1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
|
/***************************************************************************
* Copyright (C) 2005 by Dominic Rath *
* Dominic.Rath@gmx.de *
* *
* Copyright (C) 2007-2010 Øyvind Harboe *
* oyvind.harboe@zylin.com *
* *
* Copyright (C) 2008 by Spencer Oliver *
* spen@spen-soft.co.uk *
* *
* This program is free software; you can redistribute it and/or modify *
* it under the terms of the GNU General Public License as published by *
* the Free Software Foundation; either version 2 of the License, or *
* (at your option) any later version. *
* *
* This program is distributed in the hope that it will be useful, *
* but WITHOUT ANY WARRANTY; without even the implied warranty of *
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the *
* GNU General Public License for more details. *
* *
* You should have received a copy of the GNU General Public License *
* along with this program. If not, see <http://www.gnu.org/licenses/>. *
***************************************************************************/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include "telnet_server.h"
#include <target/target_request.h>
#include <helper/configuration.h>
#include <helper/list.h>
static char *telnet_port;
static char *negotiate =
"\xFF\xFB\x03" /* IAC WILL Suppress Go Ahead */
"\xFF\xFB\x01" /* IAC WILL Echo */
"\xFF\xFD\x03" /* IAC DO Suppress Go Ahead */
"\xFF\xFE\x01"; /* IAC DON'T Echo */
#define CTRL(c) (c - '@')
#define TELNET_HISTORY ".openocd_history"
/* The only way we can detect that the socket is closed is the first time
* we write to it, we will fail. Subsequent write operations will
* succeed. Shudder!
*/
static int telnet_write(struct connection *connection, const void *data,
int len)
{
struct telnet_connection *t_con = connection->priv;
if (t_con->closed)
return ERROR_SERVER_REMOTE_CLOSED;
if (connection_write(connection, data, len) == len)
return ERROR_OK;
t_con->closed = true;
return ERROR_SERVER_REMOTE_CLOSED;
}
/* output an audible bell */
static int telnet_bell(struct connection *connection)
{
/* ("\a" does not work, at least on windows) */
return telnet_write(connection, "\x07", 1);
}
static int telnet_prompt(struct connection *connection)
{
struct telnet_connection *t_con = connection->priv;
return telnet_write(connection, t_con->prompt, strlen(t_con->prompt));
}
static int telnet_outputline(struct connection *connection, const char *line)
{
int len;
/* process lines in buffer */
while (*line) {
char *line_end = strchr(line, '\n');
if (line_end)
len = line_end-line;
else
len = strlen(line);
telnet_write(connection, line, len);
if (line_end) {
telnet_write(connection, "\r\n", 2);
line += len + 1;
} else
line += len;
}
return ERROR_OK;
}
static int telnet_output(struct command_context *cmd_ctx, const char *line)
{
struct connection *connection = cmd_ctx->output_handler_priv;
return telnet_outputline(connection, line);
}
static void telnet_log_callback(void *priv, const char *file, unsigned line,
const char *function, const char *string)
{
struct connection *connection = priv;
struct telnet_connection *t_con = connection->priv;
size_t i;
size_t tmp;
/* If the prompt is not visible, simply output the message. */
if (!t_con->prompt_visible) {
telnet_outputline(connection, string);
return;
}
/* Clear the command line. */
tmp = strlen(t_con->prompt) + t_con->line_size;
for (i = 0; i < tmp; i += 16)
telnet_write(connection, "\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b",
MIN(tmp - i, 16));
for (i = 0; i < tmp; i += 16)
telnet_write(connection, " ", MIN(tmp - i, 16));
for (i = 0; i < tmp; i += 16)
telnet_write(connection, "\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b",
MIN(tmp - i, 16));
telnet_outputline(connection, string);
/* Put the command line to its previous state. */
telnet_prompt(connection);
telnet_write(connection, t_con->line, t_con->line_size);
for (i = t_con->line_cursor; i < t_con->line_size; i++)
telnet_write(connection, "\b", 1);
}
static void telnet_load_history(struct telnet_connection *t_con)
{
FILE *histfp;
char buffer[TELNET_BUFFER_SIZE];
int i = 0;
char *history = get_home_dir(TELNET_HISTORY);
if (!history) {
LOG_INFO("unable to get user home directory, telnet history will be disabled");
return;
}
histfp = fopen(history, "rb");
if (histfp) {
while (fgets(buffer, sizeof(buffer), histfp)) {
char *p = strchr(buffer, '\n');
if (p)
*p = '\0';
if (buffer[0] && i < TELNET_LINE_HISTORY_SIZE)
t_con->history[i++] = strdup(buffer);
}
t_con->next_history = i;
t_con->next_history %= TELNET_LINE_HISTORY_SIZE;
/* try to set to last entry - 1, that way we skip over any exit/shutdown cmds */
t_con->current_history = t_con->next_history > 0 ? i - 1 : 0;
fclose(histfp);
}
free(history);
}
static void telnet_save_history(struct telnet_connection *t_con)
{
FILE *histfp;
int i;
int num;
char *history = get_home_dir(TELNET_HISTORY);
if (!history) {
LOG_INFO("unable to get user home directory, telnet history will be disabled");
return;
}
histfp = fopen(history, "wb");
if (histfp) {
num = TELNET_LINE_HISTORY_SIZE;
i = t_con->current_history + 1;
i %= TELNET_LINE_HISTORY_SIZE;
while (!t_con->history[i] && num > 0) {
i++;
i %= TELNET_LINE_HISTORY_SIZE;
num--;
}
if (num > 0) {
for (; num > 0; num--) {
fprintf(histfp, "%s\n", t_con->history[i]);
i++;
i %= TELNET_LINE_HISTORY_SIZE;
}
}
fclose(histfp);
}
free(history);
}
static int telnet_new_connection(struct connection *connection)
{
struct telnet_connection *telnet_connection;
struct telnet_service *telnet_service = connection->service->priv;
int i;
telnet_connection = malloc(sizeof(struct telnet_connection));
if (!telnet_connection) {
LOG_ERROR("Failed to allocate telnet connection.");
return ERROR_FAIL;
}
connection->priv = telnet_connection;
/* initialize telnet connection information */
telnet_connection->closed = false;
telnet_connection->line_size = 0;
telnet_connection->line_cursor = 0;
telnet_connection->prompt = strdup("> ");
telnet_connection->prompt_visible = true;
telnet_connection->state = TELNET_STATE_DATA;
/* output goes through telnet connection */
command_set_output_handler(connection->cmd_ctx, telnet_output, connection);
/* negotiate telnet options */
telnet_write(connection, negotiate, strlen(negotiate));
/* print connection banner */
if (telnet_service->banner) {
telnet_write(connection, telnet_service->banner, strlen(telnet_service->banner));
telnet_write(connection, "\r\n", 2);
}
/* the prompt is always placed at the line beginning */
telnet_write(connection, "\r", 1);
telnet_prompt(connection);
/* initialize history */
for (i = 0; i < TELNET_LINE_HISTORY_SIZE; i++)
telnet_connection->history[i] = NULL;
telnet_connection->next_history = 0;
telnet_connection->current_history = 0;
telnet_load_history(telnet_connection);
log_add_callback(telnet_log_callback, connection);
return ERROR_OK;
}
static void telnet_clear_line(struct connection *connection,
struct telnet_connection *t_con)
{
/* move to end of line */
if (t_con->line_cursor < t_con->line_size)
telnet_write(connection,
t_con->line + t_con->line_cursor,
t_con->line_size - t_con->line_cursor);
/* backspace, overwrite with space, backspace */
while (t_con->line_size > 0) {
telnet_write(connection, "\b \b", 3);
t_con->line_size--;
}
t_con->line_cursor = 0;
}
static void telnet_history_go(struct connection *connection, int idx)
{
struct telnet_connection *t_con = connection->priv;
if (t_con->history[idx]) {
telnet_clear_line(connection, t_con);
t_con->line_size = strlen(t_con->history[idx]);
t_con->line_cursor = t_con->line_size;
memcpy(t_con->line, t_con->history[idx], t_con->line_size);
telnet_write(connection, t_con->line, t_con->line_size);
t_con->current_history = idx;
}
t_con->state = TELNET_STATE_DATA;
}
static void telnet_history_up(struct connection *connection)
{
struct telnet_connection *t_con = connection->priv;
size_t last_history = (t_con->current_history > 0) ?
t_con->current_history - 1 :
TELNET_LINE_HISTORY_SIZE-1;
telnet_history_go(connection, last_history);
}
static void telnet_history_down(struct connection *connection)
{
struct telnet_connection *t_con = connection->priv;
size_t next_history;
next_history = (t_con->current_history + 1) % TELNET_LINE_HISTORY_SIZE;
telnet_history_go(connection, next_history);
}
static int telnet_history_print(struct connection *connection)
{
struct telnet_connection *tc;
tc = connection->priv;
for (size_t i = 1; i < TELNET_LINE_HISTORY_SIZE; i++) {
char *line;
/*
* The tc->next_history line contains empty string (unless NULL), thus
* it is not printed.
*/
line = tc->history[(tc->next_history + i) % TELNET_LINE_HISTORY_SIZE];
if (line) {
telnet_write(connection, line, strlen(line));
telnet_write(connection, "\r\n\x00", 3);
}
}
tc->line_size = 0;
tc->line_cursor = 0;
/* The prompt is always placed at the line beginning. */
telnet_write(connection, "\r", 1);
return telnet_prompt(connection);
}
static void telnet_move_cursor(struct connection *connection, size_t pos)
{
struct telnet_connection *tc;
size_t tmp;
tc = connection->priv;
if (pos < tc->line_cursor) {
tmp = tc->line_cursor - pos;
for (size_t i = 0; i < tmp; i += 16)
telnet_write(connection, "\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b",
MIN(tmp - i, 16));
} else {
tmp = pos - tc->line_cursor;
for (size_t i = 0; i < tmp; i += 16)
telnet_write(connection, tc->line + tc->line_cursor + i,
MIN(tmp - i, 16));
}
tc->line_cursor = pos;
}
/* check buffer size leaving one spare character for string null termination */
static inline bool telnet_can_insert(struct connection *connection, size_t len)
{
struct telnet_connection *t_con = connection->priv;
return t_con->line_size + len < TELNET_LINE_MAX_SIZE;
}
/* write to telnet console, and update the telnet_connection members
* this function is capable of inserting in the middle of a line
* please ensure that data does not contain special characters (\n, \r, \t, \b ...)
*
* returns false when it fails to insert the requested data
*/
static bool telnet_insert(struct connection *connection, const void *data, size_t len)
{
struct telnet_connection *t_con = connection->priv;
if (!telnet_can_insert(connection, len)) {
telnet_bell(connection);
return false;
}
if (t_con->line_cursor < t_con->line_size) {
/* we have some content after the cursor */
memmove(t_con->line + t_con->line_cursor + len,
t_con->line + t_con->line_cursor,
t_con->line_size - t_con->line_cursor);
}
strncpy(t_con->line + t_con->line_cursor, data, len);
telnet_write(connection,
t_con->line + t_con->line_cursor,
t_con->line_size + len - t_con->line_cursor);
t_con->line_size += len;
t_con->line_cursor += len;
for (size_t i = t_con->line_cursor; i < t_con->line_size; i++)
telnet_write(connection, "\b", 1);
return true;
}
static void telnet_auto_complete(struct connection *connection)
{
struct telnet_connection *t_con = connection->priv;
struct command_context *command_context = connection->cmd_ctx;
struct cmd_match {
char *cmd;
struct list_head lh;
};
LIST_HEAD(matches);
/* user command sequence, either at line beginning
* or we start over after these characters ';', '[', '{' */
size_t seq_start = (t_con->line_cursor == 0) ? 0 : (t_con->line_cursor - 1);
while (seq_start > 0) {
char c = t_con->line[seq_start];
if (c == ';' || c == '[' || c == '{') {
seq_start++;
break;
}
seq_start--;
}
/* user command position in the line, ignore leading spaces */
size_t usr_cmd_pos = seq_start;
while ((usr_cmd_pos < t_con->line_cursor) && isspace(t_con->line[usr_cmd_pos]))
usr_cmd_pos++;
/* user command length */
size_t usr_cmd_len = t_con->line_cursor - usr_cmd_pos;
/* optimize multiple spaces in the user command,
* because info commands does not tolerate multiple spaces */
size_t optimized_spaces = 0;
char query[usr_cmd_len + 1];
for (size_t i = 0; i < usr_cmd_len; i++) {
if ((i < usr_cmd_len - 1) && isspace(t_con->line[usr_cmd_pos + i])
&& isspace(t_con->line[usr_cmd_pos + i + 1])) {
optimized_spaces++;
continue;
}
query[i - optimized_spaces] = t_con->line[usr_cmd_pos + i];
}
usr_cmd_len -= optimized_spaces;
query[usr_cmd_len] = '\0';
/* filter commands */
char *query_cmd = alloc_printf("_telnet_autocomplete_helper {%s*}", query);
if (!query_cmd) {
LOG_ERROR("Out of memory");
return;
}
int retval = Jim_EvalSource(command_context->interp, __FILE__, __LINE__, query_cmd);
free(query_cmd);
if (retval != JIM_OK)
return;
Jim_Obj *list = Jim_GetResult(command_context->interp);
Jim_IncrRefCount(list);
/* common prefix length of the matched commands */
size_t common_len = 0;
char *first_match = NULL; /* used to compute the common prefix length */
int len = Jim_ListLength(command_context->interp, list);
for (int i = 0; i < len; i++) {
Jim_Obj *elem = Jim_ListGetIndex(command_context->interp, list, i);
Jim_IncrRefCount(elem);
char *name = (char *)Jim_GetString(elem, NULL);
/* validate the command */
bool ignore_cmd = false;
Jim_Cmd *jim_cmd = Jim_GetCommand(command_context->interp, elem, JIM_NONE);
if (!jim_cmd) {
/* Why we are here? Let's ignore it! */
ignore_cmd = true;
} else if (jimcmd_is_oocd_command(jim_cmd)) {
struct command *cmd = jimcmd_privdata(jim_cmd);
if (cmd && !cmd->handler && !cmd->jim_handler) {
/* Initial part of a multi-word command. Ignore it! */
ignore_cmd = true;
} else if (cmd && cmd->mode == COMMAND_CONFIG) {
/* Not executable after config phase. Ignore it! */
ignore_cmd = true;
}
}
/* save the command in the prediction list */
if (!ignore_cmd) {
struct cmd_match *match = calloc(1, sizeof(struct cmd_match));
if (!match) {
LOG_ERROR("Out of memory");
Jim_DecrRefCount(command_context->interp, elem);
break; /* break the for loop */
}
if (list_empty(&matches)) {
common_len = strlen(name);
first_match = name;
} else {
size_t new_common_len = usr_cmd_len; /* save some loops */
while (new_common_len < common_len && first_match[new_common_len] == name[new_common_len])
new_common_len++;
common_len = new_common_len;
}
match->cmd = name;
list_add_tail(&match->lh, &matches);
}
Jim_DecrRefCount(command_context->interp, elem);
}
/* end of command filtering */
/* proceed with auto-completion */
if (list_empty(&matches))
telnet_bell(connection);
else if (common_len == usr_cmd_len && list_is_singular(&matches) && t_con->line_cursor == t_con->line_size)
telnet_insert(connection, " ", 1);
else if (common_len > usr_cmd_len) {
int completion_size = common_len - usr_cmd_len;
if (telnet_insert(connection, first_match + usr_cmd_len, completion_size)) {
/* in bash this extra space is only added when the cursor in at the end of line */
if (list_is_singular(&matches) && t_con->line_cursor == t_con->line_size)
telnet_insert(connection, " ", 1);
}
} else if (!list_is_singular(&matches)) {
telnet_write(connection, "\n\r", 2);
struct cmd_match *match;
list_for_each_entry(match, &matches, lh) {
telnet_write(connection, match->cmd, strlen(match->cmd));
telnet_write(connection, "\n\r", 2);
}
telnet_prompt(connection);
telnet_write(connection, t_con->line, t_con->line_size);
/* restore the terminal visible cursor location */
for (size_t i = t_con->line_cursor; i < t_con->line_size; i++)
telnet_write(connection, "\b", 1);
}
/* destroy the command_list */
struct cmd_match *tmp, *match;
list_for_each_entry_safe(match, tmp, &matches, lh)
free(match);
Jim_DecrRefCount(command_context->interp, list);
}
static int telnet_input(struct connection *connection)
{
int bytes_read;
unsigned char buffer[TELNET_BUFFER_SIZE];
unsigned char *buf_p;
struct telnet_connection *t_con = connection->priv;
struct command_context *command_context = connection->cmd_ctx;
bytes_read = connection_read(connection, buffer, TELNET_BUFFER_SIZE);
if (bytes_read == 0)
return ERROR_SERVER_REMOTE_CLOSED;
else if (bytes_read == -1) {
LOG_ERROR("error during read: %s", strerror(errno));
return ERROR_SERVER_REMOTE_CLOSED;
}
buf_p = buffer;
while (bytes_read) {
switch (t_con->state) {
case TELNET_STATE_DATA:
if (*buf_p == 0xff)
t_con->state = TELNET_STATE_IAC;
else {
if (isprint(*buf_p)) { /* printable character */
telnet_insert(connection, buf_p, 1);
} else { /* non-printable */
if (*buf_p == 0x1b) { /* escape */
t_con->state = TELNET_STATE_ESCAPE;
t_con->last_escape = '\x00';
} else if ((*buf_p == 0xd) || (*buf_p == 0xa)) { /* CR/LF */
int retval;
/* skip over combinations with CR/LF and NUL characters */
if ((bytes_read > 1) && ((*(buf_p + 1) == 0xa) ||
(*(buf_p + 1) == 0xd))) {
buf_p++;
bytes_read--;
}
if ((bytes_read > 1) && (*(buf_p + 1) == 0)) {
buf_p++;
bytes_read--;
}
t_con->line[t_con->line_size] = 0;
telnet_write(connection, "\r\n\x00", 3);
if (strcmp(t_con->line, "history") == 0) {
retval = telnet_history_print(connection);
if (retval != ERROR_OK)
return retval;
continue;
}
/* save only non-blank not repeating lines in the history */
char *prev_line = t_con->history[(t_con->current_history > 0) ?
t_con->current_history - 1 : TELNET_LINE_HISTORY_SIZE-1];
if (*t_con->line && (!prev_line ||
strcmp(t_con->line, prev_line))) {
/* if the history slot is already taken, free it */
free(t_con->history[t_con->next_history]);
/* add line to history */
t_con->history[t_con->next_history] = strdup(t_con->line);
/* wrap history at TELNET_LINE_HISTORY_SIZE */
t_con->next_history = (t_con->next_history + 1) %
TELNET_LINE_HISTORY_SIZE;
/* current history line starts at the new entry */
t_con->current_history =
t_con->next_history;
free(t_con->history[t_con->current_history]);
t_con->history[t_con->current_history] = strdup("");
}
t_con->line_size = 0;
/* to suppress prompt in log callback during command execution */
t_con->prompt_visible = false;
if (strcmp(t_con->line, "shutdown") == 0)
telnet_save_history(t_con);
retval = command_run_line(command_context, t_con->line);
t_con->line_cursor = 0;
t_con->prompt_visible = true;
if (retval == ERROR_COMMAND_CLOSE_CONNECTION)
return ERROR_SERVER_REMOTE_CLOSED;
/* the prompt is always * placed at the line beginning */
telnet_write(connection, "\r", 1);
retval = telnet_prompt(connection);
if (retval == ERROR_SERVER_REMOTE_CLOSED)
return ERROR_SERVER_REMOTE_CLOSED;
} else if ((*buf_p == 0x7f) || (*buf_p == 0x8)) { /* delete character */
if (t_con->line_cursor > 0) {
if (t_con->line_cursor != t_con->line_size) {
size_t i;
telnet_write(connection, "\b", 1);
t_con->line_cursor--;
t_con->line_size--;
memmove(t_con->line + t_con->line_cursor,
t_con->line + t_con->line_cursor + 1,
t_con->line_size -
t_con->line_cursor);
telnet_write(connection,
t_con->line + t_con->line_cursor,
t_con->line_size -
t_con->line_cursor);
telnet_write(connection, " \b", 2);
for (i = t_con->line_cursor; i < t_con->line_size; i++)
telnet_write(connection, "\b", 1);
} else {
t_con->line_size--;
t_con->line_cursor--;
/* back space: move the 'printer' head one char
* back, overwrite with space, move back again */
telnet_write(connection, "\b \b", 3);
}
}
} else if (*buf_p == 0x15) /* clear line */
telnet_clear_line(connection, t_con);
else if (*buf_p == CTRL('B')) { /* cursor left */
if (t_con->line_cursor > 0) {
telnet_write(connection, "\b", 1);
t_con->line_cursor--;
}
t_con->state = TELNET_STATE_DATA;
} else if (*buf_p == CTRL('F')) { /* cursor right */
if (t_con->line_cursor < t_con->line_size)
telnet_write(connection, t_con->line + t_con->line_cursor++, 1);
t_con->state = TELNET_STATE_DATA;
} else if (*buf_p == CTRL('P')) /* cursor up */
telnet_history_up(connection);
else if (*buf_p == CTRL('N')) /* cursor down */
telnet_history_down(connection);
else if (*buf_p == CTRL('A'))
telnet_move_cursor(connection, 0);
else if (*buf_p == CTRL('E'))
telnet_move_cursor(connection, t_con->line_size);
else if (*buf_p == CTRL('K')) { /* kill line to end */
if (t_con->line_cursor < t_con->line_size) {
/* overwrite with space, until end of line, move back */
for (size_t i = t_con->line_cursor; i < t_con->line_size; i++)
telnet_write(connection, " ", 1);
for (size_t i = t_con->line_cursor; i < t_con->line_size; i++)
telnet_write(connection, "\b", 1);
t_con->line[t_con->line_cursor] = '\0';
t_con->line_size = t_con->line_cursor;
}
} else if (*buf_p == '\t')
telnet_auto_complete(connection);
else
LOG_DEBUG("unhandled nonprintable: %2.2x", *buf_p);
}
}
break;
case TELNET_STATE_IAC:
switch (*buf_p) {
case 0xfe:
t_con->state = TELNET_STATE_DONT;
break;
case 0xfd:
t_con->state = TELNET_STATE_DO;
break;
case 0xfc:
t_con->state = TELNET_STATE_WONT;
break;
case 0xfb:
t_con->state = TELNET_STATE_WILL;
break;
}
break;
case TELNET_STATE_SB:
break;
case TELNET_STATE_SE:
break;
case TELNET_STATE_WILL:
case TELNET_STATE_WONT:
case TELNET_STATE_DO:
case TELNET_STATE_DONT:
t_con->state = TELNET_STATE_DATA;
break;
case TELNET_STATE_ESCAPE:
if (t_con->last_escape == '[') {
if (*buf_p == 'D') { /* cursor left */
if (t_con->line_cursor > 0) {
telnet_write(connection, "\b", 1);
t_con->line_cursor--;
}
t_con->state = TELNET_STATE_DATA;
} else if (*buf_p == 'C') { /* cursor right */
if (t_con->line_cursor < t_con->line_size)
telnet_write(connection,
t_con->line + t_con->line_cursor++, 1);
t_con->state = TELNET_STATE_DATA;
} else if (*buf_p == 'A') { /* cursor up */
telnet_history_up(connection);
} else if (*buf_p == 'B') { /* cursor down */
telnet_history_down(connection);
} else if (*buf_p == 'F') { /* end key */
telnet_move_cursor(connection, t_con->line_size);
t_con->state = TELNET_STATE_DATA;
} else if (*buf_p == 'H') { /* home key */
telnet_move_cursor(connection, 0);
t_con->state = TELNET_STATE_DATA;
} else if (*buf_p == '3')
t_con->last_escape = *buf_p;
else
t_con->state = TELNET_STATE_DATA;
} else if (t_con->last_escape == '3') {
/* Remove character */
if (*buf_p == '~') {
if (t_con->line_cursor < t_con->line_size) {
size_t i;
t_con->line_size--;
/* remove char from line buffer */
memmove(t_con->line + t_con->line_cursor,
t_con->line + t_con->line_cursor + 1,
t_con->line_size - t_con->line_cursor);
/* print remainder of buffer */
telnet_write(connection, t_con->line + t_con->line_cursor,
t_con->line_size - t_con->line_cursor);
/* overwrite last char with whitespace */
telnet_write(connection, " \b", 2);
/* move back to cursor position*/
for (i = t_con->line_cursor; i < t_con->line_size; i++)
telnet_write(connection, "\b", 1);
}
t_con->state = TELNET_STATE_DATA;
} else
t_con->state = TELNET_STATE_DATA;
} else if (t_con->last_escape == '\x00') {
if (*buf_p == '[')
t_con->last_escape = *buf_p;
else
t_con->state = TELNET_STATE_DATA;
} else {
LOG_ERROR("BUG: unexpected value in t_con->last_escape");
t_con->state = TELNET_STATE_DATA;
}
break;
default:
LOG_ERROR("unknown telnet state");
return ERROR_FAIL;
}
bytes_read--;
buf_p++;
}
return ERROR_OK;
}
static int telnet_connection_closed(struct connection *connection)
{
struct telnet_connection *t_con = connection->priv;
int i;
log_remove_callback(telnet_log_callback, connection);
free(t_con->prompt);
t_con->prompt = NULL;
/* save telnet history */
telnet_save_history(t_con);
for (i = 0; i < TELNET_LINE_HISTORY_SIZE; i++) {
free(t_con->history[i]);
t_con->history[i] = NULL;
}
/* if this connection registered a debug-message receiver delete it */
delete_debug_msg_receiver(connection->cmd_ctx, NULL);
free(connection->priv);
connection->priv = NULL;
return ERROR_OK;
}
int telnet_init(char *banner)
{
if (strcmp(telnet_port, "disabled") == 0) {
LOG_INFO("telnet server disabled");
return ERROR_OK;
}
struct telnet_service *telnet_service =
malloc(sizeof(struct telnet_service));
if (!telnet_service) {
LOG_ERROR("Failed to allocate telnet service.");
return ERROR_FAIL;
}
telnet_service->banner = banner;
int ret = add_service("telnet", telnet_port, CONNECTION_LIMIT_UNLIMITED,
telnet_new_connection, telnet_input, telnet_connection_closed,
telnet_service);
if (ret != ERROR_OK) {
free(telnet_service);
return ret;
}
return ERROR_OK;
}
/* daemon configuration command telnet_port */
COMMAND_HANDLER(handle_telnet_port_command)
{
return CALL_COMMAND_HANDLER(server_pipe_command, &telnet_port);
}
COMMAND_HANDLER(handle_exit_command)
{
return ERROR_COMMAND_CLOSE_CONNECTION;
}
static const struct command_registration telnet_command_handlers[] = {
{
.name = "exit",
.handler = handle_exit_command,
.mode = COMMAND_EXEC,
.usage = "",
.help = "exit telnet session",
},
{
.name = "telnet_port",
.handler = handle_telnet_port_command,
.mode = COMMAND_CONFIG,
.help = "Specify port on which to listen "
"for incoming telnet connections. "
"Read help on 'gdb_port'.",
.usage = "[port_num]",
},
COMMAND_REGISTRATION_DONE
};
int telnet_register_commands(struct command_context *cmd_ctx)
{
telnet_port = strdup("4444");
return register_commands(cmd_ctx, NULL, telnet_command_handlers);
}
void telnet_service_free(void)
{
free(telnet_port);
}
|