class.countryblock.php

<?php

/**
 * CountryBlock PHP implementation class.
 * Version 1.0
 *
 * @link http://countryblock.io
 * @author Kristoffer Alfheim
 * @copyright CountryBlock.io 2014
 * @license https://creativecommons.org/licenses/by-sa/4.0/ Attribution-ShareAlike 4.0 International
 */

/**
 * CountryBlock configuration.
 * @static
 * @access public
 */
class __countryblock_config
{
    /**
     * REQUIRED!!
     * Website ID.
     * @var int
     */
    const WS_ID = x;

    /**
     * REQUIRED!!
     * Website hash.
     * @var string
     */
    const WS_HASH = 'xx';

    /**
     * Enable if website is using CloudFlare.
     * @var boolean
     */
    const CLOUDFLARE = false;

    /**
     * Connection timeout in seconds.
     * @var int
     */
    const TIMEOUT_SECS = 3;

    /**
     * What happens if connection times out.
     * 'allow' or 'deny'
     * @var string
     */
    const TIMEOUT_ACTION = 'allow';

    /**
     * What happens if an unexpected error occurs.
     * 'allow' or 'deny'
     * @var string
     */
    const ERROR_ACTION = 'allow';

    /**
     * Default redirection URL.
     * In case CountryBlock is unavailable.
     * @var string
     */
    const DEFAULT_REDIR_URL = 'http://countryblock.io/blocked.php';

    /**
     * CountryBlock API URL.
     * @var string. Include http(s). No trailing slash.
     */
    const API_URL = 'http://countryblock.io/api';
}

/**
 * Main CountryBlock class.
 *
 * Do NOT edit anything below this line!
 * (unless you know what you're doing)
 *
 * @static
 */
class __countryblock_main
{
    /**
     * Version number.
     * @var string
     */
    const VERSION = '1.0';

    /**
     * Access codes
     * @var int
     */
    const ACCESS_YES = 1;
    const ACCESS_NO = 2;
    const ACCESS_ERR = 3;
    const ACCESS_TIMEOUT = 4;

    /**
     * Redirect URL gets stored here.
     * @var string
     * @access private
     */
    private static $redir_url;

    /**
     * Initialize.
     * @return void
     * @access public
     */
    public static function init()
    {
        $ac = self::get_code();
        if ($ac == self::ACCESS_NO || ($ac == self::ACCESS_ERR && __countryblock_config::ERROR_ACTION == 'deny'))
        {
            header('Location: '.(empty(self::$redir_url) ? __countryblock_config::DEFAULT_REDIR_URL : self::$redir_url));
            exit('Access denied.');
        }
    }

    /**
     * Get access code from CountryBlock servers.
     * @return int
     * @access private
     */
    private static function get_code()
    {
        if (!self::ip())
            return self::ACCESS_ERR;

        $result = function_exists('curl_init') ? self::req_curl() : self::req_file();

        if (empty($result) || mb_substr_count($result, "\n") != 1)
            return self::ACCESS_ERR;

        $result = explode("\n", $result);
        $code = intval($result[0]);
        self::$redir_url = $result[1];

        switch ($code)
        {
            case self::ACCESS_YES:
            case self::ACCESS_NO:
                return $code;

            case self::ACCESS_TIMEOUT;
                return __countryblock_config::TIMEOUT_ACTION != 'deny' ? self::ACCESS_YES : self::ACCESS_NO;
        }

        return self::ACCESS_ERR;
    }

    /**
     * Use cURL to perform HTTP request.
     * @return mixed
     * @access private
     */
    private static function req_curl()
    {
        $ch = curl_init(self::req_check_url());

        curl_setopt($ch, CURLOPT_CONNECTTIMEOUT, __countryblock_config::TIMEOUT_SECS);
        curl_setopt($ch, CURLOPT_TIMEOUT, __countryblock_config::TIMEOUT_SECS);
        curl_setopt($ch, CURLOPT_NOSIGNAL, 1);
        curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
        @curl_setopt($ch, CURLOPT_FOLLOWLOCATION, 1);
        curl_setopt($ch, CURLOPT_USERAGENT, 'class.countryblock.php '.self::VERSION.' cURL');

        $result = curl_exec($ch);
        $errno = curl_errno($ch);
        curl_close($ch);

        if ($errno != 0)
            return false;

        return $result;
    }

    /**
     * Use file_get_contents() to perform HTTP request.
     * @return string
     * @access private
     */
    private static function req_file()
    {
        $result = file_get_contents(self::req_check_url(), stream_context_create(array
        (
            'http' => array
            (
                'method' => 'GET',
                'user_agent' => 'class.countryblock.php '.self::VERSION.' file',
                'timeout' => __countryblock_config::TIMEOUT_SECS
            )
        )));

        if (!$result)
            return false;

        return $result;
    }

    /**
     * Parse check request URL.
     * @return string
     * @access private
     */
    private static function req_check_url()
    {
        return __countryblock_config::API_URL.'/check.php?i='.__countryblock_config::WS_ID.'&h='.__countryblock_config::WS_HASH.'&ip='.self::ip();
    }

    /**
     * Get the users IP address.
     * @return string, false on error
     * @access private
     */
    private static function ip()
    {
        if (__countryblock_config::CLOUDFLARE)
            $s = 'HTTP_CF_CONNECTING_IP';
        else
            $s = 'REMOTE_ADDR';

        return isset($_SERVER[$s]) ? $_SERVER[$s] : false;
    }
}

__countryblock_main::init();