<?php

if (!isset($_REQUEST)) {
        return;
    }

define("SCRIPT_ROOT", dirname(__FILE__));

// number of allowed page requests for the user
define("CONTROL_MAX_REQUESTS", 10);
// time interval to start counting page requests (seconds)
define("CONTROL_REQ_TIMEOUT", 3);
// seconds to punish the user who has exceeded in doing requests
define("CONTROL_BAN_TIME", 60);
// writable directory to keep script data
define("SCRIPT_TMP_DIR", SCRIPT_ROOT."/flood");
// you don't need to edit below this line
define("USER_IP", $_SERVER["REMOTE_ADDR"]);
define("CONTROL_DB", SCRIPT_TMP_DIR."/ctrl");
define("CONTROL_LOCK_DIR", SCRIPT_TMP_DIR."/lock");
define("CONTROL_LOCK_FILE", CONTROL_LOCK_DIR."/".md5(USER_IP));

if (file_exists(CONTROL_LOCK_FILE)) {
    if (time()-filemtime(CONTROL_LOCK_FILE) > CONTROL_BAN_TIME) {
        // this user has complete his punishment
        unlink(CONTROL_LOCK_FILE);
    } else {
        // too many requests
        echo "<h1>DENIED</h1>";
        echo "Oops, we ran into some problems.";
        echo "<hr>Please try again later.</hr>";
        touch(CONTROL_LOCK_FILE);
        die;
    }
}

function antiflood_countaccess() {
    // counting requests and last access time
    $control = Array();

    if (file_exists(CONTROL_DB)) {
        $fh = fopen(CONTROL_DB, "r");
        $control = array_merge($control, unserialize(fread($fh, filesize(CONTROL_DB))));
        fclose($fh);
    }

    if (isset($control[USER_IP])) {
        if (time()-$control[USER_IP]["t"] < CONTROL_REQ_TIMEOUT) {
            $control[USER_IP]["c"]++;
        } else {
            $control[USER_IP]["c"] = 1;
        }
    } else {
        $control[USER_IP]["c"] = 1;
    }
    $control[USER_IP]["t"] = time();

    if ($control[USER_IP]["c"] >= CONTROL_MAX_REQUESTS) {
        // this user did too many requests within a very short period of time
        $fh = fopen(CONTROL_LOCK_FILE, "w");
        fwrite($fh, USER_IP);
        fclose($fh);
    }
    // writing updated control table
    $fh = fopen(CONTROL_DB, "w");
    fwrite($fh, serialize($control));
    fclose($fh);
}

antiflood_countaccess();

$dblocation = "localhost";
$dbname = "name";
$dbuser = "use";
$dbuserpass = "pass";

$link = mysqli_connect($dblocation, $dbuser, $dbuserpass, $dbname);
if ( !$link ) die("error");

?>