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daa4106c | 1 | /* |
ea91242c KL |
2 | * Jexer - Java Text User Interface |
3 | * | |
e16dda65 | 4 | * The MIT License (MIT) |
ea91242c | 5 | * |
e16dda65 | 6 | * Copyright (C) 2016 Kevin Lamonte |
ea91242c | 7 | * |
e16dda65 KL |
8 | * Permission is hereby granted, free of charge, to any person obtaining a |
9 | * copy of this software and associated documentation files (the "Software"), | |
10 | * to deal in the Software without restriction, including without limitation | |
11 | * the rights to use, copy, modify, merge, publish, distribute, sublicense, | |
12 | * and/or sell copies of the Software, and to permit persons to whom the | |
13 | * Software is furnished to do so, subject to the following conditions: | |
ea91242c | 14 | * |
e16dda65 KL |
15 | * The above copyright notice and this permission notice shall be included in |
16 | * all copies or substantial portions of the Software. | |
ea91242c | 17 | * |
e16dda65 KL |
18 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
19 | * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, | |
20 | * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL | |
21 | * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER | |
22 | * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING | |
23 | * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER | |
24 | * DEALINGS IN THE SOFTWARE. | |
ea91242c KL |
25 | * |
26 | * @author Kevin Lamonte [kevin.lamonte@gmail.com] | |
27 | * @version 1 | |
28 | */ | |
29 | package jexer.net; | |
30 | ||
31 | import java.io.InputStream; | |
32 | import java.io.IOException; | |
9b1afdde | 33 | import java.util.ArrayList; |
ea91242c KL |
34 | import java.util.Map; |
35 | import java.util.TreeMap; | |
36 | ||
37 | import jexer.session.SessionInfo; | |
38 | import static jexer.net.TelnetSocket.*; | |
39 | ||
40 | /** | |
41 | * TelnetInputStream works with TelnetSocket to perform the telnet protocol. | |
42 | */ | |
9b1afdde KL |
43 | public final class TelnetInputStream extends InputStream |
44 | implements SessionInfo { | |
ea91242c KL |
45 | |
46 | /** | |
47 | * The root TelnetSocket that has my telnet protocol state. | |
48 | */ | |
49 | private TelnetSocket master; | |
50 | ||
51 | /** | |
52 | * The raw socket's InputStream. | |
53 | */ | |
54 | private InputStream input; | |
55 | ||
005ec497 KL |
56 | /** |
57 | * The telnet-aware OutputStream. | |
58 | */ | |
59 | private TelnetOutputStream output; | |
60 | ||
61 | /** | |
62 | * Persistent read buffer. In practice this will only be used if the | |
63 | * single-byte read() is called sometime. | |
64 | */ | |
65 | private byte [] readBuffer; | |
66 | ||
67 | /** | |
68 | * Current writing position in readBuffer - what is passed into | |
69 | * input.read(). | |
70 | */ | |
71 | private int readBufferEnd; | |
72 | ||
73 | /** | |
74 | * Current read position in readBuffer - what is passed to the client in | |
75 | * response to this.read(). | |
76 | */ | |
77 | private int readBufferStart; | |
78 | ||
ea91242c KL |
79 | /** |
80 | * Package private constructor. | |
81 | * | |
82 | * @param master the master TelnetSocket | |
83 | * @param input the underlying socket's InputStream | |
005ec497 | 84 | * @param output the telnet-aware OutputStream |
ea91242c | 85 | */ |
005ec497 KL |
86 | TelnetInputStream(final TelnetSocket master, final InputStream input, |
87 | final TelnetOutputStream output) { | |
88 | ||
ea91242c KL |
89 | this.master = master; |
90 | this.input = input; | |
005ec497 KL |
91 | this.output = output; |
92 | ||
93 | // Setup new read buffer | |
94 | readBuffer = new byte[1024]; | |
95 | readBufferStart = 0; | |
96 | readBufferEnd = 0; | |
9b1afdde | 97 | subnegBuffer = new ArrayList<Byte>(); |
ea91242c KL |
98 | } |
99 | ||
100 | // SessionInfo interface -------------------------------------------------- | |
101 | ||
102 | /** | |
103 | * User name. | |
104 | */ | |
105 | private String username = ""; | |
106 | ||
107 | /** | |
108 | * Language. | |
109 | */ | |
110 | private String language = "en_US"; | |
111 | ||
112 | /** | |
113 | * Text window width. | |
114 | */ | |
115 | private int windowWidth = 80; | |
116 | ||
117 | /** | |
118 | * Text window height. | |
119 | */ | |
120 | private int windowHeight = 24; | |
121 | ||
122 | /** | |
123 | * Username getter. | |
124 | * | |
125 | * @return the username | |
126 | */ | |
127 | public String getUsername() { | |
128 | return this.username; | |
129 | } | |
130 | ||
131 | /** | |
132 | * Username setter. | |
133 | * | |
134 | * @param username the value | |
135 | */ | |
136 | public void setUsername(final String username) { | |
137 | this.username = username; | |
138 | } | |
139 | ||
140 | /** | |
141 | * Language getter. | |
142 | * | |
143 | * @return the language | |
144 | */ | |
145 | public String getLanguage() { | |
146 | return this.language; | |
147 | } | |
148 | ||
149 | /** | |
150 | * Language setter. | |
151 | * | |
152 | * @param language the value | |
153 | */ | |
154 | public void setLanguage(final String language) { | |
155 | this.language = language; | |
156 | } | |
157 | ||
158 | /** | |
159 | * Text window width getter. | |
160 | * | |
161 | * @return the window width | |
162 | */ | |
163 | public int getWindowWidth() { | |
164 | return windowWidth; | |
165 | } | |
166 | ||
167 | /** | |
168 | * Text window height getter. | |
169 | * | |
170 | * @return the window height | |
171 | */ | |
172 | public int getWindowHeight() { | |
173 | return windowHeight; | |
174 | } | |
175 | ||
176 | /** | |
177 | * Re-query the text window size. | |
178 | */ | |
179 | public void queryWindowSize() { | |
180 | // NOP | |
181 | } | |
182 | ||
183 | // InputStream interface -------------------------------------------------- | |
184 | ||
185 | /** | |
186 | * Returns an estimate of the number of bytes that can be read (or | |
187 | * skipped over) from this input stream without blocking by the next | |
188 | * invocation of a method for this input stream. | |
189 | * | |
9b1afdde KL |
190 | * @return an estimate of the number of bytes that can be read (or |
191 | * skipped over) from this input stream without blocking or 0 when it | |
192 | * reaches the end of the input stream. | |
193 | * @throws IOException if an I/O error occurs | |
ea91242c KL |
194 | */ |
195 | @Override | |
196 | public int available() throws IOException { | |
005ec497 KL |
197 | if (readBuffer == null) { |
198 | throw new IOException("InputStream is closed"); | |
199 | } | |
200 | if (readBufferEnd - readBufferStart > 0) { | |
201 | return (readBufferEnd - readBufferStart); | |
202 | } | |
203 | return input.available(); | |
ea91242c KL |
204 | } |
205 | ||
206 | /** | |
207 | * Closes this input stream and releases any system resources associated | |
208 | * with the stream. | |
9b1afdde KL |
209 | * |
210 | * @throws IOException if an I/O error occurs | |
ea91242c KL |
211 | */ |
212 | @Override | |
213 | public void close() throws IOException { | |
005ec497 KL |
214 | if (readBuffer != null) { |
215 | readBuffer = null; | |
216 | input.close(); | |
217 | } | |
ea91242c KL |
218 | } |
219 | ||
220 | /** | |
221 | * Marks the current position in this input stream. | |
9b1afdde KL |
222 | * |
223 | * @param readLimit the maximum limit of bytes that can be read before | |
224 | * the mark position becomes invalid | |
ea91242c KL |
225 | */ |
226 | @Override | |
9b1afdde | 227 | public void mark(final int readLimit) { |
005ec497 | 228 | // Do nothing |
ea91242c KL |
229 | } |
230 | ||
231 | /** | |
232 | * Tests if this input stream supports the mark and reset methods. | |
9b1afdde KL |
233 | * |
234 | * @return true if this stream instance supports the mark and reset | |
235 | * methods; false otherwise | |
ea91242c KL |
236 | */ |
237 | @Override | |
238 | public boolean markSupported() { | |
239 | return false; | |
240 | } | |
241 | ||
242 | /** | |
243 | * Reads the next byte of data from the input stream. | |
9b1afdde KL |
244 | * |
245 | * @return the next byte of data, or -1 if there is no more data because | |
246 | * the end of the stream has been reached. | |
247 | * @throws IOException if an I/O error occurs | |
ea91242c KL |
248 | */ |
249 | @Override | |
250 | public int read() throws IOException { | |
005ec497 KL |
251 | |
252 | // If the post-processed buffer has bytes, use that. | |
253 | if (readBufferEnd - readBufferStart > 0) { | |
254 | readBufferStart++; | |
255 | return readBuffer[readBufferStart - 1]; | |
256 | } | |
257 | ||
258 | // The buffer is empty, so reset the indexes to 0. | |
259 | readBufferStart = 0; | |
260 | readBufferEnd = 0; | |
261 | ||
262 | // Read some fresh data and run it through the telnet protocol. | |
263 | int rc = readImpl(readBuffer, readBufferEnd, | |
264 | readBuffer.length - readBufferEnd); | |
265 | ||
266 | // If we got something, return it. | |
267 | if (rc > 0) { | |
268 | readBufferStart++; | |
269 | return readBuffer[readBufferStart - 1]; | |
270 | } | |
271 | // If we read 0, I screwed up big time. | |
272 | assert (rc != 0); | |
273 | ||
274 | // We read -1 (EOF). | |
275 | return rc; | |
ea91242c KL |
276 | } |
277 | ||
278 | /** | |
279 | * Reads some number of bytes from the input stream and stores them into | |
280 | * the buffer array b. | |
9b1afdde KL |
281 | * |
282 | * @param b the buffer into which the data is read. | |
283 | * @return the total number of bytes read into the buffer, or -1 if there | |
284 | * is no more data because the end of the stream has been reached. | |
285 | * @throws IOException if an I/O error occurs | |
ea91242c KL |
286 | */ |
287 | @Override | |
9b1afdde | 288 | public int read(final byte[] b) throws IOException { |
005ec497 | 289 | return read(b, 0, b.length); |
ea91242c KL |
290 | } |
291 | ||
292 | /** | |
293 | * Reads up to len bytes of data from the input stream into an array of | |
294 | * bytes. | |
9b1afdde KL |
295 | * |
296 | * @param b the buffer into which the data is read. | |
297 | * @param off the start offset in array b at which the data is written. | |
298 | * @param len the maximum number of bytes to read. | |
299 | * @return the total number of bytes read into the buffer, or -1 if there | |
300 | * is no more data because the end of the stream has been reached. | |
301 | * @throws IOException if an I/O error occurs | |
ea91242c KL |
302 | */ |
303 | @Override | |
9b1afdde KL |
304 | public int read(final byte[] b, final int off, |
305 | final int len) throws IOException { | |
306 | ||
005ec497 KL |
307 | // The only time we can return 0 is if len is 0, as per the |
308 | // InputStream contract. | |
309 | if (len == 0) { | |
310 | return 0; | |
311 | } | |
312 | ||
313 | // If the post-processed buffer has bytes, use that. | |
314 | if (readBufferEnd - readBufferStart > 0) { | |
315 | int n = Math.min(len, readBufferEnd - readBufferStart); | |
316 | System.arraycopy(b, off, readBuffer, readBufferStart, n); | |
317 | readBufferStart += n; | |
318 | return n; | |
319 | } | |
320 | ||
321 | // The buffer is empty, so reset the indexes to 0. | |
322 | readBufferStart = 0; | |
323 | readBufferEnd = 0; | |
324 | ||
325 | // The maximum number of bytes we will ask for will definitely be | |
326 | // within the bounds of what we can return in a single call. | |
327 | int n = Math.min(len, readBuffer.length); | |
328 | ||
329 | // Read some fresh data and run it through the telnet protocol. | |
330 | int rc = readImpl(readBuffer, readBufferEnd, n); | |
331 | ||
332 | // If we got something, return it. | |
333 | if (rc > 0) { | |
9b1afdde | 334 | System.arraycopy(readBuffer, 0, b, off, rc); |
005ec497 KL |
335 | return rc; |
336 | } | |
337 | // If we read 0, I screwed up big time. | |
338 | assert (rc != 0); | |
339 | ||
340 | // We read -1 (EOF). | |
341 | return rc; | |
ea91242c KL |
342 | } |
343 | ||
344 | /** | |
345 | * Repositions this stream to the position at the time the mark method | |
9b1afdde KL |
346 | * was last called on this input stream. This is not supported by |
347 | * TelnetInputStream, so IOException is always thrown. | |
348 | * | |
349 | * @throws IOException if this function is used | |
ea91242c KL |
350 | */ |
351 | @Override | |
352 | public void reset() throws IOException { | |
005ec497 | 353 | throw new IOException("InputStream does not support mark/reset"); |
ea91242c KL |
354 | } |
355 | ||
356 | /** | |
357 | * Skips over and discards n bytes of data from this input stream. | |
9b1afdde KL |
358 | * |
359 | * @param n the number of bytes to be skipped | |
360 | * @return the actual number of bytes skipped | |
361 | * @throws IOException if an I/O error occurs | |
ea91242c KL |
362 | */ |
363 | @Override | |
9b1afdde | 364 | public long skip(final long n) throws IOException { |
005ec497 KL |
365 | if (n < 0) { |
366 | return 0; | |
367 | } | |
368 | for (int i = 0; i < n; i++) { | |
369 | read(); | |
370 | } | |
371 | return n; | |
ea91242c KL |
372 | } |
373 | ||
ea91242c KL |
374 | // Telnet protocol -------------------------------------------------------- |
375 | ||
9b1afdde KL |
376 | |
377 | /** | |
378 | * When true, the last read byte from the remote side was IAC. | |
379 | */ | |
380 | private boolean iac = false; | |
381 | ||
382 | /** | |
383 | * When true, we are in the middle of a DO/DONT/WILL/WONT negotiation. | |
384 | */ | |
385 | private boolean dowill = false; | |
386 | ||
387 | /** | |
388 | * The telnet option being negotiated. | |
389 | */ | |
390 | private int dowillType = 0; | |
391 | ||
392 | /** | |
393 | * When true, we are waiting to see the end of the sub-negotiation | |
394 | * sequence. | |
395 | */ | |
396 | private boolean subnegEnd = false; | |
397 | ||
398 | /** | |
399 | * When true, the last byte read from the remote side was CR. | |
400 | */ | |
401 | private boolean readCR = false; | |
402 | ||
ea91242c KL |
403 | /** |
404 | * The subnegotiation buffer. | |
405 | */ | |
9b1afdde | 406 | private ArrayList<Byte> subnegBuffer; |
ea91242c KL |
407 | |
408 | /** | |
409 | * For debugging, return a descriptive string for this telnet option. | |
410 | * These are pulled from: http://www.iana.org/assignments/telnet-options | |
411 | * | |
9b1afdde | 412 | * @param option the telnet option byte |
ea91242c KL |
413 | * @return a string describing the telnet option code |
414 | */ | |
0d47c546 | 415 | @SuppressWarnings("unused") |
ea91242c KL |
416 | private String optionString(final int option) { |
417 | switch (option) { | |
418 | case 0: return "Binary Transmission"; | |
419 | case 1: return "Echo"; | |
420 | case 2: return "Reconnection"; | |
421 | case 3: return "Suppress Go Ahead"; | |
422 | case 4: return "Approx Message Size Negotiation"; | |
423 | case 5: return "Status"; | |
424 | case 6: return "Timing Mark"; | |
425 | case 7: return "Remote Controlled Trans and Echo"; | |
426 | case 8: return "Output Line Width"; | |
427 | case 9: return "Output Page Size"; | |
428 | case 10: return "Output Carriage-Return Disposition"; | |
429 | case 11: return "Output Horizontal Tab Stops"; | |
430 | case 12: return "Output Horizontal Tab Disposition"; | |
431 | case 13: return "Output Formfeed Disposition"; | |
432 | case 14: return "Output Vertical Tabstops"; | |
433 | case 15: return "Output Vertical Tab Disposition"; | |
434 | case 16: return "Output Linefeed Disposition"; | |
435 | case 17: return "Extended ASCII"; | |
436 | case 18: return "Logout"; | |
437 | case 19: return "Byte Macro"; | |
438 | case 20: return "Data Entry Terminal"; | |
439 | case 21: return "SUPDUP"; | |
440 | case 22: return "SUPDUP Output"; | |
441 | case 23: return "Send Location"; | |
442 | case 24: return "Terminal Type"; | |
443 | case 25: return "End of Record"; | |
444 | case 26: return "TACACS User Identification"; | |
445 | case 27: return "Output Marking"; | |
446 | case 28: return "Terminal Location Number"; | |
447 | case 29: return "Telnet 3270 Regime"; | |
448 | case 30: return "X.3 PAD"; | |
449 | case 31: return "Negotiate About Window Size"; | |
450 | case 32: return "Terminal Speed"; | |
451 | case 33: return "Remote Flow Control"; | |
452 | case 34: return "Linemode"; | |
453 | case 35: return "X Display Location"; | |
454 | case 36: return "Environment Option"; | |
455 | case 37: return "Authentication Option"; | |
456 | case 38: return "Encryption Option"; | |
457 | case 39: return "New Environment Option"; | |
458 | case 40: return "TN3270E"; | |
459 | case 41: return "XAUTH"; | |
460 | case 42: return "CHARSET"; | |
461 | case 43: return "Telnet Remote Serial Port (RSP)"; | |
462 | case 44: return "Com Port Control Option"; | |
463 | case 45: return "Telnet Suppress Local Echo"; | |
464 | case 46: return "Telnet Start TLS"; | |
465 | case 47: return "KERMIT"; | |
466 | case 48: return "SEND-URL"; | |
467 | case 49: return "FORWARD_X"; | |
468 | case 138: return "TELOPT PRAGMA LOGON"; | |
469 | case 139: return "TELOPT SSPI LOGON"; | |
470 | case 140: return "TELOPT PRAGMA HEARTBEAT"; | |
471 | case 255: return "Extended-Options-List"; | |
472 | default: | |
473 | if ((option >= 50) && (option <= 137)) { | |
474 | return "Unassigned"; | |
475 | } | |
476 | return "UNKNOWN - OTHER"; | |
477 | } | |
478 | } | |
479 | ||
480 | /** | |
481 | * Send a DO/DON'T/WILL/WON'T response to the remote side. | |
482 | * | |
483 | * @param response a TELNET_DO/DONT/WILL/WONT byte | |
484 | * @param option telnet option byte (binary mode, term type, etc.) | |
9b1afdde | 485 | * @throws IOException if an I/O error occurs |
ea91242c KL |
486 | */ |
487 | private void respond(final int response, | |
488 | final int option) throws IOException { | |
489 | ||
490 | byte [] buffer = new byte[3]; | |
491 | buffer[0] = (byte)TELNET_IAC; | |
492 | buffer[1] = (byte)response; | |
493 | buffer[2] = (byte)option; | |
494 | ||
005ec497 | 495 | output.rawWrite(buffer); |
ea91242c KL |
496 | } |
497 | ||
498 | /** | |
499 | * Tell the remote side we WILL support an option. | |
500 | * | |
501 | * @param option telnet option byte (binary mode, term type, etc.) | |
9b1afdde | 502 | * @throws IOException if an I/O error occurs |
ea91242c KL |
503 | */ |
504 | private void WILL(final int option) throws IOException { | |
505 | respond(TELNET_WILL, option); | |
506 | } | |
507 | ||
508 | /** | |
509 | * Tell the remote side we WON'T support an option. | |
510 | * | |
511 | * @param option telnet option byte (binary mode, term type, etc.) | |
9b1afdde | 512 | * @throws IOException if an I/O error occurs |
ea91242c KL |
513 | */ |
514 | private void WONT(final int option) throws IOException { | |
515 | respond(TELNET_WONT, option); | |
516 | } | |
517 | ||
518 | /** | |
519 | * Tell the remote side we DO support an option. | |
520 | * | |
521 | * @param option telnet option byte (binary mode, term type, etc.) | |
9b1afdde | 522 | * @throws IOException if an I/O error occurs |
ea91242c KL |
523 | */ |
524 | private void DO(final int option) throws IOException { | |
525 | respond(TELNET_DO, option); | |
526 | } | |
527 | ||
528 | /** | |
529 | * Tell the remote side we DON'T support an option. | |
530 | * | |
531 | * @param option telnet option byte (binary mode, term type, etc.) | |
9b1afdde | 532 | * @throws IOException if an I/O error occurs |
ea91242c KL |
533 | */ |
534 | private void DONT(final int option) throws IOException { | |
535 | respond(TELNET_DONT, option); | |
536 | } | |
537 | ||
538 | /** | |
539 | * Tell the remote side we WON't or DON'T support an option. | |
540 | * | |
541 | * @param remoteQuery a TELNET_DO/DONT/WILL/WONT byte | |
542 | * @param option telnet option byte (binary mode, term type, etc.) | |
9b1afdde | 543 | * @throws IOException if an I/O error occurs |
ea91242c KL |
544 | */ |
545 | private void refuse(final int remoteQuery, | |
546 | final int option) throws IOException { | |
547 | ||
548 | if (remoteQuery == TELNET_DO) { | |
549 | WONT(option); | |
550 | } else { | |
551 | DONT(option); | |
552 | } | |
553 | } | |
554 | ||
555 | /** | |
9b1afdde | 556 | * Build sub-negotiation packet (RFC 855). |
ea91242c KL |
557 | * |
558 | * @param option telnet option | |
559 | * @param response output buffer of response bytes | |
9b1afdde | 560 | * @throws IOException if an I/O error occurs |
ea91242c KL |
561 | */ |
562 | private void telnetSendSubnegResponse(final int option, | |
563 | final byte [] response) throws IOException { | |
564 | ||
565 | byte [] buffer = new byte[response.length + 5]; | |
566 | buffer[0] = (byte)TELNET_IAC; | |
567 | buffer[1] = (byte)TELNET_SB; | |
568 | buffer[2] = (byte)option; | |
569 | System.arraycopy(response, 0, buffer, 3, response.length); | |
570 | buffer[response.length + 3] = (byte)TELNET_IAC; | |
571 | buffer[response.length + 4] = (byte)TELNET_SE; | |
005ec497 | 572 | output.rawWrite(buffer); |
ea91242c KL |
573 | } |
574 | ||
575 | /** | |
576 | * Telnet option: Terminal Speed (RFC 1079). Client side. | |
9b1afdde KL |
577 | * |
578 | * @throws IOException if an I/O error occurs | |
ea91242c KL |
579 | */ |
580 | private void telnetSendTerminalSpeed() throws IOException { | |
581 | byte [] response = {0, '3', '8', '4', '0', '0', ',', | |
582 | '3', '8', '4', '0', '0'}; | |
583 | telnetSendSubnegResponse(32, response); | |
584 | } | |
585 | ||
586 | /** | |
587 | * Telnet option: Terminal Type (RFC 1091). Client side. | |
9b1afdde KL |
588 | * |
589 | * @throws IOException if an I/O error occurs | |
ea91242c KL |
590 | */ |
591 | private void telnetSendTerminalType() throws IOException { | |
592 | byte [] response = {0, 'v', 't', '1', '0', '0' }; | |
593 | telnetSendSubnegResponse(24, response); | |
594 | } | |
595 | ||
596 | /** | |
597 | * Telnet option: Terminal Type (RFC 1091). Server side. | |
9b1afdde KL |
598 | * |
599 | * @throws IOException if an I/O error occurs | |
ea91242c KL |
600 | */ |
601 | private void requestTerminalType() throws IOException { | |
602 | byte [] response = new byte[1]; | |
603 | response[0] = 1; | |
604 | telnetSendSubnegResponse(24, response); | |
605 | } | |
606 | ||
607 | /** | |
608 | * Telnet option: Terminal Speed (RFC 1079). Server side. | |
9b1afdde KL |
609 | * |
610 | * @throws IOException if an I/O error occurs | |
ea91242c KL |
611 | */ |
612 | private void requestTerminalSpeed() throws IOException { | |
613 | byte [] response = new byte[1]; | |
614 | response[0] = 1; | |
615 | telnetSendSubnegResponse(32, response); | |
616 | } | |
617 | ||
618 | /** | |
619 | * Telnet option: New Environment (RFC 1572). Server side. | |
9b1afdde KL |
620 | * |
621 | * @throws IOException if an I/O error occurs | |
ea91242c KL |
622 | */ |
623 | private void requestEnvironment() throws IOException { | |
624 | byte [] response = new byte[1]; | |
625 | response[0] = 1; | |
626 | telnetSendSubnegResponse(39, response); | |
627 | } | |
628 | ||
629 | /** | |
9b1afdde KL |
630 | * Send the options we want to negotiate on. |
631 | * | |
632 | * <p>The options we use are: | |
633 | * | |
634 | * <p> | |
635 | * <pre> | |
ea91242c KL |
636 | * Binary Transmission RFC 856 |
637 | * Suppress Go Ahead RFC 858 | |
638 | * Negotiate About Window Size RFC 1073 | |
639 | * Terminal Type RFC 1091 | |
640 | * Terminal Speed RFC 1079 | |
641 | * New Environment RFC 1572 | |
642 | * | |
643 | * When run as a server: | |
9b1afdde KL |
644 | * Echo RFC 857 |
645 | * </pre> | |
646 | * | |
647 | * @throws IOException if an I/O error occurs | |
ea91242c | 648 | */ |
005ec497 | 649 | void telnetSendOptions() throws IOException { |
9b1afdde | 650 | if (master.binaryMode == false) { |
ea91242c KL |
651 | // Binary Transmission: must ask both do and will |
652 | DO(0); | |
653 | WILL(0); | |
654 | } | |
655 | ||
9b1afdde | 656 | if (master.goAhead == true) { |
ea91242c KL |
657 | // Suppress Go Ahead |
658 | DO(3); | |
659 | WILL(3); | |
660 | } | |
661 | ||
662 | // Server only options | |
9b1afdde | 663 | if (master.isServer == true) { |
ea91242c KL |
664 | // Enable Echo - I echo to them, they do not echo back to me. |
665 | DONT(1); | |
666 | WILL(1); | |
667 | ||
9b1afdde | 668 | if (master.doTermType == true) { |
ea91242c KL |
669 | // Terminal type - request it |
670 | DO(24); | |
671 | } | |
672 | ||
9b1afdde | 673 | if (master.doTermSpeed == true) { |
ea91242c KL |
674 | // Terminal speed - request it |
675 | DO(32); | |
676 | } | |
677 | ||
9b1afdde | 678 | if (master.doNAWS == true) { |
ea91242c KL |
679 | // NAWS - request it |
680 | DO(31); | |
681 | } | |
682 | ||
9b1afdde | 683 | if (master.doEnvironment == true) { |
ea91242c KL |
684 | // Environment - request it |
685 | DO(39); | |
686 | } | |
687 | ||
688 | } else { | |
689 | ||
9b1afdde | 690 | if (master.doTermType == true) { |
ea91242c KL |
691 | // Terminal type - request it |
692 | WILL(24); | |
693 | } | |
694 | ||
9b1afdde | 695 | if (master.doTermSpeed == true) { |
ea91242c KL |
696 | // Terminal speed - request it |
697 | WILL(32); | |
698 | } | |
699 | ||
9b1afdde | 700 | if (master.doNAWS == true) { |
ea91242c KL |
701 | // NAWS - request it |
702 | WILL(31); | |
703 | } | |
704 | ||
9b1afdde | 705 | if (master.doEnvironment == true) { |
ea91242c KL |
706 | // Environment - request it |
707 | WILL(39); | |
708 | } | |
ea91242c | 709 | } |
9b1afdde KL |
710 | |
711 | // Push it all out | |
712 | output.flush(); | |
ea91242c KL |
713 | } |
714 | ||
715 | /** | |
716 | * New Environment parsing state. | |
717 | */ | |
718 | private enum EnvState { | |
719 | INIT, | |
720 | TYPE, | |
721 | NAME, | |
722 | VALUE | |
723 | } | |
724 | ||
725 | /** | |
726 | * Handle the New Environment option. Note that this implementation | |
727 | * fails to handle ESC as defined in RFC 1572. | |
728 | */ | |
729 | private void handleNewEnvironment() { | |
9b1afdde KL |
730 | Map<StringBuilder, StringBuilder> newEnv = |
731 | new TreeMap<StringBuilder, StringBuilder>(); | |
732 | ||
ea91242c KL |
733 | EnvState state = EnvState.INIT; |
734 | StringBuilder name = new StringBuilder(); | |
735 | StringBuilder value = new StringBuilder(); | |
736 | ||
9b1afdde KL |
737 | for (int i = 0; i < subnegBuffer.size(); i++) { |
738 | Byte b = subnegBuffer.get(i); | |
ea91242c KL |
739 | |
740 | switch (state) { | |
741 | ||
742 | case INIT: | |
743 | // Looking for "IS" | |
744 | if (b == 0) { | |
745 | state = EnvState.TYPE; | |
746 | } else { | |
747 | // The other side isn't following the rules, see ya. | |
748 | return; | |
749 | } | |
750 | break; | |
751 | ||
752 | case TYPE: | |
753 | // Looking for "VAR" or "USERVAR" | |
754 | if (b == 0) { | |
755 | // VAR | |
756 | state = EnvState.NAME; | |
757 | name = new StringBuilder(); | |
758 | } else if (b == 3) { | |
759 | // USERVAR | |
760 | state = EnvState.NAME; | |
761 | name = new StringBuilder(); | |
762 | } else { | |
763 | // The other side isn't following the rules, see ya | |
764 | return; | |
765 | } | |
766 | break; | |
767 | ||
768 | case NAME: | |
769 | // Looking for "VALUE" or a name byte | |
770 | if (b == 1) { | |
771 | // VALUE | |
772 | state = EnvState.VALUE; | |
773 | value = new StringBuilder(); | |
774 | } else { | |
775 | // Take it as an environment variable name/key byte | |
9b1afdde | 776 | name.append((char)b.byteValue()); |
ea91242c KL |
777 | } |
778 | ||
779 | break; | |
780 | ||
781 | case VALUE: | |
782 | // Looking for "VAR", "USERVAR", or a name byte, or the end | |
783 | if (b == 0) { | |
784 | // VAR | |
785 | state = EnvState.NAME; | |
786 | if (value.length() > 0) { | |
787 | newEnv.put(name, value); | |
788 | } | |
789 | name = new StringBuilder(); | |
790 | } else if (b == 3) { | |
791 | // USERVAR | |
792 | state = EnvState.NAME; | |
793 | if (value.length() > 0) { | |
794 | newEnv.put(name, value); | |
795 | } | |
796 | name = new StringBuilder(); | |
797 | } else { | |
798 | // Take it as an environment variable value byte | |
9b1afdde | 799 | value.append((char)b.byteValue()); |
ea91242c KL |
800 | } |
801 | break; | |
9b1afdde KL |
802 | |
803 | default: | |
804 | throw new RuntimeException("Invalid state: " + state); | |
805 | ||
ea91242c KL |
806 | } |
807 | } | |
808 | ||
809 | if ((name.length() > 0) && (value.length() > 0)) { | |
810 | newEnv.put(name, value); | |
811 | } | |
812 | ||
813 | for (StringBuilder key: newEnv.keySet()) { | |
814 | if (key.equals("LANG")) { | |
815 | language = newEnv.get(key).toString(); | |
816 | } | |
817 | if (key.equals("LOGNAME")) { | |
818 | username = newEnv.get(key).toString(); | |
819 | } | |
820 | if (key.equals("USER")) { | |
821 | username = newEnv.get(key).toString(); | |
822 | } | |
823 | } | |
824 | } | |
825 | ||
826 | /** | |
827 | * Handle an option sub-negotiation. | |
9b1afdde KL |
828 | * |
829 | * @throws IOException if an I/O error occurs | |
ea91242c KL |
830 | */ |
831 | private void handleSubneg() throws IOException { | |
9b1afdde | 832 | Byte option; |
ea91242c KL |
833 | |
834 | // Sanity check: there must be at least 1 byte in subnegBuffer | |
9b1afdde | 835 | if (subnegBuffer.size() < 1) { |
ea91242c KL |
836 | // Buffer too small: the other side is a broken telnetd, it did |
837 | // not send the right sub-negotiation data. Bail out now. | |
838 | return; | |
839 | } | |
9b1afdde | 840 | option = subnegBuffer.get(0); |
ea91242c KL |
841 | |
842 | switch (option) { | |
843 | ||
844 | case 24: | |
845 | // Terminal Type | |
9b1afdde | 846 | if ((subnegBuffer.size() > 1) && (subnegBuffer.get(1) == 1)) { |
ea91242c KL |
847 | // Server sent "SEND", we say "IS" |
848 | telnetSendTerminalType(); | |
849 | } | |
9b1afdde | 850 | if ((subnegBuffer.size() > 1) && (subnegBuffer.get(1) == 0)) { |
ea91242c KL |
851 | // Client sent "IS", record it |
852 | StringBuilder terminalString = new StringBuilder(); | |
9b1afdde KL |
853 | for (int i = 2; i < subnegBuffer.size(); i++) { |
854 | terminalString.append((char)subnegBuffer. | |
855 | get(i).byteValue()); | |
ea91242c | 856 | } |
9b1afdde | 857 | master.terminalType = terminalString.toString(); |
ea91242c KL |
858 | } |
859 | break; | |
860 | ||
861 | case 32: | |
862 | // Terminal Speed | |
9b1afdde | 863 | if ((subnegBuffer.size() > 1) && (subnegBuffer.get(1) == 1)) { |
ea91242c KL |
864 | // Server sent "SEND", we say "IS" |
865 | telnetSendTerminalSpeed(); | |
866 | } | |
9b1afdde | 867 | if ((subnegBuffer.size() > 1) && (subnegBuffer.get(1) == 0)) { |
ea91242c KL |
868 | // Client sent "IS", record it |
869 | StringBuilder speedString = new StringBuilder(); | |
9b1afdde KL |
870 | for (int i = 2; i < subnegBuffer.size(); i++) { |
871 | speedString.append((char)subnegBuffer.get(i).byteValue()); | |
ea91242c | 872 | } |
9b1afdde | 873 | master.terminalSpeed = speedString.toString(); |
ea91242c KL |
874 | } |
875 | break; | |
876 | ||
877 | case 31: | |
878 | // NAWS | |
9b1afdde | 879 | if (subnegBuffer.size() >= 5) { |
ea91242c KL |
880 | int i = 0; |
881 | ||
882 | i++; | |
9b1afdde | 883 | if (subnegBuffer.get(i) == (byte)TELNET_IAC) { |
ea91242c KL |
884 | i++; |
885 | } | |
9b1afdde | 886 | windowWidth = subnegBuffer.get(i) * 256; |
ea91242c KL |
887 | |
888 | i++; | |
9b1afdde | 889 | if (subnegBuffer.get(i) == (byte)TELNET_IAC) { |
ea91242c KL |
890 | i++; |
891 | } | |
9b1afdde | 892 | windowWidth += subnegBuffer.get(i); |
ea91242c KL |
893 | |
894 | i++; | |
9b1afdde | 895 | if (subnegBuffer.get(i) == (byte)TELNET_IAC) { |
ea91242c KL |
896 | i++; |
897 | } | |
9b1afdde | 898 | windowHeight = subnegBuffer.get(i) * 256; |
ea91242c KL |
899 | |
900 | i++; | |
9b1afdde | 901 | if (subnegBuffer.get(i) == (byte)TELNET_IAC) { |
ea91242c KL |
902 | i++; |
903 | } | |
9b1afdde | 904 | windowHeight += subnegBuffer.get(i); |
ea91242c KL |
905 | } |
906 | break; | |
907 | ||
908 | case 39: | |
909 | // Environment | |
910 | handleNewEnvironment(); | |
911 | break; | |
912 | ||
913 | default: | |
914 | // Ignore this one | |
915 | break; | |
916 | } | |
917 | } | |
918 | ||
005ec497 KL |
919 | /** |
920 | * Reads up to len bytes of data from the input stream into an array of | |
921 | * bytes. | |
9b1afdde KL |
922 | * |
923 | * @param buf the buffer into which the data is read. | |
924 | * @param off the start offset in array b at which the data is written. | |
925 | * @param len the maximum number of bytes to read. | |
926 | * @return the total number of bytes read into the buffer, or -1 if there | |
927 | * is no more data because the end of the stream has been reached. | |
928 | * @throws IOException if an I/O error occurs | |
005ec497 | 929 | */ |
9b1afdde KL |
930 | private int readImpl(final byte[] buf, final int off, |
931 | final int len) throws IOException { | |
932 | ||
005ec497 | 933 | assert (len > 0); |
9b1afdde KL |
934 | |
935 | // The current writing position in buf. | |
936 | int bufN = 0; | |
937 | ||
938 | // We will keep trying to read() until we have something to return. | |
939 | do { | |
940 | ||
941 | // Read up to len bytes | |
942 | byte [] buffer = new byte[len]; | |
943 | int bufferN = 0; | |
944 | ||
945 | // Read some data from the other end | |
946 | int rc = input.read(buffer); | |
947 | ||
948 | // Check for EOF or error | |
949 | if (rc > 0) { | |
950 | // More data came in | |
951 | bufferN = rc; | |
952 | } else { | |
953 | // EOF, just return it. | |
954 | return rc; | |
955 | } | |
956 | ||
957 | // Loop through the read bytes | |
958 | for (int i = 0; i < bufferN; i++) { | |
959 | byte b = buffer[i]; | |
960 | ||
961 | if (subnegEnd == true) { | |
962 | // Looking for IAC SE to end this subnegotiation | |
963 | if (b == (byte)TELNET_SE) { | |
964 | if (iac == true) { | |
965 | iac = false; | |
966 | subnegEnd = false; | |
967 | handleSubneg(); | |
968 | } | |
969 | } else if (b == (byte)TELNET_IAC) { | |
970 | if (iac == true) { | |
971 | // An argument to the subnegotiation option | |
972 | subnegBuffer.add((byte)TELNET_IAC); | |
973 | } else { | |
974 | iac = true; | |
975 | } | |
976 | } else { | |
977 | // An argument to the subnegotiation option | |
978 | subnegBuffer.add(b); | |
979 | } | |
980 | continue; | |
981 | } | |
982 | ||
983 | // Look for DO/DON'T/WILL/WON'T option | |
984 | if (dowill == true) { | |
985 | ||
986 | // Look for option/ | |
987 | switch (b) { | |
988 | ||
989 | case 0: | |
990 | // Binary Transmission | |
991 | if (dowillType == (byte)TELNET_WILL) { | |
992 | // Server will use binary transmission, yay. | |
993 | master.binaryMode = true; | |
994 | } else if (dowillType == (byte)TELNET_DO) { | |
995 | // Server asks for binary transmission. | |
996 | WILL(b); | |
997 | master.binaryMode = true; | |
998 | } else if (dowillType == (byte)TELNET_WONT) { | |
999 | // We're screwed, server won't do binary | |
1000 | // transmission. | |
1001 | master.binaryMode = false; | |
1002 | } else { | |
1003 | // Server demands NVT ASCII mode. | |
1004 | master.binaryMode = false; | |
1005 | } | |
1006 | break; | |
1007 | ||
1008 | case 1: | |
1009 | // Echo | |
1010 | if (dowillType == (byte)TELNET_WILL) { | |
1011 | // Server will use echo, yay. | |
1012 | master.echoMode = true; | |
1013 | } else if (dowillType == (byte)TELNET_DO) { | |
1014 | // Server asks for echo. | |
1015 | WILL(b); | |
1016 | master.echoMode = true; | |
1017 | } else if (dowillType == (byte)TELNET_WONT) { | |
1018 | // We're screwed, server won't do echo. | |
1019 | master.echoMode = false; | |
1020 | } else { | |
1021 | // Server demands no echo. | |
1022 | master.echoMode = false; | |
1023 | } | |
1024 | break; | |
1025 | ||
1026 | case 3: | |
1027 | // Suppress Go Ahead | |
1028 | if (dowillType == (byte)TELNET_WILL) { | |
1029 | // Server will use suppress go-ahead, yay. | |
1030 | master.goAhead = false; | |
1031 | } else if (dowillType == (byte)TELNET_DO) { | |
1032 | // Server asks for suppress go-ahead. | |
1033 | WILL(b); | |
1034 | master.goAhead = false; | |
1035 | } else if (dowillType == (byte)TELNET_WONT) { | |
1036 | // We're screwed, server won't do suppress | |
1037 | // go-ahead. | |
1038 | master.goAhead = true; | |
1039 | } else { | |
1040 | // Server demands Go-Ahead mode. | |
1041 | master.goAhead = true; | |
1042 | } | |
1043 | break; | |
1044 | ||
1045 | case 24: | |
1046 | // Terminal Type - send what's in TERM | |
1047 | if (dowillType == (byte)TELNET_WILL) { | |
1048 | // Server will use terminal type, yay. | |
1049 | if (master.isServer | |
1050 | && master.doTermType | |
1051 | ) { | |
1052 | requestTerminalType(); | |
1053 | master.doTermType = false; | |
1054 | } else if (!master.isServer) { | |
1055 | master.doTermType = true; | |
1056 | } | |
1057 | } else if (dowillType == (byte)TELNET_DO) { | |
1058 | // Server asks for terminal type. | |
1059 | WILL(b); | |
1060 | master.doTermType = true; | |
1061 | } else if (dowillType == (byte)TELNET_WONT) { | |
1062 | // We're screwed, server won't do terminal type. | |
1063 | master.doTermType = false; | |
1064 | } else { | |
1065 | // Server will not listen to terminal type. | |
1066 | master.doTermType = false; | |
1067 | } | |
1068 | break; | |
1069 | ||
1070 | case 31: | |
1071 | // NAWS | |
1072 | if (dowillType == (byte)TELNET_WILL) { | |
1073 | // Server will use NAWS, yay. | |
1074 | master.doNAWS = true; | |
1075 | // NAWS cannot be requested by the server, it is | |
1076 | // only sent by the client. | |
1077 | } else if (dowillType == (byte)TELNET_DO) { | |
1078 | // Server asks for NAWS. | |
1079 | WILL(b); | |
1080 | master.doNAWS = true; | |
1081 | } else if (dowillType == (byte)TELNET_WONT) { | |
1082 | // Server won't do NAWS. | |
1083 | master.doNAWS = false; | |
1084 | } else { | |
1085 | // Server will not listen to NAWS. | |
1086 | master.doNAWS = false; | |
1087 | } | |
1088 | break; | |
1089 | ||
1090 | case 32: | |
1091 | // Terminal Speed | |
1092 | if (dowillType == (byte)TELNET_WILL) { | |
1093 | // Server will use terminal speed, yay. | |
1094 | if (master.isServer | |
1095 | && master.doTermSpeed | |
1096 | ) { | |
1097 | requestTerminalSpeed(); | |
1098 | master.doTermSpeed = false; | |
1099 | } else if (!master.isServer) { | |
1100 | master.doTermSpeed = true; | |
1101 | } | |
1102 | } else if (dowillType == (byte)TELNET_DO) { | |
1103 | // Server asks for terminal speed. | |
1104 | WILL(b); | |
1105 | master.doTermSpeed = true; | |
1106 | } else if (dowillType == (byte)TELNET_WONT) { | |
1107 | // We're screwed, server won't do terminal speed. | |
1108 | master.doTermSpeed = false; | |
1109 | } else { | |
1110 | // Server will not listen to terminal speed. | |
1111 | master.doTermSpeed = false; | |
1112 | } | |
1113 | break; | |
1114 | ||
1115 | case 39: | |
1116 | // New Environment | |
1117 | if (dowillType == (byte)TELNET_WILL) { | |
1118 | // Server will use NewEnvironment, yay. | |
1119 | if (master.isServer | |
1120 | && master.doEnvironment | |
1121 | ) { | |
1122 | requestEnvironment(); | |
1123 | master.doEnvironment = false; | |
1124 | } else if (!master.isServer) { | |
1125 | master.doEnvironment = true; | |
1126 | } | |
1127 | } else if (dowillType == (byte)TELNET_DO) { | |
1128 | // Server asks for NewEnvironment. | |
1129 | WILL(b); | |
1130 | master.doEnvironment = true; | |
1131 | } else if (dowillType == (byte)TELNET_WONT) { | |
1132 | // Server won't do NewEnvironment. | |
1133 | master.doEnvironment = false; | |
1134 | } else { | |
1135 | // Server will not listen to New Environment. | |
1136 | master.doEnvironment = false; | |
1137 | } | |
1138 | break; | |
1139 | ||
1140 | ||
1141 | default: | |
1142 | // Other side asked for something we don't | |
1143 | // understand. Tell them we will not do this option. | |
1144 | refuse(dowillType, b); | |
1145 | break; | |
1146 | } | |
1147 | ||
1148 | dowill = false; | |
1149 | continue; | |
1150 | } // if (dowill == true) | |
1151 | ||
1152 | // Perform read processing | |
1153 | if (b == (byte)TELNET_IAC) { | |
1154 | ||
1155 | // Telnet command | |
1156 | if (iac == true) { | |
1157 | // IAC IAC -> IAC | |
1158 | buf[bufN++] = (byte)TELNET_IAC; | |
1159 | iac = false; | |
1160 | } else { | |
1161 | iac = true; | |
1162 | } | |
1163 | continue; | |
1164 | } else { | |
1165 | if (iac == true) { | |
1166 | ||
1167 | switch (b) { | |
1168 | ||
1169 | case (byte)TELNET_SE: | |
1170 | // log.debug1(" END Sub-Negotiation"); | |
1171 | break; | |
1172 | case (byte)TELNET_NOP: | |
1173 | // log.debug1(" NOP"); | |
1174 | break; | |
1175 | case (byte)TELNET_DM: | |
1176 | // log.debug1(" Data Mark"); | |
1177 | break; | |
1178 | case (byte)TELNET_BRK: | |
1179 | // log.debug1(" Break"); | |
1180 | break; | |
1181 | case (byte)TELNET_IP: | |
1182 | // log.debug1(" Interrupt Process"); | |
1183 | break; | |
1184 | case (byte)TELNET_AO: | |
1185 | // log.debug1(" Abort Output"); | |
1186 | break; | |
1187 | case (byte)TELNET_AYT: | |
1188 | // log.debug1(" Are You There?"); | |
1189 | break; | |
1190 | case (byte)TELNET_EC: | |
1191 | // log.debug1(" Erase Character"); | |
1192 | break; | |
1193 | case (byte)TELNET_EL: | |
1194 | // log.debug1(" Erase Line"); | |
1195 | break; | |
1196 | case (byte)TELNET_GA: | |
1197 | // log.debug1(" Go Ahead"); | |
1198 | break; | |
1199 | case (byte)TELNET_SB: | |
1200 | // log.debug1(" START Sub-Negotiation"); | |
1201 | // From here we wait for the IAC SE | |
1202 | subnegEnd = true; | |
1203 | subnegBuffer.clear(); | |
1204 | break; | |
1205 | case (byte)TELNET_WILL: | |
1206 | // log.debug1(" WILL"); | |
1207 | dowill = true; | |
1208 | dowillType = b; | |
1209 | break; | |
1210 | case (byte)TELNET_WONT: | |
1211 | // log.debug1(" WON'T"); | |
1212 | dowill = true; | |
1213 | dowillType = b; | |
1214 | break; | |
1215 | case (byte)TELNET_DO: | |
1216 | // log.debug1(" DO"); | |
1217 | dowill = true; | |
1218 | dowillType = b; | |
1219 | ||
1220 | if (master.binaryMode == true) { | |
1221 | // log.debug1("Telnet DO in binary mode"); | |
1222 | } | |
1223 | ||
1224 | break; | |
1225 | case (byte)TELNET_DONT: | |
1226 | // log.debug1(" DON'T"); | |
1227 | dowill = true; | |
1228 | dowillType = b; | |
1229 | break; | |
1230 | default: | |
1231 | // This should be equivalent to IAC NOP | |
1232 | // log.debug1("Will treat as IAC NOP"); | |
1233 | break; | |
1234 | } | |
1235 | iac = false; | |
1236 | continue; | |
1237 | ||
1238 | } // if (iac == true) | |
1239 | ||
1240 | /* | |
1241 | * All of the regular IAC processing is completed at this | |
1242 | * point. Now we need to handle the CR and CR LF cases. | |
1243 | * | |
1244 | * According to RFC 854, in NVT ASCII mode: | |
1245 | * Bare CR -> CR NUL | |
1246 | * CR LF -> CR LF | |
1247 | * | |
1248 | */ | |
1249 | if (master.binaryMode == false) { | |
1250 | ||
1251 | if (b == C_LF) { | |
1252 | if (readCR == true) { | |
1253 | // This is CR LF. Send CR LF and turn the cr | |
1254 | // flag off. | |
1255 | buf[bufN++] = C_CR; | |
1256 | buf[bufN++] = C_LF; | |
1257 | readCR = false; | |
1258 | continue; | |
1259 | } | |
1260 | // This is bare LF. Send LF. | |
1261 | buf[bufN++] = C_LF; | |
1262 | continue; | |
1263 | } | |
1264 | ||
1265 | if (b == C_NUL) { | |
1266 | if (readCR == true) { | |
1267 | // This is CR NUL. Send CR and turn the cr | |
1268 | // flag off. | |
1269 | buf[bufN++] = C_CR; | |
1270 | readCR = false; | |
1271 | continue; | |
1272 | } | |
1273 | // This is bare NUL. Send NUL. | |
1274 | buf[bufN++] = C_NUL; | |
1275 | continue; | |
1276 | } | |
1277 | ||
1278 | if (b == C_CR) { | |
1279 | if (readCR == true) { | |
1280 | // This is CR CR. Send a CR NUL and leave | |
1281 | // the cr flag on. | |
1282 | buf[bufN++] = C_CR; | |
1283 | buf[bufN++] = C_NUL; | |
1284 | continue; | |
1285 | } | |
1286 | // This is the first CR. Set the cr flag. | |
1287 | readCR = true; | |
1288 | continue; | |
1289 | } | |
1290 | ||
1291 | if (readCR == true) { | |
1292 | // This was a bare CR in the stream. | |
1293 | buf[bufN++] = C_CR; | |
1294 | readCR = false; | |
1295 | } | |
1296 | ||
1297 | // This is a regular character. Pass it on. | |
1298 | buf[bufN++] = b; | |
1299 | continue; | |
1300 | } | |
1301 | ||
1302 | /* | |
1303 | * This is the case for any of: | |
1304 | * | |
1305 | * 1) A NVT ASCII character that isn't CR, LF, or | |
1306 | * NUL. | |
1307 | * | |
1308 | * 2) A NVT binary character. | |
1309 | * | |
1310 | * For all of these cases, we just pass the character on. | |
1311 | */ | |
1312 | buf[bufN++] = b; | |
1313 | ||
1314 | } // if (b == TELNET_IAC) | |
1315 | ||
1316 | } // for (int i = 0; i < bufferN; i++) | |
1317 | ||
1318 | } while (bufN == 0); | |
1319 | ||
1320 | // Return bytes read | |
1321 | return bufN; | |
005ec497 KL |
1322 | } |
1323 | ||
ea91242c KL |
1324 | |
1325 | } |