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.host = "*" -- Global module
  10
  11 local hosts = _G.hosts;
  12 local lxp = require "lxp";
  13 local new_xmpp_stream = require "util.xmppstream".new;
  14 local httpserver = require "net.httpserver";
  15 local sm = require "core.sessionmanager";
  16 local sm_destroy_session = sm.destroy_session;
  17 local new_uuid = require "util.uuid".generate;
  18 local fire_event = prosody.events.fire_event;
  19 local core_process_stanza = core_process_stanza;
  20 local st = require "util.stanza";
  21 local logger = require "util.logger";
  22 local log = logger.init("mod_bosh");
  23 local timer = require "util.timer";
  24
  25 local xmlns_streams = "http://etherx.jabber.org/streams";
  26 local xmlns_xmpp_streams = "urn:ietf:params:xml:ns:xmpp-streams";
  27 local xmlns_bosh = "http://jabber.org/protocol/httpbind"; -- (hard-coded into a literal in session.send)
  28
  29 local stream_callbacks = {
  30         stream_ns = xmlns_bosh, stream_tag = "body", default_ns = "jabber:client" };
  31
  32 local BOSH_DEFAULT_HOLD = module:get_option_number("bosh_default_hold", 1);
  33 local BOSH_DEFAULT_INACTIVITY = module:get_option_number("bosh_max_inactivity", 60);
  34 local BOSH_DEFAULT_POLLING = module:get_option_number("bosh_max_polling", 5);
  35 local BOSH_DEFAULT_REQUESTS = module:get_option_number("bosh_max_requests", 2);
  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" };
  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.handler: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 local sessions = {};
  77 local inactive_sessions = {}; -- Sessions which have no open requests
  78
  79 -- Used to respond to idle sessions (those with waiting requests)
  80 local waiting_requests = {};
  81 function on_destroy_request(request)
  82         waiting_requests[request] = nil;
  83         local session = sessions[request.sid];
  84         if session then
  85                 local requests = session.requests;
  86                 for i,r in ipairs(requests) do
  87                         if r == request then
  88                                 t_remove(requests, i);
  89                                 break;
  90                         end
  91                 end
  92
  93                 -- If this session now has no requests open, mark it as inactive
  94                 local max_inactive = session.bosh_max_inactive;
  95                 if max_inactive and #requests == 0 then
  96                         inactive_sessions[session] = os_time() + max_inactive;
  97                         (session.log or log)("debug", "BOSH session marked as inactive (for %ds)", max_inactive);
  98                 end
  99         end
 100 end
 101
 102 function handle_request(method, body, request)
 103         if (not body) or request.method ~= "POST" then
 104                 if request.method == "OPTIONS" then
 105                         local headers = {};
 106                         for k,v in pairs(default_headers) do headers[k] = v; end
 107                         headers["Content-Type"] = nil;
 108                         return { headers = headers, body = "" };
 109                 else
 110                         return "<html><body>You really don't look like a BOSH client to me... what do you want?</body></html>";
 111                 end
 112         end
 113         if not method then
 114                 log("debug", "Request %s suffered error %s", tostring(request.id), body);
 115                 return;
 116         end
 117         --log("debug", "Handling new request %s: %s\n----------", request.id, tostring(body));
 118         request.notopen = true;
 119         request.log = log;
 120         request.on_destroy = on_destroy_request;
 121
 122         local stream = new_xmpp_stream(request, stream_callbacks);
 123         -- stream:feed() calls the stream_callbacks, so all stanzas in
 124         -- the body are processed in this next line before it returns.
 125         stream:feed(body);
 126
 127         local session = sessions[request.sid];
 128         if session then
 129                 -- Session was marked as inactive, since we have
 130                 -- a request open now, unmark it
 131                 if inactive_sessions[session] and #session.requests > 0 then
 132                         inactive_sessions[session] = nil;
 133                 end
 134
 135                 local r = session.requests;
 136                 log("debug", "Session %s has %d out of %d requests open", request.sid, #r, session.bosh_hold);
 137                 log("debug", "and there are %d things in the send_buffer", #session.send_buffer);
 138                 if #r > session.bosh_hold then
 139                         -- We are holding too many requests, send what's in the buffer,
 140                         log("debug", "We are holding too many requests, so...");
 141                         if #session.send_buffer > 0 then
 142                                 log("debug", "...sending what is in the buffer")
 143                                 session.send(t_concat(session.send_buffer));
 144                                 session.send_buffer = {};
 145                         else
 146                                 -- or an empty response
 147                                 log("debug", "...sending an empty response");
 148                                 session.send("");
 149                         end
 150                 elseif #session.send_buffer > 0 then
 151                         log("debug", "Session has data in the send buffer, will send now..");
 152                         local resp = t_concat(session.send_buffer);
 153                         session.send_buffer = {};
 154                         session.send(resp);
 155                 end
 156
 157                 if not request.destroyed then
 158                         -- We're keeping this request open, to respond later
 159                         log("debug", "Have nothing to say, so leaving request unanswered for now");
 160                         if session.bosh_wait then
 161                                 request.reply_before = os_time() + session.bosh_wait;
 162                                 waiting_requests[request] = true;
 163                         end
 164                 end
 165
 166                 if session.bosh_terminate then
 167                         session.log("debug", "Closing session with %d requests open", #session.requests);
 168                         session:close();
 169                         return nil;
 170                 else
 171                         return true; -- Inform httpserver we shall reply later
 172                 end
 173         end
 174 end
 175
 176
 177 local function bosh_reset_stream(session) session.notopen = true; end
 178
 179 local stream_xmlns_attr = { xmlns = "urn:ietf:params:xml:ns:xmpp-streams" };
 180
 181 local function bosh_close_stream(session, reason)
 182         (session.log or log)("info", "BOSH client disconnected");
 183
 184         local close_reply = st.stanza("body", { xmlns = xmlns_bosh, type = "terminate",
 185                 ["xmlns:stream"] = xmlns_streams });
 186
 187
 188         if reason then
 189                 close_reply.attr.condition = "remote-stream-error";
 190                 if type(reason) == "string" then -- assume stream error
 191                         close_reply:tag("stream:error")
 192                                 :tag(reason, {xmlns = xmlns_xmpp_streams});
 193                 elseif type(reason) == "table" then
 194                         if reason.condition then
 195                                 close_reply:tag("stream:error")
 196                                         :tag(reason.condition, stream_xmlns_attr):up();
 197                                 if reason.text then
 198                                         close_reply:tag("text", stream_xmlns_attr):text(reason.text):up();
 199                                 end
 200                                 if reason.extra then
 201                                         close_reply:add_child(reason.extra);
 202                                 end
 203                         elseif reason.name then -- a stanza
 204                                 close_reply = reason;
 205                         end
 206                 end
 207                 log("info", "Disconnecting client, <stream:error> is: %s", tostring(close_reply));
 208         end
 209
 210         local session_close_response = { headers = default_headers, body = tostring(close_reply) };
 211
 212         for _, held_request in ipairs(session.requests) do
 213                 held_request:send(session_close_response);
 214                 held_request:destroy();
 215         end
 216         sessions[session.sid]  = nil;
 217         inactive_sessions[session] = nil;
 218         sm_destroy_session(session);
 219 end
 220
 221 function stream_callbacks.streamopened(request, attr)
 222         local sid = attr.sid;
 223         log("debug", "BOSH body open (sid: %s)", sid or "<none>");
 224         if not sid then
 225                 -- New session request
 226                 request.notopen = nil; -- Signals that we accept this opening tag
 227
 228                 -- TODO: Sanity checks here (rid, to, known host, etc.)
 229                 if not hosts[attr.to] then
 230                         -- Unknown host
 231                         log("debug", "BOSH client tried to connect to unknown host: %s", tostring(attr.to));
 232                         local close_reply = st.stanza("body", { xmlns = xmlns_bosh, type = "terminate",
 233                                 ["xmlns:stream"] = xmlns_streams, condition = "host-unknown" });
 234                         request:send(tostring(close_reply));
 235                         return;
 236                 end
 237
 238                 -- New session
 239                 sid = new_uuid();
 240                 local session = {
 241                         type = "c2s_unauthed", conn = {}, sid = sid, rid = tonumber(attr.rid), host = attr.to,
 242                         bosh_version = attr.ver, bosh_wait = attr.wait, streamid = sid,
 243                         bosh_hold = BOSH_DEFAULT_HOLD, bosh_max_inactive = BOSH_DEFAULT_INACTIVITY,
 244                         requests = { }, send_buffer = {}, reset_stream = bosh_reset_stream,
 245                         close = bosh_close_stream, dispatch_stanza = core_process_stanza,
 246                         log = logger.init("bosh"..sid), secure = consider_bosh_secure or request.secure,
 247                         ip = get_ip_from_request(request);
 248                 };
 249                 sessions[sid] = session;
 250
 251                 session.log("debug", "BOSH session created for request from %s", session.ip);
 252                 log("info", "New BOSH session, assigned it sid '%s'", sid);
 253                 local r, send_buffer = session.requests, session.send_buffer;
 254                 local response = { headers = default_headers }
 255                 function session.send(s)
 256                         -- We need to ensure that outgoing stanzas have the jabber:client xmlns
 257                         if s.attr and not s.attr.xmlns then
 258                                 s = st.clone(s);
 259                                 s.attr.xmlns = "jabber:client";
 260                         end
 261                         --log("debug", "Sending BOSH data: %s", tostring(s));
 262                         local oldest_request = r[1];
 263                         if oldest_request then
 264                                 log("debug", "We have an open request, so sending on that");
 265                                 response.body = t_concat({
 266                                         "<body xmlns='http://jabber.org/protocol/httpbind' ",
 267                                         session.bosh_terminate and "type='terminate' " or "",
 268                                         "sid='", sid, "' xmlns:stream = 'http://etherx.jabber.org/streams'>",
 269                                         tostring(s),
 270                                         "</body>"
 271                                 });
 272                                 oldest_request:send(response);
 273                                 --log("debug", "Sent");
 274                                 if oldest_request.stayopen then
 275                                         if #r>1 then
 276                                                 -- Move front request to back
 277                                                 t_insert(r, oldest_request);
 278                                                 t_remove(r, 1);
 279                                         end
 280                                 else
 281                                         log("debug", "Destroying the request now...");
 282                                         oldest_request:destroy();
 283                                 end
 284                         elseif s ~= "" then
 285                                 log("debug", "Saved to send buffer because there are %d open requests", #r);
 286                                 -- Hmm, no requests are open :(
 287                                 t_insert(session.send_buffer, tostring(s));
 288                                 log("debug", "There are now %d things in the send_buffer", #session.send_buffer);
 289                         end
 290                         return true;
 291                 end
 292
 293                 -- Send creation response
 294
 295                 local features = st.stanza("stream:features");
 296                 hosts[session.host].events.fire_event("stream-features", { origin = session, features = features });
 297                 fire_event("stream-features", session, features);
 298                 --xmpp:version='1.0' xmlns:xmpp='urn:xmpp:xbosh'
 299                 local response = st.stanza("body", { xmlns = xmlns_bosh,
 300                         wait = attr.wait,
 301                         inactivity = tostring(BOSH_DEFAULT_INACTIVITY),
 302                         polling = tostring(BOSH_DEFAULT_POLLING),
 303                         requests = tostring(BOSH_DEFAULT_REQUESTS),
 304                         hold = tostring(session.bosh_hold),
 305                         sid = sid, authid = sid,
 306                         ver  = '1.6', from = session.host,
 307                         secure = 'true', ["xmpp:version"] = "1.0",
 308                         ["xmlns:xmpp"] = "urn:xmpp:xbosh",
 309                         ["xmlns:stream"] = "http://etherx.jabber.org/streams"
 310                 }):add_child(features);
 311                 request:send{ headers = default_headers, body = tostring(response) };
 312
 313                 request.sid = sid;
 314                 return;
 315         end
 316
 317         local session = sessions[sid];
 318         if not session then
 319                 -- Unknown sid
 320                 log("info", "Client tried to use sid '%s' which we don't know about", sid);
 321                 request:send{ headers = default_headers, body = tostring(st.stanza("body", { xmlns = xmlns_bosh, type = "terminate", condition = "item-not-found" })) };
 322                 request.notopen = nil;
 323                 return;
 324         end
 325
 326         if session.rid then
 327                 local rid = tonumber(attr.rid);
 328                 local diff = rid - session.rid;
 329                 if diff > 1 then
 330                         session.log("warn", "rid too large (means a request was lost). Last rid: %d New rid: %s", session.rid, attr.rid);
 331                 elseif diff <= 0 then
 332                         -- Repeated, ignore
 333                         session.log("debug", "rid repeated (on request %s), ignoring: %s (diff %d)", request.id, session.rid, diff);
 334                         request.notopen = nil;
 335                         request.ignore = true;
 336                         request.sid = sid;
 337                         t_insert(session.requests, request);
 338                         return;
 339                 end
 340                 session.rid = rid;
 341         end
 342
 343         if session.notopen then
 344                 local features = st.stanza("stream:features");
 345                 hosts[session.host].events.fire_event("stream-features", { origin = session, features = features });
 346                 fire_event("stream-features", session, features);
 347                 session.send(features);
 348                 session.notopen = nil;
 349         end
 350
 351         if attr.type == "terminate" then
 352                 -- Client wants to end this session, which we'll do
 353                 -- after processing any stanzas in this request
 354                 session.bosh_terminate = true;
 355         end
 356
 357         request.notopen = nil; -- Signals that we accept this opening tag
 358         t_insert(session.requests, request);
 359         request.sid = sid;
 360 end
 361
 362 function stream_callbacks.handlestanza(request, stanza)
 363         if request.ignore then return; end
 364         log("debug", "BOSH stanza received: %s\n", stanza:top_tag());
 365         local session = sessions[request.sid];
 366         if session then
 367                 if stanza.attr.xmlns == xmlns_bosh then
 368                         stanza.attr.xmlns = nil;
 369                 end
 370                 core_process_stanza(session, stanza);
 371         end
 372 end
 373
 374 function stream_callbacks.error(request, error)
 375         log("debug", "Error parsing BOSH request payload; %s", error);
 376         if not request.sid then
 377                 request:send({ headers = default_headers, status = "400 Bad Request" });
 378                 return;
 379         end
 380
 381         local session = sessions[request.sid];
 382         if error == "stream-error" then -- Remote stream error, we close normally
 383                 session:close();
 384         else
 385                 session:close({ condition = "bad-format", text = "Error processing stream" });
 386         end
 387 end
 388
 389 local dead_sessions = {};
 390 function on_timer()
 391         -- log("debug", "Checking for requests soon to timeout...");
 392         -- Identify requests timing out within the next few seconds
 393         local now = os_time() + 3;
 394         for request in pairs(waiting_requests) do
 395                 if request.reply_before <= now then
 396                         log("debug", "%s was soon to timeout, sending empty response", request.id);
 397                         -- Send empty response to let the
 398                         -- client know we're still here
 399                         if request.conn then
 400                                 sessions[request.sid].send("");
 401                         end
 402                 end
 403         end
 404
 405         now = now - 3;
 406         local n_dead_sessions = 0;
 407         for session, close_after in pairs(inactive_sessions) do
 408                 if close_after < now then
 409                         (session.log or log)("debug", "BOSH client inactive too long, destroying session at %d", now);
 410                         sessions[session.sid]  = nil;
 411                         inactive_sessions[session] = nil;
 412                         n_dead_sessions = n_dead_sessions + 1;
 413                         dead_sessions[n_dead_sessions] = session;
 414                 end
 415         end
 416
 417         for i=1,n_dead_sessions do
 418                 local session = dead_sessions[i];
 419                 dead_sessions[i] = nil;
 420                 sm_destroy_session(session, "BOSH client silent for over "..session.bosh_max_inactive.." seconds");
 421         end
 422         return 1;
 423 end
 424
 425
 426 local function setup()
 427         local ports = module:get_option_array("bosh_ports") or { 5280 };
 428         httpserver.new_from_config(ports, handle_request, { base = "http-bind" });
 429         timer.add_task(1, on_timer);
 430 end
 431 if prosody.start_time then -- already started
 432         setup();
 433 else
 434         prosody.events.add_handler("server-started", setup);
 435 end