9c6115588f43bd4e696d3f3d3d16ffd03d3d6205
[openocd.git] / src / server / telnet_server.c
1 /***************************************************************************
2 * Copyright (C) 2005 by Dominic Rath *
3 * Dominic.Rath@gmx.de *
4 * *
5 * Copyright (C) 2007,2008 √ėyvind 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 static char *negotiate =
36 "\xFF\xFB\x03" /* IAC WILL Suppress Go Ahead */
37 "\xFF\xFB\x01" /* IAC WILL Echo */
38 "\xFF\xFD\x03" /* IAC DO Suppress Go Ahead */
39 "\xFF\xFE\x01"; /* IAC DON'T Echo */
40
41 #define CTRL(c) (c - '@')
42
43 /* The only way we can detect that the socket is closed is the first time
44 * we write to it, we will fail. Subsequent write operations will
45 * succeed. Shudder!
46 */
47 int telnet_write(connection_t *connection, const void *data, int len)
48 {
49 telnet_connection_t *t_con = connection->priv;
50 if (t_con->closed)
51 return ERROR_SERVER_REMOTE_CLOSED;
52
53 if (write_socket(connection->fd, data, len) == len)
54 {
55 return ERROR_OK;
56 }
57 t_con->closed = 1;
58 return ERROR_SERVER_REMOTE_CLOSED;
59 }
60
61 int telnet_prompt(connection_t *connection)
62 {
63 telnet_connection_t *t_con = connection->priv;
64
65 telnet_write(connection, "\r", 1); /* the prompt is always placed at the line beginning */
66 return telnet_write(connection, t_con->prompt, strlen(t_con->prompt));
67 }
68
69 int telnet_outputline(connection_t *connection, const char *line)
70 {
71 int len;
72
73 /* process lines in buffer */
74 while (*line) {
75 char *line_end = strchr(line, '\n');
76
77 if (line_end)
78 len = line_end-line;
79 else
80 len = strlen(line);
81
82 telnet_write(connection, line, len);
83 if (line_end)
84 {
85 telnet_write(connection, "\r\n", 2);
86 line += len + 1;
87 }
88 else
89 {
90 line += len;
91 }
92 }
93
94 return ERROR_OK;
95 }
96
97 int telnet_output(struct command_context_s *cmd_ctx, const char* line)
98 {
99 connection_t *connection = cmd_ctx->output_handler_priv;
100
101 return telnet_outputline(connection, line);
102 }
103
104 void telnet_log_callback(void *priv, const char *file, unsigned line,
105 const char *function, const char *string)
106 {
107 connection_t *connection = priv;
108 telnet_connection_t *t_con = connection->priv;
109 int i;
110
111 /* if there is no prompt, simply output the message */
112 if (t_con->line_cursor < 0)
113 {
114 telnet_outputline(connection, string);
115 return;
116 }
117
118 /* clear the command line */
119 telnet_write(connection, "\r", 1);
120 for (i = strlen(t_con->prompt) + t_con->line_size; i > 0; i -= 16)
121 telnet_write(connection, " ", i > 16 ? 16 : i);
122 telnet_write(connection, "\r", 1);
123
124 /* output the message */
125 telnet_outputline(connection, string);
126
127 /* put the command line to its previous state */
128 telnet_prompt(connection);
129 telnet_write(connection, t_con->line, t_con->line_size);
130 for (i = t_con->line_size; i > t_con->line_cursor; i--)
131 telnet_write(connection, "\b", 1);
132 }
133
134 int telnet_new_connection(connection_t *connection)
135 {
136 telnet_connection_t *telnet_connection = malloc(sizeof(telnet_connection_t));
137 struct telnet_service *telnet_service = connection->service->priv;
138 int i;
139
140 connection->priv = telnet_connection;
141
142 /* initialize telnet connection information */
143 telnet_connection->closed = 0;
144 telnet_connection->line_size = 0;
145 telnet_connection->line_cursor = 0;
146 telnet_connection->option_size = 0;
147 telnet_connection->prompt = strdup("> ");
148 telnet_connection->state = TELNET_STATE_DATA;
149
150 /* output goes through telnet connection */
151 command_set_output_handler(connection->cmd_ctx, telnet_output, connection);
152
153 /* negotiate telnet options */
154 telnet_write(connection, negotiate, strlen(negotiate));
155
156 /* print connection banner */
157 if (telnet_service->banner)
158 {
159 telnet_write(connection, telnet_service->banner, strlen(telnet_service->banner));
160 telnet_write(connection, "\r\n", 2);
161 }
162
163 telnet_prompt(connection);
164
165 /* initialize history */
166 for (i = 0; i < TELNET_LINE_HISTORY_SIZE; i++)
167 {
168 telnet_connection->history[i] = NULL;
169 }
170 telnet_connection->next_history = 0;
171 telnet_connection->current_history = 0;
172
173 log_add_callback(telnet_log_callback, connection);
174
175 return ERROR_OK;
176 }
177
178 void telnet_clear_line(connection_t *connection, telnet_connection_t *t_con)
179 {
180 /* move to end of line */
181 if (t_con->line_cursor < t_con->line_size)
182 {
183 telnet_write(connection, t_con->line + t_con->line_cursor, t_con->line_size - t_con->line_cursor);
184 }
185
186 /* backspace, overwrite with space, backspace */
187 while (t_con->line_size > 0)
188 {
189 telnet_write(connection, "\b \b", 3);
190 t_con->line_size--;
191 }
192 t_con->line_cursor = 0;
193 }
194
195 int telnet_input(connection_t *connection)
196 {
197 int bytes_read;
198 char buffer[TELNET_BUFFER_SIZE];
199 char *buf_p;
200 telnet_connection_t *t_con = connection->priv;
201 command_context_t *command_context = connection->cmd_ctx;
202
203 bytes_read = read_socket(connection->fd, buffer, TELNET_BUFFER_SIZE);
204
205 if (bytes_read == 0)
206 return ERROR_SERVER_REMOTE_CLOSED;
207 else if (bytes_read == -1)
208 {
209 LOG_ERROR("error during read: %s", strerror(errno));
210 return ERROR_SERVER_REMOTE_CLOSED;
211 }
212
213 buf_p = buffer;
214 while (bytes_read)
215 {
216 switch (t_con->state)
217 {
218 case TELNET_STATE_DATA:
219 if (*buf_p == '\xff')
220 {
221 t_con->state = TELNET_STATE_IAC;
222 }
223 else
224 {
225 if (isprint(*buf_p)) /* printable character */
226 {
227 /* watch buffer size leaving one spare character for string null termination */
228 if (t_con->line_size == TELNET_LINE_MAX_SIZE-1)
229 {
230 /* output audible bell if buffer is full */
231 telnet_write(connection, "\x07", 1); /* "\a" does not work, at least on windows */
232 }
233 else if (t_con->line_cursor == t_con->line_size)
234 {
235 telnet_write(connection, buf_p, 1);
236 t_con->line[t_con->line_size++] = *buf_p;
237 t_con->line_cursor++;
238 }
239 else
240 {
241 int i;
242 memmove(t_con->line + t_con->line_cursor + 1, t_con->line + t_con->line_cursor, t_con->line_size - t_con->line_cursor);
243 t_con->line[t_con->line_cursor] = *buf_p;
244 t_con->line_size++;
245 telnet_write(connection, t_con->line + t_con->line_cursor, t_con->line_size - t_con->line_cursor);
246 t_con->line_cursor++;
247 for (i = t_con->line_cursor; i < t_con->line_size; i++)
248 {
249 telnet_write(connection, "\b", 1);
250 }
251 }
252 }
253 else /* non-printable */
254 {
255 if (*buf_p == 0x1b) /* escape */
256 {
257 t_con->state = TELNET_STATE_ESCAPE;
258 t_con->last_escape = '\x00';
259 }
260 else if ((*buf_p == 0xd) || (*buf_p == 0xa)) /* CR/LF */
261 {
262 int retval;
263
264 /* skip over combinations with CR/LF and NUL characters */
265 if ((bytes_read > 1) && ((*(buf_p + 1) == 0xa) || (*(buf_p + 1) == 0xd)))
266 {
267 buf_p++;
268 bytes_read--;
269 }
270 if ((bytes_read > 1) && (*(buf_p + 1) == 0))
271 {
272 buf_p++;
273 bytes_read--;
274 }
275 t_con->line[t_con->line_size] = 0;
276
277 telnet_write(connection, "\r\n\x00", 3);
278
279 if (strcmp(t_con->line, "history") == 0)
280 {
281 int i;
282 for (i = 1; i < TELNET_LINE_HISTORY_SIZE; i++)
283 {
284 /* the t_con->next_history line contains empty string (unless NULL), thus it is not printed */
285 char *history_line = t_con->history[(t_con->next_history + i) % TELNET_LINE_HISTORY_SIZE];
286 if (history_line)
287 {
288 telnet_write(connection, history_line, strlen(history_line));
289 telnet_write(connection, "\r\n\x00", 3);
290 }
291 }
292 t_con->line_size = 0;
293 t_con->line_cursor = 0;
294 continue;
295 }
296
297 /* save only non-blank not repeating lines in the history */
298 char *prev_line = t_con->history[(t_con->current_history > 0) ? t_con->current_history - 1 : TELNET_LINE_HISTORY_SIZE-1];
299 if (*t_con->line && (prev_line == NULL || strcmp(t_con->line, prev_line)))
300 {
301 /* if the history slot is already taken, free it */
302 if (t_con->history[t_con->next_history])
303 {
304 free(t_con->history[t_con->next_history]);
305 }
306
307 /* add line to history */
308 t_con->history[t_con->next_history] = strdup(t_con->line);
309
310 /* wrap history at TELNET_LINE_HISTORY_SIZE */
311 t_con->next_history = (t_con->next_history + 1) % TELNET_LINE_HISTORY_SIZE;
312
313 /* current history line starts at the new entry */
314 t_con->current_history = t_con->next_history;
315
316 if (t_con->history[t_con->current_history])
317 {
318 free(t_con->history[t_con->current_history]);
319 }
320 t_con->history[t_con->current_history] = strdup("");
321 }
322
323 t_con->line_size = 0;
324
325 t_con->line_cursor = -1; /* to supress prompt in log callback during command execution */
326
327 retval = command_run_line(command_context, t_con->line);
328
329 t_con->line_cursor = 0;
330
331 if (retval == ERROR_COMMAND_CLOSE_CONNECTION)
332 return ERROR_SERVER_REMOTE_CLOSED;
333
334 retval = telnet_prompt(connection);
335 if (retval == ERROR_SERVER_REMOTE_CLOSED)
336 return ERROR_SERVER_REMOTE_CLOSED;
337
338 }
339 else if ((*buf_p == 0x7f) || (*buf_p == 0x8)) /* delete character */
340 {
341 if (t_con->line_cursor > 0)
342 {
343 if (t_con->line_cursor != t_con->line_size)
344 {
345 int i;
346 telnet_write(connection, "\b", 1);
347 t_con->line_cursor--;
348 t_con->line_size--;
349 memmove(t_con->line + t_con->line_cursor, t_con->line + t_con->line_cursor + 1, t_con->line_size - t_con->line_cursor);
350
351 telnet_write(connection, t_con->line + t_con->line_cursor, t_con->line_size - t_con->line_cursor);
352 telnet_write(connection, " \b", 2);
353 for (i = t_con->line_cursor; i < t_con->line_size; i++)
354 {
355 telnet_write(connection, "\b", 1);
356 }
357 }
358 else
359 {
360 t_con->line_size--;
361 t_con->line_cursor--;
362 /* back space: move the 'printer' head one char back, overwrite with space, move back again */
363 telnet_write(connection, "\b \b", 3);
364 }
365 }
366 }
367 else if (*buf_p == 0x15) /* clear line */
368 {
369 telnet_clear_line(connection, t_con);
370 }
371 else if (*buf_p == CTRL('B')) /* cursor left */
372 {
373 if (t_con->line_cursor > 0)
374 {
375 telnet_write(connection, "\b", 1);
376 t_con->line_cursor--;
377 }
378 t_con->state = TELNET_STATE_DATA;
379 }
380 else if (*buf_p == CTRL('F')) /* cursor right */
381 {
382 if (t_con->line_cursor < t_con->line_size)
383 {
384 telnet_write(connection, t_con->line + t_con->line_cursor++, 1);
385 }
386 t_con->state = TELNET_STATE_DATA;
387 }
388 else
389 {
390 LOG_DEBUG("unhandled nonprintable: %2.2x", *buf_p);
391 }
392 }
393 }
394 break;
395 case TELNET_STATE_IAC:
396 switch (*buf_p)
397 {
398 case '\xfe':
399 t_con->state = TELNET_STATE_DONT;
400 break;
401 case '\xfd':
402 t_con->state = TELNET_STATE_DO;
403 break;
404 case '\xfc':
405 t_con->state = TELNET_STATE_WONT;
406 break;
407 case '\xfb':
408 t_con->state = TELNET_STATE_WILL;
409 break;
410 }
411 break;
412 case TELNET_STATE_SB:
413 break;
414 case TELNET_STATE_SE:
415 break;
416 case TELNET_STATE_WILL:
417 case TELNET_STATE_WONT:
418 case TELNET_STATE_DO:
419 case TELNET_STATE_DONT:
420 t_con->state = TELNET_STATE_DATA;
421 break;
422 case TELNET_STATE_ESCAPE:
423 if (t_con->last_escape == '[')
424 {
425 if (*buf_p == 'D') /* cursor left */
426 {
427 if (t_con->line_cursor > 0)
428 {
429 telnet_write(connection, "\b", 1);
430 t_con->line_cursor--;
431 }
432 t_con->state = TELNET_STATE_DATA;
433 }
434 else if (*buf_p == 'C') /* cursor right */
435 {
436 if (t_con->line_cursor < t_con->line_size)
437 {
438 telnet_write(connection, t_con->line + t_con->line_cursor++, 1);
439 }
440 t_con->state = TELNET_STATE_DATA;
441 }
442 else if (*buf_p == 'A') /* cursor up */
443 {
444 int last_history = (t_con->current_history > 0) ? t_con->current_history - 1 : TELNET_LINE_HISTORY_SIZE-1;
445 if (t_con->history[last_history])
446 {
447 telnet_clear_line(connection, t_con);
448 t_con->line_size = strlen(t_con->history[last_history]);
449 t_con->line_cursor = t_con->line_size;
450 memcpy(t_con->line, t_con->history[last_history], t_con->line_size);
451 telnet_write(connection, t_con->line, t_con->line_size);
452 t_con->current_history = last_history;
453 }
454 t_con->state = TELNET_STATE_DATA;
455 }
456 else if (*buf_p == 'B') /* cursor down */
457 {
458 int next_history = (t_con->current_history + 1) % TELNET_LINE_HISTORY_SIZE;
459 if (t_con->history[next_history])
460 {
461 telnet_clear_line(connection, t_con);
462 t_con->line_size = strlen(t_con->history[next_history]);
463 t_con->line_cursor = t_con->line_size;
464 memcpy(t_con->line, t_con->history[next_history], t_con->line_size);
465 telnet_write(connection, t_con->line, t_con->line_size);
466 t_con->current_history = next_history;
467 }
468 t_con->state = TELNET_STATE_DATA;
469 }
470 else if (*buf_p == '3')
471 {
472 t_con->last_escape = *buf_p;
473 }
474 else
475 {
476 t_con->state = TELNET_STATE_DATA;
477 }
478 }
479 else if (t_con->last_escape == '3')
480 {
481 /* Remove character */
482 if (*buf_p == '~')
483 {
484 if (t_con->line_cursor < t_con->line_size)
485 {
486 int i;
487 t_con->line_size--;
488 /* remove char from line buffer */
489 memmove(t_con->line + t_con->line_cursor, t_con->line + t_con->line_cursor + 1, t_con->line_size - t_con->line_cursor);
490
491 /* print remainder of buffer */
492 telnet_write(connection, t_con->line + t_con->line_cursor, t_con->line_size - t_con->line_cursor);
493 /* overwrite last char with whitespace */
494 telnet_write(connection, " \b", 2);
495
496 /* move back to cursor position*/
497 for (i = t_con->line_cursor; i < t_con->line_size; i++)
498 {
499 telnet_write(connection, "\b", 1);
500 }
501 }
502
503 t_con->state = TELNET_STATE_DATA;
504 }
505 else
506 {
507 t_con->state = TELNET_STATE_DATA;
508 }
509 }
510 else if (t_con->last_escape == '\x00')
511 {
512 if (*buf_p == '[')
513 {
514 t_con->last_escape = *buf_p;
515 }
516 else
517 {
518 t_con->state = TELNET_STATE_DATA;
519 }
520 }
521 else
522 {
523 LOG_ERROR("BUG: unexpected value in t_con->last_escape");
524 t_con->state = TELNET_STATE_DATA;
525 }
526
527 break;
528 default:
529 LOG_ERROR("unknown telnet state");
530 exit(-1);
531 }
532
533 bytes_read--;
534 buf_p++;
535 }
536
537 return ERROR_OK;
538 }
539
540 int telnet_connection_closed(connection_t *connection)
541 {
542 telnet_connection_t *t_con = connection->priv;
543 int i;
544
545 log_remove_callback(telnet_log_callback, connection);
546
547 if (t_con->prompt)
548 {
549 free(t_con->prompt);
550 t_con->prompt = NULL;
551 }
552
553 for (i = 0; i < TELNET_LINE_HISTORY_SIZE; i++)
554 {
555 if (t_con->history[i])
556 {
557 free(t_con->history[i]);
558 t_con->history[i] = NULL;
559 }
560 }
561
562 /* if this connection registered a debug-message receiver delete it */
563 delete_debug_msg_receiver(connection->cmd_ctx, NULL);
564
565 if (connection->priv)
566 {
567 free(connection->priv);
568 connection->priv = NULL;
569 }
570 else
571 {
572 LOG_ERROR("BUG: connection->priv == NULL");
573 }
574
575 return ERROR_OK;
576 }
577
578 int telnet_set_prompt(connection_t *connection, char *prompt)
579 {
580 telnet_connection_t *t_con = connection->priv;
581
582 if (t_con->prompt != NULL)
583 free(t_con->prompt);
584
585 t_con->prompt = strdup(prompt);
586
587 return ERROR_OK;
588 }
589
590 int telnet_init(char *banner)
591 {
592 struct telnet_service *telnet_service = malloc(sizeof(struct telnet_service));
593
594 if (telnet_port == 0)
595 {
596 LOG_INFO("telnet port disabled");
597 free(telnet_service);
598 return ERROR_OK;
599 }
600
601 telnet_service->banner = banner;
602
603 add_service("telnet", CONNECTION_TCP, telnet_port, 1, telnet_new_connection, telnet_input, telnet_connection_closed, telnet_service);
604
605 return ERROR_OK;
606 }
607
608 /* daemon configuration command telnet_port */
609 COMMAND_HANDLER(handle_telnet_port_command)
610 {
611 return CALL_COMMAND_HANDLER(server_port_command, &telnet_port);
612 }
613
614 COMMAND_HANDLER(handle_exit_command)
615 {
616 return ERROR_COMMAND_CLOSE_CONNECTION;
617 }
618
619 int telnet_register_commands(command_context_t *command_context)
620 {
621 register_command(command_context, NULL, "exit",
622 &handle_exit_command, COMMAND_EXEC,
623 "exit telnet session");
624
625 register_command(command_context, NULL, "telnet_port",
626 &handle_telnet_port_command, COMMAND_ANY,
627 "port on which to listen for incoming telnet connections");
628
629 return ERROR_OK;
630 }
631
632

Linking to existing account procedure

If you already have an account and want to add another login method you MUST first sign in with your existing account and then change URL to read https://review.openocd.org/login/?link to get to this page again but this time it'll work for linking. Thank you.

SSH host keys fingerprints

1024 SHA256:YKx8b7u5ZWdcbp7/4AeXNaqElP49m6QrwfXaqQGJAOk gerrit-code-review@openocd.zylin.com (DSA)
384 SHA256:jHIbSQa4REvwCFG4cq5LBlBLxmxSqelQPem/EXIrxjk gerrit-code-review@openocd.org (ECDSA)
521 SHA256:UAOPYkU9Fjtcao0Ul/Rrlnj/OsQvt+pgdYSZ4jOYdgs gerrit-code-review@openocd.org (ECDSA)
256 SHA256:A13M5QlnozFOvTllybRZH6vm7iSt0XLxbA48yfc2yfY gerrit-code-review@openocd.org (ECDSA)
256 SHA256:spYMBqEYoAOtK7yZBrcwE8ZpYt6b68Cfh9yEVetvbXg gerrit-code-review@openocd.org (ED25519)
+--[ED25519 256]--+
|=..              |
|+o..   .         |
|*.o   . .        |
|+B . . .         |
|Bo. = o S        |
|Oo.+ + =         |
|oB=.* = . o      |
| =+=.+   + E     |
|. .=o   . o      |
+----[SHA256]-----+
2048 SHA256:0Onrb7/PHjpo6iVZ7xQX2riKN83FJ3KGU0TvI0TaFG4 gerrit-code-review@openocd.zylin.com (RSA)