git.sur5r.net Git - openocd/blob - src/server/telnet_server.c

   1 /***************************************************************************
   2  *   Copyright (C) 2005 by Dominic Rath                                    *
   3  *   Dominic.Rath@gmx.de                                                   *
   4  *                                                                         *
   5  *   This program is free software; you can redistribute it and/or modify  *
   6  *   it under the terms of the GNU General Public License as published by  *
   7  *   the Free Software Foundation; either version 2 of the License, or     *
   8  *   (at your option) any later version.                                   *
   9  *                                                                         *
  10  *   This program is distributed in the hope that it will be useful,       *
  11  *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
  12  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
  13  *   GNU General Public License for more details.                          *
  14  *                                                                         *
  15  *   You should have received a copy of the GNU General Public License     *
  16  *   along with this program; if not, write to the                         *
  17  *   Free Software Foundation, Inc.,                                       *
  18  *   59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.             *
  19  ***************************************************************************/
  20 #ifdef HAVE_CONFIG_H
  21 #include "config.h"
  22 #endif
  23
  24 #include "replacements.h"
  25
  26 #include "telnet_server.h"
  27
  28 #include "server.h"
  29 #include "log.h"
  30 #include "command.h"
  31 #include "target.h"
  32 #include "target_request.h"
  33
  34 #include <stdlib.h>
  35 #include <unistd.h>
  36 #include <errno.h>
  37 #include <string.h>
  38 #include <ctype.h>
  39
  40 static unsigned short telnet_port = 0;
  41
  42 int handle_exit_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc);
  43 int handle_telnet_port_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc);
  44
  45 static char *negotiate =
  46                 "\xFF\xFB\x03"          /* IAC WILL Suppress Go Ahead */
  47                 "\xFF\xFB\x01"          /* IAC WILL Echo */
  48                 "\xFF\xFD\x03"          /* IAC DO Suppress Go Ahead */
  49                 "\xFF\xFE\x01";         /* IAC DON'T Echo */
  50
  51 #define CTRL(c) (c - '@')
  52
  53 /* The only way we can detect that the socket is closed is the first time
  54  * we write to it, we will fail. Subsequent write operations will
  55  * succeed. Shudder!
  56  */
  57 int telnet_write(connection_t *connection, void *data, int len)
  58 {
  59         telnet_connection_t *t_con = connection->priv;
  60         if (t_con->closed)
  61                 return ERROR_SERVER_REMOTE_CLOSED;
  62
  63         if (write_socket(connection->fd, data, len) == len)
  64         {
  65                 return ERROR_OK;
  66         }
  67         t_con->closed = 1;
  68         return ERROR_SERVER_REMOTE_CLOSED;
  69 }
  70
  71 int telnet_prompt(connection_t *connection)
  72 {
  73         telnet_connection_t *t_con = connection->priv;
  74
  75         return telnet_write(connection, t_con->prompt, strlen(t_con->prompt));
  76 }
  77
  78 int telnet_outputline(connection_t *connection, char* line)
  79 {
  80         telnet_write(connection, line, strlen(line));
  81         return telnet_write(connection, "\r\n\0", 3);
  82 }
  83
  84 int telnet_output(struct command_context_s *cmd_ctx, char* line)
  85 {
  86         connection_t *connection = cmd_ctx->output_handler_priv;
  87
  88         return telnet_outputline(connection, line);
  89 }
  90
  91 void telnet_log_callback(void *priv, const char *file, int line,
  92                 const char *function, const char *format, va_list args)
  93 {
  94         connection_t *connection = priv;
  95         char *t = allocPrintf(format, args);
  96         char *t2;
  97         if (t == NULL)
  98                 return;
  99         t2=t;
 100         char *endline;
 101         do
 102         {
 103                 if ((endline=strchr(t2, '\n'))!=NULL)
 104                 {
 105                         *endline=0;
 106                 }
 107                 telnet_outputline(connection, t2);
 108                 t2=endline+1;
 109         } while (endline);
 110
 111
 112         free(t);
 113 }
 114
 115 int telnet_target_callback_event_handler(struct target_s *target, enum target_event event, void *priv)
 116 {
 117         struct command_context_s *cmd_ctx = priv;
 118         connection_t *connection = cmd_ctx->output_handler_priv;
 119         telnet_connection_t *t_con = connection->priv;
 120
 121         switch (event)
 122         {
 123                 case TARGET_EVENT_HALTED:
 124                         target_arch_state(target);
 125                         if (!t_con->suppress_prompt)
 126                                 telnet_prompt(connection);
 127                         break;
 128                 case TARGET_EVENT_RESUMED:
 129                         if (!t_con->suppress_prompt)
 130                                 telnet_prompt(connection);
 131                         break;
 132                 default:
 133                         break;
 134         }
 135
 136         return ERROR_OK;
 137 }
 138
 139 int telnet_new_connection(connection_t *connection)
 140 {
 141         telnet_connection_t *telnet_connection = malloc(sizeof(telnet_connection_t));
 142         telnet_service_t *telnet_service = connection->service->priv;
 143         int i;
 144
 145         connection->priv = telnet_connection;
 146
 147         /* initialize telnet connection information */
 148         telnet_connection->closed = 0;
 149         telnet_connection->line_size = 0;
 150         telnet_connection->line_cursor = 0;
 151         telnet_connection->option_size = 0;
 152         telnet_connection->prompt = strdup("> ");
 153         telnet_connection->suppress_prompt = 0;
 154         telnet_connection->state = TELNET_STATE_DATA;
 155
 156         /* output goes through telnet connection */
 157         command_set_output_handler(connection->cmd_ctx, telnet_output, connection);
 158
 159         /* negotiate telnet options */
 160         telnet_write(connection, negotiate, strlen(negotiate));
 161
 162         /* print connection banner */
 163         if (telnet_service->banner)
 164         {
 165                 telnet_write(connection, telnet_service->banner, strlen(telnet_service->banner));
 166                 telnet_write(connection, "\r\n\0", 3);
 167         }
 168
 169         telnet_prompt(connection);
 170
 171         /* initialize history */
 172         for (i = 0; i < TELNET_LINE_HISTORY_SIZE; i++)
 173         {
 174                 telnet_connection->history[i] = NULL;
 175         }
 176         telnet_connection->next_history = 0;
 177         telnet_connection->current_history = 0;
 178
 179         target_register_event_callback(telnet_target_callback_event_handler, connection->cmd_ctx);
 180
 181         return ERROR_OK;
 182 }
 183
 184 void telnet_clear_line(connection_t *connection, telnet_connection_t *t_con)
 185 {
 186         /* move to end of line */
 187         if (t_con->line_cursor < t_con->line_size)
 188         {
 189                 telnet_write(connection, t_con->line + t_con->line_cursor, t_con->line_size - t_con->line_cursor);
 190         }
 191
 192         /* backspace, overwrite with space, backspace */
 193         while (t_con->line_size > 0)
 194         {
 195                 telnet_write(connection, "\b \b", 3);
 196                 t_con->line_size--;
 197         }
 198         t_con->line_cursor = 0;
 199 }
 200
 201 int telnet_input(connection_t *connection)
 202 {
 203         int bytes_read;
 204         char buffer[TELNET_BUFFER_SIZE];
 205         char *buf_p;
 206         telnet_connection_t *t_con = connection->priv;
 207         command_context_t *command_context = connection->cmd_ctx;
 208
 209         bytes_read = read_socket(connection->fd, buffer, TELNET_BUFFER_SIZE);
 210
 211         if (bytes_read == 0)
 212                 return ERROR_SERVER_REMOTE_CLOSED;
 213         else if (bytes_read == -1)
 214         {
 215                 ERROR("error during read: %s", strerror(errno));
 216                 return ERROR_SERVER_REMOTE_CLOSED;
 217         }
 218
 219         buf_p = buffer;
 220         while (bytes_read)
 221         {
 222                 switch (t_con->state)
 223                 {
 224                         case TELNET_STATE_DATA:
 225                                 if (*buf_p == '\xff')
 226                                 {
 227                                         t_con->state = TELNET_STATE_IAC;
 228                                 }
 229                                 else
 230                                 {
 231                                         if (isprint(*buf_p)) /* printable character */
 232                                         {
 233                                                 telnet_write(connection, buf_p, 1);
 234                                                 if (t_con->line_cursor == t_con->line_size)
 235                                                 {
 236                                                         t_con->line[t_con->line_size++] = *buf_p;
 237                                                         t_con->line_cursor++;
 238                                                 }
 239                                                 else
 240                                                 {
 241                                                         int i;
 242                                                         memmove(t_con->line + t_con->line_cursor + 1, t_con->line + t_con->line_cursor, t_con->line_size - t_con->line_cursor);
 243                                                         t_con->line[t_con->line_cursor++] = *buf_p;
 244                                                         t_con->line_size++;
 245                                                         telnet_write(connection, t_con->line + t_con->line_cursor, t_con->line_size - t_con->line_cursor);
 246                                                         for (i = t_con->line_cursor; i < t_con->line_size; i++)
 247                                                         {
 248                                                                 telnet_write(connection, "\b", 1);
 249                                                         }
 250                                                 }
 251                                         }
 252                                         else /* non-printable */
 253                                         {
 254                                                 if (*buf_p == 0x1b) /* escape */
 255                                                 {
 256                                                         t_con->state = TELNET_STATE_ESCAPE;
 257                                                         t_con->last_escape = '\x00';
 258                                                 }
 259                                                 else if ((*buf_p == 0xd) || (*buf_p == 0xa)) /* CR/LF */
 260                                                 {
 261                                                         int retval;
 262
 263                                                         /* skip over combinations with CR/LF + NUL */
 264                                                         if (((*(buf_p + 1) == 0xa) || (*(buf_p + 1) == 0xd)) && (bytes_read > 1))
 265                                                         {
 266                                                                 buf_p++;
 267                                                                 bytes_read--;
 268                                                         }
 269                                                         if ((*(buf_p + 1) == 0) && (bytes_read > 1))
 270                                                         {
 271                                                                 buf_p++;
 272                                                                 bytes_read--;
 273                                                         }
 274                                                         t_con->line[t_con->line_size] = 0;
 275
 276                                                         telnet_write(connection, "\r\n\x00", 3);
 277
 278                                                         if (strcmp(t_con->line, "history") == 0)
 279                                                         {
 280                                                                 int i;
 281                                                                 for (i = 0; i < TELNET_LINE_HISTORY_SIZE; i++)
 282                                                                 {
 283                                                                         if (t_con->history[i])
 284                                                                         {
 285                                                                                 telnet_write(connection, t_con->history[i], strlen(t_con->history[i]));
 286                                                                                 telnet_write(connection, "\r\n\x00", 3);
 287                                                                         }
 288                                                                 }
 289                                                                 telnet_prompt(connection);
 290                                                                 t_con->line_size = 0;
 291                                                                 t_con->line_cursor = 0;
 292                                                                 continue;
 293                                                         }
 294
 295                                                         log_setCallback(telnet_log_callback, connection);
 296                                                         t_con->suppress_prompt = 1;
 297
 298                                                         if ((retval = command_run_line(command_context, t_con->line)) != ERROR_OK)
 299                                                         {
 300                                                                 if (retval == ERROR_COMMAND_CLOSE_CONNECTION)
 301                                                                 {
 302                                                                         return ERROR_SERVER_REMOTE_CLOSED;
 303                                                                 }
 304                                                         }
 305
 306                                                         t_con->suppress_prompt = 0;
 307
 308                                                         /* Save only non-blank lines in the history */
 309                                                         if (t_con->line_size > 0)
 310                                                         {
 311                                                                 /* if the history slot is already taken, free it */
 312                                                                 if (t_con->history[t_con->next_history])
 313                                                                 {
 314                                                                         free(t_con->history[t_con->next_history]);
 315                                                                 }
 316
 317                                                                 /* add line to history */
 318                                                                 t_con->history[t_con->next_history] = strdup(t_con->line);
 319
 320                                                                 /* wrap history at TELNET_LINE_HISTORY_SIZE */
 321                                                                 t_con->next_history = (t_con->next_history + 1) % TELNET_LINE_HISTORY_SIZE;
 322
 323                                                                 /* current history line starts at the new entry */
 324                                                                 t_con->current_history = t_con->next_history;
 325
 326                                                                 if (t_con->history[t_con->current_history])
 327                                                                 {
 328                                                                         free(t_con->history[t_con->current_history]);
 329                                                                 }
 330                                                                 t_con->history[t_con->current_history] = strdup("");
 331                                                         }
 332
 333                                                         int t = telnet_prompt(connection);
 334                                                         if (t == ERROR_SERVER_REMOTE_CLOSED)
 335                                                                 return t;
 336
 337                                                         t_con->line_size = 0;
 338                                                         t_con->line_cursor = 0;
 339                                                 }
 340                                                 else if ((*buf_p == 0x7f) || (*buf_p == 0x8)) /* delete character */
 341                                                 {
 342                                                         if (t_con->line_cursor > 0)
 343                                                         {
 344                                                                 if (t_con->line_cursor != t_con->line_size)
 345                                                                 {
 346                                                                         int i;
 347                                                                         telnet_write(connection, "\b", 1);
 348                                                                         t_con->line_cursor--;
 349                                                                         t_con->line_size--;
 350                                                                         memmove(t_con->line + t_con->line_cursor, t_con->line + t_con->line_cursor + 1, t_con->line_size - t_con->line_cursor);
 351
 352                                                                         telnet_write(connection, t_con->line + t_con->line_cursor, t_con->line_size - t_con->line_cursor);
 353                                                                         telnet_write(connection, " \b", 2);
 354                                                                         for (i = t_con->line_cursor; i < t_con->line_size; i++)
 355                                                                         {
 356                                                                                 telnet_write(connection, "\b", 1);
 357                                                                         }
 358                                                                 }
 359                                                                 else
 360                                                                 {
 361                                                                         t_con->line_size--;
 362                                                                         t_con->line_cursor--;
 363                                                                         /* back space: move the 'printer' head one char back, overwrite with space, move back again */
 364                                                                         telnet_write(connection, "\b \b", 3);
 365                                                                 }
 366                                                         }
 367                                                 }
 368                                                 else if (*buf_p == 0x15) /* clear line */
 369                                                 {
 370                                                         telnet_clear_line(connection, t_con);
 371                                                 }
 372                                                 else if (*buf_p == CTRL('B')) /* cursor left */
 373                                                 {
 374                                                         if (t_con->line_cursor > 0)
 375                                                         {
 376                                                                 telnet_write(connection, "\b", 1);
 377                                                                 t_con->line_cursor--;
 378                                                         }
 379                                                         t_con->state = TELNET_STATE_DATA;
 380                                                 }
 381                                                 else if (*buf_p == CTRL('F')) /* cursor right */
 382                                                 {
 383                                                         if (t_con->line_cursor < t_con->line_size)
 384                                                         {
 385                                                                 telnet_write(connection, t_con->line + t_con->line_cursor++, 1);
 386                                                         }
 387                                                         t_con->state = TELNET_STATE_DATA;
 388                                                 }
 389                                                 else
 390                                                 {
 391                                                         DEBUG("unhandled nonprintable: %2.2x", *buf_p);
 392                                                 }
 393                                         }
 394                                 }
 395                                 break;
 396                         case TELNET_STATE_IAC:
 397                                 switch (*buf_p)
 398                                 {
 399                                         case '\xfe':
 400                                                 t_con->state = TELNET_STATE_DONT;
 401                                                 break;
 402                                         case '\xfd':
 403                                                 t_con->state = TELNET_STATE_DO;
 404                                                 break;
 405                                         case '\xfc':
 406                                                 t_con->state = TELNET_STATE_WONT;
 407                                                 break;
 408                                         case '\xfb':
 409                                                 t_con->state = TELNET_STATE_WILL;
 410                                                 break;
 411                                 }
 412                                 break;
 413                         case TELNET_STATE_SB:
 414                                 break;
 415                         case TELNET_STATE_SE:
 416                                 break;
 417                         case TELNET_STATE_WILL:
 418                         case TELNET_STATE_WONT:
 419                         case TELNET_STATE_DO:
 420                         case TELNET_STATE_DONT:
 421                                 t_con->state = TELNET_STATE_DATA;
 422                                 break;
 423                         case TELNET_STATE_ESCAPE:
 424                                 if (t_con->last_escape == '[')
 425                                 {
 426                                         if (*buf_p == 'D') /* cursor left */
 427                                         {
 428                                                 if (t_con->line_cursor > 0)
 429                                                 {
 430                                                         telnet_write(connection, "\b", 1);
 431                                                         t_con->line_cursor--;
 432                                                 }
 433                                                 t_con->state = TELNET_STATE_DATA;
 434                                         }
 435                                         else if (*buf_p == 'C') /* cursor right */
 436                                         {
 437                                                 if (t_con->line_cursor < t_con->line_size)
 438                                                 {
 439                                                         telnet_write(connection, t_con->line + t_con->line_cursor++, 1);
 440                                                 }
 441                                                 t_con->state = TELNET_STATE_DATA;
 442                                         }
 443                                         else if (*buf_p == 'A') /* cursor up */
 444                                         {
 445                                                 int last_history = (t_con->current_history > 0) ? t_con->current_history - 1 : TELNET_LINE_HISTORY_SIZE-1;
 446                                                 if (t_con->history[last_history])
 447                                                 {
 448                                                         telnet_clear_line(connection, t_con);
 449                                                         t_con->line_size = strlen(t_con->history[last_history]);
 450                                                         t_con->line_cursor = t_con->line_size;
 451                                                         memcpy(t_con->line, t_con->history[last_history], t_con->line_size + 1);
 452                                                         telnet_write(connection, t_con->line, t_con->line_size);
 453                                                         t_con->current_history = last_history;
 454                                                 }
 455                                                 t_con->state = TELNET_STATE_DATA;
 456                                         }
 457                                         else if (*buf_p == 'B') /* cursor down */
 458                                         {
 459                                                 int next_history = (t_con->current_history + 1) % TELNET_LINE_HISTORY_SIZE;
 460                                                 if (t_con->history[next_history])
 461                                                 {
 462                                                         telnet_clear_line(connection, t_con);
 463                                                         t_con->line_size = strlen(t_con->history[next_history]);
 464                                                         t_con->line_cursor = t_con->line_size;
 465                                                         memcpy(t_con->line, t_con->history[next_history], t_con->line_size + 1);
 466                                                         telnet_write(connection, t_con->line, t_con->line_size);
 467                                                         t_con->current_history = next_history;
 468                                                 }
 469                                                 t_con->state = TELNET_STATE_DATA;
 470                                         }
 471                                         else if (*buf_p == '3')
 472                                         {
 473                                                 t_con->last_escape = *buf_p;
 474                                         }
 475                                         else
 476                                         {
 477                                                 t_con->state = TELNET_STATE_DATA;
 478                                         }
 479                                 }
 480                                 else if (t_con->last_escape == '3')
 481                                 {
 482                                         /* Remove character */
 483                                         if (*buf_p == '~')
 484                                         {
 485                                                 if (t_con->line_cursor < t_con->line_size)
 486                                                 {
 487                                                         int i;
 488                                                         t_con->line_size--;
 489                                                         /* remove char from line buffer */
 490                                                         memmove(t_con->line + t_con->line_cursor, t_con->line + t_con->line_cursor + 1, t_con->line_size - t_con->line_cursor);
 491
 492                                                         /* print remainder of buffer */
 493                                                         telnet_write(connection, t_con->line + t_con->line_cursor, t_con->line_size - t_con->line_cursor);
 494                                                         /* overwrite last char with whitespace */
 495                                                         telnet_write(connection, " \b", 2);
 496
 497                                                         /* move back to cursor position*/
 498                                                         for (i = t_con->line_cursor; i < t_con->line_size; i++)
 499                                                         {
 500                                                                 telnet_write(connection, "\b", 1);
 501                                                         }
 502                                                 }
 503
 504                                                 t_con->state = TELNET_STATE_DATA;
 505                                         }
 506                                         else
 507                                         {
 508                                                 t_con->state = TELNET_STATE_DATA;
 509                                         }
 510                                 }
 511                                 else if (t_con->last_escape == '\x00')
 512                                 {
 513                                         if (*buf_p == '[')
 514                                         {
 515                                                 t_con->last_escape = *buf_p;
 516                                         }
 517                                         else
 518                                         {
 519                                                 t_con->state = TELNET_STATE_DATA;
 520                                         }
 521                                 }
 522                                 else
 523                                 {
 524                                         ERROR("BUG: unexpected value in t_con->last_escape");
 525                                         t_con->state = TELNET_STATE_DATA;
 526                                 }
 527
 528                                 break;
 529                         default:
 530                                 ERROR("unknown telnet state");
 531                                 exit(-1);
 532                 }
 533
 534                 bytes_read--;
 535                 buf_p++;
 536         }
 537
 538         return ERROR_OK;
 539 }
 540
 541 int telnet_connection_closed(connection_t *connection)
 542 {
 543         telnet_connection_t *t_con = connection->priv;
 544         int i;
 545
 546         if (t_con->prompt)
 547         {
 548                 free(t_con->prompt);
 549                 t_con->prompt = NULL;
 550         }
 551
 552         for (i = 0; i < TELNET_LINE_HISTORY_SIZE; i++)
 553         {
 554                 if (t_con->history[i])
 555                 {
 556                         free(t_con->history[i]);
 557                         t_con->history[i] = NULL;
 558                 }
 559         }
 560
 561         /* if this connection registered a debug-message receiver delete it */
 562         delete_debug_msg_receiver(connection->cmd_ctx, NULL);
 563
 564         if (connection->priv)
 565         {
 566                 free(connection->priv);
 567                 connection->priv = NULL;
 568         }
 569         else
 570         {
 571                 ERROR("BUG: connection->priv == NULL");
 572         }
 573
 574         target_unregister_event_callback(telnet_target_callback_event_handler, connection->cmd_ctx);
 575
 576         return ERROR_OK;
 577 }
 578
 579 int telnet_set_prompt(connection_t *connection, char *prompt)
 580 {
 581         telnet_connection_t *t_con = connection->priv;
 582
 583         t_con->prompt = strdup(prompt);
 584
 585         return ERROR_OK;
 586 }
 587
 588 int telnet_init(char *banner)
 589 {
 590         telnet_service_t *telnet_service = malloc(sizeof(telnet_service_t));
 591
 592         if (telnet_port == 0)
 593         {
 594                 WARNING("no telnet port specified, using default port 4444");
 595                 telnet_port = 4444;
 596         }
 597
 598         telnet_service->banner = banner;
 599
 600         add_service("telnet", CONNECTION_TELNET, telnet_port, 1, telnet_new_connection, telnet_input, telnet_connection_closed, telnet_service);
 601
 602         return ERROR_OK;
 603 }
 604
 605 int telnet_register_commands(command_context_t *command_context)
 606 {
 607         register_command(command_context, NULL, "exit", handle_exit_command,
 608                                          COMMAND_EXEC, "exit telnet session");
 609
 610         register_command(command_context, NULL, "telnet_port", handle_telnet_port_command,
 611                                          COMMAND_CONFIG, "");
 612
 613         return ERROR_OK;
 614 }
 615
 616 /* daemon configuration command telnet_port */
 617 int handle_telnet_port_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc)
 618 {
 619         if (argc == 0)
 620                 return ERROR_OK;
 621
 622         /* only if the port wasn't overwritten by cmdline */
 623         if (telnet_port == 0)
 624                 telnet_port = strtoul(args[0], NULL, 0);
 625
 626         return ERROR_OK;
 627 }
 628
 629 int handle_exit_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc)
 630 {
 631         return ERROR_COMMAND_CLOSE_CONNECTION;
 632 }