Initial Commit
This commit is contained in:
Riley Schneider
761
database/perl/vendor/lib/Net/DNS/Resolver.pm
vendored
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761
database/perl/vendor/lib/Net/DNS/Resolver.pm
vendored
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package Net::DNS::Resolver;
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use strict;
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use warnings;
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our $VERSION = (qw$Id: Resolver.pm 1818 2020-10-18 15:24:42Z willem $)[2];
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=head1 NAME
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Net::DNS::Resolver - DNS resolver class
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=cut
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use constant CONFIG => defined eval "require Net::DNS::Resolver::$^O"; ## no critic
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use constant OS_CONF => join '::', __PACKAGE__, CONFIG ? $^O : 'UNIX';
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use base OS_CONF;
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1;
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__END__
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=head1 SYNOPSIS
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use Net::DNS;
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$resolver = Net::DNS::Resolver->new();
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# Perform a lookup, using the searchlist if appropriate.
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$reply = $resolver->search( 'example.com' );
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# Perform a lookup, without the searchlist
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$reply = $resolver->query( 'example.com', 'MX' );
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# Perform a lookup, without pre or post-processing
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$reply = $resolver->send( 'example.com', 'MX', 'IN' );
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# Send a prebuilt query packet
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$query = Net::DNS::Packet->new( ... );
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$reply = $resolver->send( $query );
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=head1 DESCRIPTION
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Instances of the Net::DNS::Resolver class represent resolver objects.
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A program may have multiple resolver objects, each maintaining its
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own state information such as the nameservers to be queried, whether
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recursion is desired, etc.
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=head1 METHODS
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=head2 new
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# Use the default configuration
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$resolver = Net::DNS::Resolver->new();
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# Use my own configuration file
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$resolver = Net::DNS::Resolver->new( config_file => '/my/dns.conf' );
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# Set options in the constructor
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$resolver = Net::DNS::Resolver->new(
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nameservers => [ '2001:DB8::1', 'ns.example.com' ],
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recurse => 0,
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debug => 1
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);
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Returns a resolver object. If no arguments are supplied, C<new()>
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returns an object having the default configuration.
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On Unix and Linux systems,
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the default values are read from the following files,
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in the order indicated:
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=over
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F</etc/resolv.conf>,
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F<$HOME/.resolv.conf>,
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F<./.resolv.conf>
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=back
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The following keywords are recognised in resolver configuration files:
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=over
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B<nameserver> address
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IP address of a name server that the resolver should query.
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B<domain> localdomain
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The domain suffix to be appended to a short non-absolute name.
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B<search> domain ...
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A space-separated list of domains in the desired search path.
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B<options> option:value ...
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A space-separated list of key:value items.
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=back
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Except for F</etc/resolv.conf>, files will only be read if owned by the
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effective userid running the program. In addition, several environment
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variables may contain configuration information; see L</ENVIRONMENT>.
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Note that the domain and searchlist keywords are mutually exclusive.
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If both are present, the resulting behaviour is unspecified.
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If neither is present, the domain is determined from the local hostname.
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On Windows systems, an attempt is made to determine the system defaults
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using the registry. Systems with many dynamically configured network
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interfaces may confuse L<Net::DNS>.
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# Use my own configuration file
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$resolver = Net::DNS::Resolver->new( config_file => '/my/dns.conf' );
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You can include a configuration file of your own when creating a
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resolver object. This is supported on both Unix and Windows.
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If a custom configuration file is specified at first instantiation,
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all other configuration files and environment variables are ignored.
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# Set options in the constructor
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$resolver = Net::DNS::Resolver->new(
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nameservers => [ '2001:DB8::1', 'ns.example.com' ],
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recurse => 0
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);
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Explicit arguments to C<new()> override the corresponding configuration
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variables. The argument list consists of a sequence of (name=>value)
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pairs, each interpreted as an invocation of the corresponding method.
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=head2 print
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$resolver->print;
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Prints the resolver state on the standard output.
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=head2 query
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$packet = $resolver->query( 'host' );
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$packet = $resolver->query( 'host.example.com' );
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$packet = $resolver->query( '2001:DB8::1' );
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$packet = $resolver->query( 'example.com', 'MX' );
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$packet = $resolver->query( 'annotation.example.com', 'TXT', 'IN' );
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Performs a DNS query for the given name; the search list is not applied.
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If C<defnames> is true, the default domain will be appended to unqualified names.
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The record type and class can be omitted; they default to A and IN.
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If the name looks like an IP address (IPv4 or IPv6),
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then a query within in-addr.arpa or ip6.arpa will be performed.
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Returns a L<Net::DNS::Packet> object, or C<undef> if no answers were found.
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The reason for failure may be determined using C<errorstring()>.
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If you need to examine the response packet, whether it contains
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any answers or not, use the C<send()> method instead.
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=head2 search
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$packet = $resolver->search( 'host' );
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$packet = $resolver->search( 'host.example.com' );
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$packet = $resolver->search( '2001:DB8::1' );
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$packet = $resolver->search( 'example.com', 'MX' );
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$packet = $resolver->search( 'annotation.example.com', 'TXT', 'IN' );
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Performs a DNS query for the given name, applying the searchlist if
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appropriate. The search algorithm is as follows:
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If the name contains one or more non-terminal dots,
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perform an initial query using the unmodified name.
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If the number of dots is less than C<ndots>, and there is no terminal dot,
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try appending each suffix in the search list.
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The record type and class can be omitted; they default to A and IN.
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If the name looks like an IP address (IPv4 or IPv6),
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then a query within in-addr.arpa or ip6.arpa will be performed.
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Returns a L<Net::DNS::Packet> object, or C<undef> if no answers were found.
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The reason for failure may be determined using C<errorstring()>.
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If you need to examine the response packet, whether it contains
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any answers or not, use the C<send()> method instead.
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=head2 send
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$packet = $resolver->send( $query );
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$packet = $resolver->send( 'host.example.com' );
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$packet = $resolver->send( '2001:DB8::1' );
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$packet = $resolver->send( 'example.com', 'MX' );
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$packet = $resolver->send( 'annotation.example.com', 'TXT', 'IN' );
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Performs a DNS query for the given name.
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Neither the searchlist nor the default domain will be appended.
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The argument list can be either a pre-built query L<Net::DNS::Packet>
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or a list of strings.
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The record type and class can be omitted; they default to A and IN.
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If the name looks like an IP address (IPv4 or IPv6),
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then a query within in-addr.arpa or ip6.arpa will be performed.
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Returns a L<Net::DNS::Packet> object whether there were any answers or not.
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Use C<< $packet->header->ancount >> or C<< $packet->answer >> to find out
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if there were any records in the answer section.
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Returns C<undef> if no response was received.
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=head2 axfr
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@zone = $resolver->axfr();
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@zone = $resolver->axfr( 'example.com' );
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@zone = $resolver->axfr( 'example.com', 'IN' );
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$iterator = $resolver->axfr();
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$iterator = $resolver->axfr( 'example.com' );
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$iterator = $resolver->axfr( 'example.com', 'IN' );
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$rr = $iterator->();
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Performs a zone transfer using the resolver nameservers list,
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attempted in the order listed.
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If the zone is omitted, it defaults to the first zone listed
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in the resolver search list.
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If the class is omitted, it defaults to IN.
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When called in list context, C<axfr()> returns a list of L<Net::DNS::RR>
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objects. The redundant SOA record that terminates the zone transfer
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is not returned to the caller.
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In deferrence to RFC1035(6.3), a complete zone transfer is expected
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to return all records in the zone or nothing at all.
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When no resource records are returned by C<axfr()>,
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the reason for failure may be determined using C<errorstring()>.
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Here is an example that uses a timeout and TSIG verification:
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$resolver->tcp_timeout( 10 );
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$resolver->tsig( 'Khmac-sha1.example.+161+24053.private' );
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@zone = $resolver->axfr( 'example.com' );
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foreach $rr (@zone) {
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$rr->print;
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}
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When called in scalar context, C<axfr()> returns an iterator object.
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Each invocation of the iterator returns a single L<Net::DNS::RR>
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or C<undef> when the zone is exhausted.
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An exception is raised if the zone transfer can not be completed.
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The redundant SOA record that terminates the zone transfer is not
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returned to the caller.
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Here is the example above, implemented using an iterator:
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$resolver->tcp_timeout( 10 );
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$resolver->tsig( 'Khmac-sha1.example.+161+24053.private' );
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$iterator = $resolver->axfr( 'example.com' );
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while ( $rr = $iterator->() ) {
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$rr->print;
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}
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=head2 bgsend
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$handle = $resolver->bgsend( $packet ) || die $resolver->errorstring;
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$handle = $resolver->bgsend( 'host.example.com' );
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$handle = $resolver->bgsend( '2001:DB8::1' );
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$handle = $resolver->bgsend( 'example.com', 'MX' );
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$handle = $resolver->bgsend( 'annotation.example.com', 'TXT', 'IN' );
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Performs a background DNS query for the given name and returns immediately
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without waiting for the response. The program can then perform other tasks
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while awaiting the response from the nameserver.
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The argument list can be either a L<Net::DNS::Packet> object or a list
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of strings. The record type and class can be omitted; they default to
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A and IN. If the name looks like an IP address (IPv4 or IPv6),
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then a query within in-addr.arpa or ip6.arpa will be performed.
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Returns an opaque handle which is passed to subsequent invocations of
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the C<bgbusy()> and C<bgread()> methods.
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Errors are indicated by returning C<undef> in which case
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the reason for failure may be determined using C<errorstring()>.
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The response L<Net::DNS::Packet> object is obtained by calling C<bgread()>.
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B<BEWARE>:
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Programs should make no assumptions about the nature of the handles
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returned by C<bgsend()> which should be used strictly as described here.
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=head2 bgread
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$handle = $resolver->bgsend( 'www.example.com' );
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$packet = $resolver->bgread($handle);
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Reads the response following a background query.
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The argument is the handle returned by C<bgsend()>.
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Returns a L<Net::DNS::Packet> object or C<undef> if no response was
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received before the timeout interval expired.
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=head2 bgbusy
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$handle = $resolver->bgsend( 'foo.example.com' );
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while ($resolver->bgbusy($handle)) {
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...
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}
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$packet = $resolver->bgread($handle);
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Returns true while awaiting the response or for the transaction to time out.
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The argument is the handle returned by C<bgsend()>.
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Truncated UDP packets will be retried transparently using TCP while
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continuing to assert busy to the caller.
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=head2 debug
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print 'debug flag: ', $resolver->debug, "\n";
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$resolver->debug(1);
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Get or set the debug flag.
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If set, calls to C<search()>, C<query()>, and C<send()> will print
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debugging information on the standard output.
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The default is false.
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=head2 defnames
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print 'defnames flag: ', $resolver->defnames, "\n";
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$resolver->defnames(0);
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Get or set the defnames flag.
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If true, calls to C<query()> will append the default domain to
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resolve names that are not fully qualified.
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The default is true.
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=head2 dnsrch
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print 'dnsrch flag: ', $resolver->dnsrch, "\n";
|
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$resolver->dnsrch(0);
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|
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Get or set the dnsrch flag.
|
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If true, calls to C<search()> will apply the search list to resolve
|
||||
names that are not fully qualified.
|
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The default is true.
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=head2 domain
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$domain = $resolver->domain;
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$resolver->domain( 'domain.example' );
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|
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Gets or sets the resolver default domain.
|
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=head2 igntc
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print 'igntc flag: ', $resolver->igntc, "\n";
|
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$resolver->igntc(1);
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Get or set the igntc flag.
|
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If true, truncated packets will be ignored.
|
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If false, the query will be retried using TCP.
|
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The default is false.
|
||||
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|
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=head2 nameserver, nameservers
|
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|
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@nameservers = $resolver->nameservers();
|
||||
$resolver->nameservers( '2001:DB8::1', '192.0.2.1' );
|
||||
$resolver->nameservers( 'ns.domain.example.' );
|
||||
|
||||
Gets or sets the nameservers to be queried.
|
||||
|
||||
Also see the IPv6 transport notes below
|
||||
|
||||
|
||||
=head2 persistent_tcp
|
||||
|
||||
print 'Persistent TCP flag: ', $resolver->persistent_tcp, "\n";
|
||||
$resolver->persistent_tcp(1);
|
||||
|
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Get or set the persistent TCP setting.
|
||||
If true, L<Net::DNS> will keep a TCP socket open for each host:port
|
||||
to which it connects.
|
||||
This is useful if you are using TCP and need to make a lot of queries
|
||||
or updates to the same nameserver.
|
||||
|
||||
The default is false unless you are running a SOCKSified Perl,
|
||||
in which case the default is true.
|
||||
|
||||
|
||||
=head2 persistent_udp
|
||||
|
||||
print 'Persistent UDP flag: ', $resolver->persistent_udp, "\n";
|
||||
$resolver->persistent_udp(1);
|
||||
|
||||
Get or set the persistent UDP setting.
|
||||
If true, a L<Net::DNS> resolver will use the same UDP socket
|
||||
for all queries within each address family.
|
||||
|
||||
This avoids the cost of creating and tearing down UDP sockets,
|
||||
but also defeats source port randomisation.
|
||||
|
||||
|
||||
=head2 port
|
||||
|
||||
print 'sending queries to port ', $resolver->port, "\n";
|
||||
$resolver->port(9732);
|
||||
|
||||
Gets or sets the port to which queries are sent.
|
||||
Convenient for nameserver testing using a non-standard port.
|
||||
The default is port 53.
|
||||
|
||||
|
||||
=head2 recurse
|
||||
|
||||
print 'recursion flag: ', $resolver->recurse, "\n";
|
||||
$resolver->recurse(0);
|
||||
|
||||
Get or set the recursion flag.
|
||||
If true, this will direct nameservers to perform a recursive query.
|
||||
The default is true.
|
||||
|
||||
|
||||
=head2 retrans
|
||||
|
||||
print 'retrans interval: ', $resolver->retrans, "\n";
|
||||
$resolver->retrans(3);
|
||||
|
||||
Get or set the retransmission interval
|
||||
The default is 5 seconds.
|
||||
|
||||
|
||||
=head2 retry
|
||||
|
||||
print 'number of tries: ', $resolver->retry, "\n";
|
||||
$resolver->retry(2);
|
||||
|
||||
Get or set the number of times to try the query.
|
||||
The default is 4.
|
||||
|
||||
|
||||
=head2 searchlist
|
||||
|
||||
@searchlist = $resolver->searchlist;
|
||||
$resolver->searchlist( 'a.example', 'b.example', 'c.example' );
|
||||
|
||||
Gets or sets the resolver search list.
|
||||
|
||||
|
||||
=head2 srcaddr
|
||||
|
||||
$resolver->srcaddr('2001::DB8::1');
|
||||
|
||||
Sets the source address from which queries are sent.
|
||||
Convenient for forcing queries from a specific interface on a
|
||||
multi-homed host. The default is to use any local address.
|
||||
|
||||
|
||||
=head2 srcport
|
||||
|
||||
$resolver->srcport(5353);
|
||||
|
||||
Sets the port from which queries are sent.
|
||||
The default is 0, meaning any port.
|
||||
|
||||
|
||||
=head2 tcp_timeout
|
||||
|
||||
print 'TCP timeout: ', $resolver->tcp_timeout, "\n";
|
||||
$resolver->tcp_timeout(10);
|
||||
|
||||
Get or set the TCP timeout in seconds.
|
||||
The default is 120 seconds (2 minutes).
|
||||
|
||||
|
||||
=head2 udp_timeout
|
||||
|
||||
print 'UDP timeout: ', $resolver->udp_timeout, "\n";
|
||||
$resolver->udp_timeout(10);
|
||||
|
||||
Get or set the bgsend() UDP timeout in seconds.
|
||||
The default is 30 seconds.
|
||||
|
||||
|
||||
=head2 udppacketsize
|
||||
|
||||
print "udppacketsize: ", $resolver->udppacketsize, "\n";
|
||||
$resolver->udppacketsize(2048);
|
||||
|
||||
Get or set the UDP packet size.
|
||||
If set to a value not less than the default DNS packet size,
|
||||
an EDNS extension will be added indicating support for
|
||||
large UDP datagrams.
|
||||
|
||||
|
||||
=head2 usevc
|
||||
|
||||
print 'usevc flag: ', $resolver->usevc, "\n";
|
||||
$resolver->usevc(1);
|
||||
|
||||
Get or set the usevc flag.
|
||||
If true, queries will be performed using virtual circuits (TCP)
|
||||
instead of datagrams (UDP).
|
||||
The default is false.
|
||||
|
||||
|
||||
=head2 replyfrom
|
||||
|
||||
print 'last response was from: ', $resolver->replyfrom, "\n";
|
||||
|
||||
Returns the IP address from which the most recent packet was
|
||||
received in response to a query.
|
||||
|
||||
|
||||
=head2 errorstring
|
||||
|
||||
print 'query status: ', $resolver->errorstring, "\n";
|
||||
|
||||
Returns a string containing error information from the most recent
|
||||
DNS protocol interaction.
|
||||
C<errorstring()> is meaningful only when interrogated immediately
|
||||
after the corresponding method call.
|
||||
|
||||
|
||||
=head2 dnssec
|
||||
|
||||
print "dnssec flag: ", $resolver->dnssec, "\n";
|
||||
$resolver->dnssec(0);
|
||||
|
||||
The dnssec flag causes the resolver to transmit DNSSEC queries
|
||||
and to add a EDNS0 record as required by RFC2671 and RFC3225.
|
||||
The actions of, and response from, the remote nameserver is
|
||||
determined by the settings of the AD and CD flags.
|
||||
|
||||
Calling the C<dnssec()> method with a non-zero value will also set the
|
||||
UDP packet size to the default value of 2048. If that is too small or
|
||||
too big for your environment, you should call the C<udppacketsize()>
|
||||
method immediately after.
|
||||
|
||||
$resolver->dnssec(1); # DNSSEC using default packetsize
|
||||
$resolver->udppacketsize(1250); # lower the UDP packet size
|
||||
|
||||
A fatal exception will be raised if the C<dnssec()> method is called
|
||||
but the L<Net::DNS::SEC> library has not been installed.
|
||||
|
||||
|
||||
=head2 adflag
|
||||
|
||||
$resolver->dnssec(1);
|
||||
$resolver->adflag(1);
|
||||
print "authentication desired flag: ", $resolver->adflag, "\n";
|
||||
|
||||
Gets or sets the AD bit for dnssec queries. This bit indicates that
|
||||
the caller is interested in the returned AD (authentic data) bit but
|
||||
does not require any dnssec RRs to be included in the response.
|
||||
The default value is false.
|
||||
|
||||
|
||||
=head2 cdflag
|
||||
|
||||
$resolver->dnssec(1);
|
||||
$resolver->cdflag(1);
|
||||
print "checking disabled flag: ", $resolver->cdflag, "\n";
|
||||
|
||||
Gets or sets the CD bit for dnssec queries. This bit indicates that
|
||||
authentication by upstream nameservers should be suppressed.
|
||||
Any dnssec RRs required to execute the authentication procedure
|
||||
should be included in the response.
|
||||
The default value is false.
|
||||
|
||||
|
||||
=head2 tsig
|
||||
|
||||
$resolver->tsig( $tsig );
|
||||
|
||||
$resolver->tsig( 'Khmac-sha1.example.+161+24053.private' );
|
||||
|
||||
$resolver->tsig( 'Khmac-sha1.example.+161+24053.key' );
|
||||
|
||||
$resolver->tsig( 'Khmac-sha1.example.+161+24053.key',
|
||||
fudge => 60
|
||||
);
|
||||
|
||||
$resolver->tsig( $key_name, $key );
|
||||
|
||||
$resolver->tsig( undef );
|
||||
|
||||
Set the TSIG record used to automatically sign outgoing queries, zone
|
||||
transfers and updates. Automatic signing is disabled if called with
|
||||
undefined arguments.
|
||||
|
||||
The default resolver behaviour is not to sign any packets. You must
|
||||
call this method to set the key if you would like the resolver to
|
||||
sign and verify packets automatically.
|
||||
|
||||
Packets can also be signed manually; see the L<Net::DNS::Packet>
|
||||
and L<Net::DNS::Update> manual pages for examples. TSIG records
|
||||
in manually-signed packets take precedence over those that the
|
||||
resolver would add automatically.
|
||||
|
||||
|
||||
=head1 ENVIRONMENT
|
||||
|
||||
The following environment variables can also be used to configure
|
||||
the resolver:
|
||||
|
||||
=head2 RES_NAMESERVERS
|
||||
|
||||
# Bourne Shell
|
||||
RES_NAMESERVERS="2001:DB8::1 192.0.2.1"
|
||||
export RES_NAMESERVERS
|
||||
|
||||
# C Shell
|
||||
setenv RES_NAMESERVERS "2001:DB8::1 192.0.2.1"
|
||||
|
||||
A space-separated list of nameservers to query.
|
||||
|
||||
=head2 RES_SEARCHLIST
|
||||
|
||||
# Bourne Shell
|
||||
RES_SEARCHLIST="a.example.com b.example.com c.example.com"
|
||||
export RES_SEARCHLIST
|
||||
|
||||
# C Shell
|
||||
setenv RES_SEARCHLIST "a.example.com b.example.com c.example.com"
|
||||
|
||||
A space-separated list of domains to put in the search list.
|
||||
|
||||
=head2 LOCALDOMAIN
|
||||
|
||||
# Bourne Shell
|
||||
LOCALDOMAIN=example.com
|
||||
export LOCALDOMAIN
|
||||
|
||||
# C Shell
|
||||
setenv LOCALDOMAIN example.com
|
||||
|
||||
The default domain.
|
||||
|
||||
=head2 RES_OPTIONS
|
||||
|
||||
# Bourne Shell
|
||||
RES_OPTIONS="retrans:3 retry:2 inet6"
|
||||
export RES_OPTIONS
|
||||
|
||||
# C Shell
|
||||
setenv RES_OPTIONS "retrans:3 retry:2 inet6"
|
||||
|
||||
A space-separated list of resolver options to set. Options that
|
||||
take values are specified as C<option:value>.
|
||||
|
||||
|
||||
=head1 IPv4 TRANSPORT
|
||||
|
||||
The C<force_v4()>, C<force_v6()>, C<prefer_v4()>, and C<prefer_v6()> methods
|
||||
with non-zero argument may be used to configure transport selection.
|
||||
|
||||
The behaviour of the C<nameserver()> method illustrates the transport
|
||||
selection mechanism. If, for example, IPv4 transport has been forced,
|
||||
the C<nameserver()> method will only return IPv4 addresses:
|
||||
|
||||
$resolver->nameservers( '192.0.2.1', '192.0.2.2', '2001:DB8::3' );
|
||||
$resolver->force_v4(1);
|
||||
print join ' ', $resolver->nameservers();
|
||||
|
||||
will print
|
||||
|
||||
192.0.2.1 192.0.2.2
|
||||
|
||||
|
||||
=head1 CUSTOMISED RESOLVERS
|
||||
|
||||
Net::DNS::Resolver is actually an empty subclass. At compile time a
|
||||
super class is chosen based on the current platform. A side benefit of
|
||||
this allows for easy modification of the methods in Net::DNS::Resolver.
|
||||
You can simply add a method to the namespace!
|
||||
|
||||
For example, if we wanted to cache lookups:
|
||||
|
||||
package Net::DNS::Resolver;
|
||||
|
||||
my %cache;
|
||||
|
||||
sub search {
|
||||
$self = shift;
|
||||
|
||||
$cache{"@_"} ||= $self->SUPER::search(@_);
|
||||
}
|
||||
|
||||
|
||||
=head1 COPYRIGHT
|
||||
|
||||
Copyright (c)1997-2000 Michael Fuhr.
|
||||
|
||||
Portions Copyright (c)2002-2004 Chris Reinhardt.
|
||||
|
||||
Portions Copyright (c)2005 Olaf M. Kolkman, NLnet Labs.
|
||||
|
||||
Portions Copyright (c)2014,2015 Dick Franks.
|
||||
|
||||
All rights reserved.
|
||||
|
||||
|
||||
=head1 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 above copyright notice appear in all copies and that both that
|
||||
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.
|
||||
|
||||
|
||||
=head1 SEE ALSO
|
||||
|
||||
L<perl>, L<Net::DNS>, L<Net::DNS::Packet>, L<Net::DNS::Update>,
|
||||
L<Net::DNS::Header>, L<Net::DNS::Question>, L<Net::DNS::RR>,
|
||||
L<resolver(5)>, RFC 1034, RFC 1035
|
||||
|
||||
=cut
|
||||
|
||||
Reference in New Issue
Block a user