mod_smacks: XEP-0198 Stream Management acks. Initial commit - very rough, useful mainly for testing at the moment, most certainly contains bugs :)
local st = require "util.stanza";
local t_insert, t_remove = table.insert, table.remove;
local tonumber, tostring = tonumber, tostring;
local xmlns_sm = "urn:xmpp:sm:2";
local sm_attr = { xmlns = xmlns_sm };
module:add_event_hook("stream-features",
function (session, features)
features:tag("sm", sm_attr):tag("optional"):up():up();
end);
module:hook("s2s-stream-features",
function (data)
data.features:tag("sm", sm_attr):tag("optional"):up():up();
end);
module:hook_stanza(xmlns_sm, "enable",
function (session, stanza)
module:log("debug", "Enabling stream management");
session.smacks = true;
session.handled_stanza_count = 0;
-- Overwrite process_stanza() and send()
local queue, queue_length = {}, 0;
session.outgoing_stanza_queue, session.outgoing_stanza_count = queue, queue_length;
local _send = session.send;
function session.send(stanza)
local attr = stanza.attr;
if attr and not attr.xmlns then -- Stanza in default stream namespace
queue_length = queue_length + 1;
session.outgoing_stanza_count = queue_length;
queue[queue_length] = st.reply(stanza);
end
local ok, err = _send(stanza);
if ok then
return _send(st.stanza("r", { xmlns = xmlns_sm }));
end
return ok, err;
end
_send(st.stanza("enabled", sm_attr));
return true;
end);
module:hook_stanza(xmlns_sm, "r", function (origin, stanza)
if not origin.smacks then
module:log("debug", "Received ack request from non-smack-enabled session");
return;
end
module:log("debug", "Received ack request, acking for %d", origin.handled_stanza_count);
-- Reply with <a>
origin.send(st.stanza("a", { xmlns = xmlns_sm, h = tostring(origin.handled_stanza_count) }));
return true;
end);
module:hook_stanza(xmlns_sm, "a", function (origin, stanza)
if not origin.smacks then return; end
-- Remove handled stanzas from outgoing_stanza_queue
local handled_stanza_count = tonumber(stanza.attr.h)+1;
for i=1,handled_stanza_count do
t_remove(origin.outgoing_stanza_queue, 1);
end
return true;
end);
--TODO: Optimise... incoming stanzas should be handled by a per-session
-- function that has a counter as an upvalue (no table indexing for increments,
-- and won't slow non-198 sessions). We can also then remove the .handled flag
-- on stanzas
function catch_all_incoming_stanzas(data)
local origin, stanza = data.origin, data.stanza;
if origin.smacks and not stanza.handled then
stanza.handled = true;
origin.handled_stanza_count = origin.handled_stanza_count + 1;
module:log("debug", "Handled %d stanzas", origin.handled_stanza_count);
end
end
module:hook("message/bare", catch_all_incoming_stanzas, 1000);
module:hook("message/full", catch_all_incoming_stanzas, 1000);
module:hook("message/host", catch_all_incoming_stanzas, 1000);
module:hook("presence/bare", catch_all_incoming_stanzas, 1000);
module:hook("presence/full", catch_all_incoming_stanzas, 1000);
module:hook("presence/host", catch_all_incoming_stanzas, 1000);
module:hook("iq/bare", catch_all_incoming_stanzas, 1000);
module:hook("iq/full", catch_all_incoming_stanzas, 1000);
module:hook("iq/host", catch_all_incoming_stanzas, 1000);
function handle_unacked_stanzas(session)
local queue = session.outgoing_stanza_queue;
local error_attr = { type = "cancel" };
if #queue > 0 then
for i=1,#queue do
local reply = queue[i];
if reply.attr.to ~= session.full_jid then
reply.attr.type = "error";
reply:tag("error", error_attr)
:tag("recipient-unavailable", {xmlns = "urn:ietf:params:xml:ns:xmpp-stanzas"});
core_process_stanza(session, queue[i]);
end
queue[i] = nil;
end
end
end
local _destroy_session = sessionmanager.destroy_session;
function sessionmanager.destroy_session(session, err)
if session.smacks then
local queue = session.outgoing_stanza_queue;
if #queue > 0 then
module:log("warn", "Destroying session with %d unacked stanzas:", #queue);
for i=1,#queue do
module:log("warn", "::%s", tostring(queue[i]));
end
handle_unacked_stanzas(session);
end
end
return _destroy_session(session, err);
end