IPHitsLimit

<?php
/**
 * @file     IPHitsLimit.php
 * @version 1.0
 * @author   guoxiaosong <>
 * @date     2012-11-14
 * @brief    Limit ip frequency.
 */
class IPHitsLimit
{
    const INDEX_DAY = 0;
    const INDEX_HOUR = 1;
    const INDEX_MINUTE = 2;
    const INDEX_SECOND = 3;
    // MemCahe link
    private $_memCache;
    // 1 day
    private $_expiredTime = 86400;
    private $_ipWhiteLists = array();
    private $_ipBlackLists = array();

    /**
     * Constructor.
     *
     * @param   boolean     $init   Initialize the shm or not.
     */
    function __construct()
    {
        $this->_memCache = new MemCache;
        $this->_memCache->pconnect(KOPU_MEMCACHED_HOST, KOPU_MEMCACHED_PORT);

        $this->init();
    }

    /**
     * Initialize the shm.
     *
     */
    function init()
    {
        $this->_expiredTime = KOPU_IPHITS_EXPIRED_TIME;
        $this->_ipWhiteLists = Yii::app()->params->ipwhitelists;
        $this->_ipBlackLists = Yii::app()->params->ipblacklists;
    }

    /**
     * Check whether to limit $ip.
     *
     * @param   string $ip         The ip to check.
     * @return int                 0: no limit, 1: limit it.
     */

    public function check($ip)
    {
        $return = $this->_check($ip);
        if ($return == 1) {
            Yii::log($ip, CLogger::LEVEL_INFO, 'IPHitsLimit');
        }
        return $return;
    }

    private function _check($ip)
    {
        if (!($key = $this->_checkIP($ip)) || $this->_checkIPBlackList($ip)) {
            return 1;
        }

        if ($this->_checkIPWhiteList($ip)) {
            return 0;
        }

        $info = $this->_memCache->get($key);
        $time = time();
        if (empty($info)) {// new record
            $info = array(
                'time' => $time, 
                'count' => array(1, 1, 1, 1), 
                'ip' => $ip, 
            );
            $this->_memCache->set($key, $info, MEMCACHE_COMPRESSED, $this->_expiredTime);
            return 0;
        } else {
            $countTimeMap = $this->countTimeMap();
            $info['count'] = $this->_addCount($info['count']);
            if ($this->_campareTime($time, $info['time'], 'day')) {
                // IP hits up to day limits.
                if ($info['count'][self::INDEX_DAY] > $countTimeMap[self::INDEX_DAY]) {
                    $info['time'] = $time;
                    $this->_memCache->set($key, $info);
                    return 1;
                }

                if ($this->_campareTime($time, $info['time'], 'hour')) {
                    // Ip hits up to hour limits.
                    if ($info['count'][self::INDEX_HOUR] > $countTimeMap[self::INDEX_HOUR]) {
                        $info['time'] = $time;
                        $this->_memCache->set($key, $info);
                        return 1;
                    }

                    if ($this->_campareTime($time, $info['time'], 'minute')) {
                        // Ip hits up to minute limits
                        if ($info['count'][self::INDEX_MINUTE] > $countTimeMap[self::INDEX_MINUTE]) {
                            $info['time'] = $time;
                            $this->_memCache->set($key, $info);
                            return 1;
                        }

                        if ($this->_campareTime($time, $info['time'], 'second')) {
                            //Ip hits up to second limits.
                            if ($info['count'][self::INDEX_SECOND] > $countTimeMap[self::INDEX_SECOND]) {
                                $info['time'] = $time;
                                $this->_memCache->set($key, $info);
                                return 1;
                            }
                        } else {
                            $info['count'][self::INDEX_SECOND] = 1;
                        }
                    } else {
                        $info['count'][self::INDEX_MINUTE] = 1;
                        $info['count'][self::INDEX_SECOND] = 1;
                    }
                } else {
                    // new hour need to reset day,minute,second count.
                    $info['count'][self::INDEX_HOUR] = 1;
                    $info['count'][self::INDEX_MINUTE] = 1;
                    $info['count'][self::INDEX_SECOND] = 1;
                }
            } else {
                // new day need to reset all count.
                $info['count'] = array(1, 1, 1, 1);
            }
            $info['time'] = $time;
            $this->_memCache->set($key, $info);
            return 0;
        }

    }

    /**
     * @return array
     * key(seconds)
     * value(limits)
     */
    function countTimeMap()
    {
        return array(
            self::INDEX_DAY => KOPU_IPHITS_PER_DAY,
            self::INDEX_HOUR => KOPU_IPHITS_PER_HOUR,
            self::INDEX_MINUTE => KOPU_IPHITS_PER_MINUTE,
            self::INDEX_SECOND => KOPU_IPHITS_PER_SECOND
        );
    }

    /**
     * Print ip info in shm.
     *
     * @param   string $ip         The ip.
     */
    function dump($ip)
    {
        $key = ip2long($ip);
        if ($key == -1 || $key === FALSE) {// Invalid IP
            return;
        }
        $info = $this->_memCache->get($key);
        print_r($info);
        return $info;
    }

    /**
     * @return mixed
     */
    private function _addCount(array $count, $key = NULL)
    {
        if ($key == NULL || !isset($count[$key])) {
            foreach ($count as &$v) {
                $v++;
            }
            return $count;
        } else {
            $count[$key]++;
            return $count;
        }
    }

    private function _campareTime($t1, $t2, $type = 'day')
    {
        switch($type) {
            case 'day' :
                return (date('Y-m-d', $t1) == date('Y-m-d', $t2));
                break;
            case 'hour' :
                return (date('Y-m-d H:00:00', $t1) == date('Y-m-d H:00:00', $t2));
                break;
            case 'minute' :
                return (date('Y-m-d H:i:00', $t1) == date('Y-m-d H:i:00', $t2));
                break;
            case 'second' :
                return $t1 == $t2;
                break;
            default :
                return false;
                break;
        }
    }

    private function _checkIP($ip)
    {
        if (empty($ip)) {
            return false;
        }
        $key = ip2long($ip);
        if ($key == -1 || $key === FALSE) {// Invalid IP
            return false;
        }
        return $key;
    }

    private function _checkIPWhiteList($ip)
    {
        return $this->isIpMatched($ip, $this->_ipWhiteLists);
    }

    private function _checkIPBlackList($ip)
    {
        return $this->isIpMatched($ip, $this->_ipBlackLists);
    }

    /**
     * @param string $ip the IP address
     * @return boolean whether the rule applies to the IP address
     */
    protected function isIpMatched($ip, $ips)
    {
        if(empty($ips))
            return false;
        foreach($ips as $rule)
        {
            if($rule==='*' || $rule===$ip || (($pos=strpos($rule,'*'))!==false && !strncmp($ip,$rule,$pos)))
                return true;
        }
        return false;
    }

}
?>