Class: Racket::Racket

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

Constant Summary collapse

@@loaded_pcaprub = 
false

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(payload = "") ⇒ Racket

Returns a new instance of Racket.



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# File 'lib/racket/racket.rb', line 51

def initialize(payload="")
  @layers = []
  @mtu = 1500
  @timeout = 10
  @payload = payload
  1.upto(7) do |l|
    self.class.send(:define_method, "layer#{l}", lambda { @layers[l] })
    self.class.send(:define_method, "l#{l}", lambda { @layers[l] })
    self.class.send(:define_method, "layer#{l}=", lambda { |x| @layers[l] = x; })
    self.class.send(:define_method, "l#{l}=", lambda { |x| @layers[l] = x; })
  end
end

Instance Attribute Details

#iface ⇒ Object

Returns the value of attribute iface.



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# File 'lib/racket/racket.rb', line 40

def iface
  @iface
end

#layers ⇒ Object

Returns the value of attribute layers.



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# File 'lib/racket/racket.rb', line 41

def layers
  @layers
end

#mtu ⇒ Object

Returns the value of attribute mtu.



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# File 'lib/racket/racket.rb', line 40

def mtu
  @mtu
end

#payload ⇒ Object

Returns the value of attribute payload.



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# File 'lib/racket/racket.rb', line 41

def payload
  @payload
end

#timeout ⇒ Object

Returns the value of attribute timeout.



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# File 'lib/racket/racket.rb', line 40

def timeout
  @timeout
end

Instance Method Details

#pack ⇒ Object

Assemble all the pieces of this Racket as a string, ready for sending.



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# File 'lib/racket/racket.rb', line 65

def pack
  last_payload = ""
  orig_payload = ""
  @layers.compact.reverse.each do |l|
    # save the original payload
    orig_payload = l.payload
    # tack on the last payload in
    # case fix needs it...
    l.payload += last_payload
    if (l.autofix?)
      l.fix!
    end

    if (l.payload == orig_payload + last_payload)
      # payload was not modified by fix, so reset it to what
      # it used to be
      l.payload = orig_payload
    else
      # payload was modified by fix.  chop off what we added.
      # XXX: this assumes that what we added is still at the end.  
      # XXX: this is not always true
      l.payload = l.payload.slice(0, l.payload.length - last_payload.length)
    end

    # save this layer for the next guy
    last_payload += l
    
  end
  
  payload = ""
  @layers.compact.each do |l|
    payload += l
  end
  payload
end

#pretty ⇒ Object

return a pretty interpretation of this packet



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# File 'lib/racket/racket.rb', line 102

def pretty
  s = ""
  @layers.compact.each do |l|
    s << "#{l.class}: "
    s << l.pretty
    s << "\n"
  end
  s
end

#send2 ⇒ Object

Write raw layer2 frames



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# File 'lib/racket/racket.rb', line 123

def send2
  if(not @@loaded_pcaprub)
    raise RuntimeError, "Could not initialize the pcaprub library (You need pcaprub from SVN (http://rubyforge.org/projects/pcaprub/))" 
  end
  begin

    p = Pcap::open_live(@iface, @mtu, false, @timeout)
  rescue Exception => e
    puts "Pcap: can't open device '#{@iface}' (#{e})"
    return
  end

  begin
    b = p.inject(pack)
    #p.pcap_close
    return b
  rescue Exception => e
    puts "Pcap: error while sending packet on '#{@iface}' (#{e})"
  end
end

#send3 ⇒ Object

Write raw layer3 frames



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# File 'lib/racket/racket.rb', line 145

def send3
  begin
    s = Socket.open(Socket::PF_INET, Socket::SOCK_RAW, Socket::IPPROTO_RAW)

    if (Socket.const_defined?('SOL_IP'))
      s.setsockopt(Socket::SOL_IP, Socket::IP_HDRINCL, true)
    else
      # BSD
      s.setsockopt(Socket::IPPROTO_IP, Socket::IP_HDRINCL, true)
    end
  rescue Errno::EPERM
    raise ArgumentError, "Must run #{$0} as root."
  end

  return s.send(pack, 0, Socket.pack_sockaddr_in(1024, @layers[3].dst_ip))
end

#sendpacket ⇒ Object

Attempt to figure out which of send2 or send3 needs to be called.



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# File 'lib/racket/racket.rb', line 114

def sendpacket
  if (@layers[2])
    send2
  else
    send3
  end
end