NAME
Net::IP::LPM - Perl implementation of Longest Prefix Match algorithm
SYNOPSIS
use Net::IP::LPM;
my $lpm = Net::IP::LPM->new();
# add prefixes
$lpm->add('0.0.0.0/0', 'default');
$lpm->add('::/0', 'defaultv6');
$lpm->add('147.229.0.0/16', 'net1');
$lpm->add('147.229.3.0/24', 'net2');
$lpm->add('147.229.3.10/32', 'host3');
$lpm->add('147.229.3.11', 'host4');
$lpm->add('2001:67c:1220::/32', 'net16');
$lpm->add('2001:67c:1220:f565::/64', 'net26');
$lpm->add('2001:67c:1220:f565::1235/128', 'host36');
$lpm->add('2001:67c:1220:f565::1236', 'host46');
printf $lpm->lookup('147.229.100.100'); # returns net1
printf $lpm->lookup('147.229.3.10'); # returns host3
printf $lpm->lookup('2001:67c:1220::1');# returns net16DESCRIPTION
The module Net::IP::LPM implements the Longest Prefix Match algorithm to both protocols, IPv4 and IPv6. The module uses Trie algo.
PERFORMANCE
The module is able to match ~ 1 mln. lookups per second to a complete Internet BGP table (approx. 500,000 prefixes) using a common hardware (2.4GHz Xeon CPU). For more detail, make a test on the module source to check its performance on your system. Module supports both, IPv4 and IPv6 protocols.
CLASS METHODS
new - Class Constructor
$lpm = Net::IP::LPM->new( );Constructs a new Net::IP::LPM object.
OBJECT METHODS
add - Add Prefix
$code = $lpm->add( $prefix, $value );Adds a prefix $prefix into the database with value $value. Returns 1 if the prefix was added successfully. Returns 0 when an error occurs (typically the wrong address formating).
lookup - Lookup Address
$value = $lpm->$lookup( $address );Looks up the prefix in the database and returns the value. If the prefix is not found or an error occured, the undef value is returned.
Before lookups are performed the database has to be rebuilt by $lpm->rebuild() operation.
lookup_raw - Lookup Address in raw format
$value = $lpm->lookup_raw( $address );The same case as $lpm->lookup but it takes $address in raw format (result of the inet_ntop function). It is more effective than $lpm->lookup, because the conversion from text format is not necessary.
info - Returns information about the built trie
$ref = $lpm->info();Returns following items
ipv4_nodes_total - total number of allocated nodes in trie
ipv4_nodes_value - number of allocated nodes in trie that have stored some value
ipv4_trie_bytes - number of bytes allocated for trie nodes (without data)
ipv6_ - the same for IPv6 finish - Release all data in object
$lpm->finish();SEE ALSO
There are also other implementations of the Longest Prefix Match in Perl. However, most of them have some disadvantages (poor performance, lack of support for IPv6 or require a lot of time for initial database building). However, in some cases it might be usefull:
AUTHOR
Tomas Podermanski <tpoder@cis.vutbr.cz>, Martin Ministr <leadersmash@email.cz>, Brno University of Technology
COPYRIGHT AND LICENSE
Copyright (C) 2012, Brno University of Technology
This library is a free software; you can redistribute it and/or modify it under the same terms as Perl itself.