LWTUNNEL_IP6_TC
if (tb[LWTUNNEL_IP6_TC])
tun_info->key.tos = nla_get_u8(tb[LWTUNNEL_IP6_TC]);
nla_put_u8(skb, LWTUNNEL_IP6_TC, tun_info->key.tos) ||
[LWTUNNEL_IP6_TC] = { .type = NLA_U8 },