metasploit-framework/lib/rex/post/meterpreter/packet_response_waiter.rb

#!/usr/bin/env ruby

require 'timeout'
require 'thread'

module Rex
module Post
module Meterpreter

###
#
# This class handles waiting for a response to a given request
# and the subsequent response association.
#
###
class PacketResponseWaiter

	#
	# Initializes a response waiter instance for the supplied request
	# identifier.
	#
	def initialize(rid, completion_routine = nil, completion_param = nil)
		self.rid      = rid.dup
		self.response = nil

		if (completion_routine)
			self.completion_routine = completion_routine
			self.completion_param   = completion_param
		else
			self.done  = false
		end
	end

	#
	# Checks to see if this waiter instance is waiting for the supplied
	# packet based on its request identifier.
	#
	def waiting_for?(packet)
		return (packet.rid == rid)
	end

	#
	# Notifies the waiter that the supplied response packet has arrived.
	#
	def notify(response)
		self.response = response

		if (self.completion_routine)
			self.completion_routine(self.completion_param, response)
		else
			self.done = true
		end
	end

	#
	# Waits for a given time interval for the response packet to arrive.
  # If the interval is -1 we can wait forever.
	#
	def wait(interval)
    if( interval and interval == -1 )
      while(not self.done)
        select(nil, nil, nil, 0.1)
      end 
    else    
      begin
          Timeout.timeout(interval) {
            while(not self.done)
              select(nil, nil, nil, 0.1)
            end
          }
      rescue Timeout::Error
        self.response = nil
      end
    end    
		return self.response
	end

	attr_accessor :rid, :done, :response # :nodoc:
	attr_accessor :completion_routine, :completion_param # :nodoc:
end

end; end; end