1 /***************************************************************************
2 * Copyright (C) 2005 by Dominic Rath *
3 * Dominic.Rath@gmx.de *
5 * Copyright (C) 2007-2010 Øyvind Harboe *
6 * oyvind.harboe@zylin.com *
8 * Copyright (C) 2008 by Spencer Oliver *
9 * spen@spen-soft.co.uk *
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. *
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. *
21 * You should have received a copy of the GNU General Public License *
22 * along with this program; if not, write to the *
23 * Free Software Foundation, Inc., *
24 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. *
25 ***************************************************************************/
31 #include "telnet_server.h"
32 #include <target/target_request.h>
33 #include <helper/configuration.h>
35 static const char *telnet_port
;
37 static char *negotiate
=
38 "\xFF\xFB\x03" /* IAC WILL Suppress Go Ahead */
39 "\xFF\xFB\x01" /* IAC WILL Echo */
40 "\xFF\xFD\x03" /* IAC DO Suppress Go Ahead */
41 "\xFF\xFE\x01"; /* IAC DON'T Echo */
43 #define CTRL(c) (c - '@')
44 #define TELNET_HISTORY ".openocd_history"
46 /* The only way we can detect that the socket is closed is the first time
47 * we write to it, we will fail. Subsequent write operations will
50 static int telnet_write(struct connection
*connection
, const void *data
,
53 struct telnet_connection
*t_con
= connection
->priv
;
55 return ERROR_SERVER_REMOTE_CLOSED
;
57 if (connection_write(connection
, data
, len
) == len
)
60 return ERROR_SERVER_REMOTE_CLOSED
;
63 static int telnet_prompt(struct connection
*connection
)
65 struct telnet_connection
*t_con
= connection
->priv
;
67 return telnet_write(connection
, t_con
->prompt
, strlen(t_con
->prompt
));
70 static int telnet_outputline(struct connection
*connection
, const char *line
)
74 /* process lines in buffer */
76 char *line_end
= strchr(line
, '\n');
83 telnet_write(connection
, line
, len
);
85 telnet_write(connection
, "\r\n", 2);
94 static int telnet_output(struct command_context
*cmd_ctx
, const char *line
)
96 struct connection
*connection
= cmd_ctx
->output_handler_priv
;
98 return telnet_outputline(connection
, line
);
101 static void telnet_log_callback(void *priv
, const char *file
, unsigned line
,
102 const char *function
, const char *string
)
104 struct connection
*connection
= priv
;
105 struct telnet_connection
*t_con
= connection
->priv
;
108 /* if there is no prompt, simply output the message */
109 if (t_con
->line_cursor
< 0) {
110 telnet_outputline(connection
, string
);
114 /* clear the command line */
115 for (i
= strlen(t_con
->prompt
) + t_con
->line_size
; i
> 0; i
-= 16)
116 telnet_write(connection
, "\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b", i
> 16 ? 16 : i
);
117 for (i
= strlen(t_con
->prompt
) + t_con
->line_size
; i
> 0; i
-= 16)
118 telnet_write(connection
, " ", i
> 16 ? 16 : i
);
119 for (i
= strlen(t_con
->prompt
) + t_con
->line_size
; i
> 0; i
-= 16)
120 telnet_write(connection
, "\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b", i
> 16 ? 16 : i
);
122 /* output the message */
123 telnet_outputline(connection
, string
);
125 /* put the command line to its previous state */
126 telnet_prompt(connection
);
127 telnet_write(connection
, t_con
->line
, t_con
->line_size
);
128 for (i
= t_con
->line_size
; i
> t_con
->line_cursor
; i
--)
129 telnet_write(connection
, "\b", 1);
132 static void telnet_load_history(struct telnet_connection
*t_con
)
135 char buffer
[TELNET_BUFFER_SIZE
];
138 char *history
= get_home_dir(TELNET_HISTORY
);
140 if (history
== NULL
) {
141 LOG_INFO("unable to get user home directory, telnet history will be disabled");
145 histfp
= fopen(history
, "rb");
149 while (fgets(buffer
, sizeof(buffer
), histfp
) != NULL
) {
151 char *p
= strchr(buffer
, '\n');
154 if (buffer
[0] && i
< TELNET_LINE_HISTORY_SIZE
)
155 t_con
->history
[i
++] = strdup(buffer
);
158 t_con
->next_history
= i
;
159 t_con
->next_history
%= TELNET_LINE_HISTORY_SIZE
;
160 /* try to set to last entry - 1, that way we skip over any exit/shutdown cmds */
161 t_con
->current_history
= t_con
->next_history
> 0 ? i
- 1 : 0;
168 static void telnet_save_history(struct telnet_connection
*t_con
)
174 char *history
= get_home_dir(TELNET_HISTORY
);
176 if (history
== NULL
) {
177 LOG_INFO("unable to get user home directory, telnet history will be disabled");
181 histfp
= fopen(history
, "wb");
185 num
= TELNET_LINE_HISTORY_SIZE
;
186 i
= t_con
->current_history
+ 1;
187 i
%= TELNET_LINE_HISTORY_SIZE
;
189 while (t_con
->history
[i
] == NULL
&& num
> 0) {
191 i
%= TELNET_LINE_HISTORY_SIZE
;
196 for (; num
> 0; num
--) {
197 fprintf(histfp
, "%s\n", t_con
->history
[i
]);
199 i
%= TELNET_LINE_HISTORY_SIZE
;
208 static int telnet_new_connection(struct connection
*connection
)
210 struct telnet_connection
*telnet_connection
= malloc(sizeof(struct telnet_connection
));
211 struct telnet_service
*telnet_service
= connection
->service
->priv
;
214 connection
->priv
= telnet_connection
;
216 /* initialize telnet connection information */
217 telnet_connection
->closed
= 0;
218 telnet_connection
->line_size
= 0;
219 telnet_connection
->line_cursor
= 0;
220 telnet_connection
->option_size
= 0;
221 telnet_connection
->prompt
= strdup("> ");
222 telnet_connection
->state
= TELNET_STATE_DATA
;
224 /* output goes through telnet connection */
225 command_set_output_handler(connection
->cmd_ctx
, telnet_output
, connection
);
227 /* negotiate telnet options */
228 telnet_write(connection
, negotiate
, strlen(negotiate
));
230 /* print connection banner */
231 if (telnet_service
->banner
) {
232 telnet_write(connection
, telnet_service
->banner
, strlen(telnet_service
->banner
));
233 telnet_write(connection
, "\r\n", 2);
236 /* the prompt is always placed at the line beginning */
237 telnet_write(connection
, "\r", 1);
238 telnet_prompt(connection
);
240 /* initialize history */
241 for (i
= 0; i
< TELNET_LINE_HISTORY_SIZE
; i
++)
242 telnet_connection
->history
[i
] = NULL
;
243 telnet_connection
->next_history
= 0;
244 telnet_connection
->current_history
= 0;
245 telnet_load_history(telnet_connection
);
247 log_add_callback(telnet_log_callback
, connection
);
252 static void telnet_clear_line(struct connection
*connection
,
253 struct telnet_connection
*t_con
)
255 /* move to end of line */
256 if (t_con
->line_cursor
< t_con
->line_size
)
257 telnet_write(connection
,
258 t_con
->line
+ t_con
->line_cursor
,
259 t_con
->line_size
- t_con
->line_cursor
);
261 /* backspace, overwrite with space, backspace */
262 while (t_con
->line_size
> 0) {
263 telnet_write(connection
, "\b \b", 3);
266 t_con
->line_cursor
= 0;
269 static void telnet_history_go(struct connection
*connection
, int idx
)
271 struct telnet_connection
*t_con
= connection
->priv
;
273 if (t_con
->history
[idx
]) {
274 telnet_clear_line(connection
, t_con
);
275 t_con
->line_size
= strlen(t_con
->history
[idx
]);
276 t_con
->line_cursor
= t_con
->line_size
;
277 memcpy(t_con
->line
, t_con
->history
[idx
], t_con
->line_size
);
278 telnet_write(connection
, t_con
->line
, t_con
->line_size
);
279 t_con
->current_history
= idx
;
281 t_con
->state
= TELNET_STATE_DATA
;
284 static void telnet_history_up(struct connection
*connection
)
286 struct telnet_connection
*t_con
= connection
->priv
;
288 int last_history
= (t_con
->current_history
> 0) ?
289 t_con
->current_history
- 1 :
290 TELNET_LINE_HISTORY_SIZE
-1;
291 telnet_history_go(connection
, last_history
);
294 static void telnet_history_down(struct connection
*connection
)
296 struct telnet_connection
*t_con
= connection
->priv
;
298 int next_history
= (t_con
->current_history
+ 1) % TELNET_LINE_HISTORY_SIZE
;
299 telnet_history_go(connection
, next_history
);
302 static int telnet_input(struct connection
*connection
)
305 unsigned char buffer
[TELNET_BUFFER_SIZE
];
306 unsigned char *buf_p
;
307 struct telnet_connection
*t_con
= connection
->priv
;
308 struct command_context
*command_context
= connection
->cmd_ctx
;
310 bytes_read
= connection_read(connection
, buffer
, TELNET_BUFFER_SIZE
);
313 return ERROR_SERVER_REMOTE_CLOSED
;
314 else if (bytes_read
== -1) {
315 LOG_ERROR("error during read: %s", strerror(errno
));
316 return ERROR_SERVER_REMOTE_CLOSED
;
321 switch (t_con
->state
) {
322 case TELNET_STATE_DATA
:
324 t_con
->state
= TELNET_STATE_IAC
;
326 if (isprint(*buf_p
)) { /* printable character */
327 /* watch buffer size leaving one spare character for
328 * string null termination */
329 if (t_con
->line_size
== TELNET_LINE_MAX_SIZE
-1) {
330 /* output audible bell if buffer is full
331 * "\a" does not work, at least on windows */
332 telnet_write(connection
, "\x07", 1);
333 } else if (t_con
->line_cursor
== t_con
->line_size
) {
334 telnet_write(connection
, buf_p
, 1);
335 t_con
->line
[t_con
->line_size
++] = *buf_p
;
336 t_con
->line_cursor
++;
339 memmove(t_con
->line
+ t_con
->line_cursor
+ 1,
340 t_con
->line
+ t_con
->line_cursor
,
341 t_con
->line_size
- t_con
->line_cursor
);
342 t_con
->line
[t_con
->line_cursor
] = *buf_p
;
344 telnet_write(connection
,
345 t_con
->line
+ t_con
->line_cursor
,
346 t_con
->line_size
- t_con
->line_cursor
);
347 t_con
->line_cursor
++;
348 for (i
= t_con
->line_cursor
; i
< t_con
->line_size
; i
++)
349 telnet_write(connection
, "\b", 1);
351 } else { /* non-printable */
352 if (*buf_p
== 0x1b) { /* escape */
353 t_con
->state
= TELNET_STATE_ESCAPE
;
354 t_con
->last_escape
= '\x00';
355 } else if ((*buf_p
== 0xd) || (*buf_p
== 0xa)) { /* CR/LF */
358 /* skip over combinations with CR/LF and NUL characters */
359 if ((bytes_read
> 1) && ((*(buf_p
+ 1) == 0xa) ||
360 (*(buf_p
+ 1) == 0xd))) {
364 if ((bytes_read
> 1) && (*(buf_p
+ 1) == 0)) {
368 t_con
->line
[t_con
->line_size
] = 0;
370 telnet_write(connection
, "\r\n\x00", 3);
372 if (strcmp(t_con
->line
, "history") == 0) {
374 for (i
= 1; i
< TELNET_LINE_HISTORY_SIZE
; i
++) {
375 /* the t_con->next_history line contains empty string
376 * (unless NULL), thus it is not printed */
377 char *history_line
= t_con
->history
[(t_con
->
379 TELNET_LINE_HISTORY_SIZE
];
381 telnet_write(connection
, history_line
,
382 strlen(history_line
));
383 telnet_write(connection
, "\r\n\x00", 3);
386 t_con
->line_size
= 0;
387 t_con
->line_cursor
= 0;
391 /* save only non-blank not repeating lines in the history */
392 char *prev_line
= t_con
->history
[(t_con
->current_history
> 0) ?
393 t_con
->current_history
- 1 : TELNET_LINE_HISTORY_SIZE
-1];
394 if (*t_con
->line
&& (prev_line
== NULL
||
395 strcmp(t_con
->line
, prev_line
))) {
396 /* if the history slot is already taken, free it */
397 if (t_con
->history
[t_con
->next_history
])
398 free(t_con
->history
[t_con
->next_history
]);
400 /* add line to history */
401 t_con
->history
[t_con
->next_history
] = strdup(t_con
->line
);
403 /* wrap history at TELNET_LINE_HISTORY_SIZE */
404 t_con
->next_history
= (t_con
->next_history
+ 1) %
405 TELNET_LINE_HISTORY_SIZE
;
407 /* current history line starts at the new entry */
408 t_con
->current_history
=
411 if (t_con
->history
[t_con
->current_history
])
412 free(t_con
->history
[t_con
->current_history
]);
413 t_con
->history
[t_con
->current_history
] = strdup("");
416 t_con
->line_size
= 0;
418 /* to suppress prompt in log callback during command execution */
419 t_con
->line_cursor
= -1;
421 if (strcmp(t_con
->line
, "shutdown") == 0)
422 telnet_save_history(t_con
);
424 retval
= command_run_line(command_context
, t_con
->line
);
426 t_con
->line_cursor
= 0;
428 if (retval
== ERROR_COMMAND_CLOSE_CONNECTION
)
429 return ERROR_SERVER_REMOTE_CLOSED
;
431 /* the prompt is always * placed at the line beginning */
432 telnet_write(connection
, "\r", 1);
434 retval
= telnet_prompt(connection
);
435 if (retval
== ERROR_SERVER_REMOTE_CLOSED
)
436 return ERROR_SERVER_REMOTE_CLOSED
;
438 } else if ((*buf_p
== 0x7f) || (*buf_p
== 0x8)) { /* delete character */
439 if (t_con
->line_cursor
> 0) {
440 if (t_con
->line_cursor
!= t_con
->line_size
) {
442 telnet_write(connection
, "\b", 1);
443 t_con
->line_cursor
--;
445 memmove(t_con
->line
+ t_con
->line_cursor
,
446 t_con
->line
+ t_con
->line_cursor
+ 1,
450 telnet_write(connection
,
451 t_con
->line
+ t_con
->line_cursor
,
454 telnet_write(connection
, " \b", 2);
455 for (i
= t_con
->line_cursor
; i
< t_con
->line_size
; i
++)
456 telnet_write(connection
, "\b", 1);
459 t_con
->line_cursor
--;
460 /* back space: move the 'printer' head one char
461 * back, overwrite with space, move back again */
462 telnet_write(connection
, "\b \b", 3);
465 } else if (*buf_p
== 0x15) /* clear line */
466 telnet_clear_line(connection
, t_con
);
467 else if (*buf_p
== CTRL('B')) { /* cursor left */
468 if (t_con
->line_cursor
> 0) {
469 telnet_write(connection
, "\b", 1);
470 t_con
->line_cursor
--;
472 t_con
->state
= TELNET_STATE_DATA
;
473 } else if (*buf_p
== CTRL('F')) { /* cursor right */
474 if (t_con
->line_cursor
< t_con
->line_size
)
475 telnet_write(connection
, t_con
->line
+ t_con
->line_cursor
++, 1);
476 t_con
->state
= TELNET_STATE_DATA
;
477 } else if (*buf_p
== CTRL('P')) /* cursor up */
478 telnet_history_up(connection
);
479 else if (*buf_p
== CTRL('N')) /* cursor down */
480 telnet_history_down(connection
);
482 LOG_DEBUG("unhandled nonprintable: %2.2x", *buf_p
);
486 case TELNET_STATE_IAC
:
489 t_con
->state
= TELNET_STATE_DONT
;
492 t_con
->state
= TELNET_STATE_DO
;
495 t_con
->state
= TELNET_STATE_WONT
;
498 t_con
->state
= TELNET_STATE_WILL
;
502 case TELNET_STATE_SB
:
504 case TELNET_STATE_SE
:
506 case TELNET_STATE_WILL
:
507 case TELNET_STATE_WONT
:
508 case TELNET_STATE_DO
:
509 case TELNET_STATE_DONT
:
510 t_con
->state
= TELNET_STATE_DATA
;
512 case TELNET_STATE_ESCAPE
:
513 if (t_con
->last_escape
== '[') {
514 if (*buf_p
== 'D') { /* cursor left */
515 if (t_con
->line_cursor
> 0) {
516 telnet_write(connection
, "\b", 1);
517 t_con
->line_cursor
--;
519 t_con
->state
= TELNET_STATE_DATA
;
520 } else if (*buf_p
== 'C') { /* cursor right */
521 if (t_con
->line_cursor
< t_con
->line_size
)
522 telnet_write(connection
,
523 t_con
->line
+ t_con
->line_cursor
++, 1);
524 t_con
->state
= TELNET_STATE_DATA
;
525 } else if (*buf_p
== 'A') { /* cursor up */
526 telnet_history_up(connection
);
527 } else if (*buf_p
== 'B') { /* cursor down */
528 telnet_history_down(connection
);
529 } else if (*buf_p
== '3')
530 t_con
->last_escape
= *buf_p
;
532 t_con
->state
= TELNET_STATE_DATA
;
533 } else if (t_con
->last_escape
== '3') {
534 /* Remove character */
536 if (t_con
->line_cursor
< t_con
->line_size
) {
539 /* remove char from line buffer */
540 memmove(t_con
->line
+ t_con
->line_cursor
,
541 t_con
->line
+ t_con
->line_cursor
+ 1,
542 t_con
->line_size
- t_con
->line_cursor
);
544 /* print remainder of buffer */
545 telnet_write(connection
, t_con
->line
+ t_con
->line_cursor
,
546 t_con
->line_size
- t_con
->line_cursor
);
547 /* overwrite last char with whitespace */
548 telnet_write(connection
, " \b", 2);
550 /* move back to cursor position*/
551 for (i
= t_con
->line_cursor
; i
< t_con
->line_size
; i
++)
552 telnet_write(connection
, "\b", 1);
555 t_con
->state
= TELNET_STATE_DATA
;
557 t_con
->state
= TELNET_STATE_DATA
;
558 } else if (t_con
->last_escape
== '\x00') {
560 t_con
->last_escape
= *buf_p
;
562 t_con
->state
= TELNET_STATE_DATA
;
564 LOG_ERROR("BUG: unexpected value in t_con->last_escape");
565 t_con
->state
= TELNET_STATE_DATA
;
570 LOG_ERROR("unknown telnet state");
581 static int telnet_connection_closed(struct connection
*connection
)
583 struct telnet_connection
*t_con
= connection
->priv
;
586 log_remove_callback(telnet_log_callback
, connection
);
590 t_con
->prompt
= NULL
;
593 /* save telnet history */
594 telnet_save_history(t_con
);
596 for (i
= 0; i
< TELNET_LINE_HISTORY_SIZE
; i
++) {
597 if (t_con
->history
[i
]) {
598 free(t_con
->history
[i
]);
599 t_con
->history
[i
] = NULL
;
603 /* if this connection registered a debug-message receiver delete it */
604 delete_debug_msg_receiver(connection
->cmd_ctx
, NULL
);
606 if (connection
->priv
) {
607 free(connection
->priv
);
608 connection
->priv
= NULL
;
610 LOG_ERROR("BUG: connection->priv == NULL");
615 int telnet_init(char *banner
)
617 if (strcmp(telnet_port
, "disabled") == 0) {
618 LOG_INFO("telnet server disabled");
622 struct telnet_service
*telnet_service
= malloc(sizeof(struct telnet_service
));
624 telnet_service
->banner
= banner
;
626 return add_service("telnet",
629 telnet_new_connection
,
631 telnet_connection_closed
,
635 /* daemon configuration command telnet_port */
636 COMMAND_HANDLER(handle_telnet_port_command
)
638 return CALL_COMMAND_HANDLER(server_pipe_command
, &telnet_port
);
641 COMMAND_HANDLER(handle_exit_command
)
643 return ERROR_COMMAND_CLOSE_CONNECTION
;
646 static const struct command_registration telnet_command_handlers
[] = {
649 .handler
= handle_exit_command
,
650 .mode
= COMMAND_EXEC
,
652 .help
= "exit telnet session",
655 .name
= "telnet_port",
656 .handler
= handle_telnet_port_command
,
658 .help
= "Specify port on which to listen "
659 "for incoming telnet connections. "
660 "Read help on 'gdb_port'.",
661 .usage
= "[port_num]",
663 COMMAND_REGISTRATION_DONE
666 int telnet_register_commands(struct command_context
*cmd_ctx
)
668 telnet_port
= strdup("4444");
669 return register_commands(cmd_ctx
, NULL
, telnet_command_handlers
);