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如何写脚本防cc攻击

九三
160
2020-12-30 18:07:06
栏目: 网络安全

如何写脚本防cc攻击

Shell脚本代码如下:

#!/bin/bash

#Author:ZhangGe

#Desc:Auto Deny Black_IP Script.

#Date:2014-11-05

#取得参数$1为并发阈值,若留空则默认允许单IP最大100并发(实际测试发现,2M带宽,十来个并发服务器就已经无法访问了!)

if [[ -z $1 ]];then

num=50

else

num=$1

fi

#巧妙的进入到脚本工作目录

cd $(cd $(dirname $BASH_SOURCE) && pwd)

#请求检查、判断及拉黑主功能函数

function check(){

iplist=`netstat -an |grep ^tcp.*:80|egrep -v 'LISTEN|127.0.0.1'|awk -F"[ ]+|[:]" '{print $6}'|sort|uniq -c|sort -rn|awk -v str=$num '{if ($1>str){print $2}}'`

if [[ ! -z $iplist ]];

then

>./iplist/black_ip.txt

for black_ip in $iplist

do

#白名单过滤中已取消IP段的判断功能,可根据需要自行修改以下代码(请参考前天写的脚本)

#exclude_ip=`echo $black_ip | awk -F"." '{print $1"."$2"."$3}'`

#grep -q $exclude_ip ./white_ip.txt

grep -q $black_ip ./white_ip.txt

if [[ $? -eq 0 ]];then

echo "$black_ip (white_ip)" >>./black_ip.txt

else

echo $black_ip >>./black_ip.txt

iptables -nL | grep $black_ip ||(iptables -I INPUT -s $black_ip -j DROP & echo "$black_ip `date +%Y-%m-%H:%M:%S`">>./iplist/denylog.txt & echo 1 >./sendmail)

fi

done

#存在并发超过阈值的单IP就发送邮件

if [[ `cat ./sendmail` == 1 ]];then sendmsg;fi

fi

}

#发邮件函数

function sendmsg(){

netstat -nutlp | grep "sendmail" >/dev/null 2>&1 || /etc/init.d/sendmail start >/dev/null 2>&1

echo -e "From: 发邮件地址@qq.com\nTo:收邮件地址@qq.com\nSubject:Someone Attacking your system!!\nIts Ip is" >./message

cat ./black_ip.txt >>./message

/usr/sbin/sendmail -f 发邮件地址@qq.com -t 收邮件地址@qq.com -i <./message

>./sendmail

}

#间隔10s无限循环检查函数

while true

do

check

#每隔10s检查一次,时间可根据需要自定义

sleep 10

done

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