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 core_process_stanza = prosody.core_process_stanza;
  17 local st = require "util.stanza";
  18 local logger = require "util.logger";
  19 local log = logger.init("mod_bosh");
  20 local initialize_filters = require "util.filters".initialize;
  21 local math_min = math.min;
  22 local tostring, type = tostring, type;
  23 local traceback = debug.traceback;
  24 local runner = require"util.async".runner;
  25 local nameprep = require "util.encodings".stringprep.nameprep;
  26
  27 local xmlns_streams = "http://etherx.jabber.org/streams";
  28 local xmlns_xmpp_streams = "urn:ietf:params:xml:ns:xmpp-streams";
  29 local xmlns_bosh = "http://jabber.org/protocol/httpbind"; -- (hard-coded into a literal in session.send)
  30
  31 local stream_callbacks = {
  32         stream_ns = xmlns_bosh, stream_tag = "body", default_ns = "jabber:client" };
  33
  34 local BOSH_DEFAULT_HOLD = module:get_option_number("bosh_default_hold", 1);
  35 local BOSH_DEFAULT_INACTIVITY = module:get_option_number("bosh_max_inactivity", 60);
  36 local BOSH_DEFAULT_POLLING = module:get_option_number("bosh_max_polling", 5);
  37 local BOSH_DEFAULT_REQUESTS = module:get_option_number("bosh_max_requests", 2);
  38 local bosh_max_wait = module:get_option_number("bosh_max_wait", 120);
  39
  40 local consider_bosh_secure = module:get_option_boolean("consider_bosh_secure");
  41 local cross_domain = module:get_option("cross_domain_bosh", false);
  42
  43 if cross_domain == true then cross_domain = "*"; end
  44 if type(cross_domain) == "table" then cross_domain = table.concat(cross_domain, ", "); end
  45
  46 local trusted_proxies = module:get_option_set("trusted_proxies", {"127.0.0.1"})._items;
  47
  48 local function get_ip_from_request(request)
  49         local ip = request.conn:ip();
  50         local forwarded_for = request.headers.x_forwarded_for;
  51         if forwarded_for then
  52                 forwarded_for = forwarded_for..", "..ip;
  53                 for forwarded_ip in forwarded_for:gmatch("[^%s,]+") do
  54                         if not trusted_proxies[forwarded_ip] then
  55                                 ip = forwarded_ip;
  56                         end
  57                 end
  58         end
  59         return ip;
  60 end
  61
  62 local t_insert, t_remove, t_concat = table.insert, table.remove, table.concat;
  63 local os_time = os.time;
  64
  65 -- All sessions, and sessions that have no requests open
  66 local sessions, inactive_sessions = module:shared("sessions", "inactive_sessions");
  67
  68 -- Used to respond to idle sessions (those with waiting requests)
  69 local waiting_requests = module:shared("waiting_requests");
  70 function on_destroy_request(request)
  71         log("debug", "Request destroyed: %s", tostring(request));
  72         waiting_requests[request] = nil;
  73         local session = sessions[request.context.sid];
  74         if session then
  75                 local requests = session.requests;
  76                 for i, r in ipairs(requests) do
  77                         if r == request then
  78                                 t_remove(requests, i);
  79                                 break;
  80                         end
  81                 end
  82
  83                 -- If this session now has no requests open, mark it as inactive
  84                 local max_inactive = session.bosh_max_inactive;
  85                 if max_inactive and #requests == 0 then
  86                         inactive_sessions[session] = os_time() + max_inactive;
  87                         (session.log or log)("debug", "BOSH session marked as inactive (for %ds)", max_inactive);
  88                 end
  89         end
  90 end
  91
  92 local function set_cross_domain_headers(response)
  93         local headers = response.headers;
  94         headers.access_control_allow_methods = "GET, POST, OPTIONS";
  95         headers.access_control_allow_headers = "Content-Type";
  96         headers.access_control_max_age = "7200";
  97         headers.access_control_allow_origin = cross_domain;
  98         return response;
  99 end
 100
 101 function handle_OPTIONS(event)
 102         if cross_domain and event.request.headers.origin then
 103                 set_cross_domain_headers(event.response);
 104         end
 105         return "";
 106 end
 107
 108 function handle_POST(event)
 109         log("debug", "Handling new request %s: %s\n----------", tostring(event.request), tostring(event.request.body));
 110
 111         local request, response = event.request, event.response;
 112         response.on_destroy = on_destroy_request;
 113         local body = request.body;
 114
 115         local context = { request = request, response = response, notopen = true };
 116         local stream = new_xmpp_stream(context, stream_callbacks);
 117         response.context = context;
 118
 119         local headers = response.headers;
 120         headers.content_type = "text/xml; charset=utf-8";
 121
 122         if cross_domain and event.request.headers.origin then
 123                 set_cross_domain_headers(response);
 124         end
 125
 126         -- stream:feed() calls the stream_callbacks, so all stanzas in
 127         -- the body are processed in this next line before it returns.
 128         -- In particular, the streamopened() stream callback is where
 129         -- much of the session logic happens, because it's where we first
 130         -- get to see the 'sid' of this request.
 131         local ok, err = stream:feed(body);
 132         if not ok then
 133                 module:log("warn", "Error parsing BOSH payload; %s", err)
 134                 local close_reply = st.stanza("body", { xmlns = xmlns_bosh, type = "terminate",
 135                         ["xmlns:stream"] = xmlns_streams, condition = "bad-request" });
 136                 return tostring(close_reply);
 137         end
 138
 139         -- Stanzas (if any) in the request have now been processed, and
 140         -- we take care of the high-level BOSH logic here, including
 141         -- giving a response or putting the request "on hold".
 142         local session = sessions[context.sid];
 143         if session then
 144                 -- Session was marked as inactive, since we have
 145                 -- a request open now, unmark it
 146                 if session.inactive_timer and #session.requests > 0 then
 147                         session.inactive_timer:stop();
 148                         session.inactive_timer = nil;
 149                 end
 150
 151                 if session.bosh_wait_timer then
 152                         session.bosh_wait_timer:stop();
 153                         session.bosh_wait_timer = nil;
 154                 end
 155
 156                 local r = session.requests;
 157                 log("debug", "Session %s has %d out of %d requests open", context.sid, #r, session.bosh_hold);
 158                 log("debug", "and there are %d things in the send_buffer:", #session.send_buffer);
 159                 if #r > session.bosh_hold then
 160                         -- We are holding too many requests, send what's in the buffer,
 161                         log("debug", "We are holding too many requests, so...");
 162                         if #session.send_buffer > 0 then
 163                                 log("debug", "...sending what is in the buffer")
 164                                 session.send(t_concat(session.send_buffer));
 165                                 session.send_buffer = {};
 166                         else
 167                                 -- or an empty response
 168                                 log("debug", "...sending an empty response");
 169                                 session.send("");
 170                         end
 171                 elseif #session.send_buffer > 0 then
 172                         log("debug", "Session has data in the send buffer, will send now..");
 173                         local resp = t_concat(session.send_buffer);
 174                         session.send_buffer = {};
 175                         session.send(resp);
 176                 end
 177
 178                 if not response.finished then
 179                         -- We're keeping this request open, to respond later
 180                         log("debug", "Have nothing to say, so leaving request unanswered for now");
 181                         if session.bosh_wait then
 182                                 session.bosh_wait_timer = module:add_timer(session.bosh_wait, after_bosh_wait, request, session)
 183                         end
 184                 end
 185
 186                 if session.bosh_terminate then
 187                         session.log("debug", "Closing session with %d requests open", #session.requests);
 188                         session:close();
 189                         return nil;
 190                 else
 191                         return true; -- Inform http server we shall reply later
 192                 end
 193         elseif response.finished then
 194                 return; -- A response has been sent already
 195         end
 196         module:log("warn", "Unable to associate request with a session (incomplete request?)");
 197         local close_reply = st.stanza("body", { xmlns = xmlns_bosh, type = "terminate",
 198                 ["xmlns:stream"] = xmlns_streams, condition = "item-not-found" });
 199         return tostring(close_reply) .. "\n";
 200 end
 201
 202 function after_bosh_wait(now, request, session) -- luacheck: ignore 212
 203         if request.conn then
 204                 session.send("");
 205         end
 206 end
 207
 208 local function bosh_reset_stream(session) session.notopen = true; end
 209
 210 local stream_xmlns_attr = { xmlns = "urn:ietf:params:xml:ns:xmpp-streams" };
 211
 212 local function bosh_close_stream(session, reason)
 213         (session.log or log)("info", "BOSH client disconnected");
 214
 215         local close_reply = st.stanza("body", { xmlns = xmlns_bosh, type = "terminate",
 216                 ["xmlns:stream"] = xmlns_streams });
 217
 218
 219         if reason then
 220                 close_reply.attr.condition = "remote-stream-error";
 221                 if type(reason) == "string" then -- assume stream error
 222                         close_reply:tag("stream:error")
 223                                 :tag(reason, {xmlns = xmlns_xmpp_streams});
 224                 elseif type(reason) == "table" then
 225                         if reason.condition then
 226                                 close_reply:tag("stream:error")
 227                                         :tag(reason.condition, stream_xmlns_attr):up();
 228                                 if reason.text then
 229                                         close_reply:tag("text", stream_xmlns_attr):text(reason.text):up();
 230                                 end
 231                                 if reason.extra then
 232                                         close_reply:add_child(reason.extra);
 233                                 end
 234                         elseif reason.name then -- a stanza
 235                                 close_reply = reason;
 236                         end
 237                 end
 238                 log("info", "Disconnecting client, <stream:error> is: %s", tostring(close_reply));
 239         end
 240
 241         local response_body = tostring(close_reply);
 242         for _, held_request in ipairs(session.requests) do
 243                 held_request:send(response_body);
 244         end
 245         sessions[session.sid] = nil;
 246         sm_destroy_session(session);
 247 end
 248
 249 local runner_callbacks = { };
 250
 251 -- Handle the <body> tag in the request payload.
 252 function stream_callbacks.streamopened(context, attr)
 253         local request, response = context.request, context.response;
 254         local sid = attr.sid;
 255         log("debug", "BOSH body open (sid: %s)", sid or "<none>");
 256         if not sid then
 257                 -- New session request
 258                 context.notopen = nil; -- Signals that we accept this opening tag
 259
 260                 local to_host = nameprep(attr.to);
 261                 local rid = tonumber(attr.rid);
 262                 local wait = tonumber(attr.wait);
 263                 if not to_host then
 264                         log("debug", "BOSH client tried to connect to invalid host: %s", tostring(attr.to));
 265                         local close_reply = st.stanza("body", { xmlns = xmlns_bosh, type = "terminate",
 266                                 ["xmlns:stream"] = xmlns_streams, condition = "improper-addressing" });
 267                         response:send(tostring(close_reply));
 268                         return;
 269                 elseif not hosts[to_host] then
 270                         -- Unknown host
 271                         log("debug", "BOSH client tried to connect to unknown host: %s", tostring(attr.to));
 272                         local close_reply = st.stanza("body", { xmlns = xmlns_bosh, type = "terminate",
 273                                 ["xmlns:stream"] = xmlns_streams, condition = "host-unknown" });
 274                         response:send(tostring(close_reply));
 275                         return;
 276                 end
 277                 if not rid or (not wait and attr.wait or wait < 0 or wait % 1 ~= 0) then
 278                         log("debug", "BOSH client sent invalid rid or wait attributes: rid=%s, wait=%s", tostring(attr.rid), tostring(attr.wait));
 279                         local close_reply = st.stanza("body", { xmlns = xmlns_bosh, type = "terminate",
 280                                 ["xmlns:stream"] = xmlns_streams, condition = "bad-request" });
 281                         response:send(tostring(close_reply));
 282                         return;
 283                 end
 284
 285                 rid = rid - 1;
 286                 wait = math_min(wait, bosh_max_wait);
 287
 288                 -- New session
 289                 sid = new_uuid();
 290                 local session = {
 291                         type = "c2s_unauthed", conn = {}, sid = sid, rid = rid, host = attr.to,
 292                         bosh_version = attr.ver, bosh_wait = wait, streamid = sid,
 293                         bosh_hold = BOSH_DEFAULT_HOLD, bosh_max_inactive = BOSH_DEFAULT_INACTIVITY,
 294                         requests = { }, send_buffer = {}, reset_stream = bosh_reset_stream,
 295                         close = bosh_close_stream, dispatch_stanza = core_process_stanza, notopen = true,
 296                         log = logger.init("bosh"..sid), secure = consider_bosh_secure or request.secure,
 297                         ip = get_ip_from_request(request);
 298                 };
 299                 sessions[sid] = session;
 300
 301                 session.thread = runner(function (stanza)
 302                         session:dispatch_stanza(stanza);
 303                 end, runner_callbacks, session);
 304
 305                 local filter = initialize_filters(session);
 306
 307                 session.log("debug", "BOSH session created for request from %s", session.ip);
 308                 log("info", "New BOSH session, assigned it sid '%s'", sid);
 309
 310                 hosts[session.host].events.fire_event("bosh-session", { session = session, request = request });
 311
 312                 -- Send creation response
 313                 local creating_session = true;
 314
 315                 local r = session.requests;
 316                 function session.send(s)
 317                         -- We need to ensure that outgoing stanzas have the jabber:client xmlns
 318                         if s.attr and not s.attr.xmlns then
 319                                 s = st.clone(s);
 320                                 s.attr.xmlns = "jabber:client";
 321                         end
 322                         s = filter("stanzas/out", s);
 323                         --log("debug", "Sending BOSH data: %s", tostring(s));
 324                         if not s then return true end
 325                         t_insert(session.send_buffer, tostring(s));
 326
 327                         local oldest_request = r[1];
 328                         if oldest_request and not session.bosh_processing then
 329                                 log("debug", "We have an open request, so sending on that");
 330                                 local body_attr = { xmlns = "http://jabber.org/protocol/httpbind",
 331                                         ["xmlns:stream"] = "http://etherx.jabber.org/streams";
 332                                         type = session.bosh_terminate and "terminate" or nil;
 333                                         sid = sid;
 334                                 };
 335                                 if creating_session then
 336                                         creating_session = nil;
 337                                         body_attr.inactivity = tostring(BOSH_DEFAULT_INACTIVITY);
 338                                         body_attr.polling = tostring(BOSH_DEFAULT_POLLING);
 339                                         body_attr.requests = tostring(BOSH_DEFAULT_REQUESTS);
 340                                         body_attr.wait = tostring(session.bosh_wait);
 341                                         body_attr.hold = tostring(session.bosh_hold);
 342                                         body_attr.authid = sid;
 343                                         body_attr.secure = "true";
 344                                         body_attr.ver  = '1.6';
 345                                         body_attr.from = session.host;
 346                                         body_attr["xmlns:xmpp"] = "urn:xmpp:xbosh";
 347                                         body_attr["xmpp:version"] = "1.0";
 348                                 end
 349                                 oldest_request:send(st.stanza("body", body_attr):top_tag()..t_concat(session.send_buffer).."</body>");
 350                                 session.send_buffer = {};
 351                         end
 352                         return true;
 353                 end
 354                 request.sid = sid;
 355         end
 356
 357         local session = sessions[sid];
 358         if not session then
 359                 -- Unknown sid
 360                 log("info", "Client tried to use sid '%s' which we don't know about", sid);
 361                 response:send(tostring(st.stanza("body", { xmlns = xmlns_bosh, type = "terminate", condition = "item-not-found" })));
 362                 context.notopen = nil;
 363                 return;
 364         end
 365
 366         if session.rid then
 367                 local rid = tonumber(attr.rid);
 368                 local diff = rid - session.rid;
 369                 if diff > 1 then
 370                         session.log("warn", "rid too large (means a request was lost). Last rid: %d New rid: %s", session.rid, attr.rid);
 371                 elseif diff <= 0 then
 372                         -- Repeated, ignore
 373                         session.log("debug", "rid repeated, ignoring: %s (diff %d)", session.rid, diff);
 374                         context.notopen = nil;
 375                         context.ignore = true;
 376                         context.sid = sid;
 377                         t_insert(session.requests, response);
 378                         return;
 379                 end
 380                 session.rid = rid;
 381         end
 382
 383         if attr.type == "terminate" then
 384                 -- Client wants to end this session, which we'll do
 385                 -- after processing any stanzas in this request
 386                 session.bosh_terminate = true;
 387         end
 388
 389         context.notopen = nil; -- Signals that we accept this opening tag
 390         t_insert(session.requests, response);
 391         context.sid = sid;
 392         session.bosh_processing = true; -- Used to suppress replies until processing of this request is done
 393
 394         if session.notopen then
 395                 local features = st.stanza("stream:features");
 396                 hosts[session.host].events.fire_event("stream-features", { origin = session, features = features });
 397                 session.send(features);
 398                 session.notopen = nil;
 399         end
 400 end
 401
 402 local function handleerr(err) log("error", "Traceback[bosh]: %s", traceback(tostring(err), 2)); end
 403
 404 function runner_callbacks:error(err) -- luacheck: ignore 212/self
 405         return handleerr(err);
 406 end
 407
 408 function stream_callbacks.handlestanza(context, stanza)
 409         if context.ignore then return; end
 410         log("debug", "BOSH stanza received: %s\n", stanza:top_tag());
 411         local session = sessions[context.sid];
 412         if session then
 413                 if stanza.attr.xmlns == xmlns_bosh then
 414                         stanza.attr.xmlns = nil;
 415                 end
 416                 stanza = session.filter("stanzas/in", stanza);
 417                 session.thread:run(stanza);
 418         end
 419 end
 420
 421 function stream_callbacks.streamclosed(context)
 422         local session = sessions[context.sid];
 423         if session then
 424                 session.bosh_processing = false;
 425                 if #session.send_buffer > 0 then
 426                         session.send("");
 427                 end
 428         end
 429 end
 430
 431 function stream_callbacks.error(context, error)
 432         log("debug", "Error parsing BOSH request payload; %s", error);
 433         if not context.sid then
 434                 local response = context.response;
 435                 local close_reply = st.stanza("body", { xmlns = xmlns_bosh, type = "terminate",
 436                         ["xmlns:stream"] = xmlns_streams, condition = "bad-request" });
 437                 response:send(tostring(close_reply));
 438                 return;
 439         end
 440
 441         local session = sessions[context.sid];
 442         if error == "stream-error" then -- Remote stream error, we close normally
 443                 session:close();
 444         else
 445                 session:close({ condition = "bad-format", text = "Error processing stream" });
 446         end
 447 end
 448
 449 local GET_response = {
 450         headers = {
 451                 content_type = "text/html";
 452         };
 453         body = [[<html><body>
 454         <p>It works! Now point your BOSH client to this URL to connect to Prosody.</p>
 455         <p>For more information see <a href="https://prosody.im/doc/setting_up_bosh">Prosody: Setting up BOSH</a>.</p>
 456         </body></html>]];
 457 };
 458
 459 function module.add_host(module)
 460         module:depends("http");
 461         module:provides("http", {
 462                 default_path = "/http-bind";
 463                 route = {
 464                         ["GET"] = GET_response;
 465                         ["GET /"] = GET_response;
 466                         ["OPTIONS"] = handle_OPTIONS;
 467                         ["OPTIONS /"] = handle_OPTIONS;
 468                         ["POST"] = handle_POST;
 469                         ["POST /"] = handle_POST;
 470                 };
 471         });
 472 end