
796 | newEnv.put(name, value); | |
797 | } | |
798 | name = new StringBuilder(); | |
799 | } else { | |
800 | // Take it as an environment variable value byte | |
9b1afdde | 801 | value.append((char)b.byteValue()); |
ea91242c KL |
802 | } |
803 | break; | |
9b1afdde KL |
804 | |
805 | default: | |
806 | throw new RuntimeException("Invalid state: " + state); | |
807 | ||
ea91242c KL |
808 | } |
809 | } | |
810 | ||
811 | if ((name.length() > 0) && (value.length() > 0)) { | |
812 | newEnv.put(name, value); | |
813 | } | |
814 | ||
815 | for (StringBuilder key: newEnv.keySet()) { | |
816 | if (key.equals("LANG")) { | |
817 | language = newEnv.get(key).toString(); | |
818 | } | |
819 | if (key.equals("LOGNAME")) { | |
820 | username = newEnv.get(key).toString(); | |
821 | } | |
822 | if (key.equals("USER")) { | |
823 | username = newEnv.get(key).toString(); | |
824 | } | |
825 | } | |
826 | } | |
827 | ||
828 | /** | |
829 | * Handle an option sub-negotiation. | |
9b1afdde KL |
830 | * |
831 | * @throws IOException if an I/O error occurs | |
ea91242c KL |
832 | */ |
833 | private void handleSubneg() throws IOException { | |
9b1afdde | 834 | Byte option; |
ea91242c KL |
835 | |
836 | // Sanity check: there must be at least 1 byte in subnegBuffer | |
9b1afdde | 837 | if (subnegBuffer.size() < 1) { |
ea91242c KL |
838 | // Buffer too small: the other side is a broken telnetd, it did |
839 | // not send the right sub-negotiation data. Bail out now. | |
840 | return; | |
841 | } | |
9b1afdde | 842 | option = subnegBuffer.get(0); |
ea91242c KL |
843 | |
844 | switch (option) { | |
845 | ||
846 | case 24: | |
847 | // Terminal Type | |
9b1afdde | 848 | if ((subnegBuffer.size() > 1) && (subnegBuffer.get(1) == 1)) { |
ea91242c KL |
849 | // Server sent "SEND", we say "IS" |
850 | telnetSendTerminalType(); | |
851 | } | |
9b1afdde | 852 | if ((subnegBuffer.size() > 1) && (subnegBuffer.get(1) == 0)) { |
ea91242c KL |
853 | // Client sent "IS", record it |
854 | StringBuilder terminalString = new StringBuilder(); | |
9b1afdde KL |
855 | for (int i = 2; i < subnegBuffer.size(); i++) { |
856 | terminalString.append((char)subnegBuffer. | |
857 | get(i).byteValue()); | |
ea91242c | 858 | } |
9b1afdde | 859 | master.terminalType = terminalString.toString(); |
ea91242c KL |
860 | } |
861 | break; | |
862 | ||
863 | case 32: | |
864 | // Terminal Speed | |
9b1afdde | 865 | if ((subnegBuffer.size() > 1) && (subnegBuffer.get(1) == 1)) { |
ea91242c KL |
866 | // Server sent "SEND", we say "IS" |
867 | telnetSendTerminalSpeed(); | |
868 | } | |
9b1afdde | 869 | if ((subnegBuffer.size() > 1) && (subnegBuffer.get(1) == 0)) { |
ea91242c KL |
870 | // Client sent "IS", record it |
871 | StringBuilder speedString = new StringBuilder(); | |
9b1afdde KL |
872 | for (int i = 2; i < subnegBuffer.size(); i++) { |
873 | speedString.append((char)subnegBuffer.get(i).byteValue()); | |
ea91242c | 874 | } |
9b1afdde | 875 | master.terminalSpeed = speedString.toString(); |
ea91242c KL |
876 | } |
877 | break; | |
878 | ||
879 | case 31: | |
880 | // NAWS | |
9b1afdde | 881 | if (subnegBuffer.size() >= 5) { |
ea91242c KL |
882 | int i = 0; |
883 | ||
884 | i++; | |
9b1afdde | 885 | if (subnegBuffer.get(i) == (byte)TELNET_IAC) { |
ea91242c KL |
886 | i++; |
887 | } | |
9b1afdde | 888 | windowWidth = subnegBuffer.get(i) * 256; |
ea91242c KL |
889 | |
890 | i++; | |
9b1afdde | 891 | if (subnegBuffer.get(i) == (byte)TELNET_IAC) { |
ea91242c KL |
892 | i++; |
893 | } | |
9b1afdde | 894 | windowWidth += subnegBuffer.get(i); |
ea91242c KL |
895 | |
896 | i++; | |
9b1afdde | 897 | if (subnegBuffer.get(i) == (byte)TELNET_IAC) { |
ea91242c KL |
898 | i++; |
899 | } | |
9b1afdde | 900 | windowHeight = subnegBuffer.get(i) * 256; |
ea91242c KL |
901 | |
902 | i++; | |
9b1afdde | 903 | if (subnegBuffer.get(i) == (byte)TELNET_IAC) { |
ea91242c KL |
904 | i++; |
905 | } | |
9b1afdde | 906 | windowHeight += subnegBuffer.get(i); |
ea91242c KL |
907 | } |
908 | break; | |
909 | ||
910 | case 39: | |
911 | // Environment | |
912 | handleNewEnvironment(); | |
913 | break; | |
914 | ||
915 | default: | |
916 | // Ignore this one | |
917 | break; | |
918 | } | |
919 | } | |
920 | ||
005ec497 KL |
921 | /** |
922 | * Reads up to len bytes of data from the input stream into an array of | |
923 | * bytes. | |
9b1afdde KL |
924 | * |
925 | * @param buf the buffer into which the data is read. | |
926 | * @param off the start offset in array b at which the data is written. | |
927 | * @param len the maximum number of bytes to read. | |
928 | * @return the total number of bytes read into the buffer, or -1 if there | |
929 | * is no more data because the end of the stream has been reached. | |
930 | * @throws IOException if an I/O error occurs | |
005ec497 | 931 | */ |
9b1afdde KL |
932 | private int readImpl(final byte[] buf, final int off, |
933 | final int len) throws IOException { | |
934 | ||
005ec497 | 935 | assert (len > 0); |
9b1afdde KL |
936 | |
937 | // The current writing position in buf. | |
938 | int bufN = 0; | |
939 | ||
940 | // We will keep trying to read() until we have something to return. | |
941 | do { | |
942 | ||
943 | // Read up to len bytes | |
944 | byte [] buffer = new byte[len]; | |
945 | int bufferN = 0; | |
946 | ||
947 | // Read some data from the other end | |
948 | int rc = input.read(buffer); | |
949 | ||
950 | // Check for EOF or error | |
951 | if (rc > 0) { | |
952 | // More data came in | |
953 | bufferN = rc; | |
954 | } else { | |
955 | // EOF, just return it. | |
956 | return rc; | |
957 | } | |
958 | ||
959 | // Loop through the read bytes | |
960 | for (int i = 0; i < bufferN; i++) { | |
961 | byte b = buffer[i]; | |
962 | ||
963 | if (subnegEnd == true) { | |
964 | // Looking for IAC SE to end this subnegotiation | |
965 | if (b == (byte)TELNET_SE) { | |
966 | if (iac == true) { | |
967 | iac = false; | |
968 | subnegEnd = false; | |
969 | handleSubneg(); | |
970 | } | |
971 | } else if (b == (byte)TELNET_IAC) { | |
972 | if (iac == true) { | |
973 | // An argument to the subnegotiation option | |
974 | subnegBuffer.add((byte)TELNET_IAC); | |
975 | } else { | |
976 | iac = true; | |
977 | } | |
978 | } else { | |
979 | // An argument to the subnegotiation option | |
980 | subnegBuffer.add(b); | |
981 | } | |
982 | continue; | |
983 | } | |
984 | ||
985 | // Look for DO/DON'T/WILL/WON'T option | |
986 | if (dowill == true) { | |
987 | ||
988 | // Look for option/ | |
989 | switch (b) { | |
990 | ||
991 | case 0: | |
992 | // Binary Transmission | |
993 | if (dowillType == (byte)TELNET_WILL) { | |
994 | // Server will use binary transmission, yay. | |
995 | master.binaryMode = true; | |
996 | } else if (dowillType == (byte)TELNET_DO) { | |
997 | // Server asks for binary transmission. | |
998 | WILL(b); | |
999 | master.binaryMode = true; | |
1000 | } else if (dowillType == (byte)TELNET_WONT) { | |
1001 | // We're screwed, server won't do binary | |
1002 | // transmission. | |
1003 | master.binaryMode = false; | |
1004 | } else { | |
1005 | // Server demands NVT ASCII mode. | |
1006 | master.binaryMode = false; | |
1007 | } | |
1008 | break; | |
1009 | ||
1010 | case 1: | |
1011 | // Echo | |
1012 | if (dowillType == (byte)TELNET_WILL) { | |
1013 | // Server will use echo, yay. | |
1014 | master.echoMode = true; | |
1015 | } else if (dowillType == (byte)TELNET_DO) { | |
1016 | // Server asks for echo. | |
1017 | WILL(b); | |
1018 | master.echoMode = true; | |
1019 | } else if (dowillType == (byte)TELNET_WONT) { | |
1020 | // We're screwed, server won't do echo. | |
1021 | master.echoMode = false; | |
1022 | } else { | |
1023 | // Server demands no echo. | |
1024 | master.echoMode = false; | |
1025 | } | |
1026 | break; | |
1027 | ||
1028 | case 3: | |
1029 | // Suppress Go Ahead | |
1030 | if (dowillType == (byte)TELNET_WILL) { | |
1031 | // Server will use suppress go-ahead, yay. | |
1032 | master.goAhead = false; | |
1033 | } else if (dowillType == (byte)TELNET_DO) { | |
1034 | // Server asks for suppress go-ahead. | |
1035 | WILL(b); | |
1036 | master.goAhead = false; | |
1037 | } else if (dowillType == (byte)TELNET_WONT) { | |
1038 | // We're screwed, server won't do suppress | |
1039 | // go-ahead. | |
1040 | master.goAhead = true; | |
1041 | } else { | |
1042 | // Server demands Go-Ahead mode. | |
1043 | master.goAhead = true; | |
1044 | } | |
1045 | break; | |
1046 | ||
1047 | case 24: | |
1048 | // Terminal Type - send what's in TERM | |
1049 | if (dowillType == (byte)TELNET_WILL) { | |
1050 | // Server will use terminal type, yay. | |
1051 | if (master.isServer | |
1052 | && master.doTermType | |
1053 | ) { | |
1054 | requestTerminalType(); | |
1055 | master.doTermType = false; | |
1056 | } else if (!master.isServer) { | |
1057 | master.doTermType = true; | |
1058 | } | |
1059 | } else if (dowillType == (byte)TELNET_DO) { | |
1060 | // Server asks for terminal type. | |
1061 | WILL(b); | |
1062 | master.doTermType = true; | |
1063 | } else if (dowillType == (byte)TELNET_WONT) { | |
1064 | // We're screwed, server won't do terminal type. | |
1065 | master.doTermType = false; | |
1066 | } else { | |
1067 | // Server will not listen to terminal type. | |
1068 | master.doTermType = false; | |
1069 | } | |
1070 | break; | |
1071 | ||
1072 | case 31: | |
1073 | // NAWS | |
1074 | if (dowillType == (byte)TELNET_WILL) { | |
1075 | // Server will use NAWS, yay. | |
1076 | master.doNAWS = true; | |
1077 | // NAWS cannot be requested by the server, it is | |
1078 | // only sent by the client. | |
1079 | } else if (dowillType == (byte)TELNET_DO) { | |
1080 | // Server asks for NAWS. | |
1081 | WILL(b); | |
1082 | master.doNAWS = true; | |
1083 | } else if (dowillType == (byte)TELNET_WONT) { | |
1084 | // Server won't do NAWS. | |
1085 | master.doNAWS = false; | |
1086 | } else { | |
1087 | // Server will not listen to NAWS. | |
1088 | master.doNAWS = false; | |
1089 | } | |
1090 | break; | |
1091 | ||
1092 | case 32: | |
1093 | // Terminal Speed | |
1094 | if (dowillType == (byte)TELNET_WILL) { | |
1095 | // Server will use terminal speed, yay. | |
1096 | if (master.isServer | |
1097 | && master.doTermSpeed | |
1098 | ) { | |
1099 | requestTerminalSpeed(); | |
1100 | master.doTermSpeed = false; | |
1101 | } else if (!master.isServer) { | |
1102 | master.doTermSpeed = true; | |
1103 | } | |
1104 | } else if (dowillType == (byte)TELNET_DO) { | |
1105 | // Server asks for terminal speed. | |
1106 | WILL(b); | |
1107 | master.doTermSpeed = true; | |
1108 | } else if (dowillType == (byte)TELNET_WONT) { | |
1109 | // We're screwed, server won't do terminal speed. | |
1110 | master.doTermSpeed = false; | |
1111 | } else { | |
1112 | // Server will not listen to terminal speed. | |
1113 | master.doTermSpeed = false; | |
1114 | } | |
1115 | break; | |
1116 | ||
1117 | case 39: | |
1118 | // New Environment | |
1119 | if (dowillType == (byte)TELNET_WILL) { | |
1120 | // Server will use NewEnvironment, yay. | |
1121 | if (master.isServer | |
1122 | && master.doEnvironment | |
1123 | ) { | |
1124 | requestEnvironment(); | |
1125 | master.doEnvironment = false; | |
1126 | } else if (!master.isServer) { | |
1127 | master.doEnvironment = true; | |
1128 | } | |
1129 | } else if (dowillType == (byte)TELNET_DO) { | |
1130 | // Server asks for NewEnvironment. | |
1131 | WILL(b); | |
1132 | master.doEnvironment = true; | |
1133 | } else if (dowillType == (byte)TELNET_WONT) { | |
1134 | // Server won't do NewEnvironment. | |
1135 | master.doEnvironment = false; | |
1136 | } else { | |
1137 | // Server will not listen to New Environment. | |
1138 | master.doEnvironment = false; | |
1139 | } | |
1140 | break; | |
1141 | ||
1142 | ||
1143 | default: | |
1144 | // Other side asked for something we don't | |
1145 | // understand. Tell them we will not do this option. | |
1146 | refuse(dowillType, b); | |
1147 | break; | |
1148 | } | |
1149 | ||
1150 | dowill = false; | |
1151 | continue; | |
1152 | } // if (dowill == true) | |
1153 | ||
1154 | // Perform read processing | |
1155 | if (b == (byte)TELNET_IAC) { | |
1156 | ||
1157 | // Telnet command | |
1158 | if (iac == true) { | |
1159 | // IAC IAC -> IAC | |
1160 | buf[bufN++] = (byte)TELNET_IAC; | |
1161 | iac = false; | |
1162 | } else { | |
1163 | iac = true; | |
1164 | } | |
1165 | continue; | |
1166 | } else { | |
1167 | if (iac == true) { | |
1168 | ||
1169 | switch (b) { | |
1170 | ||
1171 | case (byte)TELNET_SE: | |
1172 | // log.debug1(" END Sub-Negotiation"); | |
1173 | break; | |
1174 | case (byte)TELNET_NOP: | |
1175 | // log.debug1(" NOP"); | |
1176 | break; | |
1177 | case (byte)TELNET_DM: | |
1178 | // log.debug1(" Data Mark"); | |
1179 | break; | |
1180 | case (byte)TELNET_BRK: | |
1181 | // log.debug1(" Break"); | |
1182 | break; | |
1183 | case (byte)TELNET_IP: | |
1184 | // log.debug1(" Interrupt Process"); | |
1185 | break; | |
1186 | case (byte)TELNET_AO: | |
1187 | // log.debug1(" Abort Output"); | |
1188 | break; | |
1189 | case (byte)TELNET_AYT: | |
1190 | // log.debug1(" Are You There?"); | |
1191 | break; | |
1192 | case (byte)TELNET_EC: | |
1193 | // log.debug1(" Erase Character"); | |
1194 | break; | |
1195 | case (byte)TELNET_EL: | |
1196 | // log.debug1(" Erase Line"); | |
1197 | break; | |
1198 | case (byte)TELNET_GA: | |
1199 | // log.debug1(" Go Ahead"); | |
1200 | break; | |
1201 | case (byte)TELNET_SB: | |
1202 | // log.debug1(" START Sub-Negotiation"); | |
1203 | // From here we wait for the IAC SE | |
1204 | subnegEnd = true; | |
1205 | subnegBuffer.clear(); | |
1206 | break; | |
1207 | case (byte)TELNET_WILL: | |
1208 | // log.debug1(" WILL"); | |
1209 | dowill = true; | |
1210 | dowillType = b; | |
1211 | break; | |
1212 | case (byte)TELNET_WONT: | |
1213 | // log.debug1(" WON'T"); | |
1214 | dowill = true; | |
1215 | dowillType = b; | |
1216 | break; | |
1217 | case (byte)TELNET_DO: | |
1218 | // log.debug1(" DO"); | |
1219 | dowill = true; | |
1220 | dowillType = b; | |
1221 | ||
1222 | if (master.binaryMode == true) { | |
1223 | // log.debug1("Telnet DO in binary mode"); | |
1224 | } | |
1225 | ||
1226 | break; | |
1227 | case (byte)TELNET_DONT: | |
1228 | // log.debug1(" DON'T"); | |
1229 | dowill = true; | |
1230 | dowillType = b; | |
1231 | break; | |
1232 | default: | |
1233 | // This should be equivalent to IAC NOP | |
1234 | // log.debug1("Will treat as IAC NOP"); | |
1235 | break; | |
1236 | } | |
1237 | iac = false; | |
1238 | continue; | |
1239 | ||
1240 | } // if (iac == true) | |
1241 | ||
1242 | /* | |
1243 | * All of the regular IAC processing is completed at this | |
1244 | * point. Now we need to handle the CR and CR LF cases. | |
1245 | * | |
1246 | * According to RFC 854, in NVT ASCII mode: | |
1247 | * Bare CR -> CR NUL | |
1248 | * CR LF -> CR LF | |
1249 | * | |
1250 | */ | |
1251 | if (master.binaryMode == false) { | |
1252 | ||
1253 | if (b == C_LF) { | |
1254 | if (readCR == true) { | |
1255 | // This is CR LF. Send CR LF and turn the cr | |
1256 | // flag off. | |
1257 | buf[bufN++] = C_CR; | |
1258 | buf[bufN++] = C_LF; | |
1259 | readCR = false; | |
1260 | continue; | |
1261 | } | |
1262 | // This is bare LF. Send LF. | |
1263 | buf[bufN++] = C_LF; | |
1264 | continue; | |
1265 | } | |
1266 | ||
1267 | if (b == C_NUL) { | |
1268 | if (readCR == true) { | |
1269 | // This is CR NUL. Send CR and turn the cr | |
1270 | // flag off. | |
1271 | buf[bufN++] = C_CR; | |
1272 | readCR = false; | |
1273 | continue; | |
1274 | } | |
1275 | // This is bare NUL. Send NUL. | |
1276 | buf[bufN++] = C_NUL; | |
1277 | continue; | |
1278 | } | |
1279 | ||
1280 | if (b == C_CR) { | |
1281 | if (readCR == true) { | |
1282 | // This is CR CR. Send a CR NUL and leave | |
1283 | // the cr flag on. | |
1284 | buf[bufN++] = C_CR; | |
1285 | buf[bufN++] = C_NUL; | |
1286 | continue; | |
1287 | } | |
1288 | // This is the first CR. Set the cr flag. | |
1289 | readCR = true; | |
1290 | continue; | |
1291 | } | |
1292 | ||
1293 | if (readCR == true) { | |
1294 | // This was a bare CR in the stream. | |
1295 | buf[bufN++] = C_CR; | |
1296 | readCR = false; | |
1297 | } | |
1298 | ||
1299 | // This is a regular character. Pass it on. | |
1300 | buf[bufN++] = b; | |
1301 | continue; | |
1302 | } | |
1303 | ||
1304 | /* | |
1305 | * This is the case for any of: | |
1306 | * | |
1307 | * 1) A NVT ASCII character that isn't CR, LF, or | |
1308 | * NUL. | |
1309 | * | |
1310 | * 2) A NVT binary character. | |
1311 | * | |
1312 | * For all of these cases, we just pass the character on. | |
1313 | */ | |
1314 | buf[bufN++] = b; | |
1315 | ||
1316 | } // if (b == TELNET_IAC) | |
1317 | ||
1318 | } // for (int i = 0; i < bufferN; i++) | |
1319 | ||
1320 | } while (bufN == 0); | |
1321 | ||
1322 | // Return bytes read | |
1323 | return bufN; | |
005ec497 KL |
1324 | } |
1325 | ||
ea91242c KL |
1326 | |
1327 | } |