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