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 sm = require "core.sessionmanager";
  14 local sm_destroy_session = sm.destroy_session;
  15 local new_uuid = require "util.uuid".generate;
  16 local fire_event = prosody.events.fire_event;
  17 local core_process_stanza = prosody.core_process_stanza;
  18 local st = require "util.stanza";
  19 local logger = require "util.logger";
  20 local log = logger.init("mod_bosh");
  21 local initialize_filters = require "util.filters".initialize;
  22 local math_min = math.min;
  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 local bosh_max_wait = module:get_option_number("bosh_max_wait", 120);
  36
  37 local consider_bosh_secure = module:get_option_boolean("consider_bosh_secure");
  38 local cross_domain = module:get_option("cross_domain_bosh", false);
  39
  40 if type(cross_domain) == "table" then cross_domain = table.concat(cross_domain, ", "); end
  41
  42 local trusted_proxies = module:get_option_set("trusted_proxies", {"127.0.0.1"})._items;
  43
  44 local function get_ip_from_request(request)
  45         local ip = request.conn:ip();
  46         local forwarded_for = request.headers.x_forwarded_for;
  47         if forwarded_for then
  48                 forwarded_for = forwarded_for..", "..ip;
  49                 for forwarded_ip in forwarded_for:gmatch("[^%s,]+") do
  50                         if not trusted_proxies[forwarded_ip] then
  51                                 ip = forwarded_ip;
  52                         end
  53                 end
  54         end
  55         return ip;
  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 -- All sessions, and sessions that have no requests open
  62 local sessions, inactive_sessions = module:shared("sessions", "inactive_sessions");
  63
  64 -- Used to respond to idle sessions (those with waiting requests)
  65 local waiting_requests = {};
  66 function on_destroy_request(request)
  67         log("debug", "Request destroyed: %s", tostring(request));
  68         waiting_requests[request] = nil;
  69         local session = sessions[request.context.sid];
  70         if session then
  71                 local requests = session.requests;
  72                 for i, r in ipairs(requests) do
  73                         if r == request then
  74                                 t_remove(requests, i);
  75                                 break;
  76                         end
  77                 end
  78
  79                 -- If this session now has no requests open, mark it as inactive
  80                 local max_inactive = session.bosh_max_inactive;
  81                 if max_inactive and #requests == 0 then
  82                         inactive_sessions[session] = os_time() + max_inactive;
  83                         (session.log or log)("debug", "BOSH session marked as inactive (for %ds)", max_inactive);
  84                 end
  85         end
  86 end
  87
  88 local function set_cross_domain_headers(response)
  89         local headers = response.headers;
  90         headers.access_control_allow_methods = "GET, POST, OPTIONS";
  91         headers.access_control_allow_headers = "Content-Type";
  92         headers.access_control_max_age = "7200";
  93
  94         if cross_domain == true then
  95                 headers.access_control_allow_origin = "*";
  96         else
  97                 headers.access_control_allow_origin = cross_domain;
  98         end
  99         return response;
 100 end
 101
 102 function handle_OPTIONS(event)
 103         return set_cross_domain_headers(event.response);
 104 end
 105
 106 function handle_POST(event)
 107         log("debug", "Handling new request %s: %s\n----------", tostring(event.request), tostring(event.request.body));
 108
 109         local request, response = event.request, event.response;
 110         response.on_destroy = on_destroy_request;
 111         local body = request.body;
 112
 113         local context = { request = request, response = response, notopen = true };
 114         local stream = new_xmpp_stream(context, stream_callbacks);
 115         response.context = context;
 116
 117         local headers = response.headers;
 118         headers.content_type = "text/xml; charset=utf-8";
 119
 120         if cross_domain then
 121                 set_cross_domain_headers(response);
 122         end
 123
 124         -- stream:feed() calls the stream_callbacks, so all stanzas in
 125         -- the body are processed in this next line before it returns.
 126         -- In particular, the streamopened() stream callback is where
 127         -- much of the session logic happens, because it's where we first
 128         -- get to see the 'sid' of this request.
 129         if not stream:feed(body) then
 130                 module:log("warn", "Error parsing BOSH payload")
 131                 return 400;
 132         end
 133
 134         -- Stanzas (if any) in the request have now been processed, and
 135         -- we take care of the high-level BOSH logic here, including
 136         -- giving a response or putting the request "on hold".
 137         local session = sessions[context.sid];
 138         if session then
 139                 -- Session was marked as inactive, since we have
 140                 -- a request open now, unmark it
 141                 if inactive_sessions[session] and #session.requests > 0 then
 142                         inactive_sessions[session] = nil;
 143                 end
 144
 145                 local r = session.requests;
 146                 log("debug", "Session %s has %d out of %d requests open", context.sid, #r, session.bosh_hold);
 147                 log("debug", "and there are %d things in the send_buffer:", #session.send_buffer);
 148                 if #r > session.bosh_hold then
 149                         -- We are holding too many requests, send what's in the buffer,
 150                         log("debug", "We are holding too many requests, so...");
 151                         if #session.send_buffer > 0 then
 152                                 log("debug", "...sending what is in the buffer")
 153                                 session.send(t_concat(session.send_buffer));
 154                                 session.send_buffer = {};
 155                         else
 156                                 -- or an empty response
 157                                 log("debug", "...sending an empty response");
 158                                 session.send("");
 159                         end
 160                 elseif #session.send_buffer > 0 then
 161                         log("debug", "Session has data in the send buffer, will send now..");
 162                         local resp = t_concat(session.send_buffer);
 163                         session.send_buffer = {};
 164                         session.send(resp);
 165                 end
 166
 167                 if not response.finished then
 168                         -- We're keeping this request open, to respond later
 169                         log("debug", "Have nothing to say, so leaving request unanswered for now");
 170                         if session.bosh_wait then
 171                                 waiting_requests[response] = os_time() + session.bosh_wait;
 172                         end
 173                 end
 174
 175                 if session.bosh_terminate then
 176                         session.log("debug", "Closing session with %d requests open", #session.requests);
 177                         session:close();
 178                         return nil;
 179                 else
 180                         return true; -- Inform http server we shall reply later
 181                 end
 182         end
 183         module:log("warn", "Unable to associate request with a session (incomplete request?)");
 184         return 400;
 185 end
 186
 187
 188 local function bosh_reset_stream(session) session.notopen = true; end
 189
 190 local stream_xmlns_attr = { xmlns = "urn:ietf:params:xml:ns:xmpp-streams" };
 191
 192 local function bosh_close_stream(session, reason)
 193         (session.log or log)("info", "BOSH client disconnected");
 194
 195         local close_reply = st.stanza("body", { xmlns = xmlns_bosh, type = "terminate",
 196                 ["xmlns:stream"] = xmlns_streams });
 197
 198
 199         if reason then
 200                 close_reply.attr.condition = "remote-stream-error";
 201                 if type(reason) == "string" then -- assume stream error
 202                         close_reply:tag("stream:error")
 203                                 :tag(reason, {xmlns = xmlns_xmpp_streams});
 204                 elseif type(reason) == "table" then
 205                         if reason.condition then
 206                                 close_reply:tag("stream:error")
 207                                         :tag(reason.condition, stream_xmlns_attr):up();
 208                                 if reason.text then
 209                                         close_reply:tag("text", stream_xmlns_attr):text(reason.text):up();
 210                                 end
 211                                 if reason.extra then
 212                                         close_reply:add_child(reason.extra);
 213                                 end
 214                         elseif reason.name then -- a stanza
 215                                 close_reply = reason;
 216                         end
 217                 end
 218                 log("info", "Disconnecting client, <stream:error> is: %s", tostring(close_reply));
 219         end
 220
 221         local response_body = tostring(close_reply);
 222         for _, held_request in ipairs(session.requests) do
 223                 held_request:send(response_body);
 224         end
 225         sessions[session.sid] = nil;
 226         inactive_sessions[session] = nil;
 227         sm_destroy_session(session);
 228 end
 229
 230 -- Handle the <body> tag in the request payload.
 231 function stream_callbacks.streamopened(context, attr)
 232         local request, response = context.request, context.response;
 233         local sid = attr.sid;
 234         log("debug", "BOSH body open (sid: %s)", sid or "<none>");
 235         if not sid then
 236                 -- New session request
 237                 context.notopen = nil; -- Signals that we accept this opening tag
 238
 239                 -- TODO: Sanity checks here (rid, to, known host, etc.)
 240                 if not hosts[attr.to] then
 241                         -- Unknown host
 242                         log("debug", "BOSH client tried to connect to unknown host: %s", tostring(attr.to));
 243                         local close_reply = st.stanza("body", { xmlns = xmlns_bosh, type = "terminate",
 244                                 ["xmlns:stream"] = xmlns_streams, condition = "host-unknown" });
 245                         response:send(tostring(close_reply));
 246                         return;
 247                 end
 248
 249                 -- New session
 250                 sid = new_uuid();
 251                 local session = {
 252                         type = "c2s_unauthed", conn = {}, sid = sid, rid = tonumber(attr.rid)-1, host = attr.to,
 253                         bosh_version = attr.ver, bosh_wait = math_min(attr.wait, bosh_max_wait), streamid = sid,
 254                         bosh_hold = BOSH_DEFAULT_HOLD, bosh_max_inactive = BOSH_DEFAULT_INACTIVITY,
 255                         requests = { }, send_buffer = {}, reset_stream = bosh_reset_stream,
 256                         close = bosh_close_stream, dispatch_stanza = core_process_stanza, notopen = true,
 257                         log = logger.init("bosh"..sid), secure = consider_bosh_secure or request.secure,
 258                         ip = get_ip_from_request(request);
 259                 };
 260                 sessions[sid] = session;
 261
 262                 local filter = initialize_filters(session);
 263
 264                 session.log("debug", "BOSH session created for request from %s", session.ip);
 265                 log("info", "New BOSH session, assigned it sid '%s'", sid);
 266
 267                 -- Send creation response
 268                 local creating_session = true;
 269
 270                 local r = session.requests;
 271                 function session.send(s)
 272                         -- We need to ensure that outgoing stanzas have the jabber:client xmlns
 273                         if s.attr and not s.attr.xmlns then
 274                                 s = st.clone(s);
 275                                 s.attr.xmlns = "jabber:client";
 276                         end
 277                         s = filter("stanzas/out", s);
 278                         --log("debug", "Sending BOSH data: %s", tostring(s));
 279                         t_insert(session.send_buffer, tostring(s));
 280
 281                         local oldest_request = r[1];
 282                         if oldest_request and not session.bosh_processing then
 283                                 log("debug", "We have an open request, so sending on that");
 284                                 local body_attr = { xmlns = "http://jabber.org/protocol/httpbind",
 285                                         ["xmlns:stream"] = "http://etherx.jabber.org/streams";
 286                                         type = session.bosh_terminate and "terminate" or nil;
 287                                         sid = sid;
 288                                 };
 289                                 if creating_session then
 290                                         creating_session = nil;
 291                                         body_attr.inactivity = tostring(BOSH_DEFAULT_INACTIVITY);
 292                                         body_attr.polling = tostring(BOSH_DEFAULT_POLLING);
 293                                         body_attr.requests = tostring(BOSH_DEFAULT_REQUESTS);
 294                                         body_attr.wait = tostring(session.bosh_wait);
 295                                         body_attr.hold = tostring(session.bosh_hold);
 296                                         body_attr.authid = sid;
 297                                         body_attr.secure = "true";
 298                                         body_attr.ver  = '1.6';
 299                                         body_attr.from = session.host;
 300                                         body_attr["xmlns:xmpp"] = "urn:xmpp:xbosh";
 301                                         body_attr["xmpp:version"] = "1.0";
 302                                 end
 303                                 oldest_request:send(st.stanza("body", body_attr):top_tag()..t_concat(session.send_buffer).."</body>");
 304                                 session.send_buffer = {};
 305                         end
 306                         return true;
 307                 end
 308                 request.sid = sid;
 309         end
 310
 311         local session = sessions[sid];
 312         if not session then
 313                 -- Unknown sid
 314                 log("info", "Client tried to use sid '%s' which we don't know about", sid);
 315                 response:send(tostring(st.stanza("body", { xmlns = xmlns_bosh, type = "terminate", condition = "item-not-found" })));
 316                 context.notopen = nil;
 317                 return;
 318         end
 319
 320         if session.rid then
 321                 local rid = tonumber(attr.rid);
 322                 local diff = rid - session.rid;
 323                 if diff > 1 then
 324                         session.log("warn", "rid too large (means a request was lost). Last rid: %d New rid: %s", session.rid, attr.rid);
 325                 elseif diff <= 0 then
 326                         -- Repeated, ignore
 327                         session.log("debug", "rid repeated, ignoring: %s (diff %d)", session.rid, diff);
 328                         context.notopen = nil;
 329                         context.ignore = true;
 330                         context.sid = sid;
 331                         t_insert(session.requests, response);
 332                         return;
 333                 end
 334                 session.rid = rid;
 335         end
 336
 337         if attr.type == "terminate" then
 338                 -- Client wants to end this session, which we'll do
 339                 -- after processing any stanzas in this request
 340                 session.bosh_terminate = true;
 341         end
 342
 343         context.notopen = nil; -- Signals that we accept this opening tag
 344         t_insert(session.requests, response);
 345         context.sid = sid;
 346         session.bosh_processing = true; -- Used to suppress replies until processing of this request is done
 347
 348         if session.notopen then
 349                 local features = st.stanza("stream:features");
 350                 hosts[session.host].events.fire_event("stream-features", { origin = session, features = features });
 351                 fire_event("stream-features", session, features);
 352                 session.send(tostring(features));
 353                 session.notopen = nil;
 354         end
 355 end
 356
 357 function stream_callbacks.handlestanza(context, stanza)
 358         if context.ignore then return; end
 359         log("debug", "BOSH stanza received: %s\n", stanza:top_tag());
 360         local session = sessions[context.sid];
 361         if session then
 362                 if stanza.attr.xmlns == xmlns_bosh then
 363                         stanza.attr.xmlns = nil;
 364                 end
 365                 stanza = session.filter("stanzas/in", stanza);
 366                 core_process_stanza(session, stanza);
 367         end
 368 end
 369
 370 function stream_callbacks.streamclosed(context)
 371         local session = sessions[context.sid];
 372         if session then
 373                 session.bosh_processing = false;
 374                 if #session.send_buffer > 0 then
 375                         session.send("");
 376                 end
 377         end
 378 end
 379
 380 function stream_callbacks.error(context, error)
 381         log("debug", "Error parsing BOSH request payload; %s", error);
 382         if not context.sid then
 383                 local response = context.response;
 384                 response.status_code = 400;
 385                 response:send();
 386                 return;
 387         end
 388
 389         local session = sessions[context.sid];
 390         if error == "stream-error" then -- Remote stream error, we close normally
 391                 session:close();
 392         else
 393                 session:close({ condition = "bad-format", text = "Error processing stream" });
 394         end
 395 end
 396
 397 local dead_sessions = {};
 398 function on_timer()
 399         -- log("debug", "Checking for requests soon to timeout...");
 400         -- Identify requests timing out within the next few seconds
 401         local now = os_time() + 3;
 402         for request, reply_before in pairs(waiting_requests) do
 403                 if reply_before <= now then
 404                         log("debug", "%s was soon to timeout (at %d, now %d), sending empty response", tostring(request), reply_before, now);
 405                         -- Send empty response to let the
 406                         -- client know we're still here
 407                         if request.conn then
 408                                 sessions[request.context.sid].send("");
 409                         end
 410                 end
 411         end
 412
 413         now = now - 3;
 414         local n_dead_sessions = 0;
 415         for session, close_after in pairs(inactive_sessions) do
 416                 if close_after < now then
 417                         (session.log or log)("debug", "BOSH client inactive too long, destroying session at %d", now);
 418                         sessions[session.sid]  = nil;
 419                         inactive_sessions[session] = nil;
 420                         n_dead_sessions = n_dead_sessions + 1;
 421                         dead_sessions[n_dead_sessions] = session;
 422                 end
 423         end
 424
 425         for i=1,n_dead_sessions do
 426                 local session = dead_sessions[i];
 427                 dead_sessions[i] = nil;
 428                 sm_destroy_session(session, "BOSH client silent for over "..session.bosh_max_inactive.." seconds");
 429         end
 430         return 1;
 431 end
 432 module:add_timer(1, on_timer);
 433
 434
 435 local GET_response = {
 436         headers = {
 437                 content_type = "text/html";
 438         };
 439         body = [[<html><body>
 440         <p>It works! Now point your BOSH client to this URL to connect to Prosody.</p>
 441         <p>For more information see <a href="http://prosody.im/doc/setting_up_bosh">Prosody: Setting up BOSH</a>.</p>
 442         </body></html>]];
 443 };
 444
 445 function module.add_host(module)
 446         module:depends("http");
 447         module:provides("http", {
 448                 default_path = "/http-bind";
 449                 route = {
 450                         ["GET"] = GET_response;
 451                         ["GET /"] = GET_response;
 452                         ["OPTIONS"] = handle_OPTIONS;
 453                         ["OPTIONS /"] = handle_OPTIONS;
 454                         ["POST"] = handle_POST;
 455                         ["POST /"] = handle_POST;
 456                 };
 457         });
 458 end