1 /***************************************************************************
2 * Copyright (C) 2005 by Dominic Rath *
3 * Dominic.Rath@gmx.de *
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. *
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. *
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 #include "telnet_server.h"
33 static unsigned short telnet_port = 0;
35 int handle_exit_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc);
36 int handle_telnet_port_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc);
38 static char *negotiate =
39 "\xFF\xFB\x03" /* IAC WILL Suppress Go Ahead */
40 "\xFF\xFB\x01" /* IAC WILL Echo */
41 "\xFF\xFD\x03" /* IAC DO Suppress Go Ahead */
42 "\xFF\xFE\x01"; /* IAC DON'T Echo */
44 #define CTRL(c) (c - '@')
46 void telnet_prompt(connection_t *connection)
48 telnet_connection_t *t_con = connection->priv;
50 write(connection->fd, t_con->prompt, strlen(t_con->prompt));
53 int telnet_output(struct command_context_s *cmd_ctx, char* line)
55 connection_t *connection = cmd_ctx->output_handler_priv;
57 write(connection->fd, line, strlen(line));
58 write(connection->fd, "\r\n\0", 3);
63 int telnet_target_callback_event_handler(struct target_s *target, enum target_event event, void *priv)
65 struct command_context_s *cmd_ctx = priv;
66 connection_t *connection = cmd_ctx->output_handler_priv;
67 telnet_connection_t *t_con = connection->priv;
72 case TARGET_EVENT_HALTED:
73 command_print(cmd_ctx, "Target %i halted", get_num_by_target(target));
74 target->type->arch_state(target, buffer, 512);
76 command_print(cmd_ctx, "%s", buffer);
77 telnet_prompt(connection);
78 t_con->suppress_prompt = 1;
80 case TARGET_EVENT_RESUMED:
81 command_print(cmd_ctx, "Target %i resumed", get_num_by_target(target));
82 telnet_prompt(connection);
83 t_con->suppress_prompt = 1;
92 int telnet_new_connection(connection_t *connection)
94 telnet_connection_t *telnet_connection = malloc(sizeof(telnet_connection_t));
95 telnet_service_t *telnet_service = connection->service->priv;
98 connection->priv = telnet_connection;
100 /* initialize telnet connection information */
101 telnet_connection->line_size = 0;
102 telnet_connection->line_cursor = 0;
103 telnet_connection->option_size = 0;
104 telnet_connection->prompt = strdup("> ");
105 telnet_connection->suppress_prompt = 0;
106 telnet_connection->state = TELNET_STATE_DATA;
108 /* output goes through telnet connection */
109 command_set_output_handler(connection->cmd_ctx, telnet_output, connection);
111 /* negotiate telnet options */
112 write(connection->fd, negotiate, strlen(negotiate));
114 /* print connection banner */
115 if (telnet_service->banner)
117 write(connection->fd, telnet_service->banner, strlen(telnet_service->banner));
118 write(connection->fd, "\r\n\0", 3);
121 telnet_prompt(connection);
123 /* initialize history */
124 for (i = 0; i < TELNET_LINE_HISTORY_SIZE; i++)
126 telnet_connection->history[i] = NULL;
128 telnet_connection->next_history = 0;
129 telnet_connection->current_history = 0;
131 target_register_event_callback(telnet_target_callback_event_handler, connection->cmd_ctx);
136 void telnet_clear_line(connection_t *connection, telnet_connection_t *t_con)
138 /* move to end of line */
139 if (t_con->line_cursor < t_con->line_size)
141 write(connection->fd, t_con->line + t_con->line_cursor, t_con->line_size - t_con->line_cursor);
144 /* backspace, overwrite with space, backspace */
145 while (t_con->line_size > 0)
147 write(connection->fd, "\b \b", 3);
150 t_con->line_cursor = 0;
153 int telnet_input(connection_t *connection)
156 char buffer[TELNET_BUFFER_SIZE];
158 telnet_connection_t *t_con = connection->priv;
159 command_context_t *command_context = connection->cmd_ctx;
161 bytes_read = read(connection->fd, buffer, TELNET_BUFFER_SIZE);
164 return ERROR_SERVER_REMOTE_CLOSED;
165 else if (bytes_read == -1)
167 ERROR("error during read: %s", strerror(errno));
168 return ERROR_SERVER_REMOTE_CLOSED;
174 switch (t_con->state)
176 case TELNET_STATE_DATA:
177 if (*buf_p == '\xff')
179 t_con->state = TELNET_STATE_IAC;
183 if (isprint(*buf_p)) /* printable character */
185 write(connection->fd, buf_p, 1);
186 if (t_con->line_cursor == t_con->line_size)
188 t_con->line[t_con->line_size++] = *buf_p;
189 t_con->line_cursor++;
194 memmove(t_con->line + t_con->line_cursor + 1, t_con->line + t_con->line_cursor, t_con->line_size - t_con->line_cursor);
195 t_con->line[t_con->line_cursor++] = *buf_p;
197 write(connection->fd, t_con->line + t_con->line_cursor, t_con->line_size - t_con->line_cursor);
198 for (i = t_con->line_cursor; i < t_con->line_size; i++)
200 write(connection->fd, "\b", 1);
204 else /* non-printable */
206 if (*buf_p == 0x1b) /* escape */
208 t_con->state = TELNET_STATE_ESCAPE;
209 t_con->last_escape = '\x00';
211 else if ((*buf_p == 0xd) || (*buf_p == 0xa)) /* CR/LF */
215 /* skip over combinations with CR/LF + NUL */
216 if (((*(buf_p + 1) == 0xa) || (*(buf_p + 1) == 0xd)) && (bytes_read > 1))
221 if ((*(buf_p + 1) == 0) && (bytes_read > 1))
226 t_con->line[t_con->line_size] = 0;
228 write(connection->fd, "\r\n\x00", 3);
230 if (strcmp(t_con->line, "history") == 0)
233 for (i = 0; i < TELNET_LINE_HISTORY_SIZE; i++)
235 if (t_con->history[i])
237 write(connection->fd, t_con->history[i], strlen(t_con->history[i]));
238 write(connection->fd, "\r\n\x00", 3);
241 telnet_prompt(connection);
242 t_con->line_size = 0;
243 t_con->line_cursor = 0;
247 /* we're running a command, so we need a prompt
248 * if the output handler is called, this gets set again */
249 t_con->suppress_prompt = 0;
250 if ((retval = command_run_line(command_context, t_con->line)) != ERROR_OK)
252 if (retval == ERROR_COMMAND_CLOSE_CONNECTION)
254 return ERROR_SERVER_REMOTE_CLOSED;
258 /* Save only non-blank lines in the history */
259 if (t_con->line_size > 0)
261 /* if the history slot is already taken, free it */
262 if (t_con->history[t_con->next_history])
264 free(t_con->history[t_con->next_history]);
267 /* add line to history */
268 t_con->history[t_con->next_history] = strdup(t_con->line);
270 /* wrap history at TELNET_LINE_HISTORY_SIZE */
271 t_con->next_history = (t_con->next_history + 1) % TELNET_LINE_HISTORY_SIZE;
273 /* current history line starts at the new entry */
274 t_con->current_history = t_con->next_history;
276 if (t_con->history[t_con->current_history])
278 free(t_con->history[t_con->current_history]);
280 t_con->history[t_con->current_history] = strdup("");
283 if (!t_con->suppress_prompt)
285 telnet_prompt(connection);
289 t_con->suppress_prompt = 0;
292 t_con->line_size = 0;
293 t_con->line_cursor = 0;
295 else if ((*buf_p == 0x7f) || (*buf_p == 0x8)) /* delete character */
297 if (t_con->line_cursor > 0)
299 if (t_con->line_cursor != t_con->line_size)
302 write(connection->fd, "\b", 1);
303 t_con->line_cursor--;
305 memmove(t_con->line + t_con->line_cursor, t_con->line + t_con->line_cursor + 1, t_con->line_size - t_con->line_cursor);
307 write(connection->fd, t_con->line + t_con->line_cursor, t_con->line_size - t_con->line_cursor);
308 write(connection->fd, " \b", 2);
309 for (i = t_con->line_cursor; i < t_con->line_size; i++)
311 write(connection->fd, "\b", 1);
317 t_con->line_cursor--;
318 /* back space: move the 'printer' head one char back, overwrite with space, move back again */
319 write(connection->fd, "\b \b", 3);
323 else if (*buf_p == 0x15) /* clear line */
325 telnet_clear_line(connection, t_con);
327 else if (*buf_p == CTRL('B')) /* cursor left */
329 if (t_con->line_cursor > 0)
331 write(connection->fd, "\b", 1);
332 t_con->line_cursor--;
334 t_con->state = TELNET_STATE_DATA;
336 else if (*buf_p == CTRL('F')) /* cursor right */
338 if (t_con->line_cursor < t_con->line_size)
340 write(connection->fd, t_con->line + t_con->line_cursor++, 1);
342 t_con->state = TELNET_STATE_DATA;
346 DEBUG("unhandled nonprintable: %2.2x", *buf_p);
351 case TELNET_STATE_IAC:
355 t_con->state = TELNET_STATE_DONT;
358 t_con->state = TELNET_STATE_DO;
361 t_con->state = TELNET_STATE_WONT;
364 t_con->state = TELNET_STATE_WILL;
368 case TELNET_STATE_SB:
370 case TELNET_STATE_SE:
372 case TELNET_STATE_WILL:
373 case TELNET_STATE_WONT:
374 case TELNET_STATE_DO:
375 case TELNET_STATE_DONT:
376 t_con->state = TELNET_STATE_DATA;
378 case TELNET_STATE_ESCAPE:
379 if (t_con->last_escape == '[')
381 if (*buf_p == 'D') /* cursor left */
383 if (t_con->line_cursor > 0)
385 write(connection->fd, "\b", 1);
386 t_con->line_cursor--;
388 t_con->state = TELNET_STATE_DATA;
390 else if (*buf_p == 'C') /* cursor right */
392 if (t_con->line_cursor < t_con->line_size)
394 write(connection->fd, t_con->line + t_con->line_cursor++, 1);
396 t_con->state = TELNET_STATE_DATA;
398 else if (*buf_p == 'A') /* cursor up */
400 int last_history = (t_con->current_history > 0) ? t_con->current_history - 1 : TELNET_LINE_HISTORY_SIZE-1;
401 if (t_con->history[last_history])
403 telnet_clear_line(connection, t_con);
404 t_con->line_size = strlen(t_con->history[last_history]);
405 t_con->line_cursor = t_con->line_size;
406 memcpy(t_con->line, t_con->history[last_history], t_con->line_size + 1);
407 write(connection->fd, t_con->line, t_con->line_size);
408 t_con->current_history = last_history;
410 t_con->state = TELNET_STATE_DATA;
412 else if (*buf_p == 'B') /* cursor down */
414 int next_history = (t_con->current_history + 1) % TELNET_LINE_HISTORY_SIZE;
415 if (t_con->history[next_history])
417 telnet_clear_line(connection, t_con);
418 t_con->line_size = strlen(t_con->history[next_history]);
419 t_con->line_cursor = t_con->line_size;
420 memcpy(t_con->line, t_con->history[next_history], t_con->line_size + 1);
421 write(connection->fd, t_con->line, t_con->line_size);
422 t_con->current_history = next_history;
424 t_con->state = TELNET_STATE_DATA;
426 else if (*buf_p == '3')
428 t_con->last_escape = *buf_p;
432 t_con->state = TELNET_STATE_DATA;
435 else if (t_con->last_escape == '3')
437 /* Remove character */
440 if (t_con->line_cursor < t_con->line_size)
444 /* remove char from line buffer */
445 memmove(t_con->line + t_con->line_cursor, t_con->line + t_con->line_cursor + 1, t_con->line_size - t_con->line_cursor);
447 /* print remainder of buffer */
448 write(connection->fd, t_con->line + t_con->line_cursor, t_con->line_size - t_con->line_cursor);
449 /* overwrite last char with whitespace */
450 write(connection->fd, " \b", 2);
452 /* move back to cursor position*/
453 for (i = t_con->line_cursor; i < t_con->line_size; i++)
455 write(connection->fd, "\b", 1);
459 t_con->state = TELNET_STATE_DATA;
463 t_con->state = TELNET_STATE_DATA;
466 else if (t_con->last_escape == '\x00')
470 t_con->last_escape = *buf_p;
474 t_con->state = TELNET_STATE_DATA;
479 ERROR("BUG: unexpected value in t_con->last_escape");
480 t_con->state = TELNET_STATE_DATA;
485 ERROR("unknown telnet state");
496 int telnet_connection_closed(connection_t *connection)
498 telnet_connection_t *t_con = connection->priv;
504 for (i = 0; i < TELNET_LINE_HISTORY_SIZE; i++)
506 if (t_con->history[i])
507 free(t_con->history[i]);
510 if (connection->priv)
511 free(connection->priv);
513 ERROR("BUG: connection->priv == NULL");
515 target_unregister_event_callback(telnet_target_callback_event_handler, connection->cmd_ctx);
520 int telnet_set_prompt(connection_t *connection, char *prompt)
522 telnet_connection_t *t_con = connection->priv;
524 t_con->prompt = strdup(prompt);
529 int telnet_init(char *banner)
531 telnet_service_t *telnet_service = malloc(sizeof(telnet_service_t));
533 if (telnet_port == 0)
535 WARNING("no telnet port specified, using default port 4444");
539 telnet_service->banner = banner;
541 add_service("telnet", CONNECTION_TELNET, telnet_port, 1, telnet_new_connection, telnet_input, telnet_connection_closed, telnet_service);
546 int telnet_register_commands(command_context_t *command_context)
548 register_command(command_context, NULL, "exit", handle_exit_command,
549 COMMAND_EXEC, "exit telnet session");
551 register_command(command_context, NULL, "telnet_port", handle_telnet_port_command,
557 /* daemon configuration command telnet_port */
558 int handle_telnet_port_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc)
563 /* only if the port wasn't overwritten by cmdline */
564 if (telnet_port == 0)
565 telnet_port = strtoul(args[0], NULL, 0);
570 int handle_exit_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc)
572 return ERROR_COMMAND_CLOSE_CONNECTION;