- combine similar functions in telnet_server.c
[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 void telnet_log_callback(void *priv, const char *file, int line,
71 const char *function, const char *format, va_list args)
72 {
73 connection_t *connection = priv;
74 char *t = allocPrintf(format, args);
75 if (t == NULL)
76 return;
77
78 telnet_output(connection->cmd_ctx, t);
79 free(t);
80 }
81
82 int telnet_target_callback_event_handler(struct target_s *target, enum target_event event, void *priv)
83 {
84 struct command_context_s *cmd_ctx = priv;
85 connection_t *connection = cmd_ctx->output_handler_priv;
86 telnet_connection_t *t_con = connection->priv;
87 char buffer[512];
88
89 switch (event)
90 {
91 case TARGET_EVENT_HALTED:
92 command_print(cmd_ctx, "Target %i halted", get_num_by_target(target));
93 target->type->arch_state(target, buffer, 512);
94 buffer[511] = 0;
95 command_print(cmd_ctx, "%s", buffer);
96 if (!t_con->suppress_prompt)
97 telnet_prompt(connection);
98 break;
99 case TARGET_EVENT_RESUMED:
100 command_print(cmd_ctx, "Target %i resumed", get_num_by_target(target));
101 if (!t_con->suppress_prompt)
102 telnet_prompt(connection);
103 break;
104 default:
105 break;
106 }
107
108 return ERROR_OK;
109 }
110
111 int telnet_new_connection(connection_t *connection)
112 {
113 telnet_connection_t *telnet_connection = malloc(sizeof(telnet_connection_t));
114 telnet_service_t *telnet_service = connection->service->priv;
115 int i;
116
117 connection->priv = telnet_connection;
118
119 /* initialize telnet connection information */
120 telnet_connection->line_size = 0;
121 telnet_connection->line_cursor = 0;
122 telnet_connection->option_size = 0;
123 telnet_connection->prompt = strdup("> ");
124 telnet_connection->suppress_prompt = 0;
125 telnet_connection->state = TELNET_STATE_DATA;
126
127 /* output goes through telnet connection */
128 command_set_output_handler(connection->cmd_ctx, telnet_output, connection);
129
130 /* negotiate telnet options */
131 write_socket(connection->fd, negotiate, strlen(negotiate));
132
133 /* print connection banner */
134 if (telnet_service->banner)
135 {
136 write_socket(connection->fd, telnet_service->banner, strlen(telnet_service->banner));
137 write_socket(connection->fd, "\r\n\0", 3);
138 }
139
140 telnet_prompt(connection);
141
142 /* initialize history */
143 for (i = 0; i < TELNET_LINE_HISTORY_SIZE; i++)
144 {
145 telnet_connection->history[i] = NULL;
146 }
147 telnet_connection->next_history = 0;
148 telnet_connection->current_history = 0;
149
150 target_register_event_callback(telnet_target_callback_event_handler, connection->cmd_ctx);
151
152 return ERROR_OK;
153 }
154
155 void telnet_clear_line(connection_t *connection, telnet_connection_t *t_con)
156 {
157 /* move to end of line */
158 if (t_con->line_cursor < t_con->line_size)
159 {
160 write_socket(connection->fd, t_con->line + t_con->line_cursor, t_con->line_size - t_con->line_cursor);
161 }
162
163 /* backspace, overwrite with space, backspace */
164 while (t_con->line_size > 0)
165 {
166 write_socket(connection->fd, "\b \b", 3);
167 t_con->line_size--;
168 }
169 t_con->line_cursor = 0;
170 }
171
172 int telnet_input(connection_t *connection)
173 {
174 int bytes_read;
175 char buffer[TELNET_BUFFER_SIZE];
176 char *buf_p;
177 telnet_connection_t *t_con = connection->priv;
178 command_context_t *command_context = connection->cmd_ctx;
179
180 bytes_read = read_socket(connection->fd, buffer, TELNET_BUFFER_SIZE);
181
182 if (bytes_read == 0)
183 return ERROR_SERVER_REMOTE_CLOSED;
184 else if (bytes_read == -1)
185 {
186 ERROR("error during read: %s", strerror(errno));
187 return ERROR_SERVER_REMOTE_CLOSED;
188 }
189
190 buf_p = buffer;
191 while (bytes_read)
192 {
193 switch (t_con->state)
194 {
195 case TELNET_STATE_DATA:
196 if (*buf_p == '\xff')
197 {
198 t_con->state = TELNET_STATE_IAC;
199 }
200 else
201 {
202 if (isprint(*buf_p)) /* printable character */
203 {
204 write_socket(connection->fd, buf_p, 1);
205 if (t_con->line_cursor == t_con->line_size)
206 {
207 t_con->line[t_con->line_size++] = *buf_p;
208 t_con->line_cursor++;
209 }
210 else
211 {
212 int i;
213 memmove(t_con->line + t_con->line_cursor + 1, t_con->line + t_con->line_cursor, t_con->line_size - t_con->line_cursor);
214 t_con->line[t_con->line_cursor++] = *buf_p;
215 t_con->line_size++;
216 write_socket(connection->fd, t_con->line + t_con->line_cursor, t_con->line_size - t_con->line_cursor);
217 for (i = t_con->line_cursor; i < t_con->line_size; i++)
218 {
219 write_socket(connection->fd, "\b", 1);
220 }
221 }
222 }
223 else /* non-printable */
224 {
225 if (*buf_p == 0x1b) /* escape */
226 {
227 t_con->state = TELNET_STATE_ESCAPE;
228 t_con->last_escape = '\x00';
229 }
230 else if ((*buf_p == 0xd) || (*buf_p == 0xa)) /* CR/LF */
231 {
232 int retval;
233
234 /* skip over combinations with CR/LF + NUL */
235 if (((*(buf_p + 1) == 0xa) || (*(buf_p + 1) == 0xd)) && (bytes_read > 1))
236 {
237 buf_p++;
238 bytes_read--;
239 }
240 if ((*(buf_p + 1) == 0) && (bytes_read > 1))
241 {
242 buf_p++;
243 bytes_read--;
244 }
245 t_con->line[t_con->line_size] = 0;
246
247 write_socket(connection->fd, "\r\n\x00", 3);
248
249 if (strcmp(t_con->line, "history") == 0)
250 {
251 int i;
252 for (i = 0; i < TELNET_LINE_HISTORY_SIZE; i++)
253 {
254 if (t_con->history[i])
255 {
256 write_socket(connection->fd, t_con->history[i], strlen(t_con->history[i]));
257 write_socket(connection->fd, "\r\n\x00", 3);
258 }
259 }
260 telnet_prompt(connection);
261 t_con->line_size = 0;
262 t_con->line_cursor = 0;
263 continue;
264 }
265
266 log_setCallback(telnet_log_callback, connection);
267 t_con->suppress_prompt = 1;
268
269 if ((retval = command_run_line(command_context, t_con->line)) != ERROR_OK)
270 {
271 if (retval == ERROR_COMMAND_CLOSE_CONNECTION)
272 {
273 return ERROR_SERVER_REMOTE_CLOSED;
274 }
275 }
276
277 t_con->suppress_prompt = 0;
278
279 /* Save only non-blank lines in the history */
280 if (t_con->line_size > 0)
281 {
282 /* if the history slot is already taken, free it */
283 if (t_con->history[t_con->next_history])
284 {
285 free(t_con->history[t_con->next_history]);
286 }
287
288 /* add line to history */
289 t_con->history[t_con->next_history] = strdup(t_con->line);
290
291 /* wrap history at TELNET_LINE_HISTORY_SIZE */
292 t_con->next_history = (t_con->next_history + 1) % TELNET_LINE_HISTORY_SIZE;
293
294 /* current history line starts at the new entry */
295 t_con->current_history = t_con->next_history;
296
297 if (t_con->history[t_con->current_history])
298 {
299 free(t_con->history[t_con->current_history]);
300 }
301 t_con->history[t_con->current_history] = strdup("");
302 }
303
304 /* output prompt after command */
305 telnet_prompt(connection);
306
307 t_con->line_size = 0;
308 t_con->line_cursor = 0;
309 }
310 else if ((*buf_p == 0x7f) || (*buf_p == 0x8)) /* delete character */
311 {
312 if (t_con->line_cursor > 0)
313 {
314 if (t_con->line_cursor != t_con->line_size)
315 {
316 int i;
317 write_socket(connection->fd, "\b", 1);
318 t_con->line_cursor--;
319 t_con->line_size--;
320 memmove(t_con->line + t_con->line_cursor, t_con->line + t_con->line_cursor + 1, t_con->line_size - t_con->line_cursor);
321
322 write_socket(connection->fd, t_con->line + t_con->line_cursor, t_con->line_size - t_con->line_cursor);
323 write_socket(connection->fd, " \b", 2);
324 for (i = t_con->line_cursor; i < t_con->line_size; i++)
325 {
326 write_socket(connection->fd, "\b", 1);
327 }
328 }
329 else
330 {
331 t_con->line_size--;
332 t_con->line_cursor--;
333 /* back space: move the 'printer' head one char back, overwrite with space, move back again */
334 write_socket(connection->fd, "\b \b", 3);
335 }
336 }
337 }
338 else if (*buf_p == 0x15) /* clear line */
339 {
340 telnet_clear_line(connection, t_con);
341 }
342 else if (*buf_p == CTRL('B')) /* cursor left */
343 {
344 if (t_con->line_cursor > 0)
345 {
346 write_socket(connection->fd, "\b", 1);
347 t_con->line_cursor--;
348 }
349 t_con->state = TELNET_STATE_DATA;
350 }
351 else if (*buf_p == CTRL('F')) /* cursor right */
352 {
353 if (t_con->line_cursor < t_con->line_size)
354 {
355 write_socket(connection->fd, t_con->line + t_con->line_cursor++, 1);
356 }
357 t_con->state = TELNET_STATE_DATA;
358 }
359 else
360 {
361 DEBUG("unhandled nonprintable: %2.2x", *buf_p);
362 }
363 }
364 }
365 break;
366 case TELNET_STATE_IAC:
367 switch (*buf_p)
368 {
369 case '\xfe':
370 t_con->state = TELNET_STATE_DONT;
371 break;
372 case '\xfd':
373 t_con->state = TELNET_STATE_DO;
374 break;
375 case '\xfc':
376 t_con->state = TELNET_STATE_WONT;
377 break;
378 case '\xfb':
379 t_con->state = TELNET_STATE_WILL;
380 break;
381 }
382 break;
383 case TELNET_STATE_SB:
384 break;
385 case TELNET_STATE_SE:
386 break;
387 case TELNET_STATE_WILL:
388 case TELNET_STATE_WONT:
389 case TELNET_STATE_DO:
390 case TELNET_STATE_DONT:
391 t_con->state = TELNET_STATE_DATA;
392 break;
393 case TELNET_STATE_ESCAPE:
394 if (t_con->last_escape == '[')
395 {
396 if (*buf_p == 'D') /* cursor left */
397 {
398 if (t_con->line_cursor > 0)
399 {
400 write_socket(connection->fd, "\b", 1);
401 t_con->line_cursor--;
402 }
403 t_con->state = TELNET_STATE_DATA;
404 }
405 else if (*buf_p == 'C') /* cursor right */
406 {
407 if (t_con->line_cursor < t_con->line_size)
408 {
409 write_socket(connection->fd, t_con->line + t_con->line_cursor++, 1);
410 }
411 t_con->state = TELNET_STATE_DATA;
412 }
413 else if (*buf_p == 'A') /* cursor up */
414 {
415 int last_history = (t_con->current_history > 0) ? t_con->current_history - 1 : TELNET_LINE_HISTORY_SIZE-1;
416 if (t_con->history[last_history])
417 {
418 telnet_clear_line(connection, t_con);
419 t_con->line_size = strlen(t_con->history[last_history]);
420 t_con->line_cursor = t_con->line_size;
421 memcpy(t_con->line, t_con->history[last_history], t_con->line_size + 1);
422 write_socket(connection->fd, t_con->line, t_con->line_size);
423 t_con->current_history = last_history;
424 }
425 t_con->state = TELNET_STATE_DATA;
426 }
427 else if (*buf_p == 'B') /* cursor down */
428 {
429 int next_history = (t_con->current_history + 1) % TELNET_LINE_HISTORY_SIZE;
430 if (t_con->history[next_history])
431 {
432 telnet_clear_line(connection, t_con);
433 t_con->line_size = strlen(t_con->history[next_history]);
434 t_con->line_cursor = t_con->line_size;
435 memcpy(t_con->line, t_con->history[next_history], t_con->line_size + 1);
436 write_socket(connection->fd, t_con->line, t_con->line_size);
437 t_con->current_history = next_history;
438 }
439 t_con->state = TELNET_STATE_DATA;
440 }
441 else if (*buf_p == '3')
442 {
443 t_con->last_escape = *buf_p;
444 }
445 else
446 {
447 t_con->state = TELNET_STATE_DATA;
448 }
449 }
450 else if (t_con->last_escape == '3')
451 {
452 /* Remove character */
453 if (*buf_p == '~')
454 {
455 if (t_con->line_cursor < t_con->line_size)
456 {
457 int i;
458 t_con->line_size--;
459 /* remove char from line buffer */
460 memmove(t_con->line + t_con->line_cursor, t_con->line + t_con->line_cursor + 1, t_con->line_size - t_con->line_cursor);
461
462 /* print remainder of buffer */
463 write_socket(connection->fd, t_con->line + t_con->line_cursor, t_con->line_size - t_con->line_cursor);
464 /* overwrite last char with whitespace */
465 write_socket(connection->fd, " \b", 2);
466
467 /* move back to cursor position*/
468 for (i = t_con->line_cursor; i < t_con->line_size; i++)
469 {
470 write_socket(connection->fd, "\b", 1);
471 }
472 }
473
474 t_con->state = TELNET_STATE_DATA;
475 }
476 else
477 {
478 t_con->state = TELNET_STATE_DATA;
479 }
480 }
481 else if (t_con->last_escape == '\x00')
482 {
483 if (*buf_p == '[')
484 {
485 t_con->last_escape = *buf_p;
486 }
487 else
488 {
489 t_con->state = TELNET_STATE_DATA;
490 }
491 }
492 else
493 {
494 ERROR("BUG: unexpected value in t_con->last_escape");
495 t_con->state = TELNET_STATE_DATA;
496 }
497
498 break;
499 default:
500 ERROR("unknown telnet state");
501 exit(-1);
502 }
503
504 bytes_read--;
505 buf_p++;
506 }
507
508 return ERROR_OK;
509 }
510
511 int telnet_connection_closed(connection_t *connection)
512 {
513 telnet_connection_t *t_con = connection->priv;
514 int i;
515
516 if (t_con->prompt)
517 {
518 free(t_con->prompt);
519 t_con->prompt = NULL;
520 }
521
522 for (i = 0; i < TELNET_LINE_HISTORY_SIZE; i++)
523 {
524 if (t_con->history[i])
525 {
526 free(t_con->history[i]);
527 t_con->history[i] = NULL;
528 }
529 }
530
531 /* if this connection registered a debug-message receiver delete it */
532 delete_debug_msg_receiver(connection->cmd_ctx, NULL);
533
534 if (connection->priv)
535 {
536 free(connection->priv);
537 connection->priv = NULL;
538 }
539 else
540 {
541 ERROR("BUG: connection->priv == NULL");
542 }
543
544 target_unregister_event_callback(telnet_target_callback_event_handler, connection->cmd_ctx);
545
546 return ERROR_OK;
547 }
548
549 int telnet_set_prompt(connection_t *connection, char *prompt)
550 {
551 telnet_connection_t *t_con = connection->priv;
552
553 t_con->prompt = strdup(prompt);
554
555 return ERROR_OK;
556 }
557
558 int telnet_init(char *banner)
559 {
560 telnet_service_t *telnet_service = malloc(sizeof(telnet_service_t));
561
562 if (telnet_port == 0)
563 {
564 WARNING("no telnet port specified, using default port 4444");
565 telnet_port = 4444;
566 }
567
568 telnet_service->banner = banner;
569
570 add_service("telnet", CONNECTION_TELNET, telnet_port, 1, telnet_new_connection, telnet_input, telnet_connection_closed, telnet_service);
571
572 return ERROR_OK;
573 }
574
575 int telnet_register_commands(command_context_t *command_context)
576 {
577 register_command(command_context, NULL, "exit", handle_exit_command,
578 COMMAND_EXEC, "exit telnet session");
579
580 register_command(command_context, NULL, "telnet_port", handle_telnet_port_command,
581 COMMAND_CONFIG, "");
582
583 return ERROR_OK;
584 }
585
586 /* daemon configuration command telnet_port */
587 int handle_telnet_port_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc)
588 {
589 if (argc == 0)
590 return ERROR_OK;
591
592 /* only if the port wasn't overwritten by cmdline */
593 if (telnet_port == 0)
594 telnet_port = strtoul(args[0], NULL, 0);
595
596 return ERROR_OK;
597 }
598
599 int handle_exit_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc)
600 {
601 return ERROR_COMMAND_CLOSE_CONNECTION;
602 }