Re: [PATCH v4 06/17] pif: Limit pif names to 128 bytes

[Jon Maloy <jmaloy@redhat.com>]

On 2026-04-21 00:42, David Gibson wrote:
> All current pif names are quite short, and we expect them to remain short
> when/if we allow arbitrary pifs.  However, because of the structure of
> the current code we don't enforce any limit on the length.
> 
> This will become more important with dynamic configuration updates, so
> start enforcing a length limit.  Specifically we allow pif names to be up
> to 128 bytes (PIF_NAME_SIZE), including the terminating \0.  This is
> more or less arbitrary, but seems like it should be comfortably enough for
> all the cases we have in mind.
> 
> Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

Reviewed-by: Jon Maloy <jmaloy@redhat.com>
If you fix a typo below.
> ---
>   pif.c | 2 +-
>   pif.h | 5 ++++-
>   2 files changed, 5 insertions(+), 2 deletions(-)
> 
> diff --git a/pif.c b/pif.c
> index 1e807247..d5e31613 100644
> --- a/pif.c
> +++ b/pif.c
> @@ -17,7 +17,7 @@
>   #include "inany.h"
>   #include "epoll_ctl.h"
>   
> -const char *pif_type_str[] = {
> +const char pif_type_str[][PIF_NAME_SIZE] = {
>   	[PIF_NONE]		= "<none>",
>   	[PIF_HOST]		= "HOST",
>   	[PIF_TAP]		= "TAP",
> diff --git a/pif.h b/pif.h
> index 7bb58e5c..90dd3a32 100644
> --- a/pif.h
> +++ b/pif.h
> @@ -35,7 +35,9 @@ enum pif_type {
>   	PIF_NUM_TYPES,
>   };
>   
> -extern const char *pif_type_str[];
> +/* Maxmimum size of a pif name, including \0 */

s/Maxmimum/Maximum/g


> +#define	PIF_NAME_SIZE	(128)
> +extern const char pif_type_str[][PIF_NAME_SIZE];
>   
>   static inline const char *pif_type(enum pif_type pt)
>   {
> @@ -43,6 +45,7 @@ static inline const char *pif_type(enum pif_type pt)
>   		return pif_type_str[pt];
>   	else
>   		return "?";
> +	static_assert(sizeof("?") <= PIF_NAME_SIZE);
>   }
>   
>   static inline const char *pif_name(uint8_t pif)