sudoers command now creates a safe wrapper script.

Sudoers now creates a safe wrapper script that performs sanity checks on sudo :
* wrapper generated in /usr/local/bin (name includes version to allow multiple wrappers on the same system)
* sudoers command now generates a one-line file in /etc/sudoers.d
* SudoWrapper use the new wrapper
* Removed unused Config#validate method

lib/vagrant-lxc.rb

@@ -6,5 +6,9 @@ module Vagrant
     def self.source_root
       @source_root ||= Pathname.new(File.dirname(__FILE__)).join('..').expand_path
     end
+
+    def self.sudo_wrapper_path
+      "/usr/local/bin/vagrant-lxc-wrapper-#{VERSION}"
+    end
   end
 end

lib/vagrant-lxc/command/sudoers.rb

@@ -4,6 +4,12 @@ module Vagrant
   module LXC
     module Command
       class Sudoers < Vagrant.plugin("2", :command)
+
+        def initialize(argv, env)
+          super
+          @env = env
+        end
+
         def execute
           options = { user: ENV['USER'] }
 
@@ -18,68 +24,168 @@ module Vagrant
           argv = parse_options(opts)
           return unless argv
 
-          filename = "vagrant-lxc-#{options[:user]}"
+          wrapper_path = Vagrant::LXC.sudo_wrapper_path
-          to_sudoers!(create_tempfile!(options[:user], filename), filename)
+          wrapper = create_wrapper!
+          sudoers = create_sudoers!(options[:user], wrapper_path)
+
+          su_copy([
+            {source: wrapper, target: wrapper_path, mode: "0555"},
+            {source: sudoers, target: sudoers_path, mode: "0440"}
+          ])
+        end
+
+        def sudoers_path
+          "/etc/sudoers.d/vagrant-lxc-#{Vagrant::LXC::VERSION.gsub( /\./, '-')}"
         end
 
         private
+        # REFACTOR: Make use ERB rendering after https://github.com/mitchellh/vagrant/issues/3231
+        #           lands into core
+        def create_wrapper!
+          wrapper = Tempfile.new('lxc-wrapper').tap do |file|
+            file.puts "#!/usr/bin/env ruby"
+            file.puts "# Automatically created by vagrant-lxc"
+            file.puts <<-EOF
+class Whitelist
+  class << self
+    def add(command, *args)
+      list[command] << args
+    end
+
+    def list
+      @list ||= Hash.new do |key, hsh|
+        key[hsh] = []
+      end
+    end
+
+    def allowed(command)
+      list[command] || []
+    end
+
+    def run!(argv)
+      begin
+        command, args = `which \#{argv.shift}`.chomp, argv || []
+        check!(command, args)
+        puts `\#{command} \#{args.join(" ")}`
+        exit $?.to_i
+      rescue => e
+        STDERR.puts e.message
+        exit 1
+      end
+    end
+
+    private
+    def check!(command, args)
+      allowed(command).each do |checks|
+        return if valid_args?(args, checks)
+      end
+      raise_invalid(command, args)
+    end
+
+    def valid_args?(args, checks)
+      return false unless valid_length?(args, checks)
+      check = nil
+      args.each_with_index do |provided, i|
+        check = checks[i] unless check == '**'
+        return false unless match?(provided, check)
+      end
+      true
+    end
+
+    def valid_length?(args, checks)
+      args.length == checks.length || checks.last == '**'
+    end
+
+    def match?(arg, check)
+      check == '**' || check.is_a?(Regexp) && !!check.match(arg) || arg == check
+    end
+
+    def raise_invalid(command, args)
+      raise "Invalid arguments for command \#{command}, " <<
+        "provided args: \#{args.inspect}"
+    end
+  end
+end
+
+base = "/var/lib/lxc"
+base_path = %r{\\A\#{base}/.*\\z}
+templates_path = %r{\\A/usr/(share|lib|lib64|local/lib)/lxc/templates/.*\\z}
+boxes_path = %r{\\A#{Regexp.escape(@env.boxes_path.to_s)}/.*\\z}
+gems_path = %r{\\A#{Regexp.escape(@env.gems_path.to_s)}/.*\\z}
+template_src = %r{\\A#{Vagrant::LXC.source_root.join('scripts/lxc-template').to_s}\\z}
+
+##
+# Commands from provider.rb
+# - Check lxc is installed
+Whitelist.add '/usr/bin/which', /\\Alxc-\\w+\\z/
+
+##
+# Commands from driver.rb
+# - Container config file
+Whitelist.add '/bin/cat', base_path
+# - Shared folders
+Whitelist.add '/bin/mkdir', '-p', base_path
+# - Container config customizations and pruning
+Whitelist.add '/bin/su', 'root', '-c', %r{\\A"sed -e '.*' -ibak \#{base}/.*/config"\\z}
+Whitelist.add '/bin/su', 'root', '-c', %r{\\A"echo '.*' >> \#{base}/.*/config"\\z}
+# - Template import
+Whitelist.add '/bin/cp', boxes_path, templates_path
+Whitelist.add '/bin/cp', gems_path, templates_path
+Whitelist.add '/bin/cp', template_src, templates_path
+Whitelist.add '/bin/chmod', '+x', templates_path
+# - Template removal
+Whitelist.add '/bin/rm', templates_path
+# - Packaging
+Whitelist.add '/bin/su', 'root', '-c', %r{\\A"cd \#{base}/.* && rm -f rootfs\.tar\.gz && tar --numeric-owner -czf /tmp/.*/rootfs\.tar\.gz -C \#{base}/.*/rootfs '\./\.'"\\z}
+Whitelist.add '/bin/chown', /\\A\\d+:\\d+\\z/, %r{\\A/tmp/.*/rootfs\.tar\.gz\\z}
+
+##
+# Commands from driver/cli.rb
+Whitelist.add '/usr/bin/lxc-version'
+Whitelist.add '/usr/bin/lxc-ls'
+Whitelist.add '/usr/bin/lxc-info', '--name', /.*/
+Whitelist.add '/usr/bin/lxc-create', '--template', /.*/, '--name', /.*/, '**'
+Whitelist.add '/usr/bin/lxc-destroy',  '--name', /.*/
+Whitelist.add '/usr/bin/lxc-start', '-d', '--name', /.*/, '**'
+Whitelist.add '/usr/bin/lxc-stop', '--name', /.*/
+Whitelist.add '/usr/bin/lxc-shutdown', '--name', /.*/
+Whitelist.add '/usr/bin/lxc-attach', '--name', /.*/, '**'
+Whitelist.add '/usr/bin/lxc-attach', '-h'
+
+##
+# Commands from driver/action/remove_temporary_files.rb
+Whitelist.add '/bin/rm', '-rf', %r{\\A\#{base}/.*/rootfs/tmp/.*}
+
+# Watch out for stones
+Whitelist.run!(ARGV)
+            EOF
+          end
+          wrapper.close
+          wrapper.path
+        end
 
         # REFACTOR: Make use ERB rendering after https://github.com/mitchellh/vagrant/issues/3231
         #           lands into core
-        def create_tempfile!(user, filename)
+        def create_sudoers!(user, command)
-          sudoers = Tempfile.new(filename).tap do |file|
+          sudoers = Tempfile.new('vagrant-lxc-sudoers').tap do |file|
-            file.write "# Automatically created by vagrant-lxc\n"
+            file.puts "# Automatically created by vagrant-lxc"
-            commands.each do |command|
+            file.puts "Cmnd_Alias LXC = #{command}"
-              file.write sudoers_policy(user, command[:cmd], command[:args])
+            file.puts "#{user} ALL=(root) NOPASSWD: LXC"
-            end
           end
           sudoers.close
-          File.chmod(0644, sudoers.path)
           sudoers.path
         end
 
-        def to_sudoers!(source, destination)
+        def su_copy(files)
-          destination = "/etc/sudoers.d/#{destination}"
+          commands = files.map { |file|
-          commands = [
+            [
-            "rm -f #{destination}",
+              "rm -f #{file[:target]}",
-            "cp #{source} #{destination}",
+              "cp #{file[:source]} #{file[:target]}",
-            "chmod 440 #{destination}"
+              "chown root:root #{file[:target]}",
-          ]
+              "chmod #{file[:mode]} #{file[:target]}"
-          `echo "#{commands.join('; ')}" | sudo sh`
+            ]
-        end
+          }.flatten
-
+          system "echo \"#{commands.join("; ")}\" | sudo sh"
-        def sudoers_policy(user, command, args)
-          vagrant_home = "#{`echo ~#{user}`.chomp}/.vagrant.d"
-          args = args.gsub /%\{VAGRANT_D\}/, vagrant_home
-          args = args.gsub /%\{BOXES\}/, "#{vagrant_home}/boxes"
-          "#{user} ALL=(root) NOPASSWD: #{command} #{args}\n"
-        end
-
-        def commands
-         [
-           { cmd: '/usr/bin/lxc-ls',        args: '' },
-           { cmd: '/usr/bin/lxc-info',      args: '' },
-           { cmd: '/usr/bin/lxc-attach',    args: '' },
-           { cmd: '/usr/bin/which',         args: 'lxc-*' },
-           { cmd: '/bin/cat',               args: '/var/lib/lxc/*' },
-           { cmd: '/bin/mkdir',             args: '-p /var/lib/lxc/*' },
-           { cmd: '/bin/su',                args: "root -c sed -e '*' -ibak /var/lib/lxc/*" },
-           { cmd: '/bin/su',                args: "root -c echo '*' >> /var/lib/lxc/*" },
-           { cmd: '/usr/bin/lxc-start',     args: '-d --name *' },
-           { cmd: '/bin/cp',                args: '%{BOXES}/*/lxc/lxc-template /usr/lib/lxc/templates/*' },
-           { cmd: '/bin/cp',                args: '%{VAGRANT_D}/gems/gems/vagrant-lxc-*/scripts/lxc-template /usr/lib/lxc/templates/*' },
-           { cmd: '/bin/cp',                args: '%{BOXES}/*/lxc/lxc-template /usr/share/lxc/templates/*' },
-           { cmd: '/bin/cp',                args: '%{VAGRANT_D}/gems/gems/vagrant-lxc-*/scripts/lxc-template /usr/share/lxc/templates/*' },
-           { cmd: '/bin/rm',                args: '/usr/lib/lxc/templates/*' },
-           { cmd: '/bin/rm',                args: '/usr/share/lxc/templates/*' },
-           { cmd: '/bin/chmod',             args: '+x /usr/lib/lxc/*' },
-           { cmd: '/bin/chmod',             args: '+x /usr/share/lxc/*' },
-           { cmd: '/usr/bin/lxc-create',    args: '--template * --name * -- --tarball %{BOXES}/*' },
-           { cmd: '/bin/rm',                args: '-rf /var/lib/lxc/*/rootfs/tmp/*' },
-           { cmd: '/usr/bin/lxc-shutdown',  args: '--name *' },
-           { cmd: '/usr/bin/lxc-stop',      args: '--name *' },
-           { cmd: '/usr/bin/lxc-destroy',   args: '--name *' }
-         ]
         end
       end
     end

lib/vagrant-lxc/config.rb

@@ -6,12 +6,6 @@ module Vagrant
       # @return [Array]
       attr_reader :customizations
 
-      # A String that points to a file that acts as a wrapper for sudo commands.
-      #
-      # This allows us to have a single entry when whitelisting NOPASSWD commands
-      # on /etc/sudoers
-      attr_accessor :sudo_wrapper
-
       # A string to explicitly set the container name. To use the vagrant
       # machine name, set this to :machine
       attr_accessor :container_name
@@ -41,21 +35,6 @@ module Vagrant
         @sudo_wrapper = nil if @sudo_wrapper == UNSET_VALUE
         @container_name = nil if @container_name == UNSET_VALUE
       end
-
-      def validate(machine)
-        errors = []
-
-        if @sudo_wrapper
-          hostpath = Pathname.new(@sudo_wrapper).expand_path(machine.env.root_path)
-          if ! hostpath.file?
-            errors << I18n.t('vagrant_lxc.sudo_wrapper_not_found', path: hostpath.to_s)
-          elsif ! hostpath.executable?
-            errors << I18n.t('vagrant_lxc.sudo_wrapper_not_executable', path: hostpath.to_s)
-          end
-        end
-
-        { "lxc provider" => errors }
-      end
     end
   end
 end

lib/vagrant-lxc/provider.rb

@@ -19,8 +19,9 @@ module Vagrant
 
       def sudo_wrapper
         @shell ||= begin
-          wrapper = @machine.provider_config.sudo_wrapper
+          wrapper = Pathname.new(LXC.sudo_wrapper_path).exist? &&
-          wrapper = Pathname(wrapper).expand_path(@machine.env.root_path).to_s if wrapper
+            LXC.sudo_wrapper_path || nil
+          @logger.debug("Found sudo wrapper : #{wrapper}") if wrapper
           SudoWrapper.new(wrapper)
         end
       end

lib/vagrant-lxc/sudo_wrapper.rb

@@ -10,13 +10,14 @@ module Vagrant
       end
 
       def run(*command)
-        command.unshift @wrapper_path if @wrapper_path
+        options = command.last.is_a?(Hash) ? command.last : {}
+        command.unshift @wrapper_path if @wrapper_path && !options[:no_wrapper]
         execute *(['sudo'] + command)
       end
 
-      def su_c(command)
+      def su_c(command, options={})
-        su_command = if @wrapper_path
+        su_command = if @wrapper_path && !options[:no_wrapper]
-            "#{@wrapper_path} \"#{command}\""
+            "#{@wrapper_path} su root -c \"\\\"#{command}\\\"\""
           else
             "su root -c \"#{command}\""
           end