Net::DNS::TestNS - Perl extension for simulating simple Nameservers

use Net::DNS::TestNS;

Class for setting up "simple DNS" servers.

Class to setup a number of nameservers that respond to specific DNS queries (QNAME,QTYPE) by prespecified answers. This class is to be used in test suites where you want to have servers to show predefined behavior.

If the server will do a lookup based on QNAME,QTYPE and return the specified data. If there is no QNAME, QTYPE match the server will return a SERVFAIL.

A log will be written to STDERR it contains time, IP/PORT, QNAME, QTYPE, RCODE

The class uses an XML file to read its configuration. The DTD is documented in Net::DNS::TestNS::DTD.

The setup is split in a number of servers, each with a unique IP/port number, each server has 1 or more QNAMEs it will respond to. Each QNAME can have QTYPEs specified.

For each QNAME,QTYPE an answer needs to be specified, response code and header bits can be tweaked through the qtype attributes.

The content of the packet can be specified through ans, aut and add elements, each specifying one RR record to end up in the answer, authority or additional section.

The optional 'delay' attribute in the QTYPE element specifies how many seconds the server should wait until an answer is returned.

If the query does not match against data specified in the configuration a SERVFAIL is returned.

    my $server=Net::DNS::TestNS->new($configfile, {
     Verbose => 1,
        Validate => 1,
    });

Read the configuration files and bind to ports. One can use <!-- include="file" --> anywhere inside the configuration file to include other XML configuration fragments.

The second optional argument is hash that contains customization parameters. Verbose boolean Makes the code more verbose. Validate boolean Turns on XML validation based on the DTD The parser is flexible with respect to the ordering of some of the XML elements. The DTD is not. Validation is on by default.

new returns the object reference on success and 0 on failure. On failure the class variable $Net::DNS::TestNS::errorcondition is set.

    $self->verbose(1);

Sets verbosity at run time.

Spawns off the servers and process the data.

Cleanup function that kills all the children spawned by the instance. Also known by its alias 'stop'.

<?xml version="1.0" standalone="no"?> <testns version="1.0"> <server ip="127.0.0.1" port="5354"> <qname name="bla.foo"> <qtype type="TXT" delay="1"> <header> <rcode value="NOERROR"/> <aa value="1"/> <ra value="0"/> <ad value="0"/> <qr value="0"/> <tc value="1"/> <id value="1234"/> <ancount value="1"/> <nscount value="1"/> </header> <ans> bla.foo. 3600 IN TXT "TEXT" </ans> <ans> bla.foo. 3600 IN TXT "Other text" </ans> </qtype> </qname> <qname name="raw.foo"> <qtype type="TXT" delay="1"> <header> <rcode value="NOERROR"/> <aa value="1"/> <ra value="0"/> <ad value="0"/> <qr value="0"/> <tc value="1"/> <id value="1234"/> <ancount value="1"/> </header> <raw> <!-- QNAME --> 07 74726967676572 <!-- trigger --> 03 666f6f <!-- foo --> 00 <!-- closing octet --> <!-- QTYPE --> 00 01 <!-- A RR --> <!-- QCLASS --> 00 01

   <!-- Answer section -->

     c0 0c               <!-- Points up -->
     00 01               <!-- type A -->
     00 01               <!-- class IN -->
     00 00 00 05         <!-- ttl 5 seconds  -->
     00 04               <!-- RD length 4 octets -->
     0a 00 00 01         <!-- 10.0.0.1 -->
     </raw>
   </qtype>
  </qname>

 </server>
</testns>

The module is based on Net::DNS::Nameserver. There is no way to distinguish if the query came over TCP or UDP; besides UDP truncation is not available in Net::DNS::Nameserver.

Earlier versions of this script used a different DTD that had no version number. The script only validates against version 1.0 of the DTD but parses the old files.

ALSO SEE

Net::DNS::TestNS::DTD, Net::DNS, Net::DNS::RR

Olaf Kolkman, <olaf@net-dns.org<gt>

Copyright (c) 2003-2005 RIPE NCC. Author Olaf M. Kolkman <olaf@net-dns.net>

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