Who is to load dummynet.ko?

[Luigi Rizzo]

On Sat, Mar 10, 2007 at 06:35:34PM +0300, Yar Tikhiy wrote:
> Hi folks,
> 
> Just noticed that neither ipfw(8) nor /etc/rc.d/ipfw cares to load
> dummynet.ko.  It can result in a broken setup when one migrates
> from a custom monolithic kernel to GENERIC with modules, which is
> a nice way to reduce support headache today.
> 
> There are at least two possible ways to deal with the issue.  The
> easy way is to give the task of loading dummynet.ko to /etc/rc.d/ipfw.
> The problem with it is that the script cannot know in advance if
> dummynet is really used by the ipfw rules to be loaded.  The decision
> whether to load the module is left to rc.conf(5) in this case.

i think this is a reasonable option and the one to use for all ipfw
extensions (divert, dummynet, in-kernel nat and so on).

Making the load on demand would require a bit of additional code because
it depends on the actual rules being loaded, and the rules are not
parsed at load time. Plus, i believe that in a case like this
the decision of which modules to load should be a conscious one
taken upfront by the system administrator (i.e. end up in rc.conf
or loader.conf) rather than be the result of the actual ipfw
configuration.

> The second way is to move the task of loading modules to ipfw(8).
> Then it could load ipfw.ko, divert.ko, and dummynet.ko on demand.

cheers
luigi