lubuntu.me/plugins/all-in-one-wp-security-and-firewall/classes/wp-security-utility-ip-address.php

<?php

class AIOWPSecurity_Utility_IP
{
    function __construct(){
        //NOP
    }
    
    static function get_user_ip_address()
    {
        foreach (array('HTTP_CF_CONNECTING_IP', 'HTTP_CLIENT_IP', 'HTTP_X_FORWARDED_FOR', 'HTTP_X_FORWARDED', 'HTTP_X_CLUSTER_CLIENT_IP', 'HTTP_FORWARDED_FOR', 'HTTP_FORWARDED', 'REMOTE_ADDR') as $key){
            if (array_key_exists($key, $_SERVER) === true){
                foreach (explode(',', $_SERVER[$key]) as $ip){
                    $userIP = trim($ip);
                    if (filter_var($userIP, FILTER_VALIDATE_IP) !== false){
                        return $userIP;
                    }
                }
            }
        }
        return ''; //if we get this far we have an invalid address - return empty string
    }
    
     /*
     * Returns the first three octets of a sanitized IP address so it can used as an IP address range
     */
    static function get_sanitized_ip_range($ip)
    {
        global $aio_wp_security;
        $ip_range = '';
        $valid_ip = filter_var($ip, FILTER_VALIDATE_IP); //Sanitize the IP address
        if ($valid_ip)
        {
            $ip_type = WP_Http::is_ip_address($ip); //returns 4 or 6 if ipv4 or ipv6 or false if invalid
            if($ip_type == 6 || $ip_type === false) return ''; // for now return empty if ipv6 or invalid IP
            $ip_range = substr($valid_ip, 0 , strrpos ($valid_ip, ".")); //strip last portion of address to leave an IP range
        }
        else
        {
            //Write log if the 'REMOTE_ADDR' contains something which is not an IP
            $aio_wp_security->debug_logger->log_debug("AIOWPSecurity_Utility_IP - Invalid IP received ".$ip,4);
        }
        return $ip_range;
    }

    
    static function create_ip_list_array_from_string_with_newline($ip_addresses)
    {
        $ip_list_array = explode(PHP_EOL, $ip_addresses);
        return $ip_list_array;
    }
    
    static function validate_ip_list($ip_list_array, $list_type='')
    {
        @ini_set('auto_detect_line_endings', true);
        $errors = '';

        //validate list
        $submitted_ips = $ip_list_array;
        $list = array();

        if(!empty($submitted_ips))
        {
            foreach($submitted_ips as $item) 
            {
                $item = filter_var($item, FILTER_SANITIZE_STRING);
                if (strlen( $item ) > 0) 
                {
                    //ipv6 - for now we will support only whole ipv6 addresses, NOT ranges
                    if(strpos($item, ':') !== false){
                        //possible ipv6 addr
                        $res = WP_Http::is_ip_address($item);
                        if(FALSE === $res){
                            $errors .= '<p>'.$item.__(' is not a valid ip address format.', 'all-in-one-wp-security-and-firewall').'</p>';
                        }else if($res == '6'){
                            $list[] = trim($item);
                        }
                        continue;
                    }

                    $ipParts = explode('.', $item);
                    $isIP = 0;
                    $partcount = 1;
                    $goodip = true;
                    $foundwild = false;
                    
                    if (count($ipParts) < 2)
                    {
                        $errors .= '<p>'.$item.__(' is not a valid ip address format.', 'all-in-one-wp-security-and-firewall').'</p>';
                        continue;
                    }

                    foreach ($ipParts as $part) 
                    {
                        if ($goodip == true) 
                        {
                            if ((is_numeric(trim($part)) && trim($part) <= 255 && trim($part) >= 0) || trim($part) == '*') 
                            {
                                $isIP++;
                            }

                            switch ($partcount) 
                            {
                                case 1:
                                    if (trim($part) == '*') 
                                    {
                                        $goodip = false;
                                        $errors .= '<p>'.$item.__(' is not a valid ip address format.', 'all-in-one-wp-security-and-firewall').'</p>';
                                    }
                                    break;
                                case 2:
                                    if (trim($part) == '*')
                                    {
                                        $foundwild = true;
                                    }
                                    break;
                                default:
                                    if (trim($part) != '*') 
                                    {
                                        if ($foundwild == true) 
                                        {
                                            $goodip = false;
                                            $errors .= '<p>'.$item.__(' is not a valid ip address format.', 'all-in-one-wp-security-and-firewall').'</p>';
                                        }
                                    }
                                    else 
                                    {
                                        $foundwild = true;	
                                    }
                                    break;
                            }

                            $partcount++;
                        }
                    }
                    if (ip2long(trim(str_replace('*', '0', $item))) == false) 
                    { //invalid ip 
                        $errors .= '<p>'.$item.__(' is not a valid ip address format.', 'all-in-one-wp-security-and-firewall').'</p>';
                    } 
                    elseif (strlen($item) > 4 && !in_array($item, $list)) 
                    {
                        $current_user_ip = AIOWPSecurity_Utility_IP::get_user_ip_address();
                        if ($current_user_ip == $item && $list_type == 'blacklist')
                        {
                            //You can't ban your own IP
                            $errors .= '<p>'.__('You cannot ban your own IP address: ', 'all-in-one-wp-security-and-firewall').$item.'</p>';
                        }
                        else
                        {
                            $list[] = trim($item);
                        }
                    }
                }
            }
        }
        else{
            //This function was called with an empty IP address array list
        }

        if (strlen($errors)> 0)
        {
            $return_payload = array(-1, array($errors));
            return $return_payload;
        }
        
        if (sizeof($list) >= 1) 
        {
            sort($list);
            $list = array_unique($list, SORT_STRING);
            
            $return_payload = array(1, $list);
            return $return_payload;
	}

        $return_payload = array(1, array());
        return $return_payload;
    }    
}