#!/bin/bash
#Author:ZhangGe
#Desc:Auto Deny Black_IP Script.
#Date:2014-11-05
#取得參數$1為并發閾值，若留空則默認允許單IP最大100并發(實際測試發現，2M帶寬，十來個并發服務器就已經無法訪問了！)
if [[ -z $1 ]];then
num=50
else 
num=$1
fi
#巧妙的進入到腳本工作目錄
cd $(cd $(dirname $BASH_SOURCE) && pwd)
#請求檢查、判斷及拉黑主功能函數
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
#白名單過濾中已取消IP段的判斷功能，可根據需要自行修改以下代碼(請參考前天寫的腳本)
#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
#存在并發超過閾值的單IP就發送郵件
if [[ `cat ./sendmail` == 1 ]];then sendmsg;fi
fi
}
#發郵件函數
function sendmsg(){
netstat -nutlp | grep "sendmail" >/dev/null 2>&1 || /etc/init.d/sendmail start >/dev/null 2>&1
echo -e "From: 發郵件地址@qq.com\nTo:收郵件地址@qq.com\nSubject:Someone Attacking your system!!\nIts Ip is" >./message
cat ./black_ip.txt >>./message
/usr/sbin/sendmail -f 發郵件地址@qq.com -t 收郵件地址@qq.com -i <./message
>./sendmail
}
#間隔10s無限循環檢查函數
while true
do 
check
#每隔10s檢查一次，時間可根據需要自定義
sleep 10
done