Provided by:
linux-doc-2.6.15_2.6.15-23.39_all 
NAME
__pskb_pull_tail - advance tail of skb header
SYNOPSIS
unsigned char * __pskb_pull_tail (struct sk_buff * skb, int delta);
ARGUMENTS
skb buffer to reallocate
delta number of bytes to advance tail
DESCRIPTION
The function makes a sense only on a fragmented &sk_buff, it expands
header moving its tail forward and copying necessary data from
fragmented part.
&sk_buff MUST have reference count of 1.
Returns NULL (and &sk_buff does not change) if pull failed or value of
new tail of skb in the case of success.
All the pointers pointing into skb header may change and must be
reloaded after call to this function.