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- Fixes '=' whitespace
[openocd.git] / src / server / telnet_server.c
blob82b7330e90509451ba7a4a24869d438340848454
1 /***************************************************************************
2 * Copyright (C) 2005 by Dominic Rath *
3 * Dominic.Rath@gmx.de *
4 * *
5 * Copyright (C) 2007,2008 Øyvind Harboe *
6 * oyvind.harboe@zylin.com *
7 * *
8 * Copyright (C) 2008 by Spencer Oliver *
9 * spen@spen-soft.co.uk *
10 * *
11 * This program is free software; you can redistribute it and/or modify *
12 * it under the terms of the GNU General Public License as published by *
13 * the Free Software Foundation; either version 2 of the License, or *
14 * (at your option) any later version. *
15 * *
16 * This program is distributed in the hope that it will be useful, *
17 * but WITHOUT ANY WARRANTY; without even the implied warranty of *
18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the *
19 * GNU General Public License for more details. *
20 * *
21 * You should have received a copy of the GNU General Public License *
22 * along with this program; if not, write to the *
23 * Free Software Foundation, Inc., *
24 * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. *
25 ***************************************************************************/
26 #ifdef HAVE_CONFIG_H
27 #include "config.h"
28 #endif
29
30 #include "telnet_server.h"
31 #include "target_request.h"
32
33 static unsigned short telnet_port = 4444;
34
35 int handle_exit_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc);
36 int handle_telnet_port_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc);
37
38 static char *negotiate =
39 "\xFF\xFB\x03" /* IAC WILL Suppress Go Ahead */
40 "\xFF\xFB\x01" /* IAC WILL Echo */
41 "\xFF\xFD\x03" /* IAC DO Suppress Go Ahead */
42 "\xFF\xFE\x01"; /* IAC DON'T Echo */
43
44 #define CTRL(c) (c - '@')
45
46 /* The only way we can detect that the socket is closed is the first time
47 * we write to it, we will fail. Subsequent write operations will
48 * succeed. Shudder!
49 */
50 int telnet_write(connection_t *connection, const void *data, int len)
51 {
52 telnet_connection_t *t_con = connection->priv;
53 if (t_con->closed)
54 return ERROR_SERVER_REMOTE_CLOSED;
55
56 if (write_socket(connection->fd, data, len) == len)
57 {
58 return ERROR_OK;
59 }
60 t_con->closed = 1;
61 return ERROR_SERVER_REMOTE_CLOSED;
62 }
63
64 int telnet_prompt(connection_t *connection)
65 {
66 telnet_connection_t *t_con = connection->priv;
67
68 telnet_write(connection, "\r", 1); /* the prompt is always placed at the line beginning */
69 return telnet_write(connection, t_con->prompt, strlen(t_con->prompt));
70 }
71
72 int telnet_outputline(connection_t *connection, const char *line)
73 {
74 int len;
75
76 /* process lines in buffer */
77 while (*line) {
78 char *line_end = strchr(line, '\n');
79
80 if (line_end)
81 len = line_end-line;
82 else
83 len = strlen(line);
84
85 telnet_write(connection, line, len);
86 if (line_end)
87 {
88 telnet_write(connection, "\r\n", 2);
89 line += len+1;
90 }
91 else
92 {
93 line += len;
94 }
95 }
96
97 return ERROR_OK;
98 }
99
100 int telnet_output(struct command_context_s *cmd_ctx, const char* line)
101 {
102 connection_t *connection = cmd_ctx->output_handler_priv;
103
104 return telnet_outputline(connection, line);
105 }
106
107 void telnet_log_callback(void *priv, const char *file, int line,
108 const char *function, const char *string)
109 {
110 connection_t *connection = priv;
111 telnet_connection_t *t_con = connection->priv;
112 int i;
113
114 /* if there is no prompt, simply output the message */
115 if (t_con->line_cursor < 0)
116 {
117 telnet_outputline(connection, string);
118 return;
119 }
120
121 /* clear the command line */
122 telnet_write(connection, "\r", 1);
123 for (i = strlen(t_con->prompt) + t_con->line_size; i>0; i -= 16)
124 telnet_write(connection, " ", i>16 ? 16 : i);
125 telnet_write(connection, "\r", 1);
126
127 /* output the message */
128 telnet_outputline(connection, string);
129
130 /* put the command line to its previous state */
131 telnet_prompt(connection);
132 telnet_write(connection, t_con->line, t_con->line_size);
133 for (i = t_con->line_size; i>t_con->line_cursor; i--)
134 telnet_write(connection, "\b", 1);
135 }
136
137 int telnet_new_connection(connection_t *connection)
138 {
139 telnet_connection_t *telnet_connection = malloc(sizeof(telnet_connection_t));
140 telnet_service_t *telnet_service = connection->service->priv;
141 int i;
142
143 connection->priv = telnet_connection;
144
145 /* initialize telnet connection information */
146 telnet_connection->closed = 0;
147 telnet_connection->line_size = 0;
148 telnet_connection->line_cursor = 0;
149 telnet_connection->option_size = 0;
150 telnet_connection->prompt = strdup("> ");
151 telnet_connection->state = TELNET_STATE_DATA;
152
153 /* output goes through telnet connection */
154 command_set_output_handler(connection->cmd_ctx, telnet_output, connection);
155
156 /* negotiate telnet options */
157 telnet_write(connection, negotiate, strlen(negotiate));
158
159 /* print connection banner */
160 if (telnet_service->banner)
161 {
162 telnet_write(connection, telnet_service->banner, strlen(telnet_service->banner));
163 telnet_write(connection, "\r\n", 2);
164 }
165
166 telnet_prompt(connection);
167
168 /* initialize history */
169 for (i = 0; i < TELNET_LINE_HISTORY_SIZE; i++)
170 {
171 telnet_connection->history[i] = NULL;
172 }
173 telnet_connection->next_history = 0;
174 telnet_connection->current_history = 0;
175
176 log_add_callback(telnet_log_callback, connection);
177
178 return ERROR_OK;
179 }
180
181 void telnet_clear_line(connection_t *connection, telnet_connection_t *t_con)
182 {
183 /* move to end of line */
184 if (t_con->line_cursor < t_con->line_size)
185 {
186 telnet_write(connection, t_con->line + t_con->line_cursor, t_con->line_size - t_con->line_cursor);
187 }
188
189 /* backspace, overwrite with space, backspace */
190 while (t_con->line_size > 0)
191 {
192 telnet_write(connection, "\b \b", 3);
193 t_con->line_size--;
194 }
195 t_con->line_cursor = 0;
196 }
197
198 int telnet_input(connection_t *connection)
199 {
200 int bytes_read;
201 char buffer[TELNET_BUFFER_SIZE];
202 char *buf_p;
203 telnet_connection_t *t_con = connection->priv;
204 command_context_t *command_context = connection->cmd_ctx;
205
206 bytes_read = read_socket(connection->fd, buffer, TELNET_BUFFER_SIZE);
207
208 if (bytes_read == 0)
209 return ERROR_SERVER_REMOTE_CLOSED;
210 else if (bytes_read == -1)
211 {
212 LOG_ERROR("error during read: %s", strerror(errno));
213 return ERROR_SERVER_REMOTE_CLOSED;
214 }
215
216 buf_p = buffer;
217 while (bytes_read)
218 {
219 switch (t_con->state)
220 {
221 case TELNET_STATE_DATA:
222 if (*buf_p == '\xff')
223 {
224 t_con->state = TELNET_STATE_IAC;
225 }
226 else
227 {
228 if (isprint(*buf_p)) /* printable character */
229 {
230 /* watch buffer size leaving one spare character for string null termination */
231 if (t_con->line_size == TELNET_LINE_MAX_SIZE-1)
232 {
233 /* output audible bell if buffer is full */
234 telnet_write(connection, "\x07", 1); /* "\a" does not work, at least on windows */
235 }
236 else if (t_con->line_cursor == t_con->line_size)
237 {
238 telnet_write(connection, buf_p, 1);
239 t_con->line[t_con->line_size++] = *buf_p;
240 t_con->line_cursor++;
241 }
242 else
243 {
244 int i;
245 memmove(t_con->line + t_con->line_cursor + 1, t_con->line + t_con->line_cursor, t_con->line_size - t_con->line_cursor);
246 t_con->line[t_con->line_cursor] = *buf_p;
247 t_con->line_size++;
248 telnet_write(connection, t_con->line + t_con->line_cursor, t_con->line_size - t_con->line_cursor);
249 t_con->line_cursor++;
250 for (i = t_con->line_cursor; i < t_con->line_size; i++)
251 {
252 telnet_write(connection, "\b", 1);
253 }
254 }
255 }
256 else /* non-printable */
257 {
258 if (*buf_p == 0x1b) /* escape */
259 {
260 t_con->state = TELNET_STATE_ESCAPE;
261 t_con->last_escape = '\x00';
262 }
263 else if ((*buf_p == 0xd) || (*buf_p == 0xa)) /* CR/LF */
264 {
265 int retval;
266
267 /* skip over combinations with CR/LF and NUL characters */
268 if ((bytes_read > 1) && ((*(buf_p + 1) == 0xa) || (*(buf_p + 1) == 0xd)))
269 {
270 buf_p++;
271 bytes_read--;
272 }
273 if ((bytes_read > 1) && (*(buf_p + 1) == 0))
274 {
275 buf_p++;
276 bytes_read--;
277 }
278 t_con->line[t_con->line_size] = 0;
279
280 telnet_write(connection, "\r\n\x00", 3);
281
282 if (strcmp(t_con->line, "history") == 0)
283 {
284 int i;
285 for (i = 1; i < TELNET_LINE_HISTORY_SIZE; i++)
286 {
287 /* the t_con->next_history line contains empty string (unless NULL), thus it is not printed */
288 char *history_line = t_con->history[(t_con->next_history + i) % TELNET_LINE_HISTORY_SIZE];
289 if (history_line)
290 {
291 telnet_write(connection, history_line, strlen(history_line));
292 telnet_write(connection, "\r\n\x00", 3);
293 }
294 }
295 t_con->line_size = 0;
296 t_con->line_cursor = 0;
297 continue;
298 }
299
300 /* save only non-blank not repeating lines in the history */
301 char *prev_line = t_con->history[(t_con->current_history > 0) ? t_con->current_history - 1 : TELNET_LINE_HISTORY_SIZE-1];
302 if (*t_con->line && (prev_line == NULL || strcmp(t_con->line, prev_line)))
303 {
304 /* if the history slot is already taken, free it */
305 if (t_con->history[t_con->next_history])
306 {
307 free(t_con->history[t_con->next_history]);
308 }
309
310 /* add line to history */
311 t_con->history[t_con->next_history] = strdup(t_con->line);
312
313 /* wrap history at TELNET_LINE_HISTORY_SIZE */
314 t_con->next_history = (t_con->next_history + 1) % TELNET_LINE_HISTORY_SIZE;
315
316 /* current history line starts at the new entry */
317 t_con->current_history = t_con->next_history;
318
319 if (t_con->history[t_con->current_history])
320 {
321 free(t_con->history[t_con->current_history]);
322 }
323 t_con->history[t_con->current_history] = strdup("");
324 }
325
326 t_con->line_size = 0;
327
328 t_con->line_cursor = -1; /* to supress prompt in log callback during command execution */
329
330 retval = command_run_line(command_context, t_con->line);
331
332 t_con->line_cursor = 0;
333
334 if (retval == ERROR_COMMAND_CLOSE_CONNECTION)
335 return ERROR_SERVER_REMOTE_CLOSED;
336
337 retval = telnet_prompt(connection);
338 if (retval == ERROR_SERVER_REMOTE_CLOSED)
339 return ERROR_SERVER_REMOTE_CLOSED;
340
341 }
342 else if ((*buf_p == 0x7f) || (*buf_p == 0x8)) /* delete character */
343 {
344 if (t_con->line_cursor > 0)
345 {
346 if (t_con->line_cursor != t_con->line_size)
347 {
348 int i;
349 telnet_write(connection, "\b", 1);
350 t_con->line_cursor--;
351 t_con->line_size--;
352 memmove(t_con->line + t_con->line_cursor, t_con->line + t_con->line_cursor + 1, t_con->line_size - t_con->line_cursor);
353
354 telnet_write(connection, t_con->line + t_con->line_cursor, t_con->line_size - t_con->line_cursor);
355 telnet_write(connection, " \b", 2);
356 for (i = t_con->line_cursor; i < t_con->line_size; i++)
357 {
358 telnet_write(connection, "\b", 1);
359 }
360 }
361 else
362 {
363 t_con->line_size--;
364 t_con->line_cursor--;
365 /* back space: move the 'printer' head one char back, overwrite with space, move back again */
366 telnet_write(connection, "\b \b", 3);
367 }
368 }
369 }
370 else if (*buf_p == 0x15) /* clear line */
371 {
372 telnet_clear_line(connection, t_con);
373 }
374 else if (*buf_p == CTRL('B')) /* cursor left */
375 {
376 if (t_con->line_cursor > 0)
377 {
378 telnet_write(connection, "\b", 1);
379 t_con->line_cursor--;
380 }
381 t_con->state = TELNET_STATE_DATA;
382 }
383 else if (*buf_p == CTRL('F')) /* cursor right */
384 {
385 if (t_con->line_cursor < t_con->line_size)
386 {
387 telnet_write(connection, t_con->line + t_con->line_cursor++, 1);
388 }
389 t_con->state = TELNET_STATE_DATA;
390 }
391 else
392 {
393 LOG_DEBUG("unhandled nonprintable: %2.2x", *buf_p);
394 }
395 }
396 }
397 break;
398 case TELNET_STATE_IAC:
399 switch (*buf_p)
400 {
401 case '\xfe':
402 t_con->state = TELNET_STATE_DONT;
403 break;
404 case '\xfd':
405 t_con->state = TELNET_STATE_DO;
406 break;
407 case '\xfc':
408 t_con->state = TELNET_STATE_WONT;
409 break;
410 case '\xfb':
411 t_con->state = TELNET_STATE_WILL;
412 break;
413 }
414 break;
415 case TELNET_STATE_SB:
416 break;
417 case TELNET_STATE_SE:
418 break;
419 case TELNET_STATE_WILL:
420 case TELNET_STATE_WONT:
421 case TELNET_STATE_DO:
422 case TELNET_STATE_DONT:
423 t_con->state = TELNET_STATE_DATA;
424 break;
425 case TELNET_STATE_ESCAPE:
426 if (t_con->last_escape == '[')
427 {
428 if (*buf_p == 'D') /* cursor left */
429 {
430 if (t_con->line_cursor > 0)
431 {
432 telnet_write(connection, "\b", 1);
433 t_con->line_cursor--;
434 }
435 t_con->state = TELNET_STATE_DATA;
436 }
437 else if (*buf_p == 'C') /* cursor right */
438 {
439 if (t_con->line_cursor < t_con->line_size)
440 {
441 telnet_write(connection, t_con->line + t_con->line_cursor++, 1);
442 }
443 t_con->state = TELNET_STATE_DATA;
444 }
445 else if (*buf_p == 'A') /* cursor up */
446 {
447 int last_history = (t_con->current_history > 0) ? t_con->current_history - 1 : TELNET_LINE_HISTORY_SIZE-1;
448 if (t_con->history[last_history])
449 {
450 telnet_clear_line(connection, t_con);
451 t_con->line_size = strlen(t_con->history[last_history]);
452 t_con->line_cursor = t_con->line_size;
453 memcpy(t_con->line, t_con->history[last_history], t_con->line_size);
454 telnet_write(connection, t_con->line, t_con->line_size);
455 t_con->current_history = last_history;
456 }
457 t_con->state = TELNET_STATE_DATA;
458 }
459 else if (*buf_p == 'B') /* cursor down */
460 {
461 int next_history = (t_con->current_history + 1) % TELNET_LINE_HISTORY_SIZE;
462 if (t_con->history[next_history])
463 {
464 telnet_clear_line(connection, t_con);
465 t_con->line_size = strlen(t_con->history[next_history]);
466 t_con->line_cursor = t_con->line_size;
467 memcpy(t_con->line, t_con->history[next_history], t_con->line_size);
468 telnet_write(connection, t_con->line, t_con->line_size);
469 t_con->current_history = next_history;
470 }
471 t_con->state = TELNET_STATE_DATA;
472 }
473 else if (*buf_p == '3')
474 {
475 t_con->last_escape = *buf_p;
476 }
477 else
478 {
479 t_con->state = TELNET_STATE_DATA;
480 }
481 }
482 else if (t_con->last_escape == '3')
483 {
484 /* Remove character */
485 if (*buf_p == '~')
486 {
487 if (t_con->line_cursor < t_con->line_size)
488 {
489 int i;
490 t_con->line_size--;
491 /* remove char from line buffer */
492 memmove(t_con->line + t_con->line_cursor, t_con->line + t_con->line_cursor + 1, t_con->line_size - t_con->line_cursor);
493
494 /* print remainder of buffer */
495 telnet_write(connection, t_con->line + t_con->line_cursor, t_con->line_size - t_con->line_cursor);
496 /* overwrite last char with whitespace */
497 telnet_write(connection, " \b", 2);
498
499 /* move back to cursor position*/
500 for (i = t_con->line_cursor; i < t_con->line_size; i++)
501 {
502 telnet_write(connection, "\b", 1);
503 }
504 }
505
506 t_con->state = TELNET_STATE_DATA;
507 }
508 else
509 {
510 t_con->state = TELNET_STATE_DATA;
511 }
512 }
513 else if (t_con->last_escape == '\x00')
514 {
515 if (*buf_p == '[')
516 {
517 t_con->last_escape = *buf_p;
518 }
519 else
520 {
521 t_con->state = TELNET_STATE_DATA;
522 }
523 }
524 else
525 {
526 LOG_ERROR("BUG: unexpected value in t_con->last_escape");
527 t_con->state = TELNET_STATE_DATA;
528 }
529
530 break;
531 default:
532 LOG_ERROR("unknown telnet state");
533 exit(-1);
534 }
535
536 bytes_read--;
537 buf_p++;
538 }
539
540 return ERROR_OK;
541 }
542
543 int telnet_connection_closed(connection_t *connection)
544 {
545 telnet_connection_t *t_con = connection->priv;
546 int i;
547
548 log_remove_callback(telnet_log_callback, connection);
549
550 if (t_con->prompt)
551 {
552 free(t_con->prompt);
553 t_con->prompt = NULL;
554 }
555
556 for (i = 0; i < TELNET_LINE_HISTORY_SIZE; i++)
557 {
558 if (t_con->history[i])
559 {
560 free(t_con->history[i]);
561 t_con->history[i] = NULL;
562 }
563 }
564
565 /* if this connection registered a debug-message receiver delete it */
566 delete_debug_msg_receiver(connection->cmd_ctx, NULL);
567
568 if (connection->priv)
569 {
570 free(connection->priv);
571 connection->priv = NULL;
572 }
573 else
574 {
575 LOG_ERROR("BUG: connection->priv == NULL");
576 }
577
578 return ERROR_OK;
579 }
580
581 int telnet_set_prompt(connection_t *connection, char *prompt)
582 {
583 telnet_connection_t *t_con = connection->priv;
584
585 if (t_con->prompt != NULL)
586 free(t_con->prompt);
587
588 t_con->prompt = strdup(prompt);
589
590 return ERROR_OK;
591 }
592
593 int telnet_init(char *banner)
594 {
595 telnet_service_t *telnet_service = malloc(sizeof(telnet_service_t));
596
597 if (telnet_port == 0)
598 {
599 LOG_INFO("telnet port disabled");
600 return ERROR_OK;
601 }
602
603 telnet_service->banner = banner;
604
605 add_service("telnet", CONNECTION_TCP, telnet_port, 1, telnet_new_connection, telnet_input, telnet_connection_closed, telnet_service);
606
607 return ERROR_OK;
608 }
609
610 int telnet_register_commands(command_context_t *command_context)
611 {
612 register_command(command_context, NULL, "exit", handle_exit_command,
613 COMMAND_EXEC, "exit telnet session");
614
615 register_command(command_context, NULL, "telnet_port", handle_telnet_port_command,
616 COMMAND_ANY, "port on which to listen for incoming telnet connections");
617
618 return ERROR_OK;
619 }
620
621 /* daemon configuration command telnet_port */
622 int handle_telnet_port_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc)
623 {
624 if (argc == 0)
625 {
626 command_print(cmd_ctx, "%d", telnet_port);
627 return ERROR_OK;
628 }
629
630 telnet_port = strtoul(args[0], NULL, 0);
631
632 return ERROR_OK;
633 }
634
635 int handle_exit_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc)
636 {
637 return ERROR_COMMAND_CLOSE_CONNECTION;
638 }
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