util/stanza.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
  10 local error         =         error;
  11 local t_insert      =  table.insert;
  12 local t_remove      =  table.remove;
  13 local t_concat      =  table.concat;
  14 local s_format      = string.format;
  15 local s_match       =  string.match;
  16 local tostring      =      tostring;
  17 local setmetatable  =  setmetatable;
  18 local getmetatable  =  getmetatable;
  19 local pairs         =         pairs;
  20 local ipairs        =        ipairs;
  21 local type          =          type;
  22 local s_gsub        =   string.gsub;
  23 local s_sub         =    string.sub;
  24 local s_find        =   string.find;
  25 local os            =            os;
  26
  27 local valid_utf8 = require "util.encodings".utf8.valid;
  28
  29 local do_pretty_printing = not os.getenv("WINDIR");
  30 local getstyle, getstring;
  31 if do_pretty_printing then
  32         local ok, termcolours = pcall(require, "util.termcolours");
  33         if ok then
  34                 getstyle, getstring = termcolours.getstyle, termcolours.getstring;
  35         else
  36                 do_pretty_printing = nil;
  37         end
  38 end
  39
  40 local xmlns_stanzas = "urn:ietf:params:xml:ns:xmpp-stanzas";
  41
  42 local _ENV = nil;
  43 -- luacheck: std none
  44
  45 local stanza_mt = { __name = "stanza" };
  46 stanza_mt.__index = stanza_mt;
  47
  48 local function check_name(name, name_type)
  49         if type(name) ~= "string" then
  50                 error("invalid "..name_type.." name: expected string, got "..type(name));
  51         elseif #name == 0 then
  52                 error("invalid "..name_type.." name: empty string");
  53         elseif s_find(name, "[<>& '\"]") then
  54                 error("invalid "..name_type.." name: contains invalid characters");
  55         elseif not valid_utf8(name) then
  56                 error("invalid "..name_type.." name: contains invalid utf8");
  57         end
  58 end
  59
  60 local function check_text(text, text_type)
  61         if type(text) ~= "string" then
  62                 error("invalid "..text_type.." value: expected string, got "..type(text));
  63         elseif not valid_utf8(text) then
  64                 error("invalid "..text_type.." value: contains invalid utf8");
  65         end
  66 end
  67
  68 local function check_attr(attr)
  69         if attr ~= nil then
  70                 if type(attr) ~= "table" then
  71                         error("invalid attributes, expected table got "..type(attr));
  72                 end
  73                 for k, v in pairs(attr) do
  74                         check_name(k, "attribute");
  75                         check_text(v, "attribute");
  76                         if type(v) ~= "string" then
  77                                 error("invalid attribute value for '"..k.."': expected string, got "..type(v));
  78                         elseif not valid_utf8(v) then
  79                                 error("invalid attribute value for '"..k.."': contains invalid utf8");
  80                         end
  81                 end
  82         end
  83 end
  84
  85 local function new_stanza(name, attr, namespaces)
  86         check_name(name, "tag");
  87         check_attr(attr);
  88         local stanza = { name = name, attr = attr or {}, namespaces = namespaces, tags = {} };
  89         return setmetatable(stanza, stanza_mt);
  90 end
  91
  92 local function is_stanza(s)
  93         return getmetatable(s) == stanza_mt;
  94 end
  95
  96 function stanza_mt:query(xmlns)
  97         return self:tag("query", { xmlns = xmlns });
  98 end
  99
 100 function stanza_mt:body(text, attr)
 101         return self:text_tag("body", text, attr);
 102 end
 103
 104 function stanza_mt:text_tag(name, text, attr, namespaces)
 105         return self:tag(name, attr, namespaces):text(text):up();
 106 end
 107
 108 function stanza_mt:tag(name, attr, namespaces)
 109         local s = new_stanza(name, attr, namespaces);
 110         local last_add = self.last_add;
 111         if not last_add then last_add = {}; self.last_add = last_add; end
 112         (last_add[#last_add] or self):add_direct_child(s);
 113         t_insert(last_add, s);
 114         return self;
 115 end
 116
 117 function stanza_mt:text(text)
 118         if text ~= nil and text ~= "" then
 119                 local last_add = self.last_add;
 120                 (last_add and last_add[#last_add] or self):add_direct_child(text);
 121         end
 122         return self;
 123 end
 124
 125 function stanza_mt:up()
 126         local last_add = self.last_add;
 127         if last_add then t_remove(last_add); end
 128         return self;
 129 end
 130
 131 function stanza_mt:reset()
 132         self.last_add = nil;
 133         return self;
 134 end
 135
 136 function stanza_mt:add_direct_child(child)
 137         if is_stanza(child) then
 138                 t_insert(self.tags, child);
 139                 t_insert(self, child);
 140         else
 141                 check_text(child, "text");
 142                 t_insert(self, child);
 143         end
 144 end
 145
 146 function stanza_mt:add_child(child)
 147         local last_add = self.last_add;
 148         (last_add and last_add[#last_add] or self):add_direct_child(child);
 149         return self;
 150 end
 151
 152 function stanza_mt:remove_children(name, xmlns)
 153         xmlns = xmlns or self.attr.xmlns;
 154         return self:maptags(function (tag)
 155                 if (not name or tag.name == name) and tag.attr.xmlns == xmlns then
 156                         return nil;
 157                 end
 158                 return tag;
 159         end);
 160 end
 161
 162 function stanza_mt:get_child(name, xmlns)
 163         for _, child in ipairs(self.tags) do
 164                 if (not name or child.name == name)
 165                         and ((not xmlns and self.attr.xmlns == child.attr.xmlns)
 166                                 or child.attr.xmlns == xmlns) then
 167
 168                         return child;
 169                 end
 170         end
 171 end
 172
 173 function stanza_mt:get_child_text(name, xmlns)
 174         local tag = self:get_child(name, xmlns);
 175         if tag then
 176                 return tag:get_text();
 177         end
 178         return nil;
 179 end
 180
 181 function stanza_mt:child_with_name(name)
 182         for _, child in ipairs(self.tags) do
 183                 if child.name == name then return child; end
 184         end
 185 end
 186
 187 function stanza_mt:child_with_ns(ns)
 188         for _, child in ipairs(self.tags) do
 189                 if child.attr.xmlns == ns then return child; end
 190         end
 191 end
 192
 193 function stanza_mt:children()
 194         local i = 0;
 195         return function (a)
 196                         i = i + 1
 197                         return a[i];
 198                 end, self, i;
 199 end
 200
 201 function stanza_mt:childtags(name, xmlns)
 202         local tags = self.tags;
 203         local start_i, max_i = 1, #tags;
 204         return function ()
 205                 for i = start_i, max_i do
 206                         local v = tags[i];
 207                         if (not name or v.name == name)
 208                         and ((not xmlns and self.attr.xmlns == v.attr.xmlns)
 209                                 or v.attr.xmlns == xmlns) then
 210                                 start_i = i+1;
 211                                 return v;
 212                         end
 213                 end
 214         end;
 215 end
 216
 217 function stanza_mt:maptags(callback)
 218         local tags, curr_tag = self.tags, 1;
 219         local n_children, n_tags = #self, #tags;
 220         local max_iterations = n_children + 1;
 221
 222         local i = 1;
 223         while curr_tag <= n_tags and n_tags > 0 do
 224                 if self[i] == tags[curr_tag] then
 225                         local ret = callback(self[i]);
 226                         if ret == nil then
 227                                 t_remove(self, i);
 228                                 t_remove(tags, curr_tag);
 229                                 n_children = n_children - 1;
 230                                 n_tags = n_tags - 1;
 231                                 i = i - 1;
 232                                 curr_tag = curr_tag - 1;
 233                         else
 234                                 self[i] = ret;
 235                                 tags[curr_tag] = ret;
 236                         end
 237                         curr_tag = curr_tag + 1;
 238                 end
 239                 i = i + 1;
 240                 if i > max_iterations then
 241                         -- COMPAT: Hopefully temporary guard against #981 while we
 242                         -- figure out the root cause
 243                         error("Invalid stanza state! Please report this error.");
 244                 end
 245         end
 246         return self;
 247 end
 248
 249 function stanza_mt:find(path)
 250         local pos = 1;
 251         local len = #path + 1;
 252
 253         repeat
 254                 local xmlns, name, text;
 255                 local char = s_sub(path, pos, pos);
 256                 if char == "@" then
 257                         return self.attr[s_sub(path, pos + 1)];
 258                 elseif char == "{" then
 259                         xmlns, pos = s_match(path, "^([^}]+)}()", pos + 1);
 260                 end
 261                 name, text, pos = s_match(path, "^([^@/#]*)([/#]?)()", pos);
 262                 name = name ~= "" and name or nil;
 263                 if pos == len then
 264                         if text == "#" then
 265                                 return self:get_child_text(name, xmlns);
 266                         end
 267                         return self:get_child(name, xmlns);
 268                 end
 269                 self = self:get_child(name, xmlns);
 270         until not self
 271 end
 272
 273 local function _clone(stanza, only_top)
 274         local attr, tags = {}, {};
 275         for k,v in pairs(stanza.attr) do attr[k] = v; end
 276         local old_namespaces, namespaces = stanza.namespaces;
 277         if old_namespaces then
 278                 namespaces = {};
 279                 for k,v in pairs(old_namespaces) do namespaces[k] = v; end
 280         end
 281         local new = { name = stanza.name, attr = attr, namespaces = namespaces, tags = tags };
 282         if not only_top then
 283                 for i=1,#stanza do
 284                         local child = stanza[i];
 285                         if child.name then
 286                                 child = _clone(child);
 287                                 t_insert(tags, child);
 288                         end
 289                         t_insert(new, child);
 290                 end
 291         end
 292         return setmetatable(new, stanza_mt);
 293 end
 294
 295 local function clone(stanza, only_top)
 296         if not is_stanza(stanza) then
 297                 error("bad argument to clone: expected stanza, got "..type(stanza));
 298         end
 299         return _clone(stanza, only_top);
 300 end
 301
 302 local escape_table = { ["'"] = "&apos;", ["\""] = "&quot;", ["<"] = "&lt;", [">"] = "&gt;", ["&"] = "&amp;" };
 303 local function xml_escape(str) return (s_gsub(str, "['&<>\"]", escape_table)); end
 304
 305 local function _dostring(t, buf, self, _xml_escape, parentns)
 306         local nsid = 0;
 307         local name = t.name
 308         t_insert(buf, "<"..name);
 309         for k, v in pairs(t.attr) do
 310                 if s_find(k, "\1", 1, true) then
 311                         local ns, attrk = s_match(k, "^([^\1]*)\1?(.*)$");
 312                         nsid = nsid + 1;
 313                         t_insert(buf, " xmlns:ns"..nsid.."='".._xml_escape(ns).."' ".."ns"..nsid..":"..attrk.."='".._xml_escape(v).."'");
 314                 elseif not(k == "xmlns" and v == parentns) then
 315                         t_insert(buf, " "..k.."='".._xml_escape(v).."'");
 316                 end
 317         end
 318         local len = #t;
 319         if len == 0 then
 320                 t_insert(buf, "/>");
 321         else
 322                 t_insert(buf, ">");
 323                 for n=1,len do
 324                         local child = t[n];
 325                         if child.name then
 326                                 self(child, buf, self, _xml_escape, t.attr.xmlns);
 327                         else
 328                                 t_insert(buf, _xml_escape(child));
 329                         end
 330                 end
 331                 t_insert(buf, "</"..name..">");
 332         end
 333 end
 334 function stanza_mt.__tostring(t)
 335         local buf = {};
 336         _dostring(t, buf, _dostring, xml_escape, nil);
 337         return t_concat(buf);
 338 end
 339
 340 function stanza_mt.top_tag(t)
 341         local top_tag_clone = clone(t, true);
 342         return tostring(top_tag_clone):sub(1,-3)..">";
 343 end
 344
 345 function stanza_mt.get_text(t)
 346         if #t.tags == 0 then
 347                 return t_concat(t);
 348         end
 349 end
 350
 351 function stanza_mt.get_error(stanza)
 352         local error_type, condition, text;
 353
 354         local error_tag = stanza:get_child("error");
 355         if not error_tag then
 356                 return nil, nil, nil;
 357         end
 358         error_type = error_tag.attr.type;
 359
 360         for _, child in ipairs(error_tag.tags) do
 361                 if child.attr.xmlns == xmlns_stanzas then
 362                         if not text and child.name == "text" then
 363                                 text = child:get_text();
 364                         elseif not condition then
 365                                 condition = child.name;
 366                         end
 367                         if condition and text then
 368                                 break;
 369                         end
 370                 end
 371         end
 372         return error_type, condition or "undefined-condition", text;
 373 end
 374
 375 local function preserialize(stanza)
 376         local s = { name = stanza.name, attr = stanza.attr };
 377         for _, child in ipairs(stanza) do
 378                 if type(child) == "table" then
 379                         t_insert(s, preserialize(child));
 380                 else
 381                         t_insert(s, child);
 382                 end
 383         end
 384         return s;
 385 end
 386
 387 stanza_mt.__freeze = preserialize;
 388
 389 local function deserialize(serialized)
 390         -- Set metatable
 391         if serialized then
 392                 local attr = serialized.attr;
 393                 local attrx = {};
 394                 for att, val in pairs(attr) do
 395                         if type(att) == "string" then
 396                                 if s_find(att, "|", 1, true) and not s_find(att, "\1", 1, true) then
 397                                         local ns,na = s_match(att, "^([^|]+)|(.+)$");
 398                                         attrx[ns.."\1"..na] = val;
 399                                 else
 400                                         attrx[att] = val;
 401                                 end
 402                         end
 403                 end
 404                 local stanza = new_stanza(serialized.name, attrx);
 405                 for _, child in ipairs(serialized) do
 406                         if type(child) == "table" then
 407                                 stanza:add_direct_child(deserialize(child));
 408                         elseif type(child) == "string" then
 409                                 stanza:add_direct_child(child);
 410                         end
 411                 end
 412                 return stanza;
 413         end
 414 end
 415
 416 local function message(attr, body)
 417         if not body then
 418                 return new_stanza("message", attr);
 419         else
 420                 return new_stanza("message", attr):text_tag("body", body);
 421         end
 422 end
 423 local function iq(attr)
 424         if not attr then
 425                 error("iq stanzas require id and type attributes");
 426         end
 427         if not attr.id then
 428                 error("iq stanzas require an id attribute");
 429         end
 430         if not attr.type then
 431                 error("iq stanzas require a type attribute");
 432         end
 433         return new_stanza("iq", attr);
 434 end
 435
 436 local function reply(orig)
 437         return new_stanza(orig.name,
 438                 orig.attr and {
 439                         to = orig.attr.from,
 440                         from = orig.attr.to,
 441                         id = orig.attr.id,
 442                         type = ((orig.name == "iq" and "result") or orig.attr.type)
 443                 });
 444 end
 445
 446 local xmpp_stanzas_attr = { xmlns = xmlns_stanzas };
 447 local function error_reply(orig, error_type, condition, error_message)
 448         local t = reply(orig);
 449         t.attr.type = "error";
 450         t:tag("error", {type = error_type}) --COMPAT: Some day xmlns:stanzas goes here
 451         :tag(condition, xmpp_stanzas_attr):up();
 452         if error_message then t:text_tag("text", error_message, xmpp_stanzas_attr); end
 453         return t; -- stanza ready for adding app-specific errors
 454 end
 455
 456 local function presence(attr)
 457         return new_stanza("presence", attr);
 458 end
 459
 460 if do_pretty_printing then
 461         local style_attrk = getstyle("yellow");
 462         local style_attrv = getstyle("red");
 463         local style_tagname = getstyle("red");
 464         local style_punc = getstyle("magenta");
 465
 466         local attr_format = " "..getstring(style_attrk, "%s")..getstring(style_punc, "=")..getstring(style_attrv, "'%s'");
 467         local top_tag_format = getstring(style_punc, "<")..getstring(style_tagname, "%s").."%s"..getstring(style_punc, ">");
 468         --local tag_format = getstring(style_punc, "<")..getstring(style_tagname, "%s").."%s"..getstring(style_punc, ">").."%s"..getstring(style_punc, "</")..getstring(style_tagname, "%s")..getstring(style_punc, ">");
 469         local tag_format = top_tag_format.."%s"..getstring(style_punc, "</")..getstring(style_tagname, "%s")..getstring(style_punc, ">");
 470         function stanza_mt.pretty_print(t)
 471                 local children_text = "";
 472                 for _, child in ipairs(t) do
 473                         if type(child) == "string" then
 474                                 children_text = children_text .. xml_escape(child);
 475                         else
 476                                 children_text = children_text .. child:pretty_print();
 477                         end
 478                 end
 479
 480                 local attr_string = "";
 481                 if t.attr then
 482                         for k, v in pairs(t.attr) do if type(k) == "string" then attr_string = attr_string .. s_format(attr_format, k, tostring(v)); end end
 483                 end
 484                 return s_format(tag_format, t.name, attr_string, children_text, t.name);
 485         end
 486
 487         function stanza_mt.pretty_top_tag(t)
 488                 local attr_string = "";
 489                 if t.attr then
 490                         for k, v in pairs(t.attr) do if type(k) == "string" then attr_string = attr_string .. s_format(attr_format, k, tostring(v)); end end
 491                 end
 492                 return s_format(top_tag_format, t.name, attr_string);
 493         end
 494 else
 495         -- Sorry, fresh out of colours for you guys ;)
 496         stanza_mt.pretty_print = stanza_mt.__tostring;
 497         stanza_mt.pretty_top_tag = stanza_mt.top_tag;
 498 end
 499
 500 return {
 501         stanza_mt = stanza_mt;
 502         stanza = new_stanza;
 503         is_stanza = is_stanza;
 504         preserialize = preserialize;
 505         deserialize = deserialize;
 506         clone = clone;
 507         message = message;
 508         iq = iq;
 509         reply = reply;
 510         error_reply = error_reply;
 511         presence = presence;
 512         xml_escape = xml_escape;
 513 };