Re: [PATCH dpdk v2 03/16] net: add structure for ipv6 addresses

[Stephen Hemminger <stephen@networkplumber.org>]

On Tue,  1 Oct 2024 10:17:15 +0200
Robin Jarry <rjarry@redhat.com> wrote:

> There is currently no structure defined for IPv6 addresses. Introduce
> one that is simply a uint8_t array of 16 elements without any union. The
> idea is to ensure this structure alignment is 1 so that it can be mapped
> directly on unaligned packet memory.
> 
> Signed-off-by: Robin Jarry <rjarry@redhat.com>
> ---
>  lib/net/rte_ip6.h | 10 ++++++++++
>  1 file changed, 10 insertions(+)
> 
> diff --git a/lib/net/rte_ip6.h b/lib/net/rte_ip6.h
> index 5ad1dd25db08..52c41088681e 100644
> --- a/lib/net/rte_ip6.h
> +++ b/lib/net/rte_ip6.h
> @@ -35,6 +35,16 @@
>  extern "C" {
>  #endif
>  
> +#define RTE_IPV6_ADDR_SIZE 16
> +#define RTE_IPV6_MAX_DEPTH 128
> +
> +/**
> + * IPv6 Address
> + */
> +struct rte_ipv6_addr {
> +	unsigned char a[RTE_IPV6_ADDR_SIZE];
> +};
> +

Why is RTE_IPV6_MAX_DEPTH here, it is not really a property
of the address itself.

Not sure if using a union (like struct in6_addr does) might be better
to encourage compiler alignment and allow simpler faster comparison.