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