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
  33 static char *telnet_port;
  34
  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 */
  40
  41 #define CTRL(c) (c - '@')
  42 #define TELNET_HISTORY  ".openocd_history"
  43
  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!
  47  */
  48 static int telnet_write(struct connection *connection, const void *data,
  49         int len)
  50 {
  51         struct telnet_connection *t_con = connection->priv;
  52         if (t_con->closed)
  53                 return ERROR_SERVER_REMOTE_CLOSED;
  54
  55         if (connection_write(connection, data, len) == len)
  56                 return ERROR_OK;
  57         t_con->closed = 1;
  58         return ERROR_SERVER_REMOTE_CLOSED;
  59 }
  60
  61 static int telnet_prompt(struct connection *connection)
  62 {
  63         struct telnet_connection *t_con = connection->priv;
  64
  65         return telnet_write(connection, t_con->prompt, strlen(t_con->prompt));
  66 }
  67
  68 static int telnet_outputline(struct connection *connection, const char *line)
  69 {
  70         int len;
  71
  72         /* process lines in buffer */
  73         while (*line) {
  74                 char *line_end = strchr(line, '\n');
  75
  76                 if (line_end)
  77                         len = line_end-line;
  78                 else
  79                         len = strlen(line);
  80
  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;
  87         }
  88
  89         return ERROR_OK;
  90 }
  91
  92 static int telnet_output(struct command_context *cmd_ctx, const char *line)
  93 {
  94         struct connection *connection = cmd_ctx->output_handler_priv;
  95
  96         return telnet_outputline(connection, line);
  97 }
  98
  99 static void telnet_log_callback(void *priv, const char *file, unsigned line,
 100         const char *function, const char *string)
 101 {
 102         struct connection *connection = priv;
 103         struct telnet_connection *t_con = connection->priv;
 104         int i;
 105
 106         /* if there is no prompt, simply output the message */
 107         if (t_con->line_cursor < 0) {
 108                 telnet_outputline(connection, string);
 109                 return;
 110         }
 111
 112         /* clear the command line */
 113         for (i = strlen(t_con->prompt) + t_con->line_size; i > 0; i -= 16)
 114                 telnet_write(connection, "\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b", i > 16 ? 16 : i);
 115         for (i = strlen(t_con->prompt) + t_con->line_size; i > 0; i -= 16)
 116                 telnet_write(connection, "                ", i > 16 ? 16 : i);
 117         for (i = strlen(t_con->prompt) + t_con->line_size; i > 0; i -= 16)
 118                 telnet_write(connection, "\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b", i > 16 ? 16 : i);
 119
 120         /* output the message */
 121         telnet_outputline(connection, string);
 122
 123         /* put the command line to its previous state */
 124         telnet_prompt(connection);
 125         telnet_write(connection, t_con->line, t_con->line_size);
 126         for (i = t_con->line_size; i > t_con->line_cursor; i--)
 127                 telnet_write(connection, "\b", 1);
 128 }
 129
 130 static void telnet_load_history(struct telnet_connection *t_con)
 131 {
 132         FILE *histfp;
 133         char buffer[TELNET_BUFFER_SIZE];
 134         int i = 0;
 135
 136         char *history = get_home_dir(TELNET_HISTORY);
 137
 138         if (history == NULL) {
 139                 LOG_INFO("unable to get user home directory, telnet history will be disabled");
 140                 return;
 141         }
 142
 143         histfp = fopen(history, "rb");
 144
 145         if (histfp) {
 146
 147                 while (fgets(buffer, sizeof(buffer), histfp) != NULL) {
 148
 149                         char *p = strchr(buffer, '\n');
 150                         if (p)
 151                                 *p = '\0';
 152                         if (buffer[0] && i < TELNET_LINE_HISTORY_SIZE)
 153                                 t_con->history[i++] = strdup(buffer);
 154                 }
 155
 156                 t_con->next_history = i;
 157                 t_con->next_history %= TELNET_LINE_HISTORY_SIZE;
 158                 /* try to set to last entry - 1, that way we skip over any exit/shutdown cmds */
 159                 t_con->current_history = t_con->next_history > 0 ? i - 1 : 0;
 160                 fclose(histfp);
 161         }
 162
 163         free(history);
 164 }
 165
 166 static void telnet_save_history(struct telnet_connection *t_con)
 167 {
 168         FILE *histfp;
 169         int i;
 170         int num;
 171
 172         char *history = get_home_dir(TELNET_HISTORY);
 173
 174         if (history == NULL) {
 175                 LOG_INFO("unable to get user home directory, telnet history will be disabled");
 176                 return;
 177         }
 178
 179         histfp = fopen(history, "wb");
 180
 181         if (histfp) {
 182
 183                 num = TELNET_LINE_HISTORY_SIZE;
 184                 i = t_con->current_history + 1;
 185                 i %= TELNET_LINE_HISTORY_SIZE;
 186
 187                 while (t_con->history[i] == NULL && num > 0) {
 188                         i++;
 189                         i %= TELNET_LINE_HISTORY_SIZE;
 190                         num--;
 191                 }
 192
 193                 if (num > 0) {
 194                         for (; num > 0; num--) {
 195                                 fprintf(histfp, "%s\n", t_con->history[i]);
 196                                 i++;
 197                                 i %= TELNET_LINE_HISTORY_SIZE;
 198                         }
 199                 }
 200                 fclose(histfp);
 201         }
 202
 203         free(history);
 204 }
 205
 206 static int telnet_new_connection(struct connection *connection)
 207 {
 208         struct telnet_connection *telnet_connection;
 209         struct telnet_service *telnet_service = connection->service->priv;
 210         int i;
 211
 212         telnet_connection = malloc(sizeof(struct telnet_connection));
 213
 214         if (!telnet_connection) {
 215                 LOG_ERROR("Failed to allocate telnet connection.");
 216                 return ERROR_FAIL;
 217         }
 218
 219         connection->priv = telnet_connection;
 220
 221         /* initialize telnet connection information */
 222         telnet_connection->closed = 0;
 223         telnet_connection->line_size = 0;
 224         telnet_connection->line_cursor = 0;
 225         telnet_connection->prompt = strdup("> ");
 226         telnet_connection->state = TELNET_STATE_DATA;
 227
 228         /* output goes through telnet connection */
 229         command_set_output_handler(connection->cmd_ctx, telnet_output, connection);
 230
 231         /* negotiate telnet options */
 232         telnet_write(connection, negotiate, strlen(negotiate));
 233
 234         /* print connection banner */
 235         if (telnet_service->banner) {
 236                 telnet_write(connection, telnet_service->banner, strlen(telnet_service->banner));
 237                 telnet_write(connection, "\r\n", 2);
 238         }
 239
 240         /* the prompt is always placed at the line beginning */
 241         telnet_write(connection, "\r", 1);
 242         telnet_prompt(connection);
 243
 244         /* initialize history */
 245         for (i = 0; i < TELNET_LINE_HISTORY_SIZE; i++)
 246                 telnet_connection->history[i] = NULL;
 247         telnet_connection->next_history = 0;
 248         telnet_connection->current_history = 0;
 249         telnet_load_history(telnet_connection);
 250
 251         log_add_callback(telnet_log_callback, connection);
 252
 253         return ERROR_OK;
 254 }
 255
 256 static void telnet_clear_line(struct connection *connection,
 257         struct telnet_connection *t_con)
 258 {
 259         /* move to end of line */
 260         if (t_con->line_cursor < t_con->line_size)
 261                 telnet_write(connection,
 262                         t_con->line + t_con->line_cursor,
 263                         t_con->line_size - t_con->line_cursor);
 264
 265         /* backspace, overwrite with space, backspace */
 266         while (t_con->line_size > 0) {
 267                 telnet_write(connection, "\b \b", 3);
 268                 t_con->line_size--;
 269         }
 270         t_con->line_cursor = 0;
 271 }
 272
 273 static void telnet_history_go(struct connection *connection, int idx)
 274 {
 275         struct telnet_connection *t_con = connection->priv;
 276
 277         if (t_con->history[idx]) {
 278                 telnet_clear_line(connection, t_con);
 279                 t_con->line_size = strlen(t_con->history[idx]);
 280                 t_con->line_cursor = t_con->line_size;
 281                 memcpy(t_con->line, t_con->history[idx], t_con->line_size);
 282                 telnet_write(connection, t_con->line, t_con->line_size);
 283                 t_con->current_history = idx;
 284         }
 285         t_con->state = TELNET_STATE_DATA;
 286 }
 287
 288 static void telnet_history_up(struct connection *connection)
 289 {
 290         struct telnet_connection *t_con = connection->priv;
 291
 292         int last_history = (t_con->current_history > 0) ?
 293                                 t_con->current_history - 1 :
 294                                 TELNET_LINE_HISTORY_SIZE-1;
 295         telnet_history_go(connection, last_history);
 296 }
 297
 298 static void telnet_history_down(struct connection *connection)
 299 {
 300         struct telnet_connection *t_con = connection->priv;
 301
 302         int next_history = (t_con->current_history + 1) % TELNET_LINE_HISTORY_SIZE;
 303         telnet_history_go(connection, next_history);
 304 }
 305
 306 static int telnet_input(struct connection *connection)
 307 {
 308         int bytes_read;
 309         unsigned char buffer[TELNET_BUFFER_SIZE];
 310         unsigned char *buf_p;
 311         struct telnet_connection *t_con = connection->priv;
 312         struct command_context *command_context = connection->cmd_ctx;
 313
 314         bytes_read = connection_read(connection, buffer, TELNET_BUFFER_SIZE);
 315
 316         if (bytes_read == 0)
 317                 return ERROR_SERVER_REMOTE_CLOSED;
 318         else if (bytes_read == -1) {
 319                 LOG_ERROR("error during read: %s", strerror(errno));
 320                 return ERROR_SERVER_REMOTE_CLOSED;
 321         }
 322
 323         buf_p = buffer;
 324         while (bytes_read) {
 325                 switch (t_con->state) {
 326                         case TELNET_STATE_DATA:
 327                                 if (*buf_p == 0xff)
 328                                         t_con->state = TELNET_STATE_IAC;
 329                                 else {
 330                                         if (isprint(*buf_p)) {  /* printable character */
 331                                                 /* watch buffer size leaving one spare character for
 332                                                  * string null termination */
 333                                                 if (t_con->line_size == TELNET_LINE_MAX_SIZE-1) {
 334                                                         /* output audible bell if buffer is full
 335                                                          * "\a" does not work, at least on windows */
 336                                                         telnet_write(connection, "\x07", 1);
 337                                                 } else if (t_con->line_cursor == t_con->line_size) {
 338                                                         telnet_write(connection, buf_p, 1);
 339                                                         t_con->line[t_con->line_size++] = *buf_p;
 340                                                         t_con->line_cursor++;
 341                                                 } else {
 342                                                         int i;
 343                                                         memmove(t_con->line + t_con->line_cursor + 1,
 344                                                                         t_con->line + t_con->line_cursor,
 345                                                                         t_con->line_size - t_con->line_cursor);
 346                                                         t_con->line[t_con->line_cursor] = *buf_p;
 347                                                         t_con->line_size++;
 348                                                         telnet_write(connection,
 349                                                                         t_con->line + t_con->line_cursor,
 350                                                                         t_con->line_size - t_con->line_cursor);
 351                                                         t_con->line_cursor++;
 352                                                         for (i = t_con->line_cursor; i < t_con->line_size; i++)
 353                                                                 telnet_write(connection, "\b", 1);
 354                                                 }
 355                                         } else {        /* non-printable */
 356                                                 if (*buf_p == 0x1b) {   /* escape */
 357                                                         t_con->state = TELNET_STATE_ESCAPE;
 358                                                         t_con->last_escape = '\x00';
 359                                                 } else if ((*buf_p == 0xd) || (*buf_p == 0xa)) {        /* CR/LF */
 360                                                         int retval;
 361
 362                                                         /* skip over combinations with CR/LF and NUL characters */
 363                                                         if ((bytes_read > 1) && ((*(buf_p + 1) == 0xa) ||
 364                                                                         (*(buf_p + 1) == 0xd))) {
 365                                                                 buf_p++;
 366                                                                 bytes_read--;
 367                                                         }
 368                                                         if ((bytes_read > 1) && (*(buf_p + 1) == 0)) {
 369                                                                 buf_p++;
 370                                                                 bytes_read--;
 371                                                         }
 372                                                         t_con->line[t_con->line_size] = 0;
 373
 374                                                         telnet_write(connection, "\r\n\x00", 3);
 375
 376                                                         if (strcmp(t_con->line, "history") == 0) {
 377                                                                 int i;
 378                                                                 for (i = 1; i < TELNET_LINE_HISTORY_SIZE; i++) {
 379                                                                         /* the t_con->next_history line contains empty string
 380                                                                          * (unless NULL), thus it is not printed */
 381                                                                         char *history_line = t_con->history[(t_con->
 382                                                                                         next_history + i) %
 383                                                                                         TELNET_LINE_HISTORY_SIZE];
 384                                                                         if (history_line) {
 385                                                                                 telnet_write(connection, history_line,
 386                                                                                                 strlen(history_line));
 387                                                                                 telnet_write(connection, "\r\n\x00", 3);
 388                                                                         }
 389                                                                 }
 390                                                                 t_con->line_size = 0;
 391                                                                 t_con->line_cursor = 0;
 392                                                                 continue;
 393                                                         }
 394
 395                                                         /* save only non-blank not repeating lines in the history */
 396                                                         char *prev_line = t_con->history[(t_con->current_history > 0) ?
 397                                                                         t_con->current_history - 1 : TELNET_LINE_HISTORY_SIZE-1];
 398                                                         if (*t_con->line && (prev_line == NULL ||
 399                                                                         strcmp(t_con->line, prev_line))) {
 400                                                                 /* if the history slot is already taken, free it */
 401                                                                 if (t_con->history[t_con->next_history])
 402                                                                         free(t_con->history[t_con->next_history]);
 403
 404                                                                 /* add line to history */
 405                                                                 t_con->history[t_con->next_history] = strdup(t_con->line);
 406
 407                                                                 /* wrap history at TELNET_LINE_HISTORY_SIZE */
 408                                                                 t_con->next_history = (t_con->next_history + 1) %
 409                                                                                 TELNET_LINE_HISTORY_SIZE;
 410
 411                                                                 /* current history line starts at the new entry */
 412                                                                 t_con->current_history =
 413                                                                                 t_con->next_history;
 414
 415                                                                 if (t_con->history[t_con->current_history])
 416                                                                         free(t_con->history[t_con->current_history]);
 417                                                                 t_con->history[t_con->current_history] = strdup("");
 418                                                         }
 419
 420                                                         t_con->line_size = 0;
 421
 422                                                         /* to suppress prompt in log callback during command execution */
 423                                                         t_con->line_cursor = -1;
 424
 425                                                         if (strcmp(t_con->line, "shutdown") == 0)
 426                                                                 telnet_save_history(t_con);
 427
 428                                                         retval = command_run_line(command_context, t_con->line);
 429
 430                                                         t_con->line_cursor = 0;
 431
 432                                                         if (retval == ERROR_COMMAND_CLOSE_CONNECTION)
 433                                                                 return ERROR_SERVER_REMOTE_CLOSED;
 434
 435                                                         /* the prompt is always * placed at the line beginning */
 436                                                         telnet_write(connection, "\r", 1);
 437
 438                                                         retval = telnet_prompt(connection);
 439                                                         if (retval == ERROR_SERVER_REMOTE_CLOSED)
 440                                                                 return ERROR_SERVER_REMOTE_CLOSED;
 441
 442                                                 } else if ((*buf_p == 0x7f) || (*buf_p == 0x8)) {       /* delete character */
 443                                                         if (t_con->line_cursor > 0) {
 444                                                                 if (t_con->line_cursor != t_con->line_size) {
 445                                                                         int i;
 446                                                                         telnet_write(connection, "\b", 1);
 447                                                                         t_con->line_cursor--;
 448                                                                         t_con->line_size--;
 449                                                                         memmove(t_con->line + t_con->line_cursor,
 450                                                                                         t_con->line + t_con->line_cursor + 1,
 451                                                                                         t_con->line_size -
 452                                                                                         t_con->line_cursor);
 453
 454                                                                         telnet_write(connection,
 455                                                                                         t_con->line + t_con->line_cursor,
 456                                                                                         t_con->line_size -
 457                                                                                         t_con->line_cursor);
 458                                                                         telnet_write(connection, " \b", 2);
 459                                                                         for (i = t_con->line_cursor; i < t_con->line_size; i++)
 460                                                                                 telnet_write(connection, "\b", 1);
 461                                                                 } else {
 462                                                                         t_con->line_size--;
 463                                                                         t_con->line_cursor--;
 464                                                                         /* back space: move the 'printer' head one char
 465                                                                          * back, overwrite with space, move back again */
 466                                                                         telnet_write(connection, "\b \b", 3);
 467                                                                 }
 468                                                         }
 469                                                 } else if (*buf_p == 0x15) /* clear line */
 470                                                         telnet_clear_line(connection, t_con);
 471                                                 else if (*buf_p == CTRL('B')) { /* cursor left */
 472                                                         if (t_con->line_cursor > 0) {
 473                                                                 telnet_write(connection, "\b", 1);
 474                                                                 t_con->line_cursor--;
 475                                                         }
 476                                                         t_con->state = TELNET_STATE_DATA;
 477                                                 } else if (*buf_p == CTRL('F')) {       /* cursor right */
 478                                                         if (t_con->line_cursor < t_con->line_size)
 479                                                                 telnet_write(connection, t_con->line + t_con->line_cursor++, 1);
 480                                                         t_con->state = TELNET_STATE_DATA;
 481                                                 } else if (*buf_p == CTRL('P'))         /* cursor up */
 482                                                         telnet_history_up(connection);
 483                                                 else if (*buf_p == CTRL('N'))           /* cursor down */
 484                                                         telnet_history_down(connection);
 485                                                 else
 486                                                         LOG_DEBUG("unhandled nonprintable: %2.2x", *buf_p);
 487                                         }
 488                                 }
 489                                 break;
 490                         case TELNET_STATE_IAC:
 491                                 switch (*buf_p) {
 492                                 case 0xfe:
 493                                         t_con->state = TELNET_STATE_DONT;
 494                                         break;
 495                                 case 0xfd:
 496                                         t_con->state = TELNET_STATE_DO;
 497                                         break;
 498                                 case 0xfc:
 499                                         t_con->state = TELNET_STATE_WONT;
 500                                         break;
 501                                 case 0xfb:
 502                                         t_con->state = TELNET_STATE_WILL;
 503                                         break;
 504                                 }
 505                                 break;
 506                         case TELNET_STATE_SB:
 507                                 break;
 508                         case TELNET_STATE_SE:
 509                                 break;
 510                         case TELNET_STATE_WILL:
 511                         case TELNET_STATE_WONT:
 512                         case TELNET_STATE_DO:
 513                         case TELNET_STATE_DONT:
 514                                 t_con->state = TELNET_STATE_DATA;
 515                                 break;
 516                         case TELNET_STATE_ESCAPE:
 517                                 if (t_con->last_escape == '[') {
 518                                         if (*buf_p == 'D') {    /* cursor left */
 519                                                 if (t_con->line_cursor > 0) {
 520                                                         telnet_write(connection, "\b", 1);
 521                                                         t_con->line_cursor--;
 522                                                 }
 523                                                 t_con->state = TELNET_STATE_DATA;
 524                                         } else if (*buf_p == 'C') {     /* cursor right */
 525                                                 if (t_con->line_cursor < t_con->line_size)
 526                                                         telnet_write(connection,
 527                                                                         t_con->line + t_con->line_cursor++, 1);
 528                                                 t_con->state = TELNET_STATE_DATA;
 529                                         } else if (*buf_p == 'A') {     /* cursor up */
 530                                                 telnet_history_up(connection);
 531                                         } else if (*buf_p == 'B') {     /* cursor down */
 532                                                 telnet_history_down(connection);
 533                                         } else if (*buf_p == '3')
 534                                                 t_con->last_escape = *buf_p;
 535                                         else
 536                                                 t_con->state = TELNET_STATE_DATA;
 537                                 } else if (t_con->last_escape == '3') {
 538                                         /* Remove character */
 539                                         if (*buf_p == '~') {
 540                                                 if (t_con->line_cursor < t_con->line_size) {
 541                                                         int i;
 542                                                         t_con->line_size--;
 543                                                         /* remove char from line buffer */
 544                                                         memmove(t_con->line + t_con->line_cursor,
 545                                                                         t_con->line + t_con->line_cursor + 1,
 546                                                                         t_con->line_size - t_con->line_cursor);
 547
 548                                                         /* print remainder of buffer */
 549                                                         telnet_write(connection, t_con->line + t_con->line_cursor,
 550                                                                         t_con->line_size - t_con->line_cursor);
 551                                                         /* overwrite last char with whitespace */
 552                                                         telnet_write(connection, " \b", 2);
 553
 554                                                         /* move back to cursor position*/
 555                                                         for (i = t_con->line_cursor; i < t_con->line_size; i++)
 556                                                                 telnet_write(connection, "\b", 1);
 557                                                 }
 558
 559                                                 t_con->state = TELNET_STATE_DATA;
 560                                         } else
 561                                                 t_con->state = TELNET_STATE_DATA;
 562                                 } else if (t_con->last_escape == '\x00') {
 563                                         if (*buf_p == '[')
 564                                                 t_con->last_escape = *buf_p;
 565                                         else
 566                                                 t_con->state = TELNET_STATE_DATA;
 567                                 } else {
 568                                         LOG_ERROR("BUG: unexpected value in t_con->last_escape");
 569                                         t_con->state = TELNET_STATE_DATA;
 570                                 }
 571
 572                                 break;
 573                         default:
 574                                 LOG_ERROR("unknown telnet state");
 575                                 return ERROR_FAIL;
 576                 }
 577
 578                 bytes_read--;
 579                 buf_p++;
 580         }
 581
 582         return ERROR_OK;
 583 }
 584
 585 static int telnet_connection_closed(struct connection *connection)
 586 {
 587         struct telnet_connection *t_con = connection->priv;
 588         int i;
 589
 590         log_remove_callback(telnet_log_callback, connection);
 591
 592         if (t_con->prompt) {
 593                 free(t_con->prompt);
 594                 t_con->prompt = NULL;
 595         }
 596
 597         /* save telnet history */
 598         telnet_save_history(t_con);
 599
 600         for (i = 0; i < TELNET_LINE_HISTORY_SIZE; i++) {
 601                 if (t_con->history[i]) {
 602                         free(t_con->history[i]);
 603                         t_con->history[i] = NULL;
 604                 }
 605         }
 606
 607         /* if this connection registered a debug-message receiver delete it */
 608         delete_debug_msg_receiver(connection->cmd_ctx, NULL);
 609
 610         if (connection->priv) {
 611                 free(connection->priv);
 612                 connection->priv = NULL;
 613         } else
 614                 LOG_ERROR("BUG: connection->priv == NULL");
 615
 616         return ERROR_OK;
 617 }
 618
 619 int telnet_init(char *banner)
 620 {
 621         if (strcmp(telnet_port, "disabled") == 0) {
 622                 LOG_INFO("telnet server disabled");
 623                 return ERROR_OK;
 624         }
 625
 626         struct telnet_service *telnet_service =
 627                 malloc(sizeof(struct telnet_service));
 628
 629         if (!telnet_service) {
 630                 LOG_ERROR("Failed to allocate telnet service.");
 631                 return ERROR_FAIL;
 632         }
 633
 634         telnet_service->banner = banner;
 635
 636         int ret = add_service("telnet", telnet_port, CONNECTION_LIMIT_UNLIMITED,
 637                 telnet_new_connection, telnet_input, telnet_connection_closed,
 638                 telnet_service);
 639
 640         if (ret != ERROR_OK) {
 641                 free(telnet_service);
 642                 return ret;
 643         }
 644
 645         return ERROR_OK;
 646 }
 647
 648 /* daemon configuration command telnet_port */
 649 COMMAND_HANDLER(handle_telnet_port_command)
 650 {
 651         return CALL_COMMAND_HANDLER(server_pipe_command, &telnet_port);
 652 }
 653
 654 COMMAND_HANDLER(handle_exit_command)
 655 {
 656         return ERROR_COMMAND_CLOSE_CONNECTION;
 657 }
 658
 659 static const struct command_registration telnet_command_handlers[] = {
 660         {
 661                 .name = "exit",
 662                 .handler = handle_exit_command,
 663                 .mode = COMMAND_EXEC,
 664                 .usage = "",
 665                 .help = "exit telnet session",
 666         },
 667         {
 668                 .name = "telnet_port",
 669                 .handler = handle_telnet_port_command,
 670                 .mode = COMMAND_ANY,
 671                 .help = "Specify port on which to listen "
 672                         "for incoming telnet connections.  "
 673                         "Read help on 'gdb_port'.",
 674                 .usage = "[port_num]",
 675         },
 676         COMMAND_REGISTRATION_DONE
 677 };
 678
 679 int telnet_register_commands(struct command_context *cmd_ctx)
 680 {
 681         telnet_port = strdup("4444");
 682         return register_commands(cmd_ctx, NULL, telnet_command_handlers);
 683 }