NAME Net::DNS::Resolver::Programmable - programmable DNS resolver class for offline emulation of DNS SYNOPSIS use Net::DNS::Resolver::Programmable; use Net::DNS::RR; my $resolver = Net::DNS::Resolver::Programmable->new( records => { 'example.com' => [ Net::DNS::RR->new('example.com. NS ns.example.org.'), Net::DNS::RR->new('example.com. A 192.168.0.1') ], 'ns.example.org' => [ Net::DNS::RR->new('ns.example.org. A 192.168.1.1') ] }, resolver_code => sub { my ($domain, $rr_type, $class) = @_; ... return ($result, $aa, @rrs); } ); DESCRIPTION Net::DNS::Resolver::Programmable is a Net::DNS::Resolver descendant class that allows a virtual DNS to be emulated instead of querying the real DNS. A set of static DNS records may be supplied, or arbitrary code may be specified as a means for retrieving DNS records, or even generating them on the fly. Constructor The following constructor is provided: new(%options): returns Net::DNS::Resolver::Programmable Creates a new programmed DNS resolver object. %options is a list of key/value pairs representing any of the following options: records A reference to a hash of arrays containing a static set of Net::DNS::RR objects. The hash entries must be indexed by fully qualified domain names (lower-case, without any trailing dots), and the entries themselves must be arrays of the RR objects pertaining to these domain names. For example: records => { 'example.com' => [ Net::DNS::RR->new('example.com. NS ns.example.org.'), Net::DNS::RR->new('example.com. A 192.168.0.1') ], 'www.example.com' => [ Net::DNS::RR->new('www.example.com. A 192.168.0.2') ], 'ns.example.org' => [ Net::DNS::RR->new('ns.example.org. A 192.168.1.1') ] } If this option is specified, the resolver retrieves requested RRs from this data structure. resolver_code A code reference used as a call-back for dynamically retrieving requested RRs. The code must take the following query parameters as arguments: the domain, RR type, and class. It must return a list composed of: the response's RCODE (by name, as returned by Net::DNS::Header->rcode), the aa (authoritative answer) flag (boolean, use undef if you don't care), and the Net::DNS::RR answer objects. If an error string is returned instead of a valid RCODE, a Net::DNS::Packet object is not constructed but an error condition for the resolver is signaled instead. For example: resolver_code => sub { my ($domain, $rr_type, $class) = @_; ... return ($result, $aa, @rrs); } If both this and the records option are specified, then statically programmed records are used in addition to any that are returned by the configured resolver code. defnames dnsrch domain searchlist debug These Net::DNS::Resolver options are also meaningful with Net::DNS::Resolver::Programmable. See Net::DNS::Resolver for their descriptions. Instance methods The following instance methods of Net::DNS::Resolver are also supported by Net::DNS::Resolver::Programmable: search: returns Net::DNS::Packet query: returns Net::DNS::Packet send: returns Net::DNS::Packet Performs an offline DNS query, using the statically programmed DNS RRs and/or the configured dynamic resolver code. See the "new" constructor's records and resolver_code options. See the descriptions of search, query, and send for details about the calling syntax of these methods. print string: returns string searchlist: returns list of string defnames: returns boolean dnsrch: returns boolean debug: returns boolean errorstring: returns string answerfrom: returns string answersize: returns integer See "METHODS" in Net::DNS::Resolver. Currently the following methods of Net::DNS::Resolver are not supported: axfr, axfr_start, axfr_next, nameservers, port, srcport, srcaddr, bgsend, bgread, bgisready, tsig, retrans, retry, recurse, usevc, tcp_timeout, udp_timeout, persistent_tcp, persistent_udp, igntc, dnssec, cdflag, udppacketsize. The effects of using these on Net::DNS::Resolver::Programmable objects are undefined. SEE ALSO Net::DNS::Resolver For availability, support, and license information, see the README file included with Net::DNS::Resolver::Programmable. AUTHORS David Precious (BIGPRESH) took on maintainership in July 2017 Original author Julian Mehnle