NFACCT_FILTER_MASK
[NFACCT_FILTER_MASK] = { .type = NLA_U32 },
if (!tb[NFACCT_FILTER_MASK] || !tb[NFACCT_FILTER_VALUE])
filter->mask = ntohl(nla_get_be32(tb[NFACCT_FILTER_MASK]));