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- /***************************************************************************
- * Copyright (C) 2005 by Dominic Rath *
- * Dominic.Rath@gmx.de *
- * *
- * Copyright (C) 2007-2010 Øyvind Harboe *
- * oyvind.harboe@zylin.com *
- * *
- * Copyright (C) 2008 by Spencer Oliver *
- * spen@spen-soft.co.uk *
- * *
- * This program is free software; you can redistribute it and/or modify *
- * it under the terms of the GNU General Public License as published by *
- * the Free Software Foundation; either version 2 of the License, or *
- * (at your option) any later version. *
- * *
- * This program is distributed in the hope that it will be useful, *
- * but WITHOUT ANY WARRANTY; without even the implied warranty of *
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the *
- * GNU General Public License for more details. *
- * *
- * You should have received a copy of the GNU General Public License *
- * along with this program. If not, see <http://www.gnu.org/licenses/>. *
- ***************************************************************************/
-
- #ifdef HAVE_CONFIG_H
- #include "config.h"
- #endif
-
- #include "telnet_server.h"
- #include <target/target_request.h>
- #include <helper/configuration.h>
-
- static char *telnet_port;
-
- static char *negotiate =
- "\xFF\xFB\x03" /* IAC WILL Suppress Go Ahead */
- "\xFF\xFB\x01" /* IAC WILL Echo */
- "\xFF\xFD\x03" /* IAC DO Suppress Go Ahead */
- "\xFF\xFE\x01"; /* IAC DON'T Echo */
-
- #define CTRL(c) (c - '@')
- #define TELNET_HISTORY ".openocd_history"
-
- /* The only way we can detect that the socket is closed is the first time
- * we write to it, we will fail. Subsequent write operations will
- * succeed. Shudder!
- */
- static int telnet_write(struct connection *connection, const void *data,
- int len)
- {
- struct telnet_connection *t_con = connection->priv;
- if (t_con->closed)
- return ERROR_SERVER_REMOTE_CLOSED;
-
- if (connection_write(connection, data, len) == len)
- return ERROR_OK;
- t_con->closed = 1;
- return ERROR_SERVER_REMOTE_CLOSED;
- }
-
- static int telnet_prompt(struct connection *connection)
- {
- struct telnet_connection *t_con = connection->priv;
-
- return telnet_write(connection, t_con->prompt, strlen(t_con->prompt));
- }
-
- static int telnet_outputline(struct connection *connection, const char *line)
- {
- int len;
-
- /* process lines in buffer */
- while (*line) {
- char *line_end = strchr(line, '\n');
-
- if (line_end)
- len = line_end-line;
- else
- len = strlen(line);
-
- telnet_write(connection, line, len);
- if (line_end) {
- telnet_write(connection, "\r\n", 2);
- line += len + 1;
- } else
- line += len;
- }
-
- return ERROR_OK;
- }
-
- static int telnet_output(struct command_context *cmd_ctx, const char *line)
- {
- struct connection *connection = cmd_ctx->output_handler_priv;
-
- return telnet_outputline(connection, line);
- }
-
- static void telnet_log_callback(void *priv, const char *file, unsigned line,
- const char *function, const char *string)
- {
- struct connection *connection = priv;
- struct telnet_connection *t_con = connection->priv;
- int i;
-
- /* if there is no prompt, simply output the message */
- if (t_con->line_cursor < 0) {
- telnet_outputline(connection, string);
- return;
- }
-
- /* clear the command line */
- for (i = strlen(t_con->prompt) + t_con->line_size; i > 0; i -= 16)
- telnet_write(connection, "\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b", i > 16 ? 16 : i);
- for (i = strlen(t_con->prompt) + t_con->line_size; i > 0; i -= 16)
- telnet_write(connection, " ", i > 16 ? 16 : i);
- for (i = strlen(t_con->prompt) + t_con->line_size; i > 0; i -= 16)
- telnet_write(connection, "\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b", i > 16 ? 16 : i);
-
- /* output the message */
- telnet_outputline(connection, string);
-
- /* put the command line to its previous state */
- telnet_prompt(connection);
- telnet_write(connection, t_con->line, t_con->line_size);
- for (i = t_con->line_size; i > t_con->line_cursor; i--)
- telnet_write(connection, "\b", 1);
- }
-
- static void telnet_load_history(struct telnet_connection *t_con)
- {
- FILE *histfp;
- char buffer[TELNET_BUFFER_SIZE];
- int i = 0;
-
- char *history = get_home_dir(TELNET_HISTORY);
-
- if (history == NULL) {
- LOG_INFO("unable to get user home directory, telnet history will be disabled");
- return;
- }
-
- histfp = fopen(history, "rb");
-
- if (histfp) {
-
- while (fgets(buffer, sizeof(buffer), histfp) != NULL) {
-
- char *p = strchr(buffer, '\n');
- if (p)
- *p = '\0';
- if (buffer[0] && i < TELNET_LINE_HISTORY_SIZE)
- t_con->history[i++] = strdup(buffer);
- }
-
- t_con->next_history = i;
- t_con->next_history %= TELNET_LINE_HISTORY_SIZE;
- /* try to set to last entry - 1, that way we skip over any exit/shutdown cmds */
- t_con->current_history = t_con->next_history > 0 ? i - 1 : 0;
- fclose(histfp);
- }
-
- free(history);
- }
-
- static void telnet_save_history(struct telnet_connection *t_con)
- {
- FILE *histfp;
- int i;
- int num;
-
- char *history = get_home_dir(TELNET_HISTORY);
-
- if (history == NULL) {
- LOG_INFO("unable to get user home directory, telnet history will be disabled");
- return;
- }
-
- histfp = fopen(history, "wb");
-
- if (histfp) {
-
- num = TELNET_LINE_HISTORY_SIZE;
- i = t_con->current_history + 1;
- i %= TELNET_LINE_HISTORY_SIZE;
-
- while (t_con->history[i] == NULL && num > 0) {
- i++;
- i %= TELNET_LINE_HISTORY_SIZE;
- num--;
- }
-
- if (num > 0) {
- for (; num > 0; num--) {
- fprintf(histfp, "%s\n", t_con->history[i]);
- i++;
- i %= TELNET_LINE_HISTORY_SIZE;
- }
- }
- fclose(histfp);
- }
-
- free(history);
- }
-
- static int telnet_new_connection(struct connection *connection)
- {
- struct telnet_connection *telnet_connection;
- struct telnet_service *telnet_service = connection->service->priv;
- int i;
-
- telnet_connection = malloc(sizeof(struct telnet_connection));
-
- if (!telnet_connection) {
- LOG_ERROR("Failed to allocate telnet connection.");
- return ERROR_FAIL;
- }
-
- connection->priv = telnet_connection;
-
- /* initialize telnet connection information */
- telnet_connection->closed = 0;
- telnet_connection->line_size = 0;
- telnet_connection->line_cursor = 0;
- telnet_connection->option_size = 0;
- telnet_connection->prompt = strdup("> ");
- telnet_connection->state = TELNET_STATE_DATA;
-
- /* output goes through telnet connection */
- command_set_output_handler(connection->cmd_ctx, telnet_output, connection);
-
- /* negotiate telnet options */
- telnet_write(connection, negotiate, strlen(negotiate));
-
- /* print connection banner */
- if (telnet_service->banner) {
- telnet_write(connection, telnet_service->banner, strlen(telnet_service->banner));
- telnet_write(connection, "\r\n", 2);
- }
-
- /* the prompt is always placed at the line beginning */
- telnet_write(connection, "\r", 1);
- telnet_prompt(connection);
-
- /* initialize history */
- for (i = 0; i < TELNET_LINE_HISTORY_SIZE; i++)
- telnet_connection->history[i] = NULL;
- telnet_connection->next_history = 0;
- telnet_connection->current_history = 0;
- telnet_load_history(telnet_connection);
-
- log_add_callback(telnet_log_callback, connection);
-
- return ERROR_OK;
- }
-
- static void telnet_clear_line(struct connection *connection,
- struct telnet_connection *t_con)
- {
- /* move to end of line */
- if (t_con->line_cursor < t_con->line_size)
- telnet_write(connection,
- t_con->line + t_con->line_cursor,
- t_con->line_size - t_con->line_cursor);
-
- /* backspace, overwrite with space, backspace */
- while (t_con->line_size > 0) {
- telnet_write(connection, "\b \b", 3);
- t_con->line_size--;
- }
- t_con->line_cursor = 0;
- }
-
- static void telnet_history_go(struct connection *connection, int idx)
- {
- struct telnet_connection *t_con = connection->priv;
-
- if (t_con->history[idx]) {
- telnet_clear_line(connection, t_con);
- t_con->line_size = strlen(t_con->history[idx]);
- t_con->line_cursor = t_con->line_size;
- memcpy(t_con->line, t_con->history[idx], t_con->line_size);
- telnet_write(connection, t_con->line, t_con->line_size);
- t_con->current_history = idx;
- }
- t_con->state = TELNET_STATE_DATA;
- }
-
- static void telnet_history_up(struct connection *connection)
- {
- struct telnet_connection *t_con = connection->priv;
-
- int last_history = (t_con->current_history > 0) ?
- t_con->current_history - 1 :
- TELNET_LINE_HISTORY_SIZE-1;
- telnet_history_go(connection, last_history);
- }
-
- static void telnet_history_down(struct connection *connection)
- {
- struct telnet_connection *t_con = connection->priv;
-
- int next_history = (t_con->current_history + 1) % TELNET_LINE_HISTORY_SIZE;
- telnet_history_go(connection, next_history);
- }
-
- static int telnet_input(struct connection *connection)
- {
- int bytes_read;
- unsigned char buffer[TELNET_BUFFER_SIZE];
- unsigned char *buf_p;
- struct telnet_connection *t_con = connection->priv;
- struct command_context *command_context = connection->cmd_ctx;
-
- bytes_read = connection_read(connection, buffer, TELNET_BUFFER_SIZE);
-
- if (bytes_read == 0)
- return ERROR_SERVER_REMOTE_CLOSED;
- else if (bytes_read == -1) {
- LOG_ERROR("error during read: %s", strerror(errno));
- return ERROR_SERVER_REMOTE_CLOSED;
- }
-
- buf_p = buffer;
- while (bytes_read) {
- switch (t_con->state) {
- case TELNET_STATE_DATA:
- if (*buf_p == 0xff)
- t_con->state = TELNET_STATE_IAC;
- else {
- if (isprint(*buf_p)) { /* printable character */
- /* watch buffer size leaving one spare character for
- * string null termination */
- if (t_con->line_size == TELNET_LINE_MAX_SIZE-1) {
- /* output audible bell if buffer is full
- * "\a" does not work, at least on windows */
- telnet_write(connection, "\x07", 1);
- } else if (t_con->line_cursor == t_con->line_size) {
- telnet_write(connection, buf_p, 1);
- t_con->line[t_con->line_size++] = *buf_p;
- t_con->line_cursor++;
- } else {
- int i;
- memmove(t_con->line + t_con->line_cursor + 1,
- t_con->line + t_con->line_cursor,
- t_con->line_size - t_con->line_cursor);
- t_con->line[t_con->line_cursor] = *buf_p;
- t_con->line_size++;
- telnet_write(connection,
- t_con->line + t_con->line_cursor,
- t_con->line_size - t_con->line_cursor);
- t_con->line_cursor++;
- for (i = t_con->line_cursor; i < t_con->line_size; i++)
- telnet_write(connection, "\b", 1);
- }
- } else { /* non-printable */
- if (*buf_p == 0x1b) { /* escape */
- t_con->state = TELNET_STATE_ESCAPE;
- t_con->last_escape = '\x00';
- } else if ((*buf_p == 0xd) || (*buf_p == 0xa)) { /* CR/LF */
- int retval;
-
- /* skip over combinations with CR/LF and NUL characters */
- if ((bytes_read > 1) && ((*(buf_p + 1) == 0xa) ||
- (*(buf_p + 1) == 0xd))) {
- buf_p++;
- bytes_read--;
- }
- if ((bytes_read > 1) && (*(buf_p + 1) == 0)) {
- buf_p++;
- bytes_read--;
- }
- t_con->line[t_con->line_size] = 0;
-
- telnet_write(connection, "\r\n\x00", 3);
-
- if (strcmp(t_con->line, "history") == 0) {
- int i;
- for (i = 1; i < TELNET_LINE_HISTORY_SIZE; i++) {
- /* the t_con->next_history line contains empty string
- * (unless NULL), thus it is not printed */
- char *history_line = t_con->history[(t_con->
- next_history + i) %
- TELNET_LINE_HISTORY_SIZE];
- if (history_line) {
- telnet_write(connection, history_line,
- strlen(history_line));
- telnet_write(connection, "\r\n\x00", 3);
- }
- }
- t_con->line_size = 0;
- t_con->line_cursor = 0;
- continue;
- }
-
- /* save only non-blank not repeating lines in the history */
- char *prev_line = t_con->history[(t_con->current_history > 0) ?
- t_con->current_history - 1 : TELNET_LINE_HISTORY_SIZE-1];
- if (*t_con->line && (prev_line == NULL ||
- strcmp(t_con->line, prev_line))) {
- /* if the history slot is already taken, free it */
- if (t_con->history[t_con->next_history])
- free(t_con->history[t_con->next_history]);
-
- /* add line to history */
- t_con->history[t_con->next_history] = strdup(t_con->line);
-
- /* wrap history at TELNET_LINE_HISTORY_SIZE */
- t_con->next_history = (t_con->next_history + 1) %
- TELNET_LINE_HISTORY_SIZE;
-
- /* current history line starts at the new entry */
- t_con->current_history =
- t_con->next_history;
-
- if (t_con->history[t_con->current_history])
- free(t_con->history[t_con->current_history]);
- t_con->history[t_con->current_history] = strdup("");
- }
-
- t_con->line_size = 0;
-
- /* to suppress prompt in log callback during command execution */
- t_con->line_cursor = -1;
-
- if (strcmp(t_con->line, "shutdown") == 0)
- telnet_save_history(t_con);
-
- retval = command_run_line(command_context, t_con->line);
-
- t_con->line_cursor = 0;
-
- if (retval == ERROR_COMMAND_CLOSE_CONNECTION)
- return ERROR_SERVER_REMOTE_CLOSED;
-
- /* the prompt is always * placed at the line beginning */
- telnet_write(connection, "\r", 1);
-
- retval = telnet_prompt(connection);
- if (retval == ERROR_SERVER_REMOTE_CLOSED)
- return ERROR_SERVER_REMOTE_CLOSED;
-
- } else if ((*buf_p == 0x7f) || (*buf_p == 0x8)) { /* delete character */
- if (t_con->line_cursor > 0) {
- if (t_con->line_cursor != t_con->line_size) {
- int i;
- telnet_write(connection, "\b", 1);
- t_con->line_cursor--;
- t_con->line_size--;
- memmove(t_con->line + t_con->line_cursor,
- t_con->line + t_con->line_cursor + 1,
- t_con->line_size -
- t_con->line_cursor);
-
- telnet_write(connection,
- t_con->line + t_con->line_cursor,
- t_con->line_size -
- t_con->line_cursor);
- telnet_write(connection, " \b", 2);
- for (i = t_con->line_cursor; i < t_con->line_size; i++)
- telnet_write(connection, "\b", 1);
- } else {
- t_con->line_size--;
- t_con->line_cursor--;
- /* back space: move the 'printer' head one char
- * back, overwrite with space, move back again */
- telnet_write(connection, "\b \b", 3);
- }
- }
- } else if (*buf_p == 0x15) /* clear line */
- telnet_clear_line(connection, t_con);
- else if (*buf_p == CTRL('B')) { /* cursor left */
- if (t_con->line_cursor > 0) {
- telnet_write(connection, "\b", 1);
- t_con->line_cursor--;
- }
- t_con->state = TELNET_STATE_DATA;
- } else if (*buf_p == CTRL('F')) { /* cursor right */
- if (t_con->line_cursor < t_con->line_size)
- telnet_write(connection, t_con->line + t_con->line_cursor++, 1);
- t_con->state = TELNET_STATE_DATA;
- } else if (*buf_p == CTRL('P')) /* cursor up */
- telnet_history_up(connection);
- else if (*buf_p == CTRL('N')) /* cursor down */
- telnet_history_down(connection);
- else
- LOG_DEBUG("unhandled nonprintable: %2.2x", *buf_p);
- }
- }
- break;
- case TELNET_STATE_IAC:
- switch (*buf_p) {
- case 0xfe:
- t_con->state = TELNET_STATE_DONT;
- break;
- case 0xfd:
- t_con->state = TELNET_STATE_DO;
- break;
- case 0xfc:
- t_con->state = TELNET_STATE_WONT;
- break;
- case 0xfb:
- t_con->state = TELNET_STATE_WILL;
- break;
- }
- break;
- case TELNET_STATE_SB:
- break;
- case TELNET_STATE_SE:
- break;
- case TELNET_STATE_WILL:
- case TELNET_STATE_WONT:
- case TELNET_STATE_DO:
- case TELNET_STATE_DONT:
- t_con->state = TELNET_STATE_DATA;
- break;
- case TELNET_STATE_ESCAPE:
- if (t_con->last_escape == '[') {
- if (*buf_p == 'D') { /* cursor left */
- if (t_con->line_cursor > 0) {
- telnet_write(connection, "\b", 1);
- t_con->line_cursor--;
- }
- t_con->state = TELNET_STATE_DATA;
- } else if (*buf_p == 'C') { /* cursor right */
- if (t_con->line_cursor < t_con->line_size)
- telnet_write(connection,
- t_con->line + t_con->line_cursor++, 1);
- t_con->state = TELNET_STATE_DATA;
- } else if (*buf_p == 'A') { /* cursor up */
- telnet_history_up(connection);
- } else if (*buf_p == 'B') { /* cursor down */
- telnet_history_down(connection);
- } else if (*buf_p == '3')
- t_con->last_escape = *buf_p;
- else
- t_con->state = TELNET_STATE_DATA;
- } else if (t_con->last_escape == '3') {
- /* Remove character */
- if (*buf_p == '~') {
- if (t_con->line_cursor < t_con->line_size) {
- int i;
- t_con->line_size--;
- /* remove char from line buffer */
- memmove(t_con->line + t_con->line_cursor,
- t_con->line + t_con->line_cursor + 1,
- t_con->line_size - t_con->line_cursor);
-
- /* print remainder of buffer */
- telnet_write(connection, t_con->line + t_con->line_cursor,
- t_con->line_size - t_con->line_cursor);
- /* overwrite last char with whitespace */
- telnet_write(connection, " \b", 2);
-
- /* move back to cursor position*/
- for (i = t_con->line_cursor; i < t_con->line_size; i++)
- telnet_write(connection, "\b", 1);
- }
-
- t_con->state = TELNET_STATE_DATA;
- } else
- t_con->state = TELNET_STATE_DATA;
- } else if (t_con->last_escape == '\x00') {
- if (*buf_p == '[')
- t_con->last_escape = *buf_p;
- else
- t_con->state = TELNET_STATE_DATA;
- } else {
- LOG_ERROR("BUG: unexpected value in t_con->last_escape");
- t_con->state = TELNET_STATE_DATA;
- }
-
- break;
- default:
- LOG_ERROR("unknown telnet state");
- exit(-1);
- }
-
- bytes_read--;
- buf_p++;
- }
-
- return ERROR_OK;
- }
-
- static int telnet_connection_closed(struct connection *connection)
- {
- struct telnet_connection *t_con = connection->priv;
- int i;
-
- log_remove_callback(telnet_log_callback, connection);
-
- if (t_con->prompt) {
- free(t_con->prompt);
- t_con->prompt = NULL;
- }
-
- /* save telnet history */
- telnet_save_history(t_con);
-
- for (i = 0; i < TELNET_LINE_HISTORY_SIZE; i++) {
- if (t_con->history[i]) {
- free(t_con->history[i]);
- t_con->history[i] = NULL;
- }
- }
-
- /* if this connection registered a debug-message receiver delete it */
- delete_debug_msg_receiver(connection->cmd_ctx, NULL);
-
- if (connection->priv) {
- free(connection->priv);
- connection->priv = NULL;
- } else
- LOG_ERROR("BUG: connection->priv == NULL");
-
- return ERROR_OK;
- }
-
- int telnet_init(char *banner)
- {
- int ret;
- struct telnet_service *telnet_service;
-
- if (strcmp(telnet_port, "disabled") == 0) {
- LOG_INFO("telnet server disabled");
- return ERROR_OK;
- }
-
- telnet_service = malloc(sizeof(struct telnet_service));
-
- if (!telnet_service) {
- LOG_ERROR("Failed to allocate telnet service.");
- return ERROR_FAIL;
- }
-
- telnet_service->banner = banner;
-
- ret = add_service("telnet", telnet_port, CONNECTION_LIMIT_UNLIMITED,
- telnet_new_connection, telnet_input, telnet_connection_closed,
- telnet_service);
-
- if (ret != ERROR_OK) {
- free(telnet_service);
- return ret;
- }
-
- return ERROR_OK;
- }
-
- /* daemon configuration command telnet_port */
- COMMAND_HANDLER(handle_telnet_port_command)
- {
- return CALL_COMMAND_HANDLER(server_pipe_command, &telnet_port);
- }
-
- COMMAND_HANDLER(handle_exit_command)
- {
- return ERROR_COMMAND_CLOSE_CONNECTION;
- }
-
- static const struct command_registration telnet_command_handlers[] = {
- {
- .name = "exit",
- .handler = handle_exit_command,
- .mode = COMMAND_EXEC,
- .usage = "",
- .help = "exit telnet session",
- },
- {
- .name = "telnet_port",
- .handler = handle_telnet_port_command,
- .mode = COMMAND_ANY,
- .help = "Specify port on which to listen "
- "for incoming telnet connections. "
- "Read help on 'gdb_port'.",
- .usage = "[port_num]",
- },
- COMMAND_REGISTRATION_DONE
- };
-
- int telnet_register_commands(struct command_context *cmd_ctx)
- {
- telnet_port = strdup("4444");
- return register_commands(cmd_ctx, NULL, telnet_command_handlers);
- }
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