服务器运营过程中可能会受到黑客攻击,常见的攻击方式有SYN,DDOS等。通过更换IP,查找被攻击的站点可能避开攻击,但是中断服务的时间比较长。比较彻底的解决方法是添置硬件防火墙。不过,硬件防火墙价格比较昂贵。在没有硬防的情况下,寻找软件代替是最直接的方法,比如用iptables,但是iptables不能自动屏蔽,只能手动屏蔽。这里要介绍的就是一款能够自动屏蔽DDOS攻击者IP的软件:DDoS Deflate。
DDOS deflate是一个轻量级的脚本,以协助阻止拒绝服务攻击的过程中的bash shell脚本。它使用下面的命令来创建一个连接到服务器的IP地址列表,以及与它们的连接总数。这是最简单的安装软件的解决方案之一。
# netstat -ntu | awk '{print $5}' | cut -d: -f1 | sort | uniq -c | sort -n
超过了预先配置的连接数的IP地址自动被服务器防火墙阻止
脚本特点:
1.可以配置白名单的IP地址,通过配置:/usr/local/ddos/ignore.ip.list
2.简单的配置文件:/usr/local/ddos/ddos.conf
3.IP地址被封时间是预先设定的(默认:600秒后自动解除封锁)
4.通过配置文件,脚本可以定时周期性运行(默认是:1分钟)
5.有IP地址被封锁时,可以为指定的邮箱接收电子邮件警报。
安装:
# wget http://www.inetbase.com/scripts/ddos/install.sh # chmod 0700 install.sh # cat install.sh #!/bin/sh if [ -d '/usr/local/ddos' ]; then echo; echo; echo "Please un-install the previous version first" exit 0 else mkdir /usr/local/ddos fi clear echo; echo 'Installing DOS-Deflate 0.6'; echo echo; echo -n 'Downloading source files...' wget -q -O /usr/local/ddos/ddos.conf http://www.inetbase.com/scripts/ddos/ddos.conf echo -n '.' wget -q -O /usr/local/ddos/LICENSE http://www.inetbase.com/scripts/ddos/LICENSE echo -n '.' wget -q -O /usr/local/ddos/ignore.ip.list http://www.inetbase.com/scripts/ddos/ignore.ip.list echo -n '.' wget -q -O /usr/local/ddos/ddos.sh http://www.inetbase.com/scripts/ddos/ddos.sh chmod 0755 /usr/local/ddos/ddos.sh cp -s /usr/local/ddos/ddos.sh /usr/local/sbin/ddos echo '...done'
echo; echo -n 'Creating cron to run script every minute.....(Default setting)' /usr/local/ddos/ddos.sh --cron > /dev/null 2>&1 echo '.....done' echo; echo 'Installation has completed.' echo 'Config file is at /usr/local/ddos/ddos.conf' echo 'Please send in your comments and/or suggestions to zaf@vsnl.com' echo cat /usr/local/ddos/LICENSE | less # ./install.sh |
配置文件:
# ll /usr/local/ddos/ 总用量 24 -rw-r--r--. 1 root root 971 1月 10 2006 ddos.conf -rwxr-xr-x. 1 root root 3945 1月 10 2006 ddos.sh -rw-r--r--. 1 root root 10 1月 10 2006 ignore.ip.list -rw-r--r--. 1 root root 10113 1月 10 2006 LICENSE # cat /usr/local/ddos/ddos.conf ##### Paths of the script and other files PROGDIR="/usr/local/ddos" #文件存放目录 PROG="/usr/local/ddos/ddos.sh" #主要功能脚本 IGNORE_IP_LIST="/usr/local/ddos/ignore.ip.list" #白名单地址列表 CRON="/etc/cron.d/ddos.cron" #crond定时任务脚本 APF="/etc/apf/apf" IPT="/sbin/iptables" ##### frequency in minutes for running the script ##### Caution: Every time this setting is changed, run the script with --cron ##### option so that the new frequency takes effect FREQ=1 #ddos.sh执行的频率,单位是分钟,搭配crontab来执行. ##### How many connections define a bad IP? Indicate that below. NO_OF_CONNECTIONS=150 #最大连接数设置,超过这个数字的IP就会屏蔽 ##### APF_BAN=1 (Make sure your APF version is atleast 0.96) ##### APF_BAN=0 (Uses iptables for banning ips instead of APF) APF_BAN=1 #1:使用APF 0:使用iptables,一般情况下你是使用iptables来做防火墙,所以这里你需要将APF_BAN的值改为0 ##### KILL=0 (Bad IPs are'nt banned, good for interactive execution of script) ##### KILL=1 (Recommended setting) KILL=1 #将非法的的IP加入iptables的INPUT链中,DROP之. ##### An email is sent to the following address when an IP is banned. ##### Blank would suppress sending of mails EMAIL_TO="root" #发送电子邮件报警的邮箱地址 ##### Number of seconds the banned ip should remain in blacklist. BAN_PERIOD=600 #屏蔽IP的时间,根据情况调整 # |
卸载DDOSdeflate
# wget http://www.inetbase.com/scripts/ddos/uninstall.ddos # chmod 0700 uninstall.ddos |