plugins/mod_bosh.lua

   1 -- Prosody IM
   2 -- Copyright (C) 2008-2010 Matthew Wild
   3 -- Copyright (C) 2008-2010 Waqas Hussain
   4 --
   5 -- This project is MIT/X11 licensed. Please see the
   6 -- COPYING file in the source package for more information.
   7 --
   8
   9 module.host = "*" -- Global module
  10
  11 local hosts = _G.hosts;
  12 local lxp = require "lxp";
  13 local init_xmlhandlers = require "core.xmlhandlers"
  14 local server = require "net.server";
  15 local httpserver = require "net.httpserver";
  16 local sm = require "core.sessionmanager";
  17 local sm_destroy_session = sm.destroy_session;
  18 local new_uuid = require "util.uuid".generate;
  19 local fire_event = require "core.eventmanager".fire_event;
  20 local core_process_stanza = core_process_stanza;
  21 local st = require "util.stanza";
  22 local logger = require "util.logger";
  23 local log = logger.init("mod_bosh");
  24
  25 local xmlns_bosh = "http://jabber.org/protocol/httpbind"; -- (hard-coded into a literal in session.send)
  26 local stream_callbacks = { stream_tag = "http://jabber.org/protocol/httpbind\1body", default_ns = "jabber:client" };
  27
  28 local BOSH_DEFAULT_HOLD = tonumber(module:get_option("bosh_default_hold")) or 1;
  29 local BOSH_DEFAULT_INACTIVITY = tonumber(module:get_option("bosh_max_inactivity")) or 60;
  30 local BOSH_DEFAULT_POLLING = tonumber(module:get_option("bosh_max_polling")) or 5;
  31 local BOSH_DEFAULT_REQUESTS = tonumber(module:get_option("bosh_max_requests")) or 2;
  32 local BOSH_DEFAULT_MAXPAUSE = tonumber(module:get_option("bosh_max_pause")) or 300;
  33
  34 local default_headers = { ["Content-Type"] = "text/xml; charset=utf-8" };
  35 local session_close_reply = { headers = default_headers, body = st.stanza("body", { xmlns = xmlns_bosh, type = "terminate" }), attr = {} };
  36
  37 local t_insert, t_remove, t_concat = table.insert, table.remove, table.concat;
  38 local os_time = os.time;
  39
  40 local sessions = {};
  41 local inactive_sessions = {}; -- Sessions which have no open requests
  42
  43 -- Used to respond to idle sessions (those with waiting requests)
  44 local waiting_requests = {};
  45 function on_destroy_request(request)
  46         waiting_requests[request] = nil;
  47         local session = sessions[request.sid];
  48         if session then
  49                 local requests = session.requests;
  50                 for i,r in ipairs(requests) do
  51                         if r == request then
  52                                 t_remove(requests, i);
  53                                 break;
  54                         end
  55                 end
  56
  57                 -- If this session now has no requests open, mark it as inactive
  58                 if #requests == 0 and session.bosh_max_inactive and not inactive_sessions[session] then
  59                         inactive_sessions[session] = os_time();
  60                         (session.log or log)("debug", "BOSH session marked as inactive at %d", inactive_sessions[session]);
  61                 end
  62         end
  63 end
  64
  65 function handle_request(method, body, request)
  66         if (not body) or request.method ~= "POST" then
  67                 return "<html><body>You really don't look like a BOSH client to me... what do you want?</body></html>";
  68         end
  69         if not method then
  70                 log("debug", "Request %s suffered error %s", tostring(request.id), body);
  71                 return;
  72         end
  73         --log("debug", "Handling new request %s: %s\n----------", request.id, tostring(body));
  74         request.notopen = true;
  75         request.log = log;
  76         request.on_destroy = on_destroy_request;
  77
  78         local parser = lxp.new(init_xmlhandlers(request, stream_callbacks), "\1");
  79
  80         parser:parse(body);
  81
  82         local session = sessions[request.sid];
  83         if session then
  84                 local r = session.requests;
  85                 log("debug", "Session %s has %d out of %d requests open", request.sid, #r, session.bosh_hold);
  86                 log("debug", "and there are %d things in the send_buffer", #session.send_buffer);
  87                 if #r > session.bosh_hold then
  88                         -- We are holding too many requests, send what's in the buffer,
  89                         log("debug", "We are holding too many requests, so...");
  90                         if #session.send_buffer > 0 then
  91                                 log("debug", "...sending what is in the buffer")
  92                                 session.send(t_concat(session.send_buffer));
  93                                 session.send_buffer = {};
  94                         else
  95                                 -- or an empty response
  96                                 log("debug", "...sending an empty response");
  97                                 session.send("");
  98                         end
  99                 elseif #session.send_buffer > 0 then
 100                         log("debug", "Session has data in the send buffer, will send now..");
 101                         local resp = t_concat(session.send_buffer);
 102                         session.send_buffer = {};
 103                         session.send(resp);
 104                 end
 105
 106                 if not request.destroyed then
 107                         -- We're keeping this request open, to respond later
 108                         log("debug", "Have nothing to say, so leaving request unanswered for now");
 109                         if session.bosh_wait then
 110                                 request.reply_before = os_time() + session.bosh_wait;
 111                                 waiting_requests[request] = true;
 112                         end
 113                         if inactive_sessions[session] then
 114                                 -- Session was marked as inactive, since we have
 115                                 -- a request open now, unmark it
 116                                 inactive_sessions[session] = nil;
 117                         end
 118                 end
 119
 120                 return true; -- Inform httpserver we shall reply later
 121         end
 122 end
 123
 124
 125 local function bosh_reset_stream(session) session.notopen = true; end
 126
 127 local function bosh_close_stream(session, reason)
 128         (session.log or log)("info", "BOSH client disconnected");
 129         session_close_reply.attr.condition = reason;
 130         for _, held_request in ipairs(session.requests) do
 131                 held_request:send(session_close_reply);
 132                 held_request:destroy();
 133         end
 134         sessions[session.sid]  = nil;
 135         sm_destroy_session(session);
 136 end
 137
 138 function stream_callbacks.streamopened(request, attr)
 139         log("debug", "BOSH body open (sid: %s)", attr.sid);
 140         local sid = attr.sid
 141         if not sid then
 142                 -- New session request
 143                 request.notopen = nil; -- Signals that we accept this opening tag
 144
 145                 -- TODO: Sanity checks here (rid, to, known host, etc.)
 146                 if not hosts[attr.to] then
 147                         -- Unknown host
 148                         log("debug", "BOSH client tried to connect to unknown host: %s", tostring(attr.to));
 149                         session_close_reply.body.attr.condition = "host-unknown";
 150                         request:send(session_close_reply);
 151                         request.notopen = nil
 152                         return;
 153                 end
 154
 155                 -- New session
 156                 sid = new_uuid();
 157                 local session = { type = "c2s_unauthed", conn = {}, sid = sid, rid = tonumber(attr.rid)-1, host = attr.to, bosh_version = attr.ver, bosh_wait = attr.wait, streamid = sid,
 158                                                 bosh_hold = BOSH_DEFAULT_HOLD, bosh_max_inactive = BOSH_DEFAULT_INACTIVITY,
 159                                                 requests = { }, send_buffer = {}, reset_stream = bosh_reset_stream, close = bosh_close_stream,
 160                                                 dispatch_stanza = core_process_stanza, log = logger.init("bosh"..sid), secure = request.secure };
 161                 sessions[sid] = session;
 162
 163                 log("info", "New BOSH session, assigned it sid '%s'", sid);
 164                 local r, send_buffer = session.requests, session.send_buffer;
 165                 local response = { headers = default_headers }
 166                 function session.send(s)
 167                         --log("debug", "Sending BOSH data: %s", tostring(s));
 168                         local oldest_request = r[1];
 169                         if oldest_request then
 170                                 log("debug", "We have an open request, so sending on that");
 171                                 response.body = t_concat{"<body xmlns='http://jabber.org/protocol/httpbind' sid='", sid, "' xmlns:stream = 'http://etherx.jabber.org/streams'>", tostring(s), "</body>" };
 172                                 oldest_request:send(response);
 173                                 --log("debug", "Sent");
 174                                 if oldest_request.stayopen then
 175                                         if #r>1 then
 176                                                 -- Move front request to back
 177                                                 t_insert(r, oldest_request);
 178                                                 t_remove(r, 1);
 179                                         end
 180                                 else
 181                                         log("debug", "Destroying the request now...");
 182                                         oldest_request:destroy();
 183                                 end
 184                         elseif s ~= "" then
 185                                 log("debug", "Saved to send buffer because there are %d open requests", #r);
 186                                 -- Hmm, no requests are open :(
 187                                 t_insert(session.send_buffer, tostring(s));
 188                                 log("debug", "There are now %d things in the send_buffer", #session.send_buffer);
 189                         end
 190                 end
 191
 192                 -- Send creation response
 193
 194                 local features = st.stanza("stream:features");
 195                 fire_event("stream-features", session, features);
 196                 --xmpp:version='1.0' xmlns:xmpp='urn:xmpp:xbosh'
 197                 local response = st.stanza("body", { xmlns = xmlns_bosh,
 198                                                                         inactivity = tostring(BOSH_DEFAULT_INACTIVITY), polling = tostring(BOSH_DEFAULT_POLLING), requests = tostring(BOSH_DEFAULT_REQUESTS), hold = tostring(session.bosh_hold), maxpause = "120",
 199                                                                         sid = sid, authid = sid, ver  = '1.6', from = session.host, secure = 'true', ["xmpp:version"] = "1.0",
 200                                                                         ["xmlns:xmpp"] = "urn:xmpp:xbosh", ["xmlns:stream"] = "http://etherx.jabber.org/streams" }):add_child(features);
 201                 request:send{ headers = default_headers, body = tostring(response) };
 202
 203                 request.sid = sid;
 204                 return;
 205         end
 206
 207         local session = sessions[sid];
 208         if not session then
 209                 -- Unknown sid
 210                 log("info", "Client tried to use sid '%s' which we don't know about", sid);
 211                 request:send{ headers = default_headers, body = tostring(st.stanza("body", { xmlns = xmlns_bosh, type = "terminate", condition = "item-not-found" })) };
 212                 request.notopen = nil;
 213                 return;
 214         end
 215
 216         if session.rid then
 217                 local rid = tonumber(attr.rid);
 218                 local diff = rid - session.rid;
 219                 if diff > 1 then
 220                         session.log("warn", "rid too large (means a request was lost). Last rid: %d New rid: %s", session.rid, attr.rid);
 221                 elseif diff <= 0 then
 222                         -- Repeated, ignore
 223                         session.log("debug", "rid repeated (on request %s), ignoring: %s (diff %d)", request.id, session.rid, diff);
 224                         request.notopen = nil;
 225                         request.sid = sid;
 226                         t_insert(session.requests, request);
 227                         return;
 228                 end
 229                 session.rid = rid;
 230         end
 231
 232         if attr.type == "terminate" then
 233                 -- Client wants to end this session
 234                 session:close();
 235                 request.notopen = nil;
 236                 return;
 237         end
 238
 239         if session.notopen then
 240                 local features = st.stanza("stream:features");
 241                 fire_event("stream-features", session, features);
 242                 session.send(features);
 243                 session.notopen = nil;
 244         end
 245
 246         request.notopen = nil; -- Signals that we accept this opening tag
 247         t_insert(session.requests, request);
 248         request.sid = sid;
 249 end
 250
 251 function stream_callbacks.handlestanza(request, stanza)
 252         log("debug", "BOSH stanza received: %s\n", stanza:top_tag());
 253         local session = sessions[request.sid];
 254         if session then
 255                 if stanza.attr.xmlns == xmlns_bosh then
 256                         stanza.attr.xmlns = nil;
 257                 end
 258                 session.ip = request.handler.ip();
 259                 core_process_stanza(session, stanza);
 260         end
 261 end
 262
 263 local dead_sessions = {};
 264 function on_timer()
 265         -- log("debug", "Checking for requests soon to timeout...");
 266         -- Identify requests timing out within the next few seconds
 267         local now = os_time() + 3;
 268         for request in pairs(waiting_requests) do
 269                 if request.reply_before <= now then
 270                         log("debug", "%s was soon to timeout, sending empty response", request.id);
 271                         -- Send empty response to let the
 272                         -- client know we're still here
 273                         if request.conn then
 274                                 sessions[request.sid].send("");
 275                         end
 276                 end
 277         end
 278
 279         now = now - 3;
 280         local n_dead_sessions = 0;
 281         for session, inactive_since in pairs(inactive_sessions) do
 282                 if session.bosh_max_inactive then
 283                         if now - inactive_since > session.bosh_max_inactive then
 284                                 (session.log or log)("debug", "BOSH client inactive too long, destroying session at %d", now);
 285                                 sessions[session.sid]  = nil;
 286                                 inactive_sessions[session] = nil;
 287                                 n_dead_sessions = n_dead_sessions + 1;
 288                                 dead_sessions[n_dead_sessions] = session;
 289                         end
 290                 else
 291                         inactive_sessions[session] = nil;
 292                 end
 293         end
 294
 295         for i=1,n_dead_sessions do
 296                 local session = dead_sessions[i];
 297                 dead_sessions[i] = nil;
 298                 sm_destroy_session(session, "BOSH client silent for over "..session.bosh_max_inactive.." seconds");
 299         end
 300 end
 301
 302 local ports = module:get_option("bosh_ports") or { 5280 };
 303 httpserver.new_from_config(ports, handle_request, { base = "http-bind" });
 304
 305 server.addtimer(on_timer);