L2CAP_EXT_CTRL_SIZE
skb_pull(skb, L2CAP_EXT_CTRL_SIZE);
put_unaligned_le32(control, skb_put(skb, L2CAP_EXT_CTRL_SIZE));
put_unaligned_le32(0, skb_put(skb, L2CAP_EXT_CTRL_SIZE));