Credit Card Fraud Prevention Using PHP and MySQL for IPV4

/****************************************************************************************************************/
/* Description: This snippet is provide simple way to help user Credit Card Fraud Prevention                    */
/*              suggestions for different city locations across the country.                                    */
/*              There are 1 steps in this snippet. For information, please visit IP2Location tutorial page at:  */
/*https://www.ip2location.com/tutorials/credit-card-fraud-prevention-using-php-and-mysql-database               */
/****************************************************************************************************************/
/* You can obtain free IP Country database for IPv4 at https://lite.ip2location.com/database/ip-country         */
/* You can obtain free country information data at https://www.ip2location.com/free/country-information         */

<?php
        // country in billing address, in this example, we assigned "US" for United States.
        $billingCountrySHORT = "US";

        // Replace this MYSQL server variables with actual configuration
        $mysql_server = "localhost";
        $mysql_user_name = "root";
        $mysql_user_pass = "";

        // Retrieve visitor IP address from server variable REMOTE_ADDR
        $ipaddress = $_SERVER['REMOTE_ADDR'];

        // Convert IP address to IP number for querying database
        $ipno = Dot2LongIP($ipaddress);

        // Connect to the database server
        $link = mysqli_connect($mysql_server, $mysql_user_name, $mysql_user_pass) or die("Could not connect to MySQL database");

        // Connect to the IP2Location database
        mysqli_select_db($link,"ip2location") or die("Could not select database");

        // SQL query string to match the recordset that the IP number fall between the valid range
        $query = "SELECT * FROM ip_country WHERE $ipno <= ip_to LIMIT 1";

        // Execute SQL query
        $result = mysqli_query($link,$query) or die("IP2Location Query Failed");

        // Retrieve the recordset (only one)
        $row = mysqli_fetch_assoc($result);

        // Keep the country information into two different variables
        $country_code = $row['country_code'];
        $country_name = $row['country_name'];


        // Free recordset and close database connection
        mysqli_free_result($result);
        mysqli_close($link);

         if ($country_code == $billingCountrySHORT) {
            // IP address same as country in billing address: Low Fraud Risk
            echo "Low Frauk Risk ";
          } else {
            // IP address different from country in billing address: High Fraud Risk
            echo"High Fraud risk";
          }

        exit;

        // Function to convert IP address (xxx.xxx.xxx.xxx) to IP number (0 to 256^4-1)
        function Dot2LongIP ($IPaddr)
        {
          if ($IPaddr == "") {
          return 0;
        } else {
        $ips = explode(".", "$IPaddr");
        return ($ips[3] + $ips[2] * 256 + $ips[1] * 256 * 256 + $ips[0] * 256 * 256 * 256);
         }
        }
?>