Debug/Telnet CLI enhancements

A fairly comprehensive re-work of the built-in debug and telnet CLI
to add various command line editing features and to add command history
to the debug CLI.

This may seem like a large change but a good amount of it is merely
reworking the existing CLI code (which changed its indent level).

The features this patch enables include:

- Enable history in the debug CLI.
- Put both stdin and telnet connections in char-by-char mode.
- Echo from the server, not the client, for more control.
- Add a mostly no-op but fairly complete Telnet protocol processor.
- Perform control code parsing on the input byte stream to match strings
  of both control codes and ANSI/VT100 escape sequences.
- Up/down keys scroll through the history (like ^P/^N).
- Do CRLF output cooking (\n -> \r\n) for connections that need it.
- Left/right cursor movements, insert/erase at cursor.
- Home/end cursor jumps.
- Jump left/right word at a time (Ctrl-left/right).
- Negotiate the terminal type from Telnet clients. (well, the code doesn’t
  really negotiate, it demands it, but the client is led to believe it
  was a negotiation)
- Read terminal type from TERM variable for the local debug CLI.
- Delete from cursor to end of line (^K). Delete char-right (^D/Del).
- Clear screen (^L) and repaint prompt/current command (on non-ANSI
  terminals it just newlines and repaints the line).

Change-Id: Id274b56ccfd4cc8c19ddc0f478890f21f284262a
Signed-off-by: Chris Luke <chrisy@flirble.org>

1 files changed, 8 insertions, 2 deletions

diff --git a/vlib/vlib/unix/unix.h b/vlib/vlib/unix/unix.h
index 44a8853e356..269b9df5975 100644
--- a/vlib/vlib/unix/unix.h
+++ b/vlib/vlib/unix/unix.h
@@ -41,6 +41,7 @@
 #define included_unix_unix_h
 
 #include <vppinfra/socket.h>
+#include <termios.h>
 
 struct unix_file;
 typedef clib_error_t * (unix_file_function_t) (struct unix_file * f);
@@ -102,10 +103,15 @@ typedef struct {
   /* CLI log file. GIGO. */
   u8 *log_filename;
   int log_fd;
-  /* Don't put telnet connections into character mode */
+  /* Don't put CLI connections into character mode */
   int cli_line_mode;
+
+  /* Maximum amount of command line history to keep per session */
   u32 cli_history_limit;
-  
+
+  /* Store the original state of stdin when it's a tty */
+  struct termios tio_stdin;
+  int tio_isset;
 } unix_main_t;
 
 /* Global main structure. */