suse man page for skb_copy

SKB_COPY(9)							 Linux Networking						       SKB_COPY(9)

NAME
       skb_copy - create private copy of an sk_buff

SYNOPSIS
       struct sk_buff * skb_copy(const struct sk_buff * skb, gfp_t gfp_mask);

ARGUMENTS
       skb
	   buffer to copy

       gfp_mask
	   allocation priority

DESCRIPTION
       Make a copy of both an sk_buff and its data. This is used when the caller wishes to modify the data and needs a private copy of the data to
       alter. Returns NULL on failure or the pointer to the buffer on success. The returned buffer has a reference count of 1.

       As by-product this function converts non-linear sk_buff to linear one, so that sk_buff becomes completely private and caller is allowed to
       modify all the data of returned buffer. This means that this function is not recommended for use in circumstances when only header is going
       to be modified. Use pskb_copy instead.

COPYRIGHT
Kernel Hackers Manual 2.6.					     July 2010							       SKB_COPY(9)