Enabling Connectivity Checking in NetworkManager

[Marc Deslauriers]

On Tue, 2012-07-10 at 15:29 -0400, Stéphane Graber wrote:
> On 07/10/2012 03:20 PM, Marc Deslauriers wrote:
> > On Tue, 2012-07-10 at 15:11 -0400, Stéphane Graber wrote:
> >> On 07/10/2012 03:06 PM, Ted Gould wrote:
> >>> On Tue, 2012-07-10 at 14:48 -0400, Scott Kitterman wrote:
> >>>> On Tuesday, July 10, 2012 02:41:35 PM Mathieu Trudel-Lapierre wrote:
> >>>>> As for the actual change, it is limited to the
> >>>>> /etc/NetworkManager/NetworkManager.conf file; to which the following
> >>>>> will be added:
> >>>>>
> >>>>> [connectivity]
> >>>>> uri=http://start.ubuntu.com/connectivity-check.html
> >>>>> response=Lorem ipsum
> >>>>>
> >>>>> See the manual page for NetworkManager.conf(5) for the details of what
> >>>>> these settings do.
> >>>>>
> >>>>> Please let me know if you have questions or think there are good
> >>>>> reasons not to enable this feature. If there is no response by the end
> >>>>> of the week, I'd like to proceed with a enabling this in Quantal and
> >>>>> making sure it gets well tested.
> >>>>
> >>>> I think that a significant fraction of Ubuntu's user base is (reasonably) very 
> >>>> sensitive about privacy issues.  While this is no worse the the NTP check that 
> >>>> already exists (that is controversial), I don't think it  should be enabled by 
> >>>> default.
> >>>
> >>> I think that for those who are concerned, this is trivial to disable.
> >>> But, I think what happens for those who are, is that Ubuntu "does the
> >>> right thing" by default.  If you're at a hotel or other location that
> >>> captures for a login page, you won't get your mail and apt and ... all
> >>> downloading bogus stuff.
> >>>
> >>> 		--Ted
> >>
> >> There are other ways to detect such cases without having the machine
> >> connect to an external service.
> >>
> >> Someone suggested on IRC to implement a doesnt-exist.ubuntu.com which is
> >> essentially a record that Canonical would guarantee never to exist in
> >> the ubuntu.com. zone.
> >>
> >> If you can resolve or even access that host, then you are behind some
> >> kind of captive portal/proxy.
> >>
> > 
> > That only works if the portal/proxy spoofs DNS. Some don't do that.
> > 
> > Seriously, there's a whole slew of software on the desktop that connects
> > to the Internet regularly, I don't see how this is any different. It's
> > easy to change for paranoid people, and enabling it would make Ubuntu so
> > much better for a majority of users.
> > 
> > Marc.
> 
> Just to clarify, I'm not at all against that change, being one of the
> ones who asked Mathieu to put that on this todo after looking at 2-3
> implementation of that check in ubiquity alone that I'd love to get rid off.
> 
> I'm not sure I like the idea of having NM poke that same address every 5
> minutes as it sounds like a pretty easy way for anyone to accurately
> count the number of Ubuntu machines currently running in any given network.

Meh, there are countless other things that can be used for that
currently...apt requests, ntp, browser user-agent strings, etc.

> 
> Sadly it's not how it was implemented in Network Manager, but I think
> I'd have preferred to have this check be exposed over DBUS so that
> applications like ubiquity can use that call to query the connectivity
> on demand.

I'm confused...Network Manager already exposes connectivity information
over dbus, and that's what apps are supposed to use...


> This would also have allowed to extend the check to work with other
> protocols, letting the client application query for a specific host and
> protocol if it wants to (with the default being whatever is defined in
> NetworkManager.conf).

Well, the idea is apps ask Network Manager, so it can be configured in a
central location, and not have every app try and override the default...

Marc.