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", false);
  48
  49 if cross_domain == true then cross_domain = "*"; end
  50 if type(cross_domain) == "table" then cross_domain = table.concat(cross_domain, ", "); end
  51
  52 local t_insert, t_remove, t_concat = table.insert, table.remove, table.concat;
  53
  54 -- All sessions, and sessions that have no requests open
  55 local sessions = module:shared("sessions");
  56
  57 -- Used to respond to idle sessions (those with waiting requests)
  58 function on_destroy_request(request)
  59         log("debug", "Request destroyed: %s", tostring(request));
  60         local session = sessions[request.context.sid];
  61         if session then
  62                 local requests = session.requests;
  63                 for i, r in ipairs(requests) do
  64                         if r == request then
  65                                 t_remove(requests, i);
  66                                 break;
  67                         end
  68                 end
  69
  70                 -- If this session now has no requests open, mark it as inactive
  71                 local max_inactive = session.bosh_max_inactive;
  72                 if max_inactive and #requests == 0 then
  73                         if session.inactive_timer then
  74                                 session.inactive_timer:stop();
  75                         end
  76                         session.inactive_timer = module:add_timer(max_inactive, check_inactive, session, request.context,
  77                                 "BOSH client silent for over "..max_inactive.." seconds");
  78                         (session.log or log)("debug", "BOSH session marked as inactive (for %ds)", max_inactive);
  79                 end
  80                 if session.bosh_wait_timer then
  81                         session.bosh_wait_timer:stop();
  82                         session.bosh_wait_timer = nil;
  83                 end
  84         end
  85 end
  86
  87 function check_inactive(now, session, context, reason) -- luacheck: ignore 212/now
  88         if not session.destroyed then
  89                 sessions[context.sid] = nil;
  90                 sm_destroy_session(session, reason);
  91         end
  92 end
  93
  94 local function set_cross_domain_headers(response)
  95         local headers = response.headers;
  96         headers.access_control_allow_methods = "GET, POST, OPTIONS";
  97         headers.access_control_allow_headers = "Content-Type";
  98         headers.access_control_max_age = "7200";
  99         headers.access_control_allow_origin = cross_domain;
 100         return response;
 101 end
 102
 103 function handle_OPTIONS(event)
 104         if cross_domain and event.request.headers.origin then
 105                 set_cross_domain_headers(event.response);
 106         end
 107         return "";
 108 end
 109
 110 function handle_POST(event)
 111         log("debug", "Handling new request %s: %s\n----------", tostring(event.request), tostring(event.request.body));
 112
 113         local request, response = event.request, event.response;
 114         response.on_destroy = on_destroy_request;
 115         local body = request.body;
 116
 117         local context = { request = request, response = response, notopen = true };
 118         local stream = new_xmpp_stream(context, stream_callbacks);
 119         response.context = context;
 120
 121         local headers = response.headers;
 122         headers.content_type = "text/xml; charset=utf-8";
 123
 124         if cross_domain and request.headers.origin then
 125                 set_cross_domain_headers(response);
 126         end
 127
 128         -- stream:feed() calls the stream_callbacks, so all stanzas in
 129         -- the body are processed in this next line before it returns.
 130         -- In particular, the streamopened() stream callback is where
 131         -- much of the session logic happens, because it's where we first
 132         -- get to see the 'sid' of this request.
 133         local ok, err = stream:feed(body);
 134         if not ok then
 135                 module:log("warn", "Error parsing BOSH payload; %s", err)
 136                 local close_reply = st.stanza("body", { xmlns = xmlns_bosh, type = "terminate",
 137                         ["xmlns:stream"] = xmlns_streams, condition = "bad-request" });
 138                 return tostring(close_reply);
 139         end
 140
 141         -- Stanzas (if any) in the request have now been processed, and
 142         -- we take care of the high-level BOSH logic here, including
 143         -- giving a response or putting the request "on hold".
 144         local session = sessions[context.sid];
 145         if session then
 146                 -- Session was marked as inactive, since we have
 147                 -- a request open now, unmark it
 148                 if session.inactive_timer and #session.requests > 0 then
 149                         session.inactive_timer:stop();
 150                         session.inactive_timer = nil;
 151                 end
 152
 153                 if session.bosh_wait_timer then
 154                         session.bosh_wait_timer:stop();
 155                         session.bosh_wait_timer = nil;
 156                 end
 157
 158                 local r = session.requests;
 159                 log("debug", "Session %s has %d out of %d requests open", context.sid, #r, BOSH_HOLD);
 160                 log("debug", "and there are %d things in the send_buffer:", #session.send_buffer);
 161                 if #r > BOSH_HOLD then
 162                         -- We are holding too many requests, send what's in the buffer,
 163                         log("debug", "We are holding too many requests, so...");
 164                         if #session.send_buffer > 0 then
 165                                 log("debug", "...sending what is in the buffer")
 166                                 session.send(t_concat(session.send_buffer));
 167                                 session.send_buffer = {};
 168                         else
 169                                 -- or an empty response
 170                                 log("debug", "...sending an empty response");
 171                                 session.send("");
 172                         end
 173                 elseif #session.send_buffer > 0 then
 174                         log("debug", "Session has data in the send buffer, will send now..");
 175                         local resp = t_concat(session.send_buffer);
 176                         session.send_buffer = {};
 177                         session.send(resp);
 178                 end
 179
 180                 if not response.finished then
 181                         -- We're keeping this request open, to respond later
 182                         log("debug", "Have nothing to say, so leaving request unanswered for now");
 183                 end
 184
 185                 if session.bosh_terminate then
 186                         session.log("debug", "Closing session with %d requests open", #session.requests);
 187                         session:close();
 188                         return nil;
 189                 else
 190                         if session.bosh_wait and #session.requests > 0 then
 191                                 session.bosh_wait_timer = module:add_timer(session.bosh_wait, after_bosh_wait, session.requests[1], session)
 192                         end
 193
 194                         return true; -- Inform http server we shall reply later
 195                 end
 196         elseif response.finished or context.ignore_request then
 197                 if response.finished then
 198                         module:log("debug", "Response finished");
 199                 end
 200                 if context.ignore_request then
 201                         module:log("debug", "Ignoring this request");
 202                 end
 203                 -- A response has been sent already, or we're ignoring this request
 204                 -- (e.g. so a different instance of the module can handle it)
 205                 return;
 206         end
 207         module:log("warn", "Unable to associate request with a session (incomplete request?)");
 208         local close_reply = st.stanza("body", { xmlns = xmlns_bosh, type = "terminate",
 209                 ["xmlns:stream"] = xmlns_streams, condition = "item-not-found" });
 210         return tostring(close_reply) .. "\n";
 211 end
 212
 213 function after_bosh_wait(now, request, session) -- luacheck: ignore 212
 214         if request.conn then
 215                 session.send("");
 216         end
 217 end
 218
 219 local function bosh_reset_stream(session) session.notopen = true; end
 220
 221 local stream_xmlns_attr = { xmlns = "urn:ietf:params:xml:ns:xmpp-streams" };
 222 local function bosh_close_stream(session, reason)
 223         (session.log or log)("info", "BOSH client disconnected: %s", tostring((reason and reason.condition or reason) or "session close"));
 224
 225         local close_reply = st.stanza("body", { xmlns = xmlns_bosh, type = "terminate",
 226                 ["xmlns:stream"] = xmlns_streams });
 227
 228
 229         if reason then
 230                 close_reply.attr.condition = "remote-stream-error";
 231                 if type(reason) == "string" then -- assume stream error
 232                         close_reply:tag("stream:error")
 233                                 :tag(reason, {xmlns = xmlns_xmpp_streams});
 234                 elseif type(reason) == "table" then
 235                         if reason.condition then
 236                                 close_reply:tag("stream:error")
 237                                         :tag(reason.condition, stream_xmlns_attr):up();
 238                                 if reason.text then
 239                                         close_reply:tag("text", stream_xmlns_attr):text(reason.text):up();
 240                                 end
 241                                 if reason.extra then
 242                                         close_reply:add_child(reason.extra);
 243                                 end
 244                         elseif reason.name then -- a stanza
 245                                 close_reply = reason;
 246                         end
 247                 end
 248                 log("info", "Disconnecting client, <stream:error> is: %s", tostring(close_reply));
 249         end
 250
 251         local response_body = tostring(close_reply);
 252         for _, held_request in ipairs(session.requests) do
 253                 held_request:send(response_body);
 254         end
 255         sessions[session.sid] = nil;
 256         sm_destroy_session(session);
 257 end
 258
 259 local runner_callbacks = { };
 260
 261 -- Handle the <body> tag in the request payload.
 262 function stream_callbacks.streamopened(context, attr)
 263         local request, response = context.request, context.response;
 264         local sid, rid = attr.sid, tonumber(attr.rid);
 265         log("debug", "BOSH body open (sid: %s)", sid or "<none>");
 266         context.rid = rid;
 267         if not sid then
 268                 -- New session request
 269                 context.notopen = nil; -- Signals that we accept this opening tag
 270
 271                 local to_host = nameprep(attr.to);
 272                 local wait = tonumber(attr.wait);
 273                 if not to_host then
 274                         log("debug", "BOSH client tried to connect to invalid host: %s", tostring(attr.to));
 275                         local close_reply = st.stanza("body", { xmlns = xmlns_bosh, type = "terminate",
 276                                 ["xmlns:stream"] = xmlns_streams, condition = "improper-addressing" });
 277                         response:send(tostring(close_reply));
 278                         return;
 279                 end
 280                 if not rid or (not wait and attr.wait or wait < 0 or wait % 1 ~= 0) then
 281                         log("debug", "BOSH client sent invalid rid or wait attributes: rid=%s, wait=%s", tostring(attr.rid), tostring(attr.wait));
 282                         local close_reply = st.stanza("body", { xmlns = xmlns_bosh, type = "terminate",
 283                                 ["xmlns:stream"] = xmlns_streams, condition = "bad-request" });
 284                         response:send(tostring(close_reply));
 285                         return;
 286                 end
 287
 288                 wait = math_min(wait, bosh_max_wait);
 289
 290                 -- New session
 291                 sid = new_uuid();
 292                 local session = {
 293                         type = "c2s_unauthed", conn = request.conn, sid = sid, host = attr.to,
 294                         rid = rid - 1, -- Hack for initial session setup, "previous" rid was $current_request - 1
 295                         bosh_version = attr.ver, bosh_wait = wait, streamid = sid,
 296                         bosh_max_inactive = bosh_max_inactivity, bosh_responses = cache.new(BOSH_HOLD+1):table();
 297                         requests = { }, send_buffer = {}, reset_stream = bosh_reset_stream,
 298                         close = bosh_close_stream, dispatch_stanza = core_process_stanza, notopen = true,
 299                         log = logger.init("bosh"..sid), secure = consider_bosh_secure or request.secure,
 300                         ip = request.ip;
 301                 };
 302                 sessions[sid] = session;
 303
 304                 session.thread = runner(function (stanza)
 305                         session:dispatch_stanza(stanza);
 306                 end, runner_callbacks, session);
 307
 308                 local filter = initialize_filters(session);
 309
 310                 session.log("debug", "BOSH session created for request from %s", session.ip);
 311                 log("info", "New BOSH session, assigned it sid '%s'", sid);
 312
 313                 module:fire_event("bosh-session", { session = session, request = request });
 314
 315                 -- Send creation response
 316                 local creating_session = true;
 317
 318                 local r = session.requests;
 319                 function session.send(s)
 320                         -- We need to ensure that outgoing stanzas have the jabber:client xmlns
 321                         if s.attr and not s.attr.xmlns then
 322                                 s = st.clone(s);
 323                                 s.attr.xmlns = "jabber:client";
 324                         end
 325                         s = filter("stanzas/out", s);
 326                         --log("debug", "Sending BOSH data: %s", tostring(s));
 327                         if not s then return true end
 328                         t_insert(session.send_buffer, tostring(s));
 329
 330                         local oldest_request = r[1];
 331                         if oldest_request and not session.bosh_processing then
 332                                 log("debug", "We have an open request, so sending on that");
 333                                 local body_attr = { xmlns = "http://jabber.org/protocol/httpbind",
 334                                         ["xmlns:stream"] = "http://etherx.jabber.org/streams";
 335                                         type = session.bosh_terminate and "terminate" or nil;
 336                                         sid = sid;
 337                                 };
 338                                 if creating_session then
 339                                         creating_session = nil;
 340                                         body_attr.requests = tostring(BOSH_MAX_REQUESTS);
 341                                         body_attr.hold = tostring(BOSH_HOLD);
 342                                         body_attr.inactivity = tostring(bosh_max_inactivity);
 343                                         body_attr.polling = tostring(bosh_max_polling);
 344                                         body_attr.wait = tostring(session.bosh_wait);
 345                                         body_attr.authid = sid;
 346                                         body_attr.secure = "true";
 347                                         body_attr.ver  = '1.6';
 348                                         body_attr.from = session.host;
 349                                         body_attr["xmlns:xmpp"] = "urn:xmpp:xbosh";
 350                                         body_attr["xmpp:version"] = "1.0";
 351                                 end
 352                                 local response_xml = st.stanza("body", body_attr):top_tag()..t_concat(session.send_buffer).."</body>";
 353                                 session.bosh_responses[oldest_request.context.rid] = response_xml;
 354                                 oldest_request:send(response_xml);
 355                                 session.send_buffer = {};
 356                         end
 357                         return true;
 358                 end
 359                 request.sid = sid;
 360         end
 361
 362         local session = sessions[sid];
 363         if not session then
 364                 -- Unknown sid
 365                 log("info", "Client tried to use sid '%s' which we don't know about", sid);
 366                 response:send(tostring(st.stanza("body", { xmlns = xmlns_bosh, type = "terminate", condition = "item-not-found" })));
 367                 context.notopen = nil;
 368                 return;
 369         end
 370
 371         session.conn = request.conn;
 372
 373         if session.rid then
 374                 local diff = rid - session.rid;
 375                 -- Diff should be 1 for a healthy request
 376                 session.log("debug", "rid: %d, sess: %s, diff: %d", rid, session.rid, diff)
 377                 if diff ~= 1 then
 378                         context.sid = sid;
 379                         context.notopen = nil;
 380                         if diff == 2 then -- Missed a request
 381                                 -- Hold request, but don't process it (ouch!)
 382                                 session.log("debug", "rid skipped: %d, deferring this request", rid-1)
 383                                 context.defer = true;
 384                                 session.bosh_deferred = { context = context, sid = sid, rid = rid, terminate = attr.type == "terminate" };
 385                                 return;
 386                         end
 387                         -- Set a marker to indicate that stanzas in this request should NOT be processed
 388                         -- (these stanzas will already be in the XML parser's buffer)
 389                         context.ignore = true;
 390                         if session.bosh_responses[rid] then
 391                                 -- Re-send past response, ignore stanzas in this request
 392                                 session.log("debug", "rid repeated within window, replaying old response");
 393                                 response:send(session.bosh_responses[rid]);
 394                                 return;
 395                         elseif diff == 0 then
 396                                 session.log("debug", "current rid repeated, ignoring stanzas");
 397                                 t_insert(session.requests, response);
 398                                 context.sid = sid;
 399                                 return;
 400                         end
 401                         -- Session broken, destroy it
 402                         session.log("debug", "rid out of range: %d (diff %d)", rid, diff);
 403                         response:send(tostring(st.stanza("body", { xmlns = xmlns_bosh, type = "terminate", condition = "item-not-found" })));
 404                         return;
 405                 end
 406                 session.rid = rid;
 407         end
 408
 409         if attr.type == "terminate" then
 410                 -- Client wants to end this session, which we'll do
 411                 -- after processing any stanzas in this request
 412                 session.bosh_terminate = true;
 413         end
 414
 415         context.notopen = nil; -- Signals that we accept this opening tag
 416         t_insert(session.requests, response);
 417         context.sid = sid;
 418         session.bosh_processing = true; -- Used to suppress replies until processing of this request is done
 419
 420         if session.notopen then
 421                 local features = st.stanza("stream:features");
 422                 module:context(session.host):fire_event("stream-features", { origin = session, features = features });
 423                 session.send(features);
 424                 session.notopen = nil;
 425         end
 426 end
 427
 428 local function handleerr(err) log("error", "Traceback[bosh]: %s", traceback(tostring(err), 2)); end
 429
 430 function runner_callbacks:error(err) -- luacheck: ignore 212/self
 431         return handleerr(err);
 432 end
 433
 434 function stream_callbacks.handlestanza(context, stanza)
 435         if context.ignore then return; end
 436         log("debug", "BOSH stanza received: %s\n", stanza:top_tag());
 437         local session = sessions[context.sid];
 438         if session then
 439                 if stanza.attr.xmlns == xmlns_bosh then
 440                         stanza.attr.xmlns = nil;
 441                 end
 442                 if context.defer and session.bosh_deferred then
 443                         log("debug", "Deferring this stanza");
 444                         t_insert(session.bosh_deferred, stanza);
 445                 else
 446                         stanza = session.filter("stanzas/in", stanza);
 447                         session.thread:run(stanza);
 448                 end
 449         else
 450                 log("debug", "No session for this stanza! (sid: %s)", context.sid or "none!");
 451         end
 452 end
 453
 454 function stream_callbacks.streamclosed(context)
 455         local session = sessions[context.sid];
 456         if session then
 457                 if not context.defer and session.bosh_deferred then
 458                         -- Handle deferred stanzas now
 459                         local deferred_stanzas = session.bosh_deferred;
 460                         local deferred_context = deferred_stanzas.context;
 461                         session.bosh_deferred = nil;
 462                         log("debug", "Handling deferred stanzas from rid %d", deferred_stanzas.rid);
 463                         session.rid = deferred_stanzas.rid;
 464                         t_insert(session.requests, deferred_context.response);
 465                         for _, stanza in ipairs(deferred_stanzas) do
 466                                 stream_callbacks.handlestanza(deferred_context, stanza);
 467                         end
 468                         if deferred_stanzas.terminate then
 469                                 session.bosh_terminate = true;
 470                         end
 471                 end
 472                 session.bosh_processing = false;
 473                 if #session.send_buffer > 0 then
 474                         session.send("");
 475                 end
 476         end
 477 end
 478
 479 function stream_callbacks.error(context, error)
 480         if not context.sid then
 481                 log("debug", "Error parsing BOSH request payload; %s", error);
 482                 local response = context.response;
 483                 local close_reply = st.stanza("body", { xmlns = xmlns_bosh, type = "terminate",
 484                         ["xmlns:stream"] = xmlns_streams, condition = "bad-request" });
 485                 response:send(tostring(close_reply));
 486                 return;
 487         end
 488
 489         local session = sessions[context.sid];
 490         (session and session.log or log)("warn", "Error parsing BOSH request payload; %s", error);
 491         if error == "stream-error" then -- Remote stream error, we close normally
 492                 session:close();
 493         else
 494                 session:close({ condition = "bad-format", text = "Error processing stream" });
 495         end
 496 end
 497
 498 local GET_response = {
 499         headers = {
 500                 content_type = "text/html";
 501         };
 502         body = [[<html><body>
 503         <p>It works! Now point your BOSH client to this URL to connect to Prosody.</p>
 504         <p>For more information see <a href="https://prosody.im/doc/setting_up_bosh">Prosody: Setting up BOSH</a>.</p>
 505         </body></html>]];
 506 };
 507
 508 module:depends("http");
 509 module:provides("http", {
 510         default_path = "/http-bind";
 511         route = {
 512                 ["GET"] = GET_response;
 513                 ["GET /"] = GET_response;
 514                 ["OPTIONS"] = handle_OPTIONS;
 515                 ["OPTIONS /"] = handle_OPTIONS;
 516                 ["POST"] = handle_POST;
 517                 ["POST /"] = handle_POST;
 518         };
 519 });