RFC: sysctl additional functions/macros

Poul-Henning Kamp phk at phk.freebsd.dk
Fri Jan 4 08:05:17 PST 2008


In message <477E582A.2060106 at elischer.org>, Julian Elischer writes:
>Poul-Henning Kamp wrote:
>> In message <477D931D.4000303 at elischer.org>, Julian Elischer writes:
>>> I would like to extend the current SYSCTL_INT() with 
>>> SYSCTL_INT_CLAMPED() or similar, where you also supply a
>>> maximum acceptable value. (and maybe a clue as to what to say if it is 
>>> a bad value).
>> 
>> I'm not sure I think it is a good idea.
>> 
>> Next you'll want SYSCTL_INT_BITMAP(), SYSCTL_INT_POWERS_OF_PI() and
>> so on.
>> 
>> A much better idea would be to add a code argument to a version of
>> SYSCTL_INT(), so that people could write something like:
>> 
>> SYSCTL_INT(_debug, OID_AUTO, foobar, ORD_WR, &foobar, 0,
>> 	"mumble desc mumble",
>> 	{
>> 	if (newval < 3 || newval > 70 || newval == 59)
>> 		return (EINVAL);
>> 	}
>> )
>> 
>
>
>I actually considered that already.. It has the advantage of being 
>flexible.. but is more intrusive to implement. I think you'd have to 
>extend the sysctl_oid structure.

No, you'd just expand the macro to a sysctl-function and declare the
oid as such.

-- 
Poul-Henning Kamp       | UNIX since Zilog Zeus 3.20
phk at FreeBSD.ORG         | TCP/IP since RFC 956
FreeBSD committer       | BSD since 4.3-tahoe    
Never attribute to malice what can adequately be explained by incompetence.


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