#!/usr/bin/env perl

use v5.38.2;
use strict;
use warnings;

use IO::Socket::INET;

my $server = IO::Socket::INET->new(
    LocalPort => 19132,
    LocalHost => '0.0.0.0',
    Proto     => 'udp',
);

my %sockets;

my $buf = '';
while ($server->recv($buf, 1024)) {
    my $host = $server->peerhost;
    my $port = $server->peerport;
    my $source = "$host:$port";
    generate_socket($source, $server) if !defined $sockets{$source};
    my $final_socket = $sockets{$source};
    $final_socket->send($buf);
    $buf = '';
}

sub generate_socket($source, $server) {
    $sockets{$source} = connect_final();
    my $pid = fork;
    if (!$pid) {
        my $buf = '';
        while ($sockets{$source}->recv($buf, 1024)) {
            $server->send($buf);
            $buf = '';
        }
    }
}

sub connect_udp($host, $port) {
    my $socket = IO::Socket::INET->new(
        PeerPort => $port,
        PeerHost => $host,
        Proto     => 'udp',
    );
    return $socket;
}

sub connect_final {
    return connect_udp('192.168.2.1', 19132);
}