Dealing with shared/cloned skbs?

[Marcus Sundberg <marcus@ingate.com>]

Hi,

in the 2.4 net/ipv4/netfilter directory various ways are used to
check whether an skb needs to be copied before it is modified. At
least three ways are used:

if (skb_shared(skb) || skb_cloned(skb))

if (skb_cloned(skb) && !skb->sk)

if (skb_cloned(skb))

And at the places where the skb is actually copied some of them do:

	if ((oldskb)->sk)
		skb_set_owner_w(newskb, oldskb->sk);

while some of them do not.

What is the correct way to know if an skb needs to be copied before
modified, and what should be done after a copy takes place?

//Marcus
-- 
---------------------------------------+--------------------------
   Marcus Sundberg <marcus@ingate.com>  | Firewalls with SIP & NAT
  Software Developer, Ingate Systems AB |  http://www.ingate.com/