Man page 9 : skb_dequeue_tail

skb_dequeue_tail - remove from the tail of the queue

struct sk_buff * skb_dequeue_tail(struct sk_buff_head *  list );

list
    list to dequeue from

Remove the tail of the list. The list lock is taken so the function may be used safely with other locking list functions. The tail item is returned or NULL if the list is empty.