class PacketFu::PcapNG::SPB
Pcapng::SPB represents a Section Simple Packet
Block
(SPB
) of a pcapng file.
Pcapng::SPB Definition¶ ↑
Int32 :type Default: 0x00000003 Int32 :block_len Int32 :orig_len String :data Int32 :block_len2
Constants
- MIN_SIZE
Attributes
Public Class Methods
Source
# File lib/packetfu/pcapng/spb.rb, line 22 def initialize(args={}) @endian = set_endianness(args[:endian] || :little) init_fields(args) super(args[:type], args[:block_len], args[:orig_len], args[:data], args[:block_len2]) end
Calls superclass method
Public Instance Methods
Source
# File lib/packetfu/pcapng/spb.rb, line 30 def init_fields(args={}) args[:type] = @int32.new(args[:type] || PcapNG::SPB_TYPE.to_i) args[:block_len] = @int32.new(args[:block_len] || MIN_SIZE) args[:orig_len] = @int32.new(args[:orig_len] || 0) args[:data] = StructFu::String.new(args[:data] || '') args[:block_len2] = @int32.new(args[:block_len2] || MIN_SIZE) args end
Used by initialize to set the initial fields
Source
# File lib/packetfu/pcapng/spb.rb, line 43 def read(str_or_io) if str_or_io.respond_to? :read io = str_or_io else io = StringIO.new(force_binary(str_or_io.to_s)) end return self if io.eof? self[:type].read io.read(4) self[:block_len].read io.read(4) self[:orig_len].read io.read(4) # Take care of IDB snaplen # CAUTION: snaplen == 0 -> no capture limit if interface and interface.snaplen.to_i > 0 data_len = [self[:orig_len].to_i, interface.snaplen.to_i].min else data_len = self[:orig_len].to_i end data_pad_len = (4 - (data_len % 4)) % 4 self[:data].read io.read(data_len) io.read data_pad_len self[:block_len2].read io.read(4) unless self[:block_len].to_i == self[:block_len2].to_i raise InvalidFileError, 'Incoherency in Simple Packet Block' end self end
Source
# File lib/packetfu/pcapng/spb.rb, line 74 def to_s pad_field :data recalc_block_len to_a.map(&:to_s).join end
Return the object as a String