Re: new ip settings method acceptibility

[Pavel Simerda <psimerda redhat com>]

> From: "Shawn J. Goff" <shawn7400 gmail com>
> On Tue 14 Aug 2012 12:05:15 PM EDT, Pavel Simerda wrote:
> 
> >> I disagree that this would be a misuse; care to elaborate?
> >
> > Sure. Methods are for everyday use. You want to have standard
> > automatic
> > connection? It's there. You want to have static configuration?
> > There.
> > You want to act as a router instead? Use shared.
> >
> > Method in NetworkManager is the basic mode of function. Tweaks for
> > specific
> > use cases can be done with various options for tweaking the IP
> > config. If
> > it's 'something like shared', it should probably be 'shared'.
> >
> >> I do agree that it is a corner case, which is why I'm asking now.
> >
> > Corner cases are best handled by tweaking the method with more
> > options,
> > is it good enough for you?
> 
> I would agree, but I don't think any of the existing methods could be
> tweaked into this setup.

The 'method' is just a value from an enumerated list.

> > My impression is that... if there is a good use case for that, it
> > should
> > be possible to do it with keyfile configuration. Whether it gets to
> > the
> > GUI and/or conf plugins would be the next question.
> >
> 
> Absolutely. I would definitely not expect this to be in any gui; it
> would be downright confusing for pretty much every user who uses the
> gui.

OK.

> > NM doesn't currently fit well in black magic networking, OpenWRT
> > used to
> > do slightly better. But if you can make this work well with
> > NetworkManager,
> > it'll be a pleasant surprise for me.
> 
> Agreed. I'll be looking at NCD
> (http://code.google.com/p/badvpn/wiki/NCD) as another option.

I'll be curious about any information, on-list or off-list.

> > For the first tests it might be helpful if NetworkManager can be
> > tweaked
> > *not* to commit IP addresses to the interface. Your fake address
> > and other
> > things could generally be done with dispatcher.d scripts. Many
> > things can
> > be done with helper daemons and helper scripts.
> 
> Dispatcher scripts could work. I think I've read on this list seveal
> times that it's important for NetworkManager to know the state of the
> network, so I've thought I need to avoid doing things outside of
> NetworkManager to avoid confusing its state machine.

Sort of. But this can be tweaked in various ways, at least in the code.

> If it would not be a problem, I could add a dispatcher script to do
> everything pretty simply: record the address/netmask/gateway from
> $INTERFACE, add the fake address to $INTERFACE and remove the
> original
> one, add the SNAT rule, bring up the alternate interface, start dhcpd
> with the stored info.
> 
> If this would cause problems

It probably will cause some problems at the beginning and will require
some modifications of NetworkManager for the benefit of its universality.

But I think its managable.

> maybe I should take a closer look at
> NCD
> and netifd first.

Possibly.

> > It still seems to be rather complicated but now I at least
> > understand the
> > use case. While I'm not convinced that we need another mode, and
> > I'm not
> > convinced that we need a user-friendly way to set up your use case,
> > I'll
> > be happy work out a way that makes NM usable for your use case at
> > least with
> > some scripting and possibly an external tool.
> 
> Thanks for your help.

Thanks for bringing up your use case.

Cheers,

Pavel