How to match part of string inside array - PHP

Is there a way to match a part of a string within an array in PHP?

I would like to validate a user ip against allowed IPs. Therefore I have created an array with IPs and coresponding partner_id. This works, however I also want to allow an entire subnet and would therefore need to mach against part of the array. Is this possible?

This is my code:

# define partner IPs
$partner_ips = array(
                        '192.168.56.1'      => 0,  // dev
                        '192.168.57.*'      => 1   // office ips                      
);
# test for partner IP and associate partner_id if found
if (array_key_exists($_SERVER['REMOTE_ADDR'], $partner_ips))
    $partner_id =  $partner_ips[$_SERVER['REMOTE_ADDR']];
else
    $partner_id = false;

Thank you for any help on this.

841

Answer

Solution:

Check the ip format first. Build two different arrays, one for full ip adresses and one for subnets. An example class (feel free to make it PSR-2 compliant, since you use PHP 5.6 you can also declare the two arrays as class constants instead of static variables):

class RemoteAddress {

    private $ip;
    private $id;

    private static $partners_ips = [
            '192.168.56.1' => 0,
            '192.168.58.4' => 2,
            '192.168.59.2' => 3 ];

    private static $partners_subnets = [ // note that subnets must end with a dot
            '192.168.57.' => 1,
            '192.168.60.' => 4,
            '192.168.61.' => 5 ];

    public function __construct($ip) {
        if (filter_var($ip, FILTER_VALIDATE_IP) === false)
            throw new Exception("invalid IP address");

        $this->ip = $ip;
        $this->id = $this->searchID();
    }

    public function getIDPartner() {
        return $this->id;
    }

    private function searchID() {
        if (array_key_exists($this->ip, self::$partners_ips))
            return self::$partners_ips[$this->ip];

        foreach (self::$partners_subnets as $subnet => $id) {
            if (strpos($this->ip, $subnet) === 0)
                return $id;
        }

        return false;
    }
}

You can use it like this:

try {
    if (isset($_SERVER['REMOTE_ADDR'])) {
        $remAddr = new RemoteAddress($_SERVER['REMOTE_ADDR']);
        var_dump($remAddr->getIDPartner());
    } else throw new Exception('$_SERVER[\'REMOTE_ADDR\'] is not defined');
} catch(Exception $e) {
    echo $e->getMessage();
}

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