#!/bin/bash
#Author:ZhangGe
#Desc:Auto Deny Black_IP Script.
#Date:2014-11-05
#取得參數(shù)$1為并發(fā)閾值，若留空則默認(rèn)允許單IP最大100并發(fā)(實際測試發(fā)現(xiàn)，2M帶寬，十來個并發(fā)服務(wù)器就已經(jīng)無法訪問了！)
if [[ -z $1 ]];then
    num=50
else 
    num=$1
fi

#巧妙的進(jìn)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(shù)
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(jù)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(fā)超過閾值的單IP就發(fā)送郵件
        if [[ `cat ./sendmail` == 1 ]];then sendmsg;fi
    fi
}

#發(fā)郵件函數(shù)
function sendmsg(){
    netstat -nutlp | grep "sendmail" >/dev/null 2>&1 || /etc/init.d/sendmail start >/dev/null 2>&1
    echo -e "From: 發(fā)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(fā)郵件地址@qq.com -t 收郵件地址@qq.com -i <./message
    >./sendmail
}

#間隔10s無限循環(huán)檢查函數(shù)
while true
do 
    check
    #每隔10s檢查一次，時間可根據(jù)需要自定義
    sleep 10
done

[root@Mars_Server iptables]# nohup ./deny_blackip.sh 50 & 
[1] 23630
[root@Mars_Server iptables]# nohup: ignoring input and appending output to `nohup.out'

[root@Mars_Server iptables]# ll nohup.out
-rw------- 1 root root 0 Nov 5 21:15 nohup.out

root   23630 0.0 0.2  5060 1224 pts/0  S  21:15  0:00 /bin/bash ./deny_blackip.sh
root   23964 0.0 0.0  4064  508 pts/0  S  21:19  0:00 sleep 10