Linux架设DDNS服务器之自动更新脚本

nsupdate -k K*****.key
>server 192.*.*.*        #dns server ip address
>update delete yourfqdn A delete
>update add yourFQDN 600 A your new IP

#!/bin/bash
#########################################
##
##　　　　Author:Medici.Yan@gmail.com
#########################################
PATH=/sbin:/bin:/usr/sbin:/usr/bin
export PATH
usage(){
        echo "  Usage:$0 [-i interface] [-d basedir] [-h hostname] [-t ttl] [-s servername] [-k keyfile] [-c ClientIP] [-m testdomain]"
        echo "          Default:"
        echo "                   -i eth0 -d /usr/local/ddns -t 600 -k /usr/local/ddns/*.key"
        echo ""
        echo "  Notice:  如果你自己的主机是DNS Server,那么你不能改变你自己的 hostname 与 IP"
        echo "          如果你不知道你的DNS Server是什么，就加上-m 参数，后面是测试的域名，eg:$0 -m swu.edu.cn "
        echo "  Notice:  If your PC is your DNS Server, you can‘t change your hostname and IP"
        echo "          If you don‘t know your DNS Server Address, you can use the param [-m TestDomain] to get the right server address，eg:$0 -m swu.edu.cn "
    exit 1
}

((params=$#%2))
if [[ $# -gt 14 ]]; then
        usage
#elif [ $params -eq 1 ]; then
#       usage
fi

#设置默认参数值
domain="swu.edu.cn"                             #默认测试DNS Server 地址的域名
basedir="/usr/local/ddns"                       # 基本工作目录
keyfile="$basedir"/"`ls $basedir|grep ‘.key$‘`" #公钥文件
ttl=600                                         # ttl
interface="eth0"                                # 对外的联机接口！
hostname=`hostname`
servername=`grep ‘nameserver‘ /etc/resolv.conf | head -n 1 |awk ‘{print $2}‘`   #dns Server IP
newip=`ifconfig "$interface" | grep ‘inet addr‘ | awk ‘{print $2}‘ | sed -e "s/addr\://"`       #IP地址

#处理NetworkManager管理DNS Server，基本上用不到，一般在启动NetworkManager后会自动修改resolv.conf
if [ "$servername" == "" ]; then
        servername=`nslookup $domain|grep Server|awk ‘{print $2}‘`
fi
#获取用户输入参数，如不指定则使用默认参数
while [ $# -gt 0 ]
do
        case $1 in
                -i)shift;interface=$1;shift;;
                -d)shift;basedir=$1;shift;;
                -h)shift;hostname=$1;shift;;
                -t)shift;ttl=$1;shift;;
                -s)shift;servername=$1;shift;;
                -k)shift;keyfile=$1;shift;;
                -c)shift;newip=$1;shift;;
                -m)shift;domain=$1;shift;;
                *)usage;;
        esac

done
#自动查找DNS和手动都找不到DNS则退出
if [ "$servername" == "" ]; then
        echo "Error:Can not find the DNS Server!"
        exit 1
fi

#检查IP合法性
checkip=`echo $newip | grep "^[0-9]"`

if [ "$checkip" == "" ]; then
        echo "$0: The interface can‘t connect internet...."
        exit 1

fi
#检测basedir目录是否存在,不存在则创建
if !([ -d $basedir ]);then
        mkdir -p $basedir
fi
#检测keyfile存在性
if !([ -f $keyfile ]);then
        echo "Error:$keyfile does not exist!"
        exit 1
fi

tmpfile=$basedir/tmp.txt
#如果文件不存在,则创建
if !([ -f $tmpfile ]);then
        touch $tmpfile
        #查看是否创建成功
        if !([ -f $tmpfile ]);then
                echo "Permission Denyed,Can not touch $tmpfile in $basedir"
                exit 1
        fi
fi
#写入配置文件
echo "server $servername" > $tmpfile
echo "update delete $hostname A " >> $tmpfile
echo "update add $hostname $ttl A $newip" >> $tmpfile
echo "send" >> $tmpfile
#更新
nsupdate -k $keyfile -v $tmpfile