Re: [PATCH net-next] netlink: specs: add big-endian byte-order for u32 IPv4 addresses

[Hangbin Liu <liuhangbin@gmail.com>]

On Wed, Nov 26, 2025 at 01:32:22PM +0000, Asbjørn Sloth Tønnesen wrote:
> I prefer exact-len over min-len. The current tally is:
> 
> $ git grep 'len.*: 16' Documentation/netlink/specs/ | cut -d: -f2- | sed -e 's/^ *//' | sort | uniq -c
>       7 exact-len: 16
>       5 len: 16
>       6 min-len: 16
> (assuming that only IPv6 has a length of 16)
> 
> "len: 16" as used in ovs_flow's ipv6-src and ipv6-dst only works because they
> are struct members, not attributes.


Talking about the ovs, it's looks like that the struct members are used in
flow metadata, like in ip_tun_from_nlattr():

                case OVS_TUNNEL_KEY_ATTR_IPV6_SRC:
                        SW_FLOW_KEY_PUT(match, tun_key.u.ipv6.src,
                                        nla_get_in6_addr(a), is_mask);
                        ipv6 = true;
                        break;

While attributes are used in __ip_tun_to_nlattr():

        case AF_INET6:
                if (!ipv6_addr_any(&output->u.ipv6.src) &&
                    nla_put_in6_addr(skb, OVS_TUNNEL_KEY_ATTR_IPV6_SRC,
                                     &output->u.ipv6.src))
                        return -EMSGSIZE;

So I think we can also convert the ipv6-src/ipv6-dst using exact-len? WDYT?

Thanks
Hangbin