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 local fs = require "luci.fs"
  23 local uci = require "luci.model.uci"
  24 local util = require "luci.util"
  25 local table = require "table"
  26 local string = require "string"
  27
  28 local require, pcall, ipairs, pairs = require, pcall, ipairs, pairs
  29 local type, error, tonumber, tostring = type, error, tonumber, tostring
  30 local unpack, loadfile = unpack, loadfile
  31
  32 module "luci.uvl"
  33
  34 local ERR = require "luci.uvl.errors"
  35 local datatypes = require "luci.uvl.datatypes"
  36 local validation = require "luci.uvl.validation"
  37 local dependencies = require "luci.uvl.dependencies"
  38
  39 local TYPE_SCHEME   = 0x00
  40 local TYPE_CONFIG   = 0x01
  41 local TYPE_SECTION  = 0x02
  42 local TYPE_OPTION   = 0x03
  43 local TYPE_ENUM     = 0x04
  44
  45 --- Boolean; default true;
  46 -- treat sections found in config but not in scheme as error
  47 STRICT_UNKNOWN_SECTIONS    = true
  48
  49 --- Boolean; default true;
  50 -- treat options found in config but not in scheme as error
  51 STRICT_UNKNOWN_OPTIONS     = true
  52
  53 --- Boolean; default true;
  54 -- treat failed external validators as error
  55 STRICT_EXTERNAL_VALIDATORS = true
  56
  57 --- Boolean; default true;
  58 -- treat list values stored as options like errors
  59 STRICT_LIST_TYPE           = true
  60
  61
  62 local default_schemedir = "/lib/uci/schema"
  63 local default_savedir = "/tmp/.uvl"
  64
  65
  66 --- Object constructor
  67 -- @class                       function
  68 -- @name                        UVL
  69 -- @param schemedir     Path to the scheme directory (optional)
  70 -- @return                      Instance object
  71 UVL = util.class()
  72
  73 function UVL.__init__( self, schemedir )
  74         self.schemedir  = schemedir or default_schemedir
  75         self.packages   = { }
  76         self.beenthere  = { }
  77         self.depseen    = { }
  78         self.uci                = uci
  79         self.err                = ERR
  80         self.dep                = dependencies
  81         self.datatypes  = datatypes
  82 end
  83
  84
  85 --- Parse given scheme and return the scheme tree.
  86 -- @param scheme        Name of the scheme to parse
  87 -- @return                      Table containing the parsed scheme or nil on error
  88 -- @return                      String containing the reason for errors (if any)
  89 function UVL.get_scheme( self, scheme )
  90         if not self.packages[scheme] then
  91                 local ok, err = self:read_scheme( scheme )
  92                 if not ok then
  93                         return nil, err
  94                 end
  95         end
  96         return self.packages[scheme], nil
  97 end
  98
  99 --- Validate given configuration, section or option.
 100 -- @param config        Name of the configuration to validate
 101 -- @param section       Name of the section to validate (optional)
 102 -- @param option        Name of the option to validate (optional)
 103 -- @return                      Boolean indicating whether the given config validates
 104 -- @return                      String containing the reason for errors (if any)
 105 function UVL.validate( self, config, section, option )
 106         if config and section and option then
 107                 return self:validate_option( config, section, option )
 108         elseif config and section then
 109                 return self:validate_section( config, section )
 110         elseif config then
 111                 return self:validate_config( config )
 112         end
 113 end
 114
 115 --- Validate given configuration.
 116 -- @param cfg   Name of the configuration to validate
 117 -- @return                      Boolean indicating whether the given config validates
 118 -- @return                      String containing the reason for errors (if any)
 119 function UVL.validate_config( self, cfg, uci )
 120
 121         if not self.packages[cfg] then
 122                 local ok, err = self:read_scheme(cfg)
 123                 if not ok then
 124                         return false, err
 125                 end
 126         end
 127
 128         local co = config( self, uci or cfg, uci and cfg )
 129         local sc = { }
 130
 131         self.beenthere = { }
 132         self.depseen   = { }
 133
 134         if not co:config() then
 135                 return false, co:errors()
 136         end
 137
 138         local function _uci_foreach( type, func )
 139                 for k, v in pairs(co:config()) do
 140                         if v['.type'] == type then
 141                                 sc[type] = sc[type] + 1
 142                                 local ok, err = func( k, v )
 143                                 if not ok then co:error(err) end
 144                         end
 145                 end
 146         end
 147
 148         for k, v in pairs( self.packages[cfg].sections ) do
 149                 sc[k] = 0
 150                 _uci_foreach( k,
 151                         function(s)
 152                                 return self:_validate_section( co:section(s) )
 153                         end
 154                 )
 155         end
 156
 157         if STRICT_UNKNOWN_SECTIONS then
 158                 for k, v in pairs(co:config()) do
 159                         local so = co:section(k)
 160                         if not self.beenthere[so:cid()] then
 161                                 co:error(ERR.SECT_UNKNOWN(so))
 162                         end
 163                 end
 164         end
 165
 166         for _, k in ipairs(util.keys(sc)) do
 167                 local so = co:section(k)
 168                 if so:scheme('required') and sc[k] == 0 then
 169                         co:error(ERR.SECT_REQUIRED(so))
 170                 elseif so:scheme('unique') and sc[k] > 1 then
 171                         co:error(ERR.SECT_UNIQUE(so))
 172                 end
 173         end
 174
 175         return co:ok(), co:errors()
 176 end
 177
 178 --- Validate given config section.
 179 -- @param config        Name of the configuration to validate
 180 -- @param section       Name of the section to validate
 181 -- @return                      Boolean indicating whether the given config validates
 182 -- @return                      String containing the reason for errors (if any)
 183 function UVL.validate_section( self, cfg, section, uci )
 184
 185         if not self.packages[cfg] then
 186                 local ok, err = self:read_scheme( cfg )
 187                 if not ok then
 188                         return false, err
 189                 end
 190         end
 191
 192         local co = config( self, uci or cfg, uci and cfg )
 193         local so = co:section( section )
 194
 195         self.beenthere = { }
 196         self.depseen   = { }
 197
 198         if not co:config() then
 199                 return false, co:errors()
 200         end
 201
 202         if so:config() then
 203                 return self:_validate_section( so )
 204         else
 205                 return false, ERR.SECT_NOTFOUND(so)
 206         end
 207 end
 208
 209 --- Validate given config option.
 210 -- @param config        Name of the configuration to validate
 211 -- @param section       Name of the section to validate
 212 -- @param option        Name of the option to validate
 213 -- @return                      Boolean indicating whether the given config validates
 214 -- @return                      String containing the reason for errors (if any)
 215 function UVL.validate_option( self, cfg, section, option, uci )
 216
 217         if not self.packages[cfg] then
 218                 local ok, err = self:read_scheme( cfg )
 219                 if not ok then
 220                         return false, err
 221                 end
 222         end
 223
 224         local co = config( self, uci or cfg, uci and cfg )
 225         local so = co:section( section )
 226         local oo = so:option( option )
 227
 228         if not co:config() then
 229                 return false, co:errors()
 230         end
 231
 232         if so:config() and oo:config() then
 233                 return self:_validate_option( oo )
 234         else
 235                 return false, ERR.OPT_NOTFOUND(oo)
 236         end
 237 end
 238
 239
 240 function UVL._validate_section( self, section )
 241
 242         self.beenthere[section:cid()] = true
 243
 244         if section:config() then
 245                 if section:scheme('named') == true and
 246                    section:config('.anonymous') == true
 247                 then
 248                         return false, ERR.SECT_NAMED(section)
 249                 end
 250
 251                 for _, v in ipairs(section:variables()) do
 252                         local ok, err = self:_validate_option( v )
 253                         if not ok and (
 254                                 v:scheme('required') or v:scheme('type') == "enum" or (
 255                                         not err:is(ERR.ERR_DEP_NOTEQUAL) and
 256                                         not err:is(ERR.ERR_DEP_NOVALUE)
 257                                 )
 258                         ) then
 259                                 section:error(err)
 260                         end
 261                 end
 262
 263                 local ok, err = dependencies.check( self, section )
 264                 if not ok then
 265                         section:error(err)
 266                 end
 267         else
 268                 return false, ERR.SECT_NOTFOUND(section)
 269         end
 270
 271         if STRICT_UNKNOWN_OPTIONS and not section:scheme('dynamic') then
 272                 for k, v in pairs(section:config()) do
 273                         local oo = section:option(k)
 274                         if k:sub(1,1) ~= "." and not self.beenthere[oo:cid()] then
 275                                 section:error(ERR.OPT_UNKNOWN(oo))
 276                         end
 277                 end
 278         end
 279
 280         return section:ok(), section:errors()
 281 end
 282
 283 function UVL._validate_option( self, option, nodeps )
 284
 285         self.beenthere[option:cid()] = true
 286
 287         if not option:scheme() and not option:parent():scheme('dynamic') then
 288                 if STRICT_UNKNOWN_OPTIONS then
 289                         return false, option:error(ERR.OPT_UNKNOWN(option))
 290                 else
 291                         return true
 292                 end
 293
 294         elseif option:scheme() then
 295                 if option:scheme('required') and not option:value() then
 296                         return false, option:error(ERR.OPT_REQUIRED(option))
 297
 298                 elseif option:value() then
 299                         local val = option:value()
 300
 301                         if option:scheme('type') == "reference" or
 302                            option:scheme('type') == "enum"
 303                         then
 304                                 local scheme_values = option:scheme('values') or { }
 305                                 local config_values = ( type(val) == "table" and val or { val } )
 306                                 for _, v in ipairs(config_values) do
 307                                         if not scheme_values[v] then
 308                                                 return false, option:error( ERR.OPT_BADVALUE(
 309                                                         option, { v, util.serialize_data(
 310                                                                 util.keys(scheme_values)
 311                                                         ) }
 312                                                 ) )
 313                                         end
 314                                 end
 315                         elseif option:scheme('type') == "list" then
 316                                 if type(val) ~= "table" and STRICT_LIST_TYPE then
 317                                         return false, option:error(ERR.OPT_NOTLIST(option))
 318                                 end
 319                         end
 320
 321                         if option:scheme('datatype') then
 322                                 local dt = option:scheme('datatype')
 323
 324                                 if self.datatypes[dt] then
 325                                         val = ( type(val) == "table" and val or { val } )
 326                                         for i, v in ipairs(val) do
 327                                                 if not self.datatypes[dt]( v ) then
 328                                                         return false, option:error(
 329                                                                 ERR.OPT_INVVALUE(option, { v, dt })
 330                                                         )
 331                                                 end
 332                                         end
 333                                 else
 334                                         return false, option:error(ERR.OPT_DATATYPE(option, dt))
 335                                 end
 336                         end
 337
 338                         val = ( type(val) == "table" and val or { val } )
 339                         for _, v in ipairs(val) do
 340                                 if option:scheme('minlength') then
 341                                         if #v < option:scheme('minlength') then
 342                                                 return false, option:error(ERR.OPT_RANGE(option))
 343                                         end
 344                                 end
 345
 346                                 if option:scheme('maxlength') then
 347                                         if #v > option:scheme('maxlength') then
 348                                                 return false, option:error(ERR.OPT_RANGE(option))
 349                                         end
 350                                 end
 351
 352                                 v = tonumber(v)
 353
 354                                 if option:scheme('minimum') then
 355                                         if not v or v < option:scheme('minimum') then
 356                                                 return false, option:error(ERR.OPT_RANGE(option))
 357                                         end
 358                                 end
 359
 360                                 if option:scheme('maximum') then
 361                                         if not v or v > option:scheme('maximum') then
 362                                                 return false, option:error(ERR.OPT_RANGE(option))
 363                                         end
 364                                 end
 365                         end
 366
 367                         if not nodeps then
 368                                 local ok, err = dependencies.check( self, option )
 369                                 if not ok then
 370                                         option:error(err)
 371                                 end
 372                         end
 373                 end
 374
 375                 local ok, err = validation.check( self, option )
 376                 if not ok and STRICT_EXTERNAL_VALIDATORS then
 377                         return false, option:error(err)
 378                 end
 379         end
 380
 381         return option:ok(), option:errors()
 382 end
 383
 384 --- Find all parts of given scheme and construct validation tree.
 385 -- This is normally done on demand, so you don't have to call this function
 386 -- by yourself.
 387 -- @param shm   Name of the scheme to parse
 388 -- @param alias         Create an alias for the loaded scheme
 389 function UVL.read_scheme( self, shm, alias )
 390
 391         local so = scheme( self, shm )
 392         local bc = "%s/bytecode/%s.lua" %{ self.schemedir, shm }
 393
 394         if not fs.access(bc) then
 395                 local files = fs.glob(self.schemedir .. '/*/' .. shm)
 396
 397                 if files then
 398                         local ok, err
 399                         for i, file in ipairs( files ) do
 400                                 if not fs.access(file) then
 401                                         return false, so:error(ERR.SME_READ(so,file))
 402                                 end
 403
 404                                 local uci = uci.cursor( fs.dirname(file), default_savedir )
 405
 406                                 local sname = fs.basename(file)
 407                                 local sd, err = uci:load( sname )
 408
 409                                 if not sd then
 410                                         return false, ERR.UCILOAD(so, err)
 411                                 end
 412
 413                                 ok, err = pcall(function()
 414                                         uci:foreach(sname, "package", function(s)
 415                                                 self:_parse_package(so, s[".name"], s)
 416                                         end)
 417                                         uci:foreach(sname, "section", function(s)
 418                                                 self:_parse_section(so, s[".name"], s)
 419                                         end)
 420                                         uci:foreach(sname, "variable", function(s)
 421                                                 self:_parse_var(so, s[".name"], s)
 422                                         end)
 423                                         uci:foreach(sname, "enum", function(s)
 424                                                 self:_parse_enum(so, s[".name"], s)
 425                                         end)
 426
 427                                 end)
 428                         end
 429
 430                         if ok and alias then self.packages[alias] = self.packages[shm] end
 431                         return ok and self, err
 432                 else
 433                         return false, so:error(ERR.SME_FIND(so, self.schemedir))
 434                 end
 435         else
 436                 local sc = loadfile(bc)
 437                 if sc then
 438                         self.packages[shm] = sc()
 439                         return true
 440                 else
 441                         return false, so:error(ERR.SME_READ(so,bc))
 442                 end
 443         end
 444 end
 445
 446 -- helper function to check for required fields
 447 local function _req( t, n, c, r )
 448         for i, v in ipairs(r) do
 449                 if not c[v] then
 450                         local p, o = scheme:sid(), nil
 451
 452                         if t == TYPE_SECTION then
 453                                 o = section( scheme, nil, p, n )
 454                         elseif t == TYPE_OPTION then
 455                                 o = option( scheme, nil, p, '(nil)', n )
 456                         elseif t == TYPE_ENUM then
 457                                 o = enum( scheme, nil, p, '(nil)', '(nil)', n )
 458                         end
 459
 460                         return false, ERR.SME_REQFLD(o,v)
 461                 end
 462         end
 463         return true
 464 end
 465
 466 -- helper function to validate references
 467 local function _ref( c, t )
 468         local r, k, n = {}
 469         if c == TYPE_SECTION then
 470                 k = "package"
 471                 n = 1
 472         elseif c == TYPE_OPTION then
 473                 k = "section"
 474                 n = 2
 475         elseif c == TYPE_ENUM then
 476                 k = "variable"
 477                 n = 3
 478         end
 479
 480         for o in t[k]:gmatch("[^.]+") do
 481                 r[#r+1] = o
 482         end
 483         r[1] = ( #r[1] > 0 and r[1] or scheme:sid() )
 484
 485         if #r ~= n then
 486                 return false, ERR.SME_BADREF(scheme, k)
 487         end
 488
 489         return r
 490 end
 491
 492 -- helper function to read bools
 493 local function _bool( v )
 494         return ( v == "true" or v == "yes" or v == "on" or v == "1" )
 495 end
 496
 497 -- Step 0: get package meta information
 498 function UVL._parse_package(self, scheme, k, v)
 499         local sid = scheme:sid()
 500         local pkg = self.packages[sid] or {
 501                 ["name"]      = sid;
 502                 ["sections"]  = { };
 503                 ["variables"] = { };
 504         }
 505
 506         pkg.title = v.title
 507         pkg.description = v.description
 508
 509         self.packages[sid] = pkg
 510 end
 511
 512 -- Step 1: get all sections
 513 function UVL._parse_section(self, scheme, k, v)
 514         local ok, err = _req( TYPE_SECTION, k, v, { "name", "package" } )
 515         if err then error(scheme:error(err)) end
 516
 517         local r, err = _ref( TYPE_SECTION, v )
 518         if err then error(scheme:error(err)) end
 519
 520         local p = self.packages[r[1]] or {
 521                 ["name"]      = r[1];
 522                 ["sections"]  = { };
 523                 ["variables"] = { };
 524         }
 525         p.sections[v.name]  = p.sections[v.name]  or { }
 526         p.variables[v.name] = p.variables[v.name] or { }
 527         self.packages[r[1]] = p
 528
 529         local s  = p.sections[v.name]
 530         local so = scheme:section(v.name)
 531
 532         for k, v2 in pairs(v) do
 533                 if k ~= "name" and k ~= "package" and k:sub(1,1) ~= "." then
 534                         if k == "depends" then
 535                                 s.depends = self:_read_dependency( v2, s.depends )
 536                                 if not s.depends then
 537                                         return false, scheme:error(
 538                                                 ERR.SME_BADDEP(so, util.serialize_data(s.depends))
 539                                         )
 540                                 end
 541                         elseif k == "dynamic" or k == "unique" or
 542                                k == "required" or k == "named"
 543                         then
 544                                 s[k] = _bool(v2)
 545                         else
 546                                 s[k] = v2
 547                         end
 548                 end
 549         end
 550
 551         s.dynamic  = s.dynamic  or false
 552         s.unique   = s.unique   or false
 553         s.required = s.required or false
 554         s.named    = s.named    or false
 555 end
 556
 557
 558         -- Step 2: get all variables
 559 function UVL._parse_var(self, scheme, k, v)
 560         local ok, err = _req( TYPE_OPTION, k, v, { "name", "section" } )
 561         if err then error(scheme:error(err)) end
 562
 563         local r, err = _ref( TYPE_OPTION, v )
 564         if err then error(scheme:error(err)) end
 565
 566         local p = self.packages[r[1]]
 567         if not p then
 568                 error(scheme:error(
 569                         ERR.SME_VBADPACK({scheme:sid(), '', v.name}, r[1])
 570                 ))
 571         end
 572
 573         local s = p.variables[r[2]]
 574         if not s then
 575                 error(scheme:error(
 576                         ERR.SME_VBADSECT({scheme:sid(), '', v.name}, r[2])
 577                 ))
 578         end
 579
 580         s[v.name] = s[v.name] or { }
 581
 582         local t  = s[v.name]
 583         local so = scheme:section(r[2])
 584         local to = so:option(v.name)
 585
 586         for k, v2 in pairs(v) do
 587                 if k ~= "name" and k ~= "section" and k:sub(1,1) ~= "." then
 588                         if k == "depends" then
 589                                 t.depends = self:_read_dependency( v2, t.depends )
 590                                 if not t.depends then
 591                                         error(scheme:error(so:error(
 592                                                 ERR.SME_BADDEP(to, util.serialize_data(v2))
 593                                         )))
 594                                 end
 595                         elseif k == "validator" then
 596                                 t.validators = self:_read_validator( v2, t.validators )
 597                                 if not t.validators then
 598                                         error(scheme:error(so:error(
 599                                                 ERR.SME_BADVAL(to, util.serialize_data(v2))
 600                                         )))
 601                                 end
 602                         elseif k == "valueof" then
 603                                 local values, err = self:_read_reference( v2 )
 604                                 if err then
 605                                         error(scheme:error(so:error(
 606                                                 ERR.REFERENCE(to, util.serialize_data(v2)):child(err)
 607                                         )))
 608                                 end
 609                                 t.type   = "reference"
 610                                 t.values = values
 611                                 t.valueof = type(v2) == "table" and v2 or {v2}
 612                         elseif k == "required" then
 613                                 t[k] = _bool(v2)
 614                         elseif k == "minlength" or k == "maxlength"
 615                          or k == "minimum" or k == "maximum" then
 616                                 t[k] = tonumber(v2)
 617                         else
 618                                 t[k] = t[k] or v2
 619                         end
 620                 end
 621         end
 622
 623         t.type     = t.type     or "variable"
 624         t.datatype = t.datatype or "string"
 625         t.required = t.required or false
 626 end
 627
 628 -- Step 3: get all enums
 629 function UVL._parse_enum(self, scheme, k, v)
 630         local ok, err = _req( TYPE_ENUM, k, v, { "value", "variable" } )
 631         if err then error(scheme:error(err)) end
 632
 633         local r, err = _ref( TYPE_ENUM, v )
 634         if err then error(scheme:error(err)) end
 635
 636         local p = self.packages[r[1]]
 637         if not p then
 638                 error(scheme:error(
 639                         ERR.SME_EBADPACK({scheme:sid(), '', '', v.value}, r[1])
 640                 ))
 641         end
 642
 643         local s = p.variables[r[2]]
 644         if not s then
 645                 error(scheme:error(
 646                         ERR.SME_EBADSECT({scheme:sid(), '', '', v.value}, r[2])
 647                 ))
 648         end
 649
 650         local t = s[r[3]]
 651         if not t then
 652                 error(scheme:error(
 653                         ERR.SME_EBADOPT({scheme:sid(), '', '', v.value}, r[3])
 654                 ))
 655         end
 656
 657
 658         local so = scheme:section(r[2])
 659         local oo = so:option(r[3])
 660         local eo = oo:enum(v.value)
 661
 662         if t.type ~= "enum" and t.type ~= "reference" then
 663                 error(scheme:error(ERR.SME_EBADTYPE(eo)))
 664         end
 665
 666         if not t.values then
 667                 t.values = { [v.value] = v.title or v.value }
 668                 t.valuelist = { {value = v.value, title = v.title} }
 669         else
 670                 t.values[v.value] = v.title or v.value
 671                 t.valuelist[#t.valuelist + 1] = {value = v.value, title = v.title}
 672         end
 673
 674         if not t.enum_depends then
 675                 t.enum_depends = { }
 676         end
 677
 678         if v.default then
 679                 if t.default then
 680                         error(scheme:error(ERR.SME_EBADDEF(eo)))
 681                 end
 682                 t.default = v.value
 683         end
 684
 685         if v.depends then
 686                 t.enum_depends[v.value] = self:_read_dependency(
 687                         v.depends, t.enum_depends[v.value]
 688                 )
 689
 690                 if not t.enum_depends[v.value] then
 691                         error(scheme:error(so:error(oo:error(
 692                                 ERR.SME_BADDEP(eo, util.serialize_data(v.depends))
 693                         ))))
 694                 end
 695         end
 696 end
 697
 698 -- Read a dependency specification
 699 function UVL._read_dependency( self, values, deps )
 700         local expr = "%$?[%w_]+"
 701         if values then
 702                 values = ( type(values) == "table" and values or { values } )
 703                 for _, value in ipairs(values) do
 704                         local condition = { }
 705                         for val in value:gmatch("[^,]+") do
 706                                 local k, e, v = val:match("%s*([%w$_.]+)%s*(=?)%s*(.*)")
 707
 708                                 if k and (
 709                                         k:match("^"..expr.."%."..expr.."%."..expr.."$") or
 710                                         k:match("^"..expr.."%."..expr.."$") or
 711                                         k:match("^"..expr.."$")
 712                                 ) then
 713                                         condition[k] = (e == '=') and v or true
 714                                 else
 715                                         return nil
 716                                 end
 717                         end
 718
 719                         if not deps then
 720                                 deps = { condition }
 721                         else
 722                                 deps[#deps+1] = condition
 723                         end
 724                 end
 725         end
 726
 727         return deps
 728 end
 729
 730 -- Read a validator specification
 731 function UVL._read_validator( self, values, validators )
 732         if values then
 733                 values = ( type(values) == "table" and values or { values } )
 734                 for _, value in ipairs(values) do
 735                         local validator
 736
 737                         if value:match("^exec:") then
 738                                 validator = value:gsub("^exec:","")
 739                         elseif value:match("^lua:") then
 740                                 validator = self:_resolve_function( (value:gsub("^lua:","") ) )
 741                         elseif value:match("^regexp:") then
 742                                 local pattern = value:gsub("^regexp:","")
 743                                 validator = function( type, dtype, pack, sect, optn, ... )
 744                                         local values = { ... }
 745                                         for _, v in ipairs(values) do
 746                                                 local ok, match =
 747                                                         pcall( string.match, v, pattern )
 748
 749                                                 if not ok then
 750                                                         return false, match
 751                                                 elseif not match then
 752                                                         return false,
 753                                                                 'Value "%s" does not match pattern "%s"' % {
 754                                                                         v, pattern
 755                                                                 }
 756                                                 end
 757                                         end
 758                                         return true
 759                                 end
 760                         end
 761
 762                         if validator then
 763                                 if not validators then
 764                                         validators = { validator }
 765                                 else
 766                                         validators[#validators+1] = validator
 767                                 end
 768                         else
 769                                 return nil
 770                         end
 771                 end
 772
 773                 return validators
 774         end
 775 end
 776
 777 -- Read a reference specification (XXX: We should validate external configs too...)
 778 function UVL._read_reference( self, values )
 779         local val = { }
 780         values = ( type(values) == "table" and values or { values } )
 781
 782         for _, value in ipairs(values) do
 783                 local ref = util.split(value, ".")
 784
 785                 if #ref == 2 or #ref == 3 then
 786                         local co = config( self, ref[1] )
 787                         if not co:config() then return false, co:errors() end
 788
 789                         for k, v in pairs(co:config()) do
 790                                 if v['.type'] == ref[2] then
 791                                         if #ref == 2 then
 792                                                 if v['.anonymous'] == true then
 793                                                         return false, ERR.SME_INVREF('', value)
 794                                                 end
 795                                                 val[k] = k      -- XXX: title/description would be nice
 796                                         elseif v[ref[3]] then
 797                                                 val[v[ref[3]]] = v[ref[3]]  -- XXX: dito
 798                                         end
 799                                 end
 800                         end
 801                 else
 802                         return false, ERR.SME_BADREF('', value)
 803                 end
 804         end
 805
 806         return val, nil
 807 end
 808
 809 -- Resolve given path
 810 function UVL._resolve_function( self, value )
 811         local path = util.split(value, ".")
 812
 813         for i=1, #path-1 do
 814                 local stat, mod = pcall(
 815                         require, table.concat(path, ".", 1, i)
 816                 )
 817
 818                 if stat and mod then
 819                         for j=i+1, #path-1 do
 820                                 if not type(mod) == "table" then
 821                                         break
 822                                 end
 823                                 mod = mod[path[j]]
 824                                 if not mod then
 825                                         break
 826                                 end
 827                         end
 828                         mod = type(mod) == "table" and mod[path[#path]] or nil
 829                         if type(mod) == "function" then
 830                                 return mod
 831                         end
 832                 end
 833         end
 834 end
 835
 836
 837 --- Object representation of an uvl item - base class.
 838 uvlitem = util.class()
 839
 840 function uvlitem.cid(self)
 841         if #self.cref == 1 then
 842                 return self.cref[1]
 843         else
 844                 local r = { unpack(self.cref) }
 845                 local c = self.c
 846                 if c and c[r[2]] and c[r[2]]['.anonymous'] and c[r[2]]['.index'] then
 847                         r[2] = '@' .. c[r[2]]['.type'] ..
 848                                '[' .. tostring(c[r[2]]['.index']) .. ']'
 849                 end
 850                 return table.concat( r, '.' )
 851         end
 852 end
 853
 854 function uvlitem.sid(self)
 855         return table.concat( self.sref, '.' )
 856 end
 857
 858 function uvlitem.scheme(self, opt)
 859         local s = self.s and self.s.packages
 860         s = s      and s[self.sref[1]]
 861         if #self.sref == 4 or #self.sref == 3 then
 862                 s = s      and s.variables
 863                 s = s      and s[self.sref[2]]
 864                 s = s      and s[self.sref[3]]
 865         elseif #self.sref == 2 then
 866                 s = s      and s.sections
 867                 s = s      and s[self.sref[2]]
 868         end
 869
 870         if s and opt then
 871                 return s[opt]
 872         elseif s then
 873                 return s
 874         end
 875 end
 876
 877 function uvlitem.config(self, opt)
 878         local c = self.c
 879
 880         if #self.cref >= 2 and #self.cref <= 4 then
 881                 c = c and self.c[self.cref[2]] or nil
 882                 if #self.cref >= 3 then
 883                         c = c and c[self.cref[3]] or nil
 884                 end
 885         end
 886
 887         if c and opt then
 888                 return c[opt]
 889         elseif c then
 890                 return c
 891         end
 892 end
 893
 894 function uvlitem.title(self)
 895         return self:scheme() and self:scheme('title') or
 896                 self.cref[3] or self.cref[2] or self.cref[1]
 897 end
 898
 899 function uvlitem.type(self)
 900         if self.t == TYPE_CONFIG then
 901                 return 'config'
 902         elseif self.t == TYPE_SECTION then
 903                 return 'section'
 904         elseif self.t == TYPE_OPTION then
 905                 return 'option'
 906         elseif self.t == TYPE_ENUM then
 907                 return 'enum'
 908         end
 909 end
 910
 911 function uvlitem.error(self, ...)
 912         if not self.e then
 913                 local errconst = { ERR.CONFIG, ERR.SECTION, ERR.OPTION, ERR.OPTION }
 914                 self.e = errconst[#self.cref]( self )
 915         end
 916
 917         return self.e:child( ... )
 918 end
 919
 920 function uvlitem.errors(self)
 921         return self.e
 922 end
 923
 924 function uvlitem.ok(self)
 925         return not self:errors()
 926 end
 927
 928 function uvlitem.parent(self)
 929         if self.p then
 930                 return self.p
 931         elseif #self.cref == 3 or #self.cref == 4 then
 932                 return section( self.s, self.c, self.cref[1], self.cref[2] )
 933         elseif #self.cref == 2 then
 934                 return config( self.s, self.c, self.cref[1] )
 935         else
 936                 return nil
 937         end
 938 end
 939
 940 function uvlitem._loadconf(self, co, c)
 941         co = co or self._configcache
 942         if not co then
 943                 local err
 944                 co, err = uci.cursor():get_all(c)
 945
 946                 if err then
 947                         self:error(ERR.UCILOAD(self, err))
 948                 end
 949
 950                 self._configcache = co
 951         end
 952         return co
 953 end
 954
 955
 956 --- Object representation of a scheme.
 957 -- @class       scheme
 958 -- @cstyle      instance
 959 -- @name        luci.uvl.scheme
 960
 961 --- Scheme instance constructor.
 962 -- @class                       function
 963 -- @name                        scheme
 964 -- @param scheme        Scheme instance
 965 -- @param co            Configuration data
 966 -- @param c                     Configuration name
 967 -- @return                      Config instance
 968 scheme = util.class(uvlitem)
 969
 970 function scheme.__init__(self, scheme, co, c)
 971         if not c then
 972                 c, co = co, nil
 973         end
 974
 975         self.cref = { c }
 976         self.sref = { c }
 977         self.c    = self:_loadconf(co, c)
 978         self.s    = scheme
 979         self.t    = TYPE_SCHEME
 980 end
 981
 982 --- Add an error to scheme.
 983 -- @return      Scheme error context
 984 function scheme.error(self, ...)
 985         if not self.e then self.e = ERR.SCHEME( self ) end
 986         return self.e:child( ... )
 987 end
 988
 989 --- Get an associated config object.
 990 -- @return      Config instance
 991 function scheme.config(self)
 992         local co = config( self.s, self.cref[1] )
 993               co.p = self
 994
 995         return co
 996 end
 997
 998 --- Get all section objects associated with this scheme.
 999 -- @return      Table containing all associated luci.uvl.section instances
1000 function scheme.sections(self)
1001         local v = { }
1002         if self.s.packages[self.sref[1]].sections then
1003                 for o, _ in pairs( self.s.packages[self.sref[1]].sections ) do
1004                         v[#v+1] = option(
1005                                 self.s, self.c, self.cref[1], self.cref[2], o
1006                         )
1007                 end
1008         end
1009         return v
1010 end
1011
1012 --- Get an associated section object.
1013 -- @param s     Section to select
1014 -- @return      Section instance
1015 function scheme.section(self, s)
1016         local so = section( self.s, self.c, self.cref[1], s )
1017               so.p = self
1018
1019         return so
1020 end
1021
1022
1023 --- Object representation of a config.
1024 -- @class       config
1025 -- @cstyle      instance
1026 -- @name        luci.uvl.config
1027
1028 --- Config instance constructor.
1029 -- @class                       function
1030 -- @name                        config
1031 -- @param scheme        Scheme instance
1032 -- @param co            Configuration data
1033 -- @param c                     Configuration name
1034 -- @return                      Config instance
1035 config = util.class(uvlitem)
1036
1037 function config.__init__(self, scheme, co, c)
1038         if not c then
1039                 c, co = co, nil
1040         end
1041
1042         self.cref = { c }
1043         self.sref = { c }
1044         self.c    = self:_loadconf(co, c)
1045         self.s    = scheme
1046         self.t    = TYPE_CONFIG
1047 end
1048
1049 --- Get all section objects associated with this config.
1050 -- @return      Table containing all associated luci.uvl.section instances
1051 function config.sections(self)
1052         local v = { }
1053         if self.s.packages[self.sref[1]].sections then
1054                 for o, _ in pairs( self.s.packages[self.sref[1]].sections ) do
1055                         v[#v+1] = option(
1056                                 self.s, self.c, self.cref[1], self.cref[2], o
1057                         )
1058                 end
1059         end
1060         return v
1061 end
1062
1063 --- Get an associated section object.
1064 -- @param s     Section to select
1065 -- @return      Section instance
1066 function config.section(self, s)
1067         local so = section( self.s, self.c, self.cref[1], s )
1068               so.p = self
1069
1070         return so
1071 end
1072
1073
1074 --- Object representation of a scheme/config section.
1075 -- @class       module
1076 -- @cstyle      instance
1077 -- @name        luci.uvl.section
1078
1079 --- Section instance constructor.
1080 -- @class                       function
1081 -- @name                        section
1082 -- @param scheme        Scheme instance
1083 -- @param co            Configuration data
1084 -- @param c                     Configuration name
1085 -- @param s                     Section name
1086 -- @return                      Section instance
1087 section = util.class(uvlitem)
1088
1089 function section.__init__(self, scheme, co, c, s)
1090         self.cref = { c, s }
1091         self.sref = { c, co and co[s] and co[s]['.type'] or s }
1092         self.c    = self:_loadconf(co, c)
1093         self.s    = scheme
1094         self.t    = TYPE_SECTION
1095 end
1096
1097 --- Get all option objects associated with this section.
1098 -- @return      Table containing all associated luci.uvl.option instances
1099 function section.variables(self)
1100         local v = { }
1101         if self.s.packages[self.sref[1]].variables[self.sref[2]] then
1102                 for o, _ in pairs(
1103                         self.s.packages[self.sref[1]].variables[self.sref[2]]
1104                 ) do
1105                         v[#v+1] = option(
1106                                 self.s, self.c, self.cref[1], self.cref[2], o
1107                         )
1108                 end
1109         end
1110         return v
1111 end
1112
1113 --- Get an associated option object.
1114 -- @param o     Option to select
1115 -- @return      Option instance
1116 function section.option(self, o)
1117         local oo = option( self.s, self.c, self.cref[1], self.cref[2], o )
1118               oo.p = self
1119
1120         return oo
1121 end
1122
1123
1124 --- Object representation of a scheme/config option.
1125 -- @class       module
1126 -- @cstyle      instance
1127 -- @name        luci.uvl.option
1128
1129 --- Section instance constructor.
1130 -- @class                       function
1131 -- @name                        option
1132 -- @param scheme        Scheme instance
1133 -- @param co            Configuration data
1134 -- @param c                     Configuration name
1135 -- @param s                     Section name
1136 -- @param o                     Option name
1137 -- @return                      Option instance
1138 option = util.class(uvlitem)
1139
1140 function option.__init__(self, scheme, co, c, s, o)
1141         self.cref = { c, s, o }
1142         self.sref = { c, co and co[s] and co[s]['.type'] or s, o }
1143         self.c    = self:_loadconf(co, c)
1144         self.s    = scheme
1145         self.t    = TYPE_OPTION
1146 end
1147
1148 --- Get the value of this option.
1149 -- @return      The associated configuration value
1150 function option.value(self)
1151         local v = self:config() or self:scheme('default')
1152         if v and self:scheme('multival') then
1153                 v = util.split( v, "%s+", nil, true )
1154         end
1155         return v
1156 end
1157
1158 --- Get the associated section information in scheme.
1159 -- @return      Table containing the scheme properties
1160 function option.section(self)
1161         return self.s.packages[self.sref[1]].sections[self.sref[2]]
1162 end
1163
1164 --- Construct an enum object instance from given or default value.
1165 -- @param v     Value to select
1166 -- @return      Enum instance for selected value
1167 function option.enum(self, val)
1168         return enum(
1169                 self.s, self.c,
1170                 self.cref[1], self.cref[2], self.cref[3],
1171                 val or self:value()
1172         )
1173 end
1174
1175
1176 --- Object representation of a enum value.
1177 -- @class       module
1178 -- @cstyle      instance
1179 -- @name        luci.uvl.enum
1180
1181 --- Section instance constructor.
1182 -- @class                       function
1183 -- @name                        enum
1184 -- @param scheme        Scheme instance
1185 -- @param co            Configuration data
1186 -- @param c                     Configuration name
1187 -- @param s                     Section name
1188 -- @param o                     Enum name
1189 -- @param v                     Enum value
1190 -- @return                      Enum value instance
1191 enum = util.class(option)
1192
1193 function enum.__init__(self, scheme, co, c, s, o, v)
1194         self.cref = { c, s, o, v }
1195         self.sref = { c, co and co[s] and co[s]['.type'] or s, o, v }
1196         self.c    = self:_loadconf(co, c)
1197         self.s    = scheme
1198         self.t    = TYPE_ENUM
1199 end