Re: [PATCH] netfilter: define NF_CT_EXT_* as needed

[Patrick McHardy <kaber@trash.net>]

On 15.11.2010 12:19, Changli Gao wrote:
> On Mon, Nov 15, 2010 at 7:13 PM, Patrick McHardy <kaber@trash.net> wrote:
>> On 15.11.2010 10:25, Changli Gao wrote:
>>>  #ifdef CONFIG_NF_CONNTRACK_EVENTS
>>> diff --git a/include/net/netfilter/nf_conntrack_extend.h b/include/net/netfilter/nf_conntrack_extend.h
>>> index 0772d29..1a9f96d 100644
>>> --- a/include/net/netfilter/nf_conntrack_extend.h
>>> +++ b/include/net/netfilter/nf_conntrack_extend.h
>>> @@ -7,10 +7,16 @@
>>>
>>>  enum nf_ct_ext_id {
>>>       NF_CT_EXT_HELPER,
>>> +#if defined(CONFIG_NF_NAT) || defined(CONFIG_NF_NAT_MODULE)
>>>       NF_CT_EXT_NAT,
>>> +#endif
>>>       NF_CT_EXT_ACCT,
>>> +#ifdef CONFIG_NF_CONNTRACK_EVENTS
>>>       NF_CT_EXT_ECACHE,
>>> +#endif
>>> +#ifdef CONFIG_NF_CONNTRACK_ZONES
>>>       NF_CT_EXT_ZONE,
>>> +#endif
>>>       NF_CT_EXT_NUM,
>>
>> What is the purpose of #ifdef'ing the extension IDs?
>>
> 
> struct nf_ct_ext {
>         struct rcu_head rcu;
>         u8 offset[NF_CT_EXT_NUM];
>         u8 len;
>         char data[0];
> };
> 
> Less IDs make nf_ct_ext smaller.

Right, thanks for the explanation.