2 -- Copyright (C) 2008-2010 Matthew Wild
3 -- Copyright (C) 2008-2010 Waqas Hussain
5 -- This project is MIT/X11 licensed. Please see the
6 -- COPYING file in the source package for more information.
12 local sessions = sessions;
13 local core_process_stanza = function(a, b) core_process_stanza(a, b); end
14 local add_task = require "util.timer".add_task;
15 local socket = require "socket";
16 local format = string.format;
17 local t_insert, t_sort = table.insert, table.sort;
18 local get_traceback = debug.traceback;
19 local tostring, pairs, ipairs, getmetatable, newproxy, error, tonumber, setmetatable
20 = tostring, pairs, ipairs, getmetatable, newproxy, error, tonumber, setmetatable;
22 local idna_to_ascii = require "util.encodings".idna.to_ascii;
23 local connlisteners_get = require "net.connlisteners".get;
24 local initialize_filters = require "util.filters".initialize;
25 local wrapclient = require "net.server".wrapclient;
26 local modulemanager = require "core.modulemanager";
27 local st = require "stanza";
28 local stanza = st.stanza;
29 local nameprep = require "util.encodings".stringprep.nameprep;
31 local fire_event = prosody.events.fire_event;
32 local uuid_gen = require "util.uuid".generate;
34 local logger_init = require "util.logger".init;
36 local log = logger_init("s2smanager");
38 local sha256_hash = require "util.hashes".sha256;
40 local adns, dns = require "net.adns", require "net.dns";
41 local config = require "core.configmanager";
42 local connect_timeout = config.get("*", "core", "s2s_timeout") or 60;
43 local dns_timeout = config.get("*", "core", "dns_timeout") or 15;
44 local max_dns_depth = config.get("*", "core", "dns_max_depth") or 3;
46 dns.settimeout(dns_timeout);
48 local prosody = _G.prosody;
50 prosody.incoming_s2s = incoming_s2s;
51 local incoming_s2s = incoming_s2s;
55 function compare_srv_priorities(a,b)
56 return a.priority < b.priority or (a.priority == b.priority and a.weight > b.weight);
59 local bouncy_stanzas = { message = true, presence = true, iq = true };
60 local function bounce_sendq(session, reason)
61 local sendq = session.sendq;
63 session.log("info", "sending error replies for "..#sendq.." queued stanzas because of failed outgoing connection to "..tostring(session.to_host));
67 (session.log or log)("error", "Replying to to an s2s error reply, please report this! Traceback: %s", get_traceback());
71 for i, data in ipairs(sendq) do
72 local reply = data[2];
73 if reply and not(reply.attr.xmlns) and bouncy_stanzas[reply.name] then
74 reply.attr.type = "error";
75 reply:tag("error", {type = "cancel"})
76 :tag("remote-server-not-found", {xmlns = "urn:ietf:params:xml:ns:xmpp-stanzas"}):up();
78 reply:tag("text", {xmlns = "urn:ietf:params:xml:ns:xmpp-stanzas"})
79 :text("Server-to-server connection failed: "..reason):up();
81 core_process_stanza(dummy, reply);
89 function send_to_host(from_host, to_host, data)
90 if not hosts[from_host] then
91 log("warn", "Attempt to send stanza from %s - a host we don't serve", from_host);
94 local host = hosts[from_host].s2sout[to_host];
96 -- We have a connection to this host already
97 if host.type == "s2sout_unauthed" and (data.name ~= "db:verify" or not host.dialback_key) then
98 (host.log or log)("debug", "trying to send over unauthed s2sout to "..to_host);
100 -- Queue stanza until we are able to send it
101 if host.sendq then t_insert(host.sendq, {tostring(data), data.attr.type ~= "error" and data.attr.type ~= "result" and st.reply(data)});
102 else host.sendq = { {tostring(data), data.attr.type ~= "error" and data.attr.type ~= "result" and st.reply(data)} }; end
103 host.log("debug", "stanza [%s] queued ", data.name);
104 elseif host.type == "local" or host.type == "component" then
105 log("error", "Trying to send a stanza to ourselves??")
106 log("error", "Traceback: %s", get_traceback());
107 log("error", "Stanza: %s", tostring(data));
110 (host.log or log)("debug", "going to send stanza to "..to_host.." from "..from_host);
112 if host.from_host ~= from_host then
113 log("error", "WARNING! This might, possibly, be a bug, but it might not...");
114 log("error", "We are going to send from %s instead of %s", tostring(host.from_host), tostring(from_host));
117 host.log("debug", "stanza sent over "..host.type);
120 log("debug", "opening a new outgoing connection for this stanza");
121 local host_session = new_outgoing(from_host, to_host);
124 host_session.sendq = { {tostring(data), data.attr.type ~= "error" and data.attr.type ~= "result" and st.reply(data)} };
125 log("debug", "stanza [%s] queued until connection complete", tostring(data.name));
126 if (not host_session.connecting) and (not host_session.conn) then
127 log("warn", "Connection to %s failed already, destroying session...", to_host);
128 if not destroy_session(host_session, "Connection failed") then
129 -- Already destroyed, we need to bounce our stanza
130 bounce_sendq(host_session, host_session.destruction_reason);
138 local open_sessions = 0;
140 function new_incoming(conn)
141 local session = { conn = conn, type = "s2sin_unauthed", direction = "incoming", hosts = {} };
143 session.trace = newproxy(true);
144 getmetatable(session.trace).__gc = function () open_sessions = open_sessions - 1; end;
146 open_sessions = open_sessions + 1;
147 local w, log = conn.write, logger_init("s2sin"..tostring(conn):match("[a-f0-9]+$"));
149 local filter = initialize_filters(session);
150 session.sends2s = function (t)
151 log("debug", "sending: %s", t.top_tag and t:top_tag() or t:match("^([^>]*>?)"));
153 t = filter("stanzas/out", t);
156 t = filter("bytes/out", tostring(t));
162 incoming_s2s[session] = true;
163 add_task(connect_timeout, function ()
164 if session.conn ~= conn or
165 session.type == "s2sin" then
166 return; -- Ok, we're connect[ed|ing]
168 -- Not connected, need to close session and clean up
169 (session.log or log)("debug", "Destroying incomplete session %s->%s due to inactivity",
170 session.from_host or "(unknown)", session.to_host or "(unknown)");
171 session:close("connection-timeout");
176 function new_outgoing(from_host, to_host, connect)
177 local host_session = { to_host = to_host, from_host = from_host, host = from_host,
178 notopen = true, type = "s2sout_unauthed", direction = "outgoing",
179 open_stream = session_open_stream };
181 hosts[from_host].s2sout[to_host] = host_session;
183 host_session.close = destroy_session; -- This gets replaced by xmppserver_listener later
187 local conn_name = "s2sout"..tostring(host_session):match("[a-f0-9]*$");
188 log = logger_init(conn_name);
189 host_session.log = log;
192 initialize_filters(host_session);
194 if connect ~= false then
195 -- Kick the connection attempting machine into life
196 if not attempt_connection(host_session) then
197 -- Intentionally not returning here, the
198 -- session is needed, connected or not
199 destroy_session(host_session);
203 if not host_session.sends2s then
204 -- A sends2s which buffers data (until the stream is opened)
205 -- note that data in this buffer will be sent before the stream is authed
206 -- and will not be ack'd in any way, successful or otherwise
208 function host_session.sends2s(data)
211 host_session.send_buffer = buffer;
213 log("debug", "Buffering data on unconnected s2sout to %s", to_host);
214 buffer[#buffer+1] = data;
215 log("debug", "Buffered item %d: %s", #buffer, tostring(data));
223 function attempt_connection(host_session, err)
224 local from_host, to_host = host_session.from_host, host_session.to_host;
225 local connect_host, connect_port = to_host and idna_to_ascii(to_host), 5269;
227 if not connect_host then
231 if not err then -- This is our first attempt
232 log("debug", "First attempt to connect to %s, starting with SRV lookup...", to_host);
233 host_session.connecting = true;
235 handle = adns.lookup(function (answer)
237 host_session.connecting = nil;
239 log("debug", to_host.." has SRV records, handling...");
240 local srv_hosts = {};
241 host_session.srv_hosts = srv_hosts;
242 for _, record in ipairs(answer) do
243 t_insert(srv_hosts, record.srv);
245 t_sort(srv_hosts, compare_srv_priorities);
247 local srv_choice = srv_hosts[1];
248 host_session.srv_choice = 1;
250 connect_host, connect_port = srv_choice.target or to_host, srv_choice.port or connect_port;
251 log("debug", "Best record found, will connect to %s:%d", connect_host, connect_port);
254 log("debug", to_host.." has no SRV records, falling back to A");
256 -- Try with SRV, or just the plain hostname if no SRV
257 local ok, err = try_connect(host_session, connect_host, connect_port);
259 if not attempt_connection(host_session, err) then
260 -- No more attempts will be made
261 destroy_session(host_session, err);
264 end, "_xmpp-server._tcp."..connect_host..".", "SRV");
266 return true; -- Attempt in progress
267 elseif host_session.srv_hosts and #host_session.srv_hosts > host_session.srv_choice then -- Not our first attempt, and we also have SRV
268 host_session.srv_choice = host_session.srv_choice + 1;
269 local srv_choice = host_session.srv_hosts[host_session.srv_choice];
270 connect_host, connect_port = srv_choice.target or to_host, srv_choice.port or connect_port;
271 host_session.log("info", "Connection failed (%s). Attempt #%d: This time to %s:%d", tostring(err), host_session.srv_choice, connect_host, connect_port);
273 host_session.log("info", "Out of connection options, can't connect to %s", tostring(host_session.to_host));
274 -- We're out of options
278 if not (connect_host and connect_port) then
279 -- Likely we couldn't resolve DNS
280 log("warn", "Hmm, we're without a host (%s) and port (%s) to connect to for %s, giving up :(", tostring(connect_host), tostring(connect_port), tostring(to_host));
284 return try_connect(host_session, connect_host, connect_port);
287 function try_connect(host_session, connect_host, connect_port)
288 host_session.connecting = true;
290 handle = adns.lookup(function (reply, err)
292 host_session.connecting = nil;
294 -- COMPAT: This is a compromise for all you CNAME-(ab)users :)
295 if not (reply and reply[#reply] and reply[#reply].a) then
296 local count = max_dns_depth;
297 reply = dns.peek(connect_host, "CNAME", "IN");
298 while count > 0 and reply and reply[#reply] and not reply[#reply].a and reply[#reply].cname do
299 log("debug", "Looking up %s (DNS depth is %d)", tostring(reply[#reply].cname), count);
300 reply = dns.peek(reply[#reply].cname, "A", "IN") or dns.peek(reply[#reply].cname, "CNAME", "IN");
304 -- end of CNAME resolving
306 if reply and reply[#reply] and reply[#reply].a then
307 log("debug", "DNS reply for %s gives us %s", connect_host, reply[#reply].a);
308 local ok, err = make_connect(host_session, reply[#reply].a, connect_port);
310 if not attempt_connection(host_session, err or "closed") then
311 err = err and (": "..err) or "";
312 destroy_session(host_session, "Connection failed"..err);
316 log("debug", "DNS lookup failed to get a response for %s", connect_host);
317 if not attempt_connection(host_session, "name resolution failed") then -- Retry if we can
318 log("debug", "No other records to try for %s - destroying", host_session.to_host);
319 err = err and (": "..err) or "";
320 destroy_session(host_session, "DNS resolution failed"..err); -- End of the line, we can't
323 end, connect_host, "A", "IN");
328 function make_connect(host_session, connect_host, connect_port)
329 (host_session.log or log)("info", "Beginning new connection attempt to %s (%s:%d)", host_session.to_host, connect_host, connect_port);
330 -- Ok, we're going to try to connect
332 local from_host, to_host = host_session.from_host, host_session.to_host;
334 local conn, handler = socket.tcp();
337 log("warn", "Failed to create outgoing connection, system error: %s", handler);
338 return false, handler;
342 local success, err = conn:connect(connect_host, connect_port);
343 if not success and err ~= "timeout" then
344 log("warn", "s2s connect() to %s (%s:%d) failed: %s", host_session.to_host, connect_host, connect_port, err);
348 local cl = connlisteners_get("xmppserver");
349 conn = wrapclient(conn, connect_host, connect_port, cl, cl.default_mode or 1 );
350 host_session.conn = conn;
352 local filter = initialize_filters(host_session);
353 local w, log = conn.write, host_session.log;
354 host_session.sends2s = function (t)
355 log("debug", "sending: %s", (t.top_tag and t:top_tag()) or t:match("^[^>]*>?"));
357 t = filter("stanzas/out", t);
360 t = filter("bytes/out", tostring(t));
362 return w(conn, tostring(t));
367 -- Register this outgoing connection so that xmppserver_listener knows about it
368 -- otherwise it will assume it is a new incoming connection
369 cl.register_outgoing(conn, host_session);
371 host_session:open_stream(from_host, to_host);
373 log("debug", "Connection attempt in progress...");
374 add_task(connect_timeout, function ()
375 if host_session.conn ~= conn or
376 host_session.type == "s2sout" or
377 host_session.connecting then
378 return; -- Ok, we're connect[ed|ing]
380 -- Not connected, need to close session and clean up
381 (host_session.log or log)("warn", "Destroying incomplete session %s->%s due to inactivity",
382 host_session.from_host or "(unknown)", host_session.to_host or "(unknown)");
383 host_session:close("connection-timeout");
388 function session_open_stream(session, from, to)
389 session.sends2s(st.stanza("stream:stream", {
390 xmlns='jabber:server', ["xmlns:db"]='jabber:server:dialback',
391 ["xmlns:stream"]='http://etherx.jabber.org/streams',
392 from=from, to=to, version='1.0', ["xml:lang"]='en'}):top_tag());
395 function streamopened(session, attr)
396 local send = session.sends2s;
398 -- TODO: #29: SASL/TLS on s2s streams
399 session.version = tonumber(attr.version) or 0;
401 if session.secure == false then
402 session.secure = true;
405 if session.direction == "incoming" then
406 -- Send a reply stream header
407 session.to_host = attr.to and nameprep(attr.to);
408 session.from_host = attr.from and nameprep(attr.from);
410 session.streamid = uuid_gen();
411 (session.log or log)("debug", "incoming s2s received <stream:stream>");
412 if session.to_host then
413 if not hosts[session.to_host] then
414 -- Attempting to connect to a host we don't serve
416 condition = "host-unknown";
417 text = "This host does not serve "..session.to_host
420 elseif hosts[session.to_host].disallow_s2s then
421 -- Attempting to connect to a host that disallows s2s
423 condition = "policy-violation";
424 text = "Server-to-server communication is not allowed to this host";
429 send("<?xml version='1.0'?>");
430 send(stanza("stream:stream", { xmlns='jabber:server', ["xmlns:db"]='jabber:server:dialback',
431 ["xmlns:stream"]='http://etherx.jabber.org/streams', id=session.streamid, from=session.to_host, to=session.from_host, version=(session.version > 0 and "1.0" or nil) }):top_tag());
432 if session.version >= 1.0 then
433 local features = st.stanza("stream:features");
435 if session.to_host then
436 hosts[session.to_host].events.fire_event("s2s-stream-features", { origin = session, features = features });
438 (session.log or log)("warn", "No 'to' on stream header from %s means we can't offer any features", session.from_host or "unknown host");
441 log("debug", "Sending stream features: %s", tostring(features));
444 elseif session.direction == "outgoing" then
445 -- If we are just using the connection for verifying dialback keys, we won't try and auth it
446 if not attr.id then error("stream response did not give us a streamid!!!"); end
447 session.streamid = attr.id;
449 -- Send unauthed buffer
450 -- (stanzas which are fine to send before dialback)
451 -- Note that this is *not* the stanza queue (which
452 -- we can only send if auth succeeds) :)
453 local send_buffer = session.send_buffer;
454 if send_buffer and #send_buffer > 0 then
455 log("debug", "Sending s2s send_buffer now...");
456 for i, data in ipairs(send_buffer) do
457 session.sends2s(tostring(data));
458 send_buffer[i] = nil;
461 session.send_buffer = nil;
463 -- If server is pre-1.0, don't wait for features, just do dialback
464 if session.version < 1.0 then
465 if not session.dialback_verifying then
466 log("debug", "Initiating dialback...");
467 initiate_dialback(session);
469 mark_connected(session);
473 session.notopen = nil;
476 function streamclosed(session)
477 (session.log or log)("debug", "Received </stream:stream>");
481 function initiate_dialback(session)
482 -- generate dialback key
483 session.dialback_key = generate_dialback(session.streamid, session.to_host, session.from_host);
484 session.sends2s(format("<db:result from='%s' to='%s'>%s</db:result>", session.from_host, session.to_host, session.dialback_key));
485 session.log("info", "sent dialback key on outgoing s2s stream");
488 function generate_dialback(id, to, from)
489 return sha256_hash(id..to..from..hosts[from].dialback_secret, true);
492 function verify_dialback(id, to, from, key)
493 return key == generate_dialback(id, to, from);
496 function make_authenticated(session, host)
497 if not session.secure then
498 local local_host = session.direction == "incoming" and session.to_host or session.from_host;
499 if config.get(local_host, "core", "s2s_require_encryption") then
501 condition = "policy-violation",
502 text = "Encrypted server-to-server communication is required but was not "
503 ..((session.direction == "outgoing" and "offered") or "used")
507 if session.type == "s2sout_unauthed" then
508 session.type = "s2sout";
509 elseif session.type == "s2sin_unauthed" then
510 session.type = "s2sin";
512 if not session.hosts[host] then session.hosts[host] = {}; end
513 session.hosts[host].authed = true;
515 elseif session.type == "s2sin" and host then
516 if not session.hosts[host] then session.hosts[host] = {}; end
517 session.hosts[host].authed = true;
521 session.log("debug", "connection %s->%s is now authenticated", session.from_host or "(unknown)", session.to_host or "(unknown)");
523 mark_connected(session);
528 -- Stream is authorised, and ready for normal stanzas
529 function mark_connected(session)
530 local sendq, send = session.sendq, session.sends2s;
532 local from, to = session.from_host, session.to_host;
534 session.log("info", session.direction.." s2s connection "..from.."->"..to.." complete");
536 local send_to_host = send_to_host;
537 function session.send(data) return send_to_host(to, from, data); end
539 local event_data = { session = session };
540 if session.type == "s2sout" then
541 prosody.events.fire_event("s2sout-established", event_data);
542 hosts[session.from_host].events.fire_event("s2sout-established", event_data);
544 prosody.events.fire_event("s2sin-established", event_data);
545 hosts[session.to_host].events.fire_event("s2sin-established", event_data);
548 if session.direction == "outgoing" then
550 session.log("debug", "sending "..#sendq.." queued stanzas across new outgoing connection to "..session.to_host);
551 for i, data in ipairs(sendq) do
558 session.srv_hosts = nil;
562 local resting_session = { -- Resting, not dead
564 type = "s2s_destroyed";
565 open_stream = function (session)
566 session.log("debug", "Attempt to open stream on resting session");
568 close = function (session)
569 session.log("debug", "Attempt to close already-closed session");
571 filter = function (type, data) return data; end;
572 }; resting_session.__index = resting_session;
574 function retire_session(session, reason)
575 local log = session.log or log;
576 for k in pairs(session) do
577 if k ~= "trace" and k ~= "log" and k ~= "id" then
582 session.destruction_reason = reason;
584 function session.send(data) log("debug", "Discarding data sent to resting session: %s", tostring(data)); end
585 function session.data(data) log("debug", "Discarding data received from resting session: %s", tostring(data)); end
586 return setmetatable(session, resting_session);
589 function destroy_session(session, reason)
590 if session.destroyed then return; end
591 (session.log or log)("debug", "Destroying "..tostring(session.direction).." session "..tostring(session.from_host).."->"..tostring(session.to_host));
593 if session.direction == "outgoing" then
594 hosts[session.from_host].s2sout[session.to_host] = nil;
595 bounce_sendq(session, reason);
596 elseif session.direction == "incoming" then
597 incoming_s2s[session] = nil;
600 local event_data = { session = session, reason = reason };
601 if session.type == "s2sout" then
602 prosody.events.fire_event("s2sout-destroyed", event_data);
603 if hosts[session.from_host] then
604 hosts[session.from_host].events.fire_event("s2sout-destroyed", event_data);
606 elseif session.type == "s2sin" then
607 prosody.events.fire_event("s2sin-destroyed", event_data);
608 if hosts[session.to_host] then
609 hosts[session.to_host].events.fire_event("s2sin-destroyed", event_data);
613 retire_session(session, reason); -- Clean session until it is GC'd