Class: PacketGen::Header::IPv6

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

Overview

A IPv6 header consists of:

Create a IPv6 header

# standalone
ipv6 = PacketGen::Header::IPv6.new
# in a packet
pkt = PacketGen.gen('IPv6')
# access to IPv6 header
pkt.ipv6   # => PacketGen::Header::IPv6

IPv6 attributes

ipv6.u32 = 0x60280001
# the same as
ipv6.version = 6
ipv6.traffic_class = 2
ipv6.flow_label = 0x80001

ipv6.length = 0x43
ipv6.hop = 0x40
ipv6.next = 6
ipv6.src = '::1'
ipv6.src                # => "::1"
ipv6[:src]              # => PacketGen::Header::IPv6::Addr
ipv6.dst = '2001:1234:5678:abcd::123'
ipv6.body.read 'this is a body'

Author:

  • Sylvain Daubert

Defined Under Namespace

Classes: Addr, ArrayOfAddr, Extension, HopByHop, Option, Options, Pad1

Constant Summary collapse

ETHERTYPE =

IPv6 Ether type

0x86dd

Instance Attribute Summary collapse

Attributes inherited from Base

#packet

Class Method Summary collapse

Instance Method Summary collapse

Methods inherited from Base

#added_to_packet, calculate_and_set_length, #header_id, inherited, #initialize, #ip_header, known_headers, #ll_header, #method_name, #protocol_name, protocol_name

Methods inherited from Types::Fields

#[], #[]=, #bits_on, define_bit_fields_on, define_field, define_field_after, define_field_before, delete_field, fields, #fields, #force_binary, inherited, #initialize, #is_optional?, #is_present?, #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 ⇒ Types::String, Header::Base

Returns:



82
 
# File 'lib/packetgen/header/ipv6.rb', line 82

define_field :body, Types::String

#dst ⇒ Addr

IPv6 destination address

Returns:



79
 
# File 'lib/packetgen/header/ipv6.rb', line 79

define_field :dst, Addr, default: '::1'

#flow_label ⇒ Integer

Returns 20-bit flow_label attribute.

Returns:

  • (Integer) —

    20-bit flow_label attribute



90
 
# File 'lib/packetgen/header/ipv6.rb', line 90

define_bit_fields_on :u32, :version, 4, :traffic_class, 8, :flow_label, 20

#hop ⇒ Integer

8-bit IPv6 hop limit

Returns:

  • (Integer) 


71
 
# File 'lib/packetgen/header/ipv6.rb', line 71

define_field :hop, Types::Int8, default: 64

#length ⇒ Integer

16-bit word of IPv6 payload length

Returns:

  • (Integer) 


63
 
# File 'lib/packetgen/header/ipv6.rb', line 63

define_field :length, Types::Int16

#next ⇒ Integer

8-bit IPv6 next payload value

Returns:

  • (Integer) 


67
 
# File 'lib/packetgen/header/ipv6.rb', line 67

define_field :next, Types::Int8

#src ⇒ Addr

IPv6 source address

Returns:



75
 
# File 'lib/packetgen/header/ipv6.rb', line 75

define_field :src, Addr, default: '::1'

#traffic_class ⇒ Integer

Returns 8-bit traffic_class attribute.

Returns:

  • (Integer) —

    8-bit traffic_class attribute



90
 
# File 'lib/packetgen/header/ipv6.rb', line 90

define_bit_fields_on :u32, :version, 4, :traffic_class, 8, :flow_label, 20

#u32 ⇒ Integer

First 32-bit word of IPv6 header

Returns:

  • (Integer) 


59
 
# File 'lib/packetgen/header/ipv6.rb', line 59

define_field :u32, Types::Int32, default: 0x6000_0000

#version ⇒ Integer

Returns 4-bit version attribute.

Returns:

  • (Integer) —

    4-bit version attribute



90
 
# File 'lib/packetgen/header/ipv6.rb', line 90

define_bit_fields_on :u32, :version, 4, :traffic_class, 8, :flow_label, 20

Class Method Details

.bind(header_klass, args = {}) ⇒ Object

Bind a upper header to IPv6 and its defined extension headers.

See Also:



187
188
189
190
191
192
 
# File 'lib/packetgen/header/ipv6.rb', line 187

def bind(header_klass, args={})
  IPv6.old_bind header_klass, args
  [IPv6::HopByHop].each do |klass|
    klass.bind header_klass, args
  end
end

.bind_header(header_klass, args = {}) ⇒ Object

Deprecated.

USe bind.

Bind a upper header to IPv6 and its defined extension headers.

See Also:



196
197
198
199
 
# File 'lib/packetgen/header/ipv6.rb', line 196

def bind_header(header_klass, args={})
  Deprecation.deprecated(self, __method__, 'bind', klass_method: true)
  bind header_klass, args
end

.old_bind ⇒ Object 



183
 
# File 'lib/packetgen/header/ipv6.rb', line 183

alias old_bind bind

Instance Method Details

#calc_length ⇒ Integer

Compute length and set len field

Returns:

  • (Integer) 


94
95
96
 
# File 'lib/packetgen/header/ipv6.rb', line 94

def calc_length
  Base.calculate_and_set_length self, header_in_size: false
end

#inspect ⇒ String

Returns:

  • (String) 


139
140
141
142
143
144
145
146
147
148
149
150
151
 
# File 'lib/packetgen/header/ipv6.rb', line 139

def inspect
  super do |attr|
    next unless attr == :u32

    str = Inspect.inspect_attribute(attr, self[attr])
    shift = Inspect.shift_level
    str << shift + Inspect::FMT_ATTR % ['', 'version', version]
    tclass = Inspect.int_dec_hex(traffic_class, 2)
    str << shift + Inspect::FMT_ATTR % ['', 'tclass', tclass]
    fl_value = Inspect.int_dec_hex(flow_label, 5)
    str << shift + Inspect::FMT_ATTR % ['', 'flow_label', fl_value]
  end
end

#parse? ⇒ Boolean

Check version field

Returns:

  • (Boolean)

See Also:

  • PacketGen::Header::IPv6.[Base[Base#parse?]


155
156
157
 
# File 'lib/packetgen/header/ipv6.rb', line 155

def parse?
  version == 6
end

#pseudo_header_checksum ⇒ Integer

Get IPv6 part of pseudo header checksum.

Returns:

  • (Integer) 


100
101
102
103
104
105
 
# File 'lib/packetgen/header/ipv6.rb', line 100

def pseudo_header_checksum
  sum = 0
  self[:src].to_a.each { |word| sum += word.to_i }
  self[:dst].to_a.each { |word| sum += word.to_i }
  sum
end

#reply! ⇒ self

Invert source and destination addresses

Returns:

  • (self)

Since:

  • 2.7.0



162
163
164
165
 
# File 'lib/packetgen/header/ipv6.rb', line 162

def reply!
  self[:src], self[:dst] = self[:dst], self[:src]
  self
end

#to_w(iface = nil) ⇒ void

This method returns an undefined value.

Send IPv6 packet on wire.

When sending packet at IPv6 level, version, flow_label and length fields are set by kernel. Source address should be a unicast address assigned to the host. To set any of this fields, use Eth#to_w.

Parameters:

  • iface (String) (defaults to: nil) —

    interface name

Raises:



114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
 
# File 'lib/packetgen/header/ipv6.rb', line 114

def to_w(iface=nil)
  sock = Socket.new(Socket::AF_INET6, Socket::SOCK_RAW, self.next)
  sockaddrin = Socket.sockaddr_in(0, dst)

  # IPv6 RAW sockets don't have IPHDRINCL option to send IPv6 header.
  # So, header must be built using ancillary data.
  # Only src address, traffic_class and hop_limit can be set this way.
  hop_limit = Socket::AncillaryData.int(Socket::AF_INET6,
                                        Socket::IPPROTO_IPV6,
                                        Socket::IPV6_HOPLIMIT, hop)
  tc = Socket::AncillaryData.int(Socket::AF_INET6,
                                 Socket::IPPROTO_IPV6,
                                 Socket::IPV6_TCLASS,
                                 traffic_class)

  # src address is set through PKT_INFO, which needs interface index.
  ifaddr = Socket.getifaddrs.find { |ia| ia.name == iface }
  raise WireError, "unknown #{iface} interface" if ifaddr.nil?
  pkt_info = Socket::AncillaryData.ipv6_pktinfo(Addrinfo.ip(src), ifaddr.ifindex)

  sock.sendmsg body.to_s, 0, sockaddrin, hop_limit, tc, pkt_info
  sock.close
end