Class: PacketGen::Header::IPv6::Extension Abstract

Inherits:
Base show all
Defined in:
lib/packetgen/header/ipv6/extension.rb

Overview

This class is abstract.

You should not use this class but its subclasses.

Base class to handle IPv6 extensions A IPv6 extension header has the following format:

 0                   1                   2                   3
 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|  Next Header  |  Hdr Ext Len  |                               |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+                               +
|                                                               |
.                                                               .
.                            Options                            .
.                                                               .
|                                                               |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

Such a header consists of:

Author:

  • Sylvain Daubert

Direct Known Subclasses

HopByHop

Instance Attribute Summary collapse

Instance Method Summary collapse

Methods inherited from Base

bind, calculate_and_set_length, #header_id, inherited, #initialize, #ip_header, #ll_header

Methods included from PacketGen::Headerable

#added_to_packet, included, #method_name, #packet, #packet=, #parse?, #protocol_name, #read

Methods inherited from Types::Fields

#[], #[]=, #bits_on, define_bit_fields_on, define_field, define_field_after, define_field_before, #fields, fields, inherited, #initialize, #inspect, #offset_of, #optional?, #optional_fields, #present?, #read, remove_bit_fields_on, remove_field, #sz, #to_h, #to_s, update_field

Constructor Details

This class inherits a constructor from PacketGen::Header::Base

Instance Attribute Details

#body ⇒ String, Base

Returns:



50
 
# File 'lib/packetgen/header/ipv6/extension.rb', line 50

define_field :body, Types::String

#length ⇒ Integer

8-bit extension length, in 8-octets units, not including the first 8 octets.

Returns:

  • (Integer) 


42
 
# File 'lib/packetgen/header/ipv6/extension.rb', line 42

define_field :length, Types::Int8

#next ⇒ Integer

8-bit Next header field

Returns:

  • (Integer) 


37
 
# File 'lib/packetgen/header/ipv6/extension.rb', line 37

define_field :next, Types::Int8

#options ⇒ String

Specific options of extension header

Returns:

  • (String) 


46
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# File 'lib/packetgen/header/ipv6/extension.rb', line 46

define_field :options, Types::String,
builder: ->(h, t) { t.new(length_from: -> { h.real_length }) }

Instance Method Details

#calc_length ⇒ Integer

Compute length and set len field

Returns:

  • (Integer) 


60
61
62
 
# File 'lib/packetgen/header/ipv6/extension.rb', line 60

def calc_length
  self.length = (options.sz + 2) / 8 - 1
end

#real_length ⇒ Integer

Get real extension header length

Returns:

  • (Integer) 


54
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56
 
# File 'lib/packetgen/header/ipv6/extension.rb', line 54

def real_length
  (length + 1) * 8
end