napt_table.rb

#
# NAPT TABLE implementation in TremaEdge
# Auther: Eishun Kondoh(e_kondo@ap-com.co.jp)
# Copyright (C) 2013 APCOMMUNICATIONS CO., LTD.
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License, version 2, as
# published by the Free Software Foundation.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.    See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License along
# with this program; if not, write to the Free Software Foundation, Inc.,
# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
#

require "rubygems"
require "narray"

class NaptTable

  def initialize
    @data = {}
    @free_ports = ((1025..65535).to_a).reverse
  end


  def create_entry i_local_addr, i_local_tp, i_global_addr,o_local_addr, o_local_tp
    index = i_local_addr + i_local_tp.to_s + o_local_addr + o_local_tp.to_s
    if not( @data.include?(index))
      i_global_tp = @free_ports.pop
      @data[index] = NArray[i_local_addr, i_local_tp, i_global_addr, i_global_tp, o_local_addr, o_local_tp]
    end
    return @data[index]
  end


  def napt_entry_aged_by nw_src, nw_dst, tp_src, tp_dst
    index = nw_src.to_s + tp_src.to_s + nw_dst.to_s + tp_dst.to_s
    if @data.include?(index)
      port =  @data[index][3]
      @data.delete(index)
      @free_ports.push( port )
    end
  end

end


### Local variables:
### mode: Ruby
### coding: utf-8
### indent-tabs-mode: nil
### End: