使用awk和iptables进行简单的DDoS分析与处理。
统计单个IP地址的连接数量
复制代码代码如下:
netstat -antp|awk '$5~/[1-9]/ {split($5,ip,":"); ++S[ip[1]]} END {for(i in S) print i"\t"S[i]}'
与iptables联动
复制代码代码如下:
#! /bin/bash
while [ 1 ] ; do for ip in `lsof -ni | grep httpd | grep -iv listen | awk '{print $8}' | cut -d : -f 2 | sort | uniq | sed s/"http->"//` ; # the line above gets the list of all connections and connection attempts, and produces a list of uniq IPs # and iterates through the list do noconns=`lsof -ni | grep $ip | wc -l`; # This finds how many connections there are from this particular IP address echo $ip : $noconns ; if [ "$noconns" -gt "10" ] ; # if there are more than 10 connections established or connecting from this IP then # echo More; # echo `date` "$ip has $noconns connections. Total connections to prod spider: `lsof -ni | grep httpd | grep -iv listen | wc -l`" >> /var/log/Ddos/Ddos.log # to keep track of the IPs uncomment the above two lines and make sure you can write to the appropriate place iptables -I INPUT -s $ip -p tcp -j REJECT --reject-with tcp-reset # for these connections, add an iptables statement to send resets on any packets recieved else # echo Less; fi; done sleep 60 done |