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>

1 files changed, 25 insertions, 10 deletions

diff --git a/src/vnet/gre/interface.c b/src/vnet/gre/interface.c
index d624587d8e9..d4476ac4682 100644
--- a/src/vnet/gre/interface.c
+++ b/src/vnet/gre/interface.c
@@ -491,6 +491,7 @@ create_gre_tunnel_command_fn (vlib_main_t * vm,
   u32 num_m_args = 0;
   u8 is_add = 1;
   u32 sw_if_index;
+  clib_error_t *error = NULL;
 
   /* Get a line of input. */
   if (! unformat_user (input, unformat_line_input, line_input))
@@ -508,16 +509,24 @@ create_gre_tunnel_command_fn (vlib_main_t * vm,
     else if (unformat (line_input, "teb"))
       teb = 1;
     else
-      return clib_error_return (0, "unknown input `%U'",
-                                format_unformat_error, input);
+      {
+        error = clib_error_return (0, "unknown input `%U'",
+                                   format_unformat_error, line_input);
+        goto done;
+      }
   }
-  unformat_free (line_input);
 
   if (num_m_args < 2)
-      return clib_error_return (0, "mandatory argument(s) missing");
+    {
+      error = clib_error_return (0, "mandatory argument(s) missing");
+      goto done;
+    }
 
   if (memcmp (&src, &dst, sizeof(src)) == 0)
-      return clib_error_return (0, "src and dst are identical");
+    {
+      error = clib_error_return (0, "src and dst are identical");
+      goto done;
+    }
 
   memset (a, 0, sizeof (*a));
   a->outer_fib_id = outer_fib_id;
@@ -536,15 +545,21 @@ create_gre_tunnel_command_fn (vlib_main_t * vm,
       vlib_cli_output(vm, "%U\n", format_vnet_sw_if_index_name, vnet_get_main(), sw_if_index);
       break;
     case VNET_API_ERROR_INVALID_VALUE:
-      return clib_error_return (0, "GRE tunnel already exists...");
+      error = clib_error_return (0, "GRE tunnel already exists...");
+      goto done;
     case VNET_API_ERROR_NO_SUCH_FIB:
-      return clib_error_return (0, "outer fib ID %d doesn't exist\n",
-                                outer_fib_id);
+      error = clib_error_return (0, "outer fib ID %d doesn't exist\n",
+                                 outer_fib_id);
+      goto done;
     default:
-      return clib_error_return (0, "vnet_gre_add_del_tunnel returned %d", rv);
+      error = clib_error_return (0, "vnet_gre_add_del_tunnel returned %d", rv);
+      goto done;
     }
 
-  return 0;
+done:
+  unformat_free (line_input);
+
+  return error;
 }
 
 VLIB_CLI_COMMAND (create_gre_tunnel_command, static) = {