command_registration: add empty usage field to chained commands
[openocd.git] / src / server / telnet_server.c
bloba864f5fd293ea5d520b42f89052c95aab60a821a
1 /***************************************************************************
2 * Copyright (C) 2005 by Dominic Rath *
3 * Dominic.Rath@gmx.de *
4 * *
5 * Copyright (C) 2007-2010 Øyvind 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, see <http://www.gnu.org/licenses/>. *
23 ***************************************************************************/
25 #ifdef HAVE_CONFIG_H
26 #include "config.h"
27 #endif
29 #include "telnet_server.h"
30 #include <target/target_request.h>
31 #include <helper/configuration.h>
33 static char *telnet_port;
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 */
41 #define CTRL(c) (c - '@')
42 #define TELNET_HISTORY ".openocd_history"
44 /* The only way we can detect that the socket is closed is the first time
45 * we write to it, we will fail. Subsequent write operations will
46 * succeed. Shudder!
48 static int telnet_write(struct connection *connection, const void *data,
49 int len)
51 struct telnet_connection *t_con = connection->priv;
52 if (t_con->closed)
53 return ERROR_SERVER_REMOTE_CLOSED;
55 if (connection_write(connection, data, len) == len)
56 return ERROR_OK;
57 t_con->closed = true;
58 return ERROR_SERVER_REMOTE_CLOSED;
61 static int telnet_prompt(struct connection *connection)
63 struct telnet_connection *t_con = connection->priv;
65 return telnet_write(connection, t_con->prompt, strlen(t_con->prompt));
68 static int telnet_outputline(struct connection *connection, const char *line)
70 int len;
72 /* process lines in buffer */
73 while (*line) {
74 char *line_end = strchr(line, '\n');
76 if (line_end)
77 len = line_end-line;
78 else
79 len = strlen(line);
81 telnet_write(connection, line, len);
82 if (line_end) {
83 telnet_write(connection, "\r\n", 2);
84 line += len + 1;
85 } else
86 line += len;
89 return ERROR_OK;
92 static int telnet_output(struct command_context *cmd_ctx, const char *line)
94 struct connection *connection = cmd_ctx->output_handler_priv;
96 return telnet_outputline(connection, line);
99 static void telnet_log_callback(void *priv, const char *file, unsigned line,
100 const char *function, const char *string)
102 struct connection *connection = priv;
103 struct telnet_connection *t_con = connection->priv;
104 size_t i;
105 size_t tmp;
107 /* If the prompt is not visible, simply output the message. */
108 if (!t_con->prompt_visible) {
109 telnet_outputline(connection, string);
110 return;
113 /* Clear the command line. */
114 tmp = strlen(t_con->prompt) + t_con->line_size;
116 for (i = 0; i < tmp; i += 16)
117 telnet_write(connection, "\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b",
118 MIN(tmp - i, 16));
120 for (i = 0; i < tmp; i += 16)
121 telnet_write(connection, " ", MIN(tmp - i, 16));
123 for (i = 0; i < tmp; i += 16)
124 telnet_write(connection, "\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b",
125 MIN(tmp - i, 16));
127 telnet_outputline(connection, string);
129 /* Put the command line to its previous state. */
130 telnet_prompt(connection);
131 telnet_write(connection, t_con->line, t_con->line_size);
133 for (i = t_con->line_cursor; i < t_con->line_size; i++)
134 telnet_write(connection, "\b", 1);
137 static void telnet_load_history(struct telnet_connection *t_con)
139 FILE *histfp;
140 char buffer[TELNET_BUFFER_SIZE];
141 int i = 0;
143 char *history = get_home_dir(TELNET_HISTORY);
145 if (history == NULL) {
146 LOG_INFO("unable to get user home directory, telnet history will be disabled");
147 return;
150 histfp = fopen(history, "rb");
152 if (histfp) {
154 while (fgets(buffer, sizeof(buffer), histfp) != NULL) {
156 char *p = strchr(buffer, '\n');
157 if (p)
158 *p = '\0';
159 if (buffer[0] && i < TELNET_LINE_HISTORY_SIZE)
160 t_con->history[i++] = strdup(buffer);
163 t_con->next_history = i;
164 t_con->next_history %= TELNET_LINE_HISTORY_SIZE;
165 /* try to set to last entry - 1, that way we skip over any exit/shutdown cmds */
166 t_con->current_history = t_con->next_history > 0 ? i - 1 : 0;
167 fclose(histfp);
170 free(history);
173 static void telnet_save_history(struct telnet_connection *t_con)
175 FILE *histfp;
176 int i;
177 int num;
179 char *history = get_home_dir(TELNET_HISTORY);
181 if (history == NULL) {
182 LOG_INFO("unable to get user home directory, telnet history will be disabled");
183 return;
186 histfp = fopen(history, "wb");
188 if (histfp) {
190 num = TELNET_LINE_HISTORY_SIZE;
191 i = t_con->current_history + 1;
192 i %= TELNET_LINE_HISTORY_SIZE;
194 while (t_con->history[i] == NULL && num > 0) {
195 i++;
196 i %= TELNET_LINE_HISTORY_SIZE;
197 num--;
200 if (num > 0) {
201 for (; num > 0; num--) {
202 fprintf(histfp, "%s\n", t_con->history[i]);
203 i++;
204 i %= TELNET_LINE_HISTORY_SIZE;
207 fclose(histfp);
210 free(history);
213 static int telnet_new_connection(struct connection *connection)
215 struct telnet_connection *telnet_connection;
216 struct telnet_service *telnet_service = connection->service->priv;
217 int i;
219 telnet_connection = malloc(sizeof(struct telnet_connection));
221 if (!telnet_connection) {
222 LOG_ERROR("Failed to allocate telnet connection.");
223 return ERROR_FAIL;
226 connection->priv = telnet_connection;
228 /* initialize telnet connection information */
229 telnet_connection->closed = false;
230 telnet_connection->line_size = 0;
231 telnet_connection->line_cursor = 0;
232 telnet_connection->prompt = strdup("> ");
233 telnet_connection->prompt_visible = true;
234 telnet_connection->state = TELNET_STATE_DATA;
236 /* output goes through telnet connection */
237 command_set_output_handler(connection->cmd_ctx, telnet_output, connection);
239 /* negotiate telnet options */
240 telnet_write(connection, negotiate, strlen(negotiate));
242 /* print connection banner */
243 if (telnet_service->banner) {
244 telnet_write(connection, telnet_service->banner, strlen(telnet_service->banner));
245 telnet_write(connection, "\r\n", 2);
248 /* the prompt is always placed at the line beginning */
249 telnet_write(connection, "\r", 1);
250 telnet_prompt(connection);
252 /* initialize history */
253 for (i = 0; i < TELNET_LINE_HISTORY_SIZE; i++)
254 telnet_connection->history[i] = NULL;
255 telnet_connection->next_history = 0;
256 telnet_connection->current_history = 0;
257 telnet_load_history(telnet_connection);
259 log_add_callback(telnet_log_callback, connection);
261 return ERROR_OK;
264 static void telnet_clear_line(struct connection *connection,
265 struct telnet_connection *t_con)
267 /* move to end of line */
268 if (t_con->line_cursor < t_con->line_size)
269 telnet_write(connection,
270 t_con->line + t_con->line_cursor,
271 t_con->line_size - t_con->line_cursor);
273 /* backspace, overwrite with space, backspace */
274 while (t_con->line_size > 0) {
275 telnet_write(connection, "\b \b", 3);
276 t_con->line_size--;
278 t_con->line_cursor = 0;
281 static void telnet_history_go(struct connection *connection, int idx)
283 struct telnet_connection *t_con = connection->priv;
285 if (t_con->history[idx]) {
286 telnet_clear_line(connection, t_con);
287 t_con->line_size = strlen(t_con->history[idx]);
288 t_con->line_cursor = t_con->line_size;
289 memcpy(t_con->line, t_con->history[idx], t_con->line_size);
290 telnet_write(connection, t_con->line, t_con->line_size);
291 t_con->current_history = idx;
293 t_con->state = TELNET_STATE_DATA;
296 static void telnet_history_up(struct connection *connection)
298 struct telnet_connection *t_con = connection->priv;
300 size_t last_history = (t_con->current_history > 0) ?
301 t_con->current_history - 1 :
302 TELNET_LINE_HISTORY_SIZE-1;
303 telnet_history_go(connection, last_history);
306 static void telnet_history_down(struct connection *connection)
308 struct telnet_connection *t_con = connection->priv;
309 size_t next_history;
311 next_history = (t_con->current_history + 1) % TELNET_LINE_HISTORY_SIZE;
312 telnet_history_go(connection, next_history);
315 static void telnet_move_cursor(struct connection *connection, size_t pos)
317 struct telnet_connection *tc;
318 size_t tmp;
320 tc = connection->priv;
322 if (pos < tc->line_cursor) {
323 tmp = tc->line_cursor - pos;
325 for (size_t i = 0; i < tmp; i += 16)
326 telnet_write(connection, "\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b",
327 MIN(tmp - i, 16));
328 } else {
329 tmp = pos - tc->line_cursor;
331 for (size_t i = 0; i < tmp; i += 16)
332 telnet_write(connection, tc->line + tc->line_cursor + i,
333 MIN(tmp - i, 16));
336 tc->line_cursor = pos;
339 static int telnet_input(struct connection *connection)
341 int bytes_read;
342 unsigned char buffer[TELNET_BUFFER_SIZE];
343 unsigned char *buf_p;
344 struct telnet_connection *t_con = connection->priv;
345 struct command_context *command_context = connection->cmd_ctx;
347 bytes_read = connection_read(connection, buffer, TELNET_BUFFER_SIZE);
349 if (bytes_read == 0)
350 return ERROR_SERVER_REMOTE_CLOSED;
351 else if (bytes_read == -1) {
352 LOG_ERROR("error during read: %s", strerror(errno));
353 return ERROR_SERVER_REMOTE_CLOSED;
356 buf_p = buffer;
357 while (bytes_read) {
358 switch (t_con->state) {
359 case TELNET_STATE_DATA:
360 if (*buf_p == 0xff)
361 t_con->state = TELNET_STATE_IAC;
362 else {
363 if (isprint(*buf_p)) { /* printable character */
364 /* watch buffer size leaving one spare character for
365 * string null termination */
366 if (t_con->line_size == TELNET_LINE_MAX_SIZE-1) {
367 /* output audible bell if buffer is full
368 * "\a" does not work, at least on windows */
369 telnet_write(connection, "\x07", 1);
370 } else if (t_con->line_cursor == t_con->line_size) {
371 telnet_write(connection, buf_p, 1);
372 t_con->line[t_con->line_size++] = *buf_p;
373 t_con->line_cursor++;
374 } else {
375 size_t i;
376 memmove(t_con->line + t_con->line_cursor + 1,
377 t_con->line + t_con->line_cursor,
378 t_con->line_size - t_con->line_cursor);
379 t_con->line[t_con->line_cursor] = *buf_p;
380 t_con->line_size++;
381 telnet_write(connection,
382 t_con->line + t_con->line_cursor,
383 t_con->line_size - t_con->line_cursor);
384 t_con->line_cursor++;
385 for (i = t_con->line_cursor; i < t_con->line_size; i++)
386 telnet_write(connection, "\b", 1);
388 } else { /* non-printable */
389 if (*buf_p == 0x1b) { /* escape */
390 t_con->state = TELNET_STATE_ESCAPE;
391 t_con->last_escape = '\x00';
392 } else if ((*buf_p == 0xd) || (*buf_p == 0xa)) { /* CR/LF */
393 int retval;
395 /* skip over combinations with CR/LF and NUL characters */
396 if ((bytes_read > 1) && ((*(buf_p + 1) == 0xa) ||
397 (*(buf_p + 1) == 0xd))) {
398 buf_p++;
399 bytes_read--;
401 if ((bytes_read > 1) && (*(buf_p + 1) == 0)) {
402 buf_p++;
403 bytes_read--;
405 t_con->line[t_con->line_size] = 0;
407 telnet_write(connection, "\r\n\x00", 3);
409 if (strcmp(t_con->line, "history") == 0) {
410 size_t i;
411 for (i = 1; i < TELNET_LINE_HISTORY_SIZE; i++) {
412 /* the t_con->next_history line contains empty string
413 * (unless NULL), thus it is not printed */
414 char *history_line = t_con->history[(t_con->
415 next_history + i) %
416 TELNET_LINE_HISTORY_SIZE];
417 if (history_line) {
418 telnet_write(connection, history_line,
419 strlen(history_line));
420 telnet_write(connection, "\r\n\x00", 3);
423 t_con->line_size = 0;
424 t_con->line_cursor = 0;
425 continue;
428 /* save only non-blank not repeating lines in the history */
429 char *prev_line = t_con->history[(t_con->current_history > 0) ?
430 t_con->current_history - 1 : TELNET_LINE_HISTORY_SIZE-1];
431 if (*t_con->line && (prev_line == NULL ||
432 strcmp(t_con->line, prev_line))) {
433 /* if the history slot is already taken, free it */
434 if (t_con->history[t_con->next_history])
435 free(t_con->history[t_con->next_history]);
437 /* add line to history */
438 t_con->history[t_con->next_history] = strdup(t_con->line);
440 /* wrap history at TELNET_LINE_HISTORY_SIZE */
441 t_con->next_history = (t_con->next_history + 1) %
442 TELNET_LINE_HISTORY_SIZE;
444 /* current history line starts at the new entry */
445 t_con->current_history =
446 t_con->next_history;
448 if (t_con->history[t_con->current_history])
449 free(t_con->history[t_con->current_history]);
450 t_con->history[t_con->current_history] = strdup("");
453 t_con->line_size = 0;
455 /* to suppress prompt in log callback during command execution */
456 t_con->prompt_visible = false;
458 if (strcmp(t_con->line, "shutdown") == 0)
459 telnet_save_history(t_con);
461 retval = command_run_line(command_context, t_con->line);
463 t_con->line_cursor = 0;
464 t_con->prompt_visible = true;
466 if (retval == ERROR_COMMAND_CLOSE_CONNECTION)
467 return ERROR_SERVER_REMOTE_CLOSED;
469 /* the prompt is always * placed at the line beginning */
470 telnet_write(connection, "\r", 1);
472 retval = telnet_prompt(connection);
473 if (retval == ERROR_SERVER_REMOTE_CLOSED)
474 return ERROR_SERVER_REMOTE_CLOSED;
476 } else if ((*buf_p == 0x7f) || (*buf_p == 0x8)) { /* delete character */
477 if (t_con->line_cursor > 0) {
478 if (t_con->line_cursor != t_con->line_size) {
479 size_t i;
480 telnet_write(connection, "\b", 1);
481 t_con->line_cursor--;
482 t_con->line_size--;
483 memmove(t_con->line + t_con->line_cursor,
484 t_con->line + t_con->line_cursor + 1,
485 t_con->line_size -
486 t_con->line_cursor);
488 telnet_write(connection,
489 t_con->line + t_con->line_cursor,
490 t_con->line_size -
491 t_con->line_cursor);
492 telnet_write(connection, " \b", 2);
493 for (i = t_con->line_cursor; i < t_con->line_size; i++)
494 telnet_write(connection, "\b", 1);
495 } else {
496 t_con->line_size--;
497 t_con->line_cursor--;
498 /* back space: move the 'printer' head one char
499 * back, overwrite with space, move back again */
500 telnet_write(connection, "\b \b", 3);
503 } else if (*buf_p == 0x15) /* clear line */
504 telnet_clear_line(connection, t_con);
505 else if (*buf_p == CTRL('B')) { /* cursor left */
506 if (t_con->line_cursor > 0) {
507 telnet_write(connection, "\b", 1);
508 t_con->line_cursor--;
510 t_con->state = TELNET_STATE_DATA;
511 } else if (*buf_p == CTRL('F')) { /* cursor right */
512 if (t_con->line_cursor < t_con->line_size)
513 telnet_write(connection, t_con->line + t_con->line_cursor++, 1);
514 t_con->state = TELNET_STATE_DATA;
515 } else if (*buf_p == CTRL('P')) /* cursor up */
516 telnet_history_up(connection);
517 else if (*buf_p == CTRL('N')) /* cursor down */
518 telnet_history_down(connection);
519 else if (*buf_p == CTRL('A'))
520 telnet_move_cursor(connection, 0);
521 else if (*buf_p == CTRL('E'))
522 telnet_move_cursor(connection, t_con->line_size);
523 else
524 LOG_DEBUG("unhandled nonprintable: %2.2x", *buf_p);
527 break;
528 case TELNET_STATE_IAC:
529 switch (*buf_p) {
530 case 0xfe:
531 t_con->state = TELNET_STATE_DONT;
532 break;
533 case 0xfd:
534 t_con->state = TELNET_STATE_DO;
535 break;
536 case 0xfc:
537 t_con->state = TELNET_STATE_WONT;
538 break;
539 case 0xfb:
540 t_con->state = TELNET_STATE_WILL;
541 break;
543 break;
544 case TELNET_STATE_SB:
545 break;
546 case TELNET_STATE_SE:
547 break;
548 case TELNET_STATE_WILL:
549 case TELNET_STATE_WONT:
550 case TELNET_STATE_DO:
551 case TELNET_STATE_DONT:
552 t_con->state = TELNET_STATE_DATA;
553 break;
554 case TELNET_STATE_ESCAPE:
555 if (t_con->last_escape == '[') {
556 if (*buf_p == 'D') { /* cursor left */
557 if (t_con->line_cursor > 0) {
558 telnet_write(connection, "\b", 1);
559 t_con->line_cursor--;
561 t_con->state = TELNET_STATE_DATA;
562 } else if (*buf_p == 'C') { /* cursor right */
563 if (t_con->line_cursor < t_con->line_size)
564 telnet_write(connection,
565 t_con->line + t_con->line_cursor++, 1);
566 t_con->state = TELNET_STATE_DATA;
567 } else if (*buf_p == 'A') { /* cursor up */
568 telnet_history_up(connection);
569 } else if (*buf_p == 'B') { /* cursor down */
570 telnet_history_down(connection);
571 } else if (*buf_p == '3')
572 t_con->last_escape = *buf_p;
573 else
574 t_con->state = TELNET_STATE_DATA;
575 } else if (t_con->last_escape == '3') {
576 /* Remove character */
577 if (*buf_p == '~') {
578 if (t_con->line_cursor < t_con->line_size) {
579 size_t i;
580 t_con->line_size--;
581 /* remove char from line buffer */
582 memmove(t_con->line + t_con->line_cursor,
583 t_con->line + t_con->line_cursor + 1,
584 t_con->line_size - t_con->line_cursor);
586 /* print remainder of buffer */
587 telnet_write(connection, t_con->line + t_con->line_cursor,
588 t_con->line_size - t_con->line_cursor);
589 /* overwrite last char with whitespace */
590 telnet_write(connection, " \b", 2);
592 /* move back to cursor position*/
593 for (i = t_con->line_cursor; i < t_con->line_size; i++)
594 telnet_write(connection, "\b", 1);
597 t_con->state = TELNET_STATE_DATA;
598 } else
599 t_con->state = TELNET_STATE_DATA;
600 } else if (t_con->last_escape == '\x00') {
601 if (*buf_p == '[')
602 t_con->last_escape = *buf_p;
603 else
604 t_con->state = TELNET_STATE_DATA;
605 } else {
606 LOG_ERROR("BUG: unexpected value in t_con->last_escape");
607 t_con->state = TELNET_STATE_DATA;
610 break;
611 default:
612 LOG_ERROR("unknown telnet state");
613 return ERROR_FAIL;
616 bytes_read--;
617 buf_p++;
620 return ERROR_OK;
623 static int telnet_connection_closed(struct connection *connection)
625 struct telnet_connection *t_con = connection->priv;
626 int i;
628 log_remove_callback(telnet_log_callback, connection);
630 if (t_con->prompt) {
631 free(t_con->prompt);
632 t_con->prompt = NULL;
635 /* save telnet history */
636 telnet_save_history(t_con);
638 for (i = 0; i < TELNET_LINE_HISTORY_SIZE; i++) {
639 if (t_con->history[i]) {
640 free(t_con->history[i]);
641 t_con->history[i] = NULL;
645 /* if this connection registered a debug-message receiver delete it */
646 delete_debug_msg_receiver(connection->cmd_ctx, NULL);
648 if (connection->priv) {
649 free(connection->priv);
650 connection->priv = NULL;
651 } else
652 LOG_ERROR("BUG: connection->priv == NULL");
654 return ERROR_OK;
657 int telnet_init(char *banner)
659 if (strcmp(telnet_port, "disabled") == 0) {
660 LOG_INFO("telnet server disabled");
661 return ERROR_OK;
664 struct telnet_service *telnet_service =
665 malloc(sizeof(struct telnet_service));
667 if (!telnet_service) {
668 LOG_ERROR("Failed to allocate telnet service.");
669 return ERROR_FAIL;
672 telnet_service->banner = banner;
674 int ret = add_service("telnet", telnet_port, CONNECTION_LIMIT_UNLIMITED,
675 telnet_new_connection, telnet_input, telnet_connection_closed,
676 telnet_service);
678 if (ret != ERROR_OK) {
679 free(telnet_service);
680 return ret;
683 return ERROR_OK;
686 /* daemon configuration command telnet_port */
687 COMMAND_HANDLER(handle_telnet_port_command)
689 return CALL_COMMAND_HANDLER(server_pipe_command, &telnet_port);
692 COMMAND_HANDLER(handle_exit_command)
694 return ERROR_COMMAND_CLOSE_CONNECTION;
697 static const struct command_registration telnet_command_handlers[] = {
699 .name = "exit",
700 .handler = handle_exit_command,
701 .mode = COMMAND_EXEC,
702 .usage = "",
703 .help = "exit telnet session",
706 .name = "telnet_port",
707 .handler = handle_telnet_port_command,
708 .mode = COMMAND_ANY,
709 .help = "Specify port on which to listen "
710 "for incoming telnet connections. "
711 "Read help on 'gdb_port'.",
712 .usage = "[port_num]",
714 COMMAND_REGISTRATION_DONE
717 int telnet_register_commands(struct command_context *cmd_ctx)
719 telnet_port = strdup("4444");
720 return register_commands(cmd_ctx, NULL, telnet_command_handlers);
723 void telnet_service_free(void)
725 free(telnet_port);