Re: [Tails-dev] How to replace the green onion

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Auteur: intrigeri
Date:  
À: The Tails public development discussion list
Sujet: Re: [Tails-dev] How to replace the green onion
Hi,

Alan wrote (06 Mar 2015 21:04:46 GMT) :
> intrigeri <intrigeri@???> wrote:
>> Alan wrote (22 Feb 2015 01:48:28 GMT) :


>> > The very same mechanism that currently
>> > displays the "Tor is ready" notification in Tails would trigger a
>> > notification to this DBus service that would update this onion. I admit
>> > this would be very Tails specific.
>>
>> I think we can go this way (or similar) for the first iteration, that
>> replaces what Vidalia gives us, including the buggy green onion.
>> So I've created #9002, as a child ticket of #6841 ("Replace Vidalia").
>>
>> Now, in the first iteration, the information we want to convey to that
>> Shell extension is exactly one bit ("Tor is ready", and possibly "Tor
>> is down" on network post-down).


> Really? I though we wanted bootstrap progress too, that current
> vidalia's onion provides (no onion/red > yellow > green)


Sadly, this assumption is not correct... which gives us yet another
demonstration that even *we* don't understand what these colors are
about (hence my doubts about whether it's really useful, but
thankfully I've given up on arguing about that already). In current
Tails:

a) no onion indeed means "Tor hasn't bootstrapped yet", since we start
   Vidalia only when Tor has bootstrapped
b) yellow onion means that:
   1. Vidalia is connected to the Tor control port
   2. while Tor has already successfully bootstrapped (otherwise we
      wouldn't have started Vidalia), Vidalia hasn't downloaded all
      the info it needs to display a complete UI (most notably, the
      detailed info about relays)
c) green onion means that Vidalia is connected to the Tor control port
   and has all the info it needs to display a complete UI


[No idea if/how it's different when Vidalia is integrated into other
operating systems, but who cares, we're talking about avoiding
regressions vs. the current state of Tails here.]

The only information in there that is about Tor's bootstrap progress
is "display an onion at all, or not", which is 1 bit of information.
The rest is about Vidalia's own bootstrap progress.

I don't think that the onion Shell extension needs to differentiate
between cases (b) and (c): IIRC we want it to provide some way to
start Tor Monitor, and then Tor Monitor can itself convey to the user
any relevant message regarding its own bootstrap status, that is how
much it's ready to display complete information. As I understand it,
we want the onion icon to say something about the state of Tor, not
about the state of Tor Monitor.

So, we don't need to convey any additional information to the onion
Shell extension than "we've started you, display that green onion" and
"stop displaying that green onion" (possibly by disabling the
extensions altogether).

Thoughts?

>> An alternative, for the initial iteration, is to do exactly what we're
>> doing now: when we display "Tor is ready", simply enable the Shell
>> extension that displays the green onion. And disable it when the
>> network gets disconnected. This way, we don't even need any
>> communication channel :)
>>
> This can be done by changing a GSetting. I do not find it very elegant
> to change a setting at each network status change, but it may work. I
> didn't found a DBus interface to enable/disable extensions. At first
> glance, I think DBus might still be the more appropriate.


I don't understand why, but I guess that's probably a matter of
taste... and it now seems clear that our personal taste differs a lot
regarding what's an appropriate IPC mechanism to convey one single bit
of information. Now, if there's any technical reason why you still
prefer using DBus, I'm all ears :)

> Tor always tries to build circuits, so it has circuits in "launched"
> state. We could consider Tor as "connected" as long as it has at least
> one circuit in "built" state.


This seems worth trying, but doesn't seem necessarily part of the
first iteration about replacing what we have currently (since we don't
have that feature yet).

>> > To sum up, I see three options (on order of complexity) to feed this
>> > GNOME shell extension that would provide the onion:
>>
>> > 1. through the same mechanism that displays the "Tor is ready"
>> >    notification;

[...]
>> I say let's go with (1) as far as #6841 is concerned.
>>
> I agree it's the easiest way to start with.


Oooh yeah. Are you interested in taking care of this Shell extension?
Do you want me to file whatever tickets are needed about it?

Cheers,
--
intrigeri