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 "nixio.fs"
  23 local uci = require "luci.model.uci"
  24 local util = require "luci.util"
  25 local nutil = require "nixio.util"
  26 local table = require "table"
  27 local string = require "string"
  28
  29 local require, pcall, ipairs, pairs = require, pcall, ipairs, pairs
  30 local type, error, tonumber, tostring = type, error, tonumber, tostring
  31 local unpack, loadfile = unpack, loadfile
  32
  33 module "luci.uvl"
  34
  35 local ERR = require "luci.uvl.errors"
  36 local datatypes = require "luci.uvl.datatypes"
  37 local validation = require "luci.uvl.validation"
  38 local dependencies = require "luci.uvl.dependencies"
  39
  40 local TYPE_SCHEME   = 0x00
  41 local TYPE_CONFIG   = 0x01
  42 local TYPE_SECTION  = 0x02
  43 local TYPE_OPTION   = 0x03
  44 local TYPE_ENUM     = 0x04
  45
  46 --- Boolean; default true;
  47 -- treat sections found in config but not in scheme as error
  48 STRICT_UNKNOWN_SECTIONS    = true
  49
  50 --- Boolean; default true;
  51 -- treat options found in config but not in scheme as error
  52 STRICT_UNKNOWN_OPTIONS     = true
  53
  54 --- Boolean; default true;
  55 -- treat failed external validators as error
  56 STRICT_EXTERNAL_VALIDATORS = true
  57
  58 --- Boolean; default true;
  59 -- treat list values stored as options like errors
  60 STRICT_LIST_TYPE           = true
  61
  62
  63 local default_schemedir = "/lib/uci/schema"
  64 local default_savedir = "/tmp/.uvl"
  65
  66
  67 --- Object constructor
  68 -- @class                       function
  69 -- @name                        UVL
  70 -- @param schemedir     Path to the scheme directory (optional)
  71 -- @param configdir     Override config directory (optional)
  72 -- @return                      Instance object
  73 UVL = util.class()
  74
  75 function UVL.__init__( self, schemedir, configdir )
  76         self.schemedir  = schemedir or default_schemedir
  77         self.configdir  = configdir
  78         self.packages   = { }
  79         self.beenthere  = { }
  80         self.depseen    = { }
  81         self.uci                = uci
  82         self.err                = ERR
  83         self.dep                = dependencies
  84         self.datatypes  = datatypes
  85 end
  86
  87
  88 --- Parse given scheme and return the scheme tree.
  89 -- @param scheme        Name of the scheme to parse
  90 -- @return                      Table containing the parsed scheme or nil on error
  91 -- @return                      String containing the reason for errors (if any)
  92 function UVL.get_scheme( self, scheme )
  93         if not self.packages[scheme] then
  94                 local ok, err = self:read_scheme( scheme )
  95                 if not ok then
  96                         return nil, err
  97                 end
  98         end
  99         return self.packages[scheme], nil
 100 end
 101
 102 --- Validate given configuration, section or option.
 103 -- @param config        Name of the configuration to validate
 104 -- @param section       Name of the section to validate (optional)
 105 -- @param option        Name of the option to validate (optional)
 106 -- @return                      Boolean indicating whether the given config validates
 107 -- @return                      String containing the reason for errors (if any)
 108 function UVL.validate( self, config, section, option )
 109         if config and section and option then
 110                 return self:validate_option( config, section, option )
 111         elseif config and section then
 112                 return self:validate_section( config, section )
 113         elseif config then
 114                 return self:validate_config( config )
 115         end
 116 end
 117
 118 --- Validate given configuration.
 119 -- @param cfg   Name of the configuration to validate
 120 -- @return                      Boolean indicating whether the given config validates
 121 -- @return                      String containing the reason for errors (if any)
 122 function UVL.validate_config( self, cfg, uci )
 123
 124         if not self.packages[cfg] then
 125                 local ok, err = self:read_scheme(cfg)
 126                 if not ok then
 127                         return false, err
 128                 end
 129         end
 130
 131         local co = config( self, uci or cfg, uci and cfg )
 132         local sc = { }
 133
 134         self.beenthere = { }
 135         self.depseen   = { }
 136
 137         if not co:config() then
 138                 return false, co:errors()
 139         end
 140
 141         local function _uci_foreach( type, func )
 142                 for k, v in pairs(co:config()) do
 143                         if v['.type'] == type then
 144                                 sc[type] = sc[type] + 1
 145                                 local ok, err = func( k, v )
 146                                 if not ok then co:error(err) end
 147                         end
 148                 end
 149         end
 150
 151         for k, v in pairs( self.packages[cfg].sections ) do
 152                 sc[k] = 0
 153                 _uci_foreach( k,
 154                         function(s)
 155                                 return self:_validate_section( co:section(s) )
 156                         end
 157                 )
 158         end
 159
 160         if STRICT_UNKNOWN_SECTIONS then
 161                 for k, v in pairs(co:config()) do
 162                         local so = co:section(k)
 163                         if not self.beenthere[so:cid()] then
 164                                 co:error(ERR.SECT_UNKNOWN(so))
 165                         end
 166                 end
 167         end
 168
 169         for _, k in ipairs(util.keys(sc)) do
 170                 local so = co:section(k)
 171                 if so:scheme('required') and sc[k] == 0 then
 172                         co:error(ERR.SECT_REQUIRED(so))
 173                 elseif so:scheme('unique') and sc[k] > 1 then
 174                         co:error(ERR.SECT_UNIQUE(so))
 175                 end
 176         end
 177
 178         return co:ok(), co:errors()
 179 end
 180
 181 --- Validate given config section.
 182 -- @param config        Name of the configuration to validate
 183 -- @param section       Name of the section to validate
 184 -- @return                      Boolean indicating whether the given config validates
 185 -- @return                      String containing the reason for errors (if any)
 186 function UVL.validate_section( self, cfg, section, uci )
 187
 188         if not self.packages[cfg] then
 189                 local ok, err = self:read_scheme( cfg )
 190                 if not ok then
 191                         return false, err
 192                 end
 193         end
 194
 195         local co = config( self, uci or cfg, uci and cfg )
 196         local so = co:section( section )
 197
 198         self.beenthere = { }
 199         self.depseen   = { }
 200
 201         if not co:config() then
 202                 return false, co:errors()
 203         end
 204
 205         if so:config() then
 206                 return self:_validate_section( so )
 207         else
 208                 return false, ERR.SECT_NOTFOUND(so)
 209         end
 210 end
 211
 212 --- Validate given config option.
 213 -- @param config        Name of the configuration to validate
 214 -- @param section       Name of the section to validate
 215 -- @param option        Name of the option to validate
 216 -- @return                      Boolean indicating whether the given config validates
 217 -- @return                      String containing the reason for errors (if any)
 218 function UVL.validate_option( self, cfg, section, option, uci )
 219
 220         if not self.packages[cfg] then
 221                 local ok, err = self:read_scheme( cfg )
 222                 if not ok then
 223                         return false, err
 224                 end
 225         end
 226
 227         local co = config( self, uci or cfg, uci and cfg )
 228         local so = co:section( section )
 229         local oo = so:option( option )
 230
 231         if not co:config() then
 232                 return false, co:errors()
 233         end
 234
 235         if so:config() and oo:config() then
 236                 return self:_validate_option( oo )
 237         else
 238                 return false, ERR.OPT_NOTFOUND(oo)
 239         end
 240 end
 241
 242
 243 function UVL._validate_section( self, section )
 244
 245         self.beenthere[section:cid()] = true
 246
 247         if section:config() then
 248                 if section:scheme('named') == true and
 249                    section:config('.anonymous') == true
 250                 then
 251                         return false, ERR.SECT_NAMED(section)
 252                 end
 253
 254                 for _, v in ipairs(section:variables()) do
 255                         local ok, err = self:_validate_option( v )
 256                         if not ok and (
 257                                 v:scheme('required') or v:scheme('type') == "enum" or (
 258                                         not err:is(ERR.ERR_DEP_NOTEQUAL) and
 259                                         not err:is(ERR.ERR_DEP_NOVALUE)
 260                                 )
 261                         ) then
 262                                 section:error(err)
 263                         end
 264                 end
 265
 266                 local ok, err = dependencies.check( self, section )
 267                 if not ok then
 268                         section:error(err)
 269                 end
 270         else
 271                 return false, ERR.SECT_NOTFOUND(section)
 272         end
 273
 274         if STRICT_UNKNOWN_OPTIONS and not section:scheme('dynamic') then
 275                 for k, v in pairs(section:config()) do
 276                         local oo = section:option(k)
 277                         if k:sub(1,1) ~= "." and not self.beenthere[oo:cid()] then
 278                                 section:error(ERR.OPT_UNKNOWN(oo))
 279                         end
 280                 end
 281         end
 282
 283         return section:ok(), section:errors()
 284 end
 285
 286 function UVL._validate_option( self, option, nodeps )
 287
 288         self.beenthere[option:cid()] = true
 289
 290         if not option:scheme() and not option:parent():scheme('dynamic') then
 291                 if STRICT_UNKNOWN_OPTIONS then
 292                         return false, option:error(ERR.OPT_UNKNOWN(option))
 293                 else
 294                         return true
 295                 end
 296
 297         elseif option:scheme() then
 298                 if not nodeps then
 299                         local ok, err = dependencies.check( self, option )
 300                         if not ok then
 301                                 if not err:is_all(
 302                                         ERR.ERR_OPT_REQUIRED,
 303                                         ERR.ERR_DEP_NOTEQUAL,
 304                                         ERR.ERR_DEP_NOVALUE
 305                                 ) then
 306                                         option:error(err)
 307                                         return false, option:errors()
 308                                 else
 309                                         return true
 310                                 end
 311                         end
 312                 end
 313
 314                 if option:scheme('required') and not option:value() then
 315                         return false, option:error(ERR.OPT_REQUIRED(option))
 316
 317                 elseif option:value() then
 318                         local val = option:value()
 319
 320                         if option:scheme('type') == "reference" or
 321                            option:scheme('type') == "enum"
 322                         then
 323                                 local scheme_values = option:scheme('values') or { }
 324                                 local config_values = ( type(val) == "table" and val or { val } )
 325                                 for _, v in ipairs(config_values) do
 326                                         if not scheme_values[v] then
 327                                                 return false, option:error( ERR.OPT_BADVALUE(
 328                                                         option, { v, util.serialize_data(
 329                                                                 util.keys(scheme_values)
 330                                                         ) }
 331                                                 ) )
 332                                         end
 333                                 end
 334                         elseif option:scheme('type') == "list" then
 335                                 if type(val) ~= "table" and STRICT_LIST_TYPE then
 336                                         return false, option:error(ERR.OPT_NOTLIST(option))
 337                                 end
 338                         end
 339
 340                         if option:scheme('datatype') then
 341                                 local dt = option:scheme('datatype')
 342
 343                                 if self.datatypes[dt] then
 344                                         val = ( type(val) == "table" and val or { val } )
 345                                         for i, v in ipairs(val) do
 346                                                 if not self.datatypes[dt]( v ) then
 347                                                         return false, option:error(
 348                                                                 ERR.OPT_INVVALUE(option, { v, dt })
 349                                                         )
 350                                                 end
 351                                         end
 352                                 else
 353                                         return false, option:error(ERR.OPT_DATATYPE(option, dt))
 354                                 end
 355                         end
 356
 357                         val = ( type(val) == "table" and val or { val } )
 358                         for _, v in ipairs(val) do
 359                                 if option:scheme('minlength') then
 360                                         if #v < option:scheme('minlength') then
 361                                                 return false, option:error(ERR.OPT_RANGE(option))
 362                                         end
 363                                 end
 364
 365                                 if option:scheme('maxlength') then
 366                                         if #v > option:scheme('maxlength') then
 367                                                 return false, option:error(ERR.OPT_RANGE(option))
 368                                         end
 369                                 end
 370
 371                                 local w = tonumber(v)
 372
 373                                 if option:scheme('minimum') then
 374                                         if not w or w < option:scheme('minimum') then
 375                                                 return false, option:error(ERR.OPT_RANGE(option))
 376                                         end
 377                                 end
 378
 379                                 if option:scheme('maximum') then
 380                                         if not w or w > option:scheme('maximum') then
 381                                                 return false, option:error(ERR.OPT_RANGE(option))
 382                                         end
 383                                 end
 384                         end
 385                 end
 386
 387                 local ok, err = validation.check( self, option )
 388                 if not ok and STRICT_EXTERNAL_VALIDATORS then
 389                         return false, option:error(err)
 390                 end
 391         end
 392
 393         return option:ok(), option:errors()
 394 end
 395
 396 --- Find all parts of given scheme and construct validation tree.
 397 -- This is normally done on demand, so you don't have to call this function
 398 -- by yourself.
 399 -- @param shm   Name of the scheme to parse
 400 -- @param alias         Create an alias for the loaded scheme
 401 function UVL.read_scheme( self, shm, alias )
 402
 403         local so = scheme( self, shm )
 404         local bc = "%s/bytecode/%s.lua" %{ self.schemedir, shm }
 405
 406         if not fs.access(bc) then
 407                 local files = nutil.consume((fs.glob(self.schemedir .. '/*/' .. shm)))
 408
 409                 if #files > 0 then
 410                         local ok, err
 411                         for _, file in ipairs(files) do
 412                                 if not fs.access(file) then
 413                                         return false, so:error(ERR.SME_READ(so,file))
 414                                 end
 415
 416                                 local uci = uci.cursor( fs.dirname(file), default_savedir )
 417
 418                                 local sname = fs.basename(file)
 419                                 local sd, err = uci:load( sname )
 420
 421                                 if not sd then
 422                                         return false, ERR.UCILOAD(so, err)
 423                                 end
 424
 425                                 ok, err = pcall(function()
 426                                         uci:foreach(sname, "package", function(s)
 427                                                 self:_parse_package(so, s[".name"], s)
 428                                         end)
 429                                         uci:foreach(sname, "section", function(s)
 430                                                 self:_parse_section(so, s[".name"], s)
 431                                         end)
 432                                         uci:foreach(sname, "variable", function(s)
 433                                                 self:_parse_var(so, s[".name"], s)
 434                                         end)
 435                                         uci:foreach(sname, "enum", function(s)
 436                                                 self:_parse_enum(so, s[".name"], s)
 437                                         end)
 438
 439                                 end)
 440                         end
 441
 442                         if ok and alias then self.packages[alias] = self.packages[shm] end
 443                         return ok and self, err
 444                 else
 445                         return false, so:error(ERR.SME_FIND(so, self.schemedir))
 446                 end
 447         else
 448                 local sc = loadfile(bc)
 449                 if sc then
 450                         self.packages[shm] = sc()
 451                         return true
 452                 else
 453                         return false, so:error(ERR.SME_READ(so,bc))
 454                 end
 455         end
 456 end
 457
 458 -- helper function to check for required fields
 459 local function _req( t, n, c, r )
 460         for i, v in ipairs(r) do
 461                 if not c[v] then
 462                         local p, o = scheme:sid(), nil
 463
 464                         if t == TYPE_SECTION then
 465                                 o = section( scheme, nil, p, n )
 466                         elseif t == TYPE_OPTION then
 467                                 o = option( scheme, nil, p, '(nil)', n )
 468                         elseif t == TYPE_ENUM then
 469                                 o = enum( scheme, nil, p, '(nil)', '(nil)', n )
 470                         end
 471
 472                         return false, ERR.SME_REQFLD(o,v)
 473                 end
 474         end
 475         return true
 476 end
 477
 478 -- helper function to validate references
 479 local function _ref( c, t )
 480         local r, k, n = {}
 481         if c == TYPE_SECTION then
 482                 k = "package"
 483                 n = 1
 484         elseif c == TYPE_OPTION then
 485                 k = "section"
 486                 n = 2
 487         elseif c == TYPE_ENUM then
 488                 k = "variable"
 489                 n = 3
 490         end
 491
 492         for o in t[k]:gmatch("[^.]+") do
 493                 r[#r+1] = o
 494         end
 495         r[1] = ( #r[1] > 0 and r[1] or scheme:sid() )
 496
 497         if #r ~= n then
 498                 return false, ERR.SME_BADREF(scheme, k)
 499         end
 500
 501         return r
 502 end
 503
 504 -- helper function to read bools
 505 local function _bool( v )
 506         return ( v == "true" or v == "yes" or v == "on" or v == "1" )
 507 end
 508
 509 -- Step 0: get package meta information
 510 function UVL._parse_package(self, scheme, k, v)
 511         local sid = scheme:sid()
 512         local pkg = self.packages[sid] or {
 513                 ["name"]      = sid;
 514                 ["sections"]  = { };
 515                 ["variables"] = { };
 516         }
 517
 518         pkg.title = v.title
 519         pkg.description = v.description
 520
 521         self.packages[sid] = pkg
 522 end
 523
 524 -- Step 1: get all sections
 525 function UVL._parse_section(self, scheme, k, v)
 526         local ok, err = _req( TYPE_SECTION, k, v, { "name", "package" } )
 527         if err then error(scheme:error(err)) end
 528
 529         local r, err = _ref( TYPE_SECTION, v )
 530         if err then error(scheme:error(err)) end
 531
 532         local p = self.packages[r[1]] or {
 533                 ["name"]      = r[1];
 534                 ["sections"]  = { };
 535                 ["variables"] = { };
 536         }
 537         p.sections[v.name]  = p.sections[v.name]  or { }
 538         p.variables[v.name] = p.variables[v.name] or { }
 539         self.packages[r[1]] = p
 540
 541         local s  = p.sections[v.name]
 542         local so = scheme:section(v.name)
 543
 544         for k, v2 in pairs(v) do
 545                 if k ~= "name" and k ~= "package" and k:sub(1,1) ~= "." then
 546                         if k == "depends" then
 547                                 s.depends = self:_read_dependency( v2, s.depends )
 548                                 if not s.depends then
 549                                         return false, scheme:error(
 550                                                 ERR.SME_BADDEP(so, util.serialize_data(s.depends))
 551                                         )
 552                                 end
 553                         elseif k == "dynamic" or k == "unique" or
 554                                k == "required" or k == "named"
 555                         then
 556                                 s[k] = _bool(v2)
 557                         else
 558                                 s[k] = v2
 559                         end
 560                 end
 561         end
 562
 563         s.dynamic  = s.dynamic  or false
 564         s.unique   = s.unique   or false
 565         s.required = s.required or false
 566         s.named    = s.named    or false
 567 end
 568
 569 -- Step 2: get all variables
 570 function UVL._parse_var(self, scheme, k, v)
 571         local ok, err = _req( TYPE_OPTION, k, v, { "name", "section" } )
 572         if err then error(scheme:error(err)) end
 573
 574         local r, err = _ref( TYPE_OPTION, v )
 575         if err then error(scheme:error(err)) end
 576
 577         local p = self.packages[r[1]]
 578         if not p then
 579                 error(scheme:error(
 580                         ERR.SME_VBADPACK({scheme:sid(), '', v.name}, r[1])
 581                 ))
 582         end
 583
 584         local s = p.variables[r[2]]
 585         if not s then
 586                 error(scheme:error(
 587                         ERR.SME_VBADSECT({scheme:sid(), '', v.name}, r[2])
 588                 ))
 589         end
 590
 591         s[v.name] = s[v.name] or { }
 592
 593         local t  = s[v.name]
 594         local so = scheme:section(r[2])
 595         local to = so:option(v.name)
 596
 597         for k, v2 in pairs(v) do
 598                 if k ~= "name" and k ~= "section" and k:sub(1,1) ~= "." then
 599                         if k == "depends" then
 600                                 t.depends = self:_read_dependency( v2, t.depends )
 601                                 if not t.depends then
 602                                         error(scheme:error(so:error(
 603                                                 ERR.SME_BADDEP(to, util.serialize_data(v2))
 604                                         )))
 605                                 end
 606                         elseif k == "validator" then
 607                                 t.validators = self:_read_validator( v2, t.validators )
 608                                 if not t.validators then
 609                                         error(scheme:error(so:error(
 610                                                 ERR.SME_BADVAL(to, util.serialize_data(v2))
 611                                         )))
 612                                 end
 613                         elseif k == "valueof" then
 614                                 local values, err = self:_read_reference( v2 )
 615                                 if err then
 616                                         error(scheme:error(so:error(
 617                                                 ERR.REFERENCE(to, util.serialize_data(v2)):child(err)
 618                                         )))
 619                                 end
 620                                 t.type   = "reference"
 621                                 t.values = values
 622                                 t.valueof = type(v2) == "table" and v2 or {v2}
 623                         elseif k == "required" then
 624                                 t[k] = _bool(v2)
 625                         elseif k == "minlength" or k == "maxlength" or
 626                    k == "minimum" or k == "maximum"
 627             then
 628                                 t[k] = tonumber(v2)
 629                         else
 630                                 t[k] = t[k] or v2
 631                         end
 632                 end
 633         end
 634
 635         t.type     = t.type     or "variable"
 636         t.datatype = t.datatype or "string"
 637         t.required = t.required or false
 638 end
 639
 640 -- Step 3: get all enums
 641 function UVL._parse_enum(self, scheme, k, v)
 642         local ok, err = _req( TYPE_ENUM, k, v, { "value", "variable" } )
 643         if err then error(scheme:error(err)) end
 644
 645         local r, err = _ref( TYPE_ENUM, v )
 646         if err then error(scheme:error(err)) end
 647
 648         local p = self.packages[r[1]]
 649         if not p then
 650                 error(scheme:error(
 651                         ERR.SME_EBADPACK({scheme:sid(), '', '', v.value}, r[1])
 652                 ))
 653         end
 654
 655         local s = p.variables[r[2]]
 656         if not s then
 657                 error(scheme:error(
 658                         ERR.SME_EBADSECT({scheme:sid(), '', '', v.value}, r[2])
 659                 ))
 660         end
 661
 662         local t = s[r[3]]
 663         if not t then
 664                 error(scheme:error(
 665                         ERR.SME_EBADOPT({scheme:sid(), '', '', v.value}, r[3])
 666                 ))
 667         end
 668
 669
 670         local so = scheme:section(r[2])
 671         local oo = so:option(r[3])
 672         local eo = oo:enum(v.value)
 673
 674         if t.type ~= "enum" and t.type ~= "reference" then
 675                 error(scheme:error(ERR.SME_EBADTYPE(eo)))
 676         end
 677
 678         if not t.values then
 679                 t.values = { [v.value] = v.title or v.value }
 680                 t.valuelist = { {value = v.value, title = v.title} }
 681         else
 682                 t.values[v.value] = v.title or v.value
 683                 t.valuelist[#t.valuelist + 1] = {value = v.value, title = v.title}
 684         end
 685
 686         if not t.enum_depends then
 687                 t.enum_depends = { }
 688         end
 689
 690         if v.default then
 691                 if t.default then
 692                         error(scheme:error(ERR.SME_EBADDEF(eo)))
 693                 end
 694                 t.default = v.value
 695         end
 696
 697         if v.depends then
 698                 t.enum_depends[v.value] = self:_read_dependency(
 699                         v.depends, t.enum_depends[v.value]
 700                 )
 701
 702                 if not t.enum_depends[v.value] then
 703                         error(scheme:error(so:error(oo:error(
 704                                 ERR.SME_BADDEP(eo, util.serialize_data(v.depends))
 705                         ))))
 706                 end
 707         end
 708 end
 709
 710 -- Read a dependency specification
 711 function UVL._read_dependency( self, values, deps )
 712         local expr = "%$?[%w_]+"
 713         if values then
 714                 values = ( type(values) == "table" and values or { values } )
 715                 for _, value in ipairs(values) do
 716                         local condition = { }
 717                         for val in value:gmatch("[^,]+") do
 718                                 local k, e, v = val:match("%s*([%w$_.]+)%s*(=?)%s*(.*)")
 719
 720                                 if k and (
 721                                         k:match("^"..expr.."%."..expr.."%."..expr.."$") or
 722                                         k:match("^"..expr.."%."..expr.."$") or
 723                                         k:match("^"..expr.."$")
 724                                 ) then
 725                                         condition[k] = (e == '=') and v or true
 726                                 else
 727                                         return nil
 728                                 end
 729                         end
 730
 731                         if not deps then
 732                                 deps = { condition }
 733                         else
 734                                 deps[#deps+1] = condition
 735                         end
 736                 end
 737         end
 738
 739         return deps
 740 end
 741
 742 -- Read a validator specification
 743 function UVL._read_validator( self, values, validators )
 744         if values then
 745                 values = ( type(values) == "table" and values or { values } )
 746                 for _, value in ipairs(values) do
 747                         local validator
 748
 749                         if value:match("^exec:") then
 750                                 validator = value:gsub("^exec:","")
 751                         elseif value:match("^lua:") then
 752                                 validator = self:_resolve_function( (value:gsub("^lua:","") ) )
 753                         elseif value:match("^regexp:") then
 754                                 local pattern = value:gsub("^regexp:","")
 755                                 validator = function( type, dtype, pack, sect, optn, ... )
 756                                         local values = { ... }
 757                                         for _, v in ipairs(values) do
 758                                                 local ok, match =
 759                                                         pcall( string.match, v, pattern )
 760
 761                                                 if not ok then
 762                                                         return false, match
 763                                                 elseif not match then
 764                                                         return false,
 765                                                                 'Value "%s" does not match pattern "%s"' % {
 766                                                                         v, pattern
 767                                                                 }
 768                                                 end
 769                                         end
 770                                         return true
 771                                 end
 772                         end
 773
 774                         if validator then
 775                                 if not validators then
 776                                         validators = { validator }
 777                                 else
 778                                         validators[#validators+1] = validator
 779                                 end
 780                         else
 781                                 return nil
 782                         end
 783                 end
 784
 785                 return validators
 786         end
 787 end
 788
 789 -- Read a reference specification (XXX: We should validate external configs too...)
 790 function UVL._read_reference( self, values )
 791         local val = { }
 792         values = ( type(values) == "table" and values or { values } )
 793
 794         for _, value in ipairs(values) do
 795                 local ref = util.split(value, ".")
 796
 797                 if #ref == 2 or #ref == 3 then
 798                         local co = config( self, ref[1] )
 799                         if not co:config() then return false, co:errors() end
 800
 801                         for k, v in pairs(co:config()) do
 802                                 if v['.type'] == ref[2] then
 803                                         if #ref == 2 then
 804                                                 if v['.anonymous'] == true then
 805                                                         return false, ERR.SME_INVREF('', value)
 806                                                 end
 807                                                 val[k] = k      -- XXX: title/description would be nice
 808                                         elseif v[ref[3]] then
 809                                                 val[v[ref[3]]] = v[ref[3]]  -- XXX: dito
 810                                         end
 811                                 end
 812                         end
 813                 else
 814                         return false, ERR.SME_BADREF('', value)
 815                 end
 816         end
 817
 818         return val, nil
 819 end
 820
 821 -- Resolve given path
 822 function UVL._resolve_function( self, value )
 823         local path = util.split(value, ".")
 824
 825         for i=1, #path-1 do
 826                 local stat, mod = pcall(
 827                         require, table.concat(path, ".", 1, i)
 828                 )
 829
 830                 if stat and mod then
 831                         for j=i+1, #path-1 do
 832                                 if not type(mod) == "table" then
 833                                         break
 834                                 end
 835                                 mod = mod[path[j]]
 836                                 if not mod then
 837                                         break
 838                                 end
 839                         end
 840                         mod = type(mod) == "table" and mod[path[#path]] or nil
 841                         if type(mod) == "function" then
 842                                 return mod
 843                         end
 844                 end
 845         end
 846 end
 847
 848
 849 --- Object representation of an uvl item - base class.
 850 uvlitem = util.class()
 851
 852 function uvlitem.cid(self)
 853         if #self.cref == 1 then
 854                 return self.cref[1]
 855         else
 856                 local r = { unpack(self.cref) }
 857                 local c = self.c
 858                 if c and c[r[2]] and c[r[2]]['.anonymous'] and c[r[2]]['.index'] then
 859                         r[2] = '@' .. c[r[2]]['.type'] ..
 860                                    '[' .. tostring(c[r[2]]['.index']) .. ']'
 861                 end
 862                 return table.concat( r, '.' )
 863         end
 864 end
 865
 866 function uvlitem.sid(self)
 867         return table.concat( self.sref, '.' )
 868 end
 869
 870 function uvlitem.scheme(self, opt)
 871         local s = self.s and self.s.packages
 872         s = s      and s[self.sref[1]]
 873         if #self.sref == 4 or #self.sref == 3 then
 874                 s = s      and s.variables
 875                 s = s      and s[self.sref[2]]
 876                 s = s      and s[self.sref[3]]
 877         elseif #self.sref == 2 then
 878                 s = s      and s.sections
 879                 s = s      and s[self.sref[2]]
 880         end
 881
 882         if s and opt then
 883                 return s[opt]
 884         elseif s then
 885                 return s
 886         end
 887 end
 888
 889 function uvlitem.config(self, opt)
 890         local c = self.c
 891
 892         if #self.cref >= 2 and #self.cref <= 4 then
 893                 c = c and self.c[self.cref[2]] or nil
 894                 if #self.cref >= 3 then
 895                         c = c and c[self.cref[3]] or nil
 896                 end
 897         end
 898
 899         if c and opt then
 900                 return c[opt]
 901         elseif c then
 902                 return c
 903         end
 904 end
 905
 906 function uvlitem.title(self)
 907         return self:scheme() and self:scheme('title') or
 908                 self.cref[3] or self.cref[2] or self.cref[1]
 909 end
 910
 911 function uvlitem.type(self)
 912         if self.t == TYPE_CONFIG then
 913                 return 'config'
 914         elseif self.t == TYPE_SECTION then
 915                 return 'section'
 916         elseif self.t == TYPE_OPTION then
 917                 return 'option'
 918         elseif self.t == TYPE_ENUM then
 919                 return 'enum'
 920         end
 921 end
 922
 923 function uvlitem.error(self, ...)
 924         if not self.e then
 925                 local errconst = { ERR.CONFIG, ERR.SECTION, ERR.OPTION, ERR.OPTION }
 926                 self.e = errconst[#self.cref]( self )
 927         end
 928
 929         return self.e:child( ... )
 930 end
 931
 932 function uvlitem.errors(self)
 933         return self.e
 934 end
 935
 936 function uvlitem.ok(self)
 937         return not self:errors()
 938 end
 939
 940 function uvlitem.parent(self)
 941         if self.p then
 942                 return self.p
 943         elseif #self.cref == 3 or #self.cref == 4 then
 944                 return section( self.s, self.c, self.cref[1], self.cref[2] )
 945         elseif #self.cref == 2 then
 946                 return config( self.s, self.c, self.cref[1] )
 947         else
 948                 return nil
 949         end
 950 end
 951
 952 function uvlitem._loadconf(self, co, c, configdir)
 953         co = co or self._configcache
 954         if not co then
 955                 local err
 956                 co, err = uci.cursor(configdir):get_all(c)
 957
 958                 if err then
 959                         self:error(ERR.UCILOAD(self, err))
 960                 end
 961
 962                 self._configcache = co
 963         end
 964         return co
 965 end
 966
 967
 968 --- Object representation of a scheme.
 969 -- @class       scheme
 970 -- @cstyle      instance
 971 -- @name        luci.uvl.scheme
 972
 973 --- Scheme instance constructor.
 974 -- @class                       function
 975 -- @name                        scheme
 976 -- @param scheme        Scheme instance
 977 -- @param co            Configuration data
 978 -- @param c                     Configuration name
 979 -- @return                      Config instance
 980 scheme = util.class(uvlitem)
 981
 982 function scheme.__init__(self, scheme, co, c)
 983         if not c then
 984                 c, co = co, nil
 985         end
 986
 987         self.cref = { c }
 988         self.sref = { c }
 989         self.c    = self:_loadconf(co, c, scheme.configdir)
 990         self.s    = scheme
 991         self.t    = TYPE_SCHEME
 992 end
 993
 994 --- Add an error to scheme.
 995 -- @return      Scheme error context
 996 function scheme.error(self, ...)
 997         if not self.e then self.e = ERR.SCHEME( self ) end
 998         return self.e:child( ... )
 999 end
1000
1001 --- Get an associated config object.
1002 -- @return      Config instance
1003 function scheme.config(self)
1004         local co = config( self.s, self.cref[1] )
1005               co.p = self
1006
1007         return co
1008 end
1009
1010 --- Get all section objects associated with this scheme.
1011 -- @return      Table containing all associated luci.uvl.section instances
1012 function scheme.sections(self)
1013         local v = { }
1014         if self.s.packages[self.sref[1]].sections then
1015                 for o, _ in pairs( self.s.packages[self.sref[1]].sections ) do
1016                         v[#v+1] = option(
1017                                 self.s, self.c, self.cref[1], self.cref[2], o
1018                         )
1019                 end
1020         end
1021         return v
1022 end
1023
1024 --- Get an associated section object.
1025 -- @param s     Section to select
1026 -- @return      Section instance
1027 function scheme.section(self, s)
1028         local so = section( self.s, self.c, self.cref[1], s )
1029               so.p = self
1030
1031         return so
1032 end
1033
1034
1035 --- Object representation of a config.
1036 -- @class       config
1037 -- @cstyle      instance
1038 -- @name        luci.uvl.config
1039
1040 --- Config instance constructor.
1041 -- @class                       function
1042 -- @name                        config
1043 -- @param scheme        Scheme instance
1044 -- @param co            Configuration data
1045 -- @param c                     Configuration name
1046 -- @return                      Config instance
1047 config = util.class(uvlitem)
1048
1049 function config.__init__(self, scheme, co, c)
1050         if not c then
1051                 c, co = co, nil
1052         end
1053         self.cref = { c }
1054         self.sref = { c }
1055         self.c    = self:_loadconf(co, c, scheme.configdir)
1056         self.s    = scheme
1057         self.t    = TYPE_CONFIG
1058 end
1059
1060 --- Get all section objects associated with this config.
1061 -- @return      Table containing all associated luci.uvl.section instances
1062 function config.sections(self)
1063         local v = { }
1064         if self.s.packages[self.sref[1]].sections then
1065                 for o, _ in pairs( self.s.packages[self.sref[1]].sections ) do
1066                         v[#v+1] = option(
1067                                 self.s, self.c, self.cref[1], self.cref[2], o
1068                         )
1069                 end
1070         end
1071         return v
1072 end
1073
1074 --- Get an associated section object.
1075 -- @param s     Section to select
1076 -- @return      Section instance
1077 function config.section(self, s)
1078         local so = section( self.s, self.c, self.cref[1], s )
1079               so.p = self
1080
1081         return so
1082 end
1083
1084
1085 --- Object representation of a scheme/config section.
1086 -- @class       module
1087 -- @cstyle      instance
1088 -- @name        luci.uvl.section
1089
1090 --- Section instance constructor.
1091 -- @class                       function
1092 -- @name                        section
1093 -- @param scheme        Scheme instance
1094 -- @param co            Configuration data
1095 -- @param c                     Configuration name
1096 -- @param s                     Section name
1097 -- @return                      Section instance
1098 section = util.class(uvlitem)
1099
1100 function section.__init__(self, scheme, co, c, s)
1101         self.cref = { c, s }
1102         self.sref = { c, co and co[s] and co[s]['.type'] or s }
1103         self.c    = self:_loadconf(co, c, scheme.configdir)
1104         self.s    = scheme
1105         self.t    = TYPE_SECTION
1106 end
1107
1108 --- Get all option objects associated with this section.
1109 -- @return      Table containing all associated luci.uvl.option instances
1110 function section.variables(self)
1111         local v = { }
1112         if self.s.packages[self.sref[1]].variables[self.sref[2]] then
1113                 for o, _ in pairs(
1114                         self.s.packages[self.sref[1]].variables[self.sref[2]]
1115                 ) do
1116                         v[#v+1] = option(
1117                                 self.s, self.c, self.cref[1], self.cref[2], o
1118                         )
1119                 end
1120         end
1121         return v
1122 end
1123
1124 --- Get an associated option object.
1125 -- @param o     Option to select
1126 -- @return      Option instance
1127 function section.option(self, o)
1128         local oo = option( self.s, self.c, self.cref[1], self.cref[2], o )
1129               oo.p = self
1130
1131         return oo
1132 end
1133
1134
1135 --- Object representation of a scheme/config option.
1136 -- @class       module
1137 -- @cstyle      instance
1138 -- @name        luci.uvl.option
1139
1140 --- Section instance constructor.
1141 -- @class                       function
1142 -- @name                        option
1143 -- @param scheme        Scheme instance
1144 -- @param co            Configuration data
1145 -- @param c                     Configuration name
1146 -- @param s                     Section name
1147 -- @param o                     Option name
1148 -- @return                      Option instance
1149 option = util.class(uvlitem)
1150
1151 function option.__init__(self, scheme, co, c, s, o)
1152         self.cref = { c, s, o }
1153         self.sref = { c, co and co[s] and co[s]['.type'] or s, o }
1154         self.c    = self:_loadconf(co, c, scheme.configdir)
1155         self.s    = scheme
1156         self.t    = TYPE_OPTION
1157 end
1158
1159 --- Get the value of this option.
1160 -- @return      The associated configuration value
1161 function option.value(self)
1162         local v = self:config() or self:scheme('default')
1163         if v and self:scheme('multival') then
1164                 v = util.split( v, "%s+", nil, true )
1165         end
1166         return v
1167 end
1168
1169 --- Get the associated section information in scheme.
1170 -- @return      Table containing the scheme properties
1171 function option.section(self)
1172         return self.s.packages[self.sref[1]].sections[self.sref[2]]
1173 end
1174
1175 --- Construct an enum object instance from given or default value.
1176 -- @param v     Value to select
1177 -- @return      Enum instance for selected value
1178 function option.enum(self, val)
1179         return enum(
1180                 self.s, self.c,
1181                 self.cref[1], self.cref[2], self.cref[3],
1182                 val or self:value()
1183         )
1184 end
1185
1186
1187 --- Object representation of a enum value.
1188 -- @class       module
1189 -- @cstyle      instance
1190 -- @name        luci.uvl.enum
1191
1192 --- Section instance constructor.
1193 -- @class                       function
1194 -- @name                        enum
1195 -- @param scheme        Scheme instance
1196 -- @param co            Configuration data
1197 -- @param c                     Configuration name
1198 -- @param s                     Section name
1199 -- @param o                     Enum name
1200 -- @param v                     Enum value
1201 -- @return                      Enum value instance
1202 enum = util.class(option)
1203
1204 function enum.__init__(self, scheme, co, c, s, o, v)
1205         self.cref = { c, s, o, v }
1206         self.sref = { c, co and co[s] and co[s]['.type'] or s, o, v }
1207         self.c    = self:_loadconf(co, c, scheme.configdir)
1208         self.s    = scheme
1209         self.t    = TYPE_ENUM
1210 end