NAME

Net::Frame::Layer::DNS - Domain Name System layer object

SYNOPSIS

   use Net::Frame::Simple;
   use Net::Frame::Layer::DNS qw(:consts);

   my $dns = Net::Frame::Layer::DNS->new(
      id      => getRandom16bitsInt(),
      qr      => NF_DNS_QR_QUERY,
      opcode  => NF_DNS_OPCODE_QUERY,
      flags   => NF_DNS_FLAGS_RD,
      rcode   => NF_DNS_RCODE_NOERROR,
      qdCount => 1,
      anCount => 0,
      nsCount => 0,
      arCount => 0,
   );

   #
   # Read a raw layer
   #

   my $layer = Net::Frame::Layer::DNS->new(raw => $raw);

   print $layer->print."\n";
   print 'PAYLOAD: '.unpack('H*', $layer->payload)."\n"
      if $layer->payload;

DESCRIPTION

This modules implements the encoding and decoding of the DNS layer.

RFC: ftp://ftp.rfc-editor.org/in-notes/rfc1035.txt

See also Net::Frame::Layer for other attributes and methods.

ATTRIBUTES

id

Identification - used to match request/reply packets.

qr

opcode

flags

rcode

Qr, opcode, flags and rcode fields. See CONSTANTS.

qdCount

Number of entries in the question list.

anCount

Number of entries in the answer resource record that were returned.

nsCount

Number of entries in the authority resource record list that were returned.

arCount

Number of entries in the additional resource record list that were returned.

The following are inherited attributes. See Net::Frame::Layer for more information.

raw

payload

nextLayer

METHODS

new

new (hash)

Object constructor. You can pass attributes that will overwrite default ones. See SYNOPSIS for default values.

getKey

getKeyReverse

These two methods are basically used to increase the speed when using recv method from Net::Frame::Simple. Usually, you write them when you need to write match method.

match (Net::Frame::Layer::DNS object)

This method is mostly used internally. You pass a Net::Frame::Layer::DNS layer as a parameter, and it returns true if this is a response corresponding for the request, or returns false if not.

The following are inherited methods. Some of them may be overriden in this layer, and some others may not be meaningful in this layer. See Net::Frame::Layer for more information.

layer

computeLengths

pack

unpack

encapsulate

getLength

getPayloadLength

print

dump

USEFUL SUBROUTINES

Load them: use Net::Frame::Layer::DNS qw(:subs);

dnsAton (domain name)

Takes domain name and returns the network form.

dnsNtoa (domain name network form)

Takes domain name in network format, and returns the domain name human form and number of bytes read. Call with:

   my ($name, $bytesRead) = dnsNtoa( ... ) # returns name, bytes read
   my ($name)             = dnsNtoa( ... ) # returns name only

CONSTANTS

Load them: use Net::Frame::Layer::DNS qw(:consts);

NF_DNS_QR_QUERY

NF_DNS_QR_RESPONSE

Query / Response flag.

NF_DNS_OPCODE_QUERY

NF_DNS_OPCODE_IQUERY

NF_DNS_OPCODE_STATUS

NF_DNS_OPCODE_NOTIFY

NF_DNS_OPCODE_UPDATE

Opcode values.

NF_DNS_FLAGS_AA

NF_DNS_FLAGS_TC

NF_DNS_FLAGS_RD

NF_DNS_FLAGS_RA

NF_DNS_FLAGS_Z

NF_DNS_FLAGS_AD

NF_DNS_FLAGS_CD

Flag values.

NF_DNS_RCODE_NOERROR

NF_DNS_RCODE_FORMATERROR

NF_DNS_RCODE_SERVERFAILURE

NF_DNS_RCODE_NAMEERROR

NF_DNS_RCODE_NOTIMPLEMENTED

NF_DNS_RCODE_REFUSED

NF_DNS_RCODE_YXDOMAIN

NF_DNS_RCODE_YXRRSET

NF_DNS_RCODE_NXRRSET

NF_DNS_RCODE_NOTAUTH

NF_DNS_RCODE_NOTZONE

RCode Values.

LIMITATIONS

While this module can decode DNS compression with pointers, it does not automatically encode compression with pointers.

RData encoder / decoders are provided for common RData types, but not all RData types. If an RData type is encountered during decoding for which a decoder is not present, the RData is simply displayed as a hex stream.

SEE ALSO

Net::Frame::Layer

For a non Net::Frame::Layer DNS solution in Perl, Net::DNS.

AUTHOR

Michael Vincent

COPYRIGHT AND LICENSE

Copyright (c) 2012, Michael Vincent

You may distribute this module under the terms of the Artistic license. See LICENSE.Artistic file in the source distribution archive.

cpanm Net::Frame::Layer::DNS

perl -MCPAN -e shell
install Net::Frame::Layer::DNS