plugins/muc/muc.lib.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 local select = select;
  10 local pairs, ipairs = pairs, ipairs;
  11
  12 local datamanager = require "util.datamanager";
  13 local datetime = require "util.datetime";
  14
  15 local jid_split = require "util.jid".split;
  16 local jid_bare = require "util.jid".bare;
  17 local jid_prep = require "util.jid".prep;
  18 local st = require "util.stanza";
  19 local log = require "util.logger".init("mod_muc");
  20 local multitable_new = require "util.multitable".new;
  21 local t_insert, t_remove = table.insert, table.remove;
  22 local setmetatable = setmetatable;
  23 local base64 = require "util.encodings".base64;
  24 local md5 = require "util.hashes".md5;
  25
  26 local muc_domain = nil; --module:get_host();
  27 local default_history_length = 20;
  28
  29 ------------
  30 local function filter_xmlns_from_array(array, filters)
  31         local count = 0;
  32         for i=#array,1,-1 do
  33                 local attr = array[i].attr;
  34                 if filters[attr and attr.xmlns] then
  35                         t_remove(array, i);
  36                         count = count + 1;
  37                 end
  38         end
  39         return count;
  40 end
  41 local function filter_xmlns_from_stanza(stanza, filters)
  42         if filters then
  43                 if filter_xmlns_from_array(stanza.tags, filters) ~= 0 then
  44                         return stanza, filter_xmlns_from_array(stanza, filters);
  45                 end
  46         end
  47         return stanza, 0;
  48 end
  49 local presence_filters = {["http://jabber.org/protocol/muc"]=true;["http://jabber.org/protocol/muc#user"]=true};
  50 local function get_filtered_presence(stanza)
  51         return filter_xmlns_from_stanza(st.clone(stanza):reset(), presence_filters);
  52 end
  53 local kickable_error_conditions = {
  54         ["gone"] = true;
  55         ["internal-server-error"] = true;
  56         ["item-not-found"] = true;
  57         ["jid-malformed"] = true;
  58         ["recipient-unavailable"] = true;
  59         ["redirect"] = true;
  60         ["remote-server-not-found"] = true;
  61         ["remote-server-timeout"] = true;
  62         ["service-unavailable"] = true;
  63         ["malformed error"] = true;
  64 };
  65
  66 local function get_error_condition(stanza)
  67         local _, condition = stanza:get_error();
  68         return condition or "malformed error";
  69 end
  70
  71 local function is_kickable_error(stanza)
  72         local cond = get_error_condition(stanza);
  73         return kickable_error_conditions[cond] and cond;
  74 end
  75 local function getUsingPath(stanza, path, getText)
  76         local tag = stanza;
  77         for _, name in ipairs(path) do
  78                 if type(tag) ~= 'table' then return; end
  79                 tag = tag:child_with_name(name);
  80         end
  81         if tag and getText then tag = table.concat(tag); end
  82         return tag;
  83 end
  84 local function getTag(stanza, path) return getUsingPath(stanza, path); end
  85 local function getText(stanza, path) return getUsingPath(stanza, path, true); end
  86 -----------
  87
  88 local room_mt = {};
  89 room_mt.__index = room_mt;
  90
  91 function room_mt:get_default_role(affiliation)
  92         if affiliation == "owner" or affiliation == "admin" then
  93                 return "moderator";
  94         elseif affiliation == "member" then
  95                 return "participant";
  96         elseif not affiliation then
  97                 if not self:is_members_only() then
  98                         return self:is_moderated() and "visitor" or "participant";
  99                 end
 100         end
 101 end
 102
 103 function room_mt:broadcast_presence(stanza, sid, code, nick)
 104         stanza = get_filtered_presence(stanza);
 105         local occupant = self._occupants[stanza.attr.from];
 106         stanza:tag("x", {xmlns='http://jabber.org/protocol/muc#user'})
 107                 :tag("item", {affiliation=occupant.affiliation or "none", role=occupant.role or "none", nick=nick}):up();
 108         if code then
 109                 stanza:tag("status", {code=code}):up();
 110         end
 111         self:broadcast_except_nick(stanza, stanza.attr.from);
 112         local me = self._occupants[stanza.attr.from];
 113         if me then
 114                 stanza:tag("status", {code='110'});
 115                 stanza.attr.to = sid;
 116                 self:_route_stanza(stanza);
 117         end
 118 end
 119 function room_mt:broadcast_message(stanza, historic)
 120         local to = stanza.attr.to;
 121         for occupant, o_data in pairs(self._occupants) do
 122                 for jid in pairs(o_data.sessions) do
 123                         stanza.attr.to = jid;
 124                         self:_route_stanza(stanza);
 125                 end
 126         end
 127         stanza.attr.to = to;
 128         if historic then -- add to history
 129                 local history = self._data['history'];
 130                 if not history then history = {}; self._data['history'] = history; end
 131                 stanza = st.clone(stanza);
 132                 stanza.attr.to = "";
 133                 local stamp = datetime.datetime();
 134                 local chars = #tostring(stanza);
 135                 stanza:tag("delay", {xmlns = "urn:xmpp:delay", from = muc_domain, stamp = stamp}):up(); -- XEP-0203
 136                 stanza:tag("x", {xmlns = "jabber:x:delay", from = muc_domain, stamp = datetime.legacy()}):up(); -- XEP-0091 (deprecated)
 137                 local entry = { stanza = stanza, stamp = stamp };
 138                 t_insert(history, entry);
 139                 while #history > (self._data.history_length or default_history_length) do t_remove(history, 1) end
 140         end
 141 end
 142 function room_mt:broadcast_except_nick(stanza, nick)
 143         for rnick, occupant in pairs(self._occupants) do
 144                 if rnick ~= nick then
 145                         for jid in pairs(occupant.sessions) do
 146                                 stanza.attr.to = jid;
 147                                 self:_route_stanza(stanza);
 148                         end
 149                 end
 150         end
 151 end
 152
 153 function room_mt:send_occupant_list(to)
 154         local current_nick = self._jid_nick[to];
 155         for occupant, o_data in pairs(self._occupants) do
 156                 if occupant ~= current_nick then
 157                         local pres = get_filtered_presence(o_data.sessions[o_data.jid]);
 158                         pres.attr.to, pres.attr.from = to, occupant;
 159                         pres:tag("x", {xmlns='http://jabber.org/protocol/muc#user'})
 160                                 :tag("item", {affiliation=o_data.affiliation or "none", role=o_data.role or "none"}):up();
 161                         self:_route_stanza(pres);
 162                 end
 163         end
 164 end
 165 function room_mt:send_history(to, stanza)
 166         local history = self._data['history']; -- send discussion history
 167         if history then
 168                 local x_tag = stanza and stanza:get_child("x", "http://jabber.org/protocol/muc");
 169                 local history_tag = x_tag and x_tag:get_child("history", "http://jabber.org/protocol/muc");
 170
 171                 local maxchars = history_tag and tonumber(history_tag.attr.maxchars);
 172                 if maxchars then maxchars = math.floor(maxchars); end
 173
 174                 local maxstanzas = math.floor(history_tag and tonumber(history_tag.attr.maxstanzas) or #history);
 175                 if not history_tag then maxstanzas = 20; end
 176
 177                 local seconds = history_tag and tonumber(history_tag.attr.seconds);
 178                 if seconds then seconds = datetime.datetime(os.time() - math.floor(seconds)); end
 179
 180                 local since = history_tag and history_tag.attr.since;
 181                 if since and not since:match("^%d%d%d%d%-%d%d%-%d%dT%d%d:%d%d:%d%dZ$") then since = nil; end -- FIXME timezone support
 182                 if seconds and (not since or since < seconds) then since = seconds; end
 183
 184                 local n = 0;
 185                 local charcount = 0;
 186                 local stanzacount = 0;
 187
 188                 for i=#history,1,-1 do
 189                         local entry = history[i];
 190                         if maxchars then
 191                                 if not entry.chars then
 192                                         entry.stanza.attr.to = "";
 193                                         entry.chars = #tostring(entry.stanza);
 194                                 end
 195                                 charcount = charcount + entry.chars + #to;
 196                                 if charcount > maxchars then break; end
 197                         end
 198                         if since and since > entry.stamp then break; end
 199                         if n + 1 > maxstanzas then break; end
 200                         n = n + 1;
 201                 end
 202                 for i=#history-n+1,#history do
 203                         local msg = history[i].stanza;
 204                         msg.attr.to = to;
 205                         self:_route_stanza(msg);
 206                 end
 207         end
 208         if self._data['subject'] then
 209                 self:_route_stanza(st.message({type='groupchat', from=self._data['subject_from'] or self.jid, to=to}):tag("subject"):text(self._data['subject']));
 210         end
 211 end
 212
 213 function room_mt:get_disco_info(stanza)
 214         return st.reply(stanza):query("http://jabber.org/protocol/disco#info")
 215                 :tag("identity", {category="conference", type="text", name=self:get_name()}):up()
 216                 :tag("feature", {var="http://jabber.org/protocol/muc"}):up()
 217                 :tag("feature", {var=self:get_password() and "muc_passwordprotected" or "muc_unsecured"}):up()
 218                 :tag("feature", {var=self:is_moderated() and "muc_moderated" or "muc_unmoderated"}):up()
 219                 :tag("feature", {var=self:is_members_only() and "muc_membersonly" or "muc_open"}):up()
 220                 :tag("feature", {var=self:is_persistent() and "muc_persistent" or "muc_temporary"}):up()
 221                 :tag("feature", {var=self:is_hidden() and "muc_hidden" or "muc_public"}):up()
 222                 :tag("feature", {var=self._data.whois ~= "anyone" and "muc_semianonymous" or "muc_nonanonymous"}):up()
 223                 :tag("x", {xmlns="jabber:x:data", type="result"})
 224                         :tag("field", {var="FORM_TYPE", type="hidden"})
 225                                 :tag("value"):text("http://jabber.org/protocol/muc#roominfo"):up()
 226                         :up()
 227                         :tag("field", {var="muc#roominfo_description", label="Description"})
 228                                 :tag("value"):text(self:get_description()):up()
 229                         :up()
 230                 :up()
 231         ;
 232 end
 233 function room_mt:get_disco_items(stanza)
 234         local reply = st.reply(stanza):query("http://jabber.org/protocol/disco#items");
 235         for room_jid in pairs(self._occupants) do
 236                 reply:tag("item", {jid = room_jid, name = room_jid:match("/(.*)")}):up();
 237         end
 238         return reply;
 239 end
 240 function room_mt:set_subject(current_nick, subject)
 241         -- TODO check nick's authority
 242         if subject == "" then subject = nil; end
 243         self._data['subject'] = subject;
 244         self._data['subject_from'] = current_nick;
 245         if self.save then self:save(); end
 246         local msg = st.message({type='groupchat', from=current_nick})
 247                 :tag('subject'):text(subject):up();
 248         self:broadcast_message(msg, false);
 249         return true;
 250 end
 251
 252 local function build_unavailable_presence_from_error(stanza)
 253         local type, condition, text = stanza:get_error();
 254         local error_message = "Kicked: "..(condition and condition:gsub("%-", " ") or "presence error");
 255         if text then
 256                 error_message = error_message..": "..text;
 257         end
 258         return st.presence({type='unavailable', from=stanza.attr.from, to=stanza.attr.to})
 259                 :tag('status'):text(error_message);
 260 end
 261
 262 function room_mt:set_name(name)
 263         if name == "" or type(name) ~= "string" or name == (jid_split(self.jid)) then name = nil; end
 264         if self._data.name ~= name then
 265                 self._data.name = name;
 266                 if self.save then self:save(true); end
 267         end
 268 end
 269 function room_mt:get_name()
 270         return self._data.name or jid_split(self.jid);
 271 end
 272 function room_mt:set_description(description)
 273         if description == "" or type(description) ~= "string" then description = nil; end
 274         if self._data.description ~= description then
 275                 self._data.description = description;
 276                 if self.save then self:save(true); end
 277         end
 278 end
 279 function room_mt:get_description()
 280         return self._data.description;
 281 end
 282 function room_mt:set_password(password)
 283         if password == "" or type(password) ~= "string" then password = nil; end
 284         if self._data.password ~= password then
 285                 self._data.password = password;
 286                 if self.save then self:save(true); end
 287         end
 288 end
 289 function room_mt:get_password()
 290         return self._data.password;
 291 end
 292 function room_mt:set_moderated(moderated)
 293         moderated = moderated and true or nil;
 294         if self._data.moderated ~= moderated then
 295                 self._data.moderated = moderated;
 296                 if self.save then self:save(true); end
 297         end
 298 end
 299 function room_mt:is_moderated()
 300         return self._data.moderated;
 301 end
 302 function room_mt:set_members_only(members_only)
 303         members_only = members_only and true or nil;
 304         if self._data.members_only ~= members_only then
 305                 self._data.members_only = members_only;
 306                 if self.save then self:save(true); end
 307         end
 308 end
 309 function room_mt:is_members_only()
 310         return self._data.members_only;
 311 end
 312 function room_mt:set_persistent(persistent)
 313         persistent = persistent and true or nil;
 314         if self._data.persistent ~= persistent then
 315                 self._data.persistent = persistent;
 316                 if self.save then self:save(true); end
 317         end
 318 end
 319 function room_mt:is_persistent()
 320         return self._data.persistent;
 321 end
 322 function room_mt:set_hidden(hidden)
 323         hidden = hidden and true or nil;
 324         if self._data.hidden ~= hidden then
 325                 self._data.hidden = hidden;
 326                 if self.save then self:save(true); end
 327         end
 328 end
 329 function room_mt:is_hidden()
 330         return self._data.hidden;
 331 end
 332
 333 function room_mt:handle_to_occupant(origin, stanza) -- PM, vCards, etc
 334         local from, to = stanza.attr.from, stanza.attr.to;
 335         local room = jid_bare(to);
 336         local current_nick = self._jid_nick[from];
 337         local type = stanza.attr.type;
 338         log("debug", "room: %s, current_nick: %s, stanza: %s", room or "nil", current_nick or "nil", stanza:top_tag());
 339         if (select(2, jid_split(from)) == muc_domain) then error("Presence from the MUC itself!!!"); end
 340         if stanza.name == "presence" then
 341                 local pr = get_filtered_presence(stanza);
 342                 pr.attr.from = current_nick;
 343                 if type == "error" then -- error, kick em out!
 344                         if current_nick then
 345                                 log("debug", "kicking %s from %s", current_nick, room);
 346                                 self:handle_to_occupant(origin, build_unavailable_presence_from_error(stanza));
 347                         end
 348                 elseif type == "unavailable" then -- unavailable
 349                         if current_nick then
 350                                 log("debug", "%s leaving %s", current_nick, room);
 351                                 local occupant = self._occupants[current_nick];
 352                                 local new_jid = next(occupant.sessions);
 353                                 if new_jid == from then new_jid = next(occupant.sessions, new_jid); end
 354                                 if new_jid then
 355                                         local jid = occupant.jid;
 356                                         occupant.jid = new_jid;
 357                                         occupant.sessions[from] = nil;
 358                                         pr.attr.to = from;
 359                                         pr:tag("x", {xmlns='http://jabber.org/protocol/muc#user'})
 360                                                 :tag("item", {affiliation=occupant.affiliation or "none", role='none'}):up()
 361                                                 :tag("status", {code='110'});
 362                                         self:_route_stanza(pr);
 363                                         if jid ~= new_jid then
 364                                                 pr = st.clone(occupant.sessions[new_jid])
 365                                                         :tag("x", {xmlns='http://jabber.org/protocol/muc#user'})
 366                                                         :tag("item", {affiliation=occupant.affiliation or "none", role=occupant.role or "none"});
 367                                                 pr.attr.from = current_nick;
 368                                                 self:broadcast_except_nick(pr, current_nick);
 369                                         end
 370                                 else
 371                                         occupant.role = 'none';
 372                                         self:broadcast_presence(pr, from);
 373                                         self._occupants[current_nick] = nil;
 374                                 end
 375                                 self._jid_nick[from] = nil;
 376                         end
 377                 elseif not type then -- available
 378                         if current_nick then
 379                                 --if #pr == #stanza or current_nick ~= to then -- commented because google keeps resending directed presence
 380                                         if current_nick == to then -- simple presence
 381                                                 log("debug", "%s broadcasted presence", current_nick);
 382                                                 self._occupants[current_nick].sessions[from] = pr;
 383                                                 self:broadcast_presence(pr, from);
 384                                         else -- change nick
 385                                                 local occupant = self._occupants[current_nick];
 386                                                 local is_multisession = next(occupant.sessions, next(occupant.sessions));
 387                                                 if self._occupants[to] or is_multisession then
 388                                                         log("debug", "%s couldn't change nick", current_nick);
 389                                                         local reply = st.error_reply(stanza, "cancel", "conflict"):up();
 390                                                         reply.tags[1].attr.code = "409";
 391                                                         origin.send(reply:tag("x", {xmlns = "http://jabber.org/protocol/muc"}));
 392                                                 else
 393                                                         local data = self._occupants[current_nick];
 394                                                         local to_nick = select(3, jid_split(to));
 395                                                         if to_nick then
 396                                                                 log("debug", "%s (%s) changing nick to %s", current_nick, data.jid, to);
 397                                                                 local p = st.presence({type='unavailable', from=current_nick});
 398                                                                 self:broadcast_presence(p, from, '303', to_nick);
 399                                                                 self._occupants[current_nick] = nil;
 400                                                                 self._occupants[to] = data;
 401                                                                 self._jid_nick[from] = to;
 402                                                                 pr.attr.from = to;
 403                                                                 self._occupants[to].sessions[from] = pr;
 404                                                                 self:broadcast_presence(pr, from);
 405                                                         else
 406                                                                 --TODO malformed-jid
 407                                                         end
 408                                                 end
 409                                         end
 410                                 --else -- possible rejoin
 411                                 --      log("debug", "%s had connection replaced", current_nick);
 412                                 --      self:handle_to_occupant(origin, st.presence({type='unavailable', from=from, to=to})
 413                                 --              :tag('status'):text('Replaced by new connection'):up()); -- send unavailable
 414                                 --      self:handle_to_occupant(origin, stanza); -- resend available
 415                                 --end
 416                         else -- enter room
 417                                 local new_nick = to;
 418                                 local is_merge;
 419                                 if self._occupants[to] then
 420                                         if jid_bare(from) ~= jid_bare(self._occupants[to].jid) then
 421                                                 new_nick = nil;
 422                                         end
 423                                         is_merge = true;
 424                                 end
 425                                 local password = stanza:get_child("x", "http://jabber.org/protocol/muc");
 426                                 password = password and password:get_child("password", "http://jabber.org/protocol/muc");
 427                                 password = password and password[1] ~= "" and password[1];
 428                                 if self:get_password() and self:get_password() ~= password then
 429                                         log("debug", "%s couldn't join due to invalid password: %s", from, to);
 430                                         local reply = st.error_reply(stanza, "auth", "not-authorized"):up();
 431                                         reply.tags[1].attr.code = "401";
 432                                         origin.send(reply:tag("x", {xmlns = "http://jabber.org/protocol/muc"}));
 433                                 elseif not new_nick then
 434                                         log("debug", "%s couldn't join due to nick conflict: %s", from, to);
 435                                         local reply = st.error_reply(stanza, "cancel", "conflict"):up();
 436                                         reply.tags[1].attr.code = "409";
 437                                         origin.send(reply:tag("x", {xmlns = "http://jabber.org/protocol/muc"}));
 438                                 else
 439                                         log("debug", "%s joining as %s", from, to);
 440                                         if not next(self._affiliations) then -- new room, no owners
 441                                                 self._affiliations[jid_bare(from)] = "owner";
 442                                         end
 443                                         local affiliation = self:get_affiliation(from);
 444                                         local role = self:get_default_role(affiliation)
 445                                         if role then -- new occupant
 446                                                 if not is_merge then
 447                                                         self._occupants[to] = {affiliation=affiliation, role=role, jid=from, sessions={[from]=get_filtered_presence(stanza)}};
 448                                                 else
 449                                                         self._occupants[to].sessions[from] = get_filtered_presence(stanza);
 450                                                 end
 451                                                 self._jid_nick[from] = to;
 452                                                 self:send_occupant_list(from);
 453                                                 pr.attr.from = to;
 454                                                 if not is_merge then
 455                                                         self:broadcast_presence(pr, from);
 456                                                 else
 457                                                         pr.attr.to = from;
 458                                                         self:_route_stanza(pr:tag("x", {xmlns='http://jabber.org/protocol/muc#user'})
 459                                                                 :tag("item", {affiliation=affiliation or "none", role=role or "none"}):up()
 460                                                                 :tag("status", {code='110'}));
 461                                                 end
 462                                                 self:send_history(from, stanza);
 463                                         elseif not affiliation then -- registration required for entering members-only room
 464                                                 local reply = st.error_reply(stanza, "auth", "registration-required"):up();
 465                                                 reply.tags[1].attr.code = "407";
 466                                                 origin.send(reply:tag("x", {xmlns = "http://jabber.org/protocol/muc"}));
 467                                         else -- banned
 468                                                 local reply = st.error_reply(stanza, "auth", "forbidden"):up();
 469                                                 reply.tags[1].attr.code = "403";
 470                                                 origin.send(reply:tag("x", {xmlns = "http://jabber.org/protocol/muc"}));
 471                                         end
 472                                 end
 473                         end
 474                 elseif type ~= 'result' then -- bad type
 475                         if type ~= 'visible' and type ~= 'invisible' then -- COMPAT ejabberd can broadcast or forward XEP-0018 presences
 476                                 origin.send(st.error_reply(stanza, "modify", "bad-request")); -- FIXME correct error?
 477                         end
 478                 end
 479         elseif not current_nick then -- not in room
 480                 if type == "error" or type == "result" then
 481                         local id = stanza.name == "iq" and stanza.attr.id and base64.decode(stanza.attr.id);
 482                         local _nick, _id, _hash = (id or ""):match("^(.+)%z(.*)%z(.+)$");
 483                         local occupant = self._occupants[stanza.attr.to];
 484                         if occupant and _nick and self._jid_nick[_nick] and _id and _hash then
 485                                 local id, _to = stanza.attr.id;
 486                                 for jid in pairs(occupant.sessions) do
 487                                         if md5(jid) == _hash then
 488                                                 _to = jid;
 489                                                 break;
 490                                         end
 491                                 end
 492                                 if _to then
 493                                         stanza.attr.to, stanza.attr.from, stanza.attr.id = _to, self._jid_nick[_nick], _id;
 494                                         self:_route_stanza(stanza);
 495                                         stanza.attr.to, stanza.attr.from, stanza.attr.id = to, from, id;
 496                                 end
 497                         end
 498                 else
 499                         origin.send(st.error_reply(stanza, "cancel", "not-acceptable"));
 500                 end
 501         elseif stanza.name == "message" and type == "groupchat" then -- groupchat messages not allowed in PM
 502                 origin.send(st.error_reply(stanza, "modify", "bad-request"));
 503         elseif current_nick and stanza.name == "message" and type == "error" and is_kickable_error(stanza) then
 504                 log("debug", "%s kicked from %s for sending an error message", current_nick, self.jid);
 505                 self:handle_to_occupant(origin, build_unavailable_presence_from_error(stanza)); -- send unavailable
 506         else -- private stanza
 507                 local o_data = self._occupants[to];
 508                 if o_data then
 509                         log("debug", "%s sent private stanza to %s (%s)", from, to, o_data.jid);
 510                         local jid = o_data.jid;
 511                         local bare = jid_bare(jid);
 512                         stanza.attr.to, stanza.attr.from = jid, current_nick;
 513                         local id = stanza.attr.id;
 514                         if stanza.name=='iq' and type=='get' and stanza.tags[1].attr.xmlns == 'vcard-temp' and bare ~= jid then
 515                                 stanza.attr.to = bare;
 516                                 stanza.attr.id = base64.encode(jid.."\0"..id.."\0"..md5(from));
 517                         end
 518                         self:_route_stanza(stanza);
 519                         stanza.attr.to, stanza.attr.from, stanza.attr.id = to, from, id;
 520                 elseif type ~= "error" and type ~= "result" then -- recipient not in room
 521                         origin.send(st.error_reply(stanza, "cancel", "item-not-found", "Recipient not in room"));
 522                 end
 523         end
 524 end
 525
 526 function room_mt:send_form(origin, stanza)
 527         local title = "Configuration for "..self.jid;
 528         origin.send(st.reply(stanza):query("http://jabber.org/protocol/muc#owner")
 529                 :tag("x", {xmlns='jabber:x:data', type='form'})
 530                         :tag("title"):text(title):up()
 531                         :tag("instructions"):text(title):up()
 532                         :tag("field", {type='hidden', var='FORM_TYPE'}):tag("value"):text("http://jabber.org/protocol/muc#roomconfig"):up():up()
 533                         :tag("field", {type='text-single', label='Name', var='muc#roomconfig_roomname'})
 534                                 :tag("value"):text(self:get_name() or ""):up()
 535                         :up()
 536                         :tag("field", {type='text-single', label='Description', var='muc#roomconfig_roomdesc'})
 537                                 :tag("value"):text(self:get_description() or ""):up()
 538                         :up()
 539                         :tag("field", {type='boolean', label='Make Room Persistent?', var='muc#roomconfig_persistentroom'})
 540                                 :tag("value"):text(self:is_persistent() and "1" or "0"):up()
 541                         :up()
 542                         :tag("field", {type='boolean', label='Make Room Publicly Searchable?', var='muc#roomconfig_publicroom'})
 543                                 :tag("value"):text(self:is_hidden() and "0" or "1"):up()
 544                         :up()
 545                         :tag("field", {type='list-single', label='Who May Discover Real JIDs?', var='muc#roomconfig_whois'})
 546                             :tag("value"):text(self._data.whois or 'moderators'):up()
 547                             :tag("option", {label = 'Moderators Only'})
 548                                 :tag("value"):text('moderators'):up()
 549                                 :up()
 550                             :tag("option", {label = 'Anyone'})
 551                                 :tag("value"):text('anyone'):up()
 552                                 :up()
 553                         :up()
 554                         :tag("field", {type='text-private', label='Password', var='muc#roomconfig_roomsecret'})
 555                                 :tag("value"):text(self:get_password() or ""):up()
 556                         :up()
 557                         :tag("field", {type='boolean', label='Make Room Moderated?', var='muc#roomconfig_moderatedroom'})
 558                                 :tag("value"):text(self:is_moderated() and "1" or "0"):up()
 559                         :up()
 560                         :tag("field", {type='boolean', label='Make Room Members-Only?', var='muc#roomconfig_membersonly'})
 561                                 :tag("value"):text(self:is_members_only() and "1" or "0"):up()
 562                         :up()
 563         );
 564 end
 565
 566 local valid_whois = {
 567     moderators = true,
 568     anyone = true,
 569 }
 570
 571 function room_mt:process_form(origin, stanza)
 572         local query = stanza.tags[1];
 573         local form;
 574         for _, tag in ipairs(query.tags) do if tag.name == "x" and tag.attr.xmlns == "jabber:x:data" then form = tag; break; end end
 575         if not form then origin.send(st.error_reply(stanza, "cancel", "service-unavailable")); return; end
 576         if form.attr.type == "cancel" then origin.send(st.reply(stanza)); return; end
 577         if form.attr.type ~= "submit" then origin.send(st.error_reply(stanza, "cancel", "bad-request")); return; end
 578         local fields = {};
 579         for _, field in pairs(form.tags) do
 580                 if field.name == "field" and field.attr.var and field.tags[1].name == "value" and #field.tags[1].tags == 0 then
 581                         fields[field.attr.var] = field.tags[1][1] or "";
 582                 end
 583         end
 584         if fields.FORM_TYPE ~= "http://jabber.org/protocol/muc#roomconfig" then origin.send(st.error_reply(stanza, "cancel", "bad-request")); return; end
 585
 586         local dirty = false
 587
 588         local name = fields['muc#roomconfig_roomname'];
 589         if name then
 590                 self:set_name(name);
 591         end
 592
 593         local description = fields['muc#roomconfig_roomdesc'];
 594         if description then
 595                 self:set_description(description);
 596         end
 597
 598         local persistent = fields['muc#roomconfig_persistentroom'];
 599         if persistent == "0" or persistent == "false" then persistent = nil; elseif persistent == "1" or persistent == "true" then persistent = true;
 600         else origin.send(st.error_reply(stanza, "cancel", "bad-request")); return; end
 601         dirty = dirty or (self:is_persistent() ~= persistent)
 602         module:log("debug", "persistent=%s", tostring(persistent));
 603
 604         local moderated = fields['muc#roomconfig_moderatedroom'];
 605         if moderated == "0" or moderated == "false" then moderated = nil; elseif moderated == "1" or moderated == "true" then moderated = true;
 606         else origin.send(st.error_reply(stanza, "cancel", "bad-request")); return; end
 607         dirty = dirty or (self:is_moderated() ~= moderated)
 608         module:log("debug", "moderated=%s", tostring(moderated));
 609
 610         local membersonly = fields['muc#roomconfig_membersonly'];
 611         if membersonly == "0" or membersonly == "false" then membersonly = nil; elseif membersonly == "1" or membersonly == "true" then membersonly = true;
 612         else origin.send(st.error_reply(stanza, "cancel", "bad-request")); return; end
 613         dirty = dirty or (self:is_members_only() ~= membersonly)
 614         module:log("debug", "membersonly=%s", tostring(membersonly));
 615
 616         local public = fields['muc#roomconfig_publicroom'];
 617         if public == "0" or public == "false" then public = nil; elseif public == "1" or public == "true" then public = true;
 618         else origin.send(st.error_reply(stanza, "cancel", "bad-request")); return; end
 619         dirty = dirty or (self:is_hidden() ~= (not public and true or nil))
 620
 621         local whois = fields['muc#roomconfig_whois'];
 622         if not valid_whois[whois] then
 623             origin.send(st.error_reply(stanza, 'cancel', 'bad-request'));
 624             return;
 625         end
 626         local whois_changed = self._data.whois ~= whois
 627         self._data.whois = whois
 628         module:log('debug', 'whois=%s', whois)
 629
 630         local password = fields['muc#roomconfig_roomsecret'];
 631         if password then
 632                 self:set_password(password);
 633         end
 634         self:set_moderated(moderated);
 635         self:set_members_only(membersonly);
 636         self:set_persistent(persistent);
 637         self:set_hidden(not public);
 638
 639         if self.save then self:save(true); end
 640         origin.send(st.reply(stanza));
 641
 642         if dirty or whois_changed then
 643             local msg = st.message({type='groupchat', from=self.jid})
 644                     :tag('x', {xmlns='http://jabber.org/protocol/muc#user'}):up()
 645
 646             if dirty then
 647                 msg.tags[1]:tag('status', {code = '104'})
 648             end
 649             if whois_changed then
 650                 local code = (whois == 'moderators') and 173 or 172
 651                 msg.tags[1]:tag('status', {code = code})
 652             end
 653
 654             self:broadcast_message(msg, false)
 655         end
 656 end
 657
 658 function room_mt:destroy(newjid, reason, password)
 659         local pr = st.presence({type = "unavailable"})
 660                 :tag("x", {xmlns = "http://jabber.org/protocol/muc#user"})
 661                         :tag("item", { affiliation='none', role='none' }):up()
 662                         :tag("destroy", {jid=newjid})
 663         if reason then pr:tag("reason"):text(reason):up(); end
 664         if password then pr:tag("password"):text(password):up(); end
 665         for nick, occupant in pairs(self._occupants) do
 666                 pr.attr.from = nick;
 667                 for jid in pairs(occupant.sessions) do
 668                         pr.attr.to = jid;
 669                         self:_route_stanza(pr);
 670                         self._jid_nick[jid] = nil;
 671                 end
 672                 self._occupants[nick] = nil;
 673         end
 674         self:set_persistent(false);
 675 end
 676
 677 function room_mt:handle_to_room(origin, stanza) -- presence changes and groupchat messages, along with disco/etc
 678         local type = stanza.attr.type;
 679         local xmlns = stanza.tags[1] and stanza.tags[1].attr.xmlns;
 680         if stanza.name == "iq" then
 681                 if xmlns == "http://jabber.org/protocol/disco#info" and type == "get" then
 682                         origin.send(self:get_disco_info(stanza));
 683                 elseif xmlns == "http://jabber.org/protocol/disco#items" and type == "get" then
 684                         origin.send(self:get_disco_items(stanza));
 685                 elseif xmlns == "http://jabber.org/protocol/muc#admin" then
 686                         local actor = stanza.attr.from;
 687                         local affiliation = self:get_affiliation(actor);
 688                         local current_nick = self._jid_nick[actor];
 689                         local role = current_nick and self._occupants[current_nick].role or self:get_default_role(affiliation);
 690                         local item = stanza.tags[1].tags[1];
 691                         if item and item.name == "item" then
 692                                 if type == "set" then
 693                                         local callback = function() origin.send(st.reply(stanza)); end
 694                                         if item.attr.jid then -- Validate provided JID
 695                                                 item.attr.jid = jid_prep(item.attr.jid);
 696                                                 if not item.attr.jid then
 697                                                         origin.send(st.error_reply(stanza, "modify", "jid-malformed"));
 698                                                         return;
 699                                                 end
 700                                         end
 701                                         if not item.attr.jid and item.attr.nick then -- COMPAT Workaround for Miranda sending 'nick' instead of 'jid' when changing affiliation
 702                                                 local occupant = self._occupants[self.jid.."/"..item.attr.nick];
 703                                                 if occupant then item.attr.jid = occupant.jid; end
 704                                         elseif not item.attr.nick and item.attr.jid then
 705                                                 local nick = self._jid_nick[item.attr.jid];
 706                                                 if nick then item.attr.nick = select(3, jid_split(nick)); end
 707                                         end
 708                                         local reason = item.tags[1] and item.tags[1].name == "reason" and #item.tags[1] == 1 and item.tags[1][1];
 709                                         if item.attr.affiliation and item.attr.jid and not item.attr.role then
 710                                                 local success, errtype, err = self:set_affiliation(actor, item.attr.jid, item.attr.affiliation, callback, reason);
 711                                                 if not success then origin.send(st.error_reply(stanza, errtype, err)); end
 712                                         elseif item.attr.role and item.attr.nick and not item.attr.affiliation then
 713                                                 local success, errtype, err = self:set_role(actor, self.jid.."/"..item.attr.nick, item.attr.role, callback, reason);
 714                                                 if not success then origin.send(st.error_reply(stanza, errtype, err)); end
 715                                         else
 716                                                 origin.send(st.error_reply(stanza, "cancel", "bad-request"));
 717                                         end
 718                                 elseif type == "get" then
 719                                         local _aff = item.attr.affiliation;
 720                                         local _rol = item.attr.role;
 721                                         if _aff and not _rol then
 722                                                 if affiliation == "owner" or (affiliation == "admin" and _aff ~= "owner" and _aff ~= "admin") then
 723                                                         local reply = st.reply(stanza):query("http://jabber.org/protocol/muc#admin");
 724                                                         for jid, affiliation in pairs(self._affiliations) do
 725                                                                 if affiliation == _aff then
 726                                                                         reply:tag("item", {affiliation = _aff, jid = jid}):up();
 727                                                                 end
 728                                                         end
 729                                                         origin.send(reply);
 730                                                 else
 731                                                         origin.send(st.error_reply(stanza, "auth", "forbidden"));
 732                                                 end
 733                                         elseif _rol and not _aff then
 734                                                 if role == "moderator" then
 735                                                         -- TODO allow admins and owners not in room? Provide read-only access to everyone who can see the participants anyway?
 736                                                         if _rol == "none" then _rol = nil; end
 737                                                         local reply = st.reply(stanza):query("http://jabber.org/protocol/muc#admin");
 738                                                         for occupant_jid, occupant in pairs(self._occupants) do
 739                                                                 if occupant.role == _rol then
 740                                                                         reply:tag("item", {
 741                                                                                 nick = select(3, jid_split(occupant_jid)),
 742                                                                                 role = _rol or "none",
 743                                                                                 affiliation = occupant.affiliation or "none",
 744                                                                                 jid = occupant.jid
 745                                                                                 }):up();
 746                                                                 end
 747                                                         end
 748                                                         origin.send(reply);
 749                                                 else
 750                                                         origin.send(st.error_reply(stanza, "auth", "forbidden"));
 751                                                 end
 752                                         else
 753                                                 origin.send(st.error_reply(stanza, "cancel", "bad-request"));
 754                                         end
 755                                 end
 756                         elseif type == "set" or type == "get" then
 757                                 origin.send(st.error_reply(stanza, "cancel", "bad-request"));
 758                         end
 759                 elseif xmlns == "http://jabber.org/protocol/muc#owner" and (type == "get" or type == "set") and stanza.tags[1].name == "query" then
 760                         if self:get_affiliation(stanza.attr.from) ~= "owner" then
 761                                 origin.send(st.error_reply(stanza, "auth", "forbidden"));
 762                         elseif stanza.attr.type == "get" then
 763                                 self:send_form(origin, stanza);
 764                         elseif stanza.attr.type == "set" then
 765                                 local child = stanza.tags[1].tags[1];
 766                                 if not child then
 767                                         origin.send(st.error_reply(stanza, "auth", "bad-request"));
 768                                 elseif child.name == "destroy" then
 769                                         local newjid = child.attr.jid;
 770                                         local reason, password;
 771                                         for _,tag in ipairs(child.tags) do
 772                                                 if tag.name == "reason" then
 773                                                         reason = #tag.tags == 0 and tag[1];
 774                                                 elseif tag.name == "password" then
 775                                                         password = #tag.tags == 0 and tag[1];
 776                                                 end
 777                                         end
 778                                         self:destroy(newjid, reason, password);
 779                                         origin.send(st.reply(stanza));
 780                                 else
 781                                         self:process_form(origin, stanza);
 782                                 end
 783                         end
 784                 elseif type == "set" or type == "get" then
 785                         origin.send(st.error_reply(stanza, "cancel", "service-unavailable"));
 786                 end
 787         elseif stanza.name == "message" and type == "groupchat" then
 788                 local from, to = stanza.attr.from, stanza.attr.to;
 789                 local room = jid_bare(to);
 790                 local current_nick = self._jid_nick[from];
 791                 local occupant = self._occupants[current_nick];
 792                 if not occupant then -- not in room
 793                         origin.send(st.error_reply(stanza, "cancel", "not-acceptable"));
 794                 elseif occupant.role == "visitor" then
 795                         origin.send(st.error_reply(stanza, "cancel", "forbidden"));
 796                 else
 797                         local from = stanza.attr.from;
 798                         stanza.attr.from = current_nick;
 799                         local subject = getText(stanza, {"subject"});
 800                         if subject then
 801                                 if occupant.role == "moderator" then
 802                                         self:set_subject(current_nick, subject); -- TODO use broadcast_message_stanza
 803                                 else
 804                                         stanza.attr.from = from;
 805                                         origin.send(st.error_reply(stanza, "cancel", "forbidden"));
 806                                 end
 807                         else
 808                                 self:broadcast_message(stanza, true);
 809                         end
 810                         stanza.attr.from = from;
 811                 end
 812         elseif stanza.name == "message" and type == "error" and is_kickable_error(stanza) then
 813                 local current_nick = self._jid_nick[stanza.attr.from];
 814                 log("debug", "%s kicked from %s for sending an error message", current_nick, self.jid);
 815                 self:handle_to_occupant(origin, build_unavailable_presence_from_error(stanza)); -- send unavailable
 816         elseif stanza.name == "presence" then -- hack - some buggy clients send presence updates to the room rather than their nick
 817                 local to = stanza.attr.to;
 818                 local current_nick = self._jid_nick[stanza.attr.from];
 819                 if current_nick then
 820                         stanza.attr.to = current_nick;
 821                         self:handle_to_occupant(origin, stanza);
 822                         stanza.attr.to = to;
 823                 elseif type ~= "error" and type ~= "result" then
 824                         origin.send(st.error_reply(stanza, "cancel", "service-unavailable"));
 825                 end
 826         elseif stanza.name == "message" and not stanza.attr.type and #stanza.tags == 1 and self._jid_nick[stanza.attr.from]
 827                 and stanza.tags[1].name == "x" and stanza.tags[1].attr.xmlns == "http://jabber.org/protocol/muc#user" then
 828                 local x = stanza.tags[1];
 829                 local payload = (#x.tags == 1 and x.tags[1]);
 830                 if payload and payload.name == "invite" and payload.attr.to then
 831                         local _from, _to = stanza.attr.from, stanza.attr.to;
 832                         local _invitee = jid_prep(payload.attr.to);
 833                         if _invitee then
 834                                 local _reason = payload.tags[1] and payload.tags[1].name == 'reason' and #payload.tags[1].tags == 0 and payload.tags[1][1];
 835                                 local invite = st.message({from = _to, to = _invitee, id = stanza.attr.id})
 836                                         :tag('x', {xmlns='http://jabber.org/protocol/muc#user'})
 837                                                 :tag('invite', {from=_from})
 838                                                         :tag('reason'):text(_reason or ""):up()
 839                                                 :up();
 840                                                 if self:get_password() then
 841                                                         invite:tag("password"):text(self:get_password()):up();
 842                                                 end
 843                                         invite:up()
 844                                         :tag('x', {xmlns="jabber:x:conference", jid=_to}) -- COMPAT: Some older clients expect this
 845                                                 :text(_reason or "")
 846                                         :up()
 847                                         :tag('body') -- Add a plain message for clients which don't support invites
 848                                                 :text(_from..' invited you to the room '.._to..(_reason and (' ('.._reason..')') or ""))
 849                                         :up();
 850                                 self:_route_stanza(invite);
 851                         else
 852                                 origin.send(st.error_reply(stanza, "cancel", "jid-malformed"));
 853                         end
 854                 else
 855                         origin.send(st.error_reply(stanza, "cancel", "bad-request"));
 856                 end
 857         else
 858                 if type == "error" or type == "result" then return; end
 859                 origin.send(st.error_reply(stanza, "cancel", "service-unavailable"));
 860         end
 861 end
 862
 863 function room_mt:handle_stanza(origin, stanza)
 864         local to_node, to_host, to_resource = jid_split(stanza.attr.to);
 865         if to_resource then
 866                 self:handle_to_occupant(origin, stanza);
 867         else
 868                 self:handle_to_room(origin, stanza);
 869         end
 870 end
 871
 872 function room_mt:route_stanza(stanza) end -- Replace with a routing function, e.g., function(room, stanza) core_route_stanza(origin, stanza); end
 873
 874 function room_mt:get_affiliation(jid)
 875         local node, host, resource = jid_split(jid);
 876         local bare = node and node.."@"..host or host;
 877         local result = self._affiliations[bare]; -- Affiliations are granted, revoked, and maintained based on the user's bare JID.
 878         if not result and self._affiliations[host] == "outcast" then result = "outcast"; end -- host banned
 879         return result;
 880 end
 881 function room_mt:set_affiliation(actor, jid, affiliation, callback, reason)
 882         jid = jid_bare(jid);
 883         if affiliation == "none" then affiliation = nil; end
 884         if affiliation and affiliation ~= "outcast" and affiliation ~= "owner" and affiliation ~= "admin" and affiliation ~= "member" then
 885                 return nil, "modify", "not-acceptable";
 886         end
 887         if self:get_affiliation(actor) ~= "owner" then return nil, "cancel", "not-allowed"; end
 888         if jid_bare(actor) == jid then return nil, "cancel", "not-allowed"; end
 889         self._affiliations[jid] = affiliation;
 890         local role = self:get_default_role(affiliation);
 891         local p = st.presence()
 892                 :tag("x", {xmlns = "http://jabber.org/protocol/muc#user"})
 893                         :tag("item", {affiliation=affiliation or "none", role=role or "none"})
 894                                 :tag("reason"):text(reason or ""):up()
 895                         :up();
 896         local x = p.tags[1];
 897         local item = x.tags[1];
 898         if not role then -- getting kicked
 899                 p.attr.type = "unavailable";
 900                 if affiliation == "outcast" then
 901                         x:tag("status", {code="301"}):up(); -- banned
 902                 else
 903                         x:tag("status", {code="321"}):up(); -- affiliation change
 904                 end
 905         end
 906         local modified_nicks = {};
 907         for nick, occupant in pairs(self._occupants) do
 908                 if jid_bare(occupant.jid) == jid then
 909                         t_insert(modified_nicks, nick);
 910                         if not role then -- getting kicked
 911                                 self._occupants[nick] = nil;
 912                         else
 913                                 occupant.affiliation, occupant.role = affiliation, role;
 914                         end
 915                         p.attr.from = nick;
 916                         for jid in pairs(occupant.sessions) do -- remove for all sessions of the nick
 917                                 if not role then self._jid_nick[jid] = nil; end
 918                                 p.attr.to = jid;
 919                                 self:_route_stanza(p);
 920                         end
 921                 end
 922         end
 923         if self.save then self:save(); end
 924         if callback then callback(); end
 925         for _, nick in ipairs(modified_nicks) do
 926                 p.attr.from = nick;
 927                 self:broadcast_except_nick(p, nick);
 928         end
 929         return true;
 930 end
 931
 932 function room_mt:get_role(nick)
 933         local session = self._occupants[nick];
 934         return session and session.role or nil;
 935 end
 936 function room_mt:can_set_role(actor_jid, occupant_jid, role)
 937         local actor = self._occupants[self._jid_nick[actor_jid]];
 938         local occupant = self._occupants[occupant_jid];
 939
 940         if not occupant or not actor then return nil, "modify", "not-acceptable"; end
 941
 942         if actor.role == "moderator" then
 943                 if occupant.affiliation ~= "owner" and occupant.affiliation ~= "admin" then
 944                         if actor.affiliation == "owner" or actor.affiliation == "admin" then
 945                                 return true;
 946                         elseif occupant.role ~= "moderator" and role ~= "moderator" then
 947                                 return true;
 948                         end
 949                 end
 950         end
 951         return nil, "cancel", "not-allowed";
 952 end
 953 function room_mt:set_role(actor, occupant_jid, role, callback, reason)
 954         if role == "none" then role = nil; end
 955         if role and role ~= "moderator" and role ~= "participant" and role ~= "visitor" then return nil, "modify", "not-acceptable"; end
 956         local allowed, err_type, err_condition = self:can_set_role(actor, occupant_jid, role);
 957         if not allowed then return allowed, err_type, err_condition; end
 958         local occupant = self._occupants[occupant_jid];
 959         local p = st.presence({from = occupant_jid})
 960                 :tag("x", {xmlns = "http://jabber.org/protocol/muc#user"})
 961                         :tag("item", {affiliation=occupant.affiliation or "none", nick=select(3, jid_split(occupant_jid)), role=role or "none"})
 962                                 :tag("reason"):text(reason or ""):up()
 963                         :up();
 964         if not role then -- kick
 965                 p.attr.type = "unavailable";
 966                 self._occupants[occupant_jid] = nil;
 967                 for jid in pairs(occupant.sessions) do -- remove for all sessions of the nick
 968                         self._jid_nick[jid] = nil;
 969                 end
 970                 p:tag("status", {code = "307"}):up();
 971         else
 972                 occupant.role = role;
 973         end
 974         for jid in pairs(occupant.sessions) do -- send to all sessions of the nick
 975                 p.attr.to = jid;
 976                 self:_route_stanza(p);
 977         end
 978         if callback then callback(); end
 979         self:broadcast_except_nick(p, occupant_jid);
 980         return true;
 981 end
 982
 983 function room_mt:_route_stanza(stanza)
 984         local muc_child;
 985         local to_occupant = self._occupants[self._jid_nick[stanza.attr.to]];
 986         local from_occupant = self._occupants[stanza.attr.from];
 987         if stanza.name == "presence" then
 988                 if to_occupant and from_occupant then
 989                         if self._data.whois == 'anyone' then
 990                             muc_child = stanza:get_child("x", "http://jabber.org/protocol/muc#user");
 991                         else
 992                                 if to_occupant.role == "moderator" or jid_bare(to_occupant.jid) == jid_bare(from_occupant.jid) then
 993                                         muc_child = stanza:get_child("x", "http://jabber.org/protocol/muc#user");
 994                                 end
 995                         end
 996                 end
 997         end
 998         if muc_child then
 999                 for _, item in pairs(muc_child.tags) do
1000                         if item.name == "item" then
1001                                 if from_occupant == to_occupant then
1002                                         item.attr.jid = stanza.attr.to;
1003                                 else
1004                                         item.attr.jid = from_occupant.jid;
1005                                 end
1006                         end
1007                 end
1008                 if self._data.whois == 'anyone' then
1009                     muc_child:tag('status', { code = '100' });
1010                 end
1011         end
1012         self:route_stanza(stanza);
1013         if muc_child then
1014                 for _, item in pairs(muc_child.tags) do
1015                         if item.name == "item" then
1016                                 item.attr.jid = nil;
1017                         end
1018                 end
1019         end
1020 end
1021
1022 local _M = {}; -- module "muc"
1023
1024 function _M.new_room(jid, config)
1025         return setmetatable({
1026                 jid = jid;
1027                 _jid_nick = {};
1028                 _occupants = {};
1029                 _data = {
1030                     whois = 'moderators';
1031                     history_length = (config and config.history_length);
1032                 };
1033                 _affiliations = {};
1034         }, room_mt);
1035 end
1036
1037 return _M;