Implements an UDP protocol server that will receive data packets through a port bind from any of the IPs available on the local machine and write the same content (in its entirety) to a third-party server specified in the command line.

udp-simple-wrapper.php

<?php

// code inspired from https://www.binarytides.com/udp-socket-programming-in-php/

error_reporting(~E_WARNING);

$argv = RearrangeArguments([
    ['name' => '--localPort', 'type' => 'optional', 'cast' => 'string', 'default' => '9999'],
    ['name' => '--targetHost', 'type' => 'required', 'cast' => 'string', 'default' => ''],
    ['name' => '--targetPort', 'type' => 'required', 'cast' => 'string', 'default' => ''],
]);


if (!($sock = socket_create(AF_INET, SOCK_DGRAM, 0))) {
	  $errorCode = socket_last_error();
    $errorMsg = socket_strerror($errorCode);
    die("Couldn't create socket: [$errorCode] $errorMsg \n");
}
echo "Socket created \n";

if (!socket_bind($sock, '0.0.0.0' , $argv['localPort'])) {
	  $errorCode = socket_last_error();
    $errorMsg = socket_strerror($errorCode);
    die("Could not bind socket : [$errorCode] $errorMsg \n");
}
echo 'Socket bind to "udp://0.0.0.0:' . $argv['localPort'] . '"';

echo "\n";
echo 'Software will read from any IP available in this machine (by UDP protocol) and forward content to ';
echo $argv['targetHost'] . ':' . $argv['targetPort'];
echo "\nWaiting for data ... \n";
do {
    $r = socket_recvfrom($sock, $buf, 512, 0, $remote_ip, $remote_port);
    var_dump($r);
    echo "(From:$remote_ip:$remote_port) " . $buf;
    socket_sendto($sock, $buf , strlen($buf), 0 , '192.168.0.179', 8125);
} while(true);

socket_close($sock);

/**
 * Function checks command line parameters and recreates array $argv
 * - type) must be 'required' or 'optional'
 * @param array $payload parameters being awaited. Ex: [['name' => '--database', 'type' => 'required', 'cast' => 'string', 'default' => '']],
 */
function RearrangeArguments(array $payload)
{
    global $argv;
    $result = [];
    $index = 0;

    if (array_search('--help', $argv) !== false) {
        help();
        exit();
    }

    foreach($payload AS $item) {
        if (!isset($item['default'])) {
            $item['default']='';
        }

        $index = array_search($item['name'], $argv);
        $item['name'] = substr($item['name'], 2);
        $result[$item['name']] = $item['default'];
        if ($index !== false) {
            if (isset($argv[$index+1])) {
                      $result[$item['name']] = $argv[$index+1];
            } else {
                      $result[$item['name']] = null;
            }
        } elseif ($item['type'] == 'required') {
            help();
            exit("Parameter ".$item['name']." required not provided!\n");
        }

        if ($item['cast'] == 'boolean') {
            if ($result[$item['name']] == null) {
                $result[$item['name']] = true;
            } else if ($result[$item['name']] == 'false') {
                $result[$item['name']] = false;
            }
        }
    }
    return $result;
}
function help() {
    echo "\n";
    echo " UDP Server wrapper.\n";
    echo "\n";
    echo "Sometimes a network have some blocks to receive comunication from another network\n";
    echo "this software can receive a package from UDP comunication and forward its contents\n";
    echo "to the destination network wrapping its content in another unblocked path\n";
    echo "\n";
    echo "Must use the following parameters:\n";
    echo "   --localPort: Local port to bind to and await communications\n";
    echo "  --targetHost: Host IP to forward content to after receive it\n";
    echo "  --targetPort: Host communication port to forward content to after receive it\n";
    echo "\n";
}