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  *   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         if (t == NULL)
  97                 return;
  98
  99         telnet_outputline(connection, t);
 100
 101         free(t);
 102 }
 103
 104 int telnet_target_callback_event_handler(struct target_s *target, enum target_event event, void *priv)
 105 {
 106         struct command_context_s *cmd_ctx = priv;
 107         connection_t *connection = cmd_ctx->output_handler_priv;
 108         telnet_connection_t *t_con = connection->priv;
 109         char buffer[512];
 110
 111         switch (event)
 112         {
 113                 case TARGET_EVENT_HALTED:
 114                         command_print(cmd_ctx, "Target %i halted", get_num_by_target(target));
 115                         target->type->arch_state(target, buffer, 512);
 116                         buffer[511] = 0;
 117                         command_print(cmd_ctx, "%s", buffer);
 118                         if (!t_con->suppress_prompt)
 119                                 telnet_prompt(connection);
 120                         break;
 121                 case TARGET_EVENT_RESUMED:
 122                         command_print(cmd_ctx, "Target %i resumed", get_num_by_target(target));
 123                         if (!t_con->suppress_prompt)
 124                                 telnet_prompt(connection);
 125                         break;
 126                 default:
 127                         break;
 128         }
 129
 130         return ERROR_OK;
 131 }
 132
 133 int telnet_new_connection(connection_t *connection)
 134 {
 135         telnet_connection_t *telnet_connection = malloc(sizeof(telnet_connection_t));
 136         telnet_service_t *telnet_service = connection->service->priv;
 137         int i;
 138
 139         connection->priv = telnet_connection;
 140
 141         /* initialize telnet connection information */
 142         telnet_connection->closed = 0;
 143         telnet_connection->line_size = 0;
 144         telnet_connection->line_cursor = 0;
 145         telnet_connection->option_size = 0;
 146         telnet_connection->prompt = strdup("> ");
 147         telnet_connection->suppress_prompt = 0;
 148         telnet_connection->state = TELNET_STATE_DATA;
 149
 150         /* output goes through telnet connection */
 151         command_set_output_handler(connection->cmd_ctx, telnet_output, connection);
 152
 153         /* negotiate telnet options */
 154         telnet_write(connection, negotiate, strlen(negotiate));
 155
 156         /* print connection banner */
 157         if (telnet_service->banner)
 158         {
 159                 telnet_write(connection, telnet_service->banner, strlen(telnet_service->banner));
 160                 telnet_write(connection, "\r\n\0", 3);
 161         }
 162
 163         telnet_prompt(connection);
 164
 165         /* initialize history */
 166         for (i = 0; i < TELNET_LINE_HISTORY_SIZE; i++)
 167         {
 168                 telnet_connection->history[i] = NULL;
 169         }
 170         telnet_connection->next_history = 0;
 171         telnet_connection->current_history = 0;
 172
 173         target_register_event_callback(telnet_target_callback_event_handler, connection->cmd_ctx);
 174
 175         return ERROR_OK;
 176 }
 177
 178 void telnet_clear_line(connection_t *connection, telnet_connection_t *t_con)
 179 {
 180         /* move to end of line */
 181         if (t_con->line_cursor < t_con->line_size)
 182         {
 183                 telnet_write(connection, t_con->line + t_con->line_cursor, t_con->line_size - t_con->line_cursor);
 184         }
 185
 186         /* backspace, overwrite with space, backspace */
 187         while (t_con->line_size > 0)
 188         {
 189                 telnet_write(connection, "\b \b", 3);
 190                 t_con->line_size--;
 191         }
 192         t_con->line_cursor = 0;
 193 }
 194
 195 int telnet_input(connection_t *connection)
 196 {
 197         int bytes_read;
 198         char buffer[TELNET_BUFFER_SIZE];
 199         char *buf_p;
 200         telnet_connection_t *t_con = connection->priv;
 201         command_context_t *command_context = connection->cmd_ctx;
 202
 203         bytes_read = read_socket(connection->fd, buffer, TELNET_BUFFER_SIZE);
 204
 205         if (bytes_read == 0)
 206                 return ERROR_SERVER_REMOTE_CLOSED;
 207         else if (bytes_read == -1)
 208         {
 209                 ERROR("error during read: %s", strerror(errno));
 210                 return ERROR_SERVER_REMOTE_CLOSED;
 211         }
 212
 213         buf_p = buffer;
 214         while (bytes_read)
 215         {
 216                 switch (t_con->state)
 217                 {
 218                         case TELNET_STATE_DATA:
 219                                 if (*buf_p == '\xff')
 220                                 {
 221                                         t_con->state = TELNET_STATE_IAC;
 222                                 }
 223                                 else
 224                                 {
 225                                         if (isprint(*buf_p)) /* printable character */
 226                                         {
 227                                                 telnet_write(connection, buf_p, 1);
 228                                                 if (t_con->line_cursor == t_con->line_size)
 229                                                 {
 230                                                         t_con->line[t_con->line_size++] = *buf_p;
 231                                                         t_con->line_cursor++;
 232                                                 }
 233                                                 else
 234                                                 {
 235                                                         int i;
 236                                                         memmove(t_con->line + t_con->line_cursor + 1, t_con->line + t_con->line_cursor, t_con->line_size - t_con->line_cursor);
 237                                                         t_con->line[t_con->line_cursor++] = *buf_p;
 238                                                         t_con->line_size++;
 239                                                         telnet_write(connection, t_con->line + t_con->line_cursor, t_con->line_size - t_con->line_cursor);
 240                                                         for (i = t_con->line_cursor; i < t_con->line_size; i++)
 241                                                         {
 242                                                                 telnet_write(connection, "\b", 1);
 243                                                         }
 244                                                 }
 245                                         }
 246                                         else /* non-printable */
 247                                         {
 248                                                 if (*buf_p == 0x1b) /* escape */
 249                                                 {
 250                                                         t_con->state = TELNET_STATE_ESCAPE;
 251                                                         t_con->last_escape = '\x00';
 252                                                 }
 253                                                 else if ((*buf_p == 0xd) || (*buf_p == 0xa)) /* CR/LF */
 254                                                 {
 255                                                         int retval;
 256
 257                                                         /* skip over combinations with CR/LF + NUL */
 258                                                         if (((*(buf_p + 1) == 0xa) || (*(buf_p + 1) == 0xd)) && (bytes_read > 1))
 259                                                         {
 260                                                                 buf_p++;
 261                                                                 bytes_read--;
 262                                                         }
 263                                                         if ((*(buf_p + 1) == 0) && (bytes_read > 1))
 264                                                         {
 265                                                                 buf_p++;
 266                                                                 bytes_read--;
 267                                                         }
 268                                                         t_con->line[t_con->line_size] = 0;
 269
 270                                                         telnet_write(connection, "\r\n\x00", 3);
 271
 272                                                         if (strcmp(t_con->line, "history") == 0)
 273                                                         {
 274                                                                 int i;
 275                                                                 for (i = 0; i < TELNET_LINE_HISTORY_SIZE; i++)
 276                                                                 {
 277                                                                         if (t_con->history[i])
 278                                                                         {
 279                                                                                 telnet_write(connection, t_con->history[i], strlen(t_con->history[i]));
 280                                                                                 telnet_write(connection, "\r\n\x00", 3);
 281                                                                         }
 282                                                                 }
 283                                                                 telnet_prompt(connection);
 284                                                                 t_con->line_size = 0;
 285                                                                 t_con->line_cursor = 0;
 286                                                                 continue;
 287                                                         }
 288
 289                                                         log_setCallback(telnet_log_callback, connection);
 290                                                         t_con->suppress_prompt = 1;
 291
 292                                                         if ((retval = command_run_line(command_context, t_con->line)) != ERROR_OK)
 293                                                         {
 294                                                                 if (retval == ERROR_COMMAND_CLOSE_CONNECTION)
 295                                                                 {
 296                                                                         return ERROR_SERVER_REMOTE_CLOSED;
 297                                                                 }
 298                                                         }
 299
 300                                                         t_con->suppress_prompt = 0;
 301
 302                                                         /* Save only non-blank lines in the history */
 303                                                         if (t_con->line_size > 0)
 304                                                         {
 305                                                                 /* if the history slot is already taken, free it */
 306                                                                 if (t_con->history[t_con->next_history])
 307                                                                 {
 308                                                                         free(t_con->history[t_con->next_history]);
 309                                                                 }
 310
 311                                                                 /* add line to history */
 312                                                                 t_con->history[t_con->next_history] = strdup(t_con->line);
 313
 314                                                                 /* wrap history at TELNET_LINE_HISTORY_SIZE */
 315                                                                 t_con->next_history = (t_con->next_history + 1) % TELNET_LINE_HISTORY_SIZE;
 316
 317                                                                 /* current history line starts at the new entry */
 318                                                                 t_con->current_history = t_con->next_history;
 319
 320                                                                 if (t_con->history[t_con->current_history])
 321                                                                 {
 322                                                                         free(t_con->history[t_con->current_history]);
 323                                                                 }
 324                                                                 t_con->history[t_con->current_history] = strdup("");
 325                                                         }
 326
 327                                                         int t = telnet_prompt(connection);
 328                                                         if (t == ERROR_SERVER_REMOTE_CLOSED)
 329                                                                 return t;
 330
 331                                                         t_con->line_size = 0;
 332                                                         t_con->line_cursor = 0;
 333                                                 }
 334                                                 else if ((*buf_p == 0x7f) || (*buf_p == 0x8)) /* delete character */
 335                                                 {
 336                                                         if (t_con->line_cursor > 0)
 337                                                         {
 338                                                                 if (t_con->line_cursor != t_con->line_size)
 339                                                                 {
 340                                                                         int i;
 341                                                                         telnet_write(connection, "\b", 1);
 342                                                                         t_con->line_cursor--;
 343                                                                         t_con->line_size--;
 344                                                                         memmove(t_con->line + t_con->line_cursor, t_con->line + t_con->line_cursor + 1, t_con->line_size - t_con->line_cursor);
 345
 346                                                                         telnet_write(connection, t_con->line + t_con->line_cursor, t_con->line_size - t_con->line_cursor);
 347                                                                         telnet_write(connection, " \b", 2);
 348                                                                         for (i = t_con->line_cursor; i < t_con->line_size; i++)
 349                                                                         {
 350                                                                                 telnet_write(connection, "\b", 1);
 351                                                                         }
 352                                                                 }
 353                                                                 else
 354                                                                 {
 355                                                                         t_con->line_size--;
 356                                                                         t_con->line_cursor--;
 357                                                                         /* back space: move the 'printer' head one char back, overwrite with space, move back again */
 358                                                                         telnet_write(connection, "\b \b", 3);
 359                                                                 }
 360                                                         }
 361                                                 }
 362                                                 else if (*buf_p == 0x15) /* clear line */
 363                                                 {
 364                                                         telnet_clear_line(connection, t_con);
 365                                                 }
 366                                                 else if (*buf_p == CTRL('B')) /* cursor left */
 367                                                 {
 368                                                         if (t_con->line_cursor > 0)
 369                                                         {
 370                                                                 telnet_write(connection, "\b", 1);
 371                                                                 t_con->line_cursor--;
 372                                                         }
 373                                                         t_con->state = TELNET_STATE_DATA;
 374                                                 }
 375                                                 else if (*buf_p == CTRL('F')) /* cursor right */
 376                                                 {
 377                                                         if (t_con->line_cursor < t_con->line_size)
 378                                                         {
 379                                                                 telnet_write(connection, t_con->line + t_con->line_cursor++, 1);
 380                                                         }
 381                                                         t_con->state = TELNET_STATE_DATA;
 382                                                 }
 383                                                 else
 384                                                 {
 385                                                         DEBUG("unhandled nonprintable: %2.2x", *buf_p);
 386                                                 }
 387                                         }
 388                                 }
 389                                 break;
 390                         case TELNET_STATE_IAC:
 391                                 switch (*buf_p)
 392                                 {
 393                                         case '\xfe':
 394                                                 t_con->state = TELNET_STATE_DONT;
 395                                                 break;
 396                                         case '\xfd':
 397                                                 t_con->state = TELNET_STATE_DO;
 398                                                 break;
 399                                         case '\xfc':
 400                                                 t_con->state = TELNET_STATE_WONT;
 401                                                 break;
 402                                         case '\xfb':
 403                                                 t_con->state = TELNET_STATE_WILL;
 404                                                 break;
 405                                 }
 406                                 break;
 407                         case TELNET_STATE_SB:
 408                                 break;
 409                         case TELNET_STATE_SE:
 410                                 break;
 411                         case TELNET_STATE_WILL:
 412                         case TELNET_STATE_WONT:
 413                         case TELNET_STATE_DO:
 414                         case TELNET_STATE_DONT:
 415                                 t_con->state = TELNET_STATE_DATA;
 416                                 break;
 417                         case TELNET_STATE_ESCAPE:
 418                                 if (t_con->last_escape == '[')
 419                                 {
 420                                         if (*buf_p == 'D') /* cursor left */
 421                                         {
 422                                                 if (t_con->line_cursor > 0)
 423                                                 {
 424                                                         telnet_write(connection, "\b", 1);
 425                                                         t_con->line_cursor--;
 426                                                 }
 427                                                 t_con->state = TELNET_STATE_DATA;
 428                                         }
 429                                         else if (*buf_p == 'C') /* cursor right */
 430                                         {
 431                                                 if (t_con->line_cursor < t_con->line_size)
 432                                                 {
 433                                                         telnet_write(connection, t_con->line + t_con->line_cursor++, 1);
 434                                                 }
 435                                                 t_con->state = TELNET_STATE_DATA;
 436                                         }
 437                                         else if (*buf_p == 'A') /* cursor up */
 438                                         {
 439                                                 int last_history = (t_con->current_history > 0) ? t_con->current_history - 1 : TELNET_LINE_HISTORY_SIZE-1;
 440                                                 if (t_con->history[last_history])
 441                                                 {
 442                                                         telnet_clear_line(connection, t_con);
 443                                                         t_con->line_size = strlen(t_con->history[last_history]);
 444                                                         t_con->line_cursor = t_con->line_size;
 445                                                         memcpy(t_con->line, t_con->history[last_history], t_con->line_size + 1);
 446                                                         telnet_write(connection, t_con->line, t_con->line_size);
 447                                                         t_con->current_history = last_history;
 448                                                 }
 449                                                 t_con->state = TELNET_STATE_DATA;
 450                                         }
 451                                         else if (*buf_p == 'B') /* cursor down */
 452                                         {
 453                                                 int next_history = (t_con->current_history + 1) % TELNET_LINE_HISTORY_SIZE;
 454                                                 if (t_con->history[next_history])
 455                                                 {
 456                                                         telnet_clear_line(connection, t_con);
 457                                                         t_con->line_size = strlen(t_con->history[next_history]);
 458                                                         t_con->line_cursor = t_con->line_size;
 459                                                         memcpy(t_con->line, t_con->history[next_history], t_con->line_size + 1);
 460                                                         telnet_write(connection, t_con->line, t_con->line_size);
 461                                                         t_con->current_history = next_history;
 462                                                 }
 463                                                 t_con->state = TELNET_STATE_DATA;
 464                                         }
 465                                         else if (*buf_p == '3')
 466                                         {
 467                                                 t_con->last_escape = *buf_p;
 468                                         }
 469                                         else
 470                                         {
 471                                                 t_con->state = TELNET_STATE_DATA;
 472                                         }
 473                                 }
 474                                 else if (t_con->last_escape == '3')
 475                                 {
 476                                         /* Remove character */
 477                                         if (*buf_p == '~')
 478                                         {
 479                                                 if (t_con->line_cursor < t_con->line_size)
 480                                                 {
 481                                                         int i;
 482                                                         t_con->line_size--;
 483                                                         /* remove char from line buffer */
 484                                                         memmove(t_con->line + t_con->line_cursor, t_con->line + t_con->line_cursor + 1, t_con->line_size - t_con->line_cursor);
 485
 486                                                         /* print remainder of buffer */
 487                                                         telnet_write(connection, t_con->line + t_con->line_cursor, t_con->line_size - t_con->line_cursor);
 488                                                         /* overwrite last char with whitespace */
 489                                                         telnet_write(connection, " \b", 2);
 490
 491                                                         /* move back to cursor position*/
 492                                                         for (i = t_con->line_cursor; i < t_con->line_size; i++)
 493                                                         {
 494                                                                 telnet_write(connection, "\b", 1);
 495                                                         }
 496                                                 }
 497
 498                                                 t_con->state = TELNET_STATE_DATA;
 499                                         }
 500                                         else
 501                                         {
 502                                                 t_con->state = TELNET_STATE_DATA;
 503                                         }
 504                                 }
 505                                 else if (t_con->last_escape == '\x00')
 506                                 {
 507                                         if (*buf_p == '[')
 508                                         {
 509                                                 t_con->last_escape = *buf_p;
 510                                         }
 511                                         else
 512                                         {
 513                                                 t_con->state = TELNET_STATE_DATA;
 514                                         }
 515                                 }
 516                                 else
 517                                 {
 518                                         ERROR("BUG: unexpected value in t_con->last_escape");
 519                                         t_con->state = TELNET_STATE_DATA;
 520                                 }
 521
 522                                 break;
 523                         default:
 524                                 ERROR("unknown telnet state");
 525                                 exit(-1);
 526                 }
 527
 528                 bytes_read--;
 529                 buf_p++;
 530         }
 531
 532         return ERROR_OK;
 533 }
 534
 535 int telnet_connection_closed(connection_t *connection)
 536 {
 537         telnet_connection_t *t_con = connection->priv;
 538         int i;
 539
 540         if (t_con->prompt)
 541         {
 542                 free(t_con->prompt);
 543                 t_con->prompt = NULL;
 544         }
 545
 546         for (i = 0; i < TELNET_LINE_HISTORY_SIZE; i++)
 547         {
 548                 if (t_con->history[i])
 549                 {
 550                         free(t_con->history[i]);
 551                         t_con->history[i] = NULL;
 552                 }
 553         }
 554
 555         /* if this connection registered a debug-message receiver delete it */
 556         delete_debug_msg_receiver(connection->cmd_ctx, NULL);
 557
 558         if (connection->priv)
 559         {
 560                 free(connection->priv);
 561                 connection->priv = NULL;
 562         }
 563         else
 564         {
 565                 ERROR("BUG: connection->priv == NULL");
 566         }
 567
 568         target_unregister_event_callback(telnet_target_callback_event_handler, connection->cmd_ctx);
 569
 570         return ERROR_OK;
 571 }
 572
 573 int telnet_set_prompt(connection_t *connection, char *prompt)
 574 {
 575         telnet_connection_t *t_con = connection->priv;
 576
 577         t_con->prompt = strdup(prompt);
 578
 579         return ERROR_OK;
 580 }
 581
 582 int telnet_init(char *banner)
 583 {
 584         telnet_service_t *telnet_service = malloc(sizeof(telnet_service_t));
 585
 586         if (telnet_port == 0)
 587         {
 588                 WARNING("no telnet port specified, using default port 4444");
 589                 telnet_port = 4444;
 590         }
 591
 592         telnet_service->banner = banner;
 593
 594         add_service("telnet", CONNECTION_TELNET, telnet_port, 1, telnet_new_connection, telnet_input, telnet_connection_closed, telnet_service);
 595
 596         return ERROR_OK;
 597 }
 598
 599 int telnet_register_commands(command_context_t *command_context)
 600 {
 601         register_command(command_context, NULL, "exit", handle_exit_command,
 602                                          COMMAND_EXEC, "exit telnet session");
 603
 604         register_command(command_context, NULL, "telnet_port", handle_telnet_port_command,
 605                                          COMMAND_CONFIG, "");
 606
 607         return ERROR_OK;
 608 }
 609
 610 /* daemon configuration command telnet_port */
 611 int handle_telnet_port_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc)
 612 {
 613         if (argc == 0)
 614                 return ERROR_OK;
 615
 616         /* only if the port wasn't overwritten by cmdline */
 617         if (telnet_port == 0)
 618                 telnet_port = strtoul(args[0], NULL, 0);
 619
 620         return ERROR_OK;
 621 }
 622
 623 int handle_exit_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc)
 624 {
 625         return ERROR_COMMAND_CLOSE_CONNECTION;
 626 }