Man page 9 : skb_insert

skb_insert - insert a buffer

void skb_insert(struct sk_buff *  old , struct sk_buff *  newsk , struct sk_buff_head *  list );

old
    buffer to insert before

newsk
    buffer to insert

list
    list to use

Place a packet before a given packet in a list. The list locks are taken and this function is atomic with respect to other list locked calls.

A buffer cannot be placed on two lists at the same time.