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(); -- Global module
  10
  11 local hosts = _G.hosts;
  12 local new_xmpp_stream = require "util.xmppstream".new;
  13 local sm = require "core.sessionmanager";
  14 local sm_destroy_session = sm.destroy_session;
  15 local new_uuid = require "util.uuid".generate;
  16 local core_process_stanza = prosody.core_process_stanza;
  17 local st = require "util.stanza";
  18 local logger = require "util.logger";
  19 local log = logger.init("mod_bosh");
  20 local initialize_filters = require "util.filters".initialize;
  21 local math_min = math.min;
  22 local xpcall, tostring, type = xpcall, tostring, type;
  23 local traceback = debug.traceback;
  24 local nameprep = require "util.encodings".stringprep.nameprep;
  25
  26 local xmlns_streams = "http://etherx.jabber.org/streams";
  27 local xmlns_xmpp_streams = "urn:ietf:params:xml:ns:xmpp-streams";
  28 local xmlns_bosh = "http://jabber.org/protocol/httpbind"; -- (hard-coded into a literal in session.send)
  29
  30 local stream_callbacks = {
  31         stream_ns = xmlns_bosh, stream_tag = "body", default_ns = "jabber:client" };
  32
  33 local BOSH_DEFAULT_HOLD = module:get_option_number("bosh_default_hold", 1);
  34 local BOSH_DEFAULT_INACTIVITY = module:get_option_number("bosh_max_inactivity", 60);
  35 local BOSH_DEFAULT_POLLING = module:get_option_number("bosh_max_polling", 5);
  36 local BOSH_DEFAULT_REQUESTS = module:get_option_number("bosh_max_requests", 2);
  37 local bosh_max_wait = module:get_option_number("bosh_max_wait", 120);
  38
  39 local consider_bosh_secure = module:get_option_boolean("consider_bosh_secure");
  40 local cross_domain = module:get_option("cross_domain_bosh", false);
  41
  42 if cross_domain == true then cross_domain = "*"; end
  43 if type(cross_domain) == "table" then cross_domain = table.concat(cross_domain, ", "); end
  44
  45 local trusted_proxies = module:get_option_set("trusted_proxies", {"127.0.0.1"})._items;
  46
  47 local function get_ip_from_request(request)
  48         local ip = request.conn:ip();
  49         local forwarded_for = request.headers.x_forwarded_for;
  50         if forwarded_for then
  51                 forwarded_for = forwarded_for..", "..ip;
  52                 for forwarded_ip in forwarded_for:gmatch("[^%s,]+") do
  53                         if not trusted_proxies[forwarded_ip] then
  54                                 ip = forwarded_ip;
  55                         end
  56                 end
  57         end
  58         return ip;
  59 end
  60
  61 local t_insert, t_remove, t_concat = table.insert, table.remove, table.concat;
  62 local os_time = os.time;
  63
  64 -- All sessions, and sessions that have no requests open
  65 local sessions, inactive_sessions = module:shared("sessions", "inactive_sessions");
  66
  67 -- Used to respond to idle sessions (those with waiting requests)
  68 local waiting_requests = module:shared("waiting_requests");
  69 function on_destroy_request(request)
  70         log("debug", "Request destroyed: %s", tostring(request));
  71         waiting_requests[request] = nil;
  72         local session = sessions[request.context.sid];
  73         if session then
  74                 local requests = session.requests;
  75                 for i, r in ipairs(requests) do
  76                         if r == request then
  77                                 t_remove(requests, i);
  78                                 break;
  79                         end
  80                 end
  81
  82                 -- If this session now has no requests open, mark it as inactive
  83                 local max_inactive = session.bosh_max_inactive;
  84                 if max_inactive and #requests == 0 then
  85                         inactive_sessions[session] = os_time() + max_inactive;
  86                         (session.log or log)("debug", "BOSH session marked as inactive (for %ds)", max_inactive);
  87                 end
  88         end
  89 end
  90
  91 local function set_cross_domain_headers(response)
  92         local headers = response.headers;
  93         headers.access_control_allow_methods = "GET, POST, OPTIONS";
  94         headers.access_control_allow_headers = "Content-Type";
  95         headers.access_control_max_age = "7200";
  96         headers.access_control_allow_origin = cross_domain;
  97         return response;
  98 end
  99
 100 function handle_OPTIONS(event)
 101         if cross_domain and event.request.headers.origin then
 102                 set_cross_domain_headers(event.response);
 103         end
 104         return "";
 105 end
 106
 107 function handle_POST(event)
 108         log("debug", "Handling new request %s: %s\n----------", tostring(event.request), tostring(event.request.body));
 109
 110         local request, response = event.request, event.response;
 111         response.on_destroy = on_destroy_request;
 112         local body = request.body;
 113
 114         local context = { request = request, response = response, notopen = true };
 115         local stream = new_xmpp_stream(context, stream_callbacks);
 116         response.context = context;
 117
 118         local headers = response.headers;
 119         headers.content_type = "text/xml; charset=utf-8";
 120
 121         if cross_domain and event.request.headers.origin then
 122                 set_cross_domain_headers(response);
 123         end
 124
 125         -- stream:feed() calls the stream_callbacks, so all stanzas in
 126         -- the body are processed in this next line before it returns.
 127         -- In particular, the streamopened() stream callback is where
 128         -- much of the session logic happens, because it's where we first
 129         -- get to see the 'sid' of this request.
 130         local ok, err = stream:feed(body);
 131         if not ok then
 132                 module:log("warn", "Error parsing BOSH payload; %s", err)
 133                 local close_reply = st.stanza("body", { xmlns = xmlns_bosh, type = "terminate",
 134                         ["xmlns:stream"] = xmlns_streams, condition = "bad-request" });
 135                 return tostring(close_reply);
 136         end
 137
 138         -- Stanzas (if any) in the request have now been processed, and
 139         -- we take care of the high-level BOSH logic here, including
 140         -- giving a response or putting the request "on hold".
 141         local session = sessions[context.sid];
 142         if session then
 143                 -- Session was marked as inactive, since we have
 144                 -- a request open now, unmark it
 145                 if inactive_sessions[session] and #session.requests > 0 then
 146                         inactive_sessions[session] = nil;
 147                 end
 148
 149                 local r = session.requests;
 150                 log("debug", "Session %s has %d out of %d requests open", context.sid, #r, session.bosh_hold);
 151                 log("debug", "and there are %d things in the send_buffer:", #session.send_buffer);
 152                 if #r > session.bosh_hold then
 153                         -- We are holding too many requests, send what's in the buffer,
 154                         log("debug", "We are holding too many requests, so...");
 155                         if #session.send_buffer > 0 then
 156                                 log("debug", "...sending what is in the buffer")
 157                                 session.send(t_concat(session.send_buffer));
 158                                 session.send_buffer = {};
 159                         else
 160                                 -- or an empty response
 161                                 log("debug", "...sending an empty response");
 162                                 session.send("");
 163                         end
 164                 elseif #session.send_buffer > 0 then
 165                         log("debug", "Session has data in the send buffer, will send now..");
 166                         local resp = t_concat(session.send_buffer);
 167                         session.send_buffer = {};
 168                         session.send(resp);
 169                 end
 170
 171                 if not response.finished then
 172                         -- We're keeping this request open, to respond later
 173                         log("debug", "Have nothing to say, so leaving request unanswered for now");
 174                         if session.bosh_wait then
 175                                 waiting_requests[response] = os_time() + session.bosh_wait;
 176                         end
 177                 end
 178
 179                 if session.bosh_terminate then
 180                         session.log("debug", "Closing session with %d requests open", #session.requests);
 181                         session:close();
 182                         return nil;
 183                 else
 184                         return true; -- Inform http server we shall reply later
 185                 end
 186         elseif response.finished then
 187                 return; -- A response has been sent already
 188         end
 189         module:log("warn", "Unable to associate request with a session (incomplete request?)");
 190         local close_reply = st.stanza("body", { xmlns = xmlns_bosh, type = "terminate",
 191                 ["xmlns:stream"] = xmlns_streams, condition = "item-not-found" });
 192         return tostring(close_reply) .. "\n";
 193 end
 194
 195
 196 local function bosh_reset_stream(session) session.notopen = true; end
 197
 198 local stream_xmlns_attr = { xmlns = "urn:ietf:params:xml:ns:xmpp-streams" };
 199
 200 local function bosh_close_stream(session, reason)
 201         (session.log or log)("info", "BOSH client disconnected");
 202
 203         local close_reply = st.stanza("body", { xmlns = xmlns_bosh, type = "terminate",
 204                 ["xmlns:stream"] = xmlns_streams });
 205
 206
 207         if reason then
 208                 close_reply.attr.condition = "remote-stream-error";
 209                 if type(reason) == "string" then -- assume stream error
 210                         close_reply:tag("stream:error")
 211                                 :tag(reason, {xmlns = xmlns_xmpp_streams});
 212                 elseif type(reason) == "table" then
 213                         if reason.condition then
 214                                 close_reply:tag("stream:error")
 215                                         :tag(reason.condition, stream_xmlns_attr):up();
 216                                 if reason.text then
 217                                         close_reply:tag("text", stream_xmlns_attr):text(reason.text):up();
 218                                 end
 219                                 if reason.extra then
 220                                         close_reply:add_child(reason.extra);
 221                                 end
 222                         elseif reason.name then -- a stanza
 223                                 close_reply = reason;
 224                         end
 225                 end
 226                 log("info", "Disconnecting client, <stream:error> is: %s", tostring(close_reply));
 227         end
 228
 229         local response_body = tostring(close_reply);
 230         for _, held_request in ipairs(session.requests) do
 231                 held_request:send(response_body);
 232         end
 233         sessions[session.sid] = nil;
 234         inactive_sessions[session] = nil;
 235         sm_destroy_session(session);
 236 end
 237
 238 -- Handle the <body> tag in the request payload.
 239 function stream_callbacks.streamopened(context, attr)
 240         local request, response = context.request, context.response;
 241         local sid = attr.sid;
 242         log("debug", "BOSH body open (sid: %s)", sid or "<none>");
 243         if not sid then
 244                 -- New session request
 245                 context.notopen = nil; -- Signals that we accept this opening tag
 246
 247                 local to_host = nameprep(attr.to);
 248                 local rid = tonumber(attr.rid);
 249                 local wait = tonumber(attr.wait);
 250                 if not to_host then
 251                         log("debug", "BOSH client tried to connect to invalid host: %s", tostring(attr.to));
 252                         local close_reply = st.stanza("body", { xmlns = xmlns_bosh, type = "terminate",
 253                                 ["xmlns:stream"] = xmlns_streams, condition = "improper-addressing" });
 254                         response:send(tostring(close_reply));
 255                         return;
 256                 elseif not hosts[to_host] then
 257                         -- Unknown host
 258                         log("debug", "BOSH client tried to connect to unknown host: %s", tostring(attr.to));
 259                         local close_reply = st.stanza("body", { xmlns = xmlns_bosh, type = "terminate",
 260                                 ["xmlns:stream"] = xmlns_streams, condition = "host-unknown" });
 261                         response:send(tostring(close_reply));
 262                         return;
 263                 end
 264                 if not rid or (not wait and attr.wait or wait < 0 or wait % 1 ~= 0) then
 265                         log("debug", "BOSH client sent invalid rid or wait attributes: rid=%s, wait=%s", tostring(attr.rid), tostring(attr.wait));
 266                         local close_reply = st.stanza("body", { xmlns = xmlns_bosh, type = "terminate",
 267                                 ["xmlns:stream"] = xmlns_streams, condition = "bad-request" });
 268                         response:send(tostring(close_reply));
 269                         return;
 270                 end
 271
 272                 rid = rid - 1;
 273                 wait = math_min(wait, bosh_max_wait);
 274
 275                 -- New session
 276                 sid = new_uuid();
 277                 local session = {
 278                         type = "c2s_unauthed", conn = {}, sid = sid, rid = rid, host = attr.to,
 279                         bosh_version = attr.ver, bosh_wait = wait, streamid = sid,
 280                         bosh_hold = BOSH_DEFAULT_HOLD, bosh_max_inactive = BOSH_DEFAULT_INACTIVITY,
 281                         requests = { }, send_buffer = {}, reset_stream = bosh_reset_stream,
 282                         close = bosh_close_stream, dispatch_stanza = core_process_stanza, notopen = true,
 283                         log = logger.init("bosh"..sid), secure = consider_bosh_secure or request.secure,
 284                         ip = get_ip_from_request(request);
 285                 };
 286                 sessions[sid] = session;
 287
 288                 local filter = initialize_filters(session);
 289
 290                 session.log("debug", "BOSH session created for request from %s", session.ip);
 291                 log("info", "New BOSH session, assigned it sid '%s'", sid);
 292
 293                 hosts[session.host].events.fire_event("bosh-session", { session = session, request = request });
 294
 295                 -- Send creation response
 296                 local creating_session = true;
 297
 298                 local r = session.requests;
 299                 function session.send(s)
 300                         -- We need to ensure that outgoing stanzas have the jabber:client xmlns
 301                         if s.attr and not s.attr.xmlns then
 302                                 s = st.clone(s);
 303                                 s.attr.xmlns = "jabber:client";
 304                         end
 305                         s = filter("stanzas/out", s);
 306                         --log("debug", "Sending BOSH data: %s", tostring(s));
 307                         if not s then return true end
 308                         t_insert(session.send_buffer, tostring(s));
 309
 310                         local oldest_request = r[1];
 311                         if oldest_request and not session.bosh_processing then
 312                                 log("debug", "We have an open request, so sending on that");
 313                                 local body_attr = { xmlns = "http://jabber.org/protocol/httpbind",
 314                                         ["xmlns:stream"] = "http://etherx.jabber.org/streams";
 315                                         type = session.bosh_terminate and "terminate" or nil;
 316                                         sid = sid;
 317                                 };
 318                                 if creating_session then
 319                                         creating_session = nil;
 320                                         body_attr.inactivity = tostring(BOSH_DEFAULT_INACTIVITY);
 321                                         body_attr.polling = tostring(BOSH_DEFAULT_POLLING);
 322                                         body_attr.requests = tostring(BOSH_DEFAULT_REQUESTS);
 323                                         body_attr.wait = tostring(session.bosh_wait);
 324                                         body_attr.hold = tostring(session.bosh_hold);
 325                                         body_attr.authid = sid;
 326                                         body_attr.secure = "true";
 327                                         body_attr.ver  = '1.6';
 328                                         body_attr.from = session.host;
 329                                         body_attr["xmlns:xmpp"] = "urn:xmpp:xbosh";
 330                                         body_attr["xmpp:version"] = "1.0";
 331                                 end
 332                                 oldest_request:send(st.stanza("body", body_attr):top_tag()..t_concat(session.send_buffer).."</body>");
 333                                 session.send_buffer = {};
 334                         end
 335                         return true;
 336                 end
 337                 request.sid = sid;
 338         end
 339
 340         local session = sessions[sid];
 341         if not session then
 342                 -- Unknown sid
 343                 log("info", "Client tried to use sid '%s' which we don't know about", sid);
 344                 response:send(tostring(st.stanza("body", { xmlns = xmlns_bosh, type = "terminate", condition = "item-not-found" })));
 345                 context.notopen = nil;
 346                 return;
 347         end
 348
 349         if session.rid then
 350                 local rid = tonumber(attr.rid);
 351                 local diff = rid - session.rid;
 352                 if diff > 1 then
 353                         session.log("warn", "rid too large (means a request was lost). Last rid: %d New rid: %s", session.rid, attr.rid);
 354                 elseif diff <= 0 then
 355                         -- Repeated, ignore
 356                         session.log("debug", "rid repeated, ignoring: %s (diff %d)", session.rid, diff);
 357                         context.notopen = nil;
 358                         context.ignore = true;
 359                         context.sid = sid;
 360                         t_insert(session.requests, response);
 361                         return;
 362                 end
 363                 session.rid = rid;
 364         end
 365
 366         if attr.type == "terminate" then
 367                 -- Client wants to end this session, which we'll do
 368                 -- after processing any stanzas in this request
 369                 session.bosh_terminate = true;
 370         end
 371
 372         context.notopen = nil; -- Signals that we accept this opening tag
 373         t_insert(session.requests, response);
 374         context.sid = sid;
 375         session.bosh_processing = true; -- Used to suppress replies until processing of this request is done
 376
 377         if session.notopen then
 378                 local features = st.stanza("stream:features");
 379                 hosts[session.host].events.fire_event("stream-features", { origin = session, features = features });
 380                 session.send(features);
 381                 session.notopen = nil;
 382         end
 383 end
 384
 385 local function handleerr(err) log("error", "Traceback[bosh]: %s", traceback(tostring(err), 2)); end
 386 function stream_callbacks.handlestanza(context, stanza)
 387         if context.ignore then return; end
 388         log("debug", "BOSH stanza received: %s\n", stanza:top_tag());
 389         local session = sessions[context.sid];
 390         if session then
 391                 if stanza.attr.xmlns == xmlns_bosh then
 392                         stanza.attr.xmlns = nil;
 393                 end
 394                 stanza = session.filter("stanzas/in", stanza);
 395                 if stanza then
 396                         return xpcall(function () return core_process_stanza(session, stanza) end, handleerr);
 397                 end
 398         end
 399 end
 400
 401 function stream_callbacks.streamclosed(context)
 402         local session = sessions[context.sid];
 403         if session then
 404                 session.bosh_processing = false;
 405                 if #session.send_buffer > 0 then
 406                         session.send("");
 407                 end
 408         end
 409 end
 410
 411 function stream_callbacks.error(context, error)
 412         log("debug", "Error parsing BOSH request payload; %s", error);
 413         if not context.sid then
 414                 local response = context.response;
 415                 local close_reply = st.stanza("body", { xmlns = xmlns_bosh, type = "terminate",
 416                         ["xmlns:stream"] = xmlns_streams, condition = "bad-request" });
 417                 response:send(tostring(close_reply));
 418                 return;
 419         end
 420
 421         local session = sessions[context.sid];
 422         if error == "stream-error" then -- Remote stream error, we close normally
 423                 session:close();
 424         else
 425                 session:close({ condition = "bad-format", text = "Error processing stream" });
 426         end
 427 end
 428
 429 local dead_sessions = module:shared("dead_sessions");
 430 function on_timer()
 431         -- log("debug", "Checking for requests soon to timeout...");
 432         -- Identify requests timing out within the next few seconds
 433         local now = os_time() + 3;
 434         for request, reply_before in pairs(waiting_requests) do
 435                 if reply_before <= now then
 436                         log("debug", "%s was soon to timeout (at %d, now %d), sending empty response", tostring(request), reply_before, now);
 437                         -- Send empty response to let the
 438                         -- client know we're still here
 439                         if request.conn then
 440                                 sessions[request.context.sid].send("");
 441                         end
 442                 end
 443         end
 444
 445         now = now - 3;
 446         local n_dead_sessions = 0;
 447         for session, close_after in pairs(inactive_sessions) do
 448                 if close_after < now then
 449                         (session.log or log)("debug", "BOSH client inactive too long, destroying session at %d", now);
 450                         sessions[session.sid]  = nil;
 451                         inactive_sessions[session] = nil;
 452                         n_dead_sessions = n_dead_sessions + 1;
 453                         dead_sessions[n_dead_sessions] = session;
 454                 end
 455         end
 456
 457         for i=1,n_dead_sessions do
 458                 local session = dead_sessions[i];
 459                 dead_sessions[i] = nil;
 460                 sm_destroy_session(session, "BOSH client silent for over "..session.bosh_max_inactive.." seconds");
 461         end
 462         return 1;
 463 end
 464 module:add_timer(1, on_timer);
 465
 466
 467 local GET_response = {
 468         headers = {
 469                 content_type = "text/html";
 470         };
 471         body = [[<html><body>
 472         <p>It works! Now point your BOSH client to this URL to connect to Prosody.</p>
 473         <p>For more information see <a href="http://prosody.im/doc/setting_up_bosh">Prosody: Setting up BOSH</a>.</p>
 474         </body></html>]];
 475 };
 476
 477 function module.add_host(module)
 478         module:depends("http");
 479         module:provides("http", {
 480                 default_path = "/http-bind";
 481                 route = {
 482                         ["GET"] = GET_response;
 483                         ["GET /"] = GET_response;
 484                         ["OPTIONS"] = handle_OPTIONS;
 485                         ["OPTIONS /"] = handle_OPTIONS;
 486                         ["POST"] = handle_POST;
 487                         ["POST /"] = handle_POST;
 488                 };
 489         });
 490 end