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 --- 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                 close = function ()
  60                         (session.log or log)("error", "Attempting to close the dummy origin of s2s error replies, please report this! Traceback: %s", traceback());
  61                 end;
  62         };
  63         for i, data in ipairs(sendq) do
  64                 local reply = data[2];
  65                 if reply and not(reply.attr.xmlns) and bouncy_stanzas[reply.name] then
  66                         reply.attr.type = "error";
  67                         reply:tag("error", {type = "cancel"})
  68                                 :tag("remote-server-not-found", {xmlns = "urn:ietf:params:xml:ns:xmpp-stanzas"}):up();
  69                         if reason then
  70                                 reply:tag("text", {xmlns = "urn:ietf:params:xml:ns:xmpp-stanzas"})
  71                                         :text("Server-to-server connection failed: "..reason):up();
  72                         end
  73                         core_process_stanza(dummy, reply);
  74                 end
  75                 sendq[i] = nil;
  76         end
  77         session.sendq = nil;
  78 end
  79
  80 -- Handles stanzas to existing s2s sessions
  81 function route_to_existing_session(event)
  82         local from_host, to_host, stanza = event.from_host, event.to_host, event.stanza;
  83         if not hosts[from_host] then
  84                 log("warn", "Attempt to send stanza from %s - a host we don't serve", from_host);
  85                 return false;
  86         end
  87         if hosts[to_host] then
  88                 log("warn", "Attempt to route stanza to a remote %s - a host we do serve?!", from_host);
  89                 return false;
  90         end
  91         local host = hosts[from_host].s2sout[to_host];
  92         if host then
  93                 -- We have a connection to this host already
  94                 if host.type == "s2sout_unauthed" and (stanza.name ~= "db:verify" or not host.dialback_key) then
  95                         (host.log or log)("debug", "trying to send over unauthed s2sout to "..to_host);
  96
  97                         -- Queue stanza until we are able to send it
  98                         if host.sendq then t_insert(host.sendq, {tostring(stanza), stanza.attr.type ~= "error" and stanza.attr.type ~= "result" and st.reply(stanza)});
  99                         else host.sendq = { {tostring(stanza), stanza.attr.type ~= "error" and stanza.attr.type ~= "result" and st.reply(stanza)} }; end
 100                         host.log("debug", "stanza [%s] queued ", stanza.name);
 101                         return true;
 102                 elseif host.type == "local" or host.type == "component" then
 103                         log("error", "Trying to send a stanza to ourselves??")
 104                         log("error", "Traceback: %s", traceback());
 105                         log("error", "Stanza: %s", tostring(stanza));
 106                         return false;
 107                 else
 108                         (host.log or log)("debug", "going to send stanza to "..to_host.." from "..from_host);
 109                         -- FIXME
 110                         if host.from_host ~= from_host then
 111                                 log("error", "WARNING! This might, possibly, be a bug, but it might not...");
 112                                 log("error", "We are going to send from %s instead of %s", tostring(host.from_host), tostring(from_host));
 113                         end
 114                         if host.sends2s(stanza) then
 115                                 host.log("debug", "stanza sent over %s", host.type);
 116                                 return true;
 117                         end
 118                 end
 119         end
 120 end
 121
 122 -- Create a new outgoing session for a stanza
 123 function route_to_new_session(event)
 124         local from_host, to_host, stanza = event.from_host, event.to_host, event.stanza;
 125         log("debug", "opening a new outgoing connection for this stanza");
 126         local host_session = s2s_new_outgoing(from_host, to_host);
 127
 128         -- Store in buffer
 129         host_session.bounce_sendq = bounce_sendq;
 130         host_session.sendq = { {tostring(stanza), stanza.attr.type ~= "error" and stanza.attr.type ~= "result" and st.reply(stanza)} };
 131         log("debug", "stanza [%s] queued until connection complete", tostring(stanza.name));
 132         s2sout.initiate_connection(host_session);
 133         if (not host_session.connecting) and (not host_session.conn) then
 134                 log("warn", "Connection to %s failed already, destroying session...", to_host);
 135                 s2s_destroy_session(host_session, "Connection failed");
 136                 return false;
 137         end
 138         return true;
 139 end
 140
 141 local function keepalive(event)
 142         return event.session.sends2s(' ');
 143 end
 144
 145 module:hook("s2s-read-timeout", keepalive, -1);
 146
 147 function module.add_host(module)
 148         if module:get_option_boolean("disallow_s2s", false) then
 149                 module:log("warn", "The 'disallow_s2s' config option is deprecated, please see https://prosody.im/doc/s2s#disabling");
 150                 return nil, "This host has disallow_s2s set";
 151         end
 152         module:hook("route/remote", route_to_existing_session, -1);
 153         module:hook("route/remote", route_to_new_session, -10);
 154         module:hook("s2s-authenticated", make_authenticated, -1);
 155         module:hook("s2s-read-timeout", keepalive, -1);
 156         module:hook_stanza("http://etherx.jabber.org/streams", "features", function (session, stanza)
 157                 if session.type == "s2sout" then
 158                         -- Stream is authenticated and we are seem to be done with feature negotiation,
 159                         -- so the stream is ready for stanzas.  RFC 6120 Section 4.3
 160                         mark_connected(session);
 161                         return true;
 162                 elseif not session.dialback_verifying then
 163                         session.log("warn", "No SASL EXTERNAL offer and Dialback doesn't seem to be enabled, giving up");
 164                         session:close();
 165                         return false;
 166                 end
 167         end, -1);
 168 end
 169
 170 -- Stream is authorised, and ready for normal stanzas
 171 function mark_connected(session)
 172         local sendq = session.sendq;
 173
 174         local from, to = session.from_host, session.to_host;
 175
 176         session.log("info", "%s s2s connection %s->%s complete", session.direction:gsub("^.", string.upper), from, to);
 177
 178         local event_data = { session = session };
 179         if session.type == "s2sout" then
 180                 fire_global_event("s2sout-established", event_data);
 181                 hosts[from].events.fire_event("s2sout-established", event_data);
 182         else
 183                 local host_session = hosts[to];
 184                 session.send = function(stanza)
 185                         return host_session.events.fire_event("route/remote", { from_host = to, to_host = from, stanza = stanza });
 186                 end;
 187
 188                 fire_global_event("s2sin-established", event_data);
 189                 hosts[to].events.fire_event("s2sin-established", event_data);
 190         end
 191
 192         if session.direction == "outgoing" then
 193                 if sendq then
 194                         session.log("debug", "sending %d queued stanzas across new outgoing connection to %s", #sendq, session.to_host);
 195                         local send = session.sends2s;
 196                         for i, data in ipairs(sendq) do
 197                                 send(data[1]);
 198                                 sendq[i] = nil;
 199                         end
 200                         session.sendq = nil;
 201                 end
 202
 203                 session.ip_hosts = nil;
 204                 session.srv_hosts = nil;
 205         end
 206 end
 207
 208 function make_authenticated(event)
 209         local session, host = event.session, event.host;
 210         if not session.secure then
 211                 if require_encryption or (secure_auth and not(insecure_domains[host])) or secure_domains[host] then
 212                         session:close({
 213                                 condition = "policy-violation",
 214                                 text = "Encrypted server-to-server communication is required but was not "
 215                                        ..((session.direction == "outgoing" and "offered") or "used")
 216                         });
 217                 end
 218         end
 219         if hosts[host] then
 220                 session:close({ condition = "undefined-condition", text = "Attempt to authenticate as a host we serve" });
 221         end
 222         if session.type == "s2sout_unauthed" then
 223                 session.type = "s2sout";
 224         elseif session.type == "s2sin_unauthed" then
 225                 session.type = "s2sin";
 226                 if host then
 227                         if not session.hosts[host] then session.hosts[host] = {}; end
 228                         session.hosts[host].authed = true;
 229                 end
 230         elseif session.type == "s2sin" and host then
 231                 if not session.hosts[host] then session.hosts[host] = {}; end
 232                 session.hosts[host].authed = true;
 233         else
 234                 return false;
 235         end
 236         session.log("debug", "connection %s->%s is now authenticated for %s", session.from_host, session.to_host, host);
 237
 238         if (session.type == "s2sout" and session.external_auth ~= "succeeded") or session.type == "s2sin" then
 239                 -- Stream either used dialback for authentication or is an incoming stream.
 240                 mark_connected(session);
 241         end
 242
 243         return true;
 244 end
 245
 246 --- Helper to check that a session peer's certificate is valid
 247 function check_cert_status(session)
 248         local host = session.direction == "outgoing" and session.to_host or session.from_host
 249         local conn = session.conn:socket()
 250         local cert
 251         if conn.getpeercertificate then
 252                 cert = conn:getpeercertificate()
 253         end
 254
 255         return module:fire_event("s2s-check-certificate", { host = host, session = session, cert = cert });
 256 end
 257
 258 --- XMPP stream event handlers
 259
 260 local stream_callbacks = { default_ns = "jabber:server", handlestanza =  core_process_stanza };
 261
 262 local xmlns_xmpp_streams = "urn:ietf:params:xml:ns:xmpp-streams";
 263
 264 function stream_callbacks.streamopened(session, attr)
 265         session.version = tonumber(attr.version) or 0;
 266
 267         -- TODO: Rename session.secure to session.encrypted
 268         if session.secure == false then
 269                 session.secure = true;
 270                 session.encrypted = true;
 271
 272                 local sock = session.conn:socket();
 273                 if sock.info then
 274                         local info = sock:info();
 275                         (session.log or log)("info", "Stream encrypted (%s with %s)", info.protocol, info.cipher);
 276                         session.compressed = info.compression;
 277                 else
 278                         (session.log or log)("info", "Stream encrypted");
 279                         session.compressed = sock.compression and sock:compression(); --COMPAT mw/luasec-hg
 280                 end
 281         end
 282
 283         if session.direction == "incoming" then
 284                 -- Send a reply stream header
 285
 286                 -- Validate to/from
 287                 local to, from = nameprep(attr.to), nameprep(attr.from);
 288                 if not to and attr.to then -- COMPAT: Some servers do not reliably set 'to' (especially on stream restarts)
 289                         session:close({ condition = "improper-addressing", text = "Invalid 'to' address" });
 290                         return;
 291                 end
 292                 if not from and attr.from then -- COMPAT: Some servers do not reliably set 'from' (especially on stream restarts)
 293                         session:close({ condition = "improper-addressing", text = "Invalid 'from' address" });
 294                         return;
 295                 end
 296
 297                 -- Set session.[from/to]_host if they have not been set already and if
 298                 -- this session isn't already authenticated
 299                 if session.type == "s2sin_unauthed" and from and not session.from_host then
 300                         session.from_host = from;
 301                 elseif from ~= session.from_host then
 302                         session:close({ condition = "improper-addressing", text = "New stream 'from' attribute does not match original" });
 303                         return;
 304                 end
 305                 if session.type == "s2sin_unauthed" and to and not session.to_host then
 306                         session.to_host = to;
 307                 elseif to ~= session.to_host then
 308                         session:close({ condition = "improper-addressing", text = "New stream 'to' attribute does not match original" });
 309                         return;
 310                 end
 311
 312                 -- For convenience we'll put the sanitised values into these variables
 313                 to, from = session.to_host, session.from_host;
 314
 315                 session.streamid = uuid_gen();
 316                 (session.log or log)("debug", "Incoming s2s received %s", st.stanza("stream:stream", attr):top_tag());
 317                 if to then
 318                         if not hosts[to] then
 319                                 -- Attempting to connect to a host we don't serve
 320                                 session:close({
 321                                         condition = "host-unknown";
 322                                         text = "This host does not serve "..to
 323                                 });
 324                                 return;
 325                         elseif not hosts[to].modules.s2s then
 326                                 -- Attempting to connect to a host that disallows s2s
 327                                 session:close({
 328                                         condition = "policy-violation";
 329                                         text = "Server-to-server communication is disabled for this host";
 330                                 });
 331                                 return;
 332                         end
 333                 end
 334
 335                 if hosts[from] then
 336                         session:close({ condition = "undefined-condition", text = "Attempt to connect from a host we serve" });
 337                         return;
 338                 end
 339
 340                 if session.secure and not session.cert_chain_status then
 341                         if check_cert_status(session) == false then
 342                                 return;
 343                         end
 344                 end
 345
 346                 session:open_stream(session.to_host, session.from_host)
 347                 session.notopen = nil;
 348                 if session.version >= 1.0 then
 349                         local features = st.stanza("stream:features");
 350
 351                         if to then
 352                                 hosts[to].events.fire_event("s2s-stream-features", { origin = session, features = features });
 353                         else
 354                                 (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");
 355                                 fire_global_event("s2s-stream-features-legacy", { origin = session, features = features });
 356                         end
 357
 358                         if ( session.type == "s2sin" or session.type == "s2sout" ) or features.tags[1] then
 359                                 log("debug", "Sending stream features: %s", tostring(features));
 360                                 session.sends2s(features);
 361                         else
 362                                 (session.log or log)("warn", "No features to offer, giving up");
 363                                 session:close({ condition = "undefined-condition", text = "No features to offer" });
 364                         end
 365                 end
 366         elseif session.direction == "outgoing" then
 367                 session.notopen = nil;
 368                 if not attr.id then
 369                         log("error", "Stream response from %s did not give us a stream id!", session.to_host);
 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         stanza = session.filter("stanzas/in", stanza);
 441         if stanza then
 442                 return xpcall(function () return core_process_stanza(session, stanza) end, handleerr);
 443         end
 444 end
 445
 446 local listener = {};
 447
 448 --- Session methods
 449 local stream_xmlns_attr = {xmlns='urn:ietf:params:xml:ns:xmpp-streams'};
 450 local function session_close(session, reason, remote_reason)
 451         local log = session.log or log;
 452         if session.conn then
 453                 if session.notopen then
 454                         if session.direction == "incoming" then
 455                                 session:open_stream(session.to_host, session.from_host);
 456                         else
 457                                 session:open_stream(session.from_host, session.to_host);
 458                         end
 459                 end
 460                 if reason then -- nil == no err, initiated by us, false == initiated by remote
 461                         if type(reason) == "string" then -- assume stream error
 462                                 log("debug", "Disconnecting %s[%s], <stream:error> is: %s", session.host or session.ip or "(unknown host)", session.type, reason);
 463                                 session.sends2s(st.stanza("stream:error"):tag(reason, {xmlns = 'urn:ietf:params:xml:ns:xmpp-streams' }));
 464                         elseif type(reason) == "table" then
 465                                 if reason.condition then
 466                                         local stanza = st.stanza("stream:error"):tag(reason.condition, stream_xmlns_attr):up();
 467                                         if reason.text then
 468                                                 stanza:tag("text", stream_xmlns_attr):text(reason.text):up();
 469                                         end
 470                                         if reason.extra then
 471                                                 stanza:add_child(reason.extra);
 472                                         end
 473                                         log("debug", "Disconnecting %s[%s], <stream:error> is: %s", session.host or session.ip or "(unknown host)", session.type, tostring(stanza));
 474                                         session.sends2s(stanza);
 475                                 elseif reason.name then -- a stanza
 476                                         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));
 477                                         session.sends2s(reason);
 478                                 end
 479                         end
 480                 end
 481
 482                 session.sends2s("</stream:stream>");
 483                 function session.sends2s() return false; end
 484
 485                 local reason = remote_reason or (reason and (reason.text or reason.condition)) or reason;
 486                 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");
 487
 488                 -- Authenticated incoming stream may still be sending us stanzas, so wait for </stream:stream> from remote
 489                 local conn = session.conn;
 490                 if reason == nil and not session.notopen and session.type == "s2sin" then
 491                         add_task(stream_close_timeout, function ()
 492                                 if not session.destroyed then
 493                                         session.log("warn", "Failed to receive a stream close response, closing connection anyway...");
 494                                         s2s_destroy_session(session, reason);
 495                                         conn:close();
 496                                 end
 497                         end);
 498                 else
 499                         s2s_destroy_session(session, reason);
 500                         conn:close(); -- Close immediately, as this is an outgoing connection or is not authed
 501                 end
 502         end
 503 end
 504
 505 function session_stream_attrs(session, from, to, attr)
 506         if not from or (hosts[from] and hosts[from].modules.dialback) then
 507                 attr["xmlns:db"] = 'jabber:server:dialback';
 508         end
 509         if not from then
 510                 attr.from = '';
 511         end
 512         if not to then
 513                 attr.to = '';
 514         end
 515 end
 516
 517 -- Session initialization logic shared by incoming and outgoing
 518 local function initialize_session(session)
 519         local stream = new_xmpp_stream(session, stream_callbacks);
 520         local log = session.log or log;
 521         session.stream = stream;
 522
 523         session.notopen = true;
 524
 525         function session.reset_stream()
 526                 session.notopen = true;
 527                 session.streamid = nil;
 528                 session.stream:reset();
 529         end
 530
 531         session.stream_attrs = session_stream_attrs;
 532
 533         local filter = initialize_filters(session);
 534         local conn = session.conn;
 535         local w = conn.write;
 536
 537         function session.sends2s(t)
 538                 log("debug", "sending: %s", t.top_tag and t:top_tag() or t:match("^[^>]*>?"));
 539                 if t.name then
 540                         t = filter("stanzas/out", t);
 541                 end
 542                 if t then
 543                         t = filter("bytes/out", tostring(t));
 544                         if t then
 545                                 return w(conn, t);
 546                         end
 547                 end
 548         end
 549
 550         function session.data(data)
 551                 data = filter("bytes/in", data);
 552                 if data then
 553                         local ok, err = stream:feed(data);
 554                         if ok then return; end
 555                         log("warn", "Received invalid XML: %s", data);
 556                         log("warn", "Problem was: %s", err);
 557                         session:close("not-well-formed");
 558                 end
 559         end
 560
 561         session.close = session_close;
 562
 563         local handlestanza = stream_callbacks.handlestanza;
 564         function session.dispatch_stanza(session, stanza)
 565                 return handlestanza(session, stanza);
 566         end
 567
 568         module:fire_event("s2s-created", { session = session });
 569
 570         add_task(connect_timeout, function ()
 571                 if session.type == "s2sin" or session.type == "s2sout" then
 572                         return; -- Ok, we're connected
 573                 elseif session.type == "s2s_destroyed" then
 574                         return; -- Session already destroyed
 575                 end
 576                 -- Not connected, need to close session and clean up
 577                 (session.log or log)("debug", "Destroying incomplete session %s->%s due to inactivity",
 578                 session.from_host or "(unknown)", session.to_host or "(unknown)");
 579                 session:close("connection-timeout");
 580         end);
 581 end
 582
 583 function listener.onconnect(conn)
 584         measure_connections(1);
 585         conn:setoption("keepalive", opt_keepalives);
 586         local session = sessions[conn];
 587         if not session then -- New incoming connection
 588                 session = s2s_new_incoming(conn);
 589                 sessions[conn] = session;
 590                 session.log("debug", "Incoming s2s connection");
 591                 initialize_session(session);
 592         else -- Outgoing session connected
 593                 session:open_stream(session.from_host, session.to_host);
 594         end
 595         session.ip = conn:ip();
 596 end
 597
 598 function listener.onincoming(conn, data)
 599         local session = sessions[conn];
 600         if session then
 601                 session.data(data);
 602         end
 603 end
 604
 605 function listener.onstatus(conn, status)
 606         if status == "ssl-handshake-complete" then
 607                 local session = sessions[conn];
 608                 if session and session.direction == "outgoing" then
 609                         session.log("debug", "Sending stream header...");
 610                         session:open_stream(session.from_host, session.to_host);
 611                 end
 612         end
 613 end
 614
 615 function listener.ontimeout(conn)
 616         -- Called instead of onconnect when the connection times out
 617         measure_connections(1);
 618 end
 619
 620 function listener.ondisconnect(conn, err)
 621         measure_connections(-1);
 622         local session = sessions[conn];
 623         if session then
 624                 sessions[conn] = nil;
 625                 if err and session.direction == "outgoing" and session.notopen then
 626                         (session.log or log)("debug", "s2s connection attempt failed: %s", err);
 627                         if s2sout.attempt_connection(session, err) then
 628                                 return; -- Session lives for now
 629                         end
 630                 end
 631                 (session.log or log)("debug", "s2s disconnected: %s->%s (%s)", tostring(session.from_host), tostring(session.to_host), tostring(err or "connection closed"));
 632                 s2s_destroy_session(session, err);
 633         end
 634 end
 635
 636 function listener.onreadtimeout(conn)
 637         local session = sessions[conn];
 638         local host = session.host or session.to_host;
 639         if session then
 640                 return (hosts[host] or prosody).events.fire_event("s2s-read-timeout", { session = session });
 641         end
 642 end
 643
 644 function listener.register_outgoing(conn, session)
 645         sessions[conn] = session;
 646         initialize_session(session);
 647 end
 648
 649 function listener.ondetach(conn)
 650         sessions[conn] = nil;
 651 end
 652
 653 function check_auth_policy(event)
 654         local host, session = event.host, event.session;
 655         local must_secure = secure_auth;
 656
 657         if not must_secure and secure_domains[host] then
 658                 must_secure = true;
 659         elseif must_secure and insecure_domains[host] then
 660                 must_secure = false;
 661         end
 662
 663         if must_secure and (session.cert_chain_status ~= "valid" or session.cert_identity_status ~= "valid") then
 664                 module:log("warn", "Forbidding insecure connection to/from %s", host or session.ip or "(unknown host)");
 665                 if session.direction == "incoming" then
 666                         session:close({ condition = "not-authorized", text = "Your server's certificate is invalid, expired, or not trusted by "..session.to_host });
 667                 else -- Close outgoing connections without warning
 668                         session:close(false);
 669                 end
 670                 return false;
 671         end
 672 end
 673
 674 module:hook("s2s-check-certificate", check_auth_policy, -1);
 675
 676 s2sout.set_listener(listener);
 677
 678 module:hook("server-stopping", function(event)
 679         local reason = event.reason;
 680         for _, session in pairs(sessions) do
 681                 session:close{ condition = "system-shutdown", text = reason };
 682         end
 683 end, -200);
 684
 685
 686
 687 module:provides("net", {
 688         name = "s2s";
 689         listener = listener;
 690         default_port = 5269;
 691         encryption = "starttls";
 692         multiplex = {
 693                 pattern = "^<.*:stream.*%sxmlns%s*=%s*(['\"])jabber:server%1.*>";
 694         };
 695 });
 696