Class: Arpoon::Packet

Inherits:
Object
  • Object
show all
Defined in:
lib/arpoon/packet.rb

Constant Summary collapse

Operations = 
{
  1 => :request,
  2 => :reply
}

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(interface = nil, source, destination, operation, sender_hw, sender_ip, target_hw, target_ip) ⇒ Packet

Returns a new instance of Packet.



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# File 'lib/arpoon/packet.rb', line 64

def initialize (interface = nil, source, destination, operation, sender_hw, sender_ip, target_hw, target_ip)
  @interface   = interface
  @source      = source
  @destination = destination

  @operation = operation.downcase

  @sender = Struct.new(:mac, :ip).new(sender_hw, sender_ip)
  @target = Struct.new(:mac, :ip).new(target_hw, target_ip)
end

Instance Attribute Details

#destination ⇒ Object (readonly)

Returns the value of attribute destination.



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# File 'lib/arpoon/packet.rb', line 62

def destination
  @destination
end

#interface ⇒ Object (readonly)

Returns the value of attribute interface.



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# File 'lib/arpoon/packet.rb', line 62

def interface
  @interface
end

#sender ⇒ Object (readonly)

Returns the value of attribute sender.



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# File 'lib/arpoon/packet.rb', line 62

def sender
  @sender
end

#source ⇒ Object (readonly)

Returns the value of attribute source.



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# File 'lib/arpoon/packet.rb', line 62

def source
  @source
end

#target ⇒ Object (readonly)

Returns the value of attribute target.



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# File 'lib/arpoon/packet.rb', line 62

def target
  @target
end

Class Method Details

.unpack(data, interface = nil) ⇒ Object 



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# File 'lib/arpoon/packet.rb', line 22

def self.unpack (data, interface = nil)
  source      = HWAddr.new(data[0, 6].unpack('C6'))
  destination = HWAddr.new(data[6, 6].unpack('C6'))

  unless data[12, 2].unpack('n').first == 0x0806
    raise ArgumentError, 'the passed data is not an ARP packet'
  end

  unless data[16, 2].unpack('n').first == 0x0800
    raise ArgumentError, 'the passed data is not using the IP protocol'
  end

  hw_size = data[18, 1].unpack('C').first
  pr_size = data[19, 1].unpack('C').first

  if hw_size != 6
    raise ArgumentError, "#{hw_size} is an unsupported size"
  end

  opcode = data[20, 2].unpack('n').first

  if pr_size == 4
    sender_hw = HWAddr.new(data[22, 6].unpack('C6'))
    sender_ip = IPAddr.new_ntoh(data[28, 4])

    target_hw = HWAddr.new(data[32, 6].unpack('C6'))
    target_ip = IPAddr.new_ntoh(data[38, 4])
  elsif pr_size == 16
    sender_hw = HWAddr.new(data[22, 6].unpack('C6'))
    sender_ip = IPAddr.new_ntoh(data[28, 16])

    target_hw = HWAddr.new(data[44, 6].unpack('C6'))
    target_ip = IPAddr.new_ntoh(data[50, 16])
  else
    raise ArgumentError, "#{pr_size} is an unsupported protocol size"
  end

  new(interface, source, destination, Operations[opcode], sender_hw, sender_ip, target_hw, target_ip)
end

Instance Method Details

#reply? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/arpoon/packet.rb', line 79

def reply?
  @operation == :reply
end

#request? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/arpoon/packet.rb', line 75

def request?
  @operation == :request
end

#to_sym ⇒ Object 



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# File 'lib/arpoon/packet.rb', line 83

def to_sym
  @operation
end