From 259e400276e939f7c8503068312e940dc25bdf46 Mon Sep 17 00:00:00 2001 From: Tarek BOCHKATI Date: Wed, 18 Aug 2021 18:41:49 +0100 Subject: [PATCH] server/telnet: simplify telnet_input function running complexity on this file tells that: NOTE: proc telnet_input in file telnet_server.c line 576 nesting depth reached level 8 ==> *seriously consider rewriting the procedure*. Complexity Scores Score | ln-ct | nc-lns| file-name(line): proc-name 319 272 226 src/server/telnet_server.c(576): telnet_input total nc-lns 226 so try to reduce the complexity score of telnet_input function Change-Id: I64ecb0c54da83c27a343f2a1df99fc8f9484572a Signed-off-by: Tarek BOCHKATI Reviewed-on: https://review.openocd.org/c/openocd/+/6440 Tested-by: jenkins Reviewed-by: Oleksij Rempel Reviewed-by: Antonio Borneo --- src/server/telnet_server.c | 299 +++++++++++++++++++++---------------- 1 file changed, 168 insertions(+), 131 deletions(-) diff --git a/src/server/telnet_server.c b/src/server/telnet_server.c index 36b017c58..13fbc3fda 100644 --- a/src/server/telnet_server.c +++ b/src/server/telnet_server.c @@ -320,6 +320,32 @@ static void telnet_history_down(struct connection *connection) telnet_history_go(connection, next_history); } +static void telnet_history_add(struct connection *connection) +{ + struct telnet_connection *t_con = connection->priv; + + /* 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 || strcmp(t_con->line, prev_line))) { + /* if the history slot is already taken, free it */ + 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; + + free(t_con->history[t_con->current_history]); + t_con->history[t_con->current_history] = strdup(""); + } +} + static int telnet_history_print(struct connection *connection) { struct telnet_connection *tc; @@ -423,6 +449,137 @@ static bool telnet_insert(struct connection *connection, const void *data, size_ return true; } +static void telnet_delete_character(struct connection *connection) +{ + struct telnet_connection *t_con = connection->priv; + + if (t_con->line_cursor == 0) + return; + + if (t_con->line_cursor != t_con->line_size) { + size_t 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); + } +} + +static void telnet_remove_character(struct connection *connection) +{ + struct telnet_connection *t_con = connection->priv; + + if (t_con->line_cursor < t_con->line_size) { + size_t 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); + } +} + +static int telnet_exec_line(struct connection *connection) +{ + struct telnet_connection *t_con = connection->priv; + struct command_context *command_context = connection->cmd_ctx; + int retval; + + telnet_write(connection, "\r\n\x00", 3); + + if (strcmp(t_con->line, "history") == 0) { + retval = telnet_history_print(connection); + + if (retval != ERROR_OK) + return retval; + + return ERROR_OK; + } + + telnet_history_add(connection); + + t_con->line_size = 0; + + /* to suppress prompt in log callback during command execution */ + t_con->prompt_visible = false; + + 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; + t_con->prompt_visible = true; + + 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; + + return ERROR_OK; +} + +static void telnet_cut_line_to_end(struct connection *connection) +{ + struct telnet_connection *t_con = connection->priv; + + /* FIXME: currently this function does not save to clipboard */ + + if (t_con->line_cursor < t_con->line_size) { + /* overwrite with space, until end of line, move back */ + for (size_t i = t_con->line_cursor; i < t_con->line_size; i++) + telnet_write(connection, " ", 1); + for (size_t i = t_con->line_cursor; i < t_con->line_size; i++) + telnet_write(connection, "\b", 1); + t_con->line[t_con->line_cursor] = '\0'; + t_con->line_size = t_con->line_cursor; + } +} + +static void telnet_interrupt(struct connection *connection) +{ + struct telnet_connection *t_con = connection->priv; + + /* print '^C' at line end, and display a new command prompt */ + telnet_move_cursor(connection, t_con->line_size); + telnet_write(connection, "^C\n\r", 4); + t_con->line_cursor = 0; + t_con->line_size = 0; + telnet_prompt(connection); +} + static void telnet_auto_complete(struct connection *connection) { struct telnet_connection *t_con = connection->priv; @@ -591,7 +748,6 @@ static int telnet_input(struct connection *connection) 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); @@ -630,108 +786,20 @@ static int telnet_input(struct connection *connection) } t_con->line[t_con->line_size] = 0; - telnet_write(connection, "\r\n\x00", 3); - - if (strcmp(t_con->line, "history") == 0) { - retval = telnet_history_print(connection); - - if (retval != ERROR_OK) - return retval; - - 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 || - strcmp(t_con->line, prev_line))) { - /* if the history slot is already taken, free it */ - 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; - - 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->prompt_visible = false; - - 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; - t_con->prompt_visible = true; - - 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; - + retval = telnet_exec_line(connection); + if (retval != ERROR_OK) + return retval; } 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) { - size_t 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); - } - } + telnet_delete_character(connection); } 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--; - } + telnet_move_cursor(connection, t_con->line_cursor - 1); t_con->state = TELNET_STATE_DATA; } else if (*buf_p == CTRL('C')) { /* interrupt */ - /* print '^C' at line end, and display a new command prompt */ - telnet_move_cursor(connection, t_con->line_size); - telnet_write(connection, "^C\n\r", 4); - t_con->line_cursor = 0; - t_con->line_size = 0; - telnet_prompt(connection); + telnet_interrupt(connection); } 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); + telnet_move_cursor(connection, t_con->line_cursor + 1); t_con->state = TELNET_STATE_DATA; } else if (*buf_p == CTRL('P')) { /* cursor up */ telnet_history_up(connection); @@ -742,15 +810,7 @@ static int telnet_input(struct connection *connection) } else if (*buf_p == CTRL('E')) { /* move the cursor to the end of the line */ telnet_move_cursor(connection, t_con->line_size); } else if (*buf_p == CTRL('K')) { /* kill line to end */ - if (t_con->line_cursor < t_con->line_size) { - /* overwrite with space, until end of line, move back */ - for (size_t i = t_con->line_cursor; i < t_con->line_size; i++) - telnet_write(connection, " ", 1); - for (size_t i = t_con->line_cursor; i < t_con->line_size; i++) - telnet_write(connection, "\b", 1); - t_con->line[t_con->line_cursor] = '\0'; - t_con->line_size = t_con->line_cursor; - } + telnet_cut_line_to_end(connection); } else if (*buf_p == '\t') { telnet_auto_complete(connection); } else { @@ -788,15 +848,10 @@ static int telnet_input(struct connection *connection) 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--; - } + telnet_move_cursor(connection, t_con->line_cursor - 1); 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); + telnet_move_cursor(connection, t_con->line_cursor + 1); t_con->state = TELNET_STATE_DATA; } else if (*buf_p == 'A') { /* cursor up */ telnet_history_up(connection); @@ -816,25 +871,7 @@ static int telnet_input(struct connection *connection) } else if (t_con->last_escape == '3') { /* Remove character */ if (*buf_p == '~') { - if (t_con->line_cursor < t_con->line_size) { - size_t 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); - } - + telnet_remove_character(connection); t_con->state = TELNET_STATE_DATA; } else t_con->state = TELNET_STATE_DATA;