DNS::LDNS(3)

NAME
DNS::LDNS - Perl extension for the ldns library

SYNOPSIS
  use DNS::LDNS ':all'

DESCRIPTION
DNS::LDNS is a perl OO-wrapper for the ldns library. A complete list of object methods is found in the perldoc for each of the individual classes. You may also read the documentation of the ldns library (http://www.nlnetlabs.nl/projects/ldns).

  Brief examples of usage
  use DNS::LDNS ':all';

  my $z = new DNS::LDNS::Zone(filename => '/path/to/myzone');
  print DNS::LDNS::last_error;
  my $rr = new DNS::LDNS::RR('mylabel 3600 IN A 168.10.10.10');
  print $z->soa->to_string;
  my $rrlist = $z->rrs->push($rr);
  print $z->to_string;

  my $kl = new DNS::LDNS::KeyList;
  $kl->push(new DNS::LDNS::Key(filename => 'key');
  $kl->key(0)->set_pubkey_owner(
      new DNS::LDNS::RData(LDNS_RDF_TYPE_DNAME, 'myzone.org'));
  my $signedz = $z->sign($kl);
  print $signedz->to_string;

  my $r = new DNS::LDNS::Resolver(filename => '/my/resolv.conf');
  my $p = $r->send(
    new DNS::LDNS::RData(LDNS_RDF_TYPE_DNAME, 'www.google.com'),
    LDNS_RR_TYPE_A, LDNS_RR_CLASS_IN, LDNS_RD);
  print $p->answer->to_string;
  print $p->authority->to_string;

  Classes
A description of the classes included and how they map to the ldns library structures:

DNS::LDNS
    Base class with static functions and constants

DNS::LDNS::Zone
    Represents a parsed zonefile (maps to the ldns_zone struct)

DNS::LDNS::RRList
    Represents a list of RRs. This class is also used to represent an RRSet all the dnames and types are equal, (maps to the the ldns_rr_list struct)

DNS::LDNS::RR
    Represents a resource record (RR), (maps to the ldns_rr struct)

DNS::LDNS::RData
    Represents an rdata field or a dname in an RR (maps to the ldns_rdf struct)

DNS::LDNS::Resolver
    Represents a DNS resolver (maps to the ldns_resolver struct)

DNS::LDNS::Packet
    Represents a DNS package (maps to the ldns_pkt struct)

DNS::LDNS::Key
    Represents a DNSSec private key (maps to the ldns_key struct)

DNS::LDNS::KeyList
    Represents a linked list of keys (maps to the ldns_key_list struct)

DNS::LDNS::DNSSecZone
    Represents a zone with dnssec data (maps to the ldns_dnssec_zone struct)

DNS::LDNS::RBTree
    Represents a tree of DNSSecName nodes (maps to the ldns_rbtree struct)

DNS::LDNS::RBNode
    Represents a node in the RBTree (maps to the ldns_rbnode struct)

DNS::LDNS::DNSSecName
    Represents a dname in a DNSSecZone and holds a DNSSecRRSets list for this dname, possibly with signatures (maps to the ldns_dnssec_name struct)

DNS::LDNS::DNSSecRRSets
    Represents a linked list of DNSSec RR sets, possibly with signatures (maps to the ldns_dnssec_rrsets struct)

DNS::LDNS::DNSSecRRs
    Represents a linked list of RRs (maps to the ldns_dnssec_rrs struct)

DNS::LDNS::DNSSecDataChain
    Represents a chain of RR, DNSKEY, and DS data used for building a dnssec trust tree (maps to the ldns_dnssec_data_chain struct)

DNS::LDNS::DNSSecTrustTree
    Represents a tree of chained trust relationships from a signed RR to a set of trust anchors (maps to the ldns_dnssec_trust_tree struct).

DNS::LDNS::GC
    Garbage collector. Handles ownership dependencies and freeing data used by the other classes. Used internally only.

One thing to note is that some of the classes have a seemingly overlapping functionality. The Zone and RRList are used to represent a generic zone. It may contain dnssec data but treats it like any other dns data and does not have any knowledge of its structure. The DNSSec* and RB* classes are building blocks for representing a signed zone in a more structured way.

  Static functions
  str = rr_type2str(type)
  str = rr_class2str(class)
  type = rr_type_by_name(str)
  class = rr_class_by_name(str)
  str = pkt_opcode2str(opcode)
  str = pkt_rcode2str(rcode)
  error = errorstr_by_id(status)
  str = DNS::LDNS::last_error
  status = DNS::LDNS::last_status
  rr = dnssec_create_nsec(from, to, type)
  rr = dnssec_create_nsec3(from, to, algorithm, flags, iterations, salt)
  rr = create_nsec(current, next, rrs)
  rr = create_nsec3(cur_owner, cur_zone, algorithm, flags,
                    iterations, salt, empty_nonterminals)
  algo = signing_algorithm_by_name(name)
  bool = key_algorithm_supported(algorithm)
  rr = read_anchor_file(filename)

  Object references and cloning
Since some of the objects are found as sub objects within other objects, it is important to know how the wrapper classes handle object references, dependencies and cloning. The general rule is that accessor methods just return a reference to the object while methods inserting data inserts inserts a clone of the object. Most classes have a clone method which can be used if a cloned object is what you really want.

Examples

DNS::LDNS::Zone::rrs returns a reference to the DNS::LDNS::RRList within the zone, so if you make changes to the RRList you also changes the Zone object.

DNS::LDNS::RRList::push(rr) clones the rr, then pushes the cloned rr to the list. Changing the rr afterwards will not change the list.

An exception is the Key class which does not have a clone mechanism. In this case we allow a free Key to be added to only one KeyList. Adding it to multiple lists will provoke an error.

The wrapper keeps track of allocated data structures and references. Whenever data is no longer referred to by a perl object, it will be freed.

  ERROR HANDLING
The purpose for writing this wrapper class has been to be able to process zone file data with good time performance. Data checking and error handling is a bit sparse. Calling a method with wrong argument types will some times kill the application with an intelligible error message, in other cases it may provoke a segmentation fault. Using out-of-range data values, e.g. in array indexes, may also cause unexpected results.

Most constructors and all methods returning a status will update the static DNS::LDNS::last_status variable. Most methods do not return a status and will not reset this variable even though they succeeds.

  EXPORT
None by default.

  Exportable constants
Status

  LDNS_STATUS_ADDRESS_ERR
  LDNS_STATUS_CERT_BAD_ALGORITHM
  LDNS_STATUS_CRYPTO_ALGO_NOT_IMPL
  LDNS_STATUS_CRYPTO_BOGUS
  LDNS_STATUS_CRYPTO_EXPIRATION_BEFORE_INCEPTION
  LDNS_STATUS_CRYPTO_NO_DNSKEY
  LDNS_STATUS_CRYPTO_NO_DS
  LDNS_STATUS_CRYPTO_NO_MATCHING_KEYTAG_DNSKEY
  LDNS_STATUS_CRYPTO_NO_RRSIG
  LDNS_STATUS_CRYPTO_NO_TRUSTED_DNSKEY
  LDNS_STATUS_CRYPTO_NO_TRUSTED_DS
  LDNS_STATUS_CRYPTO_SIG_EXPIRED
  LDNS_STATUS_CRYPTO_SIG_NOT_INCEPTED
  LDNS_STATUS_CRYPTO_TSIG_BOGUS
  LDNS_STATUS_CRYPTO_TSIG_ERR
  LDNS_STATUS_CRYPTO_TYPE_COVERED_ERR
  LDNS_STATUS_CRYPTO_UNKNOWN_ALGO
  LDNS_STATUS_CRYPTO_VALIDATED
  LDNS_STATUS_DDD_OVERFLOW
  LDNS_STATUS_DNSSEC_EXISTENCE_DENIED
  LDNS_STATUS_DNSSEC_NSEC3_ORIGINAL_NOT_FOUND
  LDNS_STATUS_DNSSEC_NSEC_RR_NOT_COVERED
  LDNS_STATUS_DNSSEC_NSEC_WILDCARD_NOT_COVERED
  LDNS_STATUS_DOMAINNAME_OVERFLOW
  LDNS_STATUS_DOMAINNAME_UNDERFLOW
  LDNS_STATUS_EMPTY_LABEL
  LDNS_STATUS_ENGINE_KEY_NOT_LOADED
  LDNS_STATUS_ERR
  LDNS_STATUS_FILE_ERR
  LDNS_STATUS_INTERNAL_ERR
  LDNS_STATUS_INVALID_B32_EXT
  LDNS_STATUS_INVALID_B64
  LDNS_STATUS_INVALID_HEX
  LDNS_STATUS_INVALID_INT
  LDNS_STATUS_INVALID_IP4
  LDNS_STATUS_INVALID_IP6
  LDNS_STATUS_INVALID_POINTER
  LDNS_STATUS_INVALID_STR
  LDNS_STATUS_INVALID_TIME
  LDNS_STATUS_LABEL_OVERFLOW
  LDNS_STATUS_MEM_ERR
  LDNS_STATUS_MISSING_RDATA_FIELDS_KEY
  LDNS_STATUS_MISSING_RDATA_FIELDS_RRSIG
  LDNS_STATUS_NETWORK_ERR
  LDNS_STATUS_NOT_IMPL
  LDNS_STATUS_NO_DATA
  LDNS_STATUS_NSEC3_ERR
  LDNS_STATUS_NULL
  LDNS_STATUS_OK
  LDNS_STATUS_PACKET_OVERFLOW
  LDNS_STATUS_RES_NO_NS
  LDNS_STATUS_RES_QUERY
  LDNS_STATUS_SOCKET_ERROR
  LDNS_STATUS_SSL_ERR
  LDNS_STATUS_SYNTAX_ALG_ERR
  LDNS_STATUS_SYNTAX_BAD_ESCAPE
  LDNS_STATUS_SYNTAX_CLASS_ERR
  LDNS_STATUS_SYNTAX_DNAME_ERR
  LDNS_STATUS_SYNTAX_EMPTY
  LDNS_STATUS_SYNTAX_ERR
  LDNS_STATUS_SYNTAX_INCLUDE
  LDNS_STATUS_SYNTAX_INCLUDE_ERR_NOTIMPL
  LDNS_STATUS_SYNTAX_INTEGER_OVERFLOW
  LDNS_STATUS_SYNTAX_ITERATIONS_OVERFLOW
  LDNS_STATUS_SYNTAX_KEYWORD_ERR
  LDNS_STATUS_SYNTAX_MISSING_VALUE_ERR
  LDNS_STATUS_SYNTAX_ORIGIN
  LDNS_STATUS_SYNTAX_RDATA_ERR
  LDNS_STATUS_SYNTAX_TTL
  LDNS_STATUS_SYNTAX_TTL_ERR
  LDNS_STATUS_SYNTAX_TYPE_ERR
  LDNS_STATUS_SYNTAX_VERSION_ERR
  LDNS_STATUS_UNKNOWN_INET
  LDNS_STATUS_WIRE_INCOMPLETE_ADDITIONAL
  LDNS_STATUS_WIRE_INCOMPLETE_ANSWER
  LDNS_STATUS_WIRE_INCOMPLETE_AUTHORITY
  LDNS_STATUS_WIRE_INCOMPLETE_HEADER
  LDNS_STATUS_WIRE_INCOMPLETE_QUESTION

Resolver flags and constants

  LDNS_RESOLV_ANCHOR
  LDNS_RESOLV_DEFDOMAIN
  LDNS_RESOLV_INET
  LDNS_RESOLV_INET6
  LDNS_RESOLV_INETANY
  LDNS_RESOLV_KEYWORD
  LDNS_RESOLV_KEYWORDS
  LDNS_RESOLV_NAMESERVER
  LDNS_RESOLV_OPTIONS
  LDNS_RESOLV_RTT_INF
  LDNS_RESOLV_RTT_MIN
  LDNS_RESOLV_SEARCH
  LDNS_RESOLV_SORTLIST

Resolver query flags

  LDNS_AA
  LDNS_AD
  LDNS_CD
  LDNS_QR
  LDNS_RA
  LDNS_RD
  LDNS_TC

Resolver rcodes

  LDNS_RCODE_FORMERR
  LDNS_RCODE_NOERROR
  LDNS_RCODE_NOTAUTH
  LDNS_RCODE_NOTIMPL
  LDNS_RCODE_NOTZONE
  LDNS_RCODE_NXDOMAIN
  LDNS_RCODE_NXRRSET
  LDNS_RCODE_REFUSED
  LDNS_RCODE_SERVFAIL
  LDNS_RCODE_YXDOMAIN
  LDNS_RCODE_YXRRSET

Packet types

  LDNS_PACKET_ANSWER
  LDNS_PACKET_NODATA
  LDNS_PACKET_NXDOMAIN
  LDNS_PACKET_QUESTION
  LDNS_PACKET_REFERRAL
  LDNS_PACKET_UNKNOWN

Packet opcodes

  LDNS_PACKET_IQUERY
  LDNS_PACKET_NOTIFY
  LDNS_PACKET_QUERY
  LDNS_PACKET_STATUS
  LDNS_PACKET_UPDATE

Packet sections

  LDNS_SECTION_ADDITIONAL
  LDNS_SECTION_ANSWER
  LDNS_SECTION_ANY
  LDNS_SECTION_ANY_NOQUESTION
  LDNS_SECTION_AUTHORITY
  LDNS_SECTION_QUESTION

DNSSec constants

  LDNS_DEFAULT_EXP_TIME
  LDNS_MAX_KEYLEN
  LDNS_DNSSEC_KEYPROTO

DNSSec sign policies

  LDNS_SIGNATURE_LEAVE_ADD_NEW
  LDNS_SIGNATURE_LEAVE_NO_ADD
  LDNS_SIGNATURE_REMOVE_ADD_NEW
  LDNS_SIGNATURE_REMOVE_NO_ADD
  LDNS_NSEC3_MAX_ITERATIONS

Key flags

  LDNS_KEY_REVOKE_KEY
  LDNS_KEY_SEP_KEY
  LDNS_KEY_ZONE_KEY

Key algorithms

  LDNS_DH
  LDNS_DSA
  LDNS_DSA_NSEC3
  LDNS_ECC
  LDNS_RSAMD5
  LDNS_RSASHA1
  LDNS_RSASHA1_NSEC3
  LDNS_RSASHA256
  LDNS_RSASHA512
  LDNS_ECC_GOST
  LDNS_PRIVATEDNS
  LDNS_PRIVATEOID

Signing algorithms

  LDNS_SIGN_DSA
  LDNS_SIGN_DSA_NSEC3
  LDNS_SIGN_ECC_GOST
  LDNS_SIGN_HMACSHA1
  LDNS_SIGN_HMACSHA256
  LDNS_SIGN_RSAMD5
  LDNS_SIGN_RSASHA1
  LDNS_SIGN_RSASHA1_NSEC3
  LDNS_SIGN_RSASHA256
  LDNS_SIGN_RSASHA512

Hashing algorithm

  LDNS_SHA1
  LDNS_SHA256
  LDNS_HASH_GOST

Rdata constants

  LDNS_MAX_RDFLEN
  LDNS_NSEC3_VARS_OPTOUT_MASK

  LDNS_RDF_SIZE_16BYTES
  LDNS_RDF_SIZE_6BYTES
  LDNS_RDF_SIZE_BYTE
  LDNS_RDF_SIZE_DOUBLEWORD
  LDNS_RDF_SIZE_WORD

Rdata types

  LDNS_RDF_TYPE_A
  LDNS_RDF_TYPE_AAAA
  LDNS_RDF_TYPE_ALG
  LDNS_RDF_TYPE_APL
  LDNS_RDF_TYPE_ATMA
  LDNS_RDF_TYPE_B32_EXT
  LDNS_RDF_TYPE_B64
  LDNS_RDF_TYPE_CERT_ALG
  LDNS_RDF_TYPE_CLASS
  LDNS_RDF_TYPE_DNAME
  LDNS_RDF_TYPE_HEX
  LDNS_RDF_TYPE_INT16
  LDNS_RDF_TYPE_INT16_DATA
  LDNS_RDF_TYPE_INT32
  LDNS_RDF_TYPE_INT8
  LDNS_RDF_TYPE_IPSECKEY
  LDNS_RDF_TYPE_LOC
  LDNS_RDF_TYPE_NONE
  LDNS_RDF_TYPE_NSAP
  LDNS_RDF_TYPE_NSEC
  LDNS_RDF_TYPE_NSEC3_NEXT_OWNER
  LDNS_RDF_TYPE_NSEC3_SALT
  LDNS_RDF_TYPE_PERIOD
  LDNS_RDF_TYPE_SERVICE
  LDNS_RDF_TYPE_STR
  LDNS_RDF_TYPE_TIME
  LDNS_RDF_TYPE_HIP
  LDNS_RDF_TYPE_TSIGTIME
  LDNS_RDF_TYPE_TYPE
  LDNS_RDF_TYPE_UNKNOWN
  LDNS_RDF_TYPE_WKS

Algorithms used in CERT RRs.

  LDNS_CERT_ACPKIX
  LDNS_CERT_IACPKIX
  LDNS_CERT_IPGP
  LDNS_CERT_IPKIX
  LDNS_CERT_ISPKI
  LDNS_CERT_OID
  LDNS_CERT_PGP
  LDNS_CERT_PKIX
  LDNS_CERT_SPKI
  LDNS_CERT_URI

RR compress flag

  LDNS_RR_COMPRESS
  LDNS_RR_NO_COMPRESS

RR classes

  LDNS_RR_CLASS_ANY
  LDNS_RR_CLASS_CH
  LDNS_RR_CLASS_COUNT
  LDNS_RR_CLASS_FIRST
  LDNS_RR_CLASS_HS
  LDNS_RR_CLASS_IN
  LDNS_RR_CLASS_LAST
  LDNS_RR_CLASS_NONE

RR types

  LDNS_RR_TYPE_A
  LDNS_RR_TYPE_A6
  LDNS_RR_TYPE_AAAA
  LDNS_RR_TYPE_AFSDB
  LDNS_RR_TYPE_ANY
  LDNS_RR_TYPE_APL
  LDNS_RR_TYPE_ATMA
  LDNS_RR_TYPE_AXFR
  LDNS_RR_TYPE_CERT
  LDNS_RR_TYPE_CNAME
  LDNS_RR_TYPE_COUNT
  LDNS_RR_TYPE_DHCID
  LDNS_RR_TYPE_DLV
  LDNS_RR_TYPE_DNAME
  LDNS_RR_TYPE_DNSKEY
  LDNS_RR_TYPE_DS
  LDNS_RR_TYPE_EID
  LDNS_RR_TYPE_FIRST
  LDNS_RR_TYPE_GID
  LDNS_RR_TYPE_GPOS
  LDNS_RR_TYPE_HINFO
  LDNS_RR_TYPE_IPSECKEY
  LDNS_RR_TYPE_ISDN
  LDNS_RR_TYPE_IXFR
  LDNS_RR_TYPE_KEY
  LDNS_RR_TYPE_KX
  LDNS_RR_TYPE_LAST
  LDNS_RR_TYPE_LOC
  LDNS_RR_TYPE_MAILA
  LDNS_RR_TYPE_MAILB
  LDNS_RR_TYPE_MB
  LDNS_RR_TYPE_MD
  LDNS_RR_TYPE_MF
  LDNS_RR_TYPE_MG
  LDNS_RR_TYPE_MINFO
  LDNS_RR_TYPE_MR
  LDNS_RR_TYPE_MX
  LDNS_RR_TYPE_NAPTR
  LDNS_RR_TYPE_NIMLOC
  LDNS_RR_TYPE_NS
  LDNS_RR_TYPE_NSAP
  LDNS_RR_TYPE_NSAP_PTR
  LDNS_RR_TYPE_NSEC
  LDNS_RR_TYPE_NSEC3
  LDNS_RR_TYPE_NSEC3PARAM
  LDNS_RR_TYPE_NSEC3PARAMS
  LDNS_RR_TYPE_NULL
  LDNS_RR_TYPE_NXT
  LDNS_RR_TYPE_OPT
  LDNS_RR_TYPE_PTR
  LDNS_RR_TYPE_PX
  LDNS_RR_TYPE_RP
  LDNS_RR_TYPE_RRSIG
  LDNS_RR_TYPE_RT
  LDNS_RR_TYPE_SIG
  LDNS_RR_TYPE_SINK
  LDNS_RR_TYPE_SOA
  LDNS_RR_TYPE_SPF
  LDNS_RR_TYPE_SRV
  LDNS_RR_TYPE_SSHFP
  LDNS_RR_TYPE_TALINK
  LDNS_RR_TYPE_TSIG
  LDNS_RR_TYPE_TXT
  LDNS_RR_TYPE_UID
  LDNS_RR_TYPE_UINFO
  LDNS_RR_TYPE_UNSPEC
  LDNS_RR_TYPE_WKS
  LDNS_RR_TYPE_X25

Various defaults and other constants

  LDNS_DEFAULT_TTL
  LDNS_PORT
  LDNS_IP4ADDRLEN
  LDNS_IP6ADDRLEN
  LDNS_MAX_DOMAINLEN
  LDNS_MAX_LABELLEN
  LDNS_MAX_PACKETLEN
  LDNS_MAX_POINTERS
  LDNS_RR_OVERHEAD
  LDNS_RDATA_FIELD_DESCRIPTORS_COMMON

BUGS
This package is currently in a very early stage of development. There are probably some bugs. You may also expect that method names and behaviour could still change without much considerations to backward compatibility.

SEE ALSO
http://www.nlnetlabs.nl/projects/ldns

AUTHOR
Erik Pihl Ostlyngen, <erik.ostlyngen@uninett.no>

COPYRIGHT AND LICENSE
Copyright (C) 2013 by UNINETT Norid AS

This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself, either Perl version 5.14.2 or, at your option, any later version of Perl 5 you may have available.