centos man page for skb_peek_tail

SKB_PEEK_TAIL(9)						 Linux Networking						  SKB_PEEK_TAIL(9)

NAME
       skb_peek_tail - peek at the tail of an sk_buff_head

SYNOPSIS
       struct sk_buff * skb_peek_tail(const struct sk_buff_head * list_);

ARGUMENTS
       list_
	   list to peek at

DESCRIPTION
       Peek an sk_buff. Unlike most other operations you _MUST_ be careful with this one. A peek leaves the buffer on the list and someone else
       may run off with it. You must hold the appropriate locks or have a private queue to do this.

       Returns NULL for an empty list or a pointer to the tail element. The reference count is not incremented and the reference is therefore
       volatile. Use with caution.

COPYRIGHT
Kernel Hackers Manual 3.10					     June 2014							  SKB_PEEK_TAIL(9)