protocol_body: Ruby parsing library

Protocol body represents particular payload on transport level (OSI layer 4).

Typically this payload in encapsulated into network level (OSI layer 3) packet, which includes "protocol number" field that would be used to decide what's inside the payload and how to parse it. Thanks to IANA's standardization effort, multiple network level use the same IDs for these payloads named "protocol numbers".

This is effectively a "router" type: it expects to get protocol number as a parameter, and then invokes relevant type parser based on that parameter.

KS implementation details

License: CC0-1.0
Minimal Kaitai Struct required: 0.8

This page hosts a formal specification of protocol_body using Kaitai Struct. This specification can be automatically translated into a variety of programming languages to get a parsing library.

Usage

Parse a local file and get structure in memory:

data = ProtocolBody.from_file("path/to/local/file.protocol_body")

Or parse structure from a string of bytes:

bytes = "\x00\x01\x02..."
data = ProtocolBody.new(Kaitai::Struct::Stream.new(bytes))

After that, one can get various attributes from the structure by invoking getter methods like:

data.body # => get body

Ruby source code to parse protocol_body

protocol_body.rb

# This is a generated file! Please edit source .ksy file and use kaitai-struct-compiler to rebuild

require 'kaitai/struct/struct'

unless Gem::Version.new(Kaitai::Struct::VERSION) >= Gem::Version.new('0.7')
  raise "Incompatible Kaitai Struct Ruby API: 0.7 or later is required, but you have #{Kaitai::Struct::VERSION}"
end


##
# Protocol body represents particular payload on transport level (OSI
# layer 4).
# 
# Typically this payload in encapsulated into network level (OSI layer
# 3) packet, which includes "protocol number" field that would be used
# to decide what's inside the payload and how to parse it. Thanks to
# IANA's standardization effort, multiple network level use the same
# IDs for these payloads named "protocol numbers".
# 
# This is effectively a "router" type: it expects to get protocol
# number as a parameter, and then invokes relevant type parser based
# on that parameter.
# @see http://www.iana.org/assignments/protocol-numbers/protocol-numbers.xhtml Source
class ProtocolBody < Kaitai::Struct::Struct

  PROTOCOL_ENUM = {
    0 => :protocol_enum_hopopt,
    1 => :protocol_enum_icmp,
    2 => :protocol_enum_igmp,
    3 => :protocol_enum_ggp,
    4 => :protocol_enum_ipv4,
    5 => :protocol_enum_st,
    6 => :protocol_enum_tcp,
    7 => :protocol_enum_cbt,
    8 => :protocol_enum_egp,
    9 => :protocol_enum_igp,
    10 => :protocol_enum_bbn_rcc_mon,
    11 => :protocol_enum_nvp_ii,
    12 => :protocol_enum_pup,
    13 => :protocol_enum_argus,
    14 => :protocol_enum_emcon,
    15 => :protocol_enum_xnet,
    16 => :protocol_enum_chaos,
    17 => :protocol_enum_udp,
    18 => :protocol_enum_mux,
    19 => :protocol_enum_dcn_meas,
    20 => :protocol_enum_hmp,
    21 => :protocol_enum_prm,
    22 => :protocol_enum_xns_idp,
    23 => :protocol_enum_trunk_1,
    24 => :protocol_enum_trunk_2,
    25 => :protocol_enum_leaf_1,
    26 => :protocol_enum_leaf_2,
    27 => :protocol_enum_rdp,
    28 => :protocol_enum_irtp,
    29 => :protocol_enum_iso_tp4,
    30 => :protocol_enum_netblt,
    31 => :protocol_enum_mfe_nsp,
    32 => :protocol_enum_merit_inp,
    33 => :protocol_enum_dccp,
    34 => :protocol_enum_x_3pc,
    35 => :protocol_enum_idpr,
    36 => :protocol_enum_xtp,
    37 => :protocol_enum_ddp,
    38 => :protocol_enum_idpr_cmtp,
    39 => :protocol_enum_tp_plus_plus,
    40 => :protocol_enum_il,
    41 => :protocol_enum_ipv6,
    42 => :protocol_enum_sdrp,
    43 => :protocol_enum_ipv6_route,
    44 => :protocol_enum_ipv6_frag,
    45 => :protocol_enum_idrp,
    46 => :protocol_enum_rsvp,
    47 => :protocol_enum_gre,
    48 => :protocol_enum_dsr,
    49 => :protocol_enum_bna,
    50 => :protocol_enum_esp,
    51 => :protocol_enum_ah,
    52 => :protocol_enum_i_nlsp,
    53 => :protocol_enum_swipe,
    54 => :protocol_enum_narp,
    55 => :protocol_enum_mobile,
    56 => :protocol_enum_tlsp,
    57 => :protocol_enum_skip,
    58 => :protocol_enum_ipv6_icmp,
    59 => :protocol_enum_ipv6_nonxt,
    60 => :protocol_enum_ipv6_opts,
    61 => :protocol_enum_any_host_internal_protocol,
    62 => :protocol_enum_cftp,
    63 => :protocol_enum_any_local_network,
    64 => :protocol_enum_sat_expak,
    65 => :protocol_enum_kryptolan,
    66 => :protocol_enum_rvd,
    67 => :protocol_enum_ippc,
    68 => :protocol_enum_any_distributed_file_system,
    69 => :protocol_enum_sat_mon,
    70 => :protocol_enum_visa,
    71 => :protocol_enum_ipcv,
    72 => :protocol_enum_cpnx,
    73 => :protocol_enum_cphb,
    74 => :protocol_enum_wsn,
    75 => :protocol_enum_pvp,
    76 => :protocol_enum_br_sat_mon,
    77 => :protocol_enum_sun_nd,
    78 => :protocol_enum_wb_mon,
    79 => :protocol_enum_wb_expak,
    80 => :protocol_enum_iso_ip,
    81 => :protocol_enum_vmtp,
    82 => :protocol_enum_secure_vmtp,
    83 => :protocol_enum_vines,
    84 => :protocol_enum_ttp_or_iptm,
    85 => :protocol_enum_nsfnet_igp,
    86 => :protocol_enum_dgp,
    87 => :protocol_enum_tcf,
    88 => :protocol_enum_eigrp,
    89 => :protocol_enum_ospfigp,
    90 => :protocol_enum_sprite_rpc,
    91 => :protocol_enum_larp,
    92 => :protocol_enum_mtp,
    93 => :protocol_enum_ax_25,
    94 => :protocol_enum_ipip,
    95 => :protocol_enum_micp,
    96 => :protocol_enum_scc_sp,
    97 => :protocol_enum_etherip,
    98 => :protocol_enum_encap,
    99 => :protocol_enum_any_private_encryption_scheme,
    100 => :protocol_enum_gmtp,
    101 => :protocol_enum_ifmp,
    102 => :protocol_enum_pnni,
    103 => :protocol_enum_pim,
    104 => :protocol_enum_aris,
    105 => :protocol_enum_scps,
    106 => :protocol_enum_qnx,
    107 => :protocol_enum_a_n,
    108 => :protocol_enum_ipcomp,
    109 => :protocol_enum_snp,
    110 => :protocol_enum_compaq_peer,
    111 => :protocol_enum_ipx_in_ip,
    112 => :protocol_enum_vrrp,
    113 => :protocol_enum_pgm,
    114 => :protocol_enum_any_0_hop,
    115 => :protocol_enum_l2tp,
    116 => :protocol_enum_ddx,
    117 => :protocol_enum_iatp,
    118 => :protocol_enum_stp,
    119 => :protocol_enum_srp,
    120 => :protocol_enum_uti,
    121 => :protocol_enum_smp,
    122 => :protocol_enum_sm,
    123 => :protocol_enum_ptp,
    124 => :protocol_enum_isis_over_ipv4,
    125 => :protocol_enum_fire,
    126 => :protocol_enum_crtp,
    127 => :protocol_enum_crudp,
    128 => :protocol_enum_sscopmce,
    129 => :protocol_enum_iplt,
    130 => :protocol_enum_sps,
    131 => :protocol_enum_pipe,
    132 => :protocol_enum_sctp,
    133 => :protocol_enum_fc,
    134 => :protocol_enum_rsvp_e2e_ignore,
    135 => :protocol_enum_mobility_header,
    136 => :protocol_enum_udplite,
    137 => :protocol_enum_mpls_in_ip,
    138 => :protocol_enum_manet,
    139 => :protocol_enum_hip,
    140 => :protocol_enum_shim6,
    141 => :protocol_enum_wesp,
    142 => :protocol_enum_rohc,
    255 => :protocol_enum_reserved_255,
  }
  I__PROTOCOL_ENUM = PROTOCOL_ENUM.invert
  def initialize(_io, _parent = nil, _root = self, protocol_num)
    super(_io, _parent, _root)
    @protocol_num = protocol_num
    _read
  end

  def _read
    case protocol
    when :protocol_enum_tcp
      @body = TcpSegment.new(@_io)
    when :protocol_enum_ipv6_nonxt
      @body = NoNextHeader.new(@_io, self, @_root)
    when :protocol_enum_icmp
      @body = IcmpPacket.new(@_io)
    when :protocol_enum_udp
      @body = UdpDatagram.new(@_io)
    when :protocol_enum_hopopt
      @body = OptionHopByHop.new(@_io, self, @_root)
    when :protocol_enum_ipv6
      @body = Ipv6Packet.new(@_io)
    when :protocol_enum_ipv4
      @body = Ipv4Packet.new(@_io)
    end
    self
  end

  ##
  # Dummy type for IPv6 "no next header" type, which signifies end of headers chain.
  class NoNextHeader < Kaitai::Struct::Struct
    def initialize(_io, _parent = nil, _root = self)
      super(_io, _parent, _root)
      _read
    end

    def _read
      self
    end
  end
  class OptionHopByHop < Kaitai::Struct::Struct
    def initialize(_io, _parent = nil, _root = self)
      super(_io, _parent, _root)
      _read
    end

    def _read
      @next_header_type = @_io.read_u1
      @hdr_ext_len = @_io.read_u1
      @body = @_io.read_bytes((hdr_ext_len - 1))
      @next_header = ProtocolBody.new(@_io, next_header_type)
      self
    end
    attr_reader :next_header_type
    attr_reader :hdr_ext_len
    attr_reader :body
    attr_reader :next_header
  end
  def protocol
    return @protocol unless @protocol.nil?
    @protocol = Kaitai::Struct::Stream::resolve_enum(PROTOCOL_ENUM, protocol_num)
    @protocol
  end
  attr_reader :body

  ##
  # Protocol number as an integer.
  attr_reader :protocol_num
end