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_VARIABLE = 0x03
  37 TYPE_OPTION   = 0x04
  38 TYPE_ENUM     = 0x05
  39
  40 --- Boolean; default true;
  41 -- treat sections found in config but not in scheme as error
  42 STRICT_UNKNOWN_SECTIONS    = true
  43
  44 --- Boolean; default true;
  45 -- treat options found in config but not in scheme as error
  46 STRICT_UNKNOWN_OPTIONS     = true
  47
  48 --- Boolean; default true;
  49 -- treat failed external validators as error
  50 STRICT_EXTERNAL_VALIDATORS = true
  51
  52 --- Boolean; default true;
  53 -- treat list values stored as options like errors
  54 STRICT_LIST_TYPE           = true
  55
  56
  57 local default_schemedir = "/lib/uci/schema"
  58 local default_savedir = "/tmp/.uvl"
  59 local ERR = luci.uvl.errors
  60
  61
  62 --- Object constructor
  63 -- @class                       function
  64 -- @name                        UVL
  65 -- @param schemedir     Path to the scheme directory (optional)
  66 -- @return                      Instance object
  67 UVL = luci.util.class()
  68
  69 function UVL.__init__( self, schemedir )
  70         self.schemedir  = schemedir or default_schemedir
  71         self.packages   = { }
  72         self.beenthere  = { }
  73         self.depseen    = { }
  74         self.uci                = luci.model.uci
  75         self.err                = luci.uvl.errors
  76         self.dep                = luci.uvl.dependencies
  77         self.datatypes  = luci.uvl.datatypes
  78 end
  79
  80
  81 --- Parse given scheme and return the scheme tree.
  82 -- @param scheme        Name of the scheme to parse
  83 -- @return                      Table containing the parsed scheme or nil on error
  84 -- @return                      String containing the reason for errors (if any)
  85 function UVL.get_scheme( self, scheme )
  86         if not self.packages[scheme] then
  87                 local ok, err = self:read_scheme( scheme )
  88                 if not ok then
  89                         return nil, err
  90                 end
  91         end
  92         return self.packages[scheme], nil
  93 end
  94
  95 --- Validate given configuration, section or option.
  96 -- @param config        Name of the configuration to validate
  97 -- @param section       Name of the section to validate (optional)
  98 -- @param option        Name of the option to validate (optional)
  99 -- @return                      Boolean indicating whether the given config validates
 100 -- @return                      String containing the reason for errors (if any)
 101 function UVL.validate( self, config, section, option )
 102         if config and section and option then
 103                 return self:validate_option( config, section, option )
 104         elseif config and section then
 105                 return self:validate_section( config, section )
 106         elseif config then
 107                 return self:validate_config( config )
 108         end
 109 end
 110
 111 --- Validate given configuration.
 112 -- @param config        Name of the configuration to validate
 113 -- @return                      Boolean indicating whether the given config validates
 114 -- @return                      String containing the reason for errors (if any)
 115 function UVL.validate_config( self, config, uci )
 116
 117         if not self.packages[config] then
 118                 local ok, err = self:read_scheme(config)
 119                 if not ok then
 120                         return false, err
 121                 end
 122         end
 123
 124         local co = luci.uvl.config( self, uci or config, uci and config )
 125         local sc = { }
 126
 127         self.beenthere = { }
 128         self.depseen   = { }
 129
 130         if not co:config() then
 131                 return false, co:errors()
 132         end
 133
 134         local function _uci_foreach( type, func )
 135                 for k, v in pairs(co:config()) do
 136                         if v['.type'] == type then
 137                                 sc[type] = sc[type] + 1
 138                                 local ok, err = func( k, v )
 139                                 if not ok then co:error(err) end
 140                         end
 141                 end
 142         end
 143
 144         for k, v in pairs( self.packages[config].sections ) do
 145                 sc[k] = 0
 146                 _uci_foreach( k,
 147                         function(s)
 148                                 return self:_validate_section( co:section(s) )
 149                         end
 150                 )
 151         end
 152
 153         if STRICT_UNKNOWN_SECTIONS then
 154                 for k, v in pairs(co:config()) do
 155                         local so = co:section(k)
 156                         if not self.beenthere[so:cid()] then
 157                                 co:error(ERR.SECT_UNKNOWN(so))
 158                         end
 159                 end
 160         end
 161
 162         for _, k in ipairs(luci.util.keys(sc)) do
 163                 local so = co:section(k)
 164                 if so:scheme('required') and sc[k] == 0 then
 165                         co:error(ERR.SECT_REQUIRED(so))
 166                 elseif so:scheme('unique') and sc[k] > 1 then
 167                         co:error(ERR.SECT_UNIQUE(so))
 168                 end
 169         end
 170
 171         return co:ok(), co:errors()
 172 end
 173
 174 --- Validate given config section.
 175 -- @param config        Name of the configuration to validate
 176 -- @param section       Name of the section to validate
 177 -- @return                      Boolean indicating whether the given config validates
 178 -- @return                      String containing the reason for errors (if any)
 179 function UVL.validate_section( self, config, section, uci )
 180
 181         if not self.packages[config] then
 182                 local ok, err = self:read_scheme( config )
 183                 if not ok then
 184                         return false, err
 185                 end
 186         end
 187
 188         local co = luci.uvl.config( self, uci or config, uci and config )
 189         local so = co:section( section )
 190
 191         self.beenthere = { }
 192         self.depseen   = { }
 193
 194         if not co:config() then
 195                 return false, co:errors()
 196         end
 197
 198         if so:config() then
 199                 return self:_validate_section( so )
 200         else
 201                 return false, ERR.SECT_NOTFOUND(so)
 202         end
 203 end
 204
 205 --- Validate given config option.
 206 -- @param config        Name of the configuration to validate
 207 -- @param section       Name of the section to validate
 208 -- @param option        Name of the option to validate
 209 -- @return                      Boolean indicating whether the given config validates
 210 -- @return                      String containing the reason for errors (if any)
 211 function UVL.validate_option( self, config, section, option, uci )
 212
 213         if not self.packages[config] then
 214                 local ok, err = self:read_scheme( config )
 215                 if not ok then
 216                         return false, err
 217                 end
 218         end
 219
 220         local co = luci.uvl.config( self, uci or config, uci and config )
 221         local so = co:section( section )
 222         local oo = so:option( option )
 223
 224         if not co:config() then
 225                 return false, co:errors()
 226         end
 227
 228         if so:config() and oo:config() then
 229                 return self:_validate_option( oo )
 230         else
 231                 return false, ERR.OPT_NOTFOUND(oo)
 232         end
 233 end
 234
 235
 236 function UVL._validate_section( self, section )
 237
 238         self.beenthere[section:cid()] = true
 239
 240         if section:config() then
 241                 if section:scheme('named') == true and
 242                    section:config('.anonymous') == true
 243                 then
 244                         return false, ERR.SECT_NAMED(section)
 245                 end
 246
 247                 for _, v in ipairs(section:variables()) do
 248                         local ok, err = self:_validate_option( v )
 249                         if not ok and (
 250                                 v:scheme('required') or v:scheme('type') == "enum" or (
 251                                         not err:is(ERR.ERR_DEP_NOTEQUAL) and
 252                                         not err:is(ERR.ERR_DEP_NOVALUE)
 253                                 )
 254                         ) then
 255                                 section:error(err)
 256                         end
 257                 end
 258
 259                 local ok, err = luci.uvl.dependencies.check( self, section )
 260                 if not ok then
 261                         section:error(err)
 262                 end
 263         else
 264                 return false, ERR.SECT_NOTFOUND(section)
 265         end
 266
 267         if STRICT_UNKNOWN_OPTIONS and not section:scheme('dynamic') then
 268                 for k, v in pairs(section:config()) do
 269                         local oo = section:option(k)
 270                         if k:sub(1,1) ~= "." and not self.beenthere[oo:cid()] then
 271                                 section:error(ERR.OPT_UNKNOWN(oo))
 272                         end
 273                 end
 274         end
 275
 276         return section:ok(), section:errors()
 277 end
 278
 279 function UVL._validate_option( self, option, nodeps )
 280
 281         self.beenthere[option:cid()] = true
 282
 283         if not option:scheme() and not option:parent():scheme('dynamic') then
 284                 return false, option:error(ERR.OPT_UNKNOWN(option))
 285
 286         elseif option:scheme() then
 287                 if option:scheme('required') and not option:value() then
 288                         return false, option:error(ERR.OPT_REQUIRED(option))
 289
 290                 elseif option:value() then
 291                         local val = option:value()
 292
 293                         if option:scheme('type') == "reference" or
 294                            option:scheme('type') == "enum"
 295                         then
 296                                 if not option:scheme('values') or
 297                                    not option:scheme('values')[val]
 298                                 then
 299                                         return false, option:error( ERR.OPT_BADVALUE(
 300                                                 option, luci.util.serialize_data(
 301                                                         luci.util.keys(option:scheme('values') or {})
 302                                                 )
 303                                         ) )
 304                                 end
 305                         elseif option:scheme('type') == "list" then
 306                                 if type(val) ~= "table" and STRICT_LIST_TYPE then
 307                                         return false, option:error(ERR.OPT_NOTLIST(option))
 308                                 end
 309                         elseif option:scheme('datatype') then
 310                                 local dt = option:scheme('datatype')
 311
 312                                 if self.datatypes[dt] then
 313                                         val = ( type(val) == "table" and val or { val } )
 314                                         for i, v in ipairs(val) do
 315                                                 if not self.datatypes[dt]( v ) then
 316                                                         return false, option:error(
 317                                                                 ERR.OPT_INVVALUE(option, dt)
 318                                                         )
 319                                                 end
 320                                         end
 321                                 else
 322                                         return false, option:error(ERR.OPT_DATATYPE(option, dt))
 323                                 end
 324                         end
 325                 end
 326
 327                 if not nodeps then
 328                         local ok, err = luci.uvl.dependencies.check( self, option )
 329                         if not ok then
 330                                 option:error(err)
 331                         end
 332                 end
 333
 334                 local ok, err = luci.uvl.validation.check( self, option )
 335                 if not ok and STRICT_EXTERNAL_VALIDATORS then
 336                         return false, option:error(err)
 337                 end
 338         end
 339
 340         return option:ok(), option:errors()
 341 end
 342
 343 --- Find all parts of given scheme and construct validation tree.
 344 -- This is normally done on demand, so you don't have to call this function
 345 -- by yourself.
 346 -- @param scheme        Name of the scheme to parse
 347 function UVL.read_scheme( self, scheme )
 348
 349         local so = luci.uvl.scheme( self, scheme )
 350
 351         local schemes = { }
 352         local files = luci.fs.glob(self.schemedir .. '/*/' .. scheme)
 353
 354         if files then
 355                 for i, file in ipairs( files ) do
 356                         if not luci.fs.access(file) then
 357                                 return so:error(ERR.SME_READ(so,file))
 358                         end
 359
 360                         local uci = luci.model.uci.cursor( luci.fs.dirname(file), default_savedir )
 361
 362                         local sd, err = uci:get_all( luci.fs.basename(file) )
 363
 364                         if not sd then
 365                                 return false, ERR.UCILOAD(so, err)
 366                         end
 367
 368                         table.insert( schemes, sd )
 369                 end
 370
 371                 return self:_read_scheme_parts( so, schemes )
 372         else
 373                 return false, so:error(ERR.SME_FIND(so, self.schemedir))
 374         end
 375 end
 376
 377 -- Process all given parts and construct validation tree
 378 function UVL._read_scheme_parts( self, scheme, schemes )
 379
 380         -- helper function to check for required fields
 381         local function _req( c, t, r )
 382                 for i, v in ipairs(r) do
 383                         if not t[v] then
 384                                 return false, ERR.SME_REQFLD({c,t}, v)
 385                         end
 386                 end
 387                 return true
 388         end
 389
 390         -- helper function to validate references
 391         local function _ref( c, t )
 392                 local k, n
 393                 if c == TYPE_SECTION then
 394                         k = "package"
 395                         n = 1
 396                 elseif c == TYPE_VARIABLE then
 397                         k = "section"
 398                         n = 2
 399                 elseif c == TYPE_ENUM then
 400                         k = "variable"
 401                         n = 3
 402                 end
 403
 404                 local r = luci.util.split( t[k], "." )
 405                 r[1] = ( #r[1] > 0 and r[1] or scheme:sid() )
 406
 407                 if #r ~= n then
 408                         return false, ERR.SME_BADREF(scheme, k)
 409                 end
 410
 411                 return r
 412         end
 413
 414         -- helper function to read bools
 415         local function _bool( v )
 416                 return ( v == "true" or v == "yes" or v == "on" or v == "1" )
 417         end
 418
 419
 420         local ok, err
 421
 422         -- Step 0: get package meta information
 423         for i, conf in ipairs( schemes ) do
 424                 for k, v in pairs( conf ) do
 425                         if v['.type'] == 'package' then
 426                                 self.packages[scheme:sid()] =
 427                                         self.packages[scheme:sid()] or {
 428                                                 ["name"]      = scheme:sid();
 429                                                 ["sections"]  = { };
 430                                                 ["variables"] = { };
 431                                         }
 432
 433                                 for k, v2 in pairs(v) do
 434                                         if k == "title" or k == "description" then
 435                                                 self.packages[scheme:sid()][k] = v2
 436                                         end
 437                                 end
 438                         end
 439                 end
 440         end
 441
 442         -- Step 1: get all sections
 443         for i, conf in ipairs( schemes ) do
 444                 for k, v in pairs( conf ) do
 445                         if v['.type'] == 'section' then
 446
 447                                 ok, err = _req( TYPE_SECTION, v, { "name", "package" } )
 448                                 if err then return false, scheme:error(err) end
 449
 450                                 local r, err = _ref( TYPE_SECTION, v )
 451                                 if err then return false, scheme:error(err) end
 452
 453                                 self.packages[r[1]] =
 454                                         self.packages[r[1]] or {
 455                                                 ["name"]      = r[1];
 456                                                 ["sections"]  = { };
 457                                                 ["variables"] = { };
 458                                         }
 459
 460                                 local p = self.packages[r[1]]
 461                                           p.sections[v.name]  = p.sections[v.name]  or { }
 462                                           p.variables[v.name] = p.variables[v.name] or { }
 463
 464                                 local s  = p.sections[v.name]
 465                                 local so = scheme:section(v.name)
 466
 467                                 for k, v2 in pairs(v) do
 468                                         if k ~= "name" and k ~= "package" and k:sub(1,1) ~= "." then
 469                                                 if k == "depends" then
 470                                                         s.depends = self:_read_dependency( v2, s.depends )
 471                                                         if not s.depends then
 472                                                                 return false, scheme:error(
 473                                                                         ERR.SME_BADDEP(so, luci.util.serialize_data(s.depends))
 474                                                                 )
 475                                                         end
 476                                                 elseif k == "dynamic" or k == "unique" or
 477                                                        k == "required" or k == "named"
 478                                                 then
 479                                                         s[k] = _bool(v2)
 480                                                 else
 481                                                         s[k] = v2
 482                                                 end
 483                                         end
 484                                 end
 485
 486                                 s.dynamic  = s.dynamic  or false
 487                                 s.unique   = s.unique   or false
 488                                 s.required = s.required or false
 489                                 s.named    = s.named    or false
 490                         end
 491                 end
 492         end
 493
 494         -- Step 2: get all variables
 495         for i, conf in ipairs( schemes ) do
 496                 for k, v in pairs( conf ) do
 497                         if v['.type'] == "variable" then
 498
 499                                 ok, err = _req( TYPE_VARIABLE, v, { "name", "section" } )
 500                                 if err then return false, scheme:error(err) end
 501
 502                                 local r, err = _ref( TYPE_VARIABLE, v )
 503                                 if err then return false, scheme:error(err) end
 504
 505                                 local p = self.packages[r[1]]
 506                                 if not p then
 507                                         return false, scheme:error(
 508                                                 ERR.SME_VBADPACK({scheme:sid(), '', v.name}, r[1])
 509                                         )
 510                                 end
 511
 512                                 local s = p.variables[r[2]]
 513                                 if not s then
 514                                         return false, scheme:error(
 515                                                 ERR.SME_VBADSECT({scheme:sid(), '', v.name}, r[2])
 516                                         )
 517                                 end
 518
 519                                 s[v.name] = s[v.name] or { }
 520
 521                                 local t  = s[v.name]
 522                                 local so = scheme:section(r[2])
 523                                 local to = so:option(v.name)
 524
 525                                 for k, v2 in pairs(v) do
 526                                         if k ~= "name" and k ~= "section" and k:sub(1,1) ~= "." then
 527                                                 if k == "depends" then
 528                                                         t.depends = self:_read_dependency( v2, t.depends )
 529                                                         if not t.depends then
 530                                                                 return false, scheme:error(so:error(
 531                                                                         ERR.SME_BADDEP(to, luci.util.serialize_data(v2))
 532                                                                 ))
 533                                                         end
 534                                                 elseif k == "validator" then
 535                                                         t.validators = self:_read_validator( v2, t.validators )
 536                                                         if not t.validators then
 537                                                                 return false, scheme:error(so:error(
 538                                                                         ERR.SME_BADVAL(to, luci.util.serialize_data(v2))
 539                                                                 ))
 540                                                         end
 541                                                 elseif k == "valueof" then
 542                                                         local values, err = self:_read_reference( v2 )
 543                                                         if err then
 544                                                                 return false, scheme:error(so:error(
 545                                                                         ERR.REFERENCE(to, luci.util.serialize_data(v2)):child(err)
 546                                                                 ))
 547                                                         end
 548                                                         t.type   = "reference"
 549                                                         t.values = values
 550                                                 elseif k == "required" then
 551                                                         t[k] = _bool(v2)
 552                                                 else
 553                                                         t[k] = t[k] or v2
 554                                                 end
 555                                         end
 556                                 end
 557
 558                                 t.type     = t.type     or "variable"
 559                                 t.datatype = t.datatype or "string"
 560                                 t.required = t.required or false
 561                         end
 562                 end
 563         end
 564
 565         -- Step 3: get all enums
 566         for i, conf in ipairs( schemes ) do
 567                 for k, v in pairs( conf ) do
 568                         if v['.type'] == "enum" then
 569
 570                                 ok, err = _req( TYPE_ENUM, v, { "value", "variable" } )
 571                                 if err then return false, scheme:error(err) end
 572
 573                                 local r, err = _ref( TYPE_ENUM, v )
 574                                 if err then return false, scheme:error(err) end
 575
 576                                 local p = self.packages[r[1]]
 577                                 if not p then
 578                                         return false, scheme:error(
 579                                                 ERR.SME_EBADPACK({scheme:sid(), '', '', v.value}, r[1])
 580                                         )
 581                                 end
 582
 583                                 local s = p.variables[r[2]]
 584                                 if not s then
 585                                         return false, scheme:error(
 586                                                 ERR.SME_EBADSECT({scheme:sid(), '', '', v.value}, r[2])
 587                                         )
 588                                 end
 589
 590                                 local t = s[r[3]]
 591                                 if not t then
 592                                         return false, scheme:error(
 593                                                 ERR.SME_EBADOPT({scheme:sid(), '', '', v.value}, r[3])
 594                                         )
 595                                 end
 596
 597
 598                                 local so = scheme:section(r[2])
 599                                 local oo = so:option(r[3])
 600                                 local eo = oo:enum(v.value)
 601
 602                                 if t.type ~= "enum" then
 603                                         return false, scheme:error(ERR.SME_EBADTYPE(eo))
 604                                 end
 605
 606                                 if not t.values then
 607                                         t.values = { [v.value] = v.title or v.value }
 608                                 else
 609                                         t.values[v.value] = v.title or v.value
 610                                 end
 611
 612                                 if not t.enum_depends then
 613                                         t.enum_depends = { }
 614                                 end
 615
 616                                 if v.default then
 617                                         if t.default then
 618                                                 return false, scheme:error(ERR.SME_EBADDEF(eo))
 619                                         end
 620                                         t.default = v.value
 621                                 end
 622
 623                                 if v.depends then
 624                                         t.enum_depends[v.value] = self:_read_dependency(
 625                                                 v.depends, t.enum_depends[v.value]
 626                                         )
 627
 628                                         if not t.enum_depends[v.value] then
 629                                                 return false, scheme:error(so:error(oo:error(
 630                                                         ERR.SME_BADDEP(eo, luci.util.serialize_data(v.depends))
 631                                                 )))
 632                                         end
 633                                 end
 634                         end
 635                 end
 636         end
 637
 638         return self
 639 end
 640
 641 -- Read a dependency specification
 642 function UVL._read_dependency( self, values, deps )
 643         local expr = "%$?[a-zA-Z0-9_]+"
 644         if values then
 645                 values = ( type(values) == "table" and values or { values } )
 646                 for _, value in ipairs(values) do
 647                         local parts     = luci.util.split( value, "%s*,%s*", nil, true )
 648                         local condition = { }
 649                         for i, val in ipairs(parts) do
 650                                 local k, v = unpack(luci.util.split(val, "%s*=%s*", nil, true))
 651
 652                                 if k and (
 653                                         k:match("^"..expr.."%."..expr.."%."..expr.."$") or
 654                                         k:match("^"..expr.."%."..expr.."$") or
 655                                         k:match("^"..expr.."$")
 656                                 ) then
 657                                         condition[k] = v or true
 658                                 else
 659                                         return nil
 660                                 end
 661                         end
 662
 663                         if not deps then
 664                                 deps = { condition }
 665                         else
 666                                 table.insert( deps, condition )
 667                         end
 668                 end
 669         end
 670
 671         return deps
 672 end
 673
 674 -- Read a validator specification
 675 function UVL._read_validator( self, values, validators )
 676         if values then
 677                 values = ( type(values) == "table" and values or { values } )
 678                 for _, value in ipairs(values) do
 679                         local validator
 680
 681                         if value:match("^exec:") then
 682                                 validator = value:gsub("^exec:","")
 683                         elseif value:match("^lua:") then
 684                                 validator = self:_resolve_function( (value:gsub("^lua:","") ) )
 685                         end
 686
 687                         if validator then
 688                                 if not validators then
 689                                         validators = { validator }
 690                                 else
 691                                         table.insert( validators, validator )
 692                                 end
 693                         else
 694                                 return nil
 695                         end
 696                 end
 697
 698                 return validators
 699         end
 700 end
 701
 702 -- Read a reference specification (XXX: We should validate external configs too...)
 703 function UVL._read_reference( self, values )
 704         local val = { }
 705         values = ( type(values) == "table" and values or { values } )
 706
 707         for _, value in ipairs(values) do
 708                 local ref = luci.util.split(value, ".")
 709
 710                 if #ref == 2 or #ref == 3 then
 711                         local co = luci.uvl.config( self, ref[1] )
 712                         if not co:config() then return false, co:errors() end
 713
 714                         for k, v in pairs(co:config()) do
 715                                 if v['.type'] == ref[2] then
 716                                         if #ref == 2 then
 717                                                 if v['.anonymous'] == true then
 718                                                         return false, ERR.SME_INVREF('', value)
 719                                                 end
 720                                                 val[k] = k      -- XXX: title/description would be nice
 721                                         elseif v[ref[3]] then
 722                                                 val[v[ref[3]]] = v[ref[3]]  -- XXX: dito
 723                                         end
 724                                 end
 725                         end
 726                 else
 727                         return false, ERR.SME_BADREF('', value)
 728                 end
 729         end
 730
 731         return val, nil
 732 end
 733
 734 -- Resolve given path
 735 function UVL._resolve_function( self, value )
 736         local path = luci.util.split(value, ".")
 737
 738         for i=1, #path-1 do
 739                 local stat, mod = luci.util.copcall(
 740                         require, table.concat(path, ".", 1, i)
 741                 )
 742
 743                 if stat and mod then
 744                         for j=i+1, #path-1 do
 745                                 if not type(mod) == "table" then
 746                                         break
 747                                 end
 748                                 mod = mod[path[j]]
 749                                 if not mod then
 750                                         break
 751                                 end
 752                         end
 753                         mod = type(mod) == "table" and mod[path[#path]] or nil
 754                         if type(mod) == "function" then
 755                                 return mod
 756                         end
 757                 end
 758         end
 759 end
 760
 761
 762 --- Object representation of an uvl item - base class.
 763 uvlitem = luci.util.class()
 764
 765 function uvlitem.cid(self)
 766         return table.concat( self.cref, '.' )
 767 end
 768
 769 function uvlitem.sid(self)
 770         return table.concat( self.sref, '.' )
 771 end
 772
 773 function uvlitem.scheme(self, opt)
 774         local s
 775
 776         if #self.sref == 4 or #self.sref == 3 then
 777                 s = self.s
 778                         .packages[self.sref[1]]
 779                         .variables[self.sref[2]][self.sref[3]]
 780         elseif #self.sref == 2 then
 781                 s = self.s
 782                         .packages[self.sref[1]]
 783                         .sections[self.sref[2]]
 784         else
 785                 s = self.s
 786                         .packages[self.sref[1]]
 787         end
 788
 789         if s and opt then
 790                 return s[opt]
 791         elseif s then
 792                 return s
 793         end
 794 end
 795
 796 function uvlitem.config(self, opt)
 797         local c
 798
 799         if #self.cref == 4 or #self.cref == 3 then
 800                 c = self.c and self.c[self.cref[2]] or nil
 801                 c = c      and c[self.cref[3]]      or nil
 802         elseif #self.cref == 2 then
 803                 c = self.c and self.c[self.cref[2]] or nil
 804         else
 805                 c = self.c
 806         end
 807
 808         if c and opt then
 809                 return c[opt]
 810         elseif c then
 811                 return c
 812         end
 813 end
 814
 815 function uvlitem.title(self)
 816         return self:scheme() and self:scheme('title') or
 817                 self.cref[3] or self.cref[2] or self.cref[1]
 818 end
 819
 820 function uvlitem.type(self)
 821         if self.t == luci.uvl.TYPE_CONFIG then
 822                 return 'config'
 823         elseif self.t == luci.uvl.TYPE_SECTION then
 824                 return 'section'
 825         elseif self.t == luci.uvl.TYPE_OPTION then
 826                 return 'option'
 827         elseif self.t == luci.uvl.TYPE_ENUM then
 828                 return 'enum'
 829         end
 830 end
 831
 832 function uvlitem.error(self, ...)
 833         if not self.e then
 834                 local errconst = { ERR.CONFIG, ERR.SECTION, ERR.OPTION, ERR.OPTION }
 835                 self.e = errconst[#self.cref]( self )
 836         end
 837
 838         return self.e:child( ... )
 839 end
 840
 841 function uvlitem.errors(self)
 842         return self.e
 843 end
 844
 845 function uvlitem.ok(self)
 846         return not self:errors()
 847 end
 848
 849 function uvlitem.parent(self)
 850         if self.p then
 851                 return self.p
 852         elseif #self.cref == 3 or #self.cref == 4 then
 853                 return luci.uvl.section( self.s, self.c, self.cref[1], self.cref[2] )
 854         elseif #self.cref == 2 then
 855                 return luci.uvl.config( self.s, self.c, self.cref[1] )
 856         else
 857                 return nil
 858         end
 859 end
 860
 861 function uvlitem._loadconf(self, co, c)
 862         if not co then
 863                 local uci, err = luci.model.uci.cursor(), nil
 864                 co, err = uci:get_all(c)
 865
 866                 if err then
 867                         self:error(ERR.UCILOAD(self, err))
 868                 end
 869         end
 870         return co
 871 end
 872
 873
 874 --- Object representation of a scheme.
 875 -- @class       scheme
 876 -- @cstyle      instance
 877 -- @name        luci.uvl.scheme
 878
 879 --- Scheme instance constructor.
 880 -- @class                       function
 881 -- @name                        scheme
 882 -- @param scheme        Scheme instance
 883 -- @param co            Configuration data
 884 -- @param c                     Configuration name
 885 -- @return                      Config instance
 886 scheme = luci.util.class(uvlitem)
 887
 888 function scheme.__init__(self, scheme, co, c)
 889         if not c then
 890                 c, co = co, nil
 891         end
 892
 893         self.cref = { c }
 894         self.sref = { c }
 895         self.c    = self:_loadconf(co, c)
 896         self.s    = scheme
 897         self.t    = luci.uvl.TYPE_SCHEME
 898 end
 899
 900 --- Add an error to scheme.
 901 -- @return      Scheme error context
 902 function scheme.error(self, ...)
 903         if not self.e then self.e = ERR.SCHEME( self ) end
 904         return self.e:child( ... )
 905 end
 906
 907 --- Get an associated config object.
 908 -- @return      Config instance
 909 function scheme.config(self)
 910         local co = luci.uvl.config( self.s, self.cref[1] )
 911               co.p = self
 912
 913         return co
 914 end
 915
 916 --- Get all section objects associated with this scheme.
 917 -- @return      Table containing all associated luci.uvl.section instances
 918 function scheme.sections(self)
 919         local v = { }
 920         if self.s.packages[self.sref[1]].sections then
 921                 for o, _ in pairs( self.s.packages[self.sref[1]].sections ) do
 922                         table.insert( v, luci.uvl.option(
 923                                 self.s, self.c, self.cref[1], self.cref[2], o
 924                         ) )
 925                 end
 926         end
 927         return v
 928 end
 929
 930 --- Get an associated section object.
 931 -- @param s     Section to select
 932 -- @return      Section instance
 933 function scheme.section(self, s)
 934         local so = luci.uvl.section( self.s, self.c, self.cref[1], s )
 935               so.p = self
 936
 937         return so
 938 end
 939
 940
 941 --- Object representation of a config.
 942 -- @class       config
 943 -- @cstyle      instance
 944 -- @name        luci.uvl.config
 945
 946 --- Config instance constructor.
 947 -- @class                       function
 948 -- @name                        config
 949 -- @param scheme        Scheme instance
 950 -- @param co            Configuration data
 951 -- @param c                     Configuration name
 952 -- @return                      Config instance
 953 config = luci.util.class(uvlitem)
 954
 955 function config.__init__(self, scheme, co, c)
 956         if not c then
 957                 c, co = co, nil
 958         end
 959
 960         self.cref = { c }
 961         self.sref = { c }
 962         self.c    = self:_loadconf(co, c)
 963         self.s    = scheme
 964         self.t    = luci.uvl.TYPE_CONFIG
 965 end
 966
 967 --- Get all section objects associated with this config.
 968 -- @return      Table containing all associated luci.uvl.section instances
 969 function config.sections(self)
 970         local v = { }
 971         if self.s.packages[self.sref[1]].sections then
 972                 for o, _ in pairs( self.s.packages[self.sref[1]].sections ) do
 973                         table.insert( v, luci.uvl.option(
 974                                 self.s, self.c, self.cref[1], self.cref[2], o
 975                         ) )
 976                 end
 977         end
 978         return v
 979 end
 980
 981 --- Get an associated section object.
 982 -- @param s     Section to select
 983 -- @return      Section instance
 984 function config.section(self, s)
 985         local so = luci.uvl.section( self.s, self.c, self.cref[1], s )
 986               so.p = self
 987
 988         return so
 989 end
 990
 991
 992 --- Object representation of a scheme/config section.
 993 -- @class       module
 994 -- @cstyle      instance
 995 -- @name        luci.uvl.section
 996
 997 --- Section instance constructor.
 998 -- @class                       function
 999 -- @name                        section
1000 -- @param scheme        Scheme instance
1001 -- @param co            Configuration data
1002 -- @param c                     Configuration name
1003 -- @param s                     Section name
1004 -- @return                      Section instance
1005 section = luci.util.class(uvlitem)
1006
1007 function section.__init__(self, scheme, co, c, s)
1008         self.cref = { c, s }
1009         self.sref = { c, co and co[s] and co[s]['.type'] or s }
1010         self.c    = self:_loadconf(co, c)
1011         self.s    = scheme
1012         self.t    = luci.uvl.TYPE_SECTION
1013 end
1014
1015 --- Get all option objects associated with this section.
1016 -- @return      Table containing all associated luci.uvl.option instances
1017 function section.variables(self)
1018         local v = { }
1019         if self.s.packages[self.sref[1]].variables[self.sref[2]] then
1020                 for o, _ in pairs(
1021                         self.s.packages[self.sref[1]].variables[self.sref[2]]
1022                 ) do
1023                         table.insert( v, luci.uvl.option(
1024                                 self.s, self.c, self.cref[1], self.cref[2], o
1025                         ) )
1026                 end
1027         end
1028         return v
1029 end
1030
1031 --- Get an associated option object.
1032 -- @param o     Option to select
1033 -- @return      Option instance
1034 function section.option(self, o)
1035         local oo = luci.uvl.option( self.s, self.c, self.cref[1], self.cref[2], o )
1036               oo.p = self
1037
1038         return oo
1039 end
1040
1041
1042 --- Object representation of a scheme/config option.
1043 -- @class       module
1044 -- @cstyle      instance
1045 -- @name        luci.uvl.option
1046
1047 --- Section instance constructor.
1048 -- @class                       function
1049 -- @name                        option
1050 -- @param scheme        Scheme instance
1051 -- @param co            Configuration data
1052 -- @param c                     Configuration name
1053 -- @param s                     Section name
1054 -- @param o                     Option name
1055 -- @return                      Option instance
1056 option = luci.util.class(uvlitem)
1057
1058 function option.__init__(self, scheme, co, c, s, o)
1059         self.cref = { c, s, o }
1060         self.sref = { c, co and co[s] and co[s]['.type'] or s, o }
1061         self.c    = self:_loadconf(co, c)
1062         self.s    = scheme
1063         self.t    = luci.uvl.TYPE_OPTION
1064 end
1065
1066 --- Get the value of this option.
1067 -- @return      The associated configuration value
1068 function option.value(self)
1069         return self:config()
1070 end
1071
1072 --- Get the associated section information in scheme.
1073 -- @return      Table containing the scheme properties
1074 function option.section(self)
1075         return self.s.packages[self.sref[1]].sections[self.sref[2]]
1076 end
1077
1078 --- Construct an enum object instance from given or default value.
1079 -- @param v     Value to select
1080 -- @return      Enum instance for selected value
1081 function option.enum(self, val)
1082         return enum(
1083                 self.s, self.c,
1084                 self.cref[1], self.cref[2], self.cref[3],
1085                 val or self:value()
1086         )
1087 end
1088
1089
1090 --- Object representation of a enum value.
1091 -- @class       module
1092 -- @cstyle      instance
1093 -- @name        luci.uvl.enum
1094
1095 --- Section instance constructor.
1096 -- @class                       function
1097 -- @name                        enum
1098 -- @param scheme        Scheme instance
1099 -- @param co            Configuration data
1100 -- @param c                     Configuration name
1101 -- @param s                     Section name
1102 -- @param o                     Enum name
1103 -- @param v                     Enum value
1104 -- @return                      Enum value instance
1105 enum = luci.util.class(option)
1106
1107 function enum.__init__(self, scheme, co, c, s, o, v)
1108         self.cref = { c, s, o, v }
1109         self.sref = { c, co and co[s] and co[s]['.type'] or s, o, v }
1110         self.c    = self:_loadconf(co, c)
1111         self.s    = scheme
1112         self.t    = luci.uvl.TYPE_ENUM
1113 end