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 not nodeps then
 296                         local ok, err = dependencies.check( self, option )
 297                         if not ok then
 298                                 if not err:is_all(
 299                                         ERR.ERR_OPT_REQUIRED,
 300                                         ERR.ERR_DEP_NOTEQUAL,
 301                                         ERR.ERR_DEP_NOVALUE
 302                                 ) then
 303                                         option:error(err)
 304                                         return false, option:errors()
 305                                 else
 306                                         return true
 307                                 end
 308                         end
 309                 end
 310
 311                 if option:scheme('required') and not option:value() then
 312                         return false, option:error(ERR.OPT_REQUIRED(option))
 313
 314                 elseif option:value() then
 315                         local val = option:value()
 316
 317                         if option:scheme('type') == "reference" or
 318                            option:scheme('type') == "enum"
 319                         then
 320                                 local scheme_values = option:scheme('values') or { }
 321                                 local config_values = ( type(val) == "table" and val or { val } )
 322                                 for _, v in ipairs(config_values) do
 323                                         if not scheme_values[v] then
 324                                                 return false, option:error( ERR.OPT_BADVALUE(
 325                                                         option, { v, util.serialize_data(
 326                                                                 util.keys(scheme_values)
 327                                                         ) }
 328                                                 ) )
 329                                         end
 330                                 end
 331                         elseif option:scheme('type') == "list" then
 332                                 if type(val) ~= "table" and STRICT_LIST_TYPE then
 333                                         return false, option:error(ERR.OPT_NOTLIST(option))
 334                                 end
 335                         end
 336
 337                         if option:scheme('datatype') then
 338                                 local dt = option:scheme('datatype')
 339
 340                                 if self.datatypes[dt] then
 341                                         val = ( type(val) == "table" and val or { val } )
 342                                         for i, v in ipairs(val) do
 343                                                 if not self.datatypes[dt]( v ) then
 344                                                         return false, option:error(
 345                                                                 ERR.OPT_INVVALUE(option, { v, dt })
 346                                                         )
 347                                                 end
 348                                         end
 349                                 else
 350                                         return false, option:error(ERR.OPT_DATATYPE(option, dt))
 351                                 end
 352                         end
 353
 354                         val = ( type(val) == "table" and val or { val } )
 355                         for _, v in ipairs(val) do
 356                                 if option:scheme('minlength') then
 357                                         if #v < option:scheme('minlength') then
 358                                                 return false, option:error(ERR.OPT_RANGE(option))
 359                                         end
 360                                 end
 361
 362                                 if option:scheme('maxlength') then
 363                                         if #v > option:scheme('maxlength') then
 364                                                 return false, option:error(ERR.OPT_RANGE(option))
 365                                         end
 366                                 end
 367
 368                                 local w = tonumber(v)
 369
 370                                 if option:scheme('minimum') then
 371                                         if not w or w < option:scheme('minimum') then
 372                                                 return false, option:error(ERR.OPT_RANGE(option))
 373                                         end
 374                                 end
 375
 376                                 if option:scheme('maximum') then
 377                                         if not w or w > option:scheme('maximum') then
 378                                                 return false, option:error(ERR.OPT_RANGE(option))
 379                                         end
 380                                 end
 381                         end
 382                 end
 383
 384                 local ok, err = validation.check( self, option )
 385                 if not ok and STRICT_EXTERNAL_VALIDATORS then
 386                         return false, option:error(err)
 387                 end
 388         end
 389
 390         return option:ok(), option:errors()
 391 end
 392
 393 --- Find all parts of given scheme and construct validation tree.
 394 -- This is normally done on demand, so you don't have to call this function
 395 -- by yourself.
 396 -- @param shm   Name of the scheme to parse
 397 -- @param alias         Create an alias for the loaded scheme
 398 function UVL.read_scheme( self, shm, alias )
 399
 400         local so = scheme( self, shm )
 401         local bc = "%s/bytecode/%s.lua" %{ self.schemedir, shm }
 402
 403         if not fs.access(bc) then
 404                 local files = fs.glob(self.schemedir .. '/*/' .. shm)
 405
 406                 if files then
 407                         local ok, err
 408                         for i, file in ipairs( files ) do
 409                                 if not fs.access(file) then
 410                                         return false, so:error(ERR.SME_READ(so,file))
 411                                 end
 412
 413                                 local uci = uci.cursor( fs.dirname(file), default_savedir )
 414
 415                                 local sname = fs.basename(file)
 416                                 local sd, err = uci:load( sname )
 417
 418                                 if not sd then
 419                                         return false, ERR.UCILOAD(so, err)
 420                                 end
 421
 422                                 ok, err = pcall(function()
 423                                         uci:foreach(sname, "package", function(s)
 424                                                 self:_parse_package(so, s[".name"], s)
 425                                         end)
 426                                         uci:foreach(sname, "section", function(s)
 427                                                 self:_parse_section(so, s[".name"], s)
 428                                         end)
 429                                         uci:foreach(sname, "variable", function(s)
 430                                                 self:_parse_var(so, s[".name"], s)
 431                                         end)
 432                                         uci:foreach(sname, "enum", function(s)
 433                                                 self:_parse_enum(so, s[".name"], s)
 434                                         end)
 435
 436                                 end)
 437                         end
 438
 439                         if ok and alias then self.packages[alias] = self.packages[shm] end
 440                         return ok and self, err
 441                 else
 442                         return false, so:error(ERR.SME_FIND(so, self.schemedir))
 443                 end
 444         else
 445                 local sc = loadfile(bc)
 446                 if sc then
 447                         self.packages[shm] = sc()
 448                         return true
 449                 else
 450                         return false, so:error(ERR.SME_READ(so,bc))
 451                 end
 452         end
 453 end
 454
 455 -- helper function to check for required fields
 456 local function _req( t, n, c, r )
 457         for i, v in ipairs(r) do
 458                 if not c[v] then
 459                         local p, o = scheme:sid(), nil
 460
 461                         if t == TYPE_SECTION then
 462                                 o = section( scheme, nil, p, n )
 463                         elseif t == TYPE_OPTION then
 464                                 o = option( scheme, nil, p, '(nil)', n )
 465                         elseif t == TYPE_ENUM then
 466                                 o = enum( scheme, nil, p, '(nil)', '(nil)', n )
 467                         end
 468
 469                         return false, ERR.SME_REQFLD(o,v)
 470                 end
 471         end
 472         return true
 473 end
 474
 475 -- helper function to validate references
 476 local function _ref( c, t )
 477         local r, k, n = {}
 478         if c == TYPE_SECTION then
 479                 k = "package"
 480                 n = 1
 481         elseif c == TYPE_OPTION then
 482                 k = "section"
 483                 n = 2
 484         elseif c == TYPE_ENUM then
 485                 k = "variable"
 486                 n = 3
 487         end
 488
 489         for o in t[k]:gmatch("[^.]+") do
 490                 r[#r+1] = o
 491         end
 492         r[1] = ( #r[1] > 0 and r[1] or scheme:sid() )
 493
 494         if #r ~= n then
 495                 return false, ERR.SME_BADREF(scheme, k)
 496         end
 497
 498         return r
 499 end
 500
 501 -- helper function to read bools
 502 local function _bool( v )
 503         return ( v == "true" or v == "yes" or v == "on" or v == "1" )
 504 end
 505
 506 -- Step 0: get package meta information
 507 function UVL._parse_package(self, scheme, k, v)
 508         local sid = scheme:sid()
 509         local pkg = self.packages[sid] or {
 510                 ["name"]      = sid;
 511                 ["sections"]  = { };
 512                 ["variables"] = { };
 513         }
 514
 515         pkg.title = v.title
 516         pkg.description = v.description
 517
 518         self.packages[sid] = pkg
 519 end
 520
 521 -- Step 1: get all sections
 522 function UVL._parse_section(self, scheme, k, v)
 523         local ok, err = _req( TYPE_SECTION, k, v, { "name", "package" } )
 524         if err then error(scheme:error(err)) end
 525
 526         local r, err = _ref( TYPE_SECTION, v )
 527         if err then error(scheme:error(err)) end
 528
 529         local p = self.packages[r[1]] or {
 530                 ["name"]      = r[1];
 531                 ["sections"]  = { };
 532                 ["variables"] = { };
 533         }
 534         p.sections[v.name]  = p.sections[v.name]  or { }
 535         p.variables[v.name] = p.variables[v.name] or { }
 536         self.packages[r[1]] = p
 537
 538         local s  = p.sections[v.name]
 539         local so = scheme:section(v.name)
 540
 541         for k, v2 in pairs(v) do
 542                 if k ~= "name" and k ~= "package" and k:sub(1,1) ~= "." then
 543                         if k == "depends" then
 544                                 s.depends = self:_read_dependency( v2, s.depends )
 545                                 if not s.depends then
 546                                         return false, scheme:error(
 547                                                 ERR.SME_BADDEP(so, util.serialize_data(s.depends))
 548                                         )
 549                                 end
 550                         elseif k == "dynamic" or k == "unique" or
 551                                k == "required" or k == "named"
 552                         then
 553                                 s[k] = _bool(v2)
 554                         else
 555                                 s[k] = v2
 556                         end
 557                 end
 558         end
 559
 560         s.dynamic  = s.dynamic  or false
 561         s.unique   = s.unique   or false
 562         s.required = s.required or false
 563         s.named    = s.named    or false
 564 end
 565
 566 -- Step 2: get all variables
 567 function UVL._parse_var(self, scheme, k, v)
 568         local ok, err = _req( TYPE_OPTION, k, v, { "name", "section" } )
 569         if err then error(scheme:error(err)) end
 570
 571         local r, err = _ref( TYPE_OPTION, v )
 572         if err then error(scheme:error(err)) end
 573
 574         local p = self.packages[r[1]]
 575         if not p then
 576                 error(scheme:error(
 577                         ERR.SME_VBADPACK({scheme:sid(), '', v.name}, r[1])
 578                 ))
 579         end
 580
 581         local s = p.variables[r[2]]
 582         if not s then
 583                 error(scheme:error(
 584                         ERR.SME_VBADSECT({scheme:sid(), '', v.name}, r[2])
 585                 ))
 586         end
 587
 588         s[v.name] = s[v.name] or { }
 589
 590         local t  = s[v.name]
 591         local so = scheme:section(r[2])
 592         local to = so:option(v.name)
 593
 594         for k, v2 in pairs(v) do
 595                 if k ~= "name" and k ~= "section" and k:sub(1,1) ~= "." then
 596                         if k == "depends" then
 597                                 t.depends = self:_read_dependency( v2, t.depends )
 598                                 if not t.depends then
 599                                         error(scheme:error(so:error(
 600                                                 ERR.SME_BADDEP(to, util.serialize_data(v2))
 601                                         )))
 602                                 end
 603                         elseif k == "validator" then
 604                                 t.validators = self:_read_validator( v2, t.validators )
 605                                 if not t.validators then
 606                                         error(scheme:error(so:error(
 607                                                 ERR.SME_BADVAL(to, util.serialize_data(v2))
 608                                         )))
 609                                 end
 610                         elseif k == "valueof" then
 611                                 local values, err = self:_read_reference( v2 )
 612                                 if err then
 613                                         error(scheme:error(so:error(
 614                                                 ERR.REFERENCE(to, util.serialize_data(v2)):child(err)
 615                                         )))
 616                                 end
 617                                 t.type   = "reference"
 618                                 t.values = values
 619                                 t.valueof = type(v2) == "table" and v2 or {v2}
 620                         elseif k == "required" then
 621                                 t[k] = _bool(v2)
 622                         elseif k == "minlength" or k == "maxlength" or
 623                    k == "minimum" or k == "maximum"
 624             then
 625                                 t[k] = tonumber(v2)
 626                         else
 627                                 t[k] = t[k] or v2
 628                         end
 629                 end
 630         end
 631
 632         t.type     = t.type     or "variable"
 633         t.datatype = t.datatype or "string"
 634         t.required = t.required or false
 635 end
 636
 637 -- Step 3: get all enums
 638 function UVL._parse_enum(self, scheme, k, v)
 639         local ok, err = _req( TYPE_ENUM, k, v, { "value", "variable" } )
 640         if err then error(scheme:error(err)) end
 641
 642         local r, err = _ref( TYPE_ENUM, v )
 643         if err then error(scheme:error(err)) end
 644
 645         local p = self.packages[r[1]]
 646         if not p then
 647                 error(scheme:error(
 648                         ERR.SME_EBADPACK({scheme:sid(), '', '', v.value}, r[1])
 649                 ))
 650         end
 651
 652         local s = p.variables[r[2]]
 653         if not s then
 654                 error(scheme:error(
 655                         ERR.SME_EBADSECT({scheme:sid(), '', '', v.value}, r[2])
 656                 ))
 657         end
 658
 659         local t = s[r[3]]
 660         if not t then
 661                 error(scheme:error(
 662                         ERR.SME_EBADOPT({scheme:sid(), '', '', v.value}, r[3])
 663                 ))
 664         end
 665
 666
 667         local so = scheme:section(r[2])
 668         local oo = so:option(r[3])
 669         local eo = oo:enum(v.value)
 670
 671         if t.type ~= "enum" and t.type ~= "reference" then
 672                 error(scheme:error(ERR.SME_EBADTYPE(eo)))
 673         end
 674
 675         if not t.values then
 676                 t.values = { [v.value] = v.title or v.value }
 677                 t.valuelist = { {value = v.value, title = v.title} }
 678         else
 679                 t.values[v.value] = v.title or v.value
 680                 t.valuelist[#t.valuelist + 1] = {value = v.value, title = v.title}
 681         end
 682
 683         if not t.enum_depends then
 684                 t.enum_depends = { }
 685         end
 686
 687         if v.default then
 688                 if t.default then
 689                         error(scheme:error(ERR.SME_EBADDEF(eo)))
 690                 end
 691                 t.default = v.value
 692         end
 693
 694         if v.depends then
 695                 t.enum_depends[v.value] = self:_read_dependency(
 696                         v.depends, t.enum_depends[v.value]
 697                 )
 698
 699                 if not t.enum_depends[v.value] then
 700                         error(scheme:error(so:error(oo:error(
 701                                 ERR.SME_BADDEP(eo, util.serialize_data(v.depends))
 702                         ))))
 703                 end
 704         end
 705 end
 706
 707 -- Read a dependency specification
 708 function UVL._read_dependency( self, values, deps )
 709         local expr = "%$?[%w_]+"
 710         if values then
 711                 values = ( type(values) == "table" and values or { values } )
 712                 for _, value in ipairs(values) do
 713                         local condition = { }
 714                         for val in value:gmatch("[^,]+") do
 715                                 local k, e, v = val:match("%s*([%w$_.]+)%s*(=?)%s*(.*)")
 716
 717                                 if k and (
 718                                         k:match("^"..expr.."%."..expr.."%."..expr.."$") or
 719                                         k:match("^"..expr.."%."..expr.."$") or
 720                                         k:match("^"..expr.."$")
 721                                 ) then
 722                                         condition[k] = (e == '=') and v or true
 723                                 else
 724                                         return nil
 725                                 end
 726                         end
 727
 728                         if not deps then
 729                                 deps = { condition }
 730                         else
 731                                 deps[#deps+1] = condition
 732                         end
 733                 end
 734         end
 735
 736         return deps
 737 end
 738
 739 -- Read a validator specification
 740 function UVL._read_validator( self, values, validators )
 741         if values then
 742                 values = ( type(values) == "table" and values or { values } )
 743                 for _, value in ipairs(values) do
 744                         local validator
 745
 746                         if value:match("^exec:") then
 747                                 validator = value:gsub("^exec:","")
 748                         elseif value:match("^lua:") then
 749                                 validator = self:_resolve_function( (value:gsub("^lua:","") ) )
 750                         elseif value:match("^regexp:") then
 751                                 local pattern = value:gsub("^regexp:","")
 752                                 validator = function( type, dtype, pack, sect, optn, ... )
 753                                         local values = { ... }
 754                                         for _, v in ipairs(values) do
 755                                                 local ok, match =
 756                                                         pcall( string.match, v, pattern )
 757
 758                                                 if not ok then
 759                                                         return false, match
 760                                                 elseif not match then
 761                                                         return false,
 762                                                                 'Value "%s" does not match pattern "%s"' % {
 763                                                                         v, pattern
 764                                                                 }
 765                                                 end
 766                                         end
 767                                         return true
 768                                 end
 769                         end
 770
 771                         if validator then
 772                                 if not validators then
 773                                         validators = { validator }
 774                                 else
 775                                         validators[#validators+1] = validator
 776                                 end
 777                         else
 778                                 return nil
 779                         end
 780                 end
 781
 782                 return validators
 783         end
 784 end
 785
 786 -- Read a reference specification (XXX: We should validate external configs too...)
 787 function UVL._read_reference( self, values )
 788         local val = { }
 789         values = ( type(values) == "table" and values or { values } )
 790
 791         for _, value in ipairs(values) do
 792                 local ref = util.split(value, ".")
 793
 794                 if #ref == 2 or #ref == 3 then
 795                         local co = config( self, ref[1] )
 796                         if not co:config() then return false, co:errors() end
 797
 798                         for k, v in pairs(co:config()) do
 799                                 if v['.type'] == ref[2] then
 800                                         if #ref == 2 then
 801                                                 if v['.anonymous'] == true then
 802                                                         return false, ERR.SME_INVREF('', value)
 803                                                 end
 804                                                 val[k] = k      -- XXX: title/description would be nice
 805                                         elseif v[ref[3]] then
 806                                                 val[v[ref[3]]] = v[ref[3]]  -- XXX: dito
 807                                         end
 808                                 end
 809                         end
 810                 else
 811                         return false, ERR.SME_BADREF('', value)
 812                 end
 813         end
 814
 815         return val, nil
 816 end
 817
 818 -- Resolve given path
 819 function UVL._resolve_function( self, value )
 820         local path = util.split(value, ".")
 821
 822         for i=1, #path-1 do
 823                 local stat, mod = pcall(
 824                         require, table.concat(path, ".", 1, i)
 825                 )
 826
 827                 if stat and mod then
 828                         for j=i+1, #path-1 do
 829                                 if not type(mod) == "table" then
 830                                         break
 831                                 end
 832                                 mod = mod[path[j]]
 833                                 if not mod then
 834                                         break
 835                                 end
 836                         end
 837                         mod = type(mod) == "table" and mod[path[#path]] or nil
 838                         if type(mod) == "function" then
 839                                 return mod
 840                         end
 841                 end
 842         end
 843 end
 844
 845
 846 --- Object representation of an uvl item - base class.
 847 uvlitem = util.class()
 848
 849 function uvlitem.cid(self)
 850         if #self.cref == 1 then
 851                 return self.cref[1]
 852         else
 853                 local r = { unpack(self.cref) }
 854                 local c = self.c
 855                 if c and c[r[2]] and c[r[2]]['.anonymous'] and c[r[2]]['.index'] then
 856                         r[2] = '@' .. c[r[2]]['.type'] ..
 857                                    '[' .. tostring(c[r[2]]['.index']) .. ']'
 858                 end
 859                 return table.concat( r, '.' )
 860         end
 861 end
 862
 863 function uvlitem.sid(self)
 864         return table.concat( self.sref, '.' )
 865 end
 866
 867 function uvlitem.scheme(self, opt)
 868         local s = self.s and self.s.packages
 869         s = s      and s[self.sref[1]]
 870         if #self.sref == 4 or #self.sref == 3 then
 871                 s = s      and s.variables
 872                 s = s      and s[self.sref[2]]
 873                 s = s      and s[self.sref[3]]
 874         elseif #self.sref == 2 then
 875                 s = s      and s.sections
 876                 s = s      and s[self.sref[2]]
 877         end
 878
 879         if s and opt then
 880                 return s[opt]
 881         elseif s then
 882                 return s
 883         end
 884 end
 885
 886 function uvlitem.config(self, opt)
 887         local c = self.c
 888
 889         if #self.cref >= 2 and #self.cref <= 4 then
 890                 c = c and self.c[self.cref[2]] or nil
 891                 if #self.cref >= 3 then
 892                         c = c and c[self.cref[3]] or nil
 893                 end
 894         end
 895
 896         if c and opt then
 897                 return c[opt]
 898         elseif c then
 899                 return c
 900         end
 901 end
 902
 903 function uvlitem.title(self)
 904         return self:scheme() and self:scheme('title') or
 905                 self.cref[3] or self.cref[2] or self.cref[1]
 906 end
 907
 908 function uvlitem.type(self)
 909         if self.t == TYPE_CONFIG then
 910                 return 'config'
 911         elseif self.t == TYPE_SECTION then
 912                 return 'section'
 913         elseif self.t == TYPE_OPTION then
 914                 return 'option'
 915         elseif self.t == TYPE_ENUM then
 916                 return 'enum'
 917         end
 918 end
 919
 920 function uvlitem.error(self, ...)
 921         if not self.e then
 922                 local errconst = { ERR.CONFIG, ERR.SECTION, ERR.OPTION, ERR.OPTION }
 923                 self.e = errconst[#self.cref]( self )
 924         end
 925
 926         return self.e:child( ... )
 927 end
 928
 929 function uvlitem.errors(self)
 930         return self.e
 931 end
 932
 933 function uvlitem.ok(self)
 934         return not self:errors()
 935 end
 936
 937 function uvlitem.parent(self)
 938         if self.p then
 939                 return self.p
 940         elseif #self.cref == 3 or #self.cref == 4 then
 941                 return section( self.s, self.c, self.cref[1], self.cref[2] )
 942         elseif #self.cref == 2 then
 943                 return config( self.s, self.c, self.cref[1] )
 944         else
 945                 return nil
 946         end
 947 end
 948
 949 function uvlitem._loadconf(self, co, c)
 950         co = co or self._configcache
 951         if not co then
 952                 local err
 953                 co, err = uci.cursor():get_all(c)
 954
 955                 if err then
 956                         self:error(ERR.UCILOAD(self, err))
 957                 end
 958
 959                 self._configcache = co
 960         end
 961         return co
 962 end
 963
 964
 965 --- Object representation of a scheme.
 966 -- @class       scheme
 967 -- @cstyle      instance
 968 -- @name        luci.uvl.scheme
 969
 970 --- Scheme instance constructor.
 971 -- @class                       function
 972 -- @name                        scheme
 973 -- @param scheme        Scheme instance
 974 -- @param co            Configuration data
 975 -- @param c                     Configuration name
 976 -- @return                      Config instance
 977 scheme = util.class(uvlitem)
 978
 979 function scheme.__init__(self, scheme, co, c)
 980         if not c then
 981                 c, co = co, nil
 982         end
 983
 984         self.cref = { c }
 985         self.sref = { c }
 986         self.c    = self:_loadconf(co, c)
 987         self.s    = scheme
 988         self.t    = TYPE_SCHEME
 989 end
 990
 991 --- Add an error to scheme.
 992 -- @return      Scheme error context
 993 function scheme.error(self, ...)
 994         if not self.e then self.e = ERR.SCHEME( self ) end
 995         return self.e:child( ... )
 996 end
 997
 998 --- Get an associated config object.
 999 -- @return      Config instance
1000 function scheme.config(self)
1001         local co = config( self.s, self.cref[1] )
1002               co.p = self
1003
1004         return co
1005 end
1006
1007 --- Get all section objects associated with this scheme.
1008 -- @return      Table containing all associated luci.uvl.section instances
1009 function scheme.sections(self)
1010         local v = { }
1011         if self.s.packages[self.sref[1]].sections then
1012                 for o, _ in pairs( self.s.packages[self.sref[1]].sections ) do
1013                         v[#v+1] = option(
1014                                 self.s, self.c, self.cref[1], self.cref[2], o
1015                         )
1016                 end
1017         end
1018         return v
1019 end
1020
1021 --- Get an associated section object.
1022 -- @param s     Section to select
1023 -- @return      Section instance
1024 function scheme.section(self, s)
1025         local so = section( self.s, self.c, self.cref[1], s )
1026               so.p = self
1027
1028         return so
1029 end
1030
1031
1032 --- Object representation of a config.
1033 -- @class       config
1034 -- @cstyle      instance
1035 -- @name        luci.uvl.config
1036
1037 --- Config instance constructor.
1038 -- @class                       function
1039 -- @name                        config
1040 -- @param scheme        Scheme instance
1041 -- @param co            Configuration data
1042 -- @param c                     Configuration name
1043 -- @return                      Config instance
1044 config = util.class(uvlitem)
1045
1046 function config.__init__(self, scheme, co, c)
1047         if not c then
1048                 c, co = co, nil
1049         end
1050
1051         self.cref = { c }
1052         self.sref = { c }
1053         self.c    = self:_loadconf(co, c)
1054         self.s    = scheme
1055         self.t    = TYPE_CONFIG
1056 end
1057
1058 --- Get all section objects associated with this config.
1059 -- @return      Table containing all associated luci.uvl.section instances
1060 function config.sections(self)
1061         local v = { }
1062         if self.s.packages[self.sref[1]].sections then
1063                 for o, _ in pairs( self.s.packages[self.sref[1]].sections ) do
1064                         v[#v+1] = option(
1065                                 self.s, self.c, self.cref[1], self.cref[2], o
1066                         )
1067                 end
1068         end
1069         return v
1070 end
1071
1072 --- Get an associated section object.
1073 -- @param s     Section to select
1074 -- @return      Section instance
1075 function config.section(self, s)
1076         local so = section( self.s, self.c, self.cref[1], s )
1077               so.p = self
1078
1079         return so
1080 end
1081
1082
1083 --- Object representation of a scheme/config section.
1084 -- @class       module
1085 -- @cstyle      instance
1086 -- @name        luci.uvl.section
1087
1088 --- Section instance constructor.
1089 -- @class                       function
1090 -- @name                        section
1091 -- @param scheme        Scheme instance
1092 -- @param co            Configuration data
1093 -- @param c                     Configuration name
1094 -- @param s                     Section name
1095 -- @return                      Section instance
1096 section = util.class(uvlitem)
1097
1098 function section.__init__(self, scheme, co, c, s)
1099         self.cref = { c, s }
1100         self.sref = { c, co and co[s] and co[s]['.type'] or s }
1101         self.c    = self:_loadconf(co, c)
1102         self.s    = scheme
1103         self.t    = TYPE_SECTION
1104 end
1105
1106 --- Get all option objects associated with this section.
1107 -- @return      Table containing all associated luci.uvl.option instances
1108 function section.variables(self)
1109         local v = { }
1110         if self.s.packages[self.sref[1]].variables[self.sref[2]] then
1111                 for o, _ in pairs(
1112                         self.s.packages[self.sref[1]].variables[self.sref[2]]
1113                 ) do
1114                         v[#v+1] = option(
1115                                 self.s, self.c, self.cref[1], self.cref[2], o
1116                         )
1117                 end
1118         end
1119         return v
1120 end
1121
1122 --- Get an associated option object.
1123 -- @param o     Option to select
1124 -- @return      Option instance
1125 function section.option(self, o)
1126         local oo = option( self.s, self.c, self.cref[1], self.cref[2], o )
1127               oo.p = self
1128
1129         return oo
1130 end
1131
1132
1133 --- Object representation of a scheme/config option.
1134 -- @class       module
1135 -- @cstyle      instance
1136 -- @name        luci.uvl.option
1137
1138 --- Section instance constructor.
1139 -- @class                       function
1140 -- @name                        option
1141 -- @param scheme        Scheme instance
1142 -- @param co            Configuration data
1143 -- @param c                     Configuration name
1144 -- @param s                     Section name
1145 -- @param o                     Option name
1146 -- @return                      Option instance
1147 option = util.class(uvlitem)
1148
1149 function option.__init__(self, scheme, co, c, s, o)
1150         self.cref = { c, s, o }
1151         self.sref = { c, co and co[s] and co[s]['.type'] or s, o }
1152         self.c    = self:_loadconf(co, c)
1153         self.s    = scheme
1154         self.t    = TYPE_OPTION
1155 end
1156
1157 --- Get the value of this option.
1158 -- @return      The associated configuration value
1159 function option.value(self)
1160         local v = self:config() or self:scheme('default')
1161         if v and self:scheme('multival') then
1162                 v = util.split( v, "%s+", nil, true )
1163         end
1164         return v
1165 end
1166
1167 --- Get the associated section information in scheme.
1168 -- @return      Table containing the scheme properties
1169 function option.section(self)
1170         return self.s.packages[self.sref[1]].sections[self.sref[2]]
1171 end
1172
1173 --- Construct an enum object instance from given or default value.
1174 -- @param v     Value to select
1175 -- @return      Enum instance for selected value
1176 function option.enum(self, val)
1177         return enum(
1178                 self.s, self.c,
1179                 self.cref[1], self.cref[2], self.cref[3],
1180                 val or self:value()
1181         )
1182 end
1183
1184
1185 --- Object representation of a enum value.
1186 -- @class       module
1187 -- @cstyle      instance
1188 -- @name        luci.uvl.enum
1189
1190 --- Section instance constructor.
1191 -- @class                       function
1192 -- @name                        enum
1193 -- @param scheme        Scheme instance
1194 -- @param co            Configuration data
1195 -- @param c                     Configuration name
1196 -- @param s                     Section name
1197 -- @param o                     Enum name
1198 -- @param v                     Enum value
1199 -- @return                      Enum value instance
1200 enum = util.class(option)
1201
1202 function enum.__init__(self, scheme, co, c, s, o, v)
1203         self.cref = { c, s, o, v }
1204         self.sref = { c, co and co[s] and co[s]['.type'] or s, o, v }
1205         self.c    = self:_loadconf(co, c)
1206         self.s    = scheme
1207         self.t    = TYPE_ENUM
1208 end