Net::DNS

A simple DNS resolver.

Note: If you are behind a firewall that blocks Google DNS, you will need to set DNS_TEST_HOST in your environment to pass the tests.

Example Usage

my $resolver = Net::DNS.new('8.8.8.8'); # google dns server

my @mx-ips = $resolver.lookup-mx('gmail.com');

my @all = $resolver.lookup-ips('google.com');
my @ipv4 = $resolver.lookup-ips('google.com', :inet);
my @ipv6 = $resolver.lookup-ips('google.com', :inet6);

my @dns-answers = $resolver.lookup('A', 'google.com'); # ("1.2.3.4", "5.6.7.8", ...)

Methods

• new(Str $host, $socket = IO::Socket::INET)

  Creates a new DNS resolver using the specified DNS server.

  The $socket parameter lets you inject your own socket class to use for the query (so you can do a proxy negotiation or somesuch first).

• lookup-ips(Str $name, :$inet, :$inet6)

  Looks up the specified $name, looking for A and AAAA records (only searches for A when :inet is specified, and only searches for AAAA when :inet6 is specified). Will chase down CNAME records to get you the actual IP addresses. Will return a list of A and AAAA responses.

• lookup-mx(Str $name, :$inet, :$inet6)

  Does a lookup for MX records, and then internally calls lookup-ips to find the actual addresses for the mailservers. Returns a list of A and AAAA records, in MX priority order.

• lookup(Str $type, Str $name)

  Looks up the specified type. Returns a list of response classes, specified below. A failed lookup returns an empty list.

Supported DNS Types

The return of a lookup is a list of classes. Which class depends on the request type.

The object returned will stringify to something useful, and will also provide attributes to access each piece of information that was returned.

Note that all of these classes also have a @.owner-name attribute. Normally this is the same as the domain name you did the lookup on.

• A

  Returns a class with attribute @.octets, which will have 4 elements.

  Stringifies to an ip address ("192.168.0.1")

• AAAA

  Returns a class with attribute @.octets, which will have 16 elements.

  Stringifies to an ipv6 address ("2607:f8b0:…")

• CNAME

  Returns a class with attribute @.name, which is a domain name split on '.'. To get the full domain name, call $object.name.join('.');

  Stringifies to a domain name.

• MX

  Returns a class with attributes $.priority, @.name.

  Stringifies to a domain name.

• NS

  Returns a class with attribute @.name

  Stringifies to a domain name.

• PTR

  Returns a class with attribute @.name

  Stringifies to a domain name.

• RRSIG

  Returns a class with attributes $.type-covered, $.algorithm, $.labels, $.original-ttl, $.signature-expiration, $.signature-inception, $.key-tag, $.signer-name, and $.signature.

  Stringifies to a a string with similar output to the output produced by the dig command line utility.

  Note that this module does not validate the validity of a DNSSEC signature.

• SRV

  Returns a class with the attributes $.priority, $.weight, $.port, @.name.

  Stringifies to "the.server:port".

• SPF

  Returns a class with the attribute $.text

  Stringifies to the text

• TXT

  Returns a class with the attribute $.text

  Stringifies to the text

• SOA

  Returns a class with the attributes @.mname, @.rname, $.serial, $.refresh, $.retry, $.expire, $.minimum

  Stringifies to a format similar to nslookup

• AXFR

  Zone transfer request.

  This is a special case - it returns a list of the above objects instead of it's own response type.

Exceptions

DNS Server errors will produce a Failure response on lookup(), lookup-ips(), and lookup-mx() with an X::Net::DNS object.

• server-message

  A complete Net::DNS::Message structured response from the server.

• rcode-value

  Return code Integer received from the DNS server.

• rcode-name

  Return code name received from the DNS server. Common values are SERVFAIL and NXDOMAIN.

• message

  A short english message which might be shown to users.