VPP-635: CLI Memory leak with invalid parameter

In the CLI parsing, below is a common pattern:
  /* Get a line of input. */
  if (!unformat_user (input, unformat_line_input, line_input))
    return 0;

  while (unformat_check_input (line_input) != UNFORMAT_END_OF_INPUT)
    {
      if (unformat (line_input, "x"))
	x = 1;
      :
      else
	return clib_error_return (0, "unknown input `%U'",
				  format_unformat_error, line_input);
    }
  unformat_free (line_input);

The 'else' returns if an unknown string is encountered. There a memory
leak because the 'unformat_free(line_input)' is not called. There is a
large number of instances of this pattern.

Replaced the previous pattern with:
  /* Get a line of input. */
  if (!unformat_user (input, unformat_line_input, line_input))
    return 0;

  while (unformat_check_input (line_input) != UNFORMAT_END_OF_INPUT)
    {
      if (unformat (line_input, "x"))
	x = 1;
      :
      else
        {
	  error = clib_error_return (0, "unknown input `%U'",
				     format_unformat_error, line_input);
	  goto done:
        }
    }

  /* ...Remaining code... */

done:
  unformat_free (line_input);
  return error;
}

In multiple files, 'unformat_free (line_input);' was never called, so
there was a memory leak whether an invalid string was entered or not.

Also, there were multiple instance where:
	  error = clib_error_return (0, "unknown input `%U'",
				     format_unformat_error, line_input);
used 'input' as the last parameter instead of 'line_input'. The result
is that output did not contain the substring in error, instead just an
empty string. Fixed all of those as well.

There are a lot of file, and very mind numbing work, so tried to keep
it to a pattern to avoid mistakes.

Change-Id: I8902f0c32a47dd7fb3bb3471a89818571702f1d2
Signed-off-by: Billy McFall <bmcfall@redhat.com>
Signed-off-by: Dave Barach <dave@barachs.net>
diff --git a/src/vlib/unix/cli.c b/src/vlib/unix/cli.c
index 69fca6e..88e2453 100644
--- a/src/vlib/unix/cli.c
+++ b/src/vlib/unix/cli.c
@@ -2835,6 +2835,7 @@
   unix_cli_main_t *cm = &unix_cli_main;
   unix_cli_file_t *cf;
   unformat_input_t _line_input, *line_input = &_line_input;
+  clib_error_t *error = 0;
 
   if (!unformat_user (input, unformat_line_input, line_input))
     return 0;
@@ -2852,13 +2853,17 @@
 			 "Pager limit set to %u lines; note, this is global.\n",
 			 um->cli_pager_buffer_limit);
       else
-	return clib_error_return (0, "unknown parameter: `%U`",
-				  format_unformat_error, line_input);
+	{
+	  error = clib_error_return (0, "unknown parameter: `%U`",
+				     format_unformat_error, line_input);
+	  goto done;
+	}
     }
 
+done:
   unformat_free (line_input);
 
-  return 0;
+  return error;
 }
 
 /*?
@@ -2886,6 +2891,7 @@
   unix_cli_file_t *cf;
   unformat_input_t _line_input, *line_input = &_line_input;
   u32 limit;
+  clib_error_t *error = 0;
 
   if (!unformat_user (input, unformat_line_input, line_input))
     return 0;
@@ -2901,8 +2907,11 @@
       else if (unformat (line_input, "limit %u", &cf->history_limit))
 	;
       else
-	return clib_error_return (0, "unknown parameter: `%U`",
-				  format_unformat_error, line_input);
+	{
+	  error = clib_error_return (0, "unknown parameter: `%U`",
+				     format_unformat_error, line_input);
+	  goto done;
+	}
 
       /* If we reduced history size, or turned it off, purge the history */
       limit = cf->has_history ? cf->history_limit : 0;
@@ -2914,9 +2923,10 @@
 	}
     }
 
+done:
   unformat_free (line_input);
 
-  return 0;
+  return error;
 }
 
 /*?