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 void telnet_prompt(connection_t *connection)
  54 {
  55         telnet_connection_t *t_con = connection->priv;
  56
  57         write_socket(connection->fd, t_con->prompt, strlen(t_con->prompt));
  58 }
  59
  60 int telnet_output(struct command_context_s *cmd_ctx, char* line)
  61 {
  62         connection_t *connection = cmd_ctx->output_handler_priv;
  63
  64         write_socket(connection->fd, line, strlen(line));
  65         write_socket(connection->fd, "\r\n\0", 3);
  66
  67         return ERROR_OK;
  68 }
  69
  70 void telnet_log_callback(void *priv, const char *file, int line,
  71                 const char *function, const char *format, va_list args)
  72 {
  73         connection_t *connection = priv;
  74         char *t = allocPrintf(format, args);
  75         if (t == NULL)
  76                 return;
  77
  78         telnet_output(connection->cmd_ctx, t);
  79         free(t);
  80 }
  81
  82 int telnet_target_callback_event_handler(struct target_s *target, enum target_event event, void *priv)
  83 {
  84         struct command_context_s *cmd_ctx = priv;
  85         connection_t *connection = cmd_ctx->output_handler_priv;
  86         telnet_connection_t *t_con = connection->priv;
  87         char buffer[512];
  88
  89         switch (event)
  90         {
  91                 case TARGET_EVENT_HALTED:
  92                         command_print(cmd_ctx, "Target %i halted", get_num_by_target(target));
  93                         target->type->arch_state(target, buffer, 512);
  94                         buffer[511] = 0;
  95                         command_print(cmd_ctx, "%s", buffer);
  96                         if (!t_con->suppress_prompt)
  97                                 telnet_prompt(connection);
  98                         break;
  99                 case TARGET_EVENT_RESUMED:
 100                         command_print(cmd_ctx, "Target %i resumed", get_num_by_target(target));
 101                         if (!t_con->suppress_prompt)
 102                                 telnet_prompt(connection);
 103                         break;
 104                 default:
 105                         break;
 106         }
 107
 108         return ERROR_OK;
 109 }
 110
 111 int telnet_new_connection(connection_t *connection)
 112 {
 113         telnet_connection_t *telnet_connection = malloc(sizeof(telnet_connection_t));
 114         telnet_service_t *telnet_service = connection->service->priv;
 115         int i;
 116
 117         connection->priv = telnet_connection;
 118
 119         /* initialize telnet connection information */
 120         telnet_connection->line_size = 0;
 121         telnet_connection->line_cursor = 0;
 122         telnet_connection->option_size = 0;
 123         telnet_connection->prompt = strdup("> ");
 124         telnet_connection->suppress_prompt = 0;
 125         telnet_connection->state = TELNET_STATE_DATA;
 126
 127         /* output goes through telnet connection */
 128         command_set_output_handler(connection->cmd_ctx, telnet_output, connection);
 129
 130         /* negotiate telnet options */
 131         write_socket(connection->fd, negotiate, strlen(negotiate));
 132
 133         /* print connection banner */
 134         if (telnet_service->banner)
 135         {
 136                 write_socket(connection->fd, telnet_service->banner, strlen(telnet_service->banner));
 137                 write_socket(connection->fd, "\r\n\0", 3);
 138         }
 139
 140         telnet_prompt(connection);
 141
 142         /* initialize history */
 143         for (i = 0; i < TELNET_LINE_HISTORY_SIZE; i++)
 144         {
 145                 telnet_connection->history[i] = NULL;
 146         }
 147         telnet_connection->next_history = 0;
 148         telnet_connection->current_history = 0;
 149
 150         target_register_event_callback(telnet_target_callback_event_handler, connection->cmd_ctx);
 151
 152         return ERROR_OK;
 153 }
 154
 155 void telnet_clear_line(connection_t *connection, telnet_connection_t *t_con)
 156 {
 157         /* move to end of line */
 158         if (t_con->line_cursor < t_con->line_size)
 159         {
 160                 write_socket(connection->fd, t_con->line + t_con->line_cursor, t_con->line_size - t_con->line_cursor);
 161         }
 162
 163         /* backspace, overwrite with space, backspace */
 164         while (t_con->line_size > 0)
 165         {
 166                 write_socket(connection->fd, "\b \b", 3);
 167                 t_con->line_size--;
 168         }
 169         t_con->line_cursor = 0;
 170 }
 171
 172 int telnet_input(connection_t *connection)
 173 {
 174         int bytes_read;
 175         char buffer[TELNET_BUFFER_SIZE];
 176         char *buf_p;
 177         telnet_connection_t *t_con = connection->priv;
 178         command_context_t *command_context = connection->cmd_ctx;
 179
 180         bytes_read = read_socket(connection->fd, buffer, TELNET_BUFFER_SIZE);
 181
 182         if (bytes_read == 0)
 183                 return ERROR_SERVER_REMOTE_CLOSED;
 184         else if (bytes_read == -1)
 185         {
 186                 ERROR("error during read: %s", strerror(errno));
 187                 return ERROR_SERVER_REMOTE_CLOSED;
 188         }
 189
 190         buf_p = buffer;
 191         while (bytes_read)
 192         {
 193                 switch (t_con->state)
 194                 {
 195                         case TELNET_STATE_DATA:
 196                                 if (*buf_p == '\xff')
 197                                 {
 198                                         t_con->state = TELNET_STATE_IAC;
 199                                 }
 200                                 else
 201                                 {
 202                                         if (isprint(*buf_p)) /* printable character */
 203                                         {
 204                                                 write_socket(connection->fd, buf_p, 1);
 205                                                 if (t_con->line_cursor == t_con->line_size)
 206                                                 {
 207                                                         t_con->line[t_con->line_size++] = *buf_p;
 208                                                         t_con->line_cursor++;
 209                                                 }
 210                                                 else
 211                                                 {
 212                                                         int i;
 213                                                         memmove(t_con->line + t_con->line_cursor + 1, t_con->line + t_con->line_cursor, t_con->line_size - t_con->line_cursor);
 214                                                         t_con->line[t_con->line_cursor++] = *buf_p;
 215                                                         t_con->line_size++;
 216                                                         write_socket(connection->fd, t_con->line + t_con->line_cursor, t_con->line_size - t_con->line_cursor);
 217                                                         for (i = t_con->line_cursor; i < t_con->line_size; i++)
 218                                                         {
 219                                                                 write_socket(connection->fd, "\b", 1);
 220                                                         }
 221                                                 }
 222                                         }
 223                                         else /* non-printable */
 224                                         {
 225                                                 if (*buf_p == 0x1b) /* escape */
 226                                                 {
 227                                                         t_con->state = TELNET_STATE_ESCAPE;
 228                                                         t_con->last_escape = '\x00';
 229                                                 }
 230                                                 else if ((*buf_p == 0xd) || (*buf_p == 0xa)) /* CR/LF */
 231                                                 {
 232                                                         int retval;
 233
 234                                                         /* skip over combinations with CR/LF + NUL */
 235                                                         if (((*(buf_p + 1) == 0xa) || (*(buf_p + 1) == 0xd)) && (bytes_read > 1))
 236                                                         {
 237                                                                 buf_p++;
 238                                                                 bytes_read--;
 239                                                         }
 240                                                         if ((*(buf_p + 1) == 0) && (bytes_read > 1))
 241                                                         {
 242                                                                 buf_p++;
 243                                                                 bytes_read--;
 244                                                         }
 245                                                         t_con->line[t_con->line_size] = 0;
 246
 247                                                         write_socket(connection->fd, "\r\n\x00", 3);
 248
 249                                                         if (strcmp(t_con->line, "history") == 0)
 250                                                         {
 251                                                                 int i;
 252                                                                 for (i = 0; i < TELNET_LINE_HISTORY_SIZE; i++)
 253                                                                 {
 254                                                                         if (t_con->history[i])
 255                                                                         {
 256                                                                                 write_socket(connection->fd, t_con->history[i], strlen(t_con->history[i]));
 257                                                                                 write_socket(connection->fd, "\r\n\x00", 3);
 258                                                                         }
 259                                                                 }
 260                                                                 telnet_prompt(connection);
 261                                                                 t_con->line_size = 0;
 262                                                                 t_con->line_cursor = 0;
 263                                                                 continue;
 264                                                         }
 265
 266                                                         log_setCallback(telnet_log_callback, connection);
 267                                                         t_con->suppress_prompt = 1;
 268
 269                                                         if ((retval = command_run_line(command_context, t_con->line)) != ERROR_OK)
 270                                                         {
 271                                                                 if (retval == ERROR_COMMAND_CLOSE_CONNECTION)
 272                                                                 {
 273                                                                         return ERROR_SERVER_REMOTE_CLOSED;
 274                                                                 }
 275                                                         }
 276
 277                                                         t_con->suppress_prompt = 0;
 278
 279                                                         /* Save only non-blank lines in the history */
 280                                                         if (t_con->line_size > 0)
 281                                                         {
 282                                                                 /* if the history slot is already taken, free it */
 283                                                                 if (t_con->history[t_con->next_history])
 284                                                                 {
 285                                                                         free(t_con->history[t_con->next_history]);
 286                                                                 }
 287
 288                                                                 /* add line to history */
 289                                                                 t_con->history[t_con->next_history] = strdup(t_con->line);
 290
 291                                                                 /* wrap history at TELNET_LINE_HISTORY_SIZE */
 292                                                                 t_con->next_history = (t_con->next_history + 1) % TELNET_LINE_HISTORY_SIZE;
 293
 294                                                                 /* current history line starts at the new entry */
 295                                                                 t_con->current_history = t_con->next_history;
 296
 297                                                                 if (t_con->history[t_con->current_history])
 298                                                                 {
 299                                                                         free(t_con->history[t_con->current_history]);
 300                                                                 }
 301                                                                 t_con->history[t_con->current_history] = strdup("");
 302                                                         }
 303
 304                                                         /* output prompt after command */
 305                                                         telnet_prompt(connection);
 306
 307                                                         t_con->line_size = 0;
 308                                                         t_con->line_cursor = 0;
 309                                                 }
 310                                                 else if ((*buf_p == 0x7f) || (*buf_p == 0x8)) /* delete character */
 311                                                 {
 312                                                         if (t_con->line_cursor > 0)
 313                                                         {
 314                                                                 if (t_con->line_cursor != t_con->line_size)
 315                                                                 {
 316                                                                         int i;
 317                                                                         write_socket(connection->fd, "\b", 1);
 318                                                                         t_con->line_cursor--;
 319                                                                         t_con->line_size--;
 320                                                                         memmove(t_con->line + t_con->line_cursor, t_con->line + t_con->line_cursor + 1, t_con->line_size - t_con->line_cursor);
 321
 322                                                                         write_socket(connection->fd, t_con->line + t_con->line_cursor, t_con->line_size - t_con->line_cursor);
 323                                                                         write_socket(connection->fd, " \b", 2);
 324                                                                         for (i = t_con->line_cursor; i < t_con->line_size; i++)
 325                                                                         {
 326                                                                                 write_socket(connection->fd, "\b", 1);
 327                                                                         }
 328                                                                 }
 329                                                                 else
 330                                                                 {
 331                                                                         t_con->line_size--;
 332                                                                         t_con->line_cursor--;
 333                                                                         /* back space: move the 'printer' head one char back, overwrite with space, move back again */
 334                                                                         write_socket(connection->fd, "\b \b", 3);
 335                                                                 }
 336                                                         }
 337                                                 }
 338                                                 else if (*buf_p == 0x15) /* clear line */
 339                                                 {
 340                                                         telnet_clear_line(connection, t_con);
 341                                                 }
 342                                                 else if (*buf_p == CTRL('B')) /* cursor left */
 343                                                 {
 344                                                         if (t_con->line_cursor > 0)
 345                                                         {
 346                                                                 write_socket(connection->fd, "\b", 1);
 347                                                                 t_con->line_cursor--;
 348                                                         }
 349                                                         t_con->state = TELNET_STATE_DATA;
 350                                                 }
 351                                                 else if (*buf_p == CTRL('F')) /* cursor right */
 352                                                 {
 353                                                         if (t_con->line_cursor < t_con->line_size)
 354                                                         {
 355                                                                 write_socket(connection->fd, t_con->line + t_con->line_cursor++, 1);
 356                                                         }
 357                                                         t_con->state = TELNET_STATE_DATA;
 358                                                 }
 359                                                 else
 360                                                 {
 361                                                         DEBUG("unhandled nonprintable: %2.2x", *buf_p);
 362                                                 }
 363                                         }
 364                                 }
 365                                 break;
 366                         case TELNET_STATE_IAC:
 367                                 switch (*buf_p)
 368                                 {
 369                                         case '\xfe':
 370                                                 t_con->state = TELNET_STATE_DONT;
 371                                                 break;
 372                                         case '\xfd':
 373                                                 t_con->state = TELNET_STATE_DO;
 374                                                 break;
 375                                         case '\xfc':
 376                                                 t_con->state = TELNET_STATE_WONT;
 377                                                 break;
 378                                         case '\xfb':
 379                                                 t_con->state = TELNET_STATE_WILL;
 380                                                 break;
 381                                 }
 382                                 break;
 383                         case TELNET_STATE_SB:
 384                                 break;
 385                         case TELNET_STATE_SE:
 386                                 break;
 387                         case TELNET_STATE_WILL:
 388                         case TELNET_STATE_WONT:
 389                         case TELNET_STATE_DO:
 390                         case TELNET_STATE_DONT:
 391                                 t_con->state = TELNET_STATE_DATA;
 392                                 break;
 393                         case TELNET_STATE_ESCAPE:
 394                                 if (t_con->last_escape == '[')
 395                                 {
 396                                         if (*buf_p == 'D') /* cursor left */
 397                                         {
 398                                                 if (t_con->line_cursor > 0)
 399                                                 {
 400                                                         write_socket(connection->fd, "\b", 1);
 401                                                         t_con->line_cursor--;
 402                                                 }
 403                                                 t_con->state = TELNET_STATE_DATA;
 404                                         }
 405                                         else if (*buf_p == 'C') /* cursor right */
 406                                         {
 407                                                 if (t_con->line_cursor < t_con->line_size)
 408                                                 {
 409                                                         write_socket(connection->fd, t_con->line + t_con->line_cursor++, 1);
 410                                                 }
 411                                                 t_con->state = TELNET_STATE_DATA;
 412                                         }
 413                                         else if (*buf_p == 'A') /* cursor up */
 414                                         {
 415                                                 int last_history = (t_con->current_history > 0) ? t_con->current_history - 1 : TELNET_LINE_HISTORY_SIZE-1;
 416                                                 if (t_con->history[last_history])
 417                                                 {
 418                                                         telnet_clear_line(connection, t_con);
 419                                                         t_con->line_size = strlen(t_con->history[last_history]);
 420                                                         t_con->line_cursor = t_con->line_size;
 421                                                         memcpy(t_con->line, t_con->history[last_history], t_con->line_size + 1);
 422                                                         write_socket(connection->fd, t_con->line, t_con->line_size);
 423                                                         t_con->current_history = last_history;
 424                                                 }
 425                                                 t_con->state = TELNET_STATE_DATA;
 426                                         }
 427                                         else if (*buf_p == 'B') /* cursor down */
 428                                         {
 429                                                 int next_history = (t_con->current_history + 1) % TELNET_LINE_HISTORY_SIZE;
 430                                                 if (t_con->history[next_history])
 431                                                 {
 432                                                         telnet_clear_line(connection, t_con);
 433                                                         t_con->line_size = strlen(t_con->history[next_history]);
 434                                                         t_con->line_cursor = t_con->line_size;
 435                                                         memcpy(t_con->line, t_con->history[next_history], t_con->line_size + 1);
 436                                                         write_socket(connection->fd, t_con->line, t_con->line_size);
 437                                                         t_con->current_history = next_history;
 438                                                 }
 439                                                 t_con->state = TELNET_STATE_DATA;
 440                                         }
 441                                         else if (*buf_p == '3')
 442                                         {
 443                                                 t_con->last_escape = *buf_p;
 444                                         }
 445                                         else
 446                                         {
 447                                                 t_con->state = TELNET_STATE_DATA;
 448                                         }
 449                                 }
 450                                 else if (t_con->last_escape == '3')
 451                                 {
 452                                         /* Remove character */
 453                                         if (*buf_p == '~')
 454                                         {
 455                                                 if (t_con->line_cursor < t_con->line_size)
 456                                                 {
 457                                                         int i;
 458                                                         t_con->line_size--;
 459                                                         /* remove char from line buffer */
 460                                                         memmove(t_con->line + t_con->line_cursor, t_con->line + t_con->line_cursor + 1, t_con->line_size - t_con->line_cursor);
 461
 462                                                         /* print remainder of buffer */
 463                                                         write_socket(connection->fd, t_con->line + t_con->line_cursor, t_con->line_size - t_con->line_cursor);
 464                                                         /* overwrite last char with whitespace */
 465                                                         write_socket(connection->fd, " \b", 2);
 466
 467                                                         /* move back to cursor position*/
 468                                                         for (i = t_con->line_cursor; i < t_con->line_size; i++)
 469                                                         {
 470                                                                 write_socket(connection->fd, "\b", 1);
 471                                                         }
 472                                                 }
 473
 474                                                 t_con->state = TELNET_STATE_DATA;
 475                                         }
 476                                         else
 477                                         {
 478                                                 t_con->state = TELNET_STATE_DATA;
 479                                         }
 480                                 }
 481                                 else if (t_con->last_escape == '\x00')
 482                                 {
 483                                         if (*buf_p == '[')
 484                                         {
 485                                                 t_con->last_escape = *buf_p;
 486                                         }
 487                                         else
 488                                         {
 489                                                 t_con->state = TELNET_STATE_DATA;
 490                                         }
 491                                 }
 492                                 else
 493                                 {
 494                                         ERROR("BUG: unexpected value in t_con->last_escape");
 495                                         t_con->state = TELNET_STATE_DATA;
 496                                 }
 497
 498                                 break;
 499                         default:
 500                                 ERROR("unknown telnet state");
 501                                 exit(-1);
 502                 }
 503
 504                 bytes_read--;
 505                 buf_p++;
 506         }
 507
 508         return ERROR_OK;
 509 }
 510
 511 int telnet_connection_closed(connection_t *connection)
 512 {
 513         telnet_connection_t *t_con = connection->priv;
 514         int i;
 515
 516         if (t_con->prompt)
 517         {
 518                 free(t_con->prompt);
 519                 t_con->prompt = NULL;
 520         }
 521
 522         for (i = 0; i < TELNET_LINE_HISTORY_SIZE; i++)
 523         {
 524                 if (t_con->history[i])
 525                 {
 526                         free(t_con->history[i]);
 527                         t_con->history[i] = NULL;
 528                 }
 529         }
 530
 531         /* if this connection registered a debug-message receiver delete it */
 532         delete_debug_msg_receiver(connection->cmd_ctx, NULL);
 533
 534         if (connection->priv)
 535         {
 536                 free(connection->priv);
 537                 connection->priv = NULL;
 538         }
 539         else
 540         {
 541                 ERROR("BUG: connection->priv == NULL");
 542         }
 543
 544         target_unregister_event_callback(telnet_target_callback_event_handler, connection->cmd_ctx);
 545
 546         return ERROR_OK;
 547 }
 548
 549 int telnet_set_prompt(connection_t *connection, char *prompt)
 550 {
 551         telnet_connection_t *t_con = connection->priv;
 552
 553         t_con->prompt = strdup(prompt);
 554
 555         return ERROR_OK;
 556 }
 557
 558 int telnet_init(char *banner)
 559 {
 560         telnet_service_t *telnet_service = malloc(sizeof(telnet_service_t));
 561
 562         if (telnet_port == 0)
 563         {
 564                 WARNING("no telnet port specified, using default port 4444");
 565                 telnet_port = 4444;
 566         }
 567
 568         telnet_service->banner = banner;
 569
 570         add_service("telnet", CONNECTION_TELNET, telnet_port, 1, telnet_new_connection, telnet_input, telnet_connection_closed, telnet_service);
 571
 572         return ERROR_OK;
 573 }
 574
 575 int telnet_register_commands(command_context_t *command_context)
 576 {
 577         register_command(command_context, NULL, "exit", handle_exit_command,
 578                                          COMMAND_EXEC, "exit telnet session");
 579
 580         register_command(command_context, NULL, "telnet_port", handle_telnet_port_command,
 581                                          COMMAND_CONFIG, "");
 582
 583         return ERROR_OK;
 584 }
 585
 586 /* daemon configuration command telnet_port */
 587 int handle_telnet_port_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc)
 588 {
 589         if (argc == 0)
 590                 return ERROR_OK;
 591
 592         /* only if the port wasn't overwritten by cmdline */
 593         if (telnet_port == 0)
 594                 telnet_port = strtoul(args[0], NULL, 0);
 595
 596         return ERROR_OK;
 597 }
 598
 599 int handle_exit_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc)
 600 {
 601         return ERROR_COMMAND_CLOSE_CONNECTION;
 602 }