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
  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 local BOSH_DEFAULT_MAXPAUSE = tonumber(module:get_option("bosh_max_pause")) or 300;
  37
  38 local consider_bosh_secure = module:get_option_boolean("consider_bosh_secure");
  39
  40 local default_headers = { ["Content-Type"] = "text/xml; charset=utf-8" };
  41
  42 local cross_domain = module:get_option("cross_domain_bosh");
  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 t_insert, t_remove, t_concat = table.insert, table.remove, table.concat;
  59 local os_time = os.time;
  60
  61 local sessions = {};
  62 local inactive_sessions = {}; -- Sessions which have no open requests
  63
  64 -- Used to respond to idle sessions (those with waiting requests)
  65 local waiting_requests = {};
  66 function on_destroy_request(request)
  67         waiting_requests[request] = nil;
  68         local session = sessions[request.sid];
  69         if session then
  70                 local requests = session.requests;
  71                 for i,r in ipairs(requests) do
  72                         if r == request then
  73                                 t_remove(requests, i);
  74                                 break;
  75                         end
  76                 end
  77
  78                 -- If this session now has no requests open, mark it as inactive
  79                 if #requests == 0 and session.bosh_max_inactive and not inactive_sessions[session] then
  80                         inactive_sessions[session] = os_time();
  81                         (session.log or log)("debug", "BOSH session marked as inactive at %d", inactive_sessions[session]);
  82                 end
  83         end
  84 end
  85
  86 function handle_request(method, body, request)
  87         if (not body) or request.method ~= "POST" then
  88                 if request.method == "OPTIONS" then
  89                         return { headers = default_headers, body = "" };
  90                 else
  91                         return "<html><body>You really don't look like a BOSH client to me... what do you want?</body></html>";
  92                 end
  93         end
  94         if not method then
  95                 log("debug", "Request %s suffered error %s", tostring(request.id), body);
  96                 return;
  97         end
  98         --log("debug", "Handling new request %s: %s\n----------", request.id, tostring(body));
  99         request.notopen = true;
 100         request.log = log;
 101         request.on_destroy = on_destroy_request;
 102
 103         local parser = lxp.new(init_xmlhandlers(request, stream_callbacks), "\1");
 104
 105         parser:parse(body);
 106
 107         local session = sessions[request.sid];
 108         if session then
 109                 local r = session.requests;
 110                 log("debug", "Session %s has %d out of %d requests open", request.sid, #r, session.bosh_hold);
 111                 log("debug", "and there are %d things in the send_buffer", #session.send_buffer);
 112                 if #r > session.bosh_hold then
 113                         -- We are holding too many requests, send what's in the buffer,
 114                         log("debug", "We are holding too many requests, so...");
 115                         if #session.send_buffer > 0 then
 116                                 log("debug", "...sending what is in the buffer")
 117                                 session.send(t_concat(session.send_buffer));
 118                                 session.send_buffer = {};
 119                         else
 120                                 -- or an empty response
 121                                 log("debug", "...sending an empty response");
 122                                 session.send("");
 123                         end
 124                 elseif #session.send_buffer > 0 then
 125                         log("debug", "Session has data in the send buffer, will send now..");
 126                         local resp = t_concat(session.send_buffer);
 127                         session.send_buffer = {};
 128                         session.send(resp);
 129                 end
 130
 131                 if not request.destroyed then
 132                         -- We're keeping this request open, to respond later
 133                         log("debug", "Have nothing to say, so leaving request unanswered for now");
 134                         if session.bosh_wait then
 135                                 request.reply_before = os_time() + session.bosh_wait;
 136                                 waiting_requests[request] = true;
 137                         end
 138                         if inactive_sessions[session] then
 139                                 -- Session was marked as inactive, since we have
 140                                 -- a request open now, unmark it
 141                                 inactive_sessions[session] = nil;
 142                         end
 143                 end
 144
 145                 return true; -- Inform httpserver we shall reply later
 146         end
 147 end
 148
 149
 150 local function bosh_reset_stream(session) session.notopen = true; end
 151
 152 local stream_xmlns_attr = { xmlns = "urn:ietf:params:xml:ns:xmpp-streams" };
 153
 154 local function bosh_close_stream(session, reason)
 155         (session.log or log)("info", "BOSH client disconnected");
 156
 157         local close_reply = st.stanza("body", { xmlns = xmlns_bosh, type = "terminate",
 158                 ["xmlns:streams"] = xmlns_streams });
 159
 160
 161         if reason then
 162                 close_reply.attr.condition = "remote-stream-error";
 163                 if type(reason) == "string" then -- assume stream error
 164                         close_reply:tag("stream:error")
 165                                 :tag(reason, {xmlns = xmlns_xmpp_streams});
 166                 elseif type(reason) == "table" then
 167                         if reason.condition then
 168                                 close_reply:tag("stream:error")
 169                                         :tag(reason.condition, stream_xmlns_attr):up();
 170                                 if reason.text then
 171                                         close_reply:tag("text", stream_xmlns_attr):text(reason.text):up();
 172                                 end
 173                                 if reason.extra then
 174                                         close_reply:add_child(reason.extra);
 175                                 end
 176                         elseif reason.name then -- a stanza
 177                                 close_reply = reason;
 178                         end
 179                 end
 180                 log("info", "Disconnecting client, <stream:error> is: %s", tostring(close_reply));
 181         end
 182
 183         local session_close_response = { headers = default_headers, body = tostring(close_reply) };
 184
 185         --FIXME: Quite sure we shouldn't reply to all requests with the error
 186         for _, held_request in ipairs(session.requests) do
 187                 held_request:send(session_close_response);
 188                 held_request:destroy();
 189         end
 190         sessions[session.sid]  = nil;
 191         sm_destroy_session(session);
 192 end
 193
 194 function stream_callbacks.streamopened(request, attr)
 195         log("debug", "BOSH body open (sid: %s)", attr.sid);
 196         local sid = attr.sid
 197         if not sid then
 198                 -- New session request
 199                 request.notopen = nil; -- Signals that we accept this opening tag
 200
 201                 -- TODO: Sanity checks here (rid, to, known host, etc.)
 202                 if not hosts[attr.to] then
 203                         -- Unknown host
 204                         log("debug", "BOSH client tried to connect to unknown host: %s", tostring(attr.to));
 205                         session_close_reply.body.attr.condition = "host-unknown";
 206                         request:send(session_close_reply);
 207                         request.notopen = nil
 208                         return;
 209                 end
 210
 211                 -- New session
 212                 sid = new_uuid();
 213                 local session = {
 214                         type = "c2s_unauthed", conn = {}, sid = sid, rid = tonumber(attr.rid)-1, host = attr.to,
 215                         bosh_version = attr.ver, bosh_wait = attr.wait, streamid = sid,
 216                         bosh_hold = BOSH_DEFAULT_HOLD, bosh_max_inactive = BOSH_DEFAULT_INACTIVITY,
 217                         requests = { }, send_buffer = {}, reset_stream = bosh_reset_stream,
 218                         close = bosh_close_stream, dispatch_stanza = core_process_stanza,
 219                         log = logger.init("bosh"..sid), secure = consider_bosh_secure or request.secure
 220                 };
 221                 sessions[sid] = session;
 222
 223                 log("info", "New BOSH session, assigned it sid '%s'", sid);
 224                 local r, send_buffer = session.requests, session.send_buffer;
 225                 local response = { headers = default_headers }
 226                 function session.send(s)
 227                         -- We need to ensure that outgoing stanzas have the jabber:client xmlns
 228                         if s.attr and not s.attr.xmlns then
 229                                 s = st.clone(s);
 230                                 s.attr.xmlns = "jabber:client";
 231                         end
 232                         --log("debug", "Sending BOSH data: %s", tostring(s));
 233                         local oldest_request = r[1];
 234                         if oldest_request then
 235                                 log("debug", "We have an open request, so sending on that");
 236                                 response.body = t_concat{"<body xmlns='http://jabber.org/protocol/httpbind' sid='", sid, "' xmlns:stream = 'http://etherx.jabber.org/streams'>", tostring(s), "</body>" };
 237                                 oldest_request:send(response);
 238                                 --log("debug", "Sent");
 239                                 if oldest_request.stayopen then
 240                                         if #r>1 then
 241                                                 -- Move front request to back
 242                                                 t_insert(r, oldest_request);
 243                                                 t_remove(r, 1);
 244                                         end
 245                                 else
 246                                         log("debug", "Destroying the request now...");
 247                                         oldest_request:destroy();
 248                                 end
 249                         elseif s ~= "" then
 250                                 log("debug", "Saved to send buffer because there are %d open requests", #r);
 251                                 -- Hmm, no requests are open :(
 252                                 t_insert(session.send_buffer, tostring(s));
 253                                 log("debug", "There are now %d things in the send_buffer", #session.send_buffer);
 254                         end
 255                 end
 256
 257                 -- Send creation response
 258
 259                 local features = st.stanza("stream:features");
 260                 hosts[session.host].events.fire_event("stream-features", { origin = session, features = features });
 261                 fire_event("stream-features", session, features);
 262                 --xmpp:version='1.0' xmlns:xmpp='urn:xmpp:xbosh'
 263                 local response = st.stanza("body", { xmlns = xmlns_bosh,
 264                                                                         inactivity = tostring(BOSH_DEFAULT_INACTIVITY), polling = tostring(BOSH_DEFAULT_POLLING), requests = tostring(BOSH_DEFAULT_REQUESTS), hold = tostring(session.bosh_hold), maxpause = "120",
 265                                                                         sid = sid, authid = sid, ver  = '1.6', from = session.host, secure = 'true', ["xmpp:version"] = "1.0",
 266                                                                         ["xmlns:xmpp"] = "urn:xmpp:xbosh", ["xmlns:stream"] = "http://etherx.jabber.org/streams" }):add_child(features);
 267                 request:send{ headers = default_headers, body = tostring(response) };
 268
 269                 request.sid = sid;
 270                 return;
 271         end
 272
 273         local session = sessions[sid];
 274         if not session then
 275                 -- Unknown sid
 276                 log("info", "Client tried to use sid '%s' which we don't know about", sid);
 277                 request:send{ headers = default_headers, body = tostring(st.stanza("body", { xmlns = xmlns_bosh, type = "terminate", condition = "item-not-found" })) };
 278                 request.notopen = nil;
 279                 return;
 280         end
 281
 282         if session.rid then
 283                 local rid = tonumber(attr.rid);
 284                 local diff = rid - session.rid;
 285                 if diff > 1 then
 286                         session.log("warn", "rid too large (means a request was lost). Last rid: %d New rid: %s", session.rid, attr.rid);
 287                 elseif diff <= 0 then
 288                         -- Repeated, ignore
 289                         session.log("debug", "rid repeated (on request %s), ignoring: %s (diff %d)", request.id, session.rid, diff);
 290                         request.notopen = nil;
 291                         request.ignore = true;
 292                         request.sid = sid;
 293                         t_insert(session.requests, request);
 294                         return;
 295                 end
 296                 session.rid = rid;
 297         end
 298
 299         if attr.type == "terminate" then
 300                 -- Client wants to end this session
 301                 session:close();
 302                 request.notopen = nil;
 303                 return;
 304         end
 305
 306         if session.notopen then
 307                 local features = st.stanza("stream:features");
 308                 hosts[session.host].events.fire_event("stream-features", { origin = session, features = features });
 309                 fire_event("stream-features", session, features);
 310                 session.send(features);
 311                 session.notopen = nil;
 312         end
 313
 314         request.notopen = nil; -- Signals that we accept this opening tag
 315         t_insert(session.requests, request);
 316         request.sid = sid;
 317 end
 318
 319 function stream_callbacks.handlestanza(request, stanza)
 320         if request.ignore then return; end
 321         log("debug", "BOSH stanza received: %s\n", stanza:top_tag());
 322         local session = sessions[request.sid];
 323         if session then
 324                 if stanza.attr.xmlns == xmlns_bosh then
 325                         stanza.attr.xmlns = nil;
 326                 end
 327                 session.ip = request.handler:ip();
 328                 core_process_stanza(session, stanza);
 329         end
 330 end
 331
 332 function stream_callbacks.error(request, error)
 333         log("debug", "Error parsing BOSH request payload; %s", error);
 334         if not request.sid then
 335                 request:send({ headers = default_headers, status = "400 Bad Request" });
 336                 return;
 337         end
 338
 339         local session = sessions[request.sid];
 340         if error == "stream-error" then -- Remote stream error, we close normally
 341                 session:close();
 342         else
 343                 session:close({ condition = "bad-format", text = "Error processing stream" });
 344         end
 345 end
 346
 347 local dead_sessions = {};
 348 function on_timer()
 349         -- log("debug", "Checking for requests soon to timeout...");
 350         -- Identify requests timing out within the next few seconds
 351         local now = os_time() + 3;
 352         for request in pairs(waiting_requests) do
 353                 if request.reply_before <= now then
 354                         log("debug", "%s was soon to timeout, sending empty response", request.id);
 355                         -- Send empty response to let the
 356                         -- client know we're still here
 357                         if request.conn then
 358                                 sessions[request.sid].send("");
 359                         end
 360                 end
 361         end
 362
 363         now = now - 3;
 364         local n_dead_sessions = 0;
 365         for session, inactive_since in pairs(inactive_sessions) do
 366                 if session.bosh_max_inactive then
 367                         if now - inactive_since > session.bosh_max_inactive then
 368                                 (session.log or log)("debug", "BOSH client inactive too long, destroying session at %d", now);
 369                                 sessions[session.sid]  = nil;
 370                                 inactive_sessions[session] = nil;
 371                                 n_dead_sessions = n_dead_sessions + 1;
 372                                 dead_sessions[n_dead_sessions] = session;
 373                         end
 374                 else
 375                         inactive_sessions[session] = nil;
 376                 end
 377         end
 378
 379         for i=1,n_dead_sessions do
 380                 local session = dead_sessions[i];
 381                 dead_sessions[i] = nil;
 382                 sm_destroy_session(session, "BOSH client silent for over "..session.bosh_max_inactive.." seconds");
 383         end
 384 end
 385
 386
 387 local function setup()
 388         local ports = module:get_option("bosh_ports") or { 5280 };
 389         httpserver.new_from_config(ports, handle_request, { base = "http-bind" });
 390         server.addtimer(on_timer);
 391 end
 392 if prosody.start_time then -- already started
 393         setup();
 394 else
 395         prosody.events.add_handler("server-started", setup);
 396 end