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 module( "luci.uvl", package.seeall )
  18
  19 require("luci.fs")
  20 require("luci.util")
  21 require("luci.model.uci")
  22 require("luci.uvl.datatypes")
  23
  24 TYPE_SECTION  = 0x01
  25 TYPE_VARIABLE = 0x02
  26 TYPE_ENUM     = 0x03
  27
  28
  29 local default_schemedir = "/etc/scheme"
  30 local function _assert( condition, fmt, ... )
  31         if not condition then
  32                 return assert( nil, string.format( fmt, ... ) )
  33         else
  34                 return condition
  35         end
  36 end
  37
  38 UVL = luci.util.class()
  39
  40 function UVL.__init__( self, schemedir )
  41
  42         self.schemedir  = schemedir or default_schemedir
  43         self.packages   = { }
  44         self.uci                = luci.model.uci
  45         self.datatypes  = luci.uvl.datatypes
  46 end
  47
  48 --- Validate given configuration.
  49 -- @param config        Name of the configuration to validate
  50 -- @param scheme        Scheme to validate against (optional)
  51 -- @return                      Boolean indicating weather the given config validates
  52 -- @return                      String containing the reason for errors (if any)
  53 function UVL.validate( self, config, scheme )
  54
  55         if not scheme then
  56                 return false, "No scheme found"
  57         end
  58
  59         for k, v in pairs( config ) do
  60                 local ok, err = self:validate_section( config, k, scheme )
  61
  62                 if not ok then
  63                         return ok, err
  64                 end
  65         end
  66
  67         return true, nil
  68 end
  69
  70 --- Validate given section of given configuration.
  71 -- @param config        Name of the configuration to validate
  72 -- @param section       Key of the section to validate
  73 -- @param scheme        Scheme to validate against
  74 -- @return                      Boolean indicating weather the given config validates
  75 -- @return                      String containing the reason for errors (if any)
  76 function UVL.validate_section( self, config, section, scheme )
  77
  78         if not scheme then
  79                 return false, "No scheme found"
  80         end
  81
  82         for k, v in pairs( config[section] ) do
  83                 local ok, err = self:validate_option( config, section, k, scheme )
  84
  85                 if not ok then
  86                         return ok, err
  87                 end
  88         end
  89
  90         return true, nil
  91 end
  92
  93 --- Validate given option within section of given configuration.
  94 -- @param config        Name of the configuration to validate
  95 -- @param section       Key of the section to validate
  96 -- @param option        Name of the option to validate
  97 -- @param scheme        Scheme to validate against
  98 -- @return                      Boolean indicating weather the given config validates
  99 -- @return                      String containing the reason for errors (if any)
 100 function UVL.validate_option( self, config, section, option, scheme )
 101
 102         if type(config) == "string" then
 103                 config = { ["variables"] = { [section] = { [option] = config } } }
 104         end
 105
 106         if not scheme then
 107                 return false, "No scheme found"
 108         end
 109
 110         local sv = scheme.variables[section]
 111         if not sv then return false, "Requested section not found in scheme" end
 112
 113         sv = sv[option]
 114         if not sv then return false, "Requested option not found in scheme" end
 115
 116         if not ( config[section] and config[section][option] ) and sv.required then
 117                 return false, "Mandatory variable doesn't have a value"
 118         end
 119
 120         if sv.type then
 121                 if self.datatypes[sv.type] then
 122                         if not self.datatypes[sv.type]( config[section][option] ) then
 123                                 return false, "Value of given option doesn't validate"
 124                         end
 125                 else
 126                         return false, "Unknown datatype '" .. sv.type .. "' encountered"
 127                 end
 128         end
 129
 130         return true, nil
 131 end
 132
 133 --- Find all parts of given scheme and construct validation tree
 134 -- @param scheme        Name of the scheme to parse
 135 -- @return                      Parsed scheme
 136 function UVL.read_scheme( self, scheme )
 137         local schemes = { }
 138
 139         for i, file in ipairs( luci.fs.glob(self.schemedir .. '/*/' .. scheme) ) do
 140                 _assert( luci.fs.access(file), "Can't access file '%s'", file )
 141
 142                 self.uci.set_confdir( luci.fs.dirname(file) )
 143                 self.uci.load( luci.fs.basename(file) )
 144
 145                 table.insert( schemes, self.uci.get_all( luci.fs.basename(file) ) )
 146         end
 147
 148         return self:_read_scheme_parts( scheme, schemes )
 149 end
 150
 151 -- Process all given parts and construct validation tree
 152 function UVL._read_scheme_parts( self, scheme, schemes )
 153
 154         -- helper function to construct identifiers for given elements
 155         local function _id( c, t )
 156                 if c == TYPE_SECTION then
 157                         return string.format(
 158                                 "section '%s.%s'",
 159                                         scheme, t.name or '?' )
 160                 elseif c == TYPE_VARIABLE then
 161                         return string.format(
 162                                 "variable '%s.%s.%s'",
 163                                         scheme, t.section or '?.?', t.name or '?' )
 164                 elseif c == TYPE_ENUM then
 165                         return string.format(
 166                                 "enum '%s.%s.%s'",
 167                                         scheme, t.variable or '?.?.?', t.value or '?' )
 168                 end
 169         end
 170
 171         -- helper function to check for required fields
 172         local function _req( c, t, r )
 173                 for i, v in ipairs(r) do
 174                         _assert( t[v], "Missing required field '%s' in %s", v, _id(c, t) )
 175                 end
 176         end
 177
 178         -- helper function to validate references
 179         local function _ref( c, t )
 180                 local k
 181                 if c == TYPE_SECTION then
 182                         k = "package"
 183                 elseif c == TYPE_VARIABLE then
 184                         k = "section"
 185                 elseif c == TYPE_ENUM then
 186                         k = "variable"
 187                 end
 188
 189                 local r = luci.util.split( t[k], "." )
 190                 r[1] = ( #r[1] > 0 and r[1] or scheme )
 191
 192                 _assert( #r == c, "Malformed %s reference in %s", k, _id(c, t) )
 193
 194                 return r
 195         end
 196
 197         -- Step 1: get all sections
 198         for i, conf in ipairs( schemes ) do
 199                 for k, v in pairs( conf ) do
 200                         if v['.type'] == 'section' then
 201
 202                                 _req( TYPE_SECTION, v, { "name", "package" } )
 203
 204                                 local r = _ref( TYPE_SECTION, v )
 205
 206                                 self.packages[r[1]] =
 207                                         self.packages[r[1]] or {
 208                                                 ["sections"]  = { };
 209                                                 ["variables"] = { };
 210                                         }
 211
 212                                 local p = self.packages[r[1]]
 213                                           p.sections[v.name]  = p.sections[v.name]  or { }
 214                                           p.variables[v.name] = p.variables[v.name] or { }
 215
 216                                 local s = p.sections[v.name]
 217
 218                                 for k, v2 in pairs(v) do
 219                                         if k ~= "name" and k ~= "package" and k:sub(1,1) ~= "." then
 220                                                 if k:match("^depends") then
 221                                                         s["depends"] = _assert(
 222                                                                 self:_read_depency( v2, s["depends"] ),
 223                                                                 "Section '%s' in scheme '%s' has malformed " ..
 224                                                                 "depency specification in '%s'",
 225                                                                 v.name or '<nil>', scheme or '<nil>', k
 226                                                         )
 227                                                 else
 228                                                         s[k] = v2
 229                                                 end
 230                                         end
 231                                 end
 232                         end
 233                 end
 234         end
 235
 236         -- Step 2: get all variables
 237         for i, conf in ipairs( schemes ) do
 238                 for k, v in pairs( conf ) do
 239                         if v['.type'] == "variable" then
 240
 241                                 _req( TYPE_VARIABLE, v, { "name", "type", "section" } )
 242
 243                                 local r = _ref( TYPE_VARIABLE, v )
 244
 245                                 local p = _assert( self.packages[r[1]],
 246                                         "Variable '%s' in scheme '%s' references unknown package '%s'",
 247                                         v.name, scheme, r[1] )
 248
 249                                 local s = _assert( p.variables[r[2]],
 250                                         "Variable '%s' in scheme '%s' references unknown section '%s'",
 251                                         v.name, scheme, r[2] )
 252
 253                                 s[v.name] = s[v.name] or { }
 254
 255                                 local t = s[v.name]
 256
 257                                 for k, v in pairs(v) do
 258                                         if k ~= "name" and k ~= "section" and k:sub(1,1) ~= "." then
 259                                                 if k:match("^depends") then
 260                                                         t["depends"] = _assert(
 261                                                                 self:_read_depency( v, t["depends"] ),
 262                                                                 "Variable '%s' in scheme '%s' has malformed " ..
 263                                                                 "depency specification in '%s'",
 264                                                                 v.name, scheme, k
 265                                                         )
 266                                                 elseif k:match("^validator") then
 267                                                         t["validators"] = _assert(
 268                                                                 self:_read_validator( v, t["validators"] ),
 269                                                                 "Variable '%s' in scheme '%s' has malformed " ..
 270                                                                 "validator specification in '%s'",
 271                                                                 v.name, scheme, k
 272                                                         )
 273                                                 else
 274                                                         t[k] = v
 275                                                 end
 276                                         end
 277                                 end
 278                         end
 279                 end
 280         end
 281
 282         -- Step 3: get all enums
 283         for i, conf in ipairs( schemes ) do
 284                 for k, v in pairs( conf ) do
 285                         if v['.type'] == "enum" then
 286
 287                                 _req( TYPE_ENUM, v, { "value", "variable" } )
 288
 289                                 local r = _ref( TYPE_ENUM, v )
 290
 291                                 local p = _assert( self.packages[r[1]],
 292                                         "Enum '%s' in scheme '%s' references unknown package '%s'",
 293                                         v.value, scheme, r[1] )
 294
 295                                 local s = _assert( p.variables[r[2]],
 296                                         "Enum '%s' in scheme '%s' references unknown section '%s'",
 297                                         v.value, scheme, r[2] )
 298
 299                                 local t = _assert( s[r[3]],
 300                                         "Enum '%s' in scheme '%s', section '%s' references " ..
 301                                         "unknown variable '%s'",
 302                                         v.value, scheme, r[2], r[3] )
 303
 304                                 _assert( t.type == "enum",
 305                                         "Enum '%s' in scheme '%s', section '%s' references " ..
 306                                         "variable '%s' with non enum type '%s'",
 307                                         v.value, scheme, r[2], r[3], t.type )
 308
 309                                 if not t.values then
 310                                         t.values = { [v.value] = v.title or v.value }
 311                                 else
 312                                         t.values[v.value] = v.title or v.value
 313                                 end
 314
 315                                 if v.default then
 316                                         _assert( not t.default,
 317                                                 "Enum '%s' in scheme '%s', section '%s' redeclares " ..
 318                                                 "the default value of variable '%s'",
 319                                                 v.value, scheme, r[2], v.variable )
 320
 321                                         t.default = v.value
 322                                 end
 323                         end
 324                 end
 325         end
 326
 327         return self
 328 end
 329
 330 -- Read a depency specification
 331 function UVL._read_depency( self, value, deps )
 332         local parts     = luci.util.split( value, "%s*,%s*", nil, true )
 333         local condition = { }
 334
 335         for i, val in ipairs(parts) do
 336                 local k, v = unpack(luci.util.split( val, "%s*=%s*", nil, true ))
 337
 338                 if k and (
 339                         k:match("^%$?[a-zA-Z0-9_]+%.%$?[a-zA-Z0-9_]+%.%$?[a-zA-Z0-9_]+$") or
 340                         k:match("^%$?[a-zA-Z0-9_]+%.%$?[a-zA-Z0-9_]+$") or
 341                         k:match("^%$?[a-zA-Z0-9_]+$")
 342                 ) then
 343                         condition[k] = v or true
 344                 else
 345                         return nil
 346                 end
 347         end
 348
 349         if not deps then
 350                 deps = { condition }
 351         else
 352                 table.insert( deps, condition )
 353         end
 354
 355         return deps
 356 end
 357
 358 -- Read a validator specification
 359 function UVL._read_validator( self, value, validators )
 360         local validator
 361
 362         if value and value:match("/") and self.datatypes.file(value) then
 363                 validator = value
 364         else
 365                 validator = self:_resolve_function( value )
 366         end
 367
 368         if validator then
 369                 if not validators then
 370                         validators = { validator }
 371                 else
 372                         table.insert( validators, validator )
 373                 end
 374
 375                 return validators
 376         end
 377 end
 378
 379 -- Resolve given path
 380 function UVL._resolve_function( self, value )
 381         local path = luci.util.split(value, ".")
 382
 383         for i=1, #path-1 do
 384                 local stat, mod = pcall(require, table.concat(path, ".", 1, i))
 385                 if stat and mod then
 386                         for j=i+1, #path-1 do
 387                                 if not type(mod) == "table" then
 388                                         break;
 389                                 end
 390                                 mod = mod[path[j]]
 391                                 if not mod then
 392                                         break
 393                                 end
 394                         end
 395                         mod = type(mod) == "table" and mod[path[#path]] or nil
 396                         if type(mod) == "function" then
 397                                 return mod
 398                         end
 399                 end
 400         end
 401 end