Net::DNS::Resolver::Programmable - programmable DNS resolver class for offline emulation of DNS
0.003
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, $aa, @rrs);
}
);
Net::DNS::Resolver::Programmable is a Net::DNS::Resolver descendant class that allows a virtual DNS to be emulated instead of querying the real DNS. A set of static DNS records may be supplied, or arbitrary code may be specified as a means for retrieving DNS records, or even generating them on the fly.
The following constructor is provided:
Creates a new programmed DNS resolver object.
%options is a list of key/value pairs representing any of the following options:
A reference to a hash of arrays containing a static set of Net::DNS::RR objects. The hash entries must be indexed by fully qualified domain names (lower-case, without any trailing dots), and the entries themselves must be arrays of the RR objects pertaining to these domain names. For example:
records => {
'example.com' => [
Net::DNS::RR->new('example.com. NS ns.example.org.'),
Net::DNS::RR->new('example.com. A 192.168.0.1')
],
'www.example.com' => [
Net::DNS::RR->new('www.example.com. A 192.168.0.2')
],
'ns.example.org' => [
Net::DNS::RR->new('ns.example.org. A 192.168.1.1')
]
}
If this option is specified, the resolver retrieves requested RRs from this data structure.
A code reference used as a call-back for dynamically retrieving requested RRs.
The code must take the following query parameters as arguments: the domain, RR type, and class.
It must return a list composed of: the response's RCODE (by name, as returned by Net::DNS::Header->rcode), the aa (authoritative answer) flag (boolean, use undef if you don't care), and the Net::DNS::RR answer objects. If an error string is returned instead of a valid RCODE, a Net::DNS::Packet object is not constructed but an error condition for the resolver is signaled instead.
For example:
resolver_code => sub {
my ($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.
These Net::DNS::Resolver options are also meaningful with Net::DNS::Resolver::Programmable. See Net::DNS::Resolver for their descriptions.
The following instance methods of Net::DNS::Resolver are also supported by Net::DNS::Resolver::Programmable:
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.
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.
For availability, support, and license information, see the README file included with Net::DNS::Resolver::Programmable.
Julian Mehnle <julian@mehnle.net>
