plugins/mod_bosh.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 new_xmpp_stream = require "util.xmppstream".new;
  12 local sm = require "core.sessionmanager";
  13 local sm_destroy_session = sm.destroy_session;
  14 local new_uuid = require "util.uuid".generate;
  15 local core_process_stanza = prosody.core_process_stanza;
  16 local st = require "util.stanza";
  17 local logger = require "util.logger";
  18 local log = module._log;
  19 local initialize_filters = require "util.filters".initialize;
  20 local math_min = math.min;
  21 local tostring, type = tostring, type;
  22 local traceback = debug.traceback;
  23 local runner = require"util.async".runner;
  24 local nameprep = require "util.encodings".stringprep.nameprep;
  25 local cache = require "util.cache";
  26
  27 local xmlns_streams = "http://etherx.jabber.org/streams";
  28 local xmlns_xmpp_streams = "urn:ietf:params:xml:ns:xmpp-streams";
  29 local xmlns_bosh = "http://jabber.org/protocol/httpbind"; -- (hard-coded into a literal in session.send)
  30
  31 local stream_callbacks = {
  32         stream_ns = xmlns_bosh, stream_tag = "body", default_ns = "jabber:client" };
  33
  34 -- These constants are implicitly assumed within the code, and cannot be changed
  35 local BOSH_HOLD = 1;
  36 local BOSH_MAX_REQUESTS = 2;
  37
  38 -- The number of seconds a BOSH session should remain open with no requests
  39 local bosh_max_inactivity = module:get_option_number("bosh_max_inactivity", 60);
  40 -- The minimum amount of time between requests with no payload
  41 local bosh_max_polling = module:get_option_number("bosh_max_polling", 5);
  42 -- The maximum amount of time that the server will hold onto a request before replying
  43 -- (the client can set this to a lower value when it connects, if it chooses)
  44 local bosh_max_wait = module:get_option_number("bosh_max_wait", 120);
  45
  46 local consider_bosh_secure = module:get_option_boolean("consider_bosh_secure");
  47 local cross_domain = module:get_option("cross_domain_bosh");
  48
  49 if cross_domain ~= nil then
  50         module:log("info", "The 'cross_domain_bosh' option has been deprecated");
  51 end
  52
  53 local t_insert, t_remove, t_concat = table.insert, table.remove, table.concat;
  54
  55 -- All sessions, and sessions that have no requests open
  56 local sessions = module:shared("sessions");
  57
  58 local measure_active = module:measure("active_sessions", "amount");
  59 local measure_inactive = module:measure("inactive_sessions", "amount");
  60 local report_bad_host = module:measure("bad_host", "rate");
  61 local report_bad_sid = module:measure("bad_sid", "rate");
  62 local report_new_sid = module:measure("new_sid", "rate");
  63 local report_timeout = module:measure("timeout", "rate");
  64
  65 module:hook("stats-update", function ()
  66         local active = 0;
  67         local inactive = 0;
  68         for _, session in pairs(sessions) do
  69                 if #session.requests > 0 then
  70                         active = active + 1;
  71                 else
  72                         inactive = inactive + 1;
  73                 end
  74         end
  75         measure_active(active);
  76         measure_inactive(inactive);
  77 end);
  78
  79 -- Used to respond to idle sessions (those with waiting requests)
  80 function on_destroy_request(request)
  81         log("debug", "Request destroyed: %s", request);
  82         local session = sessions[request.context.sid];
  83         if session then
  84                 local requests = session.requests;
  85                 for i, r in ipairs(requests) do
  86                         if r == request then
  87                                 t_remove(requests, i);
  88                                 break;
  89                         end
  90                 end
  91
  92                 -- If this session now has no requests open, mark it as inactive
  93                 local max_inactive = session.bosh_max_inactive;
  94                 if max_inactive and #requests == 0 then
  95                         if session.inactive_timer then
  96                                 session.inactive_timer:stop();
  97                         end
  98                         session.inactive_timer = module:add_timer(max_inactive, session_timeout, session, request.context,
  99                                 "BOSH client silent for over "..max_inactive.." seconds");
 100                         (session.log or log)("debug", "BOSH session marked as inactive (for %ds)", max_inactive);
 101                 end
 102                 if session.bosh_wait_timer then
 103                         session.bosh_wait_timer:stop();
 104                         session.bosh_wait_timer = nil;
 105                 end
 106         end
 107 end
 108
 109 function session_timeout(now, session, context, reason) -- luacheck: ignore 212/now
 110         if not session.destroyed then
 111                 report_timeout();
 112                 sessions[context.sid] = nil;
 113                 sm_destroy_session(session, reason);
 114         end
 115 end
 116
 117 function handle_POST(event)
 118         log("debug", "Handling new request %s: %s\n----------", event.request, event.request.body);
 119
 120         local request, response = event.request, event.response;
 121         response.on_destroy = on_destroy_request;
 122         local body = request.body;
 123
 124         local context = { request = request, response = response, notopen = true };
 125         local stream = new_xmpp_stream(context, stream_callbacks);
 126         response.context = context;
 127
 128         local headers = response.headers;
 129         headers.content_type = "text/xml; charset=utf-8";
 130
 131         -- stream:feed() calls the stream_callbacks, so all stanzas in
 132         -- the body are processed in this next line before it returns.
 133         -- In particular, the streamopened() stream callback is where
 134         -- much of the session logic happens, because it's where we first
 135         -- get to see the 'sid' of this request.
 136         local ok, err = stream:feed(body);
 137         if not ok then
 138                 module:log("warn", "Error parsing BOSH payload; %s", err)
 139                 local close_reply = st.stanza("body", { xmlns = xmlns_bosh, type = "terminate",
 140                         ["xmlns:stream"] = xmlns_streams, condition = "bad-request" });
 141                 return tostring(close_reply);
 142         end
 143
 144         -- Stanzas (if any) in the request have now been processed, and
 145         -- we take care of the high-level BOSH logic here, including
 146         -- giving a response or putting the request "on hold".
 147         local session = sessions[context.sid];
 148         if session then
 149                 -- Session was marked as inactive, since we have
 150                 -- a request open now, unmark it
 151                 if session.inactive_timer and #session.requests > 0 then
 152                         session.inactive_timer:stop();
 153                         session.inactive_timer = nil;
 154                 end
 155
 156                 if session.bosh_wait_timer then
 157                         session.bosh_wait_timer:stop();
 158                         session.bosh_wait_timer = nil;
 159                 end
 160
 161                 local r = session.requests;
 162                 log("debug", "Session %s has %d out of %d requests open", context.sid, #r, BOSH_HOLD);
 163                 log("debug", "and there are %d things in the send_buffer:", #session.send_buffer);
 164                 if #r > BOSH_HOLD then
 165                         -- We are holding too many requests, send what's in the buffer,
 166                         log("debug", "We are holding too many requests, so...");
 167                         if #session.send_buffer > 0 then
 168                                 log("debug", "...sending what is in the buffer")
 169                                 session.send(t_concat(session.send_buffer));
 170                                 session.send_buffer = {};
 171                         else
 172                                 -- or an empty response
 173                                 log("debug", "...sending an empty response");
 174                                 session.send("");
 175                         end
 176                 elseif #session.send_buffer > 0 then
 177                         log("debug", "Session has data in the send buffer, will send now..");
 178                         local resp = t_concat(session.send_buffer);
 179                         session.send_buffer = {};
 180                         session.send(resp);
 181                 end
 182
 183                 if not response.finished then
 184                         -- We're keeping this request open, to respond later
 185                         log("debug", "Have nothing to say, so leaving request unanswered for now");
 186                 end
 187
 188                 if session.bosh_terminate then
 189                         session.log("debug", "Closing session with %d requests open", #session.requests);
 190                         session:close();
 191                         return nil;
 192                 else
 193                         if session.bosh_wait and #session.requests > 0 then
 194                                 session.bosh_wait_timer = module:add_timer(session.bosh_wait, after_bosh_wait, session.requests[1], session)
 195                         end
 196
 197                         return true; -- Inform http server we shall reply later
 198                 end
 199         elseif response.finished or context.ignore_request then
 200                 if response.finished then
 201                         module:log("debug", "Response finished");
 202                 end
 203                 if context.ignore_request then
 204                         module:log("debug", "Ignoring this request");
 205                 end
 206                 -- A response has been sent already, or we're ignoring this request
 207                 -- (e.g. so a different instance of the module can handle it)
 208                 return;
 209         end
 210         module:log("warn", "Unable to associate request with a session (incomplete request?)");
 211         report_bad_sid();
 212         local close_reply = st.stanza("body", { xmlns = xmlns_bosh, type = "terminate",
 213                 ["xmlns:stream"] = xmlns_streams, condition = "item-not-found" });
 214         return tostring(close_reply) .. "\n";
 215 end
 216
 217 function after_bosh_wait(now, request, session) -- luacheck: ignore 212
 218         if request.conn then
 219                 session.send("");
 220         end
 221 end
 222
 223 local function bosh_reset_stream(session) session.notopen = true; end
 224
 225 local stream_xmlns_attr = { xmlns = "urn:ietf:params:xml:ns:xmpp-streams" };
 226 local function bosh_close_stream(session, reason)
 227         (session.log or log)("info", "BOSH client disconnected: %s", (reason and reason.condition or reason) or "session close");
 228
 229         local close_reply = st.stanza("body", { xmlns = xmlns_bosh, type = "terminate",
 230                 ["xmlns:stream"] = xmlns_streams });
 231
 232
 233         if reason then
 234                 close_reply.attr.condition = "remote-stream-error";
 235                 if type(reason) == "string" then -- assume stream error
 236                         close_reply:tag("stream:error")
 237                                 :tag(reason, {xmlns = xmlns_xmpp_streams});
 238                 elseif type(reason) == "table" then
 239                         if reason.condition then
 240                                 close_reply:tag("stream:error")
 241                                         :tag(reason.condition, stream_xmlns_attr):up();
 242                                 if reason.text then
 243                                         close_reply:tag("text", stream_xmlns_attr):text(reason.text):up();
 244                                 end
 245                                 if reason.extra then
 246                                         close_reply:add_child(reason.extra);
 247                                 end
 248                         elseif reason.name then -- a stanza
 249                                 close_reply = reason;
 250                         end
 251                 end
 252                 log("info", "Disconnecting client, <stream:error> is: %s", close_reply);
 253         end
 254
 255         local response_body = tostring(close_reply);
 256         for _, held_request in ipairs(session.requests) do
 257                 held_request:send(response_body);
 258         end
 259         sessions[session.sid] = nil;
 260         sm_destroy_session(session);
 261 end
 262
 263 local runner_callbacks = { };
 264
 265 -- Handle the <body> tag in the request payload.
 266 function stream_callbacks.streamopened(context, attr)
 267         local request, response = context.request, context.response;
 268         local sid, rid = attr.sid, tonumber(attr.rid);
 269         log("debug", "BOSH body open (sid: %s)", sid or "<none>");
 270         context.rid = rid;
 271         if not sid then
 272                 -- New session request
 273                 context.notopen = nil; -- Signals that we accept this opening tag
 274
 275                 local to_host = nameprep(attr.to);
 276                 local wait = tonumber(attr.wait);
 277                 if not to_host then
 278                         log("debug", "BOSH client tried to connect to invalid host: %s", attr.to);
 279                         report_bad_host();
 280                         local close_reply = st.stanza("body", { xmlns = xmlns_bosh, type = "terminate",
 281                                 ["xmlns:stream"] = xmlns_streams, condition = "improper-addressing" });
 282                         response:send(tostring(close_reply));
 283                         return;
 284                 end
 285                 if not rid or (not attr.wait or not wait or wait < 0 or wait % 1 ~= 0) then
 286                         log("debug", "BOSH client sent invalid rid or wait attributes: rid=%s, wait=%s", attr.rid, attr.wait);
 287                         local close_reply = st.stanza("body", { xmlns = xmlns_bosh, type = "terminate",
 288                                 ["xmlns:stream"] = xmlns_streams, condition = "bad-request" });
 289                         response:send(tostring(close_reply));
 290                         return;
 291                 end
 292
 293                 wait = math_min(wait, bosh_max_wait);
 294
 295                 -- New session
 296                 sid = new_uuid();
 297                 local session = {
 298                         type = "c2s_unauthed", conn = request.conn, sid = sid, host = attr.to,
 299                         rid = rid - 1, -- Hack for initial session setup, "previous" rid was $current_request - 1
 300                         bosh_version = attr.ver, bosh_wait = wait, streamid = sid,
 301                         bosh_max_inactive = bosh_max_inactivity, bosh_responses = cache.new(BOSH_HOLD+1):table();
 302                         requests = { }, send_buffer = {}, reset_stream = bosh_reset_stream,
 303                         close = bosh_close_stream, dispatch_stanza = core_process_stanza, notopen = true,
 304                         log = logger.init("bosh"..sid), secure = consider_bosh_secure or request.secure,
 305                         ip = request.ip;
 306                 };
 307                 sessions[sid] = session;
 308
 309                 session.thread = runner(function (stanza)
 310                         session:dispatch_stanza(stanza);
 311                 end, runner_callbacks, session);
 312
 313                 local filter = initialize_filters(session);
 314
 315                 session.log("debug", "BOSH session created for request from %s", session.ip);
 316                 log("info", "New BOSH session, assigned it sid '%s'", sid);
 317                 report_new_sid();
 318
 319                 module:fire_event("bosh-session", { session = session, request = request });
 320
 321                 -- Send creation response
 322                 local creating_session = true;
 323
 324                 local r = session.requests;
 325                 function session.send(s)
 326                         -- We need to ensure that outgoing stanzas have the jabber:client xmlns
 327                         if s.attr and not s.attr.xmlns then
 328                                 s = st.clone(s);
 329                                 s.attr.xmlns = "jabber:client";
 330                         end
 331                         s = filter("stanzas/out", s);
 332                         --log("debug", "Sending BOSH data: %s", s);
 333                         if not s then return true end
 334                         t_insert(session.send_buffer, tostring(s));
 335
 336                         local oldest_request = r[1];
 337                         if oldest_request and not session.bosh_processing then
 338                                 log("debug", "We have an open request, so sending on that");
 339                                 local body_attr = { xmlns = "http://jabber.org/protocol/httpbind",
 340                                         ["xmlns:stream"] = "http://etherx.jabber.org/streams";
 341                                         type = session.bosh_terminate and "terminate" or nil;
 342                                         sid = sid;
 343                                 };
 344                                 if creating_session then
 345                                         creating_session = nil;
 346                                         body_attr.requests = tostring(BOSH_MAX_REQUESTS);
 347                                         body_attr.hold = tostring(BOSH_HOLD);
 348                                         body_attr.inactivity = tostring(bosh_max_inactivity);
 349                                         body_attr.polling = tostring(bosh_max_polling);
 350                                         body_attr.wait = tostring(session.bosh_wait);
 351                                         body_attr.authid = sid;
 352                                         body_attr.secure = "true";
 353                                         body_attr.ver  = '1.6';
 354                                         body_attr.from = session.host;
 355                                         body_attr["xmlns:xmpp"] = "urn:xmpp:xbosh";
 356                                         body_attr["xmpp:version"] = "1.0";
 357                                 end
 358                                 local response_xml = st.stanza("body", body_attr):top_tag()..t_concat(session.send_buffer).."</body>";
 359                                 session.bosh_responses[oldest_request.context.rid] = response_xml;
 360                                 oldest_request:send(response_xml);
 361                                 session.send_buffer = {};
 362                         end
 363                         return true;
 364                 end
 365                 request.sid = sid;
 366         end
 367
 368         local session = sessions[sid];
 369         if not session then
 370                 -- Unknown sid
 371                 log("info", "Client tried to use sid '%s' which we don't know about", sid);
 372                 report_bad_sid();
 373                 response:send(tostring(st.stanza("body", { xmlns = xmlns_bosh, type = "terminate", condition = "item-not-found" })));
 374                 context.notopen = nil;
 375                 return;
 376         end
 377
 378         session.conn = request.conn;
 379
 380         if session.rid then
 381                 local diff = rid - session.rid;
 382                 -- Diff should be 1 for a healthy request
 383                 session.log("debug", "rid: %d, sess: %s, diff: %d", rid, session.rid, diff)
 384                 if diff ~= 1 then
 385                         context.sid = sid;
 386                         context.notopen = nil;
 387                         if diff == 2 then -- Missed a request
 388                                 -- Hold request, but don't process it (ouch!)
 389                                 session.log("debug", "rid skipped: %d, deferring this request", rid-1)
 390                                 context.defer = true;
 391                                 session.bosh_deferred = { context = context, sid = sid, rid = rid, terminate = attr.type == "terminate" };
 392                                 return;
 393                         end
 394                         -- Set a marker to indicate that stanzas in this request should NOT be processed
 395                         -- (these stanzas will already be in the XML parser's buffer)
 396                         context.ignore = true;
 397                         if session.bosh_responses[rid] then
 398                                 -- Re-send past response, ignore stanzas in this request
 399                                 session.log("debug", "rid repeated within window, replaying old response");
 400                                 response:send(session.bosh_responses[rid]);
 401                                 return;
 402                         elseif diff == 0 then
 403                                 session.log("debug", "current rid repeated, ignoring stanzas");
 404                                 t_insert(session.requests, response);
 405                                 context.sid = sid;
 406                                 return;
 407                         end
 408                         -- Session broken, destroy it
 409                         session.log("debug", "rid out of range: %d (diff %d)", rid, diff);
 410                         response:send(tostring(st.stanza("body", { xmlns = xmlns_bosh, type = "terminate", condition = "item-not-found" })));
 411                         return;
 412                 end
 413                 session.rid = rid;
 414         end
 415
 416         if attr.type == "terminate" then
 417                 -- Client wants to end this session, which we'll do
 418                 -- after processing any stanzas in this request
 419                 session.bosh_terminate = true;
 420         end
 421
 422         context.notopen = nil; -- Signals that we accept this opening tag
 423         t_insert(session.requests, response);
 424         context.sid = sid;
 425         session.bosh_processing = true; -- Used to suppress replies until processing of this request is done
 426
 427         if session.notopen then
 428                 local features = st.stanza("stream:features");
 429                 module:context(session.host):fire_event("stream-features", { origin = session, features = features });
 430                 session.send(features);
 431                 session.notopen = nil;
 432         end
 433 end
 434
 435 local function handleerr(err) log("error", "Traceback[bosh]: %s", traceback(err, 2)); end
 436
 437 function runner_callbacks:error(err) -- luacheck: ignore 212/self
 438         return handleerr(err);
 439 end
 440
 441 function stream_callbacks.handlestanza(context, stanza)
 442         if context.ignore then return; end
 443         log("debug", "BOSH stanza received: %s\n", stanza:top_tag());
 444         local session = sessions[context.sid];
 445         if session then
 446                 if stanza.attr.xmlns == xmlns_bosh then
 447                         stanza.attr.xmlns = nil;
 448                 end
 449                 if context.defer and session.bosh_deferred then
 450                         log("debug", "Deferring this stanza");
 451                         t_insert(session.bosh_deferred, stanza);
 452                 else
 453                         stanza = session.filter("stanzas/in", stanza);
 454                         session.thread:run(stanza);
 455                 end
 456         else
 457                 log("debug", "No session for this stanza! (sid: %s)", context.sid or "none!");
 458         end
 459 end
 460
 461 function stream_callbacks.streamclosed(context)
 462         local session = sessions[context.sid];
 463         if session then
 464                 if not context.defer and session.bosh_deferred then
 465                         -- Handle deferred stanzas now
 466                         local deferred_stanzas = session.bosh_deferred;
 467                         local deferred_context = deferred_stanzas.context;
 468                         session.bosh_deferred = nil;
 469                         log("debug", "Handling deferred stanzas from rid %d", deferred_stanzas.rid);
 470                         session.rid = deferred_stanzas.rid;
 471                         t_insert(session.requests, deferred_context.response);
 472                         for _, stanza in ipairs(deferred_stanzas) do
 473                                 stream_callbacks.handlestanza(deferred_context, stanza);
 474                         end
 475                         if deferred_stanzas.terminate then
 476                                 session.bosh_terminate = true;
 477                         end
 478                 end
 479                 session.bosh_processing = false;
 480                 if #session.send_buffer > 0 then
 481                         session.send("");
 482                 end
 483         end
 484 end
 485
 486 function stream_callbacks.error(context, error)
 487         if not context.sid then
 488                 log("debug", "Error parsing BOSH request payload; %s", error);
 489                 local response = context.response;
 490                 local close_reply = st.stanza("body", { xmlns = xmlns_bosh, type = "terminate",
 491                         ["xmlns:stream"] = xmlns_streams, condition = "bad-request" });
 492                 response:send(tostring(close_reply));
 493                 return;
 494         end
 495
 496         local session = sessions[context.sid];
 497         (session and session.log or log)("warn", "Error parsing BOSH request payload; %s", error);
 498         if error == "stream-error" then -- Remote stream error, we close normally
 499                 session:close();
 500         else
 501                 session:close({ condition = "bad-format", text = "Error processing stream" });
 502         end
 503 end
 504
 505 local GET_response = {
 506         headers = {
 507                 content_type = "text/html";
 508         };
 509         body = [[<html><body>
 510         <p>It works! Now point your BOSH client to this URL to connect to Prosody.</p>
 511         <p>For more information see <a href="https://prosody.im/doc/setting_up_bosh">Prosody: Setting up BOSH</a>.</p>
 512         </body></html>]];
 513 };
 514
 515 module:depends("http");
 516 module:provides("http", {
 517         default_path = "/http-bind";
 518         route = {
 519                 ["GET"] = GET_response;
 520                 ["GET /"] = GET_response;
 521                 ["POST"] = handle_POST;
 522                 ["POST /"] = handle_POST;
 523         };
 524 });