--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/mod_ping_muc/mod_ping_muc.lua Thu Dec 02 23:43:11 2021 +0100
@@ -0,0 +1,66 @@
+local id = require "util.id";
+local jid = require "util.jid";
+local set = require "util.set";
+local st = require "util.stanza";
+
+module:depends "track_muc_joins";
+module:add_feature("https://modules.prosody.im/mod_" .. module.name);
+
+local local_sessions = prosody.hosts[module.host].sessions;
+
+module:hook_global("s2s-destroyed", function(event)
+ local s2s_session = event.session;
+ if s2s_session.direction == "outgoing" and s2s_session.from_host ~= module.host then
+ return
+ elseif s2s_session.direction == "incoming" and s2s_session.to_host ~= module.host then
+ return
+ end
+
+ local related_hosts = set.new({ s2s_session.direction == "outgoing" and s2s_session.to_host or s2s_session.from_host });
+
+ if s2s_session.hosts then
+ -- While rarely used, multiplexing is still supported
+ for host, state in pairs(s2s_session.hosts) do if state.authed then related_hosts:add(host); end end
+ end
+
+ for _, user_session in pairs(local_sessions) do
+ for _, session in pairs(user_session.sessions) do
+ if session.rooms_joined then
+ for room, info in pairs(session.rooms_joined) do
+ local nick = info.nick or info;
+ local room_nick = room .. "/" .. nick;
+ if related_hosts:contains(jid.host(room)) then
+ -- User is in a MUC room for which the s2s connection was lost. Now what?
+
+ -- Self-ping
+ -- =========
+ --
+ -- Response of <iq type=result> means the user is still in the room
+ -- (and self-ping is supported), so we do nothing.
+ --
+ -- An error reply either means the user has fallen out of the room,
+ -- or that self-ping is unsupported. In the later case, whether the
+ -- user is still joined is indeterminate and we might as well
+ -- pretend they fell out.
+ module:send_iq(st.iq({ type = "get"; id = id.medium(); from = session.full_jid; to = room_nick })
+ :tag("ping", { xmlns = "urn:xmpp:ping"; }))
+ :catch(function(err)
+ module:send(
+ st.presence({ type = "unavailable"; id = id.medium(); to = session.full_jid; from = room_nick })
+ :tag("x", { xmlns = "http://jabber.org/protocol/muc#user" })
+ :tag("item", { affiliation = "none"; role = "none" })
+ :text_tag("reason", err.text or "Connection to remote server lost")
+ :up()
+ :tag("status", { code = "110" }):up()
+ :tag("status", { code = "307" }):up()
+ :tag("status", { code = "333" }):up()
+ :reset());
+ end);
+ -- TODO do this with some delay?
+ end
+ end
+
+ end
+ end
+ end
+end);