Class: PacketFu::NDPPacket

Inherits:
Packet
  • Object
show all
Includes:
EthHeaderMixin, IPv6HeaderMixin, NDPHeaderMixin
Defined in:
lib/bettercap/monkey/packetfu/utils.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Methods included from NDPHeaderMixin

#ndp_code, #ndp_code=, #ndp_laddr, #ndp_laddr=, #ndp_lla, #ndp_lla=, #ndp_lla_readable, #ndp_opt_len, #ndp_opt_len=, #ndp_opt_type, #ndp_opt_type=, #ndp_reserved, #ndp_reserved=, #ndp_set_flags=, #ndp_sum, #ndp_sum=, #ndp_sum_readable, #ndp_taddr, #ndp_taddr=, #ndp_tgt, #ndp_tgt=, #ndp_tgt_readable, #ndp_type, #ndp_type=

Methods inherited from Packet

#eth2s

Constructor Details

#initialize(args = {}) ⇒ NDPPacket

Returns a new instance of NDPPacket.



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# File 'lib/bettercap/monkey/packetfu/utils.rb', line 373

def initialize(args={})
  @eth_header = EthHeader.new(args).read(args[:eth])
  @ipv6_header = IPv6Header.new(args).read(args[:ipv6])
  @ipv6_header.ipv6_next = PacketFu::NDPHeader::PROTOCOL_NUMBER
  @ndp_header = NDPHeader.new(args).read(args[:ndp])

  @ipv6_header.body = @ndp_header
  @eth_header.body = @ipv6_header

  @headers = [@eth_header, @ipv6_header, @ndp_header]
  super
  ndp_calc_sum
end

Instance Attribute Details

#eth_header ⇒ Object

Returns the value of attribute eth_header.



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# File 'lib/bettercap/monkey/packetfu/utils.rb', line 371

def eth_header
  @eth_header
end

#ipv6_header ⇒ Object

Returns the value of attribute ipv6_header.



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# File 'lib/bettercap/monkey/packetfu/utils.rb', line 371

def ipv6_header
  @ipv6_header
end

#ndp_header ⇒ Object

Returns the value of attribute ndp_header.



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# File 'lib/bettercap/monkey/packetfu/utils.rb', line 371

def ndp_header
  @ndp_header
end

Instance Method Details

#ndp_calc_sum ⇒ Object

Calculates the checksum for the object.



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# File 'lib/bettercap/monkey/packetfu/utils.rb', line 388

def ndp_calc_sum
  checksum = 0

  # Compute sum on pseudo-header
  [ipv6_src, ipv6_dst].each do |iaddr|
    8.times { |i| checksum += (iaddr >> (i*16)) & 0xffff }
  end
  checksum += PacketFu::NDPHeader::PROTOCOL_NUMBER
  checksum += ipv6_len
  # Continue with entire ICMPv6 message.
  checksum += (ndp_type.to_i << 8) + ndp_code.to_i
  checksum += ndp_reserved.to_i >> 16
  checksum += ndp_reserved.to_i & 0xffff
  8.times { |i| checksum += (ndp_tgt.to_i >> (i*16)) & 0xffff }
  checksum += (ndp_opt_type.to_i << 8) + ndp_opt_len.to_i

  mac2int = ndp_lla.to_s.unpack('H*').first.to_i(16)
  3.times { |i| checksum += (mac2int >> (i*16)) & 0xffff }

  checksum = checksum % 0xffff
  checksum = 0xffff - checksum
  checksum == 0 ? 0xffff : checksum

end

#ndp_recalc(arg = :all) ⇒ Object

Recalculates the calculatable fields for NDP.



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# File 'lib/bettercap/monkey/packetfu/utils.rb', line 414

def ndp_recalc(arg=:all)
  arg = arg.intern if arg.respond_to? :intern
  case arg
  when :ndp_sum
    self.ndp_sum = ndp_calc_sum
  when :all
    self.ndp_sum = ndp_calc_sum
  else
    raise ArgumentError, "No such field `#{arg}'"
  end
end