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