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