MUC: Add support for presence probes (fixes #1535)
The following patch allows Prosody to respond to `probe` presences and send out the probed occupant's current presence.
This is based on line 17.3 in XEP-0045:
A MUC service MAY handle presence probes sent to the room JID <room@service> or an occupant JID <room@service/nick>
(e.g, these might be sent by an occupant's home server to determine if the room is still online or to synchronize
presence information if the user or the user's server has gone offline temporarily or has started sharing presence again,
as for instance when Stanza Interception and Filtering Technology (XEP-0273) is used).
local st = require "util.stanza";
local muc_util = module:require "muc/util";
local xmlns_hats = "xmpp:prosody.im/protocol/hats:1";
-- Strip any hats claimed by the client (to prevent spoofing)
muc_util.add_filtered_namespace(xmlns_hats);
module:hook("muc-build-occupant-presence", function (event)
local bare_jid = event.occupant and event.occupant.bare_jid or event.bare_jid;
local aff_data = event.room:get_affiliation_data(bare_jid);
local hats = aff_data and aff_data.hats;
if not hats then return; end
local hats_el;
for hat_id, hat_data in pairs(hats) do
if hat_data.active then
if not hats_el then
hats_el = st.stanza("hats", { xmlns = xmlns_hats });
end
hats_el:tag("hat", { uri = hat_id, title = hat_data.title }):up();
end
end
if not hats_el then return; end
event.stanza:add_direct_child(hats_el);
end);