libs/uvl/luasrc/uvl/dependencies.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.dependencies", package.seeall )
  18
  19 local function _assert( condition, fmt, ... )
  20         if not condition then
  21                 return assert( nil, string.format( fmt, ... ) )
  22         else
  23                 return condition
  24         end
  25 end
  26
  27
  28 function _parse_reference( r, c, s, o )
  29         local ref  = { }
  30         local vars = {
  31                 config  = c,
  32                 section = s,
  33                 option  = o
  34         }
  35
  36         for i, v in ipairs(luci.util.split(r,".")) do
  37                 table.insert( ref, (v:gsub( "%$(.+)", function(n) return vars[n] end )) )
  38         end
  39
  40         if #ref == 1 and c and s then
  41                 ref = { c, s, ref[1] }
  42         elseif #ref == 2 and c then
  43                 ref = { c, unpack(ref) }
  44         elseif #ref ~= 3 then
  45                 print("INVALID REFERENCE: "..#ref, c, s, o)
  46                 ref = nil
  47         end
  48
  49         return ref
  50 end
  51
  52 function check_dependency( self, uci, conf, sect, optn, nodeps, section2 )
  53
  54 --      print( "Depency check:    ", conf .. '.' .. sect .. ( optn and '.' .. optn or '' ) )
  55
  56         local key = conf .. '.' .. sect .. ( optn and '.' .. optn or '' )
  57         if not self.beenthere[key] then
  58                 self.beenthere[key] = true
  59         else
  60                 print("CIRCULAR DEPENDENCY!")
  61                 return false, "Recursive depency detected"
  62         end
  63
  64         -- check for config
  65         if not self.packages[conf] then self:read_scheme(conf) end
  66         local item = self.packages[conf]
  67
  68         -- check for section
  69         if sect then
  70                 item = _assert( self:_scheme_section( uci, conf, sect ) or self:_scheme_section( uci, conf, section2 ),
  71                         "Unknown section '%s' in scheme '%s' requested",
  72                         sect or '<nil>', conf or '<nil>' )
  73
  74                 -- check for option
  75                 if optn then
  76                         item = _assert( self:_scheme_option( uci, conf, sect, optn ) or
  77                                                         self:_scheme_option( uci, conf, section2, optn ),
  78                                 "Unknown variable '%s' in scheme '%s', section '%s' requested",
  79                                 optn or '<nil>', conf or '<nil>', sect or '<nil>' )
  80                 end
  81         end
  82
  83         if item.depends then
  84                 local ok = false
  85                 local valid, err
  86
  87                 for _, dep in ipairs(item.depends) do
  88                         --print("DEP:",luci.util.serialize_data(dep))
  89
  90                         local subcondition = true
  91
  92                         for k, v in pairs(dep) do
  93                                 -- XXX: better error
  94                                 local ref = _assert( _parse_reference(k,conf,sect,optn),
  95                                         "Ambiguous dependency reference '" .. k .. "' given" )
  96
  97                                 -- XXX: true -> nodeps
  98                                 valid, err = self:validate_option(ref[1], ref[2], ref[3], uci, true, section2)
  99                                 if valid then
 100                                         --print("CHK:",uci[ref[2]][ref[3]],v,unpack(ref))
 101                                         if not (
 102                                                 ( type(v) == "boolean" and uci[ref[2]][ref[3]] ) or
 103                                                 ( ref[3] and uci[ref[2]][ref[3]] ) == v
 104                                         ) then
 105                                                 subcondition = false
 106                                                 err = type(v) ~= "boolean"
 107                                                         and "Option '" .. table.concat( ref, "." ) .. "' doesn't match requested type '" .. v .. '"'
 108                                                         or  "Option '" .. table.concat( ref, "." ) .. "' has no value"
 109
 110                                                 break
 111                                         end
 112                                 else
 113                                         subcondition = false
 114                                         break
 115                                 end
 116                         end
 117
 118                         if subcondition then
 119 --                              print( " -> Success (condition matched)\n" )
 120                                 return true
 121                         end
 122                 end
 123
 124 --              print( " -> Failed\n" )
 125                 return false, err
 126         end
 127
 128 --      print( " -> Success (no depends)\n" )
 129         return true
 130 end