d7933293ae2213a7501c46a7ba23c499fbf5a012
[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->surpress_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->surpress_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->surpress_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->surpress_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 /* if the history slot is already taken, free it */
259 if (t_con->history[t_con->next_history])
260 {
261 free(t_con->history[t_con->next_history]);
262 }
263
264 /* add line to history */
265 t_con->history[t_con->next_history++] = strdup(t_con->line);
266
267 /* current history line starts at the new entry */
268 t_con->current_history = t_con->next_history;
269
270 if (t_con->history[t_con->current_history])
271 {
272 free(t_con->history[t_con->current_history]);
273 }
274 t_con->history[t_con->current_history] = strdup("");
275
276 /* wrap history at TELNET_LINE_HISTORY_SIZE */
277 if (t_con->next_history > TELNET_LINE_HISTORY_SIZE - 1)
278 t_con->next_history = 0;
279
280 if (!t_con->surpress_prompt)
281 {
282 telnet_prompt(connection);
283 }
284 else
285 {
286 t_con->surpress_prompt = 0;
287 }
288
289 t_con->line_size = 0;
290 t_con->line_cursor = 0;
291 }
292 else if ((*buf_p == 0x7f) || (*buf_p == 0x8)) /* delete character */
293 {
294 if (t_con->line_cursor > 0)
295 {
296 if (t_con->line_cursor != t_con->line_size)
297 {
298 int i;
299 write(connection->fd, "\b", 1);
300 t_con->line_cursor--;
301 t_con->line_size--;
302 memmove(t_con->line + t_con->line_cursor, t_con->line + t_con->line_cursor + 1, t_con->line_size - t_con->line_cursor);
303
304 write(connection->fd, t_con->line + t_con->line_cursor, t_con->line_size - t_con->line_cursor);
305 write(connection->fd, " \b", 2);
306 for (i = t_con->line_cursor; i < t_con->line_size; i++)
307 {
308 write(connection->fd, "\b", 1);
309 }
310 }
311 else
312 {
313 t_con->line_size--;
314 t_con->line_cursor--;
315 /* back space: move the 'printer' head one char back, overwrite with space, move back again */
316 write(connection->fd, "\b \b", 3);
317 }
318 }
319 }
320 else if (*buf_p == 0x15) /* clear line */
321 {
322 telnet_clear_line(connection, t_con);
323 }
324 else if (*buf_p == CTRL('B')) /* cursor left */
325 {
326 if (t_con->line_cursor > 0)
327 {
328 write(connection->fd, "\b", 1);
329 t_con->line_cursor--;
330 }
331 t_con->state = TELNET_STATE_DATA;
332 }
333 else if (*buf_p == CTRL('F')) /* cursor right */
334 {
335 if (t_con->line_cursor < t_con->line_size)
336 {
337 write(connection->fd, t_con->line + t_con->line_cursor++, 1);
338 }
339 t_con->state = TELNET_STATE_DATA;
340 }
341 else
342 {
343 DEBUG("unhandled nonprintable: %2.2x", *buf_p);
344 }
345 }
346 }
347 break;
348 case TELNET_STATE_IAC:
349 switch (*buf_p)
350 {
351 case '\xfe':
352 t_con->state = TELNET_STATE_DONT;
353 break;
354 case '\xfd':
355 t_con->state = TELNET_STATE_DO;
356 break;
357 case '\xfc':
358 t_con->state = TELNET_STATE_WONT;
359 break;
360 case '\xfb':
361 t_con->state = TELNET_STATE_WILL;
362 break;
363 }
364 break;
365 case TELNET_STATE_SB:
366 break;
367 case TELNET_STATE_SE:
368 break;
369 case TELNET_STATE_WILL:
370 case TELNET_STATE_WONT:
371 case TELNET_STATE_DO:
372 case TELNET_STATE_DONT:
373 t_con->state = TELNET_STATE_DATA;
374 break;
375 case TELNET_STATE_ESCAPE:
376 if (t_con->last_escape == '[')
377 {
378 if (*buf_p == 'D') /* cursor left */
379 {
380 if (t_con->line_cursor > 0)
381 {
382 write(connection->fd, "\b", 1);
383 t_con->line_cursor--;
384 }
385 t_con->state = TELNET_STATE_DATA;
386 }
387 else if (*buf_p == 'C') /* cursor right */
388 {
389 if (t_con->line_cursor < t_con->line_size)
390 {
391 write(connection->fd, t_con->line + t_con->line_cursor++, 1);
392 }
393 t_con->state = TELNET_STATE_DATA;
394 }
395 else if (*buf_p == 'A') /* cursor up */
396 {
397 int last_history = (t_con->current_history - 1 >= 0) ? t_con->current_history - 1 : 127;
398 if (t_con->history[last_history])
399 {
400 telnet_clear_line(connection, t_con);
401 t_con->line_size = strlen(t_con->history[last_history]);
402 t_con->line_cursor = t_con->line_size;
403 memcpy(t_con->line, t_con->history[last_history], t_con->line_size + 1);
404 write(connection->fd, t_con->line, t_con->line_size);
405 t_con->current_history = last_history;
406 }
407 t_con->state = TELNET_STATE_DATA;
408 }
409 else if (*buf_p == 'B') /* cursor down */
410 {
411 int next_history = (t_con->current_history + 1 < 128) ? t_con->current_history + 1 : 0;
412 if (t_con->history[next_history])
413 {
414 telnet_clear_line(connection, t_con);
415 t_con->line_size = strlen(t_con->history[next_history]);
416 t_con->line_cursor = t_con->line_size;
417 memcpy(t_con->line, t_con->history[next_history], t_con->line_size + 1);
418 write(connection->fd, t_con->line, t_con->line_size);
419 t_con->current_history = next_history;
420 }
421 t_con->state = TELNET_STATE_DATA;
422 }
423 else if (*buf_p == '3')
424 {
425 t_con->last_escape = *buf_p;
426 }
427 else
428 {
429 t_con->state = TELNET_STATE_DATA;
430 }
431 }
432 else if (t_con->last_escape == '3')
433 {
434 /* Remove character */
435 if (*buf_p == '~')
436 {
437 if (t_con->line_cursor < t_con->line_size)
438 {
439 int i;
440 t_con->line_size--;
441 /* remove char from line buffer */
442 memmove(t_con->line + t_con->line_cursor, t_con->line + t_con->line_cursor + 1, t_con->line_size - t_con->line_cursor);
443
444 /* print remainder of buffer */
445 write(connection->fd, t_con->line + t_con->line_cursor, t_con->line_size - t_con->line_cursor);
446 /* overwrite last char with whitespace */
447 write(connection->fd, " \b", 2);
448
449 /* move back to cursor position*/
450 for (i = t_con->line_cursor; i < t_con->line_size; i++)
451 {
452 write(connection->fd, "\b", 1);
453 }
454 }
455
456 t_con->state = TELNET_STATE_DATA;
457 }
458 else
459 {
460 t_con->state = TELNET_STATE_DATA;
461 }
462 }
463 else if (t_con->last_escape == '\x00')
464 {
465 if (*buf_p == '[')
466 {
467 t_con->last_escape = *buf_p;
468 }
469 else
470 {
471 t_con->state = TELNET_STATE_DATA;
472 }
473 }
474 else
475 {
476 ERROR("BUG: unexpected value in t_con->last_escape");
477 t_con->state = TELNET_STATE_DATA;
478 }
479
480 break;
481 default:
482 ERROR("unknown telnet state");
483 exit(-1);
484 }
485
486 bytes_read--;
487 buf_p++;
488 }
489
490 return ERROR_OK;
491 }
492
493 int telnet_connection_closed(connection_t *connection)
494 {
495 telnet_connection_t *t_con = connection->priv;
496 int i;
497
498 if (t_con->prompt)
499 free(t_con->prompt);
500
501 for (i = 0; i < TELNET_LINE_HISTORY_SIZE; i++)
502 {
503 if (t_con->history[i])
504 free(t_con->history[i]);
505 }
506
507 if (connection->priv)
508 free(connection->priv);
509 else
510 ERROR("BUG: connection->priv == NULL");
511
512 target_unregister_event_callback(telnet_target_callback_event_handler, connection->cmd_ctx);
513
514 return ERROR_OK;
515 }
516
517 int telnet_set_prompt(connection_t *connection, char *prompt)
518 {
519 telnet_connection_t *t_con = connection->priv;
520
521 t_con->prompt = strdup(prompt);
522
523 return ERROR_OK;
524 }
525
526 int telnet_init(char *banner)
527 {
528 telnet_service_t *telnet_service = malloc(sizeof(telnet_service_t));
529
530 if (telnet_port == 0)
531 {
532 WARNING("no telnet port specified, using default port 4444");
533 telnet_port = 4444;
534 }
535
536 telnet_service->banner = banner;
537
538 add_service("telnet", CONNECTION_TELNET, telnet_port, 1, telnet_new_connection, telnet_input, telnet_connection_closed, telnet_service);
539
540 return ERROR_OK;
541 }
542
543 int telnet_register_commands(command_context_t *command_context)
544 {
545 register_command(command_context, NULL, "exit", handle_exit_command,
546 COMMAND_EXEC, "exit telnet session");
547
548 register_command(command_context, NULL, "telnet_port", handle_telnet_port_command,
549 COMMAND_CONFIG, "");
550
551 return ERROR_OK;
552 }
553
554 /* daemon configuration command telnet_port */
555 int handle_telnet_port_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc)
556 {
557 if (argc == 0)
558 return ERROR_OK;
559
560 /* only if the port wasn't overwritten by cmdline */
561 if (telnet_port == 0)
562 telnet_port = strtoul(args[0], NULL, 0);
563
564 return ERROR_OK;
565 }
566
567 int handle_exit_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc)
568 {
569 return ERROR_COMMAND_CLOSE_CONNECTION;
570 }