NAME

       Net::DNS::Resolver::Unbound - Net::DNS resolver based on libunbound

SYNOPSIS

           use Net::DNS;
           use Net::DNS::Resolver::Unbound;
           my $resolver = Net::DNS::Resolver::Unbound->new(...);
           my $response = $resolver->send(...);

DESCRIPTION

       Net::DNS::Resolver::Unbound is designed as an extension to an existing Net::DNS
       installation which facilitates DNS(SEC) name resolution using the libunbound library
       developed by NLnet Labs.

       Net::DNS::Resolver::Unbound replaces the resolver send() and bgsend() functionality in the
       Net::DNS::Resolver::Base implementation.

       As of this writing, the implementation has some significant limitations:

       •  Selection of transport protocol and associated parameters is entirely at the discretion
          of Unbound.

       •  There is no provision for specifying DNS header flags or EDNS options in outbound
          packets.

       •  It is not possible to send a pre-constructed packet to a nameserver.  A best-effort
          attempt is made instead using (qname,qtype,qclass) extracted from the presented packet.

METHODS

   new
           my $resolver = Net::DNS::Resolver::Unbound->new(
               debug_level => 2,
               defnames    => 1,
               dnsrch,     => 1,
               domain      => 'domain',
               ndots       => 1,
               searchlist  => ['domain' ... ],
               nameservers => [ ... ],
               option => ['logfile', 'mylog.txt'] );

       Returns a new Net::DNS::Resolver::Unbound resolver object.

   nameservers
           my $stub_resolver = Net::DNS::Resolver::Unbound->new(
               nameservers => [ '127.0.0.53' ]
               );

           my $fully_recursive = Net::DNS::Resolver::Unbound->new(
               nameservers => []               # override /etc/resolv.conf
               );

           my $dnssec_resolver = Net::DNS::Resolver::Unbound->new(
               nameservers => [],
               add_ta_file => '/var/lib/unbound/root.key'
               );

           my @nameservers = $stub_resolver->nameservers;

       By default, DNS queries are sent to the IP addresses listed in /etc/resolv.conf or similar
       platform-specific sources.

   search, query, send, bgsend, bgbusy, bgread
       See Net::DNS::Resolver.

   option
           $filename = $resolver->option( 'logfile' );
           $resolver->option( 'logfile', $filename );

       Get or set Unbound resolver (name,value) context options.

   config
           $resolver->config( 'Unbound.cfg' );

       This is a power-users interface that lets you specify all sorts of Unbound configuration
       options.

   set_fwd
           $resolver->set_fwd( 'IP address' );

       Set IPv4 or IPv6 address to which DNS queries are to be directed.  The destination machine
       is expected to run a recursive resolver.  If the proxy is not DNSSEC-capable, validation
       may fail.  Can be called several times, in that case the addresses are used as backup
       servers.

   set_tls
           $resolver->set_tls( 0 );
           $resolver->set_tls( 1 );

       Use DNS over TLS for queries to nameservers specified using set_fwd().

   set_stub
           $resolver->set_stub( 'zone', '10.1.2.3', 0 );

       Add a stub zone, with given address to send to. This is for custom root hints or pointing
       to a local authoritative DNS server. For DNS resolvers and the 'DHCP DNS' IP address, use
       set_fwd().

   resolv_conf
           $resolver->resolv_conf( 'filename' );

       Extract nameserver list from resolv.conf(5) format configuration file.  Any domain,
       searchlist, ndots or other settings are ignored.

       Note that Net::DNS builds its own nameserver list using /etc/resolv.conf or other
       platform-specific sources.

   hosts
           $resolver->hosts( 'filename' );

       Read list of hosts from the filename given, usually "/etc/hosts".  These addresses are not
       flagged as DNSSEC secure when queried.

   add_ta
           $resolver->add_ta( 'trust anchor' );

       Add a trust anchor which is a string that holds a valid DNSKEY or DS RR in RFC1035
       zonefile format.

   add_ta_file
           $resolver->add_ta_file( 'filename' );

       Pass the name of a file containing DS and DNSKEY records (as from dig or drill).

   add_ta_autr
           $resolver->add_ta_autr( 'filename' );

       Add trust anchor to the given context that is tracked with RFC5011 automated trust anchor
       maintenance.  The file is written when the trust anchor is changed.

   trusted_keys
           $resolver->trusted_keys( 'filename' );

       Pass the name of a BIND-style config file containing trusted-keys{}.

   debug_out
           $resolver->debug_out( out );

       Send debug output (and error output) to the specified stream.  Pass a null argument to
       disable. Default is stderr.

   debug_level
           $resolver->debug_level(0);

       Set verbosity of the debug output directed to stderr.  Level 0 is off, 1 minimal, 2
       detailed, 3 lots, and 4 lots more.

   async_thread
           $resolver->async_thread(1);

       Set the context behaviour for asynchronous actions.  Enable a call to resolve_async() to
       create a thread to handle work in the background.  If false (by default), a process is
       forked to perform the work.

   print, string
           $resolver->print;
           print $resolver->string;

       Prints the resolver state on the standard output.

COPYRIGHT

       Copyright (c)2022 Dick Franks

       All Rights Reserved

LICENSE

       Permission to use, copy, modify, and distribute this software and its documentation for
       any purpose and without fee is hereby granted, provided that the original copyright
       notices appear in all copies and that both copyright notice and this permission notice
       appear in supporting documentation, and that the name of the author not be used in
       advertising or publicity pertaining to distribution of the software without specific prior
       written permission.

       THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
       INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
       PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE
       FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
       OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
       DEALINGS IN THE SOFTWARE.

SEE ALSO

       perl, Net::DNS, Net::DNS::Resolver, Unbound <https://www.nlnetlabs.nl/projects/unbound/>