PHP emergency code to prevent the website from being attacked, PHP emergency code to prevent the website from being attacked_PHP tutorial

php emergency code to prevent the website from being attacked, php emergency code to prevent the website

Not long ago, a website was attacked and the database was wiped out. Fortunately, there was a database backup on the client machine. When encountering such a serious problem, we must quickly find loopholes to prevent further attacks. After checking all aspects, we found that except that the server needs to be set correctly, there is no other way to start, so we have to solve this attack problem from the IP address.

If you find that a certain IP accesses the website too frequently, add it to the blacklist and prohibit access. This is not a good solution, but in an emergency, there is no better solution. It is just a stopgap measure. We will go into more detail later. Do some research.

This method can be summarized in one sentence: Prevent the website from being attacked by prohibiting frequent IP access.

<&#63;php 
header('Content-type: text/html; charset=utf-8'); 
$ip=$_SERVER['REMOTE_ADDR'];//获取当前访问者的ip 
$logFilePath='./log/';//日志记录文件保存目录 
$fileht='.htaccess2';//被禁止的ip记录文件 
$allowtime=60;//防刷新时间 
$allownum=5;//防刷新次数 
$allowRefresh=120;//在允许刷新次数之后加入禁止ip文件中 
 
if(!file_exists($fileht)){ 
  file_put_contents($fileht,''); 
} 
$filehtarr=@file($fileht); 
if(in_array($ip."\r\n",$filehtarr)){ 
  exit('警告：你的IP已经被禁止了！'); 
} 
//加入禁止ip 
$time=time(); 
$fileforbid=$logFilePath.'forbidchk.dat'; 
if(file_exists($fileforbid)){ 
  if($time-filemtime($fileforbid)>30){ 
    @unlink($fileforbid); 
  }else{ 
    $fileforbidarr=@file($fileforbid); 
    if($ip==substr($fileforbidarr[0],0,strlen($ip))){ 
      if($time-substr($fileforbidarr[1],0,strlen($time))>120){ 
        @unlink($fileforbid); 
      }else if($fileforbidarr[2]>$allowRefresh){ 
        file_put_contents($fileht,$ip."\r\n",FILE_APPEND); 
        @unlink($fileforbid); 
      }else{ 
        $fileforbidarr[2]++; 
        file_put_contents($fileforbid,$fileforbidarr); 
      } 
    } 
  } 
} 
//防刷新 
$str=''; 
$file=$logFilePath.'ipdate.dat'; 
if(!file_exists($logFilePath)&&!is_dir($logFilePath)){ 
  mkdir($logFilePath,0777); 
} 
if(!file_exists($file)){ 
  file_put_contents($file,''); 
} 
$uri=$_SERVER['REQUEST_URI'];//获取当前访问的网页文件地址 
$checkip=md5($ip); 
$checkuri=md5($uri); 
$yesno=true; 
$ipdate=@file($file); 
foreach($ipdate as $k=>$v){ 
  $iptem=substr($v,0,32); 
  $uritem=substr($v,32,32); 
  $timetem=substr($v,64,10); 
  $numtem=substr($v,74); 
  if($time-$timetem<$allowtime){ 
    if($iptem!=$checkip){ 
      $str.=$v; 
    }else{ 
      $yesno=false; 
      if($uritem!=$checkuri){ 
        $str.=$iptem.$checkuri.$time."\r\n"; 
      }else if($numtem<$allownum){ 
        $str.=$iptem.$uritem.$timetem.($numtem+1)."\r\n"; 
      } 
      else{ 
        if(!file_exists($fileforbid)){ 
          $addforbidarr=array($ip."\r\n",time()."\r\n",1); 
          file_put_contents($fileforbid,$addforbidarr); 
        } 
        file_put_contents($logFilePath.'forbided_ip.log',$ip.'--'.date('Y-m-d H:i:s',time()).'--'.$uri."\r\n",FILE_APPEND); 
        $timepass=$timetem+$allowtime-$time; 
        exit('警告：不要刷新的太频繁！'); 
      } 
    } 
  } 
} 
if($yesno){ 
  $str.=$checkip.$checkuri.$time."\r\n"; 
} 
file_put_contents($file,$str); 

The above is the entire content of this article, I hope it will be helpful to everyone’s study.

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