Why can't the IPv4 networking be built as a module?

[Greg Freemyer]

On Sun, Mar 25, 2012 at 11:59 PM, Mulyadi Santosa
<mulyadi.santosa at gmail.com> wrote:
> Hi...
>
> On Mon, Mar 26, 2012 at 07:02, Graeme Russ <graeme.russ at gmail.com> wrote:
>> Hi All,
>>
>> Naive question of the day:
>>
>> I'm trying to cut down the size of a 3.3 kernel and one thing I have
>> noticed is the TCP/IP v6 can be built as a module, but v4 cannot. Is
>> there any particular reason for this, or is it simple a case of nobody
>> has gone to the effort of modularising the v4 networking components?
>
> IMHO it's mostly a matter of lack of modularitation (or we could say
> lack of deeper code refactoring too). Almost all of networking stack
> in Linux that I know (Novell's I-forgot-the-name, token-ring, Mac
> I-forgot-too) are switchable.

I suggest it's also a matter of motivation.  How many network
developers run without IPv4?  Very few I guess, so they aren't very
motivated to do push it into a module they can disable.

If there is sponsor out there for the work, that would likely increase
the motivation.

Greg (not a kernel network guy)