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