2 -- Copyright (C) 2008-2009 Matthew Wild
3 -- Copyright (C) 2008-2009 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 socket = require "socket";
15 local format = string.format;
16 local t_insert, t_sort = table.insert, table.sort;
17 local get_traceback = debug.traceback;
18 local tostring, pairs, ipairs, getmetatable, newproxy, error, tonumber
19 = tostring, pairs, ipairs, getmetatable, newproxy, error, tonumber;
21 local idna_to_ascii = require "util.encodings".idna.to_ascii;
22 local connlisteners_get = require "net.connlisteners".get;
23 local wrapclient = require "net.server".wrapclient;
24 local modulemanager = require "core.modulemanager";
25 local st = require "stanza";
26 local stanza = st.stanza;
27 local nameprep = require "util.encodings".stringprep.nameprep;
29 local uuid_gen = require "util.uuid".generate;
31 local logger_init = require "util.logger".init;
33 local log = logger_init("s2smanager");
35 local sha256_hash = require "util.hashes".sha256;
37 local dialback_secret = sha256_hash(tostring{} .. math.random() .. socket.gettime(), true);
39 local adns = require "net.adns";
42 local incoming_s2s = incoming_s2s;
46 local function compare_srv_priorities(a,b) return a.priority < b.priority or a.weight < b.weight; end
48 local function bounce_sendq(session)
49 local sendq = session.sendq;
51 session.log("info", "sending error replies for "..#sendq.." queued stanzas because of failed outgoing connection to "..tostring(session.to_host));
55 (session.log or log)("error", "Replying to to an s2s error reply, please report this! Traceback: %s", get_traceback());
59 for i, data in ipairs(sendq) do
60 local reply = data[2];
61 local xmlns = reply.attr.xmlns;
62 if not xmlns or xmlns == "jabber:client" or xmlns == "jabber:server" then
63 reply.attr.type = "error";
64 reply:tag("error", {type = "cancel"})
65 :tag("remote-server-not-found", {xmlns = "urn:ietf:params:xml:ns:xmpp-stanzas"}):up();
66 core_process_stanza(dummy, reply);
74 function send_to_host(from_host, to_host, data)
75 local host = hosts[from_host].s2sout[to_host];
77 -- We have a connection to this host already
78 if host.type == "s2sout_unauthed" and data.name ~= "db:verify" and ((not data.xmlns) or data.xmlns == "jabber:client" or data.xmlns == "jabber:server") then
79 (host.log or log)("debug", "trying to send over unauthed s2sout to "..to_host);
80 if not host.notopen and not host.dialback_key and host.sends2s then
81 host.log("debug", "dialback had not been initiated");
82 initiate_dialback(host);
85 -- Queue stanza until we are able to send it
86 if host.sendq then t_insert(host.sendq, {tostring(data), st.reply(data)});
87 else host.sendq = { {tostring(data), st.reply(data)} }; end
88 host.log("debug", "stanza [%s] queued ", data.name);
89 elseif host.type == "local" or host.type == "component" then
90 log("error", "Trying to send a stanza to ourselves??")
91 log("error", "Traceback: %s", get_traceback());
92 log("error", "Stanza: %s", tostring(data));
94 (host.log or log)("debug", "going to send stanza to "..to_host.." from "..from_host);
96 if host.from_host ~= from_host then
97 log("error", "WARNING! This might, possibly, be a bug, but it might not...");
98 log("error", "We are going to send from %s instead of %s", tostring(host.from_host), tostring(from_host));
101 host.log("debug", "stanza sent over "..host.type);
104 log("debug", "opening a new outgoing connection for this stanza");
105 local host_session = new_outgoing(from_host, to_host);
107 host_session.sendq = { {tostring(data), st.reply(data)} };
108 log("debug", "stanza [%s] queued until connection complete", tostring(data.name));
109 if (not host_session.connecting) and (not host_session.conn) then
110 log("warn", "Connection to %s failed already, destroying session...", to_host);
111 destroy_session(host_session);
116 local open_sessions = 0;
118 function new_incoming(conn)
119 local session = { conn = conn, type = "s2sin_unauthed", direction = "incoming", hosts = {} };
121 session.trace = newproxy(true);
122 getmetatable(session.trace).__gc = function () open_sessions = open_sessions - 1; end;
124 open_sessions = open_sessions + 1;
125 local w, log = conn.write, logger_init("s2sin"..tostring(conn):match("[a-f0-9]+$"));
126 session.sends2s = function (t) log("debug", "sending: %s", tostring(t)); w(tostring(t)); end
127 incoming_s2s[session] = true;
131 function new_outgoing(from_host, to_host)
132 local host_session = { to_host = to_host, from_host = from_host, notopen = true, type = "s2sout_unauthed", direction = "outgoing" };
133 hosts[from_host].s2sout[to_host] = host_session;
137 local conn_name = "s2sout"..tostring(host_session):match("[a-f0-9]*$");
138 log = logger_init(conn_name);
139 host_session.log = log;
142 attempt_connection(host_session);
144 if not host_session.sends2s then
145 -- A sends2s which buffers data (until the stream is opened)
146 -- note that data in this buffer will be sent before the stream is authed
147 -- and will not be ack'd in any way, successful or otherwise
149 function host_session.sends2s(data)
152 host_session.send_buffer = buffer;
154 log("debug", "Buffering data on unconnected s2sout to %s", to_host);
155 buffer[#buffer+1] = data;
156 log("debug", "Buffered item %d: %s", #buffer, tostring(data));
165 function attempt_connection(host_session, err)
166 local from_host, to_host = host_session.from_host, host_session.to_host;
167 local connect_host, connect_port = idna_to_ascii(to_host), 5269;
169 if not err then -- This is our first attempt
170 log("debug", "First attempt to connect to %s, starting with SRV lookup...", to_host);
171 host_session.connecting = true;
173 adns.lookup(function (answer)
174 host_session.connecting = nil;
176 log("debug", to_host.." has SRV records, handling...");
177 local srv_hosts = {};
178 host_session.srv_hosts = srv_hosts;
179 for _, record in ipairs(answer) do
180 t_insert(srv_hosts, record.srv);
182 t_sort(srv_hosts, compare_srv_priorities);
184 local srv_choice = srv_hosts[1];
185 host_session.srv_choice = 1;
187 connect_host, connect_port = srv_choice.target or to_host, srv_choice.port or connect_port;
188 log("debug", "Best record found, will connect to %s:%d", connect_host, connect_port);
191 log("debug", to_host.." has no SRV records, falling back to A");
193 -- Try with SRV, or just the plain hostname if no SRV
194 return try_connect(host_session, connect_host, connect_port);
195 end, "_xmpp-server._tcp."..connect_host..".", "SRV");
196 log("debug", "DNS lookup for %s sent, waiting for response before we can connect", to_host);
197 return true; -- Attempt in progress
198 elseif host_session.srv_hosts and #host_session.srv_hosts > host_session.srv_choice then -- Not our first attempt, and we also have SRV
199 host_session.srv_choice = host_session.srv_choice + 1;
200 local srv_choice = host_session.srv_hosts[host_session.srv_choice];
201 connect_host, connect_port = srv_choice.target or to_host, srv_choice.port or connect_port;
202 host_session.log("info", "Connection failed (%s). Attempt #%d: This time to %s:%d", tostring(err), host_session.srv_choice, connect_host, connect_port);
204 host_session.log("info", "Out of connection options, can't connect to %s", tostring(host_session.to_host));
205 -- We're out of options
209 if not (connect_host and connect_port) then
210 -- Likely we couldn't resolve DNS
211 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));
215 return try_connect(host_session, connect_host, connect_port);
218 function try_connect(host_session, connect_host, connect_port)
219 host_session.log("info", "Beginning new connection attempt to %s (%s:%d)", host_session.to_host, connect_host, connect_port);
220 -- Ok, we're going to try to connect
222 local from_host, to_host = host_session.from_host, host_session.to_host;
224 local conn, handler = socket.tcp()
227 local success, err = conn:connect(connect_host, connect_port);
228 if not success and err ~= "timeout" then
229 log("warn", "s2s connect() failed: %s", err);
233 local cl = connlisteners_get("xmppserver");
234 conn = wrapclient(conn, connect_host, connect_port, cl, cl.default_mode or 1, hosts[from_host].ssl_ctx, false );
235 host_session.conn = conn;
237 -- Register this outgoing connection so that xmppserver_listener knows about it
238 -- otherwise it will assume it is a new incoming connection
239 cl.register_outgoing(conn, host_session);
241 local w = conn.write;
242 host_session.sends2s = function (t) log("debug", "sending: %s", tostring(t)); w(tostring(t)); end
244 conn.write(format([[<stream:stream xmlns='jabber:server' xmlns:db='jabber:server:dialback' xmlns:stream='http://etherx.jabber.org/streams' from='%s' to='%s' version='1.0'>]], from_host, to_host));
245 log("debug", "Connection attempt in progress...");
249 function streamopened(session, attr)
250 local send = session.sends2s;
252 -- TODO: #29: SASL/TLS on s2s streams
253 session.version = 0; --tonumber(attr.version) or 0;
255 if session.version >= 1.0 and not (attr.to and attr.from) then
256 log("warn", (session.to_host or "(unknown)").." failed to specify 'to' or 'from' hostname as per RFC");
259 if session.direction == "incoming" then
260 -- Send a reply stream header
261 session.to_host = attr.to and nameprep(attr.to);
262 session.from_host = attr.from and nameprep(attr.from);
264 session.streamid = uuid_gen();
265 (session.log or log)("debug", "incoming s2s received <stream:stream>");
266 send("<?xml version='1.0'?>");
267 send(stanza("stream:stream", { xmlns='jabber:server', ["xmlns:db"]='jabber:server:dialback',
268 ["xmlns:stream"]='http://etherx.jabber.org/streams', id=session.streamid, from=session.to_host }):top_tag());
269 if session.to_host and not hosts[session.to_host] then
270 -- Attempting to connect to a host we don't serve
271 session:close({ condition = "host-unknown"; text = "This host does not serve "..session.to_host });
274 if session.version >= 1.0 then
275 send(st.stanza("stream:features")
276 :tag("dialback", { xmlns='urn:xmpp:features:dialback' }):tag("optional"):up():up());
278 elseif session.direction == "outgoing" then
279 -- If we are just using the connection for verifying dialback keys, we won't try and auth it
280 if not attr.id then error("stream response did not give us a streamid!!!"); end
281 session.streamid = attr.id;
283 -- Send unauthed buffer
284 -- (stanzas which are fine to send before dialback)
285 -- Note that this is *not* the stanza queue (which
286 -- we can only send if auth succeeds) :)
287 local send_buffer = session.send_buffer;
288 if send_buffer and #send_buffer > 0 then
289 log("debug", "Sending s2s send_buffer now...");
290 for i, data in ipairs(send_buffer) do
291 session.sends2s(tostring(data));
292 send_buffer[i] = nil;
295 session.send_buffer = nil;
297 if not session.dialback_verifying then
298 initiate_dialback(session);
300 mark_connected(session);
304 session.notopen = nil;
307 function streamclosed(session)
308 (session.log or log)("debug", "</stream:stream>");
309 session.sends2s("</stream:stream>");
310 session.notopen = true;
313 function initiate_dialback(session)
314 -- generate dialback key
315 session.dialback_key = generate_dialback(session.streamid, session.to_host, session.from_host);
316 session.sends2s(format("<db:result from='%s' to='%s'>%s</db:result>", session.from_host, session.to_host, session.dialback_key));
317 session.log("info", "sent dialback key on outgoing s2s stream");
320 function generate_dialback(id, to, from)
321 return sha256_hash(id..to..from..dialback_secret, true);
324 function verify_dialback(id, to, from, key)
325 return key == generate_dialback(id, to, from);
328 function make_authenticated(session, host)
329 if session.type == "s2sout_unauthed" then
330 session.type = "s2sout";
331 elseif session.type == "s2sin_unauthed" then
332 session.type = "s2sin";
334 session.hosts[host].authed = true;
336 elseif session.type == "s2sin" and host then
337 session.hosts[host].authed = true;
341 session.log("debug", "connection %s->%s is now authenticated", session.from_host or "(unknown)", session.to_host or "(unknown)");
343 mark_connected(session);
348 function mark_connected(session)
349 local sendq, send = session.sendq, session.sends2s;
351 local from, to = session.from_host, session.to_host;
353 session.log("info", session.direction.." s2s connection "..from.."->"..to.." complete");
355 local send_to_host = send_to_host;
356 function session.send(data) send_to_host(to, from, data); end
359 if session.direction == "outgoing" then
361 session.log("debug", "sending "..#sendq.." queued stanzas across new outgoing connection to "..session.to_host);
362 for i, data in ipairs(sendq) do
371 function destroy_session(session)
372 (session.log or log)("info", "Destroying "..tostring(session.direction).." session "..tostring(session.from_host).."->"..tostring(session.to_host));
374 if session.direction == "outgoing" then
375 hosts[session.from_host].s2sout[session.to_host] = nil;
376 bounce_sendq(session);
377 elseif session.direction == "incoming" then
378 incoming_s2s[session] = nil;
381 for k in pairs(session) do