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 -- @param configdir     Override config directory (optional)
  71 -- @return                      Instance object
  72 UVL = util.class()
  73
  74 function UVL.__init__( self, schemedir, configdir )
  75         self.schemedir  = schemedir or default_schemedir
  76         self.configdir  = configdir
  77         self.packages   = { }
  78         self.beenthere  = { }
  79         self.depseen    = { }
  80         self.uci                = uci
  81         self.err                = ERR
  82         self.dep                = dependencies
  83         self.datatypes  = datatypes
  84 end
  85
  86
  87 --- Parse given scheme and return the scheme tree.
  88 -- @param scheme        Name of the scheme to parse
  89 -- @return                      Table containing the parsed scheme or nil on error
  90 -- @return                      String containing the reason for errors (if any)
  91 function UVL.get_scheme( self, scheme )
  92         if not self.packages[scheme] then
  93                 local ok, err = self:read_scheme( scheme )
  94                 if not ok then
  95                         return nil, err
  96                 end
  97         end
  98         return self.packages[scheme], nil
  99 end
 100
 101 --- Validate given configuration, section or option.
 102 -- @param config        Name of the configuration to validate
 103 -- @param section       Name of the section to validate (optional)
 104 -- @param option        Name of the option to validate (optional)
 105 -- @return                      Boolean indicating whether the given config validates
 106 -- @return                      String containing the reason for errors (if any)
 107 function UVL.validate( self, config, section, option )
 108         if config and section and option then
 109                 return self:validate_option( config, section, option )
 110         elseif config and section then
 111                 return self:validate_section( config, section )
 112         elseif config then
 113                 return self:validate_config( config )
 114         end
 115 end
 116
 117 --- Validate given configuration.
 118 -- @param cfg   Name of the configuration to validate
 119 -- @return                      Boolean indicating whether the given config validates
 120 -- @return                      String containing the reason for errors (if any)
 121 function UVL.validate_config( self, cfg, uci )
 122
 123         if not self.packages[cfg] then
 124                 local ok, err = self:read_scheme(cfg)
 125                 if not ok then
 126                         return false, err
 127                 end
 128         end
 129
 130         local co = config( self, uci or cfg, uci and cfg )
 131         local sc = { }
 132
 133         self.beenthere = { }
 134         self.depseen   = { }
 135
 136         if not co:config() then
 137                 return false, co:errors()
 138         end
 139
 140         local function _uci_foreach( type, func )
 141                 for k, v in pairs(co:config()) do
 142                         if v['.type'] == type then
 143                                 sc[type] = sc[type] + 1
 144                                 local ok, err = func( k, v )
 145                                 if not ok then co:error(err) end
 146                         end
 147                 end
 148         end
 149
 150         for k, v in pairs( self.packages[cfg].sections ) do
 151                 sc[k] = 0
 152                 _uci_foreach( k,
 153                         function(s)
 154                                 return self:_validate_section( co:section(s) )
 155                         end
 156                 )
 157         end
 158
 159         if STRICT_UNKNOWN_SECTIONS then
 160                 for k, v in pairs(co:config()) do
 161                         local so = co:section(k)
 162                         if not self.beenthere[so:cid()] then
 163                                 co:error(ERR.SECT_UNKNOWN(so))
 164                         end
 165                 end
 166         end
 167
 168         for _, k in ipairs(util.keys(sc)) do
 169                 local so = co:section(k)
 170                 if so:scheme('required') and sc[k] == 0 then
 171                         co:error(ERR.SECT_REQUIRED(so))
 172                 elseif so:scheme('unique') and sc[k] > 1 then
 173                         co:error(ERR.SECT_UNIQUE(so))
 174                 end
 175         end
 176
 177         return co:ok(), co:errors()
 178 end
 179
 180 --- Validate given config section.
 181 -- @param config        Name of the configuration to validate
 182 -- @param section       Name of the section to validate
 183 -- @return                      Boolean indicating whether the given config validates
 184 -- @return                      String containing the reason for errors (if any)
 185 function UVL.validate_section( self, cfg, section, uci )
 186
 187         if not self.packages[cfg] then
 188                 local ok, err = self:read_scheme( cfg )
 189                 if not ok then
 190                         return false, err
 191                 end
 192         end
 193
 194         local co = config( self, uci or cfg, uci and cfg )
 195         local so = co:section( section )
 196
 197         self.beenthere = { }
 198         self.depseen   = { }
 199
 200         if not co:config() then
 201                 return false, co:errors()
 202         end
 203
 204         if so:config() then
 205                 return self:_validate_section( so )
 206         else
 207                 return false, ERR.SECT_NOTFOUND(so)
 208         end
 209 end
 210
 211 --- Validate given config option.
 212 -- @param config        Name of the configuration to validate
 213 -- @param section       Name of the section to validate
 214 -- @param option        Name of the option to validate
 215 -- @return                      Boolean indicating whether the given config validates
 216 -- @return                      String containing the reason for errors (if any)
 217 function UVL.validate_option( self, cfg, section, option, uci )
 218
 219         if not self.packages[cfg] then
 220                 local ok, err = self:read_scheme( cfg )
 221                 if not ok then
 222                         return false, err
 223                 end
 224         end
 225
 226         local co = config( self, uci or cfg, uci and cfg )
 227         local so = co:section( section )
 228         local oo = so:option( option )
 229
 230         if not co:config() then
 231                 return false, co:errors()
 232         end
 233
 234         if so:config() and oo:config() then
 235                 return self:_validate_option( oo )
 236         else
 237                 return false, ERR.OPT_NOTFOUND(oo)
 238         end
 239 end
 240
 241
 242 function UVL._validate_section( self, section )
 243
 244         self.beenthere[section:cid()] = true
 245
 246         if section:config() then
 247                 if section:scheme('named') == true and
 248                    section:config('.anonymous') == true
 249                 then
 250                         return false, ERR.SECT_NAMED(section)
 251                 end
 252
 253                 for _, v in ipairs(section:variables()) do
 254                         local ok, err = self:_validate_option( v )
 255                         if not ok and (
 256                                 v:scheme('required') or v:scheme('type') == "enum" or (
 257                                         not err:is(ERR.ERR_DEP_NOTEQUAL) and
 258                                         not err:is(ERR.ERR_DEP_NOVALUE)
 259                                 )
 260                         ) then
 261                                 section:error(err)
 262                         end
 263                 end
 264
 265                 local ok, err = dependencies.check( self, section )
 266                 if not ok then
 267                         section:error(err)
 268                 end
 269         else
 270                 return false, ERR.SECT_NOTFOUND(section)
 271         end
 272
 273         if STRICT_UNKNOWN_OPTIONS and not section:scheme('dynamic') then
 274                 for k, v in pairs(section:config()) do
 275                         local oo = section:option(k)
 276                         if k:sub(1,1) ~= "." and not self.beenthere[oo:cid()] then
 277                                 section:error(ERR.OPT_UNKNOWN(oo))
 278                         end
 279                 end
 280         end
 281
 282         return section:ok(), section:errors()
 283 end
 284
 285 function UVL._validate_option( self, option, nodeps )
 286
 287         self.beenthere[option:cid()] = true
 288
 289         if not option:scheme() and not option:parent():scheme('dynamic') then
 290                 if STRICT_UNKNOWN_OPTIONS then
 291                         return false, option:error(ERR.OPT_UNKNOWN(option))
 292                 else
 293                         return true
 294                 end
 295
 296         elseif option:scheme() then
 297                 if not nodeps then
 298                         local ok, err = dependencies.check( self, option )
 299                         if not ok then
 300                                 if not err:is_all(
 301                                         ERR.ERR_OPT_REQUIRED,
 302                                         ERR.ERR_DEP_NOTEQUAL,
 303                                         ERR.ERR_DEP_NOVALUE
 304                                 ) then
 305                                         option:error(err)
 306                                         return false, option:errors()
 307                                 else
 308                                         return true
 309                                 end
 310                         end
 311                 end
 312
 313                 if option:scheme('required') and not option:value() then
 314                         return false, option:error(ERR.OPT_REQUIRED(option))
 315
 316                 elseif option:value() then
 317                         local val = option:value()
 318
 319                         if option:scheme('type') == "reference" or
 320                            option:scheme('type') == "enum"
 321                         then
 322                                 local scheme_values = option:scheme('values') or { }
 323                                 local config_values = ( type(val) == "table" and val or { val } )
 324                                 for _, v in ipairs(config_values) do
 325                                         if not scheme_values[v] then
 326                                                 return false, option:error( ERR.OPT_BADVALUE(
 327                                                         option, { v, util.serialize_data(
 328                                                                 util.keys(scheme_values)
 329                                                         ) }
 330                                                 ) )
 331                                         end
 332                                 end
 333                         elseif option:scheme('type') == "list" then
 334                                 if type(val) ~= "table" and STRICT_LIST_TYPE then
 335                                         return false, option:error(ERR.OPT_NOTLIST(option))
 336                                 end
 337                         end
 338
 339                         if option:scheme('datatype') then
 340                                 local dt = option:scheme('datatype')
 341
 342                                 if self.datatypes[dt] then
 343                                         val = ( type(val) == "table" and val or { val } )
 344                                         for i, v in ipairs(val) do
 345                                                 if not self.datatypes[dt]( v ) then
 346                                                         return false, option:error(
 347                                                                 ERR.OPT_INVVALUE(option, { v, dt })
 348                                                         )
 349                                                 end
 350                                         end
 351                                 else
 352                                         return false, option:error(ERR.OPT_DATATYPE(option, dt))
 353                                 end
 354                         end
 355
 356                         val = ( type(val) == "table" and val or { val } )
 357                         for _, v in ipairs(val) do
 358                                 if option:scheme('minlength') then
 359                                         if #v < option:scheme('minlength') then
 360                                                 return false, option:error(ERR.OPT_RANGE(option))
 361                                         end
 362                                 end
 363
 364                                 if option:scheme('maxlength') then
 365                                         if #v > option:scheme('maxlength') then
 366                                                 return false, option:error(ERR.OPT_RANGE(option))
 367                                         end
 368                                 end
 369
 370                                 local w = tonumber(v)
 371
 372                                 if option:scheme('minimum') then
 373                                         if not w or w < option:scheme('minimum') then
 374                                                 return false, option:error(ERR.OPT_RANGE(option))
 375                                         end
 376                                 end
 377
 378                                 if option:scheme('maximum') then
 379                                         if not w or w > option:scheme('maximum') then
 380                                                 return false, option:error(ERR.OPT_RANGE(option))
 381                                         end
 382                                 end
 383                         end
 384                 end
 385
 386                 local ok, err = validation.check( self, option )
 387                 if not ok and STRICT_EXTERNAL_VALIDATORS then
 388                         return false, option:error(err)
 389                 end
 390         end
 391
 392         return option:ok(), option:errors()
 393 end
 394
 395 --- Find all parts of given scheme and construct validation tree.
 396 -- This is normally done on demand, so you don't have to call this function
 397 -- by yourself.
 398 -- @param shm   Name of the scheme to parse
 399 -- @param alias         Create an alias for the loaded scheme
 400 function UVL.read_scheme( self, shm, alias )
 401
 402         local so = scheme( self, shm )
 403         local bc = "%s/bytecode/%s.lua" %{ self.schemedir, shm }
 404
 405         if not fs.access(bc) then
 406                 local files = fs.glob(self.schemedir .. '/*/' .. shm)
 407
 408                 if files then
 409                         local ok, err
 410                         for i, file in ipairs( files ) do
 411                                 if not fs.access(file) then
 412                                         return false, so:error(ERR.SME_READ(so,file))
 413                                 end
 414
 415                                 local uci = uci.cursor( fs.dirname(file), default_savedir )
 416
 417                                 local sname = fs.basename(file)
 418                                 local sd, err = uci:load( sname )
 419
 420                                 if not sd then
 421                                         return false, ERR.UCILOAD(so, err)
 422                                 end
 423
 424                                 ok, err = pcall(function()
 425                                         uci:foreach(sname, "package", function(s)
 426                                                 self:_parse_package(so, s[".name"], s)
 427                                         end)
 428                                         uci:foreach(sname, "section", function(s)
 429                                                 self:_parse_section(so, s[".name"], s)
 430                                         end)
 431                                         uci:foreach(sname, "variable", function(s)
 432                                                 self:_parse_var(so, s[".name"], s)
 433                                         end)
 434                                         uci:foreach(sname, "enum", function(s)
 435                                                 self:_parse_enum(so, s[".name"], s)
 436                                         end)
 437
 438                                 end)
 439                         end
 440
 441                         if ok and alias then self.packages[alias] = self.packages[shm] end
 442                         return ok and self, err
 443                 else
 444                         return false, so:error(ERR.SME_FIND(so, self.schemedir))
 445                 end
 446         else
 447                 local sc = loadfile(bc)
 448                 if sc then
 449                         self.packages[shm] = sc()
 450                         return true
 451                 else
 452                         return false, so:error(ERR.SME_READ(so,bc))
 453                 end
 454         end
 455 end
 456
 457 -- helper function to check for required fields
 458 local function _req( t, n, c, r )
 459         for i, v in ipairs(r) do
 460                 if not c[v] then
 461                         local p, o = scheme:sid(), nil
 462
 463                         if t == TYPE_SECTION then
 464                                 o = section( scheme, nil, p, n )
 465                         elseif t == TYPE_OPTION then
 466                                 o = option( scheme, nil, p, '(nil)', n )
 467                         elseif t == TYPE_ENUM then
 468                                 o = enum( scheme, nil, p, '(nil)', '(nil)', n )
 469                         end
 470
 471                         return false, ERR.SME_REQFLD(o,v)
 472                 end
 473         end
 474         return true
 475 end
 476
 477 -- helper function to validate references
 478 local function _ref( c, t )
 479         local r, k, n = {}
 480         if c == TYPE_SECTION then
 481                 k = "package"
 482                 n = 1
 483         elseif c == TYPE_OPTION then
 484                 k = "section"
 485                 n = 2
 486         elseif c == TYPE_ENUM then
 487                 k = "variable"
 488                 n = 3
 489         end
 490
 491         for o in t[k]:gmatch("[^.]+") do
 492                 r[#r+1] = o
 493         end
 494         r[1] = ( #r[1] > 0 and r[1] or scheme:sid() )
 495
 496         if #r ~= n then
 497                 return false, ERR.SME_BADREF(scheme, k)
 498         end
 499
 500         return r
 501 end
 502
 503 -- helper function to read bools
 504 local function _bool( v )
 505         return ( v == "true" or v == "yes" or v == "on" or v == "1" )
 506 end
 507
 508 -- Step 0: get package meta information
 509 function UVL._parse_package(self, scheme, k, v)
 510         local sid = scheme:sid()
 511         local pkg = self.packages[sid] or {
 512                 ["name"]      = sid;
 513                 ["sections"]  = { };
 514                 ["variables"] = { };
 515         }
 516
 517         pkg.title = v.title
 518         pkg.description = v.description
 519
 520         self.packages[sid] = pkg
 521 end
 522
 523 -- Step 1: get all sections
 524 function UVL._parse_section(self, scheme, k, v)
 525         local ok, err = _req( TYPE_SECTION, k, v, { "name", "package" } )
 526         if err then error(scheme:error(err)) end
 527
 528         local r, err = _ref( TYPE_SECTION, v )
 529         if err then error(scheme:error(err)) end
 530
 531         local p = self.packages[r[1]] or {
 532                 ["name"]      = r[1];
 533                 ["sections"]  = { };
 534                 ["variables"] = { };
 535         }
 536         p.sections[v.name]  = p.sections[v.name]  or { }
 537         p.variables[v.name] = p.variables[v.name] or { }
 538         self.packages[r[1]] = p
 539
 540         local s  = p.sections[v.name]
 541         local so = scheme:section(v.name)
 542
 543         for k, v2 in pairs(v) do
 544                 if k ~= "name" and k ~= "package" and k:sub(1,1) ~= "." then
 545                         if k == "depends" then
 546                                 s.depends = self:_read_dependency( v2, s.depends )
 547                                 if not s.depends then
 548                                         return false, scheme:error(
 549                                                 ERR.SME_BADDEP(so, util.serialize_data(s.depends))
 550                                         )
 551                                 end
 552                         elseif k == "dynamic" or k == "unique" or
 553                                k == "required" or k == "named"
 554                         then
 555                                 s[k] = _bool(v2)
 556                         else
 557                                 s[k] = v2
 558                         end
 559                 end
 560         end
 561
 562         s.dynamic  = s.dynamic  or false
 563         s.unique   = s.unique   or false
 564         s.required = s.required or false
 565         s.named    = s.named    or false
 566 end
 567
 568 -- Step 2: get all variables
 569 function UVL._parse_var(self, scheme, k, v)
 570         local ok, err = _req( TYPE_OPTION, k, v, { "name", "section" } )
 571         if err then error(scheme:error(err)) end
 572
 573         local r, err = _ref( TYPE_OPTION, v )
 574         if err then error(scheme:error(err)) end
 575
 576         local p = self.packages[r[1]]
 577         if not p then
 578                 error(scheme:error(
 579                         ERR.SME_VBADPACK({scheme:sid(), '', v.name}, r[1])
 580                 ))
 581         end
 582
 583         local s = p.variables[r[2]]
 584         if not s then
 585                 error(scheme:error(
 586                         ERR.SME_VBADSECT({scheme:sid(), '', v.name}, r[2])
 587                 ))
 588         end
 589
 590         s[v.name] = s[v.name] or { }
 591
 592         local t  = s[v.name]
 593         local so = scheme:section(r[2])
 594         local to = so:option(v.name)
 595
 596         for k, v2 in pairs(v) do
 597                 if k ~= "name" and k ~= "section" and k:sub(1,1) ~= "." then
 598                         if k == "depends" then
 599                                 t.depends = self:_read_dependency( v2, t.depends )
 600                                 if not t.depends then
 601                                         error(scheme:error(so:error(
 602                                                 ERR.SME_BADDEP(to, util.serialize_data(v2))
 603                                         )))
 604                                 end
 605                         elseif k == "validator" then
 606                                 t.validators = self:_read_validator( v2, t.validators )
 607                                 if not t.validators then
 608                                         error(scheme:error(so:error(
 609                                                 ERR.SME_BADVAL(to, util.serialize_data(v2))
 610                                         )))
 611                                 end
 612                         elseif k == "valueof" then
 613                                 local values, err = self:_read_reference( v2 )
 614                                 if err then
 615                                         error(scheme:error(so:error(
 616                                                 ERR.REFERENCE(to, util.serialize_data(v2)):child(err)
 617                                         )))
 618                                 end
 619                                 t.type   = "reference"
 620                                 t.values = values
 621                                 t.valueof = type(v2) == "table" and v2 or {v2}
 622                         elseif k == "required" then
 623                                 t[k] = _bool(v2)
 624                         elseif k == "minlength" or k == "maxlength" or
 625                    k == "minimum" or k == "maximum"
 626             then
 627                                 t[k] = tonumber(v2)
 628                         else
 629                                 t[k] = t[k] or v2
 630                         end
 631                 end
 632         end
 633
 634         t.type     = t.type     or "variable"
 635         t.datatype = t.datatype or "string"
 636         t.required = t.required or false
 637 end
 638
 639 -- Step 3: get all enums
 640 function UVL._parse_enum(self, scheme, k, v)
 641         local ok, err = _req( TYPE_ENUM, k, v, { "value", "variable" } )
 642         if err then error(scheme:error(err)) end
 643
 644         local r, err = _ref( TYPE_ENUM, v )
 645         if err then error(scheme:error(err)) end
 646
 647         local p = self.packages[r[1]]
 648         if not p then
 649                 error(scheme:error(
 650                         ERR.SME_EBADPACK({scheme:sid(), '', '', v.value}, r[1])
 651                 ))
 652         end
 653
 654         local s = p.variables[r[2]]
 655         if not s then
 656                 error(scheme:error(
 657                         ERR.SME_EBADSECT({scheme:sid(), '', '', v.value}, r[2])
 658                 ))
 659         end
 660
 661         local t = s[r[3]]
 662         if not t then
 663                 error(scheme:error(
 664                         ERR.SME_EBADOPT({scheme:sid(), '', '', v.value}, r[3])
 665                 ))
 666         end
 667
 668
 669         local so = scheme:section(r[2])
 670         local oo = so:option(r[3])
 671         local eo = oo:enum(v.value)
 672
 673         if t.type ~= "enum" and t.type ~= "reference" then
 674                 error(scheme:error(ERR.SME_EBADTYPE(eo)))
 675         end
 676
 677         if not t.values then
 678                 t.values = { [v.value] = v.title or v.value }
 679                 t.valuelist = { {value = v.value, title = v.title} }
 680         else
 681                 t.values[v.value] = v.title or v.value
 682                 t.valuelist[#t.valuelist + 1] = {value = v.value, title = v.title}
 683         end
 684
 685         if not t.enum_depends then
 686                 t.enum_depends = { }
 687         end
 688
 689         if v.default then
 690                 if t.default then
 691                         error(scheme:error(ERR.SME_EBADDEF(eo)))
 692                 end
 693                 t.default = v.value
 694         end
 695
 696         if v.depends then
 697                 t.enum_depends[v.value] = self:_read_dependency(
 698                         v.depends, t.enum_depends[v.value]
 699                 )
 700
 701                 if not t.enum_depends[v.value] then
 702                         error(scheme:error(so:error(oo:error(
 703                                 ERR.SME_BADDEP(eo, util.serialize_data(v.depends))
 704                         ))))
 705                 end
 706         end
 707 end
 708
 709 -- Read a dependency specification
 710 function UVL._read_dependency( self, values, deps )
 711         local expr = "%$?[%w_]+"
 712         if values then
 713                 values = ( type(values) == "table" and values or { values } )
 714                 for _, value in ipairs(values) do
 715                         local condition = { }
 716                         for val in value:gmatch("[^,]+") do
 717                                 local k, e, v = val:match("%s*([%w$_.]+)%s*(=?)%s*(.*)")
 718
 719                                 if k and (
 720                                         k:match("^"..expr.."%."..expr.."%."..expr.."$") or
 721                                         k:match("^"..expr.."%."..expr.."$") or
 722                                         k:match("^"..expr.."$")
 723                                 ) then
 724                                         condition[k] = (e == '=') and v or true
 725                                 else
 726                                         return nil
 727                                 end
 728                         end
 729
 730                         if not deps then
 731                                 deps = { condition }
 732                         else
 733                                 deps[#deps+1] = condition
 734                         end
 735                 end
 736         end
 737
 738         return deps
 739 end
 740
 741 -- Read a validator specification
 742 function UVL._read_validator( self, values, validators )
 743         if values then
 744                 values = ( type(values) == "table" and values or { values } )
 745                 for _, value in ipairs(values) do
 746                         local validator
 747
 748                         if value:match("^exec:") then
 749                                 validator = value:gsub("^exec:","")
 750                         elseif value:match("^lua:") then
 751                                 validator = self:_resolve_function( (value:gsub("^lua:","") ) )
 752                         elseif value:match("^regexp:") then
 753                                 local pattern = value:gsub("^regexp:","")
 754                                 validator = function( type, dtype, pack, sect, optn, ... )
 755                                         local values = { ... }
 756                                         for _, v in ipairs(values) do
 757                                                 local ok, match =
 758                                                         pcall( string.match, v, pattern )
 759
 760                                                 if not ok then
 761                                                         return false, match
 762                                                 elseif not match then
 763                                                         return false,
 764                                                                 'Value "%s" does not match pattern "%s"' % {
 765                                                                         v, pattern
 766                                                                 }
 767                                                 end
 768                                         end
 769                                         return true
 770                                 end
 771                         end
 772
 773                         if validator then
 774                                 if not validators then
 775                                         validators = { validator }
 776                                 else
 777                                         validators[#validators+1] = validator
 778                                 end
 779                         else
 780                                 return nil
 781                         end
 782                 end
 783
 784                 return validators
 785         end
 786 end
 787
 788 -- Read a reference specification (XXX: We should validate external configs too...)
 789 function UVL._read_reference( self, values )
 790         local val = { }
 791         values = ( type(values) == "table" and values or { values } )
 792
 793         for _, value in ipairs(values) do
 794                 local ref = util.split(value, ".")
 795
 796                 if #ref == 2 or #ref == 3 then
 797                         local co = config( self, ref[1] )
 798                         if not co:config() then return false, co:errors() end
 799
 800                         for k, v in pairs(co:config()) do
 801                                 if v['.type'] == ref[2] then
 802                                         if #ref == 2 then
 803                                                 if v['.anonymous'] == true then
 804                                                         return false, ERR.SME_INVREF('', value)
 805                                                 end
 806                                                 val[k] = k      -- XXX: title/description would be nice
 807                                         elseif v[ref[3]] then
 808                                                 val[v[ref[3]]] = v[ref[3]]  -- XXX: dito
 809                                         end
 810                                 end
 811                         end
 812                 else
 813                         return false, ERR.SME_BADREF('', value)
 814                 end
 815         end
 816
 817         return val, nil
 818 end
 819
 820 -- Resolve given path
 821 function UVL._resolve_function( self, value )
 822         local path = util.split(value, ".")
 823
 824         for i=1, #path-1 do
 825                 local stat, mod = pcall(
 826                         require, table.concat(path, ".", 1, i)
 827                 )
 828
 829                 if stat and mod then
 830                         for j=i+1, #path-1 do
 831                                 if not type(mod) == "table" then
 832                                         break
 833                                 end
 834                                 mod = mod[path[j]]
 835                                 if not mod then
 836                                         break
 837                                 end
 838                         end
 839                         mod = type(mod) == "table" and mod[path[#path]] or nil
 840                         if type(mod) == "function" then
 841                                 return mod
 842                         end
 843                 end
 844         end
 845 end
 846
 847
 848 --- Object representation of an uvl item - base class.
 849 uvlitem = util.class()
 850
 851 function uvlitem.cid(self)
 852         if #self.cref == 1 then
 853                 return self.cref[1]
 854         else
 855                 local r = { unpack(self.cref) }
 856                 local c = self.c
 857                 if c and c[r[2]] and c[r[2]]['.anonymous'] and c[r[2]]['.index'] then
 858                         r[2] = '@' .. c[r[2]]['.type'] ..
 859                                    '[' .. tostring(c[r[2]]['.index']) .. ']'
 860                 end
 861                 return table.concat( r, '.' )
 862         end
 863 end
 864
 865 function uvlitem.sid(self)
 866         return table.concat( self.sref, '.' )
 867 end
 868
 869 function uvlitem.scheme(self, opt)
 870         local s = self.s and self.s.packages
 871         s = s      and s[self.sref[1]]
 872         if #self.sref == 4 or #self.sref == 3 then
 873                 s = s      and s.variables
 874                 s = s      and s[self.sref[2]]
 875                 s = s      and s[self.sref[3]]
 876         elseif #self.sref == 2 then
 877                 s = s      and s.sections
 878                 s = s      and s[self.sref[2]]
 879         end
 880
 881         if s and opt then
 882                 return s[opt]
 883         elseif s then
 884                 return s
 885         end
 886 end
 887
 888 function uvlitem.config(self, opt)
 889         local c = self.c
 890
 891         if #self.cref >= 2 and #self.cref <= 4 then
 892                 c = c and self.c[self.cref[2]] or nil
 893                 if #self.cref >= 3 then
 894                         c = c and c[self.cref[3]] or nil
 895                 end
 896         end
 897
 898         if c and opt then
 899                 return c[opt]
 900         elseif c then
 901                 return c
 902         end
 903 end
 904
 905 function uvlitem.title(self)
 906         return self:scheme() and self:scheme('title') or
 907                 self.cref[3] or self.cref[2] or self.cref[1]
 908 end
 909
 910 function uvlitem.type(self)
 911         if self.t == TYPE_CONFIG then
 912                 return 'config'
 913         elseif self.t == TYPE_SECTION then
 914                 return 'section'
 915         elseif self.t == TYPE_OPTION then
 916                 return 'option'
 917         elseif self.t == TYPE_ENUM then
 918                 return 'enum'
 919         end
 920 end
 921
 922 function uvlitem.error(self, ...)
 923         if not self.e then
 924                 local errconst = { ERR.CONFIG, ERR.SECTION, ERR.OPTION, ERR.OPTION }
 925                 self.e = errconst[#self.cref]( self )
 926         end
 927
 928         return self.e:child( ... )
 929 end
 930
 931 function uvlitem.errors(self)
 932         return self.e
 933 end
 934
 935 function uvlitem.ok(self)
 936         return not self:errors()
 937 end
 938
 939 function uvlitem.parent(self)
 940         if self.p then
 941                 return self.p
 942         elseif #self.cref == 3 or #self.cref == 4 then
 943                 return section( self.s, self.c, self.cref[1], self.cref[2] )
 944         elseif #self.cref == 2 then
 945                 return config( self.s, self.c, self.cref[1] )
 946         else
 947                 return nil
 948         end
 949 end
 950
 951 function uvlitem._loadconf(self, co, c, configdir)
 952         co = co or self._configcache
 953         if not co then
 954                 local err
 955                 co, err = uci.cursor(configdir):get_all(c)
 956
 957                 if err then
 958                         self:error(ERR.UCILOAD(self, err))
 959                 end
 960
 961                 self._configcache = co
 962         end
 963         return co
 964 end
 965
 966
 967 --- Object representation of a scheme.
 968 -- @class       scheme
 969 -- @cstyle      instance
 970 -- @name        luci.uvl.scheme
 971
 972 --- Scheme instance constructor.
 973 -- @class                       function
 974 -- @name                        scheme
 975 -- @param scheme        Scheme instance
 976 -- @param co            Configuration data
 977 -- @param c                     Configuration name
 978 -- @return                      Config instance
 979 scheme = util.class(uvlitem)
 980
 981 function scheme.__init__(self, scheme, co, c)
 982         if not c then
 983                 c, co = co, nil
 984         end
 985
 986         self.cref = { c }
 987         self.sref = { c }
 988         self.c    = self:_loadconf(co, c, scheme.configdir)
 989         self.s    = scheme
 990         self.t    = TYPE_SCHEME
 991 end
 992
 993 --- Add an error to scheme.
 994 -- @return      Scheme error context
 995 function scheme.error(self, ...)
 996         if not self.e then self.e = ERR.SCHEME( self ) end
 997         return self.e:child( ... )
 998 end
 999
1000 --- Get an associated config object.
1001 -- @return      Config instance
1002 function scheme.config(self)
1003         local co = config( self.s, self.cref[1] )
1004               co.p = self
1005
1006         return co
1007 end
1008
1009 --- Get all section objects associated with this scheme.
1010 -- @return      Table containing all associated luci.uvl.section instances
1011 function scheme.sections(self)
1012         local v = { }
1013         if self.s.packages[self.sref[1]].sections then
1014                 for o, _ in pairs( self.s.packages[self.sref[1]].sections ) do
1015                         v[#v+1] = option(
1016                                 self.s, self.c, self.cref[1], self.cref[2], o
1017                         )
1018                 end
1019         end
1020         return v
1021 end
1022
1023 --- Get an associated section object.
1024 -- @param s     Section to select
1025 -- @return      Section instance
1026 function scheme.section(self, s)
1027         local so = section( self.s, self.c, self.cref[1], s )
1028               so.p = self
1029
1030         return so
1031 end
1032
1033
1034 --- Object representation of a config.
1035 -- @class       config
1036 -- @cstyle      instance
1037 -- @name        luci.uvl.config
1038
1039 --- Config instance constructor.
1040 -- @class                       function
1041 -- @name                        config
1042 -- @param scheme        Scheme instance
1043 -- @param co            Configuration data
1044 -- @param c                     Configuration name
1045 -- @return                      Config instance
1046 config = util.class(uvlitem)
1047
1048 function config.__init__(self, scheme, co, c)
1049         if not c then
1050                 c, co = co, nil
1051         end
1052         self.cref = { c }
1053         self.sref = { c }
1054         self.c    = self:_loadconf(co, c, scheme.configdir)
1055         self.s    = scheme
1056         self.t    = TYPE_CONFIG
1057 end
1058
1059 --- Get all section objects associated with this config.
1060 -- @return      Table containing all associated luci.uvl.section instances
1061 function config.sections(self)
1062         local v = { }
1063         if self.s.packages[self.sref[1]].sections then
1064                 for o, _ in pairs( self.s.packages[self.sref[1]].sections ) do
1065                         v[#v+1] = option(
1066                                 self.s, self.c, self.cref[1], self.cref[2], o
1067                         )
1068                 end
1069         end
1070         return v
1071 end
1072
1073 --- Get an associated section object.
1074 -- @param s     Section to select
1075 -- @return      Section instance
1076 function config.section(self, s)
1077         local so = section( self.s, self.c, self.cref[1], s )
1078               so.p = self
1079
1080         return so
1081 end
1082
1083
1084 --- Object representation of a scheme/config section.
1085 -- @class       module
1086 -- @cstyle      instance
1087 -- @name        luci.uvl.section
1088
1089 --- Section instance constructor.
1090 -- @class                       function
1091 -- @name                        section
1092 -- @param scheme        Scheme instance
1093 -- @param co            Configuration data
1094 -- @param c                     Configuration name
1095 -- @param s                     Section name
1096 -- @return                      Section instance
1097 section = util.class(uvlitem)
1098
1099 function section.__init__(self, scheme, co, c, s)
1100         self.cref = { c, s }
1101         self.sref = { c, co and co[s] and co[s]['.type'] or s }
1102         self.c    = self:_loadconf(co, c, scheme.configdir)
1103         self.s    = scheme
1104         self.t    = TYPE_SECTION
1105 end
1106
1107 --- Get all option objects associated with this section.
1108 -- @return      Table containing all associated luci.uvl.option instances
1109 function section.variables(self)
1110         local v = { }
1111         if self.s.packages[self.sref[1]].variables[self.sref[2]] then
1112                 for o, _ in pairs(
1113                         self.s.packages[self.sref[1]].variables[self.sref[2]]
1114                 ) do
1115                         v[#v+1] = option(
1116                                 self.s, self.c, self.cref[1], self.cref[2], o
1117                         )
1118                 end
1119         end
1120         return v
1121 end
1122
1123 --- Get an associated option object.
1124 -- @param o     Option to select
1125 -- @return      Option instance
1126 function section.option(self, o)
1127         local oo = option( self.s, self.c, self.cref[1], self.cref[2], o )
1128               oo.p = self
1129
1130         return oo
1131 end
1132
1133
1134 --- Object representation of a scheme/config option.
1135 -- @class       module
1136 -- @cstyle      instance
1137 -- @name        luci.uvl.option
1138
1139 --- Section instance constructor.
1140 -- @class                       function
1141 -- @name                        option
1142 -- @param scheme        Scheme instance
1143 -- @param co            Configuration data
1144 -- @param c                     Configuration name
1145 -- @param s                     Section name
1146 -- @param o                     Option name
1147 -- @return                      Option instance
1148 option = util.class(uvlitem)
1149
1150 function option.__init__(self, scheme, co, c, s, o)
1151         self.cref = { c, s, o }
1152         self.sref = { c, co and co[s] and co[s]['.type'] or s, o }
1153         self.c    = self:_loadconf(co, c, scheme.configdir)
1154         self.s    = scheme
1155         self.t    = TYPE_OPTION
1156 end
1157
1158 --- Get the value of this option.
1159 -- @return      The associated configuration value
1160 function option.value(self)
1161         local v = self:config() or self:scheme('default')
1162         if v and self:scheme('multival') then
1163                 v = util.split( v, "%s+", nil, true )
1164         end
1165         return v
1166 end
1167
1168 --- Get the associated section information in scheme.
1169 -- @return      Table containing the scheme properties
1170 function option.section(self)
1171         return self.s.packages[self.sref[1]].sections[self.sref[2]]
1172 end
1173
1174 --- Construct an enum object instance from given or default value.
1175 -- @param v     Value to select
1176 -- @return      Enum instance for selected value
1177 function option.enum(self, val)
1178         return enum(
1179                 self.s, self.c,
1180                 self.cref[1], self.cref[2], self.cref[3],
1181                 val or self:value()
1182         )
1183 end
1184
1185
1186 --- Object representation of a enum value.
1187 -- @class       module
1188 -- @cstyle      instance
1189 -- @name        luci.uvl.enum
1190
1191 --- Section instance constructor.
1192 -- @class                       function
1193 -- @name                        enum
1194 -- @param scheme        Scheme instance
1195 -- @param co            Configuration data
1196 -- @param c                     Configuration name
1197 -- @param s                     Section name
1198 -- @param o                     Enum name
1199 -- @param v                     Enum value
1200 -- @return                      Enum value instance
1201 enum = util.class(option)
1202
1203 function enum.__init__(self, scheme, co, c, s, o, v)
1204         self.cref = { c, s, o, v }
1205         self.sref = { c, co and co[s] and co[s]['.type'] or s, o, v }
1206         self.c    = self:_loadconf(co, c, scheme.configdir)
1207         self.s    = scheme
1208         self.t    = TYPE_ENUM
1209 end