Re: Xtables2 Netlink spec

[Pablo Neira Ayuso <pablo@netfilter.org>]

On 07/12/10 14:30, Jan Engelhardt wrote:
> 
> On Tuesday 2010-12-07 08:49, Pablo Neira Ayuso wrote:
>>
>>> I am skeptical about shrinkfitting something onto an older
>>> interface (nfnetlink) when there is genetlink..
>>
>> That's an empty argument. Tell me one feature that nfnetlink does not have have
>> but genetlink does.
> 
> I was thinking about the name resolution of netlink subsubsystems. In
> plain netlink and nfnetlink, subsys pointers are kept in a static
> array, which means the more subsystems are defined, the more memory
> is used (for n -> infinity) even if only one subsys is used.
> Would that be a reasonable concern?

The number of nfnetlink subsystem is small and it will remain small
along time I guess. I would not spend time on such optimization.

Anyway, the static subsys ID number is a good thing IMO.

The floating genetlink ID allows to have out-of-tree subsystems, which
is something that I don't like that. Moreover, you have to send an
initial message to resolve the ID number and subscribe to possible
changes in it.