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