ubuntu-phone team mailing list archive

[Jamie Strandboge <jamie@xxxxxxxxxxxxx>]

On 08/01/2013 08:23 AM, Jamie Strandboge wrote:
> On 08/01/2013 05:23 AM, Iain Lane wrote:
>> On Wed, Jul 31, 2013 at 05:42:43PM +0100, Iain Lane wrote:
>>> On Wed, Jul 31, 2013 at 03:18:27PM +0400, Alberto Mardegan wrote:
>>>> On 07/30/2013 07:50 PM, Iain Lane wrote:
>>>>> Admittedly I didn't know about it ;-) But looking at that API reference
>>>>> it seems to be more about mobile stuff whereas my question is a bit more
>>>>> generic than that — I want to know if there's an internet connection of
>>>>> any type available.
>>>>>
>>>>> Maybe I can't see it on this API or maybe Qt has something else for that
>>>>> in which case I'd be happy to switch over.
>>>>
>>>> QNetworkAccessManager::networkAccessible():
>>>>
>>>> https://qt-project.org/doc/qt-5.0/qtnetwork/qnetworkaccessmanager.html#networkAccessible-prop
>>>
>>> Thanks for the tip. It looks like it should work, however I always get
>>> QNetworkAccessManager::UnknownAccessibility returned. Is there a trick?
>>
>> I found [0] and followed that. Then I get Accessible back. I was happy,
>> until I tried disconnecting from the network (on my desktop) and still
>> got Accessible.
>>
>> All the while NM has known the correct state, so if I could use that
>> we'd be in happy land.
>>
>> Ho hum?
>>
>> [0]
>> http://www.qtcentre.org/threads/37514-use-of-QNetworkAccessManager-networkAccessible?p=188372#post188372
>>
> Along these lines-- we really need to define and document the canonical way for
> determining network accessibility. My team is tasked with defining apparmor
> policy for this, and SDK app developers should ideally do this one way and then
> my team can write tests to make sure that it works for that use case. Everyone
> coming up with their own method won't work with application confinement.
> 
I looked into this a bit today. We should *not* rely on anything that uses
network-manager to obtain this information. Its DBus API does not currently
provide the answer to "Can I use the internet?" without granting a whole bunch
of other accesses.

Instead, apps should use qtdeclarative5-systeminfo-plugin, specifically
NetworkInfo[1]. I played with this today and rather than talking to
network-manager, it just reads various files in /sys, /proc and needs 'inet
stream' and 'inet dgram'. I'll be updating the apparmor policy group for
'connectivity' to allow these accesses so it works with
qtdeclarative5-systeminfo-plugin. I also tested (a bit) with C++ using
QHostAddress and QNetworkInterface.

[1]http://doc.qt.digia.com/qtmobility-1.2/qml-networkinfo.html

-- 
Jamie Strandboge                 http://www.ubuntu.com/