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 = unpack
  31
  32 module "luci.uvl"
  33
  34 local ERR = require "luci.uvl.errors"
  35 local datatypes = require "luci.uvl.datatypes"
  36 local validation = require "luci.uvl.validation"
  37 local dependencies = require "luci.uvl.dependencies"
  38
  39 local TYPE_SCHEME   = 0x00
  40 local TYPE_CONFIG   = 0x01
  41 local TYPE_SECTION  = 0x02
  42 local TYPE_OPTION   = 0x03
  43 local TYPE_ENUM     = 0x04
  44
  45 --- Boolean; default true;
  46 -- treat sections found in config but not in scheme as error
  47 STRICT_UNKNOWN_SECTIONS    = true
  48
  49 --- Boolean; default true;
  50 -- treat options found in config but not in scheme as error
  51 STRICT_UNKNOWN_OPTIONS     = true
  52
  53 --- Boolean; default true;
  54 -- treat failed external validators as error
  55 STRICT_EXTERNAL_VALIDATORS = true
  56
  57 --- Boolean; default true;
  58 -- treat list values stored as options like errors
  59 STRICT_LIST_TYPE           = true
  60
  61
  62 local default_schemedir = "/lib/uci/schema"
  63 local default_savedir = "/tmp/.uvl"
  64
  65
  66 --- Object constructor
  67 -- @class                       function
  68 -- @name                        UVL
  69 -- @param schemedir     Path to the scheme directory (optional)
  70 -- @return                      Instance object
  71 UVL = util.class()
  72
  73 function UVL.__init__( self, schemedir )
  74         self.schemedir  = schemedir or default_schemedir
  75         self.packages   = { }
  76         self.beenthere  = { }
  77         self.depseen    = { }
  78         self.uci                = uci
  79         self.err                = ERR
  80         self.dep                = dependencies
  81         self.datatypes  = datatypes
  82 end
  83
  84
  85 --- Parse given scheme and return the scheme tree.
  86 -- @param scheme        Name of the scheme to parse
  87 -- @return                      Table containing the parsed scheme or nil on error
  88 -- @return                      String containing the reason for errors (if any)
  89 function UVL.get_scheme( self, scheme )
  90         if not self.packages[scheme] then
  91                 local ok, err = self:read_scheme( scheme )
  92                 if not ok then
  93                         return nil, err
  94                 end
  95         end
  96         return self.packages[scheme], nil
  97 end
  98
  99 --- Validate given configuration, section or option.
 100 -- @param config        Name of the configuration to validate
 101 -- @param section       Name of the section to validate (optional)
 102 -- @param option        Name of the option to validate (optional)
 103 -- @return                      Boolean indicating whether the given config validates
 104 -- @return                      String containing the reason for errors (if any)
 105 function UVL.validate( self, config, section, option )
 106         if config and section and option then
 107                 return self:validate_option( config, section, option )
 108         elseif config and section then
 109                 return self:validate_section( config, section )
 110         elseif config then
 111                 return self:validate_config( config )
 112         end
 113 end
 114
 115 --- Validate given configuration.
 116 -- @param cfg   Name of the configuration to validate
 117 -- @return                      Boolean indicating whether the given config validates
 118 -- @return                      String containing the reason for errors (if any)
 119 function UVL.validate_config( self, cfg, uci )
 120
 121         if not self.packages[cfg] then
 122                 local ok, err = self:read_scheme(cfg)
 123                 if not ok then
 124                         return false, err
 125                 end
 126         end
 127
 128         local co = config( self, uci or cfg, uci and cfg )
 129         local sc = { }
 130
 131         self.beenthere = { }
 132         self.depseen   = { }
 133
 134         if not co:config() then
 135                 return false, co:errors()
 136         end
 137
 138         local function _uci_foreach( type, func )
 139                 for k, v in pairs(co:config()) do
 140                         if v['.type'] == type then
 141                                 sc[type] = sc[type] + 1
 142                                 local ok, err = func( k, v )
 143                                 if not ok then co:error(err) end
 144                         end
 145                 end
 146         end
 147
 148         for k, v in pairs( self.packages[cfg].sections ) do
 149                 sc[k] = 0
 150                 _uci_foreach( k,
 151                         function(s)
 152                                 return self:_validate_section( co:section(s) )
 153                         end
 154                 )
 155         end
 156
 157         if STRICT_UNKNOWN_SECTIONS then
 158                 for k, v in pairs(co:config()) do
 159                         local so = co:section(k)
 160                         if not self.beenthere[so:cid()] then
 161                                 co:error(ERR.SECT_UNKNOWN(so))
 162                         end
 163                 end
 164         end
 165
 166         for _, k in ipairs(util.keys(sc)) do
 167                 local so = co:section(k)
 168                 if so:scheme('required') and sc[k] == 0 then
 169                         co:error(ERR.SECT_REQUIRED(so))
 170                 elseif so:scheme('unique') and sc[k] > 1 then
 171                         co:error(ERR.SECT_UNIQUE(so))
 172                 end
 173         end
 174
 175         return co:ok(), co:errors()
 176 end
 177
 178 --- Validate given config section.
 179 -- @param config        Name of the configuration to validate
 180 -- @param section       Name of the section to validate
 181 -- @return                      Boolean indicating whether the given config validates
 182 -- @return                      String containing the reason for errors (if any)
 183 function UVL.validate_section( self, cfg, section, uci )
 184
 185         if not self.packages[cfg] then
 186                 local ok, err = self:read_scheme( cfg )
 187                 if not ok then
 188                         return false, err
 189                 end
 190         end
 191
 192         local co = config( self, uci or cfg, uci and cfg )
 193         local so = co:section( section )
 194
 195         self.beenthere = { }
 196         self.depseen   = { }
 197
 198         if not co:config() then
 199                 return false, co:errors()
 200         end
 201
 202         if so:config() then
 203                 return self:_validate_section( so )
 204         else
 205                 return false, ERR.SECT_NOTFOUND(so)
 206         end
 207 end
 208
 209 --- Validate given config option.
 210 -- @param config        Name of the configuration to validate
 211 -- @param section       Name of the section to validate
 212 -- @param option        Name of the option to validate
 213 -- @return                      Boolean indicating whether the given config validates
 214 -- @return                      String containing the reason for errors (if any)
 215 function UVL.validate_option( self, cfg, section, option, uci )
 216
 217         if not self.packages[cfg] then
 218                 local ok, err = self:read_scheme( cfg )
 219                 if not ok then
 220                         return false, err
 221                 end
 222         end
 223
 224         local co = config( self, uci or cfg, uci and cfg )
 225         local so = co:section( section )
 226         local oo = so:option( option )
 227
 228         if not co:config() then
 229                 return false, co:errors()
 230         end
 231
 232         if so:config() and oo:config() then
 233                 return self:_validate_option( oo )
 234         else
 235                 return false, ERR.OPT_NOTFOUND(oo)
 236         end
 237 end
 238
 239
 240 function UVL._validate_section( self, section )
 241
 242         self.beenthere[section:cid()] = true
 243
 244         if section:config() then
 245                 if section:scheme('named') == true and
 246                    section:config('.anonymous') == true
 247                 then
 248                         return false, ERR.SECT_NAMED(section)
 249                 end
 250
 251                 for _, v in ipairs(section:variables()) do
 252                         local ok, err = self:_validate_option( v )
 253                         if not ok and (
 254                                 v:scheme('required') or v:scheme('type') == "enum" or (
 255                                         not err:is(ERR.ERR_DEP_NOTEQUAL) and
 256                                         not err:is(ERR.ERR_DEP_NOVALUE)
 257                                 )
 258                         ) then
 259                                 section:error(err)
 260                         end
 261                 end
 262
 263                 local ok, err = dependencies.check( self, section )
 264                 if not ok then
 265                         section:error(err)
 266                 end
 267         else
 268                 return false, ERR.SECT_NOTFOUND(section)
 269         end
 270
 271         if STRICT_UNKNOWN_OPTIONS and not section:scheme('dynamic') then
 272                 for k, v in pairs(section:config()) do
 273                         local oo = section:option(k)
 274                         if k:sub(1,1) ~= "." and not self.beenthere[oo:cid()] then
 275                                 section:error(ERR.OPT_UNKNOWN(oo))
 276                         end
 277                 end
 278         end
 279
 280         return section:ok(), section:errors()
 281 end
 282
 283 function UVL._validate_option( self, option, nodeps )
 284
 285         self.beenthere[option:cid()] = true
 286
 287         if not option:scheme() and not option:parent():scheme('dynamic') then
 288                 if STRICT_UNKNOWN_OPTIONS then
 289                         return false, option:error(ERR.OPT_UNKNOWN(option))
 290                 else
 291                         return true
 292                 end
 293
 294         elseif option:scheme() then
 295                 if option:scheme('required') and not option:value() then
 296                         return false, option:error(ERR.OPT_REQUIRED(option))
 297
 298                 elseif option:value() then
 299                         local val = option:value()
 300
 301                         if option:scheme('type') == "reference" or
 302                            option:scheme('type') == "enum"
 303                         then
 304                                 local scheme_values = option:scheme('values') or { }
 305                                 local config_values = ( type(val) == "table" and val or { val } )
 306                                 for _, v in ipairs(config_values) do
 307                                         if not scheme_values[v] then
 308                                                 return false, option:error( ERR.OPT_BADVALUE(
 309                                                         option, { v, util.serialize_data(
 310                                                                 util.keys(scheme_values)
 311                                                         ) }
 312                                                 ) )
 313                                         end
 314                                 end
 315                         elseif option:scheme('type') == "list" then
 316                                 if type(val) ~= "table" and STRICT_LIST_TYPE then
 317                                         return false, option:error(ERR.OPT_NOTLIST(option))
 318                                 end
 319                         end
 320
 321                         if option:scheme('datatype') then
 322                                 local dt = option:scheme('datatype')
 323
 324                                 if self.datatypes[dt] then
 325                                         val = ( type(val) == "table" and val or { val } )
 326                                         for i, v in ipairs(val) do
 327                                                 if not self.datatypes[dt]( v ) then
 328                                                         return false, option:error(
 329                                                                 ERR.OPT_INVVALUE(option, { v, dt })
 330                                                         )
 331                                                 end
 332                                         end
 333                                 else
 334                                         return false, option:error(ERR.OPT_DATATYPE(option, dt))
 335                                 end
 336                         end
 337                 end
 338
 339                 if not nodeps then
 340                         local ok, err = dependencies.check( self, option )
 341                         if not ok then
 342                                 option:error(err)
 343                         end
 344                 end
 345
 346                 local ok, err = validation.check( self, option )
 347                 if not ok and STRICT_EXTERNAL_VALIDATORS then
 348                         return false, option:error(err)
 349                 end
 350         end
 351
 352         return option:ok(), option:errors()
 353 end
 354
 355 --- Find all parts of given scheme and construct validation tree.
 356 -- This is normally done on demand, so you don't have to call this function
 357 -- by yourself.
 358 -- @param shm   Name of the scheme to parse
 359 -- @param alias         Create an alias for the loaded scheme
 360 function UVL.read_scheme( self, shm, alias )
 361
 362         local so = scheme( self, shm )
 363         local bc = "%s/bytecode/%s.lua" %{ self.schemedir, shm }
 364
 365         if not fs.access(bc) then
 366                 local files = fs.glob(self.schemedir .. '/*/' .. shm)
 367
 368                 if files then
 369                         local ok, err
 370                         for i, file in ipairs( files ) do
 371                                 if not fs.access(file) then
 372                                         return false, so:error(ERR.SME_READ(so,file))
 373                                 end
 374
 375                                 local uci = uci.cursor( fs.dirname(file), default_savedir )
 376
 377                                 local sname = fs.basename(file)
 378                                 local sd, err = uci:load( sname )
 379
 380                                 if not sd then
 381                                         return false, ERR.UCILOAD(so, err)
 382                                 end
 383
 384                                 ok, err = pcall(function()
 385                                         uci:foreach(sname, "package", function(s)
 386                                                 self:_parse_package(so, s[".name"], s)
 387                                         end)
 388                                         uci:foreach(sname, "section", function(s)
 389                                                 self:_parse_section(so, s[".name"], s)
 390                                         end)
 391                                         uci:foreach(sname, "variable", function(s)
 392                                                 self:_parse_var(so, s[".name"], s)
 393                                         end)
 394                                         uci:foreach(sname, "enum", function(s)
 395                                                 self:_parse_enum(so, s[".name"], s)
 396                                         end)
 397
 398                                 end)
 399                         end
 400
 401                         if ok and alias then self.packages[alias] = self.packages[shm] end
 402                         return ok and self, err
 403                 else
 404                         return false, so:error(ERR.SME_FIND(so, self.schemedir))
 405                 end
 406         else
 407                 local sc = loadfile(bc)
 408                 if sc then
 409                         self.packages[shm] = sc()
 410                         return true
 411                 else
 412                         return false, so:error(ERR.SME_READ(so,bc))
 413                 end
 414         end
 415 end
 416
 417 -- helper function to check for required fields
 418 local function _req( t, n, c, r )
 419         for i, v in ipairs(r) do
 420                 if not c[v] then
 421                         local p, o = scheme:sid(), nil
 422
 423                         if t == TYPE_SECTION then
 424                                 o = section( scheme, nil, p, n )
 425                         elseif t == TYPE_OPTION then
 426                                 o = option( scheme, nil, p, '(nil)', n )
 427                         elseif t == TYPE_ENUM then
 428                                 o = enum( scheme, nil, p, '(nil)', '(nil)', n )
 429                         end
 430
 431                         return false, ERR.SME_REQFLD(o,v)
 432                 end
 433         end
 434         return true
 435 end
 436
 437 -- helper function to validate references
 438 local function _ref( c, t )
 439         local r, k, n = {}
 440         if c == TYPE_SECTION then
 441                 k = "package"
 442                 n = 1
 443         elseif c == TYPE_OPTION then
 444                 k = "section"
 445                 n = 2
 446         elseif c == TYPE_ENUM then
 447                 k = "variable"
 448                 n = 3
 449         end
 450
 451         for o in t[k]:gmatch("[^.]+") do
 452                 r[#r+1] = o
 453         end
 454         r[1] = ( #r[1] > 0 and r[1] or scheme:sid() )
 455
 456         if #r ~= n then
 457                 return false, ERR.SME_BADREF(scheme, k)
 458         end
 459
 460         return r
 461 end
 462
 463 -- helper function to read bools
 464 local function _bool( v )
 465         return ( v == "true" or v == "yes" or v == "on" or v == "1" )
 466 end
 467
 468 -- Step 0: get package meta information
 469 function UVL._parse_package(self, scheme, k, v)
 470         local sid = scheme:sid()
 471         local pkg = self.packages[sid] or {
 472                 ["name"]      = sid;
 473                 ["sections"]  = { };
 474                 ["variables"] = { };
 475         }
 476
 477         pkg.title = v.title
 478         pkg.description = v.description
 479
 480         self.packages[sid] = pkg
 481 end
 482
 483 -- Step 1: get all sections
 484 function UVL._parse_section(self, scheme, k, v)
 485         local ok, err = _req( TYPE_SECTION, k, v, { "name", "package" } )
 486         if err then error(scheme:error(err)) end
 487
 488         local r, err = _ref( TYPE_SECTION, v )
 489         if err then error(scheme:error(err)) end
 490
 491         local p = self.packages[r[1]] or {
 492                 ["name"]      = r[1];
 493                 ["sections"]  = { };
 494                 ["variables"] = { };
 495         }
 496         p.sections[v.name]  = p.sections[v.name]  or { }
 497         p.variables[v.name] = p.variables[v.name] or { }
 498         self.packages[r[1]] = p
 499
 500         local s  = p.sections[v.name]
 501         local so = scheme:section(v.name)
 502
 503         for k, v2 in pairs(v) do
 504                 if k ~= "name" and k ~= "package" and k:sub(1,1) ~= "." then
 505                         if k == "depends" then
 506                                 s.depends = self:_read_dependency( v2, s.depends )
 507                                 if not s.depends then
 508                                         return false, scheme:error(
 509                                                 ERR.SME_BADDEP(so, util.serialize_data(s.depends))
 510                                         )
 511                                 end
 512                         elseif k == "dynamic" or k == "unique" or
 513                                k == "required" or k == "named"
 514                         then
 515                                 s[k] = _bool(v2)
 516                         else
 517                                 s[k] = v2
 518                         end
 519                 end
 520         end
 521
 522         s.dynamic  = s.dynamic  or false
 523         s.unique   = s.unique   or false
 524         s.required = s.required or false
 525         s.named    = s.named    or false
 526 end
 527
 528
 529         -- Step 2: get all variables
 530 function UVL._parse_var(self, scheme, k, v)
 531         local ok, err = _req( TYPE_OPTION, k, v, { "name", "section" } )
 532         if err then error(scheme:error(err)) end
 533
 534         local r, err = _ref( TYPE_OPTION, v )
 535         if err then error(scheme:error(err)) end
 536
 537         local p = self.packages[r[1]]
 538         if not p then
 539                 error(scheme:error(
 540                         ERR.SME_VBADPACK({scheme:sid(), '', v.name}, r[1])
 541                 ))
 542         end
 543
 544         local s = p.variables[r[2]]
 545         if not s then
 546                 error(scheme:error(
 547                         ERR.SME_VBADSECT({scheme:sid(), '', v.name}, r[2])
 548                 ))
 549         end
 550
 551         s[v.name] = s[v.name] or { }
 552
 553         local t  = s[v.name]
 554         local so = scheme:section(r[2])
 555         local to = so:option(v.name)
 556
 557         for k, v2 in pairs(v) do
 558                 if k ~= "name" and k ~= "section" and k:sub(1,1) ~= "." then
 559                         if k == "depends" then
 560                                 t.depends = self:_read_dependency( v2, t.depends )
 561                                 if not t.depends then
 562                                         error(scheme:error(so:error(
 563                                                 ERR.SME_BADDEP(to, util.serialize_data(v2))
 564                                         )))
 565                                 end
 566                         elseif k == "validator" then
 567                                 t.validators = self:_read_validator( v2, t.validators )
 568                                 if not t.validators then
 569                                         error(scheme:error(so:error(
 570                                                 ERR.SME_BADVAL(to, util.serialize_data(v2))
 571                                         )))
 572                                 end
 573                         elseif k == "valueof" then
 574                                 local values, err = self:_read_reference( v2 )
 575                                 if err then
 576                                         error(scheme:error(so:error(
 577                                                 ERR.REFERENCE(to, util.serialize_data(v2)):child(err)
 578                                         )))
 579                                 end
 580                                 t.type   = "reference"
 581                                 t.values = values
 582                         elseif k == "required" then
 583                                 t[k] = _bool(v2)
 584                         else
 585                                 t[k] = t[k] or v2
 586                         end
 587                 end
 588         end
 589
 590         t.type     = t.type     or "variable"
 591         t.datatype = t.datatype or "string"
 592         t.required = t.required or false
 593 end
 594
 595 -- Step 3: get all enums
 596 function UVL._parse_enum(self, scheme, k, v)
 597         local ok, err = _req( TYPE_ENUM, k, v, { "value", "variable" } )
 598         if err then error(scheme:error(err)) end
 599
 600         local r, err = _ref( TYPE_ENUM, v )
 601         if err then error(scheme:error(err)) end
 602
 603         local p = self.packages[r[1]]
 604         if not p then
 605                 error(scheme:error(
 606                         ERR.SME_EBADPACK({scheme:sid(), '', '', v.value}, r[1])
 607                 ))
 608         end
 609
 610         local s = p.variables[r[2]]
 611         if not s then
 612                 error(scheme:error(
 613                         ERR.SME_EBADSECT({scheme:sid(), '', '', v.value}, r[2])
 614                 ))
 615         end
 616
 617         local t = s[r[3]]
 618         if not t then
 619                 error(scheme:error(
 620                         ERR.SME_EBADOPT({scheme:sid(), '', '', v.value}, r[3])
 621                 ))
 622         end
 623
 624
 625         local so = scheme:section(r[2])
 626         local oo = so:option(r[3])
 627         local eo = oo:enum(v.value)
 628
 629         if t.type ~= "enum" and t.type ~= "reference" then
 630                 error(scheme:error(ERR.SME_EBADTYPE(eo)))
 631         end
 632
 633         if not t.values then
 634                 t.values = { [v.value] = v.title or v.value }
 635         else
 636                 t.values[v.value] = v.title or v.value
 637         end
 638
 639         if not t.enum_depends then
 640                 t.enum_depends = { }
 641         end
 642
 643         if v.default then
 644                 if t.default then
 645                         error(scheme:error(ERR.SME_EBADDEF(eo)))
 646                 end
 647                 t.default = v.value
 648         end
 649
 650         if v.depends then
 651                 t.enum_depends[v.value] = self:_read_dependency(
 652                         v.depends, t.enum_depends[v.value]
 653                 )
 654
 655                 if not t.enum_depends[v.value] then
 656                         error(scheme:error(so:error(oo:error(
 657                                 ERR.SME_BADDEP(eo, util.serialize_data(v.depends))
 658                         ))))
 659                 end
 660         end
 661 end
 662
 663 -- Read a dependency specification
 664 function UVL._read_dependency( self, values, deps )
 665         local expr = "%$?[a-zA-Z0-9_]+"
 666         if values then
 667                 values = ( type(values) == "table" and values or { values } )
 668                 for _, value in ipairs(values) do
 669                         local condition = { }
 670                         for val in value:gmatch("[^%s,]+") do
 671                                 local k, v = val:match("([^%s]+)%s*=*%s*([^%s]*)")
 672
 673                                 if k and (
 674                                         k:match("^"..expr.."%."..expr.."%."..expr.."$") or
 675                                         k:match("^"..expr.."%."..expr.."$") or
 676                                         k:match("^"..expr.."$")
 677                                 ) then
 678                                         condition[k] = v or true
 679                                 else
 680                                         return nil
 681                                 end
 682                         end
 683
 684                         if not deps then
 685                                 deps = { condition }
 686                         else
 687                                 deps[#deps+1] = condition
 688                         end
 689                 end
 690         end
 691
 692         return deps
 693 end
 694
 695 -- Read a validator specification
 696 function UVL._read_validator( self, values, validators )
 697         if values then
 698                 values = ( type(values) == "table" and values or { values } )
 699                 for _, value in ipairs(values) do
 700                         local validator
 701
 702                         if value:match("^exec:") then
 703                                 validator = value:gsub("^exec:","")
 704                         elseif value:match("^lua:") then
 705                                 validator = self:_resolve_function( (value:gsub("^lua:","") ) )
 706                         elseif value:match("^regexp:") then
 707                                 local pattern = value:gsub("^regexp:","")
 708                                 validator = function( type, dtype, pack, sect, optn, ... )
 709                                         local values = { ... }
 710                                         for _, v in ipairs(values) do
 711                                                 local ok, match =
 712                                                         pcall( string.match, v, pattern )
 713
 714                                                 if not ok then
 715                                                         return false, match
 716                                                 elseif not match then
 717                                                         return false,
 718                                                                 'Value "%s" does not match pattern "%s"' % {
 719                                                                         v, pattern
 720                                                                 }
 721                                                 end
 722                                         end
 723                                         return true
 724                                 end
 725                         end
 726
 727                         if validator then
 728                                 if not validators then
 729                                         validators = { validator }
 730                                 else
 731                                         validators[#validators+1] = validator
 732                                 end
 733                         else
 734                                 return nil
 735                         end
 736                 end
 737
 738                 return validators
 739         end
 740 end
 741
 742 -- Read a reference specification (XXX: We should validate external configs too...)
 743 function UVL._read_reference( self, values )
 744         local val = { }
 745         values = ( type(values) == "table" and values or { values } )
 746
 747         for _, value in ipairs(values) do
 748                 local ref = util.split(value, ".")
 749
 750                 if #ref == 2 or #ref == 3 then
 751                         local co = config( self, ref[1] )
 752                         if not co:config() then return false, co:errors() end
 753
 754                         for k, v in pairs(co:config()) do
 755                                 if v['.type'] == ref[2] then
 756                                         if #ref == 2 then
 757                                                 if v['.anonymous'] == true then
 758                                                         return false, ERR.SME_INVREF('', value)
 759                                                 end
 760                                                 val[k] = k      -- XXX: title/description would be nice
 761                                         elseif v[ref[3]] then
 762                                                 val[v[ref[3]]] = v[ref[3]]  -- XXX: dito
 763                                         end
 764                                 end
 765                         end
 766                 else
 767                         return false, ERR.SME_BADREF('', value)
 768                 end
 769         end
 770
 771         return val, nil
 772 end
 773
 774 -- Resolve given path
 775 function UVL._resolve_function( self, value )
 776         local path = util.split(value, ".")
 777
 778         for i=1, #path-1 do
 779                 local stat, mod = pcall(
 780                         require, table.concat(path, ".", 1, i)
 781                 )
 782
 783                 if stat and mod then
 784                         for j=i+1, #path-1 do
 785                                 if not type(mod) == "table" then
 786                                         break
 787                                 end
 788                                 mod = mod[path[j]]
 789                                 if not mod then
 790                                         break
 791                                 end
 792                         end
 793                         mod = type(mod) == "table" and mod[path[#path]] or nil
 794                         if type(mod) == "function" then
 795                                 return mod
 796                         end
 797                 end
 798         end
 799 end
 800
 801
 802 --- Object representation of an uvl item - base class.
 803 uvlitem = util.class()
 804
 805 function uvlitem.cid(self)
 806         if #self.cref == 1 then
 807                 return self.cref[1]
 808         else
 809                 local r = { unpack(self.cref) }
 810                 local c = self.c
 811                 if c and c[r[2]] and c[r[2]]['.anonymous'] and c[r[2]]['.index'] then
 812                         r[2] = '@' .. c[r[2]]['.type'] ..
 813                                '[' .. tostring(c[r[2]]['.index']) .. ']'
 814                 end
 815                 return table.concat( r, '.' )
 816         end
 817 end
 818
 819 function uvlitem.sid(self)
 820         return table.concat( self.sref, '.' )
 821 end
 822
 823 function uvlitem.scheme(self, opt)
 824         local s = self.s and self.s.packages
 825         s = s      and s[self.sref[1]]
 826         if #self.sref == 4 or #self.sref == 3 then
 827                 s = s      and s.variables
 828                 s = s      and s[self.sref[2]]
 829                 s = s      and s[self.sref[3]]
 830         elseif #self.sref == 2 then
 831                 s = s      and s.sections
 832                 s = s      and s[self.sref[2]]
 833         end
 834
 835         if s and opt then
 836                 return s[opt]
 837         elseif s then
 838                 return s
 839         end
 840 end
 841
 842 function uvlitem.config(self, opt)
 843         local c = self.c
 844
 845         if #self.cref >= 2 and #self.cref <= 4 then
 846                 c = c and self.c[self.cref[2]] or nil
 847                 if #self.cref >= 3 then
 848                         c = c and c[self.cref[3]] or nil
 849                 end
 850         end
 851
 852         if c and opt then
 853                 return c[opt]
 854         elseif c then
 855                 return c
 856         end
 857 end
 858
 859 function uvlitem.title(self)
 860         return self:scheme() and self:scheme('title') or
 861                 self.cref[3] or self.cref[2] or self.cref[1]
 862 end
 863
 864 function uvlitem.type(self)
 865         if self.t == TYPE_CONFIG then
 866                 return 'config'
 867         elseif self.t == TYPE_SECTION then
 868                 return 'section'
 869         elseif self.t == TYPE_OPTION then
 870                 return 'option'
 871         elseif self.t == TYPE_ENUM then
 872                 return 'enum'
 873         end
 874 end
 875
 876 function uvlitem.error(self, ...)
 877         if not self.e then
 878                 local errconst = { ERR.CONFIG, ERR.SECTION, ERR.OPTION, ERR.OPTION }
 879                 self.e = errconst[#self.cref]( self )
 880         end
 881
 882         return self.e:child( ... )
 883 end
 884
 885 function uvlitem.errors(self)
 886         return self.e
 887 end
 888
 889 function uvlitem.ok(self)
 890         return not self:errors()
 891 end
 892
 893 function uvlitem.parent(self)
 894         if self.p then
 895                 return self.p
 896         elseif #self.cref == 3 or #self.cref == 4 then
 897                 return section( self.s, self.c, self.cref[1], self.cref[2] )
 898         elseif #self.cref == 2 then
 899                 return config( self.s, self.c, self.cref[1] )
 900         else
 901                 return nil
 902         end
 903 end
 904
 905 function uvlitem._loadconf(self, co, c)
 906         co = co or self._configcache
 907         if not co then
 908                 local err
 909                 co, err = uci.cursor():get_all(c)
 910
 911                 if err then
 912                         self:error(ERR.UCILOAD(self, err))
 913                 end
 914
 915                 self._configcache = co
 916         end
 917         return co
 918 end
 919
 920
 921 --- Object representation of a scheme.
 922 -- @class       scheme
 923 -- @cstyle      instance
 924 -- @name        luci.uvl.scheme
 925
 926 --- Scheme instance constructor.
 927 -- @class                       function
 928 -- @name                        scheme
 929 -- @param scheme        Scheme instance
 930 -- @param co            Configuration data
 931 -- @param c                     Configuration name
 932 -- @return                      Config instance
 933 scheme = util.class(uvlitem)
 934
 935 function scheme.__init__(self, scheme, co, c)
 936         if not c then
 937                 c, co = co, nil
 938         end
 939
 940         self.cref = { c }
 941         self.sref = { c }
 942         self.c    = self:_loadconf(co, c)
 943         self.s    = scheme
 944         self.t    = TYPE_SCHEME
 945 end
 946
 947 --- Add an error to scheme.
 948 -- @return      Scheme error context
 949 function scheme.error(self, ...)
 950         if not self.e then self.e = ERR.SCHEME( self ) end
 951         return self.e:child( ... )
 952 end
 953
 954 --- Get an associated config object.
 955 -- @return      Config instance
 956 function scheme.config(self)
 957         local co = config( self.s, self.cref[1] )
 958               co.p = self
 959
 960         return co
 961 end
 962
 963 --- Get all section objects associated with this scheme.
 964 -- @return      Table containing all associated luci.uvl.section instances
 965 function scheme.sections(self)
 966         local v = { }
 967         if self.s.packages[self.sref[1]].sections then
 968                 for o, _ in pairs( self.s.packages[self.sref[1]].sections ) do
 969                         v[#v+1] = option(
 970                                 self.s, self.c, self.cref[1], self.cref[2], o
 971                         )
 972                 end
 973         end
 974         return v
 975 end
 976
 977 --- Get an associated section object.
 978 -- @param s     Section to select
 979 -- @return      Section instance
 980 function scheme.section(self, s)
 981         local so = section( self.s, self.c, self.cref[1], s )
 982               so.p = self
 983
 984         return so
 985 end
 986
 987
 988 --- Object representation of a config.
 989 -- @class       config
 990 -- @cstyle      instance
 991 -- @name        luci.uvl.config
 992
 993 --- Config instance constructor.
 994 -- @class                       function
 995 -- @name                        config
 996 -- @param scheme        Scheme instance
 997 -- @param co            Configuration data
 998 -- @param c                     Configuration name
 999 -- @return                      Config instance
1000 config = util.class(uvlitem)
1001
1002 function config.__init__(self, scheme, co, c)
1003         if not c then
1004                 c, co = co, nil
1005         end
1006
1007         self.cref = { c }
1008         self.sref = { c }
1009         self.c    = self:_loadconf(co, c)
1010         self.s    = scheme
1011         self.t    = TYPE_CONFIG
1012 end
1013
1014 --- Get all section objects associated with this config.
1015 -- @return      Table containing all associated luci.uvl.section instances
1016 function config.sections(self)
1017         local v = { }
1018         if self.s.packages[self.sref[1]].sections then
1019                 for o, _ in pairs( self.s.packages[self.sref[1]].sections ) do
1020                         v[#v+1] = option(
1021                                 self.s, self.c, self.cref[1], self.cref[2], o
1022                         )
1023                 end
1024         end
1025         return v
1026 end
1027
1028 --- Get an associated section object.
1029 -- @param s     Section to select
1030 -- @return      Section instance
1031 function config.section(self, s)
1032         local so = section( self.s, self.c, self.cref[1], s )
1033               so.p = self
1034
1035         return so
1036 end
1037
1038
1039 --- Object representation of a scheme/config section.
1040 -- @class       module
1041 -- @cstyle      instance
1042 -- @name        luci.uvl.section
1043
1044 --- Section instance constructor.
1045 -- @class                       function
1046 -- @name                        section
1047 -- @param scheme        Scheme instance
1048 -- @param co            Configuration data
1049 -- @param c                     Configuration name
1050 -- @param s                     Section name
1051 -- @return                      Section instance
1052 section = util.class(uvlitem)
1053
1054 function section.__init__(self, scheme, co, c, s)
1055         self.cref = { c, s }
1056         self.sref = { c, co and co[s] and co[s]['.type'] or s }
1057         self.c    = self:_loadconf(co, c)
1058         self.s    = scheme
1059         self.t    = TYPE_SECTION
1060 end
1061
1062 --- Get all option objects associated with this section.
1063 -- @return      Table containing all associated luci.uvl.option instances
1064 function section.variables(self)
1065         local v = { }
1066         if self.s.packages[self.sref[1]].variables[self.sref[2]] then
1067                 for o, _ in pairs(
1068                         self.s.packages[self.sref[1]].variables[self.sref[2]]
1069                 ) do
1070                         v[#v+1] = option(
1071                                 self.s, self.c, self.cref[1], self.cref[2], o
1072                         )
1073                 end
1074         end
1075         return v
1076 end
1077
1078 --- Get an associated option object.
1079 -- @param o     Option to select
1080 -- @return      Option instance
1081 function section.option(self, o)
1082         local oo = option( self.s, self.c, self.cref[1], self.cref[2], o )
1083               oo.p = self
1084
1085         return oo
1086 end
1087
1088
1089 --- Object representation of a scheme/config option.
1090 -- @class       module
1091 -- @cstyle      instance
1092 -- @name        luci.uvl.option
1093
1094 --- Section instance constructor.
1095 -- @class                       function
1096 -- @name                        option
1097 -- @param scheme        Scheme instance
1098 -- @param co            Configuration data
1099 -- @param c                     Configuration name
1100 -- @param s                     Section name
1101 -- @param o                     Option name
1102 -- @return                      Option instance
1103 option = util.class(uvlitem)
1104
1105 function option.__init__(self, scheme, co, c, s, o)
1106         self.cref = { c, s, o }
1107         self.sref = { c, co and co[s] and co[s]['.type'] or s, o }
1108         self.c    = self:_loadconf(co, c)
1109         self.s    = scheme
1110         self.t    = TYPE_OPTION
1111 end
1112
1113 --- Get the value of this option.
1114 -- @return      The associated configuration value
1115 function option.value(self)
1116         local v = self:config() or self:scheme('default')
1117         if v and self:scheme('multival') then
1118                 v = util.split( v, "%s+", nil, true )
1119         end
1120         return v
1121 end
1122
1123 --- Get the associated section information in scheme.
1124 -- @return      Table containing the scheme properties
1125 function option.section(self)
1126         return self.s.packages[self.sref[1]].sections[self.sref[2]]
1127 end
1128
1129 --- Construct an enum object instance from given or default value.
1130 -- @param v     Value to select
1131 -- @return      Enum instance for selected value
1132 function option.enum(self, val)
1133         return enum(
1134                 self.s, self.c,
1135                 self.cref[1], self.cref[2], self.cref[3],
1136                 val or self:value()
1137         )
1138 end
1139
1140
1141 --- Object representation of a enum value.
1142 -- @class       module
1143 -- @cstyle      instance
1144 -- @name        luci.uvl.enum
1145
1146 --- Section instance constructor.
1147 -- @class                       function
1148 -- @name                        enum
1149 -- @param scheme        Scheme instance
1150 -- @param co            Configuration data
1151 -- @param c                     Configuration name
1152 -- @param s                     Section name
1153 -- @param o                     Enum name
1154 -- @param v                     Enum value
1155 -- @return                      Enum value instance
1156 enum = util.class(option)
1157
1158 function enum.__init__(self, scheme, co, c, s, o, v)
1159         self.cref = { c, s, o, v }
1160         self.sref = { c, co and co[s] and co[s]['.type'] or s, o, v }
1161         self.c    = self:_loadconf(co, c)
1162         self.s    = scheme
1163         self.t    = TYPE_ENUM
1164 end