plugins/mod_s2s/mod_s2s.lua

   1 -- Prosody IM
   2 -- Copyright (C) 2008-2010 Matthew Wild
   3 -- Copyright (C) 2008-2010 Waqas Hussain
   4 --
   5 -- This project is MIT/X11 licensed. Please see the
   6 -- COPYING file in the source package for more information.
   7 --
   8
   9 module:set_global();
  10
  11 local prosody = prosody;
  12 local hosts = prosody.hosts;
  13 local core_process_stanza = prosody.core_process_stanza;
  14
  15 local tostring, type = tostring, type;
  16 local t_insert = table.insert;
  17 local xpcall, traceback = xpcall, debug.traceback;
  18 local NULL = {};
  19
  20 local add_task = require "util.timer".add_task;
  21 local st = require "util.stanza";
  22 local initialize_filters = require "util.filters".initialize;
  23 local nameprep = require "util.encodings".stringprep.nameprep;
  24 local new_xmpp_stream = require "util.xmppstream".new;
  25 local s2s_new_incoming = require "core.s2smanager".new_incoming;
  26 local s2s_new_outgoing = require "core.s2smanager".new_outgoing;
  27 local s2s_destroy_session = require "core.s2smanager".destroy_session;
  28 local uuid_gen = require "util.uuid".generate;
  29 local cert_verify_identity = require "util.x509".verify_identity;
  30 local fire_global_event = prosody.events.fire_event;
  31
  32 local s2sout = module:require("s2sout");
  33
  34 local connect_timeout = module:get_option_number("s2s_timeout", 90);
  35 local stream_close_timeout = module:get_option_number("s2s_close_timeout", 5);
  36 local opt_keepalives = module:get_option_boolean("s2s_tcp_keepalives", module:get_option_boolean("tcp_keepalives", true));
  37 local secure_auth = module:get_option_boolean("s2s_secure_auth", false); -- One day...
  38 local secure_domains, insecure_domains =
  39         module:get_option_set("s2s_secure_domains", {})._items, module:get_option_set("s2s_insecure_domains", {})._items;
  40 local require_encryption = module:get_option_boolean("s2s_require_encryption", false);
  41
  42 local sessions = module:shared("sessions");
  43
  44 local log = module._log;
  45
  46 --- Handle stanzas to remote domains
  47
  48 local bouncy_stanzas = { message = true, presence = true, iq = true };
  49 local function bounce_sendq(session, reason)
  50         local sendq = session.sendq;
  51         if not sendq then return; end
  52         session.log("info", "Sending error replies for "..#sendq.." queued stanzas because of failed outgoing connection to "..tostring(session.to_host));
  53         local dummy = {
  54                 type = "s2sin";
  55                 send = function(s)
  56                         (session.log or log)("error", "Replying to to an s2s error reply, please report this! Traceback: %s", traceback());
  57                 end;
  58                 dummy = true;
  59         };
  60         for i, data in ipairs(sendq) do
  61                 local reply = data[2];
  62                 if reply and not(reply.attr.xmlns) and bouncy_stanzas[reply.name] 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                         if reason then
  67                                 reply:tag("text", {xmlns = "urn:ietf:params:xml:ns:xmpp-stanzas"})
  68                                         :text("Server-to-server connection failed: "..reason):up();
  69                         end
  70                         core_process_stanza(dummy, reply);
  71                 end
  72                 sendq[i] = nil;
  73         end
  74         session.sendq = nil;
  75 end
  76
  77 -- Handles stanzas to existing s2s sessions
  78 function route_to_existing_session(event)
  79         local from_host, to_host, stanza = event.from_host, event.to_host, event.stanza;
  80         if not hosts[from_host] then
  81                 log("warn", "Attempt to send stanza from %s - a host we don't serve", from_host);
  82                 return false;
  83         end
  84         if hosts[to_host] then
  85                 log("warn", "Attempt to route stanza to a remote %s - a host we do serve?!", from_host);
  86                 return false;
  87         end
  88         local host = hosts[from_host].s2sout[to_host];
  89         if host then
  90                 -- We have a connection to this host already
  91                 if host.type == "s2sout_unauthed" and (stanza.name ~= "db:verify" or not host.dialback_key) then
  92                         (host.log or log)("debug", "trying to send over unauthed s2sout to "..to_host);
  93
  94                         -- Queue stanza until we are able to send it
  95                         if host.sendq then t_insert(host.sendq, {tostring(stanza), stanza.attr.type ~= "error" and stanza.attr.type ~= "result" and st.reply(stanza)});
  96                         else host.sendq = { {tostring(stanza), stanza.attr.type ~= "error" and stanza.attr.type ~= "result" and st.reply(stanza)} }; end
  97                         host.log("debug", "stanza [%s] queued ", stanza.name);
  98                         return true;
  99                 elseif host.type == "local" or host.type == "component" then
 100                         log("error", "Trying to send a stanza to ourselves??")
 101                         log("error", "Traceback: %s", traceback());
 102                         log("error", "Stanza: %s", tostring(stanza));
 103                         return false;
 104                 else
 105                         (host.log or log)("debug", "going to send stanza to "..to_host.." from "..from_host);
 106                         -- FIXME
 107                         if host.from_host ~= from_host then
 108                                 log("error", "WARNING! This might, possibly, be a bug, but it might not...");
 109                                 log("error", "We are going to send from %s instead of %s", tostring(host.from_host), tostring(from_host));
 110                         end
 111                         if host.sends2s(stanza) then
 112                                 host.log("debug", "stanza sent over %s", host.type);
 113                                 return true;
 114                         end
 115                 end
 116         end
 117 end
 118
 119 -- Create a new outgoing session for a stanza
 120 function route_to_new_session(event)
 121         local from_host, to_host, stanza = event.from_host, event.to_host, event.stanza;
 122         log("debug", "opening a new outgoing connection for this stanza");
 123         local host_session = s2s_new_outgoing(from_host, to_host);
 124
 125         -- Store in buffer
 126         host_session.bounce_sendq = bounce_sendq;
 127         host_session.sendq = { {tostring(stanza), stanza.attr.type ~= "error" and stanza.attr.type ~= "result" and st.reply(stanza)} };
 128         log("debug", "stanza [%s] queued until connection complete", tostring(stanza.name));
 129         s2sout.initiate_connection(host_session);
 130         if (not host_session.connecting) and (not host_session.conn) then
 131                 log("warn", "Connection to %s failed already, destroying session...", to_host);
 132                 s2s_destroy_session(host_session, "Connection failed");
 133                 return false;
 134         end
 135         return true;
 136 end
 137
 138 function module.add_host(module)
 139         if module:get_option_boolean("disallow_s2s", false) then
 140                 module:log("warn", "The 'disallow_s2s' config option is deprecated, please see http://prosody.im/doc/s2s#disabling");
 141                 return nil, "This host has disallow_s2s set";
 142         end
 143         module:hook("route/remote", route_to_existing_session, -1);
 144         module:hook("route/remote", route_to_new_session, -10);
 145         module:hook("s2s-authenticated", make_authenticated, -1);
 146 end
 147
 148 -- Stream is authorised, and ready for normal stanzas
 149 function mark_connected(session)
 150         local sendq, send = session.sendq, session.sends2s;
 151
 152         local from, to = session.from_host, session.to_host;
 153
 154         session.log("info", "%s s2s connection %s->%s complete", session.direction, from, to);
 155
 156         local event_data = { session = session };
 157         if session.type == "s2sout" then
 158                 fire_global_event("s2sout-established", event_data);
 159                 hosts[from].events.fire_event("s2sout-established", event_data);
 160         else
 161                 local host_session = hosts[to];
 162                 session.send = function(stanza)
 163                         return host_session.events.fire_event("route/remote", { from_host = to, to_host = from, stanza = stanza });
 164                 end;
 165
 166                 fire_global_event("s2sin-established", event_data);
 167                 hosts[to].events.fire_event("s2sin-established", event_data);
 168         end
 169
 170         if session.direction == "outgoing" then
 171                 if sendq then
 172                         session.log("debug", "sending %d queued stanzas across new outgoing connection to %s", #sendq, session.to_host);
 173                         for i, data in ipairs(sendq) do
 174                                 send(data[1]);
 175                                 sendq[i] = nil;
 176                         end
 177                         session.sendq = nil;
 178                 end
 179
 180                 session.ip_hosts = nil;
 181                 session.srv_hosts = nil;
 182         end
 183 end
 184
 185 function make_authenticated(event)
 186         local session, host = event.session, event.host;
 187         if not session.secure then
 188                 if require_encryption or (secure_auth and not(insecure_domains[host])) or secure_domains[host] then
 189                         session:close({
 190                                 condition = "policy-violation",
 191                                 text = "Encrypted server-to-server communication is required but was not "
 192                                        ..((session.direction == "outgoing" and "offered") or "used")
 193                         });
 194                 end
 195         end
 196         if hosts[host] then
 197                 session:close({ condition = "undefined-condition", text = "Attempt to authenticate as a host we serve" });
 198         end
 199         if session.type == "s2sout_unauthed" then
 200                 session.type = "s2sout";
 201         elseif session.type == "s2sin_unauthed" then
 202                 session.type = "s2sin";
 203                 if host then
 204                         if not session.hosts[host] then session.hosts[host] = {}; end
 205                         session.hosts[host].authed = true;
 206                 end
 207         elseif session.type == "s2sin" and host then
 208                 if not session.hosts[host] then session.hosts[host] = {}; end
 209                 session.hosts[host].authed = true;
 210         else
 211                 return false;
 212         end
 213         session.log("debug", "connection %s->%s is now authenticated for %s", session.from_host, session.to_host, host);
 214
 215         mark_connected(session);
 216
 217         return true;
 218 end
 219
 220 --- Helper to check that a session peer's certificate is valid
 221 local function check_cert_status(session)
 222         local host = session.direction == "outgoing" and session.to_host or session.from_host
 223         local conn = session.conn:socket()
 224         local cert
 225         if conn.getpeercertificate then
 226                 cert = conn:getpeercertificate()
 227         end
 228
 229         if cert then
 230                 local chain_valid, errors;
 231                 if conn.getpeerverification then
 232                         chain_valid, errors = conn:getpeerverification();
 233                 elseif conn.getpeerchainvalid then -- COMPAT mw/luasec-hg
 234                         chain_valid, errors = conn:getpeerchainvalid();
 235                         errors = (not chain_valid) and { { errors } } or nil;
 236                 else
 237                         chain_valid, errors = false, { { "Chain verification not supported by this version of LuaSec" } };
 238                 end
 239                 -- Is there any interest in printing out all/the number of errors here?
 240                 if not chain_valid then
 241                         (session.log or log)("debug", "certificate chain validation result: invalid");
 242                         for depth, t in pairs(errors or NULL) do
 243                                 (session.log or log)("debug", "certificate error(s) at depth %d: %s", depth-1, table.concat(t, ", "))
 244                         end
 245                         session.cert_chain_status = "invalid";
 246                 else
 247                         (session.log or log)("debug", "certificate chain validation result: valid");
 248                         session.cert_chain_status = "valid";
 249
 250                         -- We'll go ahead and verify the asserted identity if the
 251                         -- connecting server specified one.
 252                         if host then
 253                                 if cert_verify_identity(host, "xmpp-server", cert) then
 254                                         session.cert_identity_status = "valid"
 255                                 else
 256                                         session.cert_identity_status = "invalid"
 257                                 end
 258                                 (session.log or log)("debug", "certificate identity validation result: %s", session.cert_identity_status);
 259                         end
 260                 end
 261         end
 262         return module:fire_event("s2s-check-certificate", { host = host, session = session, cert = cert });
 263 end
 264
 265 --- XMPP stream event handlers
 266
 267 local stream_callbacks = { default_ns = "jabber:server", handlestanza =  core_process_stanza };
 268
 269 local xmlns_xmpp_streams = "urn:ietf:params:xml:ns:xmpp-streams";
 270
 271 function stream_callbacks.streamopened(session, attr)
 272         local send = session.sends2s;
 273
 274         session.version = tonumber(attr.version) or 0;
 275
 276         -- TODO: Rename session.secure to session.encrypted
 277         if session.secure == false then
 278                 session.secure = true;
 279
 280                 -- Check if TLS compression is used
 281                 local sock = session.conn:socket();
 282                 if sock.info then
 283                         session.compressed = sock:info"compression";
 284                 elseif sock.compression then
 285                         session.compressed = sock:compression(); --COMPAT mw/luasec-hg
 286                 end
 287         end
 288
 289         if session.direction == "incoming" then
 290                 -- Send a reply stream header
 291
 292                 -- Validate to/from
 293                 local to, from = nameprep(attr.to), nameprep(attr.from);
 294                 if not to and attr.to then -- COMPAT: Some servers do not reliably set 'to' (especially on stream restarts)
 295                         session:close({ condition = "improper-addressing", text = "Invalid 'to' address" });
 296                         return;
 297                 end
 298                 if not from and attr.from then -- COMPAT: Some servers do not reliably set 'from' (especially on stream restarts)
 299                         session:close({ condition = "improper-addressing", text = "Invalid 'from' address" });
 300                         return;
 301                 end
 302
 303                 -- Set session.[from/to]_host if they have not been set already and if
 304                 -- this session isn't already authenticated
 305                 if session.type == "s2sin_unauthed" and from and not session.from_host then
 306                         session.from_host = from;
 307                 elseif from ~= session.from_host then
 308                         session:close({ condition = "improper-addressing", text = "New stream 'from' attribute does not match original" });
 309                         return;
 310                 end
 311                 if session.type == "s2sin_unauthed" and to and not session.to_host then
 312                         session.to_host = to;
 313                 elseif to ~= session.to_host then
 314                         session:close({ condition = "improper-addressing", text = "New stream 'to' attribute does not match original" });
 315                         return;
 316                 end
 317
 318                 -- For convenience we'll put the sanitised values into these variables
 319                 to, from = session.to_host, session.from_host;
 320
 321                 session.streamid = uuid_gen();
 322                 (session.log or log)("debug", "Incoming s2s received %s", st.stanza("stream:stream", attr):top_tag());
 323                 if to then
 324                         if not hosts[to] then
 325                                 -- Attempting to connect to a host we don't serve
 326                                 session:close({
 327                                         condition = "host-unknown";
 328                                         text = "This host does not serve "..to
 329                                 });
 330                                 return;
 331                         elseif not hosts[to].modules.s2s then
 332                                 -- Attempting to connect to a host that disallows s2s
 333                                 session:close({
 334                                         condition = "policy-violation";
 335                                         text = "Server-to-server communication is disabled for this host";
 336                                 });
 337                                 return;
 338                         end
 339                 end
 340
 341                 if hosts[from] then
 342                         session:close({ condition = "undefined-condition", text = "Attempt to connect from a host we serve" });
 343                         return;
 344                 end
 345
 346                 if session.secure and not session.cert_chain_status then
 347                         if check_cert_status(session) == false then
 348                                 return;
 349                         end
 350                 end
 351
 352                 session:open_stream(session.to_host, session.from_host)
 353                 if session.version >= 1.0 then
 354                         local features = st.stanza("stream:features");
 355
 356                         if to then
 357                                 hosts[to].events.fire_event("s2s-stream-features", { origin = session, features = features });
 358                         else
 359                                 (session.log or log)("warn", "No 'to' on stream header from %s means we can't offer any features", from or session.ip or "unknown host");
 360                         end
 361
 362                         log("debug", "Sending stream features: %s", tostring(features));
 363                         send(features);
 364                 end
 365                 session.notopen = nil;
 366         elseif session.direction == "outgoing" then
 367                 session.notopen = nil;
 368                 if not attr.id then
 369                         log("error", "Stream response did not give us a stream id!");
 370                         session:close({ condition = "undefined-condition", text = "Missing stream ID" });
 371                         return;
 372                 end
 373                 session.streamid = attr.id;
 374
 375                 if session.secure and not session.cert_chain_status then
 376                         if check_cert_status(session) == false then
 377                                 return;
 378                         end
 379                 end
 380
 381                 -- Send unauthed buffer
 382                 -- (stanzas which are fine to send before dialback)
 383                 -- Note that this is *not* the stanza queue (which
 384                 -- we can only send if auth succeeds) :)
 385                 local send_buffer = session.send_buffer;
 386                 if send_buffer and #send_buffer > 0 then
 387                         log("debug", "Sending s2s send_buffer now...");
 388                         for i, data in ipairs(send_buffer) do
 389                                 session.sends2s(tostring(data));
 390                                 send_buffer[i] = nil;
 391                         end
 392                 end
 393                 session.send_buffer = nil;
 394
 395                 -- If server is pre-1.0, don't wait for features, just do dialback
 396                 if session.version < 1.0 then
 397                         if not session.dialback_verifying then
 398                                 hosts[session.from_host].events.fire_event("s2sout-authenticate-legacy", { origin = session });
 399                         else
 400                                 mark_connected(session);
 401                         end
 402                 end
 403         end
 404 end
 405
 406 function stream_callbacks.streamclosed(session)
 407         (session.log or log)("debug", "Received </stream:stream>");
 408         session:close(false);
 409 end
 410
 411 function stream_callbacks.error(session, error, data)
 412         if error == "no-stream" then
 413                 session.log("debug", "Invalid opening stream header (%s)", (data:gsub("^([^\1]+)\1", "{%1}")));
 414                 session:close("invalid-namespace");
 415         elseif error == "parse-error" then
 416                 session.log("debug", "Server-to-server XML parse error: %s", tostring(error));
 417                 session:close("not-well-formed");
 418         elseif error == "stream-error" then
 419                 local condition, text = "undefined-condition";
 420                 for child in data:children() do
 421                         if child.attr.xmlns == xmlns_xmpp_streams then
 422                                 if child.name ~= "text" then
 423                                         condition = child.name;
 424                                 else
 425                                         text = child:get_text();
 426                                 end
 427                                 if condition ~= "undefined-condition" and text then
 428                                         break;
 429                                 end
 430                         end
 431                 end
 432                 text = condition .. (text and (" ("..text..")") or "");
 433                 session.log("info", "Session closed by remote with error: %s", text);
 434                 session:close(nil, text);
 435         end
 436 end
 437
 438 local function handleerr(err) log("error", "Traceback[s2s]: %s", traceback(tostring(err), 2)); end
 439 function stream_callbacks.handlestanza(session, stanza)
 440         if stanza.attr.xmlns == "jabber:client" then --COMPAT: Prosody pre-0.6.2 may send jabber:client
 441                 stanza.attr.xmlns = nil;
 442         end
 443         stanza = session.filter("stanzas/in", stanza);
 444         if stanza then
 445                 return xpcall(function () return core_process_stanza(session, stanza) end, handleerr);
 446         end
 447 end
 448
 449 local listener = {};
 450
 451 --- Session methods
 452 local stream_xmlns_attr = {xmlns='urn:ietf:params:xml:ns:xmpp-streams'};
 453 local function session_close(session, reason, remote_reason)
 454         local log = session.log or log;
 455         if session.conn then
 456                 if session.notopen then
 457                         if session.direction == "incoming" then
 458                                 session:open_stream(session.to_host, session.from_host);
 459                         else
 460                                 session:open_stream(session.from_host, session.to_host);
 461                         end
 462                 end
 463                 if reason then -- nil == no err, initiated by us, false == initiated by remote
 464                         if type(reason) == "string" then -- assume stream error
 465                                 log("debug", "Disconnecting %s[%s], <stream:error> is: %s", session.host or session.ip or "(unknown host)", session.type, reason);
 466                                 session.sends2s(st.stanza("stream:error"):tag(reason, {xmlns = 'urn:ietf:params:xml:ns:xmpp-streams' }));
 467                         elseif type(reason) == "table" then
 468                                 if reason.condition then
 469                                         local stanza = st.stanza("stream:error"):tag(reason.condition, stream_xmlns_attr):up();
 470                                         if reason.text then
 471                                                 stanza:tag("text", stream_xmlns_attr):text(reason.text):up();
 472                                         end
 473                                         if reason.extra then
 474                                                 stanza:add_child(reason.extra);
 475                                         end
 476                                         log("debug", "Disconnecting %s[%s], <stream:error> is: %s", session.host or session.ip or "(unknown host)", session.type, tostring(stanza));
 477                                         session.sends2s(stanza);
 478                                 elseif reason.name then -- a stanza
 479                                         log("debug", "Disconnecting %s->%s[%s], <stream:error> is: %s", session.from_host or "(unknown host)", session.to_host or "(unknown host)", session.type, tostring(reason));
 480                                         session.sends2s(reason);
 481                                 end
 482                         end
 483                 end
 484
 485                 session.sends2s("</stream:stream>");
 486                 function session.sends2s() return false; end
 487
 488                 local reason = remote_reason or (reason and (reason.text or reason.condition)) or reason;
 489                 session.log("info", "%s s2s stream %s->%s closed: %s", session.direction, session.from_host or "(unknown host)", session.to_host or "(unknown host)", reason or "stream closed");
 490
 491                 -- Authenticated incoming stream may still be sending us stanzas, so wait for </stream:stream> from remote
 492                 local conn = session.conn;
 493                 if reason == nil and not session.notopen and session.type == "s2sin" then
 494                         add_task(stream_close_timeout, function ()
 495                                 if not session.destroyed then
 496                                         session.log("warn", "Failed to receive a stream close response, closing connection anyway...");
 497                                         s2s_destroy_session(session, reason);
 498                                         conn:close();
 499                                 end
 500                         end);
 501                 else
 502                         s2s_destroy_session(session, reason);
 503                         conn:close(); -- Close immediately, as this is an outgoing connection or is not authed
 504                 end
 505         end
 506 end
 507
 508 function session_open_stream(session, from, to)
 509         local attr = {
 510                 ["xmlns:stream"] = 'http://etherx.jabber.org/streams',
 511                 xmlns = 'jabber:server',
 512                 version = session.version and (session.version > 0 and "1.0" or nil),
 513                 ["xml:lang"] = 'en',
 514                 id = session.streamid,
 515                 from = from or "", to = to or "",
 516         }
 517         if not from or (hosts[from] and hosts[from].modules.dialback) then
 518                 attr["xmlns:db"] = 'jabber:server:dialback';
 519         end
 520
 521         session.sends2s("<?xml version='1.0'?>");
 522         session.sends2s(st.stanza("stream:stream", attr):top_tag());
 523         return true;
 524 end
 525
 526 -- Session initialization logic shared by incoming and outgoing
 527 local function initialize_session(session)
 528         local stream = new_xmpp_stream(session, stream_callbacks);
 529         session.stream = stream;
 530
 531         session.notopen = true;
 532
 533         function session.reset_stream()
 534                 session.notopen = true;
 535                 session.streamid = nil;
 536                 session.stream:reset();
 537         end
 538
 539         session.open_stream = session_open_stream;
 540
 541         local filter = session.filter;
 542         function session.data(data)
 543                 data = filter("bytes/in", data);
 544                 if data then
 545                         local ok, err = stream:feed(data);
 546                         if ok then return; end
 547                         (session.log or log)("warn", "Received invalid XML: %s", data);
 548                         (session.log or log)("warn", "Problem was: %s", err);
 549                         session:close("not-well-formed");
 550                 end
 551         end
 552
 553         session.close = session_close;
 554
 555         local handlestanza = stream_callbacks.handlestanza;
 556         function session.dispatch_stanza(session, stanza)
 557                 return handlestanza(session, stanza);
 558         end
 559
 560         add_task(connect_timeout, function ()
 561                 if session.type == "s2sin" or session.type == "s2sout" then
 562                         return; -- Ok, we're connected
 563                 elseif session.type == "s2s_destroyed" then
 564                         return; -- Session already destroyed
 565                 end
 566                 -- Not connected, need to close session and clean up
 567                 (session.log or log)("debug", "Destroying incomplete session %s->%s due to inactivity",
 568                 session.from_host or "(unknown)", session.to_host or "(unknown)");
 569                 session:close("connection-timeout");
 570         end);
 571 end
 572
 573 function listener.onconnect(conn)
 574         conn:setoption("keepalive", opt_keepalives);
 575         local session = sessions[conn];
 576         if not session then -- New incoming connection
 577                 session = s2s_new_incoming(conn);
 578                 sessions[conn] = session;
 579                 session.log("debug", "Incoming s2s connection");
 580
 581                 local filter = initialize_filters(session);
 582                 local w = conn.write;
 583                 session.sends2s = function (t)
 584                         log("debug", "sending: %s", t.top_tag and t:top_tag() or t:match("^([^>]*>?)"));
 585                         if t.name then
 586                                 t = filter("stanzas/out", t);
 587                         end
 588                         if t then
 589                                 t = filter("bytes/out", tostring(t));
 590                                 if t then
 591                                         return w(conn, t);
 592                                 end
 593                         end
 594                 end
 595
 596                 initialize_session(session);
 597         else -- Outgoing session connected
 598                 session:open_stream(session.from_host, session.to_host);
 599         end
 600 end
 601
 602 function listener.onincoming(conn, data)
 603         local session = sessions[conn];
 604         if session then
 605                 session.data(data);
 606         end
 607 end
 608
 609 function listener.onstatus(conn, status)
 610         if status == "ssl-handshake-complete" then
 611                 local session = sessions[conn];
 612                 if session and session.direction == "outgoing" then
 613                         session.log("debug", "Sending stream header...");
 614                         session:open_stream(session.from_host, session.to_host);
 615                 end
 616         end
 617 end
 618
 619 function listener.ondisconnect(conn, err)
 620         local session = sessions[conn];
 621         if session then
 622                 sessions[conn] = nil;
 623                 if err and session.direction == "outgoing" and session.notopen then
 624                         (session.log or log)("debug", "s2s connection attempt failed: %s", err);
 625                         if s2sout.attempt_connection(session, err) then
 626                                 (session.log or log)("debug", "...so we're going to try another target");
 627                                 return; -- Session lives for now
 628                         end
 629                 end
 630                 (session.log or log)("debug", "s2s disconnected: %s->%s (%s)", tostring(session.from_host), tostring(session.to_host), tostring(err or "connection closed"));
 631                 s2s_destroy_session(session, err);
 632         end
 633 end
 634
 635 function listener.register_outgoing(conn, session)
 636         session.direction = "outgoing";
 637         sessions[conn] = session;
 638         initialize_session(session);
 639 end
 640
 641 function listener.ondetach(conn)
 642         sessions[conn] = nil;
 643 end
 644
 645 function check_auth_policy(event)
 646         local host, session = event.host, event.session;
 647         local must_secure = secure_auth;
 648
 649         if not must_secure and secure_domains[host] then
 650                 must_secure = true;
 651         elseif must_secure and insecure_domains[host] then
 652                 must_secure = false;
 653         end
 654
 655         if must_secure and (session.cert_chain_status ~= "valid" or session.cert_identity_status ~= "valid") then
 656                 module:log("warn", "Forbidding insecure connection to/from %s", host or session.ip or "(unknown host)");
 657                 if session.direction == "incoming" then
 658                         session:close({ condition = "not-authorized", text = "Your server's certificate is invalid, expired, or not trusted by "..session.to_host });
 659                 else -- Close outgoing connections without warning
 660                         session:close(false);
 661                 end
 662                 return false;
 663         end
 664 end
 665
 666 module:hook("s2s-check-certificate", check_auth_policy, -1);
 667
 668 s2sout.set_listener(listener);
 669
 670 module:hook("server-stopping", function(event)
 671         local reason = event.reason;
 672         for _, session in pairs(sessions) do
 673                 session:close{ condition = "system-shutdown", text = reason };
 674         end
 675 end,500);
 676
 677
 678
 679 module:provides("net", {
 680         name = "s2s";
 681         listener = listener;
 682         default_port = 5269;
 683         encryption = "starttls";
 684         multiplex = {
 685                 pattern = "^<.*:stream.*%sxmlns%s*=%s*(['\"])jabber:server%1.*>";
 686         };
 687 });
 688