server: use register_commands
[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(struct connection *connection, const void *data, int len)
48 {
49 struct telnet_connection *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(struct connection *connection)
62 {
63 struct telnet_connection *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(struct connection *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 *cmd_ctx, const char* line)
98 {
99 struct connection *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 struct connection *connection = priv;
108 struct telnet_connection *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(struct connection *connection)
135 {
136 struct telnet_connection *telnet_connection = malloc(sizeof(struct telnet_connection));
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(struct connection *connection, struct telnet_connection *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(struct connection *connection)
196 {
197 int bytes_read;
198 char buffer[TELNET_BUFFER_SIZE];
199 char *buf_p;
200 struct telnet_connection *t_con = connection->priv;
201 struct command_context *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(struct connection *connection)
541 {
542 struct telnet_connection *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(struct connection *connection, char *prompt)
579 {
580 struct telnet_connection *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 static const struct command_registration telnet_command_handlers[] = {
620 {
621 .name = "exit",
622 .handler = &handle_exit_command,
623 .mode = COMMAND_EXEC,
624 .help = "exit telnet session",
625 },
626 {
627 .name = "telnet_port",
628 .handler = &handle_telnet_port_command,
629 .mode = COMMAND_ANY,
630 .help = "port on which to listen "
631 "for incoming telnet connections",
632 .usage = "<port>",
633 },
634 COMMAND_REGISTRATION_DONE
635 };
636
637 int telnet_register_commands(struct command_context *cmd_ctx)
638 {
639 return register_commands(cmd_ctx, NULL, telnet_command_handlers);
640 }