GTPA_FAMILY
family = nla_get_u8_default(info->attrs[GTPA_FAMILY], AF_INET);
family = nla_get_u8_default(nla[GTPA_FAMILY], AF_INET);
nla_put_u8(skb, GTPA_FAMILY, pctx->af))
[GTPA_FAMILY] = { .type = NLA_U8, },