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module Telephony
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class Modem
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  attr_accessor :serialport, :sp, :sock
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  attr_accessor :baud, :data_bits, :parity, :stop_bits
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  attr_accessor :flowcontrol
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  attr_accessor :display
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  attr_reader   :commandstate
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  NONE  = SerialPort::NONE
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  HARD  = SerialPort::HARD
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  SOFT  = SerialPort::SOFT
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  SPACE = SerialPort::SPACE
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  MARK  = SerialPort::MARK
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  EVEN  = SerialPort::EVEN
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  ODD   = SerialPort::ODD
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  def initialize(serialport = '/dev/ttyS0')
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    @serialport = serialport || '/dev/ttyS0'
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    @sp = nil
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    @baud = 2400
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    @data_bits = 8
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    @parity = NONE
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    @stop_bits = 1
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    @flowcontrol = NONE
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    @commandstate = true
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    @display = true
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    # Connect to and init modem
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    begin
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      #print("Opening Serial Port #{@serialport} (#{@baud} #{@data_bits}#{@parity}#{@stop_bits})\r\n")
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      @sp = SerialPort.create(serialport)
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      @sp.modem_params = {'baud' => @baud, 'data_bits' => @data_bits, 'parity' => @parity, 'stop_bits' => @stop_bits}
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      @sp.read_timeout = -1
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      @sp.rts = 1
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      @sp.dtr = 1 if sp.respond_to?:dtr= # unsupported in windows ):
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      @sock = @sp
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      @sock.extend(Rex::IO::Stream)
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      @sock.extend(Rex::IO::StreamAbstraction::Ext)
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    rescue ::Interrupt
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      raise $!
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    rescue ::Exception => e
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      print("Error opening serial port #{@serialport} : #{e.class} #{e} #{e.backtrace}\r\n")
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      return true
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    end
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  end
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  # This provides pass-through method support for the SerialPort object
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  def method_missing(meth, *args); self.sp.send(meth, *args); end
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  def put_command(command, timeout)
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    switchback = false
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    if ! @commandstate
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      commandstate
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      switchback = true
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    end
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    begin
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      self.flush  # TODO: This doesn't work in exploits for some reason but it does in aux modules
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      @sp.puts command + "\r\n"
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      echo = get_response(timeout) # read back the echoed command (not really a response)
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    rescue ::Interrupt
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      raise $!
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    rescue ::Exception => e
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      print("Error sending command to modem: #{e.class} #{e} #{e.backtrace}\r\n")
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      return
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    end
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    result = get_response(timeout)
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    datastate if switchback == true
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    return result
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  end
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  def get_response(timeout)
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    time = Time.now
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    @sp.read_timeout = -1
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    result = ''
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    while Time.now <= time + timeout
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      # get a char from the modem
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      begin
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        c = @sp.getc
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        if c
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          c = c.chr
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          result += c
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          if c == "\n"
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            result = result.chomp
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            break if result.length > 0
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          end
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        end
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      rescue ::Interrupt
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        raise $!
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      rescue ::Exception => e
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        print("Error reading from modem: #{e.class} #{e} #{e.backtrace}\r\n")
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        return
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      end
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    end
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    if result.length > 0
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      print "[m] #{result}\r\n" if @display
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    else
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      result = 'TIMEOUT'
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    end
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    return result
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  end
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  def commandstate
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    if ! @commandstate 
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      @sp.break 10 # tenths of a second
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      @sp.puts '+++'
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      @sp.break 10 # tenths of a second
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      result = get_response(3)
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      if result != 'OK'
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        print( "Error switching to command state: FAILED\r\n" )
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        return false
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      else
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        @commandstate = true
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      end
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    end
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    return true	
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  end
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  def datastate
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    if @commandstate
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      result = put_command('ATO0', 3)
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      if result =~ /CONNECT/i
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        @commandstate = false
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      else
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        print( "Error switching to data state: FAILED\r\n" )
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        return false
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      end
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    end
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    return true
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  end
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  def hangup
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    flush
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    if @commandstate == true
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      #print( "Hanging up... (commandstate ATH0)\r\n" )
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      result = put_command('ATH0', 3)
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      return true if result == 'OK' or result == 'NO CARRIER'
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    else
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      if @sp.respond_to?:dtr= # unsupported in windows ):
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        #print( "Hanging up... (DTR = 0)\r\n" )
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        @sp.dtr = 0
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        sleep 0.75
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        @sp.dtr = 1
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        result = get_response(3)
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        @commandstate = true if result == 'NO CARRIER'
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        return true
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      else
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        #print( "Hanging up... (datastate ATH0)\r\n" )
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        commandstate
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        result = put_command('ATH0', 3)
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        return true if result == 'OK'
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      end
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    end
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    return false
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  end
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  # flush any stale data in the read buffer
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  def flush
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    @sp.read_timeout = -1
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    while @sp.getc; end
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  end
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  # TODO: convert all calls to Modem.params to Modem.modem_params and remove this def
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  def params=(params)
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    @sp.modem_params = params
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  end
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end
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end
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