From d10141ef07644fc6a39211d60e811a868d91c575 Mon Sep 17 00:00:00 2001
From: Tarek BOCHKATI <tarek.bouchkati@gmail.com>
Date: Thu, 11 Mar 2021 03:38:54 +0100
Subject: [PATCH] telnet: auto-completion of "registered" commands
auto-completion behavior:
- if there is only one matched command complete the user-command
- else if multiple matches add the common part then in second step
list all matched commands
- sub-commands are handled in the same way
- auto-completion restarts after these characters ';', '[', '{'
Change-Id: I1b81dd19191a5785e68d0bb5cd244e01a4dd0587
Signed-off-by: Tarek BOCHKATI <tarek.bouchkati@gmail.com>
Reviewed-on: http://openocd.zylin.com/6095
Tested-by: jenkins
Reviewed-by: Antonio Borneo <borneo.antonio@gmail.com>
---
src/server/telnet_server.c | 248 +++++++++++++++++++++++++++++++++----
1 file changed, 223 insertions(+), 25 deletions(-)
diff --git a/src/server/telnet_server.c b/src/server/telnet_server.c
index e9de4f033..d5e0353c8 100644
--- a/src/server/telnet_server.c
+++ b/src/server/telnet_server.c
@@ -29,6 +29,7 @@
#include "telnet_server.h"
#include <target/target_request.h>
#include <helper/configuration.h>
+#include <helper/list.h>
static char *telnet_port;
@@ -58,6 +59,13 @@ static int telnet_write(struct connection *connection, const void *data,
return ERROR_SERVER_REMOTE_CLOSED;
}
+/* output an audible bell */
+static int telnet_bell(struct connection *connection)
+{
+ /* ("\a" does not work, at least on windows) */
+ return telnet_write(connection, "\x07", 1);
+}
+
static int telnet_prompt(struct connection *connection)
{
struct telnet_connection *t_con = connection->priv;
@@ -366,6 +374,217 @@ static void telnet_move_cursor(struct connection *connection, size_t pos)
tc->line_cursor = pos;
}
+/* check buffer size leaving one spare character for string null termination */
+static inline bool telnet_can_insert(struct connection *connection, size_t len)
+{
+ struct telnet_connection *t_con = connection->priv;
+
+ return t_con->line_size + len < TELNET_LINE_MAX_SIZE;
+}
+
+/* write to telnet console, and update the telnet_connection members
+ * this function is capable of inserting in the middle of a line
+ * please ensure that data does not contain special characters (\n, \r, \t, \b ...)
+ *
+ * returns false when it fails to insert the requested data
+ */
+static bool telnet_insert(struct connection *connection, const void *data, size_t len)
+{
+ struct telnet_connection *t_con = connection->priv;
+
+ if (!telnet_can_insert(connection, len)) {
+ telnet_bell(connection);
+ return false;
+ }
+
+ if (t_con->line_cursor < t_con->line_size) {
+ /* we have some content after the cursor */
+ memmove(t_con->line + t_con->line_cursor + len,
+ t_con->line + t_con->line_cursor,
+ t_con->line_size - t_con->line_cursor);
+ }
+
+ strncpy(t_con->line + t_con->line_cursor, data, len);
+
+ telnet_write(connection,
+ t_con->line + t_con->line_cursor,
+ t_con->line_size + len - t_con->line_cursor);
+
+ t_con->line_size += len;
+ t_con->line_cursor += len;
+
+ for (size_t i = t_con->line_cursor; i < t_con->line_size; i++)
+ telnet_write(connection, "\b", 1);
+
+ return true;
+}
+
+static void telnet_auto_complete(struct connection *connection)
+{
+ struct telnet_connection *t_con = connection->priv;
+ struct command_context *command_context = connection->cmd_ctx;
+
+ struct cmd_match {
+ char *cmd;
+ struct list_head lh;
+ };
+
+ LIST_HEAD(matches);
+
+ /* user command sequence, either at line beginning
+ * or we start over after these characters ';', '[', '{' */
+ size_t seq_start = (t_con->line_cursor == 0) ? 0 : (t_con->line_cursor - 1);
+ while (seq_start > 0) {
+ char c = t_con->line[seq_start];
+ if (c == ';' || c == '[' || c == '{') {
+ seq_start++;
+ break;
+ }
+
+ seq_start--;
+ }
+
+ /* user command position in the line, ignore leading spaces */
+ size_t usr_cmd_pos = seq_start;
+ while ((usr_cmd_pos < t_con->line_cursor) && isspace(t_con->line[usr_cmd_pos]))
+ usr_cmd_pos++;
+
+ /* user command length */
+ size_t usr_cmd_len = t_con->line_cursor - usr_cmd_pos;
+
+ /* optimize multiple spaces in the user command,
+ * because info commands does not tolerate multiple spaces */
+ size_t optimized_spaces = 0;
+ char query[usr_cmd_len + 1];
+ for (size_t i = 0; i < usr_cmd_len; i++) {
+ if ((i < usr_cmd_len - 1) && isspace(t_con->line[usr_cmd_pos + i])
+ && isspace(t_con->line[usr_cmd_pos + i + 1])) {
+ optimized_spaces++;
+ continue;
+ }
+
+ query[i - optimized_spaces] = t_con->line[usr_cmd_pos + i];
+ }
+
+ usr_cmd_len -= optimized_spaces;
+ query[usr_cmd_len] = '\0';
+
+ /* filter commands */
+ char *query_cmd = alloc_printf("lsort [info commands {%s*}]", query);
+
+ if (!query_cmd) {
+ LOG_ERROR("Out of memory");
+ return;
+ }
+
+ int retval = Jim_EvalSource(command_context->interp, __FILE__, __LINE__, query_cmd);
+ free(query_cmd);
+ if (retval != JIM_OK)
+ return;
+
+ Jim_Obj *list = Jim_GetResult(command_context->interp);
+ Jim_IncrRefCount(list);
+
+ /* common prefix length of the matched commands */
+ size_t common_len = 0;
+ char *first_match = NULL; /* used to compute the common prefix length */
+
+ int len = Jim_ListLength(command_context->interp, list);
+ for (int i = 0; i < len; i++) {
+ Jim_Obj *elem = Jim_ListGetIndex(command_context->interp, list, i);
+ Jim_IncrRefCount(elem);
+
+ char *name = (char *)Jim_GetString(elem, NULL);
+
+ /* validate the command */
+ bool ignore_cmd = false;
+ Jim_Cmd *jim_cmd = Jim_GetCommand(command_context->interp, elem, JIM_NONE);
+
+ if (!jim_cmd)
+ ignore_cmd = true;
+ else {
+ if (!jim_cmd->isproc) {
+ /* ignore commands without handler
+ * and those with COMMAND_CONFIG mode */
+ /* FIXME it's better to use jimcmd_is_ocd_command(jim_cmd)
+ * or command_find_from_name(command_context->interp, name) */
+ struct command *cmd = jim_cmd->u.native.privData;
+ if (!cmd)
+ ignore_cmd = true;
+ /* make Valgrind happy by checking that cmd is not NULL */
+ else if (cmd != NULL && !cmd->handler && !cmd->jim_handler)
+ ignore_cmd = true;
+ else if (cmd != NULL && cmd->mode == COMMAND_CONFIG)
+ ignore_cmd = true;
+ }
+ }
+
+ /* save the command in the prediction list */
+ if (!ignore_cmd) {
+ struct cmd_match *match = calloc(1, sizeof(struct cmd_match));
+ if (!match) {
+ LOG_ERROR("Out of memory");
+ Jim_DecrRefCount(command_context->interp, elem);
+ break; /* break the for loop */
+ }
+
+ if (list_empty(&matches)) {
+ common_len = strlen(name);
+ first_match = name;
+ } else {
+ size_t new_common_len = usr_cmd_len; /* save some loops */
+
+ while (new_common_len < common_len && first_match[new_common_len] == name[new_common_len])
+ new_common_len++;
+
+ common_len = new_common_len;
+ }
+
+ match->cmd = name;
+ list_add_tail(&match->lh, &matches);
+ }
+
+ Jim_DecrRefCount(command_context->interp, elem);
+ }
+ /* end of command filtering */
+
+ /* proceed with auto-completion */
+ if (list_empty(&matches))
+ telnet_bell(connection);
+ else if (common_len == usr_cmd_len && list_is_singular(&matches) && t_con->line_cursor == t_con->line_size)
+ telnet_insert(connection, " ", 1);
+ else if (common_len > usr_cmd_len) {
+ int completion_size = common_len - usr_cmd_len;
+ if (telnet_insert(connection, first_match + usr_cmd_len, completion_size)) {
+ /* in bash this extra space is only added when the cursor in at the end of line */
+ if (list_is_singular(&matches) && t_con->line_cursor == t_con->line_size)
+ telnet_insert(connection, " ", 1);
+ }
+ } else if (!list_is_singular(&matches)) {
+ telnet_write(connection, "\n\r", 2);
+
+ struct cmd_match *match;
+ list_for_each_entry(match, &matches, lh) {
+ telnet_write(connection, match->cmd, strlen(match->cmd));
+ telnet_write(connection, "\n\r", 2);
+ }
+
+ telnet_prompt(connection);
+ telnet_write(connection, t_con->line, t_con->line_size);
+
+ /* restore the terminal visible cursor location */
+ for (size_t i = t_con->line_cursor; i < t_con->line_size; i++)
+ telnet_write(connection, "\b", 1);
+ }
+
+ /* destroy the command_list */
+ struct cmd_match *tmp, *match;
+ list_for_each_entry_safe(match, tmp, &matches, lh)
+ free(match);
+
+ Jim_DecrRefCount(command_context->interp, list);
+}
+
static int telnet_input(struct connection *connection)
{
int bytes_read;
@@ -391,30 +610,7 @@ static int telnet_input(struct connection *connection)
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 {
- 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);
- 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);
- }
+ telnet_insert(connection, buf_p, 1);
} else { /* non-printable */
if (*buf_p == 0x1b) { /* escape */
t_con->state = TELNET_STATE_ESCAPE;
@@ -548,7 +744,9 @@ static int telnet_input(struct connection *connection)
t_con->line[t_con->line_cursor] = '\0';
t_con->line_size = t_con->line_cursor;
}
- } else
+ } else if (*buf_p == '\t')
+ telnet_auto_complete(connection);
+ else
LOG_DEBUG("unhandled nonprintable: %2.2x", *buf_p);
}
}