local st = require "util.stanza"; local t_insert, t_remove = table.insert, table.remove; local math_min = math.min; local tonumber, tostring = tonumber, tostring; local add_filter = require "util.filters".add_filter; local timer = require "util.timer"; local xmlns_sm = "urn:xmpp:sm:2"; local sm_attr = { xmlns = xmlns_sm }; local resume_timeout = 300; local max_unacked_stanzas = 0; 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; -- Overwrite process_stanza() and send() local queue = {}; session.outgoing_stanza_queue = queue; session.last_acknowledged_stanza = 0; local _send = session.sends2s or session.send; local function new_send(stanza) local attr = stanza.attr; if attr and not attr.xmlns then -- Stanza in default stream namespace queue[#queue+1] = st.clone(stanza); end local ok, err = _send(stanza); if ok and #queue > max_unacked_stanzas and not session.awaiting_ack then session.awaiting_ack = true; return _send(st.stanza("r", { xmlns = xmlns_sm })); end return ok, err; end if session.sends2s then session.sends2s = new_send; else session.send = new_send; end session.handled_stanza_count = 0; add_filter(session, "stanzas/in", function (stanza) if not stanza.attr.xmlns then session.handled_stanza_count = session.handled_stanza_count + 1; session.log("debug", "Handled %d incoming stanzas", session.handled_stanza_count); end return stanza; end); if not stanza.attr.resume then -- FIXME: Resumption should be a different spec :/ _send(st.stanza("enabled", sm_attr)); return true; end end, 100); 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 (origin.sends2s or 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 origin.awaiting_ack = nil; -- Remove handled stanzas from outgoing_stanza_queue --log("debug", "ACK: h=%s, last=%s", stanza.attr.h or "", origin.last_acknowledged_stanza or ""); local handled_stanza_count = tonumber(stanza.attr.h)-origin.last_acknowledged_stanza; local queue = origin.outgoing_stanza_queue; if handled_stanza_count > #queue then module:log("warn", "The client says it handled %d new stanzas, but we only sent %d :)", handled_stanza_count, #queue); for i=1,#queue do module:log("debug", "Q item %d: %s", i, tostring(queue[i])); end end for i=1,math_min(handled_stanza_count,#queue) do t_remove(origin.outgoing_stanza_queue, 1); end origin.last_acknowledged_stanza = origin.last_acknowledged_stanza + handled_stanza_count; 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 handle_unacked_stanzas(session) local queue = session.outgoing_stanza_queue; local error_attr = { type = "cancel" }; if #queue > 0 then session.outgoing_stanza_queue = {}; for i=1,#queue do local reply = st.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, reply); end end end end local _destroy_session = sessionmanager.destroy_session; function sessionmanager.destroy_session(session, err) if session.smacks then if not session.resumption_token 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 else session.hibernating = true; timer.add_task(resume_timeout, function () if session.hibernating then session.resumption_token = nil; sessionmanager.destroy_session(session); -- Re-destroy end end); return; -- Postpone destruction for now end end return _destroy_session(session, err); end