IMMED_PKT_SIZE
struct sk_buff *skb = alloc_skb(IMMED_PKT_SIZE, GFP_ATOMIC);
__skb_put(skb, IMMED_PKT_SIZE);
BUILD_BUG_ON(IMMED_PKT_SIZE != sizeof(resp->immediate));
skb_copy_to_linear_data(skb, &resp->immediate, IMMED_PKT_SIZE);