Class: Sandbox::Safe

Inherits:
Full
  • Object
show all
Defined in:
lib/sandbox/safe.rb

Instance Method Summary collapse

Instance Method Details

#activate! ⇒ Object 



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# File 'lib/sandbox/safe.rb', line 7

def activate!
  activate_fakefs

  keep_singleton_methods(:Kernel, KERNEL_S_METHODS)
  keep_singleton_methods(:Symbol, SYMBOL_S_METHODS)
  keep_singleton_methods(:String, STRING_S_METHODS)
  keep_singleton_methods(:IO, IO_S_METHODS)

  keep_methods(:Kernel, KERNEL_METHODS)
  keep_methods(:NilClass, NILCLASS_METHODS)
  keep_methods(:Symbol, SYMBOL_METHODS)
  keep_methods(:TrueClass, TRUECLASS_METHODS)
  keep_methods(:FalseClass, FALSECLASS_METHODS)
  keep_methods(:Enumerable, ENUMERABLE_METHODS)
  keep_methods(:String, STRING_METHODS)

  # FIXME: Blacklisting Object methods is not a scalable solution.
  # Whitelisting using #keep_methods is safer.
  remove_method(:Object, :java_import)

  Kernel.class_eval do
    def `(*args)
      raise NoMethodError, "` is unavailable"
    end

    def system(*args)
      raise NoMethodError, "system is unavailable"
    end
  end
end

#activate_fakefs ⇒ Object 



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# File 'lib/sandbox/safe.rb', line 38

def activate_fakefs
  require "fileutils"

  # unfortunately, the authors of FakeFS used `extend self` in FileUtils, instead of `module_function`.
  # I fixed it for them
  (FakeFS::FileUtils.methods - Module.methods - Kernel.methods).each do |module_method_name|
    FakeFS::FileUtils.send(:module_function, module_method_name)
  end

  import  FakeFS
  ref     FakeFS::Dir
  ref     FakeFS::File
  ref     FakeFS::FileTest
  import  FakeFS::FileUtils #import FileUtils because it is a module

  # this is basically what FakeFS.activate! does, but we want to do it in the sandbox
  # so we have to live with this:
  eval "    Object.class_eval do\n      remove_const(:Dir)\n      remove_const(:File)\n      remove_const(:FileTest)\n      remove_const(:FileUtils)\n\n      const_set(:Dir,       FakeFS::Dir)\n      const_set(:File,      FakeFS::File)\n      const_set(:FileUtils, FakeFS::FileUtils)\n      const_set(:FileTest,  FakeFS::FileTest)\n    end\n\n    [Dir, File, FileUtils, FileTest].each do |fake_class|\n      fake_class.class_eval do\n        def self.class_eval\n          raise NoMethodError, \"class_eval is unavailable\"\n        end\n        def self.instance_eval\n          raise NoMethodError, \"instance_eval is unavailable\"\n        end\n      end\n    end\n  RUBY\n\n  FakeFS::FileSystem.clear\nend\n"

#eval(code, options = {}) ⇒ Object 



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# File 'lib/sandbox/safe.rb', line 83

def eval(code, options={})
  if seconds = options[:timeout]
    sandbox_timeout(code, seconds) do
      super code
    end
  else
    super code
  end
end