On Tue, Mar 30, 2010 at 07:55:07AM +0300, Timo Teräs wrote:
quoted text
> Herbert Xu wrote:
>> On Mon, Mar 29, 2010 at 05:12:38PM +0300, Timo Teras wrote:
>>> @@ -1132,7 +1119,7 @@ int xfrm_sk_policy_insert(struct sock *sk, int dir, struct xfrm_policy *pol)
>>>  		__xfrm_policy_link(pol, XFRM_POLICY_MAX+dir);
>>>  	}
>>>  	if (old_pol)
>>> -		__xfrm_policy_unlink(old_pol, XFRM_POLICY_MAX+dir);
>>> +		old_pol = __xfrm_policy_unlink(old_pol, XFRM_POLICY_MAX+dir);
>>>  	write_unlock_bh(&xfrm_policy_lock);
>>>   	if (old_pol) {
>>
>> So when can this actually fail?
>
> Considering that the socket reference is received from the sk->sk_policy,
> and the hash bucket we use is "XFRM_POLICY_MAX+dir", it's non-obvious if
> it can fail or not.
>
> It would look like the timer can kill a policy and unlink it, but it
> would still be found from sk_policy.

Socket policies cannot expire.

In fact, they probably shouldn't even be on the bydst or any other
hash table.  I think the only reason they're there at all is because
the hash table was added to __xfrm_policy_link which happens to be
used by socket policies.

Cheers,
-- 
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Email: Herbert Xu ~{PmV>HI~} <herbert@gondor.apana.org.au>
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