Re: nf-next: netfilter: xt_recent: Add an entry reaper

[Tim Gardner <tim.gardner@canonical.com>]

On 03/16/2010 02:31 PM, Jan Engelhardt wrote:
>
> On Tuesday 2010-03-16 20:43, Tim Gardner wrote:
>>>>
>>>> One of the problems with the way xt_recent is implemented is that
>>>> there is no efficient way to remove expired entries. Of course,
>>>> one can write a rule '-m recent --remove', but you have to know
>>>> beforehand which entry to delete. This commit adds reaper
>>>> logic which checks the head of the LRU list when a rule
>>>> is invoked that has a '--seconds' value and XT_RECENT_REAP set. If an
>>>> entry ceases to accumulate time stamps, then it will eventually bubble
>>>> to the top of the LRU list where it is then reaped.
>>>
>>> Thanks, this looks fine. My only concern is that we currently
>>> don't catch unknown flags, so userspace won't get an error if
>>> the option is used and the kernel doesn't support it. If you
>>> document this clearly we can ignore it this one time, but I'd
>>> appreciate if you could send me a patch on top to check for
>>> unknown flags and refuse them.
>>>
>>>> Signed-off-by: Tim Gardner<tim.gardner@canonical.com>
>>>
>>> Applied, thanks.
>>
>> Thusly? (attached)
>
> [patch]
>
> Why not make this an enum constant like the rest of the flags?
> It's perfectly fine to say
>
> enum {
> 	a,
> 	c = a | b,
> };
>
> as long as it's const/compile-time-computable.
>

I guess because I'm old school I just hacked out a macro without really 
thinking about it. Its long been my habit to never used a signed 
quantity in a device driver unless signedness is really called for.

rtg
-- 
Tim Gardner tim.gardner@canonical.com