NAME
Net::DNS::Nameserver::Trivial - Trivial DNS server, that is based on
Net::DNS::Nameserver module.
SYNOPSIS
use Net::DNS::Nameserver::Trivial;
# Configuration of zone(s) -----------------------------------------
my $zones = {
'_' => {
'slaves' => '10.1.0.1'
},
'A' => {
'ns.example.com' => '10.11.12.13',
'mail.example.com' => '10.11.12.14',
'web.example.com' => '10.11.12.15',
'srv.example.com' => '10.11.12.16'
},
'AAAA' => {
'v6.example.com' => 'fe80::20c:29ff:fee2:ed62',
},
'CNAME' => {
'srv.example.com' => 'dns.example.com'
},
'MX' => {
'example.com' => 'mail.example.com'
},
'NS' => {
'example.com' => 'ns.example.com'
},
'SOA' => {
'example.com' => 'ns.example.com'
}
};
# Configuration of server ------------------------------------------
my $params = {
'_' => {
'IdleTimeout' => '5', # seconds
'LocalAddr' => '0.0.0.0', # all interfaces
'LocalPort' => '53', # port
'Truncate' => '1', # truncate to big
'Verbose' => '0',
'cache_size' => '32m', # cache for DNS
'expire_time' => '3d', # expire of cache
'init_file' => '0', # clear cache at startup
'log_file' => '/var/log/dns.log',
'log_level' => 'INFO',
'share_file' => '/var/lib/dns/cache.db', # cache
'tcp_timeout' => '5',
'udp_timeout' => '5',
'unlink_on_exit' => '0' # destroy cache on exit
}
};
# Run server -------------------------------------------------------
my $ns = Net::DNS::Nameserver::Trivial->new( $zones, $params );
$ns->main_loop;
#
# ...OR SHORT VERSION with configuration files
#
use Config::Tiny;
use Net::DNS::Nameserver::Trivial;
# Read in config of zone -------------------------------------------
my $zones = Config::Tiny->read( '../etc/dom.ini' );
# Read in config of server -----------------------------------------
my $params = Config::Tiny->read( '../etc/dns.ini' );
# Run server -------------------------------------------------------
my $ns = Net::DNS::Nameserver::Trivial->new( $zones, $params );
$ns->main_loop;
DESCRIPTION
The "Net::DNS::Nameserver::Trivial" is a very simple nameserver, that is
sufficient for local domains. It supports cacheing, slaves, zone
transfer and common records such as A, AAAA, SOA, NS, MX, TXT, PTR,
CNAME. This module was tested in an environment with over 1000 users and
for now is running in a production environment.
The main goal was to produce server, that is very easy in configuration
and it can be setup in a few seconds. So You should consider BIND if for
some reasons You need more powerful and complex nameserver.
This module was prepared to cooperete with "Config::Tiny", so it is
possible to prepare configuration files and run server with them, as it
was shown in an example above.
SUBROUTINES/METHODS
new( $zones, $params )
This is constructor. You have to pass to it hash with configuration
of zones and second hash - with configuration for server.
The first hash sould contains sections (as shown in a SINOPSIS):
"_" This section is a hash, that should contains information of
slaves of our server. For example:
'_' => {
'slaves' => '10.1.0.1'
}
"A" This section is a hash, that is a mapping FDQN to IPv4, for
example:
'A' => {
'ns.example.com' => '10.11.12.13',
'mail.example.com' => '10.11.12.14',
'web.example.com' => '10.11.12.15',
'srv.example.com' => '10.11.12.16'
}
"AAAA" This section is a hash, that is a mapping FDQN to IPv6, for
example:
'AAAA' => {
'v6.example.com' => 'fe80::20c:29ff:fee2:ed62',
}
"MX" This section is a hash, that contains information about mail
servers for domains. For example, if *mail.example.com* is a
mail server for domain *example.com*, a configuration should
looks like this:
'MX' => {
'example.com' => 'mail.example.com'
}
"CNAME" This section is a hash, that contains aliases for hosts. For
example, if alias.example.com and alias1.example.com are
aliases for a server srv.example.com, a configuration should
looks like this:
'CNAME' => {
'srv.example.com' => 'alias.example.com, alias1.example.com'
}
"NS" This section is a hash, that contains information about
nameservers for a domain. For example:
'NS' => {
'example.com' => 'ns.example.com'
}
"SOA" This section is a hash, that contains information about
authoritative nameserver for a domain. For example:
'SOA' => {
'example.com' => 'ns.example.com'
}
The second hash should contains variables sufficient for
configuration of server, cache, logs, etc. The meaning of hash
elements was shown below.
"IdleTimeout"
Timeout for idle connections.
"LocalAddr"
Local IP address to listen on. Server will be listenting on
all interfecas if You specify 0.0.0.0.
"LocalPort"
Local port to listen on.
"Truncate"
Truncates UDP packets that are to big for the reply
"Verbose"
Be verbose. It is useful only for debugging.
"cache_size"
A size of cache, that will be used by server.
"expire_time"
Expiration time of entries in a cache. It can be diffrent
than TTL value. It is effective if makeing of connection to
other server is too expensive (i.e. too long).
"init_file"
Clear cache at startup.
"log_file"
A path to log file.
"log_level"
Log level.
"share_file"
A path to cache file.
"tcp_timeout"
A timeout for TCP connections.
"udp_timeout"
A timeout for UDP connections.
"unlink_on_exit"
Unlink a cache file on exit.
"main_loop()"
This method starts main loop of a nameserver. See an example in a
SINOPSIS.
USING CONFIGURATION FILES - examples
"Net::DNS::Nameserver::Trivial" was prepared to cooperate with
"Config::Tiny" module. It is possible to prepare configuration files for
zones and for server and then make server server run using those files.
Config file for zone *example.com* could looks like this:
slaves = 10.1.0.1
[NS]
example.com = ns.example.com
[SOA]
example.com = ns.example.com
[MX]
example.com = mail.example.com'
[AAAA]
[CNAME]
srv.example.com = alias.example.com, alias1.example.com
[A]
ns.example.com = 10.11.12.13
mail.example.com = 10.11.12.14
web.example.com = 10.11.12.15
srv.example.com = 10.11.12.16
Config file for server could looks like this:
tcp_timeout = 5
udp_timeout = 5
cache_size = 32m
expire_time = 3d
init_file = 0
unlink_on_exit = 0
share_file = /var/lib/dns/cache.db
LocalAddr = 0.0.0.0
LocalPort = 53
Verbose = 0
Truncate = 1
IdleTimeout = 5
log_file = /var/log/dns.log
log_level = INFO
And then a code of server shold looks like this:
use Config::Tiny;
use Net::DNS::Nameserver::Trivial;
# Read in config of zone -------------------------------------------
my $zones = Config::Tiny->read( '/path/to/zone/file.ini' );
# Read in config of server -----------------------------------------
my $params = Config::Tiny->read( '/path/to/server/config.ini' );
# Run server -------------------------------------------------------
my $ns = Net::DNS::Nameserver::Trivial->new( $zones, $params );
$ns->main_loop;
A complete example is placed in the example directory.
DEPENDENCIES
Net::IP::XS
Net::DNS
Log::Tiny
List::MoreUtils
Cache::FastMmap
Regexp::IPv6
INCOMPATIBILITIES
None known.
BUGS AND LIMITATIONS
I'm sure, that they must be there :-) ...but if You found one, give me a
feedback.
AUTHOR
Strzelecki Łukasz <
[email protected]>
LICENCE AND COPYRIGHT
This program is free software; you can redistribute it and/or modify it
under the same terms as Perl itself.
See
http://www.perl.com/perl/misc/Artistic.html
