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