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
  19 local add_task = require "util.timer".add_task;
  20 local st = require "util.stanza";
  21 local initialize_filters = require "util.filters".initialize;
  22 local nameprep = require "util.encodings".stringprep.nameprep;
  23 local new_xmpp_stream = require "util.xmppstream".new;
  24 local s2s_new_incoming = require "core.s2smanager".new_incoming;
  25 local s2s_new_outgoing = require "core.s2smanager".new_outgoing;
  26 local s2s_destroy_session = require "core.s2smanager".destroy_session;
  27 local uuid_gen = require "util.uuid".generate;
  28 local fire_global_event = prosody.events.fire_event;
  29
  30 local s2sout = module:require("s2sout");
  31
  32 local connect_timeout = module:get_option_number("s2s_timeout", 90);
  33 local stream_close_timeout = module:get_option_number("s2s_close_timeout", 5);
  34 local opt_keepalives = module:get_option_boolean("s2s_tcp_keepalives", module:get_option_boolean("tcp_keepalives", true));
  35 local secure_auth = module:get_option_boolean("s2s_secure_auth", false); -- One day...
  36 local secure_domains, insecure_domains =
  37         module:get_option_set("s2s_secure_domains", {})._items, module:get_option_set("s2s_insecure_domains", {})._items;
  38 local require_encryption = module:get_option_boolean("s2s_require_encryption", false);
  39
  40 local measure_connections = module:measure("connections", "counter");
  41
  42 local sessions = module:shared("sessions");
  43
  44 local log = module._log;
  45
  46 do
  47         -- Connection counter resets to 0 on load and reload
  48         -- Bump it up to current value
  49         local count = 0;
  50         for _ in pairs(sessions) do
  51                 count = count + 1;
  52         end
  53         measure_connections(count);
  54 end
  55
  56 --- Handle stanzas to remote domains
  57
  58 local bouncy_stanzas = { message = true, presence = true, iq = true };
  59 local function bounce_sendq(session, reason)
  60         local sendq = session.sendq;
  61         if not sendq then return; end
  62         session.log("info", "Sending error replies for "..#sendq.." queued stanzas because of failed outgoing connection to "..tostring(session.to_host));
  63         local dummy = {
  64                 type = "s2sin";
  65                 send = function(s)
  66                         (session.log or log)("error", "Replying to to an s2s error reply, please report this! Traceback: %s", traceback());
  67                 end;
  68                 dummy = true;
  69         };
  70         for i, data in ipairs(sendq) do
  71                 local reply = data[2];
  72                 if reply and not(reply.attr.xmlns) and bouncy_stanzas[reply.name] then
  73                         reply.attr.type = "error";
  74                         reply:tag("error", {type = "cancel"})
  75                                 :tag("remote-server-not-found", {xmlns = "urn:ietf:params:xml:ns:xmpp-stanzas"}):up();
  76                         if reason then
  77                                 reply:tag("text", {xmlns = "urn:ietf:params:xml:ns:xmpp-stanzas"})
  78                                         :text("Server-to-server connection failed: "..reason):up();
  79                         end
  80                         core_process_stanza(dummy, reply);
  81                 end
  82                 sendq[i] = nil;
  83         end
  84         session.sendq = nil;
  85 end
  86
  87 -- Handles stanzas to existing s2s sessions
  88 function route_to_existing_session(event)
  89         local from_host, to_host, stanza = event.from_host, event.to_host, event.stanza;
  90         if not hosts[from_host] then
  91                 log("warn", "Attempt to send stanza from %s - a host we don't serve", from_host);
  92                 return false;
  93         end
  94         if hosts[to_host] then
  95                 log("warn", "Attempt to route stanza to a remote %s - a host we do serve?!", from_host);
  96                 return false;
  97         end
  98         local host = hosts[from_host].s2sout[to_host];
  99         if host then
 100                 -- We have a connection to this host already
 101                 if host.type == "s2sout_unauthed" and (stanza.name ~= "db:verify" or not host.dialback_key) then
 102                         (host.log or log)("debug", "trying to send over unauthed s2sout to "..to_host);
 103
 104                         -- Queue stanza until we are able to send it
 105                         if host.sendq then t_insert(host.sendq, {tostring(stanza), stanza.attr.type ~= "error" and stanza.attr.type ~= "result" and st.reply(stanza)});
 106                         else host.sendq = { {tostring(stanza), stanza.attr.type ~= "error" and stanza.attr.type ~= "result" and st.reply(stanza)} }; end
 107                         host.log("debug", "stanza [%s] queued ", stanza.name);
 108                         return true;
 109                 elseif host.type == "local" or host.type == "component" then
 110                         log("error", "Trying to send a stanza to ourselves??")
 111                         log("error", "Traceback: %s", traceback());
 112                         log("error", "Stanza: %s", tostring(stanza));
 113                         return false;
 114                 else
 115                         (host.log or log)("debug", "going to send stanza to "..to_host.." from "..from_host);
 116                         -- FIXME
 117                         if host.from_host ~= from_host then
 118                                 log("error", "WARNING! This might, possibly, be a bug, but it might not...");
 119                                 log("error", "We are going to send from %s instead of %s", tostring(host.from_host), tostring(from_host));
 120                         end
 121                         if host.sends2s(stanza) then
 122                                 host.log("debug", "stanza sent over %s", host.type);
 123                                 return true;
 124                         end
 125                 end
 126         end
 127 end
 128
 129 -- Create a new outgoing session for a stanza
 130 function route_to_new_session(event)
 131         local from_host, to_host, stanza = event.from_host, event.to_host, event.stanza;
 132         log("debug", "opening a new outgoing connection for this stanza");
 133         local host_session = s2s_new_outgoing(from_host, to_host);
 134
 135         -- Store in buffer
 136         host_session.bounce_sendq = bounce_sendq;
 137         host_session.sendq = { {tostring(stanza), stanza.attr.type ~= "error" and stanza.attr.type ~= "result" and st.reply(stanza)} };
 138         log("debug", "stanza [%s] queued until connection complete", tostring(stanza.name));
 139         s2sout.initiate_connection(host_session);
 140         if (not host_session.connecting) and (not host_session.conn) then
 141                 log("warn", "Connection to %s failed already, destroying session...", to_host);
 142                 s2s_destroy_session(host_session, "Connection failed");
 143                 return false;
 144         end
 145         return true;
 146 end
 147
 148 local function keepalive(event)
 149         return event.session.sends2s(' ');
 150 end
 151
 152 module:hook("s2s-read-timeout", keepalive, -1);
 153
 154 function module.add_host(module)
 155         if module:get_option_boolean("disallow_s2s", false) then
 156                 module:log("warn", "The 'disallow_s2s' config option is deprecated, please see http://prosody.im/doc/s2s#disabling");
 157                 return nil, "This host has disallow_s2s set";
 158         end
 159         module:hook("route/remote", route_to_existing_session, -1);
 160         module:hook("route/remote", route_to_new_session, -10);
 161         module:hook("s2s-authenticated", make_authenticated, -1);
 162         module:hook("s2s-read-timeout", keepalive, -1);
 163         module:hook_stanza("http://etherx.jabber.org/streams", "features", function (session, stanza)
 164                 if session.type == "s2sout" then
 165                         -- Stream is authenticated and we are seem to be done with feature negotiation,
 166                         -- so the stream is ready for stanzas.  RFC 6120 Section 4.3
 167                         mark_connected(session);
 168                         return true;
 169                 elseif not session.dialback_verifying then
 170                         session.log("warn", "No SASL EXTERNAL offer and Dialback doesn't seem to be enabled, giving up");
 171                         session:close();
 172                         return false;
 173                 end
 174         end, -1);
 175 end
 176
 177 -- Stream is authorised, and ready for normal stanzas
 178 function mark_connected(session)
 179         local sendq = session.sendq;
 180
 181         local from, to = session.from_host, session.to_host;
 182
 183         session.log("info", "%s s2s connection %s->%s complete", session.direction:gsub("^.", string.upper), from, to);
 184
 185         local event_data = { session = session };
 186         if session.type == "s2sout" then
 187                 fire_global_event("s2sout-established", event_data);
 188                 hosts[from].events.fire_event("s2sout-established", event_data);
 189         else
 190                 local host_session = hosts[to];
 191                 session.send = function(stanza)
 192                         return host_session.events.fire_event("route/remote", { from_host = to, to_host = from, stanza = stanza });
 193                 end;
 194
 195                 fire_global_event("s2sin-established", event_data);
 196                 hosts[to].events.fire_event("s2sin-established", event_data);
 197         end
 198
 199         if session.direction == "outgoing" then
 200                 if sendq then
 201                         session.log("debug", "sending %d queued stanzas across new outgoing connection to %s", #sendq, session.to_host);
 202                         local send = session.sends2s;
 203                         for i, data in ipairs(sendq) do
 204                                 send(data[1]);
 205                                 sendq[i] = nil;
 206                         end
 207                         session.sendq = nil;
 208                 end
 209
 210                 session.ip_hosts = nil;
 211                 session.srv_hosts = nil;
 212         end
 213 end
 214
 215 function make_authenticated(event)
 216         local session, host = event.session, event.host;
 217         if not session.secure then
 218                 if require_encryption or (secure_auth and not(insecure_domains[host])) or secure_domains[host] then
 219                         session:close({
 220                                 condition = "policy-violation",
 221                                 text = "Encrypted server-to-server communication is required but was not "
 222                                        ..((session.direction == "outgoing" and "offered") or "used")
 223                         });
 224                 end
 225         end
 226         if hosts[host] then
 227                 session:close({ condition = "undefined-condition", text = "Attempt to authenticate as a host we serve" });
 228         end
 229         if session.type == "s2sout_unauthed" then
 230                 session.type = "s2sout";
 231         elseif session.type == "s2sin_unauthed" then
 232                 session.type = "s2sin";
 233                 if host then
 234                         if not session.hosts[host] then session.hosts[host] = {}; end
 235                         session.hosts[host].authed = true;
 236                 end
 237         elseif session.type == "s2sin" and host then
 238                 if not session.hosts[host] then session.hosts[host] = {}; end
 239                 session.hosts[host].authed = true;
 240         else
 241                 return false;
 242         end
 243         session.log("debug", "connection %s->%s is now authenticated for %s", session.from_host, session.to_host, host);
 244
 245         if (session.type == "s2sout" and session.external_auth ~= "succeeded") or session.type == "s2sin" then
 246                 -- Stream either used dialback for authentication or is an incoming stream.
 247                 mark_connected(session);
 248         end
 249
 250         return true;
 251 end
 252
 253 --- Helper to check that a session peer's certificate is valid
 254 function check_cert_status(session)
 255         local host = session.direction == "outgoing" and session.to_host or session.from_host
 256         local conn = session.conn:socket()
 257         local cert
 258         if conn.getpeercertificate then
 259                 cert = conn:getpeercertificate()
 260         end
 261
 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         session.version = tonumber(attr.version) or 0;
 273
 274         -- TODO: Rename session.secure to session.encrypted
 275         if session.secure == false then
 276                 session.secure = true;
 277                 session.encrypted = true;
 278
 279                 local sock = session.conn:socket();
 280                 if sock.info then
 281                         local info = sock:info();
 282                         (session.log or log)("info", "Stream encrypted (%s with %s)", info.protocol, info.cipher);
 283                         session.compressed = info.compression;
 284                 else
 285                         (session.log or log)("info", "Stream encrypted");
 286                         session.compressed = sock.compression and sock:compression(); --COMPAT mw/luasec-hg
 287                 end
 288         end
 289
 290         if session.direction == "incoming" then
 291                 -- Send a reply stream header
 292
 293                 -- Validate to/from
 294                 local to, from = nameprep(attr.to), nameprep(attr.from);
 295                 if not to and attr.to then -- COMPAT: Some servers do not reliably set 'to' (especially on stream restarts)
 296                         session:close({ condition = "improper-addressing", text = "Invalid 'to' address" });
 297                         return;
 298                 end
 299                 if not from and attr.from then -- COMPAT: Some servers do not reliably set 'from' (especially on stream restarts)
 300                         session:close({ condition = "improper-addressing", text = "Invalid 'from' address" });
 301                         return;
 302                 end
 303
 304                 -- Set session.[from/to]_host if they have not been set already and if
 305                 -- this session isn't already authenticated
 306                 if session.type == "s2sin_unauthed" and from and not session.from_host then
 307                         session.from_host = from;
 308                 elseif from ~= session.from_host then
 309                         session:close({ condition = "improper-addressing", text = "New stream 'from' attribute does not match original" });
 310                         return;
 311                 end
 312                 if session.type == "s2sin_unauthed" and to and not session.to_host then
 313                         session.to_host = to;
 314                 elseif to ~= session.to_host then
 315                         session:close({ condition = "improper-addressing", text = "New stream 'to' attribute does not match original" });
 316                         return;
 317                 end
 318
 319                 -- For convenience we'll put the sanitised values into these variables
 320                 to, from = session.to_host, session.from_host;
 321
 322                 session.streamid = uuid_gen();
 323                 (session.log or log)("debug", "Incoming s2s received %s", st.stanza("stream:stream", attr):top_tag());
 324                 if to then
 325                         if not hosts[to] then
 326                                 -- Attempting to connect to a host we don't serve
 327                                 session:close({
 328                                         condition = "host-unknown";
 329                                         text = "This host does not serve "..to
 330                                 });
 331                                 return;
 332                         elseif not hosts[to].modules.s2s then
 333                                 -- Attempting to connect to a host that disallows s2s
 334                                 session:close({
 335                                         condition = "policy-violation";
 336                                         text = "Server-to-server communication is disabled for this host";
 337                                 });
 338                                 return;
 339                         end
 340                 end
 341
 342                 if hosts[from] then
 343                         session:close({ condition = "undefined-condition", text = "Attempt to connect from a host we serve" });
 344                         return;
 345                 end
 346
 347                 if session.secure and not session.cert_chain_status then
 348                         if check_cert_status(session) == false then
 349                                 return;
 350                         end
 351                 end
 352
 353                 session:open_stream(session.to_host, session.from_host)
 354                 session.notopen = nil;
 355                 if session.version >= 1.0 then
 356                         local features = st.stanza("stream:features");
 357
 358                         if to then
 359                                 hosts[to].events.fire_event("s2s-stream-features", { origin = session, features = features });
 360                         else
 361                                 (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");
 362                                 fire_global_event("s2s-stream-features-legacy", { origin = session, features = features });
 363                         end
 364
 365                         if ( session.type == "s2sin" or session.type == "s2sout" ) or features.tags[1] then
 366                                 log("debug", "Sending stream features: %s", tostring(features));
 367                                 session.sends2s(features);
 368                         else
 369                                 (session.log or log)("warn", "No features to offer, giving up");
 370                                 session:close({ condition = "undefined-condition", text = "No features to offer" });
 371                         end
 372                 end
 373         elseif session.direction == "outgoing" then
 374                 session.notopen = nil;
 375                 if not attr.id then
 376                         log("error", "Stream response from %s did not give us a stream id!", session.to_host);
 377                         session:close({ condition = "undefined-condition", text = "Missing stream ID" });
 378                         return;
 379                 end
 380                 session.streamid = attr.id;
 381
 382                 if session.secure and not session.cert_chain_status then
 383                         if check_cert_status(session) == false then
 384                                 return;
 385                         end
 386                 end
 387
 388                 -- Send unauthed buffer
 389                 -- (stanzas which are fine to send before dialback)
 390                 -- Note that this is *not* the stanza queue (which
 391                 -- we can only send if auth succeeds) :)
 392                 local send_buffer = session.send_buffer;
 393                 if send_buffer and #send_buffer > 0 then
 394                         log("debug", "Sending s2s send_buffer now...");
 395                         for i, data in ipairs(send_buffer) do
 396                                 session.sends2s(tostring(data));
 397                                 send_buffer[i] = nil;
 398                         end
 399                 end
 400                 session.send_buffer = nil;
 401
 402                 -- If server is pre-1.0, don't wait for features, just do dialback
 403                 if session.version < 1.0 then
 404                         if not session.dialback_verifying then
 405                                 hosts[session.from_host].events.fire_event("s2sout-authenticate-legacy", { origin = session });
 406                         else
 407                                 mark_connected(session);
 408                         end
 409                 end
 410         end
 411 end
 412
 413 function stream_callbacks.streamclosed(session)
 414         (session.log or log)("debug", "Received </stream:stream>");
 415         session:close(false);
 416 end
 417
 418 function stream_callbacks.error(session, error, data)
 419         if error == "no-stream" then
 420                 session.log("debug", "Invalid opening stream header (%s)", (data:gsub("^([^\1]+)\1", "{%1}")));
 421                 session:close("invalid-namespace");
 422         elseif error == "parse-error" then
 423                 session.log("debug", "Server-to-server XML parse error: %s", tostring(error));
 424                 session:close("not-well-formed");
 425         elseif error == "stream-error" then
 426                 local condition, text = "undefined-condition";
 427                 for child in data:children() do
 428                         if child.attr.xmlns == xmlns_xmpp_streams then
 429                                 if child.name ~= "text" then
 430                                         condition = child.name;
 431                                 else
 432                                         text = child:get_text();
 433                                 end
 434                                 if condition ~= "undefined-condition" and text then
 435                                         break;
 436                                 end
 437                         end
 438                 end
 439                 text = condition .. (text and (" ("..text..")") or "");
 440                 session.log("info", "Session closed by remote with error: %s", text);
 441                 session:close(nil, text);
 442         end
 443 end
 444
 445 local function handleerr(err) log("error", "Traceback[s2s]: %s", traceback(tostring(err), 2)); end
 446 function stream_callbacks.handlestanza(session, stanza)
 447         stanza = session.filter("stanzas/in", stanza);
 448         if stanza then
 449                 return xpcall(function () return core_process_stanza(session, stanza) end, handleerr);
 450         end
 451 end
 452
 453 local listener = {};
 454
 455 --- Session methods
 456 local stream_xmlns_attr = {xmlns='urn:ietf:params:xml:ns:xmpp-streams'};
 457 local function session_close(session, reason, remote_reason)
 458         local log = session.log or log;
 459         if session.conn then
 460                 if session.notopen then
 461                         if session.direction == "incoming" then
 462                                 session:open_stream(session.to_host, session.from_host);
 463                         else
 464                                 session:open_stream(session.from_host, session.to_host);
 465                         end
 466                 end
 467                 if reason then -- nil == no err, initiated by us, false == initiated by remote
 468                         if type(reason) == "string" then -- assume stream error
 469                                 log("debug", "Disconnecting %s[%s], <stream:error> is: %s", session.host or session.ip or "(unknown host)", session.type, reason);
 470                                 session.sends2s(st.stanza("stream:error"):tag(reason, {xmlns = 'urn:ietf:params:xml:ns:xmpp-streams' }));
 471                         elseif type(reason) == "table" then
 472                                 if reason.condition then
 473                                         local stanza = st.stanza("stream:error"):tag(reason.condition, stream_xmlns_attr):up();
 474                                         if reason.text then
 475                                                 stanza:tag("text", stream_xmlns_attr):text(reason.text):up();
 476                                         end
 477                                         if reason.extra then
 478                                                 stanza:add_child(reason.extra);
 479                                         end
 480                                         log("debug", "Disconnecting %s[%s], <stream:error> is: %s", session.host or session.ip or "(unknown host)", session.type, tostring(stanza));
 481                                         session.sends2s(stanza);
 482                                 elseif reason.name then -- a stanza
 483                                         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));
 484                                         session.sends2s(reason);
 485                                 end
 486                         end
 487                 end
 488
 489                 session.sends2s("</stream:stream>");
 490                 function session.sends2s() return false; end
 491
 492                 local reason = remote_reason or (reason and (reason.text or reason.condition)) or reason;
 493                 session.log("info", "%s s2s stream %s->%s closed: %s", session.direction:gsub("^.", string.upper), session.from_host or "(unknown host)", session.to_host or "(unknown host)", reason or "stream closed");
 494
 495                 -- Authenticated incoming stream may still be sending us stanzas, so wait for </stream:stream> from remote
 496                 local conn = session.conn;
 497                 if reason == nil and not session.notopen and session.type == "s2sin" then
 498                         add_task(stream_close_timeout, function ()
 499                                 if not session.destroyed then
 500                                         session.log("warn", "Failed to receive a stream close response, closing connection anyway...");
 501                                         s2s_destroy_session(session, reason);
 502                                         conn:close();
 503                                 end
 504                         end);
 505                 else
 506                         s2s_destroy_session(session, reason);
 507                         conn:close(); -- Close immediately, as this is an outgoing connection or is not authed
 508                 end
 509         end
 510 end
 511
 512 function session_stream_attrs(session, from, to, attr)
 513         if not from or (hosts[from] and hosts[from].modules.dialback) then
 514                 attr["xmlns:db"] = 'jabber:server:dialback';
 515         end
 516         if not from then
 517                 attr.from = '';
 518         end
 519         if not to then
 520                 attr.to = '';
 521         end
 522 end
 523
 524 -- Session initialization logic shared by incoming and outgoing
 525 local function initialize_session(session)
 526         local stream = new_xmpp_stream(session, stream_callbacks);
 527         local log = session.log or log;
 528         session.stream = stream;
 529
 530         session.notopen = true;
 531
 532         function session.reset_stream()
 533                 session.notopen = true;
 534                 session.streamid = nil;
 535                 session.stream:reset();
 536         end
 537
 538         session.stream_attrs = session_stream_attrs;
 539
 540         local filter = initialize_filters(session);
 541         local conn = session.conn;
 542         local w = conn.write;
 543
 544         function session.sends2s(t)
 545                 log("debug", "sending: %s", t.top_tag and t:top_tag() or t:match("^[^>]*>?"));
 546                 if t.name then
 547                         t = filter("stanzas/out", t);
 548                 end
 549                 if t then
 550                         t = filter("bytes/out", tostring(t));
 551                         if t then
 552                                 return w(conn, t);
 553                         end
 554                 end
 555         end
 556
 557         function session.data(data)
 558                 data = filter("bytes/in", data);
 559                 if data then
 560                         local ok, err = stream:feed(data);
 561                         if ok then return; end
 562                         log("warn", "Received invalid XML: %s", data);
 563                         log("warn", "Problem was: %s", err);
 564                         session:close("not-well-formed");
 565                 end
 566         end
 567
 568         session.close = session_close;
 569
 570         local handlestanza = stream_callbacks.handlestanza;
 571         function session.dispatch_stanza(session, stanza)
 572                 return handlestanza(session, stanza);
 573         end
 574
 575         module:fire_event("s2s-created", { session = session });
 576
 577         add_task(connect_timeout, function ()
 578                 if session.type == "s2sin" or session.type == "s2sout" then
 579                         return; -- Ok, we're connected
 580                 elseif session.type == "s2s_destroyed" then
 581                         return; -- Session already destroyed
 582                 end
 583                 -- Not connected, need to close session and clean up
 584                 (session.log or log)("debug", "Destroying incomplete session %s->%s due to inactivity",
 585                 session.from_host or "(unknown)", session.to_host or "(unknown)");
 586                 session:close("connection-timeout");
 587         end);
 588 end
 589
 590 function listener.onconnect(conn)
 591         measure_connections(1);
 592         conn:setoption("keepalive", opt_keepalives);
 593         local session = sessions[conn];
 594         if not session then -- New incoming connection
 595                 session = s2s_new_incoming(conn);
 596                 sessions[conn] = session;
 597                 session.log("debug", "Incoming s2s connection");
 598                 initialize_session(session);
 599         else -- Outgoing session connected
 600                 session:open_stream(session.from_host, session.to_host);
 601         end
 602         session.ip = conn:ip();
 603 end
 604
 605 function listener.onincoming(conn, data)
 606         local session = sessions[conn];
 607         if session then
 608                 session.data(data);
 609         end
 610 end
 611
 612 function listener.onstatus(conn, status)
 613         if status == "ssl-handshake-complete" then
 614                 local session = sessions[conn];
 615                 if session and session.direction == "outgoing" then
 616                         session.log("debug", "Sending stream header...");
 617                         session:open_stream(session.from_host, session.to_host);
 618                 end
 619         end
 620 end
 621
 622 function listener.ontimeout(conn)
 623         -- Called instead of onconnect when the connection times out
 624         measure_connections(1);
 625 end
 626
 627 function listener.ondisconnect(conn, err)
 628         measure_connections(-1);
 629         local session = sessions[conn];
 630         if session then
 631                 sessions[conn] = nil;
 632                 if err and session.direction == "outgoing" and session.notopen then
 633                         (session.log or log)("debug", "s2s connection attempt failed: %s", err);
 634                         if s2sout.attempt_connection(session, err) then
 635                                 return; -- Session lives for now
 636                         end
 637                 end
 638                 (session.log or log)("debug", "s2s disconnected: %s->%s (%s)", tostring(session.from_host), tostring(session.to_host), tostring(err or "connection closed"));
 639                 s2s_destroy_session(session, err);
 640         end
 641 end
 642
 643 function listener.onreadtimeout(conn)
 644         local session = sessions[conn];
 645         local host = session.host or session.to_host;
 646         if session then
 647                 return (hosts[host] or prosody).events.fire_event("s2s-read-timeout", { session = session });
 648         end
 649 end
 650
 651 function listener.register_outgoing(conn, session)
 652         sessions[conn] = session;
 653         initialize_session(session);
 654 end
 655
 656 function listener.ondetach(conn)
 657         sessions[conn] = nil;
 658 end
 659
 660 function check_auth_policy(event)
 661         local host, session = event.host, event.session;
 662         local must_secure = secure_auth;
 663
 664         if not must_secure and secure_domains[host] then
 665                 must_secure = true;
 666         elseif must_secure and insecure_domains[host] then
 667                 must_secure = false;
 668         end
 669
 670         if must_secure and (session.cert_chain_status ~= "valid" or session.cert_identity_status ~= "valid") then
 671                 module:log("warn", "Forbidding insecure connection to/from %s", host or session.ip or "(unknown host)");
 672                 if session.direction == "incoming" then
 673                         session:close({ condition = "not-authorized", text = "Your server's certificate is invalid, expired, or not trusted by "..session.to_host });
 674                 else -- Close outgoing connections without warning
 675                         session:close(false);
 676                 end
 677                 return false;
 678         end
 679 end
 680
 681 module:hook("s2s-check-certificate", check_auth_policy, -1);
 682
 683 s2sout.set_listener(listener);
 684
 685 module:hook("server-stopping", function(event)
 686         local reason = event.reason;
 687         for _, session in pairs(sessions) do
 688                 session:close{ condition = "system-shutdown", text = reason };
 689         end
 690 end, -200);
 691
 692
 693
 694 module:provides("net", {
 695         name = "s2s";
 696         listener = listener;
 697         default_port = 5269;
 698         encryption = "starttls";
 699         multiplex = {
 700                 pattern = "^<.*:stream.*%sxmlns%s*=%s*(['\"])jabber:server%1.*>";
 701         };
 702 });
 703