#!/bin/bash 

function installVPN(){ 
echo "begin to install VPN services"; 
#check wether vps suppot ppp and tun 

yum remove -y pptpd ppp 
iptables --flush POSTROUTING --table nat 
iptables --flush FORWARD 
rm -rf /etc/pptpd.conf 
rm -rf /etc/ppp 

arch=`uname -m` 

wget   
wget   
wget   
wget  $arch.rpm 
wget  $arch.rpm 


yum -y install make libpcap iptables gcc-c++ logrotate tar cpio perl pam tcp_wrappers 
rpm -ivh dkms-2.0.17.5-1.noarch.rpm 
rpm -ivh kernel_ppp_mppe-1.0.2-3dkms.noarch.rpm 
rpm -qa kernel_ppp_mppe 
rpm -Uvh ppp-2.4.5-17.0.rhel6.$arch.rpm 
rpm -ivh pptpd-1.3.4-2.el6.$arch.rpm 

mknod /dev/ppp c 108 0 
echo 1 > /proc/sys/net/ipv4/ip_forward 
echo "mknod /dev/ppp c 108 0" >> /etc/rc.local 
echo "echo 1 > /proc/sys/net/ipv4/ip_forward" >> /etc/rc.local 
echo "localip 172.16.36.1" >> /etc/pptpd.conf 
echo "remoteip 172.16.36.2-254" >> /etc/pptpd.conf 
echo "ms-dns 8.8.8.8" >> /etc/ppp/options.pptpd 
echo "ms-dns 8.8.4.4" >> /etc/ppp/options.pptpd 

pass=`openssl rand 6 -base64` 
if [ "$1" != "" ] 
then pass=$1 
fi 

echo "vpn pptpd ${pass} *" >> /etc/ppp/chap-secrets 

iptables -t nat -A POSTROUTING -s 172.16.36.0/24 -j SNAT --to-source `ifconfig | grep 'inet addr:'| grep -v '127.0.0.1' | cut -d: -f2 | awk 'NR==1 { print $1}'` 
iptables -A FORWARD -p tcp --syn -s 172.16.36.0/24 -j TCPMSS --set-mss 1356 
service iptables save 

chkconfig iptables on 
chkconfig pptpd on 

service iptables start 
service pptpd start 

echo "VPN service is installed, your VPN username is vpn, VPN password is ${pass}" 

} 

function repaireVPN(){ 
echo "begin to repaire VPN"; 
mknod /dev/ppp c 108 0 
service iptables restart 
service pptpd start 
} 

function addVPNuser(){ 
echo "input user name:" 
read username 
echo "input password:" 
read userpassword 
echo "${username} pptpd ${userpassword} *" >> /etc/ppp/chap-secrets 
service iptables restart 
service pptpd start 
} 

echo "which do you want to?input the number." 
echo "1. install VPN service" 
echo "2. repaire VPN service" 
echo "3. add VPN user" 
read num 

case "$num" in 
[1] ) (installVPN);; 
[2] ) (repaireVPN);; 
[3] ) (addVPNuser);; 
*) echo "nothing,exit";; 

esac

本文转自谢无赖51CTO博客，原文链接： http://blog.51cto.com/xieping/1569665，如需转载请自行联系原作者