Class: IP::Address::IPv4

Inherits:
IP::Address show all
Defined in:
lib/ip/address.rb

Overview

Support for IPv4

Instance Attribute Summary

Attributes inherited from IP::Address

#ip_address, #octets

Instance Method Summary collapse

Methods inherited from IP::Address

#[]

Constructor Details

#initialize(ip_address) ⇒ IPv4

Constructs an IP::Address::IPv4 object.

This can take two types of input. Either a string that contains a dotted-quad formatted address, or an integer that contains the data. This integer is expected to be constructed in the way that IP::Address::Util.pack_ipv4 would generate such an integer.

This constructor will throw IP::AddressException on any parse errors.



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# File 'lib/ip/address.rb', line 57

def initialize(ip_address)
  if ip_address.kind_of? Integer
    # unpack to generate a string, and parse that.
    # overwrites 'ip_address'
    # horribly inefficient, but general.
    
    raw = IP::Address::Util.raw_unpack(ip_address)[0..1]
    octets = []
    
    2.times do |x|
      octets.push(raw[x] & 0x00FF)
      octets.push((raw[x] & 0xFF00) >> 8)
    end
    
    ip_address = octets.reverse.join(".")
  end
  
  if ! ip_address.kind_of? String
    raise IP::AddressException.new("Fed IP address '#{ip_address}' is not String or Fixnum")
  end
  
  @ip_address = ip_address
  
  #
  # Unbeknowest by me, to_i will not throw an exception if the string
  # can't be converted cleanly - it just truncates, similar to atoi() and perl's int().
  #
  # Code below does a final sanity check.
  #
  
  octets = ip_address.split(/\./)
  octets_i = octets.collect { |x| x.to_i }
  
  0.upto(octets.length - 1) do |octet|
    if octets[octet] != octets_i[octet].to_s
      raise IP::AddressException.new("Integer conversion failed")
    end
  end
  
  @octets = octets_i
  
  # I made a design decision to allow 0.0.0.0 here.
  if @octets.length != 4 or @octets.find_all { |x| x > 255 }.length > 0
    raise IP::AddressException.new("IP address is improperly formed")
  end
end

Instance Method Details

#pack ⇒ Object

Returns a 128-bit integer representing the address.



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# File 'lib/ip/address.rb', line 107

def pack
  # this routine does relatively little. all it does is ensure
  # that the IP address is of a certain size and has certain numeric limits.
  myip = self.octets
  packval = [0] * 6
  
  #
  # this ensures that the octets are 8 bit, and combines the octets in order to
  # form two 16-bit integers suitable for pushing into the last places in 'packval'
  #
  
  (0..3).step(2) { |x| packval.push(((myip[x] & 0xFF) << 8) | (myip[x+1] & 0xFF)) }
  
  return IP::Address::Util.raw_pack(packval)
end