Re: [PATCH v5 12/18] pesto: Expose list of pifs to pesto and optionally display

[Jon Maloy <jmaloy@redhat.com>]

On 2026-04-21 02:25, David Gibson wrote:
> Extend the dynamic update protocol to expose the pif indices and names
> from a running passt/pasta to the pesto tool.  pesto records that data
> and, if requested with a new --show flag, prints it out.
> 
> Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
> ---
>   Makefile    |   1 +
>   common.h    |   2 +
>   conf.c      |  41 ++++++++++++++++
>   pesto.c     | 132 ++++++++++++++++++++++++++++++++++++++++++++++++++++
>   pesto.h     |  19 +++++++-
>   pif.h       |   4 +-
>   serialise.c |   4 ++
>   serialise.h |   1 +
>   util.h      |   2 -
>   9 files changed, 200 insertions(+), 6 deletions(-)
> 

[...]

> diff --git a/pesto.h b/pesto.h
> index 92d4df3a..ac4c2b58 100644
> --- a/pesto.h
> +++ b/pesto.h
> @@ -17,18 +17,33 @@
>   /* Version 0 is reserved for unreleased / unsupported experimental versions */
>   #define PESTO_PROTOCOL_VERSION	0
>   
> +/* Maxmimum size of a pif name, including \0 */
> +#define	PIF_NAME_SIZE	(128)
> +#define PIF_NONE	0
> +
>   /**
>    * struct pesto_hello - Server introduction message
> - * @magic:	PESTO_SERVER_MAGIC
> - * @version:	Version number
> + * @magic:		PESTO_SERVER_MAGIC
> + * @version:		Version number
> + * @pif_name_size:	Server's value for PIF_NAME_SIZE
>    */
>   struct pesto_hello {
>   	char magic[8];
>   	uint32_t version;
> +	uint32_t pif_name_size;
>   } __attribute__ ((__packed__));
>   
>   static_assert(sizeof(PESTO_SERVER_MAGIC)
>   	      == sizeof(((struct pesto_hello *)0)->magic),
>   	      "PESTO_SERVER_MAGIC has wrong size");
>   
> +/**
> + * struct pesto_pif_info - Message with basic metadata about a pif
> + * @resv_:	Alignment gap (must be 0)

You forgot to remove this one.


> + * @name:	Name (\0 terminated)
> + */
> +struct pesto_pif_info {
> +	char name[PIF_NAME_SIZE];
> +} __attribute__ ((__packed__));
> +
>   #endif /* PESTO_H */
> diff --git a/pif.h b/pif.h
> index 90dd3a32..d7708603 100644
> --- a/pif.h
> +++ b/pif.h
> @@ -11,6 +11,7 @@
>   
>   #include <netinet/in.h>
>   
> +#include "pesto.h"
>   #include "epoll_type.h"
>   
>   union inany_addr;
> @@ -24,7 +25,7 @@ union sockaddr_inany;
>    */
>   enum pif_type {
>   	/* Invalid or not present pif */
> -	PIF_NONE = 0,
> +	PIF_NONE_ = PIF_NONE,

This looks a bit weird. As fara as I can see this one is never used.
If it is important that PIF_NONE is zero and PIF_HOST is 1,
you could just do:

enum pif_type { 

       PIF_HOST = 1, 

       PIF_TAP,
       PIF_SPLICE, 

       PIF_NUM_TYPES,
   };

or
#define PESTO_PIF_END  0
in pesto.h
and leave this one as is.

/jon

[...]

item) - (array) < ARRAY_SIZE(array); (item)++)
>