Pavel Chromy: telnet line buffer size checking, history does not store repeating...
[openocd.git] / src / server / telnet_server.c
index 95fe422bf82f21a503c624f66434802a41b952c5..73579e4ba0be40430c485e21592576e790870a02 100644 (file)
@@ -47,9 +47,9 @@ static char *negotiate =
                "\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 - '@')
-       
+
 /* 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!
@@ -72,18 +72,18 @@ int telnet_prompt(connection_t *connection)
 {
        telnet_connection_t *t_con = connection->priv;
 
-    telnet_write(connection, "\r", 1); /* the prompt is always placed at the line beginning */
+       telnet_write(connection, "\r", 1); /* the prompt is always placed at the line beginning */
        return telnet_write(connection, t_con->prompt, strlen(t_con->prompt));
 }
 
 int telnet_outputline(connection_t *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
@@ -100,32 +100,40 @@ int telnet_outputline(connection_t *connection, const char *line)
                        line += len;
                }
        }
-       
+
        return ERROR_OK;
 }
 
 int telnet_output(struct command_context_s *cmd_ctx, char* line)
 {
        connection_t *connection = cmd_ctx->output_handler_priv;
-       
+
        return telnet_outputline(connection, line);
 }
 
-void telnet_log_callback(void *priv, const char *file, int line, 
+void telnet_log_callback(void *priv, const char *file, int line,
                const char *function, const char *string)
 {
        connection_t *connection = priv;
        telnet_connection_t *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 */
        telnet_write(connection, "\r", 1);
        for (i = strlen(t_con->prompt) + t_con->line_size; i>0; i-=16)
                telnet_write(connection, "                ", i>16 ? 16 : i);
-
        telnet_write(connection, "\r", 1);
+
+       /* 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);
@@ -152,9 +160,9 @@ int telnet_new_connection(connection_t *connection)
        telnet_connection_t *telnet_connection = malloc(sizeof(telnet_connection_t));
        telnet_service_t *telnet_service = connection->service->priv;
        int i;
-       
+
        connection->priv = telnet_connection;
-       
+
        /* initialize telnet connection information */
        telnet_connection->closed = 0;
        telnet_connection->line_size = 0;
@@ -162,22 +170,22 @@ int telnet_new_connection(connection_t *connection)
        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\0", 3);
        }
-       
+
        telnet_prompt(connection);
-       
+
        /* initialize history */
        for (i = 0; i < TELNET_LINE_HISTORY_SIZE; i++)
        {
@@ -187,11 +195,11 @@ int telnet_new_connection(connection_t *connection)
        telnet_connection->current_history = 0;
 
        target_register_event_callback(telnet_target_callback_event_handler, connection->cmd_ctx);
-       
+
        log_add_callback(telnet_log_callback, connection);
 
 
-       
+
        return ERROR_OK;
 }
 
@@ -219,9 +227,9 @@ int telnet_input(connection_t *connection)
        char *buf_p;
        telnet_connection_t *t_con = connection->priv;
        command_context_t *command_context = connection->cmd_ctx;
-       
+
        bytes_read = read_socket(connection->fd, buffer, TELNET_BUFFER_SIZE);
-       
+
        if (bytes_read == 0)
                return ERROR_SERVER_REMOTE_CLOSED;
        else if (bytes_read == -1)
@@ -229,7 +237,7 @@ int telnet_input(connection_t *connection)
                ERROR("error during read: %s", strerror(errno));
                return ERROR_SERVER_REMOTE_CLOSED;
        }
-       
+
        buf_p = buffer;
        while (bytes_read)
        {
@@ -244,9 +252,15 @@ int telnet_input(connection_t *connection)
                                {
                                        if (isprint(*buf_p)) /* printable character */
                                        {
-                                               telnet_write(connection, buf_p, 1);
-                                               if (t_con->line_cursor == t_con->line_size)
+                                               /* 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 */
+                                                       telnet_write(connection, "\x07", 1); /* "\a" does not work, at least on windows */
+                                               }
+                                               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++;
                                                }
@@ -254,9 +268,10 @@ int telnet_input(connection_t *connection)
                                                {
                                                        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[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);
@@ -273,30 +288,32 @@ int telnet_input(connection_t *connection)
                                                else if ((*buf_p == 0xd) || (*buf_p == 0xa)) /* CR/LF */
                                                {
                                                        int retval;
-                                                       
-                                                       /* skip over combinations with CR/LF + NUL */
-                                                       if (((*(buf_p + 1) == 0xa) || (*(buf_p + 1) == 0xd)) && (bytes_read > 1))
+
+                                                       /* 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 ((*(buf_p + 1) == 0) && (bytes_read > 1))
+                                                       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 = 0; i < TELNET_LINE_HISTORY_SIZE; i++)
+                                                               for (i = 1; i < TELNET_LINE_HISTORY_SIZE; i++)
                                                                {
-                                                                       if (t_con->history[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, t_con->history[i], strlen(t_con->history[i]));
+                                                                               telnet_write(connection, history_line, strlen(history_line));
                                                                                telnet_write(connection, "\r\n\x00", 3);
                                                                        }
                                                                }
@@ -304,43 +321,46 @@ int telnet_input(connection_t *connection)
                                                                t_con->line_cursor = 0;
                                                                continue;
                                                        }
-                                                       
-                                                       /* Save only non-blank lines in the history */
-                                                       if (t_con->line_size > 0)
+
+                                                       /* 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;
-                                                       t_con->line_cursor = 0;
 
+                                                       t_con->line_cursor = -1; /* to supress prompt in log callback during command execution */
                                                        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;
 
                                                        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 */
                                                {
@@ -353,7 +373,7 @@ int telnet_input(connection_t *connection)
                                                                        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++)
@@ -453,7 +473,7 @@ int telnet_input(connection_t *connection)
                                                        telnet_clear_line(connection, t_con);
                                                        t_con->line_size = strlen(t_con->history[last_history]);
                                                        t_con->line_cursor = t_con->line_size;
-                                                       memcpy(t_con->line, t_con->history[last_history], t_con->line_size + 1);
+                                                       memcpy(t_con->line, t_con->history[last_history], t_con->line_size);
                                                        telnet_write(connection, t_con->line, t_con->line_size);
                                                        t_con->current_history = last_history;
                                                }
@@ -467,7 +487,7 @@ int telnet_input(connection_t *connection)
                                                        telnet_clear_line(connection, t_con);
                                                        t_con->line_size = strlen(t_con->history[next_history]);
                                                        t_con->line_cursor = t_con->line_size;
-                                                       memcpy(t_con->line, t_con->history[next_history], t_con->line_size + 1);
+                                                       memcpy(t_con->line, t_con->history[next_history], t_con->line_size);
                                                        telnet_write(connection, t_con->line, t_con->line_size);
                                                        t_con->current_history = next_history;
                                                }
@@ -493,19 +513,19 @@ int telnet_input(connection_t *connection)
                                                        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
@@ -529,7 +549,7 @@ int telnet_input(connection_t *connection)
                                        ERROR("BUG: unexpected value in t_con->last_escape");
                                        t_con->state = TELNET_STATE_DATA;
                                }
-                               
+
                                break;
                        default:
                                ERROR("unknown telnet state");
@@ -539,7 +559,7 @@ int telnet_input(connection_t *connection)
                bytes_read--;
                buf_p++;
        }
-       
+
        return ERROR_OK;
 }
 
@@ -547,15 +567,15 @@ int telnet_connection_closed(connection_t *connection)
 {
        telnet_connection_t *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;
        }
-       
+
        for (i = 0; i < TELNET_LINE_HISTORY_SIZE; i++)
        {
                if (t_con->history[i])
@@ -564,10 +584,10 @@ int telnet_connection_closed(connection_t *connection)
                        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);
@@ -577,7 +597,7 @@ int telnet_connection_closed(connection_t *connection)
        {
                ERROR("BUG: connection->priv == NULL");
        }
-       
+
        target_unregister_event_callback(telnet_target_callback_event_handler, connection->cmd_ctx);
 
        return ERROR_OK;
@@ -588,27 +608,27 @@ int telnet_set_prompt(connection_t *connection, char *prompt)
        telnet_connection_t *t_con = connection->priv;
 
        if (t_con->prompt != NULL)
-           free(t_con->prompt);
-       
+               free(t_con->prompt);
+
        t_con->prompt = strdup(prompt);
-       
+
        return ERROR_OK;
 }
 
 int telnet_init(char *banner)
 {
        telnet_service_t *telnet_service = malloc(sizeof(telnet_service_t));
-       
+
        if (telnet_port == 0)
        {
                WARNING("no telnet port specified, using default port 4444");
                telnet_port = 4444;
        }
-       
+
        telnet_service->banner = banner;
-       
+
        add_service("telnet", CONNECTION_TELNET, telnet_port, 1, telnet_new_connection, telnet_input, telnet_connection_closed, telnet_service);
-       
+
        return ERROR_OK;
 }
 
@@ -616,10 +636,10 @@ int telnet_register_commands(command_context_t *command_context)
 {
        register_command(command_context, NULL, "exit", handle_exit_command,
                                         COMMAND_EXEC, "exit telnet session");
-       
+
        register_command(command_context, NULL, "telnet_port", handle_telnet_port_command,
                                         COMMAND_CONFIG, "");
-       
+
        return ERROR_OK;
 }
 

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