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 local auto_cork = module:get_option_boolean("bosh_auto_cork", false);
  39
  40 local default_headers = { ["Content-Type"] = "text/xml; charset=utf-8" };
  41
  42 local cross_domain = module:get_option("cross_domain_bosh", false);
  43 if cross_domain then
  44         default_headers["Access-Control-Allow-Methods"] = "GET, POST, OPTIONS";
  45         default_headers["Access-Control-Allow-Headers"] = "Content-Type";
  46         default_headers["Access-Control-Max-Age"] = "7200";
  47
  48         if cross_domain == true then
  49                 default_headers["Access-Control-Allow-Origin"] = "*";
  50         elseif type(cross_domain) == "table" then
  51                 cross_domain = table.concat(cross_domain, ", ");
  52         end
  53         if type(cross_domain) == "string" then
  54                 default_headers["Access-Control-Allow-Origin"] = cross_domain;
  55         end
  56 end
  57
  58 local trusted_proxies = module:get_option_set("trusted_proxies", {"127.0.0.1"})._items;
  59
  60 local function get_ip_from_request(request)
  61         local ip = request.conn:ip();
  62         local forwarded_for = request.headers["x-forwarded-for"];
  63         if forwarded_for then
  64                 forwarded_for = forwarded_for..", "..ip;
  65                 for forwarded_ip in forwarded_for:gmatch("[^%s,]+") do
  66                         if not trusted_proxies[forwarded_ip] then
  67                                 ip = forwarded_ip;
  68                         end
  69                 end
  70         end
  71         return ip;
  72 end
  73
  74 local t_insert, t_remove, t_concat = table.insert, table.remove, table.concat;
  75 local os_time = os.time;
  76
  77 local sessions = {};
  78 local inactive_sessions = {}; -- Sessions which have no open requests
  79
  80 -- Used to respond to idle sessions (those with waiting requests)
  81 local waiting_requests = {};
  82 function on_destroy_request(request)
  83         waiting_requests[request] = nil;
  84         local session = sessions[request.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_request(method, body, request)
 104         if (not body) or request.method ~= "POST" then
 105                 if request.method == "OPTIONS" then
 106                         local headers = {};
 107                         for k,v in pairs(default_headers) do headers[k] = v; end
 108                         headers["Content-Type"] = nil;
 109                         return { headers = headers, body = "" };
 110                 else
 111                         return "<html><body>You really don't look like a BOSH client to me... what do you want?</body></html>";
 112                 end
 113         end
 114         if not method then
 115                 log("debug", "Request %s suffered error %s", tostring(request.id), body);
 116                 return;
 117         end
 118         --log("debug", "Handling new request %s: %s\n----------", request.id, tostring(body));
 119         request.notopen = true;
 120         request.log = log;
 121         request.on_destroy = on_destroy_request;
 122
 123         local stream = new_xmpp_stream(request, stream_callbacks);
 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         stream:feed(body);
 131
 132         -- Stanzas (if any) in the request have now been processed, and
 133         -- we take care of the high-level BOSH logic here, including
 134         -- giving a response or putting the request "on hold".
 135         local session = sessions[request.sid];
 136         if session then
 137                 -- Session was marked as inactive, since we have
 138                 -- a request open now, unmark it
 139                 if inactive_sessions[session] and #session.requests > 0 then
 140                         inactive_sessions[session] = nil;
 141                 end
 142
 143                 local r = session.requests;
 144                 log("debug", "Session %s has %d out of %d requests open", request.sid, #r, session.bosh_hold);
 145                 log("debug", "and there are %d things in the send_buffer", #session.send_buffer);
 146                 if #r > session.bosh_hold then
 147                         -- We are holding too many requests, send what's in the buffer,
 148                         log("debug", "We are holding too many requests, so...");
 149                         if #session.send_buffer > 0 then
 150                                 log("debug", "...sending what is in the buffer")
 151                                 session.send(t_concat(session.send_buffer));
 152                                 session.send_buffer = {};
 153                         else
 154                                 -- or an empty response
 155                                 log("debug", "...sending an empty response");
 156                                 session.send("");
 157                         end
 158                 elseif #session.send_buffer > 0 then
 159                         log("debug", "Session has data in the send buffer, will send now..");
 160                         local resp = t_concat(session.send_buffer);
 161                         session.send_buffer = {};
 162                         session.send(resp);
 163                 end
 164
 165                 if not request.destroyed then
 166                         -- We're keeping this request open, to respond later
 167                         log("debug", "Have nothing to say, so leaving request unanswered for now");
 168                         if session.bosh_wait then
 169                                 request.reply_before = os_time() + session.bosh_wait;
 170                                 waiting_requests[request] = true;
 171                         end
 172                 end
 173
 174                 if session.bosh_terminate then
 175                         session.log("debug", "Closing session with %d requests open", #session.requests);
 176                         session:close();
 177                         return nil;
 178                 else
 179                         return true; -- Inform httpserver we shall reply later
 180                 end
 181         end
 182 end
 183
 184
 185 local function bosh_reset_stream(session) session.notopen = true; end
 186
 187 local stream_xmlns_attr = { xmlns = "urn:ietf:params:xml:ns:xmpp-streams" };
 188
 189 local function bosh_close_stream(session, reason)
 190         (session.log or log)("info", "BOSH client disconnected");
 191
 192         local close_reply = st.stanza("body", { xmlns = xmlns_bosh, type = "terminate",
 193                 ["xmlns:stream"] = xmlns_streams });
 194
 195
 196         if reason then
 197                 close_reply.attr.condition = "remote-stream-error";
 198                 if type(reason) == "string" then -- assume stream error
 199                         close_reply:tag("stream:error")
 200                                 :tag(reason, {xmlns = xmlns_xmpp_streams});
 201                 elseif type(reason) == "table" then
 202                         if reason.condition then
 203                                 close_reply:tag("stream:error")
 204                                         :tag(reason.condition, stream_xmlns_attr):up();
 205                                 if reason.text then
 206                                         close_reply:tag("text", stream_xmlns_attr):text(reason.text):up();
 207                                 end
 208                                 if reason.extra then
 209                                         close_reply:add_child(reason.extra);
 210                                 end
 211                         elseif reason.name then -- a stanza
 212                                 close_reply = reason;
 213                         end
 214                 end
 215                 log("info", "Disconnecting client, <stream:error> is: %s", tostring(close_reply));
 216         end
 217
 218         local session_close_response = { headers = default_headers, body = tostring(close_reply) };
 219
 220         for _, held_request in ipairs(session.requests) do
 221                 held_request:send(session_close_response);
 222                 held_request:destroy();
 223         end
 224         sessions[session.sid]  = nil;
 225         inactive_sessions[session] = nil;
 226         sm_destroy_session(session);
 227 end
 228
 229 -- Handle the <body> tag in the request payload.
 230 function stream_callbacks.streamopened(request, attr)
 231         local sid = attr.sid;
 232         log("debug", "BOSH body open (sid: %s)", sid or "<none>");
 233         if not sid then
 234                 -- New session request
 235                 request.notopen = nil; -- Signals that we accept this opening tag
 236
 237                 -- TODO: Sanity checks here (rid, to, known host, etc.)
 238                 if not hosts[attr.to] then
 239                         -- Unknown host
 240                         log("debug", "BOSH client tried to connect to unknown host: %s", tostring(attr.to));
 241                         local close_reply = st.stanza("body", { xmlns = xmlns_bosh, type = "terminate",
 242                                 ["xmlns:stream"] = xmlns_streams, condition = "host-unknown" });
 243                         request:send(tostring(close_reply));
 244                         return;
 245                 end
 246
 247                 -- New session
 248                 sid = new_uuid();
 249                 local session = {
 250                         type = "c2s_unauthed", conn = {}, sid = sid, rid = tonumber(attr.rid), host = attr.to,
 251                         bosh_version = attr.ver, bosh_wait = attr.wait, streamid = sid,
 252                         bosh_hold = BOSH_DEFAULT_HOLD, bosh_max_inactive = BOSH_DEFAULT_INACTIVITY,
 253                         requests = { }, send_buffer = {}, reset_stream = bosh_reset_stream,
 254                         close = bosh_close_stream, dispatch_stanza = core_process_stanza,
 255                         log = logger.init("bosh"..sid), secure = consider_bosh_secure or request.secure,
 256                         ip = get_ip_from_request(request);
 257                 };
 258                 sessions[sid] = 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                 local r, send_buffer = session.requests, session.send_buffer;
 263                 local response = { headers = default_headers }
 264                 function session.send(s)
 265                         -- We need to ensure that outgoing stanzas have the jabber:client xmlns
 266                         if s.attr and not s.attr.xmlns then
 267                                 s = st.clone(s);
 268                                 s.attr.xmlns = "jabber:client";
 269                         end
 270                         --log("debug", "Sending BOSH data: %s", tostring(s));
 271                         local oldest_request = r[1];
 272                         if oldest_request and (not(auto_cork) or waiting_requests[oldest_request]) then
 273                                 log("debug", "We have an open request, so sending on that");
 274                                 response.body = t_concat({
 275                                         "<body xmlns='http://jabber.org/protocol/httpbind' ",
 276                                         session.bosh_terminate and "type='terminate' " or "",
 277                                         "sid='", sid, "' xmlns:stream = 'http://etherx.jabber.org/streams'>",
 278                                         tostring(s),
 279                                         "</body>"
 280                                 });
 281                                 oldest_request:send(response);
 282                                 --log("debug", "Sent");
 283                                 if oldest_request.stayopen then
 284                                         if #r>1 then
 285                                                 -- Move front request to back
 286                                                 t_insert(r, oldest_request);
 287                                                 t_remove(r, 1);
 288                                         end
 289                                 else
 290                                         log("debug", "Destroying the request now...");
 291                                         oldest_request:destroy();
 292                                 end
 293                         elseif s ~= "" then
 294                                 log("debug", "Saved to send buffer because there are %d open requests", #r);
 295                                 -- Hmm, no requests are open :(
 296                                 t_insert(session.send_buffer, tostring(s));
 297                                 log("debug", "There are now %d things in the send_buffer", #session.send_buffer);
 298                         end
 299                         return true;
 300                 end
 301
 302                 -- Send creation response
 303
 304                 local features = st.stanza("stream:features");
 305                 hosts[session.host].events.fire_event("stream-features", { origin = session, features = features });
 306                 fire_event("stream-features", session, features);
 307                 --xmpp:version='1.0' xmlns:xmpp='urn:xmpp:xbosh'
 308                 local response = st.stanza("body", { xmlns = xmlns_bosh,
 309                         wait = attr.wait,
 310                         inactivity = tostring(BOSH_DEFAULT_INACTIVITY),
 311                         polling = tostring(BOSH_DEFAULT_POLLING),
 312                         requests = tostring(BOSH_DEFAULT_REQUESTS),
 313                         hold = tostring(session.bosh_hold),
 314                         sid = sid, authid = sid,
 315                         ver  = '1.6', from = session.host,
 316                         secure = 'true', ["xmpp:version"] = "1.0",
 317                         ["xmlns:xmpp"] = "urn:xmpp:xbosh",
 318                         ["xmlns:stream"] = "http://etherx.jabber.org/streams"
 319                 }):add_child(features);
 320                 request:send{ headers = default_headers, body = tostring(response) };
 321
 322                 request.sid = sid;
 323                 return;
 324         end
 325
 326         local session = sessions[sid];
 327         if not session then
 328                 -- Unknown sid
 329                 log("info", "Client tried to use sid '%s' which we don't know about", sid);
 330                 request:send{ headers = default_headers, body = tostring(st.stanza("body", { xmlns = xmlns_bosh, type = "terminate", condition = "item-not-found" })) };
 331                 request.notopen = nil;
 332                 return;
 333         end
 334
 335         if session.rid then
 336                 local rid = tonumber(attr.rid);
 337                 local diff = rid - session.rid;
 338                 if diff > 1 then
 339                         session.log("warn", "rid too large (means a request was lost). Last rid: %d New rid: %s", session.rid, attr.rid);
 340                 elseif diff <= 0 then
 341                         -- Repeated, ignore
 342                         session.log("debug", "rid repeated (on request %s), ignoring: %s (diff %d)", request.id, session.rid, diff);
 343                         request.notopen = nil;
 344                         request.ignore = true;
 345                         request.sid = sid;
 346                         t_insert(session.requests, request);
 347                         return;
 348                 end
 349                 session.rid = rid;
 350         end
 351
 352         if attr.type == "terminate" then
 353                 -- Client wants to end this session, which we'll do
 354                 -- after processing any stanzas in this request
 355                 session.bosh_terminate = true;
 356         end
 357
 358         request.notopen = nil; -- Signals that we accept this opening tag
 359         t_insert(session.requests, request);
 360         request.sid = sid;
 361
 362         if session.notopen then
 363                 local features = st.stanza("stream:features");
 364                 hosts[session.host].events.fire_event("stream-features", { origin = session, features = features });
 365                 fire_event("stream-features", session, features);
 366                 session.send(features);
 367                 session.notopen = nil;
 368         end
 369 end
 370
 371 function stream_callbacks.handlestanza(request, stanza)
 372         if request.ignore then return; end
 373         log("debug", "BOSH stanza received: %s\n", stanza:top_tag());
 374         local session = sessions[request.sid];
 375         if session then
 376                 if stanza.attr.xmlns == xmlns_bosh then
 377                         stanza.attr.xmlns = nil;
 378                 end
 379                 core_process_stanza(session, stanza);
 380         end
 381 end
 382
 383 function stream_callbacks.error(request, error)
 384         log("debug", "Error parsing BOSH request payload; %s", error);
 385         if not request.sid then
 386                 request:send({ headers = default_headers, status = "400 Bad Request" });
 387                 return;
 388         end
 389
 390         local session = sessions[request.sid];
 391         if error == "stream-error" then -- Remote stream error, we close normally
 392                 session:close();
 393         else
 394                 session:close({ condition = "bad-format", text = "Error processing stream" });
 395         end
 396 end
 397
 398 local dead_sessions = {};
 399 function on_timer()
 400         -- log("debug", "Checking for requests soon to timeout...");
 401         -- Identify requests timing out within the next few seconds
 402         local now = os_time() + 3;
 403         for request in pairs(waiting_requests) do
 404                 if request.reply_before <= now then
 405                         log("debug", "%s was soon to timeout, sending empty response", request.id);
 406                         -- Send empty response to let the
 407                         -- client know we're still here
 408                         if request.conn then
 409                                 sessions[request.sid].send("");
 410                         end
 411                 end
 412         end
 413
 414         now = now - 3;
 415         local n_dead_sessions = 0;
 416         for session, close_after in pairs(inactive_sessions) do
 417                 if close_after < now then
 418                         (session.log or log)("debug", "BOSH client inactive too long, destroying session at %d", now);
 419                         sessions[session.sid]  = nil;
 420                         inactive_sessions[session] = nil;
 421                         n_dead_sessions = n_dead_sessions + 1;
 422                         dead_sessions[n_dead_sessions] = session;
 423                 end
 424         end
 425
 426         for i=1,n_dead_sessions do
 427                 local session = dead_sessions[i];
 428                 dead_sessions[i] = nil;
 429                 sm_destroy_session(session, "BOSH client silent for over "..session.bosh_max_inactive.." seconds");
 430         end
 431         return 1;
 432 end
 433
 434
 435 local function setup()
 436         local ports = module:get_option_array("bosh_ports") or { 5280 };
 437         httpserver.new_from_config(ports, handle_request, { base = "http-bind" });
 438         timer.add_task(1, on_timer);
 439 end
 440 if prosody.start_time then -- already started
 441         setup();
 442 else
 443         prosody.events.add_handler("server-started", setup);
 444 end