5353369a1669c60fa9d5350bf5ac76145a6ed98e
[openocd.git] / src / server / telnet_server.c
1 /***************************************************************************
2 * Copyright (C) 2005 by Dominic Rath *
3 * Dominic.Rath@gmx.de *
4 * *
5 * This program is free software; you can redistribute it and/or modify *
6 * it under the terms of the GNU General Public License as published by *
7 * the Free Software Foundation; either version 2 of the License, or *
8 * (at your option) any later version. *
9 * *
10 * This program is distributed in the hope that it will be useful, *
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of *
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the *
13 * GNU General Public License for more details. *
14 * *
15 * You should have received a copy of the GNU General Public License *
16 * along with this program; if not, write to the *
17 * Free Software Foundation, Inc., *
18 * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. *
19 ***************************************************************************/
20 #ifdef HAVE_CONFIG_H
21 #include "config.h"
22 #endif
23
24 #include "replacements.h"
25
26 #include "telnet_server.h"
27
28 #include "server.h"
29 #include "log.h"
30 #include "command.h"
31 #include "target.h"
32 #include "target_request.h"
33
34 #include <stdlib.h>
35 #include <unistd.h>
36 #include <errno.h>
37 #include <string.h>
38 #include <ctype.h>
39
40 static unsigned short telnet_port = 0;
41
42 int handle_exit_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc);
43 int handle_telnet_port_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc);
44
45 static char *negotiate =
46 "\xFF\xFB\x03" /* IAC WILL Suppress Go Ahead */
47 "\xFF\xFB\x01" /* IAC WILL Echo */
48 "\xFF\xFD\x03" /* IAC DO Suppress Go Ahead */
49 "\xFF\xFE\x01"; /* IAC DON'T Echo */
50
51 #define CTRL(c) (c - '@')
52
53 void telnet_prompt(connection_t *connection)
54 {
55 telnet_connection_t *t_con = connection->priv;
56
57 write_socket(connection->fd, t_con->prompt, strlen(t_con->prompt));
58 }
59
60 int telnet_output(struct command_context_s *cmd_ctx, char* line)
61 {
62 connection_t *connection = cmd_ctx->output_handler_priv;
63
64 write_socket(connection->fd, line, strlen(line));
65 write_socket(connection->fd, "\r\n\0", 3);
66
67 return ERROR_OK;
68 }
69
70 int telnet_target_callback_event_handler(struct target_s *target, enum target_event event, void *priv)
71 {
72 struct command_context_s *cmd_ctx = priv;
73 connection_t *connection = cmd_ctx->output_handler_priv;
74 telnet_connection_t *t_con = connection->priv;
75 char buffer[512];
76
77 switch (event)
78 {
79 case TARGET_EVENT_HALTED:
80 command_print(cmd_ctx, "Target %i halted", get_num_by_target(target));
81 target->type->arch_state(target, buffer, 512);
82 buffer[511] = 0;
83 command_print(cmd_ctx, "%s", buffer);
84 telnet_prompt(connection);
85 t_con->suppress_prompt = 1;
86 break;
87 case TARGET_EVENT_RESUMED:
88 command_print(cmd_ctx, "Target %i resumed", get_num_by_target(target));
89 telnet_prompt(connection);
90 t_con->suppress_prompt = 1;
91 break;
92 default:
93 break;
94 }
95
96 return ERROR_OK;
97 }
98
99 int telnet_new_connection(connection_t *connection)
100 {
101 telnet_connection_t *telnet_connection = malloc(sizeof(telnet_connection_t));
102 telnet_service_t *telnet_service = connection->service->priv;
103 int i;
104
105 connection->priv = telnet_connection;
106
107 /* initialize telnet connection information */
108 telnet_connection->line_size = 0;
109 telnet_connection->line_cursor = 0;
110 telnet_connection->option_size = 0;
111 telnet_connection->prompt = strdup("> ");
112 telnet_connection->suppress_prompt = 0;
113 telnet_connection->state = TELNET_STATE_DATA;
114
115 /* output goes through telnet connection */
116 command_set_output_handler(connection->cmd_ctx, telnet_output, connection);
117
118 /* negotiate telnet options */
119 write_socket(connection->fd, negotiate, strlen(negotiate));
120
121 /* print connection banner */
122 if (telnet_service->banner)
123 {
124 write_socket(connection->fd, telnet_service->banner, strlen(telnet_service->banner));
125 write_socket(connection->fd, "\r\n\0", 3);
126 }
127
128 telnet_prompt(connection);
129
130 /* initialize history */
131 for (i = 0; i < TELNET_LINE_HISTORY_SIZE; i++)
132 {
133 telnet_connection->history[i] = NULL;
134 }
135 telnet_connection->next_history = 0;
136 telnet_connection->current_history = 0;
137
138 target_register_event_callback(telnet_target_callback_event_handler, connection->cmd_ctx);
139
140 return ERROR_OK;
141 }
142
143 void telnet_clear_line(connection_t *connection, telnet_connection_t *t_con)
144 {
145 /* move to end of line */
146 if (t_con->line_cursor < t_con->line_size)
147 {
148 write_socket(connection->fd, t_con->line + t_con->line_cursor, t_con->line_size - t_con->line_cursor);
149 }
150
151 /* backspace, overwrite with space, backspace */
152 while (t_con->line_size > 0)
153 {
154 write_socket(connection->fd, "\b \b", 3);
155 t_con->line_size--;
156 }
157 t_con->line_cursor = 0;
158 }
159
160 int telnet_input(connection_t *connection)
161 {
162 int bytes_read;
163 char buffer[TELNET_BUFFER_SIZE];
164 char *buf_p;
165 telnet_connection_t *t_con = connection->priv;
166 command_context_t *command_context = connection->cmd_ctx;
167
168 bytes_read = read_socket(connection->fd, buffer, TELNET_BUFFER_SIZE);
169
170 if (bytes_read == 0)
171 return ERROR_SERVER_REMOTE_CLOSED;
172 else if (bytes_read == -1)
173 {
174 ERROR("error during read: %s", strerror(errno));
175 return ERROR_SERVER_REMOTE_CLOSED;
176 }
177
178 buf_p = buffer;
179 while (bytes_read)
180 {
181 switch (t_con->state)
182 {
183 case TELNET_STATE_DATA:
184 if (*buf_p == '\xff')
185 {
186 t_con->state = TELNET_STATE_IAC;
187 }
188 else
189 {
190 if (isprint(*buf_p)) /* printable character */
191 {
192 write_socket(connection->fd, buf_p, 1);
193 if (t_con->line_cursor == t_con->line_size)
194 {
195 t_con->line[t_con->line_size++] = *buf_p;
196 t_con->line_cursor++;
197 }
198 else
199 {
200 int i;
201 memmove(t_con->line + t_con->line_cursor + 1, t_con->line + t_con->line_cursor, t_con->line_size - t_con->line_cursor);
202 t_con->line[t_con->line_cursor++] = *buf_p;
203 t_con->line_size++;
204 write_socket(connection->fd, t_con->line + t_con->line_cursor, t_con->line_size - t_con->line_cursor);
205 for (i = t_con->line_cursor; i < t_con->line_size; i++)
206 {
207 write_socket(connection->fd, "\b", 1);
208 }
209 }
210 }
211 else /* non-printable */
212 {
213 if (*buf_p == 0x1b) /* escape */
214 {
215 t_con->state = TELNET_STATE_ESCAPE;
216 t_con->last_escape = '\x00';
217 }
218 else if ((*buf_p == 0xd) || (*buf_p == 0xa)) /* CR/LF */
219 {
220 int retval;
221
222 /* skip over combinations with CR/LF + NUL */
223 if (((*(buf_p + 1) == 0xa) || (*(buf_p + 1) == 0xd)) && (bytes_read > 1))
224 {
225 buf_p++;
226 bytes_read--;
227 }
228 if ((*(buf_p + 1) == 0) && (bytes_read > 1))
229 {
230 buf_p++;
231 bytes_read--;
232 }
233 t_con->line[t_con->line_size] = 0;
234
235 write_socket(connection->fd, "\r\n\x00", 3);
236
237 if (strcmp(t_con->line, "history") == 0)
238 {
239 int i;
240 for (i = 0; i < TELNET_LINE_HISTORY_SIZE; i++)
241 {
242 if (t_con->history[i])
243 {
244 write_socket(connection->fd, t_con->history[i], strlen(t_con->history[i]));
245 write_socket(connection->fd, "\r\n\x00", 3);
246 }
247 }
248 telnet_prompt(connection);
249 t_con->line_size = 0;
250 t_con->line_cursor = 0;
251 continue;
252 }
253
254 /* we're running a command, so we need a prompt
255 * if the output handler is called, this gets set again */
256 t_con->suppress_prompt = 0;
257 if ((retval = command_run_line(command_context, t_con->line)) != ERROR_OK)
258 {
259 if (retval == ERROR_COMMAND_CLOSE_CONNECTION)
260 {
261 return ERROR_SERVER_REMOTE_CLOSED;
262 }
263 }
264
265 /* Save only non-blank lines in the history */
266 if (t_con->line_size > 0)
267 {
268 /* if the history slot is already taken, free it */
269 if (t_con->history[t_con->next_history])
270 {
271 free(t_con->history[t_con->next_history]);
272 }
273
274 /* add line to history */
275 t_con->history[t_con->next_history] = strdup(t_con->line);
276
277 /* wrap history at TELNET_LINE_HISTORY_SIZE */
278 t_con->next_history = (t_con->next_history + 1) % TELNET_LINE_HISTORY_SIZE;
279
280 /* current history line starts at the new entry */
281 t_con->current_history = t_con->next_history;
282
283 if (t_con->history[t_con->current_history])
284 {
285 free(t_con->history[t_con->current_history]);
286 }
287 t_con->history[t_con->current_history] = strdup("");
288 }
289
290 if (!t_con->suppress_prompt)
291 {
292 telnet_prompt(connection);
293 }
294 else
295 {
296 t_con->suppress_prompt = 0;
297 }
298
299 t_con->line_size = 0;
300 t_con->line_cursor = 0;
301 }
302 else if ((*buf_p == 0x7f) || (*buf_p == 0x8)) /* delete character */
303 {
304 if (t_con->line_cursor > 0)
305 {
306 if (t_con->line_cursor != t_con->line_size)
307 {
308 int i;
309 write_socket(connection->fd, "\b", 1);
310 t_con->line_cursor--;
311 t_con->line_size--;
312 memmove(t_con->line + t_con->line_cursor, t_con->line + t_con->line_cursor + 1, t_con->line_size - t_con->line_cursor);
313
314 write_socket(connection->fd, t_con->line + t_con->line_cursor, t_con->line_size - t_con->line_cursor);
315 write_socket(connection->fd, " \b", 2);
316 for (i = t_con->line_cursor; i < t_con->line_size; i++)
317 {
318 write_socket(connection->fd, "\b", 1);
319 }
320 }
321 else
322 {
323 t_con->line_size--;
324 t_con->line_cursor--;
325 /* back space: move the 'printer' head one char back, overwrite with space, move back again */
326 write_socket(connection->fd, "\b \b", 3);
327 }
328 }
329 }
330 else if (*buf_p == 0x15) /* clear line */
331 {
332 telnet_clear_line(connection, t_con);
333 }
334 else if (*buf_p == CTRL('B')) /* cursor left */
335 {
336 if (t_con->line_cursor > 0)
337 {
338 write_socket(connection->fd, "\b", 1);
339 t_con->line_cursor--;
340 }
341 t_con->state = TELNET_STATE_DATA;
342 }
343 else if (*buf_p == CTRL('F')) /* cursor right */
344 {
345 if (t_con->line_cursor < t_con->line_size)
346 {
347 write_socket(connection->fd, t_con->line + t_con->line_cursor++, 1);
348 }
349 t_con->state = TELNET_STATE_DATA;
350 }
351 else
352 {
353 DEBUG("unhandled nonprintable: %2.2x", *buf_p);
354 }
355 }
356 }
357 break;
358 case TELNET_STATE_IAC:
359 switch (*buf_p)
360 {
361 case '\xfe':
362 t_con->state = TELNET_STATE_DONT;
363 break;
364 case '\xfd':
365 t_con->state = TELNET_STATE_DO;
366 break;
367 case '\xfc':
368 t_con->state = TELNET_STATE_WONT;
369 break;
370 case '\xfb':
371 t_con->state = TELNET_STATE_WILL;
372 break;
373 }
374 break;
375 case TELNET_STATE_SB:
376 break;
377 case TELNET_STATE_SE:
378 break;
379 case TELNET_STATE_WILL:
380 case TELNET_STATE_WONT:
381 case TELNET_STATE_DO:
382 case TELNET_STATE_DONT:
383 t_con->state = TELNET_STATE_DATA;
384 break;
385 case TELNET_STATE_ESCAPE:
386 if (t_con->last_escape == '[')
387 {
388 if (*buf_p == 'D') /* cursor left */
389 {
390 if (t_con->line_cursor > 0)
391 {
392 write_socket(connection->fd, "\b", 1);
393 t_con->line_cursor--;
394 }
395 t_con->state = TELNET_STATE_DATA;
396 }
397 else if (*buf_p == 'C') /* cursor right */
398 {
399 if (t_con->line_cursor < t_con->line_size)
400 {
401 write_socket(connection->fd, t_con->line + t_con->line_cursor++, 1);
402 }
403 t_con->state = TELNET_STATE_DATA;
404 }
405 else if (*buf_p == 'A') /* cursor up */
406 {
407 int last_history = (t_con->current_history > 0) ? t_con->current_history - 1 : TELNET_LINE_HISTORY_SIZE-1;
408 if (t_con->history[last_history])
409 {
410 telnet_clear_line(connection, t_con);
411 t_con->line_size = strlen(t_con->history[last_history]);
412 t_con->line_cursor = t_con->line_size;
413 memcpy(t_con->line, t_con->history[last_history], t_con->line_size + 1);
414 write_socket(connection->fd, t_con->line, t_con->line_size);
415 t_con->current_history = last_history;
416 }
417 t_con->state = TELNET_STATE_DATA;
418 }
419 else if (*buf_p == 'B') /* cursor down */
420 {
421 int next_history = (t_con->current_history + 1) % TELNET_LINE_HISTORY_SIZE;
422 if (t_con->history[next_history])
423 {
424 telnet_clear_line(connection, t_con);
425 t_con->line_size = strlen(t_con->history[next_history]);
426 t_con->line_cursor = t_con->line_size;
427 memcpy(t_con->line, t_con->history[next_history], t_con->line_size + 1);
428 write_socket(connection->fd, t_con->line, t_con->line_size);
429 t_con->current_history = next_history;
430 }
431 t_con->state = TELNET_STATE_DATA;
432 }
433 else if (*buf_p == '3')
434 {
435 t_con->last_escape = *buf_p;
436 }
437 else
438 {
439 t_con->state = TELNET_STATE_DATA;
440 }
441 }
442 else if (t_con->last_escape == '3')
443 {
444 /* Remove character */
445 if (*buf_p == '~')
446 {
447 if (t_con->line_cursor < t_con->line_size)
448 {
449 int i;
450 t_con->line_size--;
451 /* remove char from line buffer */
452 memmove(t_con->line + t_con->line_cursor, t_con->line + t_con->line_cursor + 1, t_con->line_size - t_con->line_cursor);
453
454 /* print remainder of buffer */
455 write_socket(connection->fd, t_con->line + t_con->line_cursor, t_con->line_size - t_con->line_cursor);
456 /* overwrite last char with whitespace */
457 write_socket(connection->fd, " \b", 2);
458
459 /* move back to cursor position*/
460 for (i = t_con->line_cursor; i < t_con->line_size; i++)
461 {
462 write_socket(connection->fd, "\b", 1);
463 }
464 }
465
466 t_con->state = TELNET_STATE_DATA;
467 }
468 else
469 {
470 t_con->state = TELNET_STATE_DATA;
471 }
472 }
473 else if (t_con->last_escape == '\x00')
474 {
475 if (*buf_p == '[')
476 {
477 t_con->last_escape = *buf_p;
478 }
479 else
480 {
481 t_con->state = TELNET_STATE_DATA;
482 }
483 }
484 else
485 {
486 ERROR("BUG: unexpected value in t_con->last_escape");
487 t_con->state = TELNET_STATE_DATA;
488 }
489
490 break;
491 default:
492 ERROR("unknown telnet state");
493 exit(-1);
494 }
495
496 bytes_read--;
497 buf_p++;
498 }
499
500 return ERROR_OK;
501 }
502
503 int telnet_connection_closed(connection_t *connection)
504 {
505 telnet_connection_t *t_con = connection->priv;
506 int i;
507
508 if (t_con->prompt)
509 {
510 free(t_con->prompt);
511 t_con->prompt = NULL;
512 }
513
514 for (i = 0; i < TELNET_LINE_HISTORY_SIZE; i++)
515 {
516 if (t_con->history[i])
517 {
518 free(t_con->history[i]);
519 t_con->history[i] = NULL;
520 }
521 }
522
523 /* if this connection registered a debug-message receiver delete it */
524 delete_debug_msg_receiver(connection->cmd_ctx, NULL);
525
526 if (connection->priv)
527 {
528 free(connection->priv);
529 connection->priv = NULL;
530 }
531 else
532 {
533 ERROR("BUG: connection->priv == NULL");
534 }
535
536 target_unregister_event_callback(telnet_target_callback_event_handler, connection->cmd_ctx);
537
538 return ERROR_OK;
539 }
540
541 int telnet_set_prompt(connection_t *connection, char *prompt)
542 {
543 telnet_connection_t *t_con = connection->priv;
544
545 t_con->prompt = strdup(prompt);
546
547 return ERROR_OK;
548 }
549
550 int telnet_init(char *banner)
551 {
552 telnet_service_t *telnet_service = malloc(sizeof(telnet_service_t));
553
554 if (telnet_port == 0)
555 {
556 WARNING("no telnet port specified, using default port 4444");
557 telnet_port = 4444;
558 }
559
560 telnet_service->banner = banner;
561
562 add_service("telnet", CONNECTION_TELNET, telnet_port, 1, telnet_new_connection, telnet_input, telnet_connection_closed, telnet_service);
563
564 return ERROR_OK;
565 }
566
567 int telnet_register_commands(command_context_t *command_context)
568 {
569 register_command(command_context, NULL, "exit", handle_exit_command,
570 COMMAND_EXEC, "exit telnet session");
571
572 register_command(command_context, NULL, "telnet_port", handle_telnet_port_command,
573 COMMAND_CONFIG, "");
574
575 return ERROR_OK;
576 }
577
578 /* daemon configuration command telnet_port */
579 int handle_telnet_port_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc)
580 {
581 if (argc == 0)
582 return ERROR_OK;
583
584 /* only if the port wasn't overwritten by cmdline */
585 if (telnet_port == 0)
586 telnet_port = strtoul(args[0], NULL, 0);
587
588 return ERROR_OK;
589 }
590
591 int handle_exit_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc)
592 {
593 return ERROR_COMMAND_CLOSE_CONNECTION;
594 }