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 init_xmlhandlers = require "core.xmlhandlers"
  14 local server = require "net.server";
  15 local httpserver = require "net.httpserver";
  16 local sm = require "core.sessionmanager";
  17 local sm_destroy_session = sm.destroy_session;
  18 local new_uuid = require "util.uuid".generate;
  19 local fire_event = prosody.events.fire_event;
  20 local core_process_stanza = core_process_stanza;
  21 local st = require "util.stanza";
  22 local logger = require "util.logger";
  23 local log = logger.init("mod_bosh");
  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 local stream_callbacks = { stream_ns = "http://jabber.org/protocol/httpbind", stream_tag = "body", default_ns = "jabber:client" };
  29
  30 local BOSH_DEFAULT_HOLD = tonumber(module:get_option("bosh_default_hold")) or 1;
  31 local BOSH_DEFAULT_INACTIVITY = tonumber(module:get_option("bosh_max_inactivity")) or 60;
  32 local BOSH_DEFAULT_POLLING = tonumber(module:get_option("bosh_max_polling")) or 5;
  33 local BOSH_DEFAULT_REQUESTS = tonumber(module:get_option("bosh_max_requests")) or 2;
  34 local BOSH_DEFAULT_MAXPAUSE = tonumber(module:get_option("bosh_max_pause")) or 300;
  35
  36 local consider_bosh_secure = module:get_option_boolean("consider_bosh_secure");
  37
  38 local default_headers = { ["Content-Type"] = "text/xml; charset=utf-8" };
  39
  40 local cross_domain = module:get_option("cross_domain_bosh");
  41 if cross_domain then
  42         default_headers["Access-Control-Allow-Methods"] = "GET, POST, OPTIONS";
  43         default_headers["Access-Control-Allow-Headers"] = "Content-Type";
  44         default_headers["Access-Control-Max-Age"] = "7200";
  45
  46         if cross_domain == true then
  47                 default_headers["Access-Control-Allow-Origin"] = "*";
  48         elseif type(cross_domain) == "table" then
  49                 cross_domain = table.concat(cross_domain, ", ");
  50         end
  51         if type(cross_domain) == "string" then
  52                 default_headers["Access-Control-Allow-Origin"] = cross_domain;
  53         end
  54 end
  55
  56 local t_insert, t_remove, t_concat = table.insert, table.remove, table.concat;
  57 local os_time = os.time;
  58
  59 local sessions = {};
  60 local inactive_sessions = {}; -- Sessions which have no open requests
  61
  62 -- Used to respond to idle sessions (those with waiting requests)
  63 local waiting_requests = {};
  64 function on_destroy_request(request)
  65         waiting_requests[request] = nil;
  66         local session = sessions[request.sid];
  67         if session then
  68                 local requests = session.requests;
  69                 for i,r in ipairs(requests) do
  70                         if r == request then
  71                                 t_remove(requests, i);
  72                                 break;
  73                         end
  74                 end
  75
  76                 -- If this session now has no requests open, mark it as inactive
  77                 if #requests == 0 and session.bosh_max_inactive and not inactive_sessions[session] then
  78                         inactive_sessions[session] = os_time();
  79                         (session.log or log)("debug", "BOSH session marked as inactive at %d", inactive_sessions[session]);
  80                 end
  81         end
  82 end
  83
  84 function handle_request(method, body, request)
  85         if (not body) or request.method ~= "POST" then
  86                 if request.method == "OPTIONS" then
  87                         return { headers = default_headers, body = "" };
  88                 else
  89                         return "<html><body>You really don't look like a BOSH client to me... what do you want?</body></html>";
  90                 end
  91         end
  92         if not method then
  93                 log("debug", "Request %s suffered error %s", tostring(request.id), body);
  94                 return;
  95         end
  96         --log("debug", "Handling new request %s: %s\n----------", request.id, tostring(body));
  97         request.notopen = true;
  98         request.log = log;
  99         request.on_destroy = on_destroy_request;
 100
 101         local parser = lxp.new(init_xmlhandlers(request, stream_callbacks), "\1");
 102
 103         parser:parse(body);
 104
 105         local session = sessions[request.sid];
 106         if session then
 107                 local r = session.requests;
 108                 log("debug", "Session %s has %d out of %d requests open", request.sid, #r, session.bosh_hold);
 109                 log("debug", "and there are %d things in the send_buffer", #session.send_buffer);
 110                 if #r > session.bosh_hold then
 111                         -- We are holding too many requests, send what's in the buffer,
 112                         log("debug", "We are holding too many requests, so...");
 113                         if #session.send_buffer > 0 then
 114                                 log("debug", "...sending what is in the buffer")
 115                                 session.send(t_concat(session.send_buffer));
 116                                 session.send_buffer = {};
 117                         else
 118                                 -- or an empty response
 119                                 log("debug", "...sending an empty response");
 120                                 session.send("");
 121                         end
 122                 elseif #session.send_buffer > 0 then
 123                         log("debug", "Session has data in the send buffer, will send now..");
 124                         local resp = t_concat(session.send_buffer);
 125                         session.send_buffer = {};
 126                         session.send(resp);
 127                 end
 128
 129                 if not request.destroyed then
 130                         -- We're keeping this request open, to respond later
 131                         log("debug", "Have nothing to say, so leaving request unanswered for now");
 132                         if session.bosh_wait then
 133                                 request.reply_before = os_time() + session.bosh_wait;
 134                                 waiting_requests[request] = true;
 135                         end
 136                         if inactive_sessions[session] then
 137                                 -- Session was marked as inactive, since we have
 138                                 -- a request open now, unmark it
 139                                 inactive_sessions[session] = nil;
 140                         end
 141                 end
 142
 143                 return true; -- Inform httpserver we shall reply later
 144         end
 145 end
 146
 147
 148 local function bosh_reset_stream(session) session.notopen = true; end
 149
 150 local stream_xmlns_attr = { xmlns = "urn:ietf:params:xml:ns:xmpp-streams" };
 151
 152 local function bosh_close_stream(session, reason)
 153         (session.log or log)("info", "BOSH client disconnected");
 154
 155         local close_reply = st.stanza("body", { xmlns = xmlns_bosh, type = "terminate",
 156                 ["xmlns:streams"] = xmlns_streams });
 157
 158
 159         if reason then
 160                 close_reply.attr.condition = "remote-stream-error";
 161                 if type(reason) == "string" then -- assume stream error
 162                         close_reply:tag("stream:error")
 163                                 :tag(reason, {xmlns = xmlns_xmpp_streams});
 164                 elseif type(reason) == "table" then
 165                         if reason.condition then
 166                                 close_reply:tag("stream:error")
 167                                         :tag(reason.condition, stream_xmlns_attr):up();
 168                                 if reason.text then
 169                                         close_reply:tag("text", stream_xmlns_attr):text(reason.text):up();
 170                                 end
 171                                 if reason.extra then
 172                                         close_reply:add_child(reason.extra);
 173                                 end
 174                         elseif reason.name then -- a stanza
 175                                 close_reply = reason;
 176                         end
 177                 end
 178                 log("info", "Disconnecting client, <stream:error> is: %s", tostring(close_reply));
 179         end
 180
 181         local session_close_response = { headers = default_headers, body = tostring(close_reply) };
 182
 183         --FIXME: Quite sure we shouldn't reply to all requests with the error
 184         for _, held_request in ipairs(session.requests) do
 185                 held_request:send(session_close_response);
 186                 held_request:destroy();
 187         end
 188         sessions[session.sid]  = nil;
 189         sm_destroy_session(session);
 190 end
 191
 192 function stream_callbacks.streamopened(request, attr)
 193         log("debug", "BOSH body open (sid: %s)", attr.sid);
 194         local sid = attr.sid
 195         if not sid then
 196                 -- New session request
 197                 request.notopen = nil; -- Signals that we accept this opening tag
 198
 199                 -- TODO: Sanity checks here (rid, to, known host, etc.)
 200                 if not hosts[attr.to] then
 201                         -- Unknown host
 202                         log("debug", "BOSH client tried to connect to unknown host: %s", tostring(attr.to));
 203                         session_close_reply.body.attr.condition = "host-unknown";
 204                         request:send(session_close_reply);
 205                         request.notopen = nil
 206                         return;
 207                 end
 208
 209                 -- New session
 210                 sid = new_uuid();
 211                 local session = {
 212                         type = "c2s_unauthed", conn = {}, sid = sid, rid = tonumber(attr.rid)-1, host = attr.to,
 213                         bosh_version = attr.ver, bosh_wait = attr.wait, streamid = sid,
 214                         bosh_hold = BOSH_DEFAULT_HOLD, bosh_max_inactive = BOSH_DEFAULT_INACTIVITY,
 215                         requests = { }, send_buffer = {}, reset_stream = bosh_reset_stream,
 216                         close = bosh_close_stream, dispatch_stanza = core_process_stanza,
 217                         log = logger.init("bosh"..sid), secure = consider_bosh_secure or request.secure
 218                 };
 219                 sessions[sid] = session;
 220
 221                 log("info", "New BOSH session, assigned it sid '%s'", sid);
 222                 local r, send_buffer = session.requests, session.send_buffer;
 223                 local response = { headers = default_headers }
 224                 function session.send(s)
 225                         -- We need to ensure that outgoing stanzas have the jabber:client xmlns
 226                         if s.attr and not s.attr.xmlns then
 227                                 s = st.clone(s);
 228                                 s.attr.xmlns = "jabber:client";
 229                         end
 230                         --log("debug", "Sending BOSH data: %s", tostring(s));
 231                         local oldest_request = r[1];
 232                         if oldest_request then
 233                                 log("debug", "We have an open request, so sending on that");
 234                                 response.body = t_concat{"<body xmlns='http://jabber.org/protocol/httpbind' sid='", sid, "' xmlns:stream = 'http://etherx.jabber.org/streams'>", tostring(s), "</body>" };
 235                                 oldest_request:send(response);
 236                                 --log("debug", "Sent");
 237                                 if oldest_request.stayopen then
 238                                         if #r>1 then
 239                                                 -- Move front request to back
 240                                                 t_insert(r, oldest_request);
 241                                                 t_remove(r, 1);
 242                                         end
 243                                 else
 244                                         log("debug", "Destroying the request now...");
 245                                         oldest_request:destroy();
 246                                 end
 247                         elseif s ~= "" then
 248                                 log("debug", "Saved to send buffer because there are %d open requests", #r);
 249                                 -- Hmm, no requests are open :(
 250                                 t_insert(session.send_buffer, tostring(s));
 251                                 log("debug", "There are now %d things in the send_buffer", #session.send_buffer);
 252                         end
 253                 end
 254
 255                 -- Send creation response
 256
 257                 local features = st.stanza("stream:features");
 258                 hosts[session.host].events.fire_event("stream-features", { origin = session, features = features });
 259                 fire_event("stream-features", session, features);
 260                 --xmpp:version='1.0' xmlns:xmpp='urn:xmpp:xbosh'
 261                 local response = st.stanza("body", { xmlns = xmlns_bosh,
 262                                                                         inactivity = tostring(BOSH_DEFAULT_INACTIVITY), polling = tostring(BOSH_DEFAULT_POLLING), requests = tostring(BOSH_DEFAULT_REQUESTS), hold = tostring(session.bosh_hold), maxpause = "120",
 263                                                                         sid = sid, authid = sid, ver  = '1.6', from = session.host, secure = 'true', ["xmpp:version"] = "1.0",
 264                                                                         ["xmlns:xmpp"] = "urn:xmpp:xbosh", ["xmlns:stream"] = "http://etherx.jabber.org/streams" }):add_child(features);
 265                 request:send{ headers = default_headers, body = tostring(response) };
 266
 267                 request.sid = sid;
 268                 return;
 269         end
 270
 271         local session = sessions[sid];
 272         if not session then
 273                 -- Unknown sid
 274                 log("info", "Client tried to use sid '%s' which we don't know about", sid);
 275                 request:send{ headers = default_headers, body = tostring(st.stanza("body", { xmlns = xmlns_bosh, type = "terminate", condition = "item-not-found" })) };
 276                 request.notopen = nil;
 277                 return;
 278         end
 279
 280         if session.rid then
 281                 local rid = tonumber(attr.rid);
 282                 local diff = rid - session.rid;
 283                 if diff > 1 then
 284                         session.log("warn", "rid too large (means a request was lost). Last rid: %d New rid: %s", session.rid, attr.rid);
 285                 elseif diff <= 0 then
 286                         -- Repeated, ignore
 287                         session.log("debug", "rid repeated (on request %s), ignoring: %s (diff %d)", request.id, session.rid, diff);
 288                         request.notopen = nil;
 289                         request.sid = sid;
 290                         t_insert(session.requests, request);
 291                         return;
 292                 end
 293                 session.rid = rid;
 294         end
 295
 296         if attr.type == "terminate" then
 297                 -- Client wants to end this session
 298                 session:close();
 299                 request.notopen = nil;
 300                 return;
 301         end
 302
 303         if session.notopen then
 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                 session.send(features);
 308                 session.notopen = nil;
 309         end
 310
 311         request.notopen = nil; -- Signals that we accept this opening tag
 312         t_insert(session.requests, request);
 313         request.sid = sid;
 314 end
 315
 316 function stream_callbacks.handlestanza(request, stanza)
 317         log("debug", "BOSH stanza received: %s\n", stanza:top_tag());
 318         local session = sessions[request.sid];
 319         if session then
 320                 if stanza.attr.xmlns == xmlns_bosh then
 321                         stanza.attr.xmlns = nil;
 322                 end
 323                 session.ip = request.handler:ip();
 324                 core_process_stanza(session, stanza);
 325         end
 326 end
 327
 328 function stream_callbacks.error(request, error)
 329         log("debug", "Error parsing BOSH request payload; %s", error);
 330         if not request.sid then
 331                 request:send({ headers = default_headers, status = "400 Bad Request" });
 332                 return;
 333         end
 334
 335         local session = sessions[request.sid];
 336         if error == "stream-error" then -- Remote stream error, we close normally
 337                 session:close();
 338         else
 339                 session:close({ condition = "bad-format", text = "Error processing stream" });
 340         end
 341 end
 342
 343 local dead_sessions = {};
 344 function on_timer()
 345         -- log("debug", "Checking for requests soon to timeout...");
 346         -- Identify requests timing out within the next few seconds
 347         local now = os_time() + 3;
 348         for request in pairs(waiting_requests) do
 349                 if request.reply_before <= now then
 350                         log("debug", "%s was soon to timeout, sending empty response", request.id);
 351                         -- Send empty response to let the
 352                         -- client know we're still here
 353                         if request.conn then
 354                                 sessions[request.sid].send("");
 355                         end
 356                 end
 357         end
 358
 359         now = now - 3;
 360         local n_dead_sessions = 0;
 361         for session, inactive_since in pairs(inactive_sessions) do
 362                 if session.bosh_max_inactive then
 363                         if now - inactive_since > session.bosh_max_inactive then
 364                                 (session.log or log)("debug", "BOSH client inactive too long, destroying session at %d", now);
 365                                 sessions[session.sid]  = nil;
 366                                 inactive_sessions[session] = nil;
 367                                 n_dead_sessions = n_dead_sessions + 1;
 368                                 dead_sessions[n_dead_sessions] = session;
 369                         end
 370                 else
 371                         inactive_sessions[session] = nil;
 372                 end
 373         end
 374
 375         for i=1,n_dead_sessions do
 376                 local session = dead_sessions[i];
 377                 dead_sessions[i] = nil;
 378                 sm_destroy_session(session, "BOSH client silent for over "..session.bosh_max_inactive.." seconds");
 379         end
 380 end
 381
 382
 383 local function setup()
 384         local ports = module:get_option("bosh_ports") or { 5280 };
 385         httpserver.new_from_config(ports, handle_request, { base = "http-bind" });
 386         server.addtimer(on_timer);
 387 end
 388 if prosody.start_time then -- already started
 389         setup();
 390 else
 391         prosody.events.add_handler("server-started", setup);
 392 end