CGW_MOD_SET
if (nla_put(skb, CGW_MOD_SET, sizeof(mb), &mb) < 0)
[CGW_MOD_SET] = { .len = sizeof(struct cgw_frame_mod) },
if (tb[CGW_MOD_SET]) {
nla_memcpy(&mb, tb[CGW_MOD_SET], CGW_MODATTR_LEN);