[Sugar-devel] Telepathy Salut on Sugar 0.102 on Fedora 20 almost works

Martin Abente martin.abente.lahaye at gmail.com
Tue Sep 16 14:14:56 EDT 2014


James, Gonzalo,

Regarding the IBSS/Ad-hoc scenario, if I set the address manually,
collaborations work just fine. So this must be related to network discovery.

My test goes like this:

* I use one XO with fc18+S0.100 to create an ad-hoc network network.
* From another XO, with fc20+S0.102, I connect to that ad-hoc network.

The second XO ip address does not match the first one's network. But when I
manually configure it, then buddy icons appears and collaboration works...

On Tue, Sep 16, 2014 at 11:01 AM, Martin Abente <
martin.abente.lahaye at gmail.com> wrote:

> Hello James,
>
> I included the new kernel  (and reverted that commit) and now
> collaboration works even between fc20+S0.102 and F18+S0.100.
>
> I tested it using a wifi network (with DHCP enabled) and Chat activity.
>
> Really awesome work James!
>
> On Tue, Sep 16, 2014 at 3:53 AM, James Cameron <quozl at laptop.org> wrote:
>
>> Summary: partially solved with new kernel.
>>
>> The Chat activity was run with debug logging in Terminal:
>>
>>         % SUGAR_LOGGER_LEVEL=debug sugar-launch org.laptop.Chat
>>
>> At the time the activity was shared, the log showed:
>>
>> 1410842095.436535 DEBUG sugar3.presence.activity: <_ShareCommand object
>> at 0x527dc8 (sugar3+presence+activity+_ShareCommand at 0x4f7c20)>: Join
>> finished DBusException(dbus.String(u'Failed to connect to multicast
>> group'),)
>>
>> Telepathy Salut was failing to setup the multicast group, because it
>> was calling setsockopt with SO_REUSEPORT, because Fedora 20 header
>> files define SO_REUSEPORT, but the OLPC kernel did not.
>>
>> (It is bad that the failure was not reported to the user or to the
>> logs unless debug logging was turned on.  If someone cares, they can
>> raise a bug.)
>>
>> Adding SO_REUSEPORT support to the kernel [2] solved for Salut over
>> networks where DHCP is available; such as wired or wireless access
>> points.  The new kernel is in the dropbox [3].  The previous change to
>> avahi-daemon configuration is removed [4].
>>
>> A different problem occurs with Salut over link local addresses; IBSS
>> ad-hoc wireless.  The buddy icons are missing.
>>
>>         # avahi-browse -t _presence._tcp # shows no output
>>
>> References:
>>
>> 1.
>>
>> http://code.metager.de/source/xref/freedesktop/telepathy/salut/lib/gibber/gibber-multicast-transport.c
>>
>> 2.
>> http://dev.laptop.org/git/olpc-kernel/log/?h=arm-3.5
>>
>> 3.
>> http://rpmdropbox.laptop.org/f20-xo4/
>> kernel-3.5.7_xo4-20140916.0607.olpc.5196e01.armv7hl.rpm
>>
>> 4.
>>
>> http://dev.laptop.org/git/projects/olpc-os-builder/commit/?id=f34ddb8b83ca6b9cb657e115df117ffa3704eea5
>>
>>
>> On Thu, Sep 11, 2014 at 06:24:20PM +1000, James Cameron wrote:
>> > G'day,
>> >
>> > Activities shared by Fedora 20 systems do not appear in Network
>> > Neighbourhood on Fedora 18 or Fedora 20 systems.  Buddies appear.
>> > Activities shared by Fedora 18 Sugar 0.98 systems appear.
>> >
>> > So this is a failure to announce sharing of activities on Sugar 0.102
>> > on Fedora 20.
>> >
>> > tcpdump shows mDNS packets for every operation except when an activity
>> > is shared on Fedora 20.
>> >
>> > avahi-browse output is consistent with Network Neighbourhood.
>> >
>> >       avahi-browse -t _presence._tcp # for buddies
>> >       avahi-browse -t _clique._udp # for activities
>> >
>> > (avahi-daemon needed tweaking to compensate for lack of SO_REUSEPORT
>> > support in 3.5 kernel; change /etc/avahi/avahi-daemon.conf to set
>> > disallow-other-stacks=yes)
>> >
>> > I have tried http://wiki.sugarlabs.org/go/BugSquad/Telepathy_Debugging
>> > but there is no interesting output corresponding to the event.
>> >
>> > I have used strace and seen possible D-Bus activity relating to the
>> > event.  sendmsg(11, {msg_name(0)=NULL,
>> msg_iov(2)=[{"l\1\0\1<\0\0\0/\0\0\0\252\0\0\0\1\1o\0?\0\0\0/org/fre"...,
>> 192}, {"+\0\0\0org.freedesktop.Telepathy.Ch"..., 60}], msg_controllen=0,
>> msg_flags=0}, MSG_NOSIGNAL) = 252
>> >
>> > I welcome any suggestions for further diagnosing this problem.
>> >
>> > --
>> > James Cameron
>> > http://quozl.linux.org.au/
>>
>> --
>> James Cameron
>> http://quozl.linux.org.au/
>> _______________________________________________
>> Devel mailing list
>> Devel at lists.laptop.org
>> http://lists.laptop.org/listinfo/devel
>>
>
>
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