libs/uvl/luasrc/uvl.lua

   1 --[[
   2
   3 UCI Validation Layer - Main Library
   4 (c) 2008 Jo-Philipp Wich <xm@leipzig.freifunk.net>
   5 (c) 2008 Steven Barth <steven@midlink.org>
   6
   7 Licensed under the Apache License, Version 2.0 (the "License");
   8 you may not use this file except in compliance with the License.
   9 You may obtain a copy of the License at
  10
  11         http://www.apache.org/licenses/LICENSE-2.0
  12
  13 $Id$
  14
  15 ]]--
  16
  17
  18 --- UVL - UCI Validation Layer
  19 -- @class       module
  20 -- @cstyle      instance
  21
  22 module( "luci.uvl", package.seeall )
  23
  24 require("luci.fs")
  25 require("luci.util")
  26 require("luci.model.uci")
  27 require("luci.uvl.errors")
  28 require("luci.uvl.datatypes")
  29 require("luci.uvl.validation")
  30 require("luci.uvl.dependencies")
  31
  32
  33 TYPE_SCHEME   = 0x00
  34 TYPE_CONFIG   = 0x01
  35 TYPE_SECTION  = 0x02
  36 TYPE_OPTION   = 0x03
  37 TYPE_ENUM     = 0x04
  38
  39 --- Boolean; default true;
  40 -- treat sections found in config but not in scheme as error
  41 STRICT_UNKNOWN_SECTIONS    = true
  42
  43 --- Boolean; default true;
  44 -- treat options found in config but not in scheme as error
  45 STRICT_UNKNOWN_OPTIONS     = true
  46
  47 --- Boolean; default true;
  48 -- treat failed external validators as error
  49 STRICT_EXTERNAL_VALIDATORS = true
  50
  51 --- Boolean; default true;
  52 -- treat list values stored as options like errors
  53 STRICT_LIST_TYPE           = true
  54
  55
  56 local default_schemedir = "/lib/uci/schema"
  57 local default_savedir = "/tmp/.uvl"
  58 local ERR = luci.uvl.errors
  59
  60
  61 --- Object constructor
  62 -- @class                       function
  63 -- @name                        UVL
  64 -- @param schemedir     Path to the scheme directory (optional)
  65 -- @return                      Instance object
  66 UVL = luci.util.class()
  67
  68 function UVL.__init__( self, schemedir )
  69         self.schemedir  = schemedir or default_schemedir
  70         self.packages   = { }
  71         self.beenthere  = { }
  72         self.depseen    = { }
  73         self.uci                = luci.model.uci
  74         self.err                = luci.uvl.errors
  75         self.dep                = luci.uvl.dependencies
  76         self.datatypes  = luci.uvl.datatypes
  77 end
  78
  79
  80 --- Parse given scheme and return the scheme tree.
  81 -- @param scheme        Name of the scheme to parse
  82 -- @return                      Table containing the parsed scheme or nil on error
  83 -- @return                      String containing the reason for errors (if any)
  84 function UVL.get_scheme( self, scheme )
  85         if not self.packages[scheme] then
  86                 local ok, err = self:read_scheme( scheme )
  87                 if not ok then
  88                         return nil, err
  89                 end
  90         end
  91         return self.packages[scheme], nil
  92 end
  93
  94 --- Validate given configuration, section or option.
  95 -- @param config        Name of the configuration to validate
  96 -- @param section       Name of the section to validate (optional)
  97 -- @param option        Name of the option to validate (optional)
  98 -- @return                      Boolean indicating whether the given config validates
  99 -- @return                      String containing the reason for errors (if any)
 100 function UVL.validate( self, config, section, option )
 101         if config and section and option then
 102                 return self:validate_option( config, section, option )
 103         elseif config and section then
 104                 return self:validate_section( config, section )
 105         elseif config then
 106                 return self:validate_config( config )
 107         end
 108 end
 109
 110 --- Validate given configuration.
 111 -- @param config        Name of the configuration to validate
 112 -- @return                      Boolean indicating whether the given config validates
 113 -- @return                      String containing the reason for errors (if any)
 114 function UVL.validate_config( self, config, uci )
 115
 116         if not self.packages[config] then
 117                 local ok, err = self:read_scheme(config)
 118                 if not ok then
 119                         return false, err
 120                 end
 121         end
 122
 123         local co = luci.uvl.config( self, uci or config, uci and config )
 124         local sc = { }
 125
 126         self.beenthere = { }
 127         self.depseen   = { }
 128
 129         if not co:config() then
 130                 return false, co:errors()
 131         end
 132
 133         local function _uci_foreach( type, func )
 134                 for k, v in pairs(co:config()) do
 135                         if v['.type'] == type then
 136                                 sc[type] = sc[type] + 1
 137                                 local ok, err = func( k, v )
 138                                 if not ok then co:error(err) end
 139                         end
 140                 end
 141         end
 142
 143         for k, v in pairs( self.packages[config].sections ) do
 144                 sc[k] = 0
 145                 _uci_foreach( k,
 146                         function(s)
 147                                 return self:_validate_section( co:section(s) )
 148                         end
 149                 )
 150         end
 151
 152         if STRICT_UNKNOWN_SECTIONS then
 153                 for k, v in pairs(co:config()) do
 154                         local so = co:section(k)
 155                         if not self.beenthere[so:cid()] then
 156                                 co:error(ERR.SECT_UNKNOWN(so))
 157                         end
 158                 end
 159         end
 160
 161         for _, k in ipairs(luci.util.keys(sc)) do
 162                 local so = co:section(k)
 163                 if so:scheme('required') and sc[k] == 0 then
 164                         co:error(ERR.SECT_REQUIRED(so))
 165                 elseif so:scheme('unique') and sc[k] > 1 then
 166                         co:error(ERR.SECT_UNIQUE(so))
 167                 end
 168         end
 169
 170         return co:ok(), co:errors()
 171 end
 172
 173 --- Validate given config section.
 174 -- @param config        Name of the configuration to validate
 175 -- @param section       Name of the section to validate
 176 -- @return                      Boolean indicating whether the given config validates
 177 -- @return                      String containing the reason for errors (if any)
 178 function UVL.validate_section( self, config, section, uci )
 179
 180         if not self.packages[config] then
 181                 local ok, err = self:read_scheme( config )
 182                 if not ok then
 183                         return false, err
 184                 end
 185         end
 186
 187         local co = luci.uvl.config( self, uci or config, uci and config )
 188         local so = co:section( section )
 189
 190         self.beenthere = { }
 191         self.depseen   = { }
 192
 193         if not co:config() then
 194                 return false, co:errors()
 195         end
 196
 197         if so:config() then
 198                 return self:_validate_section( so )
 199         else
 200                 return false, ERR.SECT_NOTFOUND(so)
 201         end
 202 end
 203
 204 --- Validate given config option.
 205 -- @param config        Name of the configuration to validate
 206 -- @param section       Name of the section to validate
 207 -- @param option        Name of the option to validate
 208 -- @return                      Boolean indicating whether the given config validates
 209 -- @return                      String containing the reason for errors (if any)
 210 function UVL.validate_option( self, config, section, option, uci )
 211
 212         if not self.packages[config] then
 213                 local ok, err = self:read_scheme( config )
 214                 if not ok then
 215                         return false, err
 216                 end
 217         end
 218
 219         local co = luci.uvl.config( self, uci or config, uci and config )
 220         local so = co:section( section )
 221         local oo = so:option( option )
 222
 223         if not co:config() then
 224                 return false, co:errors()
 225         end
 226
 227         if so:config() and oo:config() then
 228                 return self:_validate_option( oo )
 229         else
 230                 return false, ERR.OPT_NOTFOUND(oo)
 231         end
 232 end
 233
 234
 235 function UVL._validate_section( self, section )
 236
 237         self.beenthere[section:cid()] = true
 238
 239         if section:config() then
 240                 if section:scheme('named') == true and
 241                    section:config('.anonymous') == true
 242                 then
 243                         return false, ERR.SECT_NAMED(section)
 244                 end
 245
 246                 for _, v in ipairs(section:variables()) do
 247                         local ok, err = self:_validate_option( v )
 248                         if not ok and (
 249                                 v:scheme('required') or v:scheme('type') == "enum" or (
 250                                         not err:is(ERR.ERR_DEP_NOTEQUAL) and
 251                                         not err:is(ERR.ERR_DEP_NOVALUE)
 252                                 )
 253                         ) then
 254                                 section:error(err)
 255                         end
 256                 end
 257
 258                 local ok, err = luci.uvl.dependencies.check( self, section )
 259                 if not ok then
 260                         section:error(err)
 261                 end
 262         else
 263                 return false, ERR.SECT_NOTFOUND(section)
 264         end
 265
 266         if STRICT_UNKNOWN_OPTIONS and not section:scheme('dynamic') then
 267                 for k, v in pairs(section:config()) do
 268                         local oo = section:option(k)
 269                         if k:sub(1,1) ~= "." and not self.beenthere[oo:cid()] then
 270                                 section:error(ERR.OPT_UNKNOWN(oo))
 271                         end
 272                 end
 273         end
 274
 275         return section:ok(), section:errors()
 276 end
 277
 278 function UVL._validate_option( self, option, nodeps )
 279
 280         self.beenthere[option:cid()] = true
 281
 282         if not option:scheme() and not option:parent():scheme('dynamic') then
 283                 return false, option:error(ERR.OPT_UNKNOWN(option))
 284
 285         elseif option:scheme() then
 286                 if option:scheme('required') and not option:value() then
 287                         return false, option:error(ERR.OPT_REQUIRED(option))
 288
 289                 elseif option:value() then
 290                         local val = option:value()
 291
 292                         if option:scheme('type') == "reference" or
 293                            option:scheme('type') == "enum"
 294                         then
 295                                 if not option:scheme('values') or
 296                                    not option:scheme('values')[val]
 297                                 then
 298                                         return false, option:error( ERR.OPT_BADVALUE(
 299                                                 option, luci.util.serialize_data(
 300                                                         luci.util.keys(option:scheme('values') or {})
 301                                                 )
 302                                         ) )
 303                                 end
 304                         elseif option:scheme('type') == "list" then
 305                                 if type(val) ~= "table" and STRICT_LIST_TYPE then
 306                                         return false, option:error(ERR.OPT_NOTLIST(option))
 307                                 end
 308                         end
 309
 310                         if option:scheme('datatype') then
 311                                 local dt = option:scheme('datatype')
 312
 313                                 if self.datatypes[dt] then
 314                                         val = ( type(val) == "table" and val or { val } )
 315                                         for i, v in ipairs(val) do
 316                                                 if not self.datatypes[dt]( v ) then
 317                                                         return false, option:error(
 318                                                                 ERR.OPT_INVVALUE(option, dt)
 319                                                         )
 320                                                 end
 321                                         end
 322                                 else
 323                                         return false, option:error(ERR.OPT_DATATYPE(option, dt))
 324                                 end
 325                         end
 326                 end
 327
 328                 if not nodeps then
 329                         local ok, err = luci.uvl.dependencies.check( self, option )
 330                         if not ok then
 331                                 option:error(err)
 332                         end
 333                 end
 334
 335                 local ok, err = luci.uvl.validation.check( self, option )
 336                 if not ok and STRICT_EXTERNAL_VALIDATORS then
 337                         return false, option:error(err)
 338                 end
 339         end
 340
 341         return option:ok(), option:errors()
 342 end
 343
 344 --- Find all parts of given scheme and construct validation tree.
 345 -- This is normally done on demand, so you don't have to call this function
 346 -- by yourself.
 347 -- @param scheme        Name of the scheme to parse
 348 function UVL.read_scheme( self, scheme )
 349
 350         local so = luci.uvl.scheme( self, scheme )
 351
 352         local schemes = { }
 353         local files = luci.fs.glob(self.schemedir .. '/*/' .. scheme)
 354
 355         if files then
 356                 for i, file in ipairs( files ) do
 357                         if not luci.fs.access(file) then
 358                                 return so:error(ERR.SME_READ(so,file))
 359                         end
 360
 361                         local uci = luci.model.uci.cursor( luci.fs.dirname(file), default_savedir )
 362
 363                         local sd, err = uci:get_all( luci.fs.basename(file) )
 364
 365                         if not sd then
 366                                 return false, ERR.UCILOAD(so, err)
 367                         end
 368
 369                         table.insert( schemes, sd )
 370                 end
 371
 372                 return self:_read_scheme_parts( so, schemes )
 373         else
 374                 return false, so:error(ERR.SME_FIND(so, self.schemedir))
 375         end
 376 end
 377
 378 -- Process all given parts and construct validation tree
 379 function UVL._read_scheme_parts( self, scheme, schemes )
 380
 381         -- helper function to check for required fields
 382         local function _req( t, n, c, r )
 383                 for i, v in ipairs(r) do
 384                         if not c[v] then
 385                                 local p, o = scheme:sid(), nil
 386
 387                                 if t == TYPE_SECTION then
 388                                         o = section( scheme, nil, p, n )
 389                                 elseif t == TYPE_OPTION then
 390                                         o = option( scheme, nil, p, '(nil)', n )
 391                                 elseif t == TYPE_ENUM then
 392                                         o = enum( scheme, nil, p, '(nil)', '(nil)', n )
 393                                 end
 394
 395                                 return false, ERR.SME_REQFLD(o,v)
 396                         end
 397                 end
 398                 return true
 399         end
 400
 401         -- helper function to validate references
 402         local function _ref( c, t )
 403                 local k, n
 404                 if c == TYPE_SECTION then
 405                         k = "package"
 406                         n = 1
 407                 elseif c == TYPE_OPTION then
 408                         k = "section"
 409                         n = 2
 410                 elseif c == TYPE_ENUM then
 411                         k = "variable"
 412                         n = 3
 413                 end
 414
 415                 local r = luci.util.split( t[k], "." )
 416                 r[1] = ( #r[1] > 0 and r[1] or scheme:sid() )
 417
 418                 if #r ~= n then
 419                         return false, ERR.SME_BADREF(scheme, k)
 420                 end
 421
 422                 return r
 423         end
 424
 425         -- helper function to read bools
 426         local function _bool( v )
 427                 return ( v == "true" or v == "yes" or v == "on" or v == "1" )
 428         end
 429
 430
 431         local ok, err
 432
 433         -- Step 0: get package meta information
 434         for i, conf in ipairs( schemes ) do
 435                 for k, v in pairs( conf ) do
 436                         if v['.type'] == 'package' then
 437                                 self.packages[scheme:sid()] =
 438                                         self.packages[scheme:sid()] or {
 439                                                 ["name"]      = scheme:sid();
 440                                                 ["sections"]  = { };
 441                                                 ["variables"] = { };
 442                                         }
 443
 444                                 for k, v2 in pairs(v) do
 445                                         if k == "title" or k == "description" then
 446                                                 self.packages[scheme:sid()][k] = v2
 447                                         end
 448                                 end
 449                         end
 450                 end
 451         end
 452
 453         -- Step 1: get all sections
 454         for i, conf in ipairs( schemes ) do
 455                 for k, v in pairs( conf ) do
 456                         if v['.type'] == 'section' then
 457
 458                                 ok, err = _req( TYPE_SECTION, k, v, { "name", "package" } )
 459                                 if err then return false, scheme:error(err) end
 460
 461                                 local r, err = _ref( TYPE_SECTION, v )
 462                                 if err then return false, scheme:error(err) end
 463
 464                                 self.packages[r[1]] =
 465                                         self.packages[r[1]] or {
 466                                                 ["name"]      = r[1];
 467                                                 ["sections"]  = { };
 468                                                 ["variables"] = { };
 469                                         }
 470
 471                                 local p = self.packages[r[1]]
 472                                           p.sections[v.name]  = p.sections[v.name]  or { }
 473                                           p.variables[v.name] = p.variables[v.name] or { }
 474
 475                                 local s  = p.sections[v.name]
 476                                 local so = scheme:section(v.name)
 477
 478                                 for k, v2 in pairs(v) do
 479                                         if k ~= "name" and k ~= "package" and k:sub(1,1) ~= "." then
 480                                                 if k == "depends" then
 481                                                         s.depends = self:_read_dependency( v2, s.depends )
 482                                                         if not s.depends then
 483                                                                 return false, scheme:error(
 484                                                                         ERR.SME_BADDEP(so, luci.util.serialize_data(s.depends))
 485                                                                 )
 486                                                         end
 487                                                 elseif k == "dynamic" or k == "unique" or
 488                                                        k == "required" or k == "named"
 489                                                 then
 490                                                         s[k] = _bool(v2)
 491                                                 else
 492                                                         s[k] = v2
 493                                                 end
 494                                         end
 495                                 end
 496
 497                                 s.dynamic  = s.dynamic  or false
 498                                 s.unique   = s.unique   or false
 499                                 s.required = s.required or false
 500                                 s.named    = s.named    or false
 501                         end
 502                 end
 503         end
 504
 505         -- Step 2: get all variables
 506         for i, conf in ipairs( schemes ) do
 507                 for k, v in pairs( conf ) do
 508                         if v['.type'] == "variable" then
 509
 510                                 ok, err = _req( TYPE_OPTION, k, v, { "name", "section" } )
 511                                 if err then return false, scheme:error(err) end
 512
 513                                 local r, err = _ref( TYPE_OPTION, v )
 514                                 if err then return false, scheme:error(err) end
 515
 516                                 local p = self.packages[r[1]]
 517                                 if not p then
 518                                         return false, scheme:error(
 519                                                 ERR.SME_VBADPACK({scheme:sid(), '', v.name}, r[1])
 520                                         )
 521                                 end
 522
 523                                 local s = p.variables[r[2]]
 524                                 if not s then
 525                                         return false, scheme:error(
 526                                                 ERR.SME_VBADSECT({scheme:sid(), '', v.name}, r[2])
 527                                         )
 528                                 end
 529
 530                                 s[v.name] = s[v.name] or { }
 531
 532                                 local t  = s[v.name]
 533                                 local so = scheme:section(r[2])
 534                                 local to = so:option(v.name)
 535
 536                                 for k, v2 in pairs(v) do
 537                                         if k ~= "name" and k ~= "section" and k:sub(1,1) ~= "." then
 538                                                 if k == "depends" then
 539                                                         t.depends = self:_read_dependency( v2, t.depends )
 540                                                         if not t.depends then
 541                                                                 return false, scheme:error(so:error(
 542                                                                         ERR.SME_BADDEP(to, luci.util.serialize_data(v2))
 543                                                                 ))
 544                                                         end
 545                                                 elseif k == "validator" then
 546                                                         t.validators = self:_read_validator( v2, t.validators )
 547                                                         if not t.validators then
 548                                                                 return false, scheme:error(so:error(
 549                                                                         ERR.SME_BADVAL(to, luci.util.serialize_data(v2))
 550                                                                 ))
 551                                                         end
 552                                                 elseif k == "valueof" then
 553                                                         local values, err = self:_read_reference( v2 )
 554                                                         if err then
 555                                                                 return false, scheme:error(so:error(
 556                                                                         ERR.REFERENCE(to, luci.util.serialize_data(v2)):child(err)
 557                                                                 ))
 558                                                         end
 559                                                         t.type   = "reference"
 560                                                         t.values = values
 561                                                 elseif k == "required" then
 562                                                         t[k] = _bool(v2)
 563                                                 else
 564                                                         t[k] = t[k] or v2
 565                                                 end
 566                                         end
 567                                 end
 568
 569                                 t.type     = t.type     or "variable"
 570                                 t.datatype = t.datatype or "string"
 571                                 t.required = t.required or false
 572                         end
 573                 end
 574         end
 575
 576         -- Step 3: get all enums
 577         for i, conf in ipairs( schemes ) do
 578                 for k, v in pairs( conf ) do
 579                         if v['.type'] == "enum" then
 580
 581                                 ok, err = _req( TYPE_ENUM, k, v, { "value", "variable" } )
 582                                 if err then return false, scheme:error(err) end
 583
 584                                 local r, err = _ref( TYPE_ENUM, v )
 585                                 if err then return false, scheme:error(err) end
 586
 587                                 local p = self.packages[r[1]]
 588                                 if not p then
 589                                         return false, scheme:error(
 590                                                 ERR.SME_EBADPACK({scheme:sid(), '', '', v.value}, r[1])
 591                                         )
 592                                 end
 593
 594                                 local s = p.variables[r[2]]
 595                                 if not s then
 596                                         return false, scheme:error(
 597                                                 ERR.SME_EBADSECT({scheme:sid(), '', '', v.value}, r[2])
 598                                         )
 599                                 end
 600
 601                                 local t = s[r[3]]
 602                                 if not t then
 603                                         return false, scheme:error(
 604                                                 ERR.SME_EBADOPT({scheme:sid(), '', '', v.value}, r[3])
 605                                         )
 606                                 end
 607
 608
 609                                 local so = scheme:section(r[2])
 610                                 local oo = so:option(r[3])
 611                                 local eo = oo:enum(v.value)
 612
 613                                 if t.type ~= "enum" then
 614                                         return false, scheme:error(ERR.SME_EBADTYPE(eo))
 615                                 end
 616
 617                                 if not t.values then
 618                                         t.values = { [v.value] = v.title or v.value }
 619                                 else
 620                                         t.values[v.value] = v.title or v.value
 621                                 end
 622
 623                                 if not t.enum_depends then
 624                                         t.enum_depends = { }
 625                                 end
 626
 627                                 if v.default then
 628                                         if t.default then
 629                                                 return false, scheme:error(ERR.SME_EBADDEF(eo))
 630                                         end
 631                                         t.default = v.value
 632                                 end
 633
 634                                 if v.depends then
 635                                         t.enum_depends[v.value] = self:_read_dependency(
 636                                                 v.depends, t.enum_depends[v.value]
 637                                         )
 638
 639                                         if not t.enum_depends[v.value] then
 640                                                 return false, scheme:error(so:error(oo:error(
 641                                                         ERR.SME_BADDEP(eo, luci.util.serialize_data(v.depends))
 642                                                 )))
 643                                         end
 644                                 end
 645                         end
 646                 end
 647         end
 648
 649         return self
 650 end
 651
 652 -- Read a dependency specification
 653 function UVL._read_dependency( self, values, deps )
 654         local expr = "%$?[a-zA-Z0-9_]+"
 655         if values then
 656                 values = ( type(values) == "table" and values or { values } )
 657                 for _, value in ipairs(values) do
 658                         local parts     = luci.util.split( value, "%s*,%s*", nil, true )
 659                         local condition = { }
 660                         for i, val in ipairs(parts) do
 661                                 local k, v = unpack(luci.util.split(val, "%s*=%s*", nil, true))
 662
 663                                 if k and (
 664                                         k:match("^"..expr.."%."..expr.."%."..expr.."$") or
 665                                         k:match("^"..expr.."%."..expr.."$") or
 666                                         k:match("^"..expr.."$")
 667                                 ) then
 668                                         condition[k] = v or true
 669                                 else
 670                                         return nil
 671                                 end
 672                         end
 673
 674                         if not deps then
 675                                 deps = { condition }
 676                         else
 677                                 table.insert( deps, condition )
 678                         end
 679                 end
 680         end
 681
 682         return deps
 683 end
 684
 685 -- Read a validator specification
 686 function UVL._read_validator( self, values, validators )
 687         if values then
 688                 values = ( type(values) == "table" and values or { values } )
 689                 for _, value in ipairs(values) do
 690                         local validator
 691
 692                         if value:match("^exec:") then
 693                                 validator = value:gsub("^exec:","")
 694                         elseif value:match("^lua:") then
 695                                 validator = self:_resolve_function( (value:gsub("^lua:","") ) )
 696                         elseif value:match("^regexp:") then
 697                                 local pattern = value:gsub("^regexp:","")
 698                                 validator = function( type, dtype, pack, sect, optn, ... )
 699                                         local values = { ... }
 700                                         for _, v in ipairs(values) do
 701                                                 local ok, match =
 702                                                         luci.util.copcall( string.match, v, pattern )
 703
 704                                                 if not ok then
 705                                                         return false, match
 706                                                 elseif not match then
 707                                                         return false,
 708                                                                 'Value "%s" does not match pattern "%s"' % {
 709                                                                         v, pattern
 710                                                                 }
 711                                                 end
 712                                         end
 713                                         return true
 714                                 end
 715                         end
 716
 717                         if validator then
 718                                 if not validators then
 719                                         validators = { validator }
 720                                 else
 721                                         table.insert( validators, validator )
 722                                 end
 723                         else
 724                                 return nil
 725                         end
 726                 end
 727
 728                 return validators
 729         end
 730 end
 731
 732 -- Read a reference specification (XXX: We should validate external configs too...)
 733 function UVL._read_reference( self, values )
 734         local val = { }
 735         values = ( type(values) == "table" and values or { values } )
 736
 737         for _, value in ipairs(values) do
 738                 local ref = luci.util.split(value, ".")
 739
 740                 if #ref == 2 or #ref == 3 then
 741                         local co = luci.uvl.config( self, ref[1] )
 742                         if not co:config() then return false, co:errors() end
 743
 744                         for k, v in pairs(co:config()) do
 745                                 if v['.type'] == ref[2] then
 746                                         if #ref == 2 then
 747                                                 if v['.anonymous'] == true then
 748                                                         return false, ERR.SME_INVREF('', value)
 749                                                 end
 750                                                 val[k] = k      -- XXX: title/description would be nice
 751                                         elseif v[ref[3]] then
 752                                                 val[v[ref[3]]] = v[ref[3]]  -- XXX: dito
 753                                         end
 754                                 end
 755                         end
 756                 else
 757                         return false, ERR.SME_BADREF('', value)
 758                 end
 759         end
 760
 761         return val, nil
 762 end
 763
 764 -- Resolve given path
 765 function UVL._resolve_function( self, value )
 766         local path = luci.util.split(value, ".")
 767
 768         for i=1, #path-1 do
 769                 local stat, mod = luci.util.copcall(
 770                         require, table.concat(path, ".", 1, i)
 771                 )
 772
 773                 if stat and mod then
 774                         for j=i+1, #path-1 do
 775                                 if not type(mod) == "table" then
 776                                         break
 777                                 end
 778                                 mod = mod[path[j]]
 779                                 if not mod then
 780                                         break
 781                                 end
 782                         end
 783                         mod = type(mod) == "table" and mod[path[#path]] or nil
 784                         if type(mod) == "function" then
 785                                 return mod
 786                         end
 787                 end
 788         end
 789 end
 790
 791
 792 --- Object representation of an uvl item - base class.
 793 uvlitem = luci.util.class()
 794
 795 function uvlitem.cid(self)
 796         return table.concat( self.cref, '.' )
 797 end
 798
 799 function uvlitem.sid(self)
 800         return table.concat( self.sref, '.' )
 801 end
 802
 803 function uvlitem.scheme(self, opt)
 804         local s
 805
 806         if #self.sref == 4 or #self.sref == 3 then
 807                 s = self.s and self.s.packages
 808                 s = s      and s[self.sref[1]]
 809                 s = s      and s.variables
 810                 s = s      and s[self.sref[2]]
 811                 s = s      and s[self.sref[3]]
 812         elseif #self.sref == 2 then
 813                 s = self.s and self.s.packages
 814                 s = s      and s[self.sref[1]]
 815                 s = s      and s.sections
 816                 s = s      and s[self.sref[2]]
 817         else
 818                 s = self.s and self.s.packages
 819                 s = s      and s[self.sref[1]]
 820         end
 821
 822         if s and opt then
 823                 return s[opt]
 824         elseif s then
 825                 return s
 826         end
 827 end
 828
 829 function uvlitem.config(self, opt)
 830         local c
 831
 832         if #self.cref == 4 or #self.cref == 3 then
 833                 c = self.c and self.c[self.cref[2]] or nil
 834                 c = c      and c[self.cref[3]]      or nil
 835         elseif #self.cref == 2 then
 836                 c = self.c and self.c[self.cref[2]] or nil
 837         else
 838                 c = self.c
 839         end
 840
 841         if c and opt then
 842                 return c[opt]
 843         elseif c then
 844                 return c
 845         end
 846 end
 847
 848 function uvlitem.title(self)
 849         return self:scheme() and self:scheme('title') or
 850                 self.cref[3] or self.cref[2] or self.cref[1]
 851 end
 852
 853 function uvlitem.type(self)
 854         if self.t == luci.uvl.TYPE_CONFIG then
 855                 return 'config'
 856         elseif self.t == luci.uvl.TYPE_SECTION then
 857                 return 'section'
 858         elseif self.t == luci.uvl.TYPE_OPTION then
 859                 return 'option'
 860         elseif self.t == luci.uvl.TYPE_ENUM then
 861                 return 'enum'
 862         end
 863 end
 864
 865 function uvlitem.error(self, ...)
 866         if not self.e then
 867                 local errconst = { ERR.CONFIG, ERR.SECTION, ERR.OPTION, ERR.OPTION }
 868                 self.e = errconst[#self.cref]( self )
 869         end
 870
 871         return self.e:child( ... )
 872 end
 873
 874 function uvlitem.errors(self)
 875         return self.e
 876 end
 877
 878 function uvlitem.ok(self)
 879         return not self:errors()
 880 end
 881
 882 function uvlitem.parent(self)
 883         if self.p then
 884                 return self.p
 885         elseif #self.cref == 3 or #self.cref == 4 then
 886                 return luci.uvl.section( self.s, self.c, self.cref[1], self.cref[2] )
 887         elseif #self.cref == 2 then
 888                 return luci.uvl.config( self.s, self.c, self.cref[1] )
 889         else
 890                 return nil
 891         end
 892 end
 893
 894 function uvlitem._loadconf(self, co, c)
 895         if not co then
 896                 local uci, err = luci.model.uci.cursor(), nil
 897                 co, err = uci:get_all(c)
 898
 899                 if err then
 900                         self:error(ERR.UCILOAD(self, err))
 901                 end
 902         end
 903         return co
 904 end
 905
 906
 907 --- Object representation of a scheme.
 908 -- @class       scheme
 909 -- @cstyle      instance
 910 -- @name        luci.uvl.scheme
 911
 912 --- Scheme instance constructor.
 913 -- @class                       function
 914 -- @name                        scheme
 915 -- @param scheme        Scheme instance
 916 -- @param co            Configuration data
 917 -- @param c                     Configuration name
 918 -- @return                      Config instance
 919 scheme = luci.util.class(uvlitem)
 920
 921 function scheme.__init__(self, scheme, co, c)
 922         if not c then
 923                 c, co = co, nil
 924         end
 925
 926         self.cref = { c }
 927         self.sref = { c }
 928         self.c    = self:_loadconf(co, c)
 929         self.s    = scheme
 930         self.t    = luci.uvl.TYPE_SCHEME
 931 end
 932
 933 --- Add an error to scheme.
 934 -- @return      Scheme error context
 935 function scheme.error(self, ...)
 936         if not self.e then self.e = ERR.SCHEME( self ) end
 937         return self.e:child( ... )
 938 end
 939
 940 --- Get an associated config object.
 941 -- @return      Config instance
 942 function scheme.config(self)
 943         local co = luci.uvl.config( self.s, self.cref[1] )
 944               co.p = self
 945
 946         return co
 947 end
 948
 949 --- Get all section objects associated with this scheme.
 950 -- @return      Table containing all associated luci.uvl.section instances
 951 function scheme.sections(self)
 952         local v = { }
 953         if self.s.packages[self.sref[1]].sections then
 954                 for o, _ in pairs( self.s.packages[self.sref[1]].sections ) do
 955                         table.insert( v, luci.uvl.option(
 956                                 self.s, self.c, self.cref[1], self.cref[2], o
 957                         ) )
 958                 end
 959         end
 960         return v
 961 end
 962
 963 --- Get an associated section object.
 964 -- @param s     Section to select
 965 -- @return      Section instance
 966 function scheme.section(self, s)
 967         local so = luci.uvl.section( self.s, self.c, self.cref[1], s )
 968               so.p = self
 969
 970         return so
 971 end
 972
 973
 974 --- Object representation of a config.
 975 -- @class       config
 976 -- @cstyle      instance
 977 -- @name        luci.uvl.config
 978
 979 --- Config instance constructor.
 980 -- @class                       function
 981 -- @name                        config
 982 -- @param scheme        Scheme instance
 983 -- @param co            Configuration data
 984 -- @param c                     Configuration name
 985 -- @return                      Config instance
 986 config = luci.util.class(uvlitem)
 987
 988 function config.__init__(self, scheme, co, c)
 989         if not c then
 990                 c, co = co, nil
 991         end
 992
 993         self.cref = { c }
 994         self.sref = { c }
 995         self.c    = self:_loadconf(co, c)
 996         self.s    = scheme
 997         self.t    = luci.uvl.TYPE_CONFIG
 998 end
 999
1000 --- Get all section objects associated with this config.
1001 -- @return      Table containing all associated luci.uvl.section instances
1002 function config.sections(self)
1003         local v = { }
1004         if self.s.packages[self.sref[1]].sections then
1005                 for o, _ in pairs( self.s.packages[self.sref[1]].sections ) do
1006                         table.insert( v, luci.uvl.option(
1007                                 self.s, self.c, self.cref[1], self.cref[2], o
1008                         ) )
1009                 end
1010         end
1011         return v
1012 end
1013
1014 --- Get an associated section object.
1015 -- @param s     Section to select
1016 -- @return      Section instance
1017 function config.section(self, s)
1018         local so = luci.uvl.section( self.s, self.c, self.cref[1], s )
1019               so.p = self
1020
1021         return so
1022 end
1023
1024
1025 --- Object representation of a scheme/config section.
1026 -- @class       module
1027 -- @cstyle      instance
1028 -- @name        luci.uvl.section
1029
1030 --- Section instance constructor.
1031 -- @class                       function
1032 -- @name                        section
1033 -- @param scheme        Scheme instance
1034 -- @param co            Configuration data
1035 -- @param c                     Configuration name
1036 -- @param s                     Section name
1037 -- @return                      Section instance
1038 section = luci.util.class(uvlitem)
1039
1040 function section.__init__(self, scheme, co, c, s)
1041         self.cref = { c, s }
1042         self.sref = { c, co and co[s] and co[s]['.type'] or s }
1043         self.c    = self:_loadconf(co, c)
1044         self.s    = scheme
1045         self.t    = luci.uvl.TYPE_SECTION
1046 end
1047
1048 --- Get all option objects associated with this section.
1049 -- @return      Table containing all associated luci.uvl.option instances
1050 function section.variables(self)
1051         local v = { }
1052         if self.s.packages[self.sref[1]].variables[self.sref[2]] then
1053                 for o, _ in pairs(
1054                         self.s.packages[self.sref[1]].variables[self.sref[2]]
1055                 ) do
1056                         table.insert( v, luci.uvl.option(
1057                                 self.s, self.c, self.cref[1], self.cref[2], o
1058                         ) )
1059                 end
1060         end
1061         return v
1062 end
1063
1064 --- Get an associated option object.
1065 -- @param o     Option to select
1066 -- @return      Option instance
1067 function section.option(self, o)
1068         local oo = luci.uvl.option( self.s, self.c, self.cref[1], self.cref[2], o )
1069               oo.p = self
1070
1071         return oo
1072 end
1073
1074
1075 --- Object representation of a scheme/config option.
1076 -- @class       module
1077 -- @cstyle      instance
1078 -- @name        luci.uvl.option
1079
1080 --- Section instance constructor.
1081 -- @class                       function
1082 -- @name                        option
1083 -- @param scheme        Scheme instance
1084 -- @param co            Configuration data
1085 -- @param c                     Configuration name
1086 -- @param s                     Section name
1087 -- @param o                     Option name
1088 -- @return                      Option instance
1089 option = luci.util.class(uvlitem)
1090
1091 function option.__init__(self, scheme, co, c, s, o)
1092         self.cref = { c, s, o }
1093         self.sref = { c, co and co[s] and co[s]['.type'] or s, o }
1094         self.c    = self:_loadconf(co, c)
1095         self.s    = scheme
1096         self.t    = luci.uvl.TYPE_OPTION
1097 end
1098
1099 --- Get the value of this option.
1100 -- @return      The associated configuration value
1101 function option.value(self)
1102         return self:config()
1103 end
1104
1105 --- Get the associated section information in scheme.
1106 -- @return      Table containing the scheme properties
1107 function option.section(self)
1108         return self.s.packages[self.sref[1]].sections[self.sref[2]]
1109 end
1110
1111 --- Construct an enum object instance from given or default value.
1112 -- @param v     Value to select
1113 -- @return      Enum instance for selected value
1114 function option.enum(self, val)
1115         return enum(
1116                 self.s, self.c,
1117                 self.cref[1], self.cref[2], self.cref[3],
1118                 val or self:value()
1119         )
1120 end
1121
1122
1123 --- Object representation of a enum value.
1124 -- @class       module
1125 -- @cstyle      instance
1126 -- @name        luci.uvl.enum
1127
1128 --- Section instance constructor.
1129 -- @class                       function
1130 -- @name                        enum
1131 -- @param scheme        Scheme instance
1132 -- @param co            Configuration data
1133 -- @param c                     Configuration name
1134 -- @param s                     Section name
1135 -- @param o                     Enum name
1136 -- @param v                     Enum value
1137 -- @return                      Enum value instance
1138 enum = luci.util.class(option)
1139
1140 function enum.__init__(self, scheme, co, c, s, o, v)
1141         self.cref = { c, s, o, v }
1142         self.sref = { c, co and co[s] and co[s]['.type'] or s, o, v }
1143         self.c    = self:_loadconf(co, c)
1144         self.s    = scheme
1145         self.t    = luci.uvl.TYPE_ENUM
1146 end