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