Class: Hijack::Payload

Inherits:
Object
  • Object
show all
Defined in:
lib/hijack/payload.rb

Class Method Summary collapse

Class Method Details

.inject(pid) ⇒ Object 



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# File 'lib/hijack/payload.rb', line 3

def self.inject(pid)
  gdb = nil
  trap('SIGINT') do
    puts
    @received_sigint = true
  end
  gdb = GDB.new(pid)
  gdb.eval(payload(pid))
  gdb.quit
  exit if @received_sigint
end

.payload(pid) ⇒ Object 



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# File 'lib/hijack/payload.rb', line 15

def self.payload(pid)
  <<-RUBY
    require 'stringio'
    require 'drb'

    debug = #{Hijack.options[:debug] || false}
    puts 'Hijack: Debugging enabled' if debug
    module Hijack
      class OutputCopier
        def self.remote
          @remote
        end

        def self.stop
          @remote = nil
          [$stdout, $stderr].each do |io|
            if io.respond_to?(:write_with_copying)
              class << io
                alias_method :write, :write_without_copying
                remove_method :write_with_copying
              end
            end
          end
        end

        def self.start(pid)
          @remote = DRbObject.new(nil, 'drbunix://tmp/hijack.' + pid.to_s + '.sock')
          puts @remote.inspect if Hijack.debug?

          class << $stdout
            def write_with_copying(str)
              write_without_copying(str)
              begin
                Hijack::OutputCopier.remote.write('stdout', str)
              rescue Exception => e
                write_without_copying(e.message) if Hijack.debug?
                Hijack.stop
              end
            end
            alias_method :write_without_copying, :write
            alias_method :write, :write_with_copying
          end

          class << $stderr
            def write_with_copying(str)
              write_without_copying(str)
              begin
                Hijack::OutputCopier.remote.write('stderr', str)
              rescue Exception => e
                write_without_copying(e.message) if Hijack.debug?
                Hijack.stop
              end
            end
            alias_method :write_without_copying, :write
            alias_method :write, :write_with_copying
          end
        end
      end

      class Evaluator
        def initialize(context)
          @context = context
        end

        def evaluate(rb)
          @context.instance_eval(rb)
        end
      end

      def self.debug?
        @debug
      end

      def self.start(context, debug)
        return if @service && @service.alive?
        @debug = debug
        evaluator = Hijack::Evaluator.new(context)
        @service = DRb.start_service('#{Hijack.socket_for(pid)}', evaluator)
        File.chmod(0600, '#{Hijack.socket_path_for(pid)}')
      end

      def self.stop
        begin
          OutputCopier.stop
          @service.stop_service
          @service = nil
        rescue Exception
        end
      end
    end
    Hijack.start(self, #{Hijack.options[:debug] || false})
  RUBY
end