server/telnet: Handle Ctrl+K
[fw/openocd] / src / server / telnet_server.c
index 5d2e3bc9c15f30b7efa899580a2ba2cd80336573..407ab68aefcd74d41d31f205e6e16fb3828cbef2 100644 (file)
@@ -19,9 +19,7 @@
  *   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, write to the                         *
- *   Free Software Foundation, Inc.,                                       *
- *   59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.             *
+ *   along with this program.  If not, see <http://www.gnu.org/licenses/>. *
  ***************************************************************************/
 
 #ifdef HAVE_CONFIG_H
@@ -30,8 +28,9 @@
 
 #include "telnet_server.h"
 #include <target/target_request.h>
+#include <helper/configuration.h>
 
-static const char *telnet_port;
+static char *telnet_port;
 
 static char *negotiate =
        "\xFF\xFB\x03"                  /* IAC WILL Suppress Go Ahead */
@@ -40,6 +39,7 @@ static char *negotiate =
        "\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
@@ -54,7 +54,7 @@ static int telnet_write(struct connection *connection, const void *data,
 
        if (connection_write(connection, data, len) == len)
                return ERROR_OK;
-       t_con->closed = 1;
+       t_con->closed = true;
        return ERROR_SERVER_REMOTE_CLOSED;
 }
 
@@ -101,46 +101,136 @@ static void telnet_log_callback(void *priv, const char *file, unsigned line,
 {
        struct connection *connection = priv;
        struct telnet_connection *t_con = connection->priv;
-       int i;
+       size_t i;
+       size_t tmp;
 
-       /* if there is no prompt, simply output the message */
-       if (t_con->line_cursor < 0) {
+       /* If the prompt is not visible, simply output the message. */
+       if (!t_con->prompt_visible) {
                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);
+       /* Clear the command line. */
+       tmp = strlen(t_con->prompt) + t_con->line_size;
+
+       for (i = 0; i < tmp; i += 16)
+               telnet_write(connection, "\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b",
+                       MIN(tmp - i, 16));
+
+       for (i = 0; i < tmp; i += 16)
+               telnet_write(connection, "                ", MIN(tmp - i, 16));
+
+       for (i = 0; i < tmp; i += 16)
+               telnet_write(connection, "\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b",
+                       MIN(tmp - i, 16));
 
-       /* output the message */
        telnet_outputline(connection, string);
 
-       /* put the command line to its previous state */
+       /* 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--)
+
+       for (i = t_con->line_cursor; i < t_con->line_size; 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 = malloc(sizeof(struct telnet_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->closed = false;
        telnet_connection->line_size = 0;
        telnet_connection->line_cursor = 0;
-       telnet_connection->option_size = 0;
        telnet_connection->prompt = strdup("> ");
+       telnet_connection->prompt_visible = true;
        telnet_connection->state = TELNET_STATE_DATA;
 
        /* output goes through telnet connection */
@@ -155,8 +245,8 @@ static int telnet_new_connection(struct connection *connection)
                telnet_write(connection, "\r\n", 2);
        }
 
-       telnet_write(connection, "\r", 1);      /* the prompt is always placed at the line beginning
-                                                **/
+       /* the prompt is always placed at the line beginning */
+       telnet_write(connection, "\r", 1);
        telnet_prompt(connection);
 
        /* initialize history */
@@ -164,6 +254,7 @@ static int telnet_new_connection(struct connection *connection)
                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);
 
@@ -187,6 +278,94 @@ static void telnet_clear_line(struct connection *connection,
        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;
+
+       size_t 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;
+       size_t next_history;
+
+       next_history = (t_con->current_history + 1) % TELNET_LINE_HISTORY_SIZE;
+       telnet_history_go(connection, next_history);
+}
+
+static int telnet_history_print(struct connection *connection)
+{
+       struct telnet_connection *tc;
+
+       tc = connection->priv;
+
+       for (size_t i = 1; i < TELNET_LINE_HISTORY_SIZE; i++) {
+               char *line;
+
+               /*
+                * The tc->next_history line contains empty string (unless NULL), thus
+                * it is not printed.
+                */
+               line = tc->history[(tc->next_history + i) % TELNET_LINE_HISTORY_SIZE];
+
+               if (line) {
+                       telnet_write(connection, line, strlen(line));
+                       telnet_write(connection, "\r\n\x00", 3);
+               }
+       }
+
+       tc->line_size = 0;
+       tc->line_cursor = 0;
+
+       /* The prompt is always placed at the line beginning. */
+       telnet_write(connection, "\r", 1);
+
+       return telnet_prompt(connection);
+}
+
+static void telnet_move_cursor(struct connection *connection, size_t pos)
+{
+       struct telnet_connection *tc;
+       size_t tmp;
+
+       tc = connection->priv;
+
+       if (pos < tc->line_cursor) {
+               tmp = tc->line_cursor - pos;
+
+               for (size_t i = 0; i < tmp; i += 16)
+                       telnet_write(connection, "\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b",
+                               MIN(tmp - i, 16));
+       } else {
+               tmp = pos - tc->line_cursor;
+
+               for (size_t i = 0; i < tmp; i += 16)
+                       telnet_write(connection, tc->line + tc->line_cursor + i,
+                               MIN(tmp - i, 16));
+       }
+
+       tc->line_cursor = pos;
+}
+
 static int telnet_input(struct connection *connection)
 {
        int bytes_read;
@@ -213,25 +392,17 @@ static int telnet_input(struct connection *connection)
                                else {
                                        if (isprint(*buf_p)) {  /* printable character */
                                                /* watch buffer size leaving one spare character for
-                                                *string null termination */
+                                                * 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
-                                                                                                **/
+                                                       /* 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;
+                                                       size_t 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);
@@ -248,13 +419,10 @@ static int telnet_input(struct connection *connection)
                                                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
-                                                                                                **/
+                                               } else if ((*buf_p == 0xd) || (*buf_p == 0xa)) {        /* CR/LF */
                                                        int retval;
 
-                                                       /* skip over combinations with CR/LF and NUL
-                                                        *characters */
+                                                       /* skip over combinations with CR/LF and NUL characters */
                                                        if ((bytes_read > 1) && ((*(buf_p + 1) == 0xa) ||
                                                                        (*(buf_p + 1) == 0xd))) {
                                                                buf_p++;
@@ -269,91 +437,64 @@ static int telnet_input(struct connection *connection)
                                                        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;
+                                                               retval = telnet_history_print(connection);
+
+                                                               if (retval != ERROR_OK)
+                                                                       return retval;
+
                                                                continue;
                                                        }
 
-                                                       /* save only non-blank not repeating lines
-                                                        *in the history */
+                                                       /* 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]);
+                                                               /* 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 */
+                                                               /* 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 */
+                                                               /* 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]);
+                                                               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 = -1;        /* to supress prompt
-                                                                                *in log callback
-                                                                                *during command
-                                                                                *execution */
+                                                       /* 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;
 
-                                                       telnet_write(connection, "\r", 1);              /*
-                                                                                                *the
-                                                                                                *prompt
-                                                                                                *is
-                                                                                                *always
-                                                                                                *placed
-                                                                                                *at
-                                                                                                *the
-                                                                                                *line
-                                                                                                *beginning
-                                                                                                **/
+                                                       /* 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
-                                                                                                **/
+                                               } 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;
+                                                                       size_t i;
                                                                        telnet_write(connection, "\b", 1);
                                                                        t_con->line_cursor--;
                                                                        t_con->line_size--;
@@ -372,10 +513,8 @@ static int telnet_input(struct connection *connection)
                                                                } else {
                                                                        t_con->line_size--;
                                                                        t_con->line_cursor--;
-                                                                       /* back space: move the
-                                                                        *'printer' head one char
-                                                                        *back, overwrite with
-                                                                        *space, move back again */
+                                                                       /* back space: move the 'printer' head one char
+                                                                        * back, overwrite with space, move back again */
                                                                        telnet_write(connection, "\b \b", 3);
                                                                }
                                                        }
@@ -391,6 +530,24 @@ static int telnet_input(struct connection *connection)
                                                        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 if (*buf_p == CTRL('A'))
+                                                       telnet_move_cursor(connection, 0);
+                                               else if (*buf_p == CTRL('E'))
+                                                       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;
+                                                       }
                                                } else
                                                        LOG_DEBUG("unhandled nonprintable: %2.2x", *buf_p);
                                        }
@@ -436,28 +593,9 @@ static int telnet_input(struct connection *connection)
                                                                        t_con->line + t_con->line_cursor++, 1);
                                                t_con->state = TELNET_STATE_DATA;
                                        } else if (*buf_p == 'A') {     /* cursor up */
-                                               int last_history = (t_con->current_history > 0) ?
-                                                               t_con->current_history - 1 : TELNET_LINE_HISTORY_SIZE-1;
-                                               if (t_con->history[last_history]) {
-                                                       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);
-                                                       telnet_write(connection, t_con->line, t_con->line_size);
-                                                       t_con->current_history = last_history;
-                                               }
-                                               t_con->state = TELNET_STATE_DATA;
+                                               telnet_history_up(connection);
                                        } else if (*buf_p == 'B') {     /* cursor down */
-                                               int next_history = (t_con->current_history + 1) % TELNET_LINE_HISTORY_SIZE;
-                                               if (t_con->history[next_history]) {
-                                                       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);
-                                                       telnet_write(connection, t_con->line, t_con->line_size);
-                                                       t_con->current_history = next_history;
-                                               }
-                                               t_con->state = TELNET_STATE_DATA;
+                                               telnet_history_down(connection);
                                        } else if (*buf_p == '3')
                                                t_con->last_escape = *buf_p;
                                        else
@@ -466,7 +604,7 @@ static int telnet_input(struct connection *connection)
                                        /* Remove character */
                                        if (*buf_p == '~') {
                                                if (t_con->line_cursor < t_con->line_size) {
-                                                       int i;
+                                                       size_t i;
                                                        t_con->line_size--;
                                                        /* remove char from line buffer */
                                                        memmove(t_con->line + t_con->line_cursor,
@@ -500,7 +638,7 @@ static int telnet_input(struct connection *connection)
                                break;
                        default:
                                LOG_ERROR("unknown telnet state");
-                               exit(-1);
+                               return ERROR_FAIL;
                }
 
                bytes_read--;
@@ -517,26 +655,22 @@ static int telnet_connection_closed(struct connection *connection)
 
        log_remove_callback(telnet_log_callback, connection);
 
-       if (t_con->prompt) {
-               free(t_con->prompt);
-               t_con->prompt = NULL;
-       }
+       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;
-               }
+               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");
+       free(connection->priv);
+       connection->priv = NULL;
 
        return ERROR_OK;
 }
@@ -548,17 +682,26 @@ int telnet_init(char *banner)
                return ERROR_OK;
        }
 
-       struct telnet_service *telnet_service = malloc(sizeof(struct telnet_service));
+       struct telnet_service *telnet_service =
+               malloc(sizeof(struct telnet_service));
+
+       if (!telnet_service) {
+               LOG_ERROR("Failed to allocate telnet service.");
+               return ERROR_FAIL;
+       }
 
        telnet_service->banner = banner;
 
-       return add_service("telnet",
-               telnet_port,
-               1,
-               telnet_new_connection,
-               telnet_input,
-               telnet_connection_closed,
+       int 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 */
@@ -583,7 +726,7 @@ static const struct command_registration telnet_command_handlers[] = {
        {
                .name = "telnet_port",
                .handler = handle_telnet_port_command,
-               .mode = COMMAND_ANY,
+               .mode = COMMAND_CONFIG,
                .help = "Specify port on which to listen "
                        "for incoming telnet connections.  "
                        "Read help on 'gdb_port'.",
@@ -597,3 +740,8 @@ int telnet_register_commands(struct command_context *cmd_ctx)
        telnet_port = strdup("4444");
        return register_commands(cmd_ctx, NULL, telnet_command_handlers);
 }
+
+void telnet_service_free(void)
+{
+       free(telnet_port);
+}