SKB_COW(9) Linux Networking SKB_COW(9)NAMEskb_cow - copy header of skb when it is required
SYNOPSIS
int skb_cow(struct sk_buff * skb, unsigned int headroom);
ARGUMENTS
skb
buffer to cow
headroom
needed headroom
DESCRIPTION
If the skb passed lacks sufficient headroom or its data part is shared,
data is reallocated. If reallocation fails, an error is returned and
original skb is not changed.
The result is skb with writable area skb->head...skb->tail and at least
headroom of space at head.
COPYRIGHTKernel Hackers Manual 2.6. November 2013 SKB_COW(9)