NAME

Net::WDNS - Perl extension for the wdns low-level DNS library

SYNOPSIS

# The primary interface to libwdns is through Net::WDNS::Msg objects:

use Net::WDNS qw(:func);

for my $pkt (@pkt_source) {
  my $msg = parse_message($pkt); # same as Net::WDNS::Msg->new($pkt)
  print $msg->as_str, "\n" if $msg->flags->{aa}; # or print "$msg\n"
}

DESCRIPTION

Net::WDNS is a perl binding to libwdns, the low-level DNS library. The library is designed to parse, examine, and render raw DNS packets.

Net::WDNS exports functions and constants from libwdns. Typically interactions with the library will be through the parse_message() function and, subsequently, Net::Nmsg::Msg objects. The rest of the functions exported here are provided for development purposes.

EXPORTED CONSTANTS AND FUNCTIONS

Functions and constants are individually exportable. To export everything, use ':all'. When functions describe dealing with "raw" formats, it means formatted for over the wire. The following tag groups are also available:

Tag group :func

parse_message($pkt)

message_to_str($raw_msg)

Convert a raw message type to a human-readable string.

domain_to_str($raw_domain)

Convert a raw domain name to a human-readable string.

opcode_to_str($int)

Convert a numeric opcode to a descriptive string.

rcode_to_str($int)

Convert a numeric rcode to a descriptive string.

str_to_rcode($str)

Convert a string description of an rcode to its numeric equivalent.

rrclass_to_str($int)

Convert a numeric rrclass to a descriptive string.

str_to_rrclass($str)

Convert a string description of rrclass to its numeric equivalent.

rrtype_to_str($int)

Convert a numeric rrtype to a descriptive string. See also str_to_rrtype().

rdata_to_str($raw_rdata, $rrtype, $rrclass)

Convert a raw rdata type to a human-readable string.

str_to_rdata($str, $rrtype, $rrclass)

Convert a string representation of an rdata type to raw format.

str_to_rrtype($str)

Convert a string to a raw rrtype. See also rrtype_to_str().

str_to_name($str)

Convert a string to a raw domain. See also domain_to_str().

str_to_name_case($str)

Convert a string to a raw domain, preserving case.

len_name($raw_domain)

Return the length of a raw (uncompressed wire format) domain name.

reverse_name($raw_domain)

Return a reversed raw domain.

left_chop($raw_domain)

Return a raw domain with the leftmost domain component (label) removed.

count_labels($raw_domain)

Return the number of components in a raw domain.

is_subdomain($raw_domain1, $raw_domain2)

Return whether or not the first raw domain is a sub-domain of the second.

clear_message($raw_msg)

Free the memory assosciated with the raw msg. This normally happens during the DESTROY() call to a Net::WDNS::Msg object.

get_id($raw_msg)

Return the numeric id of a raw msg.

get_flags($raw_msg)

Return the bit-encoded flags of a raw msg.

get_rcode($raw_msg)

Return the numeric rcode of a raw msg.

get_opcode($raw_msg)

Return the numeric opcode of a raw msg.

get_section($raw_msg)

Return the section (0-3) of a raw msg as an array of blessed objects (Net::Nmsg::Question or Net::Nmsg::RR)

Tag group :const

WDNS_LEN_HEADER
WDNS_MAXLEN_NAME

WDNS_MSG_SEC_QUESTION
WDNS_MSG_SEC_ANSWER
WDNS_MSG_SEC_AUTHORITY
WDNS_MSG_SEC_ADDITIONAL
WDNS_MSG_SEC_MAX

WDNS_PRESLEN_NAME
WDNS_PRESLEN_TYPE_A
WDNS_PRESLEN_TYPE_AAAA

WDNS_OP_QUERY
WDNS_OP_IQUERY
WDNS_OP_STATUS
WDNS_OP_NOTIFY
WDNS_OP_UPDATE

WDNS_R_NOERROR
WDNS_R_FORMERR
WDNS_R_SERVFAIL
WDNS_R_NXDOMAIN
WDNS_R_NOTIMP
WDNS_R_REFUSED
WDNS_R_YXDOMAIN
WDNS_R_YXRRSET
WDNS_R_NXRRSET
WDNS_R_NOTAUTH
WDNS_R_NOTZONE
WDNS_R_BADVERS

WDNS_CLASS_IN
WDNS_CLASS_CH
WDNS_CLASS_HS
WDNS_CLASS_NONE
WDNS_CLASS_ANY

WDNS_TYPE_A
WDNS_TYPE_NS
WDNS_TYPE_MD
WDNS_TYPE_MF
WDNS_TYPE_CNAME
WDNS_TYPE_SOA
WDNS_TYPE_MB
WDNS_TYPE_MG
WDNS_TYPE_MR
WDNS_TYPE_NULL
WDNS_TYPE_WKS
WDNS_TYPE_PTR
WDNS_TYPE_HINFO
WDNS_TYPE_MINFO
WDNS_TYPE_MX
WDNS_TYPE_TXT
WDNS_TYPE_RP
WDNS_TYPE_AFSDB
WDNS_TYPE_X25
WDNS_TYPE_ISDN
WDNS_TYPE_RT
WDNS_TYPE_NSAP
WDNS_TYPE_NSAP_PTR
WDNS_TYPE_SIG
WDNS_TYPE_KEY
WDNS_TYPE_PX
WDNS_TYPE_GPOS
WDNS_TYPE_AAAA
WDNS_TYPE_LOC
WDNS_TYPE_NXT
WDNS_TYPE_EID
WDNS_TYPE_NIMLOC
WDNS_TYPE_SRV
WDNS_TYPE_ATMA
WDNS_TYPE_NAPTR
WDNS_TYPE_KX
WDNS_TYPE_CERT
WDNS_TYPE_A6
WDNS_TYPE_DNAME
WDNS_TYPE_SINK
WDNS_TYPE_OPT
WDNS_TYPE_APL
WDNS_TYPE_DS
WDNS_TYPE_SSHFP
WDNS_TYPE_IPSECKEY
WDNS_TYPE_RRSIG
WDNS_TYPE_NSEC
WDNS_TYPE_DNSKEY
WDNS_TYPE_DHCID
WDNS_TYPE_NSEC3
WDNS_TYPE_NSEC3PARAM
WDNS_TYPE_HIP
WDNS_TYPE_NINFO
WDNS_TYPE_RKEY
WDNS_TYPE_TALINK
WDNS_TYPE_CDS
WDNS_TYPE_SPF
WDNS_TYPE_TKEY
WDNS_TYPE_TSIG
WDNS_TYPE_IXFR
WDNS_TYPE_AXFR
WDNS_TYPE_MAILB
WDNS_TYPE_MAILA
WDNS_TYPE_ANY
WDNS_TYPE_URI
WDNS_TYPE_CAA
WDNS_TYPE_TA
WDNS_TYPE_DLV

SEE ALSO

Net::WDNS::Msg, Net::WDNS::Question, Net::WDNS::RD, Net::WDNS::RR, Net::Nmsg

The wdns library can be downloaded from: https://github.com/farsightsec/wdns

AUTHOR

Matthew Sisk, <sisk@cert.org>

COPYRIGHT AND LICENSE

Copyright (C) 2015-2016 by Carnegie Mellon University

This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License, as published by the Free Software Foundation, under the terms pursuant to Version 2, June 1991.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.