Re: [nft PATCH v2] evaluate: fix check for unknown in cmd_op_to_name

[Phil Sutter <phil@nwl.cc>]

On Wed, Feb 07, 2024 at 12:27:57PM +0000, 谢致邦 (XIE Zhibang) wrote:
> Example:
> nft --debug=all destroy table ip missingtable
> 
> Before:
> Evaluate unknown
> 
> After:
> Evaluate destroy
> 
> Fixes: e1dfd5cc4c46 ("src: add support to command "destroy"")
> Signed-off-by: 谢致邦 (XIE Zhibang) <Yeking@Red54.com>
> ---
> V1 -> V2: Update subject and message
> 
>  src/evaluate.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/src/evaluate.c b/src/evaluate.c
> index 68cfd7765381..57da4044e8c0 100644
> --- a/src/evaluate.c
> +++ b/src/evaluate.c
> @@ -6048,7 +6048,7 @@ static const char * const cmd_op_name[] = {
>  
>  static const char *cmd_op_to_name(enum cmd_ops op)
>  {
> -	if (op > CMD_DESCRIBE)
> +	if (op > CMD_DESTROY)
>  		return "unknown";
>  
>  	return cmd_op_name[op];

Maybe eliminate this source of error once and for all by making it:

| if (op >= array_size(cmd_op_name)

We may still return a NULL pointer if there are uninitialized array
elements, but it's used for format strings only so should not harm.

Cheers, Phil