<div dir="ltr">Hello James,<div><br></div><div>I included the new kernel (and reverted that commit) and now collaboration works even between fc20+S0.102 and F18+S0.100.</div><div><br></div><div>I tested it using a wifi network (with DHCP enabled) and Chat activity.</div><div><br></div><div>Really awesome work James!</div></div><div class="gmail_extra"><br><div class="gmail_quote">On Tue, Sep 16, 2014 at 3:53 AM, James Cameron <span dir="ltr"><<a href="mailto:quozl@laptop.org" target="_blank">quozl@laptop.org</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">Summary: partially solved with new kernel.<br>
<br>
The Chat activity was run with debug logging in Terminal:<br>
<br>
% SUGAR_LOGGER_LEVEL=debug sugar-launch org.laptop.Chat<br>
<br>
At the time the activity was shared, the log showed:<br>
<br>
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'),)<br>
<br>
Telepathy Salut was failing to setup the multicast group, because it<br>
was calling setsockopt with SO_REUSEPORT, because Fedora 20 header<br>
files define SO_REUSEPORT, but the OLPC kernel did not.<br>
<br>
(It is bad that the failure was not reported to the user or to the<br>
logs unless debug logging was turned on. If someone cares, they can<br>
raise a bug.)<br>
<br>
Adding SO_REUSEPORT support to the kernel [2] solved for Salut over<br>
networks where DHCP is available; such as wired or wireless access<br>
points. The new kernel is in the dropbox [3]. The previous change to<br>
avahi-daemon configuration is removed [4].<br>
<br>
A different problem occurs with Salut over link local addresses; IBSS<br>
ad-hoc wireless. The buddy icons are missing.<br>
<br>
# avahi-browse -t _presence._tcp # shows no output<br>
<br>
References:<br>
<br>
1.<br>
<a href="http://code.metager.de/source/xref/freedesktop/telepathy/salut/lib/gibber/gibber-multicast-transport.c" target="_blank">http://code.metager.de/source/xref/freedesktop/telepathy/salut/lib/gibber/gibber-multicast-transport.c</a><br>
<br>
2.<br>
<a href="http://dev.laptop.org/git/olpc-kernel/log/?h=arm-3.5" target="_blank">http://dev.laptop.org/git/olpc-kernel/log/?h=arm-3.5</a><br>
<br>
3.<br>
<a href="http://rpmdropbox.laptop.org/f20-xo4/" target="_blank">http://rpmdropbox.laptop.org/f20-xo4/</a><br>
kernel-3.5.7_xo4-20140916.0607.olpc.5196e01.armv7hl.rpm<br>
<br>
4.<br>
<a href="http://dev.laptop.org/git/projects/olpc-os-builder/commit/?id=f34ddb8b83ca6b9cb657e115df117ffa3704eea5" target="_blank">http://dev.laptop.org/git/projects/olpc-os-builder/commit/?id=f34ddb8b83ca6b9cb657e115df117ffa3704eea5</a><br>
<div><div class="h5"><br>
<br>
On Thu, Sep 11, 2014 at 06:24:20PM +1000, James Cameron wrote:<br>
> G'day,<br>
><br>
> Activities shared by Fedora 20 systems do not appear in Network<br>
> Neighbourhood on Fedora 18 or Fedora 20 systems. Buddies appear.<br>
> Activities shared by Fedora 18 Sugar 0.98 systems appear.<br>
><br>
> So this is a failure to announce sharing of activities on Sugar 0.102<br>
> on Fedora 20.<br>
><br>
> tcpdump shows mDNS packets for every operation except when an activity<br>
> is shared on Fedora 20.<br>
><br>
> avahi-browse output is consistent with Network Neighbourhood.<br>
><br>
> avahi-browse -t _presence._tcp # for buddies<br>
> avahi-browse -t _clique._udp # for activities<br>
><br>
> (avahi-daemon needed tweaking to compensate for lack of SO_REUSEPORT<br>
> support in 3.5 kernel; change /etc/avahi/avahi-daemon.conf to set<br>
> disallow-other-stacks=yes)<br>
><br>
> I have tried <a href="http://wiki.sugarlabs.org/go/BugSquad/Telepathy_Debugging" target="_blank">http://wiki.sugarlabs.org/go/BugSquad/Telepathy_Debugging</a><br>
> but there is no interesting output corresponding to the event.<br>
><br>
> I have used strace and seen possible D-Bus activity relating to the<br>
> 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\<a href="http://0org.freedesktop.Telepathy.Ch" target="_blank">0org.freedesktop.Telepathy.Ch</a>"..., 60}], msg_controllen=0, msg_flags=0}, MSG_NOSIGNAL) = 252<br>
><br>
> I welcome any suggestions for further diagnosing this problem.<br>
><br>
> --<br>
> James Cameron<br>
> <a href="http://quozl.linux.org.au/" target="_blank">http://quozl.linux.org.au/</a><br>
<br>
--<br>
James Cameron<br>
<a href="http://quozl.linux.org.au/" target="_blank">http://quozl.linux.org.au/</a><br>
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</blockquote></div><br></div>