git.gag.com Git - fw/openocd/blob - src/server/telnet_server.c

   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  ***************************************************************************/
  24
  25 #ifdef HAVE_CONFIG_H
  26 #include "config.h"
  27 #endif
  28
  29 #include "telnet_server.h"
  30 #include <target/target_request.h>
  31 #include <helper/configuration.h>
  32 #include <helper/list.h>
  33
  34 static char *telnet_port;
  35
  36 static char *negotiate =
  37         "\xFF\xFB\x03"                  /* IAC WILL Suppress Go Ahead */
  38         "\xFF\xFB\x01"                  /* IAC WILL Echo */
  39         "\xFF\xFD\x03"                  /* IAC DO Suppress Go Ahead */
  40         "\xFF\xFE\x01";                 /* IAC DON'T Echo */
  41
  42 #define CTRL(c) (c - '@')
  43 #define TELNET_HISTORY  ".openocd_history"
  44
  45 /* The only way we can detect that the socket is closed is the first time
  46  * we write to it, we will fail. Subsequent write operations will
  47  * succeed. Shudder!
  48  */
  49 static int telnet_write(struct connection *connection, const void *data,
  50         int len)
  51 {
  52         struct telnet_connection *t_con = connection->priv;
  53         if (t_con->closed)
  54                 return ERROR_SERVER_REMOTE_CLOSED;
  55
  56         if (connection_write(connection, data, len) == len)
  57                 return ERROR_OK;
  58         t_con->closed = true;
  59         return ERROR_SERVER_REMOTE_CLOSED;
  60 }
  61
  62 /* output an audible bell */
  63 static int telnet_bell(struct connection *connection)
  64 {
  65         /* ("\a" does not work, at least on windows) */
  66         return telnet_write(connection, "\x07", 1);
  67 }
  68
  69 static int telnet_prompt(struct connection *connection)
  70 {
  71         struct telnet_connection *t_con = connection->priv;
  72
  73         return telnet_write(connection, t_con->prompt, strlen(t_con->prompt));
  74 }
  75
  76 static int telnet_outputline(struct connection *connection, const char *line)
  77 {
  78         int len;
  79
  80         /* process lines in buffer */
  81         while (*line) {
  82                 char *line_end = strchr(line, '\n');
  83
  84                 if (line_end)
  85                         len = line_end-line;
  86                 else
  87                         len = strlen(line);
  88
  89                 telnet_write(connection, line, len);
  90                 if (line_end) {
  91                         telnet_write(connection, "\r\n", 2);
  92                         line += len + 1;
  93                 } else
  94                         line += len;
  95         }
  96
  97         return ERROR_OK;
  98 }
  99
 100 static int telnet_output(struct command_context *cmd_ctx, const char *line)
 101 {
 102         struct connection *connection = cmd_ctx->output_handler_priv;
 103
 104         return telnet_outputline(connection, line);
 105 }
 106
 107 static void telnet_log_callback(void *priv, const char *file, unsigned line,
 108         const char *function, const char *string)
 109 {
 110         struct connection *connection = priv;
 111         struct telnet_connection *t_con = connection->priv;
 112         size_t i;
 113         size_t tmp;
 114
 115         /* If the prompt is not visible, simply output the message. */
 116         if (!t_con->prompt_visible) {
 117                 telnet_outputline(connection, string);
 118                 return;
 119         }
 120
 121         /* Clear the command line. */
 122         tmp = strlen(t_con->prompt) + t_con->line_size;
 123
 124         for (i = 0; i < tmp; i += 16)
 125                 telnet_write(connection, "\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b",
 126                         MIN(tmp - i, 16));
 127
 128         for (i = 0; i < tmp; i += 16)
 129                 telnet_write(connection, "                ", MIN(tmp - i, 16));
 130
 131         for (i = 0; i < tmp; i += 16)
 132                 telnet_write(connection, "\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b",
 133                         MIN(tmp - i, 16));
 134
 135         telnet_outputline(connection, string);
 136
 137         /* Put the command line to its previous state. */
 138         telnet_prompt(connection);
 139         telnet_write(connection, t_con->line, t_con->line_size);
 140
 141         for (i = t_con->line_cursor; i < t_con->line_size; i++)
 142                 telnet_write(connection, "\b", 1);
 143 }
 144
 145 static void telnet_load_history(struct telnet_connection *t_con)
 146 {
 147         FILE *histfp;
 148         char buffer[TELNET_BUFFER_SIZE];
 149         int i = 0;
 150
 151         char *history = get_home_dir(TELNET_HISTORY);
 152
 153         if (!history) {
 154                 LOG_INFO("unable to get user home directory, telnet history will be disabled");
 155                 return;
 156         }
 157
 158         histfp = fopen(history, "rb");
 159
 160         if (histfp) {
 161
 162                 while (fgets(buffer, sizeof(buffer), histfp)) {
 163
 164                         char *p = strchr(buffer, '\n');
 165                         if (p)
 166                                 *p = '\0';
 167                         if (buffer[0] && i < TELNET_LINE_HISTORY_SIZE)
 168                                 t_con->history[i++] = strdup(buffer);
 169                 }
 170
 171                 t_con->next_history = i;
 172                 t_con->next_history %= TELNET_LINE_HISTORY_SIZE;
 173                 /* try to set to last entry - 1, that way we skip over any exit/shutdown cmds */
 174                 t_con->current_history = t_con->next_history > 0 ? i - 1 : 0;
 175                 fclose(histfp);
 176         }
 177
 178         free(history);
 179 }
 180
 181 static void telnet_save_history(struct telnet_connection *t_con)
 182 {
 183         FILE *histfp;
 184         int i;
 185         int num;
 186
 187         char *history = get_home_dir(TELNET_HISTORY);
 188
 189         if (!history) {
 190                 LOG_INFO("unable to get user home directory, telnet history will be disabled");
 191                 return;
 192         }
 193
 194         histfp = fopen(history, "wb");
 195
 196         if (histfp) {
 197
 198                 num = TELNET_LINE_HISTORY_SIZE;
 199                 i = t_con->current_history + 1;
 200                 i %= TELNET_LINE_HISTORY_SIZE;
 201
 202                 while (!t_con->history[i] && num > 0) {
 203                         i++;
 204                         i %= TELNET_LINE_HISTORY_SIZE;
 205                         num--;
 206                 }
 207
 208                 if (num > 0) {
 209                         for (; num > 0; num--) {
 210                                 fprintf(histfp, "%s\n", t_con->history[i]);
 211                                 i++;
 212                                 i %= TELNET_LINE_HISTORY_SIZE;
 213                         }
 214                 }
 215                 fclose(histfp);
 216         }
 217
 218         free(history);
 219 }
 220
 221 static int telnet_new_connection(struct connection *connection)
 222 {
 223         struct telnet_connection *telnet_connection;
 224         struct telnet_service *telnet_service = connection->service->priv;
 225         int i;
 226
 227         telnet_connection = malloc(sizeof(struct telnet_connection));
 228
 229         if (!telnet_connection) {
 230                 LOG_ERROR("Failed to allocate telnet connection.");
 231                 return ERROR_FAIL;
 232         }
 233
 234         connection->priv = telnet_connection;
 235
 236         /* initialize telnet connection information */
 237         telnet_connection->closed = false;
 238         telnet_connection->line_size = 0;
 239         telnet_connection->line_cursor = 0;
 240         telnet_connection->prompt = strdup("> ");
 241         telnet_connection->prompt_visible = true;
 242         telnet_connection->state = TELNET_STATE_DATA;
 243
 244         /* output goes through telnet connection */
 245         command_set_output_handler(connection->cmd_ctx, telnet_output, connection);
 246
 247         /* negotiate telnet options */
 248         telnet_write(connection, negotiate, strlen(negotiate));
 249
 250         /* print connection banner */
 251         if (telnet_service->banner) {
 252                 telnet_write(connection, telnet_service->banner, strlen(telnet_service->banner));
 253                 telnet_write(connection, "\r\n", 2);
 254         }
 255
 256         /* the prompt is always placed at the line beginning */
 257         telnet_write(connection, "\r", 1);
 258         telnet_prompt(connection);
 259
 260         /* initialize history */
 261         for (i = 0; i < TELNET_LINE_HISTORY_SIZE; i++)
 262                 telnet_connection->history[i] = NULL;
 263         telnet_connection->next_history = 0;
 264         telnet_connection->current_history = 0;
 265         telnet_load_history(telnet_connection);
 266
 267         log_add_callback(telnet_log_callback, connection);
 268
 269         return ERROR_OK;
 270 }
 271
 272 static void telnet_clear_line(struct connection *connection,
 273         struct telnet_connection *t_con)
 274 {
 275         /* move to end of line */
 276         if (t_con->line_cursor < t_con->line_size)
 277                 telnet_write(connection,
 278                         t_con->line + t_con->line_cursor,
 279                         t_con->line_size - t_con->line_cursor);
 280
 281         /* backspace, overwrite with space, backspace */
 282         while (t_con->line_size > 0) {
 283                 telnet_write(connection, "\b \b", 3);
 284                 t_con->line_size--;
 285         }
 286         t_con->line_cursor = 0;
 287 }
 288
 289 static void telnet_history_go(struct connection *connection, int idx)
 290 {
 291         struct telnet_connection *t_con = connection->priv;
 292
 293         if (t_con->history[idx]) {
 294                 telnet_clear_line(connection, t_con);
 295                 t_con->line_size = strlen(t_con->history[idx]);
 296                 t_con->line_cursor = t_con->line_size;
 297                 memcpy(t_con->line, t_con->history[idx], t_con->line_size);
 298                 telnet_write(connection, t_con->line, t_con->line_size);
 299                 t_con->current_history = idx;
 300         }
 301         t_con->state = TELNET_STATE_DATA;
 302 }
 303
 304 static void telnet_history_up(struct connection *connection)
 305 {
 306         struct telnet_connection *t_con = connection->priv;
 307
 308         size_t last_history = (t_con->current_history > 0) ?
 309                                 t_con->current_history - 1 :
 310                                 TELNET_LINE_HISTORY_SIZE-1;
 311         telnet_history_go(connection, last_history);
 312 }
 313
 314 static void telnet_history_down(struct connection *connection)
 315 {
 316         struct telnet_connection *t_con = connection->priv;
 317         size_t next_history;
 318
 319         next_history = (t_con->current_history + 1) % TELNET_LINE_HISTORY_SIZE;
 320         telnet_history_go(connection, next_history);
 321 }
 322
 323 static void telnet_history_add(struct connection *connection)
 324 {
 325         struct telnet_connection *t_con = connection->priv;
 326
 327         /* save only non-blank not repeating lines in the history */
 328         char *prev_line = t_con->history[(t_con->current_history > 0) ?
 329                         t_con->current_history - 1 : TELNET_LINE_HISTORY_SIZE-1];
 330
 331         if (*t_con->line && (!prev_line || strcmp(t_con->line, prev_line))) {
 332                 /* if the history slot is already taken, free it */
 333                 free(t_con->history[t_con->next_history]);
 334
 335                 /* add line to history */
 336                 t_con->history[t_con->next_history] = strdup(t_con->line);
 337
 338                 /* wrap history at TELNET_LINE_HISTORY_SIZE */
 339                 t_con->next_history = (t_con->next_history + 1) % TELNET_LINE_HISTORY_SIZE;
 340
 341                 /* current history line starts at the new entry */
 342                 t_con->current_history = t_con->next_history;
 343
 344                 free(t_con->history[t_con->current_history]);
 345                 t_con->history[t_con->current_history] = strdup("");
 346         }
 347 }
 348
 349 static int telnet_history_print(struct connection *connection)
 350 {
 351         struct telnet_connection *tc;
 352
 353         tc = connection->priv;
 354
 355         for (size_t i = 1; i < TELNET_LINE_HISTORY_SIZE; i++) {
 356                 char *line;
 357
 358                 /*
 359                  * The tc->next_history line contains empty string (unless NULL), thus
 360                  * it is not printed.
 361                  */
 362                 line = tc->history[(tc->next_history + i) % TELNET_LINE_HISTORY_SIZE];
 363
 364                 if (line) {
 365                         telnet_write(connection, line, strlen(line));
 366                         telnet_write(connection, "\r\n\x00", 3);
 367                 }
 368         }
 369
 370         tc->line_size = 0;
 371         tc->line_cursor = 0;
 372
 373         /* The prompt is always placed at the line beginning. */
 374         telnet_write(connection, "\r", 1);
 375
 376         return telnet_prompt(connection);
 377 }
 378
 379 static void telnet_move_cursor(struct connection *connection, size_t pos)
 380 {
 381         struct telnet_connection *tc = connection->priv;
 382         size_t tmp;
 383
 384         if (pos == tc->line_cursor) /* nothing to do */
 385                 return;
 386
 387         if (pos > tc->line_size) /* out of bounds */
 388                 return;
 389
 390         if (pos < tc->line_cursor) {
 391                 tmp = tc->line_cursor - pos;
 392
 393                 for (size_t i = 0; i < tmp; i += 16)
 394                         telnet_write(connection, "\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b",
 395                                 MIN(tmp - i, 16));
 396         } else {
 397                 tmp = pos - tc->line_cursor;
 398
 399                 for (size_t i = 0; i < tmp; i += 16)
 400                         telnet_write(connection, tc->line + tc->line_cursor + i,
 401                                 MIN(tmp - i, 16));
 402         }
 403
 404         tc->line_cursor = pos;
 405 }
 406
 407 /* check buffer size leaving one spare character for string null termination */
 408 static inline bool telnet_can_insert(struct connection *connection, size_t len)
 409 {
 410         struct telnet_connection *t_con = connection->priv;
 411
 412         return t_con->line_size + len < TELNET_LINE_MAX_SIZE;
 413 }
 414
 415 /* write to telnet console, and update the telnet_connection members
 416  * this function is capable of inserting in the middle of a line
 417  * please ensure that data does not contain special characters (\n, \r, \t, \b ...)
 418  *
 419  * returns false when it fails to insert the requested data
 420  */
 421 static bool telnet_insert(struct connection *connection, const void *data, size_t len)
 422 {
 423         struct telnet_connection *t_con = connection->priv;
 424
 425         if (!telnet_can_insert(connection, len)) {
 426                 telnet_bell(connection);
 427                 return false;
 428         }
 429
 430         if (t_con->line_cursor < t_con->line_size) {
 431                 /* we have some content after the cursor */
 432                 memmove(t_con->line + t_con->line_cursor + len,
 433                                 t_con->line + t_con->line_cursor,
 434                                 t_con->line_size - t_con->line_cursor);
 435         }
 436
 437         strncpy(t_con->line + t_con->line_cursor, data, len);
 438
 439         telnet_write(connection,
 440                         t_con->line + t_con->line_cursor,
 441                         t_con->line_size + len - t_con->line_cursor);
 442
 443         t_con->line_size += len;
 444         t_con->line_cursor += len;
 445
 446         for (size_t i = t_con->line_cursor; i < t_con->line_size; i++)
 447                 telnet_write(connection, "\b", 1);
 448
 449         return true;
 450 }
 451
 452 static void telnet_delete_character(struct connection *connection)
 453 {
 454         struct telnet_connection *t_con = connection->priv;
 455
 456         if (t_con->line_cursor == 0)
 457                 return;
 458
 459         if (t_con->line_cursor != t_con->line_size) {
 460                 size_t i;
 461                 telnet_write(connection, "\b", 1);
 462                 t_con->line_cursor--;
 463                 t_con->line_size--;
 464                 memmove(t_con->line + t_con->line_cursor,
 465                                 t_con->line + t_con->line_cursor + 1,
 466                                 t_con->line_size -
 467                                 t_con->line_cursor);
 468
 469                 telnet_write(connection,
 470                                 t_con->line + t_con->line_cursor,
 471                                 t_con->line_size -
 472                                 t_con->line_cursor);
 473                 telnet_write(connection, " \b", 2);
 474                 for (i = t_con->line_cursor; i < t_con->line_size; i++)
 475                         telnet_write(connection, "\b", 1);
 476         } else {
 477                 t_con->line_size--;
 478                 t_con->line_cursor--;
 479                 /* back space: move the 'printer' head one char
 480                  * back, overwrite with space, move back again */
 481                 telnet_write(connection, "\b \b", 3);
 482         }
 483 }
 484
 485 static void telnet_remove_character(struct connection *connection)
 486 {
 487         struct telnet_connection *t_con = connection->priv;
 488
 489         if (t_con->line_cursor < t_con->line_size) {
 490                 size_t i;
 491                 t_con->line_size--;
 492                 /* remove char from line buffer */
 493                 memmove(t_con->line + t_con->line_cursor,
 494                                 t_con->line + t_con->line_cursor + 1,
 495                                 t_con->line_size - t_con->line_cursor);
 496
 497                 /* print remainder of buffer */
 498                 telnet_write(connection, t_con->line + t_con->line_cursor,
 499                                 t_con->line_size - t_con->line_cursor);
 500                 /* overwrite last char with whitespace */
 501                 telnet_write(connection, " \b", 2);
 502
 503                 /* move back to cursor position*/
 504                 for (i = t_con->line_cursor; i < t_con->line_size; i++)
 505                         telnet_write(connection, "\b", 1);
 506         }
 507 }
 508
 509 static int telnet_exec_line(struct connection *connection)
 510 {
 511         struct telnet_connection *t_con = connection->priv;
 512         struct command_context *command_context = connection->cmd_ctx;
 513         int retval;
 514
 515         telnet_write(connection, "\r\n\x00", 3);
 516
 517         if (strcmp(t_con->line, "history") == 0) {
 518                 retval = telnet_history_print(connection);
 519
 520                 if (retval != ERROR_OK)
 521                         return retval;
 522
 523                 return ERROR_OK;
 524         }
 525
 526         telnet_history_add(connection);
 527
 528         t_con->line_size = 0;
 529
 530         /* to suppress prompt in log callback during command execution */
 531         t_con->prompt_visible = false;
 532
 533         if (strcmp(t_con->line, "shutdown") == 0)
 534                 telnet_save_history(t_con);
 535
 536         retval = command_run_line(command_context, t_con->line);
 537
 538         t_con->line_cursor = 0;
 539         t_con->prompt_visible = true;
 540
 541         if (retval == ERROR_COMMAND_CLOSE_CONNECTION)
 542                 return ERROR_SERVER_REMOTE_CLOSED;
 543
 544         /* the prompt is always placed at the line beginning */
 545         telnet_write(connection, "\r", 1);
 546
 547         retval = telnet_prompt(connection);
 548         if (retval == ERROR_SERVER_REMOTE_CLOSED)
 549                 return ERROR_SERVER_REMOTE_CLOSED;
 550
 551         return ERROR_OK;
 552 }
 553
 554 static void telnet_cut_line_to_end(struct connection *connection)
 555 {
 556         struct telnet_connection *t_con = connection->priv;
 557
 558         /* FIXME: currently this function does not save to clipboard */
 559
 560         if (t_con->line_cursor < t_con->line_size) {
 561                 /* overwrite with space, until end of line, move back */
 562                 for (size_t i = t_con->line_cursor; i < t_con->line_size; i++)
 563                         telnet_write(connection, " ", 1);
 564                 for (size_t i = t_con->line_cursor; i < t_con->line_size; i++)
 565                         telnet_write(connection, "\b", 1);
 566                 t_con->line[t_con->line_cursor] = '\0';
 567                 t_con->line_size = t_con->line_cursor;
 568         }
 569 }
 570
 571 static void telnet_interrupt(struct connection *connection)
 572 {
 573         struct telnet_connection *t_con = connection->priv;
 574
 575         /* print '^C' at line end, and display a new command prompt */
 576         telnet_move_cursor(connection, t_con->line_size);
 577         telnet_write(connection, "^C\n\r", 4);
 578         t_con->line_cursor = 0;
 579         t_con->line_size = 0;
 580         telnet_prompt(connection);
 581 }
 582
 583 static void telnet_auto_complete(struct connection *connection)
 584 {
 585         struct telnet_connection *t_con = connection->priv;
 586         struct command_context *command_context = connection->cmd_ctx;
 587
 588         struct cmd_match {
 589                 char *cmd;
 590                 struct list_head lh;
 591         };
 592
 593         LIST_HEAD(matches);
 594
 595         /* - user command sequence, either at line beginning
 596          *   or we start over after these characters ';', '[', '{'
 597          * - user variable sequence, start after the character '$'
 598          *   and do not contain white spaces */
 599         bool is_variable_auto_completion = false;
 600         bool have_spaces = false;
 601         size_t seq_start = (t_con->line_cursor == 0) ? 0 : (t_con->line_cursor - 1);
 602         while (1) {
 603                 char c = t_con->line[seq_start];
 604
 605                 if (c == ';' || c == '[' || c == '{') {
 606                         seq_start++;
 607                         break;
 608                 } else if (c == ' ') {
 609                         have_spaces = true;
 610                 } else if (c == '$' && !have_spaces) {
 611                         is_variable_auto_completion = true;
 612                         seq_start++;
 613                         break;
 614                 }
 615
 616                 if (seq_start == 0)
 617                         break;
 618
 619                 seq_start--;
 620         }
 621
 622         /* user command position in the line, ignore leading spaces */
 623         size_t usr_cmd_pos = seq_start;
 624         while ((usr_cmd_pos < t_con->line_cursor) && isspace(t_con->line[usr_cmd_pos]))
 625                 usr_cmd_pos++;
 626
 627         /* user command length */
 628         size_t usr_cmd_len = t_con->line_cursor - usr_cmd_pos;
 629
 630         /* optimize multiple spaces in the user command,
 631          * because info commands does not tolerate multiple spaces */
 632         size_t optimized_spaces = 0;
 633         char query[usr_cmd_len + 1];
 634         for (size_t i = 0; i < usr_cmd_len; i++) {
 635                 if ((i < usr_cmd_len - 1) && isspace(t_con->line[usr_cmd_pos + i])
 636                                 && isspace(t_con->line[usr_cmd_pos + i + 1])) {
 637                         optimized_spaces++;
 638                         continue;
 639                 }
 640
 641                 query[i - optimized_spaces] = t_con->line[usr_cmd_pos + i];
 642         }
 643
 644         usr_cmd_len -= optimized_spaces;
 645         query[usr_cmd_len] = '\0';
 646
 647         /* filter commands */
 648         char *query_cmd;
 649
 650         if (is_variable_auto_completion)
 651                 query_cmd = alloc_printf("lsort [info vars {%s*}]", query);
 652         else
 653                 query_cmd = alloc_printf("_telnet_autocomplete_helper {%s*}", query);
 654
 655         if (!query_cmd) {
 656                 LOG_ERROR("Out of memory");
 657                 return;
 658         }
 659
 660         int retval = Jim_EvalSource(command_context->interp, __FILE__, __LINE__, query_cmd);
 661         free(query_cmd);
 662         if (retval != JIM_OK)
 663                 return;
 664
 665         Jim_Obj *list = Jim_GetResult(command_context->interp);
 666         Jim_IncrRefCount(list);
 667
 668         /* common prefix length of the matched commands */
 669         size_t common_len = 0;
 670         char *first_match = NULL; /* used to compute the common prefix length */
 671
 672         int len = Jim_ListLength(command_context->interp, list);
 673         for (int i = 0; i < len; i++) {
 674                 Jim_Obj *elem = Jim_ListGetIndex(command_context->interp, list, i);
 675                 Jim_IncrRefCount(elem);
 676
 677                 char *name = (char *)Jim_GetString(elem, NULL);
 678
 679                 /* validate the command */
 680                 bool ignore_cmd = false;
 681                 if (!is_variable_auto_completion) {
 682                         Jim_Cmd *jim_cmd = Jim_GetCommand(command_context->interp, elem, JIM_NONE);
 683
 684                         if (!jim_cmd) {
 685                                 /* Why we are here? Let's ignore it! */
 686                                 ignore_cmd = true;
 687                         } else if (jimcmd_is_oocd_command(jim_cmd)) {
 688                                 struct command *cmd = jimcmd_privdata(jim_cmd);
 689
 690                                 if (cmd && !cmd->handler && !cmd->jim_handler) {
 691                                         /* Initial part of a multi-word command. Ignore it! */
 692                                         ignore_cmd = true;
 693                                 } else if (cmd && cmd->mode == COMMAND_CONFIG) {
 694                                         /* Not executable after config phase. Ignore it! */
 695                                         ignore_cmd = true;
 696                                 }
 697                         }
 698                 }
 699
 700                 /* save the command in the prediction list */
 701                 if (!ignore_cmd) {
 702                         struct cmd_match *match = calloc(1, sizeof(struct cmd_match));
 703                         if (!match) {
 704                                 LOG_ERROR("Out of memory");
 705                                 Jim_DecrRefCount(command_context->interp, elem);
 706                                 break; /* break the for loop */
 707                         }
 708
 709                         if (list_empty(&matches)) {
 710                                 common_len = strlen(name);
 711                                 first_match = name;
 712                         } else {
 713                                 size_t new_common_len = usr_cmd_len; /* save some loops */
 714
 715                                 while (new_common_len < common_len && first_match[new_common_len] == name[new_common_len])
 716                                         new_common_len++;
 717
 718                                 common_len = new_common_len;
 719                         }
 720
 721                         match->cmd = name;
 722                         list_add_tail(&match->lh, &matches);
 723                 }
 724
 725                 Jim_DecrRefCount(command_context->interp, elem);
 726         }
 727         /* end of command filtering */
 728
 729         /* proceed with auto-completion */
 730         if (list_empty(&matches))
 731                 telnet_bell(connection);
 732         else if (common_len == usr_cmd_len && list_is_singular(&matches) && t_con->line_cursor == t_con->line_size)
 733                 telnet_insert(connection, " ", 1);
 734         else if (common_len > usr_cmd_len) {
 735                 int completion_size = common_len - usr_cmd_len;
 736                 if (telnet_insert(connection, first_match + usr_cmd_len, completion_size)) {
 737                         /* in bash this extra space is only added when the cursor in at the end of line */
 738                         if (list_is_singular(&matches) && t_con->line_cursor == t_con->line_size)
 739                                 telnet_insert(connection, " ", 1);
 740                 }
 741         } else if (!list_is_singular(&matches)) {
 742                 telnet_write(connection, "\n\r", 2);
 743
 744                 struct cmd_match *match;
 745                 list_for_each_entry(match, &matches, lh) {
 746                         telnet_write(connection, match->cmd, strlen(match->cmd));
 747                         telnet_write(connection, "\n\r", 2);
 748                 }
 749
 750                 telnet_prompt(connection);
 751                 telnet_write(connection, t_con->line, t_con->line_size);
 752
 753                 /* restore the terminal visible cursor location */
 754                 for (size_t i = t_con->line_cursor; i < t_con->line_size; i++)
 755                         telnet_write(connection, "\b", 1);
 756         }
 757
 758         /* destroy the command_list */
 759         struct cmd_match *tmp, *match;
 760         list_for_each_entry_safe(match, tmp, &matches, lh)
 761                 free(match);
 762
 763         Jim_DecrRefCount(command_context->interp, list);
 764 }
 765
 766 static int telnet_input(struct connection *connection)
 767 {
 768         int bytes_read;
 769         unsigned char buffer[TELNET_BUFFER_SIZE];
 770         unsigned char *buf_p;
 771         struct telnet_connection *t_con = connection->priv;
 772
 773         bytes_read = connection_read(connection, buffer, TELNET_BUFFER_SIZE);
 774
 775         if (bytes_read == 0)
 776                 return ERROR_SERVER_REMOTE_CLOSED;
 777         else if (bytes_read == -1) {
 778                 LOG_ERROR("error during read: %s", strerror(errno));
 779                 return ERROR_SERVER_REMOTE_CLOSED;
 780         }
 781
 782         buf_p = buffer;
 783         while (bytes_read) {
 784                 switch (t_con->state) {
 785                         case TELNET_STATE_DATA:
 786                                 if (*buf_p == 0xff) {
 787                                         t_con->state = TELNET_STATE_IAC;
 788                                 } else {
 789                                         if (isprint(*buf_p)) {  /* printable character */
 790                                                 telnet_insert(connection, buf_p, 1);
 791                                         } else { /* non-printable */
 792                                                 if (*buf_p == 0x1b) {   /* escape */
 793                                                         t_con->state = TELNET_STATE_ESCAPE;
 794                                                         t_con->last_escape = '\x00';
 795                                                 } else if ((*buf_p == 0xd) || (*buf_p == 0xa)) { /* CR/LF */
 796                                                         int retval;
 797
 798                                                         /* skip over combinations with CR/LF and NUL characters */
 799                                                         if ((bytes_read > 1) && ((*(buf_p + 1) == 0xa) ||
 800                                                                         (*(buf_p + 1) == 0xd))) {
 801                                                                 buf_p++;
 802                                                                 bytes_read--;
 803                                                         }
 804                                                         if ((bytes_read > 1) && (*(buf_p + 1) == 0)) {
 805                                                                 buf_p++;
 806                                                                 bytes_read--;
 807                                                         }
 808                                                         t_con->line[t_con->line_size] = 0;
 809
 810                                                         retval = telnet_exec_line(connection);
 811                                                         if (retval != ERROR_OK)
 812                                                                 return retval;
 813                                                 } else if ((*buf_p == 0x7f) || (*buf_p == 0x8)) {       /* delete character */
 814                                                         telnet_delete_character(connection);
 815                                                 } else if (*buf_p == 0x15) {    /* clear line */
 816                                                         telnet_clear_line(connection, t_con);
 817                                                 } else if (*buf_p == CTRL('B')) {       /* cursor left */
 818                                                         telnet_move_cursor(connection, t_con->line_cursor - 1);
 819                                                         t_con->state = TELNET_STATE_DATA;
 820                                                 } else if (*buf_p == CTRL('C')) {       /* interrupt */
 821                                                         telnet_interrupt(connection);
 822                                                 } else if (*buf_p == CTRL('F')) {       /* cursor right */
 823                                                         telnet_move_cursor(connection, t_con->line_cursor + 1);
 824                                                         t_con->state = TELNET_STATE_DATA;
 825                                                 } else if (*buf_p == CTRL('P')) {       /* cursor up */
 826                                                         telnet_history_up(connection);
 827                                                 } else if (*buf_p == CTRL('N')) {       /* cursor down */
 828                                                         telnet_history_down(connection);
 829                                                 } else if (*buf_p == CTRL('A')) {       /* move the cursor to the beginning of the line */
 830                                                         telnet_move_cursor(connection, 0);
 831                                                 } else if (*buf_p == CTRL('E')) {       /* move the cursor to the end of the line */
 832                                                         telnet_move_cursor(connection, t_con->line_size);
 833                                                 } else if (*buf_p == CTRL('K')) {       /* kill line to end */
 834                                                         telnet_cut_line_to_end(connection);
 835                                                 } else if (*buf_p == '\t') {
 836                                                         telnet_auto_complete(connection);
 837                                                 } else {
 838                                                         LOG_DEBUG("unhandled nonprintable: %2.2x", *buf_p);
 839                                                 }
 840                                         }
 841                                 }
 842                                 break;
 843                         case TELNET_STATE_IAC:
 844                                 switch (*buf_p) {
 845                                 case 0xfe:
 846                                         t_con->state = TELNET_STATE_DONT;
 847                                         break;
 848                                 case 0xfd:
 849                                         t_con->state = TELNET_STATE_DO;
 850                                         break;
 851                                 case 0xfc:
 852                                         t_con->state = TELNET_STATE_WONT;
 853                                         break;
 854                                 case 0xfb:
 855                                         t_con->state = TELNET_STATE_WILL;
 856                                         break;
 857                                 }
 858                                 break;
 859                         case TELNET_STATE_SB:
 860                                 break;
 861                         case TELNET_STATE_SE:
 862                                 break;
 863                         case TELNET_STATE_WILL:
 864                         case TELNET_STATE_WONT:
 865                         case TELNET_STATE_DO:
 866                         case TELNET_STATE_DONT:
 867                                 t_con->state = TELNET_STATE_DATA;
 868                                 break;
 869                         case TELNET_STATE_ESCAPE:
 870                                 if (t_con->last_escape == '[') {
 871                                         if (*buf_p == 'D') {    /* cursor left */
 872                                                 telnet_move_cursor(connection, t_con->line_cursor - 1);
 873                                                 t_con->state = TELNET_STATE_DATA;
 874                                         } else if (*buf_p == 'C') {     /* cursor right */
 875                                                 telnet_move_cursor(connection, t_con->line_cursor + 1);
 876                                                 t_con->state = TELNET_STATE_DATA;
 877                                         } else if (*buf_p == 'A') {     /* cursor up */
 878                                                 telnet_history_up(connection);
 879                                         } else if (*buf_p == 'B') {     /* cursor down */
 880                                                 telnet_history_down(connection);
 881                                         } else if (*buf_p == 'F') { /* end key */
 882                                                 telnet_move_cursor(connection, t_con->line_size);
 883                                                 t_con->state = TELNET_STATE_DATA;
 884                                         } else if (*buf_p == 'H') { /* home key */
 885                                                 telnet_move_cursor(connection, 0);
 886                                                 t_con->state = TELNET_STATE_DATA;
 887                                         } else if (*buf_p == '3') {
 888                                                 t_con->last_escape = *buf_p;
 889                                         } else {
 890                                                 t_con->state = TELNET_STATE_DATA;
 891                                         }
 892                                 } else if (t_con->last_escape == '3') {
 893                                         /* Remove character */
 894                                         if (*buf_p == '~') {
 895                                                 telnet_remove_character(connection);
 896                                                 t_con->state = TELNET_STATE_DATA;
 897                                         } else
 898                                                 t_con->state = TELNET_STATE_DATA;
 899                                 } else if (t_con->last_escape == '\x00') {
 900                                         if (*buf_p == '[')
 901                                                 t_con->last_escape = *buf_p;
 902                                         else
 903                                                 t_con->state = TELNET_STATE_DATA;
 904                                 } else {
 905                                         LOG_ERROR("BUG: unexpected value in t_con->last_escape");
 906                                         t_con->state = TELNET_STATE_DATA;
 907                                 }
 908
 909                                 break;
 910                         default:
 911                                 LOG_ERROR("unknown telnet state");
 912                                 return ERROR_FAIL;
 913                 }
 914
 915                 bytes_read--;
 916                 buf_p++;
 917         }
 918
 919         return ERROR_OK;
 920 }
 921
 922 static int telnet_connection_closed(struct connection *connection)
 923 {
 924         struct telnet_connection *t_con = connection->priv;
 925         int i;
 926
 927         log_remove_callback(telnet_log_callback, connection);
 928
 929         free(t_con->prompt);
 930         t_con->prompt = NULL;
 931
 932         /* save telnet history */
 933         telnet_save_history(t_con);
 934
 935         for (i = 0; i < TELNET_LINE_HISTORY_SIZE; i++) {
 936                 free(t_con->history[i]);
 937                 t_con->history[i] = NULL;
 938         }
 939
 940         /* if this connection registered a debug-message receiver delete it */
 941         delete_debug_msg_receiver(connection->cmd_ctx, NULL);
 942
 943         free(connection->priv);
 944         connection->priv = NULL;
 945
 946         return ERROR_OK;
 947 }
 948
 949 static const struct service_driver telnet_service_driver = {
 950         .name = "telnet",
 951         .new_connection_during_keep_alive_handler = NULL,
 952         .new_connection_handler = telnet_new_connection,
 953         .input_handler = telnet_input,
 954         .connection_closed_handler = telnet_connection_closed,
 955         .keep_client_alive_handler = NULL,
 956 };
 957
 958 int telnet_init(char *banner)
 959 {
 960         if (strcmp(telnet_port, "disabled") == 0) {
 961                 LOG_INFO("telnet server disabled");
 962                 return ERROR_OK;
 963         }
 964
 965         struct telnet_service *telnet_service =
 966                 malloc(sizeof(struct telnet_service));
 967
 968         if (!telnet_service) {
 969                 LOG_ERROR("Failed to allocate telnet service.");
 970                 return ERROR_FAIL;
 971         }
 972
 973         telnet_service->banner = banner;
 974
 975         int ret = add_service(&telnet_service_driver, telnet_port, CONNECTION_LIMIT_UNLIMITED,
 976                 telnet_service);
 977
 978         if (ret != ERROR_OK) {
 979                 free(telnet_service);
 980                 return ret;
 981         }
 982
 983         return ERROR_OK;
 984 }
 985
 986 /* daemon configuration command telnet_port */
 987 COMMAND_HANDLER(handle_telnet_port_command)
 988 {
 989         return CALL_COMMAND_HANDLER(server_pipe_command, &telnet_port);
 990 }
 991
 992 COMMAND_HANDLER(handle_exit_command)
 993 {
 994         return ERROR_COMMAND_CLOSE_CONNECTION;
 995 }
 996
 997 static const struct command_registration telnet_command_handlers[] = {
 998         {
 999                 .name = "exit",
1000                 .handler = handle_exit_command,
1001                 .mode = COMMAND_EXEC,
1002                 .usage = "",
1003                 .help = "exit telnet session",
1004         },
1005         {
1006                 .name = "telnet_port",
1007                 .handler = handle_telnet_port_command,
1008                 .mode = COMMAND_CONFIG,
1009                 .help = "Specify port on which to listen "
1010                         "for incoming telnet connections.  "
1011                         "Read help on 'gdb_port'.",
1012                 .usage = "[port_num]",
1013         },
1014         COMMAND_REGISTRATION_DONE
1015 };
1016
1017 int telnet_register_commands(struct command_context *cmd_ctx)
1018 {
1019         telnet_port = strdup("4444");
1020         return register_commands(cmd_ctx, NULL, telnet_command_handlers);
1021 }
1022
1023 void telnet_service_free(void)
1024 {
1025         free(telnet_port);
1026 }