This page hosts a formal specification of IPv4 network packet using Kaitai Struct. This specification can be automatically translated into a variety of programming languages to get a parsing library.
# This is a generated file! Please edit source .ksy file and use kaitai-struct-compiler to rebuild
use strict;
use warnings;
use IO::KaitaiStruct 0.009_000;
use ProtocolBody;
########################################################################
package Ipv4Packet;
our @ISA = 'IO::KaitaiStruct::Struct';
sub from_file {
my ($class, $filename) = @_;
my $fd;
open($fd, '<', $filename) or return undef;
binmode($fd);
return new($class, IO::KaitaiStruct::Stream->new($fd));
}
sub new {
my ($class, $_io, $_parent, $_root) = @_;
my $self = IO::KaitaiStruct::Struct->new($_io);
bless $self, $class;
$self->{_parent} = $_parent;
$self->{_root} = $_root || $self;;
$self->_read();
return $self;
}
sub _read {
my ($self) = @_;
$self->{b1} = $self->{_io}->read_u1();
$self->{b2} = $self->{_io}->read_u1();
$self->{total_length} = $self->{_io}->read_u2be();
$self->{identification} = $self->{_io}->read_u2be();
$self->{b67} = $self->{_io}->read_u2be();
$self->{ttl} = $self->{_io}->read_u1();
$self->{protocol} = $self->{_io}->read_u1();
$self->{header_checksum} = $self->{_io}->read_u2be();
$self->{src_ip_addr} = $self->{_io}->read_bytes(4);
$self->{dst_ip_addr} = $self->{_io}->read_bytes(4);
$self->{_raw_options} = $self->{_io}->read_bytes(($self->ihl_bytes() - 20));
my $io__raw_options = IO::KaitaiStruct::Stream->new($self->{_raw_options});
$self->{options} = Ipv4Packet::Ipv4Options->new($io__raw_options, $self, $self->{_root});
$self->{_raw_body} = $self->{_io}->read_bytes(($self->total_length() - $self->ihl_bytes()));
my $io__raw_body = IO::KaitaiStruct::Stream->new($self->{_raw_body});
$self->{body} = ProtocolBody->new($io__raw_body);
}
sub version {
my ($self) = @_;
return $self->{version} if ($self->{version});
$self->{version} = (($self->b1() & 240) >> 4);
return $self->{version};
}
sub ihl {
my ($self) = @_;
return $self->{ihl} if ($self->{ihl});
$self->{ihl} = ($self->b1() & 15);
return $self->{ihl};
}
sub ihl_bytes {
my ($self) = @_;
return $self->{ihl_bytes} if ($self->{ihl_bytes});
$self->{ihl_bytes} = ($self->ihl() * 4);
return $self->{ihl_bytes};
}
sub b1 {
my ($self) = @_;
return $self->{b1};
}
sub b2 {
my ($self) = @_;
return $self->{b2};
}
sub total_length {
my ($self) = @_;
return $self->{total_length};
}
sub identification {
my ($self) = @_;
return $self->{identification};
}
sub b67 {
my ($self) = @_;
return $self->{b67};
}
sub ttl {
my ($self) = @_;
return $self->{ttl};
}
sub protocol {
my ($self) = @_;
return $self->{protocol};
}
sub header_checksum {
my ($self) = @_;
return $self->{header_checksum};
}
sub src_ip_addr {
my ($self) = @_;
return $self->{src_ip_addr};
}
sub dst_ip_addr {
my ($self) = @_;
return $self->{dst_ip_addr};
}
sub options {
my ($self) = @_;
return $self->{options};
}
sub body {
my ($self) = @_;
return $self->{body};
}
sub _raw_options {
my ($self) = @_;
return $self->{_raw_options};
}
sub _raw_body {
my ($self) = @_;
return $self->{_raw_body};
}
########################################################################
package Ipv4Packet::Ipv4Options;
our @ISA = 'IO::KaitaiStruct::Struct';
sub from_file {
my ($class, $filename) = @_;
my $fd;
open($fd, '<', $filename) or return undef;
binmode($fd);
return new($class, IO::KaitaiStruct::Stream->new($fd));
}
sub new {
my ($class, $_io, $_parent, $_root) = @_;
my $self = IO::KaitaiStruct::Struct->new($_io);
bless $self, $class;
$self->{_parent} = $_parent;
$self->{_root} = $_root || $self;;
$self->_read();
return $self;
}
sub _read {
my ($self) = @_;
$self->{entries} = ();
while (!$self->{_io}->is_eof()) {
push @{$self->{entries}}, Ipv4Packet::Ipv4Option->new($self->{_io}, $self, $self->{_root});
}
}
sub entries {
my ($self) = @_;
return $self->{entries};
}
########################################################################
package Ipv4Packet::Ipv4Option;
our @ISA = 'IO::KaitaiStruct::Struct';
sub from_file {
my ($class, $filename) = @_;
my $fd;
open($fd, '<', $filename) or return undef;
binmode($fd);
return new($class, IO::KaitaiStruct::Stream->new($fd));
}
sub new {
my ($class, $_io, $_parent, $_root) = @_;
my $self = IO::KaitaiStruct::Struct->new($_io);
bless $self, $class;
$self->{_parent} = $_parent;
$self->{_root} = $_root || $self;;
$self->_read();
return $self;
}
sub _read {
my ($self) = @_;
$self->{b1} = $self->{_io}->read_u1();
$self->{len} = $self->{_io}->read_u1();
$self->{body} = $self->{_io}->read_bytes(($self->len() > 2 ? ($self->len() - 2) : 0));
}
sub copy {
my ($self) = @_;
return $self->{copy} if ($self->{copy});
$self->{copy} = (($self->b1() & 128) >> 7);
return $self->{copy};
}
sub opt_class {
my ($self) = @_;
return $self->{opt_class} if ($self->{opt_class});
$self->{opt_class} = (($self->b1() & 96) >> 5);
return $self->{opt_class};
}
sub number {
my ($self) = @_;
return $self->{number} if ($self->{number});
$self->{number} = ($self->b1() & 31);
return $self->{number};
}
sub b1 {
my ($self) = @_;
return $self->{b1};
}
sub len {
my ($self) = @_;
return $self->{len};
}
sub body {
my ($self) = @_;
return $self->{body};
}
1;