kernels/linux-2.4.0/include/linux/skbuff.h
/** 
 *	skb_share_check - check if buffer is shared and if so clone it
 *	@skb: buffer to check
 *	@pri: priority for memory allocation
 *	
 *	If the buffer is shared the buffer is cloned and the old copy
 *	drops a reference. A new clone with a single reference is returned.
 *	If the buffer is not shared the original buffer is returned. When
 *	being called from interrupt status or with spinlocks held pri must
 *	be GFP_ATOMIC.
 *
 *	NULL is returned on a memory allocation failure.
 */
check if buffer is shared and if so clone it
@skb: buffer to check
@pri: priority for memory allocation

If the buffer is shared the buffer is cloned and the old copy
drops a reference. A new clone with a single reference is returned.
If the buffer is not shared the original buffer is returned. When
being called from interrupt status or with spinlocks held pri must
be GFP_ATOMIC.

NULL is returned on a memory allocation failure.
check if buffer is shared and if so clone it @skb : buffer to check @pri : priority for memory allocation If the buffer is shared the buffer is cloned and the old copy drops a reference . A new clone with a single reference is returned . If the buffer is not shared the original buffer is returned . When being called from interrupt status or with spinlocks held pri must be GFP_ATOMIC . NULL is returned on a memory allocation failure .
static inline struct sk_buff *skb_share_check(struct sk_buff *skb, int pri)
{
	if (skb_shared(skb)) {
		struct sk_buff *nskb;
		nskb = skb_clone(skb, pri);
		kfree_skb(skb);
		return nskb;
	}
	return skb;
}
static inline struct sk_buff * skb_share_check ( struct sk_buff * skb , int pri ) { if ( skb_shared ( skb ) ) { struct sk_buff * nskb ; nskb = skb_clone ( skb , pri ) ; kfree_skb ( skb ) ; return nskb ; } return skb ; }
skb_share_check - check if buffer is shared and if so clone it
      @skb: buffer to check
      @pri: priority for memory allocation
skb_share_check - check if buffer is shared and if so clone it @skb : buffer to check @pri : priority for memory allocation