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:set_global(); -- Global module
  10
  11 local hosts = _G.hosts;
  12 local new_xmpp_stream = require "util.xmppstream".new;
  13 local httpserver = require "net.httpserver";
  14 local sm = require "core.sessionmanager";
  15 local sm_destroy_session = sm.destroy_session;
  16 local new_uuid = require "util.uuid".generate;
  17 local fire_event = prosody.events.fire_event;
  18 local core_process_stanza = core_process_stanza;
  19 local st = require "util.stanza";
  20 local logger = require "util.logger";
  21 local log = logger.init("mod_bosh");
  22 local timer = require "util.timer";
  23
  24 local xmlns_streams = "http://etherx.jabber.org/streams";
  25 local xmlns_xmpp_streams = "urn:ietf:params:xml:ns:xmpp-streams";
  26 local xmlns_bosh = "http://jabber.org/protocol/httpbind"; -- (hard-coded into a literal in session.send)
  27
  28 local stream_callbacks = {
  29         stream_ns = xmlns_bosh, stream_tag = "body", default_ns = "jabber:client" };
  30
  31 local BOSH_DEFAULT_HOLD = module:get_option_number("bosh_default_hold", 1);
  32 local BOSH_DEFAULT_INACTIVITY = module:get_option_number("bosh_max_inactivity", 60);
  33 local BOSH_DEFAULT_POLLING = module:get_option_number("bosh_max_polling", 5);
  34 local BOSH_DEFAULT_REQUESTS = module:get_option_number("bosh_max_requests", 2);
  35
  36 local consider_bosh_secure = module:get_option_boolean("consider_bosh_secure");
  37 local auto_cork = module:get_option_boolean("bosh_auto_cork", false);
  38
  39 local default_headers = { ["Content-Type"] = "text/xml; charset=utf-8" };
  40
  41 local cross_domain = module:get_option("cross_domain_bosh", false);
  42 if cross_domain then
  43         default_headers["Access-Control-Allow-Methods"] = "GET, POST, OPTIONS";
  44         default_headers["Access-Control-Allow-Headers"] = "Content-Type";
  45         default_headers["Access-Control-Max-Age"] = "7200";
  46
  47         if cross_domain == true then
  48                 default_headers["Access-Control-Allow-Origin"] = "*";
  49         elseif type(cross_domain) == "table" then
  50                 cross_domain = table.concat(cross_domain, ", ");
  51         end
  52         if type(cross_domain) == "string" then
  53                 default_headers["Access-Control-Allow-Origin"] = cross_domain;
  54         end
  55 end
  56
  57 local trusted_proxies = module:get_option_set("trusted_proxies", {"127.0.0.1"})._items;
  58
  59 local function get_ip_from_request(request)
  60         local ip = request.conn:ip();
  61         local forwarded_for = request.headers["x-forwarded-for"];
  62         if forwarded_for then
  63                 forwarded_for = forwarded_for..", "..ip;
  64                 for forwarded_ip in forwarded_for:gmatch("[^%s,]+") do
  65                         if not trusted_proxies[forwarded_ip] then
  66                                 ip = forwarded_ip;
  67                         end
  68                 end
  69         end
  70         return ip;
  71 end
  72
  73 local t_insert, t_remove, t_concat = table.insert, table.remove, table.concat;
  74 local os_time = os.time;
  75
  76 local sessions = {};
  77 local inactive_sessions = {}; -- Sessions which have no open requests
  78
  79 -- Used to respond to idle sessions (those with waiting requests)
  80 local waiting_requests = {};
  81 function on_destroy_request(request)
  82         log("debug", "Request destroyed: %s", tostring(request));
  83         waiting_requests[request] = nil;
  84         local session = sessions[request.context.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                 local max_inactive = session.bosh_max_inactive;
  96                 if max_inactive and #requests == 0 then
  97                         inactive_sessions[session] = os_time() + max_inactive;
  98                         (session.log or log)("debug", "BOSH session marked as inactive (for %ds)", max_inactive);
  99                 end
 100         end
 101 end
 102
 103 local function handle_GET(request)
 104         return [[<html><body>
 105         <p>It works! Now point your BOSH client to this URL to connect to Prosody.</p>
 106         <p>For more information see <a href="http://prosody.im/doc/setting_up_bosh">Prosody: Setting up BOSH</a>.</p>
 107 </body></html>]];
 108 end
 109
 110 function handle_OPTIONS(request)
 111         local headers = {};
 112         for k,v in pairs(default_headers) do headers[k] = v; end
 113         headers["Content-Type"] = nil;
 114         return { headers = headers, body = "" };
 115 end
 116
 117 function handle_POST(event)
 118         log("debug", "Handling new request %s: %s\n----------", tostring(event.request), tostring(event.request.body));
 119
 120         local request, response = event.request, event.response;
 121         response.on_destroy = on_destroy_request;
 122         local body = request.body;
 123
 124         local context = { request = request, response = response, notopen = true };
 125         local stream = new_xmpp_stream(context, stream_callbacks);
 126         response.context = context;
 127
 128         -- stream:feed() calls the stream_callbacks, so all stanzas in
 129         -- the body are processed in this next line before it returns.
 130         -- In particular, the streamopened() stream callback is where
 131         -- much of the session logic happens, because it's where we first
 132         -- get to see the 'sid' of this request.
 133         stream:feed(body);
 134
 135         -- Stanzas (if any) in the request have now been processed, and
 136         -- we take care of the high-level BOSH logic here, including
 137         -- giving a response or putting the request "on hold".
 138         local session = sessions[context.sid];
 139         if session then
 140                 -- Session was marked as inactive, since we have
 141                 -- a request open now, unmark it
 142                 if inactive_sessions[session] and #session.requests > 0 then
 143                         inactive_sessions[session] = nil;
 144                 end
 145
 146                 local r = session.requests;
 147                 log("debug", "Session %s has %d out of %d requests open", context.sid, #r, session.bosh_hold);
 148                 log("debug", "and there are %d things in the send_buffer:", #session.send_buffer);
 149                 for i, thing in ipairs(session.send_buffer) do
 150                         log("debug", "    %s", tostring(thing));
 151                 end
 152                 if #r > session.bosh_hold then
 153                         -- We are holding too many requests, send what's in the buffer,
 154                         log("debug", "We are holding too many requests, so...");
 155                         if #session.send_buffer > 0 then
 156                                 log("debug", "...sending what is in the buffer")
 157                                 session.send(t_concat(session.send_buffer));
 158                                 session.send_buffer = {};
 159                         else
 160                                 -- or an empty response
 161                                 log("debug", "...sending an empty response");
 162                                 session.send("");
 163                         end
 164                 elseif #session.send_buffer > 0 then
 165                         log("debug", "Session has data in the send buffer, will send now..");
 166                         local resp = t_concat(session.send_buffer);
 167                         session.send_buffer = {};
 168                         session.send(resp);
 169                 end
 170
 171                 if not response.finished then
 172                         -- We're keeping this request open, to respond later
 173                         log("debug", "Have nothing to say, so leaving request unanswered for now");
 174                         if session.bosh_wait then
 175                                 waiting_requests[response] = os_time() + session.bosh_wait;
 176                         end
 177                 end
 178
 179                 if session.bosh_terminate then
 180                         session.log("debug", "Closing session with %d requests open", #session.requests);
 181                         session:close();
 182                         return nil;
 183                 else
 184                         return true; -- Inform httpserver we shall reply later
 185                 end
 186         end
 187 end
 188
 189
 190 local function bosh_reset_stream(session) session.notopen = true; end
 191
 192 local stream_xmlns_attr = { xmlns = "urn:ietf:params:xml:ns:xmpp-streams" };
 193
 194 local function bosh_close_stream(session, reason)
 195         (session.log or log)("info", "BOSH client disconnected");
 196
 197         local close_reply = st.stanza("body", { xmlns = xmlns_bosh, type = "terminate",
 198                 ["xmlns:stream"] = xmlns_streams });
 199
 200
 201         if reason then
 202                 close_reply.attr.condition = "remote-stream-error";
 203                 if type(reason) == "string" then -- assume stream error
 204                         close_reply:tag("stream:error")
 205                                 :tag(reason, {xmlns = xmlns_xmpp_streams});
 206                 elseif type(reason) == "table" then
 207                         if reason.condition then
 208                                 close_reply:tag("stream:error")
 209                                         :tag(reason.condition, stream_xmlns_attr):up();
 210                                 if reason.text then
 211                                         close_reply:tag("text", stream_xmlns_attr):text(reason.text):up();
 212                                 end
 213                                 if reason.extra then
 214                                         close_reply:add_child(reason.extra);
 215                                 end
 216                         elseif reason.name then -- a stanza
 217                                 close_reply = reason;
 218                         end
 219                 end
 220                 log("info", "Disconnecting client, <stream:error> is: %s", tostring(close_reply));
 221         end
 222
 223         local response_body = tostring(close_reply);
 224         for _, held_request in ipairs(session.requests) do
 225                 held_request.headers = default_headers;
 226                 held_request:send(response_body);
 227         end
 228         sessions[session.sid]  = nil;
 229         inactive_sessions[session] = nil;
 230         sm_destroy_session(session);
 231 end
 232
 233 -- Handle the <body> tag in the request payload.
 234 function stream_callbacks.streamopened(context, attr)
 235         local request, response = context.request, context.response;
 236         local sid = attr.sid;
 237         log("debug", "BOSH body open (sid: %s)", sid or "<none>");
 238         if not sid then
 239                 -- New session request
 240                 context.notopen = nil; -- Signals that we accept this opening tag
 241
 242                 -- TODO: Sanity checks here (rid, to, known host, etc.)
 243                 if not hosts[attr.to] then
 244                         -- Unknown host
 245                         log("debug", "BOSH client tried to connect to unknown host: %s", tostring(attr.to));
 246                         local close_reply = st.stanza("body", { xmlns = xmlns_bosh, type = "terminate",
 247                                 ["xmlns:stream"] = xmlns_streams, condition = "host-unknown" });
 248                         response:send(tostring(close_reply));
 249                         return;
 250                 end
 251
 252                 -- New session
 253                 sid = new_uuid();
 254                 local session = {
 255                         type = "c2s_unauthed", conn = {}, sid = sid, rid = tonumber(attr.rid), host = attr.to,
 256                         bosh_version = attr.ver, bosh_wait = attr.wait, streamid = sid,
 257                         bosh_hold = BOSH_DEFAULT_HOLD, bosh_max_inactive = BOSH_DEFAULT_INACTIVITY,
 258                         requests = { }, send_buffer = {}, reset_stream = bosh_reset_stream,
 259                         close = bosh_close_stream, dispatch_stanza = core_process_stanza,
 260                         log = logger.init("bosh"..sid), secure = consider_bosh_secure or request.secure,
 261                         ip = get_ip_from_request(request);
 262                 };
 263                 sessions[sid] = session;
 264
 265                 session.log("debug", "BOSH session created for request from %s", session.ip);
 266                 log("info", "New BOSH session, assigned it sid '%s'", sid);
 267                 local r, send_buffer = session.requests, session.send_buffer;
 268                 function session.send(s)
 269                         -- We need to ensure that outgoing stanzas have the jabber:client xmlns
 270                         if s.attr and not s.attr.xmlns then
 271                                 s = st.clone(s);
 272                                 s.attr.xmlns = "jabber:client";
 273                         end
 274                         --log("debug", "Sending BOSH data: %s", tostring(s));
 275                         local oldest_request = r[1];
 276                         if oldest_request and (not(auto_cork) or waiting_requests[oldest_request]) then
 277                                 log("debug", "We have an open request, so sending on that");
 278                                 oldest_request.headers = default_headers;
 279                                 oldest_request:send(t_concat({
 280                                         "<body xmlns='http://jabber.org/protocol/httpbind' ",
 281                                         session.bosh_terminate and "type='terminate' " or "",
 282                                         "sid='", sid, "' xmlns:stream = 'http://etherx.jabber.org/streams'>",
 283                                         tostring(s),
 284                                         "</body>"
 285                                 }));
 286                         elseif s ~= "" then
 287                                 log("debug", "Saved to send buffer because there are %d open requests", #r);
 288                                 -- Hmm, no requests are open :(
 289                                 t_insert(session.send_buffer, tostring(s));
 290                                 log("debug", "There are now %d things in the send_buffer", #session.send_buffer);
 291                         end
 292                         return true;
 293                 end
 294
 295                 -- Send creation response
 296
 297                 local features = st.stanza("stream:features");
 298                 hosts[session.host].events.fire_event("stream-features", { origin = session, features = features });
 299                 fire_event("stream-features", session, features);
 300                 --xmpp:version='1.0' xmlns:xmpp='urn:xmpp:xbosh'
 301                 local body = st.stanza("body", { xmlns = xmlns_bosh,
 302                         wait = attr.wait,
 303                         inactivity = tostring(BOSH_DEFAULT_INACTIVITY),
 304                         polling = tostring(BOSH_DEFAULT_POLLING),
 305                         requests = tostring(BOSH_DEFAULT_REQUESTS),
 306                         hold = tostring(session.bosh_hold),
 307                         sid = sid, authid = sid,
 308                         ver  = '1.6', from = session.host,
 309                         secure = 'true', ["xmpp:version"] = "1.0",
 310                         ["xmlns:xmpp"] = "urn:xmpp:xbosh",
 311                         ["xmlns:stream"] = "http://etherx.jabber.org/streams"
 312                 }):add_child(features);
 313                 response.headers = default_headers;
 314                 response:send(tostring(body));
 315
 316                 request.sid = sid;
 317                 return;
 318         end
 319
 320         local session = sessions[sid];
 321         if not session then
 322                 -- Unknown sid
 323                 log("info", "Client tried to use sid '%s' which we don't know about", sid);
 324                 response.headers = default_headers;
 325                 response:send(tostring(st.stanza("body", { xmlns = xmlns_bosh, type = "terminate", condition = "item-not-found" })));
 326                 context.notopen = nil;
 327                 return;
 328         end
 329
 330         if session.rid then
 331                 local rid = tonumber(attr.rid);
 332                 local diff = rid - session.rid;
 333                 if diff > 1 then
 334                         session.log("warn", "rid too large (means a request was lost). Last rid: %d New rid: %s", session.rid, attr.rid);
 335                 elseif diff <= 0 then
 336                         -- Repeated, ignore
 337                         session.log("debug", "rid repeated (on request %s), ignoring: %s (diff %d)", request.id, session.rid, diff);
 338                         context.notopen = nil;
 339                         context.ignore = true;
 340                         context.sid = sid;
 341                         t_insert(session.requests, response);
 342                         return;
 343                 end
 344                 session.rid = rid;
 345         end
 346
 347         if attr.type == "terminate" then
 348                 -- Client wants to end this session, which we'll do
 349                 -- after processing any stanzas in this request
 350                 session.bosh_terminate = true;
 351         end
 352
 353         context.notopen = nil; -- Signals that we accept this opening tag
 354         t_insert(session.requests, response);
 355         context.sid = sid;
 356
 357         if session.notopen then
 358                 local features = st.stanza("stream:features");
 359                 hosts[session.host].events.fire_event("stream-features", { origin = session, features = features });
 360                 fire_event("stream-features", session, features);
 361                 session.send(features);
 362                 session.notopen = nil;
 363         end
 364 end
 365
 366 function stream_callbacks.handlestanza(context, stanza)
 367         if context.ignore then return; end
 368         log("debug", "BOSH stanza received: %s\n", stanza:top_tag());
 369         local session = sessions[context.sid];
 370         if session then
 371                 if stanza.attr.xmlns == xmlns_bosh then
 372                         stanza.attr.xmlns = nil;
 373                 end
 374                 core_process_stanza(session, stanza);
 375         end
 376 end
 377
 378 function stream_callbacks.error(context, error)
 379         log("debug", "Error parsing BOSH request payload; %s", error);
 380         if not context.sid then
 381                 local response = context.response;
 382                 response.headers = default_headers;
 383                 response.status_code = 400;
 384                 request:send();
 385                 return;
 386         end
 387
 388         local session = sessions[context.sid];
 389         if error == "stream-error" then -- Remote stream error, we close normally
 390                 session:close();
 391         else
 392                 session:close({ condition = "bad-format", text = "Error processing stream" });
 393         end
 394 end
 395
 396 local dead_sessions = {};
 397 function on_timer()
 398         -- log("debug", "Checking for requests soon to timeout...");
 399         -- Identify requests timing out within the next few seconds
 400         local now = os_time() + 3;
 401         for request, reply_before in pairs(waiting_requests) do
 402                 if reply_before <= now then
 403                         log("debug", "%s was soon to timeout (at %d, now %d), sending empty response", tostring(request), reply_before, now);
 404                         -- Send empty response to let the
 405                         -- client know we're still here
 406                         if request.conn then
 407                                 sessions[request.context.sid].send("");
 408                         end
 409                 end
 410         end
 411
 412         now = now - 3;
 413         local n_dead_sessions = 0;
 414         for session, close_after in pairs(inactive_sessions) do
 415                 if close_after < now then
 416                         (session.log or log)("debug", "BOSH client inactive too long, destroying session at %d", now);
 417                         sessions[session.sid]  = nil;
 418                         inactive_sessions[session] = nil;
 419                         n_dead_sessions = n_dead_sessions + 1;
 420                         dead_sessions[n_dead_sessions] = session;
 421                 end
 422         end
 423
 424         for i=1,n_dead_sessions do
 425                 local session = dead_sessions[i];
 426                 dead_sessions[i] = nil;
 427                 sm_destroy_session(session, "BOSH client silent for over "..session.bosh_max_inactive.." seconds");
 428         end
 429         return 1;
 430 end
 431 module:add_timer(1, on_timer);
 432
 433 function module.add_host(module)
 434         module:depends("http");
 435         module:provides("http", {
 436                 default_path = "/http-bind";
 437                 route = {
 438                         ["GET /"] = handle_GET;
 439                         ["OPTIONS /"] = handle_OPTIONS;
 440                         ["POST /"] = handle_POST;
 441                 };
 442         });
 443 end