plugins/mod_bosh.lua

   1 -- Prosody IM
   2 -- Copyright (C) 2008-2009 Matthew Wild
   3 -- Copyright (C) 2008-2009 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 = require "core.eventmanager".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_bosh = "http://jabber.org/protocol/httpbind"; -- (hard-coded into a literal in session.send)
  26 local stream_callbacks = { stream_ns = "http://jabber.org/protocol/httpbind", stream_tag = "body", default_ns = xmlns_bosh };
  27
  28 local BOSH_DEFAULT_HOLD = tonumber(module:get_option("bosh_default_hold")) or 1;
  29 local BOSH_DEFAULT_INACTIVITY = tonumber(module:get_option("bosh_max_inactivity")) or 60;
  30 local BOSH_DEFAULT_POLLING = tonumber(module:get_option("bosh_max_polling")) or 5;
  31 local BOSH_DEFAULT_REQUESTS = tonumber(module:get_option("bosh_max_requests")) or 2;
  32 local BOSH_DEFAULT_MAXPAUSE = tonumber(module:get_option("bosh_max_pause")) or 300;
  33
  34 local default_headers = { ["Content-Type"] = "text/xml; charset=utf-8" };
  35 local session_close_reply = { headers = default_headers, body = st.stanza("body", { xmlns = xmlns_bosh, type = "terminate" }), attr = {} };
  36
  37 local http_options, http_denied_options = { headers = {} }, { headers = {} };
  38 local cross_domain = module:get_option("cross_domain_bosh");
  39 if cross_domain ~= false then
  40         http_options.headers["Access-Control-Allow-Methods"] = "GET, POST, OPTIONS";
  41         http_options.headers["Access-Control-Allow-Headers"] = "Content-Type";
  42         http_options.headers["Access-Control-Max-Age"] = "86400";
  43
  44         if cross_domain == true then
  45                 http_options.headers["Access-Control-Allow-Origin"] = "*";
  46         elseif type(cross_domain) == "table" then
  47                 cross_domain = table.concat(cross_domain, ", ");
  48         end
  49         if type(cross_domain) == "string" then
  50                 http_options.headers["Access-Control-Allow-Origin"] = cross_domain;
  51         end
  52 end
  53
  54 local t_insert, t_remove, t_concat = table.insert, table.remove, table.concat;
  55 local os_time = os.time;
  56
  57 local sessions = {};
  58 local inactive_sessions = {}; -- Sessions which have no open requests
  59
  60 -- Used to respond to idle sessions (those with waiting requests)
  61 local waiting_requests = {};
  62 function on_destroy_request(request)
  63         waiting_requests[request] = nil;
  64         local session = sessions[request.sid];
  65         if session then
  66                 local requests = session.requests;
  67                 for i,r in pairs(requests) do
  68                         if r == request then requests[i] = nil; break; end
  69                 end
  70
  71                 -- If this session now has no requests open, mark it as inactive
  72                 if #requests == 0 and session.bosh_max_inactive and not inactive_sessions[session] then
  73                         inactive_sessions[session] = os_time();
  74                         (session.log or log)("debug", "BOSH session marked as inactive at %d", inactive_sessions[session]);
  75                 end
  76         end
  77 end
  78
  79 local function send_options_headers(request)
  80         if cross_domain == nil then
  81                 local host = request.headers.host and request.headers.host:match("^[^:]+");
  82                 if hosts[host] then
  83                         http_options.headers["Access-Control-Allow-Origin"] = "http://"..host;
  84                 else
  85                         return http_denied_options; -- We don't want to reveal the hosts we serve
  86                 end
  87         end
  88         return http_options;
  89 end
  90
  91 function handle_request(method, body, request)
  92         if (not body) or request.method ~= "POST" then
  93                 if request.method == "OPTIONS" then
  94                         return send_options_headers(request);
  95                 else
  96                         return "<html><body>You really don't look like a BOSH client to me... what do you want?</body></html>";
  97                 end
  98         end
  99         if not method then
 100                 log("debug", "Request %s suffered error %s", tostring(request.id), body);
 101                 return;
 102         end
 103         --log("debug", "Handling new request %s: %s\n----------", request.id, tostring(body));
 104         request.notopen = true;
 105         request.log = log;
 106         local parser = lxp.new(init_xmlhandlers(request, stream_callbacks), "\1");
 107
 108         parser:parse(body);
 109
 110         local session = sessions[request.sid];
 111         if session then
 112                 local r = session.requests;
 113                 log("debug", "Session %s has %d out of %d requests open", request.sid, #r, session.bosh_hold);
 114                 log("debug", "and there are %d things in the send_buffer", #session.send_buffer);
 115                 if #r > session.bosh_hold then
 116                         -- We are holding too many requests, send what's in the buffer,
 117                         log("debug", "We are holding too many requests, so...");
 118                         if #session.send_buffer > 0 then
 119                                 log("debug", "...sending what is in the buffer")
 120                                 session.send(t_concat(session.send_buffer));
 121                                 session.send_buffer = {};
 122                         else
 123                                 -- or an empty response
 124                                 log("debug", "...sending an empty response");
 125                                 session.send("");
 126                         end
 127                 elseif #session.send_buffer > 0 then
 128                         log("debug", "Session has data in the send buffer, will send now..");
 129                         local resp = t_concat(session.send_buffer);
 130                         session.send_buffer = {};
 131                         session.send(resp);
 132                 end
 133
 134                 if not request.destroyed and session.bosh_wait then
 135                         request.reply_before = os_time() + session.bosh_wait;
 136                         request.on_destroy = on_destroy_request;
 137                         waiting_requests[request] = true;
 138                 end
 139
 140                 log("debug", "Have nothing to say, so leaving request unanswered for now");
 141                 return true;
 142         end
 143 end
 144
 145
 146 local function bosh_reset_stream(session) session.notopen = true; end
 147
 148 local function bosh_close_stream(session, reason)
 149         (session.log or log)("info", "BOSH client disconnected");
 150         session_close_reply.attr.condition = reason;
 151         for _, held_request in ipairs(session.requests) do
 152                 held_request:send(session_close_reply);
 153                 held_request:destroy();
 154         end
 155         sessions[session.sid]  = nil;
 156         sm_destroy_session(session);
 157 end
 158
 159 function stream_callbacks.streamopened(request, attr)
 160         log("debug", "BOSH body open (sid: %s)", attr.sid);
 161         local sid = attr.sid
 162         if not sid then
 163                 -- New session request
 164                 request.notopen = nil; -- Signals that we accept this opening tag
 165
 166                 -- TODO: Sanity checks here (rid, to, known host, etc.)
 167                 if not hosts[attr.to] then
 168                         -- Unknown host
 169                         log("debug", "BOSH client tried to connect to unknown host: %s", tostring(attr.to));
 170                         session_close_reply.body.attr.condition = "host-unknown";
 171                         request:send(session_close_reply);
 172                         request.notopen = nil
 173                         return;
 174                 end
 175
 176                 -- New session
 177                 sid = new_uuid();
 178                 local session = { type = "c2s_unauthed", conn = {}, sid = sid, rid = tonumber(attr.rid), host = attr.to, bosh_version = attr.ver, bosh_wait = attr.wait, streamid = sid,
 179                                                 bosh_hold = BOSH_DEFAULT_HOLD, bosh_max_inactive = BOSH_DEFAULT_INACTIVITY,
 180                                                 requests = { }, send_buffer = {}, reset_stream = bosh_reset_stream, close = bosh_close_stream,
 181                                                 dispatch_stanza = core_process_stanza, log = logger.init("bosh"..sid), secure = request.secure };
 182                 sessions[sid] = session;
 183
 184                 log("info", "New BOSH session, assigned it sid '%s'", sid);
 185                 local r, send_buffer = session.requests, session.send_buffer;
 186                 local response = { headers = default_headers }
 187                 function session.send(s)
 188                         --log("debug", "Sending BOSH data: %s", tostring(s));
 189                         local oldest_request = r[1];
 190                         while oldest_request and oldest_request.destroyed do
 191                                 t_remove(r, 1);
 192                                 waiting_requests[oldest_request] = nil;
 193                                 oldest_request = r[1];
 194                         end
 195                         if oldest_request then
 196                                 log("debug", "We have an open request, so sending on that");
 197                                 response.body = t_concat{"<body xmlns='http://jabber.org/protocol/httpbind' sid='", sid, "' xmlns:stream = 'http://etherx.jabber.org/streams'>", tostring(s), "</body>" };
 198                                 oldest_request:send(response);
 199                                 --log("debug", "Sent");
 200                                 if oldest_request.stayopen then
 201                                         if #r>1 then
 202                                                 -- Move front request to back
 203                                                 t_insert(r, oldest_request);
 204                                                 t_remove(r, 1);
 205                                         end
 206                                 else
 207                                         log("debug", "Destroying the request now...");
 208                                         oldest_request:destroy();
 209                                         t_remove(r, 1);
 210                                 end
 211                         elseif s ~= "" then
 212                                 log("debug", "Saved to send buffer because there are %d open requests", #r);
 213                                 -- Hmm, no requests are open :(
 214                                 t_insert(session.send_buffer, tostring(s));
 215                                 log("debug", "There are now %d things in the send_buffer", #session.send_buffer);
 216                         end
 217                 end
 218
 219                 -- Send creation response
 220
 221                 local features = st.stanza("stream:features");
 222                 fire_event("stream-features", session, features);
 223                 --xmpp:version='1.0' xmlns:xmpp='urn:xmpp:xbosh'
 224                 local response = st.stanza("body", { xmlns = xmlns_bosh,
 225                                                                         inactivity = tostring(BOSH_DEFAULT_INACTIVITY), polling = tostring(BOSH_DEFAULT_POLLING), requests = tostring(BOSH_DEFAULT_REQUESTS), hold = tostring(session.bosh_hold), maxpause = "120",
 226                                                                         sid = sid, authid = sid, ver  = '1.6', from = session.host, secure = 'true', ["xmpp:version"] = "1.0",
 227                                                                         ["xmlns:xmpp"] = "urn:xmpp:xbosh", ["xmlns:stream"] = "http://etherx.jabber.org/streams" }):add_child(features);
 228                 request:send{ headers = default_headers, body = tostring(response) };
 229
 230                 request.sid = sid;
 231                 return;
 232         end
 233
 234         local session = sessions[sid];
 235         if not session then
 236                 -- Unknown sid
 237                 log("info", "Client tried to use sid '%s' which we don't know about", sid);
 238                 request:send{ headers = default_headers, body = tostring(st.stanza("body", { xmlns = xmlns_bosh, type = "terminate", condition = "item-not-found" })) };
 239                 request.notopen = nil;
 240                 return;
 241         end
 242
 243         if session.rid then
 244                 local rid = tonumber(attr.rid);
 245                 local diff = rid - session.rid;
 246                 if diff > 1 then
 247                         session.log("warn", "rid too large (means a request was lost). Last rid: %d New rid: %s", session.rid, attr.rid);
 248                 elseif diff <= 0 then
 249                         -- Repeated, ignore
 250                         session.log("debug", "rid repeated (on request %s), ignoring: %d", request.id, session.rid);
 251                         request.notopen = nil;
 252                         t_insert(session.requests, request);
 253                         return;
 254                 end
 255                 session.rid = rid;
 256         end
 257
 258         if attr.type == "terminate" then
 259                 -- Client wants to end this session
 260                 session:close();
 261                 request.notopen = nil;
 262                 return;
 263         end
 264
 265         -- If session was inactive, make sure it is now marked as not
 266         if #session.requests == 0 then
 267                 (session.log or log)("debug", "BOSH client now active again at %d", os_time());
 268                 inactive_sessions[session] = nil;
 269         end
 270
 271         if session.notopen then
 272                 local features = st.stanza("stream:features");
 273                 fire_event("stream-features", session, features);
 274                 session.send(features);
 275                 session.notopen = nil;
 276         end
 277
 278         request.notopen = nil; -- Signals that we accept this opening tag
 279         t_insert(session.requests, request);
 280         request.sid = sid;
 281 end
 282
 283 function stream_callbacks.handlestanza(request, stanza)
 284         log("debug", "BOSH stanza received: %s\n", stanza:top_tag());
 285         local session = sessions[request.sid];
 286         if session then
 287                 if stanza.attr.xmlns == xmlns_bosh then
 288                         stanza.attr.xmlns = "jabber:client";
 289                 end
 290                 session.ip = request.handler:ip();
 291                 core_process_stanza(session, stanza);
 292         end
 293 end
 294
 295 local dead_sessions = {};
 296 function on_timer()
 297         -- log("debug", "Checking for requests soon to timeout...");
 298         -- Identify requests timing out within the next few seconds
 299         local now = os_time() + 3;
 300         for request in pairs(waiting_requests) do
 301                 if request.reply_before <= now then
 302                         log("debug", "%s was soon to timeout, sending empty response", request.id);
 303                         -- Send empty response to let the
 304                         -- client know we're still here
 305                         if request.conn then
 306                                 sessions[request.sid].send("");
 307                         end
 308                 end
 309         end
 310
 311         now = now - 3;
 312         local n_dead_sessions = 0;
 313         for session, inactive_since in pairs(inactive_sessions) do
 314                 if session.bosh_max_inactive then
 315                         if now - inactive_since > session.bosh_max_inactive then
 316                                 (session.log or log)("debug", "BOSH client inactive too long, destroying session at %d", now);
 317                                 sessions[session.sid]  = nil;
 318                                 inactive_sessions[session] = nil;
 319                                 n_dead_sessions = n_dead_sessions + 1;
 320                                 dead_sessions[n_dead_sessions] = session;
 321                         end
 322                 else
 323                         inactive_sessions[session] = nil;
 324                 end
 325         end
 326
 327         for i=1,n_dead_sessions do
 328                 local session = dead_sessions[i];
 329                 dead_sessions[i] = nil;
 330                 sm_destroy_session(session, "BOSH client silent for over "..session.bosh_max_inactive.." seconds");
 331         end
 332 end
 333
 334
 335 local function setup()
 336         local ports = module:get_option("bosh_ports") or { 5280 };
 337         httpserver.new_from_config(ports, handle_request, { base = "http-bind" });
 338         server.addtimer(on_timer);
 339 end
 340 if prosody.start_time then -- already started
 341         setup();
 342 else
 343         prosody.events.add_handler("server-started", setup);
 344 end