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Subject: Re: [RFC net-next 1/1] seg6: add counters support for SRv6 Behaviors
To:     Andrea Mayer <andrea.mayer@uniroma2.it>,
        "David S. Miller" <davem@davemloft.net>,
        Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>,
        David Ahern <dsahern@kernel.org>,
        Jakub Kicinski <kuba@kernel.org>, linux-kernel@vger.kernel.org,
        netdev@vger.kernel.org
Cc:     Stefano Salsano <stefano.salsano@uniroma2.it>,
        Paolo Lungaroni <paolo.lungaroni@uniroma2.it>,
        Ahmed Abdelsalam <ahabdels.dev@gmail.com>
References: <20210407180332.29775-1-andrea.mayer@uniroma2.it>
 <20210407180332.29775-2-andrea.mayer@uniroma2.it>
From:   David Ahern <dsahern@gmail.com>
Message-ID: <26222d31-2a27-c250-97e2-9220c098d836@gmail.com>
Date:   Wed, 7 Apr 2021 16:55:41 -0600
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On 4/7/21 12:03 PM, Andrea Mayer wrote:
> diff --git a/include/uapi/linux/seg6_local.h b/include/uapi/linux/seg6_local.h
> index 3b39ef1dbb46..ae5e3fd12b73 100644
> --- a/include/uapi/linux/seg6_local.h
> +++ b/include/uapi/linux/seg6_local.h
> @@ -27,6 +27,7 @@ enum {
>  	SEG6_LOCAL_OIF,
>  	SEG6_LOCAL_BPF,
>  	SEG6_LOCAL_VRFTABLE,
> +	SEG6_LOCAL_COUNTERS,
>  	__SEG6_LOCAL_MAX,
>  };
>  #define SEG6_LOCAL_MAX (__SEG6_LOCAL_MAX - 1)
> @@ -78,4 +79,11 @@ enum {
>  
>  #define SEG6_LOCAL_BPF_PROG_MAX (__SEG6_LOCAL_BPF_PROG_MAX - 1)
>  
> +/* SRv6 Behavior counters */
> +struct seg6_local_counters {
> +	__u64 rx_packets;
> +	__u64 rx_bytes;
> +	__u64 rx_errors;
> +};
> +
>  #endif

It's highly likely that more stats would get added over time. It would
be good to document that here for interested parties and then make sure
iproute2 can handle different sized stats structs. e.g., commit support
to your repo, then add a new one (e.g, rx_drops) and verify the
combinations handle it. e.g., old kernel - new iproute2, new kernel -
old iproute, old - old and new-new.