L2CAP_ENH_CTRL_SIZE
skb_pull(skb, L2CAP_ENH_CTRL_SIZE);
put_unaligned_le16(control, skb_put(skb, L2CAP_ENH_CTRL_SIZE));
put_unaligned_le16(0, skb_put(skb, L2CAP_ENH_CTRL_SIZE));