local st = require "util.stanza"; local uuid_generate = require "util.uuid".generate; local t_insert, t_remove = table.insert, table.remove; local math_min = math.min; local os_time = os.time; local tonumber, tostring = tonumber, tostring; local add_filter = require "util.filters".add_filter; local timer = require "util.timer"; local datetime = require "util.datetime"; local xmlns_sm = "urn:xmpp:sm:2"; local xmlns_errors = "urn:ietf:params:xml:ns:xmpp-stanzas"; local xmlns_delay = "urn:xmpp:delay"; local sm_attr = { xmlns = xmlns_sm }; local resume_timeout = module:get_option("smacks_hibernation_time", 300); local s2s_smacks = module:get_option_boolean("smacks_enabled_s2s", false); local max_unacked_stanzas = 0; local session_registry = {}; local function can_do_smacks(session, advertise_only) if session.smacks then return false, "unexpected-request", "Stream management is already enabled"; end local session_type = session.type; if session_type == "c2s" then if not(advertise_only) and not(session.resource) then -- Fail unless we're only advertising sm return false, "unexpected-request", "Client must bind a resource before enabling stream management"; end return true; elseif s2s_smacks and (session_type == "s2sin" or session_type == "s2sout") then return true; end return false, "service-unavailable", "Stream management is not available for this stream"; end module:hook("stream-features", function (event) if can_do_smacks(event.origin, true) then event.features:tag("sm", sm_attr):tag("optional"):up():up(); end end); module:hook("s2s-stream-features", function (event) if can_do_smacks(event.origin, true) then event.features:tag("sm", sm_attr):tag("optional"):up():up(); end end); module:hook_stanza("http://etherx.jabber.org/streams", "features", function (session, stanza) if can_do_smacks(session) and stanza:get_child("sm", xmlns_sm) then session.sends2s(st.stanza("enable", sm_attr)); end end); local function wrap_session(session, resume) -- Overwrite process_stanza() and send() local queue; if not resume then queue = {}; session.outgoing_stanza_queue = queue; session.last_acknowledged_stanza = 0; else queue = session.outgoing_stanza_queue; end 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 local cached_stanza = st.clone(stanza); if cached_stanza and cached_stanza:get_child("delay", xmlns_delay) == nil then cached_stanza = cached_stanza:tag("delay", { xmlns = xmlns_delay, from = session.host, stamp = datetime.datetime()}); end queue[#queue+1] = cached_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", sm_attr)); end return ok, err; end if session.sends2s then session.sends2s = new_send; else session.send = new_send; end if not resume then 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); end return session; end module:hook_stanza(xmlns_sm, "enable", function (session, stanza) local ok, err, err_text = can_do_smacks(session); if not ok then session.log("warn", "Failed to enable smacks: %s", err_text); -- TODO: XEP doesn't say we can send error text, should it? session.send(st.stanza("failed", { xmlns = xmlns_sm }):tag(err, { xmlns = xmlns_errors})); return true; end module:log("debug", "Enabling stream management"); session.smacks = true; wrap_session(session); local resume_token; local resume = stanza.attr.resume; if resume == "true" or resume == "1" then resume_token = uuid_generate(); session_registry[resume_token] = session; session.resumption_token = resume_token; end (session.sends2s or session.send)(st.stanza("enabled", { xmlns = xmlns_sm, id = resume_token, resume = resume })); return true; end, 100); module:hook_stanza(xmlns_sm, "enabled", function (session, stanza) module:log("debug", "Enabling stream management"); session.smacks = true; wrap_session(session); -- FIXME Resume? return true; 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); module:log("debug", "Client h: %d, our h: %d", tonumber(stanza.attr.h), origin.last_acknowledged_stanza); 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 module:hook("pre-resource-unbind", function (event) local session, err = event.session, event.error; 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.log("debug", "mod_smacks hibernating session for up to %d seconds", resume_timeout); local hibernate_time = os_time(); -- Track the time we went into hibernation session.hibernating = hibernate_time; local resumption_token = session.resumption_token; timer.add_task(resume_timeout, function () session.log("debug", "mod_smacks hibernation timeout reached..."); -- We need to check the current resumption token for this resource -- matches the smacks session this timer is for in case it changed -- (for example, the client may have bound a new resource and -- started a new smacks session, or not be using smacks) local curr_session = hosts[session.host].sessions[session.username].sessions[session.resource]; if curr_session.resumption_token == resumption_token -- Check the hibernate time still matches what we think it is, -- otherwise the session resumed and re-hibernated. and session.hibernating == hibernate_time then session.log("debug", "Destroying session for hibernating too long"); session_registry[session.resumption_token] = nil; session.resumption_token = nil; sessionmanager.destroy_session(session); else session.log("debug", "Session resumed before hibernation timeout, all is well") end end); return true; -- Postpone destruction for now end end end); module:hook_stanza(xmlns_sm, "resume", function (session, stanza) local id = stanza.attr.previd; local original_session = session_registry[id]; if not original_session then session.log("debug", "Tried to resume non-existent session with id %s", id); session.send(st.stanza("failed", sm_attr) :tag("item-not-found", { xmlns = xmlns_errors }) ); elseif session.username == original_session.username and session.host == original_session.host then session.log("debug", "mod_smacks resuming existing session..."); -- TODO: All this should move to sessionmanager (e.g. session:replace(new_session)) original_session.ip = session.ip; original_session.conn = session.conn; original_session.send = session.send; original_session.stream = session.stream; original_session.secure = session.secure; original_session.hibernating = nil; local filter = original_session.filter; local stream = session.stream; local log = session.log; function original_session.data(data) data = filter("bytes/in", data); if data then local ok, err = stream:feed(data); if ok then return; end log("debug", "Received invalid XML (%s) %d bytes: %s", tostring(err), #data, data:sub(1, 300):gsub("[\r\n]+", " "):gsub("[%z\1-\31]", "_")); original_session:close("xml-not-well-formed"); end end wrap_session(original_session, true); -- Inform xmppstream of the new session (passed to its callbacks) stream:set_session(original_session); -- Similar for connlisteners require "net.connlisteners".get("xmppclient").associate_session(session.conn, original_session); session.send(st.stanza("resumed", { xmlns = xmlns_sm, h = original_session.handled_stanza_count, previd = id })); -- Fake an with the h of the from the client original_session:dispatch_stanza(st.stanza("a", { xmlns = xmlns_sm, h = stanza.attr.h })); -- Ok, we need to re-send any stanzas that the client didn't see -- ...they are what is now left in the outgoing stanza queue local queue = original_session.outgoing_stanza_queue; for i=1,#queue do session.send(queue[i]); end else log("warn", "Client %s@%s[%s] tried to resume stream for %s@%s[%s]", session.username or "?", session.host or "?", session.type, original_session.username or "?", original_session.host or "?", original_session.type); session.send(st.stanza("failed", sm_attr) :tag("not-authorized", { xmlns = xmlns_errors })); end return true; end);